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) 2001-2021 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 headers->first = new_headers->first;
1215 headers->last = new_headers->last;
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 &&
1295 !list_is_empty(csp->config->ordered_client_headers) &&
1296 csp->headers->first->str != NULL)
1298 enforce_header_order(csp->headers, csp->config->ordered_client_headers);
1305 #ifdef FEATURE_HTTPS_INSPECTION
1306 /*********************************************************************
1308 * Function : sed_https
1310 * Description : add, delete or modify lines in the HTTPS client
1311 * header streams. Wrapper around sed().
1314 * 1 : csp = Current client state (buffers, headers, etc...)
1316 * Returns : JB_ERR_OK in case off success, or
1317 * JB_ERR_MEMORY on some out-of-memory errors, or
1318 * JB_ERR_PARSE in case of fatal parse errors.
1320 *********************************************************************/
1321 jb_err sed_https(struct client_state *csp)
1324 struct list headers;
1327 * Temporarily replace csp->headers with csp->https_headers
1328 * to trick sed() into filtering the https headers.
1330 headers.first = csp->headers->first;
1331 headers.last = csp->headers->last;
1332 csp->headers->first = csp->https_headers->first;
1333 csp->headers->last = csp->https_headers->last;
1336 * Start with fresh tags. Already existing tags may
1337 * be set again. This is necessary to overrule
1338 * URL-based patterns.
1340 destroy_list(csp->tags);
1343 * We want client header filters and taggers
1344 * so temporarily remove the flag.
1346 csp->flags &= ~CSP_FLAG_CLIENT_HEADER_PARSING_DONE;
1347 err = sed(csp, FILTER_CLIENT_HEADERS);
1348 csp->flags |= CSP_FLAG_CLIENT_HEADER_PARSING_DONE;
1351 * Update the https headers list which may have
1352 * been modified due to header additions or header
1355 csp->https_headers->first = csp->headers->first;
1356 csp->https_headers->last = csp->headers->last;
1358 csp->headers->first = headers.first;
1359 csp->headers->last = headers.last;
1363 #endif /* def FEATURE_HTTPS_INSPECTION */
1366 /*********************************************************************
1368 * Function : update_server_headers
1370 * Description : Updates server headers after the body has been modified.
1373 * 1 : csp = Current client state (buffers, headers, etc...)
1375 * Returns : JB_ERR_OK in case off success, or
1376 * JB_ERR_MEMORY on out-of-memory error.
1378 *********************************************************************/
1379 jb_err update_server_headers(struct client_state *csp)
1381 jb_err err = JB_ERR_OK;
1383 static const struct parsers server_patterns_light[] = {
1384 { "Content-Length:", 15, server_adjust_content_length },
1385 { "Transfer-Encoding:", 18, server_transfer_coding },
1387 { "Content-Encoding:", 17, server_adjust_content_encoding },
1388 #endif /* def FEATURE_ZLIB */
1392 if (strncmpic(csp->http->cmd, "HEAD", 4))
1394 const struct parsers *v;
1395 struct list_entry *p;
1397 for (v = server_patterns_light; (err == JB_ERR_OK) && (v->str != NULL); v++)
1399 for (p = csp->headers->first; (err == JB_ERR_OK) && (p != NULL); p = p->next)
1401 /* Header crunch()ed in previous run? -> ignore */
1402 if (p->str == NULL) continue;
1404 /* Does the current parser handle this header? */
1405 if (strncmpic(p->str, v->str, v->len) == 0)
1407 err = v->parser(csp, (char **)&(p->str));
1413 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1414 if ((JB_ERR_OK == err)
1415 && (csp->flags & CSP_FLAG_MODIFIED)
1416 && (csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
1417 && !(csp->flags & CSP_FLAG_SERVER_CONTENT_LENGTH_SET))
1421 create_content_length_header(csp->content_length, header, sizeof(header));
1422 err = enlist(csp->headers, header);
1423 if (JB_ERR_OK == err)
1425 log_error(LOG_LEVEL_HEADER,
1426 "Content modified with no Content-Length header set. "
1427 "Created: %s.", header);
1428 csp->flags |= CSP_FLAG_SERVER_CONTENT_LENGTH_SET;
1431 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
1433 #ifdef FEATURE_COMPRESSION
1434 if ((JB_ERR_OK == err)
1435 && (csp->flags & CSP_FLAG_BUFFERED_CONTENT_DEFLATED))
1437 err = enlist_unique_header(csp->headers, "Content-Encoding", "deflate");
1438 if (JB_ERR_OK == err)
1440 log_error(LOG_LEVEL_HEADER, "Added header: Content-Encoding: deflate");
1449 /*********************************************************************
1451 * Function : header_tagger
1453 * Description : Executes all text substitutions from applying
1454 * tag actions and saves the result as tag.
1456 * XXX: Shares enough code with filter_header() and
1457 * pcrs_filter_response() to warrant some helper functions.
1460 * 1 : csp = Current client state (buffers, headers, etc...)
1461 * 2 : header = Header that is used as tagger input
1463 * Returns : JB_ERR_OK on success and always succeeds
1465 *********************************************************************/
1466 static jb_err header_tagger(struct client_state *csp, char *header)
1468 enum filter_type wanted_filter_type;
1469 int multi_action_index;
1472 struct re_filterfile_spec *b;
1473 struct list_entry *tag_name;
1475 const size_t header_length = strlen(header);
1477 if (csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
1479 wanted_filter_type = FT_SERVER_HEADER_TAGGER;
1480 multi_action_index = ACTION_MULTI_SERVER_HEADER_TAGGER;
1484 wanted_filter_type = FT_CLIENT_HEADER_TAGGER;
1485 multi_action_index = ACTION_MULTI_CLIENT_HEADER_TAGGER;
1488 if (list_is_empty(csp->action->multi[multi_action_index])
1489 || filters_available(csp) == FALSE)
1491 /* Return early if no taggers apply or if none are available. */
1495 /* Execute all applying taggers */
1496 for (tag_name = csp->action->multi[multi_action_index]->first;
1497 NULL != tag_name; tag_name = tag_name->next)
1499 char *modified_tag = NULL;
1501 size_t size = header_length;
1504 b = get_filter(csp, tag_name->str, wanted_filter_type);
1510 joblist = b->joblist;
1512 if (b->dynamic) joblist = compile_dynamic_pcrs_job_list(csp, b);
1514 if (NULL == joblist)
1516 log_error(LOG_LEVEL_TAGGING,
1517 "Tagger %s has empty joblist. Nothing to do.", b->name);
1521 /* execute their pcrs_joblist on the header. */
1522 for (job = joblist; NULL != job; job = job->next)
1524 const int hits = pcrs_execute(job, tag, size, &modified_tag, &size);
1528 /* Success, continue with the modified version. */
1537 /* Tagger doesn't match */
1540 /* Regex failure, log it but continue anyway. */
1541 assert(NULL != header);
1542 log_error(LOG_LEVEL_ERROR,
1543 "Problems with tagger \'%s\' and header \'%s\': %s",
1544 b->name, header, pcrs_strerror(hits));
1546 freez(modified_tag);
1550 if (b->dynamic) pcrs_free_joblist(joblist);
1552 /* If this tagger matched */
1558 * There is no technical limitation which makes
1559 * it impossible to use empty tags, but I assume
1560 * no one would do it intentionally.
1563 log_error(LOG_LEVEL_TAGGING,
1564 "Tagger \'%s\' created an empty tag. Ignored.", b->name);
1568 if (list_contains_item(csp->action->multi[ACTION_MULTI_SUPPRESS_TAG], tag))
1570 log_error(LOG_LEVEL_TAGGING,
1571 "Tagger \'%s\' didn't add tag \'%s\': suppressed",
1577 if (!list_contains_item(csp->tags, tag))
1579 if (JB_ERR_OK != enlist(csp->tags, tag))
1581 log_error(LOG_LEVEL_ERROR,
1582 "Insufficient memory to add tag \'%s\', "
1583 "based on tagger \'%s\' and header \'%s\'",
1584 tag, b->name, header);
1588 char *action_message;
1590 * update the action bits right away, to make
1591 * tagging based on tags set by earlier taggers
1592 * of the same kind possible.
1594 if (update_action_bits_for_tag(csp, tag))
1596 action_message = "Action bits updated accordingly.";
1600 action_message = "No action bits update necessary.";
1603 log_error(LOG_LEVEL_TAGGING,
1604 "Tagger \'%s\' added tag \'%s\'. %s",
1605 b->name, tag, action_message);
1610 /* XXX: Is this log-worthy? */
1611 log_error(LOG_LEVEL_TAGGING,
1612 "Tagger \'%s\' didn't add tag \'%s\'. Tag already present",
1622 /* here begins the family of parser functions that reformat header lines */
1624 /*********************************************************************
1626 * Function : filter_header
1628 * Description : Executes all text substitutions from all applying
1629 * +(server|client)-header-filter actions on the header.
1630 * Most of the code was copied from pcrs_filter_response,
1631 * including the rather short variable names
1634 * 1 : csp = Current client state (buffers, headers, etc...)
1635 * 2 : header = On input, pointer to header to modify.
1636 * On output, pointer to the modified header, or NULL
1637 * to remove the header. This function frees the
1638 * original string if necessary.
1640 * Returns : JB_ERR_OK on success and always succeeds
1642 *********************************************************************/
1643 static jb_err filter_header(struct client_state *csp, char **header)
1647 size_t size = strlen(*header);
1649 char *newheader = NULL;
1652 struct re_filterfile_spec *b;
1653 struct list_entry *filtername;
1655 enum filter_type wanted_filter_type;
1656 int multi_action_index;
1658 if (csp->flags & CSP_FLAG_NO_FILTERING)
1663 if (csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
1665 wanted_filter_type = FT_SERVER_HEADER_FILTER;
1666 multi_action_index = ACTION_MULTI_SERVER_HEADER_FILTER;
1670 wanted_filter_type = FT_CLIENT_HEADER_FILTER;
1671 multi_action_index = ACTION_MULTI_CLIENT_HEADER_FILTER;
1674 if (list_is_empty(csp->action->multi[multi_action_index])
1675 || filters_available(csp) == FALSE)
1677 /* Return early if no filters apply or if none are available. */
1681 /* Execute all applying header filters */
1682 for (filtername = csp->action->multi[multi_action_index]->first;
1683 filtername != NULL; filtername = filtername->next)
1685 int current_hits = 0;
1688 b = get_filter(csp, filtername->str, wanted_filter_type);
1694 joblist = b->joblist;
1696 if (b->dynamic) joblist = compile_dynamic_pcrs_job_list(csp, b);
1698 if (NULL == joblist)
1700 log_error(LOG_LEVEL_RE_FILTER,
1701 "Filter %s has empty joblist. Nothing to do.", b->name);
1705 log_error(LOG_LEVEL_RE_FILTER, "filtering \'%s\' (size %lu) with \'%s\' ...",
1706 *header, size, b->name);
1708 /* Apply all jobs from the joblist */
1709 for (job = joblist; NULL != job; job = job->next)
1711 matches = pcrs_execute(job, *header, size, &newheader, &size);
1714 current_hits += matches;
1715 log_error(LOG_LEVEL_HEADER,
1716 "Transforming \"%s\" to \"%s\"", *header, newheader);
1718 *header = newheader;
1720 else if (0 == matches)
1722 /* Filter doesn't change header */
1728 log_error(LOG_LEVEL_ERROR,
1729 "Filtering \'%s\' with \'%s\' didn't work out: %s",
1730 *header, b->name, pcrs_strerror(matches));
1731 if (newheader != NULL)
1733 log_error(LOG_LEVEL_ERROR, "Freeing what's left: %s", newheader);
1739 if (b->dynamic) pcrs_free_joblist(joblist);
1741 log_error(LOG_LEVEL_RE_FILTER,
1742 "... produced %d hits (new size %lu).", current_hits, size);
1743 hits += current_hits;
1747 * Additionally checking for hits is important because if
1748 * the continue hack is triggered, server headers can
1749 * arrive empty to separate multiple heads from each other.
