1 /*********************************************************************
2 *
3 * File : $Source: /cvsroot/ijbswa/current/parsers.c,v $
4 *
5 * Purpose : Declares functions to parse/crunch headers and pages.
6 *
7 * Copyright : Written by and Copyright (C) 2001-2021 the
8 * Privoxy team. https://www.privoxy.org/
9 *
10 * Based on the Internet Junkbuster originally written
11 * by and Copyright (C) 1997 Anonymous Coders and
12 * Junkbusters Corporation. http://www.junkbusters.com
13 *
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.
19 *
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.
25 *
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.
31 *
32 *********************************************************************/
33
34
35 #include "config.h"
36
37 #ifndef _WIN32
38 #include <stdio.h>
39 #include <sys/types.h>
40 #endif
41
42 #include <stdlib.h>
43 #include <ctype.h>
44 #include <assert.h>
45 #include <string.h>
46
47 #ifdef __GLIBC__
48 /*
49 * Convince GNU's libc to provide a strptime prototype.
50 */
51 #define __USE_XOPEN
52 #endif /*__GLIBC__ */
53 #include <time.h>
54
55 #ifdef FEATURE_ZLIB
56 #include <zlib.h>
57
58 #define GZIP_IDENTIFIER_1 0x1f
59 #define GZIP_IDENTIFIER_2 0x8b
60
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
66 #endif
67 #ifdef FEATURE_BROTLI
68 #include <brotli/decode.h>
69 #endif
70
71 #if !defined(_WIN32)
72 #include <unistd.h>
73 #endif
74
75 #include "project.h"
76
77 #ifdef FEATURE_PTHREAD
78 #include "jcc.h"
79 /* jcc.h is for mutex semapores only */
80 #endif /* def FEATURE_PTHREAD */
81 #include "list.h"
82 #include "parsers.h"
83 #include "ssplit.h"
84 #include "errlog.h"
85 #include "jbsockets.h"
86 #include "miscutil.h"
87 #include "list.h"
88 #include "actions.h"
89 #include "filters.h"
90 #ifdef FEATURE_HTTPS_INSPECTION
91 #include "ssl.h"
92 #endif
93
94 #ifndef HAVE_STRPTIME
95 #include "strptime.h"
96 #endif
97
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);
103
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);
135 #ifdef FEATURE_ZLIB
136 static jb_err server_adjust_content_encoding(struct client_state *csp, char **header);
137 #endif
138
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 */
146
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);
157
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);
164
165 /*
166 * List of functions to run on a list of headers.
167 */
168 struct parsers
169 {
170 /** The header prefix to match */
171 const char *str;
172
173 /** The length of the prefix to match */
174 const size_t len;
175
176 /** The function to apply to this line */
177 const parser_func_ptr parser;
178 };
179
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 },
195 #else
196 { "Keep-Alive:", 11, crumble },
197 { "Proxy-Connection:", 17, crumble },
198 #endif
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 },
208 #if 0
209 { "Transfer-Encoding:", 18, client_transfer_encoding },
210 #endif
211 { "Expect:", 7, client_expect },
212 { "*", 0, crunch_client_header },
213 { "*", 0, filter_header },
214 { NULL, 0, NULL }
215 };
216
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 },
228 #else
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 },
237 { NULL, 0, NULL }
238 };
239
240 static const add_header_func_ptr add_client_headers[] = {
241 client_host_adder,
242 client_x_forwarded_for_adder,
243 client_xtra_adder,
244 client_connection_header_adder,
245 NULL
246 };
247
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 */
253 NULL
254 };
255
256 /*********************************************************************
257 *
258 * Function : flush_iob
259 *
260 * Description : Write any pending "buffered" content.
261 *
262 * Parameters :
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
266 *
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.
273 *
274 *********************************************************************/
flush_iob(jb_socket fd,struct iob * iob,unsigned int delay)275 long flush_iob(jb_socket fd, struct iob *iob, unsigned int delay)
276 {
277 long len = iob->eod - iob->cur;
278
279 if (len <= 0)
280 {
281 return(0);
282 }
283
284 if (write_socket_delayed(fd, iob->cur, (size_t)len, delay))
285 {
286 return(-1);
287 }
288 iob->eod = iob->cur = iob->buf;
289 return(len);
290
291 }
292
293
294 /*********************************************************************
295 *
296 * Function : can_add_to_iob
297 *
298 * Description : Checks if the given number of bytes can be added to the given iob
299 * without exceeding the given buffer limit.
300 *
301 * Parameters :
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
305 *
306 * Returns : TRUE if the given iob can handle given number of bytes
307 * FALSE buffer limit will be exceeded
308 *
309 *********************************************************************/
can_add_to_iob(const struct iob * iob,const size_t buffer_limit,size_t n)310 int can_add_to_iob(const struct iob *iob, const size_t buffer_limit, size_t n)
311 {
312 return ((size_t)(iob->eod - iob->buf) + n + 1) > buffer_limit ? FALSE : TRUE;
313 }
314
315 /*********************************************************************
316 *
317 * Function : add_to_iob
318 *
319 * Description : Add content to the buffer, expanding the
320 * buffer if necessary.
