Spell out 'version' in the http_request struct
[privoxy.git] / jcc.c
1 /*********************************************************************
2  *
3  * File        :  $Source: /cvsroot/ijbswa/current/jcc.c,v $
4  *
5  * Purpose     :  Main file.  Contains main() method, main loop, and
6  *                the main connection-handling function.
7  *
8  * Copyright   :  Written by and Copyright (C) 2001-2020 the
9  *                Privoxy team. https://www.privoxy.org/
10  *
11  *                Based on the Internet Junkbuster originally written
12  *                by and Copyright (C) 1997 Anonymous Coders and
13  *                Junkbusters Corporation.  http://www.junkbusters.com
14  *
15  *                This program is free software; you can redistribute it
16  *                and/or modify it under the terms of the GNU General
17  *                Public License as published by the Free Software
18  *                Foundation; either version 2 of the License, or (at
19  *                your option) any later version.
20  *
21  *                This program is distributed in the hope that it will
22  *                be useful, but WITHOUT ANY WARRANTY; without even the
23  *                implied warranty of MERCHANTABILITY or FITNESS FOR A
24  *                PARTICULAR PURPOSE.  See the GNU General Public
25  *                License for more details.
26  *
27  *                The GNU General Public License should be included with
28  *                this file.  If not, you can view it at
29  *                http://www.gnu.org/copyleft/gpl.html
30  *                or write to the Free Software Foundation, Inc., 59
31  *                Temple Place - Suite 330, Boston, MA  02111-1307, USA.
32  *
33  *********************************************************************/
34
35
36 #include "config.h"
37
38 #include <stdio.h>
39 #include <sys/types.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <signal.h>
43 #include <fcntl.h>
44 #include <errno.h>
45 #include <assert.h>
46
47 #ifdef _WIN32
48 # ifndef FEATURE_PTHREAD
49 #  ifndef STRICT
50 #   define STRICT
51 #  endif
52 #  include <winsock2.h>
53 #  include <windows.h>
54 #  include <process.h>
55 # endif /* ndef FEATURE_PTHREAD */
56
57 # include "win32.h"
58 # ifndef _WIN_CONSOLE
59 #  include "w32log.h"
60 # endif /* ndef _WIN_CONSOLE */
61 # include "w32svrapi.h"
62
63 #else /* ifndef _WIN32 */
64
65 # if !defined (__OS2__)
66 # include <unistd.h>
67 # include <sys/wait.h>
68 # endif /* ndef __OS2__ */
69 # include <sys/time.h>
70 # include <sys/stat.h>
71 # include <sys/ioctl.h>
72
73 #ifdef sun
74 #include <sys/termios.h>
75 #endif /* sun */
76
77 #ifdef unix
78 #include <pwd.h>
79 #include <grp.h>
80 #endif
81
82 # include <signal.h>
83
84 # ifdef __BEOS__
85 #  include <socket.h>  /* BeOS has select() for sockets only. */
86 #  include <OS.h>      /* declarations for threads and stuff. */
87 # endif
88
89 # if defined(__EMX__) || defined(__OS2__)
90 #  include <sys/select.h>  /* OS/2/EMX needs a little help with select */
91 # endif
92 # ifdef __OS2__
93 #define INCL_DOS
94 # include <os2.h>
95 # endif
96
97 #ifdef HAVE_POLL
98 #ifdef __GLIBC__
99 #include <sys/poll.h>
100 #else
101 #include <poll.h>
102 #endif /* def __GLIBC__ */
103 #else
104 # ifndef FD_ZERO
105 #  include <select.h>
106 # endif
107 #warning poll() appears to be unavailable. Your platform will become unsupported in the future.
108 #endif /* HAVE_POLL */
109
110 #endif
111
112 #include "project.h"
113 #include "list.h"
114 #include "jcc.h"
115 #ifdef FEATURE_HTTPS_INSPECTION
116 #include "ssl.h"
117 #endif
118 #include "filters.h"
119 #include "loaders.h"
120 #include "parsers.h"
121 #include "miscutil.h"
122 #include "errlog.h"
123 #include "jbsockets.h"
124 #include "gateway.h"
125 #include "actions.h"
126 #include "cgi.h"
127 #include "loadcfg.h"
128 #include "urlmatch.h"
129 #ifdef FEATURE_CLIENT_TAGS
130 #include "client-tags.h"
131 #endif
132
133 int daemon_mode = 1;
134 struct client_states clients[1];
135 struct file_list     files[1];
136
137 #ifdef FEATURE_STATISTICS
138 int urls_read     = 0;     /* total nr of urls read inc rejected */
139 int urls_rejected = 0;     /* total nr of urls rejected */
140 #endif /* def FEATURE_STATISTICS */
141
142 #ifdef FEATURE_GRACEFUL_TERMINATION
143 int g_terminate = 0;
144 #endif
145
146 #if !defined(_WIN32) && !defined(__OS2__)
147 static void sig_handler(int the_signal);
148 #endif
149 static int client_protocol_is_unsupported(struct client_state *csp, char *req);
150 static jb_err get_request_destination_elsewhere(struct client_state *csp, struct list *headers);
151 static jb_err get_server_headers(struct client_state *csp);
152 static const char *crunch_reason(const struct http_response *rsp);
153 static void send_crunch_response(struct client_state *csp, struct http_response *rsp);
154 static char *get_request_line(struct client_state *csp);
155 static jb_err receive_client_request(struct client_state *csp);
156 static jb_err parse_client_request(struct client_state *csp);
157 static void build_request_line(struct client_state *csp, const struct forward_spec *fwd, char **request_line);
158 static jb_err change_request_destination(struct client_state *csp);
159 static void chat(struct client_state *csp);
160 static void serve(struct client_state *csp);
161 #if !defined(_WIN32) || defined(_WIN_CONSOLE)
162 static void usage(const char *myname);
163 #endif
164 static void initialize_mutexes(void);
165 static jb_socket bind_port_helper(const char *haddr, int hport, int backlog);
166 static void bind_ports_helper(struct configuration_spec *config, jb_socket sockets[]);
167 static void close_ports_helper(jb_socket sockets[]);
168 static void listen_loop(void);
169 static void serve(struct client_state *csp);
170
171 #ifdef __BEOS__
172 static int32 server_thread(void *data);
173 #endif /* def __BEOS__ */
174
175 #ifdef _WIN32
176 #define sleep(N)  Sleep(((N) * 1000))
177 #endif
178
179 #ifdef __OS2__
180 #define sleep(N)  DosSleep(((N) * 100))
181 #endif
182
183 #ifdef FUZZ
184 int process_fuzzed_input(char *fuzz_input_type, char *fuzz_input_file);
185 void show_fuzz_usage(const char *name);
186 #endif
187
188 #ifdef MUTEX_LOCKS_AVAILABLE
189 /*
190  * XXX: Does the locking stuff really belong in this file?
191  */
192 privoxy_mutex_t log_mutex;
193 privoxy_mutex_t log_init_mutex;
194 privoxy_mutex_t connection_reuse_mutex;
195
196 #ifdef FEATURE_HTTPS_INSPECTION
197 privoxy_mutex_t certificate_mutex;
198 privoxy_mutex_t rng_mutex;
199 #endif
200
201 #ifdef FEATURE_EXTERNAL_FILTERS
202 privoxy_mutex_t external_filter_mutex;
203 #endif
204 #ifdef FEATURE_CLIENT_TAGS
205 privoxy_mutex_t client_tags_mutex;
206 #endif
207
208 #if !defined(HAVE_GETHOSTBYADDR_R) || !defined(HAVE_GETHOSTBYNAME_R)
209 privoxy_mutex_t resolver_mutex;
210 #endif /* !defined(HAVE_GETHOSTBYADDR_R) || !defined(HAVE_GETHOSTBYNAME_R) */
211
212 #ifndef HAVE_GMTIME_R
213 privoxy_mutex_t gmtime_mutex;
214 #endif /* ndef HAVE_GMTIME_R */
215
216 #ifndef HAVE_LOCALTIME_R
217 privoxy_mutex_t localtime_mutex;
218 #endif /* ndef HAVE_GMTIME_R */
219
220 #if !defined(HAVE_ARC4RANDOM) && !defined(HAVE_RANDOM)
221 privoxy_mutex_t rand_mutex;
222 #endif /* !defined(HAVE_ARC4RANDOM) && !defined(HAVE_RANDOM) */
223
224 #endif /* def MUTEX_LOCKS_AVAILABLE */
225
226 #if defined(unix)
227 const char *basedir = NULL;
228 const char *pidfile = NULL;
229 static int received_hup_signal = 0;
230 #endif /* defined unix */
231
232 /* HTTP snipplets. */
233 static const char CSUCCEED[] =
234    "HTTP/1.1 200 Connection established\r\n\r\n";
235
236 static const char CHEADER[] =
237    "HTTP/1.1 400 Invalid header received from client\r\n"
238    "Content-Type: text/plain\r\n"
239    "Connection: close\r\n\r\n"
240    "Invalid header received from client.\r\n";
241
242 static const char FTP_RESPONSE[] =
243    "HTTP/1.1 400 Invalid request received from client\r\n"
244    "Content-Type: text/plain\r\n"
245    "Connection: close\r\n\r\n"
246    "Invalid request. Privoxy doesn't support FTP.\r\n";
247
248 static const char GOPHER_RESPONSE[] =
249    "HTTP/1.1 400 Invalid request received from client\r\n"
250    "Content-Type: text/plain\r\n"
251    "Connection: close\r\n\r\n"
252    "Invalid request. Privoxy doesn't support gopher.\r\n";
253
254 /* XXX: should be a template */
255 static const char MISSING_DESTINATION_RESPONSE[] =
256    "HTTP/1.1 400 Bad request received from client\r\n"
257    "Content-Type: text/plain\r\n"
258    "Connection: close\r\n\r\n"
259    "Bad request. Privoxy was unable to extract the destination.\r\n";
260
261 /* XXX: should be a template */
262 static const char INVALID_SERVER_HEADERS_RESPONSE[] =
263    "HTTP/1.1 502 Server or forwarder response invalid\r\n"
264    "Content-Type: text/plain\r\n"
265    "Connection: close\r\n\r\n"
266    "Bad response. The server or forwarder response doesn't look like HTTP.\r\n";
267
268 /* XXX: should be a template */
269 static const char MESSED_UP_REQUEST_RESPONSE[] =
270    "HTTP/1.1 400 Malformed request after rewriting\r\n"
271    "Content-Type: text/plain\r\n"
272    "Connection: close\r\n\r\n"
273    "Bad request. Messed up with header filters.\r\n";
274
275 static const char TOO_MANY_CONNECTIONS_RESPONSE[] =
276    "HTTP/1.1 503 Too many open connections\r\n"
277    "Content-Type: text/plain\r\n"
278    "Connection: close\r\n\r\n"
279    "Maximum number of open connections reached.\r\n";
280
281 static const char CLIENT_CONNECTION_TIMEOUT_RESPONSE[] =
282    "HTTP/1.1 504 Connection timeout\r\n"
283    "Content-Type: text/plain\r\n"
284    "Connection: close\r\n\r\n"
285    "The connection timed out because the client request didn't arrive in time.\r\n";
286
287 static const char CLIENT_BODY_PARSE_ERROR_RESPONSE[] =
288    "HTTP/1.1 400 Failed reading client body\r\n"
289    "Content-Type: text/plain\r\n"
290    "Connection: close\r\n\r\n"
291    "Failed parsing or buffering the chunk-encoded client body.\r\n";
292
293 static const char UNSUPPORTED_CLIENT_EXPECTATION_ERROR_RESPONSE[] =
294    "HTTP/1.1 417 Expecting too much\r\n"
295    "Content-Type: text/plain\r\n"
296    "Connection: close\r\n\r\n"
297    "Privoxy detected an unsupported Expect header value.\r\n";
298
299 /* A function to crunch a response */
300 typedef struct http_response *(*crunch_func_ptr)(struct client_state *);
301
302 /* Crunch function flags */
303 #define CF_NO_FLAGS        0
304 /* Cruncher applies to forced requests as well */
305 #define CF_IGNORE_FORCE    1
306 /* Crunched requests are counted for the block statistics */
307 #define CF_COUNT_AS_REJECT 2
308
309 /* A crunch function and its flags */
310 struct cruncher
311 {
312    const crunch_func_ptr cruncher;
313    const int flags;
314 };
315
316 static int crunch_response_triggered(struct client_state *csp, const struct cruncher crunchers[]);
317
318 /* Complete list of cruncher functions */
319 static const struct cruncher crunchers_all[] = {
320    { direct_response, CF_COUNT_AS_REJECT|CF_IGNORE_FORCE},
321    { block_url,       CF_COUNT_AS_REJECT },
322 #ifdef FEATURE_TRUST
323    { trust_url,       CF_COUNT_AS_REJECT },
324 #endif /* def FEATURE_TRUST */
325    { redirect_url,    CF_NO_FLAGS  },
326    { dispatch_cgi,    CF_IGNORE_FORCE},
327    { NULL,            0 }
328 };
329
330 /* Light version, used after tags are applied */
331 static const struct cruncher crunchers_light[] = {
332    { block_url,       CF_COUNT_AS_REJECT },
333    { redirect_url,    CF_NO_FLAGS },
334    { NULL,            0 }
335 };
336
337
338 /*
339  * XXX: Don't we really mean
340  *
341  * #if defined(unix)
342  *
343  * here?
344  */
345 #if !defined(_WIN32) && !defined(__OS2__)
346 /*********************************************************************
347  *
348  * Function    :  sig_handler
349  *
350  * Description :  Signal handler for different signals.
351  *                Exit gracefully on TERM and INT
352  *                or set a flag that will cause the errlog
353  *                to be reopened by the main thread on HUP.
354  *
355  * Parameters  :
356  *          1  :  the_signal = the signal cause this function to call
357  *
358  * Returns     :  -
359  *
360  *********************************************************************/
361 static void sig_handler(int the_signal)
362 {
363    switch(the_signal)
364    {
365       case SIGTERM:
366       case SIGINT:
367          log_error(LOG_LEVEL_INFO, "exiting by signal %d .. bye", the_signal);
368 #if defined(unix)
369          if (pidfile)
370          {
371             unlink(pidfile);
372          }
373 #endif /* unix */
374          exit(the_signal);
375          break;
376
377       case SIGHUP:
378 #if defined(unix)
379          received_hup_signal = 1;
380 #endif
381          break;
382
383       default:
384          /*
385           * We shouldn't be here, unless we catch signals
386           * in main() that we can't handle here!
387           */
388          log_error(LOG_LEVEL_FATAL, "sig_handler: exiting on unexpected signal %d", the_signal);
389    }
390    return;
391
392 }
393 #endif
394
395
396 /*********************************************************************
397  *
398  * Function    :  get_write_delay
399  *
400  * Description :  Parse the delay-response parameter.
401  *
402  * Parameters  :
403  *          1  :  csp = Current client state (buffers, headers, etc...)
404  *
405  * Returns     :  Number of milliseconds to delay writes.
406  *
407  *********************************************************************/
408 static unsigned int get_write_delay(const struct client_state *csp)
409 {
410    unsigned int delay;
411    char *endptr;
412    char *newval;
413
414    if ((csp->action->flags & ACTION_DELAY_RESPONSE) == 0)
415    {
416       return 0;
417    }
418    newval = csp->action->string[ACTION_STRING_DELAY_RESPONSE];
419
420    delay = (unsigned)strtol(newval, &endptr, 0);
421    if (*endptr != '\0')
422    {
423       log_error(LOG_LEVEL_FATAL,
424          "Invalid delay-response{} parameter: '%s'", newval);
425    }
426
427    return delay;
428
429 }
430
431
432 /*********************************************************************
433  *
434  * Function    :  client_protocol_is_unsupported
435  *
436  * Description :  Checks if the client used a known unsupported
437  *                protocol and deals with it by sending an error
438  *                response.
439  *
440  * Parameters  :
441  *          1  :  csp = Current client state (buffers, headers, etc...)
442  *          2  :  req = the first request line send by the client
443  *
444  * Returns     :  TRUE if an error response has been generated, or
445  *                FALSE if the request doesn't look invalid.
446  *
447  *********************************************************************/
448 static int client_protocol_is_unsupported(struct client_state *csp, char *req)
449 {
450    /*
451     * If it's a FTP or gopher request, we don't support it.
452     *
453     * These checks are better than nothing, but they might
454     * not work in all configurations and some clients might
455     * have problems digesting the answer.
456     *
457     * They should, however, never cause more problems than
458     * Privoxy's old behaviour (returning the misleading HTML
459     * error message:
460     *
461     * "Could not resolve http://(ftp|gopher)://example.org").
462     */
463    if (!strncmpic(req, "GET ftp://", 10) || !strncmpic(req, "GET gopher://", 13))
464    {
465       const char *response = NULL;
466       const char *protocol = NULL;
467
468       if (!strncmpic(req, "GET ftp://", 10))
469       {
470          response = FTP_RESPONSE;
471          protocol = "FTP";
472       }
473       else
474       {
475          response = GOPHER_RESPONSE;
476          protocol = "GOPHER";
477       }
478       log_error(LOG_LEVEL_ERROR,
479          "%s tried to use Privoxy as %s proxy: %s",
480          csp->ip_addr_str, protocol, req);
481       log_error(LOG_LEVEL_CLF,
482          "%s - - [%T] \"%s\" 400 0", csp->ip_addr_str, req);
483       freez(req);
484
485 #ifdef FEATURE_HTTPS_INSPECTION
486       if (client_use_ssl(csp))
487       {
488          ssl_send_data(&(csp->mbedtls_client_attr.ssl),
489             (const unsigned char *)response, strlen(response));
490       }
491       else
492 #endif
493       {
494          write_socket_delayed(csp->cfd, response, strlen(response),
495             get_write_delay(csp));
496       }
497
498       return TRUE;
499    }
500
501    return FALSE;
502 }
503
504
505 /*********************************************************************
506  *
507  * Function    :  client_has_unsupported_expectations
508  *
509  * Description :  Checks if the client used an unsupported expectation
510  *                in which case an error message is delivered.
511  *
512  * Parameters  :
513  *          1  :  csp = Current client state (buffers, headers, etc...)
514  *
515  * Returns     :  TRUE if an error response has been generated, or
516  *                FALSE if the request doesn't look invalid.
517  *
518  *********************************************************************/
519 static int client_has_unsupported_expectations(const struct client_state *csp)
520 {
521    if ((csp->flags & CSP_FLAG_UNSUPPORTED_CLIENT_EXPECTATION))
522    {
523       log_error(LOG_LEVEL_ERROR,
524          "Rejecting request from client %s with unsupported Expect header value",
525          csp->ip_addr_str);
526       log_error(LOG_LEVEL_CLF,
527          "%s - - [%T] \"%s\" 417 0", csp->ip_addr_str, csp->http->cmd);
528       write_socket_delayed(csp->cfd,
529          UNSUPPORTED_CLIENT_EXPECTATION_ERROR_RESPONSE,
530          strlen(UNSUPPORTED_CLIENT_EXPECTATION_ERROR_RESPONSE),
531          get_write_delay(csp));
532
533       return TRUE;
534    }
535
536    return FALSE;
537
538 }
539
540
541 /*********************************************************************
542  *
543  * Function    :  get_request_destination_elsewhere
544  *
545  * Description :  If the client's request was redirected into
546  *                Privoxy without the client's knowledge,
547  *                the request line lacks the destination host.
548  *
549  *                This function tries to get it elsewhere,
550  *                provided accept-intercepted-requests is enabled.
551  *
552  *                "Elsewhere" currently only means "Host: header",
553  *                but in the future we may ask the redirecting
554  *                packet filter to look the destination up.