1751 if ((0 == size) && hits)
1753 log_error(LOG_LEVEL_HEADER, "Removing empty header %s", *header);
1761 /*********************************************************************
1763 * Function : server_connection
1765 * Description : Makes sure a proper "Connection:" header is
1766 * set and signals connection_header_adder to
1770 * 1 : csp = Current client state (buffers, headers, etc...)
1771 * 2 : header = On input, pointer to header to modify.
1772 * On output, pointer to the modified header, or NULL
1773 * to remove the header. This function frees the
1774 * original string if necessary.
1776 * Returns : JB_ERR_OK on success.
1778 *********************************************************************/
1779 static jb_err server_connection(struct client_state *csp, char **header)
1781 if (!strcmpic(*header, "Connection: keep-alive")
1782 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1783 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
1787 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1788 if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE))
1790 csp->flags |= CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE;
1793 if ((csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE))
1795 log_error(LOG_LEVEL_HEADER,
1796 "Keeping the server header '%s' around.", *header);
1799 #endif /* FEATURE_CONNECTION_KEEP_ALIVE */
1801 char *old_header = *header;
1803 *header = strdup_or_die("Connection: close");
1804 log_error(LOG_LEVEL_HEADER, "Replaced: \'%s\' with \'%s\'", old_header, *header);
1809 /* Signal server_connection_adder() to return early. */
1810 csp->flags |= CSP_FLAG_SERVER_CONNECTION_HEADER_SET;
1816 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1817 /*********************************************************************
1819 * Function : server_keep_alive
1821 * Description : Stores the server's keep alive timeout.
1824 * 1 : csp = Current client state (buffers, headers, etc...)
1825 * 2 : header = On input, pointer to header to modify.
1826 * On output, pointer to the modified header, or NULL
1827 * to remove the header. This function frees the
1828 * original string if necessary.
1830 * Returns : JB_ERR_OK.
1832 *********************************************************************/
1833 static jb_err server_keep_alive(struct client_state *csp, char **header)
1835 unsigned int keep_alive_timeout;
1836 const char *timeout_position = strstr(*header, "timeout=");
1838 if ((NULL == timeout_position)
1839 || (1 != sscanf(timeout_position, "timeout=%u", &keep_alive_timeout)))
1841 log_error(LOG_LEVEL_ERROR, "Couldn't parse: %s", *header);
1845 if (keep_alive_timeout < csp->server_connection.keep_alive_timeout)
1847 log_error(LOG_LEVEL_HEADER,
1848 "Reducing keep-alive timeout from %u to %u.",
1849 csp->server_connection.keep_alive_timeout, keep_alive_timeout);
1850 csp->server_connection.keep_alive_timeout = keep_alive_timeout;
1854 /* XXX: Is this log worthy? */
1855 log_error(LOG_LEVEL_HEADER,
1856 "Server keep-alive timeout is %u. Sticking with %u.",
1857 keep_alive_timeout, csp->server_connection.keep_alive_timeout);
1859 csp->flags |= CSP_FLAG_SERVER_KEEP_ALIVE_TIMEOUT_SET;
1868 /*********************************************************************
1870 * Function : server_proxy_connection
1872 * Description : Figures out whether or not we should add a
1873 * Proxy-Connection header.
1876 * 1 : csp = Current client state (buffers, headers, etc...)
1877 * 2 : header = On input, pointer to header to modify.
1878 * On output, pointer to the modified header, or NULL
1879 * to remove the header. This function frees the
1880 * original string if necessary.
1882 * Returns : JB_ERR_OK.
1884 *********************************************************************/
1885 static jb_err server_proxy_connection(struct client_state *csp, char **header)
1887 csp->flags |= CSP_FLAG_SERVER_PROXY_CONNECTION_HEADER_SET;
1890 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
1893 /*********************************************************************
1895 * Function : proxy_authentication
1897 * Description : Removes headers that are relevant for proxy
1898 * authentication unless forwarding them has
1899 * been explicitly requested.
1902 * 1 : csp = Current client state (buffers, headers, etc...)
1903 * 2 : header = On input, pointer to header to modify.
1904 * On output, pointer to the modified header, or NULL
1905 * to remove the header. This function frees the
1906 * original string if necessary.
1908 * Returns : JB_ERR_OK.
1910 *********************************************************************/
1911 static jb_err proxy_authentication(struct client_state *csp, char **header)
1913 if ((csp->config->feature_flags &
1914 RUNTIME_FEATURE_FORWARD_PROXY_AUTHENTICATION_HEADERS) == 0) {
1915 log_error(LOG_LEVEL_HEADER,
1916 "Forwarding proxy authentication headers is disabled. Crunching: %s", *header);
1923 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1924 /*********************************************************************
1926 * Function : client_keep_alive
1928 * Description : Stores the client's keep alive timeout.
1931 * 1 : csp = Current client state (buffers, headers, etc...)
1932 * 2 : header = On input, pointer to header to modify.
1933 * On output, pointer to the modified header, or NULL
1934 * to remove the header. This function frees the
1935 * original string if necessary.
1937 * Returns : JB_ERR_OK.
1939 *********************************************************************/
1940 static jb_err client_keep_alive(struct client_state *csp, char **header)
1942 unsigned int keep_alive_timeout;
1943 char *timeout_position;
1945 if (!(csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE))
1947 log_error(LOG_LEVEL_HEADER,
1948 "keep-alive support is disabled. Crunching: %s.", *header);
1953 /* Check for parameter-less format "Keep-Alive: 100" */
1954 timeout_position = strstr(*header, ": ");
1955 if ((NULL == timeout_position)
1956 || (1 != sscanf(timeout_position, ": %u", &keep_alive_timeout)))
1958 /* Assume parameter format "Keep-Alive: timeout=100" */
1959 timeout_position = strstr(*header, "timeout=");
1960 if ((NULL == timeout_position)
1961 || (1 != sscanf(timeout_position, "timeout=%u", &keep_alive_timeout)))
1963 log_error(LOG_LEVEL_HEADER,
1964 "Couldn't parse: '%s'. Using default timeout %u",
1965 *header, csp->config->keep_alive_timeout);
1972 if (keep_alive_timeout < csp->config->keep_alive_timeout)
1974 log_error(LOG_LEVEL_HEADER,
1975 "Reducing keep-alive timeout from %u to %u.",
1976 csp->config->keep_alive_timeout, keep_alive_timeout);
1977 csp->server_connection.keep_alive_timeout = keep_alive_timeout;
1981 /* XXX: Is this log worthy? */
1982 log_error(LOG_LEVEL_HEADER,
1983 "Client keep-alive timeout is %u. Sticking with %u.",
1984 keep_alive_timeout, csp->config->keep_alive_timeout);
1990 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
1993 /*********************************************************************
1995 * Function : get_content_length
1997 * Description : Gets the content length specified in a
1998 * Content-Length header.
2001 * 1 : header_value = The Content-Length header value.
2002 * 2 : length = Storage to return the value.
2004 * Returns : JB_ERR_OK on success, or
2005 * JB_ERR_PARSE if no value is recognized.
2007 *********************************************************************/
2008 static jb_err get_content_length(const char *header_value, unsigned long long *length)
2011 #if SIZEOF_LONG_LONG < 8
2012 #error sizeof(unsigned long long) too small
2014 if (1 != sscanf(header_value, "%I64u", length))
2016 if (1 != sscanf(header_value, "%llu", length))
2019 return JB_ERR_PARSE;
2026 /*********************************************************************
2028 * Function : client_save_content_length
2030 * Description : Save the Content-Length sent by the client.
2033 * 1 : csp = Current client state (buffers, headers, etc...)
2034 * 2 : header = pointer to the Content-Length header
2036 * Returns : JB_ERR_OK on success, or
2037 * JB_ERR_MEMORY on out-of-memory error.
2039 *********************************************************************/
2040 static jb_err client_save_content_length(struct client_state *csp, char **header)
2042 unsigned long long content_length = 0;
2043 const char *header_value;
2045 assert(*(*header+14) == ':');
2047 header_value = *header + 15;
2048 if (JB_ERR_OK != get_content_length(header_value, &content_length))
2050 log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
2055 csp->expected_client_content_length = content_length;
2062 /*********************************************************************
2064 * Function : client_connection
2066 * Description : Makes sure a proper "Connection:" header is
2067 * set and signals connection_header_adder
2071 * 1 : csp = Current client state (buffers, headers, etc...)
2072 * 2 : header = On input, pointer to header to modify.
2073 * On output, pointer to the modified header, or NULL
2074 * to remove the header. This function frees the
2075 * original string if necessary.
2077 * Returns : JB_ERR_OK on success.
2079 *********************************************************************/
2080 static jb_err client_connection(struct client_state *csp, char **header)
2082 static const char connection_close[] = "Connection: close";
2084 if (!strcmpic(*header, connection_close))
2086 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2087 if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
2088 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
2089 #ifdef FEATURE_HTTPS_INSPECTION
2090 && !client_use_ssl(csp)
2094 if (!strcmpic(csp->http->version, "HTTP/1.1"))
2096 log_error(LOG_LEVEL_HEADER,
2097 "Removing \'%s\' to imply keep-alive.", *header);
2100 * While we imply keep-alive to the server,
2101 * we have to remember that the client didn't.
2103 csp->flags &= ~CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
2107 char *old_header = *header;
2109 *header = strdup_or_die("Connection: keep-alive");
2110 log_error(LOG_LEVEL_HEADER,
2111 "Replaced: \'%s\' with \'%s\'", old_header, *header);
2117 log_error(LOG_LEVEL_HEADER,
2118 "Keeping the client header '%s' around. "
2119 "The connection will not be kept alive.",
2121 csp->flags &= ~CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
2124 else if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
2125 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED))
2127 log_error(LOG_LEVEL_HEADER,
2128 "Keeping the client header '%s' around. "
2129 "The server connection will be kept alive if possible.",
2131 csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
2132 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2136 char *old_header = *header;
2138 *header = strdup_or_die(connection_close);
2139 log_error(LOG_LEVEL_HEADER,
2140 "Replaced: \'%s\' with \'%s\'", old_header, *header);
2144 /* Signal client_connection_header_adder() to return early. */
2145 csp->flags |= CSP_FLAG_CLIENT_CONNECTION_HEADER_SET;
2151 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2152 /*********************************************************************
2154 * Function : client_proxy_connection
2156 * Description : Sets the CLIENT_CONNECTION_KEEP_ALIVE flag when
2157 * appropriate and removes the Proxy-Connection
2161 * 1 : csp = Current client state (buffers, headers, etc...)
2162 * 2 : header = On input, pointer to header to modify.
2163 * On output, pointer to the modified header, or NULL
2164 * to remove the header. This function frees the
2165 * original string if necessary.
2167 * Returns : JB_ERR_OK
2169 *********************************************************************/
2170 static jb_err client_proxy_connection(struct client_state *csp, char **header)
2172 if (0 == (csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
2173 && (csp->http->ssl == 0)
2174 && (NULL == strstr(*header, "close")))
2176 log_error(LOG_LEVEL_HEADER,
2177 "The client connection can be kept alive due to: %s", *header);
2178 csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
2180 crumble(csp, header);
2184 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2187 /*********************************************************************
2189 * Function : client_transfer_encoding
2191 * Description : Raise the CSP_FLAG_CHUNKED_CLIENT_BODY flag if
2192 * the request body is "chunked"
2194 * XXX: Currently not called through sed() as we
2195 * need the flag earlier on. Should be fixed.
2198 * 1 : csp = Current client state (buffers, headers, etc...)
2199 * 2 : header = On input, pointer to header to modify.
2200 * On output, pointer to the modified header, or NULL
2201 * to remove the header. This function frees the
2202 * original string if necessary.
2204 * Returns : JB_ERR_OK on success, or
2206 *********************************************************************/
2207 jb_err client_transfer_encoding(struct client_state *csp, char **header)
2209 if (strstr(*header, "chunked"))
2211 csp->flags |= CSP_FLAG_CHUNKED_CLIENT_BODY;
2212 log_error(LOG_LEVEL_HEADER, "Expecting chunked client body");
2219 /*********************************************************************
2221 * Function : client_expect
2223 * Description : Raise the CSP_FLAG_UNSUPPORTED_CLIENT_EXPECTATION
2224 * if the Expect header value is unsupported.
