Fix indentation in handle_established_connection()
[privoxy.git] / jcc.c
1 const char jcc_rcs[] = "$Id: jcc.c,v 1.459 2017/05/29 10:12:50 fabiankeil Exp $";
2 /*********************************************************************
3  *
4  * File        :  $Source: /cvsroot/ijbswa/current/jcc.c,v $
5  *
6  * Purpose     :  Main file.  Contains main() method, main loop, and
7  *                the main connection-handling function.
8  *
9  * Copyright   :  Written by and Copyright (C) 2001-2017 the
10  *                Privoxy team. http://www.privoxy.org/
11  *
12  *                Based on the Internet Junkbuster originally written
13  *                by and Copyright (C) 1997 Anonymous Coders and
14  *                Junkbusters Corporation.  http://www.junkbusters.com
15  *
16  *                This program is free software; you can redistribute it
17  *                and/or modify it under the terms of the GNU General
18  *                Public License as published by the Free Software
19  *                Foundation; either version 2 of the License, or (at
20  *                your option) any later version.
21  *
22  *                This program is distributed in the hope that it will
23  *                be useful, but WITHOUT ANY WARRANTY; without even the
24  *                implied warranty of MERCHANTABILITY or FITNESS FOR A
25  *                PARTICULAR PURPOSE.  See the GNU General Public
26  *                License for more details.
27  *
28  *                The GNU General Public License should be included with
29  *                this file.  If not, you can view it at
30  *                http://www.gnu.org/copyleft/gpl.html
31  *                or write to the Free Software Foundation, Inc., 59
32  *                Temple Place - Suite 330, Boston, MA  02111-1307, USA.
33  *
34  *********************************************************************/
35
36
37 #include "config.h"
38
39 #include <stdio.h>
40 #include <sys/types.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <signal.h>
44 #include <fcntl.h>
45 #include <errno.h>
46 #include <assert.h>
47
48 #ifdef _WIN32
49 # ifndef FEATURE_PTHREAD
50 #  ifndef STRICT
51 #   define STRICT
52 #  endif
53 #  include <winsock2.h>
54 #  include <windows.h>
55 #  include <process.h>
56 # endif /* ndef FEATURE_PTHREAD */
57
58 # include "win32.h"
59 # ifndef _WIN_CONSOLE
60 #  include "w32log.h"
61 # endif /* ndef _WIN_CONSOLE */
62 # include "w32svrapi.h"
63
64 #else /* ifndef _WIN32 */
65
66 # if !defined (__OS2__)
67 # include <unistd.h>
68 # include <sys/wait.h>
69 # endif /* ndef __OS2__ */
70 # include <sys/time.h>
71 # include <sys/stat.h>
72 # include <sys/ioctl.h>
73
74 #ifdef sun
75 #include <sys/termios.h>
76 #endif /* sun */
77
78 #ifdef unix
79 #include <pwd.h>
80 #include <grp.h>
81 #endif
82
83 # include <signal.h>
84
85 # ifdef __BEOS__
86 #  include <socket.h>  /* BeOS has select() for sockets only. */
87 #  include <OS.h>      /* declarations for threads and stuff. */
88 # endif
89
90 # if defined(__EMX__) || defined(__OS2__)
91 #  include <sys/select.h>  /* OS/2/EMX needs a little help with select */
92 # endif
93 # ifdef __OS2__
94 #define INCL_DOS
95 # include <os2.h>
96 # endif
97
98 #ifdef HAVE_POLL
99 #ifdef __GLIBC__
100 #include <sys/poll.h>
101 #else
102 #include <poll.h>
103 #endif /* def __GLIBC__ */
104 #else
105 # ifndef FD_ZERO
106 #  include <select.h>
107 # endif
108 #endif /* HAVE_POLL */
109
110 #endif
111
112 #include "project.h"
113 #include "list.h"
114 #include "jcc.h"
115 #include "filters.h"
116 #include "loaders.h"
117 #include "parsers.h"
118 #include "miscutil.h"
119 #include "errlog.h"
120 #include "jbsockets.h"
121 #include "gateway.h"
122 #include "actions.h"
123 #include "cgi.h"
124 #include "loadcfg.h"
125 #include "urlmatch.h"
126 #ifdef FEATURE_CLIENT_TAGS
127 #include "client-tags.h"
128 #endif
129
130 const char jcc_h_rcs[] = JCC_H_VERSION;
131 const char project_h_rcs[] = PROJECT_H_VERSION;
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__) && !defined(AMIGA)
147 static void sig_handler(int the_signal);
148 #endif
149 static int client_protocol_is_unsupported(const 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(const 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);
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
170 #ifdef AMIGA
171 void serve(struct client_state *csp);
172 #else /* ifndef AMIGA */
173 static void serve(struct client_state *csp);
174 #endif /* def AMIGA */
175
176 #ifdef __BEOS__
177 static int32 server_thread(void *data);
178 #endif /* def __BEOS__ */
179
180 #ifdef _WIN32
181 #define sleep(N)  Sleep(((N) * 1000))
182 #endif
183
184 #ifdef __OS2__
185 #define sleep(N)  DosSleep(((N) * 100))
186 #endif
187
188 #ifdef FUZZ
189 int process_fuzzed_input(char *fuzz_input_type, char *fuzz_input_file);
190 void show_fuzz_usage(const char *name);
191 #endif
192
193 #ifdef MUTEX_LOCKS_AVAILABLE
194 /*
195  * XXX: Does the locking stuff really belong in this file?
196  */
197 privoxy_mutex_t log_mutex;
198 privoxy_mutex_t log_init_mutex;
199 privoxy_mutex_t connection_reuse_mutex;
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__) && !defined(AMIGA)
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    :  client_protocol_is_unsupported
399  *
400  * Description :  Checks if the client used a known unsupported
401  *                protocol and deals with it by sending an error
402  *                response.
403  *
404  * Parameters  :
405  *          1  :  csp = Current client state (buffers, headers, etc...)
406  *          2  :  req = the first request line send by the client
407  *
408  * Returns     :  TRUE if an error response has been generated, or
409  *                FALSE if the request doesn't look invalid.
410  *
411  *********************************************************************/
412 static int client_protocol_is_unsupported(const struct client_state *csp, char *req)
413 {
414    /*
415     * If it's a FTP or gopher request, we don't support it.
416     *
417     * These checks are better than nothing, but they might
418     * not work in all configurations and some clients might
419     * have problems digesting the answer.
420     *
421     * They should, however, never cause more problems than
422     * Privoxy's old behaviour (returning the misleading HTML
423     * error message:
424     *
425     * "Could not resolve http://(ftp|gopher)://example.org").
426     */
427    if (!strncmpic(req, "GET ftp://", 10) || !strncmpic(req, "GET gopher://", 13))
428    {
429       const char *response = NULL;
430       const char *protocol = NULL;
431
432       if (!strncmpic(req, "GET ftp://", 10))
433       {
434          response = FTP_RESPONSE;
435          protocol = "FTP";
436       }
437       else
438       {
439          response = GOPHER_RESPONSE;
440          protocol = "GOPHER";
441       }
442       log_error(LOG_LEVEL_ERROR,
443          "%s tried to use Privoxy as %s proxy: %s",
444          csp->ip_addr_str, protocol, req);
445       log_error(LOG_LEVEL_CLF,
446          "%s - - [%T] \"%s\" 400 0", csp->ip_addr_str, req);
447       freez(req);
448       write_socket(csp->cfd, response, strlen(response));
449
450       return TRUE;
451    }
452
453    return FALSE;
454 }
455
456
457 /*********************************************************************
458  *
459  * Function    :  client_has_unsupported_expectations
460  *
461  * Description :  Checks if the client used an unsupported expectation
462  *                in which case an error message is delivered.
463  *
464  * Parameters  :
465  *          1  :  csp = Current client state (buffers, headers, etc...)
466  *
467  * Returns     :  TRUE if an error response has been generated, or
468  *                FALSE if the request doesn't look invalid.
469  *
470  *********************************************************************/
471 static int client_has_unsupported_expectations(const struct client_state *csp)
472 {
473    if ((csp->flags & CSP_FLAG_UNSUPPORTED_CLIENT_EXPECTATION))
474    {
475       log_error(LOG_LEVEL_ERROR,
476          "Rejecting request from client %s with unsupported Expect header value",
477          csp->ip_addr_str);
478       log_error(LOG_LEVEL_CLF,
479          "%s - - [%T] \"%s\" 417 0", csp->ip_addr_str, csp->http->cmd);
480       write_socket(csp->cfd, UNSUPPORTED_CLIENT_EXPECTATION_ERROR_RESPONSE,
481          strlen(UNSUPPORTED_CLIENT_EXPECTATION_ERROR_RESPONSE));
482
483       return TRUE;
484    }
485
486    return FALSE;
487
488 }
489
490
491 /*********************************************************************
492  *
493  * Function    :  get_request_destination_elsewhere
494  *
495  * Description :  If the client's request was redirected into
496  *                Privoxy without the client's knowledge,
497  *                the request line lacks the destination host.
498  *
499  *                This function tries to get it elsewhere,
500  *                provided accept-intercepted-requests is enabled.
501  *
502  *                "Elsewhere" currently only means "Host: header",
503  *                but in the future we may ask the redirecting
504  *                packet filter to look the destination up.
505  *
506  *                If the destination stays unknown, an error
507  *                response is send to the client and headers
508  *                are freed so that chat() can return directly.
509  *
510  * Parameters  :
511  *          1  :  csp = Current client state (buffers, headers, etc...)
512  *          2  :  headers = a header list
513  *
514  * Returns     :  JB_ERR_OK if the destination is now known, or
515  *                JB_ERR_PARSE if it isn't.
516  *
517  *********************************************************************/
518 static jb_err get_request_destination_elsewhere(struct client_state *csp, struct list *headers)
519 {
520    char *req;
521
522    if (!(csp->config->feature_flags & RUNTIME_FEATURE_ACCEPT_INTERCEPTED_REQUESTS))
523    {
524       log_error(LOG_LEVEL_ERROR, "%s's request: \'%s\' is invalid."
525          " Privoxy isn't configured to accept intercepted requests.",
526          csp->ip_addr_str, csp->http->cmd);
527       /* XXX: Use correct size */
528       log_error(LOG_LEVEL_CLF, "%s - - [%T] \"%s\" 400 0",
529          csp->ip_addr_str, csp->http->cmd);
530
531       write_socket(csp->cfd, CHEADER, strlen(CHEADER));
532       destroy_list(headers);
533
534       return JB_ERR_PARSE;
535    }
536    else if (JB_ERR_OK == get_destination_from_headers(headers, csp->http))
537    {
538 #ifndef FEATURE_EXTENDED_HOST_PATTERNS
539       /* Split the domain we just got for pattern matching */
540       init_domain_components(csp->http);
541 #endif
542
543       return JB_ERR_OK;
544    }
545    else
546    {
547       /* We can't work without destination. Go spread the news.*/
548
549       req = list_to_text(headers);
550       chomp(req);
551       /* XXX: Use correct size */
552       log_error(LOG_LEVEL_CLF, "%s - - [%T] \"%s\" 400 0",
553          csp->ip_addr_str, csp->http->cmd);
554       log_error(LOG_LEVEL_ERROR,
555          "Privoxy was unable to get the destination for %s's request:\n%s\n%s",
556          csp->ip_addr_str, csp->http->cmd, req);
557       freez(req);
558
559       write_socket(csp->cfd, MISSING_DESTINATION_RESPONSE, strlen(MISSING_DESTINATION_RESPONSE));
560       destroy_list(headers);
561
562       return JB_ERR_PARSE;
563    }
564    /*
565     * TODO: If available, use PF's ioctl DIOCNATLOOK as last resort
566     * to get the destination IP address, use it as host directly
567     * or do a reverse DNS lookup first.
568     */
569 }
570
571
572 /*********************************************************************
573  *
574  * Function    :  get_server_headers
575  *
576  * Description :  Parses server headers in iob and fills them
577  *                into csp->headers so that they can later be
578  *                handled by sed().
579  *
580  * Parameters  :
581  *          1  :  csp = Current client state (buffers, headers, etc...)
582  *
583  * Returns     :  JB_ERR_OK if everything went fine, or
584  *                JB_ERR_PARSE if the headers were incomplete.
585  *
586  *********************************************************************/
587 static jb_err get_server_headers(struct client_state *csp)
588 {
589    int continue_hack_in_da_house = 0;
590    char * header;
591
592    while (((header = get_header(csp->iob)) != NULL) || continue_hack_in_da_house)
593    {
594       if (header == NULL)
595       {
596          /*
597           * continue hack in da house. Ignore the ending of
598           * this head and continue enlisting header lines.
599           * The reason is described below.
600           */
601          enlist(csp->headers, "");
602          continue_hack_in_da_house = 0;
603          continue;
604       }
605       else if (0 == strncmpic(header, "HTTP/1.1 100", 12))
606       {
607          /*
608           * It's a bodyless continue response, don't
609           * stop header parsing after reaching its end.
610           *
611           * As a result Privoxy will concatenate the
612           * next response's head and parse and deliver
613           * the headers as if they belonged to one request.
614           *
615           * The client will separate them because of the
616           * empty line between them.
617           *
618           * XXX: What we're doing here is clearly against
619           * the intended purpose of the continue header,
620           * and under some conditions (HTTP/1.0 client request)
621           * it's a standard violation.
622           *
623           * Anyway, "sort of against the spec" is preferable
624           * to "always getting confused by Continue responses"
625           * (Privoxy's behaviour before this hack was added)
626           */
627          log_error(LOG_LEVEL_HEADER, "Continue hack in da house.");
628          continue_hack_in_da_house = 1;
629       }
630       else if (*header == '\0')
631       {
632          /*
633           * If the header is empty, but the Continue hack
634           * isn't active, we can assume that we reached the
635           * end of the buffer before we hit the end of the
636           * head.
637           *
638           * Inform the caller an let it decide how to handle it.
639           */
640          return JB_ERR_PARSE;
641       }
642
643       if (JB_ERR_MEMORY == enlist(csp->headers, header))
644       {
645          /*
646           * XXX: Should we quit the request and return a
647           * out of memory error page instead?
648           */
649          log_error(LOG_LEVEL_ERROR,
650             "Out of memory while enlisting server headers. %s lost.",
651             header);
652       }
653       freez(header);
654    }
655
656    return JB_ERR_OK;
657 }
658
659
660 /*********************************************************************
661  *
662  * Function    :  crunch_reason
663  *
664  * Description :  Translates the crunch reason code into a string.
665  *
666  * Parameters  :
667  *          1  :  rsp = a http_response
668  *
669  * Returns     :  A string with the crunch reason or an error description.
670  *
671  *********************************************************************/
672 static const char *crunch_reason(const struct http_response *rsp)
673 {
674    char * reason = NULL;
675
676    assert(rsp != NULL);
677    if (rsp == NULL)
678    {
679       return "Internal error while searching for crunch reason";
680    }
681
682    switch (rsp->crunch_reason)
683    {
684       case UNSUPPORTED:
685          reason = "Unsupported HTTP feature";
686          break;
687       case BLOCKED:
688          reason = "Blocked";
689          break;
690       case UNTRUSTED:
691          reason = "Untrusted";
692          break;
693       case REDIRECTED:
694          reason = "Redirected";
695          break;
696       case CGI_CALL:
697          reason = "CGI Call";
698          break;
699       case NO_SUCH_DOMAIN:
700          reason = "DNS failure";
701          break;
702       case FORWARDING_FAILED:
703          reason = "Forwarding failed";
704          break;
705       case CONNECT_FAILED:
706          reason = "Connection failure";
707          break;
708       case OUT_OF_MEMORY:
709          reason = "Out of memory (may mask other reasons)";
710          break;
711       case CONNECTION_TIMEOUT:
712          reason = "Connection timeout";
713          break;
714       case NO_SERVER_DATA:
715          reason = "No server data received";
716          break;
717       default:
718          reason = "No reason recorded";
719          break;
720    }
721
722    return reason;
723 }
724
725
726 /*********************************************************************
727  *
728  * Function    :  log_applied_actions
729  *
730  * Description :  Logs the applied actions if LOG_LEVEL_ACTIONS is
731  *                enabled.