321 *
322 * Parameters :
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
327 *
328 * Returns : JB_ERR_OK on success, JB_ERR_MEMORY if out-of-memory
329 * or buffer limit reached.
330 *
331 *********************************************************************/
add_to_iob(struct iob * iob,const size_t buffer_limit,const char * src,long n)332 jb_err add_to_iob(struct iob *iob, const size_t buffer_limit, const char *src, long n)
333 {
334 size_t used, offset, need;
335 char *p;
336
337 if (n <= 0) return JB_ERR_OK;
338
339 used = (size_t)(iob->eod - iob->buf);
340 offset = (size_t)(iob->cur - iob->buf);
341 need = used + (size_t)n + 1;
342
343 /*
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.
346 */
347 if (need > buffer_limit)
348 {
349 log_error(LOG_LEVEL_INFO,
350 "Buffer limit reached while extending the buffer (iob). Needed: %lu. Limit: %lu",
351 need, buffer_limit);
352 return JB_ERR_MEMORY;
353 }
354
355 if (need > iob->size)
356 {
357 size_t want = iob->size ? iob->size : 512;
358
359 while (want <= need)
360 {
361 want *= 2;
362 }
363
364 if (want <= buffer_limit && NULL != (p = (char *)realloc(iob->buf, want)))
365 {
366 iob->size = want;
367 }
368 else if (NULL != (p = (char *)realloc(iob->buf, need)))
369 {
370 iob->size = need;
371 }
372 else
373 {
374 log_error(LOG_LEVEL_ERROR, "Extending the buffer (iob) failed: %E");
375 return JB_ERR_MEMORY;
376 }
377
378 /* Update the iob pointers */
379 iob->cur = p + offset;
380 iob->eod = p + used;
381 iob->buf = p;
382 }
383
384 /* copy the new data into the iob buffer */
385 memcpy(iob->eod, src, (size_t)n);
386
387 /* point to the end of the data */
388 iob->eod += n;
389
390 /* null terminate == cheap insurance */
391 *iob->eod = '\0';
392
393 return JB_ERR_OK;
394
395 }
396
397
398 /*********************************************************************
399 *
400 * Function : clear_iob
401 *
402 * Description : Frees the memory allocated for an I/O buffer and
403 * resets the structure.
404 *
405 * Parameters :
406 * 1 : iob = I/O buffer to clear.
407 *
408 * Returns : N/A
409 *
410 *********************************************************************/
clear_iob(struct iob * iob)411 void clear_iob(struct iob *iob)
412 {
413 free(iob->buf);
414 memset(iob, '\0', sizeof(*iob));
415 }
416
417
418 #ifdef FEATURE_ZLIB
419 #ifdef FEATURE_BROTLI
420 /*********************************************************************
421 *
422 * Function : decompress_iob_with_brotli
423 *
424 * Description : Decompress buffered page using Brotli.
425 *
426 * Parameters :
427 * 1 : csp = Current client state (buffers, headers, etc...)
428 *
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.
432 *
433 *********************************************************************/
decompress_iob_with_brotli(struct client_state * csp)434 static jb_err decompress_iob_with_brotli(struct client_state *csp)
435 {
436 BrotliDecoderResult result;
437 char *decoded_buffer;
438 size_t decoded_size;
439 size_t decoded_buffer_size;
440 size_t encoded_size;
441 enum { MAX_COMPRESSION_FACTOR = 15 };
442
443 encoded_size = (size_t)(csp->iob->eod - csp->iob->cur);
444 /*
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.
450 */
451 decoded_buffer_size = encoded_size * MAX_COMPRESSION_FACTOR;
452
453 if (decoded_buffer_size > csp->config->buffer_limit)
454 {
455 log_error(LOG_LEVEL_ERROR,
456 "Buffer limit reached before decompressing iob with Brotli");
457 return JB_ERR_MEMORY;
458 }
459
460 decoded_buffer = malloc(decoded_buffer_size);
461 if (decoded_buffer == NULL)
462 {
463 log_error(LOG_LEVEL_ERROR,
464 "Failed to allocate %lu bytes for Brotli decompression",
465 decoded_buffer_size);
466 return JB_ERR_MEMORY;
467 }
468
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)
474 {
475 /*
476 * Update the iob, since the decompression was successful.
477 */
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;
483
484 log_error(LOG_LEVEL_RE_FILTER,
485 "Decompression successful. Old size: %lu, new size: %lu.",
486 encoded_size, decoded_size);
487
488 return JB_ERR_OK;
489 }
490 else
491 {
492 log_error(LOG_LEVEL_ERROR, "Failed to decompress buffer with Brotli");
493 freez(decoded_buffer);
494
495 return JB_ERR_COMPRESS;
496 }
497 }
498 #endif
499
500 /*********************************************************************
501 *
502 * Function : decompress_iob
503 *
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.
508 *
509 * Parameters :
510 * 1 : csp = Current client state (buffers, headers, etc...)
511 *
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.