2226 * Rejecting unsupported expectations is a RFC 7231 5.1.1
2227 * MAY and a RFC 2616 (obsolete) MUST.
2230 * 1 : csp = Current client state (buffers, headers, etc...)
2231 * 2 : header = On input, pointer to header to modify.
2232 * On output, pointer to the modified header, or NULL
2233 * to remove the header. This function frees the
2234 * original string if necessary.
2236 * Returns : JB_ERR_OK on success, or
2238 *********************************************************************/
2239 jb_err client_expect(struct client_state *csp, char **header)
2241 if (0 != strcmpic(*header, "Expect: 100-continue"))
2243 csp->flags |= CSP_FLAG_UNSUPPORTED_CLIENT_EXPECTATION;
2244 log_error(LOG_LEVEL_HEADER,
2245 "Unsupported client expectaction: %s", *header);
2253 /*********************************************************************
2255 * Function : crumble
2257 * Description : This is called if a header matches a pattern to "crunch"
2260 * 1 : csp = Current client state (buffers, headers, etc...)
2261 * 2 : header = On input, pointer to header to modify.
2262 * On output, pointer to the modified header, or NULL
2263 * to remove the header. This function frees the
2264 * original string if necessary.
2266 * Returns : JB_ERR_OK on success, or
2267 * JB_ERR_MEMORY on out-of-memory error.
2269 *********************************************************************/
2270 static jb_err crumble(struct client_state *csp, char **header)
2273 log_error(LOG_LEVEL_HEADER, "crumble crunched: %s!", *header);
2279 /*********************************************************************
2281 * Function : crunch_server_header
2283 * Description : Crunch server header if it matches a string supplied by the
2284 * user. Called from `sed'.
2287 * 1 : csp = Current client state (buffers, headers, etc...)
2288 * 2 : header = On input, pointer to header to modify.
2289 * On output, pointer to the modified header, or NULL
2290 * to remove the header. This function frees the
2291 * original string if necessary.
2293 * Returns : JB_ERR_OK on success and always succeeds
2295 *********************************************************************/
2296 static jb_err crunch_server_header(struct client_state *csp, char **header)
2298 const char *crunch_pattern;
2300 /* Do we feel like crunching? */
2301 if ((csp->action->flags & ACTION_CRUNCH_SERVER_HEADER))
2303 crunch_pattern = csp->action->string[ACTION_STRING_SERVER_HEADER];
2305 /* Is the current header the lucky one? */
2306 if (strstr(*header, crunch_pattern))
2308 log_error(LOG_LEVEL_HEADER, "Crunching server header: %s (contains: %s)", *header, crunch_pattern);
2317 /*********************************************************************
2319 * Function : server_content_type
2321 * Description : Set the content-type for filterable types (text/.*,
2322 * .*xml.*, .*script.* and image/gif) unless filtering has been
2323 * forbidden (CT_TABOO) while parsing earlier headers.
2324 * NOTE: Since text/plain is commonly used by web servers
2325 * for files whose correct type is unknown, we don't
2326 * set CT_TEXT for it.
2329 * 1 : csp = Current client state (buffers, headers, etc...)
2330 * 2 : header = On input, pointer to header to modify.
2331 * On output, pointer to the modified header, or NULL
2332 * to remove the header. This function frees the
2333 * original string if necessary.
2335 * Returns : JB_ERR_OK on success, or
2336 * JB_ERR_MEMORY on out-of-memory error.
2338 *********************************************************************/
2339 static jb_err server_content_type(struct client_state *csp, char **header)
2341 /* Remove header if it isn't the first Content-Type header */
2342 if ((csp->content_type & CT_DECLARED))
2344 if (content_filters_enabled(csp->action))
2347 * Making sure the client interprets the content the same way
2348 * Privoxy did is only relevant if Privoxy modified it.
2350 * Checking for this is "hard" as it's not yet known when
2351 * this function is called, thus go shopping and and just
2352 * check if Privoxy could filter it.
2354 * The main thing is that we don't mess with the headers
2355 * unless the user signalled that it's acceptable.
2357 log_error(LOG_LEVEL_HEADER,
2358 "Multiple Content-Type headers detected. "
2359 "Removing and ignoring: %s",
2367 * Signal that the Content-Type has been set.
2369 csp->content_type |= CT_DECLARED;
2371 if (!(csp->content_type & CT_TABOO))
2374 * XXX: The assumption that text/plain is a sign of
2375 * binary data seems to be somewhat unreasonable nowadays
2376 * and should be dropped after 3.0.8 is out.
2378 if ((strstr(*header, "text/") && !strstr(*header, "plain"))
2379 || strstr(*header, "xml")
2380 || strstr(*header, "script"))
2382 csp->content_type |= CT_TEXT;
2384 else if (strstr(*header, "image/gif"))
2386 csp->content_type |= CT_GIF;
2391 * Are we messing with the content type?
2393 if (csp->action->flags & ACTION_CONTENT_TYPE_OVERWRITE)
2396 * Make sure the user doesn't accidentally
2397 * change the content type of binary documents.
2399 if ((csp->content_type & CT_TEXT) || (csp->action->flags & ACTION_FORCE_TEXT_MODE))
2403 *header = strdup_or_die("Content-Type: ");
2405 err = string_append(header, csp->action->string[ACTION_STRING_CONTENT_TYPE]);
2406 if (JB_ERR_OK != err)
2408 log_error(LOG_LEVEL_HEADER, "Insufficient memory to replace Content-Type!");
2409 return JB_ERR_MEMORY;
2411 log_error(LOG_LEVEL_HEADER, "Modified: %s!", *header);
2415 log_error(LOG_LEVEL_HEADER, "%s not replaced. "
2416 "It doesn't look like a content type that should be filtered. "
2417 "Enable force-text-mode if you know what you're doing.", *header);
2425 /*********************************************************************
2427 * Function : server_transfer_coding
2429 * Description : - Prohibit filtering (CT_TABOO) if transfer coding compresses
2430 * - Raise the CSP_FLAG_CHUNKED flag if coding is "chunked"
2431 * - Remove header if body was chunked but has been
2432 * de-chunked for filtering.
2435 * 1 : csp = Current client state (buffers, headers, etc...)
2436 * 2 : header = On input, pointer to header to modify.
2437 * On output, pointer to the modified header, or NULL
2438 * to remove the header. This function frees the
2439 * original string if necessary.
2441 * Returns : JB_ERR_OK on success, or
2442 * JB_ERR_MEMORY on out-of-memory error.
2444 *********************************************************************/
2445 static jb_err server_transfer_coding(struct client_state *csp, char **header)
2448 * Turn off pcrs and gif filtering if body compressed
2450 if (strstr(*header, "gzip") || strstr(*header, "compress") || strstr(*header, "deflate"))
2454 * XXX: Added to test if we could use CT_GZIP and CT_DEFLATE here.
2456 log_error(LOG_LEVEL_INFO, "Marking content type for %s as CT_TABOO because of %s.",
2457 csp->http->cmd, *header);
2458 #endif /* def FEATURE_ZLIB */
2459 csp->content_type = CT_TABOO;
2463 * Raise flag if body chunked
2465 if (strstr(*header, "chunked"))
2467 csp->flags |= CSP_FLAG_CHUNKED;
2470 * If the body was modified, it has been de-chunked first
2471 * and the header must be removed.
2473 * FIXME: If there is more than one transfer encoding,
2474 * only the "chunked" part should be removed here.
2476 if (csp->flags & CSP_FLAG_MODIFIED)
2478 log_error(LOG_LEVEL_HEADER, "Removing: %s", *header);
2487 /*********************************************************************
2489 * Function : server_content_encoding
2491 * Description : Used to check if the content is compressed, and if
2492 * FEATURE_ZLIB is disabled, filtering is disabled as
2495 * If FEATURE_ZLIB is enabled and the compression type
2496 * supported, the content is marked for decompression.
2498 * XXX: Doesn't properly deal with multiple or with
2499 * unsupported but unknown encodings.
2500 * Is case-sensitive but shouldn't be.
2503 * 1 : csp = Current client state (buffers, headers, etc...)
2504 * 2 : header = On input, pointer to header to modify.
2505 * On output, pointer to the modified header, or NULL
2506 * to remove the header. This function frees the
2507 * original string if necessary.
2509 * Returns : JB_ERR_OK on success, or
2510 * JB_ERR_MEMORY on out-of-memory error.
2512 *********************************************************************/
2513 static jb_err server_content_encoding(struct client_state *csp, char **header)
2516 if (strstr(*header, "sdch"))
2519 * Shared Dictionary Compression over HTTP isn't supported,
2520 * filtering it anyway is pretty much guaranteed to mess up
2523 csp->content_type |= CT_TABOO;
2526 * Log a warning if the user expects the content to be filtered.
2528 if (content_filters_enabled(csp->action))
2530 log_error(LOG_LEVEL_INFO,
2531 "SDCH-compressed content detected, content filtering disabled. "
2532 "Consider suppressing SDCH offers made by the client.");
2535 else if (strstr(*header, "gzip"))
2537 /* Mark for gzip decompression */
2538 csp->content_type |= CT_GZIP;
2540 else if (strstr(*header, "deflate"))
2542 /* Mark for zlib decompression */
2543 csp->content_type |= CT_DEFLATE;
2545 else if (strstr(*header, "br"))
2547 #ifdef FEATURE_BROTLI
2548 /* Mark for Brotli decompression */
2549 csp->content_type |= CT_BROTLI;
2551 csp->content_type |= CT_TABOO;
2554 else if (strstr(*header, "compress"))
2557 * We can't decompress this; therefore we can't filter
2560 csp->content_type |= CT_TABOO;
2562 #else /* !defined(FEATURE_ZLIB) */
2564 * XXX: Using a black list here isn't the right approach.
2566 * In case of SDCH, building with zlib support isn't
2569 if (strstr(*header, "gzip") ||
2570 strstr(*header, "compress") ||
2571 strstr(*header, "deflate") ||
2572 strstr(*header, "sdch"))
2575 * Body is compressed, turn off pcrs and gif filtering.
2577 csp->content_type |= CT_TABOO;
2580 * Log a warning if the user expects the content to be filtered.
2582 if (content_filters_enabled(csp->action))
2584 log_error(LOG_LEVEL_INFO,
2585 "Compressed content detected, content filtering disabled. "
2586 "Consider recompiling Privoxy with zlib support or "
2587 "enable the prevent-compression action.");
2590 #endif /* defined(FEATURE_ZLIB) */
2598 /*********************************************************************
2600 * Function : server_adjust_content_encoding
2602 * Description : Remove the Content-Encoding header if the
2603 * decompression was successful and the content
2604 * has been modified.
2607 * 1 : csp = Current client state (buffers, headers, etc...)
2608 * 2 : header = On input, pointer to header to modify.
2609 * On output, pointer to the modified header, or NULL
2610 * to remove the header. This function frees the
2611 * original string if necessary.
2613 * Returns : JB_ERR_OK on success, or
2614 * JB_ERR_MEMORY on out-of-memory error.
2616 *********************************************************************/
2617 static jb_err server_adjust_content_encoding(struct client_state *csp, char **header)
2619 if ((csp->flags & CSP_FLAG_MODIFIED)
2620 && ((csp->content_type & (CT_GZIP | CT_DEFLATE))
2621 #ifdef FEATURE_BROTLI
2622 || (csp->content_type & CT_BROTLI)
2628 * We successfully decompressed the content,
2629 * and have to clean the header now, so the
2630 * client no longer expects compressed data.
2632 * XXX: There is a difference between cleaning
2633 * and removing it completely.
2635 log_error(LOG_LEVEL_HEADER, "Crunching: %s", *header);
2642 #endif /* defined(FEATURE_ZLIB) */
2645 /*********************************************************************
2647 * Function : header_adjust_content_length
2649 * Description : Replace given header with new Content-Length header.
2652 * 1 : header = On input, pointer to header to modify.
2653 * On output, pointer to the modified header, or NULL
2654 * to remove the header. This function frees the
2655 * original string if necessary.
2656 * 2 : content_length = content length value to set
2658 * Returns : JB_ERR_OK on success, or
2659 * JB_ERR_MEMORY on out-of-memory error.