732  *
733  * Parameters  :
734  *          1  :  actions = Current action spec to log
735  *
736  * Returns     :  Nothing.
737  *
738  *********************************************************************/
739 static void log_applied_actions(const struct current_action_spec *actions)
740 {
741    /*
742     * The conversion to text requires lots of memory allocations so
743     * we only do the conversion if the user is actually interested.
744     */
745    if (debug_level_is_enabled(LOG_LEVEL_ACTIONS))
746    {
747       char *actions_as_text = actions_to_line_of_text(actions);
748       log_error(LOG_LEVEL_ACTIONS, "%s", actions_as_text);
749       freez(actions_as_text);
750    }
751 }
752
753
754 /*********************************************************************
755  *
756  * Function    :  send_crunch_response
757  *
758  * Description :  Delivers already prepared response for
759  *                intercepted requests, logs the interception
760  *                and frees the response.
761  *
762  * Parameters  :
763  *          1  :  csp = Current client state (buffers, headers, etc...)
764  *          1  :  rsp = Fully prepared response. Will be freed on exit.
765  *
766  * Returns     :  Nothing.
767  *
768  *********************************************************************/
769 static void send_crunch_response(const struct client_state *csp, struct http_response *rsp)
770 {
771       const struct http_request *http = csp->http;
772       char status_code[4];
773
774       assert(rsp != NULL);
775       assert(rsp->head != NULL);
776
777       if (rsp == NULL)
778       {
779          log_error(LOG_LEVEL_FATAL, "NULL response in send_crunch_response.");
780       }
781
782       /*
783        * Extract the status code from the actual head
784        * that will be send to the client. It is the only
785        * way to get it right for all requests, including
786        * the fixed ones for out-of-memory problems.
787        *
788        * A head starts like this: 'HTTP/1.1 200...'
789        *                           0123456789|11
790        *                                     10
791        */
792       status_code[0] = rsp->head[9];
793       status_code[1] = rsp->head[10];
794       status_code[2] = rsp->head[11];
795       status_code[3] = '\0';
796
797       /* Log that the request was crunched and why. */
798       log_applied_actions(csp->action);
799       log_error(LOG_LEVEL_CRUNCH, "%s: %s", crunch_reason(rsp), http->url);
800       log_error(LOG_LEVEL_CLF, "%s - - [%T] \"%s\" %s %u",
801          csp->ip_addr_str, http->ocmd, status_code, rsp->content_length);
802
803       /* Write the answer to the client */
804       if (write_socket(csp->cfd, rsp->head, rsp->head_length)
805        || write_socket(csp->cfd, rsp->body, rsp->content_length))
806       {
807          /* There is nothing we can do about it. */
808          log_error(LOG_LEVEL_ERROR,
809             "Couldn't deliver the error message through client socket %d: %E",
810             csp->cfd);
811       }
812
813       /* Clean up and return */
814       if (cgi_error_memory() != rsp)
815       {
816          free_http_response(rsp);
817       }
818       return;
819 }
820
821
822 /*********************************************************************
823  *
824  * Function    :  crunch_response_triggered
825  *
826  * Description :  Checks if the request has to be crunched,
827  *                and delivers the crunch response if necessary.
828  *
829  * Parameters  :
830  *          1  :  csp = Current client state (buffers, headers, etc...)
831  *          2  :  crunchers = list of cruncher functions to run
832  *
833  * Returns     :  TRUE if the request was answered with a crunch response
834  *                FALSE otherwise.
835  *
836  *********************************************************************/
837 static int crunch_response_triggered(struct client_state *csp, const struct cruncher crunchers[])
838 {
839    struct http_response *rsp = NULL;
840    const struct cruncher *c;
841
842    /*
843     * If CGI request crunching is disabled,
844     * check the CGI dispatcher out of order to
845     * prevent unintentional blocks or redirects.
846     */
847    if (!(csp->config->feature_flags & RUNTIME_FEATURE_CGI_CRUNCHING)
848        && (NULL != (rsp = dispatch_cgi(csp))))
849    {
850       /* Deliver, log and free the interception response. */
851       send_crunch_response(csp, rsp);
852       csp->flags |= CSP_FLAG_CRUNCHED;
853       return TRUE;
854    }
855
856    for (c = crunchers; c->cruncher != NULL; c++)
857    {
858       /*
859        * Check the cruncher if either Privoxy is toggled
860        * on and the request isn't forced, or if the cruncher
861        * applies to forced requests as well.
862        */
863       if (((csp->flags & CSP_FLAG_TOGGLED_ON) &&
864           !(csp->flags & CSP_FLAG_FORCED)) ||
865           (c->flags & CF_IGNORE_FORCE))
866       {
867          rsp = c->cruncher(csp);
868          if (NULL != rsp)
869          {
870             /* Deliver, log and free the interception response. */
871             send_crunch_response(csp, rsp);
872             csp->flags |= CSP_FLAG_CRUNCHED;
873 #ifdef FEATURE_STATISTICS
874             if (c->flags & CF_COUNT_AS_REJECT)
875             {
876                csp->flags |= CSP_FLAG_REJECTED;
877             }
878 #endif /* def FEATURE_STATISTICS */
879
880             return TRUE;
881          }
882       }
883    }
884
885    return FALSE;
886 }
887
888
889 /*********************************************************************
890  *
891  * Function    :  build_request_line
892  *
893  * Description :  Builds the HTTP request line.
894  *
895  *                If a HTTP forwarder is used it expects the whole URL,
896  *                web servers only get the path.
897  *
898  * Parameters  :
899  *          1  :  csp = Current client state (buffers, headers, etc...)
900  *          2  :  fwd = The forwarding spec used for the request
901  *                XXX: Should use http->fwd instead.
902  *          3  :  request_line = The old request line which will be replaced.
903  *
904  * Returns     :  Nothing. Terminates in case of memory problems.
905  *
906  *********************************************************************/
907 static void build_request_line(struct client_state *csp, const struct forward_spec *fwd, char **request_line)
908 {
909    struct http_request *http = csp->http;
910
911    assert(http->ssl == 0);
912
913    /*
914     * Downgrade http version from 1.1 to 1.0
915     * if +downgrade action applies.
916     */
917    if ((csp->action->flags & ACTION_DOWNGRADE)
918      && (!strcmpic(http->ver, "HTTP/1.1")))
919    {
920       freez(http->ver);
921       http->ver = strdup_or_die("HTTP/1.0");
922    }
923
924    /*
925     * Rebuild the request line.
926     */
927    freez(*request_line);
928    *request_line = strdup(http->gpc);
929    string_append(request_line, " ");
930
931    if (fwd->forward_host && fwd->type != FORWARD_WEBSERVER)
932    {
933       string_append(request_line, http->url);
934    }
935    else
936    {
937       string_append(request_line, http->path);
938    }
939    string_append(request_line, " ");
940    string_append(request_line, http->ver);
941
942    if (*request_line == NULL)
943    {
944       log_error(LOG_LEVEL_FATAL, "Out of memory writing HTTP command");
945    }
946    log_error(LOG_LEVEL_HEADER, "New HTTP Request-Line: %s", *request_line);
947 }
948
949
950 /*********************************************************************
951  *
952  * Function    :  change_request_destination
953  *
954  * Description :  Parse a (rewritten) request line and regenerate
955  *                the http request data.
956  *
957  * Parameters  :
958  *          1  :  csp = Current client state (buffers, headers, etc...)
959  *
960  * Returns     :  Forwards the parse_http_request() return code.
961  *                Terminates in case of memory problems.
962  *
963  *********************************************************************/
964 static jb_err change_request_destination(struct client_state *csp)
965 {
966    struct http_request *http = csp->http;
967    jb_err err;
968
969    log_error(LOG_LEVEL_REDIRECTS, "Rewrite detected: %s",
970       csp->headers->first->str);
971    free_http_request(http);
972    err = parse_http_request(csp->headers->first->str, http);
973    if (JB_ERR_OK != err)
974    {
975       log_error(LOG_LEVEL_ERROR, "Couldn't parse rewritten request: %s.",
976          jb_err_to_string(err));
977    }
978
979    return err;
980 }
981
982
983 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
984 /*********************************************************************
985  *
986  * Function    :  server_response_is_complete
987  *
988  * Description :  Determines whether we should stop reading
989  *                from the server socket.
990  *
991  * Parameters  :
992  *          1  :  csp = Current client state (buffers, headers, etc...)
993  *          2  :  content_length = Length of content received so far.
994  *
995  * Returns     :  TRUE if the response is complete,
996  *                FALSE otherwise.
997  *
998  *********************************************************************/
999 static int server_response_is_complete(struct client_state *csp,
1000    unsigned long long content_length)
1001 {
1002    int content_length_known = !!(csp->flags & CSP_FLAG_CONTENT_LENGTH_SET);
1003
1004    if (!strcmpic(csp->http->gpc, "HEAD"))
1005    {
1006       /*
1007        * "HEAD" implies no body, we are thus expecting
1008        * no content. XXX: incomplete "list" of methods?
1009        */
1010       csp->expected_content_length = 0;
1011       content_length_known = TRUE;
1012       csp->flags |= CSP_FLAG_SERVER_CONTENT_LENGTH_SET;
1013    }
1014
1015    if (csp->http->status == 204 || csp->http->status == 304)
1016    {
1017       /*
1018        * Expect no body. XXX: incomplete "list" of status codes?
1019        */
1020       csp->expected_content_length = 0;
1021       content_length_known = TRUE;
1022       csp->flags |= CSP_FLAG_SERVER_CONTENT_LENGTH_SET;
1023    }
1024
1025    return (content_length_known && ((0 == csp->expected_content_length)
1026             || (csp->expected_content_length <= content_length)));
1027 }
1028
1029
1030 #ifdef FEATURE_CONNECTION_SHARING
1031 /*********************************************************************
1032  *
1033  * Function    :  wait_for_alive_connections
1034  *
1035  * Description :  Waits for alive connections to timeout.
1036  *
1037  * Parameters  :  N/A
1038  *
1039  * Returns     :  N/A
1040  *
1041  *********************************************************************/
1042 static void wait_for_alive_connections(void)
1043 {
1044    int connections_alive = close_unusable_connections();
1045
1046    while (0 < connections_alive)
1047    {
1048       log_error(LOG_LEVEL_CONNECT,
1049          "Waiting for %d connections to timeout.",
1050          connections_alive);
1051       sleep(60);
1052       connections_alive = close_unusable_connections();
1053    }
1054
1055    log_error(LOG_LEVEL_CONNECT, "No connections to wait for left.");
1056
1057 }
1058 #endif /* def FEATURE_CONNECTION_SHARING */
1059
1060
1061 /*********************************************************************
1062  *
1063  * Function    :  save_connection_destination
1064  *
1065  * Description :  Remembers a connection for reuse later on.
1066  *
1067  * Parameters  :
1068  *          1  :  sfd  = Open socket to remember.
1069  *          2  :  http = The destination for the connection.
1070  *          3  :  fwd  = The forwarder settings used.
1071  *          3  :  server_connection  = storage.
1072  *
1073  * Returns     : void
1074  *
1075  *********************************************************************/
1076 void save_connection_destination(jb_socket sfd,
1077                                  const struct http_request *http,
1078                                  const struct forward_spec *fwd,
1079                                  struct reusable_connection *server_connection)
1080 {
1081    assert(sfd != JB_INVALID_SOCKET);
1082    assert(NULL != http->host);
1083
1084    server_connection->sfd = sfd;
1085    server_connection->host = strdup_or_die(http->host);
1086    server_connection->port = http->port;
1087
1088    assert(NULL != fwd);
1089    assert(server_connection->gateway_host == NULL);
1090    assert(server_connection->gateway_port == 0);
1091    assert(server_connection->forwarder_type == 0);
1092    assert(server_connection->forward_host == NULL);
1093    assert(server_connection->forward_port == 0);
1094
1095    server_connection->forwarder_type = fwd->type;
1096    if (NULL != fwd->gateway_host)
1097    {
1098       server_connection->gateway_host = strdup_or_die(fwd->gateway_host);
1099    }
1100    else
1101    {
1102       server_connection->gateway_host = NULL;
1103    }
1104    server_connection->gateway_port = fwd->gateway_port;
1105
1106    if (NULL != fwd->forward_host)
1107    {
1108       server_connection->forward_host = strdup_or_die(fwd->forward_host);
1109    }
1110    else
1111    {
1112       server_connection->forward_host = NULL;
1113    }
1114    server_connection->forward_port = fwd->forward_port;
1115 }
1116
1117
1118 /*********************************************************************
1119  *
1120  * Function    : verify_request_length
1121  *
1122  * Description : Checks if we already got the whole client requests
1123  *               and sets CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ if
1124  *               we do.
1125  *
1126  *               Data that doesn't belong to the current request is
1127  *               either thrown away to let the client retry on a clean
1128  *               socket, or stashed to be dealt with after the current
1129  *               request is served.
1130  *
1131  * Parameters  :
1132  *          1  :  csp = Current client state (buffers, headers, etc...)
1133  *
1134  * Returns     :  void
1135  *
1136  *********************************************************************/
1137 static void verify_request_length(struct client_state *csp)
1138 {
1139    unsigned long long buffered_request_bytes =
1140       (unsigned long long)(csp->client_iob->eod - csp->client_iob->cur);
1141
1142    if ((csp->expected_client_content_length != 0)
1143       && (buffered_request_bytes != 0))
1144    {
1145       if (csp->expected_client_content_length >= buffered_request_bytes)
1146       {
1147          csp->expected_client_content_length -= buffered_request_bytes;
1148          log_error(LOG_LEVEL_CONNECT, "Reduced expected bytes to %llu "
1149             "to account for the %llu ones we already got.",
1150             csp->expected_client_content_length, buffered_request_bytes);
1151       }
1152       else
1153       {
1154          assert(csp->client_iob->eod > csp->client_iob->cur + csp->expected_client_content_length);
1155          csp->client_iob->eod = csp->client_iob->cur + csp->expected_client_content_length;
1156          log_error(LOG_LEVEL_CONNECT, "Reducing expected bytes to 0. "
1157             "Marking the server socket tainted after throwing %llu bytes away.",
1158             buffered_request_bytes - csp->expected_client_content_length);
1159          csp->expected_client_content_length = 0;
1160          csp->flags |= CSP_FLAG_SERVER_SOCKET_TAINTED;
1161       }
1162
1163       if (csp->expected_client_content_length == 0)
1164       {
1165          csp->flags |= CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ;
1166       }
1167    }
1168
1169    if (!(csp->flags & CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ)
1170       && ((csp->client_iob->cur < csp->client_iob->eod)
1171          || (csp->expected_client_content_length != 0)))
1172    {
1173       if (strcmpic(csp->http->gpc, "GET")
1174          && strcmpic(csp->http->gpc, "HEAD")
1175          && strcmpic(csp->http->gpc, "TRACE")
1176          && strcmpic(csp->http->gpc, "OPTIONS")
1177          && strcmpic(csp->http->gpc, "DELETE"))
1178       {
1179          /* XXX: this is an incomplete hack */
1180          csp->flags &= ~CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ;
1181          log_error(LOG_LEVEL_CONNECT, "There better be a request body.");
1182       }
1183       else
1184       {
1185          csp->flags |= CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ;
1186
1187          if ((csp->config->feature_flags & RUNTIME_FEATURE_TOLERATE_PIPELINING) == 0)
1188          {
1189             csp->flags |= CSP_FLAG_SERVER_SOCKET_TAINTED;
1190             log_error(LOG_LEVEL_CONNECT,
1191                "Possible pipeline attempt detected. The connection will not "
1192                "be kept alive and we will only serve the first request.");
1193             /* Nuke the pipelined requests from orbit, just to be sure. */
1194             clear_iob(csp->client_iob);
1195          }
1196          else
1197          {
1198             /*
1199              * Keep the pipelined data around for now, we'll deal with
1200              * it once we're done serving the current request.
