1 /*********************************************************************
3 * File : $Source: /cvsroot/ijbswa/current/parsers.c,v $
5 * Purpose : Declares functions to parse/crunch headers and pages.
7 * Copyright : Written by and Copyright (C) 2001-2020 the
8 * Privoxy team. https://www.privoxy.org/
10 * Based on the Internet Junkbuster originally written
11 * by and Copyright (C) 1997 Anonymous Coders and
12 * Junkbusters Corporation. http://www.junkbusters.com
14 * This program is free software; you can redistribute it
15 * and/or modify it under the terms of the GNU General
16 * Public License as published by the Free Software
17 * Foundation; either version 2 of the License, or (at
18 * your option) any later version.
20 * This program is distributed in the hope that it will
21 * be useful, but WITHOUT ANY WARRANTY; without even the
22 * implied warranty of MERCHANTABILITY or FITNESS FOR A
23 * PARTICULAR PURPOSE. See the GNU General Public
24 * License for more details.
26 * The GNU General Public License should be included with
27 * this file. If not, you can view it at
28 * http://www.gnu.org/copyleft/gpl.html
29 * or write to the Free Software Foundation, Inc., 59
30 * Temple Place - Suite 330, Boston, MA 02111-1307, USA.
32 *********************************************************************/
39 #include <sys/types.h>
49 * Convince GNU's libc to provide a strptime prototype.
58 #define GZIP_IDENTIFIER_1 0x1f
59 #define GZIP_IDENTIFIER_2 0x8b
61 #define GZIP_FLAG_CHECKSUM 0x02
62 #define GZIP_FLAG_EXTRA_FIELDS 0x04
63 #define GZIP_FLAG_FILE_NAME 0x08
64 #define GZIP_FLAG_COMMENT 0x10
65 #define GZIP_FLAG_RESERVED_BITS 0xe0
68 #include <brotli/decode.h>
77 #ifdef FEATURE_PTHREAD
79 /* jcc.h is for mutex semapores only */
80 #endif /* def FEATURE_PTHREAD */
85 #include "jbsockets.h"
90 #ifdef FEATURE_HTTPS_INSPECTION
98 static char *get_header_line(struct iob *iob);
99 static jb_err scan_headers(struct client_state *csp);
100 static jb_err header_tagger(struct client_state *csp, char *header);
101 static jb_err parse_header_time(const char *header_time, time_t *result);
102 static jb_err parse_time_header(const char *header, time_t *result);
104 static jb_err crumble (struct client_state *csp, char **header);
105 static jb_err filter_header (struct client_state *csp, char **header);
106 static jb_err client_connection (struct client_state *csp, char **header);
107 static jb_err client_referrer (struct client_state *csp, char **header);
108 static jb_err client_uagent (struct client_state *csp, char **header);
109 static jb_err client_ua (struct client_state *csp, char **header);
110 static jb_err client_from (struct client_state *csp, char **header);
111 static jb_err client_send_cookie (struct client_state *csp, char **header);
112 static jb_err client_x_forwarded (struct client_state *csp, char **header);
113 static jb_err client_accept_encoding (struct client_state *csp, char **header);
114 static jb_err client_te (struct client_state *csp, char **header);
115 static jb_err client_max_forwards (struct client_state *csp, char **header);
116 static jb_err client_host (struct client_state *csp, char **header);
117 static jb_err client_if_modified_since (struct client_state *csp, char **header);
118 static jb_err client_accept_language (struct client_state *csp, char **header);
119 static jb_err client_if_none_match (struct client_state *csp, char **header);
120 static jb_err crunch_client_header (struct client_state *csp, char **header);
121 static jb_err client_x_filter (struct client_state *csp, char **header);
122 static jb_err client_range (struct client_state *csp, char **header);
123 static jb_err client_expect (struct client_state *csp, char **header);
124 static jb_err server_set_cookie (struct client_state *csp, char **header);
125 static jb_err server_connection (struct client_state *csp, char **header);
126 static jb_err server_content_type (struct client_state *csp, char **header);
127 static jb_err server_adjust_content_length(struct client_state *csp, char **header);
128 static jb_err server_content_md5 (struct client_state *csp, char **header);
129 static jb_err server_content_encoding (struct client_state *csp, char **header);
130 static jb_err server_transfer_coding (struct client_state *csp, char **header);
131 static jb_err server_http (struct client_state *csp, char **header);
132 static jb_err crunch_server_header (struct client_state *csp, char **header);
133 static jb_err server_last_modified (struct client_state *csp, char **header);
134 static jb_err server_content_disposition(struct client_state *csp, char **header);
136 static jb_err server_adjust_content_encoding(struct client_state *csp, char **header);
139 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
140 static jb_err server_save_content_length(struct client_state *csp, char **header);
141 static jb_err server_keep_alive(struct client_state *csp, char **header);
142 static jb_err server_proxy_connection(struct client_state *csp, char **header);
143 static jb_err client_keep_alive(struct client_state *csp, char **header);
144 static jb_err client_proxy_connection(struct client_state *csp, char **header);
145 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
147 static jb_err client_save_content_length(struct client_state *csp, char **header);
148 static jb_err client_host_adder (struct client_state *csp);
149 static jb_err client_xtra_adder (struct client_state *csp);
150 static jb_err client_x_forwarded_for_adder(struct client_state *csp);
151 static jb_err client_connection_header_adder(struct client_state *csp);
152 static jb_err server_connection_adder(struct client_state *csp);
153 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
154 static jb_err server_proxy_connection_adder(struct client_state *csp);
155 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
156 static jb_err proxy_authentication(struct client_state *csp, char **header);
158 static jb_err create_forged_referrer(char **header, const char *hostport);
159 static jb_err create_fake_referrer(char **header, const char *fake_referrer);
160 static jb_err handle_conditional_hide_referrer_parameter(char **header,
161 const char *host, const int parameter_conditional_block);
162 static void create_content_length_header(unsigned long long content_length,
163 char *header, size_t buffer_length);
166 * List of functions to run on a list of headers.
170 /** The header prefix to match */
173 /** The length of the prefix to match */
176 /** The function to apply to this line */
177 const parser_func_ptr parser;
180 static const struct parsers client_patterns[] = {
181 { "referer:", 8, client_referrer },
182 { "user-agent:", 11, client_uagent },
183 { "ua-", 3, client_ua },
184 { "from:", 5, client_from },
185 { "cookie:", 7, client_send_cookie },
186 { "x-forwarded-for:", 16, client_x_forwarded },
187 { "Accept-Encoding:", 16, client_accept_encoding },
188 { "TE:", 3, client_te },
189 { "Host:", 5, client_host },
190 { "if-modified-since:", 18, client_if_modified_since },
191 { "Content-Length:", 15, client_save_content_length },
192 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
193 { "Keep-Alive:", 11, client_keep_alive },
194 { "Proxy-Connection:", 17, client_proxy_connection },
196 { "Keep-Alive:", 11, crumble },
197 { "Proxy-Connection:", 17, crumble },
199 { "connection:", 11, client_connection },
200 { "max-forwards:", 13, client_max_forwards },
201 { "Accept-Language:", 16, client_accept_language },
202 { "if-none-match:", 14, client_if_none_match },
203 { "Range:", 6, client_range },
204 { "Request-Range:", 14, client_range },
205 { "If-Range:", 9, client_range },
206 { "X-Filter:", 9, client_x_filter },
207 { "Proxy-Authorization:", 20, proxy_authentication },
209 { "Transfer-Encoding:", 18, client_transfer_encoding },
211 { "Expect:", 7, client_expect },
212 { "*", 0, crunch_client_header },
213 { "*", 0, filter_header },
217 static const struct parsers server_patterns[] = {
218 { "HTTP/", 5, server_http },
219 { "set-cookie:", 11, server_set_cookie },
220 { "connection:", 11, server_connection },
221 { "Content-Type:", 13, server_content_type },
222 { "Content-MD5:", 12, server_content_md5 },
223 { "Content-Encoding:", 17, server_content_encoding },
224 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
225 { "Content-Length:", 15, server_save_content_length },
226 { "Keep-Alive:", 11, server_keep_alive },
227 { "Proxy-Connection:", 17, server_proxy_connection },
229 { "Keep-Alive:", 11, crumble },
230 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
231 { "Transfer-Encoding:", 18, server_transfer_coding },
232 { "content-disposition:", 20, server_content_disposition },
233 { "Last-Modified:", 14, server_last_modified },
234 { "Proxy-Authenticate:", 19, proxy_authentication },
235 { "*", 0, crunch_server_header },
236 { "*", 0, filter_header },
240 static const add_header_func_ptr add_client_headers[] = {
242 client_x_forwarded_for_adder,
244 client_connection_header_adder,
248 static const add_header_func_ptr add_server_headers[] = {
249 server_connection_adder,
250 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
251 server_proxy_connection_adder,
252 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
256 /*********************************************************************
258 * Function : flush_iob
260 * Description : Write any pending "buffered" content.
263 * 1 : fd = file descriptor of the socket to read
264 * 2 : iob = The I/O buffer to flush, usually csp->iob.
265 * 3 : delay = Number of milliseconds to delay the writes
267 * Returns : On success, the number of bytes written are returned (zero
268 * indicates nothing was written). On error, -1 is returned,
269 * and errno is set appropriately. If count is zero and the
270 * file descriptor refers to a regular file, 0 will be
271 * returned without causing any other effect. For a special
272 * file, the results are not portable.
274 *********************************************************************/
275 long flush_iob(jb_socket fd, struct iob *iob, unsigned int delay)
277 long len = iob->eod - iob->cur;
284 if (write_socket_delayed(fd, iob->cur, (size_t)len, delay))
288 iob->eod = iob->cur = iob->buf;
294 /*********************************************************************
296 * Function : can_add_to_iob
298 * Description : Checks if the given number of bytes can be added to the given iob
299 * without exceeding the given buffer limit.
302 * 1 : iob = Destination buffer.
303 * 2 : buffer_limit = Limit to which the destination may grow
304 * 3 : n = number of bytes to be added
306 * Returns : TRUE if the given iob can handle given number of bytes
307 * FALSE buffer limit will be exceeded
309 *********************************************************************/
310 int can_add_to_iob(const struct iob *iob, const size_t buffer_limit, size_t n)
312 return ((size_t)(iob->eod - iob->buf) + n + 1) > buffer_limit ? FALSE : TRUE;
315 /*********************************************************************
317 * Function : add_to_iob
319 * Description : Add content to the buffer, expanding the
320 * buffer if necessary.
323 * 1 : iob = Destination buffer.
324 * 2 : buffer_limit = Limit to which the destination may grow
325 * 3 : src = holds the content to be added
326 * 4 : n = number of bytes to be added
328 * Returns : JB_ERR_OK on success, JB_ERR_MEMORY if out-of-memory
329 * or buffer limit reached.
331 *********************************************************************/
332 jb_err add_to_iob(struct iob *iob, const size_t buffer_limit, const char *src, long n)
334 size_t used, offset, need;
337 if (n <= 0) return JB_ERR_OK;
339 used = (size_t)(iob->eod - iob->buf);
340 offset = (size_t)(iob->cur - iob->buf);
341 need = used + (size_t)n + 1;
344 * If the buffer can't hold the new data, extend it first.
345 * Use the next power of two if possible, else use the actual need.
347 if (need > buffer_limit)
349 log_error(LOG_LEVEL_INFO,
350 "Buffer limit reached while extending the buffer (iob). Needed: %lu. Limit: %lu",
352 return JB_ERR_MEMORY;
355 if (need > iob->size)
357 size_t want = iob->size ? iob->size : 512;
364 if (want <= buffer_limit && NULL != (p = (char *)realloc(iob->buf, want)))
368 else if (NULL != (p = (char *)realloc(iob->buf, need)))
374 log_error(LOG_LEVEL_ERROR, "Extending the buffer (iob) failed: %E");
375 return JB_ERR_MEMORY;
378 /* Update the iob pointers */
379 iob->cur = p + offset;
384 /* copy the new data into the iob buffer */
385 memcpy(iob->eod, src, (size_t)n);
387 /* point to the end of the data */
390 /* null terminate == cheap insurance */
398 /*********************************************************************
400 * Function : clear_iob
402 * Description : Frees the memory allocated for an I/O buffer and
403 * resets the structure.
406 * 1 : iob = I/O buffer to clear.
410 *********************************************************************/
411 void clear_iob(struct iob *iob)
414 memset(iob, '\0', sizeof(*iob));
419 #ifdef FEATURE_BROTLI
420 /*********************************************************************
422 * Function : decompress_iob_with_brotli
424 * Description : Decompress buffered page using Brotli.
427 * 1 : csp = Current client state (buffers, headers, etc...)
429 * Returns : JB_ERR_OK on success,
430 * JB_ERR_MEMORY if out-of-memory limit reached, and
431 * JB_ERR_COMPRESS if error decompressing buffer.
433 *********************************************************************/
434 static jb_err decompress_iob_with_brotli(struct client_state *csp)
436 BrotliDecoderResult result;
437 char *decoded_buffer;
439 size_t decoded_buffer_size;
441 enum { MAX_COMPRESSION_FACTOR = 15 };
443 encoded_size = (size_t)(csp->iob->eod - csp->iob->cur);
445 * The BrotliDecoderDecompress() api is a bit unfortunate
446 * and requires the caller to reserve enough memory for
447 * the decompressed content. Hopefully reserving
448 * MAX_COMPRESSION_FACTOR times the original size is
449 * sufficient. If not, BrotliDecoderDecompress() will fail.
451 decoded_buffer_size = encoded_size * MAX_COMPRESSION_FACTOR;
453 if (decoded_buffer_size > csp->config->buffer_limit)
455 log_error(LOG_LEVEL_ERROR,
456 "Buffer limit reached before decompressing iob with Brotli");
457 return JB_ERR_MEMORY;
460 decoded_buffer = malloc(decoded_buffer_size);
461 if (decoded_buffer == NULL)
463 log_error(LOG_LEVEL_ERROR,
464 "Failed to allocate %lu bytes for Brotli decompression",
465 decoded_buffer_size);
466 return JB_ERR_MEMORY;
469 decoded_size = decoded_buffer_size;
470 result = BrotliDecoderDecompress(encoded_size,
471 (const uint8_t *)csp->iob->cur, &decoded_size,
472 (uint8_t *)decoded_buffer);
473 if (result == BROTLI_DECODER_RESULT_SUCCESS)
476 * Update the iob, since the decompression was successful.
478 freez(csp->iob->buf);
479 csp->iob->buf = decoded_buffer;
480 csp->iob->cur = csp->iob->buf;
481 csp->iob->eod = csp->iob->cur + decoded_size;
482 csp->iob->size = decoded_buffer_size;
484 log_error(LOG_LEVEL_RE_FILTER,
485 "Decompression successful. Old size: %lu, new size: %lu.",
486 encoded_size, decoded_size);
492 log_error(LOG_LEVEL_ERROR, "Failed to decompress buffer with Brotli");
493 freez(decoded_buffer);
495 return JB_ERR_COMPRESS;
500 /*********************************************************************
502 * Function : decompress_iob
504 * Description : Decompress buffered page, expanding the
505 * buffer as necessary. csp->iob->cur
506 * should point to the the beginning of the
507 * compressed data block.
510 * 1 : csp = Current client state (buffers, headers, etc...)
512 * Returns : JB_ERR_OK on success,
513 * JB_ERR_MEMORY if out-of-memory limit reached, and
514 * JB_ERR_COMPRESS if error decompressing buffer.
516 *********************************************************************/
517 jb_err decompress_iob(struct client_state *csp)
519 char *buf; /* new, uncompressed buffer */
520 char *cur; /* Current iob position (to keep the original
521 * iob->cur unmodified if we return early) */
522 size_t bufsize; /* allocated size of the new buffer */
523 size_t old_size; /* Content size before decompression */
524 size_t skip_size; /* Number of bytes at the beginning of the iob
525 that we should NOT decompress. */
526 int status; /* return status of the inflate() call */
527 z_stream zstr; /* used by calls to zlib */
530 assert(csp->iob->cur - csp->iob->buf >= 0);
531 assert(csp->iob->eod - csp->iob->cur >= 0);
533 assert(csp->iob->cur - csp->iob->buf > 0);
534 assert(csp->iob->eod - csp->iob->cur > 0);
537 bufsize = csp->iob->size;
538 skip_size = (size_t)(csp->iob->cur - csp->iob->buf);
539 old_size = (size_t)(csp->iob->eod - csp->iob->cur);
543 if (bufsize < (size_t)10)
546 * This is to protect the parsing of gzipped data,
547 * but it should(?) be valid for deflated data also.
