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 (old_size < (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,
581 "Invalid gzip header when decompressing.");
582 return JB_ERR_COMPRESS;
587 if (flags & GZIP_FLAG_RESERVED_BITS)
589 /* The gzip header has reserved bits set; bail out. */
590 log_error(LOG_LEVEL_ERROR,
591 "Invalid gzip header flags when decompressing.");
592 return JB_ERR_COMPRESS;
596 * Skip mtime (4 bytes), extra flags (1 byte)
597 * and OS type (1 byte).
601 /* Skip extra fields if necessary. */
602 if (flags & GZIP_FLAG_EXTRA_FIELDS)
605 * Skip a given number of bytes, specified
606 * as a 16-bit little-endian value.
608 * XXX: this code is untested and should probably be removed.
612 if (cur + 2 >= csp->iob->eod)
614 log_error(LOG_LEVEL_ERROR,
615 "gzip extra field flag set but insufficient data available.");
616 return JB_ERR_COMPRESS;
620 skip_bytes += (unsigned char)*cur++ << 8;
623 * The number of bytes to skip should be positive
624 * and we'd like to stay in the buffer.
626 if ((skip_bytes < 0) || (skip_bytes >= (csp->iob->eod - cur)))
628 log_error(LOG_LEVEL_ERROR,
629 "Unreasonable amount of bytes to skip (%d). "
630 "Stopping decompression.",
632 return JB_ERR_COMPRESS;
634 log_error(LOG_LEVEL_INFO,
635 "Skipping %d bytes for gzip compression. "
636 "Does this sound right?",
641 /* Skip the filename if necessary. */
642 if (flags & GZIP_FLAG_FILE_NAME)
644 /* A null-terminated string is supposed to follow. */
645 while ((cur < csp->iob->eod) && *cur++);
648 /* Skip the comment if necessary. */
649 if (flags & GZIP_FLAG_COMMENT)
651 /* A null-terminated string is supposed to follow. */
652 while ((cur < csp->iob->eod) && *cur++);
655 /* Skip the CRC if necessary. */
656 if (flags & GZIP_FLAG_CHECKSUM)
661 if (cur >= csp->iob->eod)
664 * If the current position pointer reached or passed
665 * the buffer end, we were obviously tricked to skip
668 log_error(LOG_LEVEL_ERROR,
669 "Malformed gzip header detected. Aborting decompression.");
670 return JB_ERR_COMPRESS;
674 else if (csp->content_type & CT_DEFLATE)
677 * In theory (that is, according to RFC 1950), deflate-compressed
678 * data should begin with a two-byte zlib header and have an
679 * adler32 checksum at the end. It seems that in practice only
680 * the raw compressed data is sent. Note that this means that
681 * we are not RFC 1950-compliant here, but the advantage is that
682 * this actually works. :)
684 * We add a dummy null byte to tell zlib where the data ends,
685 * and later inform it not to expect a header.
687 * Fortunately, add_to_iob() has thoughtfully null-terminated
688 * the buffer; we can just increment the end pointer to include
695 log_error(LOG_LEVEL_ERROR,
696 "Unable to determine compression format for decompression.");
697 return JB_ERR_COMPRESS;
700 /* Set up the fields required by zlib. */
701 zstr.next_in = (Bytef *)cur;
702 zstr.avail_in = (unsigned int)(csp->iob->eod - cur);
703 zstr.zalloc = Z_NULL;
705 zstr.opaque = Z_NULL;
708 * Passing -MAX_WBITS to inflateInit2 tells the library
709 * that there is no zlib header.
711 if (inflateInit2(&zstr, -MAX_WBITS) != Z_OK)
713 log_error(LOG_LEVEL_ERROR, "Error initializing decompression.");
714 return JB_ERR_COMPRESS;
718 * Next, we allocate new storage for the inflated data.
719 * We don't modify the existing iob yet, so in case there
720 * is an error in decompression we can recover gracefully.
722 buf = zalloc(bufsize);
725 log_error(LOG_LEVEL_ERROR, "Out of memory decompressing iob.");
726 return JB_ERR_MEMORY;
729 assert(bufsize >= skip_size);
730 memcpy(buf, csp->iob->buf, skip_size);
731 zstr.avail_out = (uInt)(bufsize - skip_size);
732 zstr.next_out = (Bytef *)buf + skip_size;
734 /* Try to decompress the whole stream in one shot. */
735 while (Z_BUF_ERROR == (status = inflate(&zstr, Z_FINISH)))
737 /* We need to allocate more memory for the output buffer. */
739 char *tmpbuf; /* used for realloc'ing the buffer */
740 size_t oldbufsize = bufsize; /* keep track of the old bufsize */
742 if (0 == zstr.avail_in)
745 * If zlib wants more data then there's a problem, because
746 * the complete compressed file should have been buffered.
748 log_error(LOG_LEVEL_ERROR,
749 "Unexpected end of compressed iob. Using what we got so far.");
754 * If we reached the buffer limit and still didn't have enough
755 * memory, just give up. Due to the ceiling enforced by the next
756 * if block we could actually check for equality here, but as it
757 * can be easily mistaken for a bug we don't.
759 if (bufsize >= csp->config->buffer_limit)
761 log_error(LOG_LEVEL_ERROR,
762 "Buffer limit reached while decompressing iob.");
765 return JB_ERR_MEMORY;
768 /* Try doubling the buffer size each time. */
771 /* Don't exceed the buffer limit. */
772 if (bufsize > csp->config->buffer_limit)
774 bufsize = csp->config->buffer_limit;
777 /* Try to allocate the new buffer. */
778 tmpbuf = realloc(buf, bufsize);
781 log_error(LOG_LEVEL_ERROR,
782 "Out of memory decompressing iob.");
785 return JB_ERR_MEMORY;
790 char *oldnext_out = (char *)zstr.next_out;
793 * Update the fields for inflate() to use the new
794 * buffer, which may be in a location different from
797 zstr.avail_out += (uInt)(bufsize - oldbufsize);
798 zstr.next_out = (Bytef *)tmpbuf + bufsize - zstr.avail_out;
801 * Compare with an uglier method of calculating these values
802 * that doesn't require the extra oldbufsize variable.
804 assert(zstr.avail_out == tmpbuf + bufsize - (char *)zstr.next_out);
805 assert((char *)zstr.next_out == tmpbuf + ((char *)oldnext_out - buf));
811 if (Z_STREAM_ERROR == inflateEnd(&zstr))
813 log_error(LOG_LEVEL_ERROR,
814 "Inconsistent stream state after decompression: %s", zstr.msg);
816 * XXX: Intentionally no return.
818 * According to zlib.h, Z_STREAM_ERROR is returned
819 * "if the stream state was inconsistent".
821 * I assume in this case inflate()'s status
822 * would also be something different than Z_STREAM_END
823 * so this check should be redundant, but lets see.
827 if ((status != Z_STREAM_END) && (0 != zstr.avail_in))
830 * We failed to decompress the stream and it's
831 * not simply because of missing data.
833 log_error(LOG_LEVEL_ERROR,
834 "Unexpected error while decompressing to the buffer (iob): %s",
837 return JB_ERR_COMPRESS;
841 * Finally, we can actually update the iob, since the
842 * decompression was successful. First, free the old
845 freez(csp->iob->buf);
847 /* Now, update the iob to use the new buffer. */
849 csp->iob->cur = csp->iob->buf + skip_size;
850 csp->iob->eod = (char *)zstr.next_out;
851 csp->iob->size = bufsize;
854 * Make sure the new uncompressed iob obeys some minimal
855 * consistency conditions.
857 if ((csp->iob->buf <= csp->iob->cur)
858 && (csp->iob->cur <= csp->iob->eod)
859 && (csp->iob->eod <= csp->iob->buf + csp->iob->size))
861 const size_t new_size = (size_t)(csp->iob->eod - csp->iob->cur);
862 if (new_size > (size_t)0)
864 log_error(LOG_LEVEL_RE_FILTER,
865 "Decompression successful. Old size: %lu, new size: %lu.",
870 /* zlib thinks this is OK, so let's do the same. */
871 log_error(LOG_LEVEL_RE_FILTER,
872 "Decompression didn't result in any content.");
877 /* It seems that zlib did something weird. */
878 log_error(LOG_LEVEL_ERROR,
879 "Inconsistent buffer after decompression.");
880 return JB_ERR_COMPRESS;
886 #endif /* defined(FEATURE_ZLIB) */
889 /*********************************************************************
891 * Function : normalize_lws
893 * Description : Reduces unquoted linear whitespace in headers to
894 * a single space in accordance with RFC 7230 3.2.4.
895 * This simplifies parsing and filtering later on.
898 * 1 : header = A header with linear whitespace to reduce.
902 *********************************************************************/
903 static void normalize_lws(char *header)
909 if (privoxy_isspace(*p) && privoxy_isspace(*(p+1)))
913 while (privoxy_isspace(*q))
917 log_error(LOG_LEVEL_HEADER, "Reducing whitespace in '%s'", header);
923 log_error(LOG_LEVEL_HEADER,
924 "Converting tab to space in '%s'", header);
929 char *end_of_token = strstr(p+1, "\"");
931 if (NULL != end_of_token)
933 /* Don't mess with quoted text. */
938 log_error(LOG_LEVEL_HEADER,
939 "Ignoring single quote in '%s'", header);
945 p = strchr(header, ':');
946 if ((p != NULL) && (p != header) && privoxy_isspace(*(p-1)))
949 * There's still space before the colon.
957 /*********************************************************************
959 * Function : get_header
961 * Description : This (odd) routine will parse the csp->iob
962 * to get the next complete header.
965 * 1 : iob = The I/O buffer to parse, usually csp->iob.
967 * Returns : Any one of the following:
969 * 1) a pointer to a dynamically allocated string that contains a header line
970 * 2) NULL indicating that the end of the header was reached
971 * 3) "" indicating that the end of the iob was reached before finding
972 * a complete header line.
974 *********************************************************************/
975 char *get_header(struct iob *iob)
979 header = get_header_line(iob);
981 if ((header == NULL) || (*header == '\0'))
984 * No complete header read yet, tell the client.
989 while ((iob->cur[0] == ' ') || (iob->cur[0] == '\t'))
992 * Header spans multiple lines, append the next one.
994 char *continued_header;
996 continued_header = get_header_line(iob);
997 if ((continued_header == NULL) || (*continued_header == '\0'))
1000 * No complete header read yet, return what we got.
1001 * XXX: Should "unread" header instead.
1003 log_error(LOG_LEVEL_INFO,
1004 "Failed to read a multi-line header properly: '%s'",
1009 if (JB_ERR_OK != string_join(&header, continued_header))
1011 log_error(LOG_LEVEL_FATAL,
1012 "Out of memory while appending multiple headers.");
1016 /* XXX: remove before next stable release. */
1017 log_error(LOG_LEVEL_HEADER,
1018 "Merged multiple header lines to: '%s'",
1023 normalize_lws(header);
1030 /*********************************************************************
1032 * Function : get_header_line
1034 * Description : This (odd) routine will parse the csp->iob
1035 * to get the next header line.
1038 * 1 : iob = The I/O buffer to parse, usually csp->iob.
1040 * Returns : Any one of the following:
1042 * 1) a pointer to a dynamically allocated string that contains a header line
1043 * 2) NULL indicating that the end of the header was reached
1044 * 3) "" indicating that the end of the iob was reached before finding
1045 * a complete header line.
1047 *********************************************************************/
1048 static char *get_header_line(struct iob *iob)
1052 if ((iob->cur == NULL)
1053 || ((p = strchr(iob->cur, '\n')) == NULL))
1055 return(""); /* couldn't find a complete header */
1060 ret = strdup(iob->cur);
1063 /* FIXME No way to handle error properly */
1064 log_error(LOG_LEVEL_FATAL, "Out of memory in get_header_line()");
1066 assert(ret != NULL);
1070 if ((q = strchr(ret, '\r')) != NULL) *q = '\0';
1072 /* is this a blank line (i.e. the end of the header) ? */
1084 /*********************************************************************
1086 * Function : get_header_value
1088 * Description : Get the value of a given header from a chained list
1089 * of header lines or return NULL if no such header is
1090 * present in the list.
1093 * 1 : header_list = pointer to list
1094 * 2 : header_name = string with name of header to look for.
1095 * Trailing colon required, capitalization
1098 * Returns : NULL if not found, else value of header
1100 *********************************************************************/
1101 char *get_header_value(const struct list *header_list, const char *header_name)
1103 struct list_entry *cur_entry;
1107 assert(header_list);
1108 assert(header_name);
1109 length = strlen(header_name);
1111 for (cur_entry = header_list->first; cur_entry ; cur_entry = cur_entry->next)
1115 if (!strncmpic(cur_entry->str, header_name, length))
1118 * Found: return pointer to start of value
1120 ret = cur_entry->str + length;
1121 while (*ret && privoxy_isspace(*ret)) ret++;
1135 /*********************************************************************
1137 * Function : scan_headers
1139 * Description : Scans headers, applies tags and updates action bits.
1142 * 1 : csp = Current client state (buffers, headers, etc...)
1144 * Returns : JB_ERR_OK
1146 *********************************************************************/
1147 static jb_err scan_headers(struct client_state *csp)
1149 struct list_entry *h; /* Header */
1150 jb_err err = JB_ERR_OK;
1152 for (h = csp->headers->first; (err == JB_ERR_OK) && (h != NULL) ; h = h->next)
1154 /* Header crunch()ed in previous run? -> ignore */
1155 if (h->str == NULL) continue;
1156 log_error(LOG_LEVEL_HEADER, "scan: %s", h->str);
1157 err = header_tagger(csp, h->str);
1164 /*********************************************************************
1166 * Function : enforce_header_order
1168 * Description : Enforces a given header order.
1171 * 1 : headers = List of headers to order.
1172 * 2 : ordered_headers = List of ordered header names.