2661 *********************************************************************/
2662 jb_err header_adjust_content_length(char **header, size_t content_length)
2664 const size_t header_length = 50;
2666 *header = malloc(header_length);
2667 if (*header == NULL)
2669 return JB_ERR_MEMORY;
2671 create_content_length_header(content_length, *header, header_length);
2676 /*********************************************************************
2678 * Function : server_adjust_content_length
2680 * Description : Adjust Content-Length header if we modified
2684 * 1 : csp = Current client state (buffers, headers, etc...)
2685 * 2 : header = On input, pointer to header to modify.
2686 * On output, pointer to the modified header, or NULL
2687 * to remove the header. This function frees the
2688 * original string if necessary.
2690 * Returns : JB_ERR_OK on success, or
2691 * JB_ERR_MEMORY on out-of-memory error.
2693 *********************************************************************/
2694 static jb_err server_adjust_content_length(struct client_state *csp, char **header)
2696 /* Regenerate header if the content was modified. */
2697 if (csp->flags & CSP_FLAG_MODIFIED)
2699 if (JB_ERR_OK != header_adjust_content_length(header, csp->content_length))
2701 return JB_ERR_MEMORY;
2703 log_error(LOG_LEVEL_HEADER,
2704 "Adjusted Content-Length to %llu", csp->content_length);
2711 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2712 /*********************************************************************
2714 * Function : server_save_content_length
2716 * Description : Save the Content-Length sent by the server.
2719 * 1 : csp = Current client state (buffers, headers, etc...)
2720 * 2 : header = On input, pointer to header to modify.
2721 * On output, pointer to the modified header, or NULL
2722 * to remove the header. This function frees the
2723 * original string if necessary.
2725 * Returns : JB_ERR_OK on success, or
2726 * JB_ERR_MEMORY on out-of-memory error.
2728 *********************************************************************/
2729 static jb_err server_save_content_length(struct client_state *csp, char **header)
2731 unsigned long long content_length = 0;
2732 const char *header_value;
2734 assert(*(*header+14) == ':');
2736 header_value = *header + 15;
2737 if (JB_ERR_OK != get_content_length(header_value, &content_length))
2739 log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
2744 csp->expected_content_length = content_length;
2745 csp->flags |= CSP_FLAG_SERVER_CONTENT_LENGTH_SET;
2746 csp->flags |= CSP_FLAG_CONTENT_LENGTH_SET;
2751 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2754 /*********************************************************************
2756 * Function : server_content_md5
2758 * Description : Crumble any Content-MD5 headers if the document was
2759 * modified. FIXME: Should we re-compute instead?
2762 * 1 : csp = Current client state (buffers, headers, etc...)
2763 * 2 : header = On input, pointer to header to modify.
2764 * On output, pointer to the modified header, or NULL
2765 * to remove the header. This function frees the
2766 * original string if necessary.
2768 * Returns : JB_ERR_OK on success, or
2769 * JB_ERR_MEMORY on out-of-memory error.
2771 *********************************************************************/
2772 static jb_err server_content_md5(struct client_state *csp, char **header)
2774 if (csp->flags & CSP_FLAG_MODIFIED)
2776 log_error(LOG_LEVEL_HEADER, "Crunching Content-MD5");
2784 /*********************************************************************
2786 * Function : server_content_disposition
2788 * Description : If enabled, blocks or modifies the "Content-Disposition" header.
2789 * Called from `sed'.
2792 * 1 : csp = Current client state (buffers, headers, etc...)
2793 * 2 : header = On input, pointer to header to modify.
2794 * On output, pointer to the modified header, or NULL
2795 * to remove the header. This function frees the
2796 * original string if necessary.
2798 * Returns : JB_ERR_OK on success, or
2799 * JB_ERR_MEMORY on out-of-memory error.
2801 *********************************************************************/
2802 static jb_err server_content_disposition(struct client_state *csp, char **header)
2807 * Are we messing with the Content-Disposition header?
2809 if ((csp->action->flags & ACTION_HIDE_CONTENT_DISPOSITION) == 0)
2815 newval = csp->action->string[ACTION_STRING_CONTENT_DISPOSITION];
2817 if ((newval == NULL) || (0 == strcmpic(newval, "block")))
2820 * Blocking content-disposition header
2822 log_error(LOG_LEVEL_HEADER, "Crunching %s!", *header);
2829 * Replacing Content-Disposition header
2832 *header = strdup("Content-Disposition: ");
2833 string_append(header, newval);
2835 if (*header != NULL)
2837 log_error(LOG_LEVEL_HEADER,
2838 "Content-Disposition header crunched and replaced with: %s", *header);
2841 return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
2845 /*********************************************************************
2847 * Function : server_last_modified
2849 * Description : Changes Last-Modified header to the actual date
2850 * to help hide-if-modified-since.
2851 * Called from `sed'.
2854 * 1 : csp = Current client state (buffers, headers, etc...)
2855 * 2 : header = On input, pointer to header to modify.
2856 * On output, pointer to the modified header, or NULL
2857 * to remove the header. This function frees the
2858 * original string if necessary.
2860 * Returns : JB_ERR_OK on success, or
2861 * JB_ERR_MEMORY on out-of-memory error.
2863 *********************************************************************/
2864 static jb_err server_last_modified(struct client_state *csp, char **header)
2867 time_t last_modified;
2871 * Are we messing with the Last-Modified header?
2873 if ((csp->action->flags & ACTION_OVERWRITE_LAST_MODIFIED) == 0)
2879 newval = csp->action->string[ACTION_STRING_LAST_MODIFIED];
2881 if (0 == strcmpic(newval, "block"))
2884 * Blocking Last-Modified header. Useless but why not.
2886 log_error(LOG_LEVEL_HEADER, "Crunching %s!", *header);
2890 else if (0 == strcmpic(newval, "reset-to-request-time"))
2893 * Setting Last-Modified Header to now.
2896 get_http_time(0, buf, sizeof(buf));
2898 *header = strdup("Last-Modified: ");
2899 string_append(header, buf);
2901 if (*header == NULL)
2903 log_error(LOG_LEVEL_HEADER, "Insufficient memory. Last-Modified header got lost, boohoo.");
2907 log_error(LOG_LEVEL_HEADER, "Reset to present time: %s", *header);
2910 else if (0 == strcmpic(newval, "randomize"))
2912 log_error(LOG_LEVEL_HEADER, "Randomizing: %s", *header);
2914 if (JB_ERR_OK != parse_time_header(*header, &last_modified))
2916 log_error(LOG_LEVEL_HEADER,
2917 "Couldn't parse time in %s (crunching!)", *header);
2923 struct tm *timeptr = NULL;
2928 rtime = (long int)difftime(now, last_modified);
2931 long int days, hours, minutes, seconds;
2932 const int negative_delta = (rtime < 0);
2937 log_error(LOG_LEVEL_HEADER, "Server time in the future.");
2939 rtime = pick_from_range(rtime);
2944 last_modified += rtime;
2945 timeptr = privoxy_gmtime_r(&last_modified, &gmt);
2946 if ((NULL == timeptr) || !strftime(newheader,
2947 sizeof(newheader), "%a, %d %b %Y %H:%M:%S GMT", timeptr))
2949 log_error(LOG_LEVEL_ERROR,
2950 "Randomizing '%s' failed. Crunching the header without replacement.",
2956 *header = strdup("Last-Modified: ");
2957 string_append(header, newheader);
2959 if (*header == NULL)
2961 log_error(LOG_LEVEL_ERROR, "Insufficient memory, header crunched without replacement.");
2962 return JB_ERR_MEMORY;
2965 days = rtime / (3600 * 24);
2966 hours = rtime / 3600 % 24;
2967 minutes = rtime / 60 % 60;
2968 seconds = rtime % 60;
2970 log_error(LOG_LEVEL_HEADER,
2971 "Randomized: %s (added %ld da%s %ld hou%s %ld minut%s %ld second%s",
2972 *header, days, (days == 1) ? "y" : "ys", hours, (hours == 1) ? "r" : "rs",
2973 minutes, (minutes == 1) ? "e" : "es", seconds, (seconds == 1) ? ")" : "s)");
2977 log_error(LOG_LEVEL_HEADER, "Randomized ... or not. No time difference to work with.");
2986 /*********************************************************************
2988 * Function : client_accept_encoding
2990 * Description : Rewrite the client's Accept-Encoding header so that
2991 * if doesn't allow compression, if the action applies.
2992 * Note: For HTTP/1.0 the absence of the header is enough.
2995 * 1 : csp = Current client state (buffers, headers, etc...)
2996 * 2 : header = On input, pointer to header to modify.
2997 * On output, pointer to the modified header, or NULL
2998 * to remove the header. This function frees the
2999 * original string if necessary.
3001 * Returns : JB_ERR_OK on success, or
3002 * JB_ERR_MEMORY on out-of-memory error.
3004 *********************************************************************/
3005 static jb_err client_accept_encoding(struct client_state *csp, char **header)
3007 #ifdef FEATURE_COMPRESSION
3008 if ((csp->config->feature_flags & RUNTIME_FEATURE_COMPRESSION)
3009 && strstr(*header, "deflate"))
3011 csp->flags |= CSP_FLAG_CLIENT_SUPPORTS_DEFLATE;
3014 if ((csp->action->flags & ACTION_NO_COMPRESSION) != 0)
3016 log_error(LOG_LEVEL_HEADER, "Suppressed offer to compress content");
3024 /*********************************************************************
3026 * Function : client_te
3028 * Description : Rewrite the client's TE header so that
3029 * if doesn't allow compression, if the action applies.
3032 * 1 : csp = Current client state (buffers, headers, etc...)
3033 * 2 : header = On input, pointer to header to modify.
3034 * On output, pointer to the modified header, or NULL
3035 * to remove the header. This function frees the
3036 * original string if necessary.
3038 * Returns : JB_ERR_OK on success, or
3039 * JB_ERR_MEMORY on out-of-memory error.
3041 *********************************************************************/
3042 static jb_err client_te(struct client_state *csp, char **header)
3044 if ((csp->action->flags & ACTION_NO_COMPRESSION) != 0)
3047 log_error(LOG_LEVEL_HEADER, "Suppressed offer to compress transfer");
3054 /*********************************************************************
3056 * Function : client_referrer
3058 * Description : Handle the "referer" config setting properly.
3059 * Called from `sed'.
3062 * 1 : csp = Current client state (buffers, headers, etc...)
3063 * 2 : header = On input, pointer to header to modify.
3064 * On output, pointer to the modified header, or NULL
3065 * to remove the header. This function frees the
3066 * original string if necessary.
3068 * Returns : JB_ERR_OK on success, or
3069 * JB_ERR_MEMORY on out-of-memory error.
3071 *********************************************************************/
3072 static jb_err client_referrer(struct client_state *csp, char **header)
3074 const char *parameter;
3075 /* booleans for parameters we have to check multiple times */
3076 int parameter_conditional_block;
3077 int parameter_conditional_forge;
3079 #ifdef FEATURE_FORCE_LOAD
3081 * Since the referrer can include the prefix even
3082 * if the request itself is non-forced, we must
3083 * clean it unconditionally.
3085 * XXX: strclean is too broad
3087 strclean(*header, FORCE_PREFIX);
3088 #endif /* def FEATURE_FORCE_LOAD */
3090 if ((csp->action->flags & ACTION_HIDE_REFERER) == 0)
3092 /* Nothing left to do */
3096 parameter = csp->action->string[ACTION_STRING_REFERER];
3097 assert(parameter != NULL);
3098 parameter_conditional_block = (0 == strcmpic(parameter, "conditional-block"));
3099 parameter_conditional_forge = (0 == strcmpic(parameter, "conditional-forge"));
3101 if (!parameter_conditional_block && !parameter_conditional_forge)
3104 * As conditional-block and conditional-forge are the only
3105 * parameters that rely on the original referrer, we can
3106 * remove it now for all the others.
3111 if (0 == strcmpic(parameter, "block"))
3113 log_error(LOG_LEVEL_HEADER, "Referer crunched!");
3116 else if (parameter_conditional_block || parameter_conditional_forge)
3118 return handle_conditional_hide_referrer_parameter(header,
3119 csp->http->hostport, parameter_conditional_block);
3121 else if (0 == strcmpic(parameter, "forge"))
3123 return create_forged_referrer(header, csp->http->hostport);
3127 /* interpret parameter as user-supplied referer to fake */
3128 return create_fake_referrer(header, parameter);
3133 /*********************************************************************
3135 * Function : client_accept_language
3137 * Description : Handle the "Accept-Language" config setting properly.