555  *
556  *                If the destination stays unknown, an error
557  *                response is send to the client and headers
558  *                are freed so that chat() can return directly.
559  *
560  * Parameters  :
561  *          1  :  csp = Current client state (buffers, headers, etc...)
562  *          2  :  headers = a header list
563  *
564  * Returns     :  JB_ERR_OK if the destination is now known, or
565  *                JB_ERR_PARSE if it isn't.
566  *
567  *********************************************************************/
568 static jb_err get_request_destination_elsewhere(struct client_state *csp, struct list *headers)
569 {
570    char *req;
571
572    if (!(csp->config->feature_flags & RUNTIME_FEATURE_ACCEPT_INTERCEPTED_REQUESTS))
573    {
574       log_error(LOG_LEVEL_ERROR, "%s's request: \'%s\' is invalid."
575          " Privoxy isn't configured to accept intercepted requests.",
576          csp->ip_addr_str, csp->http->cmd);
577       /* XXX: Use correct size */
578       log_error(LOG_LEVEL_CLF, "%s - - [%T] \"%s\" 400 0",
579          csp->ip_addr_str, csp->http->cmd);
580
581       write_socket_delayed(csp->cfd, CHEADER, strlen(CHEADER),
582          get_write_delay(csp));
583       destroy_list(headers);
584
585       return JB_ERR_PARSE;
586    }
587    else if (JB_ERR_OK == get_destination_from_headers(headers, csp->http))
588    {
589 #ifndef FEATURE_EXTENDED_HOST_PATTERNS
590       /* Split the domain we just got for pattern matching */
591       init_domain_components(csp->http);
592 #endif
593
594       return JB_ERR_OK;
595    }
596    else
597    {
598       /* We can't work without destination. Go spread the news.*/
599
600       req = list_to_text(headers);
601       chomp(req);
602       /* XXX: Use correct size */
603       log_error(LOG_LEVEL_CLF, "%s - - [%T] \"%s\" 400 0",
604          csp->ip_addr_str, csp->http->cmd);
605       log_error(LOG_LEVEL_ERROR,
606          "Privoxy was unable to get the destination for %s's request:\n%s\n%s",
607          csp->ip_addr_str, csp->http->cmd, req);
608       freez(req);
609
610       write_socket_delayed(csp->cfd, MISSING_DESTINATION_RESPONSE,
611          strlen(MISSING_DESTINATION_RESPONSE), get_write_delay(csp));
612       destroy_list(headers);
613
614       return JB_ERR_PARSE;
615    }
616    /*
617     * TODO: If available, use PF's ioctl DIOCNATLOOK as last resort
618     * to get the destination IP address, use it as host directly
619     * or do a reverse DNS lookup first.
620     */
621 }
622
623
624 /*********************************************************************
625  *
626  * Function    :  get_server_headers
627  *
628  * Description :  Parses server headers in iob and fills them
629  *                into csp->headers so that they can later be
630  *                handled by sed().
631  *
632  * Parameters  :
633  *          1  :  csp = Current client state (buffers, headers, etc...)
634  *
635  * Returns     :  JB_ERR_OK if everything went fine, or
636  *                JB_ERR_PARSE if the headers were incomplete.
637  *
638  *********************************************************************/
639 static jb_err get_server_headers(struct client_state *csp)
640 {
641    int continue_hack_in_da_house = 0;
642    char * header;
643
644    while (((header = get_header(csp->iob)) != NULL) || continue_hack_in_da_house)
645    {
646       if (header == NULL)
647       {
648          /*
649           * continue hack in da house. Ignore the ending of
650           * this head and continue enlisting header lines.
651           * The reason is described below.
652           */
653          enlist(csp->headers, "");
654          continue_hack_in_da_house = 0;
655          continue;
656       }
657       else if (0 == strncmpic(header, "HTTP/1.1 100", 12))
658       {
659          /*
660           * It's a bodyless continue response, don't
661           * stop header parsing after reaching its end.
662           *
663           * As a result Privoxy will concatenate the
664           * next response's head and parse and deliver
665           * the headers as if they belonged to one request.
666           *
667           * The client will separate them because of the
668           * empty line between them.
669           *
670           * XXX: What we're doing here is clearly against
671           * the intended purpose of the continue header,
672           * and under some conditions (HTTP/1.0 client request)
673           * it's a standard violation.
674           *
675           * Anyway, "sort of against the spec" is preferable
676           * to "always getting confused by Continue responses"
677           * (Privoxy's behaviour before this hack was added)
678           */
679          log_error(LOG_LEVEL_HEADER, "Continue hack in da house.");
680          continue_hack_in_da_house = 1;
681       }
682       else if (*header == '\0')
683       {
684          /*
685           * If the header is empty, but the Continue hack
686           * isn't active, we can assume that we reached the
687           * end of the buffer before we hit the end of the
688           * head.
689           *
690           * Inform the caller an let it decide how to handle it.
691           */
692          return JB_ERR_PARSE;
693       }
694
695       if (JB_ERR_MEMORY == enlist(csp->headers, header))
696       {
697          /*
698           * XXX: Should we quit the request and return a
699           * out of memory error page instead?
700           */
701          log_error(LOG_LEVEL_ERROR,
702             "Out of memory while enlisting server headers. %s lost.",
703             header);
704       }
705       freez(header);
706    }
707
708    return JB_ERR_OK;
709 }
710
711
712 /*********************************************************************
713  *
714  * Function    :  crunch_reason
715  *
716  * Description :  Translates the crunch reason code into a string.
717  *
718  * Parameters  :
719  *          1  :  rsp = a http_response
720  *
721  * Returns     :  A string with the crunch reason or an error description.
722  *
723  *********************************************************************/
724 static const char *crunch_reason(const struct http_response *rsp)
725 {
726    char * reason = NULL;
727
728    assert(rsp != NULL);
729    if (rsp == NULL)
730    {
731       return "Internal error while searching for crunch reason";
732    }
733
734    switch (rsp->crunch_reason)
735    {
736       case UNSUPPORTED:
737          reason = "Unsupported HTTP feature";
738          break;
739       case BLOCKED:
740          reason = "Blocked";
741          break;
742       case UNTRUSTED:
743          reason = "Untrusted";
744          break;
745       case REDIRECTED:
746          reason = "Redirected";
747          break;
748       case CGI_CALL:
749          reason = "CGI Call";
750          break;
751       case NO_SUCH_DOMAIN:
752          reason = "DNS failure";
753          break;
754       case FORWARDING_FAILED:
755          reason = "Forwarding failed";
756          break;
757       case CONNECT_FAILED:
758          reason = "Connection failure";
759          break;
760       case OUT_OF_MEMORY:
761          reason = "Out of memory (may mask other reasons)";
762          break;
763       case CONNECTION_TIMEOUT:
764          reason = "Connection timeout";
765          break;
766       case NO_SERVER_DATA:
767          reason = "No server data received";
768          break;
769       default:
770          reason = "No reason recorded";
771          break;
772    }
773
774    return reason;
775 }
776
777
778 /*********************************************************************
779  *
780  * Function    :  log_applied_actions
781  *
782  * Description :  Logs the applied actions if LOG_LEVEL_ACTIONS is
783  *                enabled.
784  *
785  * Parameters  :
786  *          1  :  actions = Current action spec to log
787  *
788  * Returns     :  Nothing.
789  *
790  *********************************************************************/
791 static void log_applied_actions(const struct current_action_spec *actions)
792 {
793    /*
794     * The conversion to text requires lots of memory allocations so
795     * we only do the conversion if the user is actually interested.
796     */
797    if (debug_level_is_enabled(LOG_LEVEL_ACTIONS))
798    {
799       char *actions_as_text = actions_to_line_of_text(actions);
800       log_error(LOG_LEVEL_ACTIONS, "%s", actions_as_text);
801       freez(actions_as_text);
802    }
803 }
804
805
806 /*********************************************************************
807  *
808  * Function    :  send_crunch_response
809  *
810  * Description :  Delivers already prepared response for
811  *                intercepted requests, logs the interception
812  *                and frees the response.
813  *
814  * Parameters  :
815  *          1  :  csp = Current client state (buffers, headers, etc...)
816  *          2  :  rsp = Fully prepared response. Will be freed on exit.
817  *
818  * Returns     :  Nothing.
819  *
820  *********************************************************************/
821 static void send_crunch_response(struct client_state *csp, struct http_response *rsp)
822 {
823       const struct http_request *http = csp->http;
824       char status_code[4];
825
826       assert(rsp != NULL);
827       assert(rsp->head != NULL);
828
829       if (rsp == NULL)
830       {
831          log_error(LOG_LEVEL_FATAL, "NULL response in send_crunch_response.");
832       }
833
834       /*
835        * Extract the status code from the actual head
836        * that will be send to the client. It is the only
837        * way to get it right for all requests, including
838        * the fixed ones for out-of-memory problems.
839        *
840        * A head starts like this: 'HTTP/1.1 200...'
841        *                           0123456789|11
842        *                                     10
843        */
844       status_code[0] = rsp->head[9];
845       status_code[1] = rsp->head[10];
846       status_code[2] = rsp->head[11];
847       status_code[3] = '\0';
848
849       /* Log that the request was crunched and why. */
850       log_applied_actions(csp->action);
851 #ifdef FEATURE_HTTPS_INSPECTION
852       if (client_use_ssl(csp))
853       {
854          log_error(LOG_LEVEL_CRUNCH, "%s: https://%s%s", crunch_reason(rsp),
855             http->hostport, http->path);
856          log_error(LOG_LEVEL_CLF, "%s - - [%T] \"%s https://%s%s %s\" %s %llu",
857             csp->ip_addr_str, http->gpc, http->hostport, http->path,
858             http->version, status_code, rsp->content_length);
859       }
860       else
861 #endif
862       {
863          log_error(LOG_LEVEL_CRUNCH, "%s: %s", crunch_reason(rsp), http->url);
864          log_error(LOG_LEVEL_CLF, "%s - - [%T] \"%s\" %s %u",
865             csp->ip_addr_str, http->ocmd, status_code, rsp->content_length);
866       }
867       /* Write the answer to the client */
868 #ifdef FEATURE_HTTPS_INSPECTION
869       if (client_use_ssl(csp))
870       {
871          if ((ssl_send_data(&(csp->mbedtls_client_attr.ssl),
872                  (const unsigned char *)rsp->head, rsp->head_length) < 0)
873           || (ssl_send_data(&(csp->mbedtls_client_attr.ssl),
874                  (const unsigned char *)rsp->body, rsp->content_length) < 0))
875          {
876             /* There is nothing we can do about it. */
877             log_error(LOG_LEVEL_CONNECT, "Couldn't deliver the error message "
878                "for %s through client socket %d using TLS/SSL",
879                http->url, csp->cfd);
880          }
881       }
882       else
883 #endif
884       {
885          if (write_socket_delayed(csp->cfd, rsp->head, rsp->head_length,
886                 get_write_delay(csp))
887           || write_socket_delayed(csp->cfd, rsp->body, rsp->content_length,
888                 get_write_delay(csp)))
889          {
890             /* There is nothing we can do about it. */
891             log_error(LOG_LEVEL_CONNECT,
892                "Couldn't deliver the error message for %s through client socket %d: %E",
893                http->url, csp->cfd);
894          }
895       }
896
897       /* Clean up and return */
898       if (cgi_error_memory() != rsp)
899       {
900          free_http_response(rsp);
901       }
902       return;
903 }
904
905
906 /*********************************************************************
907  *
908  * Function    :  crunch_response_triggered
909  *
910  * Description :  Checks if the request has to be crunched,
911  *                and delivers the crunch response if necessary.
912  *
913  * Parameters  :
914  *          1  :  csp = Current client state (buffers, headers, etc...)
915  *          2  :  crunchers = list of cruncher functions to run
916  *
917  * Returns     :  TRUE if the request was answered with a crunch response
918  *                FALSE otherwise.
919  *
920  *********************************************************************/
921 static int crunch_response_triggered(struct client_state *csp, const struct cruncher crunchers[])
922 {
923    struct http_response *rsp = NULL;
924    const struct cruncher *c;
925
926    /*
927     * If CGI request crunching is disabled,
928     * check the CGI dispatcher out of order to
929     * prevent unintentional blocks or redirects.
930     */
931    if (!(csp->config->feature_flags & RUNTIME_FEATURE_CGI_CRUNCHING)
932        && (NULL != (rsp = dispatch_cgi(csp))))
933    {
934       /* Deliver, log and free the interception response. */
935       send_crunch_response(csp, rsp);
936       csp->flags |= CSP_FLAG_CRUNCHED;
937       return TRUE;
938    }
939
940    for (c = crunchers; c->cruncher != NULL; c++)
941    {
942       /*
943        * Check the cruncher if either Privoxy is toggled
944        * on and the request isn't forced, or if the cruncher
945        * applies to forced requests as well.
946        */
947       if (((csp->flags & CSP_FLAG_TOGGLED_ON) &&
948           !(csp->flags & CSP_FLAG_FORCED)) ||
949           (c->flags & CF_IGNORE_FORCE))
950       {
951          rsp = c->cruncher(csp);
952          if (NULL != rsp)
953          {
954             /* Deliver, log and free the interception response. */
955             send_crunch_response(csp, rsp);
956             csp->flags |= CSP_FLAG_CRUNCHED;
957 #ifdef FEATURE_STATISTICS
958             if (c->flags & CF_COUNT_AS_REJECT)
959             {
960                csp->flags |= CSP_FLAG_REJECTED;
961             }
962 #endif /* def FEATURE_STATISTICS */
963
964             return TRUE;
965          }
966       }
967    }
968
969    return FALSE;
970 }
971
972
973 /*********************************************************************
974  *
975  * Function    :  build_request_line
976  *
977  * Description :  Builds the HTTP request line.
978  *
979  *                If a HTTP forwarder is used it expects the whole URL,
980  *                web servers only get the path.
981  *
982  * Parameters  :
983  *          1  :  csp = Current client state (buffers, headers, etc...)
984  *          2  :  fwd = The forwarding spec used for the request
985  *                XXX: Should use http->fwd instead.
986  *          3  :  request_line = The old request line which will be replaced.
987  *
988  * Returns     :  Nothing. Terminates in case of memory problems.
989  *
990  *********************************************************************/
991 static void build_request_line(struct client_state *csp, const struct forward_spec *fwd, char **request_line)
992 {
993    struct http_request *http = csp->http;
994
995    /*
996     * Downgrade http version from 1.1 to 1.0
997     * if +downgrade action applies.
998     */
999    if ((csp->action->flags & ACTION_DOWNGRADE)
1000      && (!strcmpic(http->version, "HTTP/1.1")))
1001    {
1002       freez(http->version);
1003       http->version = strdup_or_die("HTTP/1.0");
1004    }
1005
1006    /*
1007     * Rebuild the request line.
1008     */
1009    freez(*request_line);
1010    *request_line = strdup(http->gpc);
1011    string_append(request_line, " ");
1012
1013    if (fwd->forward_host && fwd->type != FORWARD_WEBSERVER)
1014    {
1015       string_append(request_line, http->url);
1016    }
1017    else
1018    {
1019       string_append(request_line, http->path);
1020    }
1021    string_append(request_line, " ");
1022    string_append(request_line, http->version);
1023
1024    if (*request_line == NULL)
1025    {
1026       log_error(LOG_LEVEL_FATAL, "Out of memory writing HTTP command");
1027    }
1028    log_error(LOG_LEVEL_HEADER, "New HTTP Request-Line: %s", *request_line);
1029 }
1030
1031
1032 /*********************************************************************
1033  *
1034  * Function    :  change_request_destination
1035  *
1036  * Description :  Parse a (rewritten) request line and regenerate
1037  *                the http request data.
1038  *
1039  * Parameters  :
1040  *          1  :  csp = Current client state (buffers, headers, etc...)
1041  *
1042  * Returns     :  Forwards the parse_http_request() return code.
1043  *                Terminates in case of memory problems.
1044  *
1045  *********************************************************************/
1046 static jb_err change_request_destination(struct client_state *csp)
1047 {
1048    struct http_request *http = csp->http;
1049    jb_err err;
1050
1051    log_error(LOG_LEVEL_REDIRECTS, "Rewrite detected: %s",
1052       csp->headers->first->str);
1053    free_http_request(http);
1054    err = parse_http_request(csp->headers->first->str, http);
1055    if (JB_ERR_OK != err)
1056    {
1057       log_error(LOG_LEVEL_ERROR, "Couldn't parse rewritten request: %s.",
1058          jb_err_to_string(err));
1059    }
1060
1061    return err;
1062 }
1063
1064
1065 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1066 /*********************************************************************
1067  *
1068  * Function    :  server_response_is_complete
1069  *
1070  * Description :  Determines whether we should stop reading
1071  *                from the server socket.
1072  *
1073  * Parameters  :
1074  *          1  :  csp = Current client state (buffers, headers, etc...)
1075  *          2  :  content_length = Length of content received so far.
1076  *
1077  * Returns     :  TRUE if the response is complete,
1078  *                FALSE otherwise.
1079  *
1080  *********************************************************************/
1081 static int server_response_is_complete(struct client_state *csp,
1082    unsigned long long content_length)
1083 {
1084    int content_length_known = !!(csp->flags & CSP_FLAG_CONTENT_LENGTH_SET);
1085
1086    if (!strcmpic(csp->http->gpc, "HEAD"))
1087    {
1088       /*
1089        * "HEAD" implies no body, we are thus expecting
1090        * no content. XXX: incomplete "list" of methods?
1091        */
1092       csp->expected_content_length = 0;
1093       content_length_known = TRUE;
1094       csp->flags |= CSP_FLAG_SERVER_CONTENT_LENGTH_SET;
1095    }
1096
1097    if (csp->http->status == 204 || csp->http->status == 304)
1098    {
1099       /*
1100        * Expect no body. XXX: incomplete "list" of status codes?
1101        */
1102       csp->expected_content_length = 0;
1103       content_length_known = TRUE;
1104       csp->flags |= CSP_FLAG_SERVER_CONTENT_LENGTH_SET;
1105    }
1106
1107    return (content_length_known && ((0 == csp->expected_content_length)
1108             || (csp->expected_content_length <= content_length)));
1109 }
1110
1111
1112 #ifdef FEATURE_CONNECTION_SHARING
1113 /*********************************************************************
1114  *
1115  * Function    :  wait_for_alive_connections
1116  *
1117  * Description :  Waits for alive connections to timeout.
1118  *
1119  * Parameters  :  N/A
1120  *
1121  * Returns     :  N/A
1122  *
1123  *********************************************************************/
1124 static void wait_for_alive_connections(void)
1125 {
1126    int connections_alive = close_unusable_connections();
1127
1128    while (0 < connections_alive)
1129    {
1130       log_error(LOG_LEVEL_CONNECT,
1131          "Waiting for %d connections to timeout.",
1132          connections_alive);
1133       sleep(60);
1134       connections_alive = close_unusable_connections();
1135    }
1136
1137    log_error(LOG_LEVEL_CONNECT, "No connections to wait for left.");
1138
1139 }
1140 #endif /* def FEATURE_CONNECTION_SHARING */
1141
1142
1143 /*********************************************************************
1144  *
1145  * Function    :  save_connection_destination
1146  *
1147  * Description :  Remembers a connection for reuse later on.
1148  *
1149  * Parameters  :
1150  *          1  :  sfd  = Open socket to remember.
1151  *          2  :  http = The destination for the connection.
1152  *          3  :  fwd  = The forwarder settings used.
1153  *          4  :  server_connection  = storage.