1176 *********************************************************************/
1177 static void enforce_header_order(struct list *headers, const struct list *ordered_headers)
1179 struct list_entry *sorted_header;
1180 struct list new_headers[1];
1181 struct list_entry *header;
1183 init_list(new_headers);
1185 /* The request line is always the first "header" */
1187 assert(NULL != headers->first->str);
1188 enlist(new_headers, headers->first->str);
1189 freez(headers->first->str)
1191 /* Enlist the specified headers in the given order */
1193 for (sorted_header = ordered_headers->first; sorted_header != NULL;
1194 sorted_header = sorted_header->next)
1196 const size_t sorted_header_length = strlen(sorted_header->str);
1197 for (header = headers->first; header != NULL; header = header->next)
1199 /* Header enlisted in previous run? -> ignore */
1200 if (header->str == NULL) continue;
1202 if (0 == strncmpic(sorted_header->str, header->str, sorted_header_length)
1203 && (header->str[sorted_header_length] == ':'))
1205 log_error(LOG_LEVEL_HEADER, "Enlisting sorted 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);
1215 /* Enlist the rest of the headers behind the ordered ones */
1216 for (header = headers->first; header != NULL; header = header->next)
1218 /* Header enlisted in previous run? -> ignore */
1219 if (header->str == NULL) continue;
1221 log_error(LOG_LEVEL_HEADER,
1222 "Enlisting left-over header %s", header->str);
1223 if (JB_ERR_OK != enlist(new_headers, header->str))
1225 log_error(LOG_LEVEL_HEADER, "Failed to enlist %s", header->str);
1230 list_remove_all(headers);
1231 headers->first = new_headers->first;
1232 headers->last = new_headers->last;
1238 /*********************************************************************
1242 * Description : add, delete or modify lines in the HTTP header streams.
1243 * On entry, it receives a linked list of headers space
1244 * that was allocated dynamically (both the list nodes
1245 * and the header contents).
1247 * As a side effect it frees the space used by the original
1251 * 1 : csp = Current client state (buffers, headers, etc...)
1252 * 2 : filter_server_headers = Boolean to switch between
1253 * server and header filtering.
1255 * Returns : JB_ERR_OK in case off success, or
1256 * JB_ERR_MEMORY on some out-of-memory errors, or
1257 * JB_ERR_PARSE in case of fatal parse errors.
1259 *********************************************************************/
1260 jb_err sed(struct client_state *csp, int filter_server_headers)
1262 /* XXX: use more descriptive names. */
1263 struct list_entry *p;
1264 const struct parsers *v;
1265 const add_header_func_ptr *f;
1266 jb_err err = JB_ERR_OK;
1270 if (filter_server_headers)
1272 v = server_patterns;
1273 f = add_server_headers;
1274 check_negative_tag_patterns(csp, PATTERN_SPEC_NO_RESPONSE_TAG_PATTERN);
1278 v = client_patterns;
1279 f = add_client_headers;
1280 check_negative_tag_patterns(csp, PATTERN_SPEC_NO_REQUEST_TAG_PATTERN);
1283 while (v->str != NULL)
1285 for (p = csp->headers->first; p != NULL; p = p->next)
1287 /* Header crunch()ed in previous run? -> ignore */
1288 if (p->str == NULL) continue;
1290 /* Does the current parser handle this header? */
1291 if ((strncmpic(p->str, v->str, v->len) == 0) ||
1292 (v->len == CHECK_EVERY_HEADER_REMAINING))
1294 err = v->parser(csp, &(p->str));
1295 if (err != JB_ERR_OK)
1304 /* place additional headers on the csp->headers list */
1305 while ((err == JB_ERR_OK) && (*f))
1311 if (!filter_server_headers &&
1312 !list_is_empty(csp->config->ordered_client_headers) &&
1313 csp->headers->first->str != NULL)
1315 enforce_header_order(csp->headers, csp->config->ordered_client_headers);
1322 #ifdef FEATURE_HTTPS_INSPECTION
1323 /*********************************************************************
1325 * Function : sed_https
1327 * Description : add, delete or modify lines in the HTTPS client
1328 * header streams. Wrapper around sed().
1331 * 1 : csp = Current client state (buffers, headers, etc...)
1333 * Returns : JB_ERR_OK in case off success, or
1334 * JB_ERR_MEMORY on some out-of-memory errors, or
1335 * JB_ERR_PARSE in case of fatal parse errors.
1337 *********************************************************************/
1338 jb_err sed_https(struct client_state *csp)
1341 struct list headers;
1344 * Temporarily replace csp->headers with csp->https_headers
1345 * to trick sed() into filtering the https headers.
1347 headers.first = csp->headers->first;
1348 headers.last = csp->headers->last;
1349 csp->headers->first = csp->https_headers->first;
1350 csp->headers->last = csp->https_headers->last;
1353 * Start with fresh tags. Already existing tags may
1354 * be set again. This is necessary to overrule
1355 * URL-based patterns.
1357 destroy_list(csp->tags);
1360 * We want client header filters and taggers
1361 * so temporarily remove the flag.
1363 csp->flags &= ~CSP_FLAG_CLIENT_HEADER_PARSING_DONE;
1364 err = sed(csp, FILTER_CLIENT_HEADERS);
1365 csp->flags |= CSP_FLAG_CLIENT_HEADER_PARSING_DONE;
1368 * Update the https headers list which may have
1369 * been modified due to header additions or header
1372 csp->https_headers->first = csp->headers->first;
1373 csp->https_headers->last = csp->headers->last;
1375 csp->headers->first = headers.first;
1376 csp->headers->last = headers.last;
1380 #endif /* def FEATURE_HTTPS_INSPECTION */
1383 /*********************************************************************
1385 * Function : update_server_headers
1387 * Description : Updates server headers after the body has been modified.
1390 * 1 : csp = Current client state (buffers, headers, etc...)
1392 * Returns : JB_ERR_OK in case off success, or
1393 * JB_ERR_MEMORY on out-of-memory error.
1395 *********************************************************************/
1396 jb_err update_server_headers(struct client_state *csp)
1398 jb_err err = JB_ERR_OK;
1400 static const struct parsers server_patterns_light[] = {
1401 { "Content-Length:", 15, server_adjust_content_length },
1402 { "Transfer-Encoding:", 18, server_transfer_coding },
1404 { "Content-Encoding:", 17, server_adjust_content_encoding },
1405 #endif /* def FEATURE_ZLIB */
1409 if (strncmpic(csp->http->cmd, "HEAD", 4))
1411 const struct parsers *v;
1412 struct list_entry *p;
1414 for (v = server_patterns_light; (err == JB_ERR_OK) && (v->str != NULL); v++)
1416 for (p = csp->headers->first; (err == JB_ERR_OK) && (p != NULL); p = p->next)
1418 /* Header crunch()ed in previous run? -> ignore */
1419 if (p->str == NULL) continue;
1421 /* Does the current parser handle this header? */
1422 if (strncmpic(p->str, v->str, v->len) == 0)
1424 err = v->parser(csp, (char **)&(p->str));
1430 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1431 if ((JB_ERR_OK == err)
1432 && (csp->flags & CSP_FLAG_MODIFIED)
1433 && (csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
1434 && !(csp->flags & CSP_FLAG_SERVER_CONTENT_LENGTH_SET))
1438 create_content_length_header(csp->content_length, header, sizeof(header));
1439 err = enlist(csp->headers, header);
1440 if (JB_ERR_OK == err)
1442 log_error(LOG_LEVEL_HEADER,
1443 "Content modified with no Content-Length header set. "
1444 "Created: %s.", header);
1445 csp->flags |= CSP_FLAG_SERVER_CONTENT_LENGTH_SET;
1448 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
1450 #ifdef FEATURE_COMPRESSION
1451 if ((JB_ERR_OK == err)
1452 && (csp->flags & CSP_FLAG_BUFFERED_CONTENT_DEFLATED))
1454 err = enlist_unique_header(csp->headers, "Content-Encoding", "deflate");
1455 if (JB_ERR_OK == err)
1457 log_error(LOG_LEVEL_HEADER, "Added header: Content-Encoding: deflate");
1466 /*********************************************************************
1468 * Function : header_tagger
1470 * Description : Executes all text substitutions from applying
1471 * tag actions and saves the result as tag.
1473 * XXX: Shares enough code with filter_header() and
1474 * pcrs_filter_response() to warrant some helper functions.
1477 * 1 : csp = Current client state (buffers, headers, etc...)
1478 * 2 : header = Header that is used as tagger input
1480 * Returns : JB_ERR_OK on success and always succeeds
1482 *********************************************************************/
1483 static jb_err header_tagger(struct client_state *csp, char *header)
1485 enum filter_type wanted_filter_type;
1486 int multi_action_index;
1489 struct re_filterfile_spec *b;
1490 struct list_entry *tag_name;
1492 const size_t header_length = strlen(header);
1494 if (csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
1496 wanted_filter_type = FT_SERVER_HEADER_TAGGER;
1497 multi_action_index = ACTION_MULTI_SERVER_HEADER_TAGGER;
1501 wanted_filter_type = FT_CLIENT_HEADER_TAGGER;
1502 multi_action_index = ACTION_MULTI_CLIENT_HEADER_TAGGER;
1505 if (list_is_empty(csp->action->multi[multi_action_index])
1506 || filters_available(csp) == FALSE)
1508 /* Return early if no taggers apply or if none are available. */
1512 /* Execute all applying taggers */
1513 for (tag_name = csp->action->multi[multi_action_index]->first;
1514 NULL != tag_name; tag_name = tag_name->next)
1516 char *modified_tag = NULL;
1518 size_t size = header_length;
1521 b = get_filter(csp, tag_name->str, wanted_filter_type);
1527 joblist = b->joblist;
1529 if (b->dynamic) joblist = compile_dynamic_pcrs_job_list(csp, b);
1531 if (NULL == joblist)
1533 log_error(LOG_LEVEL_TAGGING,
1534 "Tagger %s has empty joblist. Nothing to do.", b->name);
1538 /* execute their pcrs_joblist on the header. */
1539 for (job = joblist; NULL != job; job = job->next)
1541 const int hits = pcrs_execute(job, tag, size, &modified_tag, &size);
1545 /* Success, continue with the modified version. */
1554 /* Tagger doesn't match */
1557 /* Regex failure, log it but continue anyway. */
1558 assert(NULL != header);
1559 log_error(LOG_LEVEL_ERROR,
1560 "Problems with tagger \'%s\' and header \'%s\': %s",
1561 b->name, header, pcrs_strerror(hits));
1563 freez(modified_tag);
1567 if (b->dynamic) pcrs_free_joblist(joblist);
1569 /* If this tagger matched */
1575 * There is no technical limitation which makes
1576 * it impossible to use empty tags, but I assume
1577 * no one would do it intentionally.
1580 log_error(LOG_LEVEL_TAGGING,
1581 "Tagger \'%s\' created an empty tag. Ignored.", b->name);
1585 if (list_contains_item(csp->action->multi[ACTION_MULTI_SUPPRESS_TAG], tag))
1587 log_error(LOG_LEVEL_TAGGING,
1588 "Tagger \'%s\' didn't add tag \'%s\': suppressed",
1594 if (!list_contains_item(csp->tags, tag))
1596 if (JB_ERR_OK != enlist(csp->tags, tag))
1598 log_error(LOG_LEVEL_ERROR,
1599 "Insufficient memory to add tag \'%s\', "
1600 "based on tagger \'%s\' and header \'%s\'",
1601 tag, b->name, header);
1605 char *action_message;
1607 * update the action bits right away, to make
1608 * tagging based on tags set by earlier taggers
1609 * of the same kind possible.
1611 if (update_action_bits_for_tag(csp, tag))
1613 action_message = "Action bits updated accordingly.";
1617 action_message = "No action bits update necessary.";
1620 log_error(LOG_LEVEL_TAGGING,
1621 "Tagger \'%s\' added tag \'%s\'. %s",
1622 b->name, tag, action_message);
1627 /* XXX: Is this log-worthy? */
1628 log_error(LOG_LEVEL_TAGGING,
1629 "Tagger \'%s\' didn't add tag \'%s\'. Tag already present",
1639 /* here begins the family of parser functions that reformat header lines */
1641 /*********************************************************************
1643 * Function : filter_header
1645 * Description : Executes all text substitutions from all applying
1646 * +(server|client)-header-filter actions on the header.
1647 * Most of the code was copied from pcrs_filter_response,
1648 * including the rather short variable names
1651 * 1 : csp = Current client state (buffers, headers, etc...)
1652 * 2 : header = On input, pointer to header to modify.
1653 * On output, pointer to the modified header, or NULL
1654 * to remove the header. This function frees the
1655 * original string if necessary.
1657 * Returns : JB_ERR_OK on success and always succeeds
1659 *********************************************************************/
1660 static jb_err filter_header(struct client_state *csp, char **header)
1664 size_t size = strlen(*header);
1666 char *newheader = NULL;
1669 struct re_filterfile_spec *b;
1670 struct list_entry *filtername;
1672 enum filter_type wanted_filter_type;
1673 int multi_action_index;
1675 if (csp->flags & CSP_FLAG_NO_FILTERING)
1680 if (csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
1682 wanted_filter_type = FT_SERVER_HEADER_FILTER;
1683 multi_action_index = ACTION_MULTI_SERVER_HEADER_FILTER;
1687 wanted_filter_type = FT_CLIENT_HEADER_FILTER;
1688 multi_action_index = ACTION_MULTI_CLIENT_HEADER_FILTER;
1691 if (list_is_empty(csp->action->multi[multi_action_index])
1692 || filters_available(csp) == FALSE)
1694 /* Return early if no filters apply or if none are available. */
1698 /* Execute all applying header filters */
1699 for (filtername = csp->action->multi[multi_action_index]->first;
1700 filtername != NULL; filtername = filtername->next)
1702 int current_hits = 0;
1705 b = get_filter(csp, filtername->str, wanted_filter_type);
1711 joblist = b->joblist;
1713 if (b->dynamic) joblist = compile_dynamic_pcrs_job_list(csp, b);
1715 if (NULL == joblist)
1717 log_error(LOG_LEVEL_RE_FILTER,
1718 "Filter %s has empty joblist. Nothing to do.", b->name);
1722 log_error(LOG_LEVEL_RE_FILTER, "filtering \'%s\' (size %lu) with \'%s\' ...",
1723 *header, size, b->name);
1725 /* Apply all jobs from the joblist */
1726 for (job = joblist; NULL != job; job = job->next)
1728 matches = pcrs_execute(job, *header, size, &newheader, &size);
1731 current_hits += matches;
1732 log_error(LOG_LEVEL_HEADER,
1733 "Transforming \"%s\" to \"%s\"", *header, newheader);
1735 *header = newheader;
1737 else if (0 == matches)
1739 /* Filter doesn't change header */
1745 log_error(LOG_LEVEL_ERROR,
1746 "Filtering \'%s\' with \'%s\' didn't work out: %s",
1747 *header, b->name, pcrs_strerror(matches));
1748 if (newheader != NULL)
1750 log_error(LOG_LEVEL_ERROR, "Freeing what's left: %s", newheader);
1756 if (b->dynamic) pcrs_free_joblist(joblist);
1758 log_error(LOG_LEVEL_RE_FILTER,
1759 "... produced %d hits (new size %lu).", current_hits, size);
1760 hits += current_hits;
1764 * Additionally checking for hits is important because if
1765 * the continue hack is triggered, server headers can
1766 * arrive empty to separate multiple heads from each other.