515 *
516 *********************************************************************/
decompress_iob(struct client_state * csp)517 jb_err decompress_iob(struct client_state *csp)
518 {
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 */
528
529 #ifdef FUZZ
530 assert(csp->iob->cur - csp->iob->buf >= 0);
531 assert(csp->iob->eod - csp->iob->cur >= 0);
532 #else
533 assert(csp->iob->cur - csp->iob->buf > 0);
534 assert(csp->iob->eod - csp->iob->cur > 0);
535 #endif
536
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);
540
541 cur = csp->iob->cur;
542
543 if (old_size < (size_t)10)
544 {
545 /*
546 * This is to protect the parsing of gzipped data,
547 * but it should(?) be valid for deflated data also.
548 */
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;
553 }
554
555 #ifdef FEATURE_BROTLI
556 if (csp->content_type & CT_BROTLI)
557 {
558 return decompress_iob_with_brotli(csp);
559 }
560 #endif
561
562 if (csp->content_type & CT_GZIP)
563 {
564 /*
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.
570 */
571
572 /*
573 * Strip off the gzip header. Please see RFC 1952 for more
574 * explanation of the appropriate fields.
575 */
576 if (((*cur++ & 0xff) != GZIP_IDENTIFIER_1)
577 || ((*cur++ & 0xff) != GZIP_IDENTIFIER_2)
578 || (*cur++ != Z_DEFLATED))
579 {
580 log_error(LOG_LEVEL_ERROR,
581 "Invalid gzip header when decompressing.");
582 return JB_ERR_COMPRESS;
583 }
584 else
585 {
586 int flags = *cur++;
587 if (flags & GZIP_FLAG_RESERVED_BITS)
588 {
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;
593 }
594
595 /*
596 * Skip mtime (4 bytes), extra flags (1 byte)
597 * and OS type (1 byte).
598 */
599 cur += 6;
600
601 /* Skip extra fields if necessary. */
602 if (flags & GZIP_FLAG_EXTRA_FIELDS)
603 {
604 /*
605 * Skip a given number of bytes, specified
606 * as a 16-bit little-endian value.
607 *
608 * XXX: this code is untested and should probably be removed.
609 */
610 int skip_bytes;
611
612 if (cur + 2 >= csp->iob->eod)
613 {
614 log_error(LOG_LEVEL_ERROR,
615 "gzip extra field flag set but insufficient data available.");
616 return JB_ERR_COMPRESS;
617 }
618
619 skip_bytes = *cur++;
620 skip_bytes += (unsigned char)*cur++ << 8;
621
622 /*
623 * The number of bytes to skip should be positive
624 * and we'd like to stay in the buffer.
625 */
626 if ((skip_bytes < 0) || (skip_bytes >= (csp->iob->eod - cur)))
627 {
628 log_error(LOG_LEVEL_ERROR,
629 "Unreasonable amount of bytes to skip (%d). "
630 "Stopping decompression.",
631 skip_bytes);
632 return JB_ERR_COMPRESS;
633 }
634 log_error(LOG_LEVEL_INFO,
635 "Skipping %d bytes for gzip compression. "
636 "Does this sound right?",
637 skip_bytes);
638 cur += skip_bytes;
639 }
640
641 /* Skip the filename if necessary. */
642 if (flags & GZIP_FLAG_FILE_NAME)
643 {
644 /* A null-terminated string is supposed to follow. */
645 while ((cur < csp->iob->eod) && *cur++);
646 }
647
648 /* Skip the comment if necessary. */
649 if (flags & GZIP_FLAG_COMMENT)
650 {
651 /* A null-terminated string is supposed to follow. */
652 while ((cur < csp->iob->eod) && *cur++);
653 }
654
655 /* Skip the CRC if necessary. */
656 if (flags & GZIP_FLAG_CHECKSUM)
657 {
658 cur += 2;
659 }
660
661 if (cur >= csp->iob->eod)
662 {
663 /*
664 * If the current position pointer reached or passed
665 * the buffer end, we were obviously tricked to skip
666 * too much.
667 */
668 log_error(LOG_LEVEL_ERROR,
669 "Malformed gzip header detected. Aborting decompression.");
670 return JB_ERR_COMPRESS;
671 }
672 }
673 }
674 else if (csp->content_type & CT_DEFLATE)
675 {
676 /*
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. :)
683 *
684 * We add a dummy null byte to tell zlib where the data ends,
685 * and later inform it not to expect a header.
686 *
687 * Fortunately, add_to_iob() has thoughtfully null-terminated
688 * the buffer; we can just increment the end pointer to include
689 * the dummy byte.
690 */
691 csp->iob->eod++;
692 }
693 else
694 {
695 log_error(LOG_LEVEL_ERROR,
696 "Unable to determine compression format for decompression.");
697 return JB_ERR_COMPRESS;
698 }
699
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;
704 zstr.zfree = Z_NULL;
705 zstr.opaque = Z_NULL;
706
707 /*
708 * Passing -MAX_WBITS to inflateInit2 tells the library
709 * that there is no zlib header.
710 */
711 if (inflateInit2(&zstr, -MAX_WBITS) != Z_OK)
712 {
713 log_error(LOG_LEVEL_ERROR, "Error initializing decompression.");
714 return JB_ERR_COMPRESS;
715 }
716
717 /*
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.