1154  *
1155  * Returns     : void
1156  *
1157  *********************************************************************/
1158 void save_connection_destination(jb_socket sfd,
1159                                  const struct http_request *http,
1160                                  const struct forward_spec *fwd,
1161                                  struct reusable_connection *server_connection)
1162 {
1163    assert(sfd != JB_INVALID_SOCKET);
1164    assert(NULL != http->host);
1165
1166    server_connection->sfd = sfd;
1167    server_connection->host = strdup_or_die(http->host);
1168    server_connection->port = http->port;
1169
1170    assert(NULL != fwd);
1171    assert(server_connection->gateway_host == NULL);
1172    assert(server_connection->gateway_port == 0);
1173    assert(server_connection->forwarder_type == 0);
1174    assert(server_connection->forward_host == NULL);
1175    assert(server_connection->forward_port == 0);
1176
1177    server_connection->forwarder_type = fwd->type;
1178    if (NULL != fwd->gateway_host)
1179    {
1180       server_connection->gateway_host = strdup_or_die(fwd->gateway_host);
1181    }
1182    else
1183    {
1184       server_connection->gateway_host = NULL;
1185    }
1186    server_connection->gateway_port = fwd->gateway_port;
1187
1188    if (NULL != fwd->forward_host)
1189    {
1190       server_connection->forward_host = strdup_or_die(fwd->forward_host);
1191    }
1192    else
1193    {
1194       server_connection->forward_host = NULL;
1195    }
1196    server_connection->forward_port = fwd->forward_port;
1197 }
1198
1199
1200 /*********************************************************************
1201  *
1202  * Function    : verify_request_length
1203  *
1204  * Description : Checks if we already got the whole client requests
1205  *               and sets CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ if
1206  *               we do.
1207  *
1208  *               Data that doesn't belong to the current request is
1209  *               either thrown away to let the client retry on a clean
1210  *               socket, or stashed to be dealt with after the current
1211  *               request is served.
1212  *
1213  * Parameters  :
1214  *          1  :  csp = Current client state (buffers, headers, etc...)
1215  *
1216  * Returns     :  void
1217  *
1218  *********************************************************************/
1219 static void verify_request_length(struct client_state *csp)
1220 {
1221    unsigned long long buffered_request_bytes =
1222       (unsigned long long)(csp->client_iob->eod - csp->client_iob->cur);
1223
1224    if ((csp->expected_client_content_length != 0)
1225       && (buffered_request_bytes != 0))
1226    {
1227       if (csp->expected_client_content_length >= buffered_request_bytes)
1228       {
1229          csp->expected_client_content_length -= buffered_request_bytes;
1230          log_error(LOG_LEVEL_CONNECT, "Reduced expected bytes to %llu "
1231             "to account for the %llu ones we already got.",
1232             csp->expected_client_content_length, buffered_request_bytes);
1233       }
1234       else
1235       {
1236          assert(csp->client_iob->eod > csp->client_iob->cur + csp->expected_client_content_length);
1237          csp->client_iob->eod = csp->client_iob->cur + csp->expected_client_content_length;
1238          log_error(LOG_LEVEL_CONNECT, "Reducing expected bytes to 0. "
1239             "Marking the server socket tainted after throwing %llu bytes away.",
1240             buffered_request_bytes - csp->expected_client_content_length);
1241          csp->expected_client_content_length = 0;
1242          csp->flags |= CSP_FLAG_SERVER_SOCKET_TAINTED;
1243       }
1244
1245       if (csp->expected_client_content_length == 0)
1246       {
1247          csp->flags |= CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ;
1248       }
1249    }
1250
1251    if (!(csp->flags & CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ)
1252       && ((csp->client_iob->cur < csp->client_iob->eod)
1253          || (csp->expected_client_content_length != 0)))
1254    {
1255       if (strcmpic(csp->http->gpc, "GET")
1256          && strcmpic(csp->http->gpc, "HEAD")
1257          && strcmpic(csp->http->gpc, "TRACE")
1258          && strcmpic(csp->http->gpc, "OPTIONS")
1259          && strcmpic(csp->http->gpc, "DELETE"))
1260       {
1261          /* XXX: this is an incomplete hack */
1262          csp->flags &= ~CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ;
1263          log_error(LOG_LEVEL_CONNECT, "There better be a request body.");
1264       }
1265       else
1266       {
1267          csp->flags |= CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ;
1268
1269          if ((csp->config->feature_flags & RUNTIME_FEATURE_TOLERATE_PIPELINING) == 0)
1270          {
1271             csp->flags |= CSP_FLAG_SERVER_SOCKET_TAINTED;
1272             log_error(LOG_LEVEL_CONNECT,
1273                "Possible pipeline attempt detected. The connection will not "
1274                "be kept alive and we will only serve the first request.");
1275             /* Nuke the pipelined requests from orbit, just to be sure. */
1276             clear_iob(csp->client_iob);
1277          }
1278          else
1279          {
1280             /*
1281              * Keep the pipelined data around for now, we'll deal with
1282              * it once we're done serving the current request.
1283              */
1284             csp->flags |= CSP_FLAG_PIPELINED_REQUEST_WAITING;
1285             assert(csp->client_iob->eod >= csp->client_iob->cur);
1286             log_error(LOG_LEVEL_CONNECT, "Complete client request followed by "
1287                "%d bytes of pipelined data received.",
1288                (int)(csp->client_iob->eod - csp->client_iob->cur));
1289          }
1290       }
1291    }
1292    else
1293    {
1294       csp->flags |= CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ;
1295       log_error(LOG_LEVEL_CONNECT, "Complete client request received.");
1296    }
1297 }
1298 #endif /* FEATURE_CONNECTION_KEEP_ALIVE */
1299
1300
1301 /*********************************************************************
1302  *
1303  * Function    :  mark_server_socket_tainted
1304  *
1305  * Description :  Makes sure we don't reuse a server socket
1306  *                (if we didn't read everything the server sent
1307  *                us reusing the socket would lead to garbage).
1308  *
1309  * Parameters  :
1310  *          1  :  csp = Current client state (buffers, headers, etc...)
1311  *
1312  * Returns     :  void.
1313  *
1314  *********************************************************************/
1315 static void mark_server_socket_tainted(struct client_state *csp)
1316 {
1317    /*
1318     * For consistency we always mark the server socket
1319     * tainted, however, to reduce the log noise we only
1320     * emit a log message if the server socket could have
1321     * actually been reused.
1322     */
1323    if ((csp->flags & CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE)
1324       && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED))
1325    {
1326       log_error(LOG_LEVEL_CONNECT,
1327          "Marking the server socket %d tainted.",
1328          csp->server_connection.sfd);
1329    }
1330    csp->flags |= CSP_FLAG_SERVER_SOCKET_TAINTED;
1331 }
1332
1333 /*********************************************************************
1334  *
1335  * Function    :  get_request_line
1336  *
1337  * Description : Read the client request line.
1338  *
1339  * Parameters  :
1340  *          1  :  csp = Current client state (buffers, headers, etc...)
1341  *
1342  * Returns     :  Pointer to request line or NULL in case of errors.
1343  *
1344  *********************************************************************/
1345 static char *get_request_line(struct client_state *csp)
1346 {
1347    char buf[BUFFER_SIZE];
1348    char *request_line = NULL;
1349    int len;
1350
1351    memset(buf, 0, sizeof(buf));
1352
1353    if ((csp->flags & CSP_FLAG_PIPELINED_REQUEST_WAITING) != 0)
1354    {
1355       /*
1356        * If there are multiple pipelined requests waiting,
1357        * the flag will be set again once the next request
1358        * has been parsed.
1359        */
1360       csp->flags &= ~CSP_FLAG_PIPELINED_REQUEST_WAITING;
1361
1362       request_line = get_header(csp->client_iob);
1363       if ((NULL != request_line) && ('\0' != *request_line))
1364       {
1365          return request_line;
1366       }
1367       else
1368       {
1369          log_error(LOG_LEVEL_CONNECT, "No complete request line "
1370             "received yet. Continuing reading from %d.", csp->cfd);
1371       }
1372    }
1373
1374    do
1375    {
1376       if (
1377 #ifdef FUZZ
1378           0 == (csp->flags & CSP_FLAG_FUZZED_INPUT) &&
1379 #endif
1380           !data_is_available(csp->cfd, csp->config->socket_timeout)
1381           )
1382       {
1383          if (socket_is_still_alive(csp->cfd))
1384          {
1385             log_error(LOG_LEVEL_CONNECT,
1386                "No request line on socket %d received in time. Timeout: %d.",
1387                csp->cfd, csp->config->socket_timeout);
1388             write_socket_delayed(csp->cfd, CLIENT_CONNECTION_TIMEOUT_RESPONSE,
1389                strlen(CLIENT_CONNECTION_TIMEOUT_RESPONSE),
1390                get_write_delay(csp));
1391          }
1392          else
1393          {
1394             log_error(LOG_LEVEL_CONNECT,
1395                "The client side of the connection on socket %d got "
1396                "closed without sending a complete request line.", csp->cfd);
1397          }
1398          return NULL;
1399       }
1400
1401       len = read_socket(csp->cfd, buf, sizeof(buf) - 1);
1402
1403       if (len <= 0) return NULL;
1404
1405       /*
1406        * If there is no memory left for buffering the
1407        * request, there is nothing we can do but hang up
1408        */
1409       if (add_to_iob(csp->client_iob, csp->config->buffer_limit, buf, len))
1410       {
1411          return NULL;
1412       }
1413
1414       request_line = get_header(csp->client_iob);
1415
1416    } while ((NULL != request_line) && ('\0' == *request_line));
1417
1418    return request_line;
1419
1420 }
1421
1422 enum chunk_status
1423 {
1424    CHUNK_STATUS_MISSING_DATA,
1425    CHUNK_STATUS_BODY_COMPLETE,
1426    CHUNK_STATUS_PARSE_ERROR
1427 };
1428
1429
1430 /*********************************************************************
1431  *
1432  * Function    :  chunked_body_is_complete
1433  *
1434  * Description :  Figures out whether or not a chunked body is complete.
1435  *
1436  *                Currently it always starts at the beginning of the
1437  *                buffer which is somewhat wasteful and prevents Privoxy
1438  *                from starting to forward the correctly parsed chunks
1439  *                as soon as theoretically possible.
1440  *
1441  *                Should be modified to work with a common buffer,
1442  *                and allow the caller to skip already parsed chunks.
1443  *
1444  *                This would allow the function to be used for unbuffered
1445  *                response bodies as well.
1446  *
1447  * Parameters  :
1448  *          1  :  iob = Buffer with the body to check.
1449  *          2  :  length = Length of complete body
1450  *
1451  * Returns     :  Enum with the result of the check.
1452  *
1453  *********************************************************************/
1454 static enum chunk_status chunked_body_is_complete(struct iob *iob, size_t *length)
1455 {
1456    unsigned int chunksize;
1457    char *p = iob->cur;
1458
1459    do
1460    {
1461       /*
1462        * We need at least a single digit, followed by "\r\n",
1463        * followed by an unknown amount of data, followed by "\r\n".
1464        */
1465       if (p + 5 > iob->eod)
1466       {
1467          return CHUNK_STATUS_MISSING_DATA;
1468       }
1469       if (sscanf(p, "%x", &chunksize) != 1)
1470       {
1471          return CHUNK_STATUS_PARSE_ERROR;
1472       }
1473
1474       /*
1475        * We want at least a single digit, followed by "\r\n",
1476        * followed by the specified amount of data, followed by "\r\n".
1477        */
1478       if (p + chunksize + 5 > iob->eod)
1479       {
1480          return CHUNK_STATUS_MISSING_DATA;
1481       }
1482
1483       /* Skip chunk-size. */
1484       p = strstr(p, "\r\n");
1485       if (NULL == p)
1486       {
1487          return CHUNK_STATUS_PARSE_ERROR;
1488       }
1489       /* Move beyond the chunkdata. */
1490       p += 2 + chunksize;
1491
1492       /* There should be another "\r\n" to skip */
1493       if (memcmp(p, "\r\n", 2))
1494       {
1495          return CHUNK_STATUS_PARSE_ERROR;
1496       }
1497       p += 2;
1498    } while (chunksize > 0U);
1499
1500    *length = (size_t)(p - iob->cur);
1501    assert(*length <= (size_t)(iob->eod - iob->cur));
1502    assert(p <= iob->eod);
1503
1504    return CHUNK_STATUS_BODY_COMPLETE;
1505
1506 }
1507
1508
1509 /*********************************************************************
1510  *
1511  * Function    : receive_chunked_client_request_body
1512  *
1513  * Description : Read the chunk-encoded client request body.
1514  *               Failures are dealt with.
1515  *
1516  * Parameters  :
1517  *          1  :  csp = Current client state (buffers, headers, etc...)
1518  *
1519  * Returns     :  JB_ERR_OK or JB_ERR_PARSE
1520  *
1521  *********************************************************************/
1522 static jb_err receive_chunked_client_request_body(struct client_state *csp)
1523 {
1524    size_t body_length;
1525    enum chunk_status status;
1526
1527    while (CHUNK_STATUS_MISSING_DATA ==
1528       (status = chunked_body_is_complete(csp->client_iob, &body_length)))
1529    {
1530       char buf[BUFFER_SIZE];
1531       int len;
1532
1533       if (!data_is_available(csp->cfd, csp->config->socket_timeout))
1534       {
1535          log_error(LOG_LEVEL_ERROR,
1536             "Timeout while waiting for the client body.");
1537          break;
1538       }
1539       len = read_socket(csp->cfd, buf, sizeof(buf) - 1);
1540       if (len <= 0)
1541       {
1542          log_error(LOG_LEVEL_ERROR, "Read the client body failed: %E");
1543          break;
1544       }
1545       if (add_to_iob(csp->client_iob, csp->config->buffer_limit, buf, len))
1546       {
1547          break;
1548       }
1549    }
1550    if (status != CHUNK_STATUS_BODY_COMPLETE)
1551    {
1552       write_socket_delayed(csp->cfd, CLIENT_BODY_PARSE_ERROR_RESPONSE,
1553          strlen(CLIENT_BODY_PARSE_ERROR_RESPONSE), get_write_delay(csp));
1554       log_error(LOG_LEVEL_CLF,
1555          "%s - - [%T] \"Failed reading chunked client body\" 400 0", csp->ip_addr_str);
1556       return JB_ERR_PARSE;
1557    }
1558    log_error(LOG_LEVEL_CONNECT,
1559       "Chunked client body completely read. Length: %d", body_length);
1560    csp->expected_client_content_length = body_length;
1561
1562    return JB_ERR_OK;
1563
1564 }
1565
1566
1567 #ifdef FUZZ
1568 /*********************************************************************
1569  *
1570  * Function    :  fuzz_chunked_transfer_encoding
1571  *
1572  * Description :  Treat the fuzzed input as chunked transfer encoding
1573  *                to check and dechunk.
1574  *
1575  * Parameters  :
1576  *          1  :  csp      = Used to store the data.
1577  *          2  :  fuzz_input_file = File to read the input from.
1578  *
1579  * Returns     : Result of dechunking
1580  *
1581  *********************************************************************/
1582 extern int fuzz_chunked_transfer_encoding(struct client_state *csp, char *fuzz_input_file)
1583 {
1584    size_t length;
1585    size_t size = (size_t)(csp->iob->eod - csp->iob->cur);
1586    enum chunk_status status;
1587
1588    status = chunked_body_is_complete(csp->iob, &length);
1589    if (CHUNK_STATUS_BODY_COMPLETE != status)
1590    {
1591       log_error(LOG_LEVEL_INFO, "Chunked body is incomplete or invalid");
1592    }
1593
1594    return (JB_ERR_OK == remove_chunked_transfer_coding(csp->iob->cur, &size));
1595
1596 }
1597
1598
1599 /*********************************************************************
1600  *
1601  * Function    : fuzz_client_request
1602  *
1603  * Description : Try to get a client request from the fuzzed input.
1604  *
1605  * Parameters  :
1606  *          1  :  csp = Current client state (buffers, headers, etc...)
1607  *          2  :  fuzz_input_file = File to read the input from.
1608  *
1609  * Returns     :  Result of fuzzing.
1610  *
1611  *********************************************************************/
1612 extern int fuzz_client_request(struct client_state *csp, char *fuzz_input_file)
1613 {
1614    jb_err err;
1615
1616    csp->cfd = 0;
1617    csp->ip_addr_str = "fuzzer";
1618
1619    if (strcmp(fuzz_input_file, "-") != 0)
1620    {
1621       log_error(LOG_LEVEL_FATAL,
1622          "Fuzzed client requests can currenty only be read from stdin (-).");
1623    }
1624    err = receive_client_request(csp);
1625    if (err != JB_ERR_OK)
1626    {
1627       return 1;
1628    }
1629    err = parse_client_request(csp);
1630    if (err != JB_ERR_OK)
1631    {
1632       return 1;
1633    }
1634
1635    return 0;
1636
1637 }
1638 #endif  /* def FUZZ */
1639
1640
1641 #ifdef FEATURE_FORCE_LOAD
1642 /*********************************************************************
1643  *
1644  * Function    :  force_required
1645  *
1646  * Description : Checks a request line to see if it contains
1647  *               the FORCE_PREFIX. If it does, it is removed
1648  *               unless enforcing requests has beend disabled.
1649  *
1650  * Parameters  :
1651  *          1  :  request_line = HTTP request line
1652  *
1653  * Returns     :  TRUE if force is required, FALSE otherwise.
1654  *
1655  *********************************************************************/
1656 static int force_required(const struct client_state *csp, char *request_line)
1657 {
1658    char *p;
1659
1660    p = strstr(request_line, "http://");
1661    if (p != NULL)
1662    {
1663       /* Skip protocol */
1664       p += strlen("http://");
1665    }
1666    else
1667    {
1668       /* Intercepted request usually don't specify the protocol. */
1669       p = request_line;
1670    }
1671
1672    /* Go to the beginning of the path */
1673    p = strstr(p, "/");
1674    if (p == NULL)
1675    {
1676       /*
1677        * If the path is missing the request line is invalid and we
1678        * are done here. The client-visible rejection happens later on.
1679        */
1680       return 0;
1681    }
1682
1683    if (0 == strncmpic(p, FORCE_PREFIX, strlen(FORCE_PREFIX) - 1))
1684    {
1685       if (!(csp->config->feature_flags & RUNTIME_FEATURE_ENFORCE_BLOCKS))
1686       {
1687          /* XXX: Should clean more carefully */
1688          strclean(request_line, FORCE_PREFIX);
1689          log_error(LOG_LEVEL_FORCE,
1690             "Enforcing request: \"%s\".", request_line);
1691
1692          return 1;
1693       }
1694       log_error(LOG_LEVEL_FORCE,
1695          "Ignored force prefix in request: \"%s\".", request_line);
1696    }
1697
1698    return 0;
1699
1700 }
1701 #endif /* def FEATURE_FORCE_LOAD */
1702
1703
1704 /*********************************************************************
1705  *
1706  * Function    :  receive_client_request
1707  *
1708  * Description : Read the client's request (more precisely the
1709  *               client headers) and answer it if necessary.
1710  *
1711  * Parameters  :
1712  *          1  :  csp = Current client state (buffers, headers, etc...)