1768 if ((0 == size) && hits)
1770 log_error(LOG_LEVEL_HEADER, "Removing empty header %s", *header);
1778 /*********************************************************************
1780 * Function : server_connection
1782 * Description : Makes sure a proper "Connection:" header is
1783 * set and signals connection_header_adder to
1787 * 1 : csp = Current client state (buffers, headers, etc...)
1788 * 2 : header = On input, pointer to header to modify.
1789 * On output, pointer to the modified header, or NULL
1790 * to remove the header. This function frees the
1791 * original string if necessary.
1793 * Returns : JB_ERR_OK on success.
1795 *********************************************************************/
1796 static jb_err server_connection(struct client_state *csp, char **header)
1798 if (!strcmpic(*header, "Connection: keep-alive")
1799 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1800 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
1804 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1805 if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE))
1807 csp->flags |= CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE;
1810 if ((csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE))
1812 log_error(LOG_LEVEL_HEADER,
1813 "Keeping the server header '%s' around.", *header);
1816 #endif /* FEATURE_CONNECTION_KEEP_ALIVE */
1818 char *old_header = *header;
1820 *header = strdup_or_die("Connection: close");
1821 log_error(LOG_LEVEL_HEADER, "Replaced: \'%s\' with \'%s\'", old_header, *header);
1826 /* Signal server_connection_adder() to return early. */
1827 csp->flags |= CSP_FLAG_SERVER_CONNECTION_HEADER_SET;
1833 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1834 /*********************************************************************
1836 * Function : server_keep_alive
1838 * Description : Stores the server's keep alive timeout.
1841 * 1 : csp = Current client state (buffers, headers, etc...)
1842 * 2 : header = On input, pointer to header to modify.
1843 * On output, pointer to the modified header, or NULL
1844 * to remove the header. This function frees the
1845 * original string if necessary.
1847 * Returns : JB_ERR_OK.
1849 *********************************************************************/
1850 static jb_err server_keep_alive(struct client_state *csp, char **header)
1852 unsigned int keep_alive_timeout;
1853 const char *timeout_position = strstr(*header, "timeout=");
1855 if ((NULL == timeout_position)
1856 || (1 != sscanf(timeout_position, "timeout=%u", &keep_alive_timeout)))
1858 log_error(LOG_LEVEL_ERROR, "Couldn't parse: %s", *header);
1862 if (keep_alive_timeout < csp->server_connection.keep_alive_timeout)
1864 log_error(LOG_LEVEL_HEADER,
1865 "Reducing keep-alive timeout from %u to %u.",
1866 csp->server_connection.keep_alive_timeout, keep_alive_timeout);
1867 csp->server_connection.keep_alive_timeout = keep_alive_timeout;
1871 /* XXX: Is this log worthy? */
1872 log_error(LOG_LEVEL_HEADER,
1873 "Server keep-alive timeout is %u. Sticking with %u.",
1874 keep_alive_timeout, csp->server_connection.keep_alive_timeout);
1876 csp->flags |= CSP_FLAG_SERVER_KEEP_ALIVE_TIMEOUT_SET;
1885 /*********************************************************************
1887 * Function : server_proxy_connection
1889 * Description : Figures out whether or not we should add a
1890 * Proxy-Connection header.
1893 * 1 : csp = Current client state (buffers, headers, etc...)
1894 * 2 : header = On input, pointer to header to modify.
1895 * On output, pointer to the modified header, or NULL
1896 * to remove the header. This function frees the
1897 * original string if necessary.
1899 * Returns : JB_ERR_OK.
1901 *********************************************************************/
1902 static jb_err server_proxy_connection(struct client_state *csp, char **header)
1904 csp->flags |= CSP_FLAG_SERVER_PROXY_CONNECTION_HEADER_SET;
1907 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
1910 /*********************************************************************
1912 * Function : proxy_authentication
1914 * Description : Removes headers that are relevant for proxy
1915 * authentication unless forwarding them has
1916 * been explicitly requested.
1919 * 1 : csp = Current client state (buffers, headers, etc...)
1920 * 2 : header = On input, pointer to header to modify.
1921 * On output, pointer to the modified header, or NULL
1922 * to remove the header. This function frees the
1923 * original string if necessary.
1925 * Returns : JB_ERR_OK.
1927 *********************************************************************/
1928 static jb_err proxy_authentication(struct client_state *csp, char **header)
1930 if ((csp->config->feature_flags &
1931 RUNTIME_FEATURE_FORWARD_PROXY_AUTHENTICATION_HEADERS) == 0) {
1932 log_error(LOG_LEVEL_HEADER,
1933 "Forwarding proxy authentication headers is disabled. Crunching: %s", *header);
1940 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1941 /*********************************************************************
1943 * Function : client_keep_alive
1945 * Description : Stores the client's keep alive timeout.
1948 * 1 : csp = Current client state (buffers, headers, etc...)
1949 * 2 : header = On input, pointer to header to modify.
1950 * On output, pointer to the modified header, or NULL
1951 * to remove the header. This function frees the
1952 * original string if necessary.
1954 * Returns : JB_ERR_OK.
1956 *********************************************************************/
1957 static jb_err client_keep_alive(struct client_state *csp, char **header)
1959 unsigned int keep_alive_timeout;
1960 char *timeout_position;
1962 if (!(csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE))
1964 log_error(LOG_LEVEL_HEADER,
1965 "keep-alive support is disabled. Crunching: %s.", *header);
1970 /* Check for parameter-less format "Keep-Alive: 100" */
1971 timeout_position = strstr(*header, ": ");
1972 if ((NULL == timeout_position)
1973 || (1 != sscanf(timeout_position, ": %u", &keep_alive_timeout)))
1975 /* Assume parameter format "Keep-Alive: timeout=100" */
1976 timeout_position = strstr(*header, "timeout=");
1977 if ((NULL == timeout_position)
1978 || (1 != sscanf(timeout_position, "timeout=%u", &keep_alive_timeout)))
1980 log_error(LOG_LEVEL_HEADER,
1981 "Couldn't parse: '%s'. Using default timeout %u",
1982 *header, csp->config->keep_alive_timeout);
1989 if (keep_alive_timeout < csp->config->keep_alive_timeout)
1991 log_error(LOG_LEVEL_HEADER,
1992 "Reducing keep-alive timeout from %u to %u.",
1993 csp->config->keep_alive_timeout, keep_alive_timeout);
1994 csp->server_connection.keep_alive_timeout = keep_alive_timeout;
1998 /* XXX: Is this log worthy? */
1999 log_error(LOG_LEVEL_HEADER,
2000 "Client keep-alive timeout is %u. Sticking with %u.",
2001 keep_alive_timeout, csp->config->keep_alive_timeout);
2007 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2010 /*********************************************************************
2012 * Function : get_content_length
2014 * Description : Gets the content length specified in a
2015 * Content-Length header.
2018 * 1 : header_value = The Content-Length header value.
2019 * 2 : length = Storage to return the value.
2021 * Returns : JB_ERR_OK on success, or
2022 * JB_ERR_PARSE if no value is recognized.
2024 *********************************************************************/
2025 static jb_err get_content_length(const char *header_value, unsigned long long *length)
2028 #if SIZEOF_LONG_LONG < 8
2029 #error sizeof(unsigned long long) too small
2031 if (1 != sscanf(header_value, "%I64u", length))
2033 if (1 != sscanf(header_value, "%llu", length))
2036 return JB_ERR_PARSE;
2043 /*********************************************************************
2045 * Function : client_save_content_length
2047 * Description : Save the Content-Length sent by the client.
2050 * 1 : csp = Current client state (buffers, headers, etc...)
2051 * 2 : header = pointer to the Content-Length header
2053 * Returns : JB_ERR_OK on success, or
2054 * JB_ERR_MEMORY on out-of-memory error.
2056 *********************************************************************/
2057 static jb_err client_save_content_length(struct client_state *csp, char **header)
2059 unsigned long long content_length = 0;
2060 const char *header_value;
2062 assert(*(*header+14) == ':');
2064 header_value = *header + 15;
2065 if (JB_ERR_OK != get_content_length(header_value, &content_length))
2067 log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
2072 csp->expected_client_content_length = content_length;
2079 /*********************************************************************
2081 * Function : client_connection
2083 * Description : Makes sure a proper "Connection:" header is
2084 * set and signals connection_header_adder
2088 * 1 : csp = Current client state (buffers, headers, etc...)
2089 * 2 : header = On input, pointer to header to modify.
2090 * On output, pointer to the modified header, or NULL
2091 * to remove the header. This function frees the
2092 * original string if necessary.
2094 * Returns : JB_ERR_OK on success.
2096 *********************************************************************/
2097 static jb_err client_connection(struct client_state *csp, char **header)
2099 static const char connection_close[] = "Connection: close";
2101 if (!strcmpic(*header, connection_close))
2103 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2104 if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
2105 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
2106 #ifdef FEATURE_HTTPS_INSPECTION
2107 && !client_use_ssl(csp)
2111 if (!strcmpic(csp->http->version, "HTTP/1.1"))
2113 log_error(LOG_LEVEL_HEADER,
2114 "Removing \'%s\' to imply keep-alive.", *header);
2117 * While we imply keep-alive to the server,
2118 * we have to remember that the client didn't.
2120 csp->flags &= ~CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
2124 char *old_header = *header;
2126 *header = strdup_or_die("Connection: keep-alive");
2127 log_error(LOG_LEVEL_HEADER,
2128 "Replaced: \'%s\' with \'%s\'", old_header, *header);
2134 log_error(LOG_LEVEL_HEADER,
2135 "Keeping the client header '%s' around. "
2136 "The connection will not be kept alive.",
2138 csp->flags &= ~CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
2141 else if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
2142 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED))
2144 log_error(LOG_LEVEL_HEADER,
2145 "Keeping the client header '%s' around. "
2146 "The server connection will be kept alive if possible.",
2148 csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
2149 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2153 char *old_header = *header;
2155 *header = strdup_or_die(connection_close);
2156 log_error(LOG_LEVEL_HEADER,
2157 "Replaced: \'%s\' with \'%s\'", old_header, *header);
2161 /* Signal client_connection_header_adder() to return early. */
2162 csp->flags |= CSP_FLAG_CLIENT_CONNECTION_HEADER_SET;
2168 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2169 /*********************************************************************
2171 * Function : client_proxy_connection
2173 * Description : Sets the CLIENT_CONNECTION_KEEP_ALIVE flag when
2174 * appropriate and removes the Proxy-Connection
2178 * 1 : csp = Current client state (buffers, headers, etc...)
2179 * 2 : header = On input, pointer to header to modify.
2180 * On output, pointer to the modified header, or NULL
2181 * to remove the header. This function frees the
2182 * original string if necessary.
2184 * Returns : JB_ERR_OK
2186 *********************************************************************/
2187 static jb_err client_proxy_connection(struct client_state *csp, char **header)
2189 if (0 == (csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
2190 && (csp->http->ssl == 0)
2191 && (NULL == strstr(*header, "close")))
2193 log_error(LOG_LEVEL_HEADER,
2194 "The client connection can be kept alive due to: %s", *header);
2195 csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
2197 crumble(csp, header);
2201 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2204 /*********************************************************************
2206 * Function : client_transfer_encoding
2208 * Description : Raise the CSP_FLAG_CHUNKED_CLIENT_BODY flag if
2209 * the request body is "chunked"
2211 * XXX: Currently not called through sed() as we
2212 * need the flag earlier on. Should be fixed.
2215 * 1 : csp = Current client state (buffers, headers, etc...)
2216 * 2 : header = On input, pointer to header to modify.
2217 * On output, pointer to the modified header, or NULL
2218 * to remove the header. This function frees the
2219 * original string if necessary.
2221 * Returns : JB_ERR_OK on success, or
2223 *********************************************************************/
2224 jb_err client_transfer_encoding(struct client_state *csp, char **header)
2226 if (strstr(*header, "chunked"))
2228 csp->flags |= CSP_FLAG_CHUNKED_CLIENT_BODY;
2229 log_error(LOG_LEVEL_HEADER, "Expecting chunked client body");
2236 /*********************************************************************
2238 * Function : client_expect
2240 * Description : Raise the CSP_FLAG_UNSUPPORTED_CLIENT_EXPECTATION
2241 * if the Expect header value is unsupported.
2243 * Rejecting unsupported expectations is a RFC 7231 5.1.1
2244 * MAY and a RFC 2616 (obsolete) MUST.
2247 * 1 : csp = Current client state (buffers, headers, etc...)
2248 * 2 : header = On input, pointer to header to modify.
2249 * On output, pointer to the modified header, or NULL
2250 * to remove the header. This function frees the
2251 * original string if necessary.
2253 * Returns : JB_ERR_OK on success, or
2255 *********************************************************************/
2256 jb_err client_expect(struct client_state *csp, char **header)
2258 if (0 != strcmpic(*header, "Expect: 100-continue"))
2260 csp->flags |= CSP_FLAG_UNSUPPORTED_CLIENT_EXPECTATION;
2261 log_error(LOG_LEVEL_HEADER,
2262 "Unsupported client expectaction: %s", *header);
2270 /*********************************************************************
2272 * Function : crumble
2274 * Description : This is called if a header matches a pattern to "crunch"
2277 * 1 : csp = Current client state (buffers, headers, etc...)
2278 * 2 : header = On input, pointer to header to modify.
2279 * On output, pointer to the modified header, or NULL
2280 * to remove the header. This function frees the
2281 * original string if necessary.
2283 * Returns : JB_ERR_OK on success, or
2284 * JB_ERR_MEMORY on out-of-memory error.