549 log_error(LOG_LEVEL_ERROR,
550 "Insufficient data to start decompression. Bytes in buffer: %ld",
551 csp->iob->eod - csp->iob->cur);
552 return JB_ERR_COMPRESS;
555 #ifdef FEATURE_BROTLI
556 if (csp->content_type & CT_BROTLI)
558 return decompress_iob_with_brotli(csp);
562 if (csp->content_type & CT_GZIP)
565 * Our task is slightly complicated by the facts that data
566 * compressed by gzip does not include a zlib header, and
567 * that there is no easily accessible interface in zlib to
568 * handle a gzip header. We strip off the gzip header by
569 * hand, and later inform zlib not to expect a header.
573 * Strip off the gzip header. Please see RFC 1952 for more
574 * explanation of the appropriate fields.
576 if (((*cur++ & 0xff) != GZIP_IDENTIFIER_1)
577 || ((*cur++ & 0xff) != GZIP_IDENTIFIER_2)
578 || (*cur++ != Z_DEFLATED))
580 log_error(LOG_LEVEL_ERROR, "Invalid gzip header when decompressing");
581 return JB_ERR_COMPRESS;
586 if (flags & GZIP_FLAG_RESERVED_BITS)
588 /* The gzip header has reserved bits set; bail out. */
589 log_error(LOG_LEVEL_ERROR, "Invalid gzip header flags when decompressing");
590 return JB_ERR_COMPRESS;
594 * Skip mtime (4 bytes), extra flags (1 byte)
595 * and OS type (1 byte).
599 /* Skip extra fields if necessary. */
600 if (flags & GZIP_FLAG_EXTRA_FIELDS)
603 * Skip a given number of bytes, specified
604 * as a 16-bit little-endian value.
606 * XXX: this code is untested and should probably be removed.
610 skip_bytes += *cur++ << 8;
613 * The number of bytes to skip should be positive
614 * and we'd like to stay in the buffer.
616 if ((skip_bytes < 0) || (skip_bytes >= (csp->iob->eod - cur)))
618 log_error(LOG_LEVEL_ERROR,
619 "Unreasonable amount of bytes to skip (%d). Stopping decompression",
621 return JB_ERR_COMPRESS;
623 log_error(LOG_LEVEL_INFO,
624 "Skipping %d bytes for gzip compression. Does this sound right?",
629 /* Skip the filename if necessary. */
630 if (flags & GZIP_FLAG_FILE_NAME)
632 /* A null-terminated string is supposed to follow. */
633 while (*cur++ && (cur < csp->iob->eod));
636 /* Skip the comment if necessary. */
637 if (flags & GZIP_FLAG_COMMENT)
639 /* A null-terminated string is supposed to follow. */
640 while (*cur++ && (cur < csp->iob->eod));
643 /* Skip the CRC if necessary. */
644 if (flags & GZIP_FLAG_CHECKSUM)
649 if (cur >= csp->iob->eod)
652 * If the current position pointer reached or passed
653 * the buffer end, we were obviously tricked to skip
656 log_error(LOG_LEVEL_ERROR,
657 "Malformed gzip header detected. Aborting decompression.");
658 return JB_ERR_COMPRESS;
662 else if (csp->content_type & CT_DEFLATE)
665 * In theory (that is, according to RFC 1950), deflate-compressed
666 * data should begin with a two-byte zlib header and have an
667 * adler32 checksum at the end. It seems that in practice only
668 * the raw compressed data is sent. Note that this means that
669 * we are not RFC 1950-compliant here, but the advantage is that
670 * this actually works. :)
672 * We add a dummy null byte to tell zlib where the data ends,
673 * and later inform it not to expect a header.
675 * Fortunately, add_to_iob() has thoughtfully null-terminated
676 * the buffer; we can just increment the end pointer to include
683 log_error(LOG_LEVEL_ERROR,
684 "Unable to determine compression format for decompression");
685 return JB_ERR_COMPRESS;
688 /* Set up the fields required by zlib. */
689 zstr.next_in = (Bytef *)cur;
690 zstr.avail_in = (unsigned int)(csp->iob->eod - cur);
691 zstr.zalloc = Z_NULL;
693 zstr.opaque = Z_NULL;
696 * Passing -MAX_WBITS to inflateInit2 tells the library
697 * that there is no zlib header.
699 if (inflateInit2(&zstr, -MAX_WBITS) != Z_OK)
701 log_error(LOG_LEVEL_ERROR, "Error initializing decompression");
702 return JB_ERR_COMPRESS;
706 * Next, we allocate new storage for the inflated data.
707 * We don't modify the existing iob yet, so in case there
708 * is error in decompression we can recover gracefully.
710 buf = zalloc(bufsize);
713 log_error(LOG_LEVEL_ERROR, "Out of memory decompressing iob");
714 return JB_ERR_MEMORY;
717 assert(bufsize >= skip_size);
718 memcpy(buf, csp->iob->buf, skip_size);
719 zstr.avail_out = (uInt)(bufsize - skip_size);
720 zstr.next_out = (Bytef *)buf + skip_size;
722 /* Try to decompress the whole stream in one shot. */
723 while (Z_BUF_ERROR == (status = inflate(&zstr, Z_FINISH)))
725 /* We need to allocate more memory for the output buffer. */
727 char *tmpbuf; /* used for realloc'ing the buffer */
728 size_t oldbufsize = bufsize; /* keep track of the old bufsize */
730 if (0 == zstr.avail_in)
733 * If zlib wants more data then there's a problem, because
734 * the complete compressed file should have been buffered.
736 log_error(LOG_LEVEL_ERROR,
737 "Unexpected end of compressed iob. Using what we got so far.");
742 * If we reached the buffer limit and still didn't have enough
743 * memory, just give up. Due to the ceiling enforced by the next
744 * if block we could actually check for equality here, but as it
745 * can be easily mistaken for a bug we don't.
747 if (bufsize >= csp->config->buffer_limit)
749 log_error(LOG_LEVEL_ERROR, "Buffer limit reached while decompressing iob");
752 return JB_ERR_MEMORY;
755 /* Try doubling the buffer size each time. */
758 /* Don't exceed the buffer limit. */
759 if (bufsize > csp->config->buffer_limit)
761 bufsize = csp->config->buffer_limit;
764 /* Try to allocate the new buffer. */
765 tmpbuf = realloc(buf, bufsize);
768 log_error(LOG_LEVEL_ERROR, "Out of memory decompressing iob");
771 return JB_ERR_MEMORY;
775 char *oldnext_out = (char *)zstr.next_out;
778 * Update the fields for inflate() to use the new
779 * buffer, which may be in a location different from
782 zstr.avail_out += (uInt)(bufsize - oldbufsize);
783 zstr.next_out = (Bytef *)tmpbuf + bufsize - zstr.avail_out;
786 * Compare with an uglier method of calculating these values
787 * that doesn't require the extra oldbufsize variable.
789 assert(zstr.avail_out == tmpbuf + bufsize - (char *)zstr.next_out);
790 assert((char *)zstr.next_out == tmpbuf + ((char *)oldnext_out - buf));
796 if (Z_STREAM_ERROR == inflateEnd(&zstr))
798 log_error(LOG_LEVEL_ERROR,
799 "Inconsistent stream state after decompression: %s", zstr.msg);
801 * XXX: Intentionally no return.
803 * According to zlib.h, Z_STREAM_ERROR is returned
804 * "if the stream state was inconsistent".
806 * I assume in this case inflate()'s status
807 * would also be something different than Z_STREAM_END
808 * so this check should be redundant, but lets see.
812 if ((status != Z_STREAM_END) && (0 != zstr.avail_in))
815 * We failed to decompress the stream and it's
816 * not simply because of missing data.
818 log_error(LOG_LEVEL_ERROR,
819 "Unexpected error while decompressing to the buffer (iob): %s",
821 return JB_ERR_COMPRESS;
825 * Finally, we can actually update the iob, since the
826 * decompression was successful. First, free the old
829 freez(csp->iob->buf);
831 /* Now, update the iob to use the new buffer. */
833 csp->iob->cur = csp->iob->buf + skip_size;
834 csp->iob->eod = (char *)zstr.next_out;
835 csp->iob->size = bufsize;
838 * Make sure the new uncompressed iob obeys some minimal
839 * consistency conditions.
841 if ((csp->iob->buf <= csp->iob->cur)
842 && (csp->iob->cur <= csp->iob->eod)
843 && (csp->iob->eod <= csp->iob->buf + csp->iob->size))
845 const size_t new_size = (size_t)(csp->iob->eod - csp->iob->cur);
846 if (new_size > (size_t)0)
848 log_error(LOG_LEVEL_RE_FILTER,
849 "Decompression successful. Old size: %lu, new size: %lu.",
854 /* zlib thinks this is OK, so let's do the same. */
855 log_error(LOG_LEVEL_RE_FILTER,
856 "Decompression didn't result in any content.");
861 /* It seems that zlib did something weird. */
862 log_error(LOG_LEVEL_ERROR, "Inconsistent buffer after decompression");
863 return JB_ERR_COMPRESS;
869 #endif /* defined(FEATURE_ZLIB) */
872 /*********************************************************************
874 * Function : normalize_lws
876 * Description : Reduces unquoted linear whitespace in headers to
877 * a single space in accordance with RFC 7230 3.2.4.
878 * This simplifies parsing and filtering later on.
881 * 1 : header = A header with linear whitespace to reduce.
885 *********************************************************************/
886 static void normalize_lws(char *header)
892 if (privoxy_isspace(*p) && privoxy_isspace(*(p+1)))
896 while (privoxy_isspace(*q))
900 log_error(LOG_LEVEL_HEADER, "Reducing whitespace in '%s'", header);
906 log_error(LOG_LEVEL_HEADER,
907 "Converting tab to space in '%s'", header);
912 char *end_of_token = strstr(p+1, "\"");
914 if (NULL != end_of_token)
916 /* Don't mess with quoted text. */
921 log_error(LOG_LEVEL_HEADER,
922 "Ignoring single quote in '%s'", header);
928 p = strchr(header, ':');
929 if ((p != NULL) && (p != header) && privoxy_isspace(*(p-1)))
932 * There's still space before the colon.
940 /*********************************************************************
942 * Function : get_header
944 * Description : This (odd) routine will parse the csp->iob
945 * to get the next complete header.
948 * 1 : iob = The I/O buffer to parse, usually csp->iob.
950 * Returns : Any one of the following:
952 * 1) a pointer to a dynamically allocated string that contains a header line
953 * 2) NULL indicating that the end of the header was reached
954 * 3) "" indicating that the end of the iob was reached before finding
955 * a complete header line.
957 *********************************************************************/
958 char *get_header(struct iob *iob)
962 header = get_header_line(iob);
964 if ((header == NULL) || (*header == '\0'))
967 * No complete header read yet, tell the client.
972 while ((iob->cur[0] == ' ') || (iob->cur[0] == '\t'))
975 * Header spans multiple lines, append the next one.
977 char *continued_header;
979 continued_header = get_header_line(iob);
980 if ((continued_header == NULL) || (*continued_header == '\0'))
983 * No complete header read yet, return what we got.
984 * XXX: Should "unread" header instead.
986 log_error(LOG_LEVEL_INFO,
987 "Failed to read a multi-line header properly: '%s'",
992 if (JB_ERR_OK != string_join(&header, continued_header))
994 log_error(LOG_LEVEL_FATAL,
995 "Out of memory while appending multiple headers.");
999 /* XXX: remove before next stable release. */
1000 log_error(LOG_LEVEL_HEADER,
1001 "Merged multiple header lines to: '%s'",
1006 normalize_lws(header);
1013 /*********************************************************************
1015 * Function : get_header_line
1017 * Description : This (odd) routine will parse the csp->iob
1018 * to get the next header line.
1021 * 1 : iob = The I/O buffer to parse, usually csp->iob.
1023 * Returns : Any one of the following:
1025 * 1) a pointer to a dynamically allocated string that contains a header line
1026 * 2) NULL indicating that the end of the header was reached
1027 * 3) "" indicating that the end of the iob was reached before finding
1028 * a complete header line.
1030 *********************************************************************/
1031 static char *get_header_line(struct iob *iob)
1035 if ((iob->cur == NULL)
1036 || ((p = strchr(iob->cur, '\n')) == NULL))
1038 return(""); /* couldn't find a complete header */
1043 ret = strdup(iob->cur);
1046 /* FIXME No way to handle error properly */
1047 log_error(LOG_LEVEL_FATAL, "Out of memory in get_header_line()");
1049 assert(ret != NULL);
1053 if ((q = strchr(ret, '\r')) != NULL) *q = '\0';
1055 /* is this a blank line (i.e. the end of the header) ? */
1067 /*********************************************************************
1069 * Function : get_header_value
1071 * Description : Get the value of a given header from a chained list
1072 * of header lines or return NULL if no such header is
1073 * present in the list.
1076 * 1 : header_list = pointer to list
1077 * 2 : header_name = string with name of header to look for.
1078 * Trailing colon required, capitalization
1081 * Returns : NULL if not found, else value of header
1083 *********************************************************************/
1084 char *get_header_value(const struct list *header_list, const char *header_name)
1086 struct list_entry *cur_entry;
1090 assert(header_list);
1091 assert(header_name);
1092 length = strlen(header_name);
1094 for (cur_entry = header_list->first; cur_entry ; cur_entry = cur_entry->next)
1098 if (!strncmpic(cur_entry->str, header_name, length))
1101 * Found: return pointer to start of value
1103 ret = cur_entry->str + length;
1104 while (*ret && privoxy_isspace(*ret)) ret++;
1118 /*********************************************************************
1120 * Function : scan_headers
1122 * Description : Scans headers, applies tags and updates action bits.
1125 * 1 : csp = Current client state (buffers, headers, etc...)
1127 * Returns : JB_ERR_OK
1129 *********************************************************************/
1130 static jb_err scan_headers(struct client_state *csp)
1132 struct list_entry *h; /* Header */
1133 jb_err err = JB_ERR_OK;
1135 for (h = csp->headers->first; (err == JB_ERR_OK) && (h != NULL) ; h = h->next)
1137 /* Header crunch()ed in previous run? -> ignore */
1138 if (h->str == NULL) continue;
1139 log_error(LOG_LEVEL_HEADER, "scan: %s", h->str);
1140 err = header_tagger(csp, h->str);
1147 /*********************************************************************
1149 * Function : enforce_header_order
1151 * Description : Enforces a given header order.
1154 * 1 : headers = List of headers to order.
1155 * 2 : ordered_headers = List of ordered header names.
1159 *********************************************************************/
1160 static void enforce_header_order(struct list *headers, const struct list *ordered_headers)
1162 struct list_entry *sorted_header;
1163 struct list new_headers[1];
1164 struct list_entry *header;
1166 init_list(new_headers);
1168 /* The request line is always the first "header" */
1170 assert(NULL != headers->first->str);
1171 enlist(new_headers, headers->first->str);
1172 freez(headers->first->str)
1174 /* Enlist the specified headers in the given order */
1176 for (sorted_header = ordered_headers->first; sorted_header != NULL;
1177 sorted_header = sorted_header->next)
1179 const size_t sorted_header_length = strlen(sorted_header->str);
1180 for (header = headers->first; header != NULL; header = header->next)
1182 /* Header enlisted in previous run? -> ignore */
1183 if (header->str == NULL) continue;
1185 if (0 == strncmpic(sorted_header->str, header->str, sorted_header_length)
1186 && (header->str[sorted_header_length] == ':'))
1188 log_error(LOG_LEVEL_HEADER, "Enlisting sorted header %s", header->str);
1189 if (JB_ERR_OK != enlist(new_headers, header->str))
1191 log_error(LOG_LEVEL_HEADER, "Failed to enlist %s", header->str);
1198 /* Enlist the rest of the headers behind the ordered ones */
1199 for (header = headers->first; header != NULL; header = header->next)
1201 /* Header enlisted in previous run? -> ignore */
1202 if (header->str == NULL) continue;
1204 log_error(LOG_LEVEL_HEADER,
1205 "Enlisting left-over header %s", header->str);
1206 if (JB_ERR_OK != enlist(new_headers, header->str))
1208 log_error(LOG_LEVEL_HEADER, "Failed to enlist %s", header->str);
1213 list_remove_all(headers);
1214 list_duplicate(headers, new_headers);
1215 list_remove_all(new_headers);
1221 /*********************************************************************
1225 * Description : add, delete or modify lines in the HTTP header streams.