3138 * Called from `sed'.
3141 * 1 : csp = Current client state (buffers, headers, etc...)
3142 * 2 : header = On input, pointer to header to modify.
3143 * On output, pointer to the modified header, or NULL
3144 * to remove the header. This function frees the
3145 * original string if necessary.
3147 * Returns : JB_ERR_OK on success, or
3148 * JB_ERR_MEMORY on out-of-memory error.
3150 *********************************************************************/
3151 static jb_err client_accept_language(struct client_state *csp, char **header)
3156 * Are we messing with the Accept-Language?
3158 if ((csp->action->flags & ACTION_HIDE_ACCEPT_LANGUAGE) == 0)
3160 /*I don't think so*/
3164 newval = csp->action->string[ACTION_STRING_LANGUAGE];
3166 if ((newval == NULL) || (0 == strcmpic(newval, "block")))
3169 * Blocking Accept-Language header
3171 log_error(LOG_LEVEL_HEADER, "Crunching Accept-Language!");
3178 * Replacing Accept-Language header
3181 *header = strdup("Accept-Language: ");
3182 string_append(header, newval);
3184 if (*header == NULL)
3186 log_error(LOG_LEVEL_ERROR,
3187 "Insufficient memory. Accept-Language header crunched without replacement.");
3191 log_error(LOG_LEVEL_HEADER,
3192 "Accept-Language header crunched and replaced with: %s", *header);
3195 return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
3199 /*********************************************************************
3201 * Function : crunch_client_header
3203 * Description : Crunch client header if it matches a string supplied by the
3204 * user. Called from `sed'.
3207 * 1 : csp = Current client state (buffers, headers, etc...)
3208 * 2 : header = On input, pointer to header to modify.
3209 * On output, pointer to the modified header, or NULL
3210 * to remove the header. This function frees the
3211 * original string if necessary.
3213 * Returns : JB_ERR_OK on success and always succeeds
3215 *********************************************************************/
3216 static jb_err crunch_client_header(struct client_state *csp, char **header)
3218 const char *crunch_pattern;
3220 /* Do we feel like crunching? */
3221 if ((csp->action->flags & ACTION_CRUNCH_CLIENT_HEADER))
3223 crunch_pattern = csp->action->string[ACTION_STRING_CLIENT_HEADER];
3225 /* Is the current header the lucky one? */
3226 if (strstr(*header, crunch_pattern))
3228 log_error(LOG_LEVEL_HEADER, "Crunching client header: %s (contains: %s)", *header, crunch_pattern);
3236 /*********************************************************************
3238 * Function : client_uagent
3240 * Description : Handle the "user-agent" config setting properly
3241 * and remember its original value to enable browser
3242 * bug workarounds. Called from `sed'.
3245 * 1 : csp = Current client state (buffers, headers, etc...)
3246 * 2 : header = On input, pointer to header to modify.
3247 * On output, pointer to the modified header, or NULL
3248 * to remove the header. This function frees the
3249 * original string if necessary.
3251 * Returns : JB_ERR_OK on success, or
3252 * JB_ERR_MEMORY on out-of-memory error.
3254 *********************************************************************/
3255 static jb_err client_uagent(struct client_state *csp, char **header)
3259 if ((csp->action->flags & ACTION_HIDE_USER_AGENT) == 0)
3264 newval = csp->action->string[ACTION_STRING_USER_AGENT];
3271 *header = strdup("User-Agent: ");
3272 string_append(header, newval);
3274 log_error(LOG_LEVEL_HEADER, "Modified: %s", *header);
3276 return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
3280 /*********************************************************************
3282 * Function : client_ua
3284 * Description : Handle "ua-" headers properly. Called from `sed'.
3287 * 1 : csp = Current client state (buffers, headers, etc...)
3288 * 2 : header = On input, pointer to header to modify.
3289 * On output, pointer to the modified header, or NULL
3290 * to remove the header. This function frees the
3291 * original string if necessary.
3293 * Returns : JB_ERR_OK on success, or
3294 * JB_ERR_MEMORY on out-of-memory error.
3296 *********************************************************************/
3297 static jb_err client_ua(struct client_state *csp, char **header)
3299 if ((csp->action->flags & ACTION_HIDE_USER_AGENT) != 0)
3301 log_error(LOG_LEVEL_HEADER, "crunched User-Agent!");
3309 /*********************************************************************
3311 * Function : client_from
3313 * Description : Handle the "from" config setting properly.
3314 * Called from `sed'.
3317 * 1 : csp = Current client state (buffers, headers, etc...)
3318 * 2 : header = On input, pointer to header to modify.
3319 * On output, pointer to the modified header, or NULL
3320 * to remove the header. This function frees the
3321 * original string if necessary.
3323 * Returns : JB_ERR_OK on success, or
3324 * JB_ERR_MEMORY on out-of-memory error.
3326 *********************************************************************/
3327 static jb_err client_from(struct client_state *csp, char **header)
3331 if ((csp->action->flags & ACTION_HIDE_FROM) == 0)
3338 newval = csp->action->string[ACTION_STRING_FROM];
3341 * Are we blocking the e-mail address?
3343 if ((newval == NULL) || (0 == strcmpic(newval, "block")))
3345 log_error(LOG_LEVEL_HEADER, "crunched From!");
3349 log_error(LOG_LEVEL_HEADER, " modified");
3351 *header = strdup("From: ");
3352 string_append(header, newval);
3354 return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
3358 /*********************************************************************
3360 * Function : client_send_cookie
3362 * Description : Crunches the "cookie" header if necessary.
3363 * Called from `sed'.
3365 * XXX: Stupid name, doesn't send squat.
3368 * 1 : csp = Current client state (buffers, headers, etc...)
3369 * 2 : header = On input, pointer to header to modify.
3370 * On output, pointer to the modified header, or NULL
3371 * to remove the header. This function frees the
3372 * original string if necessary.
3374 * Returns : JB_ERR_OK on success, or
3375 * JB_ERR_MEMORY on out-of-memory error.
3377 *********************************************************************/
3378 static jb_err client_send_cookie(struct client_state *csp, char **header)
3380 if (csp->action->flags & ACTION_CRUNCH_OUTGOING_COOKIES)
3382 log_error(LOG_LEVEL_HEADER, "Crunched outgoing cookie: %s", *header);
3390 /*********************************************************************
3392 * Function : client_x_forwarded
3394 * Description : Handle the "x-forwarded-for" config setting properly,
3395 * also used in the add_client_headers list. Called from `sed'.
3398 * 1 : csp = Current client state (buffers, headers, etc...)
3399 * 2 : header = On input, pointer to header to modify.
3400 * On output, pointer to the modified header, or NULL
3401 * to remove the header. This function frees the
3402 * original string if necessary.
3404 * Returns : JB_ERR_OK on success, or
3405 * JB_ERR_MEMORY on out-of-memory error.
3407 *********************************************************************/
3408 jb_err client_x_forwarded(struct client_state *csp, char **header)
3410 if (0 != (csp->action->flags & ACTION_CHANGE_X_FORWARDED_FOR))
3412 const char *parameter = csp->action->string[ACTION_STRING_CHANGE_X_FORWARDED_FOR];
3414 if (0 == strcmpic(parameter, "block"))
3417 log_error(LOG_LEVEL_HEADER, "crunched x-forwarded-for!");
3419 else if (0 == strcmpic(parameter, "add"))
3421 string_append(header, ", ");
3422 string_append(header, csp->ip_addr_str);
3424 if (*header == NULL)
3426 return JB_ERR_MEMORY;
3428 log_error(LOG_LEVEL_HEADER,
3429 "Appended client IP address to %s", *header);
3430 csp->flags |= CSP_FLAG_X_FORWARDED_FOR_APPENDED;
3434 log_error(LOG_LEVEL_FATAL,
3435 "Invalid change-x-forwarded-for parameter: '%s'", parameter);
3443 /*********************************************************************
3445 * Function : client_max_forwards
3447 * Description : If the HTTP method is OPTIONS or TRACE, subtract one
3448 * from the value of the Max-Forwards header field.
3451 * 1 : csp = Current client state (buffers, headers, etc...)
3452 * 2 : header = On input, pointer to header to modify.
3453 * On output, pointer to the modified header, or NULL
3454 * to remove the header. This function frees the
3455 * original string if necessary.
3457 * Returns : JB_ERR_OK on success, or
3458 * JB_ERR_MEMORY on out-of-memory error.
3460 *********************************************************************/
3461 static jb_err client_max_forwards(struct client_state *csp, char **header)
3465 if ((0 == strcmpic(csp->http->gpc, "trace")) ||
3466 (0 == strcmpic(csp->http->gpc, "options")))
3468 assert(*(*header+12) == ':');
3469 if (1 == sscanf(*header+12, ": %d", &max_forwards))
3471 if (max_forwards > 0)
3473 snprintf(*header, strlen(*header)+1, "Max-Forwards: %d", --max_forwards);
3474 log_error(LOG_LEVEL_HEADER,
3475 "Max-Forwards value for %s request reduced to %d.",
3476 csp->http->gpc, max_forwards);
3478 else if (max_forwards < 0)
3480 log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
3486 log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
3495 /*********************************************************************
3497 * Function : client_host
3499 * Description : If the request URI did not contain host and
3500 * port information, parse and evaluate the Host
3504 * 1 : csp = Current client state (buffers, headers, etc...)
3505 * 2 : header = On input, pointer to header to modify.
3506 * On output, pointer to the modified header, or NULL
3507 * to remove the header. This function frees the
3508 * original string if necessary.
3510 * Returns : JB_ERR_OK on success, or
3511 * JB_ERR_MEMORY on out-of-memory error.
3513 *********************************************************************/
3514 static jb_err client_host(struct client_state *csp, char **header)
3518 if (strlen(*header) < 7)
3520 log_error(LOG_LEVEL_HEADER, "Removing empty Host header");
3525 if (!csp->http->hostport || (*csp->http->hostport == '*') ||
3526 *csp->http->hostport == ' ' || *csp->http->hostport == '\0')
3529 p = strdup_or_die((*header)+6);
3531 q = strdup_or_die(p);
3533 freez(csp->http->hostport);
3534 csp->http->hostport = p;
3535 freez(csp->http->host);
3536 csp->http->host = q;
3537 q = strchr(csp->http->host, ':');
3540 /* Terminate hostname and evaluate port string */
3542 csp->http->port = atoi(q);
3546 csp->http->port = csp->http->ssl ? 443 : 80;
3549 log_error(LOG_LEVEL_HEADER, "New host and port from Host field: %s = %s:%d",
3550 csp->http->hostport, csp->http->host, csp->http->port);
3553 /* Signal client_host_adder() to return right away */
3554 csp->flags |= CSP_FLAG_HOST_HEADER_IS_SET;
3560 /*********************************************************************
3562 * Function : client_if_modified_since
3564 * Description : Remove or modify the If-Modified-Since header.
3567 * 1 : csp = Current client state (buffers, headers, etc...)
3568 * 2 : header = On input, pointer to header to modify.
3569 * On output, pointer to the modified header, or NULL
3570 * to remove the header. This function frees the
3571 * original string if necessary.
3573 * Returns : JB_ERR_OK on success, or
3574 * JB_ERR_MEMORY on out-of-memory error.
3576 *********************************************************************/
3577 static jb_err client_if_modified_since(struct client_state *csp, char **header)
3581 struct tm *timeptr = NULL;
3586 if (0 == strcmpic(*header, "If-Modified-Since: Wed, 08 Jun 1955 12:00:00 GMT"))
3589 * The client got an error message because of a temporary problem,
3590 * the problem is gone and the client now tries to revalidate our
3591 * error message on the real server. The revalidation would always
3592 * end with the transmission of the whole document and there is
3593 * no need to expose the bogus If-Modified-Since header.