1713  *
1714  * Returns     :  JB_ERR_OK, JB_ERR_PARSE or JB_ERR_MEMORY
1715  *
1716  *********************************************************************/
1717 static jb_err receive_client_request(struct client_state *csp)
1718 {
1719    char buf[BUFFER_SIZE];
1720    char *p;
1721    char *req = NULL;
1722    struct http_request *http;
1723    int len;
1724    jb_err err;
1725
1726    /* Temporary copy of the client's headers before they get enlisted in csp->headers */
1727    struct list header_list;
1728    struct list *headers = &header_list;
1729
1730    /* We don't care if the arriving data is a valid HTTP request or not. */
1731    csp->requests_received_total++;
1732
1733    http = csp->http;
1734
1735    memset(buf, 0, sizeof(buf));
1736
1737    req = get_request_line(csp);
1738    if (req == NULL)
1739    {
1740       mark_server_socket_tainted(csp);
1741       return JB_ERR_PARSE;
1742    }
1743    assert(*req != '\0');
1744
1745    if (client_protocol_is_unsupported(csp, req))
1746    {
1747       return JB_ERR_PARSE;
1748    }
1749
1750 #ifdef FEATURE_FORCE_LOAD
1751    if (force_required(csp, req))
1752    {
1753       csp->flags |= CSP_FLAG_FORCED;
1754    }
1755 #endif /* def FEATURE_FORCE_LOAD */
1756
1757    err = parse_http_request(req, http);
1758    freez(req);
1759    if (JB_ERR_OK != err)
1760    {
1761       write_socket_delayed(csp->cfd, CHEADER, strlen(CHEADER),
1762          get_write_delay(csp));
1763       /* XXX: Use correct size */
1764       log_error(LOG_LEVEL_CLF, "%s - - [%T] \"Invalid request\" 400 0", csp->ip_addr_str);
1765       log_error(LOG_LEVEL_ERROR,
1766          "Couldn't parse request line received from %s: %s",
1767          csp->ip_addr_str, jb_err_to_string(err));
1768
1769       free_http_request(http);
1770       return JB_ERR_PARSE;
1771    }
1772
1773    /* grab the rest of the client's headers */
1774    init_list(headers);
1775    for (;;)
1776    {
1777       p = get_header(csp->client_iob);
1778
1779       if (p == NULL)
1780       {
1781          /* There are no additional headers to read. */
1782          break;
1783       }
1784
1785       if (*p == '\0')
1786       {
1787          /*
1788           * We didn't receive a complete header
1789           * line yet, get the rest of it.
1790           */
1791          if (!data_is_available(csp->cfd, csp->config->socket_timeout))
1792          {
1793             log_error(LOG_LEVEL_ERROR,
1794                "Stopped grabbing the client headers.");
1795             destroy_list(headers);
1796             return JB_ERR_PARSE;
1797          }
1798
1799          len = read_socket(csp->cfd, buf, sizeof(buf) - 1);
1800          if (len <= 0)
1801          {
1802             log_error(LOG_LEVEL_ERROR, "read from client failed: %E");
1803             destroy_list(headers);
1804             return JB_ERR_PARSE;
1805          }
1806
1807          if (add_to_iob(csp->client_iob, csp->config->buffer_limit, buf, len))
1808          {
1809             /*
1810              * If there is no memory left for buffering the
1811              * request, there is nothing we can do but hang up
1812              */
1813             destroy_list(headers);
1814             return JB_ERR_MEMORY;
1815          }
1816       }
1817       else
1818       {
1819          if (!strncmpic(p, "Transfer-Encoding:", 18))
1820          {
1821             /*
1822              * XXX: should be called through sed()
1823              *      but currently can't.
1824              */
1825             client_transfer_encoding(csp, &p);
1826          }
1827          /*
1828           * We were able to read a complete
1829           * header and can finally enlist it.
1830           */
1831          enlist(headers, p);
1832          freez(p);
1833       }
1834    }
1835
1836    if (http->host == NULL)
1837    {
1838       /*
1839        * If we still don't know the request destination,
1840        * the request is invalid or the client uses
1841        * Privoxy without its knowledge.
1842        */
1843       if (JB_ERR_OK != get_request_destination_elsewhere(csp, headers))
1844       {
1845          /*
1846           * Our attempts to get the request destination
1847           * elsewhere failed or Privoxy is configured
1848           * to only accept proxy requests.
1849           *
1850           * An error response has already been send
1851           * and we're done here.
1852           */
1853          return JB_ERR_PARSE;
1854       }
1855    }
1856
1857 #ifdef FEATURE_CLIENT_TAGS
1858    /* XXX: If the headers were enlisted sooner, passing csp would do. */
1859    set_client_address(csp, headers);
1860    get_tag_list_for_client(csp->client_tags, csp->client_address);
1861 #endif
1862
1863    /*
1864     * Determine the actions for this URL
1865     */
1866 #ifdef FEATURE_TOGGLE
1867    if (!(csp->flags & CSP_FLAG_TOGGLED_ON))
1868    {
1869       /* Most compatible set of actions (i.e. none) */
1870       init_current_action(csp->action);
1871    }
1872    else
1873 #endif /* ndef FEATURE_TOGGLE */
1874    {
1875       get_url_actions(csp, http);
1876    }
1877
1878    enlist(csp->headers, http->cmd);
1879
1880    /* Append the previously read headers */
1881    err = list_append_list_unique(csp->headers, headers);
1882    destroy_list(headers);
1883
1884    return err;
1885
1886 }
1887
1888
1889 /*********************************************************************
1890  *
1891  * Function    : parse_client_request
1892  *
1893  * Description : Parses the client's request and decides what to do
1894  *               with it.
1895  *
1896  *               Note that since we're not using select() we could get
1897  *               blocked here if a client connected, then didn't say
1898  *               anything!
1899  *
1900  * Parameters  :
1901  *          1  :  csp = Current client state (buffers, headers, etc...)
1902  *
1903  * Returns     :  JB_ERR_OK or JB_ERR_PARSE
1904  *
1905  *********************************************************************/
1906 static jb_err parse_client_request(struct client_state *csp)
1907 {
1908    struct http_request *http = csp->http;
1909    jb_err err;
1910
1911 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1912    if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
1913     && (!strcmpic(csp->http->version, "HTTP/1.1"))
1914     && (csp->http->ssl == 0))
1915    {
1916       /* Assume persistence until further notice */
1917       csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
1918    }
1919
1920    if (csp->http->ssl == 0)
1921    {
1922       /*
1923        * This whole block belongs to chat() but currently
1924        * has to be executed before sed().
1925        */
1926       if (csp->flags & CSP_FLAG_CHUNKED_CLIENT_BODY)
1927       {
1928          if (receive_chunked_client_request_body(csp) != JB_ERR_OK)
1929          {
1930             return JB_ERR_PARSE;
1931          }
1932       }
1933       else
1934       {
1935          csp->expected_client_content_length = get_expected_content_length(csp->headers);
1936       }
1937       verify_request_length(csp);
1938    }
1939    else
1940    {
1941       csp->flags |= CSP_FLAG_SERVER_SOCKET_TAINTED;
1942    }
1943 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
1944
1945    err = sed(csp, FILTER_CLIENT_HEADERS);
1946    if (JB_ERR_OK != err)
1947    {
1948       log_error(LOG_LEVEL_ERROR, "Failed to parse client request from %s.",
1949          csp->ip_addr_str);
1950       log_error(LOG_LEVEL_CLF, "%s - - [%T] \"%s\" 400 0",
1951          csp->ip_addr_str, csp->http->cmd);
1952       write_socket_delayed(csp->cfd, CHEADER, strlen(CHEADER), get_write_delay(csp));
1953       return JB_ERR_PARSE;
1954    }
1955    csp->flags |= CSP_FLAG_CLIENT_HEADER_PARSING_DONE;
1956
1957    /* Check request line for rewrites. */
1958    if ((NULL == csp->headers->first->str)
1959       || (strcmp(http->cmd, csp->headers->first->str) &&
1960          (JB_ERR_OK != change_request_destination(csp))))
1961    {
1962       /*
1963        * A header filter broke the request line - bail out.
1964        */
1965       write_socket_delayed(csp->cfd, MESSED_UP_REQUEST_RESPONSE,
1966          strlen(MESSED_UP_REQUEST_RESPONSE), get_write_delay(csp));
1967       /* XXX: Use correct size */
1968       log_error(LOG_LEVEL_CLF,
1969          "%s - - [%T] \"Invalid request generated\" 500 0", csp->ip_addr_str);
1970       log_error(LOG_LEVEL_ERROR,
1971          "Invalid request line after applying header filters.");
1972       free_http_request(http);
1973
1974       return JB_ERR_PARSE;
1975    }
1976
1977    if (client_has_unsupported_expectations(csp))
1978    {
1979       return JB_ERR_PARSE;
1980    }
1981
1982    return JB_ERR_OK;
1983
1984 }
1985
1986
1987 /*********************************************************************
1988  *
1989  * Function    : send_http_request
1990  *
1991  * Description : Sends the HTTP headers from the client request
1992  *               and all the body data that has already been received.
1993  *
1994  * Parameters  :
1995  *          1  :  csp = Current client state (buffers, headers, etc...)
1996  *
1997  * Returns     :  0 on success, anything else is an error.
1998  *
1999  *********************************************************************/
2000 static int send_http_request(struct client_state *csp)
2001 {
2002    char *hdr;
2003    int write_failure;
2004
2005    hdr = list_to_text(csp->headers);
2006    if (hdr == NULL)
2007    {
2008       /* FIXME Should handle error properly */
2009       log_error(LOG_LEVEL_FATAL, "Out of memory parsing client header");
2010    }
2011    list_remove_all(csp->headers);
2012
2013    /*
2014     * Write the client's (modified) header to the server
2015     * (along with anything else that may be in the buffer)
2016     */
2017    write_failure = 0 != write_socket(csp->server_connection.sfd, hdr, strlen(hdr));
2018    freez(hdr);
2019
2020    if (write_failure)
2021    {
2022       log_error(LOG_LEVEL_CONNECT, "Failed sending request headers to: %s: %E",
2023          csp->http->hostport);
2024    }
2025    else if (((csp->flags & CSP_FLAG_PIPELINED_REQUEST_WAITING) == 0)
2026       && (flush_iob(csp->server_connection.sfd, csp->client_iob, 0) < 0))
2027    {
2028       write_failure = 1;
2029       log_error(LOG_LEVEL_CONNECT, "Failed sending request body to: %s: %E",
2030          csp->http->hostport);
2031    }
2032
2033    return write_failure;
2034
2035 }
2036
2037
2038 #ifdef FEATURE_HTTPS_INSPECTION
2039 /*********************************************************************
2040  *
2041  * Function    : receive_and_send_encrypted_post_data
2042  *
2043  * Description : Reads remaining POST data from the client and sends
2044  *               it to the server.
2045  *
2046  * Parameters  :
2047  *          1  :  csp = Current client state (buffers, headers, etc...)
2048  *
2049  * Returns     :  0 on success, anything else is an error.
2050  *
2051  *********************************************************************/
2052 static jb_err receive_and_send_encrypted_post_data(struct client_state *csp)
2053 {
2054    int content_length_known = csp->expected_client_content_length != 0;
2055
2056    while (is_ssl_pending(&(csp->mbedtls_client_attr.ssl)))
2057    {
2058       unsigned char buf[BUFFER_SIZE];
2059       int len;
2060       int max_bytes_to_read = sizeof(buf);
2061
2062       if (content_length_known && csp->expected_client_content_length < sizeof(buf))
2063       {
2064          max_bytes_to_read = (int)csp->expected_client_content_length;
2065       }
2066       log_error(LOG_LEVEL_CONNECT,
2067          "Waiting for up to %d bytes of POST data from the client.",
2068          max_bytes_to_read);
2069       len = ssl_recv_data(&(csp->mbedtls_client_attr.ssl), buf,
2070          (unsigned)max_bytes_to_read);
2071       if (len == -1)
2072       {
2073          return 1;
2074       }
2075       if (len == 0)
2076       {
2077          /* XXX: Does this actually happen? */
2078          break;
2079       }
2080       log_error(LOG_LEVEL_HEADER, "Forwarding %d bytes of encrypted POST data",
2081          len);
2082       len = ssl_send_data(&(csp->mbedtls_server_attr.ssl), buf, (size_t)len);
2083       if (len == -1)
2084       {
2085          return 1;
2086       }
2087       if (csp->expected_client_content_length != 0)
2088       {
2089          if (csp->expected_client_content_length >= len)
2090          {
2091             csp->expected_client_content_length -= (unsigned)len;
2092          }
2093          if (csp->expected_client_content_length == 0)
2094          {
2095             log_error(LOG_LEVEL_HEADER, "Forwarded the last %d bytes", len);
2096             break;
2097          }
2098       }
2099    }
2100
2101    log_error(LOG_LEVEL_HEADER, "Done forwarding encrypted POST data");
2102
2103    return 0;
2104
2105 }
2106
2107
2108 /*********************************************************************
2109  *
2110  * Function    : send_https_request
2111  *
2112  * Description : Sends the HTTP headers from the client request
2113  *               and all the body data that has already been received.
2114  *
2115  * Parameters  :
2116  *          1  :  csp = Current client state (buffers, headers, etc...)
2117  *
2118  * Returns     :  0 on success, anything else is an error.
2119  *
2120  *********************************************************************/
2121 static int send_https_request(struct client_state *csp)
2122 {
2123    char *hdr;
2124    int ret;
2125    long flushed = 0;
2126
2127    hdr = list_to_text(csp->https_headers);
2128    if (hdr == NULL)
2129    {
2130       /* FIXME Should handle error properly */
2131       log_error(LOG_LEVEL_FATAL, "Out of memory parsing client header");
2132    }
2133    list_remove_all(csp->https_headers);
2134
2135    /*
2136     * Write the client's (modified) header to the server
2137     * (along with anything else that may be in the buffer)
2138     */
2139    ret = ssl_send_data(&(csp->mbedtls_server_attr.ssl),
2140       (const unsigned char *)hdr, strlen(hdr));
2141    freez(hdr);
2142
2143    if (ret < 0)
2144    {
2145       log_error(LOG_LEVEL_CONNECT,
2146          "Failed sending encrypted request headers to: %s: %E",
2147          csp->http->hostport);
2148       mark_server_socket_tainted(csp);
2149       return 1;
2150    }
2151
2152    if (((csp->flags & CSP_FLAG_PIPELINED_REQUEST_WAITING) == 0)
2153       && ((flushed = ssl_flush_socket(&(csp->mbedtls_server_attr.ssl),
2154             csp->client_iob)) < 0))
2155    {
2156       log_error(LOG_LEVEL_CONNECT, "Failed sending request body to: %s: %E",
2157          csp->http->hostport);
2158       return 1;
2159    }
2160    if (flushed != 0)
2161    {
2162       if (csp->expected_client_content_length != 0)
2163       {
2164          if (csp->expected_client_content_length < flushed)
2165          {
2166             log_error(LOG_LEVEL_ERROR,
2167                "Flushed %d bytes of request body while only expecting %llu",
2168                flushed, csp->expected_client_content_length);
2169             csp->expected_client_content_length = 0;
2170          }
2171          else
2172          {
2173             log_error(LOG_LEVEL_CONNECT,
2174                "Flushed %d bytes of request body while expecting %llu",
2175                flushed, csp->expected_client_content_length);
2176             csp->expected_client_content_length -= (unsigned)flushed;
2177             if (receive_and_send_encrypted_post_data(csp))
2178             {
2179                return 1;
2180             }
2181          }
2182       }
2183       else
2184       {
2185          log_error(LOG_LEVEL_CONNECT,
2186             "Flushed %d bytes of request body", flushed);
2187       }
2188    }
2189
2190    log_error(LOG_LEVEL_CONNECT, "Encrypted request sent");
2191
2192    return 0;
2193
2194 }
2195
2196
2197 /*********************************************************************
2198  *
2199  * Function    :  receive_encrypted_request
2200  *
2201  * Description :  Receives an encrypted request.
2202  *
2203  * Parameters  :
2204  *          1  :  csp = Current client state (buffers, headers, etc...)
2205  *
2206  * Returns     :  JB_ERR_OK on success,
2207  *                JB_ERR_PARSE or JB_ERR_MEMORY otherwise
2208  *
2209  *********************************************************************/
2210 static jb_err receive_encrypted_request(struct client_state *csp)
2211 {
2212    char buf[BUFFER_SIZE];
2213    int len;
2214    char *p;
2215
2216    do
2217    {
2218       log_error(LOG_LEVEL_HEADER, "Reading encrypted headers");
2219       if (!data_is_available(csp->cfd, (int)csp->config->keep_alive_timeout))
2220       {
2221          log_error(LOG_LEVEL_CONNECT,
2222             "Socket %d timed out while waiting for client headers", csp->cfd);
2223          return JB_ERR_PARSE;
2224       }
2225       len = ssl_recv_data(&(csp->mbedtls_client_attr.ssl),
2226          (unsigned char *)buf, sizeof(buf));
2227       if (len == -1)
2228       {
2229          return JB_ERR_PARSE;
2230       }
2231       if (add_to_iob(csp->client_iob, csp->config->buffer_limit, buf, len))
2232       {
2233          return JB_ERR_MEMORY;
2234       }
2235       p = strstr(csp->client_iob->cur, "\r\n\r\n");
2236    } while (p == NULL);
2237
2238    log_error(LOG_LEVEL_HEADER, "Encrypted headers received completely");
2239
2240    return JB_ERR_OK;
2241 }
2242
2243
2244 /*********************************************************************
2245  *
2246  * Function    :  process_encrypted_request
2247  *
2248  * Description :  Receives and parses an encrypted request.
2249  *
2250  * Parameters  :
2251  *          1  :  csp = Current client state (buffers, headers, etc...)
2252  *
2253  * Returns     :  JB_ERR_OK on success,
2254  *                JB_ERR_PARSE or JB_ERR_MEMORY otherwise
2255  *
2256  *********************************************************************/
2257 static jb_err process_encrypted_request(struct client_state *csp)
2258 {
2259    char *p;
2260    char *request_line;
2261    jb_err err;
2262    /* Temporary copy of the client's headers before they get enlisted in csp->https_headers */
2263    struct list header_list;
2264    struct list *headers = &header_list;
2265
2266    err = receive_encrypted_request(csp);
2267    if (err != JB_ERR_OK)
2268    {
2269       /* XXX: Also used for JB_ERR_MEMORY */
2270       log_error(LOG_LEVEL_ERROR, "Failed to receive encrypted request: %s",
2271          jb_err_to_string(err));
2272       ssl_send_data(&(csp->mbedtls_client_attr.ssl),
2273          (const unsigned char *)CHEADER, strlen(CHEADER));
2274       return err;
2275    }
2276
2277    /* We don't need get_request_line() because the whole HTTP head is buffered. */
2278    request_line = get_header(csp->client_iob);
2279    if (request_line == NULL)
2280    {
2281       log_error(LOG_LEVEL_ERROR, "Failed to get the encrypted request line");
2282       ssl_send_data(&(csp->mbedtls_client_attr.ssl),
2283          (const unsigned char *)CHEADER, strlen(CHEADER));
2284       return JB_ERR_PARSE;
2285    }
2286    assert(*request_line != '\0');
2287
2288    if (client_protocol_is_unsupported(csp, request_line))
2289    {
2290       /*
2291        * If the protocol is unsupported we're done here.
2292        * client_protocol_is_unsupported() took care of sending
2293        * the error response and logging the error message.