1226 * On entry, it receives a linked list of headers space
1227 * that was allocated dynamically (both the list nodes
1228 * and the header contents).
1230 * As a side effect it frees the space used by the original
1234 * 1 : csp = Current client state (buffers, headers, etc...)
1235 * 2 : filter_server_headers = Boolean to switch between
1236 * server and header filtering.
1238 * Returns : JB_ERR_OK in case off success, or
1239 * JB_ERR_MEMORY on some out-of-memory errors, or
1240 * JB_ERR_PARSE in case of fatal parse errors.
1242 *********************************************************************/
1243 jb_err sed(struct client_state *csp, int filter_server_headers)
1245 /* XXX: use more descriptive names. */
1246 struct list_entry *p;
1247 const struct parsers *v;
1248 const add_header_func_ptr *f;
1249 jb_err err = JB_ERR_OK;
1253 if (filter_server_headers)
1255 v = server_patterns;
1256 f = add_server_headers;
1257 check_negative_tag_patterns(csp, PATTERN_SPEC_NO_RESPONSE_TAG_PATTERN);
1261 v = client_patterns;
1262 f = add_client_headers;
1263 check_negative_tag_patterns(csp, PATTERN_SPEC_NO_REQUEST_TAG_PATTERN);
1266 while (v->str != NULL)
1268 for (p = csp->headers->first; p != NULL; p = p->next)
1270 /* Header crunch()ed in previous run? -> ignore */
1271 if (p->str == NULL) continue;
1273 /* Does the current parser handle this header? */
1274 if ((strncmpic(p->str, v->str, v->len) == 0) ||
1275 (v->len == CHECK_EVERY_HEADER_REMAINING))
1277 err = v->parser(csp, &(p->str));
1278 if (err != JB_ERR_OK)
1287 /* place additional headers on the csp->headers list */
1288 while ((err == JB_ERR_OK) && (*f))
1294 if (!filter_server_headers && !list_is_empty(csp->config->ordered_client_headers))
1296 enforce_header_order(csp->headers, csp->config->ordered_client_headers);
1303 #ifdef FEATURE_HTTPS_INSPECTION
1304 /*********************************************************************
1306 * Function : sed_https
1308 * Description : add, delete or modify lines in the HTTPS client
1309 * header streams. Wrapper around sed().
1312 * 1 : csp = Current client state (buffers, headers, etc...)
1314 * Returns : JB_ERR_OK in case off success, or
1315 * JB_ERR_MEMORY on some out-of-memory errors, or
1316 * JB_ERR_PARSE in case of fatal parse errors.
1318 *********************************************************************/
1319 jb_err sed_https(struct client_state *csp)
1322 struct list headers;
1325 * Temporarily replace csp->headers with csp->https_headers
1326 * to trick sed() into filtering the https headers.
1328 headers.first = csp->headers->first;
1329 headers.last = csp->headers->last;
1330 csp->headers->first = csp->https_headers->first;
1331 csp->headers->last = csp->https_headers->last;
1334 * Start with fresh tags. Already existing tags may
1335 * be set again. This is necessary to overrule
1336 * URL-based patterns.
1338 destroy_list(csp->tags);
1341 * We want client header filters and taggers
1342 * so temporarily remove the flag.
1344 csp->flags &= ~CSP_FLAG_CLIENT_HEADER_PARSING_DONE;
1345 err = sed(csp, FILTER_CLIENT_HEADERS);
1346 csp->flags |= CSP_FLAG_CLIENT_HEADER_PARSING_DONE;
1349 * Update the https headers list which may have
1350 * been modified due to header additions or header
1353 csp->https_headers->first = csp->headers->first;
1354 csp->https_headers->last = csp->headers->last;
1356 csp->headers->first = headers.first;
1357 csp->headers->last = headers.last;
1361 #endif /* def FEATURE_HTTPS_INSPECTION */
1364 /*********************************************************************
1366 * Function : update_server_headers
1368 * Description : Updates server headers after the body has been modified.
1371 * 1 : csp = Current client state (buffers, headers, etc...)
1373 * Returns : JB_ERR_OK in case off success, or
1374 * JB_ERR_MEMORY on out-of-memory error.
1376 *********************************************************************/
1377 jb_err update_server_headers(struct client_state *csp)
1379 jb_err err = JB_ERR_OK;
1381 static const struct parsers server_patterns_light[] = {
1382 { "Content-Length:", 15, server_adjust_content_length },
1383 { "Transfer-Encoding:", 18, server_transfer_coding },
1385 { "Content-Encoding:", 17, server_adjust_content_encoding },
1386 #endif /* def FEATURE_ZLIB */
1390 if (strncmpic(csp->http->cmd, "HEAD", 4))
1392 const struct parsers *v;
1393 struct list_entry *p;
1395 for (v = server_patterns_light; (err == JB_ERR_OK) && (v->str != NULL); v++)
1397 for (p = csp->headers->first; (err == JB_ERR_OK) && (p != NULL); p = p->next)
1399 /* Header crunch()ed in previous run? -> ignore */
1400 if (p->str == NULL) continue;
1402 /* Does the current parser handle this header? */
1403 if (strncmpic(p->str, v->str, v->len) == 0)
1405 err = v->parser(csp, (char **)&(p->str));
1411 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1412 if ((JB_ERR_OK == err)
1413 && (csp->flags & CSP_FLAG_MODIFIED)
1414 && (csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
1415 && !(csp->flags & CSP_FLAG_SERVER_CONTENT_LENGTH_SET))
1419 create_content_length_header(csp->content_length, header, sizeof(header));
1420 err = enlist(csp->headers, header);
1421 if (JB_ERR_OK == err)
1423 log_error(LOG_LEVEL_HEADER,
1424 "Content modified with no Content-Length header set. "
1425 "Created: %s.", header);
1426 csp->flags |= CSP_FLAG_SERVER_CONTENT_LENGTH_SET;
1429 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
1431 #ifdef FEATURE_COMPRESSION
1432 if ((JB_ERR_OK == err)
1433 && (csp->flags & CSP_FLAG_BUFFERED_CONTENT_DEFLATED))
1435 err = enlist_unique_header(csp->headers, "Content-Encoding", "deflate");
1436 if (JB_ERR_OK == err)
1438 log_error(LOG_LEVEL_HEADER, "Added header: Content-Encoding: deflate");
1447 /*********************************************************************
1449 * Function : header_tagger
1451 * Description : Executes all text substitutions from applying
1452 * tag actions and saves the result as tag.
1454 * XXX: Shares enough code with filter_header() and
1455 * pcrs_filter_response() to warrant some helper functions.
1458 * 1 : csp = Current client state (buffers, headers, etc...)
1459 * 2 : header = Header that is used as tagger input
1461 * Returns : JB_ERR_OK on success and always succeeds
1463 *********************************************************************/
1464 static jb_err header_tagger(struct client_state *csp, char *header)
1466 enum filter_type wanted_filter_type;
1467 int multi_action_index;
1470 struct re_filterfile_spec *b;
1471 struct list_entry *tag_name;
1473 const size_t header_length = strlen(header);
1475 if (csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
1477 wanted_filter_type = FT_SERVER_HEADER_TAGGER;
1478 multi_action_index = ACTION_MULTI_SERVER_HEADER_TAGGER;
1482 wanted_filter_type = FT_CLIENT_HEADER_TAGGER;
1483 multi_action_index = ACTION_MULTI_CLIENT_HEADER_TAGGER;
1486 if (list_is_empty(csp->action->multi[multi_action_index])
1487 || filters_available(csp) == FALSE)
1489 /* Return early if no taggers apply or if none are available. */
1493 /* Execute all applying taggers */
1494 for (tag_name = csp->action->multi[multi_action_index]->first;
1495 NULL != tag_name; tag_name = tag_name->next)
1497 char *modified_tag = NULL;
1499 size_t size = header_length;
1502 b = get_filter(csp, tag_name->str, wanted_filter_type);
1508 joblist = b->joblist;
1510 if (b->dynamic) joblist = compile_dynamic_pcrs_job_list(csp, b);
1512 if (NULL == joblist)
1514 log_error(LOG_LEVEL_TAGGING,
1515 "Tagger %s has empty joblist. Nothing to do.", b->name);
1519 /* execute their pcrs_joblist on the header. */
1520 for (job = joblist; NULL != job; job = job->next)
1522 const int hits = pcrs_execute(job, tag, size, &modified_tag, &size);
1526 /* Success, continue with the modified version. */
1535 /* Tagger doesn't match */
1538 /* Regex failure, log it but continue anyway. */
1539 assert(NULL != header);
1540 log_error(LOG_LEVEL_ERROR,
1541 "Problems with tagger \'%s\' and header \'%s\': %s",
1542 b->name, header, pcrs_strerror(hits));
1544 freez(modified_tag);
1548 if (b->dynamic) pcrs_free_joblist(joblist);
1550 /* If this tagger matched */
1556 * There is no technical limitation which makes
1557 * it impossible to use empty tags, but I assume
1558 * no one would do it intentionally.
1561 log_error(LOG_LEVEL_TAGGING,
1562 "Tagger \'%s\' created an empty tag. Ignored.", b->name);
1566 if (list_contains_item(csp->action->multi[ACTION_MULTI_SUPPRESS_TAG], tag))
1568 log_error(LOG_LEVEL_TAGGING,
1569 "Tagger \'%s\' didn't add tag \'%s\': suppressed",
1575 if (!list_contains_item(csp->tags, tag))
1577 if (JB_ERR_OK != enlist(csp->tags, tag))
1579 log_error(LOG_LEVEL_ERROR,
1580 "Insufficient memory to add tag \'%s\', "
1581 "based on tagger \'%s\' and header \'%s\'",
1582 tag, b->name, header);
1586 char *action_message;
1588 * update the action bits right away, to make
1589 * tagging based on tags set by earlier taggers
1590 * of the same kind possible.
1592 if (update_action_bits_for_tag(csp, tag))
1594 action_message = "Action bits updated accordingly.";
1598 action_message = "No action bits update necessary.";
1601 log_error(LOG_LEVEL_TAGGING,
1602 "Tagger \'%s\' added tag \'%s\'. %s",
1603 b->name, tag, action_message);
1608 /* XXX: Is this log-worthy? */
1609 log_error(LOG_LEVEL_TAGGING,
1610 "Tagger \'%s\' didn't add tag \'%s\'. Tag already present",
1620 /* here begins the family of parser functions that reformat header lines */
1622 /*********************************************************************
1624 * Function : filter_header
1626 * Description : Executes all text substitutions from all applying
1627 * +(server|client)-header-filter actions on the header.
1628 * Most of the code was copied from pcrs_filter_response,
1629 * including the rather short variable names
1632 * 1 : csp = Current client state (buffers, headers, etc...)
1633 * 2 : header = On input, pointer to header to modify.
1634 * On output, pointer to the modified header, or NULL
1635 * to remove the header. This function frees the
1636 * original string if necessary.
1638 * Returns : JB_ERR_OK on success and always succeeds
1640 *********************************************************************/
1641 static jb_err filter_header(struct client_state *csp, char **header)
1645 size_t size = strlen(*header);
1647 char *newheader = NULL;
1650 struct re_filterfile_spec *b;
1651 struct list_entry *filtername;
1653 enum filter_type wanted_filter_type;
1654 int multi_action_index;
1656 if (csp->flags & CSP_FLAG_NO_FILTERING)
1661 if (csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
1663 wanted_filter_type = FT_SERVER_HEADER_FILTER;
1664 multi_action_index = ACTION_MULTI_SERVER_HEADER_FILTER;
1668 wanted_filter_type = FT_CLIENT_HEADER_FILTER;
1669 multi_action_index = ACTION_MULTI_CLIENT_HEADER_FILTER;
1672 if (list_is_empty(csp->action->multi[multi_action_index])
1673 || filters_available(csp) == FALSE)
1675 /* Return early if no filters apply or if none are available. */
1679 /* Execute all applying header filters */
1680 for (filtername = csp->action->multi[multi_action_index]->first;
1681 filtername != NULL; filtername = filtername->next)
1683 int current_hits = 0;
1686 b = get_filter(csp, filtername->str, wanted_filter_type);
1692 joblist = b->joblist;
1694 if (b->dynamic) joblist = compile_dynamic_pcrs_job_list(csp, b);
1696 if (NULL == joblist)
1698 log_error(LOG_LEVEL_RE_FILTER, "Filter %s has empty joblist. Nothing to do.", b->name);
1702 log_error(LOG_LEVEL_RE_FILTER, "filtering \'%s\' (size %lu) with \'%s\' ...",
1703 *header, size, b->name);
1705 /* Apply all jobs from the joblist */
1706 for (job = joblist; NULL != job; job = job->next)
1708 matches = pcrs_execute(job, *header, size, &newheader, &size);
1711 current_hits += matches;
1712 log_error(LOG_LEVEL_HEADER, "Transforming \"%s\" to \"%s\"", *header, newheader);
1714 *header = newheader;
1716 else if (0 == matches)
1718 /* Filter doesn't change header */
1724 log_error(LOG_LEVEL_ERROR, "Filtering \'%s\' with \'%s\' didn't work out: %s",
1725 *header, b->name, pcrs_strerror(matches));
1726 if (newheader != NULL)
1728 log_error(LOG_LEVEL_ERROR, "Freeing what's left: %s", newheader);
1734 if (b->dynamic) pcrs_free_joblist(joblist);
1736 log_error(LOG_LEVEL_RE_FILTER,
1737 "... produced %d hits (new size %lu).", current_hits, size);
1738 hits += current_hits;
1742 * Additionally checking for hits is important because if
1743 * the continue hack is triggered, server headers can
1744 * arrive empty to separate multiple heads from each other.
1746 if ((0 == size) && hits)
1748 log_error(LOG_LEVEL_HEADER, "Removing empty header %s", *header);
1756 /*********************************************************************
1758 * Function : server_connection
1760 * Description : Makes sure a proper "Connection:" header is
1761 * set and signals connection_header_adder to
1765 * 1 : csp = Current client state (buffers, headers, etc...)
1766 * 2 : header = On input, pointer to header to modify.
1767 * On output, pointer to the modified header, or NULL
1768 * to remove the header. This function frees the
1769 * original string if necessary.
1771 * Returns : JB_ERR_OK on success.
1773 *********************************************************************/
1774 static jb_err server_connection(struct client_state *csp, char **header)
1776 if (!strcmpic(*header, "Connection: keep-alive")
1777 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1778 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
1782 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1783 if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE))
1785 csp->flags |= CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE;
1788 if ((csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE))
1790 log_error(LOG_LEVEL_HEADER,
1791 "Keeping the server header '%s' around.", *header);
1794 #endif /* FEATURE_CONNECTION_KEEP_ALIVE */
1796 char *old_header = *header;
1798 *header = strdup_or_die("Connection: close");
1799 log_error(LOG_LEVEL_HEADER, "Replaced: \'%s\' with \'%s\'", old_header, *header);
1804 /* Signal server_connection_adder() to return early. */
1805 csp->flags |= CSP_FLAG_SERVER_CONNECTION_HEADER_SET;
1811 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1812 /*********************************************************************
1814 * Function : server_keep_alive
1816 * Description : Stores the server's keep alive timeout.
1819 * 1 : csp = Current client state (buffers, headers, etc...)
1820 * 2 : header = On input, pointer to header to modify.
1821 * On output, pointer to the modified header, or NULL
1822 * to remove the header. This function frees the
1823 * original string if necessary.
1825 * Returns : JB_ERR_OK.
1827 *********************************************************************/
1828 static jb_err server_keep_alive(struct client_state *csp, char **header)
1830 unsigned int keep_alive_timeout;
1831 const char *timeout_position = strstr(*header, "timeout=");
1833 if ((NULL == timeout_position)
1834 || (1 != sscanf(timeout_position, "timeout=%u", &keep_alive_timeout)))
1836 log_error(LOG_LEVEL_ERROR, "Couldn't parse: %s", *header);
1840 if (keep_alive_timeout < csp->server_connection.keep_alive_timeout)
1842 log_error(LOG_LEVEL_HEADER,
1843 "Reducing keep-alive timeout from %u to %u.",
1844 csp->server_connection.keep_alive_timeout, keep_alive_timeout);
1845 csp->server_connection.keep_alive_timeout = keep_alive_timeout;
1849 /* XXX: Is this log worthy? */
1850 log_error(LOG_LEVEL_HEADER,
1851 "Server keep-alive timeout is %u. Sticking with %u.",
1852 keep_alive_timeout, csp->server_connection.keep_alive_timeout);
1854 csp->flags |= CSP_FLAG_SERVER_KEEP_ALIVE_TIMEOUT_SET;
1863 /*********************************************************************
1865 * Function : server_proxy_connection
1867 * Description : Figures out whether or not we should add a
1868 * Proxy-Connection header.