1201              */
1202             csp->flags |= CSP_FLAG_PIPELINED_REQUEST_WAITING;
1203             assert(csp->client_iob->eod >= csp->client_iob->cur);
1204             log_error(LOG_LEVEL_CONNECT, "Complete client request followed by "
1205                "%d bytes of pipelined data received.",
1206                (int)(csp->client_iob->eod - csp->client_iob->cur));
1207          }
1208       }
1209    }
1210    else
1211    {
1212       csp->flags |= CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ;
1213       log_error(LOG_LEVEL_CONNECT, "Complete client request received.");
1214    }
1215 }
1216 #endif /* FEATURE_CONNECTION_KEEP_ALIVE */
1217
1218
1219 /*********************************************************************
1220  *
1221  * Function    :  mark_server_socket_tainted
1222  *
1223  * Description :  Makes sure we don't reuse a server socket
1224  *                (if we didn't read everything the server sent
1225  *                us reusing the socket would lead to garbage).
1226  *
1227  * Parameters  :
1228  *          1  :  csp = Current client state (buffers, headers, etc...)
1229  *
1230  * Returns     :  void.
1231  *
1232  *********************************************************************/
1233 static void mark_server_socket_tainted(struct client_state *csp)
1234 {
1235    /*
1236     * For consistency we always mark the server socket
1237     * tainted, however, to reduce the log noise we only
1238     * emit a log message if the server socket could have
1239     * actually been reused.
1240     */
1241    if ((csp->flags & CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE)
1242       && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED))
1243    {
1244       log_error(LOG_LEVEL_CONNECT,
1245          "Marking the server socket %d tainted.",
1246          csp->server_connection.sfd);
1247    }
1248    csp->flags |= CSP_FLAG_SERVER_SOCKET_TAINTED;
1249 }
1250
1251 /*********************************************************************
1252  *
1253  * Function    :  get_request_line
1254  *
1255  * Description : Read the client request line.
1256  *
1257  * Parameters  :
1258  *          1  :  csp = Current client state (buffers, headers, etc...)
1259  *
1260  * Returns     :  Pointer to request line or NULL in case of errors.
1261  *
1262  *********************************************************************/
1263 static char *get_request_line(struct client_state *csp)
1264 {
1265    char buf[BUFFER_SIZE];
1266    char *request_line = NULL;
1267    int len;
1268
1269    memset(buf, 0, sizeof(buf));
1270
1271    if ((csp->flags & CSP_FLAG_PIPELINED_REQUEST_WAITING) != 0)
1272    {
1273       /*
1274        * If there are multiple pipelined requests waiting,
1275        * the flag will be set again once the next request
1276        * has been parsed.
1277        */
1278       csp->flags &= ~CSP_FLAG_PIPELINED_REQUEST_WAITING;
1279
1280       request_line = get_header(csp->client_iob);
1281       if ((NULL != request_line) && ('\0' != *request_line))
1282       {
1283          return request_line;
1284       }
1285       else
1286       {
1287          log_error(LOG_LEVEL_CONNECT, "No complete request line "
1288             "received yet. Continuing reading from %d.", csp->cfd);
1289       }
1290    }
1291
1292    do
1293    {
1294       if (
1295 #ifdef FUZZ
1296           0 == (csp->flags & CSP_FLAG_FUZZED_INPUT) &&
1297 #endif
1298           !data_is_available(csp->cfd, csp->config->socket_timeout)
1299           )
1300       {
1301          if (socket_is_still_alive(csp->cfd))
1302          {
1303             log_error(LOG_LEVEL_CONNECT,
1304                "No request line on socket %d received in time. Timeout: %d.",
1305                csp->cfd, csp->config->socket_timeout);
1306             write_socket(csp->cfd, CLIENT_CONNECTION_TIMEOUT_RESPONSE,
1307                strlen(CLIENT_CONNECTION_TIMEOUT_RESPONSE));
1308          }
1309          else
1310          {
1311             log_error(LOG_LEVEL_CONNECT,
1312                "The client side of the connection on socket %d got "
1313                "closed without sending a complete request line.", csp->cfd);
1314          }
1315          return NULL;
1316       }
1317
1318       len = read_socket(csp->cfd, buf, sizeof(buf) - 1);
1319
1320       if (len <= 0) return NULL;
1321
1322       /*
1323        * If there is no memory left for buffering the
1324        * request, there is nothing we can do but hang up
1325        */
1326       if (add_to_iob(csp->client_iob, csp->config->buffer_limit, buf, len))
1327       {
1328          return NULL;
1329       }
1330
1331       request_line = get_header(csp->client_iob);
1332
1333    } while ((NULL != request_line) && ('\0' == *request_line));
1334
1335    return request_line;
1336
1337 }
1338
1339 enum chunk_status
1340 {
1341    CHUNK_STATUS_MISSING_DATA,
1342    CHUNK_STATUS_BODY_COMPLETE,
1343    CHUNK_STATUS_PARSE_ERROR
1344 };
1345
1346
1347 /*********************************************************************
1348  *
1349  * Function    :  chunked_body_is_complete
1350  *
1351  * Description :  Figures out whether or not a chunked body is complete.
1352  *
1353  *                Currently it always starts at the beginning of the
1354  *                buffer which is somewhat wasteful and prevents Privoxy
1355  *                from starting to forward the correctly parsed chunks
1356  *                as soon as theoretically possible.
1357  *
1358  *                Should be modified to work with a common buffer,
1359  *                and allow the caller to skip already parsed chunks.
1360  *
1361  *                This would allow the function to be used for unbuffered
1362  *                response bodies as well.
1363  *
1364  * Parameters  :
1365  *          1  :  iob = Buffer with the body to check.
1366  *          2  :  length = Length of complete body
1367  *
1368  * Returns     :  Enum with the result of the check.
1369  *
1370  *********************************************************************/
1371 static enum chunk_status chunked_body_is_complete(struct iob *iob, size_t *length)
1372 {
1373    unsigned int chunksize;
1374    char *p = iob->cur;
1375
1376    do
1377    {
1378       /*
1379        * We need at least a single digit, followed by "\r\n",
1380        * followed by an unknown amount of data, followed by "\r\n".
1381        */
1382       if (p + 5 > iob->eod)
1383       {
1384          return CHUNK_STATUS_MISSING_DATA;
1385       }
1386       if (sscanf(p, "%x", &chunksize) != 1)
1387       {
1388          return CHUNK_STATUS_PARSE_ERROR;
1389       }
1390
1391       /*
1392        * We want at least a single digit, followed by "\r\n",
1393        * followed by the specified amount of data, followed by "\r\n".
1394        */
1395       if (p + chunksize + 5 > iob->eod)
1396       {
1397          return CHUNK_STATUS_MISSING_DATA;
1398       }
1399
1400       /* Skip chunk-size. */
1401       p = strstr(p, "\r\n");
1402       if (NULL == p)
1403       {
1404          return CHUNK_STATUS_PARSE_ERROR;
1405       }
1406       /* Move beyond the chunkdata. */
1407       p += 2 + chunksize;
1408
1409       /* There should be another "\r\n" to skip */
1410       if (memcmp(p, "\r\n", 2))
1411       {
1412          return CHUNK_STATUS_PARSE_ERROR;
1413       }
1414       p += 2;
1415    } while (chunksize > 0U);
1416
1417    *length = (size_t)(p - iob->cur);
1418    assert(*length <= (size_t)(iob->eod - iob->cur));
1419    assert(p <= iob->eod);
1420
1421    return CHUNK_STATUS_BODY_COMPLETE;
1422
1423 }
1424
1425
1426 /*********************************************************************
1427  *
1428  * Function    : receive_chunked_client_request_body
1429  *
1430  * Description : Read the chunk-encoded client request body.
1431  *               Failures are dealt with.
1432  *
1433  * Parameters  :
1434  *          1  :  csp = Current client state (buffers, headers, etc...)
1435  *
1436  * Returns     :  JB_ERR_OK or JB_ERR_PARSE
1437  *
1438  *********************************************************************/
1439 static jb_err receive_chunked_client_request_body(struct client_state *csp)
1440 {
1441    size_t body_length;
1442    enum chunk_status status;
1443
1444    while (CHUNK_STATUS_MISSING_DATA ==
1445       (status = chunked_body_is_complete(csp->client_iob, &body_length)))
1446    {
1447       char buf[BUFFER_SIZE];
1448       int len;
1449
1450       if (!data_is_available(csp->cfd, csp->config->socket_timeout))
1451       {
1452          log_error(LOG_LEVEL_ERROR,
1453             "Timeout while waiting for the client body.");
1454          break;
1455       }
1456       len = read_socket(csp->cfd, buf, sizeof(buf) - 1);
1457       if (len <= 0)
1458       {
1459          log_error(LOG_LEVEL_ERROR, "Read the client body failed: %E");
1460          break;
1461       }
1462       if (add_to_iob(csp->client_iob, csp->config->buffer_limit, buf, len))
1463       {
1464          break;
1465       }
1466    }
1467    if (status != CHUNK_STATUS_BODY_COMPLETE)
1468    {
1469       write_socket(csp->cfd, CLIENT_BODY_PARSE_ERROR_RESPONSE,
1470          strlen(CLIENT_BODY_PARSE_ERROR_RESPONSE));
1471       log_error(LOG_LEVEL_CLF,
1472          "%s - - [%T] \"Failed reading chunked client body\" 400 0", csp->ip_addr_str);
1473       return JB_ERR_PARSE;
1474    }
1475    log_error(LOG_LEVEL_CONNECT,
1476       "Chunked client body completely read. Length: %d", body_length);
1477    csp->expected_client_content_length = body_length;
1478
1479    return JB_ERR_OK;
1480
1481 }
1482
1483
1484 #ifdef FUZZ
1485 /*********************************************************************
1486  *
1487  * Function    :  fuzz_chunked_transfer_encoding
1488  *
1489  * Description :  Treat the fuzzed input as chunked transfer encoding
1490  *                to check and dechunk.
1491  *
1492  * Parameters  :
1493  *          1  :  csp      = Used to store the data.
1494  *          2  :  fuzz_input_file = File to read the input from.
1495  *
1496  * Returns     : Result of dechunking
1497  *
1498  *********************************************************************/
1499 extern int fuzz_chunked_transfer_encoding(struct client_state *csp, char *fuzz_input_file)
1500 {
1501    size_t length;
1502    size_t size = (size_t)(csp->iob->eod - csp->iob->cur);
1503    enum chunk_status status;
1504
1505    status = chunked_body_is_complete(csp->iob, &length);
1506    if (CHUNK_STATUS_BODY_COMPLETE != status)
1507    {
1508       log_error(LOG_LEVEL_INFO, "Chunked body is incomplete or invalid");
1509    }
1510
1511    return (JB_ERR_OK == remove_chunked_transfer_coding(csp->iob->cur, &size));
1512
1513 }
1514
1515
1516 /*********************************************************************
1517  *
1518  * Function    : fuzz_client_request
1519  *
1520  * Description : Try to get a client request from the fuzzed input.
1521  *
1522  * Parameters  :
1523  *          1  :  csp = Current client state (buffers, headers, etc...)
1524  *          2  :  fuzz_input_file = File to read the input from.
1525  *
1526  * Returns     :  Result of fuzzing.
1527  *
1528  *********************************************************************/
1529 extern int fuzz_client_request(struct client_state *csp, char *fuzz_input_file)
1530 {
1531    jb_err err;
1532
1533    csp->cfd = 0;
1534    csp->ip_addr_str = "fuzzer";
1535
1536    if (strcmp(fuzz_input_file, "-") != 0)
1537    {
1538       log_error(LOG_LEVEL_FATAL,
1539          "Fuzzed client requests can currenty only be read from stdin (-).");
1540    }
1541    err = receive_client_request(csp);
1542    if (err != JB_ERR_OK)
1543    {
1544       return 1;
1545    }
1546    err = parse_client_request(csp);
1547    if (err != JB_ERR_OK)
1548    {
1549       return 1;
1550    }
1551
1552    return 0;
1553
1554 }
1555 #endif  /* def FUZZ */
1556
1557
1558 #ifdef FEATURE_FORCE_LOAD
1559 /*********************************************************************
1560  *
1561  * Function    :  force_required
1562  *
1563  * Description : Checks a request line to see if it contains
1564  *               the FORCE_PREFIX. If it does, it is removed
1565  *               unless enforcing requests has beend disabled.
1566  *
1567  * Parameters  :
1568  *          1  :  request_line = HTTP request line
1569  *
1570  * Returns     :  TRUE if force is required, FALSE otherwise.
1571  *
1572  *********************************************************************/
1573 static int force_required(const struct client_state *csp, char *request_line)
1574 {
1575    char *p;
1576
1577    p = strstr(request_line, "http://");
1578    if (p != NULL)
1579    {
1580       /* Skip protocol */
1581       p += strlen("http://");
1582    }
1583    else
1584    {
1585       /* Intercepted request usually don't specify the protocol. */
1586       p = request_line;
1587    }
1588
1589    /* Go to the beginning of the path */
1590    p = strstr(p, "/");
1591    if (p == NULL)
1592    {
1593       /*
1594        * If the path is missing the request line is invalid and we
1595        * are done here. The client-visible rejection happens later on.
1596        */
1597       return 0;
1598    }
1599
1600    if (0 == strncmpic(p, FORCE_PREFIX, strlen(FORCE_PREFIX) - 1))
1601    {
1602       if (!(csp->config->feature_flags & RUNTIME_FEATURE_ENFORCE_BLOCKS))
1603       {
1604          /* XXX: Should clean more carefully */
1605          strclean(request_line, FORCE_PREFIX);
1606          log_error(LOG_LEVEL_FORCE,
1607             "Enforcing request: \"%s\".", request_line);
1608
1609          return 1;
1610       }
1611       log_error(LOG_LEVEL_FORCE,
1612          "Ignored force prefix in request: \"%s\".", request_line);
1613    }
1614
1615    return 0;
1616
1617 }
1618 #endif /* def FEATURE_FORCE_LOAD */
1619
1620
1621 /*********************************************************************
1622  *
1623  * Function    :  receive_client_request
1624  *
1625  * Description : Read the client's request (more precisely the
1626  *               client headers) and answer it if necessary.
1627  *
1628  * Parameters  :
1629  *          1  :  csp = Current client state (buffers, headers, etc...)