2294        */
2295       return JB_ERR_PARSE;
2296    }
2297
2298 #ifdef FEATURE_FORCE_LOAD
2299    if (force_required(csp, request_line))
2300    {
2301       csp->flags |= CSP_FLAG_FORCED;
2302    }
2303 #endif /* def FEATURE_FORCE_LOAD */
2304
2305    free_http_request(csp->http);
2306
2307    err = parse_http_request(request_line, csp->http);
2308    /* XXX: Restore ssl setting. This is ugly */
2309    csp->http->client_ssl = 1;
2310    csp->http->server_ssl = 1;
2311
2312    freez(request_line);
2313    if (JB_ERR_OK != err)
2314    {
2315       ssl_send_data(&(csp->mbedtls_client_attr.ssl),
2316          (const unsigned char *)CHEADER, strlen(CHEADER));
2317       /* XXX: Use correct size */
2318       log_error(LOG_LEVEL_CLF, "%s - - [%T] \"Invalid request\" 400 0", csp->ip_addr_str);
2319       log_error(LOG_LEVEL_ERROR,
2320          "Couldn't parse request line received from %s: %s",
2321          csp->ip_addr_str, jb_err_to_string(err));
2322
2323       free_http_request(csp->http);
2324       return JB_ERR_PARSE;
2325    }
2326
2327    /* Parse the rest of the client's headers. */
2328    init_list(headers);
2329    for (;;)
2330    {
2331       p = get_header(csp->client_iob);
2332
2333       if (p == NULL)
2334       {
2335          /* There are no additional headers to read. */
2336          break;
2337       }
2338       enlist(headers, p);
2339       freez(p);
2340    }
2341
2342    if (JB_ERR_OK != get_destination_from_https_headers(headers, csp->http))
2343    {
2344       /*
2345        * Our attempts to get the request destination
2346        * elsewhere failed.
2347        */
2348       log_error(LOG_LEVEL_ERROR,
2349          "Failed to get the encrypted request destination");
2350       ssl_send_data(&(csp->mbedtls_client_attr.ssl),
2351          (const unsigned char *)CHEADER, strlen(CHEADER));
2352       return JB_ERR_PARSE;
2353    }
2354
2355 #ifndef FEATURE_EXTENDED_HOST_PATTERNS
2356    /* Split the domain we just got for pattern matching */
2357    init_domain_components(csp->http);
2358 #endif
2359
2360 #ifdef FEATURE_TOGGLE
2361    if ((csp->flags & CSP_FLAG_TOGGLED_ON) != 0)
2362 #endif
2363    {
2364       /* Determine the actions for this URL */
2365       get_url_actions(csp, csp->http);
2366    }
2367
2368    enlist(csp->https_headers, csp->http->cmd);
2369
2370    /* Append the previously read headers */
2371    err = list_append_list_unique(csp->https_headers, headers);
2372    destroy_list(headers);
2373    if (JB_ERR_OK != err)
2374    {
2375       /* XXX: Send error message */
2376       return err;
2377    }
2378
2379    /* XXX: Work around crash */
2380    csp->error_message = NULL;
2381
2382    /* XXX: Why do this here? */
2383    csp->http->ssl = 1;
2384
2385    err = sed_https(csp);
2386    if (JB_ERR_OK != err)
2387    {
2388       ssl_send_data(&(csp->mbedtls_client_attr.ssl),
2389          (const unsigned char *)CHEADER, strlen(CHEADER));
2390       log_error(LOG_LEVEL_ERROR, "Failed to parse client request from %s.",
2391          csp->ip_addr_str);
2392       log_error(LOG_LEVEL_CLF, "%s - - [%T] \"%s\" 400 0",
2393          csp->ip_addr_str, csp->http->cmd);
2394       return JB_ERR_PARSE;
2395    }
2396
2397    log_error(LOG_LEVEL_HEADER, "Encrypted request processed");
2398    log_applied_actions(csp->action);
2399    log_error(LOG_LEVEL_GPC, "https://%s%s", csp->http->hostport,
2400       csp->http->path);
2401
2402    return err;
2403
2404 }
2405 #endif
2406
2407
2408 /*********************************************************************
2409  *
2410  * Function    :  handle_established_connection
2411  *
2412  * Description :  Shuffle data between client and server once the
2413  *                connection has been established.
2414  *
2415  * Parameters  :
2416  *          1  :  csp = Current client state (buffers, headers, etc...)
2417  *
2418  * Returns     :  Nothing.
2419  *
2420  *********************************************************************/
2421 static void handle_established_connection(struct client_state *csp)
2422 {
2423    char *hdr;
2424    char *p;
2425    int n;
2426 #ifdef HAVE_POLL
2427    struct pollfd poll_fds[2];
2428 #else
2429    fd_set rfds;
2430    jb_socket maxfd;
2431    struct timeval timeout;
2432 #endif
2433    int server_body;
2434    int ms_iis5_hack = 0;
2435    unsigned long long byte_count = 0;
2436    struct http_request *http;
2437    long len = 0; /* for buffer sizes (and negative error codes) */
2438    int buffer_and_filter_content = 0;
2439    unsigned int write_delay;
2440 #ifdef FEATURE_HTTPS_INSPECTION
2441    int ret = 0;
2442    int use_ssl_tunnel = 0;
2443    csp->dont_verify_certificate = 0;
2444
2445    if (csp->http->ssl && !(csp->action->flags & ACTION_HTTPS_INSPECTION))
2446    {
2447       /* Pass encrypted content without filtering. */
2448       use_ssl_tunnel = 1;
2449    }
2450 #endif
2451
2452    /* Skeleton for HTTP response, if we should intercept the request */
2453    struct http_response *rsp;
2454 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2455    int watch_client_socket;
2456 #endif
2457
2458    csp->receive_buffer_size = csp->config->receive_buffer_size;
2459    csp->receive_buffer = zalloc(csp->receive_buffer_size + 1);
2460    if (csp->receive_buffer == NULL)
2461    {
2462       log_error(LOG_LEVEL_ERROR,
2463          "Out of memory. Failed to allocate the receive buffer.");
2464       rsp = cgi_error_memory();
2465       send_crunch_response(csp, rsp);
2466       return;
2467    }
2468
2469    http = csp->http;
2470
2471 #ifndef HAVE_POLL
2472    maxfd = (csp->cfd > csp->server_connection.sfd) ?
2473       csp->cfd : csp->server_connection.sfd;
2474 #endif
2475
2476    /* pass data between the client and server
2477     * until one or the other shuts down the connection.
2478     */
2479
2480    server_body = 0;
2481
2482 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2483    watch_client_socket = 0 == (csp->flags & CSP_FLAG_PIPELINED_REQUEST_WAITING);
2484 #endif
2485    write_delay = get_write_delay(csp);
2486
2487    for (;;)
2488    {
2489 #ifndef HAVE_POLL
2490 #ifdef __OS2__
2491       /*
2492        * FD_ZERO here seems to point to an errant macro which crashes.
2493        * So do this by hand for now...
2494        */
2495       memset(&rfds,0x00,sizeof(fd_set));
2496 #else
2497       FD_ZERO(&rfds);
2498 #endif
2499 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2500       if (!watch_client_socket)
2501       {
2502          maxfd = csp->server_connection.sfd;
2503       }
2504       else
2505 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2506       {
2507          FD_SET(csp->cfd, &rfds);
2508       }
2509
2510       FD_SET(csp->server_connection.sfd, &rfds);
2511 #endif /* ndef HAVE_POLL */
2512
2513 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2514       if ((csp->flags & CSP_FLAG_CHUNKED)
2515          && !(csp->flags & CSP_FLAG_CONTENT_LENGTH_SET)
2516          && ((csp->iob->eod - csp->iob->cur) >= 5)
2517          && !memcmp(csp->iob->eod-5, "0\r\n\r\n", 5))
2518       {
2519          /*
2520           * XXX: This check should be obsolete now,
2521           *      but let's wait a while to be sure.
2522           */
2523          log_error(LOG_LEVEL_CONNECT,
2524             "Looks like we got the last chunk together with "
2525             "the server headers but didn't detect it earlier. "
2526             "We better stop reading.");
2527          byte_count = (unsigned long long)(csp->iob->eod - csp->iob->cur);
2528          csp->expected_content_length = byte_count;
2529          csp->flags |= CSP_FLAG_CONTENT_LENGTH_SET;
2530       }
2531       if (server_body && server_response_is_complete(csp, byte_count))
2532       {
2533          if (csp->expected_content_length == byte_count)
2534          {
2535             log_error(LOG_LEVEL_CONNECT,
2536                "Done reading from server. Content length: %llu as expected. "
2537                "Bytes most recently read: %d.",
2538                byte_count, len);
2539          }
2540          else
2541          {
2542             log_error(LOG_LEVEL_CONNECT,
2543                "Done reading from server. Expected content length: %llu. "
2544                "Actual content length: %llu. Bytes most recently read: %d.",
2545                csp->expected_content_length, byte_count, len);
2546          }
2547          len = 0;
2548          /*
2549           * XXX: Should not jump around, handle_established_connection()
2550           * is complicated enough already.
2551           */
2552          goto reading_done;
2553       }
2554 #endif  /* FEATURE_CONNECTION_KEEP_ALIVE */
2555
2556 #ifdef HAVE_POLL
2557       poll_fds[0].fd = csp->cfd;
2558 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2559       if (!watch_client_socket)
2560       {
2561          /*
2562           * Ignore incoming data, but still watch out
2563           * for disconnects etc. These flags are always
2564           * implied anyway but explicitly setting them
2565           * doesn't hurt.
2566           */
2567          poll_fds[0].events = POLLERR|POLLHUP;
2568       }
2569       else
2570 #endif
2571       {
2572          poll_fds[0].events = POLLIN;
2573       }
2574       poll_fds[1].fd = csp->server_connection.sfd;
2575       poll_fds[1].events = POLLIN;
2576       n = poll(poll_fds, 2, csp->config->socket_timeout * 1000);
2577 #else
2578       timeout.tv_sec = csp->config->socket_timeout;
2579       timeout.tv_usec = 0;
2580       n = select((int)maxfd + 1, &rfds, NULL, NULL, &timeout);
2581 #endif /* def HAVE_POLL */
2582
2583       /*server or client not responding in timeout */
2584       if (n == 0)
2585       {
2586          log_error(LOG_LEVEL_CONNECT, "Socket timeout %d reached: %s",
2587             csp->config->socket_timeout, http->url);
2588          if ((byte_count == 0) && (http->ssl == 0))
2589          {
2590             send_crunch_response(csp, error_response(csp, "connection-timeout"));
2591          }
2592          mark_server_socket_tainted(csp);
2593 #ifdef FEATURE_HTTPS_INSPECTION
2594          close_client_and_server_ssl_connections(csp);
2595 #endif
2596          return;
2597       }
2598       else if (n < 0)
2599       {
2600 #ifdef HAVE_POLL
2601          log_error(LOG_LEVEL_ERROR, "poll() failed!: %E");
2602 #else
2603          log_error(LOG_LEVEL_ERROR, "select() failed!: %E");
2604 #endif
2605          mark_server_socket_tainted(csp);
2606 #ifdef FEATURE_HTTPS_INSPECTION
2607          close_client_and_server_ssl_connections(csp);
2608 #endif
2609          return;
2610       }
2611
2612       /*
2613        * This is the body of the browser's request,
2614        * just read and write it.
2615        *
2616        * Receives data from browser and sends it to server
2617        *
2618        * XXX: Make sure the client doesn't use pipelining
2619        * behind Privoxy's back.
2620        */
2621 #ifdef HAVE_POLL
2622       if ((poll_fds[0].revents & (POLLERR|POLLHUP|POLLNVAL)) != 0)
2623       {
2624          log_error(LOG_LEVEL_CONNECT,
2625             "The client socket %d has become unusable while "
2626             "the server socket %d is still open.",
2627             csp->cfd, csp->server_connection.sfd);
2628          mark_server_socket_tainted(csp);
2629          break;
2630       }
2631
2632       if (poll_fds[0].revents != 0)
2633 #else
2634       if (FD_ISSET(csp->cfd, &rfds))
2635 #endif /* def HAVE_POLL*/
2636       {
2637          int max_bytes_to_read = (int)csp->receive_buffer_size;
2638
2639 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2640          if ((csp->flags & CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ))
2641          {
2642             if (data_is_available(csp->cfd, 0))
2643             {
2644                /*
2645                 * If the next request is already waiting, we have
2646                 * to stop select()ing the client socket. Otherwise
2647                 * we would always return right away and get nothing
2648                 * else done.
2649                 */
2650                watch_client_socket = 0;
2651                log_error(LOG_LEVEL_CONNECT,
2652                   "Stop watching client socket %d. "
2653                   "There's already another request waiting.",
2654                   csp->cfd);
2655                continue;
2656             }
2657             /*
2658              * If the client socket is set, but there's no data
2659              * available on the socket, the client went fishing
2660              * and continuing talking to the server makes no sense.
2661              */
2662             log_error(LOG_LEVEL_CONNECT,
2663                "The client closed socket %d while "
2664                "the server socket %d is still open.",
2665                csp->cfd, csp->server_connection.sfd);
2666             mark_server_socket_tainted(csp);
2667             break;
2668          }
2669          if (csp->expected_client_content_length != 0)
2670          {
2671             if (csp->expected_client_content_length < csp->receive_buffer_size)
2672             {
2673                max_bytes_to_read = (int)csp->expected_client_content_length;
2674             }
2675             log_error(LOG_LEVEL_CONNECT,
2676                "Waiting for up to %d bytes from the client.",
2677                max_bytes_to_read);
2678          }
2679          assert(max_bytes_to_read <= csp->receive_buffer_size);
2680 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2681
2682 #ifdef FEATURE_HTTPS_INSPECTION
2683          if (client_use_ssl(csp))
2684          {
2685             log_error(LOG_LEVEL_CONNECT, "Breaking with TLS/SSL.");
2686             break;
2687          }
2688          else
2689 #endif /* def FEATURE_HTTPS_INSPECTION */
2690          {
2691             len = read_socket(csp->cfd, csp->receive_buffer, max_bytes_to_read);
2692
2693             if (len <= 0)
2694             {
2695                /* XXX: not sure if this is necessary. */
2696                mark_server_socket_tainted(csp);
2697                break; /* "game over, man" */
2698             }
2699
2700 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2701             if (csp->expected_client_content_length != 0)
2702             {
2703                assert(len <= max_bytes_to_read);
2704                csp->expected_client_content_length -= (unsigned)len;
2705                log_error(LOG_LEVEL_CONNECT,
2706                   "Expected client content length set to %llu "
2707                   "after reading %d bytes.",
2708                   csp->expected_client_content_length, len);
2709                if (csp->expected_client_content_length == 0)
2710                {
2711                   log_error(LOG_LEVEL_CONNECT,
2712                      "Done reading from the client.");
2713                   csp->flags |= CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ;
2714                }
2715             }
2716 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2717
2718             if (write_socket(csp->server_connection.sfd, csp->receive_buffer, (size_t)len))
2719             {
2720                log_error(LOG_LEVEL_ERROR, "write to: %s failed: %E", http->host);
2721                mark_server_socket_tainted(csp);
2722                return;
2723             }
2724          }
2725          continue;
2726       }
2727
2728       /*
2729        * The server wants to talk. It could be the header or the body.
2730        * If `hdr' is null, then it's the header otherwise it's the body.
2731        * FIXME: Does `hdr' really mean `host'? No.
2732        */
2733 #ifdef HAVE_POLL
2734       if (poll_fds[1].revents != 0)
2735 #else
2736       if (FD_ISSET(csp->server_connection.sfd, &rfds))
2737 #endif /* HAVE_POLL */
2738       {
2739 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2740          /*
2741           * If we are buffering content, we don't want to eat up to
2742           * buffer-limit bytes if the client no longer cares about them.
2743           * If we aren't buffering, however, a dead client socket will be
2744           * noticed pretty much right away anyway, so we can reduce the
2745           * overhead by skipping the check.
2746           */
2747          if (buffer_and_filter_content && !socket_is_still_alive(csp->cfd))
2748          {
2749 #ifdef _WIN32
2750             log_error(LOG_LEVEL_CONNECT,
2751                "The server still wants to talk, but the client may already have hung up on us.");
2752 #else
2753             log_error(LOG_LEVEL_CONNECT,
2754                "The server still wants to talk, but the client hung up on us.");
2755             mark_server_socket_tainted(csp);
2756 #ifdef FEATURE_HTTPS_INSPECTION
2757             close_client_and_server_ssl_connections(csp);
2758 #endif
2759             return;
2760 #endif /* def _WIN32 */
2761          }
2762 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2763
2764 #ifdef FEATURE_HTTPS_INSPECTION
2765          /*
2766           * Reading data from standard or secured connection (HTTP/HTTPS)
2767           */
2768          if (server_use_ssl(csp))
2769          {
2770             len = ssl_recv_data(&(csp->mbedtls_server_attr.ssl),
2771                (unsigned char *)csp->receive_buffer, csp->receive_buffer_size);
2772          }
2773          else
2774 #endif
2775          {
2776             len = read_socket(csp->server_connection.sfd, csp->receive_buffer,
2777                (int)csp->receive_buffer_size);
2778          }
2779
2780          if (len < 0)
2781          {
2782             log_error(LOG_LEVEL_ERROR, "read from: %s failed: %E", http->host);
2783
2784             if ((http->ssl && (csp->fwd == NULL))
2785 #ifdef FEATURE_HTTPS_INSPECTION
2786                && use_ssl_tunnel
2787 #endif
2788                 )
2789             {
2790                /*
2791                 * Just hang up. We already confirmed the client's CONNECT
2792                 * request with status code 200 and unencrypted content is
2793                 * no longer welcome.
2794                 */
2795                log_error(LOG_LEVEL_ERROR,
2796                   "CONNECT already confirmed. Unable to tell the client about the problem.");
2797                return;
2798             }
2799             else if (byte_count)
2800             {
2801                /*
2802                 * Just hang up. We already transmitted the original headers
2803                 * and parts of the original content and therefore missed the
2804                 * chance to send an error message (without risking data corruption).
2805                 *
2806                 * XXX: we could retry with a fancy range request here.
2807                 */
2808                log_error(LOG_LEVEL_ERROR, "Already forwarded the original headers. "
2809                   "Unable to tell the client about the problem.");
2810                mark_server_socket_tainted(csp);
2811 #ifdef FEATURE_HTTPS_INSPECTION
2812                close_client_and_server_ssl_connections(csp);
2813 #endif
2814                return;
2815             }
2816             /*
2817              * XXX: Consider handling the cases above the same.
2818              */
2819             mark_server_socket_tainted(csp);
2820             len = 0;
2821          }
2822
2823 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2824          if (csp->flags & CSP_FLAG_CHUNKED)
2825          {
2826             if ((len >= 5) && !memcmp(csp->receive_buffer+len-5, "0\r\n\r\n", 5))
2827             {
2828                /* XXX: this is a temporary hack */
2829                log_error(LOG_LEVEL_CONNECT,
2830                   "Looks like we reached the end of the last chunk. "
2831                   "We better stop reading.");
2832                csp->expected_content_length = byte_count + (unsigned long long)len;
2833                csp->flags |= CSP_FLAG_CONTENT_LENGTH_SET;
2834             }
2835          }
2836          reading_done:
2837 #endif  /* FEATURE_CONNECTION_KEEP_ALIVE */
2838
2839          /*
2840           * This is guaranteed by allocating with zalloc_or_die()
2841           * and never (intentionally) writing to the last byte.
2842           *
2843           * csp->receive_buffer_size is the size of the part of the
2844           * buffer we intentionally write to, but we actually
2845           * allocated csp->receive_buffer_size+1 bytes so the assertion
2846           * stays within the allocated range.
2847           */
2848          assert(csp->receive_buffer[csp->receive_buffer_size] == '\0');
2849
2850          /*
2851           * Add a trailing zero to let be able to use string operations.
2852           * XXX: do we still need this with filter_popups gone?
2853           */
2854          assert(len <= csp->receive_buffer_size);
2855          csp->receive_buffer[len] = '\0';
2856
2857          /*
2858           * Normally, this would indicate that we've read
2859           * as much as the server has sent us and we can
2860           * close the client connection.  However, Microsoft
2861           * in its wisdom has released IIS/5 with a bug that
2862           * prevents it from sending the trailing \r\n in
2863           * a 302 redirect header (and possibly other headers).