1871 * 1 : csp = Current client state (buffers, headers, etc...)
1872 * 2 : header = On input, pointer to header to modify.
1873 * On output, pointer to the modified header, or NULL
1874 * to remove the header. This function frees the
1875 * original string if necessary.
1877 * Returns : JB_ERR_OK.
1879 *********************************************************************/
1880 static jb_err server_proxy_connection(struct client_state *csp, char **header)
1882 csp->flags |= CSP_FLAG_SERVER_PROXY_CONNECTION_HEADER_SET;
1885 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
1888 /*********************************************************************
1890 * Function : proxy_authentication
1892 * Description : Removes headers that are relevant for proxy
1893 * authentication unless forwarding them has
1894 * been explicitly requested.
1897 * 1 : csp = Current client state (buffers, headers, etc...)
1898 * 2 : header = On input, pointer to header to modify.
1899 * On output, pointer to the modified header, or NULL
1900 * to remove the header. This function frees the
1901 * original string if necessary.
1903 * Returns : JB_ERR_OK.
1905 *********************************************************************/
1906 static jb_err proxy_authentication(struct client_state *csp, char **header)
1908 if ((csp->config->feature_flags &
1909 RUNTIME_FEATURE_FORWARD_PROXY_AUTHENTICATION_HEADERS) == 0) {
1910 log_error(LOG_LEVEL_HEADER,
1911 "Forwarding proxy authentication headers is disabled. Crunching: %s", *header);
1918 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1919 /*********************************************************************
1921 * Function : client_keep_alive
1923 * Description : Stores the client's keep alive timeout.
1926 * 1 : csp = Current client state (buffers, headers, etc...)
1927 * 2 : header = On input, pointer to header to modify.
1928 * On output, pointer to the modified header, or NULL
1929 * to remove the header. This function frees the
1930 * original string if necessary.
1932 * Returns : JB_ERR_OK.
1934 *********************************************************************/
1935 static jb_err client_keep_alive(struct client_state *csp, char **header)
1937 unsigned int keep_alive_timeout;
1938 char *timeout_position;
1940 if (!(csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE))
1942 log_error(LOG_LEVEL_HEADER,
1943 "keep-alive support is disabled. Crunching: %s.", *header);
1948 /* Check for parameter-less format "Keep-Alive: 100" */
1949 timeout_position = strstr(*header, ": ");
1950 if ((NULL == timeout_position)
1951 || (1 != sscanf(timeout_position, ": %u", &keep_alive_timeout)))
1953 /* Assume parameter format "Keep-Alive: timeout=100" */
1954 timeout_position = strstr(*header, "timeout=");
1955 if ((NULL == timeout_position)
1956 || (1 != sscanf(timeout_position, "timeout=%u", &keep_alive_timeout)))
1958 log_error(LOG_LEVEL_HEADER,
1959 "Couldn't parse: '%s'. Using default timeout %u",
1960 *header, csp->config->keep_alive_timeout);
1967 if (keep_alive_timeout < csp->config->keep_alive_timeout)
1969 log_error(LOG_LEVEL_HEADER,
1970 "Reducing keep-alive timeout from %u to %u.",
1971 csp->config->keep_alive_timeout, keep_alive_timeout);
1972 csp->server_connection.keep_alive_timeout = keep_alive_timeout;
1976 /* XXX: Is this log worthy? */
1977 log_error(LOG_LEVEL_HEADER,
1978 "Client keep-alive timeout is %u. Sticking with %u.",
1979 keep_alive_timeout, csp->config->keep_alive_timeout);
1985 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
1988 /*********************************************************************
1990 * Function : get_content_length
1992 * Description : Gets the content length specified in a
1993 * Content-Length header.
1996 * 1 : header_value = The Content-Length header value.
1997 * 2 : length = Storage to return the value.
1999 * Returns : JB_ERR_OK on success, or
2000 * JB_ERR_PARSE if no value is recognized.
2002 *********************************************************************/
2003 static jb_err get_content_length(const char *header_value, unsigned long long *length)
2006 #if SIZEOF_LONG_LONG < 8
2007 #error sizeof(unsigned long long) too small
2009 if (1 != sscanf(header_value, "%I64u", length))
2011 if (1 != sscanf(header_value, "%llu", length))
2014 return JB_ERR_PARSE;
2021 /*********************************************************************
2023 * Function : client_save_content_length
2025 * Description : Save the Content-Length sent by the client.
2028 * 1 : csp = Current client state (buffers, headers, etc...)
2029 * 2 : header = pointer to the Content-Length header
2031 * Returns : JB_ERR_OK on success, or
2032 * JB_ERR_MEMORY on out-of-memory error.
2034 *********************************************************************/
2035 static jb_err client_save_content_length(struct client_state *csp, char **header)
2037 unsigned long long content_length = 0;
2038 const char *header_value;
2040 assert(*(*header+14) == ':');
2042 header_value = *header + 15;
2043 if (JB_ERR_OK != get_content_length(header_value, &content_length))
2045 log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
2050 csp->expected_client_content_length = content_length;
2057 /*********************************************************************
2059 * Function : client_connection
2061 * Description : Makes sure a proper "Connection:" header is
2062 * set and signals connection_header_adder
2066 * 1 : csp = Current client state (buffers, headers, etc...)
2067 * 2 : header = On input, pointer to header to modify.
2068 * On output, pointer to the modified header, or NULL
2069 * to remove the header. This function frees the
2070 * original string if necessary.
2072 * Returns : JB_ERR_OK on success.
2074 *********************************************************************/
2075 static jb_err client_connection(struct client_state *csp, char **header)
2077 static const char connection_close[] = "Connection: close";
2079 if (!strcmpic(*header, connection_close))
2081 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2082 if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
2083 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
2084 #ifdef FEATURE_HTTPS_INSPECTION
2085 && !client_use_ssl(csp)
2089 if (!strcmpic(csp->http->version, "HTTP/1.1"))
2091 log_error(LOG_LEVEL_HEADER,
2092 "Removing \'%s\' to imply keep-alive.", *header);
2095 * While we imply keep-alive to the server,
2096 * we have to remember that the client didn't.
2098 csp->flags &= ~CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
2102 char *old_header = *header;
2104 *header = strdup_or_die("Connection: keep-alive");
2105 log_error(LOG_LEVEL_HEADER,
2106 "Replaced: \'%s\' with \'%s\'", old_header, *header);
2112 log_error(LOG_LEVEL_HEADER,
2113 "Keeping the client header '%s' around. "
2114 "The connection will not be kept alive.",
2116 csp->flags &= ~CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
2119 else if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
2120 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED))
2122 log_error(LOG_LEVEL_HEADER,
2123 "Keeping the client header '%s' around. "
2124 "The server connection will be kept alive if possible.",
2126 csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
2127 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2131 char *old_header = *header;
2133 *header = strdup_or_die(connection_close);
2134 log_error(LOG_LEVEL_HEADER,
2135 "Replaced: \'%s\' with \'%s\'", old_header, *header);
2139 /* Signal client_connection_header_adder() to return early. */
2140 csp->flags |= CSP_FLAG_CLIENT_CONNECTION_HEADER_SET;
2146 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2147 /*********************************************************************
2149 * Function : client_proxy_connection
2151 * Description : Sets the CLIENT_CONNECTION_KEEP_ALIVE flag when
2152 * appropriate and removes the Proxy-Connection
2156 * 1 : csp = Current client state (buffers, headers, etc...)
2157 * 2 : header = On input, pointer to header to modify.
2158 * On output, pointer to the modified header, or NULL
2159 * to remove the header. This function frees the
2160 * original string if necessary.
2162 * Returns : JB_ERR_OK
2164 *********************************************************************/
2165 static jb_err client_proxy_connection(struct client_state *csp, char **header)
2167 if (0 == (csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
2168 && (csp->http->ssl == 0)
2169 && (NULL == strstr(*header, "close")))
2171 log_error(LOG_LEVEL_HEADER,
2172 "The client connection can be kept alive due to: %s", *header);
2173 csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
2175 crumble(csp, header);
2179 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2182 /*********************************************************************
2184 * Function : client_transfer_encoding
2186 * Description : Raise the CSP_FLAG_CHUNKED_CLIENT_BODY flag if
2187 * the request body is "chunked"
2189 * XXX: Currently not called through sed() as we
2190 * need the flag earlier on. Should be fixed.
2193 * 1 : csp = Current client state (buffers, headers, etc...)
2194 * 2 : header = On input, pointer to header to modify.
2195 * On output, pointer to the modified header, or NULL
2196 * to remove the header. This function frees the
2197 * original string if necessary.
2199 * Returns : JB_ERR_OK on success, or
2201 *********************************************************************/
2202 jb_err client_transfer_encoding(struct client_state *csp, char **header)
2204 if (strstr(*header, "chunked"))
2206 csp->flags |= CSP_FLAG_CHUNKED_CLIENT_BODY;
2207 log_error(LOG_LEVEL_HEADER, "Expecting chunked client body");
2214 /*********************************************************************
2216 * Function : client_expect
2218 * Description : Raise the CSP_FLAG_UNSUPPORTED_CLIENT_EXPECTATION
2219 * if the Expect header value is unsupported.
2221 * Rejecting unsupported expectations is a RFC 7231 5.1.1
2222 * MAY and a RFC 2616 (obsolete) MUST.
2225 * 1 : csp = Current client state (buffers, headers, etc...)
2226 * 2 : header = On input, pointer to header to modify.
2227 * On output, pointer to the modified header, or NULL
2228 * to remove the header. This function frees the
2229 * original string if necessary.
2231 * Returns : JB_ERR_OK on success, or
2233 *********************************************************************/
2234 jb_err client_expect(struct client_state *csp, char **header)
2236 if (0 != strcmpic(*header, "Expect: 100-continue"))
2238 csp->flags |= CSP_FLAG_UNSUPPORTED_CLIENT_EXPECTATION;
2239 log_error(LOG_LEVEL_HEADER,
2240 "Unsupported client expectaction: %s", *header);
2248 /*********************************************************************
2250 * Function : crumble
2252 * Description : This is called if a header matches a pattern to "crunch"
2255 * 1 : csp = Current client state (buffers, headers, etc...)
2256 * 2 : header = On input, pointer to header to modify.
2257 * On output, pointer to the modified header, or NULL
2258 * to remove the header. This function frees the
2259 * original string if necessary.
2261 * Returns : JB_ERR_OK on success, or
2262 * JB_ERR_MEMORY on out-of-memory error.
2264 *********************************************************************/
2265 static jb_err crumble(struct client_state *csp, char **header)
2268 log_error(LOG_LEVEL_HEADER, "crumble crunched: %s!", *header);
2274 /*********************************************************************
2276 * Function : crunch_server_header
2278 * Description : Crunch server header if it matches a string supplied by the
2279 * user. Called from `sed'.
2282 * 1 : csp = Current client state (buffers, headers, etc...)
2283 * 2 : header = On input, pointer to header to modify.
2284 * On output, pointer to the modified header, or NULL
2285 * to remove the header. This function frees the
2286 * original string if necessary.
2288 * Returns : JB_ERR_OK on success and always succeeds
2290 *********************************************************************/
2291 static jb_err crunch_server_header(struct client_state *csp, char **header)
2293 const char *crunch_pattern;
2295 /* Do we feel like crunching? */
2296 if ((csp->action->flags & ACTION_CRUNCH_SERVER_HEADER))
2298 crunch_pattern = csp->action->string[ACTION_STRING_SERVER_HEADER];
2300 /* Is the current header the lucky one? */
2301 if (strstr(*header, crunch_pattern))
2303 log_error(LOG_LEVEL_HEADER, "Crunching server header: %s (contains: %s)", *header, crunch_pattern);
2312 /*********************************************************************
2314 * Function : server_content_type
2316 * Description : Set the content-type for filterable types (text/.*,
2317 * .*xml.*, .*script.* and image/gif) unless filtering has been
2318 * forbidden (CT_TABOO) while parsing earlier headers.
2319 * NOTE: Since text/plain is commonly used by web servers
2320 * for files whose correct type is unknown, we don't
2321 * set CT_TEXT for it.
2324 * 1 : csp = Current client state (buffers, headers, etc...)
2325 * 2 : header = On input, pointer to header to modify.
2326 * On output, pointer to the modified header, or NULL
2327 * to remove the header. This function frees the
2328 * original string if necessary.
2330 * Returns : JB_ERR_OK on success, or
2331 * JB_ERR_MEMORY on out-of-memory error.
2333 *********************************************************************/
2334 static jb_err server_content_type(struct client_state *csp, char **header)
2336 /* Remove header if it isn't the first Content-Type header */
2337 if ((csp->content_type & CT_DECLARED))
2339 if (content_filters_enabled(csp->action))
2342 * Making sure the client interprets the content the same way
2343 * Privoxy did is only relevant if Privoxy modified it.
2345 * Checking for this is "hard" as it's not yet known when
2346 * this function is called, thus go shopping and and just
2347 * check if Privoxy could filter it.
2349 * The main thing is that we don't mess with the headers
2350 * unless the user signalled that it's acceptable.
2352 log_error(LOG_LEVEL_HEADER,
2353 "Multiple Content-Type headers detected. "
2354 "Removing and ignoring: %s",
2362 * Signal that the Content-Type has been set.
2364 csp->content_type |= CT_DECLARED;
2366 if (!(csp->content_type & CT_TABOO))
2369 * XXX: The assumption that text/plain is a sign of
2370 * binary data seems to be somewhat unreasonable nowadays
2371 * and should be dropped after 3.0.8 is out.
2373 if ((strstr(*header, "text/") && !strstr(*header, "plain"))
2374 || strstr(*header, "xml")
2375 || strstr(*header, "script"))
2377 csp->content_type |= CT_TEXT;
2379 else if (strstr(*header, "image/gif"))
2381 csp->content_type |= CT_GIF;
2386 * Are we messing with the content type?
2388 if (csp->action->flags & ACTION_CONTENT_TYPE_OVERWRITE)
2391 * Make sure the user doesn't accidentally
2392 * change the content type of binary documents.
2394 if ((csp->content_type & CT_TEXT) || (csp->action->flags & ACTION_FORCE_TEXT_MODE))
2398 *header = strdup_or_die("Content-Type: ");
2400 err = string_append(header, csp->action->string[ACTION_STRING_CONTENT_TYPE]);
2401 if (JB_ERR_OK != err)
2403 log_error(LOG_LEVEL_HEADER, "Insufficient memory to replace Content-Type!");
2404 return JB_ERR_MEMORY;
2406 log_error(LOG_LEVEL_HEADER, "Modified: %s!", *header);
2410 log_error(LOG_LEVEL_HEADER, "%s not replaced. "
2411 "It doesn't look like a content type that should be filtered. "
2412 "Enable force-text-mode if you know what you're doing.", *header);
2420 /*********************************************************************
2422 * Function : server_transfer_coding
2424 * Description : - Prohibit filtering (CT_TABOO) if transfer coding compresses
2425 * - Raise the CSP_FLAG_CHUNKED flag if coding is "chunked"
2426 * - Remove header if body was chunked but has been
2427 * de-chunked for filtering.
2430 * 1 : csp = Current client state (buffers, headers, etc...)
2431 * 2 : header = On input, pointer to header to modify.
2432 * On output, pointer to the modified header, or NULL
2433 * to remove the header. This function frees the
2434 * original string if necessary.
2436 * Returns : JB_ERR_OK on success, or
2437 * JB_ERR_MEMORY on out-of-memory error.
2439 *********************************************************************/
2440 static jb_err server_transfer_coding(struct client_state *csp, char **header)
2443 * Turn off pcrs and gif filtering if body compressed
2445 if (strstr(*header, "gzip") || strstr(*header, "compress") || strstr(*header, "deflate"))
2449 * XXX: Added to test if we could use CT_GZIP and CT_DEFLATE here.
2451 log_error(LOG_LEVEL_INFO, "Marking content type for %s as CT_TABOO because of %s.",
2452 csp->http->cmd, *header);
2453 #endif /* def FEATURE_ZLIB */
2454 csp->content_type = CT_TABOO;
2458 * Raise flag if body chunked
2460 if (strstr(*header, "chunked"))
2462 csp->flags |= CSP_FLAG_CHUNKED;
2465 * If the body was modified, it has been de-chunked first
2466 * and the header must be removed.