1630  *
1631  * Returns     :  JB_ERR_OK, JB_ERR_PARSE or JB_ERR_MEMORY
1632  *
1633  *********************************************************************/
1634 static jb_err receive_client_request(struct client_state *csp)
1635 {
1636    char buf[BUFFER_SIZE];
1637    char *p;
1638    char *req = NULL;
1639    struct http_request *http;
1640    int len;
1641    jb_err err;
1642
1643    /* Temporary copy of the client's headers before they get enlisted in csp->headers */
1644    struct list header_list;
1645    struct list *headers = &header_list;
1646
1647    /* We don't care if the arriving data is a valid HTTP request or not. */
1648    csp->requests_received_total++;
1649
1650    http = csp->http;
1651
1652    memset(buf, 0, sizeof(buf));
1653
1654    req = get_request_line(csp);
1655    if (req == NULL)
1656    {
1657       mark_server_socket_tainted(csp);
1658       return JB_ERR_PARSE;
1659    }
1660    assert(*req != '\0');
1661
1662    if (client_protocol_is_unsupported(csp, req))
1663    {
1664       return JB_ERR_PARSE;
1665    }
1666
1667 #ifdef FEATURE_FORCE_LOAD
1668    if (force_required(csp, req))
1669    {
1670       csp->flags |= CSP_FLAG_FORCED;
1671    }
1672 #endif /* def FEATURE_FORCE_LOAD */
1673
1674    err = parse_http_request(req, http);
1675    freez(req);
1676    if (JB_ERR_OK != err)
1677    {
1678       write_socket(csp->cfd, CHEADER, strlen(CHEADER));
1679       /* XXX: Use correct size */
1680       log_error(LOG_LEVEL_CLF, "%s - - [%T] \"Invalid request\" 400 0", csp->ip_addr_str);
1681       log_error(LOG_LEVEL_ERROR,
1682          "Couldn't parse request line received from %s: %s",
1683          csp->ip_addr_str, jb_err_to_string(err));
1684
1685       free_http_request(http);
1686       return JB_ERR_PARSE;
1687    }
1688
1689    /* grab the rest of the client's headers */
1690    init_list(headers);
1691    for (;;)
1692    {
1693       p = get_header(csp->client_iob);
1694
1695       if (p == NULL)
1696       {
1697          /* There are no additional headers to read. */
1698          break;
1699       }
1700
1701       if (*p == '\0')
1702       {
1703          /*
1704           * We didn't receive a complete header
1705           * line yet, get the rest of it.
1706           */
1707          if (!data_is_available(csp->cfd, csp->config->socket_timeout))
1708          {
1709             log_error(LOG_LEVEL_ERROR,
1710                "Stopped grabbing the client headers.");
1711             destroy_list(headers);
1712             return JB_ERR_PARSE;
1713          }
1714
1715          len = read_socket(csp->cfd, buf, sizeof(buf) - 1);
1716          if (len <= 0)
1717          {
1718             log_error(LOG_LEVEL_ERROR, "read from client failed: %E");
1719             destroy_list(headers);
1720             return JB_ERR_PARSE;
1721          }
1722
1723          if (add_to_iob(csp->client_iob, csp->config->buffer_limit, buf, len))
1724          {
1725             /*
1726              * If there is no memory left for buffering the
1727              * request, there is nothing we can do but hang up
1728              */
1729             destroy_list(headers);
1730             return JB_ERR_MEMORY;
1731          }
1732       }
1733       else
1734       {
1735          if (!strncmpic(p, "Transfer-Encoding:", 18))
1736          {
1737             /*
1738              * XXX: should be called through sed()
1739              *      but currently can't.
1740              */
1741             client_transfer_encoding(csp, &p);
1742          }
1743          /*
1744           * We were able to read a complete
1745           * header and can finally enlist it.
1746           */
1747          enlist(headers, p);
1748          freez(p);
1749       }
1750    }
1751
1752    if (http->host == NULL)
1753    {
1754       /*
1755        * If we still don't know the request destination,
1756        * the request is invalid or the client uses
1757        * Privoxy without its knowledge.
1758        */
1759       if (JB_ERR_OK != get_request_destination_elsewhere(csp, headers))
1760       {
1761          /*
1762           * Our attempts to get the request destination
1763           * elsewhere failed or Privoxy is configured
1764           * to only accept proxy requests.
1765           *
1766           * An error response has already been send
1767           * and we're done here.
1768           */
1769          return JB_ERR_PARSE;
1770       }
1771    }
1772
1773 #ifdef FEATURE_CLIENT_TAGS
1774    /* XXX: If the headers were enlisted sooner, passing csp would do. */
1775    set_client_address(csp, headers);
1776    get_tag_list_for_client(csp->client_tags, csp->client_address);
1777 #endif
1778
1779    /*
1780     * Determine the actions for this URL
1781     */
1782 #ifdef FEATURE_TOGGLE
1783    if (!(csp->flags & CSP_FLAG_TOGGLED_ON))
1784    {
1785       /* Most compatible set of actions (i.e. none) */
1786       init_current_action(csp->action);
1787    }
1788    else
1789 #endif /* ndef FEATURE_TOGGLE */
1790    {
1791       get_url_actions(csp, http);
1792    }
1793
1794    enlist(csp->headers, http->cmd);
1795
1796    /* Append the previously read headers */
1797    err = list_append_list_unique(csp->headers, headers);
1798    destroy_list(headers);
1799
1800    return err;
1801
1802 }
1803
1804
1805 /*********************************************************************
1806  *
1807  * Function    : parse_client_request
1808  *
1809  * Description : Parses the client's request and decides what to do
1810  *               with it.
1811  *
1812  *               Note that since we're not using select() we could get
1813  *               blocked here if a client connected, then didn't say
1814  *               anything!
1815  *
1816  * Parameters  :
1817  *          1  :  csp = Current client state (buffers, headers, etc...)
1818  *
1819  * Returns     :  JB_ERR_OK or JB_ERR_PARSE
1820  *
1821  *********************************************************************/
1822 static jb_err parse_client_request(struct client_state *csp)
1823 {
1824    struct http_request *http = csp->http;
1825    jb_err err;
1826
1827 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1828    if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
1829     && (!strcmpic(csp->http->ver, "HTTP/1.1"))
1830     && (csp->http->ssl == 0))
1831    {
1832       /* Assume persistence until further notice */
1833       csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
1834    }
1835
1836    if (csp->http->ssl == 0)
1837    {
1838       /*
1839        * This whole block belongs to chat() but currently
1840        * has to be executed before sed().
1841        */
1842       if (csp->flags & CSP_FLAG_CHUNKED_CLIENT_BODY)
1843       {
1844          if (receive_chunked_client_request_body(csp) != JB_ERR_OK)
1845          {
1846             return JB_ERR_PARSE;
1847          }
1848       }
1849       else
1850       {
1851          csp->expected_client_content_length = get_expected_content_length(csp->headers);
1852       }
1853       verify_request_length(csp);
1854    }
1855 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
1856
1857    err = sed(csp, FILTER_CLIENT_HEADERS);
1858    if (JB_ERR_OK != err)
1859    {
1860       log_error(LOG_LEVEL_ERROR, "Failed to parse client request from %s.",
1861          csp->ip_addr_str);
1862       log_error(LOG_LEVEL_CLF, "%s - - [%T] \"%s\" 400 0",
1863          csp->ip_addr_str, csp->http->cmd);
1864       write_socket(csp->cfd, CHEADER, strlen(CHEADER));
1865       return JB_ERR_PARSE;
1866    }
1867    csp->flags |= CSP_FLAG_CLIENT_HEADER_PARSING_DONE;
1868
1869    /* Check request line for rewrites. */
1870    if ((NULL == csp->headers->first->str)
1871       || (strcmp(http->cmd, csp->headers->first->str) &&
1872          (JB_ERR_OK != change_request_destination(csp))))
1873    {
1874       /*
1875        * A header filter broke the request line - bail out.
1876        */
1877       write_socket(csp->cfd, MESSED_UP_REQUEST_RESPONSE, strlen(MESSED_UP_REQUEST_RESPONSE));
1878       /* XXX: Use correct size */
1879       log_error(LOG_LEVEL_CLF,
1880          "%s - - [%T] \"Invalid request generated\" 500 0", csp->ip_addr_str);
1881       log_error(LOG_LEVEL_ERROR,
1882          "Invalid request line after applying header filters.");
1883       free_http_request(http);
1884
1885       return JB_ERR_PARSE;
1886    }
1887
1888    if (client_has_unsupported_expectations(csp))
1889    {
1890       return JB_ERR_PARSE;
1891    }
1892
1893    return JB_ERR_OK;
1894
1895 }
1896
1897
1898 /*********************************************************************
1899  *
1900  * Function    : send_http_request
1901  *
1902  * Description : Sends the HTTP headers from the client request
1903  *               and all the body data that has already been received.
1904  *
1905  * Parameters  :
1906  *          1  :  csp = Current client state (buffers, headers, etc...)
1907  *
1908  * Returns     :  0 on success, anything else is na error.
1909  *
1910  *********************************************************************/
1911 static int send_http_request(struct client_state *csp)
1912 {
1913    char *hdr;
1914    int write_failure;
1915
1916    hdr = list_to_text(csp->headers);
1917    if (hdr == NULL)
1918    {
1919       /* FIXME Should handle error properly */
1920       log_error(LOG_LEVEL_FATAL, "Out of memory parsing client header");
1921    }
1922    list_remove_all(csp->headers);
1923
1924    /*
1925     * Write the client's (modified) header to the server
1926     * (along with anything else that may be in the buffer)
1927     */
1928    write_failure = 0 != write_socket(csp->server_connection.sfd, hdr, strlen(hdr));
1929    freez(hdr);
1930
1931    if (write_failure)
1932    {
1933       log_error(LOG_LEVEL_CONNECT, "Failed sending request headers to: %s: %E",
1934          csp->http->hostport);
1935    }
1936    else if (((csp->flags & CSP_FLAG_PIPELINED_REQUEST_WAITING) == 0)
1937       && (flush_socket(csp->server_connection.sfd, csp->client_iob) < 0))
1938    {
1939       write_failure = 1;
1940       log_error(LOG_LEVEL_CONNECT, "Failed sending request body to: %s: %E",
1941          csp->http->hostport);
1942    }
1943
1944    return write_failure;
1945
1946 }
1947
1948
1949 /*********************************************************************
1950  *
1951  * Function    :  handle_established_connection
1952  *
1953  * Description :  Shuffle data between client and server once the
1954  *                connection has been established.
1955  *
1956  * Parameters  :
1957  *          1  :  csp = Current client state (buffers, headers, etc...)
1958  *
1959  * Returns     :  Nothing.
1960  *
1961  *********************************************************************/
1962 static void handle_established_connection(struct client_state *csp,
1963                                           const struct forward_spec *fwd)
1964 {
1965    char *receive_buffer;
1966    char *hdr;
1967    char *p;
1968    int n;
1969 #ifdef HAVE_POLL
1970    struct pollfd poll_fds[2];
1971 #else
1972    fd_set rfds;
1973    jb_socket maxfd;
1974    struct timeval timeout;
1975 #endif
1976    int server_body;
1977    int ms_iis5_hack = 0;
1978    unsigned long long byte_count = 0;
1979    struct http_request *http;
1980    long len = 0; /* for buffer sizes (and negative error codes) */
1981    int buffer_and_filter_content = 0;
1982
1983    /* Skeleton for HTTP response, if we should intercept the request */
1984    struct http_response *rsp;
1985 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1986    int watch_client_socket;
1987 #endif
1988    const size_t receive_buffer_size = csp->config->receive_buffer_size;
1989
1990    receive_buffer = zalloc(receive_buffer_size + 1);
1991    if (receive_buffer == NULL)
1992    {
1993       log_error(LOG_LEVEL_ERROR,
1994          "Out of memory. Failed to allocate the receive buffer.");
1995       rsp = cgi_error_memory();
1996       send_crunch_response(csp, rsp);
1997       return;
1998    }
1999
2000    http = csp->http;
2001
2002 #ifndef HAVE_POLL
2003    maxfd = (csp->cfd > csp->server_connection.sfd) ?
2004       csp->cfd : csp->server_connection.sfd;
2005 #endif
2006
2007    /* pass data between the client and server
2008     * until one or the other shuts down the connection.
2009     */
2010
2011    server_body = 0;
2012
2013 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2014    watch_client_socket = 0 == (csp->flags & CSP_FLAG_PIPELINED_REQUEST_WAITING);
2015 #endif
2016
2017    for (;;)
2018    {
2019 #ifndef HAVE_POLL
2020 #ifdef __OS2__
2021       /*
2022        * FD_ZERO here seems to point to an errant macro which crashes.
2023        * So do this by hand for now...
2024        */
2025       memset(&rfds,0x00,sizeof(fd_set));
2026 #else
2027       FD_ZERO(&rfds);
2028 #endif
2029 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2030       if (!watch_client_socket)
2031       {
2032          maxfd = csp->server_connection.sfd;
2033       }
2034       else
2035 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2036       {
2037          FD_SET(csp->cfd, &rfds);
2038       }
2039
2040       FD_SET(csp->server_connection.sfd, &rfds);
2041 #endif /* ndef HAVE_POLL */
2042
2043 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2044       if ((csp->flags & CSP_FLAG_CHUNKED)
2045          && !(csp->flags & CSP_FLAG_CONTENT_LENGTH_SET)
2046          && ((csp->iob->eod - csp->iob->cur) >= 5)
2047          && !memcmp(csp->iob->eod-5, "0\r\n\r\n", 5))
2048       {
2049          /*
2050           * XXX: This check should be obsolete now,
2051           *      but let's wait a while to be sure.
2052           */
2053          log_error(LOG_LEVEL_CONNECT,
2054             "Looks like we got the last chunk together with "
2055             "the server headers but didn't detect it earlier. "
2056             "We better stop reading.");
2057          byte_count = (unsigned long long)(csp->iob->eod - csp->iob->cur);
2058          csp->expected_content_length = byte_count;
2059          csp->flags |= CSP_FLAG_CONTENT_LENGTH_SET;
2060       }
2061       if (server_body && server_response_is_complete(csp, byte_count))
2062       {
2063          if (csp->expected_content_length == byte_count)
2064          {
2065             log_error(LOG_LEVEL_CONNECT,
2066                "Done reading from server. Content length: %llu as expected. "
2067                "Bytes most recently read: %d.",
2068                byte_count, len);
2069          }
2070          else
2071          {
2072             log_error(LOG_LEVEL_CONNECT,
2073                "Done reading from server. Expected content length: %llu. "
2074                "Actual content length: %llu. Bytes most recently read: %d.",
2075                csp->expected_content_length, byte_count, len);
2076          }
2077          len = 0;
2078          /*
2079           * XXX: should not jump around,
2080           * chat() is complicated enough already.
2081           */
2082          goto reading_done;
2083       }
2084 #endif  /* FEATURE_CONNECTION_KEEP_ALIVE */
2085
2086 #ifdef HAVE_POLL
2087       poll_fds[0].fd = csp->cfd;
2088 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2089       if (!watch_client_socket)
2090       {
2091          /*
2092           * Ignore incoming data, but still watch out
2093           * for disconnects etc. These flags are always
2094           * implied anyway but explicitly setting them
2095           * doesn't hurt.