2286 *********************************************************************/
2287 static jb_err crumble(struct client_state *csp, char **header)
2290 log_error(LOG_LEVEL_HEADER, "crumble crunched: %s!", *header);
2296 /*********************************************************************
2298 * Function : crunch_server_header
2300 * Description : Crunch server header if it matches a string supplied by the
2301 * user. Called from `sed'.
2304 * 1 : csp = Current client state (buffers, headers, etc...)
2305 * 2 : header = On input, pointer to header to modify.
2306 * On output, pointer to the modified header, or NULL
2307 * to remove the header. This function frees the
2308 * original string if necessary.
2310 * Returns : JB_ERR_OK on success and always succeeds
2312 *********************************************************************/
2313 static jb_err crunch_server_header(struct client_state *csp, char **header)
2315 const char *crunch_pattern;
2317 /* Do we feel like crunching? */
2318 if ((csp->action->flags & ACTION_CRUNCH_SERVER_HEADER))
2320 crunch_pattern = csp->action->string[ACTION_STRING_SERVER_HEADER];
2322 /* Is the current header the lucky one? */
2323 if (strstr(*header, crunch_pattern))
2325 log_error(LOG_LEVEL_HEADER, "Crunching server header: %s (contains: %s)", *header, crunch_pattern);
2334 /*********************************************************************
2336 * Function : server_content_type
2338 * Description : Set the content-type for filterable types (text/.*,
2339 * .*xml.*, .*script.* and image/gif) unless filtering has been
2340 * forbidden (CT_TABOO) while parsing earlier headers.
2341 * NOTE: Since text/plain is commonly used by web servers
2342 * for files whose correct type is unknown, we don't
2343 * set CT_TEXT for it.
2346 * 1 : csp = Current client state (buffers, headers, etc...)
2347 * 2 : header = On input, pointer to header to modify.
2348 * On output, pointer to the modified header, or NULL
2349 * to remove the header. This function frees the
2350 * original string if necessary.
2352 * Returns : JB_ERR_OK on success, or
2353 * JB_ERR_MEMORY on out-of-memory error.
2355 *********************************************************************/
2356 static jb_err server_content_type(struct client_state *csp, char **header)
2358 /* Remove header if it isn't the first Content-Type header */
2359 if ((csp->content_type & CT_DECLARED))
2361 if (content_filters_enabled(csp->action))
2364 * Making sure the client interprets the content the same way
2365 * Privoxy did is only relevant if Privoxy modified it.
2367 * Checking for this is "hard" as it's not yet known when
2368 * this function is called, thus go shopping and and just
2369 * check if Privoxy could filter it.
2371 * The main thing is that we don't mess with the headers
2372 * unless the user signalled that it's acceptable.
2374 log_error(LOG_LEVEL_HEADER,
2375 "Multiple Content-Type headers detected. "
2376 "Removing and ignoring: %s",
2384 * Signal that the Content-Type has been set.
2386 csp->content_type |= CT_DECLARED;
2388 if (!(csp->content_type & CT_TABOO))
2391 * XXX: The assumption that text/plain is a sign of
2392 * binary data seems to be somewhat unreasonable nowadays
2393 * and should be dropped after 3.0.8 is out.
2395 if ((strstr(*header, "text/") && !strstr(*header, "plain"))
2396 || strstr(*header, "xml")
2397 || strstr(*header, "script"))
2399 csp->content_type |= CT_TEXT;
2401 else if (strstr(*header, "image/gif"))
2403 csp->content_type |= CT_GIF;
2408 * Are we messing with the content type?
2410 if (csp->action->flags & ACTION_CONTENT_TYPE_OVERWRITE)
2413 * Make sure the user doesn't accidentally
2414 * change the content type of binary documents.
2416 if ((csp->content_type & CT_TEXT) || (csp->action->flags & ACTION_FORCE_TEXT_MODE))
2420 *header = strdup_or_die("Content-Type: ");
2422 err = string_append(header, csp->action->string[ACTION_STRING_CONTENT_TYPE]);
2423 if (JB_ERR_OK != err)
2425 log_error(LOG_LEVEL_HEADER, "Insufficient memory to replace Content-Type!");
2426 return JB_ERR_MEMORY;
2428 log_error(LOG_LEVEL_HEADER, "Modified: %s!", *header);
2432 log_error(LOG_LEVEL_HEADER, "%s not replaced. "
2433 "It doesn't look like a content type that should be filtered. "
2434 "Enable force-text-mode if you know what you're doing.", *header);
2442 /*********************************************************************
2444 * Function : server_transfer_coding
2446 * Description : - Prohibit filtering (CT_TABOO) if transfer coding compresses
2447 * - Raise the CSP_FLAG_CHUNKED flag if coding is "chunked"
2448 * - Remove header if body was chunked but has been
2449 * de-chunked for filtering.
2452 * 1 : csp = Current client state (buffers, headers, etc...)
2453 * 2 : header = On input, pointer to header to modify.
2454 * On output, pointer to the modified header, or NULL
2455 * to remove the header. This function frees the
2456 * original string if necessary.
2458 * Returns : JB_ERR_OK on success, or
2459 * JB_ERR_MEMORY on out-of-memory error.
2461 *********************************************************************/
2462 static jb_err server_transfer_coding(struct client_state *csp, char **header)
2465 * Turn off pcrs and gif filtering if body compressed
2467 if (strstr(*header, "gzip") || strstr(*header, "compress") || strstr(*header, "deflate"))
2471 * XXX: Added to test if we could use CT_GZIP and CT_DEFLATE here.
2473 log_error(LOG_LEVEL_INFO, "Marking content type for %s as CT_TABOO because of %s.",
2474 csp->http->cmd, *header);
2475 #endif /* def FEATURE_ZLIB */
2476 csp->content_type = CT_TABOO;
2480 * Raise flag if body chunked
2482 if (strstr(*header, "chunked"))
2484 csp->flags |= CSP_FLAG_CHUNKED;
2487 * If the body was modified, it has been de-chunked first
2488 * and the header must be removed.
2490 * FIXME: If there is more than one transfer encoding,
2491 * only the "chunked" part should be removed here.
2493 if (csp->flags & CSP_FLAG_MODIFIED)
2495 log_error(LOG_LEVEL_HEADER, "Removing: %s", *header);
2504 /*********************************************************************
2506 * Function : server_content_encoding
2508 * Description : Used to check if the content is compressed, and if
2509 * FEATURE_ZLIB is disabled, filtering is disabled as
2512 * If FEATURE_ZLIB is enabled and the compression type
2513 * supported, the content is marked for decompression.
2515 * XXX: Doesn't properly deal with multiple or with
2516 * unsupported but unknown encodings.
2517 * Is case-sensitive but shouldn't be.
2520 * 1 : csp = Current client state (buffers, headers, etc...)
2521 * 2 : header = On input, pointer to header to modify.
2522 * On output, pointer to the modified header, or NULL
2523 * to remove the header. This function frees the
2524 * original string if necessary.
2526 * Returns : JB_ERR_OK on success, or
2527 * JB_ERR_MEMORY on out-of-memory error.
2529 *********************************************************************/
2530 static jb_err server_content_encoding(struct client_state *csp, char **header)
2533 if (strstr(*header, "sdch"))
2536 * Shared Dictionary Compression over HTTP isn't supported,
2537 * filtering it anyway is pretty much guaranteed to mess up
2540 csp->content_type |= CT_TABOO;
2543 * Log a warning if the user expects the content to be filtered.
2545 if (content_filters_enabled(csp->action))
2547 log_error(LOG_LEVEL_INFO,
2548 "SDCH-compressed content detected, content filtering disabled. "
2549 "Consider suppressing SDCH offers made by the client.");
2552 else if (strstr(*header, "gzip"))
2554 /* Mark for gzip decompression */
2555 csp->content_type |= CT_GZIP;
2557 else if (strstr(*header, "deflate"))
2559 /* Mark for zlib decompression */
2560 csp->content_type |= CT_DEFLATE;
2562 else if (strstr(*header, "br"))
2564 #ifdef FEATURE_BROTLI
2565 /* Mark for Brotli decompression */
2566 csp->content_type |= CT_BROTLI;
2568 csp->content_type |= CT_TABOO;
2571 else if (strstr(*header, "compress"))
2574 * We can't decompress this; therefore we can't filter
2577 csp->content_type |= CT_TABOO;
2579 #else /* !defined(FEATURE_ZLIB) */
2581 * XXX: Using a black list here isn't the right approach.
2583 * In case of SDCH, building with zlib support isn't
2586 if (strstr(*header, "gzip") ||
2587 strstr(*header, "compress") ||
2588 strstr(*header, "deflate") ||
2589 strstr(*header, "sdch"))
2592 * Body is compressed, turn off pcrs and gif filtering.
2594 csp->content_type |= CT_TABOO;
2597 * Log a warning if the user expects the content to be filtered.
2599 if (content_filters_enabled(csp->action))
2601 log_error(LOG_LEVEL_INFO,
2602 "Compressed content detected, content filtering disabled. "
2603 "Consider recompiling Privoxy with zlib support or "
2604 "enable the prevent-compression action.");
2607 #endif /* defined(FEATURE_ZLIB) */
2615 /*********************************************************************
2617 * Function : server_adjust_content_encoding
2619 * Description : Remove the Content-Encoding header if the
2620 * decompression was successful and the content
2621 * has been modified.
2624 * 1 : csp = Current client state (buffers, headers, etc...)
2625 * 2 : header = On input, pointer to header to modify.
2626 * On output, pointer to the modified header, or NULL
2627 * to remove the header. This function frees the
2628 * original string if necessary.
2630 * Returns : JB_ERR_OK on success, or
2631 * JB_ERR_MEMORY on out-of-memory error.
2633 *********************************************************************/
2634 static jb_err server_adjust_content_encoding(struct client_state *csp, char **header)
2636 if ((csp->flags & CSP_FLAG_MODIFIED)
2637 && ((csp->content_type & (CT_GZIP | CT_DEFLATE))
2638 #ifdef FEATURE_BROTLI
2639 || (csp->content_type & CT_BROTLI)
2645 * We successfully decompressed the content,
2646 * and have to clean the header now, so the
2647 * client no longer expects compressed data.
2649 * XXX: There is a difference between cleaning
2650 * and removing it completely.
2652 log_error(LOG_LEVEL_HEADER, "Crunching: %s", *header);
2659 #endif /* defined(FEATURE_ZLIB) */
2662 /*********************************************************************
2664 * Function : header_adjust_content_length
2666 * Description : Replace given header with new Content-Length header.
2669 * 1 : header = On input, pointer to header to modify.
2670 * On output, pointer to the modified header, or NULL
2671 * to remove the header. This function frees the
2672 * original string if necessary.
2673 * 2 : content_length = content length value to set
2675 * Returns : JB_ERR_OK on success, or
2676 * JB_ERR_MEMORY on out-of-memory error.
2678 *********************************************************************/
2679 jb_err header_adjust_content_length(char **header, size_t content_length)
2681 const size_t header_length = 50;
2683 *header = malloc(header_length);
2684 if (*header == NULL)
2686 return JB_ERR_MEMORY;
2688 create_content_length_header(content_length, *header, header_length);
2693 /*********************************************************************
2695 * Function : server_adjust_content_length
2697 * Description : Adjust Content-Length header if we modified
2701 * 1 : csp = Current client state (buffers, headers, etc...)
2702 * 2 : header = On input, pointer to header to modify.
2703 * On output, pointer to the modified header, or NULL
2704 * to remove the header. This function frees the
2705 * original string if necessary.
2707 * Returns : JB_ERR_OK on success, or
2708 * JB_ERR_MEMORY on out-of-memory error.
2710 *********************************************************************/
2711 static jb_err server_adjust_content_length(struct client_state *csp, char **header)
2713 /* Regenerate header if the content was modified. */
2714 if (csp->flags & CSP_FLAG_MODIFIED)
2716 if (JB_ERR_OK != header_adjust_content_length(header, csp->content_length))
2718 return JB_ERR_MEMORY;
2720 log_error(LOG_LEVEL_HEADER,
2721 "Adjusted Content-Length to %llu", csp->content_length);
2728 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2729 /*********************************************************************
2731 * Function : server_save_content_length
2733 * Description : Save the Content-Length sent by the server.
2736 * 1 : csp = Current client state (buffers, headers, etc...)
2737 * 2 : header = On input, pointer to header to modify.
2738 * On output, pointer to the modified header, or NULL
2739 * to remove the header. This function frees the
2740 * original string if necessary.
2742 * Returns : JB_ERR_OK on success, or
2743 * JB_ERR_MEMORY on out-of-memory error.
2745 *********************************************************************/
2746 static jb_err server_save_content_length(struct client_state *csp, char **header)
2748 unsigned long long content_length = 0;
2749 const char *header_value;
2751 assert(*(*header+14) == ':');
2753 header_value = *header + 15;
2754 if (JB_ERR_OK != get_content_length(header_value, &content_length))
2756 log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
2761 csp->expected_content_length = content_length;
2762 csp->flags |= CSP_FLAG_SERVER_CONTENT_LENGTH_SET;
2763 csp->flags |= CSP_FLAG_CONTENT_LENGTH_SET;
2768 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2771 /*********************************************************************
2773 * Function : server_content_md5
2775 * Description : Crumble any Content-MD5 headers if the document was
2776 * modified. FIXME: Should we re-compute instead?
2779 * 1 : csp = Current client state (buffers, headers, etc...)
2780 * 2 : header = On input, pointer to header to modify.
2781 * On output, pointer to the modified header, or NULL
2782 * to remove the header. This function frees the
2783 * original string if necessary.
2785 * Returns : JB_ERR_OK on success, or
2786 * JB_ERR_MEMORY on out-of-memory error.
2788 *********************************************************************/
2789 static jb_err server_content_md5(struct client_state *csp, char **header)
2791 if (csp->flags & CSP_FLAG_MODIFIED)
2793 log_error(LOG_LEVEL_HEADER, "Crunching Content-MD5");
2801 /*********************************************************************
2803 * Function : server_content_disposition
2805 * Description : If enabled, blocks or modifies the "Content-Disposition" header.
2806 * Called from `sed'.
2809 * 1 : csp = Current client state (buffers, headers, etc...)
2810 * 2 : header = On input, pointer to header to modify.
2811 * On output, pointer to the modified header, or NULL
2812 * to remove the header. This function frees the
2813 * original string if necessary.