2468 * FIXME: If there is more than one transfer encoding,
2469 * only the "chunked" part should be removed here.
2471 if (csp->flags & CSP_FLAG_MODIFIED)
2473 log_error(LOG_LEVEL_HEADER, "Removing: %s", *header);
2482 /*********************************************************************
2484 * Function : server_content_encoding
2486 * Description : Used to check if the content is compressed, and if
2487 * FEATURE_ZLIB is disabled, filtering is disabled as
2490 * If FEATURE_ZLIB is enabled and the compression type
2491 * supported, the content is marked for decompression.
2493 * XXX: Doesn't properly deal with multiple or with
2494 * unsupported but unknown encodings.
2495 * Is case-sensitive but shouldn't be.
2498 * 1 : csp = Current client state (buffers, headers, etc...)
2499 * 2 : header = On input, pointer to header to modify.
2500 * On output, pointer to the modified header, or NULL
2501 * to remove the header. This function frees the
2502 * original string if necessary.
2504 * Returns : JB_ERR_OK on success, or
2505 * JB_ERR_MEMORY on out-of-memory error.
2507 *********************************************************************/
2508 static jb_err server_content_encoding(struct client_state *csp, char **header)
2511 if (strstr(*header, "sdch"))
2514 * Shared Dictionary Compression over HTTP isn't supported,
2515 * filtering it anyway is pretty much guaranteed to mess up
2518 csp->content_type |= CT_TABOO;
2521 * Log a warning if the user expects the content to be filtered.
2523 if (content_filters_enabled(csp->action))
2525 log_error(LOG_LEVEL_INFO,
2526 "SDCH-compressed content detected, content filtering disabled. "
2527 "Consider suppressing SDCH offers made by the client.");
2530 else if (strstr(*header, "gzip"))
2532 /* Mark for gzip decompression */
2533 csp->content_type |= CT_GZIP;
2535 else if (strstr(*header, "deflate"))
2537 /* Mark for zlib decompression */
2538 csp->content_type |= CT_DEFLATE;
2540 else if (strstr(*header, "br"))
2542 #ifdef FEATURE_BROTLI
2543 /* Mark for Brotli decompression */
2544 csp->content_type |= CT_BROTLI;
2546 csp->content_type |= CT_TABOO;
2549 else if (strstr(*header, "compress"))
2552 * We can't decompress this; therefore we can't filter
2555 csp->content_type |= CT_TABOO;
2557 #else /* !defined(FEATURE_ZLIB) */
2559 * XXX: Using a black list here isn't the right approach.
2561 * In case of SDCH, building with zlib support isn't
2564 if (strstr(*header, "gzip") ||
2565 strstr(*header, "compress") ||
2566 strstr(*header, "deflate") ||
2567 strstr(*header, "sdch"))
2570 * Body is compressed, turn off pcrs and gif filtering.
2572 csp->content_type |= CT_TABOO;
2575 * Log a warning if the user expects the content to be filtered.
2577 if (content_filters_enabled(csp->action))
2579 log_error(LOG_LEVEL_INFO,
2580 "Compressed content detected, content filtering disabled. "
2581 "Consider recompiling Privoxy with zlib support or "
2582 "enable the prevent-compression action.");
2585 #endif /* defined(FEATURE_ZLIB) */
2593 /*********************************************************************
2595 * Function : server_adjust_content_encoding
2597 * Description : Remove the Content-Encoding header if the
2598 * decompression was successful and the content
2599 * has been modified.
2602 * 1 : csp = Current client state (buffers, headers, etc...)
2603 * 2 : header = On input, pointer to header to modify.
2604 * On output, pointer to the modified header, or NULL
2605 * to remove the header. This function frees the
2606 * original string if necessary.
2608 * Returns : JB_ERR_OK on success, or
2609 * JB_ERR_MEMORY on out-of-memory error.
2611 *********************************************************************/
2612 static jb_err server_adjust_content_encoding(struct client_state *csp, char **header)
2614 if ((csp->flags & CSP_FLAG_MODIFIED)
2615 && ((csp->content_type & (CT_GZIP | CT_DEFLATE))
2616 #ifdef FEATURE_BROTLI
2617 || (csp->content_type & CT_BROTLI)
2623 * We successfully decompressed the content,
2624 * and have to clean the header now, so the
2625 * client no longer expects compressed data.
2627 * XXX: There is a difference between cleaning
2628 * and removing it completely.
2630 log_error(LOG_LEVEL_HEADER, "Crunching: %s", *header);
2637 #endif /* defined(FEATURE_ZLIB) */
2640 /*********************************************************************
2642 * Function : header_adjust_content_length
2644 * Description : Replace given header with new Content-Length header.
2647 * 1 : header = On input, pointer to header to modify.
2648 * On output, pointer to the modified header, or NULL
2649 * to remove the header. This function frees the
2650 * original string if necessary.
2651 * 2 : content_length = content length value to set
2653 * Returns : JB_ERR_OK on success, or
2654 * JB_ERR_MEMORY on out-of-memory error.
2656 *********************************************************************/
2657 jb_err header_adjust_content_length(char **header, size_t content_length)
2659 const size_t header_length = 50;
2661 *header = malloc(header_length);
2662 if (*header == NULL)
2664 return JB_ERR_MEMORY;
2666 create_content_length_header(content_length, *header, header_length);
2671 /*********************************************************************
2673 * Function : server_adjust_content_length
2675 * Description : Adjust Content-Length header if we modified
2679 * 1 : csp = Current client state (buffers, headers, etc...)
2680 * 2 : header = On input, pointer to header to modify.
2681 * On output, pointer to the modified header, or NULL
2682 * to remove the header. This function frees the
2683 * original string if necessary.
2685 * Returns : JB_ERR_OK on success, or
2686 * JB_ERR_MEMORY on out-of-memory error.
2688 *********************************************************************/
2689 static jb_err server_adjust_content_length(struct client_state *csp, char **header)
2691 /* Regenerate header if the content was modified. */
2692 if (csp->flags & CSP_FLAG_MODIFIED)
2694 if (JB_ERR_OK != header_adjust_content_length(header, csp->content_length))
2696 return JB_ERR_MEMORY;
2698 log_error(LOG_LEVEL_HEADER,
2699 "Adjusted Content-Length to %llu", csp->content_length);
2706 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2707 /*********************************************************************
2709 * Function : server_save_content_length
2711 * Description : Save the Content-Length sent by the server.
2714 * 1 : csp = Current client state (buffers, headers, etc...)
2715 * 2 : header = On input, pointer to header to modify.
2716 * On output, pointer to the modified header, or NULL
2717 * to remove the header. This function frees the
2718 * original string if necessary.
2720 * Returns : JB_ERR_OK on success, or
2721 * JB_ERR_MEMORY on out-of-memory error.
2723 *********************************************************************/
2724 static jb_err server_save_content_length(struct client_state *csp, char **header)
2726 unsigned long long content_length = 0;
2727 const char *header_value;
2729 assert(*(*header+14) == ':');
2731 header_value = *header + 15;
2732 if (JB_ERR_OK != get_content_length(header_value, &content_length))
2734 log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
2739 csp->expected_content_length = content_length;
2740 csp->flags |= CSP_FLAG_SERVER_CONTENT_LENGTH_SET;
2741 csp->flags |= CSP_FLAG_CONTENT_LENGTH_SET;
2746 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2749 /*********************************************************************
2751 * Function : server_content_md5
2753 * Description : Crumble any Content-MD5 headers if the document was
2754 * modified. FIXME: Should we re-compute instead?
2757 * 1 : csp = Current client state (buffers, headers, etc...)
2758 * 2 : header = On input, pointer to header to modify.
2759 * On output, pointer to the modified header, or NULL
2760 * to remove the header. This function frees the
2761 * original string if necessary.
2763 * Returns : JB_ERR_OK on success, or
2764 * JB_ERR_MEMORY on out-of-memory error.
2766 *********************************************************************/
2767 static jb_err server_content_md5(struct client_state *csp, char **header)
2769 if (csp->flags & CSP_FLAG_MODIFIED)
2771 log_error(LOG_LEVEL_HEADER, "Crunching Content-MD5");
2779 /*********************************************************************
2781 * Function : server_content_disposition
2783 * Description : If enabled, blocks or modifies the "Content-Disposition" header.
2784 * Called from `sed'.
2787 * 1 : csp = Current client state (buffers, headers, etc...)
2788 * 2 : header = On input, pointer to header to modify.
2789 * On output, pointer to the modified header, or NULL
2790 * to remove the header. This function frees the
2791 * original string if necessary.
2793 * Returns : JB_ERR_OK on success, or
2794 * JB_ERR_MEMORY on out-of-memory error.
2796 *********************************************************************/
2797 static jb_err server_content_disposition(struct client_state *csp, char **header)
2802 * Are we messing with the Content-Disposition header?
2804 if ((csp->action->flags & ACTION_HIDE_CONTENT_DISPOSITION) == 0)
2810 newval = csp->action->string[ACTION_STRING_CONTENT_DISPOSITION];
2812 if ((newval == NULL) || (0 == strcmpic(newval, "block")))
2815 * Blocking content-disposition header
2817 log_error(LOG_LEVEL_HEADER, "Crunching %s!", *header);
2824 * Replacing Content-Disposition header
2827 *header = strdup("Content-Disposition: ");
2828 string_append(header, newval);
2830 if (*header != NULL)
2832 log_error(LOG_LEVEL_HEADER,
2833 "Content-Disposition header crunched and replaced with: %s", *header);
2836 return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
2840 /*********************************************************************
2842 * Function : server_last_modified
2844 * Description : Changes Last-Modified header to the actual date
2845 * to help hide-if-modified-since.
2846 * Called from `sed'.
2849 * 1 : csp = Current client state (buffers, headers, etc...)
2850 * 2 : header = On input, pointer to header to modify.
2851 * On output, pointer to the modified header, or NULL
2852 * to remove the header. This function frees the
2853 * original string if necessary.
2855 * Returns : JB_ERR_OK on success, or
2856 * JB_ERR_MEMORY on out-of-memory error.
2858 *********************************************************************/
2859 static jb_err server_last_modified(struct client_state *csp, char **header)
2862 time_t last_modified;
2866 * Are we messing with the Last-Modified header?
2868 if ((csp->action->flags & ACTION_OVERWRITE_LAST_MODIFIED) == 0)
2874 newval = csp->action->string[ACTION_STRING_LAST_MODIFIED];
2876 if (0 == strcmpic(newval, "block"))
2879 * Blocking Last-Modified header. Useless but why not.
2881 log_error(LOG_LEVEL_HEADER, "Crunching %s!", *header);
2885 else if (0 == strcmpic(newval, "reset-to-request-time"))
2888 * Setting Last-Modified Header to now.
2891 get_http_time(0, buf, sizeof(buf));
2893 *header = strdup("Last-Modified: ");
2894 string_append(header, buf);
2896 if (*header == NULL)
2898 log_error(LOG_LEVEL_HEADER, "Insufficient memory. Last-Modified header got lost, boohoo.");
2902 log_error(LOG_LEVEL_HEADER, "Reset to present time: %s", *header);
2905 else if (0 == strcmpic(newval, "randomize"))
2907 log_error(LOG_LEVEL_HEADER, "Randomizing: %s", *header);
2909 if (JB_ERR_OK != parse_time_header(*header, &last_modified))
2911 log_error(LOG_LEVEL_HEADER,
2912 "Couldn't parse time in %s (crunching!)", *header);
2918 struct tm *timeptr = NULL;
2923 rtime = (long int)difftime(now, last_modified);
2926 long int days, hours, minutes, seconds;
2927 const int negative_delta = (rtime < 0);
2932 log_error(LOG_LEVEL_HEADER, "Server time in the future.");
2934 rtime = pick_from_range(rtime);
2939 last_modified += rtime;
2940 timeptr = privoxy_gmtime_r(&last_modified, &gmt);
2941 if ((NULL == timeptr) || !strftime(newheader,
2942 sizeof(newheader), "%a, %d %b %Y %H:%M:%S GMT", timeptr))
2944 log_error(LOG_LEVEL_ERROR,
2945 "Randomizing '%s' failed. Crunching the header without replacement.",
2951 *header = strdup("Last-Modified: ");
2952 string_append(header, newheader);
2954 if (*header == NULL)
2956 log_error(LOG_LEVEL_ERROR, "Insufficient memory, header crunched without replacement.");
2957 return JB_ERR_MEMORY;
2960 days = rtime / (3600 * 24);
2961 hours = rtime / 3600 % 24;
2962 minutes = rtime / 60 % 60;
2963 seconds = rtime % 60;
2965 log_error(LOG_LEVEL_HEADER,
2966 "Randomized: %s (added %ld da%s %ld hou%s %ld minut%s %ld second%s",
2967 *header, days, (days == 1) ? "y" : "ys", hours, (hours == 1) ? "r" : "rs",
2968 minutes, (minutes == 1) ? "e" : "es", seconds, (seconds == 1) ? ")" : "s)");
2972 log_error(LOG_LEVEL_HEADER, "Randomized ... or not. No time difference to work with.");
2981 /*********************************************************************
2983 * Function : client_accept_encoding
2985 * Description : Rewrite the client's Accept-Encoding header so that
2986 * if doesn't allow compression, if the action applies.
2987 * Note: For HTTP/1.0 the absence of the header is enough.
2990 * 1 : csp = Current client state (buffers, headers, etc...)
2991 * 2 : header = On input, pointer to header to modify.
2992 * On output, pointer to the modified header, or NULL
2993 * to remove the header. This function frees the
2994 * original string if necessary.
2996 * Returns : JB_ERR_OK on success, or
2997 * JB_ERR_MEMORY on out-of-memory error.
2999 *********************************************************************/
3000 static jb_err client_accept_encoding(struct client_state *csp, char **header)
3002 #ifdef FEATURE_COMPRESSION
3003 if ((csp->config->feature_flags & RUNTIME_FEATURE_COMPRESSION)
3004 && strstr(*header, "deflate"))
3006 csp->flags |= CSP_FLAG_CLIENT_SUPPORTS_DEFLATE;
3009 if ((csp->action->flags & ACTION_NO_COMPRESSION) != 0)
3011 log_error(LOG_LEVEL_HEADER, "Suppressed offer to compress content");
3019 /*********************************************************************
3021 * Function : client_te
3023 * Description : Rewrite the client's TE header so that
3024 * if doesn't allow compression, if the action applies.
3027 * 1 : csp = Current client state (buffers, headers, etc...)
3028 * 2 : header = On input, pointer to header to modify.
3029 * On output, pointer to the modified header, or NULL
3030 * to remove the header. This function frees the
3031 * original string if necessary.
3033 * Returns : JB_ERR_OK on success, or
3034 * JB_ERR_MEMORY on out-of-memory error.
3036 *********************************************************************/
3037 static jb_err client_te(struct client_state *csp, char **header)
3039 if ((csp->action->flags & ACTION_NO_COMPRESSION) != 0)
3042 log_error(LOG_LEVEL_HEADER, "Suppressed offer to compress transfer");
3049 /*********************************************************************
3051 * Function : client_referrer
3053 * Description : Handle the "referer" config setting properly.
3054 * Called from `sed'.
3057 * 1 : csp = Current client state (buffers, headers, etc...)
3058 * 2 : header = On input, pointer to header to modify.
3059 * On output, pointer to the modified header, or NULL
3060 * to remove the header. This function frees the
3061 * original string if necessary.
3063 * Returns : JB_ERR_OK on success, or
3064 * JB_ERR_MEMORY on out-of-memory error.
3066 *********************************************************************/
3067 static jb_err client_referrer(struct client_state *csp, char **header)
3069 const char *parameter;
3070 /* booleans for parameters we have to check multiple times */
3071 int parameter_conditional_block;
3072 int parameter_conditional_forge;
3074 #ifdef FEATURE_FORCE_LOAD
3076 * Since the referrer can include the prefix even
3077 * if the request itself is non-forced, we must
3078 * clean it unconditionally.