3595 log_error(LOG_LEVEL_HEADER, "Crunching useless If-Modified-Since header.");
3598 else if (csp->action->flags & ACTION_HIDE_IF_MODIFIED_SINCE)
3600 newval = csp->action->string[ACTION_STRING_IF_MODIFIED_SINCE];
3602 if ((0 == strcmpic(newval, "block")))
3604 log_error(LOG_LEVEL_HEADER, "Crunching %s", *header);
3607 else /* add random value */
3609 if (JB_ERR_OK != parse_time_header(*header, &tm))
3611 log_error(LOG_LEVEL_HEADER,
3612 "Couldn't parse time in %s (crunching!)", *header);
3617 long int hours, minutes, seconds;
3618 long int rtime = strtol(newval, &endptr, 0);
3619 const int negative_range = (rtime < 0);
3623 log_error(LOG_LEVEL_HEADER, "Randomizing: %s (random range: %ld minut%s)",
3624 *header, rtime, (rtime == 1 || rtime == -1) ? "e": "es");
3630 rtime = pick_from_range(rtime);
3634 log_error(LOG_LEVEL_ERROR,
3635 "Random range is 0. Assuming time transformation test.");
3637 tm += rtime * (negative_range ? -1 : 1);
3638 timeptr = privoxy_gmtime_r(&tm, &gmt);
3639 if ((NULL == timeptr) || !strftime(newheader,
3640 sizeof(newheader), "%a, %d %b %Y %H:%M:%S GMT", timeptr))
3642 log_error(LOG_LEVEL_ERROR,
3643 "Randomizing '%s' failed. Crunching the header without replacement.",
3649 *header = strdup("If-Modified-Since: ");
3650 string_append(header, newheader);
3652 if (*header == NULL)
3654 log_error(LOG_LEVEL_HEADER, "Insufficient memory, header crunched without replacement.");
3655 return JB_ERR_MEMORY;
3658 hours = rtime / 3600;
3659 minutes = rtime / 60 % 60;
3660 seconds = rtime % 60;
3662 log_error(LOG_LEVEL_HEADER,
3663 "Randomized: %s (%s %ld hou%s %ld minut%s %ld second%s",
3664 *header, (negative_range) ? "subtracted" : "added", hours,
3665 (hours == 1) ? "r" : "rs", minutes, (minutes == 1) ? "e" : "es",
3666 seconds, (seconds == 1) ? ")" : "s)");
3675 /*********************************************************************
3677 * Function : client_if_none_match
3679 * Description : Remove the If-None-Match header.
3682 * 1 : csp = Current client state (buffers, headers, etc...)
3683 * 2 : header = On input, pointer to header to modify.
3684 * On output, pointer to the modified header, or NULL
3685 * to remove the header. This function frees the
3686 * original string if necessary.
3688 * Returns : JB_ERR_OK on success, or
3689 * JB_ERR_MEMORY on out-of-memory error.
3691 *********************************************************************/
3692 static jb_err client_if_none_match(struct client_state *csp, char **header)
3694 if (csp->action->flags & ACTION_CRUNCH_IF_NONE_MATCH)
3696 log_error(LOG_LEVEL_HEADER, "Crunching %s", *header);
3704 /*********************************************************************
3706 * Function : client_x_filter
3708 * Description : Disables filtering if the client set "X-Filter: No".
3709 * Called from `sed'.
3712 * 1 : csp = Current client state (buffers, headers, etc...)
3713 * 2 : header = On input, pointer to header to modify.
3714 * On output, pointer to the modified header, or NULL
3715 * to remove the header. This function frees the
3716 * original string if necessary.
3718 * Returns : JB_ERR_OK on success
3720 *********************************************************************/
3721 jb_err client_x_filter(struct client_state *csp, char **header)
3723 if (0 == strcmpic(*header, "X-Filter: No"))
3725 if (!(csp->config->feature_flags & RUNTIME_FEATURE_HTTP_TOGGLE))
3727 log_error(LOG_LEVEL_INFO, "Ignored the client's request to fetch without filtering.");
3731 if (csp->action->flags & ACTION_FORCE_TEXT_MODE)
3733 log_error(LOG_LEVEL_HEADER,
3734 "force-text-mode overruled the client's request to fetch without filtering!");
3738 csp->content_type = CT_TABOO; /* XXX: This hack shouldn't be necessary */
3739 csp->flags |= CSP_FLAG_NO_FILTERING;
3740 log_error(LOG_LEVEL_HEADER, "Accepted the client's request to fetch without filtering.");
3742 log_error(LOG_LEVEL_HEADER, "Crunching %s", *header);
3750 /*********************************************************************
3752 * Function : client_range
3754 * Description : Removes Range, Request-Range and If-Range headers if
3755 * content filtering is enabled and the range doesn't
3758 * If the client's version of the document has been
3759 * altered by Privoxy, the server could interpret the
3760 * range differently than the client intended in which
3761 * case the user could end up with corrupted content.
3763 * If the range starts at byte 0 this isn't an issue
3764 * so the header can pass. Partial requests like this
3765 * are used to render preview images for videos without
3766 * downloading the whole video.
3768 * While HTTP doesn't require that range requests are
3769 * honoured and the client could simply abort the download
3770 * after receiving a sufficient amount of data, various
3771 * clients don't handle complete responses to range
3772 * requests gracefully and emit misleading error messages
3776 * 1 : csp = Current client state (buffers, headers, etc...)
3777 * 2 : header = On input, pointer to header to modify.
3778 * On output, pointer to the modified header, or NULL
3779 * to remove the header. This function frees the
3780 * original string if necessary.
3782 * Returns : JB_ERR_OK
3784 *********************************************************************/
3785 static jb_err client_range(struct client_state *csp, char **header)
3787 if (content_filters_enabled(csp->action)
3788 && (0 != strncmpic(strstr(*header, ":"), ": bytes=0-", 10)))
3790 log_error(LOG_LEVEL_HEADER, "Content filtering is enabled."
3791 " Crunching: \'%s\' to prevent range-mismatch problems.", *header);
3798 /* the following functions add headers directly to the header list */
3800 /*********************************************************************
3802 * Function : client_host_adder
3804 * Description : Adds the Host: header field if it is missing.
3805 * Called from `sed'.
3808 * 1 : csp = Current client state (buffers, headers, etc...)
3810 * Returns : JB_ERR_OK on success, or
3811 * JB_ERR_MEMORY on out-of-memory error.
3813 *********************************************************************/
3814 static jb_err client_host_adder(struct client_state *csp)
3819 if (csp->flags & CSP_FLAG_HOST_HEADER_IS_SET)
3821 /* Header already set by the client, nothing to do. */
3825 if (!csp->http->hostport || !*(csp->http->hostport))
3827 log_error(LOG_LEVEL_ERROR, "Destination host unknown.");
3828 return JB_ERR_PARSE;
3832 * remove 'user:pass@' from 'proto://user:pass@host'
3834 if ((p = strchr( csp->http->hostport, '@')) != NULL)
3840 p = csp->http->hostport;
3843 /* XXX: Just add it, we already made sure that it will be unique */
3844 log_error(LOG_LEVEL_HEADER, "addh-unique: Host: %s", p);
3845 err = enlist_unique_header(csp->headers, "Host", p);
3851 /*********************************************************************
3853 * Function : client_xtra_adder
3855 * Description : Used in the add_client_headers list. Called from `sed'.
3858 * 1 : csp = Current client state (buffers, headers, etc...)
3860 * Returns : JB_ERR_OK on success, or
3861 * JB_ERR_MEMORY on out-of-memory error.
3863 *********************************************************************/
3864 static jb_err client_xtra_adder(struct client_state *csp)
3866 struct list_entry *lst;
3869 for (lst = csp->action->multi[ACTION_MULTI_ADD_HEADER]->first;
3870 lst ; lst = lst->next)
3872 log_error(LOG_LEVEL_HEADER, "addh: %s", lst->str);
3873 err = enlist(csp->headers, lst->str);
3885 /*********************************************************************
3887 * Function : client_x_forwarded_for_adder
3889 * Description : Used in the add_client_headers list. Called from `sed'.
3892 * 1 : csp = Current client state (buffers, headers, etc...)
3894 * Returns : JB_ERR_OK on success, or
3895 * JB_ERR_MEMORY on out-of-memory error.
3897 *********************************************************************/
3898 static jb_err client_x_forwarded_for_adder(struct client_state *csp)
3900 char *header = NULL;
3903 if (!((csp->action->flags & ACTION_CHANGE_X_FORWARDED_FOR)
3904 && (0 == strcmpic(csp->action->string[ACTION_STRING_CHANGE_X_FORWARDED_FOR], "add")))
3905 || (csp->flags & CSP_FLAG_X_FORWARDED_FOR_APPENDED))
3908 * If we aren't adding X-Forwarded-For headers,
3909 * or we already appended an existing X-Forwarded-For
3910 * header, there's nothing left to do here.
3915 header = strdup("X-Forwarded-For: ");
3916 string_append(&header, csp->ip_addr_str);
3920 return JB_ERR_MEMORY;
3923 log_error(LOG_LEVEL_HEADER, "addh: %s", header);
3924 err = enlist(csp->headers, header);
3931 /*********************************************************************
3933 * Function : server_connection_adder
3935 * Description : Adds an appropriate "Connection:" header to csp->headers
3936 * unless the header was already present. Called from `sed'.
3939 * 1 : csp = Current client state (buffers, headers, etc...)
3941 * Returns : JB_ERR_OK on success, or
3942 * JB_ERR_MEMORY on out-of-memory error.
3944 *********************************************************************/
3945 static jb_err server_connection_adder(struct client_state *csp)
3947 const unsigned int flags = csp->flags;
3948 const char *response_status_line = csp->headers->first->str;
3949 static const char connection_close[] = "Connection: close";
3951 if ((flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
3952 && (flags & CSP_FLAG_SERVER_CONNECTION_HEADER_SET))
3958 * XXX: if we downgraded the response, this check will fail.
3960 if ((csp->config->feature_flags &
3961 RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
3962 && (NULL != response_status_line)
3963 && !strncmpic(response_status_line, "HTTP/1.1", 8)
3964 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
3965 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
3969 log_error(LOG_LEVEL_HEADER, "A HTTP/1.1 response "
3970 "without Connection header implies keep-alive.");
3971 csp->flags |= CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE;
3975 log_error(LOG_LEVEL_HEADER, "Adding: %s", connection_close);
3977 return enlist(csp->headers, connection_close);
3981 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
3982 /*********************************************************************
3984 * Function : server_proxy_connection_adder
3986 * Description : Adds a "Proxy-Connection: keep-alive" header to
3987 * csp->headers when appropriate.
3990 * 1 : csp = Current client state (buffers, headers, etc...)
3992 * Returns : JB_ERR_OK on success, or
3993 * JB_ERR_MEMORY on out-of-memory error.
3995 *********************************************************************/
3996 static jb_err server_proxy_connection_adder(struct client_state *csp)
3998 static const char proxy_connection_header[] = "Proxy-Connection: keep-alive";
3999 jb_err err = JB_ERR_OK;
4001 if ((csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
4002 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
4003 && !(csp->flags & CSP_FLAG_SERVER_PROXY_CONNECTION_HEADER_SET)
4004 && ((csp->flags & CSP_FLAG_SERVER_CONTENT_LENGTH_SET)
4005 || (csp->flags & CSP_FLAG_CHUNKED))
4006 #ifdef FEATURE_HTTPS_INSPECTION
4007 && !client_use_ssl(csp)
4012 log_error(LOG_LEVEL_HEADER, "Adding: %s", proxy_connection_header);
4013 err = enlist(csp->headers, proxy_connection_header);
4018 #endif /* FEATURE_CONNECTION_KEEP_ALIVE */
4021 /*********************************************************************
4023 * Function : client_connection_header_adder
4025 * Description : Adds a proper "Connection:" header to csp->headers
4026 * unless the header was already present or it's a
4027 * CONNECT request. Called from `sed'.
4030 * 1 : csp = Current client state (buffers, headers, etc...)
4032 * Returns : JB_ERR_OK on success, or
4033 * JB_ERR_MEMORY on out-of-memory error.
4035 *********************************************************************/
4036 static jb_err client_connection_header_adder(struct client_state *csp)
4038 static const char connection_close[] = "Connection: close";
4040 if (!(csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
4041 && (csp->flags & CSP_FLAG_CLIENT_CONNECTION_HEADER_SET))
4047 * In case of CONNECT requests "Connection: close" is implied,
4048 * but actually setting the header has been reported to cause
4049 * problems with some forwarding proxies that close the
4050 * connection prematurely.