2864           * To work around this if we've haven't parsed
2865           * a full header we'll append a trailing \r\n
2866           * and see if this now generates a valid one.
2867           *
2868           * This hack shouldn't have any impacts.  If we've
2869           * already transmitted the header or if this is a
2870           * SSL connection, then we won't bother with this
2871           * hack.  So we only work on partially received
2872           * headers.  If we append a \r\n and this still
2873           * doesn't generate a valid header, then we won't
2874           * transmit anything to the client.
2875           */
2876          if (len == 0)
2877          {
2878
2879             if (server_body || (http->ssl
2880 #ifdef FEATURE_HTTPS_INSPECTION
2881                   && use_ssl_tunnel
2882 #endif
2883                ))
2884             {
2885                /*
2886                 * If we have been buffering up the document,
2887                 * now is the time to apply content modification
2888                 * and send the result to the client.
2889                 */
2890                if (buffer_and_filter_content)
2891                {
2892                   p = execute_content_filters(csp);
2893                   /*
2894                    * If content filtering fails, use the original
2895                    * buffer and length.
2896                    * (see p != NULL ? p : csp->iob->cur below)
2897                    */
2898                   if (NULL == p)
2899                   {
2900                      csp->content_length = (size_t)(csp->iob->eod - csp->iob->cur);
2901                   }
2902 #ifdef FEATURE_COMPRESSION
2903                   else if ((csp->flags & CSP_FLAG_CLIENT_SUPPORTS_DEFLATE)
2904                      && (csp->content_length > LOWER_LENGTH_LIMIT_FOR_COMPRESSION))
2905                   {
2906                      char *compressed_content = compress_buffer(p,
2907                         (size_t *)&csp->content_length, csp->config->compression_level);
2908                      if (compressed_content != NULL)
2909                      {
2910                         freez(p);
2911                         p = compressed_content;
2912                         csp->flags |= CSP_FLAG_BUFFERED_CONTENT_DEFLATED;
2913                      }
2914                   }
2915 #endif
2916
2917                   if (JB_ERR_OK != update_server_headers(csp))
2918                   {
2919                      log_error(LOG_LEVEL_FATAL,
2920                         "Failed to update server headers. after filtering.");
2921                   }
2922
2923                   hdr = list_to_text(csp->headers);
2924                   if (hdr == NULL)
2925                   {
2926                      /* FIXME Should handle error properly */
2927                      log_error(LOG_LEVEL_FATAL, "Out of memory parsing server header");
2928                   }
2929
2930 #ifdef FEATURE_HTTPS_INSPECTION
2931                   /*
2932                    * Sending data with standard or secured connection (HTTP/HTTPS)
2933                    */
2934                   if (client_use_ssl(csp))
2935                   {
2936                      if ((ssl_send_data(&(csp->mbedtls_client_attr.ssl),
2937                             (const unsigned char *)hdr, strlen(hdr)) < 0)
2938                         || (ssl_send_data(&(csp->mbedtls_client_attr.ssl),
2939                               (const unsigned char *) ((p != NULL) ? p : csp->iob->cur),
2940                               csp->content_length) < 0))
2941                      {
2942                         log_error(LOG_LEVEL_ERROR, "write modified content to "
2943                            "client over TLS/SSL failed");
2944                         freez(hdr);
2945                         freez(p);
2946                         mark_server_socket_tainted(csp);
2947                         close_client_and_server_ssl_connections(csp);
2948                         return;
2949                      }
2950                   }
2951                   else
2952 #endif /* def FEATURE_HTTPS_INSPECTION */
2953                   {
2954                      if (write_socket_delayed(csp->cfd, hdr, strlen(hdr), write_delay)
2955                       || write_socket_delayed(csp->cfd, ((p != NULL) ? p : csp->iob->cur),
2956                          (size_t)csp->content_length, write_delay))
2957                      {
2958                         log_error(LOG_LEVEL_ERROR, "write modified content to client failed: %E");
2959                         freez(hdr);
2960                         freez(p);
2961                         mark_server_socket_tainted(csp);
2962                         return;
2963                      }
2964                   }
2965
2966                   freez(hdr);
2967                   freez(p);
2968                }
2969
2970                break; /* "game over, man" */
2971             }
2972
2973             /*
2974              * This is NOT the body, so
2975              * Let's pretend the server just sent us a blank line.
2976              */
2977             snprintf(csp->receive_buffer, csp->receive_buffer_size, "\r\n");
2978             len = (int)strlen(csp->receive_buffer);
2979
2980             /*
2981              * Now, let the normal header parsing algorithm below do its
2982              * job.  If it fails, we'll exit instead of continuing.
2983              */
2984
2985             ms_iis5_hack = 1;
2986          }
2987
2988          /*
2989           * If we're in the body of the server document, just write it to
2990           * the client, unless we need to buffer the body for later
2991           * content-filtering.
2992           */
2993          if (server_body || (http->ssl
2994 #ifdef FEATURE_HTTPS_INSPECTION
2995                && use_ssl_tunnel
2996 #endif
2997             ))
2998          {
2999             if (buffer_and_filter_content)
3000             {
3001                /*
3002                 * If there is no memory left for buffering the content, or the buffer limit
3003                 * has been reached, switch to non-filtering mode, i.e. make & write the
3004                 * header, flush the iob and buf, and get out of the way.
3005                 */
3006                if (add_to_iob(csp->iob, csp->config->buffer_limit, csp->receive_buffer, len))
3007                {
3008                   size_t hdrlen;
3009                   long flushed;
3010
3011                   log_error(LOG_LEVEL_INFO,
3012                      "Flushing header and buffers. Stepping back from filtering.");
3013
3014                   hdr = list_to_text(csp->headers);
3015                   if (hdr == NULL)
3016                   {
3017                      /*
3018                       * Memory is too tight to even generate the header.
3019                       * Send our static "Out-of-memory" page.
3020                       */
3021                      log_error(LOG_LEVEL_ERROR, "Out of memory while trying to flush.");
3022                      rsp = cgi_error_memory();
3023                      send_crunch_response(csp, rsp);
3024                      mark_server_socket_tainted(csp);
3025 #ifdef FEATURE_HTTPS_INSPECTION
3026                      close_client_and_server_ssl_connections(csp);
3027 #endif
3028                      return;
3029                   }
3030                   hdrlen = strlen(hdr);
3031
3032 #ifdef FEATURE_HTTPS_INSPECTION
3033                   /*
3034                    * Sending data with standard or secured connection (HTTP/HTTPS)
3035                    */
3036                   if (client_use_ssl(csp))
3037                   {
3038                      if ((ssl_send_data(&(csp->mbedtls_client_attr.ssl),
3039                             (const unsigned char *)hdr, hdrlen) < 0)
3040                         || ((flushed = ssl_flush_socket(&(csp->mbedtls_client_attr.ssl),
3041                                 csp->iob)) < 0)
3042                         || (ssl_send_data(&(csp->mbedtls_client_attr.ssl),
3043                               (const unsigned char *)csp->receive_buffer, (size_t)len) < 0))
3044                      {
3045                         log_error(LOG_LEVEL_CONNECT,
3046                            "Flush header and buffers to client failed");
3047                         freez(hdr);
3048                         mark_server_socket_tainted(csp);
3049                         close_client_and_server_ssl_connections(csp);
3050                         return;
3051                      }
3052                   }
3053                   else
3054 #endif /* def FEATURE_HTTPS_INSPECTION */
3055                   {
3056                      if (write_socket_delayed(csp->cfd, hdr, hdrlen, write_delay)
3057                       || ((flushed = flush_iob(csp->cfd, csp->iob, write_delay)) < 0)
3058                       || write_socket_delayed(csp->cfd, csp->receive_buffer, (size_t)len,
3059                             write_delay))
3060                      {
3061                         log_error(LOG_LEVEL_CONNECT,
3062                            "Flush header and buffers to client failed: %E");
3063                         freez(hdr);
3064                         mark_server_socket_tainted(csp);
3065                         return;
3066                      }
3067                   }
3068
3069                   /*
3070                    * Reset the byte_count to the amount of bytes
3071                    * we just flushed. len will be added a few lines below,
3072                    * hdrlen doesn't matter for LOG_LEVEL_CLF.
3073                    */
3074                   byte_count = (unsigned long long)flushed;
3075                   freez(hdr);
3076                   buffer_and_filter_content = 0;
3077                   server_body = 1;
3078                }
3079             }
3080             else
3081             {
3082 #ifdef FEATURE_HTTPS_INSPECTION
3083                /*
3084                 * Sending data with standard or secured connection (HTTP/HTTPS)
3085                 */
3086                if (client_use_ssl(csp))
3087                {
3088                   ret = ssl_send_data(&(csp->mbedtls_client_attr.ssl),
3089                      (const unsigned char *)csp->receive_buffer, (size_t)len);
3090                   if (ret < 0)
3091                   {
3092                      log_error(LOG_LEVEL_ERROR,
3093                         "Sending data to client failed");
3094                      mark_server_socket_tainted(csp);
3095                      close_client_and_server_ssl_connections(csp);
3096                      return;
3097                   }
3098                }
3099                else
3100 #endif /* def FEATURE_HTTPS_INSPECTION */
3101                {
3102                   if (write_socket_delayed(csp->cfd, csp->receive_buffer,
3103                         (size_t)len, write_delay))
3104                   {
3105                      log_error(LOG_LEVEL_ERROR, "write to client failed: %E");
3106                      mark_server_socket_tainted(csp);
3107                      return;
3108                   }
3109                }
3110             }
3111             byte_count += (unsigned long long)len;
3112             continue;
3113          }
3114          else
3115          {
3116             /*
3117              * We're still looking for the end of the server's header.
3118              * Buffer up the data we just read.  If that fails, there's
3119              * little we can do but send our static out-of-memory page.
3120              */
3121             if (add_to_iob(csp->iob, csp->config->buffer_limit, csp->receive_buffer, len))
3122             {
3123                log_error(LOG_LEVEL_ERROR, "Out of memory while looking for end of server headers.");
3124                rsp = cgi_error_memory();
3125                send_crunch_response(csp, rsp);
3126                mark_server_socket_tainted(csp);
3127 #ifdef FEATURE_HTTPS_INSPECTION
3128                close_client_and_server_ssl_connections(csp);
3129 #endif
3130                return;
3131             }
3132
3133             /* Convert iob into something sed() can digest */
3134             if (JB_ERR_PARSE == get_server_headers(csp))
3135             {
3136                if (ms_iis5_hack)
3137                {
3138                   /*
3139                    * Well, we tried our MS IIS/5 hack and it didn't work.
3140                    * The header is incomplete and there isn't anything
3141                    * we can do about it.
3142                    */
3143                   log_error(LOG_LEVEL_ERROR, "Invalid server headers. "
3144                      "Applying the MS IIS5 hack didn't help.");
3145                   log_error(LOG_LEVEL_CLF,
3146                      "%s - - [%T] \"%s\" 502 0", csp->ip_addr_str, http->cmd);
3147 #ifdef FEATURE_HTTPS_INSPECTION
3148                   /*
3149                    * Sending data with standard or secured connection (HTTP/HTTPS)
3150                    */
3151                   if (client_use_ssl(csp))
3152                   {
3153                      ssl_send_data(&(csp->mbedtls_client_attr.ssl),
3154                         (const unsigned char *)INVALID_SERVER_HEADERS_RESPONSE,
3155                         strlen(INVALID_SERVER_HEADERS_RESPONSE));
3156                   }
3157                   else
3158 #endif /* def FEATURE_HTTPS_INSPECTION */
3159                   {
3160                      write_socket_delayed(csp->cfd,
3161                         INVALID_SERVER_HEADERS_RESPONSE,
3162                         strlen(INVALID_SERVER_HEADERS_RESPONSE), write_delay);
3163                   }
3164                   mark_server_socket_tainted(csp);
3165 #ifdef FEATURE_HTTPS_INSPECTION
3166                   close_client_and_server_ssl_connections(csp);
3167 #endif
3168                   return;
3169                }
3170                else
3171                {
3172                   /*
3173                    * Since we have to wait for more from the server before
3174                    * we can parse the headers we just continue here.
3175                    */
3176                   log_error(LOG_LEVEL_CONNECT,
3177                      "Continuing buffering server headers from socket %d. "
3178                      "Bytes most recently read: %d.", csp->cfd, len);
3179                   continue;
3180                }
3181             }
3182             else
3183             {
3184                /*
3185                 * Account for the content bytes we
3186                 * might have gotten with the headers.
3187                 */
3188                assert(csp->iob->eod >= csp->iob->cur);
3189                byte_count = (unsigned long long)(csp->iob->eod - csp->iob->cur);
3190             }
3191
3192             /* Did we actually get anything? */
3193             if (NULL == csp->headers->first)
3194             {
3195                if ((csp->flags & CSP_FLAG_REUSED_CLIENT_CONNECTION))
3196                {
3197                   log_error(LOG_LEVEL_ERROR,
3198                      "No server or forwarder response received on socket %d. "
3199                      "Closing client socket %d without sending data.",
3200                      csp->server_connection.sfd, csp->cfd);
3201                   log_error(LOG_LEVEL_CLF,
3202                      "%s - - [%T] \"%s\" 502 0", csp->ip_addr_str, http->cmd);
3203                }
3204                else
3205                {
3206                   log_error(LOG_LEVEL_ERROR,
3207                      "No server or forwarder response received on socket %d.",
3208                      csp->server_connection.sfd);
3209                   send_crunch_response(csp, error_response(csp, "no-server-data"));
3210                }
3211                free_http_request(http);
3212                mark_server_socket_tainted(csp);
3213 #ifdef FEATURE_HTTPS_INSPECTION
3214                close_client_and_server_ssl_connections(csp);
3215 #endif
3216                return;
3217             }
3218
3219             if (!csp->headers->first->str)
3220             {
3221                log_error(LOG_LEVEL_ERROR, "header search: csp->headers->first->str == NULL, assert will be called");
3222             }
3223             assert(csp->headers->first->str);
3224
3225             if (strncmpic(csp->headers->first->str, "HTTP", 4) &&
3226                 strncmpic(csp->headers->first->str, "ICY", 3))
3227             {
3228                /*
3229                 * It doesn't look like a HTTP (or Shoutcast) response:
3230                 * tell the client and log the problem.
3231                 */
3232                if (strlen(csp->headers->first->str) > 30)
3233                {
3234                   csp->headers->first->str[30] = '\0';
3235                }
3236                log_error(LOG_LEVEL_ERROR,
3237                   "Invalid server or forwarder response. Starts with: %s",
3238                   csp->headers->first->str);
3239                log_error(LOG_LEVEL_CLF,
3240                   "%s - - [%T] \"%s\" 502 0", csp->ip_addr_str, http->cmd);
3241 #ifdef FEATURE_HTTPS_INSPECTION
3242                /*
3243                 * Sending data with standard or secured connection (HTTP/HTTPS)
3244                 */
3245                if (client_use_ssl(csp))
3246                {
3247                   ssl_send_data(&(csp->mbedtls_client_attr.ssl),
3248                      (const unsigned char *)INVALID_SERVER_HEADERS_RESPONSE,
3249                      strlen(INVALID_SERVER_HEADERS_RESPONSE));
3250                }
3251                else
3252 #endif /* def FEATURE_HTTPS_INSPECTION */
3253                {
3254                   write_socket_delayed(csp->cfd, INVALID_SERVER_HEADERS_RESPONSE,
3255                      strlen(INVALID_SERVER_HEADERS_RESPONSE), write_delay);
3256                }
3257                free_http_request(http);
3258                mark_server_socket_tainted(csp);
3259 #ifdef FEATURE_HTTPS_INSPECTION
3260                close_client_and_server_ssl_connections(csp);
3261 #endif
3262                return;
3263             }
3264
3265             /*
3266              * We have now received the entire server header,
3267              * filter it and send the result to the client
3268              */
3269             if (JB_ERR_OK != sed(csp, FILTER_SERVER_HEADERS))
3270             {
3271                log_error(LOG_LEVEL_CLF,
3272                   "%s - - [%T] \"%s\" 502 0", csp->ip_addr_str, http->cmd);
3273 #ifdef FEATURE_HTTPS_INSPECTION
3274                /*
3275                 * Sending data with standard or secured connection (HTTP/HTTPS)
3276                 */
3277                if (client_use_ssl(csp))
3278                {
3279                   ssl_send_data(&(csp->mbedtls_client_attr.ssl),
3280                      (const unsigned char *)INVALID_SERVER_HEADERS_RESPONSE,
3281                      strlen(INVALID_SERVER_HEADERS_RESPONSE));
3282                }
3283                else
3284 #endif
3285                {
3286                   write_socket_delayed(csp->cfd, INVALID_SERVER_HEADERS_RESPONSE,
3287                      strlen(INVALID_SERVER_HEADERS_RESPONSE), write_delay);
3288                }
3289                free_http_request(http);
3290                mark_server_socket_tainted(csp);
3291 #ifdef FEATURE_HTTPS_INSPECTION
3292                close_client_and_server_ssl_connections(csp);
3293 #endif
3294                return;
3295             }
3296             hdr = list_to_text(csp->headers);
3297             if (hdr == NULL)
3298             {
3299                /* FIXME Should handle error properly */
3300                log_error(LOG_LEVEL_FATAL, "Out of memory parsing server header");
3301             }
3302
3303             if ((csp->flags & CSP_FLAG_CHUNKED)
3304                && !(csp->flags & CSP_FLAG_CONTENT_LENGTH_SET)
3305                && ((csp->iob->eod - csp->iob->cur) >= 5)
3306                && !memcmp(csp->iob->eod-5, "0\r\n\r\n", 5))
3307             {
3308                log_error(LOG_LEVEL_CONNECT,
3309                   "Looks like we got the last chunk together with "
3310                   "the server headers. We better stop reading.");
3311                byte_count = (unsigned long long)(csp->iob->eod - csp->iob->cur);
3312                csp->expected_content_length = byte_count;
3313                csp->flags |= CSP_FLAG_CONTENT_LENGTH_SET;
3314             }
3315
3316             csp->server_connection.response_received = time(NULL);
3317
3318             if (crunch_response_triggered(csp, crunchers_light))
3319             {
3320                /*
3321                 * One of the tags created by a server-header
3322                 * tagger triggered a crunch. We already
3323                 * delivered the crunch response to the client
3324                 * and are done here after cleaning up.
3325                 */
3326                freez(hdr);
3327                mark_server_socket_tainted(csp);
3328 #ifdef FEATURE_HTTPS_INSPECTION
3329                close_client_and_server_ssl_connections(csp);
3330 #endif
3331                return;
3332             }
3333
3334             /* Buffer and pcrs filter this if appropriate. */
3335             buffer_and_filter_content = content_requires_filtering(csp);
3336
3337             if (!buffer_and_filter_content)
3338             {
3339                /*
3340                 * Write the server's (modified) header to
3341                 * the client (along with anything else that
3342                 * may be in the buffer). Use standard or secured
3343                 * connection.
3344                 */
3345 #ifdef FEATURE_HTTPS_INSPECTION
3346                if (client_use_ssl(csp))
3347                {
3348                   if ((ssl_send_data(&(csp->mbedtls_client_attr.ssl),
3349                           (const unsigned char *)hdr, strlen(hdr)) < 0)
3350                      || (len = ssl_flush_socket(&(csp->mbedtls_client_attr.ssl),
3351                             csp->iob) < 0))
3352                   {
3353                      log_error(LOG_LEVEL_CONNECT, "Write header to client failed");
3354
3355                      /*
3356                       * The write failed, so don't bother mentioning it
3357                       * to the client... it probably can't hear us anyway.