3080 * XXX: strclean is too broad
3082 strclean(*header, FORCE_PREFIX);
3083 #endif /* def FEATURE_FORCE_LOAD */
3085 if ((csp->action->flags & ACTION_HIDE_REFERER) == 0)
3087 /* Nothing left to do */
3091 parameter = csp->action->string[ACTION_STRING_REFERER];
3092 assert(parameter != NULL);
3093 parameter_conditional_block = (0 == strcmpic(parameter, "conditional-block"));
3094 parameter_conditional_forge = (0 == strcmpic(parameter, "conditional-forge"));
3096 if (!parameter_conditional_block && !parameter_conditional_forge)
3099 * As conditional-block and conditional-forge are the only
3100 * parameters that rely on the original referrer, we can
3101 * remove it now for all the others.
3106 if (0 == strcmpic(parameter, "block"))
3108 log_error(LOG_LEVEL_HEADER, "Referer crunched!");
3111 else if (parameter_conditional_block || parameter_conditional_forge)
3113 return handle_conditional_hide_referrer_parameter(header,
3114 csp->http->hostport, parameter_conditional_block);
3116 else if (0 == strcmpic(parameter, "forge"))
3118 return create_forged_referrer(header, csp->http->hostport);
3122 /* interpret parameter as user-supplied referer to fake */
3123 return create_fake_referrer(header, parameter);
3128 /*********************************************************************
3130 * Function : client_accept_language
3132 * Description : Handle the "Accept-Language" config setting properly.
3133 * Called from `sed'.
3136 * 1 : csp = Current client state (buffers, headers, etc...)
3137 * 2 : header = On input, pointer to header to modify.
3138 * On output, pointer to the modified header, or NULL
3139 * to remove the header. This function frees the
3140 * original string if necessary.
3142 * Returns : JB_ERR_OK on success, or
3143 * JB_ERR_MEMORY on out-of-memory error.
3145 *********************************************************************/
3146 static jb_err client_accept_language(struct client_state *csp, char **header)
3151 * Are we messing with the Accept-Language?
3153 if ((csp->action->flags & ACTION_HIDE_ACCEPT_LANGUAGE) == 0)
3155 /*I don't think so*/
3159 newval = csp->action->string[ACTION_STRING_LANGUAGE];
3161 if ((newval == NULL) || (0 == strcmpic(newval, "block")))
3164 * Blocking Accept-Language header
3166 log_error(LOG_LEVEL_HEADER, "Crunching Accept-Language!");
3173 * Replacing Accept-Language header
3176 *header = strdup("Accept-Language: ");
3177 string_append(header, newval);
3179 if (*header == NULL)
3181 log_error(LOG_LEVEL_ERROR,
3182 "Insufficient memory. Accept-Language header crunched without replacement.");
3186 log_error(LOG_LEVEL_HEADER,
3187 "Accept-Language header crunched and replaced with: %s", *header);
3190 return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
3194 /*********************************************************************
3196 * Function : crunch_client_header
3198 * Description : Crunch client header if it matches a string supplied by the
3199 * user. Called from `sed'.
3202 * 1 : csp = Current client state (buffers, headers, etc...)
3203 * 2 : header = On input, pointer to header to modify.
3204 * On output, pointer to the modified header, or NULL
3205 * to remove the header. This function frees the
3206 * original string if necessary.
3208 * Returns : JB_ERR_OK on success and always succeeds
3210 *********************************************************************/
3211 static jb_err crunch_client_header(struct client_state *csp, char **header)
3213 const char *crunch_pattern;
3215 /* Do we feel like crunching? */
3216 if ((csp->action->flags & ACTION_CRUNCH_CLIENT_HEADER))
3218 crunch_pattern = csp->action->string[ACTION_STRING_CLIENT_HEADER];
3220 /* Is the current header the lucky one? */
3221 if (strstr(*header, crunch_pattern))
3223 log_error(LOG_LEVEL_HEADER, "Crunching client header: %s (contains: %s)", *header, crunch_pattern);
3231 /*********************************************************************
3233 * Function : client_uagent
3235 * Description : Handle the "user-agent" config setting properly
3236 * and remember its original value to enable browser
3237 * bug workarounds. Called from `sed'.
3240 * 1 : csp = Current client state (buffers, headers, etc...)
3241 * 2 : header = On input, pointer to header to modify.
3242 * On output, pointer to the modified header, or NULL
3243 * to remove the header. This function frees the
3244 * original string if necessary.
3246 * Returns : JB_ERR_OK on success, or
3247 * JB_ERR_MEMORY on out-of-memory error.
3249 *********************************************************************/
3250 static jb_err client_uagent(struct client_state *csp, char **header)
3254 if ((csp->action->flags & ACTION_HIDE_USER_AGENT) == 0)
3259 newval = csp->action->string[ACTION_STRING_USER_AGENT];
3266 *header = strdup("User-Agent: ");
3267 string_append(header, newval);
3269 log_error(LOG_LEVEL_HEADER, "Modified: %s", *header);
3271 return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
3275 /*********************************************************************
3277 * Function : client_ua
3279 * Description : Handle "ua-" headers properly. Called from `sed'.
3282 * 1 : csp = Current client state (buffers, headers, etc...)
3283 * 2 : header = On input, pointer to header to modify.
3284 * On output, pointer to the modified header, or NULL
3285 * to remove the header. This function frees the
3286 * original string if necessary.
3288 * Returns : JB_ERR_OK on success, or
3289 * JB_ERR_MEMORY on out-of-memory error.
3291 *********************************************************************/
3292 static jb_err client_ua(struct client_state *csp, char **header)
3294 if ((csp->action->flags & ACTION_HIDE_USER_AGENT) != 0)
3296 log_error(LOG_LEVEL_HEADER, "crunched User-Agent!");
3304 /*********************************************************************
3306 * Function : client_from
3308 * Description : Handle the "from" config setting properly.
3309 * Called from `sed'.
3312 * 1 : csp = Current client state (buffers, headers, etc...)
3313 * 2 : header = On input, pointer to header to modify.
3314 * On output, pointer to the modified header, or NULL
3315 * to remove the header. This function frees the
3316 * original string if necessary.
3318 * Returns : JB_ERR_OK on success, or
3319 * JB_ERR_MEMORY on out-of-memory error.
3321 *********************************************************************/
3322 static jb_err client_from(struct client_state *csp, char **header)
3326 if ((csp->action->flags & ACTION_HIDE_FROM) == 0)
3333 newval = csp->action->string[ACTION_STRING_FROM];
3336 * Are we blocking the e-mail address?
3338 if ((newval == NULL) || (0 == strcmpic(newval, "block")))
3340 log_error(LOG_LEVEL_HEADER, "crunched From!");
3344 log_error(LOG_LEVEL_HEADER, " modified");
3346 *header = strdup("From: ");
3347 string_append(header, newval);
3349 return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
3353 /*********************************************************************
3355 * Function : client_send_cookie
3357 * Description : Crunches the "cookie" header if necessary.
3358 * Called from `sed'.
3360 * XXX: Stupid name, doesn't send squat.
3363 * 1 : csp = Current client state (buffers, headers, etc...)
3364 * 2 : header = On input, pointer to header to modify.
3365 * On output, pointer to the modified header, or NULL
3366 * to remove the header. This function frees the
3367 * original string if necessary.
3369 * Returns : JB_ERR_OK on success, or
3370 * JB_ERR_MEMORY on out-of-memory error.
3372 *********************************************************************/
3373 static jb_err client_send_cookie(struct client_state *csp, char **header)
3375 if (csp->action->flags & ACTION_CRUNCH_OUTGOING_COOKIES)
3377 log_error(LOG_LEVEL_HEADER, "Crunched outgoing cookie: %s", *header);
3385 /*********************************************************************
3387 * Function : client_x_forwarded
3389 * Description : Handle the "x-forwarded-for" config setting properly,
3390 * also used in the add_client_headers list. Called from `sed'.
3393 * 1 : csp = Current client state (buffers, headers, etc...)
3394 * 2 : header = On input, pointer to header to modify.
3395 * On output, pointer to the modified header, or NULL
3396 * to remove the header. This function frees the
3397 * original string if necessary.
3399 * Returns : JB_ERR_OK on success, or
3400 * JB_ERR_MEMORY on out-of-memory error.
3402 *********************************************************************/
3403 jb_err client_x_forwarded(struct client_state *csp, char **header)
3405 if (0 != (csp->action->flags & ACTION_CHANGE_X_FORWARDED_FOR))
3407 const char *parameter = csp->action->string[ACTION_STRING_CHANGE_X_FORWARDED_FOR];
3409 if (0 == strcmpic(parameter, "block"))
3412 log_error(LOG_LEVEL_HEADER, "crunched x-forwarded-for!");
3414 else if (0 == strcmpic(parameter, "add"))
3416 string_append(header, ", ");
3417 string_append(header, csp->ip_addr_str);
3419 if (*header == NULL)
3421 return JB_ERR_MEMORY;
3423 log_error(LOG_LEVEL_HEADER,
3424 "Appended client IP address to %s", *header);
3425 csp->flags |= CSP_FLAG_X_FORWARDED_FOR_APPENDED;
3429 log_error(LOG_LEVEL_FATAL,
3430 "Invalid change-x-forwarded-for parameter: '%s'", parameter);
3438 /*********************************************************************
3440 * Function : client_max_forwards
3442 * Description : If the HTTP method is OPTIONS or TRACE, subtract one
3443 * from the value of the Max-Forwards header field.
3446 * 1 : csp = Current client state (buffers, headers, etc...)
3447 * 2 : header = On input, pointer to header to modify.
3448 * On output, pointer to the modified header, or NULL
3449 * to remove the header. This function frees the
3450 * original string if necessary.
3452 * Returns : JB_ERR_OK on success, or
3453 * JB_ERR_MEMORY on out-of-memory error.
3455 *********************************************************************/
3456 static jb_err client_max_forwards(struct client_state *csp, char **header)
3460 if ((0 == strcmpic(csp->http->gpc, "trace")) ||
3461 (0 == strcmpic(csp->http->gpc, "options")))
3463 assert(*(*header+12) == ':');
3464 if (1 == sscanf(*header+12, ": %d", &max_forwards))
3466 if (max_forwards > 0)
3468 snprintf(*header, strlen(*header)+1, "Max-Forwards: %d", --max_forwards);
3469 log_error(LOG_LEVEL_HEADER,
3470 "Max-Forwards value for %s request reduced to %d.",
3471 csp->http->gpc, max_forwards);
3473 else if (max_forwards < 0)
3475 log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
3481 log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
3490 /*********************************************************************
3492 * Function : client_host
3494 * Description : If the request URI did not contain host and
3495 * port information, parse and evaluate the Host
3499 * 1 : csp = Current client state (buffers, headers, etc...)
3500 * 2 : header = On input, pointer to header to modify.
3501 * On output, pointer to the modified header, or NULL
3502 * to remove the header. This function frees the
3503 * original string if necessary.
3505 * Returns : JB_ERR_OK on success, or
3506 * JB_ERR_MEMORY on out-of-memory error.
3508 *********************************************************************/
3509 static jb_err client_host(struct client_state *csp, char **header)
3513 if (strlen(*header) < 7)
3515 log_error(LOG_LEVEL_HEADER, "Removing empty Host header");
3520 if (!csp->http->hostport || (*csp->http->hostport == '*') ||
3521 *csp->http->hostport == ' ' || *csp->http->hostport == '\0')
3524 p = strdup_or_die((*header)+6);
3526 q = strdup_or_die(p);
3528 freez(csp->http->hostport);
3529 csp->http->hostport = p;
3530 freez(csp->http->host);
3531 csp->http->host = q;
3532 q = strchr(csp->http->host, ':');
3535 /* Terminate hostname and evaluate port string */
3537 csp->http->port = atoi(q);
3541 csp->http->port = csp->http->ssl ? 443 : 80;
3544 log_error(LOG_LEVEL_HEADER, "New host and port from Host field: %s = %s:%d",
3545 csp->http->hostport, csp->http->host, csp->http->port);
3548 /* Signal client_host_adder() to return right away */
3549 csp->flags |= CSP_FLAG_HOST_HEADER_IS_SET;
3555 /*********************************************************************
3557 * Function : client_if_modified_since
3559 * Description : Remove or modify the If-Modified-Since header.
3562 * 1 : csp = Current client state (buffers, headers, etc...)
3563 * 2 : header = On input, pointer to header to modify.
3564 * On output, pointer to the modified header, or NULL
3565 * to remove the header. This function frees the
3566 * original string if necessary.
3568 * Returns : JB_ERR_OK on success, or
3569 * JB_ERR_MEMORY on out-of-memory error.
3571 *********************************************************************/
3572 static jb_err client_if_modified_since(struct client_state *csp, char **header)
3576 struct tm *timeptr = NULL;
3581 if (0 == strcmpic(*header, "If-Modified-Since: Wed, 08 Jun 1955 12:00:00 GMT"))
3584 * The client got an error message because of a temporary problem,
3585 * the problem is gone and the client now tries to revalidate our
3586 * error message on the real server. The revalidation would always
3587 * end with the transmission of the whole document and there is
3588 * no need to expose the bogus If-Modified-Since header.
3590 log_error(LOG_LEVEL_HEADER, "Crunching useless If-Modified-Since header.");
3593 else if (csp->action->flags & ACTION_HIDE_IF_MODIFIED_SINCE)
3595 newval = csp->action->string[ACTION_STRING_IF_MODIFIED_SINCE];
3597 if ((0 == strcmpic(newval, "block")))
3599 log_error(LOG_LEVEL_HEADER, "Crunching %s", *header);
3602 else /* add random value */
3604 if (JB_ERR_OK != parse_time_header(*header, &tm))
3606 log_error(LOG_LEVEL_HEADER,
3607 "Couldn't parse time in %s (crunching!)", *header);
3612 long int hours, minutes, seconds;
3613 long int rtime = strtol(newval, &endptr, 0);
3614 const int negative_range = (rtime < 0);
3618 log_error(LOG_LEVEL_HEADER, "Randomizing: %s (random range: %ld minut%s)",
3619 *header, rtime, (rtime == 1 || rtime == -1) ? "e": "es");
3625 rtime = pick_from_range(rtime);
3629 log_error(LOG_LEVEL_ERROR,
3630 "Random range is 0. Assuming time transformation test.");
3632 tm += rtime * (negative_range ? -1 : 1);
3633 timeptr = privoxy_gmtime_r(&tm, &gmt);
3634 if ((NULL == timeptr) || !strftime(newheader,
3635 sizeof(newheader), "%a, %d %b %Y %H:%M:%S GMT", timeptr))
3637 log_error(LOG_LEVEL_ERROR,
3638 "Randomizing '%s' failed. Crunching the header without replacement.",
3644 *header = strdup("If-Modified-Since: ");
3645 string_append(header, newheader);
3647 if (*header == NULL)
3649 log_error(LOG_LEVEL_HEADER, "Insufficient memory, header crunched without replacement.");
3650 return JB_ERR_MEMORY;
3653 hours = rtime / 3600;
3654 minutes = rtime / 60 % 60;
3655 seconds = rtime % 60;
3657 log_error(LOG_LEVEL_HEADER,
3658 "Randomized: %s (%s %ld hou%s %ld minut%s %ld second%s",
3659 *header, (negative_range) ? "subtracted" : "added", hours,
3660 (hours == 1) ? "r" : "rs", minutes, (minutes == 1) ? "e" : "es",
3661 seconds, (seconds == 1) ? ")" : "s)");
3670 /*********************************************************************
3672 * Function : client_if_none_match
3674 * Description : Remove the If-None-Match header.
3677 * 1 : csp = Current client state (buffers, headers, etc...)
3678 * 2 : header = On input, pointer to header to modify.
3679 * On output, pointer to the modified header, or NULL
3680 * to remove the header. This function frees the
3681 * original string if necessary.
3683 * Returns : JB_ERR_OK on success, or
3684 * JB_ERR_MEMORY on out-of-memory error.
3686 *********************************************************************/
3687 static jb_err client_if_none_match(struct client_state *csp, char **header)
3689 if (csp->action->flags & ACTION_CRUNCH_IF_NONE_MATCH)
3691 log_error(LOG_LEVEL_HEADER, "Crunching %s", *header);
3699 /*********************************************************************
3701 * Function : client_x_filter
3703 * Description : Disables filtering if the client set "X-Filter: No".
3704 * Called from `sed'.
3707 * 1 : csp = Current client state (buffers, headers, etc...)
3708 * 2 : header = On input, pointer to header to modify.
3709 * On output, pointer to the modified header, or NULL
3710 * to remove the header. This function frees the
3711 * original string if necessary.