2096           */
2097          poll_fds[0].events = POLLERR|POLLHUP;
2098       }
2099       else
2100 #endif
2101       {
2102          poll_fds[0].events = POLLIN;
2103       }
2104       poll_fds[1].fd = csp->server_connection.sfd;
2105       poll_fds[1].events = POLLIN;
2106       n = poll(poll_fds, 2, csp->config->socket_timeout * 1000);
2107 #else
2108       timeout.tv_sec = csp->config->socket_timeout;
2109       timeout.tv_usec = 0;
2110       n = select((int)maxfd+1, &rfds, NULL, NULL, &timeout);
2111 #endif /* def HAVE_POLL */
2112
2113       if (n == 0)
2114       {
2115          log_error(LOG_LEVEL_ERROR,
2116             "Didn't receive data in time: %s", http->url);
2117          if ((byte_count == 0) && (http->ssl == 0))
2118          {
2119             send_crunch_response(csp, error_response(csp, "connection-timeout"));
2120          }
2121          mark_server_socket_tainted(csp);
2122          freez(receive_buffer);
2123          return;
2124       }
2125       else if (n < 0)
2126       {
2127 #ifdef HAVE_POLL
2128          log_error(LOG_LEVEL_ERROR, "poll() failed!: %E");
2129 #else
2130          log_error(LOG_LEVEL_ERROR, "select() failed!: %E");
2131 #endif
2132          mark_server_socket_tainted(csp);
2133          freez(receive_buffer);
2134          return;
2135       }
2136
2137       /*
2138        * This is the body of the browser's request,
2139        * just read and write it.
2140        *
2141        * XXX: Make sure the client doesn't use pipelining
2142        * behind Privoxy's back.
2143        */
2144 #ifdef HAVE_POLL
2145       if ((poll_fds[0].revents & (POLLERR|POLLHUP|POLLNVAL)) != 0)
2146       {
2147          log_error(LOG_LEVEL_CONNECT,
2148             "The client socket %d has become unusable while "
2149             "the server socket %d is still open.",
2150             csp->cfd, csp->server_connection.sfd);
2151          mark_server_socket_tainted(csp);
2152          break;
2153       }
2154
2155       if (poll_fds[0].revents != 0)
2156 #else
2157       if (FD_ISSET(csp->cfd, &rfds))
2158 #endif /* def HAVE_POLL*/
2159       {
2160          int max_bytes_to_read = (int)receive_buffer_size;
2161
2162 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2163          if ((csp->flags & CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ))
2164          {
2165             if (data_is_available(csp->cfd, 0))
2166             {
2167                /*
2168                 * If the next request is already waiting, we have
2169                 * to stop select()ing the client socket. Otherwise
2170                 * we would always return right away and get nothing
2171                 * else done.
2172                 */
2173                watch_client_socket = 0;
2174                log_error(LOG_LEVEL_CONNECT,
2175                   "Stopping to watch the client socket %d. "
2176                   "There's already another request waiting.",
2177                   csp->cfd);
2178                continue;
2179             }
2180             /*
2181              * If the client socket is set, but there's no data
2182              * available on the socket, the client went fishing
2183              * and continuing talking to the server makes no sense.
2184              */
2185             log_error(LOG_LEVEL_CONNECT,
2186                "The client closed socket %d while "
2187                "the server socket %d is still open.",
2188                csp->cfd, csp->server_connection.sfd);
2189             mark_server_socket_tainted(csp);
2190             break;
2191          }
2192          if (csp->expected_client_content_length != 0)
2193          {
2194             if (csp->expected_client_content_length < receive_buffer_size)
2195             {
2196                max_bytes_to_read = (int)csp->expected_client_content_length;
2197             }
2198             log_error(LOG_LEVEL_CONNECT,
2199                "Waiting for up to %d bytes from the client.",
2200                max_bytes_to_read);
2201          }
2202          assert(max_bytes_to_read <= receive_buffer_size);
2203 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2204
2205          len = read_socket(csp->cfd, receive_buffer, max_bytes_to_read);
2206
2207          if (len <= 0)
2208          {
2209             /* XXX: not sure if this is necessary. */
2210             mark_server_socket_tainted(csp);
2211             break; /* "game over, man" */
2212          }
2213
2214 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2215          if (csp->expected_client_content_length != 0)
2216          {
2217             assert(len <= max_bytes_to_read);
2218             csp->expected_client_content_length -= (unsigned)len;
2219             log_error(LOG_LEVEL_CONNECT,
2220                "Expected client content length set to %llu "
2221                "after reading %d bytes.",
2222                csp->expected_client_content_length, len);
2223             if (csp->expected_client_content_length == 0)
2224             {
2225                log_error(LOG_LEVEL_CONNECT,
2226                   "Done reading from the client.");
2227                csp->flags |= CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ;
2228             }
2229          }
2230 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2231
2232          if (write_socket(csp->server_connection.sfd, receive_buffer, (size_t)len))
2233          {
2234             log_error(LOG_LEVEL_ERROR, "write to: %s failed: %E", http->host);
2235             mark_server_socket_tainted(csp);
2236             freez(receive_buffer);
2237             return;
2238          }
2239          continue;
2240       }
2241
2242       /*
2243        * The server wants to talk. It could be the header or the body.
2244        * If `hdr' is null, then it's the header otherwise it's the body.
2245        * FIXME: Does `hdr' really mean `host'? No.
2246        */
2247 #ifdef HAVE_POLL
2248       if (poll_fds[1].revents != 0)
2249 #else
2250       if (FD_ISSET(csp->server_connection.sfd, &rfds))
2251 #endif /* HAVE_POLL */
2252       {
2253 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2254          /*
2255           * If we are buffering content, we don't want to eat up to
2256           * buffer-limit bytes if the client no longer cares about them.
2257           * If we aren't buffering, however, a dead client socket will be
2258           * noticed pretty much right away anyway, so we can reduce the
2259           * overhead by skipping the check.
2260           */
2261          if (buffer_and_filter_content && !socket_is_still_alive(csp->cfd))
2262          {
2263 #ifdef _WIN32
2264             log_error(LOG_LEVEL_CONNECT,
2265                "The server still wants to talk, but the client may already have hung up on us.");
2266 #else
2267             log_error(LOG_LEVEL_CONNECT,
2268                "The server still wants to talk, but the client hung up on us.");
2269             mark_server_socket_tainted(csp);
2270             freez(receive_buffer);
2271             return;
2272 #endif /* def _WIN32 */
2273          }
2274 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2275
2276          len = read_socket(csp->server_connection.sfd, receive_buffer, (int)receive_buffer_size);
2277
2278          if (len < 0)
2279          {
2280             log_error(LOG_LEVEL_ERROR, "read from: %s failed: %E", http->host);
2281
2282             if (http->ssl && (fwd->forward_host == NULL))
2283             {
2284                /*
2285                 * Just hang up. We already confirmed the client's CONNECT
2286                 * request with status code 200 and unencrypted content is
2287                 * no longer welcome.
2288                 */
2289                log_error(LOG_LEVEL_ERROR,
2290                   "CONNECT already confirmed. Unable to tell the client about the problem.");
2291                freez(receive_buffer);
2292                return;
2293             }
2294             else if (byte_count)
2295             {
2296                /*
2297                 * Just hang up. We already transmitted the original headers
2298                 * and parts of the original content and therefore missed the
2299                 * chance to send an error message (without risking data corruption).
2300                 *
2301                 * XXX: we could retry with a fancy range request here.
2302                 */
2303                log_error(LOG_LEVEL_ERROR, "Already forwarded the original headers. "
2304                   "Unable to tell the client about the problem.");
2305                mark_server_socket_tainted(csp);
2306                freez(receive_buffer);
2307                return;
2308             }
2309             /*
2310              * XXX: Consider handling the cases above the same.
2311              */
2312             mark_server_socket_tainted(csp);
2313             len = 0;
2314          }
2315
2316 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2317          if (csp->flags & CSP_FLAG_CHUNKED)
2318          {
2319             if ((len >= 5) && !memcmp(receive_buffer+len-5, "0\r\n\r\n", 5))
2320             {
2321                /* XXX: this is a temporary hack */
2322                log_error(LOG_LEVEL_CONNECT,
2323                   "Looks like we reached the end of the last chunk. "
2324                   "We better stop reading.");
2325                csp->expected_content_length = byte_count + (unsigned long long)len;
2326                csp->flags |= CSP_FLAG_CONTENT_LENGTH_SET;
2327             }
2328          }
2329          reading_done:
2330 #endif  /* FEATURE_CONNECTION_KEEP_ALIVE */
2331
2332          /*
2333           * This is guaranteed by allocating with zalloc_or_die()
2334           * and never (intentionally) writing to the last byte.
2335           *
2336           * receive_buffer_size is the size of the part of the
2337           * buffer we intentionally write to, but we actually
2338           * allocated receive_buffer_size+1 bytes so the assertion
2339           * stays within the allocated range.
2340           */
2341          assert(receive_buffer[receive_buffer_size] == '\0');
2342
2343          /*
2344           * Add a trailing zero to let be able to use string operations.
2345           * XXX: do we still need this with filter_popups gone?
2346           */
2347          assert(len <= receive_buffer_size);
2348          receive_buffer[len] = '\0';
2349
2350          /*
2351           * Normally, this would indicate that we've read
2352           * as much as the server has sent us and we can
2353           * close the client connection.  However, Microsoft
2354           * in its wisdom has released IIS/5 with a bug that
2355           * prevents it from sending the trailing \r\n in
2356           * a 302 redirect header (and possibly other headers).
2357           * To work around this if we've haven't parsed
2358           * a full header we'll append a trailing \r\n
2359           * and see if this now generates a valid one.
2360           *
2361           * This hack shouldn't have any impacts.  If we've
2362           * already transmitted the header or if this is a
2363           * SSL connection, then we won't bother with this
2364           * hack.  So we only work on partially received
2365           * headers.  If we append a \r\n and this still
2366           * doesn't generate a valid header, then we won't
2367           * transmit anything to the client.
2368           */
2369          if (len == 0)
2370          {
2371
2372             if (server_body || http->ssl)
2373             {
2374                /*
2375                 * If we have been buffering up the document,
2376                 * now is the time to apply content modification
2377                 * and send the result to the client.
2378                 */
2379                if (buffer_and_filter_content)
2380                {
2381                   p = execute_content_filters(csp);
2382                   /*
2383                    * If content filtering fails, use the original
2384                    * buffer and length.
2385                    * (see p != NULL ? p : csp->iob->cur below)
2386                    */
2387                   if (NULL == p)
2388                   {
2389                      csp->content_length = (size_t)(csp->iob->eod - csp->iob->cur);
2390                   }
2391 #ifdef FEATURE_COMPRESSION
2392                   else if ((csp->flags & CSP_FLAG_CLIENT_SUPPORTS_DEFLATE)
2393                      && (csp->content_length > LOWER_LENGTH_LIMIT_FOR_COMPRESSION))
2394                   {
2395                      char *compressed_content = compress_buffer(p,
2396                         (size_t *)&csp->content_length, csp->config->compression_level);
2397                      if (compressed_content != NULL)
2398                      {
2399                         freez(p);
2400                         p = compressed_content;
2401                         csp->flags |= CSP_FLAG_BUFFERED_CONTENT_DEFLATED;
2402                      }
2403                   }
2404 #endif
2405
2406                   if (JB_ERR_OK != update_server_headers(csp))
2407                   {
2408                      log_error(LOG_LEVEL_FATAL,
2409                         "Failed to update server headers. after filtering.");
2410                   }
2411
2412                   hdr = list_to_text(csp->headers);
2413                   if (hdr == NULL)
2414                   {
2415                      /* FIXME Should handle error properly */
2416                      log_error(LOG_LEVEL_FATAL, "Out of memory parsing server header");
2417                   }
2418
2419                   if (write_socket(csp->cfd, hdr, strlen(hdr))
2420                    || write_socket(csp->cfd,
2421                          ((p != NULL) ? p : csp->iob->cur), (size_t)csp->content_length))
2422                   {
2423                      log_error(LOG_LEVEL_ERROR, "write modified content to client failed: %E");
2424                      freez(hdr);
2425                      freez(p);
2426                      mark_server_socket_tainted(csp);
2427                      freez(receive_buffer);
2428                      return;
2429                   }
2430
2431                   freez(hdr);
2432                   freez(p);
2433                }
2434
2435                break; /* "game over, man" */
2436             }
2437
2438             /*
2439              * This is NOT the body, so
2440              * Let's pretend the server just sent us a blank line.
2441              */
2442             snprintf(receive_buffer, receive_buffer_size, "\r\n");
2443             len = (int)strlen(receive_buffer);
2444
2445             /*
2446              * Now, let the normal header parsing algorithm below do its
2447              * job.  If it fails, we'll exit instead of continuing.
2448              */
2449
2450             ms_iis5_hack = 1;
2451          }
2452
2453          /*
2454           * If this is an SSL connection or we're in the body
2455           * of the server document, just write it to the client,
2456           * unless we need to buffer the body for later content-filtering
2457           */
2458          if (server_body || http->ssl)
2459          {
2460             if (buffer_and_filter_content)
2461             {
2462                /*
2463                 * If there is no memory left for buffering the content, or the buffer limit
2464                 * has been reached, switch to non-filtering mode, i.e. make & write the
2465                 * header, flush the iob and buf, and get out of the way.
2466                 */
2467                if (add_to_iob(csp->iob, csp->config->buffer_limit, receive_buffer, len))
2468                {
2469                   size_t hdrlen;
2470                   long flushed;
2471
2472                   log_error(LOG_LEVEL_INFO,
2473                      "Flushing header and buffers. Stepping back from filtering.");
2474
2475                   hdr = list_to_text(csp->headers);
2476                   if (hdr == NULL)
2477                   {
2478                      /*
2479                       * Memory is too tight to even generate the header.
2480                       * Send our static "Out-of-memory" page.
2481                       */
2482                      log_error(LOG_LEVEL_ERROR, "Out of memory while trying to flush.");
2483                      rsp = cgi_error_memory();
2484                      send_crunch_response(csp, rsp);
2485                      mark_server_socket_tainted(csp);
2486                      freez(receive_buffer);
2487                      return;
2488                   }
2489                   hdrlen = strlen(hdr);
2490
2491                   if (write_socket(csp->cfd, hdr, hdrlen)
2492                    || ((flushed = flush_socket(csp->cfd, csp->iob)) < 0)
2493                    || (write_socket(csp->cfd, receive_buffer, (size_t)len)))
2494                   {
2495                      log_error(LOG_LEVEL_CONNECT,
2496                         "Flush header and buffers to client failed: %E");
2497                      freez(hdr);
2498                      mark_server_socket_tainted(csp);
2499                      freez(receive_buffer);
2500                      return;
2501                   }
2502
2503                   /*
2504                    * Reset the byte_count to the amount of bytes
2505                    * we just flushed. len will be added a few lines below,
2506                    * hdrlen doesn't matter for LOG_LEVEL_CLF.
2507                    */
2508                   byte_count = (unsigned long long)flushed;
2509                   freez(hdr);
2510                   buffer_and_filter_content = 0;
2511                   server_body = 1;
2512                }
2513             }
2514             else
2515             {
2516                if (write_socket(csp->cfd, receive_buffer, (size_t)len))
2517                {
2518                   log_error(LOG_LEVEL_ERROR, "write to client failed: %E");
2519                   mark_server_socket_tainted(csp);
2520                   freez(receive_buffer);
2521                   return;
2522                }
2523             }
2524             byte_count += (unsigned long long)len;
2525             continue;
2526          }
2527          else
2528          {
2529             /*
2530              * We're still looking for the end of the server's header.