4052 if (csp->http->ssl != 0)
4057 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
4058 if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
4059 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
4060 && !strcmpic(csp->http->version, "HTTP/1.1"))
4062 csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
4065 #endif /* FEATURE_CONNECTION_KEEP_ALIVE */
4067 log_error(LOG_LEVEL_HEADER, "Adding: %s", connection_close);
4069 return enlist(csp->headers, connection_close);
4073 /*********************************************************************
4075 * Function : server_http
4077 * Description : - Save the HTTP Status into csp->http->status
4078 * - Set CT_TABOO to prevent filtering if the answer
4079 * is a partial range (HTTP status 206)
4080 * - Rewrite HTTP/1.1 answers to HTTP/1.0 if +downgrade
4082 * - Normalize the HTTP-version.
4085 * 1 : csp = Current client state (buffers, headers, etc...)
4086 * 2 : header = On input, pointer to header to modify.
4087 * On output, pointer to the modified header, or NULL
4088 * to remove the header. This function frees the
4089 * original string if necessary.
4091 * Returns : JB_ERR_OK on success, or
4092 * JB_ERR_PARSE on fatal parse errors.
4094 *********************************************************************/
4095 static jb_err server_http(struct client_state *csp, char **header)
4097 char *reason_phrase = NULL;
4098 char *new_response_line;
4101 unsigned int major_version;
4102 unsigned int minor_version;
4104 /* Get the reason phrase which start after the second whitespace */
4105 p = strchr(*header, ' ');
4109 reason_phrase = strchr(p, ' ');
4112 if (reason_phrase != NULL)
4118 log_error(LOG_LEVEL_ERROR,
4119 "Response line lacks reason phrase: %s", *header);
4123 if (3 != sscanf(*header, "HTTP/%u.%u %d", &major_version,
4124 &minor_version, &(csp->http->status)))
4126 log_error(LOG_LEVEL_ERROR,
4127 "Failed to parse the response line: %s", *header);
4128 return JB_ERR_PARSE;
4131 if (csp->http->status == 101 ||
4132 csp->http->status == 206)
4134 csp->content_type = CT_TABOO;
4137 if (major_version != 1 || (minor_version != 0 && minor_version != 1))
4140 * According to RFC 7230 2.6 intermediaries MUST send
4141 * their own HTTP-version in forwarded messages.
4143 log_error(LOG_LEVEL_ERROR,
4144 "Unsupported HTTP version. Downgrading to 1.1.");
4149 if (((csp->action->flags & ACTION_DOWNGRADE) != 0) && (minor_version == 1))
4151 log_error(LOG_LEVEL_HEADER, "Downgrading answer to HTTP/1.0");
4155 /* Rebuild response line. */
4156 length = sizeof("HTTP/1.1 200 ") + strlen(reason_phrase) + 1;
4157 new_response_line = malloc_or_die(length);
4159 snprintf(new_response_line, length, "HTTP/%u.%u %d %s",
4160 major_version, minor_version, csp->http->status, reason_phrase);
4162 if (0 != strcmp(*header, new_response_line))
4164 log_error(LOG_LEVEL_HEADER, "Response line '%s' changed to '%s'",
4165 *header, new_response_line);
4169 *header = new_response_line;
4174 /*********************************************************************
4176 * Function : add_cooky_expiry_date
4178 * Description : Adds a cookie expiry date to a string.
4181 * 1 : cookie = On input, pointer to cookie to modify.
4182 * On output, pointer to the modified header.
4183 * The original string is freed.
4184 * 2 : lifetime = Seconds the cookie should be valid
4188 *********************************************************************/
4189 static void add_cookie_expiry_date(char **cookie, time_t lifetime)
4192 struct tm *timeptr = NULL;
4193 time_t expiry_date = time(NULL) + lifetime;
4196 timeptr = privoxy_gmtime_r(&expiry_date, &gmt);
4197 if (NULL == timeptr)
4199 log_error(LOG_LEVEL_FATAL,
4200 "Failed to get the time in add_cooky_expiry_date()");
4202 strftime(tmp, sizeof(tmp), "; expires=%a, %d-%b-%Y %H:%M:%S GMT", timeptr);
4203 if (JB_ERR_OK != string_append(cookie, tmp))
4205 log_error(LOG_LEVEL_FATAL, "Out of memory in add_cooky_expiry()");
4210 /*********************************************************************
4212 * Function : server_set_cookie
4214 * Description : Handle the server "cookie" header properly.
4215 * Crunch, accept or rewrite it to a session cookie.
4216 * Called from `sed'.
4219 * 1 : csp = Current client state (buffers, headers, etc...)
4220 * 2 : header = On input, pointer to header to modify.
4221 * On output, pointer to the modified header, or NULL
4222 * to remove the header. This function frees the
4223 * original string if necessary.
4225 * Returns : JB_ERR_OK on success, or
4226 * JB_ERR_MEMORY on out-of-memory error.
4228 *********************************************************************/
4229 static jb_err server_set_cookie(struct client_state *csp, char **header)
4231 if ((csp->action->flags & ACTION_CRUNCH_INCOMING_COOKIES) != 0)
4233 log_error(LOG_LEVEL_HEADER, "Crunching incoming cookie: %s", *header);
4236 else if ((0 != (csp->action->flags & ACTION_SESSION_COOKIES_ONLY))
4237 || (0 != (csp->action->flags & ACTION_LIMIT_COOKIE_LIFETIME)))
4241 long cookie_lifetime = 0;
4244 NO_EXPIRY_DATE_SPECIFIED,
4245 EXPIRY_DATE_ACCEPTABLE,
4246 EXPIRY_DATE_UNACCEPTABLE
4247 } expiry_date_status = NO_EXPIRY_DATE_SPECIFIED;
4249 /* A variable to store the tag we're working on */
4252 /* Skip "Set-Cookie:" (11 characters) in header */
4253 cur_tag = *header + 11;
4255 /* skip whitespace between "Set-Cookie:" and value */
4256 while (*cur_tag && privoxy_isspace(*cur_tag))
4263 if ((csp->action->flags & ACTION_LIMIT_COOKIE_LIFETIME) != 0)
4265 const char *param = csp->action->string[ACTION_STRING_LIMIT_COOKIE_LIFETIME];
4267 cookie_lifetime = strtol(param, NULL, 0);
4268 if (cookie_lifetime < 0)
4270 log_error(LOG_LEVEL_FATAL, "Invalid cookie lifetime limit: %s", param);
4272 cookie_lifetime *= 60;
4275 /* Loop through each tag in the cookie */
4279 char *next_tag = strchr(cur_tag, ';');
4280 if (next_tag != NULL)
4282 /* Skip the ';' character itself */
4285 /* skip whitespace ";" and start of tag */
4286 while (*next_tag && privoxy_isspace(*next_tag))
4293 /* "Next tag" is the end of the string */
4294 next_tag = cur_tag + strlen(cur_tag);
4298 * Check the expiration date to see
4299 * if the cookie is still valid, if yes,
4300 * rewrite it to a session cookie.
4302 if ((strncmpic(cur_tag, "expires=", 8) == 0) && *(cur_tag + 8))
4304 char *expiration_date = cur_tag + 8; /* Skip "[Ee]xpires=" */
4306 if ((expiration_date[0] == '"')
4307 && (expiration_date[1] != '\0'))
4310 * Skip quotation mark. RFC 2109 10.1.2 seems to hint
4311 * that the expiration date isn't supposed to be quoted,
4312 * but some servers do it anyway.
4317 /* Did we detect the date properly? */
4318 if (JB_ERR_OK != parse_header_time(expiration_date, &cookie_time))
4321 * Nope, treat it as if it was still valid.
4323 * XXX: Should we remove the whole cookie instead?
4325 log_error(LOG_LEVEL_ERROR,
4326 "Can't parse \'%s\', send by %s. Unsupported time format?", cur_tag, csp->http->url);
4327 string_move(cur_tag, next_tag);
4328 expiry_date_status = EXPIRY_DATE_UNACCEPTABLE;
4333 * Yes. Check if the cookie is still valid.
4335 * If the cookie is already expired it's probably
4336 * a delete cookie and even if it isn't, the browser
4337 * will discard it anyway.
4341 * XXX: timegm() isn't available on some AmigaOS
4342 * versions and our replacement doesn't work.
4344 * Our options are to either:
4346 * - disable session-cookies-only completely if timegm
4349 * - to simply remove all expired tags, like it has
4350 * been done until Privoxy 3.0.6 and to live with
4351 * the consequence that it can cause login/logout
4352 * problems on servers that don't validate their
4353 * input properly, or
4355 * - to replace it with mktime in which
4356 * case there is a slight chance of valid cookies
4357 * passing as already expired.
4359 * This is the way it's currently done and it's not
4360 * as bad as it sounds. If the missing GMT offset is
4361 * enough to change the result of the expiration check
4362 * the cookie will be only valid for a few hours
4363 * anyway, which in many cases will be shorter
4364 * than a browser session.
4366 if (cookie_time < now)
4368 log_error(LOG_LEVEL_HEADER,
4369 "Cookie \'%s\' is already expired and can pass unmodified.", *header);
4370 /* Just in case some clown sets more then one expiration date */
4372 expiry_date_status = EXPIRY_DATE_ACCEPTABLE;
4374 else if ((cookie_lifetime != 0) && (cookie_time < (now + cookie_lifetime)))
4376 log_error(LOG_LEVEL_HEADER, "Cookie \'%s\' can pass unmodified. "
4377 "Its lifetime is below the limit.", *header);
4378 /* Just in case some clown sets more then one expiration date */
4380 expiry_date_status = EXPIRY_DATE_ACCEPTABLE;
4385 * Still valid, delete expiration date by copying
4386 * the rest of the string over it.
4388 string_move(cur_tag, next_tag);
4390 /* That changed the header, need to issue a log message */
4391 expiry_date_status = EXPIRY_DATE_UNACCEPTABLE;
4394 * Note that the next tag has now been moved to *cur_tag,
4395 * so we do not need to update the cur_tag pointer.
4403 /* Move on to next cookie tag */
4408 if (expiry_date_status != EXPIRY_DATE_ACCEPTABLE)
4410 assert(NULL != *header);
4411 if (cookie_lifetime != 0)
4413 add_cookie_expiry_date(header, cookie_lifetime);
4414 log_error(LOG_LEVEL_HEADER, "Cookie rewritten to: %s", *header);
4416 else if (expiry_date_status != NO_EXPIRY_DATE_SPECIFIED)
4418 log_error(LOG_LEVEL_HEADER,
4419 "Cookie rewritten to a temporary one: %s", *header);
4428 #ifdef FEATURE_FORCE_LOAD
4429 /*********************************************************************
4431 * Function : strclean
4433 * Description : In-Situ-Eliminate all occurrences of substring in
4437 * 1 : string = string to clean
4438 * 2 : substring = substring to eliminate
4440 * Returns : Number of eliminations
4442 *********************************************************************/
4443 int strclean(char *string, const char *substring)
4449 len = strlen(substring);
4451 while((pos = strstr(string, substring)) != NULL)
4458 while (*p++ != '\0');
4465 #endif /* def FEATURE_FORCE_LOAD */
4468 /*********************************************************************
4470 * Function : parse_header_time
4472 * Description : Parses time formats used in HTTP header strings
4473 * to get the numerical respresentation.
4476 * 1 : header_time = HTTP header time as string.
4477 * 2 : result = storage for header_time in seconds
4479 * Returns : JB_ERR_OK if the time format was recognized, or
4480 * JB_ERR_PARSE otherwise.
4482 *********************************************************************/
4483 static jb_err parse_header_time(const char *header_time, time_t *result)
4487 * Checking for two-digit years first in an
4488 * attempt to work around GNU libc's strptime()
4489 * reporting negative year values when using %Y.