2815 * Returns : JB_ERR_OK on success, or
2816 * JB_ERR_MEMORY on out-of-memory error.
2818 *********************************************************************/
2819 static jb_err server_content_disposition(struct client_state *csp, char **header)
2824 * Are we messing with the Content-Disposition header?
2826 if ((csp->action->flags & ACTION_HIDE_CONTENT_DISPOSITION) == 0)
2832 newval = csp->action->string[ACTION_STRING_CONTENT_DISPOSITION];
2834 if ((newval == NULL) || (0 == strcmpic(newval, "block")))
2837 * Blocking content-disposition header
2839 log_error(LOG_LEVEL_HEADER, "Crunching %s!", *header);
2846 * Replacing Content-Disposition header
2849 *header = strdup("Content-Disposition: ");
2850 string_append(header, newval);
2852 if (*header != NULL)
2854 log_error(LOG_LEVEL_HEADER,
2855 "Content-Disposition header crunched and replaced with: %s", *header);
2858 return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
2862 /*********************************************************************
2864 * Function : server_last_modified
2866 * Description : Changes Last-Modified header to the actual date
2867 * to help hide-if-modified-since.
2868 * Called from `sed'.
2871 * 1 : csp = Current client state (buffers, headers, etc...)
2872 * 2 : header = On input, pointer to header to modify.
2873 * On output, pointer to the modified header, or NULL
2874 * to remove the header. This function frees the
2875 * original string if necessary.
2877 * Returns : JB_ERR_OK on success, or
2878 * JB_ERR_MEMORY on out-of-memory error.
2880 *********************************************************************/
2881 static jb_err server_last_modified(struct client_state *csp, char **header)
2884 time_t last_modified;
2888 * Are we messing with the Last-Modified header?
2890 if ((csp->action->flags & ACTION_OVERWRITE_LAST_MODIFIED) == 0)
2896 newval = csp->action->string[ACTION_STRING_LAST_MODIFIED];
2898 if (0 == strcmpic(newval, "block"))
2901 * Blocking Last-Modified header. Useless but why not.
2903 log_error(LOG_LEVEL_HEADER, "Crunching %s!", *header);
2907 else if (0 == strcmpic(newval, "reset-to-request-time"))
2910 * Setting Last-Modified Header to now.
2913 get_http_time(0, buf, sizeof(buf));
2915 *header = strdup("Last-Modified: ");
2916 string_append(header, buf);
2918 if (*header == NULL)
2920 log_error(LOG_LEVEL_HEADER, "Insufficient memory. Last-Modified header got lost, boohoo.");
2924 log_error(LOG_LEVEL_HEADER, "Reset to present time: %s", *header);
2927 else if (0 == strcmpic(newval, "randomize"))
2929 log_error(LOG_LEVEL_HEADER, "Randomizing: %s", *header);
2931 if (JB_ERR_OK != parse_time_header(*header, &last_modified))
2933 log_error(LOG_LEVEL_HEADER,
2934 "Couldn't parse time in %s (crunching!)", *header);
2940 struct tm *timeptr = NULL;
2945 rtime = (long int)difftime(now, last_modified);
2948 long int days, hours, minutes, seconds;
2949 const int negative_delta = (rtime < 0);
2954 log_error(LOG_LEVEL_HEADER, "Server time in the future.");
2956 rtime = pick_from_range(rtime);
2961 last_modified += rtime;
2962 timeptr = privoxy_gmtime_r(&last_modified, &gmt);
2963 if ((NULL == timeptr) || !strftime(newheader,
2964 sizeof(newheader), "%a, %d %b %Y %H:%M:%S GMT", timeptr))
2966 log_error(LOG_LEVEL_ERROR,
2967 "Randomizing '%s' failed. Crunching the header without replacement.",
2973 *header = strdup("Last-Modified: ");
2974 string_append(header, newheader);
2976 if (*header == NULL)
2978 log_error(LOG_LEVEL_ERROR, "Insufficient memory, header crunched without replacement.");
2979 return JB_ERR_MEMORY;
2982 days = rtime / (3600 * 24);
2983 hours = rtime / 3600 % 24;
2984 minutes = rtime / 60 % 60;
2985 seconds = rtime % 60;
2987 log_error(LOG_LEVEL_HEADER,
2988 "Randomized: %s (added %ld da%s %ld hou%s %ld minut%s %ld second%s",
2989 *header, days, (days == 1) ? "y" : "ys", hours, (hours == 1) ? "r" : "rs",
2990 minutes, (minutes == 1) ? "e" : "es", seconds, (seconds == 1) ? ")" : "s)");
2994 log_error(LOG_LEVEL_HEADER, "Randomized ... or not. No time difference to work with.");
3003 /*********************************************************************
3005 * Function : client_accept_encoding
3007 * Description : Rewrite the client's Accept-Encoding header so that
3008 * if doesn't allow compression, if the action applies.
3009 * Note: For HTTP/1.0 the absence of the header is enough.
3012 * 1 : csp = Current client state (buffers, headers, etc...)
3013 * 2 : header = On input, pointer to header to modify.
3014 * On output, pointer to the modified header, or NULL
3015 * to remove the header. This function frees the
3016 * original string if necessary.
3018 * Returns : JB_ERR_OK on success, or
3019 * JB_ERR_MEMORY on out-of-memory error.
3021 *********************************************************************/
3022 static jb_err client_accept_encoding(struct client_state *csp, char **header)
3024 #ifdef FEATURE_COMPRESSION
3025 if ((csp->config->feature_flags & RUNTIME_FEATURE_COMPRESSION)
3026 && strstr(*header, "deflate"))
3028 csp->flags |= CSP_FLAG_CLIENT_SUPPORTS_DEFLATE;
3031 if ((csp->action->flags & ACTION_NO_COMPRESSION) != 0)
3033 log_error(LOG_LEVEL_HEADER, "Suppressed offer to compress content");
3041 /*********************************************************************
3043 * Function : client_te
3045 * Description : Rewrite the client's TE header so that
3046 * if doesn't allow compression, if the action applies.
3049 * 1 : csp = Current client state (buffers, headers, etc...)
3050 * 2 : header = On input, pointer to header to modify.
3051 * On output, pointer to the modified header, or NULL
3052 * to remove the header. This function frees the
3053 * original string if necessary.
3055 * Returns : JB_ERR_OK on success, or
3056 * JB_ERR_MEMORY on out-of-memory error.
3058 *********************************************************************/
3059 static jb_err client_te(struct client_state *csp, char **header)
3061 if ((csp->action->flags & ACTION_NO_COMPRESSION) != 0)
3064 log_error(LOG_LEVEL_HEADER, "Suppressed offer to compress transfer");
3071 /*********************************************************************
3073 * Function : client_referrer
3075 * Description : Handle the "referer" config setting properly.
3076 * Called from `sed'.
3079 * 1 : csp = Current client state (buffers, headers, etc...)
3080 * 2 : header = On input, pointer to header to modify.
3081 * On output, pointer to the modified header, or NULL
3082 * to remove the header. This function frees the
3083 * original string if necessary.
3085 * Returns : JB_ERR_OK on success, or
3086 * JB_ERR_MEMORY on out-of-memory error.
3088 *********************************************************************/
3089 static jb_err client_referrer(struct client_state *csp, char **header)
3091 const char *parameter;
3092 /* booleans for parameters we have to check multiple times */
3093 int parameter_conditional_block;
3094 int parameter_conditional_forge;
3096 #ifdef FEATURE_FORCE_LOAD
3098 * Since the referrer can include the prefix even
3099 * if the request itself is non-forced, we must
3100 * clean it unconditionally.
3102 * XXX: strclean is too broad
3104 strclean(*header, FORCE_PREFIX);
3105 #endif /* def FEATURE_FORCE_LOAD */
3107 if ((csp->action->flags & ACTION_HIDE_REFERER) == 0)
3109 /* Nothing left to do */
3113 parameter = csp->action->string[ACTION_STRING_REFERER];
3114 assert(parameter != NULL);
3115 parameter_conditional_block = (0 == strcmpic(parameter, "conditional-block"));
3116 parameter_conditional_forge = (0 == strcmpic(parameter, "conditional-forge"));
3118 if (!parameter_conditional_block && !parameter_conditional_forge)
3121 * As conditional-block and conditional-forge are the only
3122 * parameters that rely on the original referrer, we can
3123 * remove it now for all the others.
3128 if (0 == strcmpic(parameter, "block"))
3130 log_error(LOG_LEVEL_HEADER, "Referer crunched!");
3133 else if (parameter_conditional_block || parameter_conditional_forge)
3135 return handle_conditional_hide_referrer_parameter(header,
3136 csp->http->hostport, parameter_conditional_block);
3138 else if (0 == strcmpic(parameter, "forge"))
3140 return create_forged_referrer(header, csp->http->hostport);
3144 /* interpret parameter as user-supplied referer to fake */
3145 return create_fake_referrer(header, parameter);
3150 /*********************************************************************
3152 * Function : client_accept_language
3154 * Description : Handle the "Accept-Language" config setting properly.
3155 * Called from `sed'.
3158 * 1 : csp = Current client state (buffers, headers, etc...)
3159 * 2 : header = On input, pointer to header to modify.
3160 * On output, pointer to the modified header, or NULL
3161 * to remove the header. This function frees the
3162 * original string if necessary.
3164 * Returns : JB_ERR_OK on success, or
3165 * JB_ERR_MEMORY on out-of-memory error.
3167 *********************************************************************/
3168 static jb_err client_accept_language(struct client_state *csp, char **header)
3173 * Are we messing with the Accept-Language?
3175 if ((csp->action->flags & ACTION_HIDE_ACCEPT_LANGUAGE) == 0)
3177 /*I don't think so*/
3181 newval = csp->action->string[ACTION_STRING_LANGUAGE];
3183 if ((newval == NULL) || (0 == strcmpic(newval, "block")))
3186 * Blocking Accept-Language header
3188 log_error(LOG_LEVEL_HEADER, "Crunching Accept-Language!");
3195 * Replacing Accept-Language header
3198 *header = strdup("Accept-Language: ");
3199 string_append(header, newval);
3201 if (*header == NULL)
3203 log_error(LOG_LEVEL_ERROR,
3204 "Insufficient memory. Accept-Language header crunched without replacement.");
3208 log_error(LOG_LEVEL_HEADER,
3209 "Accept-Language header crunched and replaced with: %s", *header);
3212 return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
3216 /*********************************************************************
3218 * Function : crunch_client_header
3220 * Description : Crunch client header if it matches a string supplied by the
3221 * user. Called from `sed'.
3224 * 1 : csp = Current client state (buffers, headers, etc...)
3225 * 2 : header = On input, pointer to header to modify.
3226 * On output, pointer to the modified header, or NULL
3227 * to remove the header. This function frees the
3228 * original string if necessary.
3230 * Returns : JB_ERR_OK on success and always succeeds
3232 *********************************************************************/
3233 static jb_err crunch_client_header(struct client_state *csp, char **header)
3235 const char *crunch_pattern;
3237 /* Do we feel like crunching? */
3238 if ((csp->action->flags & ACTION_CRUNCH_CLIENT_HEADER))
3240 crunch_pattern = csp->action->string[ACTION_STRING_CLIENT_HEADER];
3242 /* Is the current header the lucky one? */
3243 if (strstr(*header, crunch_pattern))
3245 log_error(LOG_LEVEL_HEADER, "Crunching client header: %s (contains: %s)", *header, crunch_pattern);
3253 /*********************************************************************
3255 * Function : client_uagent
3257 * Description : Handle the "user-agent" config setting properly
3258 * and remember its original value to enable browser
3259 * bug workarounds. Called from `sed'.
3262 * 1 : csp = Current client state (buffers, headers, etc...)
3263 * 2 : header = On input, pointer to header to modify.
3264 * On output, pointer to the modified header, or NULL
3265 * to remove the header. This function frees the
3266 * original string if necessary.
3268 * Returns : JB_ERR_OK on success, or
3269 * JB_ERR_MEMORY on out-of-memory error.
3271 *********************************************************************/
3272 static jb_err client_uagent(struct client_state *csp, char **header)
3276 if ((csp->action->flags & ACTION_HIDE_USER_AGENT) == 0)
3281 newval = csp->action->string[ACTION_STRING_USER_AGENT];
3288 *header = strdup("User-Agent: ");
3289 string_append(header, newval);
3291 log_error(LOG_LEVEL_HEADER, "Modified: %s", *header);
3293 return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
3297 /*********************************************************************
3299 * Function : client_ua
3301 * Description : Handle "ua-" headers properly. Called from `sed'.
3304 * 1 : csp = Current client state (buffers, headers, etc...)
3305 * 2 : header = On input, pointer to header to modify.
3306 * On output, pointer to the modified header, or NULL
3307 * to remove the header. This function frees the
3308 * original string if necessary.
3310 * Returns : JB_ERR_OK on success, or
3311 * JB_ERR_MEMORY on out-of-memory error.
3313 *********************************************************************/
3314 static jb_err client_ua(struct client_state *csp, char **header)
3316 if ((csp->action->flags & ACTION_HIDE_USER_AGENT) != 0)
3318 log_error(LOG_LEVEL_HEADER, "crunched User-Agent!");
3326 /*********************************************************************
3328 * Function : client_from
3330 * Description : Handle the "from" config setting properly.
3331 * Called from `sed'.
3334 * 1 : csp = Current client state (buffers, headers, etc...)
3335 * 2 : header = On input, pointer to header to modify.
3336 * On output, pointer to the modified header, or NULL
3337 * to remove the header. This function frees the
3338 * original string if necessary.
3340 * Returns : JB_ERR_OK on success, or
3341 * JB_ERR_MEMORY on out-of-memory error.
3343 *********************************************************************/
3344 static jb_err client_from(struct client_state *csp, char **header)
3348 if ((csp->action->flags & ACTION_HIDE_FROM) == 0)
3355 newval = csp->action->string[ACTION_STRING_FROM];
3358 * Are we blocking the e-mail address?
3360 if ((newval == NULL) || (0 == strcmpic(newval, "block")))
3362 log_error(LOG_LEVEL_HEADER, "crunched From!");
3366 log_error(LOG_LEVEL_HEADER, " modified");
3368 *header = strdup("From: ");
3369 string_append(header, newval);
3371 return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
3375 /*********************************************************************
3377 * Function : client_send_cookie
3379 * Description : Crunches the "cookie" header if necessary.