2531              * Buffer up the data we just read.  If that fails, there's
2532              * little we can do but send our static out-of-memory page.
2533              */
2534             if (add_to_iob(csp->iob, csp->config->buffer_limit, receive_buffer, len))
2535             {
2536                log_error(LOG_LEVEL_ERROR, "Out of memory while looking for end of server headers.");
2537                rsp = cgi_error_memory();
2538                send_crunch_response(csp, rsp);
2539                mark_server_socket_tainted(csp);
2540                freez(receive_buffer);
2541                return;
2542             }
2543
2544             /* Convert iob into something sed() can digest */
2545             if (JB_ERR_PARSE == get_server_headers(csp))
2546             {
2547                if (ms_iis5_hack)
2548                {
2549                   /*
2550                    * Well, we tried our MS IIS/5 hack and it didn't work.
2551                    * The header is incomplete and there isn't anything
2552                    * we can do about it.
2553                    */
2554                   log_error(LOG_LEVEL_ERROR, "Invalid server headers. "
2555                      "Applying the MS IIS5 hack didn't help.");
2556                   log_error(LOG_LEVEL_CLF,
2557                      "%s - - [%T] \"%s\" 502 0", csp->ip_addr_str, http->cmd);
2558                   write_socket(csp->cfd, INVALID_SERVER_HEADERS_RESPONSE,
2559                      strlen(INVALID_SERVER_HEADERS_RESPONSE));
2560                   mark_server_socket_tainted(csp);
2561                   freez(receive_buffer);
2562                   return;
2563                }
2564                else
2565                {
2566                   /*
2567                    * Since we have to wait for more from the server before
2568                    * we can parse the headers we just continue here.
2569                    */
2570                   log_error(LOG_LEVEL_CONNECT,
2571                      "Continuing buffering server headers from socket %d. "
2572                      "Bytes most recently read: %d.", csp->cfd, len);
2573                   continue;
2574                }
2575             }
2576             else
2577             {
2578                /*
2579                 * Account for the content bytes we
2580                 * might have gotten with the headers.
2581                 */
2582                assert(csp->iob->eod >= csp->iob->cur);
2583                byte_count = (unsigned long long)(csp->iob->eod - csp->iob->cur);
2584             }
2585
2586             /* Did we actually get anything? */
2587             if (NULL == csp->headers->first)
2588             {
2589                if ((csp->flags & CSP_FLAG_REUSED_CLIENT_CONNECTION))
2590                {
2591                   log_error(LOG_LEVEL_ERROR,
2592                      "No server or forwarder response received on socket %d. "
2593                      "Closing client socket %d without sending data.",
2594                      csp->server_connection.sfd, csp->cfd);
2595                   log_error(LOG_LEVEL_CLF,
2596                      "%s - - [%T] \"%s\" 502 0", csp->ip_addr_str, http->cmd);
2597                }
2598                else
2599                {
2600                   log_error(LOG_LEVEL_ERROR,
2601                      "No server or forwarder response received on socket %d.",
2602                      csp->server_connection.sfd);
2603                   send_crunch_response(csp, error_response(csp, "no-server-data"));
2604                }
2605                free_http_request(http);
2606                mark_server_socket_tainted(csp);
2607                freez(receive_buffer);
2608                return;
2609             }
2610
2611             assert(csp->headers->first->str);
2612             assert(!http->ssl);
2613             if (strncmpic(csp->headers->first->str, "HTTP", 4) &&
2614                 strncmpic(csp->headers->first->str, "ICY", 3))
2615             {
2616                /*
2617                 * It doesn't look like a HTTP (or Shoutcast) response:
2618                 * tell the client and log the problem.
2619                 */
2620                if (strlen(csp->headers->first->str) > 30)
2621                {
2622                   csp->headers->first->str[30] = '\0';
2623                }
2624                log_error(LOG_LEVEL_ERROR,
2625                   "Invalid server or forwarder response. Starts with: %s",
2626                   csp->headers->first->str);
2627                log_error(LOG_LEVEL_CLF,
2628                   "%s - - [%T] \"%s\" 502 0", csp->ip_addr_str, http->cmd);
2629                write_socket(csp->cfd, INVALID_SERVER_HEADERS_RESPONSE,
2630                   strlen(INVALID_SERVER_HEADERS_RESPONSE));
2631                free_http_request(http);
2632                mark_server_socket_tainted(csp);
2633                return;
2634             }
2635
2636             /*
2637              * We have now received the entire server header,
2638              * filter it and send the result to the client
2639              */
2640             if (JB_ERR_OK != sed(csp, FILTER_SERVER_HEADERS))
2641             {
2642                log_error(LOG_LEVEL_CLF,
2643                   "%s - - [%T] \"%s\" 502 0", csp->ip_addr_str, http->cmd);
2644                write_socket(csp->cfd, INVALID_SERVER_HEADERS_RESPONSE,
2645                   strlen(INVALID_SERVER_HEADERS_RESPONSE));
2646                free_http_request(http);
2647                mark_server_socket_tainted(csp);
2648                freez(receive_buffer);
2649                return;
2650             }
2651             hdr = list_to_text(csp->headers);
2652             if (hdr == NULL)
2653             {
2654                /* FIXME Should handle error properly */
2655                log_error(LOG_LEVEL_FATAL, "Out of memory parsing server header");
2656             }
2657
2658             if ((csp->flags & CSP_FLAG_CHUNKED)
2659                && !(csp->flags & CSP_FLAG_CONTENT_LENGTH_SET)
2660                && ((csp->iob->eod - csp->iob->cur) >= 5)
2661                && !memcmp(csp->iob->eod-5, "0\r\n\r\n", 5))
2662             {
2663                log_error(LOG_LEVEL_CONNECT,
2664                   "Looks like we got the last chunk together with "
2665                   "the server headers. We better stop reading.");
2666                byte_count = (unsigned long long)(csp->iob->eod - csp->iob->cur);
2667                csp->expected_content_length = byte_count;
2668                csp->flags |= CSP_FLAG_CONTENT_LENGTH_SET;
2669             }
2670
2671             csp->server_connection.response_received = time(NULL);
2672
2673             if (crunch_response_triggered(csp, crunchers_light))
2674             {
2675                /*
2676                 * One of the tags created by a server-header
2677                 * tagger triggered a crunch. We already
2678                 * delivered the crunch response to the client
2679                 * and are done here after cleaning up.
2680                 */
2681                freez(hdr);
2682                mark_server_socket_tainted(csp);
2683                freez(receive_buffer);
2684                return;
2685             }
2686             /* Buffer and pcrs filter this if appropriate. */
2687
2688             if (!http->ssl) /* We talk plaintext */
2689             {
2690                buffer_and_filter_content = content_requires_filtering(csp);
2691             }
2692             /*
2693              * Only write if we're not buffering for content modification
2694              */
2695             if (!buffer_and_filter_content)
2696             {
2697                /*
2698                 * Write the server's (modified) header to
2699                 * the client (along with anything else that
2700                 * may be in the buffer)
2701                 */
2702
2703                if (write_socket(csp->cfd, hdr, strlen(hdr))
2704                 || ((len = flush_socket(csp->cfd, csp->iob)) < 0))
2705                {
2706                   log_error(LOG_LEVEL_CONNECT, "write header to client failed: %E");
2707
2708                   /*
2709                    * The write failed, so don't bother mentioning it
2710                    * to the client... it probably can't hear us anyway.
2711                    */
2712                   freez(hdr);
2713                   mark_server_socket_tainted(csp);
2714                   freez(receive_buffer);
2715                   return;
2716                }
2717             }
2718
2719             /* we're finished with the server's header */
2720
2721             freez(hdr);
2722             server_body = 1;
2723
2724             /*
2725              * If this was a MS IIS/5 hack then it means the server
2726              * has already closed the connection. Nothing more to read.
2727              * Time to bail.
2728              */
2729             if (ms_iis5_hack)
2730             {
2731                log_error(LOG_LEVEL_ERROR,
2732                   "Closed server connection detected. "
2733                   "Applying the MS IIS5 hack didn't help.");
2734                log_error(LOG_LEVEL_CLF,
2735                   "%s - - [%T] \"%s\" 502 0", csp->ip_addr_str, http->cmd);
2736                write_socket(csp->cfd, INVALID_SERVER_HEADERS_RESPONSE,
2737                   strlen(INVALID_SERVER_HEADERS_RESPONSE));
2738                mark_server_socket_tainted(csp);
2739                freez(receive_buffer);
2740                return;
2741             }
2742          }
2743          continue;
2744       }
2745       mark_server_socket_tainted(csp);
2746       freez(receive_buffer);
2747       return; /* huh? we should never get here */
2748    }
2749    freez(receive_buffer);
2750
2751    if (csp->content_length == 0)
2752    {
2753       /*
2754        * If Privoxy didn't recalculate the Content-Length,
2755        * byte_count is still correct.
2756        */
2757       csp->content_length = byte_count;
2758    }
2759
2760 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2761    if ((csp->flags & CSP_FLAG_CONTENT_LENGTH_SET)
2762       && (csp->expected_content_length != byte_count))
2763    {
2764       log_error(LOG_LEVEL_CONNECT,
2765          "Received %llu bytes while expecting %llu.",
2766          byte_count, csp->expected_content_length);
2767       mark_server_socket_tainted(csp);
2768    }
2769 #endif
2770
2771    log_error(LOG_LEVEL_CLF, "%s - - [%T] \"%s\" 200 %llu",
2772       csp->ip_addr_str, http->ocmd, csp->content_length);
2773
2774    csp->server_connection.timestamp = time(NULL);
2775 }
2776
2777
2778 /*********************************************************************
2779  *
2780  * Function    :  chat
2781  *
2782  * Description :  Once a connection from the client has been accepted,
2783  *                this function is called (via serve()) to handle the
2784  *                main business of the communication.  This function
2785  *                returns after dealing with a single request. It can
2786  *                be called multiple times with the same client socket
2787  *                if the client is keeping the connection alive.
2788  *
2789  *                The decision whether or not a client connection will
2790  *                be kept alive is up to the caller which also must
2791  *                close the client socket when done.
2792  *
2793  *                FIXME: chat is nearly thousand lines long.
2794  *                Ridiculous.
2795  *
2796  * Parameters  :
2797  *          1  :  csp = Current client state (buffers, headers, etc...)
2798  *
2799  * Returns     :  Nothing.
2800  *
2801  *********************************************************************/
2802 static void chat(struct client_state *csp)
2803 {
2804    const struct forward_spec *fwd;
2805    struct http_request *http;
2806    /* Skeleton for HTTP response, if we should intercept the request */
2807    struct http_response *rsp;
2808
2809    http = csp->http;
2810
2811    if (receive_client_request(csp) != JB_ERR_OK)
2812    {
2813       return;
2814    }
2815    if (parse_client_request(csp) != JB_ERR_OK)
2816    {
2817       return;
2818    }
2819
2820    /* decide how to route the HTTP request */
2821    fwd = forward_url(csp, http);
2822    if (NULL == fwd)
2823    {
2824       log_error(LOG_LEVEL_FATAL, "gateway spec is NULL!?!?  This can't happen!");
2825       /* Never get here - LOG_LEVEL_FATAL causes program exit */
2826       return;
2827    }
2828
2829    /*
2830     * build the http request to send to the server
2831     * we have to do one of the following:
2832     *
2833     * create = use the original HTTP request to create a new
2834     *          HTTP request that has either the path component
2835     *          without the http://domainspec (w/path) or the
2836     *          full orininal URL (w/url)
2837     *          Note that the path and/or the HTTP version may
2838     *          have been altered by now.
2839     *
2840     * connect = Open a socket to the host:port of the server
2841     *           and short-circuit server and client socket.
2842     *
2843     * pass =  Pass the request unchanged if forwarding a CONNECT
2844     *         request to a parent proxy. Note that we'll be sending
2845     *         the CFAIL message ourselves if connecting to the parent
2846     *         fails, but we won't send a CSUCCEED message if it works,
2847     *         since that would result in a double message (ours and the
2848     *         parent's). After sending the request to the parent, we simply
2849     *         tunnel.
2850     *
2851     * here's the matrix:
2852     *                        SSL
2853     *                    0        1
2854     *                +--------+--------+
2855     *                |        |        |
2856     *             0  | create | connect|
2857     *                | w/path |        |
2858     *  Forwarding    +--------+--------+
2859     *                |        |        |
2860     *             1  | create | pass   |
2861     *                | w/url  |        |
2862     *                +--------+--------+
2863     *
2864     */
2865
2866    if (http->ssl && connect_port_is_forbidden(csp))
2867    {
2868       const char *acceptable_connect_ports =
2869          csp->action->string[ACTION_STRING_LIMIT_CONNECT];
2870       assert(NULL != acceptable_connect_ports);
2871       log_error(LOG_LEVEL_INFO, "Request from %s marked for blocking. "
2872          "limit-connect{%s} doesn't allow CONNECT requests to %s",
2873          csp->ip_addr_str, acceptable_connect_ports, csp->http->hostport);
2874       csp->action->flags |= ACTION_BLOCK;
2875       http->ssl = 0;
2876    }
2877
2878    if (http->ssl == 0)
2879    {
2880       freez(csp->headers->first->str);
2881       build_request_line(csp, fwd, &csp->headers->first->str);
2882    }
2883
2884    /*
2885     * We have a request. Check if one of the crunchers wants it.
2886     */
2887    if (crunch_response_triggered(csp, crunchers_all))
2888    {
2889       /*
2890        * Yes. The client got the crunch response and we're done here.
2891        */
2892       return;
2893    }
2894
2895    log_applied_actions(csp->action);
2896    log_error(LOG_LEVEL_GPC, "%s%s", http->hostport, http->path);
2897
2898    if (fwd->forward_host)
2899    {
2900       log_error(LOG_LEVEL_CONNECT, "via [%s]:%d to: %s",
2901          fwd->forward_host, fwd->forward_port, http->hostport);
2902    }
2903    else
2904    {
2905       log_error(LOG_LEVEL_CONNECT, "to %s", http->hostport);
2906    }
2907
2908    /* here we connect to the server, gateway, or the forwarder */
2909
2910 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2911    if ((csp->server_connection.sfd != JB_INVALID_SOCKET)
2912       && socket_is_still_alive(csp->server_connection.sfd)
2913       && connection_destination_matches(&csp->server_connection, http, fwd))
2914    {
2915       log_error(LOG_LEVEL_CONNECT,
2916          "Reusing server socket %d connected to %s. Total requests: %u.",
2917          csp->server_connection.sfd, csp->server_connection.host,
2918          csp->server_connection.requests_sent_total);
2919    }
2920    else
2921    {
2922       if (csp->server_connection.sfd != JB_INVALID_SOCKET)
2923       {
2924 #ifdef FEATURE_CONNECTION_SHARING
2925          if (csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
2926          {
2927             remember_connection(&csp->server_connection);
2928          }
2929          else
2930 #endif /* def FEATURE_CONNECTION_SHARING */
2931          {
2932             log_error(LOG_LEVEL_CONNECT,
2933                "Closing server socket %d connected to %s. Total requests: %u.",
2934                csp->server_connection.sfd, csp->server_connection.host,
2935                csp->server_connection.requests_sent_total);
2936             close_socket(csp->server_connection.sfd);
2937          }
2938          mark_connection_closed(&csp->server_connection);
2939       }
2940 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2941
2942       csp->server_connection.sfd = forwarded_connect(fwd, http, csp);
2943
2944       if (csp->server_connection.sfd == JB_INVALID_SOCKET)
2945       {
2946          if (fwd->type != SOCKS_NONE)
2947          {
2948             /* Socks error. */
2949             rsp = error_response(csp, "forwarding-failed");
2950          }
2951          else if (errno == EINVAL)
2952          {
2953             rsp = error_response(csp, "no-such-domain");
2954          }
2955          else
2956          {
2957             rsp = error_response(csp, "connect-failed");
2958          }
2959
2960          /* Write the answer to the client */
2961          if (rsp != NULL)
2962          {
2963             send_crunch_response(csp, rsp);
2964          }
2965
2966          /*
2967           * Temporary workaround to prevent already-read client
2968           * bodies from being parsed as new requests. For now we
2969           * err on the safe side and throw all the following
2970           * requests under the bus, even if no client body has been
2971           * buffered. A compliant client will repeat the dropped
2972           * requests on an untainted connection.