721 */
722 buf = zalloc(bufsize);
723 if (NULL == buf)
724 {
725 log_error(LOG_LEVEL_ERROR, "Out of memory decompressing iob.");
726 return JB_ERR_MEMORY;
727 }
728
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;
733
734 /* Try to decompress the whole stream in one shot. */
735 while (Z_BUF_ERROR == (status = inflate(&zstr, Z_FINISH)))
736 {
737 /* We need to allocate more memory for the output buffer. */
738
739 char *tmpbuf; /* used for realloc'ing the buffer */
740 size_t oldbufsize = bufsize; /* keep track of the old bufsize */
741
742 if (0 == zstr.avail_in)
743 {
744 /*
745 * If zlib wants more data then there's a problem, because
746 * the complete compressed file should have been buffered.
747 */
748 log_error(LOG_LEVEL_ERROR,
749 "Unexpected end of compressed iob. Using what we got so far.");
750 break;
751 }
752
753 /*
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.
758 */
759 if (bufsize >= csp->config->buffer_limit)
760 {
761 log_error(LOG_LEVEL_ERROR,
762 "Buffer limit reached while decompressing iob.");
763 freez(buf);
764 inflateEnd(&zstr);
765 return JB_ERR_MEMORY;
766 }
767
768 /* Try doubling the buffer size each time. */
769 bufsize *= 2;
770
771 /* Don't exceed the buffer limit. */
772 if (bufsize > csp->config->buffer_limit)
773 {
774 bufsize = csp->config->buffer_limit;
775 }
776
777 /* Try to allocate the new buffer. */
778 tmpbuf = realloc(buf, bufsize);
779 if (NULL == tmpbuf)
780 {
781 log_error(LOG_LEVEL_ERROR,
782 "Out of memory decompressing iob.");
783 freez(buf);
784 inflateEnd(&zstr);
785 return JB_ERR_MEMORY;
786 }
787 else
788 {
789 #ifndef NDEBUG
790 char *oldnext_out = (char *)zstr.next_out;
791 #endif
792 /*
793 * Update the fields for inflate() to use the new
794 * buffer, which may be in a location different from
795 * the old one.
796 */
797 zstr.avail_out += (uInt)(bufsize - oldbufsize);
798 zstr.next_out = (Bytef *)tmpbuf + bufsize - zstr.avail_out;
799
800 /*
801 * Compare with an uglier method of calculating these values
802 * that doesn't require the extra oldbufsize variable.
803 */
804 assert(zstr.avail_out == tmpbuf + bufsize - (char *)zstr.next_out);
805 assert((char *)zstr.next_out == tmpbuf + ((char *)oldnext_out - buf));
806
807 buf = tmpbuf;
808 }
809 }
810
811 if (Z_STREAM_ERROR == inflateEnd(&zstr))
812 {
813 log_error(LOG_LEVEL_ERROR,
814 "Inconsistent stream state after decompression: %s", zstr.msg);
815 /*
816 * XXX: Intentionally no return.
817 *
818 * According to zlib.h, Z_STREAM_ERROR is returned
819 * "if the stream state was inconsistent".
820 *
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.
824 */
825 }
826
827 if ((status != Z_STREAM_END) && (0 != zstr.avail_in))
828 {
829 /*
830 * We failed to decompress the stream and it's
831 * not simply because of missing data.
832 */
833 log_error(LOG_LEVEL_ERROR,
834 "Unexpected error while decompressing to the buffer (iob): %s",
835 zstr.msg);
836 freez(buf);
837 return JB_ERR_COMPRESS;
838 }
839
840 /*
841 * Finally, we can actually update the iob, since the
842 * decompression was successful. First, free the old
843 * buffer.
844 */
845 freez(csp->iob->buf);
846
847 /* Now, update the iob to use the new buffer. */
848 csp->iob->buf = buf;
849 csp->iob->cur = csp->iob->buf + skip_size;
850 csp->iob->eod = (char *)zstr.next_out;
851 csp->iob->size = bufsize;
852
853 /*
854 * Make sure the new uncompressed iob obeys some minimal
855 * consistency conditions.
856 */
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))
860 {
861 const size_t new_size = (size_t)(csp->iob->eod - csp->iob->cur);
862 if (new_size > (size_t)0)
863 {
864 log_error(LOG_LEVEL_RE_FILTER,
865 "Decompression successful. Old size: %lu, new size: %lu.",
866 old_size, new_size);
867 }
868 else
869 {
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.");
873 }
874 }
875 else
876 {
877 /* It seems that zlib did something weird. */
878 log_error(LOG_LEVEL_ERROR,
879 "Inconsistent buffer after decompression.");
880 return JB_ERR_COMPRESS;
881 }
882
883 return JB_ERR_OK;
884
885 }
886 #endif /* defined(FEATURE_ZLIB) */
887
888
889 /*********************************************************************
890 *
891 * Function : normalize_lws
892 *
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.
896 *
897 * Parameters :
898 * 1 : header = A header with linear whitespace to reduce.