3713 * Returns : JB_ERR_OK on success
3715 *********************************************************************/
3716 jb_err client_x_filter(struct client_state *csp, char **header)
3718 if (0 == strcmpic(*header, "X-Filter: No"))
3720 if (!(csp->config->feature_flags & RUNTIME_FEATURE_HTTP_TOGGLE))
3722 log_error(LOG_LEVEL_INFO, "Ignored the client's request to fetch without filtering.");
3726 if (csp->action->flags & ACTION_FORCE_TEXT_MODE)
3728 log_error(LOG_LEVEL_HEADER,
3729 "force-text-mode overruled the client's request to fetch without filtering!");
3733 csp->content_type = CT_TABOO; /* XXX: This hack shouldn't be necessary */
3734 csp->flags |= CSP_FLAG_NO_FILTERING;
3735 log_error(LOG_LEVEL_HEADER, "Accepted the client's request to fetch without filtering.");
3737 log_error(LOG_LEVEL_HEADER, "Crunching %s", *header);
3745 /*********************************************************************
3747 * Function : client_range
3749 * Description : Removes Range, Request-Range and If-Range headers if
3750 * content filtering is enabled and the range doesn't
3753 * If the client's version of the document has been
3754 * altered by Privoxy, the server could interpret the
3755 * range differently than the client intended in which
3756 * case the user could end up with corrupted content.
3758 * If the range starts at byte 0 this isn't an issue
3759 * so the header can pass. Partial requests like this
3760 * are used to render preview images for videos without
3761 * downloading the whole video.
3763 * While HTTP doesn't require that range requests are
3764 * honoured and the client could simply abort the download
3765 * after receiving a sufficient amount of data, various
3766 * clients don't handle complete responses to range
3767 * requests gracefully and emit misleading error messages
3771 * 1 : csp = Current client state (buffers, headers, etc...)
3772 * 2 : header = On input, pointer to header to modify.
3773 * On output, pointer to the modified header, or NULL
3774 * to remove the header. This function frees the
3775 * original string if necessary.
3777 * Returns : JB_ERR_OK
3779 *********************************************************************/
3780 static jb_err client_range(struct client_state *csp, char **header)
3782 if (content_filters_enabled(csp->action)
3783 && (0 != strncmpic(strstr(*header, ":"), ": bytes=0-", 10)))
3785 log_error(LOG_LEVEL_HEADER, "Content filtering is enabled."
3786 " Crunching: \'%s\' to prevent range-mismatch problems.", *header);
3793 /* the following functions add headers directly to the header list */
3795 /*********************************************************************
3797 * Function : client_host_adder
3799 * Description : Adds the Host: header field if it is missing.
3800 * Called from `sed'.
3803 * 1 : csp = Current client state (buffers, headers, etc...)
3805 * Returns : JB_ERR_OK on success, or
3806 * JB_ERR_MEMORY on out-of-memory error.
3808 *********************************************************************/
3809 static jb_err client_host_adder(struct client_state *csp)
3814 if (csp->flags & CSP_FLAG_HOST_HEADER_IS_SET)
3816 /* Header already set by the client, nothing to do. */
3820 if (!csp->http->hostport || !*(csp->http->hostport))
3822 log_error(LOG_LEVEL_ERROR, "Destination host unknown.");
3823 return JB_ERR_PARSE;
3827 * remove 'user:pass@' from 'proto://user:pass@host'
3829 if ((p = strchr( csp->http->hostport, '@')) != NULL)
3835 p = csp->http->hostport;
3838 /* XXX: Just add it, we already made sure that it will be unique */
3839 log_error(LOG_LEVEL_HEADER, "addh-unique: Host: %s", p);
3840 err = enlist_unique_header(csp->headers, "Host", p);
3846 /*********************************************************************
3848 * Function : client_xtra_adder
3850 * Description : Used in the add_client_headers list. Called from `sed'.
3853 * 1 : csp = Current client state (buffers, headers, etc...)
3855 * Returns : JB_ERR_OK on success, or
3856 * JB_ERR_MEMORY on out-of-memory error.
3858 *********************************************************************/
3859 static jb_err client_xtra_adder(struct client_state *csp)
3861 struct list_entry *lst;
3864 for (lst = csp->action->multi[ACTION_MULTI_ADD_HEADER]->first;
3865 lst ; lst = lst->next)
3867 log_error(LOG_LEVEL_HEADER, "addh: %s", lst->str);
3868 err = enlist(csp->headers, lst->str);
3880 /*********************************************************************
3882 * Function : client_x_forwarded_for_adder
3884 * Description : Used in the add_client_headers list. Called from `sed'.
3887 * 1 : csp = Current client state (buffers, headers, etc...)
3889 * Returns : JB_ERR_OK on success, or
3890 * JB_ERR_MEMORY on out-of-memory error.
3892 *********************************************************************/
3893 static jb_err client_x_forwarded_for_adder(struct client_state *csp)
3895 char *header = NULL;
3898 if (!((csp->action->flags & ACTION_CHANGE_X_FORWARDED_FOR)
3899 && (0 == strcmpic(csp->action->string[ACTION_STRING_CHANGE_X_FORWARDED_FOR], "add")))
3900 || (csp->flags & CSP_FLAG_X_FORWARDED_FOR_APPENDED))
3903 * If we aren't adding X-Forwarded-For headers,
3904 * or we already appended an existing X-Forwarded-For
3905 * header, there's nothing left to do here.
3910 header = strdup("X-Forwarded-For: ");
3911 string_append(&header, csp->ip_addr_str);
3915 return JB_ERR_MEMORY;
3918 log_error(LOG_LEVEL_HEADER, "addh: %s", header);
3919 err = enlist(csp->headers, header);
3926 /*********************************************************************
3928 * Function : server_connection_adder
3930 * Description : Adds an appropriate "Connection:" header to csp->headers
3931 * unless the header was already present. Called from `sed'.
3934 * 1 : csp = Current client state (buffers, headers, etc...)
3936 * Returns : JB_ERR_OK on success, or
3937 * JB_ERR_MEMORY on out-of-memory error.
3939 *********************************************************************/
3940 static jb_err server_connection_adder(struct client_state *csp)
3942 const unsigned int flags = csp->flags;
3943 const char *response_status_line = csp->headers->first->str;
3944 static const char connection_close[] = "Connection: close";
3946 if ((flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
3947 && (flags & CSP_FLAG_SERVER_CONNECTION_HEADER_SET))
3953 * XXX: if we downgraded the response, this check will fail.
3955 if ((csp->config->feature_flags &
3956 RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
3957 && (NULL != response_status_line)
3958 && !strncmpic(response_status_line, "HTTP/1.1", 8)
3959 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
3960 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
3964 log_error(LOG_LEVEL_HEADER, "A HTTP/1.1 response "
3965 "without Connection header implies keep-alive.");
3966 csp->flags |= CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE;
3970 log_error(LOG_LEVEL_HEADER, "Adding: %s", connection_close);
3972 return enlist(csp->headers, connection_close);
3976 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
3977 /*********************************************************************
3979 * Function : server_proxy_connection_adder
3981 * Description : Adds a "Proxy-Connection: keep-alive" header to
3982 * csp->headers when appropriate.
3985 * 1 : csp = Current client state (buffers, headers, etc...)
3987 * Returns : JB_ERR_OK on success, or
3988 * JB_ERR_MEMORY on out-of-memory error.
3990 *********************************************************************/
3991 static jb_err server_proxy_connection_adder(struct client_state *csp)
3993 static const char proxy_connection_header[] = "Proxy-Connection: keep-alive";
3994 jb_err err = JB_ERR_OK;
3996 if ((csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
3997 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
3998 && !(csp->flags & CSP_FLAG_SERVER_PROXY_CONNECTION_HEADER_SET)
3999 && ((csp->flags & CSP_FLAG_SERVER_CONTENT_LENGTH_SET)
4000 || (csp->flags & CSP_FLAG_CHUNKED))
4001 #ifdef FEATURE_HTTPS_INSPECTION
4002 && !client_use_ssl(csp)
4007 log_error(LOG_LEVEL_HEADER, "Adding: %s", proxy_connection_header);
4008 err = enlist(csp->headers, proxy_connection_header);
4013 #endif /* FEATURE_CONNECTION_KEEP_ALIVE */
4016 /*********************************************************************
4018 * Function : client_connection_header_adder
4020 * Description : Adds a proper "Connection:" header to csp->headers
4021 * unless the header was already present or it's a
4022 * CONNECT request. Called from `sed'.
4025 * 1 : csp = Current client state (buffers, headers, etc...)
4027 * Returns : JB_ERR_OK on success, or
4028 * JB_ERR_MEMORY on out-of-memory error.
4030 *********************************************************************/
4031 static jb_err client_connection_header_adder(struct client_state *csp)
4033 static const char connection_close[] = "Connection: close";
4035 if (!(csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
4036 && (csp->flags & CSP_FLAG_CLIENT_CONNECTION_HEADER_SET))
4042 * In case of CONNECT requests "Connection: close" is implied,
4043 * but actually setting the header has been reported to cause
4044 * problems with some forwarding proxies that close the
4045 * connection prematurely.
4047 if (csp->http->ssl != 0)
4052 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
4053 if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
4054 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
4055 && !strcmpic(csp->http->version, "HTTP/1.1"))
4057 csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
4060 #endif /* FEATURE_CONNECTION_KEEP_ALIVE */
4062 log_error(LOG_LEVEL_HEADER, "Adding: %s", connection_close);
4064 return enlist(csp->headers, connection_close);
4068 /*********************************************************************
4070 * Function : server_http
4072 * Description : - Save the HTTP Status into csp->http->status
4073 * - Set CT_TABOO to prevent filtering if the answer
4074 * is a partial range (HTTP status 206)
4075 * - Rewrite HTTP/1.1 answers to HTTP/1.0 if +downgrade
4077 * - Normalize the HTTP-version.
4080 * 1 : csp = Current client state (buffers, headers, etc...)
4081 * 2 : header = On input, pointer to header to modify.
4082 * On output, pointer to the modified header, or NULL
4083 * to remove the header. This function frees the
4084 * original string if necessary.
4086 * Returns : JB_ERR_OK on success, or
4087 * JB_ERR_PARSE on fatal parse errors.
4089 *********************************************************************/
4090 static jb_err server_http(struct client_state *csp, char **header)
4092 char *reason_phrase = NULL;
4093 char *new_response_line;
4096 unsigned int major_version;
4097 unsigned int minor_version;
4099 /* Get the reason phrase which start after the second whitespace */
4100 p = strchr(*header, ' ');
4104 reason_phrase = strchr(p, ' ');
4107 if (reason_phrase != NULL)
4113 log_error(LOG_LEVEL_ERROR,
4114 "Response line lacks reason phrase: %s", *header);
4118 if (3 != sscanf(*header, "HTTP/%u.%u %d", &major_version,
4119 &minor_version, &(csp->http->status)))
4121 log_error(LOG_LEVEL_ERROR,
4122 "Failed to parse the response line: %s", *header);
4123 return JB_ERR_PARSE;
4126 if (csp->http->status == 101 ||
4127 csp->http->status == 206)
4129 csp->content_type = CT_TABOO;
4132 if (major_version != 1 || (minor_version != 0 && minor_version != 1))
4135 * According to RFC 7230 2.6 intermediaries MUST send
4136 * their own HTTP-version in forwarded messages.
4138 log_error(LOG_LEVEL_ERROR,
4139 "Unsupported HTTP version. Downgrading to 1.1.");
4144 if (((csp->action->flags & ACTION_DOWNGRADE) != 0) && (minor_version == 1))
4146 log_error(LOG_LEVEL_HEADER, "Downgrading answer to HTTP/1.0");
4150 /* Rebuild response line. */
4151 length = sizeof("HTTP/1.1 200 ") + strlen(reason_phrase) + 1;
4152 new_response_line = malloc_or_die(length);
4154 snprintf(new_response_line, length, "HTTP/%u.%u %d %s",
4155 major_version, minor_version, csp->http->status, reason_phrase);
4157 if (0 != strcmp(*header, new_response_line))
4159 log_error(LOG_LEVEL_HEADER, "Response line '%s' changed to '%s'",
4160 *header, new_response_line);
4164 *header = new_response_line;
4169 /*********************************************************************
4171 * Function : add_cooky_expiry_date
4173 * Description : Adds a cookie expiry date to a string.
4176 * 1 : cookie = On input, pointer to cookie to modify.
4177 * On output, pointer to the modified header.
4178 * The original string is freed.
4179 * 2 : lifetime = Seconds the cookie should be valid
4183 *********************************************************************/
4184 static void add_cookie_expiry_date(char **cookie, time_t lifetime)
4187 struct tm *timeptr = NULL;
4188 time_t expiry_date = time(NULL) + lifetime;
4191 timeptr = privoxy_gmtime_r(&expiry_date, &gmt);
4192 if (NULL == timeptr)
4194 log_error(LOG_LEVEL_FATAL,
4195 "Failed to get the time in add_cooky_expiry_date()");
4197 strftime(tmp, sizeof(tmp), "; expires=%a, %d-%b-%Y %H:%M:%S GMT", timeptr);
4198 if (JB_ERR_OK != string_append(cookie, tmp))
4200 log_error(LOG_LEVEL_FATAL, "Out of memory in add_cooky_expiry()");
4205 /*********************************************************************
4207 * Function : server_set_cookie
4209 * Description : Handle the server "cookie" header properly.
4210 * Crunch, accept or rewrite it to a session cookie.
4211 * Called from `sed'.
4214 * 1 : csp = Current client state (buffers, headers, etc...)
4215 * 2 : header = On input, pointer to header to modify.
4216 * On output, pointer to the modified header, or NULL
4217 * to remove the header. This function frees the
4218 * original string if necessary.
4220 * Returns : JB_ERR_OK on success, or
4221 * JB_ERR_MEMORY on out-of-memory error.
4223 *********************************************************************/
4224 static jb_err server_set_cookie(struct client_state *csp, char **header)
4226 if ((csp->action->flags & ACTION_CRUNCH_INCOMING_COOKIES) != 0)
4228 log_error(LOG_LEVEL_HEADER, "Crunching incoming cookie: %s", *header);
4231 else if ((0 != (csp->action->flags & ACTION_SESSION_COOKIES_ONLY))
4232 || (0 != (csp->action->flags & ACTION_LIMIT_COOKIE_LIFETIME)))
4236 long cookie_lifetime = 0;
4239 NO_EXPIRY_DATE_SPECIFIED,
4240 EXPIRY_DATE_ACCEPTABLE,
4241 EXPIRY_DATE_UNACCEPTABLE
4242 } expiry_date_status = NO_EXPIRY_DATE_SPECIFIED;
4244 /* A variable to store the tag we're working on */
4247 /* Skip "Set-Cookie:" (11 characters) in header */
4248 cur_tag = *header + 11;
4250 /* skip whitespace between "Set-Cookie:" and value */
4251 while (*cur_tag && privoxy_isspace(*cur_tag))
4258 if ((csp->action->flags & ACTION_LIMIT_COOKIE_LIFETIME) != 0)
4260 const char *param = csp->action->string[ACTION_STRING_LIMIT_COOKIE_LIFETIME];
4262 cookie_lifetime = strtol(param, NULL, 0);
4263 if (cookie_lifetime < 0)
4265 log_error(LOG_LEVEL_FATAL, "Invalid cookie lifetime limit: %s", param);
4267 cookie_lifetime *= 60;
4270 /* Loop through each tag in the cookie */
4274 char *next_tag = strchr(cur_tag, ';');
4275 if (next_tag != NULL)
4277 /* Skip the ';' character itself */
4280 /* skip whitespace ";" and start of tag */
4281 while (*next_tag && privoxy_isspace(*next_tag))
4288 /* "Next tag" is the end of the string */
4289 next_tag = cur_tag + strlen(cur_tag);
4293 * Check the expiration date to see
4294 * if the cookie is still valid, if yes,
4295 * rewrite it to a session cookie.
4297 if ((strncmpic(cur_tag, "expires=", 8) == 0) && *(cur_tag + 8))
4299 char *expiration_date = cur_tag + 8; /* Skip "[Ee]xpires=" */
4301 if ((expiration_date[0] == '"')
4302 && (expiration_date[1] != '\0'))
4305 * Skip quotation mark. RFC 2109 10.1.2 seems to hint
4306 * that the expiration date isn't supposed to be quoted,
4307 * but some servers do it anyway.
4312 /* Did we detect the date properly? */
4313 if (JB_ERR_OK != parse_header_time(expiration_date, &cookie_time))
4316 * Nope, treat it as if it was still valid.