2973           *
2974           * The proper fix is to discard the no longer needed
2975           * client body in the buffer (if there is one) and to
2976           * continue parsing the bytes that follow.
2977           */
2978          drain_and_close_socket(csp->cfd);
2979          csp->cfd = JB_INVALID_SOCKET;
2980
2981          return;
2982       }
2983 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2984       save_connection_destination(csp->server_connection.sfd,
2985          http, fwd, &csp->server_connection);
2986       csp->server_connection.keep_alive_timeout =
2987          (unsigned)csp->config->keep_alive_timeout;
2988    }
2989 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2990
2991    csp->server_connection.requests_sent_total++;
2992
2993    if ((fwd->type == SOCKS_5T) && (NULL == csp->headers->first))
2994    {
2995       /* Client headers have been sent optimistically */
2996       assert(csp->headers->last == NULL);
2997    }
2998    else if (fwd->forward_host || (http->ssl == 0))
2999    {
3000       if (send_http_request(csp))
3001       {
3002          rsp = error_response(csp, "connect-failed");
3003          if (rsp)
3004          {
3005             send_crunch_response(csp, rsp);
3006          }
3007          return;
3008       }
3009    }
3010    else
3011    {
3012       /*
3013        * We're running an SSL tunnel and we're not forwarding,
3014        * so just ditch the client headers, send the "connect succeeded"
3015        * message to the client, flush the rest, and get out of the way.
3016        */
3017       list_remove_all(csp->headers);
3018       if (write_socket(csp->cfd, CSUCCEED, strlen(CSUCCEED)))
3019       {
3020          return;
3021       }
3022       clear_iob(csp->client_iob);
3023    }
3024
3025    log_error(LOG_LEVEL_CONNECT, "to %s successful", http->hostport);
3026
3027    /* XXX: should the time start earlier for optimistically sent data? */
3028    csp->server_connection.request_sent = time(NULL);
3029
3030    handle_established_connection(csp, fwd);
3031 }
3032
3033
3034 #ifdef FUZZ
3035 /*********************************************************************
3036  *
3037  * Function    :  fuzz_server_response
3038  *
3039  * Description :  Treat the input as a whole server response.
3040  *
3041  * Parameters  :
3042  *          1  :  csp = Current client state (buffers, headers, etc...)
3043  *          2  :  fuzz_input_file = File to read the input from.
3044  *
3045  * Returns     :  0
3046  *
3047  *********************************************************************/
3048 extern int fuzz_server_response(struct client_state *csp, char *fuzz_input_file)
3049 {
3050    static struct forward_spec fwd; /* Zero'd due to being static */
3051    csp->cfd = 0;
3052
3053    if (strcmp(fuzz_input_file, "-") == 0)
3054    {
3055       /* XXX: Doesn'T work yet. */
3056       csp->server_connection.sfd = 0;
3057    }
3058    else
3059    {
3060       csp->server_connection.sfd = open(fuzz_input_file, O_RDONLY);
3061       if (csp->server_connection.sfd == -1)
3062       {
3063          log_error(LOG_LEVEL_FATAL, "Failed to open %s: %E",
3064             fuzz_input_file);
3065       }
3066    }
3067    csp->content_type |= CT_GIF;
3068    csp->action->flags |= ACTION_DEANIMATE;
3069    csp->action->string[ACTION_STRING_DEANIMATE] = "last";
3070
3071    csp->http->path = strdup_or_die("/");
3072    csp->http->host = strdup_or_die("fuzz.example.org");
3073    csp->http->hostport = strdup_or_die("fuzz.example.org:80");
3074    /* Prevent client socket monitoring */
3075    csp->flags |= CSP_FLAG_PIPELINED_REQUEST_WAITING;
3076    csp->flags |= CSP_FLAG_CHUNKED;
3077
3078    csp->config->feature_flags |= RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE;
3079    csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
3080
3081    csp->content_type |= CT_DECLARED|CT_GIF;
3082
3083    csp->config->socket_timeout = 0;
3084
3085    cgi_init_error_messages();
3086
3087    handle_established_connection(csp, &fwd);
3088
3089    return 0;
3090 }
3091 #endif
3092
3093
3094 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
3095 /*********************************************************************
3096  *
3097  * Function    :  prepare_csp_for_next_request
3098  *
3099  * Description :  Put the csp in a mostly vergin state.
3100  *
3101  * Parameters  :
3102  *          1  :  csp = Current client state (buffers, headers, etc...)
3103  *
3104  * Returns     :  N/A
3105  *
3106  *********************************************************************/
3107 static void prepare_csp_for_next_request(struct client_state *csp)
3108 {
3109    csp->content_type = 0;
3110    csp->content_length = 0;
3111    csp->expected_content_length = 0;
3112    csp->expected_client_content_length = 0;
3113    list_remove_all(csp->headers);
3114    clear_iob(csp->iob);
3115    freez(csp->error_message);
3116    free_http_request(csp->http);
3117    destroy_list(csp->headers);
3118    destroy_list(csp->tags);
3119 #ifdef FEATURE_CLIENT_TAGS
3120    destroy_list(csp->client_tags);
3121    freez(csp->client_address);
3122 #endif
3123    free_current_action(csp->action);
3124    if (NULL != csp->fwd)
3125    {
3126       unload_forward_spec(csp->fwd);
3127       csp->fwd = NULL;
3128    }
3129    /* XXX: Store per-connection flags someplace else. */
3130    csp->flags = (CSP_FLAG_ACTIVE | CSP_FLAG_REUSED_CLIENT_CONNECTION);
3131 #ifdef FEATURE_TOGGLE
3132    if (global_toggle_state)
3133 #endif /* def FEATURE_TOGGLE */
3134    {
3135       csp->flags |= CSP_FLAG_TOGGLED_ON;
3136    }
3137
3138    if (csp->client_iob->eod > csp->client_iob->cur)
3139    {
3140       long bytes_to_shift = csp->client_iob->cur - csp->client_iob->buf;
3141       size_t data_length  = (size_t)(csp->client_iob->eod - csp->client_iob->cur);
3142
3143       assert(bytes_to_shift > 0);
3144       assert(data_length > 0);
3145
3146       log_error(LOG_LEVEL_CONNECT, "Shifting %d pipelined bytes by %d bytes",
3147          data_length, bytes_to_shift);
3148       memmove(csp->client_iob->buf, csp->client_iob->cur, data_length);
3149       csp->client_iob->cur = csp->client_iob->buf;
3150       assert(csp->client_iob->eod == csp->client_iob->buf + bytes_to_shift + data_length);
3151       csp->client_iob->eod = csp->client_iob->buf + data_length;
3152       memset(csp->client_iob->eod, '\0', (size_t)bytes_to_shift);
3153
3154       csp->flags |= CSP_FLAG_PIPELINED_REQUEST_WAITING;
3155    }
3156    else
3157    {
3158       /*
3159        * We mainly care about resetting client_iob->cur so we don't
3160        * waste buffer space at the beginning and don't mess up the
3161        * request restoration done by cgi_show_request().
3162        *
3163        * Freeing the buffer itself isn't technically necessary,
3164        * but makes debugging more convenient.
3165        */
3166       clear_iob(csp->client_iob);
3167    }
3168 }
3169 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
3170
3171
3172 /*********************************************************************
3173  *
3174  * Function    :  serve
3175  *
3176  * Description :  This is little more than chat.  We only "serve" to
3177  *                to close (or remember) any socket that chat may have
3178  *                opened.
3179  *
3180  * Parameters  :
3181  *          1  :  csp = Current client state (buffers, headers, etc...)
3182  *
3183  * Returns     :  N/A
3184  *
3185  *********************************************************************/
3186 #ifdef AMIGA
3187 void serve(struct client_state *csp)
3188 #else /* ifndef AMIGA */
3189 static void serve(struct client_state *csp)
3190 #endif /* def AMIGA */
3191 {
3192    int config_file_change_detected = 0; /* Only used for debugging */
3193 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
3194 #ifdef FEATURE_CONNECTION_SHARING
3195    static int monitor_thread_running = 0;
3196 #endif /* def FEATURE_CONNECTION_SHARING */
3197    int continue_chatting = 0;
3198
3199    log_error(LOG_LEVEL_CONNECT, "Accepted connection from %s on socket %d",
3200       csp->ip_addr_str, csp->cfd);
3201
3202    do
3203    {
3204       unsigned int latency;
3205
3206       chat(csp);
3207
3208       /*
3209        * If the request has been crunched,
3210        * the calculated latency is zero.
3211        */
3212       latency = (unsigned)(csp->server_connection.response_received -
3213          csp->server_connection.request_sent) / 2;
3214
3215       if ((csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
3216          && (csp->flags & CSP_FLAG_CRUNCHED)
3217          && (csp->expected_client_content_length != 0))
3218       {
3219          csp->flags |= CSP_FLAG_SERVER_SOCKET_TAINTED;
3220          log_error(LOG_LEVEL_CONNECT,
3221             "Tainting client socket %d due to unread data.", csp->cfd);
3222       }
3223
3224       continue_chatting = (csp->config->feature_flags
3225          & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
3226          && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
3227          && (csp->cfd != JB_INVALID_SOCKET)
3228          && (csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
3229          && ((csp->flags & CSP_FLAG_SERVER_CONTENT_LENGTH_SET)
3230             || (csp->flags & CSP_FLAG_CHUNKED));
3231
3232       if (!(csp->flags & CSP_FLAG_CRUNCHED)
3233          && (csp->server_connection.sfd != JB_INVALID_SOCKET))
3234       {
3235          if (!(csp->flags & CSP_FLAG_SERVER_KEEP_ALIVE_TIMEOUT_SET))
3236          {
3237             csp->server_connection.keep_alive_timeout = csp->config->default_server_timeout;
3238          }
3239          if (!(csp->flags & CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE)
3240             || (csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
3241             || !socket_is_still_alive(csp->server_connection.sfd)
3242             || !(latency < csp->server_connection.keep_alive_timeout))
3243          {
3244             log_error(LOG_LEVEL_CONNECT,
3245                "Closing server socket %d connected to %s. "
3246                "Keep-alive %u. Tainted: %u. Socket alive %u. Timeout: %u.",
3247                csp->server_connection.sfd, csp->server_connection.host,
3248                0 != (csp->flags & CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE),
3249                0 != (csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED),
3250                socket_is_still_alive(csp->server_connection.sfd),
3251                csp->server_connection.keep_alive_timeout);
3252 #ifdef FEATURE_CONNECTION_SHARING
3253             if (csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
3254             {
3255                forget_connection(csp->server_connection.sfd);
3256             }
3257 #endif /* def FEATURE_CONNECTION_SHARING */
3258             close_socket(csp->server_connection.sfd);
3259             mark_connection_closed(&csp->server_connection);
3260          }
3261       }
3262
3263       if (continue_chatting && any_loaded_file_changed(csp))
3264       {
3265          continue_chatting = 0;
3266          config_file_change_detected = 1;
3267       }
3268
3269       if (continue_chatting)
3270       {
3271          if (((csp->flags & CSP_FLAG_PIPELINED_REQUEST_WAITING) != 0)
3272             && socket_is_still_alive(csp->cfd))
3273          {
3274             log_error(LOG_LEVEL_CONNECT, "Client request %d has been "
3275                "pipelined on socket %d and the socket is still alive.",
3276                csp->requests_received_total+1, csp->cfd);
3277             prepare_csp_for_next_request(csp);
3278             continue;
3279          }
3280
3281          if (0 != (csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE))
3282          {
3283             if (csp->server_connection.sfd != JB_INVALID_SOCKET)
3284             {
3285                log_error(LOG_LEVEL_CONNECT,
3286                   "Waiting for the next client request on socket %d. "
3287                   "Keeping the server socket %d to %s open.",
3288                   csp->cfd, csp->server_connection.sfd, csp->server_connection.host);
3289             }
3290             else
3291             {
3292                log_error(LOG_LEVEL_CONNECT,
3293                   "Waiting for the next client request on socket %d. "
3294                   "No server socket to keep open.", csp->cfd);
3295             }
3296          }
3297
3298          if ((csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
3299             && data_is_available(csp->cfd, (int)csp->config->keep_alive_timeout)
3300             && socket_is_still_alive(csp->cfd))
3301          {
3302             log_error(LOG_LEVEL_CONNECT,
3303                "Client request %u arrived in time on socket %d.",
3304                csp->requests_received_total+1, csp->cfd);
3305             prepare_csp_for_next_request(csp);
3306          }
3307          else
3308          {
3309 #ifdef FEATURE_CONNECTION_SHARING
3310             if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
3311                && (csp->server_connection.sfd != JB_INVALID_SOCKET)
3312                && (socket_is_still_alive(csp->server_connection.sfd)))
3313             {
3314                time_t time_open = time(NULL) - csp->server_connection.timestamp;
3315
3316                if (csp->server_connection.keep_alive_timeout < time_open - (time_t)latency)
3317                {
3318                   break;
3319                }
3320
3321                remember_connection(&csp->server_connection);
3322                csp->server_connection.sfd = JB_INVALID_SOCKET;
3323                drain_and_close_socket(csp->cfd);
3324                csp->cfd = JB_INVALID_SOCKET;
3325                privoxy_mutex_lock(&connection_reuse_mutex);
3326                if (!monitor_thread_running)
3327                {
3328                   monitor_thread_running = 1;
3329                   privoxy_mutex_unlock(&connection_reuse_mutex);
3330                   wait_for_alive_connections();
3331                   privoxy_mutex_lock(&connection_reuse_mutex);
3332                   monitor_thread_running = 0;
3333                }
3334                privoxy_mutex_unlock(&connection_reuse_mutex);
3335             }
3336 #endif /* def FEATURE_CONNECTION_SHARING */
3337             break;
3338          }
3339       }
3340       else if (csp->server_connection.sfd != JB_INVALID_SOCKET)
3341       {
3342          log_error(LOG_LEVEL_CONNECT,
3343             "Closing server socket %d connected to %s. Keep-alive: %u. "
3344             "Tainted: %u. Socket alive: %u. Timeout: %u. "
3345             "Configuration file change detected: %u",
3346             csp->server_connection.sfd, csp->server_connection.host,
3347             0 != (csp->flags & CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE),
3348             0 != (csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED),
3349             socket_is_still_alive(csp->server_connection.sfd),
3350             csp->server_connection.keep_alive_timeout,
3351             config_file_change_detected);
3352       }
3353    } while (continue_chatting);
3354
3355 #else
3356    chat(csp);
3357 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
3358
3359    if (csp->server_connection.sfd != JB_INVALID_SOCKET)
3360    {
3361 #ifdef FEATURE_CONNECTION_SHARING
3362       if (csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
3363       {
3364          forget_connection(csp->server_connection.sfd);
3365       }
3366 #endif /* def FEATURE_CONNECTION_SHARING */
3367       close_socket(csp->server_connection.sfd);
3368    }
3369
3370 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
3371    mark_connection_closed(&csp->server_connection);
3372 #endif
3373
3374    if (csp->cfd != JB_INVALID_SOCKET)
3375    {
3376       log_error(LOG_LEVEL_CONNECT, "Closing client socket %d. "
3377          "Keep-alive: %u. Socket alive: %u. Data available: %u. "
3378          "Configuration file change detected: %u. Requests received: %u.",
3379          csp->cfd, 0 != (csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE),
3380          socket_is_still_alive(csp->cfd), data_is_available(csp->cfd, 0),
3381          config_file_change_detected, csp->requests_received_total);
3382       drain_and_close_socket(csp->cfd);
3383    }
3384
3385    csp->flags &= ~CSP_FLAG_ACTIVE;
3386
3387 }
3388
3389
3390 #ifdef __BEOS__
3391 /*********************************************************************
3392  *
3393  * Function    :  server_thread
3394  *
3395  * Description :  We only exist to call `serve' in a threaded environment.