3358                       */
3359                      freez(hdr);
3360                      mark_server_socket_tainted(csp);
3361 #ifdef FEATURE_HTTPS_INSPECTION
3362                      close_client_and_server_ssl_connections(csp);
3363 #endif
3364                      return;
3365                   }
3366                }
3367                else
3368 #endif /* def FEATURE_HTTPS_INSPECTION */
3369                {
3370                   if (write_socket_delayed(csp->cfd, hdr, strlen(hdr), write_delay)
3371                      || ((len = flush_iob(csp->cfd, csp->iob, write_delay)) < 0))
3372                   {
3373                      log_error(LOG_LEVEL_ERROR,
3374                         "write header to client failed");
3375                      /*
3376                       * The write failed, so don't bother mentioning it
3377                       * to the client... it probably can't hear us anyway.
3378                       */
3379                      freez(hdr);
3380                      mark_server_socket_tainted(csp);
3381                      return;
3382                   }
3383                }
3384                                 }
3385
3386             /* we're finished with the server's header */
3387
3388             freez(hdr);
3389             server_body = 1;
3390
3391             /*
3392              * If this was a MS IIS/5 hack then it means the server
3393              * has already closed the connection. Nothing more to read.
3394              * Time to bail.
3395              */
3396             if (ms_iis5_hack)
3397             {
3398                log_error(LOG_LEVEL_ERROR,
3399                   "Closed server connection detected. "
3400                   "Applying the MS IIS5 hack didn't help.");
3401                log_error(LOG_LEVEL_CLF,
3402                   "%s - - [%T] \"%s\" 502 0", csp->ip_addr_str, http->cmd);
3403 #ifdef FEATURE_HTTPS_INSPECTION
3404                /*
3405                 * Sending data with standard or secured connection (HTTP/HTTPS)
3406                 */
3407                if (client_use_ssl(csp))
3408                {
3409                   ssl_send_data(&(csp->mbedtls_client_attr.ssl),
3410                      (const unsigned char *)INVALID_SERVER_HEADERS_RESPONSE,
3411                      strlen(INVALID_SERVER_HEADERS_RESPONSE));
3412                }
3413                else
3414 #endif /* def FEATURE_HTTPS_INSPECTION */
3415                {
3416                   write_socket_delayed(csp->cfd, INVALID_SERVER_HEADERS_RESPONSE,
3417                      strlen(INVALID_SERVER_HEADERS_RESPONSE), write_delay);
3418                }
3419                mark_server_socket_tainted(csp);
3420 #ifdef FEATURE_HTTPS_INSPECTION
3421                close_client_and_server_ssl_connections(csp);
3422 #endif
3423                return;
3424             }
3425          }
3426          continue;
3427       }
3428       mark_server_socket_tainted(csp);
3429 #ifdef FEATURE_HTTPS_INSPECTION
3430       close_client_and_server_ssl_connections(csp);
3431 #endif
3432       return; /* huh? we should never get here */
3433    }
3434 #ifdef FEATURE_HTTPS_INSPECTION
3435    close_client_and_server_ssl_connections(csp);
3436 #endif
3437    if (csp->content_length == 0)
3438    {
3439       /*
3440        * If Privoxy didn't recalculate the Content-Length,
3441        * byte_count is still correct.
3442        */
3443       csp->content_length = byte_count;
3444    }
3445
3446 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
3447    if ((csp->flags & CSP_FLAG_CONTENT_LENGTH_SET)
3448       && (csp->expected_content_length != byte_count))
3449    {
3450       log_error(LOG_LEVEL_CONNECT,
3451          "Received %llu bytes while expecting %llu.",
3452          byte_count, csp->expected_content_length);
3453       mark_server_socket_tainted(csp);
3454    }
3455 #endif
3456
3457 #ifdef FEATURE_HTTPS_INSPECTION
3458    if (client_use_ssl(csp))
3459    {
3460       log_error(LOG_LEVEL_CLF, "%s - - [%T] \"%s https://%s%s %s\" 200 %llu",
3461          csp->ip_addr_str, http->gpc, http->hostport, http->path,
3462          http->version, csp->content_length);
3463    }
3464    else
3465 #endif
3466    {
3467       log_error(LOG_LEVEL_CLF, "%s - - [%T] \"%s\" 200 %llu",
3468          csp->ip_addr_str, http->ocmd, csp->content_length);
3469    }
3470    csp->server_connection.timestamp = time(NULL);
3471 }
3472
3473
3474 /*********************************************************************
3475  *
3476  * Function    :  chat
3477  *
3478  * Description :  Once a connection from the client has been accepted,
3479  *                this function is called (via serve()) to handle the
3480  *                main business of the communication.  This function
3481  *                returns after dealing with a single request. It can
3482  *                be called multiple times with the same client socket
3483  *                if the client is keeping the connection alive.
3484  *
3485  *                The decision whether or not a client connection will
3486  *                be kept alive is up to the caller which also must
3487  *                close the client socket when done.
3488  *
3489  *                FIXME: chat is nearly thousand lines long.
3490  *                Ridiculous.
3491  *
3492  * Parameters  :
3493  *          1  :  csp = Current client state (buffers, headers, etc...)
3494  *
3495  * Returns     :  Nothing.
3496  *
3497  *********************************************************************/
3498 static void chat(struct client_state *csp)
3499 {
3500    const struct forward_spec *fwd;
3501    struct http_request *http;
3502    /* Skeleton for HTTP response, if we should intercept the request */
3503    struct http_response *rsp;
3504 #ifdef FEATURE_HTTPS_INSPECTION
3505    int use_ssl_tunnel = 0;
3506 #endif
3507
3508    http = csp->http;
3509
3510    if (receive_client_request(csp) != JB_ERR_OK)
3511    {
3512       return;
3513    }
3514    if (parse_client_request(csp) != JB_ERR_OK)
3515    {
3516       return;
3517    }
3518
3519    /* decide how to route the HTTP request */
3520    fwd = forward_url(csp, http);
3521    if (NULL == fwd)
3522    {
3523       log_error(LOG_LEVEL_FATAL, "gateway spec is NULL!?!?  This can't happen!");
3524       /* Never get here - LOG_LEVEL_FATAL causes program exit */
3525       return;
3526    }
3527
3528 #ifdef FEATURE_HTTPS_INSPECTION
3529    /*
3530     * Setting flags to use old solution with SSL tunnel and to disable
3531     * certificates verification.
3532     */
3533    if (csp->http->ssl && !(csp->action->flags & ACTION_HTTPS_INSPECTION))
3534    {
3535       use_ssl_tunnel = 1;
3536    }
3537
3538    if (http->ssl && csp->action->flags & ACTION_IGNORE_CERTIFICATE_ERRORS)
3539    {
3540       csp->dont_verify_certificate = 1;
3541    }
3542 #endif
3543
3544    /*
3545     * build the http request to send to the server
3546     * we have to do one of the following:
3547     *
3548     * create =    use the original HTTP request to create a new
3549     *             HTTP request that has either the path component
3550     *             without the http://domainspec (w/path) or the
3551     *             full orininal URL (w/url)
3552     *             Note that the path and/or the HTTP version may
3553     *             have been altered by now.
3554     *
3555     * SSL proxy = Open a socket to the host:port of the server
3556     *             and create TLS/SSL connection with server and
3557     *             with client. Then behave like mediator between
3558     *             client and server over TLS/SSL.
3559     *
3560     * SSL proxy = Pass the request unchanged if forwarding a CONNECT
3561     *    with     request to a parent proxy. Note that we'll be sending
3562     * forwarding  the CFAIL message ourselves if connecting to the parent
3563     *             fails, but we won't send a CSUCCEED message if it works,
3564     *             since that would result in a double message (ours and the
3565     *             parent's). After sending the request to the parent, we
3566     *             must parse answer and send it to client. If connection
3567     *             with server is established, we do TLS/SSL proxy. Otherwise
3568     *             we send parent response to client and close connections.
3569     *
3570     * here's the matrix:
3571     *                        SSL
3572     *                    0        1
3573     *                +--------+--------+
3574     *                |        |        |
3575     *             0  | create |   SSL  |
3576     *                | w/path |  proxy |
3577     *  Forwarding    +--------+--------+
3578     *                |        |   SSL  |
3579     *             1  | create |  proxy |
3580     *                | w/url  |+forward|
3581     *                +--------+--------+
3582     *
3583     */
3584
3585 #ifdef FEATURE_HTTPS_INSPECTION
3586    /*
3587     * Presetting SSL client and server flags
3588     */
3589    if (http->ssl && !use_ssl_tunnel)
3590    {
3591       http->client_ssl = 1;
3592       http->server_ssl = 1;
3593    }
3594    else
3595    {
3596       http->client_ssl = 0;
3597       http->server_ssl = 0;
3598    }
3599 #endif
3600
3601    if (http->ssl && connect_port_is_forbidden(csp))
3602    {
3603       const char *acceptable_connect_ports =
3604          csp->action->string[ACTION_STRING_LIMIT_CONNECT];
3605       assert(NULL != acceptable_connect_ports);
3606       log_error(LOG_LEVEL_INFO, "Request from %s marked for blocking. "
3607          "limit-connect{%s} doesn't allow CONNECT requests to %s",
3608          csp->ip_addr_str, acceptable_connect_ports, csp->http->hostport);
3609       csp->action->flags |= ACTION_BLOCK;
3610       http->ssl = 0;
3611 #ifdef FEATURE_HTTPS_INSPECTION
3612       http->client_ssl = 0;
3613       http->server_ssl = 0;
3614 #endif
3615    }
3616
3617
3618    freez(csp->headers->first->str);
3619    build_request_line(csp, fwd, &csp->headers->first->str);
3620
3621    /*
3622     * We have a request. Check if one of the crunchers wants it
3623     * unless the client wants to use TLS/SSL in which case we
3624     * haven't setup the TLS context yet and will send the crunch
3625     * response later.
3626     */
3627    if (
3628 #ifdef FEATURE_HTTPS_INSPECTION
3629        !client_use_ssl(csp) &&
3630 #endif
3631        crunch_response_triggered(csp, crunchers_all))
3632    {
3633       /*
3634        * Yes. The client got the crunch response and we're done here.
3635        */
3636       return;
3637    }
3638
3639    log_applied_actions(csp->action);
3640 #ifdef FEATURE_HTTPS_INSPECTION
3641    /*
3642     * Log the request unless we're https inspecting
3643     * in which case we don't have the path yet and
3644     * will log the request later.
3645     */
3646    if (!client_use_ssl(csp))
3647 #endif
3648    {
3649       log_error(LOG_LEVEL_GPC, "%s%s", http->hostport, http->path);
3650    }
3651    if (fwd->forward_host)
3652    {
3653       log_error(LOG_LEVEL_CONNECT, "via [%s]:%d to: %s",
3654          fwd->forward_host, fwd->forward_port, http->hostport);
3655    }
3656    else
3657    {
3658       log_error(LOG_LEVEL_CONNECT, "to %s", http->hostport);
3659    }
3660
3661    /* here we connect to the server, gateway, or the forwarder */
3662
3663 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
3664    if ((csp->server_connection.sfd != JB_INVALID_SOCKET)
3665       && socket_is_still_alive(csp->server_connection.sfd)
3666       && connection_destination_matches(&csp->server_connection, http, fwd))
3667    {
3668       log_error(LOG_LEVEL_CONNECT,
3669          "Reusing server socket %d connected to %s. Total requests: %u.",
3670          csp->server_connection.sfd, csp->server_connection.host,
3671          csp->server_connection.requests_sent_total);
3672    }
3673    else
3674    {
3675       if (csp->server_connection.sfd != JB_INVALID_SOCKET)
3676       {
3677 #ifdef FEATURE_CONNECTION_SHARING
3678          if (csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
3679          {
3680             remember_connection(&csp->server_connection);
3681          }
3682          else
3683 #endif /* def FEATURE_CONNECTION_SHARING */
3684          {
3685             log_error(LOG_LEVEL_CONNECT,
3686                "Closing server socket %d connected to %s. Total requests: %u.",
3687                csp->server_connection.sfd, csp->server_connection.host,
3688                csp->server_connection.requests_sent_total);
3689             close_socket(csp->server_connection.sfd);
3690          }
3691          mark_connection_closed(&csp->server_connection);
3692       }
3693 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
3694 #ifdef FEATURE_HTTPS_INSPECTION
3695       if (http->ssl && !use_ssl_tunnel)
3696       {
3697          int ret;
3698          /*
3699           * Creating an SSL proxy. If forwarding is disabled, we must send
3700           * CSUCCEED mesage to client. Then TLS/SSL connection with client
3701           * is created.
3702           */
3703
3704          if (fwd->forward_host == NULL)
3705          {
3706             /*
3707              * We're lying to the client as the connection hasn't actually
3708              * been established yet. We don't establish the connection until
3709              * we have seen and parsed the encrypted client headers.
3710              */
3711             if (write_socket_delayed(csp->cfd, CSUCCEED,
3712                   strlen(CSUCCEED), get_write_delay(csp)) != 0)
3713             {
3714                log_error(LOG_LEVEL_ERROR, "Sending SUCCEED to client failed");
3715                return;
3716             }
3717          }
3718
3719          ret = create_client_ssl_connection(csp);
3720          if (ret != 0)
3721          {
3722             log_error(LOG_LEVEL_ERROR,
3723                "Can't open secure connection with client");
3724             close_client_ssl_connection(csp); /* XXX: Is this needed? */
3725             return;
3726          }
3727          if (JB_ERR_OK != process_encrypted_request(csp))
3728          {
3729             log_error(LOG_LEVEL_ERROR, "Failed to parse encrypted request.");
3730             close_client_ssl_connection(csp);
3731             return;
3732          }
3733          /*
3734           * We have an encrypted request. Check if one of the crunchers now
3735           * wants it (for example because the previously invisible path was
3736           * required to match).
3737           */
3738          if (crunch_response_triggered(csp, crunchers_all))
3739          {
3740             /*
3741              * Yes. The client got the crunch response and we're done here.
3742              */
3743             close_client_ssl_connection(csp);
3744             return;
3745          }
3746       }
3747 #endif
3748       /*
3749        * Connecting to destination server
3750        */
3751       csp->server_connection.sfd = forwarded_connect(fwd, http, csp);
3752
3753       if (csp->server_connection.sfd == JB_INVALID_SOCKET)
3754       {
3755          if (fwd->type != SOCKS_NONE)
3756          {
3757             /* Socks error. */
3758             rsp = error_response(csp, "forwarding-failed");
3759          }
3760          else if (errno == EINVAL)
3761          {
3762             rsp = error_response(csp, "no-such-domain");
3763          }
3764          else
3765          {
3766             rsp = error_response(csp, "connect-failed");
3767          }
3768
3769          /* Write the answer to the client */
3770          if (rsp != NULL)
3771          {
3772             send_crunch_response(csp, rsp);
3773          }
3774
3775          /*
3776           * Temporary workaround to prevent already-read client
3777           * bodies from being parsed as new requests. For now we
3778           * err on the safe side and throw all the following
3779           * requests under the bus, even if no client body has been
3780           * buffered. A compliant client will repeat the dropped
3781           * requests on an untainted connection.
3782           *
3783           * The proper fix is to discard the no longer needed
3784           * client body in the buffer (if there is one) and to
3785           * continue parsing the bytes that follow.
3786           */
3787 #ifdef FEATURE_HTTPS_INSPECTION
3788          close_client_ssl_connection(csp);
3789 #endif
3790          drain_and_close_socket(csp->cfd);
3791          csp->cfd = JB_INVALID_SOCKET;
3792
3793          return;
3794       }
3795
3796 #ifdef FEATURE_HTTPS_INSPECTION
3797       /*
3798        * Creating TLS/SSL connections with destination server or parent
3799        * proxy. If forwarding is enabled, we must send client request to
3800        * parent proxy and receive, parse and resend parent proxy answer.
3801        */
3802       if (http->ssl && !use_ssl_tunnel)
3803       {
3804          if (fwd->forward_host != NULL)
3805          {
3806             char server_response[BUFFER_SIZE];
3807             int ret = 0;
3808             int len = 0;
3809             char *hdr = list_to_text(csp->headers);
3810             memset(server_response, 0, sizeof(server_response));
3811
3812             if (hdr == NULL)
3813             {
3814                log_error(LOG_LEVEL_FATAL,
3815                   "Out of memory parsing client header");
3816             }
3817             list_remove_all(csp->headers);
3818
3819             /*
3820              * Sending client's CONNECT request to the parent proxy
3821              */
3822             ret = write_socket(csp->server_connection.sfd, hdr, strlen(hdr));
3823
3824             freez(hdr);
3825
3826             if (ret != 0)
3827             {
3828                log_error(LOG_LEVEL_CONNECT,
3829                   "Sending request headers to: %s failed", http->hostport);
3830                mark_server_socket_tainted(csp);
3831                close_client_ssl_connection(csp);
3832                return;
3833             }
3834
3835             /* Waiting for parent proxy server response */
3836             len = read_socket(csp->server_connection.sfd, server_response,
3837                sizeof(server_response)-1);
3838
3839             if (len <= 0)
3840             {
3841                log_error(LOG_LEVEL_ERROR, "No response from parent proxy "
3842                   "server on socket %d.", csp->server_connection.sfd);
3843
3844                rsp = error_response(csp, "no-server-data");
3845                if (rsp)
3846                {
3847                   send_crunch_response(csp, rsp);
3848                }
3849                mark_server_socket_tainted(csp);
3850                close_client_ssl_connection(csp);
3851                return;
3852             }
3853
3854             /*
3855              * Test if connection with destination server was established
3856              * successfully by parent proxy. Then we can send response to
3857              * the client and continue or stop.
3858              */
3859             if (!tunnel_established_successfully(server_response, (unsigned int)len))
3860             {
3861                log_error(LOG_LEVEL_ERROR, "Forwarder hasn't established "
3862                   "connection with destination server.");
3863
3864                write_socket(csp->cfd, server_response, (size_t)len);
3865                mark_server_socket_tainted(csp);
3866                close_client_ssl_connection(csp);
3867                return;
3868             }
3869
3870             /*
3871              * Parent proxy has established connection with destination server.
3872              * Now we must create TLS/SSL connection with parent proxy.
3873              */
3874             ret = create_server_ssl_connection(csp);
3875
3876             /*
3877             * If TLS/SSL connection wasn't created and invalid certificate
3878             * wasn't detected, we can interrupt this function. Otherwise, we
3879             * must inform the client about invalid server certificate.
3880             */
3881             if (ret != 0
3882                && (csp->server_cert_verification_result == SSL_CERT_NOT_VERIFIED
3883                   || csp->server_cert_verification_result == SSL_CERT_VALID))
3884             {
3885                rsp = error_response(csp, "connect-failed");
3886                if (rsp)
3887                {
3888                   send_crunch_response(csp, rsp);
3889                }
3890                return;
3891             }
3892
3893             /*
3894              * TLS/SSL connection with parent proxy is established, we can
3895              * inform client about success.
3896              */
3897             ret = write_socket(csp->cfd, server_response, (size_t)len);
3898             if (ret != 0)
3899             {
3900                log_error(LOG_LEVEL_ERROR,
3901                   "Sending parent proxy response to client failed");
3902                mark_server_socket_tainted(csp);
3903                close_client_ssl_connection(csp);
3904                return;
3905             }
3906          }/* -END- if (fwd->forward_host != NULL) */
3907          else
3908          {
3909             /*
3910              * Parent proxy is not used, we can just create TLS/SSL connection
3911              * with destination server
3912              */
3913             int ret = create_server_ssl_connection(csp);
3914             if (ret != 0)
3915             {
3916                if (csp->server_cert_verification_result != SSL_CERT_VALID &&
3917                    csp->server_cert_verification_result != SSL_CERT_NOT_VERIFIED)
3918                {
3919                   /*
3920                    * If the server certificate is invalid, we must inform
3921                    * the client and then close connection to the client.