899 *
900 * Returns : N/A
901 *
902 *********************************************************************/
normalize_lws(char * header)903 static void normalize_lws(char *header)
904 {
905 char *p = header;
906
907 while (*p != '\0')
908 {
909 if (privoxy_isspace(*p) && privoxy_isspace(*(p+1)))
910 {
911 char *q = p+1;
912
913 while (privoxy_isspace(*q))
914 {
915 q++;
916 }
917 log_error(LOG_LEVEL_HEADER, "Reducing whitespace in '%s'", header);
918 string_move(p+1, q);
919 }
920
921 if (*p == '\t')
922 {
923 log_error(LOG_LEVEL_HEADER,
924 "Converting tab to space in '%s'", header);
925 *p = ' ';
926 }
927 else if (*p == '"')
928 {
929 char *end_of_token = strstr(p+1, "\"");
930
931 if (NULL != end_of_token)
932 {
933 /* Don't mess with quoted text. */
934 p = end_of_token;
935 }
936 else
937 {
938 log_error(LOG_LEVEL_HEADER,
939 "Ignoring single quote in '%s'", header);
940 }
941 }
942 p++;
943 }
944
945 p = strchr(header, ':');
946 if ((p != NULL) && (p != header) && privoxy_isspace(*(p-1)))
947 {
948 /*
949 * There's still space before the colon.
950 * We don't want it.
951 */
952 string_move(p-1, p);
953 }
954 }
955
956
957 /*********************************************************************
958 *
959 * Function : get_header
960 *
961 * Description : This (odd) routine will parse the csp->iob
962 * to get the next complete header.
963 *
964 * Parameters :
965 * 1 : iob = The I/O buffer to parse, usually csp->iob.
966 *
967 * Returns : Any one of the following:
968 *
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.
973 *
974 *********************************************************************/
get_header(struct iob * iob)975 char *get_header(struct iob *iob)
976 {
977 char *header;
978
979 header = get_header_line(iob);
980
981 if ((header == NULL) || (*header == '\0'))
982 {
983 /*
984 * No complete header read yet, tell the client.
985 */
986 return header;
987 }
988
989 while ((iob->cur[0] == ' ') || (iob->cur[0] == '\t'))
990 {
991 /*
992 * Header spans multiple lines, append the next one.
993 */
994 char *continued_header;
995
996 continued_header = get_header_line(iob);
997 if ((continued_header == NULL) || (*continued_header == '\0'))
998 {
999 /*
1000 * No complete header read yet, return what we got.
1001 * XXX: Should "unread" header instead.
1002 */
1003 log_error(LOG_LEVEL_INFO,
1004 "Failed to read a multi-line header properly: '%s'",
1005 header);
1006 break;
1007 }
1008
1009 if (JB_ERR_OK != string_join(&header, continued_header))
1010 {
1011 log_error(LOG_LEVEL_FATAL,
1012 "Out of memory while appending multiple headers.");
1013 }
1014 else
1015 {
1016 /* XXX: remove before next stable release. */
1017 log_error(LOG_LEVEL_HEADER,
1018 "Merged multiple header lines to: '%s'",
1019 header);
1020 }
1021 }
1022
1023 normalize_lws(header);
1024
1025 return header;
1026
1027 }
1028
1029
1030 /*********************************************************************
1031 *
1032 * Function : get_header_line
1033 *
1034 * Description : This (odd) routine will parse the csp->iob
1035 * to get the next header line.
1036 *
1037 * Parameters :
1038 * 1 : iob = The I/O buffer to parse, usually csp->iob.
1039 *
1040 * Returns : Any one of the following:
1041 *
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.
1046 *
1047 *********************************************************************/
get_header_line(struct iob * iob)1048 static char *get_header_line(struct iob *iob)
1049 {
1050 char *p, *q, *ret;
1051
1052 if ((iob->cur == NULL)
1053 || ((p = strchr(iob->cur, '\n')) == NULL))
1054 {
1055 return(""); /* couldn't find a complete header */
1056 }
1057
1058 *p = '\0';
1059
1060 ret = strdup(iob->cur);
1061 if (ret == NULL)
1062 {
1063 /* FIXME No way to handle error properly */
1064 log_error(LOG_LEVEL_FATAL, "Out of memory in get_header_line()");
1065 }
1066 assert(ret != NULL);
1067
1068 iob->cur = p+1;
1069
1070 if ((q = strchr(ret, '\r')) != NULL) *q = '\0';
1071
1072 /* is this a blank line (i.e. the end of the header) ? */
1073 if (*ret == '\0')
1074 {
1075 freez(ret);
1076 return NULL;
1077 }
1078
1079 return ret;
1080
1081 }
1082
1083
1084 /*********************************************************************
1085 *
1086 * Function : get_header_value
1087 *
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.
1091 *
1092 * Parameters :
1093 * 1 : header_list = pointer to list
1094 * 2 : header_name = string with name of header to look for.
1095 * Trailing colon required, capitalization
1096 * doesn't matter.