3380 * Called from `sed'.
3382 * XXX: Stupid name, doesn't send squat.
3385 * 1 : csp = Current client state (buffers, headers, etc...)
3386 * 2 : header = On input, pointer to header to modify.
3387 * On output, pointer to the modified header, or NULL
3388 * to remove the header. This function frees the
3389 * original string if necessary.
3391 * Returns : JB_ERR_OK on success, or
3392 * JB_ERR_MEMORY on out-of-memory error.
3394 *********************************************************************/
3395 static jb_err client_send_cookie(struct client_state *csp, char **header)
3397 if (csp->action->flags & ACTION_CRUNCH_OUTGOING_COOKIES)
3399 log_error(LOG_LEVEL_HEADER, "Crunched outgoing cookie: %s", *header);
3407 /*********************************************************************
3409 * Function : client_x_forwarded
3411 * Description : Handle the "x-forwarded-for" config setting properly,
3412 * also used in the add_client_headers list. Called from `sed'.
3415 * 1 : csp = Current client state (buffers, headers, etc...)
3416 * 2 : header = On input, pointer to header to modify.
3417 * On output, pointer to the modified header, or NULL
3418 * to remove the header. This function frees the
3419 * original string if necessary.
3421 * Returns : JB_ERR_OK on success, or
3422 * JB_ERR_MEMORY on out-of-memory error.
3424 *********************************************************************/
3425 jb_err client_x_forwarded(struct client_state *csp, char **header)
3427 if (0 != (csp->action->flags & ACTION_CHANGE_X_FORWARDED_FOR))
3429 const char *parameter = csp->action->string[ACTION_STRING_CHANGE_X_FORWARDED_FOR];
3431 if (0 == strcmpic(parameter, "block"))
3434 log_error(LOG_LEVEL_HEADER, "crunched x-forwarded-for!");
3436 else if (0 == strcmpic(parameter, "add"))
3438 string_append(header, ", ");
3439 string_append(header, csp->ip_addr_str);
3441 if (*header == NULL)
3443 return JB_ERR_MEMORY;
3445 log_error(LOG_LEVEL_HEADER,
3446 "Appended client IP address to %s", *header);
3447 csp->flags |= CSP_FLAG_X_FORWARDED_FOR_APPENDED;
3451 log_error(LOG_LEVEL_FATAL,
3452 "Invalid change-x-forwarded-for parameter: '%s'", parameter);
3460 /*********************************************************************
3462 * Function : client_max_forwards
3464 * Description : If the HTTP method is OPTIONS or TRACE, subtract one
3465 * from the value of the Max-Forwards header field.
3468 * 1 : csp = Current client state (buffers, headers, etc...)
3469 * 2 : header = On input, pointer to header to modify.
3470 * On output, pointer to the modified header, or NULL
3471 * to remove the header. This function frees the
3472 * original string if necessary.
3474 * Returns : JB_ERR_OK on success, or
3475 * JB_ERR_MEMORY on out-of-memory error.
3477 *********************************************************************/
3478 static jb_err client_max_forwards(struct client_state *csp, char **header)
3482 if ((0 == strcmpic(csp->http->gpc, "trace")) ||
3483 (0 == strcmpic(csp->http->gpc, "options")))
3485 assert(*(*header+12) == ':');
3486 if (1 == sscanf(*header+12, ": %d", &max_forwards))
3488 if (max_forwards > 0)
3490 snprintf(*header, strlen(*header)+1, "Max-Forwards: %d", --max_forwards);
3491 log_error(LOG_LEVEL_HEADER,
3492 "Max-Forwards value for %s request reduced to %d.",
3493 csp->http->gpc, max_forwards);
3495 else if (max_forwards < 0)
3497 log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
3503 log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
3512 /*********************************************************************
3514 * Function : client_host
3516 * Description : If the request URI did not contain host and
3517 * port information, parse and evaluate the Host
3521 * 1 : csp = Current client state (buffers, headers, etc...)
3522 * 2 : header = On input, pointer to header to modify.
3523 * On output, pointer to the modified header, or NULL
3524 * to remove the header. This function frees the
3525 * original string if necessary.
3527 * Returns : JB_ERR_OK on success, or
3528 * JB_ERR_MEMORY on out-of-memory error.
3530 *********************************************************************/
3531 static jb_err client_host(struct client_state *csp, char **header)
3535 if (strlen(*header) < 7)
3537 log_error(LOG_LEVEL_HEADER, "Removing empty Host header");
3542 if (!csp->http->hostport || (*csp->http->hostport == '*') ||
3543 *csp->http->hostport == ' ' || *csp->http->hostport == '\0')
3546 p = strdup_or_die((*header)+6);
3548 q = strdup_or_die(p);
3550 freez(csp->http->hostport);
3551 csp->http->hostport = p;
3552 freez(csp->http->host);
3553 csp->http->host = q;
3554 q = strchr(csp->http->host, ':');
3557 /* Terminate hostname and evaluate port string */
3559 csp->http->port = atoi(q);
3563 csp->http->port = csp->http->ssl ? 443 : 80;
3566 log_error(LOG_LEVEL_HEADER, "New host and port from Host field: %s = %s:%d",
3567 csp->http->hostport, csp->http->host, csp->http->port);
3570 /* Signal client_host_adder() to return right away */
3571 csp->flags |= CSP_FLAG_HOST_HEADER_IS_SET;
3577 /*********************************************************************
3579 * Function : client_if_modified_since
3581 * Description : Remove or modify the If-Modified-Since header.
3584 * 1 : csp = Current client state (buffers, headers, etc...)
3585 * 2 : header = On input, pointer to header to modify.
3586 * On output, pointer to the modified header, or NULL
3587 * to remove the header. This function frees the
3588 * original string if necessary.
3590 * Returns : JB_ERR_OK on success, or
3591 * JB_ERR_MEMORY on out-of-memory error.
3593 *********************************************************************/
3594 static jb_err client_if_modified_since(struct client_state *csp, char **header)
3598 struct tm *timeptr = NULL;
3603 if (0 == strcmpic(*header, "If-Modified-Since: Wed, 08 Jun 1955 12:00:00 GMT"))
3606 * The client got an error message because of a temporary problem,
3607 * the problem is gone and the client now tries to revalidate our
3608 * error message on the real server. The revalidation would always
3609 * end with the transmission of the whole document and there is
3610 * no need to expose the bogus If-Modified-Since header.
3612 log_error(LOG_LEVEL_HEADER, "Crunching useless If-Modified-Since header.");
3615 else if (csp->action->flags & ACTION_HIDE_IF_MODIFIED_SINCE)
3617 newval = csp->action->string[ACTION_STRING_IF_MODIFIED_SINCE];
3619 if ((0 == strcmpic(newval, "block")))
3621 log_error(LOG_LEVEL_HEADER, "Crunching %s", *header);
3624 else /* add random value */
3626 if (JB_ERR_OK != parse_time_header(*header, &tm))
3628 log_error(LOG_LEVEL_HEADER,
3629 "Couldn't parse time in %s (crunching!)", *header);
3634 long int hours, minutes, seconds;
3635 long int rtime = strtol(newval, &endptr, 0);
3636 const int negative_range = (rtime < 0);
3640 log_error(LOG_LEVEL_HEADER, "Randomizing: %s (random range: %ld minut%s)",
3641 *header, rtime, (rtime == 1 || rtime == -1) ? "e": "es");
3647 rtime = pick_from_range(rtime);
3651 log_error(LOG_LEVEL_ERROR,
3652 "Random range is 0. Assuming time transformation test.");
3654 tm += rtime * (negative_range ? -1 : 1);
3655 timeptr = privoxy_gmtime_r(&tm, &gmt);
3656 if ((NULL == timeptr) || !strftime(newheader,
3657 sizeof(newheader), "%a, %d %b %Y %H:%M:%S GMT", timeptr))
3659 log_error(LOG_LEVEL_ERROR,
3660 "Randomizing '%s' failed. Crunching the header without replacement.",
3666 *header = strdup("If-Modified-Since: ");
3667 string_append(header, newheader);
3669 if (*header == NULL)
3671 log_error(LOG_LEVEL_HEADER, "Insufficient memory, header crunched without replacement.");
3672 return JB_ERR_MEMORY;
3675 hours = rtime / 3600;
3676 minutes = rtime / 60 % 60;
3677 seconds = rtime % 60;
3679 log_error(LOG_LEVEL_HEADER,
3680 "Randomized: %s (%s %ld hou%s %ld minut%s %ld second%s",
3681 *header, (negative_range) ? "subtracted" : "added", hours,
3682 (hours == 1) ? "r" : "rs", minutes, (minutes == 1) ? "e" : "es",
3683 seconds, (seconds == 1) ? ")" : "s)");
3692 /*********************************************************************
3694 * Function : client_if_none_match
3696 * Description : Remove the If-None-Match header.
3699 * 1 : csp = Current client state (buffers, headers, etc...)
3700 * 2 : header = On input, pointer to header to modify.
3701 * On output, pointer to the modified header, or NULL
3702 * to remove the header. This function frees the
3703 * original string if necessary.
3705 * Returns : JB_ERR_OK on success, or
3706 * JB_ERR_MEMORY on out-of-memory error.
3708 *********************************************************************/
3709 static jb_err client_if_none_match(struct client_state *csp, char **header)
3711 if (csp->action->flags & ACTION_CRUNCH_IF_NONE_MATCH)
3713 log_error(LOG_LEVEL_HEADER, "Crunching %s", *header);
3721 /*********************************************************************
3723 * Function : client_x_filter
3725 * Description : Disables filtering if the client set "X-Filter: No".
3726 * Called from `sed'.
3729 * 1 : csp = Current client state (buffers, headers, etc...)
3730 * 2 : header = On input, pointer to header to modify.
3731 * On output, pointer to the modified header, or NULL
3732 * to remove the header. This function frees the
3733 * original string if necessary.
3735 * Returns : JB_ERR_OK on success
3737 *********************************************************************/
3738 jb_err client_x_filter(struct client_state *csp, char **header)
3740 if (0 == strcmpic(*header, "X-Filter: No"))
3742 if (!(csp->config->feature_flags & RUNTIME_FEATURE_HTTP_TOGGLE))
3744 log_error(LOG_LEVEL_INFO, "Ignored the client's request to fetch without filtering.");
3748 if (csp->action->flags & ACTION_FORCE_TEXT_MODE)
3750 log_error(LOG_LEVEL_HEADER,
3751 "force-text-mode overruled the client's request to fetch without filtering!");
3755 csp->content_type = CT_TABOO; /* XXX: This hack shouldn't be necessary */
3756 csp->flags |= CSP_FLAG_NO_FILTERING;
3757 log_error(LOG_LEVEL_HEADER, "Accepted the client's request to fetch without filtering.");
3759 log_error(LOG_LEVEL_HEADER, "Crunching %s", *header);
3767 /*********************************************************************
3769 * Function : client_range
3771 * Description : Removes Range, Request-Range and If-Range headers if
3772 * content filtering is enabled and the range doesn't
3775 * If the client's version of the document has been
3776 * altered by Privoxy, the server could interpret the
3777 * range differently than the client intended in which
3778 * case the user could end up with corrupted content.
3780 * If the range starts at byte 0 this isn't an issue
3781 * so the header can pass. Partial requests like this
3782 * are used to render preview images for videos without
3783 * downloading the whole video.
3785 * While HTTP doesn't require that range requests are
3786 * honoured and the client could simply abort the download
3787 * after receiving a sufficient amount of data, various
3788 * clients don't handle complete responses to range
3789 * requests gracefully and emit misleading error messages
3793 * 1 : csp = Current client state (buffers, headers, etc...)
3794 * 2 : header = On input, pointer to header to modify.
3795 * On output, pointer to the modified header, or NULL
3796 * to remove the header. This function frees the
3797 * original string if necessary.
3799 * Returns : JB_ERR_OK
3801 *********************************************************************/
3802 static jb_err client_range(struct client_state *csp, char **header)
3804 if (content_filters_enabled(csp->action)
3805 && (0 != strncmpic(strstr(*header, ":"), ": bytes=0-", 10)))
3807 log_error(LOG_LEVEL_HEADER, "Content filtering is enabled."
3808 " Crunching: \'%s\' to prevent range-mismatch problems.", *header);
3815 /* the following functions add headers directly to the header list */
3817 /*********************************************************************
3819 * Function : client_host_adder
3821 * Description : Adds the Host: header field if it is missing.
3822 * Called from `sed'.
3825 * 1 : csp = Current client state (buffers, headers, etc...)
3827 * Returns : JB_ERR_OK on success, or
3828 * JB_ERR_MEMORY on out-of-memory error.
3830 *********************************************************************/
3831 static jb_err client_host_adder(struct client_state *csp)
3836 if (csp->flags & CSP_FLAG_HOST_HEADER_IS_SET)
3838 /* Header already set by the client, nothing to do. */
3842 if (!csp->http->hostport || !*(csp->http->hostport))
3844 log_error(LOG_LEVEL_ERROR, "Destination host unknown.");
3845 return JB_ERR_PARSE;
3849 * remove 'user:pass@' from 'proto://user:pass@host'
3851 if ((p = strchr( csp->http->hostport, '@')) != NULL)
3857 p = csp->http->hostport;
3860 /* XXX: Just add it, we already made sure that it will be unique */
3861 log_error(LOG_LEVEL_HEADER, "addh-unique: Host: %s", p);
3862 err = enlist_unique_header(csp->headers, "Host", p);
3868 /*********************************************************************
3870 * Function : client_xtra_adder
3872 * Description : Used in the add_client_headers list. Called from `sed'.
3875 * 1 : csp = Current client state (buffers, headers, etc...)
3877 * Returns : JB_ERR_OK on success, or
3878 * JB_ERR_MEMORY on out-of-memory error.
3880 *********************************************************************/
3881 static jb_err client_xtra_adder(struct client_state *csp)
3883 struct list_entry *lst;
3886 for (lst = csp->action->multi[ACTION_MULTI_ADD_HEADER]->first;
3887 lst ; lst = lst->next)
3889 log_error(LOG_LEVEL_HEADER, "addh: %s", lst->str);
3890 err = enlist(csp->headers, lst->str);
3902 /*********************************************************************
3904 * Function : client_x_forwarded_for_adder
3906 * Description : Used in the add_client_headers list. Called from `sed'.