3922                    */
3923                   ssl_send_certificate_error(csp);
3924                   close_client_and_server_ssl_connections(csp);
3925                   return;
3926                }
3927                if (csp->server_cert_verification_result == SSL_CERT_NOT_VERIFIED
3928                 || csp->server_cert_verification_result == SSL_CERT_VALID)
3929                {
3930                   /*
3931                    * The TLS/SSL connection wasn't created but an invalid
3932                    * certificate wasn't detected. Report it as connection
3933                    * failure.
3934                    */
3935                   rsp = error_response(csp, "connect-failed");
3936                   if (rsp)
3937                   {
3938                      send_crunch_response(csp, rsp);
3939                   }
3940                   close_client_and_server_ssl_connections(csp);
3941                   return;
3942                }
3943             }
3944          }
3945       }/* -END- if (http->ssl) */
3946 #endif /* def FEATURE_HTTPS_INSPECTION */
3947
3948 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
3949       save_connection_destination(csp->server_connection.sfd,
3950          http, fwd, &csp->server_connection);
3951       csp->server_connection.keep_alive_timeout =
3952          (unsigned)csp->config->keep_alive_timeout;
3953    }
3954 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
3955
3956    csp->server_connection.requests_sent_total++;
3957
3958    if ((fwd->type == SOCKS_5T) && (NULL == csp->headers->first))
3959    {
3960       /* Client headers have been sent optimistically */
3961       assert(csp->headers->last == NULL);
3962    }
3963    else if (http->ssl == 0 || (fwd->forward_host
3964 #ifdef FEATURE_HTTPS_INSPECTION
3965          && use_ssl_tunnel
3966 #endif
3967            ))
3968    {
3969       if (send_http_request(csp))
3970       {
3971          rsp = error_response(csp, "connect-failed");
3972          if (rsp)
3973          {
3974             send_crunch_response(csp, rsp);
3975          }
3976          return;
3977       }
3978    }
3979    else
3980    {
3981       /*
3982        * Using old solution with SSL tunnel or new solution with SSL proxy
3983        */
3984       list_remove_all(csp->headers);
3985 #ifdef FEATURE_HTTPS_INSPECTION
3986       if (use_ssl_tunnel)
3987 #endif
3988       {
3989          /*
3990          * We're running an SSL tunnel and we're not forwarding,
3991          * so just ditch the client headers, send the "connect succeeded"
3992          * message to the client, flush the rest, and get out of the way.
3993          */
3994          if (write_socket_delayed(csp->cfd, CSUCCEED,
3995                strlen(CSUCCEED), get_write_delay(csp)))
3996          {
3997             return;
3998          }
3999       }
4000 #ifdef FEATURE_HTTPS_INSPECTION
4001       else
4002       {
4003          /*
4004           * If server certificate is invalid, we must inform client and then
4005           * close connection with client.
4006           */
4007          if (csp->server_cert_verification_result != SSL_CERT_VALID)
4008          {
4009             ssl_send_certificate_error(csp);
4010             close_client_and_server_ssl_connections(csp);
4011             return;
4012          }
4013          if (send_https_request(csp))
4014          {
4015             rsp = error_response(csp, "connect-failed");
4016             if (rsp)
4017             {
4018                send_crunch_response(csp, rsp);
4019             }
4020             close_client_and_server_ssl_connections(csp);
4021             return;
4022          }
4023       }
4024 #endif /* def FEATURE_HTTPS_INSPECTION */
4025       clear_iob(csp->client_iob);
4026    }/* -END- else ... if (http->ssl == 1) */
4027
4028    log_error(LOG_LEVEL_CONNECT, "to %s successful", http->hostport);
4029
4030    /* XXX: should the time start earlier for optimistically sent data? */
4031    csp->server_connection.request_sent = time(NULL);
4032
4033    handle_established_connection(csp);
4034    freez(csp->receive_buffer);
4035 }
4036
4037
4038 #ifdef FUZZ
4039 /*********************************************************************
4040  *
4041  * Function    :  fuzz_server_response
4042  *
4043  * Description :  Treat the input as a whole server response.
4044  *
4045  * Parameters  :
4046  *          1  :  csp = Current client state (buffers, headers, etc...)
4047  *          2  :  fuzz_input_file = File to read the input from.
4048  *
4049  * Returns     :  0
4050  *
4051  *********************************************************************/
4052 extern int fuzz_server_response(struct client_state *csp, char *fuzz_input_file)
4053 {
4054    static struct forward_spec fwd; /* Zero'd due to being static */
4055    csp->cfd = 0;
4056
4057    if (strcmp(fuzz_input_file, "-") == 0)
4058    {
4059       /* XXX: Doesn'T work yet. */
4060       csp->server_connection.sfd = 0;
4061    }
4062    else
4063    {
4064       csp->server_connection.sfd = open(fuzz_input_file, O_RDONLY);
4065       if (csp->server_connection.sfd == -1)
4066       {
4067          log_error(LOG_LEVEL_FATAL, "Failed to open %s: %E",
4068             fuzz_input_file);
4069       }
4070    }
4071    csp->fwd = &fwd;
4072    csp->content_type |= CT_GIF;
4073    csp->action->flags |= ACTION_DEANIMATE;
4074    csp->action->string[ACTION_STRING_DEANIMATE] = "last";
4075
4076    csp->http->path = strdup_or_die("/");
4077    csp->http->host = strdup_or_die("fuzz.example.org");
4078    csp->http->hostport = strdup_or_die("fuzz.example.org:80");
4079    /* Prevent client socket monitoring */
4080    csp->flags |= CSP_FLAG_PIPELINED_REQUEST_WAITING;
4081    csp->flags |= CSP_FLAG_CHUNKED;
4082
4083    csp->config->feature_flags |= RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE;
4084    csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
4085
4086    csp->content_type |= CT_DECLARED|CT_GIF;
4087
4088    csp->config->socket_timeout = 0;
4089
4090    cgi_init_error_messages();
4091
4092    handle_established_connection(csp);
4093    freez(csp->receive_buffer);
4094
4095    return 0;
4096 }
4097 #endif
4098
4099
4100 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
4101 /*********************************************************************
4102  *
4103  * Function    :  prepare_csp_for_next_request
4104  *
4105  * Description :  Put the csp in a mostly vergin state.
4106  *
4107  * Parameters  :
4108  *          1  :  csp = Current client state (buffers, headers, etc...)
4109  *
4110  * Returns     :  N/A
4111  *
4112  *********************************************************************/
4113 static void prepare_csp_for_next_request(struct client_state *csp)
4114 {
4115    csp->content_type = 0;
4116    csp->content_length = 0;
4117    csp->expected_content_length = 0;
4118    csp->expected_client_content_length = 0;
4119    list_remove_all(csp->headers);
4120    clear_iob(csp->iob);
4121    freez(csp->error_message);
4122    free_http_request(csp->http);
4123    destroy_list(csp->headers);
4124    destroy_list(csp->tags);
4125 #ifdef FEATURE_CLIENT_TAGS
4126    destroy_list(csp->client_tags);
4127    freez(csp->client_address);
4128 #endif
4129    free_current_action(csp->action);
4130    if (NULL != csp->fwd)
4131    {
4132       unload_forward_spec(csp->fwd);
4133       csp->fwd = NULL;
4134    }
4135    /* XXX: Store per-connection flags someplace else. */
4136    csp->flags = (CSP_FLAG_ACTIVE | CSP_FLAG_REUSED_CLIENT_CONNECTION);
4137 #ifdef FEATURE_TOGGLE
4138    if (global_toggle_state)
4139 #endif /* def FEATURE_TOGGLE */
4140    {
4141       csp->flags |= CSP_FLAG_TOGGLED_ON;
4142    }
4143
4144    if (csp->client_iob->eod > csp->client_iob->cur)
4145    {
4146       long bytes_to_shift = csp->client_iob->cur - csp->client_iob->buf;
4147       size_t data_length  = (size_t)(csp->client_iob->eod - csp->client_iob->cur);
4148
4149       assert(bytes_to_shift > 0);
4150       assert(data_length > 0);
4151
4152       log_error(LOG_LEVEL_CONNECT, "Shifting %d pipelined bytes by %d bytes",
4153          data_length, bytes_to_shift);
4154       memmove(csp->client_iob->buf, csp->client_iob->cur, data_length);
4155       csp->client_iob->cur = csp->client_iob->buf;
4156       assert(csp->client_iob->eod == csp->client_iob->buf + bytes_to_shift + data_length);
4157       csp->client_iob->eod = csp->client_iob->buf + data_length;
4158       memset(csp->client_iob->eod, '\0', (size_t)bytes_to_shift);
4159
4160       csp->flags |= CSP_FLAG_PIPELINED_REQUEST_WAITING;
4161    }
4162    else
4163    {
4164       /*
4165        * We mainly care about resetting client_iob->cur so we don't
4166        * waste buffer space at the beginning and don't mess up the
4167        * request restoration done by cgi_show_request().
4168        *
4169        * Freeing the buffer itself isn't technically necessary,
4170        * but makes debugging more convenient.
4171        */
4172       clear_iob(csp->client_iob);
4173    }
4174 }
4175 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
4176
4177
4178 /*********************************************************************
4179  *
4180  * Function    :  serve
4181  *
4182  * Description :  This is little more than chat.  We only "serve" to
4183  *                to close (or remember) any socket that chat may have
4184  *                opened.
4185  *
4186  * Parameters  :
4187  *          1  :  csp = Current client state (buffers, headers, etc...)
4188  *
4189  * Returns     :  N/A
4190  *
4191  *********************************************************************/
4192 static void serve(struct client_state *csp)
4193 {
4194    int config_file_change_detected = 0; /* Only used for debugging */
4195 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
4196 #ifdef FEATURE_CONNECTION_SHARING
4197    static int monitor_thread_running = 0;
4198 #endif /* def FEATURE_CONNECTION_SHARING */
4199    int continue_chatting = 0;
4200
4201    log_error(LOG_LEVEL_CONNECT, "Accepted connection from %s on socket %d",
4202       csp->ip_addr_str, csp->cfd);
4203
4204    do
4205    {
4206       unsigned int latency;
4207
4208       chat(csp);
4209
4210       /*
4211        * If the request has been crunched,
4212        * the calculated latency is zero.
4213        */
4214       latency = (unsigned)(csp->server_connection.response_received -
4215          csp->server_connection.request_sent) / 2;
4216
4217       if ((csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
4218          && (csp->flags & CSP_FLAG_CRUNCHED)
4219          && (csp->expected_client_content_length != 0))
4220       {
4221          csp->flags |= CSP_FLAG_SERVER_SOCKET_TAINTED;
4222          log_error(LOG_LEVEL_CONNECT,
4223             "Tainting client socket %d due to unread data.", csp->cfd);
4224       }
4225
4226       continue_chatting = (csp->config->feature_flags
4227          & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
4228          && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
4229          && (csp->cfd != JB_INVALID_SOCKET)
4230          && (csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
4231          && ((csp->flags & CSP_FLAG_SERVER_CONTENT_LENGTH_SET)
4232             || (csp->flags & CSP_FLAG_CHUNKED));
4233
4234       if (!(csp->flags & CSP_FLAG_CRUNCHED)
4235          && (csp->server_connection.sfd != JB_INVALID_SOCKET))
4236       {
4237          if (!(csp->flags & CSP_FLAG_SERVER_KEEP_ALIVE_TIMEOUT_SET))
4238          {
4239             csp->server_connection.keep_alive_timeout = csp->config->default_server_timeout;
4240          }
4241          if (!(csp->flags & CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE)
4242             || (csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
4243             || !socket_is_still_alive(csp->server_connection.sfd)
4244             || !(latency < csp->server_connection.keep_alive_timeout))
4245          {
4246             log_error(LOG_LEVEL_CONNECT,
4247                "Closing server socket %d connected to %s. "
4248                "Keep-alive %u. Tainted: %u. Socket alive %u. Timeout: %u.",
4249                csp->server_connection.sfd, csp->server_connection.host,
4250                0 != (csp->flags & CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE),
4251                0 != (csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED),
4252                socket_is_still_alive(csp->server_connection.sfd),
4253                csp->server_connection.keep_alive_timeout);
4254 #ifdef FEATURE_CONNECTION_SHARING
4255             if (csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
4256             {
4257                forget_connection(csp->server_connection.sfd);
4258             }
4259 #endif /* def FEATURE_CONNECTION_SHARING */
4260             close_socket(csp->server_connection.sfd);
4261             mark_connection_closed(&csp->server_connection);
4262          }
4263       }
4264
4265       if (continue_chatting && any_loaded_file_changed(csp))
4266       {
4267          continue_chatting = 0;
4268          config_file_change_detected = 1;
4269       }
4270
4271       if (continue_chatting)
4272       {
4273          if (((csp->flags & CSP_FLAG_PIPELINED_REQUEST_WAITING) != 0)
4274             && socket_is_still_alive(csp->cfd))
4275          {
4276             log_error(LOG_LEVEL_CONNECT, "Client request %d has been "
4277                "pipelined on socket %d and the socket is still alive.",
4278                csp->requests_received_total+1, csp->cfd);
4279             prepare_csp_for_next_request(csp);
4280             continue;
4281          }
4282
4283          if (0 != (csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE))
4284          {
4285             if (csp->server_connection.sfd != JB_INVALID_SOCKET)
4286             {
4287                log_error(LOG_LEVEL_CONNECT,
4288                   "Waiting for the next client request on socket %d. "
4289                   "Keeping the server socket %d to %s open.",
4290                   csp->cfd, csp->server_connection.sfd, csp->server_connection.host);
4291             }
4292             else
4293             {
4294                log_error(LOG_LEVEL_CONNECT,
4295                   "Waiting for the next client request on socket %d. "
4296                   "No server socket to keep open.", csp->cfd);
4297             }
4298          }
4299
4300          if ((csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
4301             && data_is_available(csp->cfd, (int)csp->config->keep_alive_timeout)
4302             && socket_is_still_alive(csp->cfd))
4303          {
4304             log_error(LOG_LEVEL_CONNECT,
4305                "Client request %u arrived in time on socket %d.",
4306                csp->requests_received_total+1, csp->cfd);
4307             prepare_csp_for_next_request(csp);
4308          }
4309          else
4310          {
4311 #ifdef FEATURE_CONNECTION_SHARING
4312             if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
4313                && (csp->server_connection.sfd != JB_INVALID_SOCKET)
4314                && (socket_is_still_alive(csp->server_connection.sfd)))
4315             {
4316                time_t time_open = time(NULL) - csp->server_connection.timestamp;
4317
4318                if (csp->server_connection.keep_alive_timeout < time_open - (time_t)latency)
4319                {
4320                   break;
4321                }
4322
4323                remember_connection(&csp->server_connection);
4324                csp->server_connection.sfd = JB_INVALID_SOCKET;
4325                drain_and_close_socket(csp->cfd);
4326                csp->cfd = JB_INVALID_SOCKET;
4327                privoxy_mutex_lock(&connection_reuse_mutex);
4328                if (!monitor_thread_running)
4329                {
4330                   monitor_thread_running = 1;
4331                   privoxy_mutex_unlock(&connection_reuse_mutex);
4332                   wait_for_alive_connections();
4333                   privoxy_mutex_lock(&connection_reuse_mutex);
4334                   monitor_thread_running = 0;
4335                }
4336                privoxy_mutex_unlock(&connection_reuse_mutex);
4337             }
4338 #endif /* def FEATURE_CONNECTION_SHARING */
4339             break;
4340          }
4341       }
4342       else if (csp->server_connection.sfd != JB_INVALID_SOCKET)
4343       {
4344          log_error(LOG_LEVEL_CONNECT,
4345             "Closing server socket %d connected to %s. Keep-alive: %u. "
4346             "Tainted: %u. Socket alive: %u. Timeout: %u. "
4347             "Configuration file change detected: %u",
4348             csp->server_connection.sfd, csp->server_connection.host,
4349             0 != (csp->flags & CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE),
4350             0 != (csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED),
4351             socket_is_still_alive(csp->server_connection.sfd),
4352             csp->server_connection.keep_alive_timeout,
4353             config_file_change_detected);
4354       }
4355    } while (continue_chatting);
4356
4357 #else
4358    chat(csp);
4359 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
4360
4361    if (csp->server_connection.sfd != JB_INVALID_SOCKET)
4362    {
4363 #ifdef FEATURE_CONNECTION_SHARING
4364       if (csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
4365       {
4366          forget_connection(csp->server_connection.sfd);
4367       }
4368 #endif /* def FEATURE_CONNECTION_SHARING */
4369       close_socket(csp->server_connection.sfd);
4370    }
4371
4372 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
4373    mark_connection_closed(&csp->server_connection);
4374 #endif
4375
4376    if (csp->cfd != JB_INVALID_SOCKET)
4377    {
4378       log_error(LOG_LEVEL_CONNECT, "Closing client socket %d. "
4379          "Keep-alive: %u. Socket alive: %u. Data available: %u. "
4380          "Configuration file change detected: %u. Requests received: %u.",
4381          csp->cfd, 0 != (csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE),
4382          socket_is_still_alive(csp->cfd), data_is_available(csp->cfd, 0),
4383          config_file_change_detected, csp->requests_received_total);
4384       drain_and_close_socket(csp->cfd);
4385    }
4386
4387    free_csp_resources(csp);
4388
4389    csp->flags &= ~CSP_FLAG_ACTIVE;
4390
4391 }
4392
4393
4394 #ifdef __BEOS__
4395 /*********************************************************************
4396  *
4397  * Function    :  server_thread
4398  *
4399  * Description :  We only exist to call `serve' in a threaded environment.
4400  *
4401  * Parameters  :
4402  *          1  :  data = Current client state (buffers, headers, etc...)
4403  *
4404  * Returns     :  Always 0.
4405  *
4406  *********************************************************************/
4407 static int32 server_thread(void *data)
4408 {
4409    serve((struct client_state *) data);
4410    return 0;
4411
4412 }
4413 #endif
4414
4415
4416 #if !defined(_WIN32) || defined(_WIN_CONSOLE)
4417 /*********************************************************************
4418  *
4419  * Function    :  usage
4420  *
4421  * Description :  Print usage info & exit.
4422  *
4423  * Parameters  :  Pointer to argv[0] for identifying ourselves
4424  *
4425  * Returns     :  No. ,-)
4426  *
4427  *********************************************************************/
4428 static void usage(const char *name)
4429 {
4430    printf("Privoxy version " VERSION " (" HOME_PAGE_URL ")\n"
4431           "Usage: %s [--config-test] "
4432 #if defined(unix)
4433           "[--chroot] "
4434 #endif /* defined(unix) */
4435           "[--help] "
4436 #if defined(unix)
4437           "[--no-daemon] [--pidfile pidfile] [--pre-chroot-nslookup hostname] [--user user[.group]] "
4438 #endif /* defined(unix) */
4439          "[--version] [configfile]\n",
4440           name);
4441
4442 #ifdef FUZZ
4443    show_fuzz_usage(name);
4444 #endif
4445
4446    printf("Aborting\n");
4447
4448    exit(2);
4449
4450 }
4451 #endif /* #if !defined(_WIN32) || defined(_WIN_CONSOLE) */
4452
4453
4454 #ifdef MUTEX_LOCKS_AVAILABLE
4455 /*********************************************************************
4456  *
4457  * Function    :  privoxy_mutex_lock
4458  *
4459  * Description :  Locks a mutex.
4460  *