1097 *
1098 * Returns : NULL if not found, else value of header
1099 *
1100 *********************************************************************/
get_header_value(const struct list * header_list,const char * header_name)1101 char *get_header_value(const struct list *header_list, const char *header_name)
1102 {
1103 struct list_entry *cur_entry;
1104 char *ret = NULL;
1105 size_t length = 0;
1106
1107 assert(header_list);
1108 assert(header_name);
1109 length = strlen(header_name);
1110
1111 for (cur_entry = header_list->first; cur_entry ; cur_entry = cur_entry->next)
1112 {
1113 if (cur_entry->str)
1114 {
1115 if (!strncmpic(cur_entry->str, header_name, length))
1116 {
1117 /*
1118 * Found: return pointer to start of value
1119 */
1120 ret = cur_entry->str + length;
1121 while (*ret && privoxy_isspace(*ret)) ret++;
1122 return ret;
1123 }
1124 }
1125 }
1126
1127 /*
1128 * Not found
1129 */
1130 return NULL;
1131
1132 }
1133
1134
1135 /*********************************************************************
1136 *
1137 * Function : scan_headers
1138 *
1139 * Description : Scans headers, applies tags and updates action bits.
1140 *
1141 * Parameters :
1142 * 1 : csp = Current client state (buffers, headers, etc...)
1143 *
1144 * Returns : JB_ERR_OK
1145 *
1146 *********************************************************************/
scan_headers(struct client_state * csp)1147 static jb_err scan_headers(struct client_state *csp)
1148 {
1149 struct list_entry *h; /* Header */
1150 jb_err err = JB_ERR_OK;
1151
1152 for (h = csp->headers->first; (err == JB_ERR_OK) && (h != NULL) ; h = h->next)
1153 {
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);
1158 }
1159
1160 return err;
1161 }
1162
1163
1164 /*********************************************************************
1165 *
1166 * Function : enforce_header_order
1167 *
1168 * Description : Enforces a given header order.
1169 *
1170 * Parameters :
1171 * 1 : headers = List of headers to order.
1172 * 2 : ordered_headers = List of ordered header names.
1173 *
1174 * Returns : N/A
1175 *
1176 *********************************************************************/
enforce_header_order(struct list * headers,const struct list * ordered_headers)1177 static void enforce_header_order(struct list *headers, const struct list *ordered_headers)
1178 {
1179 struct list_entry *sorted_header;
1180 struct list new_headers[1];
1181 struct list_entry *header;
1182
1183 init_list(new_headers);
1184
1185 /* The request line is always the first "header" */
1186
1187 assert(NULL != headers->first->str);
1188 enlist(new_headers, headers->first->str);
1189 freez(headers->first->str)
1190
1191 /* Enlist the specified headers in the given order */
1192
1193 for (sorted_header = ordered_headers->first; sorted_header != NULL;
1194 sorted_header = sorted_header->next)
1195 {
1196 const size_t sorted_header_length = strlen(sorted_header->str);
1197 for (header = headers->first; header != NULL; header = header->next)
1198 {
1199 /* Header enlisted in previous run? -> ignore */
1200 if (header->str == NULL) continue;
1201
1202 if (0 == strncmpic(sorted_header->str, header->str, sorted_header_length)
1203 && (header->str[sorted_header_length] == ':'))
1204 {
1205 log_error(LOG_LEVEL_HEADER, "Enlisting sorted header %s", header->str);
1206 if (JB_ERR_OK != enlist(new_headers, header->str))
1207 {
1208 log_error(LOG_LEVEL_HEADER, "Failed to enlist %s", header->str);
1209 }
1210 freez(header->str);
1211 }
1212 }
1213 }
1214
1215 /* Enlist the rest of the headers behind the ordered ones */
1216 for (header = headers->first; header != NULL; header = header->next)
1217 {
1218 /* Header enlisted in previous run? -> ignore */
1219 if (header->str == NULL) continue;
1220
1221 log_error(LOG_LEVEL_HEADER,
1222 "Enlisting left-over header %s", header->str);
1223 if (JB_ERR_OK != enlist(new_headers, header->str))
1224 {
1225 log_error(LOG_LEVEL_HEADER, "Failed to enlist %s", header->str);
1226 }
1227 freez(header->str);
1228 }
1229
1230 list_remove_all(headers);
1231 headers->first = new_headers->first;
1232 headers->last = new_headers->last;
1233
1234 return;
1235 }
1236
1237
1238 /*********************************************************************
1239 *
1240 * Function : sed
1241 *
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).
1246 *
1247 * As a side effect it frees the space used by the original
1248 * header lines.
1249 *
1250 * Parameters :
1251 * 1 : csp = Current client state (buffers, headers, etc...)
1252 * 2 : filter_server_headers = Boolean to switch between
1253 * server and header filtering.
1254 *
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.