3396  *
3397  * Parameters  :
3398  *          1  :  data = Current client state (buffers, headers, etc...)
3399  *
3400  * Returns     :  Always 0.
3401  *
3402  *********************************************************************/
3403 static int32 server_thread(void *data)
3404 {
3405    serve((struct client_state *) data);
3406    return 0;
3407
3408 }
3409 #endif
3410
3411
3412 #if !defined(_WIN32) || defined(_WIN_CONSOLE)
3413 /*********************************************************************
3414  *
3415  * Function    :  usage
3416  *
3417  * Description :  Print usage info & exit.
3418  *
3419  * Parameters  :  Pointer to argv[0] for identifying ourselves
3420  *
3421  * Returns     :  No. ,-)
3422  *
3423  *********************************************************************/
3424 static void usage(const char *name)
3425 {
3426    printf("Privoxy version " VERSION " (" HOME_PAGE_URL ")\n"
3427           "Usage: %s [--config-test] "
3428 #if defined(unix)
3429           "[--chroot] "
3430 #endif /* defined(unix) */
3431           "[--help] "
3432 #if defined(unix)
3433           "[--no-daemon] [--pidfile pidfile] [--pre-chroot-nslookup hostname] [--user user[.group]] "
3434 #endif /* defined(unix) */
3435          "[--version] [configfile]\n",
3436           name);
3437
3438 #ifdef FUZZ
3439    show_fuzz_usage(name);
3440 #endif
3441
3442    printf("Aborting\n");
3443
3444    exit(2);
3445
3446 }
3447 #endif /* #if !defined(_WIN32) || defined(_WIN_CONSOLE) */
3448
3449
3450 #ifdef MUTEX_LOCKS_AVAILABLE
3451 /*********************************************************************
3452  *
3453  * Function    :  privoxy_mutex_lock
3454  *
3455  * Description :  Locks a mutex.
3456  *
3457  * Parameters  :
3458  *          1  :  mutex = The mutex to lock.
3459  *
3460  * Returns     :  Void. May exit in case of errors.
3461  *
3462  *********************************************************************/
3463 void privoxy_mutex_lock(privoxy_mutex_t *mutex)
3464 {
3465 #ifdef FEATURE_PTHREAD
3466    int err = pthread_mutex_lock(mutex);
3467    if (err)
3468    {
3469       if (mutex != &log_mutex)
3470       {
3471          log_error(LOG_LEVEL_FATAL,
3472             "Mutex locking failed: %s.\n", strerror(err));
3473       }
3474       exit(1);
3475    }
3476 #else
3477    EnterCriticalSection(mutex);
3478 #endif /* def FEATURE_PTHREAD */
3479 }
3480
3481
3482 /*********************************************************************
3483  *
3484  * Function    :  privoxy_mutex_unlock
3485  *
3486  * Description :  Unlocks a mutex.
3487  *
3488  * Parameters  :
3489  *          1  :  mutex = The mutex to unlock.
3490  *
3491  * Returns     :  Void. May exit in case of errors.
3492  *
3493  *********************************************************************/
3494 void privoxy_mutex_unlock(privoxy_mutex_t *mutex)
3495 {
3496 #ifdef FEATURE_PTHREAD
3497    int err = pthread_mutex_unlock(mutex);
3498    if (err)
3499    {
3500       if (mutex != &log_mutex)
3501       {
3502          log_error(LOG_LEVEL_FATAL,
3503             "Mutex unlocking failed: %s.\n", strerror(err));
3504       }
3505       exit(1);
3506    }
3507 #else
3508    LeaveCriticalSection(mutex);
3509 #endif /* def FEATURE_PTHREAD */
3510 }
3511
3512
3513 /*********************************************************************
3514  *
3515  * Function    :  privoxy_mutex_init
3516  *
3517  * Description :  Prepares a mutex.
3518  *
3519  * Parameters  :
3520  *          1  :  mutex = The mutex to initialize.
3521  *
3522  * Returns     :  Void. May exit in case of errors.
3523  *
3524  *********************************************************************/
3525 static void privoxy_mutex_init(privoxy_mutex_t *mutex)
3526 {
3527 #ifdef FEATURE_PTHREAD
3528    int err = pthread_mutex_init(mutex, 0);
3529    if (err)
3530    {
3531       printf("Fatal error. Mutex initialization failed: %s.\n",
3532          strerror(err));
3533       exit(1);
3534    }
3535 #else
3536    InitializeCriticalSection(mutex);
3537 #endif /* def FEATURE_PTHREAD */
3538 }
3539 #endif /* def MUTEX_LOCKS_AVAILABLE */
3540
3541 /*********************************************************************
3542  *
3543  * Function    :  initialize_mutexes
3544  *
3545  * Description :  Prepares mutexes if mutex support is available.
3546  *
3547  * Parameters  :  None
3548  *
3549  * Returns     :  Void, exits in case of errors.
3550  *
3551  *********************************************************************/
3552 static void initialize_mutexes(void)
3553 {
3554 #ifdef MUTEX_LOCKS_AVAILABLE
3555    /*
3556     * Prepare global mutex semaphores
3557     */
3558    privoxy_mutex_init(&log_mutex);
3559    privoxy_mutex_init(&log_init_mutex);
3560    privoxy_mutex_init(&connection_reuse_mutex);
3561 #ifdef FEATURE_EXTERNAL_FILTERS
3562    privoxy_mutex_init(&external_filter_mutex);
3563 #endif
3564 #ifdef FEATURE_CLIENT_TAGS
3565    privoxy_mutex_init(&client_tags_mutex);
3566 #endif
3567
3568    /*
3569     * XXX: The assumptions below are a bit naive
3570     * and can cause locks that aren't necessary.
3571     *
3572     * For example older FreeBSD versions (< 6.x?)
3573     * have no gethostbyname_r, but gethostbyname is
3574     * thread safe.
3575     */
3576 #if !defined(HAVE_GETHOSTBYADDR_R) || !defined(HAVE_GETHOSTBYNAME_R)
3577    privoxy_mutex_init(&resolver_mutex);
3578 #endif /* !defined(HAVE_GETHOSTBYADDR_R) || !defined(HAVE_GETHOSTBYNAME_R) */
3579    /*
3580     * XXX: should we use a single mutex for
3581     * localtime() and gmtime() as well?
3582     */
3583 #ifndef HAVE_GMTIME_R
3584    privoxy_mutex_init(&gmtime_mutex);
3585 #endif /* ndef HAVE_GMTIME_R */
3586
3587 #ifndef HAVE_LOCALTIME_R
3588    privoxy_mutex_init(&localtime_mutex);
3589 #endif /* ndef HAVE_GMTIME_R */
3590
3591 #if !defined(HAVE_ARC4RANDOM) && !defined(HAVE_RANDOM)
3592    privoxy_mutex_init(&rand_mutex);
3593 #endif /* !defined(HAVE_ARC4RANDOM) && !defined(HAVE_RANDOM) */
3594
3595 #endif /* def MUTEX_LOCKS_AVAILABLE */
3596 }
3597
3598 /*********************************************************************
3599  *
3600  * Function    :  main
3601  *
3602  * Description :  Load the config file and start the listen loop.
3603  *                This function is a lot more *sane* with the `load_config'
3604  *                and `listen_loop' functions; although it stills does
3605  *                a *little* too much for my taste.
3606  *
3607  * Parameters  :
3608  *          1  :  argc = Number of parameters (including $0).
3609  *          2  :  argv = Array of (char *)'s to the parameters.
3610  *
3611  * Returns     :  1 if : can't open config file, unrecognized directive,
3612  *                stats requested in multi-thread mode, can't open the
3613  *                log file, can't open the jar file, listen port is invalid,
3614  *                any load fails, and can't bind port.
3615  *
3616  *                Else main never returns, the process must be signaled
3617  *                to terminate execution.  Or, on Windows, use the
3618  *                "File", "Exit" menu option.
3619  *
3620  *********************************************************************/
3621 #ifdef __MINGW32__
3622 int real_main(int argc, char **argv)
3623 #else
3624 int main(int argc, char **argv)
3625 #endif
3626 {
3627    int argc_pos = 0;
3628    int do_config_test = 0;
3629 #ifndef HAVE_ARC4RANDOM
3630    unsigned int random_seed;
3631 #endif
3632 #ifdef unix
3633    struct passwd *pw = NULL;
3634    struct group *grp = NULL;
3635    int do_chroot = 0;
3636    char *pre_chroot_nslookup_to_load_resolver = NULL;
3637 #endif
3638 #ifdef FUZZ
3639    char *fuzz_input_type = NULL;
3640    char *fuzz_input_file = NULL;
3641 #endif
3642
3643    Argc = argc;
3644    Argv = argv;
3645
3646    configfile =
3647 #if !defined(_WIN32)
3648    "config"
3649 #else
3650    "config.txt"
3651 #endif
3652       ;
3653
3654    /* Prepare mutexes if supported and necessary. */
3655    initialize_mutexes();
3656
3657    /* Enable logging until further notice. */
3658    init_log_module();
3659
3660    /*
3661     * Parse the command line arguments
3662     *
3663     * XXX: simply printing usage information in case of
3664     * invalid arguments isn't particularly user friendly.
3665     */
3666    while (++argc_pos < argc)
3667    {
3668 #ifdef _WIN32
3669       /* Check to see if the service must be installed or uninstalled */
3670       if (strncmp(argv[argc_pos], "--install", 9) == 0)
3671       {
3672          const char *pName = argv[argc_pos] + 9;
3673          if (*pName == ':')
3674             pName++;
3675          exit((install_service(pName)) ? 0 : 1);
3676       }
3677       else if (strncmp(argv[argc_pos], "--uninstall", 11) == 0)
3678       {
3679          const char *pName = argv[argc_pos] + 11;
3680          if (*pName == ':')
3681             pName++;
3682          exit((uninstall_service(pName)) ? 0 : 1);
3683       }
3684       else if (strcmp(argv[argc_pos], "--service") == 0)
3685       {
3686          bRunAsService = TRUE;
3687          w32_set_service_cwd();
3688          atexit(w32_service_exit_notify);
3689       }
3690       else
3691 #endif /* defined(_WIN32) */
3692
3693
3694 #if !defined(_WIN32) || defined(_WIN_CONSOLE)
3695
3696       if (strcmp(argv[argc_pos], "--help") == 0)
3697       {
3698          usage(argv[0]);
3699       }
3700
3701       else if (strcmp(argv[argc_pos], "--version") == 0)
3702       {
3703          printf("Privoxy version " VERSION " (" HOME_PAGE_URL ")\n");
3704          exit(0);
3705       }
3706
3707 #if defined(unix)
3708
3709       else if (strcmp(argv[argc_pos], "--no-daemon") == 0)
3710       {
3711          set_debug_level(LOG_LEVEL_FATAL | LOG_LEVEL_ERROR | LOG_LEVEL_INFO);
3712          daemon_mode = 0;
3713       }
3714
3715       else if (strcmp(argv[argc_pos], "--pidfile") == 0)
3716       {
3717          if (++argc_pos == argc) usage(argv[0]);
3718          pidfile = strdup_or_die(argv[argc_pos]);
3719       }
3720
3721       else if (strcmp(argv[argc_pos], "--user") == 0)
3722       {
3723          char *user_arg;
3724          char *group_name;
3725
3726          if (++argc_pos == argc) usage(argv[argc_pos]);
3727
3728          user_arg = strdup_or_die(argv[argc_pos]);
3729          group_name = strchr(user_arg, '.');
3730          if (NULL != group_name)
3731          {
3732             /* Nul-terminate the user name */
3733             *group_name = '\0';
3734
3735             /* Skip the former delimiter to actually reach the group name */
3736             group_name++;
3737
3738             grp = getgrnam(group_name);
3739             if (NULL == grp)
3740             {
3741                log_error(LOG_LEVEL_FATAL, "Group '%s' not found.", group_name);
3742             }
3743          }
3744          pw = getpwnam(user_arg);
3745          if (NULL == pw)
3746          {
3747             log_error(LOG_LEVEL_FATAL, "User '%s' not found.", user_arg);
3748          }
3749
3750          freez(user_arg);
3751       }
3752
3753       else if (strcmp(argv[argc_pos], "--pre-chroot-nslookup") == 0)
3754       {
3755          if (++argc_pos == argc) usage(argv[0]);
3756          pre_chroot_nslookup_to_load_resolver = strdup_or_die(argv[argc_pos]);
3757       }
3758
3759       else if (strcmp(argv[argc_pos], "--chroot") == 0)
3760       {
3761          do_chroot = 1;
3762       }
3763 #endif /* defined(unix) */
3764
3765       else if (strcmp(argv[argc_pos], "--config-test") == 0)
3766       {
3767          do_config_test = 1;
3768       }
3769 #ifdef FUZZ
3770       else if (strcmp(argv[argc_pos], "--fuzz") == 0)
3771       {
3772          argc_pos++;
3773          if (argc < argc_pos + 2) usage(argv[0]);
3774          fuzz_input_type = argv[argc_pos];
3775          argc_pos++;
3776          fuzz_input_file = argv[argc_pos];
3777       }
3778       else if (strcmp(argv[argc_pos], "--stfu") == 0)
3779       {
3780          set_debug_level(LOG_LEVEL_STFU);
3781       }
3782 #endif
3783       else if (argc_pos + 1 != argc)
3784       {
3785          /*
3786           * This is neither the last command line
3787           * option, nor was it recognized before,
3788           * therefore it must be invalid.
3789           */
3790          usage(argv[0]);
3791       }
3792       else
3793
3794 #endif /* defined(_WIN32) && !defined(_WIN_CONSOLE) */
3795       {
3796          configfile = argv[argc_pos];
3797       }
3798
3799    } /* -END- while (more arguments) */
3800
3801    show_version(Argv[0]);
3802
3803 #if defined(unix)
3804    if (*configfile != '/')
3805    {
3806       char cwd[BUFFER_SIZE];
3807       char *abs_file;
3808       size_t abs_file_size;
3809
3810       /* make config-filename absolute here */
3811       if (NULL == getcwd(cwd, sizeof(cwd)))
3812       {
3813          perror("failed to get current working directory");
3814          exit(1);
3815       }
3816
3817       basedir = strdup_or_die(cwd);
3818       /* XXX: why + 5? */