3909 * 1 : csp = Current client state (buffers, headers, etc...)
3911 * Returns : JB_ERR_OK on success, or
3912 * JB_ERR_MEMORY on out-of-memory error.
3914 *********************************************************************/
3915 static jb_err client_x_forwarded_for_adder(struct client_state *csp)
3917 char *header = NULL;
3920 if (!((csp->action->flags & ACTION_CHANGE_X_FORWARDED_FOR)
3921 && (0 == strcmpic(csp->action->string[ACTION_STRING_CHANGE_X_FORWARDED_FOR], "add")))
3922 || (csp->flags & CSP_FLAG_X_FORWARDED_FOR_APPENDED))
3925 * If we aren't adding X-Forwarded-For headers,
3926 * or we already appended an existing X-Forwarded-For
3927 * header, there's nothing left to do here.
3932 header = strdup("X-Forwarded-For: ");
3933 string_append(&header, csp->ip_addr_str);
3937 return JB_ERR_MEMORY;
3940 log_error(LOG_LEVEL_HEADER, "addh: %s", header);
3941 err = enlist(csp->headers, header);
3948 /*********************************************************************
3950 * Function : server_connection_adder
3952 * Description : Adds an appropriate "Connection:" header to csp->headers
3953 * unless the header was already present. Called from `sed'.
3956 * 1 : csp = Current client state (buffers, headers, etc...)
3958 * Returns : JB_ERR_OK on success, or
3959 * JB_ERR_MEMORY on out-of-memory error.
3961 *********************************************************************/
3962 static jb_err server_connection_adder(struct client_state *csp)
3964 const unsigned int flags = csp->flags;
3965 const char *response_status_line = csp->headers->first->str;
3966 static const char connection_close[] = "Connection: close";
3968 if ((flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
3969 && (flags & CSP_FLAG_SERVER_CONNECTION_HEADER_SET))
3975 * XXX: if we downgraded the response, this check will fail.
3977 if ((csp->config->feature_flags &
3978 RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
3979 && (NULL != response_status_line)
3980 && !strncmpic(response_status_line, "HTTP/1.1", 8)
3981 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
3982 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
3986 log_error(LOG_LEVEL_HEADER, "A HTTP/1.1 response "
3987 "without Connection header implies keep-alive.");
3988 csp->flags |= CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE;
3992 log_error(LOG_LEVEL_HEADER, "Adding: %s", connection_close);
3994 return enlist(csp->headers, connection_close);
3998 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
3999 /*********************************************************************
4001 * Function : server_proxy_connection_adder
4003 * Description : Adds a "Proxy-Connection: keep-alive" header to
4004 * csp->headers when appropriate.
4007 * 1 : csp = Current client state (buffers, headers, etc...)
4009 * Returns : JB_ERR_OK on success, or
4010 * JB_ERR_MEMORY on out-of-memory error.
4012 *********************************************************************/
4013 static jb_err server_proxy_connection_adder(struct client_state *csp)
4015 static const char proxy_connection_header[] = "Proxy-Connection: keep-alive";
4016 jb_err err = JB_ERR_OK;
4018 if ((csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
4019 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
4020 && !(csp->flags & CSP_FLAG_SERVER_PROXY_CONNECTION_HEADER_SET)
4021 && ((csp->flags & CSP_FLAG_SERVER_CONTENT_LENGTH_SET)
4022 || (csp->flags & CSP_FLAG_CHUNKED))
4023 #ifdef FEATURE_HTTPS_INSPECTION
4024 && !client_use_ssl(csp)
4029 log_error(LOG_LEVEL_HEADER, "Adding: %s", proxy_connection_header);
4030 err = enlist(csp->headers, proxy_connection_header);
4035 #endif /* FEATURE_CONNECTION_KEEP_ALIVE */
4038 /*********************************************************************
4040 * Function : client_connection_header_adder
4042 * Description : Adds a proper "Connection:" header to csp->headers
4043 * unless the header was already present or it's a
4044 * CONNECT request. Called from `sed'.
4047 * 1 : csp = Current client state (buffers, headers, etc...)
4049 * Returns : JB_ERR_OK on success, or
4050 * JB_ERR_MEMORY on out-of-memory error.
4052 *********************************************************************/
4053 static jb_err client_connection_header_adder(struct client_state *csp)
4055 static const char connection_close[] = "Connection: close";
4057 if (!(csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
4058 && (csp->flags & CSP_FLAG_CLIENT_CONNECTION_HEADER_SET))
4064 * In case of CONNECT requests "Connection: close" is implied,
4065 * but actually setting the header has been reported to cause
4066 * problems with some forwarding proxies that close the
4067 * connection prematurely.
4069 if (csp->http->ssl != 0)
4074 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
4075 if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
4076 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
4077 && !strcmpic(csp->http->version, "HTTP/1.1"))
4079 csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
4082 #endif /* FEATURE_CONNECTION_KEEP_ALIVE */
4084 log_error(LOG_LEVEL_HEADER, "Adding: %s", connection_close);
4086 return enlist(csp->headers, connection_close);
4090 /*********************************************************************
4092 * Function : server_http
4094 * Description : - Save the HTTP Status into csp->http->status
4095 * - Set CT_TABOO to prevent filtering if the answer
4096 * is a partial range (HTTP status 206)
4097 * - Rewrite HTTP/1.1 answers to HTTP/1.0 if +downgrade
4099 * - Normalize the HTTP-version.
4102 * 1 : csp = Current client state (buffers, headers, etc...)
4103 * 2 : header = On input, pointer to header to modify.
4104 * On output, pointer to the modified header, or NULL
4105 * to remove the header. This function frees the
4106 * original string if necessary.
4108 * Returns : JB_ERR_OK on success, or
4109 * JB_ERR_PARSE on fatal parse errors.
4111 *********************************************************************/
4112 static jb_err server_http(struct client_state *csp, char **header)
4114 char *reason_phrase = NULL;
4115 char *new_response_line;
4118 unsigned int major_version;
4119 unsigned int minor_version;
4121 /* Get the reason phrase which start after the second whitespace */
4122 p = strchr(*header, ' ');
4126 reason_phrase = strchr(p, ' ');
4129 if (reason_phrase != NULL)
4135 log_error(LOG_LEVEL_ERROR,
4136 "Response line lacks reason phrase: %s", *header);
4140 if (3 != sscanf(*header, "HTTP/%u.%u %d", &major_version,
4141 &minor_version, &(csp->http->status)))
4143 log_error(LOG_LEVEL_ERROR,
4144 "Failed to parse the response line: %s", *header);
4145 return JB_ERR_PARSE;
4148 if (csp->http->status == 101 ||
4149 csp->http->status == 206)
4151 csp->content_type = CT_TABOO;
4154 if (major_version != 1 || (minor_version != 0 && minor_version != 1))
4157 * According to RFC 7230 2.6 intermediaries MUST send
4158 * their own HTTP-version in forwarded messages.
4160 log_error(LOG_LEVEL_ERROR,
4161 "Unsupported HTTP version. Downgrading to 1.1.");
4166 if (((csp->action->flags & ACTION_DOWNGRADE) != 0) && (minor_version == 1))
4168 log_error(LOG_LEVEL_HEADER, "Downgrading answer to HTTP/1.0");
4172 /* Rebuild response line. */
4173 length = sizeof("HTTP/1.1 200 ") + strlen(reason_phrase) + 1;
4174 new_response_line = malloc_or_die(length);
4176 snprintf(new_response_line, length, "HTTP/%u.%u %d %s",
4177 major_version, minor_version, csp->http->status, reason_phrase);
4179 if (0 != strcmp(*header, new_response_line))
4181 log_error(LOG_LEVEL_HEADER, "Response line '%s' changed to '%s'",
4182 *header, new_response_line);
4186 *header = new_response_line;
4191 /*********************************************************************
4193 * Function : add_cooky_expiry_date
4195 * Description : Adds a cookie expiry date to a string.
4198 * 1 : cookie = On input, pointer to cookie to modify.
4199 * On output, pointer to the modified header.
4200 * The original string is freed.
4201 * 2 : lifetime = Seconds the cookie should be valid
4205 *********************************************************************/
4206 static void add_cookie_expiry_date(char **cookie, time_t lifetime)
4209 struct tm *timeptr = NULL;
4210 time_t expiry_date = time(NULL) + lifetime;
4213 timeptr = privoxy_gmtime_r(&expiry_date, &gmt);
4214 if (NULL == timeptr)
4216 log_error(LOG_LEVEL_FATAL,
4217 "Failed to get the time in add_cooky_expiry_date()");
4219 strftime(tmp, sizeof(tmp), "; expires=%a, %d-%b-%Y %H:%M:%S GMT", timeptr);
4220 if (JB_ERR_OK != string_append(cookie, tmp))
4222 log_error(LOG_LEVEL_FATAL, "Out of memory in add_cooky_expiry()");
4227 /*********************************************************************
4229 * Function : server_set_cookie
4231 * Description : Handle the server "cookie" header properly.
4232 * Crunch, accept or rewrite it to a session cookie.
4233 * Called from `sed'.
4236 * 1 : csp = Current client state (buffers, headers, etc...)
4237 * 2 : header = On input, pointer to header to modify.
4238 * On output, pointer to the modified header, or NULL
4239 * to remove the header. This function frees the
4240 * original string if necessary.
4242 * Returns : JB_ERR_OK on success, or
4243 * JB_ERR_MEMORY on out-of-memory error.
4245 *********************************************************************/
4246 static jb_err server_set_cookie(struct client_state *csp, char **header)
4248 if ((csp->action->flags & ACTION_CRUNCH_INCOMING_COOKIES) != 0)
4250 log_error(LOG_LEVEL_HEADER, "Crunching incoming cookie: %s", *header);
4253 else if ((0 != (csp->action->flags & ACTION_SESSION_COOKIES_ONLY))
4254 || (0 != (csp->action->flags & ACTION_LIMIT_COOKIE_LIFETIME)))
4258 long cookie_lifetime = 0;
4261 NO_EXPIRY_DATE_SPECIFIED,
4262 EXPIRY_DATE_ACCEPTABLE,
4263 EXPIRY_DATE_UNACCEPTABLE
4264 } expiry_date_status = NO_EXPIRY_DATE_SPECIFIED;
4266 /* A variable to store the tag we're working on */
4269 /* Skip "Set-Cookie:" (11 characters) in header */
4270 cur_tag = *header + 11;
4272 /* skip whitespace between "Set-Cookie:" and value */
4273 while (*cur_tag && privoxy_isspace(*cur_tag))
4280 if ((csp->action->flags & ACTION_LIMIT_COOKIE_LIFETIME) != 0)
4282 const char *param = csp->action->string[ACTION_STRING_LIMIT_COOKIE_LIFETIME];
4284 cookie_lifetime = strtol(param, NULL, 0);
4285 if (cookie_lifetime < 0)
4287 log_error(LOG_LEVEL_FATAL, "Invalid cookie lifetime limit: %s", param);
4289 cookie_lifetime *= 60;
4292 /* Loop through each tag in the cookie */
4296 char *next_tag = strchr(cur_tag, ';');
4297 if (next_tag != NULL)
4299 /* Skip the ';' character itself */
4302 /* skip whitespace ";" and start of tag */
4303 while (*next_tag && privoxy_isspace(*next_tag))
4310 /* "Next tag" is the end of the string */
4311 next_tag = cur_tag + strlen(cur_tag);
4315 * Check the expiration date to see
4316 * if the cookie is still valid, if yes,
4317 * rewrite it to a session cookie.
4319 if ((strncmpic(cur_tag, "expires=", 8) == 0) && *(cur_tag + 8))
4321 char *expiration_date = cur_tag + 8; /* Skip "[Ee]xpires=" */
4323 if ((expiration_date[0] == '"')
4324 && (expiration_date[1] != '\0'))
4327 * Skip quotation mark. RFC 2109 10.1.2 seems to hint
4328 * that the expiration date isn't supposed to be quoted,
4329 * but some servers do it anyway.
4334 /* Did we detect the date properly? */
4335 if (JB_ERR_OK != parse_header_time(expiration_date, &cookie_time))
4338 * Nope, treat it as if it was still valid.
4340 * XXX: Should we remove the whole cookie instead?
4342 log_error(LOG_LEVEL_ERROR,
4343 "Can't parse \'%s\', send by %s. Unsupported time format?", cur_tag, csp->http->url);
4344 string_move(cur_tag, next_tag);
4345 expiry_date_status = EXPIRY_DATE_UNACCEPTABLE;
4350 * Yes. Check if the cookie is still valid.
4352 * If the cookie is already expired it's probably
4353 * a delete cookie and even if it isn't, the browser
4354 * will discard it anyway.
4358 * XXX: timegm() isn't available on some AmigaOS
4359 * versions and our replacement doesn't work.
4361 * Our options are to either:
4363 * - disable session-cookies-only completely if timegm
4366 * - to simply remove all expired tags, like it has
4367 * been done until Privoxy 3.0.6 and to live with
4368 * the consequence that it can cause login/logout
4369 * problems on servers that don't validate their
4370 * input properly, or
4372 * - to replace it with mktime in which
4373 * case there is a slight chance of valid cookies
4374 * passing as already expired.
4376 * This is the way it's currently done and it's not
4377 * as bad as it sounds. If the missing GMT offset is
4378 * enough to change the result of the expiration check
4379 * the cookie will be only valid for a few hours
4380 * anyway, which in many cases will be shorter
4381 * than a browser session.
4383 if (cookie_time < now)
4385 log_error(LOG_LEVEL_HEADER,
4386 "Cookie \'%s\' is already expired and can pass unmodified.", *header);
4387 /* Just in case some clown sets more then one expiration date */
4389 expiry_date_status = EXPIRY_DATE_ACCEPTABLE;
4391 else if ((cookie_lifetime != 0) && (cookie_time < (now + cookie_lifetime)))
4393 log_error(LOG_LEVEL_HEADER, "Cookie \'%s\' can pass unmodified. "
4394 "Its lifetime is below the limit.", *header);
4395 /* Just in case some clown sets more then one expiration date */
4397 expiry_date_status = EXPIRY_DATE_ACCEPTABLE;
4402 * Still valid, delete expiration date by copying
4403 * the rest of the string over it.