1258 *
1259 *********************************************************************/
sed(struct client_state * csp,int filter_server_headers)1260 jb_err sed(struct client_state *csp, int filter_server_headers)
1261 {
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;
1267
1268 scan_headers(csp);
1269
1270 if (filter_server_headers)
1271 {
1272 v = server_patterns;
1273 f = add_server_headers;
1274 check_negative_tag_patterns(csp, PATTERN_SPEC_NO_RESPONSE_TAG_PATTERN);
1275 }
1276 else
1277 {
1278 v = client_patterns;
1279 f = add_client_headers;
1280 check_negative_tag_patterns(csp, PATTERN_SPEC_NO_REQUEST_TAG_PATTERN);
1281 }
1282
1283 while (v->str != NULL)
1284 {
1285 for (p = csp->headers->first; p != NULL; p = p->next)
1286 {
1287 /* Header crunch()ed in previous run? -> ignore */
1288 if (p->str == NULL) continue;
1289
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))
1293 {
1294 err = v->parser(csp, &(p->str));
1295 if (err != JB_ERR_OK)
1296 {
1297 return err;
1298 }
1299 }
1300 }
1301 v++;
1302 }
1303
1304 if (filter_server_headers &&
1305 (csp->flags & CSP_FLAG_SERVER_CONTENT_LENGTH_SET) &&
1306 (csp->flags & CSP_FLAG_CHUNKED))
1307 {
1308 /* RFC 2616 4.4 3 */
1309 log_error(LOG_LEVEL_HEADER, "Ignoring the Content-Length header "
1310 "sent by the server as the response is chunk-encoded.");
1311 csp->flags &= ~CSP_FLAG_CONTENT_LENGTH_SET;
1312 csp->expected_content_length = 0;
1313 }
1314
1315 /* place additional headers on the csp->headers list */
1316 while ((err == JB_ERR_OK) && (*f))
1317 {
1318 err = (*f)(csp);
1319 f++;
1320 }
1321
1322 if (!filter_server_headers &&
1323 !list_is_empty(csp->config->ordered_client_headers) &&
1324 csp->headers->first->str != NULL)
1325 {
1326 enforce_header_order(csp->headers, csp->config->ordered_client_headers);
1327 }
1328
1329 return err;
1330 }
1331
1332
1333 #ifdef FEATURE_HTTPS_INSPECTION
1334 /*********************************************************************
1335 *
1336 * Function : sed_https
1337 *
1338 * Description : add, delete or modify lines in the HTTPS client
1339 * header streams. Wrapper around sed().
1340 *
1341 * Parameters :
1342 * 1 : csp = Current client state (buffers, headers, etc...)
1343 *
1344 * Returns : JB_ERR_OK in case off success, or
1345 * JB_ERR_MEMORY on some out-of-memory errors, or
1346 * JB_ERR_PARSE in case of fatal parse errors.
1347 *
1348 *********************************************************************/
sed_https(struct client_state * csp)1349 jb_err sed_https(struct client_state *csp)
1350 {
1351 jb_err err;
1352 struct list headers;
1353
1354 /*
1355 * Temporarily replace csp->headers with csp->https_headers
1356 * to trick sed() into filtering the https headers.
1357 */
1358 headers.first = csp->headers->first;
1359 headers.last = csp->headers->last;
1360 csp->headers->first = csp->https_headers->first;
1361 csp->headers->last = csp->https_headers->last;
1362
1363 /*
1364 * Start with fresh tags. Already existing tags may
1365 * be set again. This is necessary to overrule
1366 * URL-based patterns.
1367 */
1368 destroy_list(csp->tags);
1369
1370 /*
1371 * We want client header filters and taggers
1372 * so temporarily remove the flag.
1373 */
1374 csp->flags &= ~CSP_FLAG_CLIENT_HEADER_PARSING_DONE;
1375 err = sed(csp, FILTER_CLIENT_HEADERS);
1376 csp->flags |= CSP_FLAG_CLIENT_HEADER_PARSING_DONE;
1377
1378 /*
1379 * Update the https headers list which may have
1380 * been modified due to header additions or header
1381 * reordering.
1382 */
1383 csp->https_headers->first = csp->headers->first;
1384 csp->https_headers->last = csp->headers->last;
1385
1386 csp->headers->first = headers.first;
1387 csp->headers->last = headers.last;
1388
1389 return err;
1390 }
1391 #endif /* def FEATURE_HTTPS_INSPECTION */
1392
1393
1394 /*********************************************************************
1395 *
1396 * Function : update_server_headers
1397 *
1398 * Description : Updates server headers after the body has been modified.
1399 *
1400 * Parameters :
1401 * 1 : csp = Current client state (buffers, headers, etc...)
1402 *
1403 * Returns : JB_ERR_OK in case off success, or
1404 * JB_ERR_MEMORY on out-of-memory error.