4491 static const char time_formats[][22] = {
4492 /* Tue, 02-Jun-37 20:00:00 */
4493 "%a, %d-%b-%y %H:%M:%S",
4494 /* Tue, 02 Jun 2037 20:00:00 */
4495 "%a, %d %b %Y %H:%M:%S",
4496 /* Tue, 02-Jun-2037 20:00:00 */
4497 "%a, %d-%b-%Y %H:%M:%S",
4498 /* Tuesday, 02-Jun-2037 20:00:00 */
4499 "%A, %d-%b-%Y %H:%M:%S",
4500 /* Tuesday Jun 02 20:00:00 2037 */
4501 "%A %b %d %H:%M:%S %Y"
4505 for (i = 0; i < SZ(time_formats); i++)
4508 * Zero out gmt to prevent time zone offsets.
4509 * Documented to be required for GNU libc.
4511 memset(&gmt, 0, sizeof(gmt));
4513 if (NULL != strptime(header_time, time_formats[i], &gmt))
4515 /* Sanity check for GNU libc. */
4516 if (gmt.tm_year < 0)
4518 log_error(LOG_LEVEL_HEADER,
4519 "Failed to parse '%s' using '%s'. Moving on.",
4520 header_time, time_formats[i]);
4523 *result = timegm(&gmt);
4525 #ifdef FEATURE_STRPTIME_SANITY_CHECKS
4527 * Verify that parsing the date recreated from the first
4528 * parse operation gets the previous result. If it doesn't,
4529 * either strptime() or strftime() are malfunctioning.
4531 * We could string-compare the recreated date with the original
4532 * header date, but this leads to false positives as strptime()
4533 * may let %a accept all day formats while strftime() will only
4537 char recreated_date[100];
4542 tm = privoxy_gmtime_r(result, &storage);
4543 if (!strftime(recreated_date, sizeof(recreated_date),
4544 time_formats[i], tm))
4546 log_error(LOG_LEVEL_ERROR, "Failed to recreate date '%s' with '%s'.",
4547 header_time, time_formats[i]);
4550 memset(&gmt, 0, sizeof(gmt));
4551 if (NULL == strptime(recreated_date, time_formats[i], &gmt))
4553 log_error(LOG_LEVEL_ERROR,
4554 "Failed to parse '%s' generated with '%s' to recreate '%s'.",
4555 recreated_date, time_formats[i], header_time);
4558 result2 = timegm(&gmt);
4559 if (*result != result2)
4561 log_error(LOG_LEVEL_ERROR, "strftime() and strptime() disagree. "
4562 "Format: '%s'. In: '%s', out: '%s'. %ld != %ld. Rejecting.",
4563 time_formats[i], header_time, recreated_date, *result, result2);
4573 return JB_ERR_PARSE;
4577 /*********************************************************************
4579 * Function : parse_time_header
4581 * Description : Parses the time in an HTTP time header to get
4582 * the numerical respresentation.
4585 * 1 : header = HTTP header with a time value
4586 * 2 : result = storage for header_time in seconds
4588 * Returns : JB_ERR_OK if the time format was recognized, or
4589 * JB_ERR_PARSE otherwise.
4591 *********************************************************************/
4592 static jb_err parse_time_header(const char *header, time_t *result)
4594 const char *header_time;
4596 header_time = strchr(header, ':');
4599 * Currently this can't happen as all callers are called
4600 * through sed() which requires a header name followed by
4603 assert(header_time != NULL);
4606 if (*header_time == ' ')
4611 return parse_header_time(header_time, result);
4616 /*********************************************************************
4618 * Function : get_destination_from_headers
4620 * Description : Parse the "Host:" header to get the request's destination.
4621 * Only needed if the client's request was forcefully
4622 * redirected into Privoxy.
4624 * Code mainly copied from client_host() which is currently
4625 * run too late for this purpose.
4628 * 1 : headers = List of headers (one of them hopefully being
4629 * the "Host:" header)
4630 * 2 : http = storage for the result (host, port and hostport).
4632 * Returns : JB_ERR_MEMORY (or terminates) in case of memory problems,
4633 * JB_ERR_PARSE if the host header couldn't be found,
4634 * JB_ERR_OK otherwise.
4636 *********************************************************************/
4637 jb_err get_destination_from_headers(const struct list *headers, struct http_request *http)
4643 host = get_header_value(headers, "Host:");
4647 log_error(LOG_LEVEL_ERROR, "No \"Host:\" header found.");
4648 return JB_ERR_PARSE;
4651 p = string_tolower(host);
4654 return JB_ERR_MEMORY;
4657 q = strdup_or_die(p);
4659 freez(http->hostport);
4663 q = strchr(http->host, ':');
4666 /* Terminate hostname and evaluate port string */
4668 http->port = atoi(q);
4675 /* Rebuild request URL */
4677 http->url = strdup("http://");
4678 string_append(&http->url, http->hostport);
4679 string_append(&http->url, http->path);
4680 if (http->url == NULL)
4682 return JB_ERR_MEMORY;
4685 log_error(LOG_LEVEL_HEADER,
4686 "Destination extracted from \"Host\" header. New request URL: %s",
4690 * Regenerate request line in "proxy format"
4691 * to make rewrites more convenient.
4693 assert(http->cmd != NULL);
4695 http->cmd = strdup_or_die(http->gpc);
4696 string_append(&http->cmd, " ");
4697 string_append(&http->cmd, http->url);
4698 string_append(&http->cmd, " ");
4699 string_append(&http->cmd, http->version);
4700 if (http->cmd == NULL)
4702 return JB_ERR_MEMORY;
4710 #ifdef FEATURE_HTTPS_INSPECTION
4711 /*********************************************************************
4713 * Function : get_destination_from_https_headers
4715 * Description : Parse the previously encrypted "Host:" header to
4716 * get the request's destination.
4719 * 1 : headers = List of headers (one of them hopefully being
4720 * the "Host:" header)
4721 * 2 : http = storage for the result (host, port and hostport).
4723 * Returns : JB_ERR_MEMORY (or terminates) in case of memory problems,
4724 * JB_ERR_PARSE if the host header couldn't be found,
4725 * JB_ERR_OK otherwise.
4727 *********************************************************************/
4728 jb_err get_destination_from_https_headers(const struct list *headers, struct http_request *http)
4734 host = get_header_value(headers, "Host:");
4738 log_error(LOG_LEVEL_ERROR, "No \"Host:\" header found.");
4739 return JB_ERR_PARSE;
4742 p = string_tolower(host);
4745 return JB_ERR_MEMORY;
4748 q = strdup_or_die(p);
4750 freez(http->hostport);
4754 q = strchr(http->host, ':');
4757 /* Terminate hostname and evaluate port string */
4759 http->port = atoi(q);
4766 /* Rebuild request URL */
4768 http->url = strdup_or_die(http->path);
4770 log_error(LOG_LEVEL_HEADER,
4771 "Destination extracted from \"Host\" header. New request URL: %s",
4775 * Regenerate request line in "proxy format"
4776 * to make rewrites more convenient.
4778 assert(http->cmd != NULL);
4780 http->cmd = strdup_or_die(http->gpc);
4781 string_append(&http->cmd, " ");
4782 string_append(&http->cmd, http->url);
4783 string_append(&http->cmd, " ");
4784 string_append(&http->cmd, http->version);
4785 if (http->cmd == NULL)
4787 return JB_ERR_MEMORY;
4793 #endif /* def FEATURE_HTTPS_INSPECTION */
4796 /*********************************************************************
4798 * Function : create_forged_referrer
4800 * Description : Helper for client_referrer to forge a referer as
4801 * 'http://hostname[:port]/' to fool stupid
4802 * checks for in-site links
4805 * 1 : header = Pointer to header pointer
4806 * 2 : hostport = Host and optionally port as string
4808 * Returns : JB_ERR_OK in case of success, or
4809 * JB_ERR_MEMORY in case of memory problems.
4811 *********************************************************************/
4812 static jb_err create_forged_referrer(char **header, const char *hostport)
4814 assert(NULL == *header);
4816 *header = strdup("Referer: http://");
4817 string_append(header, hostport);
4818 string_append(header, "/");
4820 if (NULL == *header)
4822 return JB_ERR_MEMORY;
4825 log_error(LOG_LEVEL_HEADER, "Referer forged to: %s", *header);
4832 /*********************************************************************
4834 * Function : create_fake_referrer
4836 * Description : Helper for client_referrer to create a fake referrer
4837 * based on a string supplied by the user.
4840 * 1 : header = Pointer to header pointer
4841 * 2 : hosthost = Referrer to fake
4843 * Returns : JB_ERR_OK in case of success, or
4844 * JB_ERR_MEMORY in case of memory problems.
4846 *********************************************************************/
4847 static jb_err create_fake_referrer(char **header, const char *fake_referrer)
4849 assert(NULL == *header);
4851 if ((0 != strncmpic(fake_referrer, "http://", 7)) && (0 != strncmpic(fake_referrer, "https://", 8)))
4853 log_error(LOG_LEVEL_HEADER,
4854 "Parameter: +hide-referrer{%s} is a bad idea, but I don't care.", fake_referrer);
4856 *header = strdup("Referer: ");
4857 string_append(header, fake_referrer);
4859 if (NULL == *header)
4861 return JB_ERR_MEMORY;
4864 log_error(LOG_LEVEL_HEADER, "Referer replaced with: %s", *header);
4871 /*********************************************************************
4873 * Function : handle_conditional_hide_referrer_parameter
4875 * Description : Helper for client_referrer to crunch or forge
4876 * the referrer header if the host has changed.
4879 * 1 : header = Pointer to header pointer
4880 * 2 : host = The target host (may include the port)
4881 * 3 : parameter_conditional_block = Boolean to signal
4882 * if we're in conditional-block mode. If not set,
4883 * we're in conditional-forge mode.
4885 * Returns : JB_ERR_OK in case of success, or
4886 * JB_ERR_MEMORY in case of memory problems.
4888 *********************************************************************/
4889 static jb_err handle_conditional_hide_referrer_parameter(char **header,
4890 const char *host, const int parameter_conditional_block)
4892 char *referer = strdup_or_die(*header);
4893 const size_t hostlength = strlen(host);
4894 const char *referer_url = NULL;
4896 /* referer begins with 'Referer: http[s]://' */
4897 if ((hostlength+17) < strlen(referer))
4900 * Shorten referer to make sure the referer is blocked
4901 * if www.example.org/www.example.com-shall-see-the-referer/
4902 * links to www.example.com/
4904 referer[hostlength+17] = '\0';
4906 referer_url = strstr(referer, "http://");
4907 if (NULL == referer_url)
4909 referer_url = strstr(referer, "https://");
4911 if ((NULL == referer_url) || (NULL == strstr(referer_url, host)))
4913 /* Host has changed, Referer is invalid or a https URL. */
4914 if (parameter_conditional_block)
4916 log_error(LOG_LEVEL_HEADER, "New host is: %s. Crunching %s!", host, *header);
4923 return create_forged_referrer(header, host);
4933 /*********************************************************************
4935 * Function : create_content_length_header
4937 * Description : Creates a Content-Length header.
4940 * 1 : content_length = The content length to be used in the header.
4941 * 2 : header = Allocated space to safe the header.
4942 * 3 : buffer_length = The length of the allocated space.
4946 *********************************************************************/
4947 static void create_content_length_header(unsigned long long content_length,
4948 char *header, size_t buffer_length)
4951 #if SIZEOF_LONG_LONG < 8
4952 #error sizeof(unsigned long long) too small
4954 snprintf(header, buffer_length, "Content-Length: %I64u", content_length);
4956 snprintf(header, buffer_length, "Content-Length: %llu", content_length);
4961 /*********************************************************************
4963 * Function : get_expected_content_length
4965 * Description : Figures out the content length from a list of headers.
4968 * 1 : headers = List of headers
4970 * Returns : Number of bytes to expect
4972 *********************************************************************/
4973 unsigned long long get_expected_content_length(struct list *headers)
4975 const char *content_length_header;
4976 unsigned long long content_length = 0;
4978 content_length_header = get_header_value(headers, "Content-Length:");
4979 if (content_length_header != NULL)
4981 if (JB_ERR_OK != get_content_length(content_length_header, &content_length))
4983 log_error(LOG_LEVEL_ERROR,
4984 "Failed to get the Content-Length in %s", content_length_header);
4985 /* XXX: The header will be removed later on */
4990 return content_length;