4318 * XXX: Should we remove the whole cookie instead?
4320 log_error(LOG_LEVEL_ERROR,
4321 "Can't parse \'%s\', send by %s. Unsupported time format?", cur_tag, csp->http->url);
4322 string_move(cur_tag, next_tag);
4323 expiry_date_status = EXPIRY_DATE_UNACCEPTABLE;
4328 * Yes. Check if the cookie is still valid.
4330 * If the cookie is already expired it's probably
4331 * a delete cookie and even if it isn't, the browser
4332 * will discard it anyway.
4336 * XXX: timegm() isn't available on some AmigaOS
4337 * versions and our replacement doesn't work.
4339 * Our options are to either:
4341 * - disable session-cookies-only completely if timegm
4344 * - to simply remove all expired tags, like it has
4345 * been done until Privoxy 3.0.6 and to live with
4346 * the consequence that it can cause login/logout
4347 * problems on servers that don't validate their
4348 * input properly, or
4350 * - to replace it with mktime in which
4351 * case there is a slight chance of valid cookies
4352 * passing as already expired.
4354 * This is the way it's currently done and it's not
4355 * as bad as it sounds. If the missing GMT offset is
4356 * enough to change the result of the expiration check
4357 * the cookie will be only valid for a few hours
4358 * anyway, which in many cases will be shorter
4359 * than a browser session.
4361 if (cookie_time < now)
4363 log_error(LOG_LEVEL_HEADER,
4364 "Cookie \'%s\' is already expired and can pass unmodified.", *header);
4365 /* Just in case some clown sets more then one expiration date */
4367 expiry_date_status = EXPIRY_DATE_ACCEPTABLE;
4369 else if ((cookie_lifetime != 0) && (cookie_time < (now + cookie_lifetime)))
4371 log_error(LOG_LEVEL_HEADER, "Cookie \'%s\' can pass unmodified. "
4372 "Its lifetime is below the limit.", *header);
4373 /* Just in case some clown sets more then one expiration date */
4375 expiry_date_status = EXPIRY_DATE_ACCEPTABLE;
4380 * Still valid, delete expiration date by copying
4381 * the rest of the string over it.
4383 string_move(cur_tag, next_tag);
4385 /* That changed the header, need to issue a log message */
4386 expiry_date_status = EXPIRY_DATE_UNACCEPTABLE;
4389 * Note that the next tag has now been moved to *cur_tag,
4390 * so we do not need to update the cur_tag pointer.
4398 /* Move on to next cookie tag */
4403 if (expiry_date_status != EXPIRY_DATE_ACCEPTABLE)
4405 assert(NULL != *header);
4406 if (cookie_lifetime != 0)
4408 add_cookie_expiry_date(header, cookie_lifetime);
4409 log_error(LOG_LEVEL_HEADER, "Cookie rewritten to: %s", *header);
4411 else if (expiry_date_status != NO_EXPIRY_DATE_SPECIFIED)
4413 log_error(LOG_LEVEL_HEADER,
4414 "Cookie rewritten to a temporary one: %s", *header);
4423 #ifdef FEATURE_FORCE_LOAD
4424 /*********************************************************************
4426 * Function : strclean
4428 * Description : In-Situ-Eliminate all occurrences of substring in
4432 * 1 : string = string to clean
4433 * 2 : substring = substring to eliminate
4435 * Returns : Number of eliminations
4437 *********************************************************************/
4438 int strclean(char *string, const char *substring)
4444 len = strlen(substring);
4446 while((pos = strstr(string, substring)) != NULL)
4453 while (*p++ != '\0');
4460 #endif /* def FEATURE_FORCE_LOAD */
4463 /*********************************************************************
4465 * Function : parse_header_time
4467 * Description : Parses time formats used in HTTP header strings
4468 * to get the numerical respresentation.
4471 * 1 : header_time = HTTP header time as string.
4472 * 2 : result = storage for header_time in seconds
4474 * Returns : JB_ERR_OK if the time format was recognized, or
4475 * JB_ERR_PARSE otherwise.
4477 *********************************************************************/
4478 static jb_err parse_header_time(const char *header_time, time_t *result)
4482 * Checking for two-digit years first in an
4483 * attempt to work around GNU libc's strptime()
4484 * reporting negative year values when using %Y.
4486 static const char time_formats[][22] = {
4487 /* Tue, 02-Jun-37 20:00:00 */
4488 "%a, %d-%b-%y %H:%M:%S",
4489 /* Tue, 02 Jun 2037 20:00:00 */
4490 "%a, %d %b %Y %H:%M:%S",
4491 /* Tue, 02-Jun-2037 20:00:00 */
4492 "%a, %d-%b-%Y %H:%M:%S",
4493 /* Tuesday, 02-Jun-2037 20:00:00 */
4494 "%A, %d-%b-%Y %H:%M:%S",
4495 /* Tuesday Jun 02 20:00:00 2037 */
4496 "%A %b %d %H:%M:%S %Y"
4500 for (i = 0; i < SZ(time_formats); i++)
4503 * Zero out gmt to prevent time zone offsets.
4504 * Documented to be required for GNU libc.
4506 memset(&gmt, 0, sizeof(gmt));
4508 if (NULL != strptime(header_time, time_formats[i], &gmt))
4510 /* Sanity check for GNU libc. */
4511 if (gmt.tm_year < 0)
4513 log_error(LOG_LEVEL_HEADER,
4514 "Failed to parse '%s' using '%s'. Moving on.",
4515 header_time, time_formats[i]);
4518 *result = timegm(&gmt);
4520 #ifdef FEATURE_STRPTIME_SANITY_CHECKS
4522 * Verify that parsing the date recreated from the first
4523 * parse operation gets the previous result. If it doesn't,
4524 * either strptime() or strftime() are malfunctioning.
4526 * We could string-compare the recreated date with the original
4527 * header date, but this leads to false positives as strptime()
4528 * may let %a accept all day formats while strftime() will only
4532 char recreated_date[100];
4537 tm = privoxy_gmtime_r(result, &storage);
4538 if (!strftime(recreated_date, sizeof(recreated_date),
4539 time_formats[i], tm))
4541 log_error(LOG_LEVEL_ERROR, "Failed to recreate date '%s' with '%s'.",
4542 header_time, time_formats[i]);
4545 memset(&gmt, 0, sizeof(gmt));
4546 if (NULL == strptime(recreated_date, time_formats[i], &gmt))
4548 log_error(LOG_LEVEL_ERROR,
4549 "Failed to parse '%s' generated with '%s' to recreate '%s'.",
4550 recreated_date, time_formats[i], header_time);
4553 result2 = timegm(&gmt);
4554 if (*result != result2)
4556 log_error(LOG_LEVEL_ERROR, "strftime() and strptime() disagree. "
4557 "Format: '%s'. In: '%s', out: '%s'. %ld != %ld. Rejecting.",
4558 time_formats[i], header_time, recreated_date, *result, result2);
4568 return JB_ERR_PARSE;
4572 /*********************************************************************
4574 * Function : parse_time_header
4576 * Description : Parses the time in an HTTP time header to get
4577 * the numerical respresentation.
4580 * 1 : header = HTTP header with a time value
4581 * 2 : result = storage for header_time in seconds
4583 * Returns : JB_ERR_OK if the time format was recognized, or
4584 * JB_ERR_PARSE otherwise.
4586 *********************************************************************/
4587 static jb_err parse_time_header(const char *header, time_t *result)
4589 const char *header_time;
4591 header_time = strchr(header, ':');
4594 * Currently this can't happen as all callers are called
4595 * through sed() which requires a header name followed by
4598 assert(header_time != NULL);
4601 if (*header_time == ' ')
4606 return parse_header_time(header_time, result);
4611 /*********************************************************************
4613 * Function : get_destination_from_headers
4615 * Description : Parse the "Host:" header to get the request's destination.
4616 * Only needed if the client's request was forcefully
4617 * redirected into Privoxy.
4619 * Code mainly copied from client_host() which is currently
4620 * run too late for this purpose.
4623 * 1 : headers = List of headers (one of them hopefully being
4624 * the "Host:" header)
4625 * 2 : http = storage for the result (host, port and hostport).
4627 * Returns : JB_ERR_MEMORY (or terminates) in case of memory problems,
4628 * JB_ERR_PARSE if the host header couldn't be found,
4629 * JB_ERR_OK otherwise.
4631 *********************************************************************/
4632 jb_err get_destination_from_headers(const struct list *headers, struct http_request *http)
4638 host = get_header_value(headers, "Host:");
4642 log_error(LOG_LEVEL_ERROR, "No \"Host:\" header found.");
4643 return JB_ERR_PARSE;
4646 p = string_tolower(host);
4649 return JB_ERR_MEMORY;
4652 q = strdup_or_die(p);
4654 freez(http->hostport);
4658 q = strchr(http->host, ':');
4661 /* Terminate hostname and evaluate port string */
4663 http->port = atoi(q);
4670 /* Rebuild request URL */
4672 http->url = strdup("http://");
4673 string_append(&http->url, http->hostport);
4674 string_append(&http->url, http->path);
4675 if (http->url == NULL)
4677 return JB_ERR_MEMORY;
4680 log_error(LOG_LEVEL_HEADER,
4681 "Destination extracted from \"Host\" header. New request URL: %s",
4685 * Regenerate request line in "proxy format"
4686 * to make rewrites more convenient.
4688 assert(http->cmd != NULL);
4690 http->cmd = strdup_or_die(http->gpc);
4691 string_append(&http->cmd, " ");
4692 string_append(&http->cmd, http->url);
4693 string_append(&http->cmd, " ");
4694 string_append(&http->cmd, http->version);
4695 if (http->cmd == NULL)
4697 return JB_ERR_MEMORY;
4705 #ifdef FEATURE_HTTPS_INSPECTION
4706 /*********************************************************************
4708 * Function : get_destination_from_https_headers
4710 * Description : Parse the previously encrypted "Host:" header to
4711 * get the request's destination.
4714 * 1 : headers = List of headers (one of them hopefully being
4715 * the "Host:" header)
4716 * 2 : http = storage for the result (host, port and hostport).
4718 * Returns : JB_ERR_MEMORY (or terminates) in case of memory problems,
4719 * JB_ERR_PARSE if the host header couldn't be found,
4720 * JB_ERR_OK otherwise.
4722 *********************************************************************/
4723 jb_err get_destination_from_https_headers(const struct list *headers, struct http_request *http)
4729 host = get_header_value(headers, "Host:");
4733 log_error(LOG_LEVEL_ERROR, "No \"Host:\" header found.");
4734 return JB_ERR_PARSE;
4737 p = string_tolower(host);
4740 return JB_ERR_MEMORY;
4743 q = strdup_or_die(p);
4745 freez(http->hostport);
4749 q = strchr(http->host, ':');
4752 /* Terminate hostname and evaluate port string */
4754 http->port = atoi(q);
4761 /* Rebuild request URL */
4763 http->url = strdup_or_die(http->path);
4765 log_error(LOG_LEVEL_HEADER,
4766 "Destination extracted from \"Host\" header. New request URL: %s",
4770 * Regenerate request line in "proxy format"
4771 * to make rewrites more convenient.
4773 assert(http->cmd != NULL);
4775 http->cmd = strdup_or_die(http->gpc);
4776 string_append(&http->cmd, " ");
4777 string_append(&http->cmd, http->url);
4778 string_append(&http->cmd, " ");
4779 string_append(&http->cmd, http->version);
4780 if (http->cmd == NULL)
4782 return JB_ERR_MEMORY;
4788 #endif /* def FEATURE_HTTPS_INSPECTION */
4791 /*********************************************************************
4793 * Function : create_forged_referrer
4795 * Description : Helper for client_referrer to forge a referer as
4796 * 'http://hostname[:port]/' to fool stupid
4797 * checks for in-site links
4800 * 1 : header = Pointer to header pointer
4801 * 2 : hostport = Host and optionally port as string
4803 * Returns : JB_ERR_OK in case of success, or
4804 * JB_ERR_MEMORY in case of memory problems.
4806 *********************************************************************/
4807 static jb_err create_forged_referrer(char **header, const char *hostport)
4809 assert(NULL == *header);
4811 *header = strdup("Referer: http://");
4812 string_append(header, hostport);
4813 string_append(header, "/");
4815 if (NULL == *header)
4817 return JB_ERR_MEMORY;
4820 log_error(LOG_LEVEL_HEADER, "Referer forged to: %s", *header);
4827 /*********************************************************************
4829 * Function : create_fake_referrer
4831 * Description : Helper for client_referrer to create a fake referrer
4832 * based on a string supplied by the user.
4835 * 1 : header = Pointer to header pointer
4836 * 2 : hosthost = Referrer to fake
4838 * Returns : JB_ERR_OK in case of success, or
4839 * JB_ERR_MEMORY in case of memory problems.
4841 *********************************************************************/
4842 static jb_err create_fake_referrer(char **header, const char *fake_referrer)
4844 assert(NULL == *header);
4846 if ((0 != strncmpic(fake_referrer, "http://", 7)) && (0 != strncmpic(fake_referrer, "https://", 8)))
4848 log_error(LOG_LEVEL_HEADER,
4849 "Parameter: +hide-referrer{%s} is a bad idea, but I don't care.", fake_referrer);
4851 *header = strdup("Referer: ");
4852 string_append(header, fake_referrer);
4854 if (NULL == *header)
4856 return JB_ERR_MEMORY;
4859 log_error(LOG_LEVEL_HEADER, "Referer replaced with: %s", *header);
4866 /*********************************************************************
4868 * Function : handle_conditional_hide_referrer_parameter
4870 * Description : Helper for client_referrer to crunch or forge
4871 * the referrer header if the host has changed.
4874 * 1 : header = Pointer to header pointer
4875 * 2 : host = The target host (may include the port)
4876 * 3 : parameter_conditional_block = Boolean to signal
4877 * if we're in conditional-block mode. If not set,
4878 * we're in conditional-forge mode.
4880 * Returns : JB_ERR_OK in case of success, or
4881 * JB_ERR_MEMORY in case of memory problems.
4883 *********************************************************************/
4884 static jb_err handle_conditional_hide_referrer_parameter(char **header,
4885 const char *host, const int parameter_conditional_block)
4887 char *referer = strdup_or_die(*header);
4888 const size_t hostlength = strlen(host);
4889 const char *referer_url = NULL;
4891 /* referer begins with 'Referer: http[s]://' */
4892 if ((hostlength+17) < strlen(referer))
4895 * Shorten referer to make sure the referer is blocked
4896 * if www.example.org/www.example.com-shall-see-the-referer/
4897 * links to www.example.com/
4899 referer[hostlength+17] = '\0';
4901 referer_url = strstr(referer, "http://");
4902 if (NULL == referer_url)
4904 referer_url = strstr(referer, "https://");
4906 if ((NULL == referer_url) || (NULL == strstr(referer_url, host)))
4908 /* Host has changed, Referer is invalid or a https URL. */
4909 if (parameter_conditional_block)
4911 log_error(LOG_LEVEL_HEADER, "New host is: %s. Crunching %s!", host, *header);
4918 return create_forged_referrer(header, host);
4928 /*********************************************************************
4930 * Function : create_content_length_header
4932 * Description : Creates a Content-Length header.
4935 * 1 : content_length = The content length to be used in the header.
4936 * 2 : header = Allocated space to safe the header.
4937 * 3 : buffer_length = The length of the allocated space.
4941 *********************************************************************/
4942 static void create_content_length_header(unsigned long long content_length,
4943 char *header, size_t buffer_length)
4946 #if SIZEOF_LONG_LONG < 8
4947 #error sizeof(unsigned long long) too small
4949 snprintf(header, buffer_length, "Content-Length: %I64u", content_length);
4951 snprintf(header, buffer_length, "Content-Length: %llu", content_length);
4956 /*********************************************************************
4958 * Function : get_expected_content_length
4960 * Description : Figures out the content length from a list of headers.
4963 * 1 : headers = List of headers
4965 * Returns : Number of bytes to expect
4967 *********************************************************************/
4968 unsigned long long get_expected_content_length(struct list *headers)
4970 const char *content_length_header;
4971 unsigned long long content_length = 0;
4973 content_length_header = get_header_value(headers, "Content-Length:");
4974 if (content_length_header != NULL)
4976 if (JB_ERR_OK != get_content_length(content_length_header, &content_length))
4978 log_error(LOG_LEVEL_ERROR,
4979 "Failed to get the Content-Length in %s", content_length_header);
4980 /* XXX: The header will be removed later on */
4985 return content_length;