4405 string_move(cur_tag, next_tag);
4407 /* That changed the header, need to issue a log message */
4408 expiry_date_status = EXPIRY_DATE_UNACCEPTABLE;
4411 * Note that the next tag has now been moved to *cur_tag,
4412 * so we do not need to update the cur_tag pointer.
4420 /* Move on to next cookie tag */
4425 if (expiry_date_status != EXPIRY_DATE_ACCEPTABLE)
4427 assert(NULL != *header);
4428 if (cookie_lifetime != 0)
4430 add_cookie_expiry_date(header, cookie_lifetime);
4431 log_error(LOG_LEVEL_HEADER, "Cookie rewritten to: %s", *header);
4433 else if (expiry_date_status != NO_EXPIRY_DATE_SPECIFIED)
4435 log_error(LOG_LEVEL_HEADER,
4436 "Cookie rewritten to a temporary one: %s", *header);
4445 #ifdef FEATURE_FORCE_LOAD
4446 /*********************************************************************
4448 * Function : strclean
4450 * Description : In-Situ-Eliminate all occurrences of substring in
4454 * 1 : string = string to clean
4455 * 2 : substring = substring to eliminate
4457 * Returns : Number of eliminations
4459 *********************************************************************/
4460 int strclean(char *string, const char *substring)
4466 len = strlen(substring);
4468 while((pos = strstr(string, substring)) != NULL)
4475 while (*p++ != '\0');
4482 #endif /* def FEATURE_FORCE_LOAD */
4485 /*********************************************************************
4487 * Function : parse_header_time
4489 * Description : Parses time formats used in HTTP header strings
4490 * to get the numerical respresentation.
4493 * 1 : header_time = HTTP header time as string.
4494 * 2 : result = storage for header_time in seconds
4496 * Returns : JB_ERR_OK if the time format was recognized, or
4497 * JB_ERR_PARSE otherwise.
4499 *********************************************************************/
4500 static jb_err parse_header_time(const char *header_time, time_t *result)
4504 * Checking for two-digit years first in an
4505 * attempt to work around GNU libc's strptime()
4506 * reporting negative year values when using %Y.
4508 static const char time_formats[][22] = {
4509 /* Tue, 02-Jun-37 20:00:00 */
4510 "%a, %d-%b-%y %H:%M:%S",
4511 /* Tue, 02 Jun 2037 20:00:00 */
4512 "%a, %d %b %Y %H:%M:%S",
4513 /* Tue, 02-Jun-2037 20:00:00 */
4514 "%a, %d-%b-%Y %H:%M:%S",
4515 /* Tuesday, 02-Jun-2037 20:00:00 */
4516 "%A, %d-%b-%Y %H:%M:%S",
4517 /* Tuesday Jun 02 20:00:00 2037 */
4518 "%A %b %d %H:%M:%S %Y"
4522 for (i = 0; i < SZ(time_formats); i++)
4525 * Zero out gmt to prevent time zone offsets.
4526 * Documented to be required for GNU libc.
4528 memset(&gmt, 0, sizeof(gmt));
4530 if (NULL != strptime(header_time, time_formats[i], &gmt))
4532 /* Sanity check for GNU libc. */
4533 if (gmt.tm_year < 0)
4535 log_error(LOG_LEVEL_HEADER,
4536 "Failed to parse '%s' using '%s'. Moving on.",
4537 header_time, time_formats[i]);
4540 *result = timegm(&gmt);
4542 #ifdef FEATURE_STRPTIME_SANITY_CHECKS
4544 * Verify that parsing the date recreated from the first
4545 * parse operation gets the previous result. If it doesn't,
4546 * either strptime() or strftime() are malfunctioning.
4548 * We could string-compare the recreated date with the original
4549 * header date, but this leads to false positives as strptime()
4550 * may let %a accept all day formats while strftime() will only
4554 char recreated_date[100];
4559 tm = privoxy_gmtime_r(result, &storage);
4560 if (!strftime(recreated_date, sizeof(recreated_date),
4561 time_formats[i], tm))
4563 log_error(LOG_LEVEL_ERROR, "Failed to recreate date '%s' with '%s'.",
4564 header_time, time_formats[i]);
4567 memset(&gmt, 0, sizeof(gmt));
4568 if (NULL == strptime(recreated_date, time_formats[i], &gmt))
4570 log_error(LOG_LEVEL_ERROR,
4571 "Failed to parse '%s' generated with '%s' to recreate '%s'.",
4572 recreated_date, time_formats[i], header_time);
4575 result2 = timegm(&gmt);
4576 if (*result != result2)
4578 log_error(LOG_LEVEL_ERROR, "strftime() and strptime() disagree. "
4579 "Format: '%s'. In: '%s', out: '%s'. %ld != %ld. Rejecting.",
4580 time_formats[i], header_time, recreated_date, *result, result2);
4590 return JB_ERR_PARSE;
4594 /*********************************************************************
4596 * Function : parse_time_header
4598 * Description : Parses the time in an HTTP time header to get
4599 * the numerical respresentation.
4602 * 1 : header = HTTP header with a time value
4603 * 2 : result = storage for header_time in seconds
4605 * Returns : JB_ERR_OK if the time format was recognized, or
4606 * JB_ERR_PARSE otherwise.
4608 *********************************************************************/
4609 static jb_err parse_time_header(const char *header, time_t *result)
4611 const char *header_time;
4613 header_time = strchr(header, ':');
4616 * Currently this can't happen as all callers are called
4617 * through sed() which requires a header name followed by
4620 assert(header_time != NULL);
4623 if (*header_time == ' ')
4628 return parse_header_time(header_time, result);
4633 /*********************************************************************
4635 * Function : get_destination_from_headers
4637 * Description : Parse the "Host:" header to get the request's destination.
4638 * Only needed if the client's request was forcefully
4639 * redirected into Privoxy.
4641 * Code mainly copied from client_host() which is currently
4642 * run too late for this purpose.
4645 * 1 : headers = List of headers (one of them hopefully being
4646 * the "Host:" header)
4647 * 2 : http = storage for the result (host, port and hostport).
4649 * Returns : JB_ERR_MEMORY (or terminates) in case of memory problems,
4650 * JB_ERR_PARSE if the host header couldn't be found,
4651 * JB_ERR_OK otherwise.
4653 *********************************************************************/
4654 jb_err get_destination_from_headers(const struct list *headers, struct http_request *http)
4660 host = get_header_value(headers, "Host:");
4664 log_error(LOG_LEVEL_ERROR, "No \"Host:\" header found.");
4665 return JB_ERR_PARSE;
4668 p = string_tolower(host);
4671 return JB_ERR_MEMORY;
4674 q = strdup_or_die(p);
4676 freez(http->hostport);
4680 q = strchr(http->host, ':');
4683 /* Terminate hostname and evaluate port string */
4685 http->port = atoi(q);
4692 /* Rebuild request URL */
4694 http->url = strdup("http://");
4695 string_append(&http->url, http->hostport);
4696 string_append(&http->url, http->path);
4697 if (http->url == NULL)
4699 return JB_ERR_MEMORY;
4702 log_error(LOG_LEVEL_HEADER,
4703 "Destination extracted from \"Host\" header. New request URL: %s",
4707 * Regenerate request line in "proxy format"
4708 * to make rewrites more convenient.
4710 assert(http->cmd != NULL);
4712 http->cmd = strdup_or_die(http->gpc);
4713 string_append(&http->cmd, " ");
4714 string_append(&http->cmd, http->url);
4715 string_append(&http->cmd, " ");
4716 string_append(&http->cmd, http->version);
4717 if (http->cmd == NULL)
4719 return JB_ERR_MEMORY;
4727 #ifdef FEATURE_HTTPS_INSPECTION
4728 /*********************************************************************
4730 * Function : get_destination_from_https_headers
4732 * Description : Parse the previously encrypted "Host:" header to
4733 * get the request's destination.
4736 * 1 : headers = List of headers (one of them hopefully being
4737 * the "Host:" header)
4738 * 2 : http = storage for the result (host, port and hostport).
4740 * Returns : JB_ERR_MEMORY (or terminates) in case of memory problems,
4741 * JB_ERR_PARSE if the host header couldn't be found,
4742 * JB_ERR_OK otherwise.
4744 *********************************************************************/
4745 jb_err get_destination_from_https_headers(const struct list *headers, struct http_request *http)
4751 host = get_header_value(headers, "Host:");
4755 log_error(LOG_LEVEL_ERROR, "No \"Host:\" header found.");
4756 return JB_ERR_PARSE;
4759 p = string_tolower(host);
4762 return JB_ERR_MEMORY;
4765 q = strdup_or_die(p);
4767 freez(http->hostport);
4771 q = strchr(http->host, ':');
4774 /* Terminate hostname and evaluate port string */
4776 http->port = atoi(q);
4783 /* Rebuild request URL */
4785 http->url = strdup_or_die(http->path);
4787 log_error(LOG_LEVEL_HEADER,
4788 "Destination extracted from \"Host\" header. New request URL: %s",
4792 * Regenerate request line in "proxy format"
4793 * to make rewrites more convenient.
4795 assert(http->cmd != NULL);
4797 http->cmd = strdup_or_die(http->gpc);
4798 string_append(&http->cmd, " ");
4799 string_append(&http->cmd, http->url);
4800 string_append(&http->cmd, " ");
4801 string_append(&http->cmd, http->version);
4802 if (http->cmd == NULL)
4804 return JB_ERR_MEMORY;
4810 #endif /* def FEATURE_HTTPS_INSPECTION */
4813 /*********************************************************************
4815 * Function : create_forged_referrer
4817 * Description : Helper for client_referrer to forge a referer as
4818 * 'http://hostname[:port]/' to fool stupid
4819 * checks for in-site links
4822 * 1 : header = Pointer to header pointer
4823 * 2 : hostport = Host and optionally port as string
4825 * Returns : JB_ERR_OK in case of success, or
4826 * JB_ERR_MEMORY in case of memory problems.
4828 *********************************************************************/
4829 static jb_err create_forged_referrer(char **header, const char *hostport)
4831 assert(NULL == *header);
4833 *header = strdup("Referer: http://");
4834 string_append(header, hostport);
4835 string_append(header, "/");
4837 if (NULL == *header)
4839 return JB_ERR_MEMORY;
4842 log_error(LOG_LEVEL_HEADER, "Referer forged to: %s", *header);
4849 /*********************************************************************
4851 * Function : create_fake_referrer
4853 * Description : Helper for client_referrer to create a fake referrer
4854 * based on a string supplied by the user.
4857 * 1 : header = Pointer to header pointer
4858 * 2 : hosthost = Referrer to fake
4860 * Returns : JB_ERR_OK in case of success, or
4861 * JB_ERR_MEMORY in case of memory problems.
4863 *********************************************************************/
4864 static jb_err create_fake_referrer(char **header, const char *fake_referrer)
4866 assert(NULL == *header);
4868 if ((0 != strncmpic(fake_referrer, "http://", 7)) && (0 != strncmpic(fake_referrer, "https://", 8)))
4870 log_error(LOG_LEVEL_HEADER,
4871 "Parameter: +hide-referrer{%s} is a bad idea, but I don't care.", fake_referrer);
4873 *header = strdup("Referer: ");
4874 string_append(header, fake_referrer);
4876 if (NULL == *header)
4878 return JB_ERR_MEMORY;
4881 log_error(LOG_LEVEL_HEADER, "Referer replaced with: %s", *header);
4888 /*********************************************************************
4890 * Function : handle_conditional_hide_referrer_parameter
4892 * Description : Helper for client_referrer to crunch or forge
4893 * the referrer header if the host has changed.
4896 * 1 : header = Pointer to header pointer
4897 * 2 : host = The target host (may include the port)
4898 * 3 : parameter_conditional_block = Boolean to signal
4899 * if we're in conditional-block mode. If not set,
4900 * we're in conditional-forge mode.
4902 * Returns : JB_ERR_OK in case of success, or
4903 * JB_ERR_MEMORY in case of memory problems.
4905 *********************************************************************/
4906 static jb_err handle_conditional_hide_referrer_parameter(char **header,
4907 const char *host, const int parameter_conditional_block)
4909 char *referer = strdup_or_die(*header);
4910 const size_t hostlength = strlen(host);
4911 const char *referer_url = NULL;
4913 /* referer begins with 'Referer: http[s]://' */
4914 if ((hostlength+17) < strlen(referer))
4917 * Shorten referer to make sure the referer is blocked
4918 * if www.example.org/www.example.com-shall-see-the-referer/
4919 * links to www.example.com/
4921 referer[hostlength+17] = '\0';
4923 referer_url = strstr(referer, "http://");
4924 if (NULL == referer_url)
4926 referer_url = strstr(referer, "https://");
4928 if ((NULL == referer_url) || (NULL == strstr(referer_url, host)))
4930 /* Host has changed, Referer is invalid or a https URL. */
4931 if (parameter_conditional_block)
4933 log_error(LOG_LEVEL_HEADER, "New host is: %s. Crunching %s!", host, *header);
4940 return create_forged_referrer(header, host);
4950 /*********************************************************************
4952 * Function : create_content_length_header
4954 * Description : Creates a Content-Length header.
4957 * 1 : content_length = The content length to be used in the header.
4958 * 2 : header = Allocated space to safe the header.
4959 * 3 : buffer_length = The length of the allocated space.
4963 *********************************************************************/
4964 static void create_content_length_header(unsigned long long content_length,
4965 char *header, size_t buffer_length)
4968 #if SIZEOF_LONG_LONG < 8
4969 #error sizeof(unsigned long long) too small
4971 snprintf(header, buffer_length, "Content-Length: %I64u", content_length);
4973 snprintf(header, buffer_length, "Content-Length: %llu", content_length);
4978 /*********************************************************************
4980 * Function : get_expected_content_length
4982 * Description : Figures out the content length from a list of headers.
4985 * 1 : headers = List of headers
4987 * Returns : Number of bytes to expect
4989 *********************************************************************/
4990 unsigned long long get_expected_content_length(struct list *headers)
4992 const char *content_length_header;
4993 unsigned long long content_length = 0;
4995 content_length_header = get_header_value(headers, "Content-Length:");
4996 if (content_length_header != NULL)
4998 if (JB_ERR_OK != get_content_length(content_length_header, &content_length))
5000 log_error(LOG_LEVEL_ERROR,
5001 "Failed to get the Content-Length in %s", content_length_header);
5002 /* XXX: The header will be removed later on */
5007 return content_length;