1405 *
1406 *********************************************************************/
update_server_headers(struct client_state * csp)1407 jb_err update_server_headers(struct client_state *csp)
1408 {
1409 jb_err err = JB_ERR_OK;
1410
1411 static const struct parsers server_patterns_light[] = {
1412 { "Content-Length:", 15, server_adjust_content_length },
1413 { "Transfer-Encoding:", 18, server_transfer_coding },
1414 #ifdef FEATURE_ZLIB
1415 { "Content-Encoding:", 17, server_adjust_content_encoding },
1416 #endif /* def FEATURE_ZLIB */
1417 { NULL, 0, NULL }
1418 };
1419
1420 if (strncmpic(csp->http->cmd, "HEAD", 4))
1421 {
1422 const struct parsers *v;
1423 struct list_entry *p;
1424
1425 for (v = server_patterns_light; (err == JB_ERR_OK) && (v->str != NULL); v++)
1426 {
1427 for (p = csp->headers->first; (err == JB_ERR_OK) && (p != NULL); p = p->next)
1428 {
1429 /* Header crunch()ed in previous run? -> ignore */
1430 if (p->str == NULL) continue;
1431
1432 /* Does the current parser handle this header? */
1433 if (strncmpic(p->str, v->str, v->len) == 0)
1434 {
1435 err = v->parser(csp, (char **)&(p->str));
1436 }
1437 }
1438 }
1439 }
1440
1441 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1442 if ((JB_ERR_OK == err)
1443 && (csp->flags & CSP_FLAG_MODIFIED)
1444 && (csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
1445 && !(csp->flags & CSP_FLAG_SERVER_CONTENT_LENGTH_SET))
1446 {
1447 char header[50];
1448
1449 create_content_length_header(csp->content_length, header, sizeof(header));
1450 err = enlist(csp->headers, header);
1451 if (JB_ERR_OK == err)
1452 {
1453 log_error(LOG_LEVEL_HEADER,
1454 "Content modified with no Content-Length header set. "
1455 "Created: %s.", header);
1456 csp->flags |= CSP_FLAG_SERVER_CONTENT_LENGTH_SET;
1457 }
1458 }
1459 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
1460
1461 #ifdef FEATURE_COMPRESSION
1462 if ((JB_ERR_OK == err)
1463 && (csp->flags & CSP_FLAG_BUFFERED_CONTENT_DEFLATED))
1464 {
1465 err = enlist_unique_header(csp->headers, "Content-Encoding", "deflate");
1466 if (JB_ERR_OK == err)
1467 {
1468 log_error(LOG_LEVEL_HEADER, "Added header: Content-Encoding: deflate");
1469 }
1470 }
1471 #endif
1472
1473 return err;
1474 }
1475
1476
1477 /*********************************************************************
1478 *
1479 * Function : header_tagger
1480 *
1481 * Description : Executes all text substitutions from applying
1482 * tag actions and saves the result as tag.
1483 *
1484 * XXX: Shares enough code with filter_header() and
1485 * pcrs_filter_response() to warrant some helper functions.
1486 *
1487 * Parameters :
1488 * 1 : csp = Current client state (buffers, headers, etc...)
1489 * 2 : header = Header that is used as tagger input
1490 *
1491 * Returns : JB_ERR_OK on success and always succeeds
1492 *
1493 *********************************************************************/
header_tagger(struct client_state * csp,char * header)1494 static jb_err header_tagger(struct client_state *csp, char *header)
1495 {
1496 enum filter_type wanted_filter_type;
1497 int multi_action_index;
1498 pcrs_job *job;
1499
1500 struct re_filterfile_spec *b;
1501 struct list_entry *tag_name;
1502
1503 const size_t header_length = strlen(header);
1504
1505 if (csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
1506 {
1507 wanted_filter_type = FT_SERVER_HEADER_TAGGER;
1508 multi_action_index = ACTION_MULTI_SERVER_HEADER_TAGGER;
1509 }
1510 else
1511 {
1512 wanted_filter_type = FT_CLIENT_HEADER_TAGGER;
1513 multi_action_index = ACTION_MULTI_CLIENT_HEADER_TAGGER;
1514 }
1515
1516 if (list_is_empty(csp->action->multi[multi_action_index])
1517 || filters_available(csp) == FALSE)
1518 {
1519 /* Return early if no taggers apply or if none are available. */
1520 return JB_ERR_OK;
1521 }
1522
1523 /* Execute all applying taggers */
1524 for (tag_name = csp->action->multi[multi_action_index]->first;
1525 NULL != tag_name; tag_name = tag_name->next)
1526 {
1527 char *modified_tag = NULL;
1528 char *tag = header;
1529 size_t size = header_length;
1530 pcrs_job *joblist;
1531
1532 b = get_filter(csp, tag_name->str, wanted_filter_type);
1533 if (b == NULL)
1534 {
1535 continue;
1536 }
1537
1538 joblist = b->joblist;
1539
1540 if (b->dynamic) joblist = compile_dynamic_pcrs_job_list(csp, b);
1541
1542 if (NULL == joblist)
1543 {
1544 log_error(LOG_LEVEL_TAGGING,
1545 "Tagger %s has empty joblist. Nothing to do.", b->name);
1546 continue;
1547 }
1548
1549 /* execute their pcrs_joblist on the header. */
1550 for (job = joblist; NULL != job; job = job->next)
1551 {
1552 const int hits = pcrs_execute(job, tag, size, &modified_tag, &size);
1553
1554 if (0 < hits)
1555 {
1556 /* Success, continue with the modified version. */
1557 if (tag != header)
1558 {
1559 freez(tag);
1560 }
1561 tag = modified_tag;
1562 }
1563 else
1564 {
1565 /* Tagger doesn't match */
1566 if (0 > hits)
1567 {
1568 /* Regex failure, log it but continue anyway. */
1569 assert(NULL != header);
1570 log_error(LOG_LEVEL_ERROR,
1571 "Problems with tagger \'%s\' and header \'%s\': %s",
1572 b->name, header, pcrs_strerror(hits));
1573 }
1574 freez(modified_tag);
1575 }
1576 }
1577
1578 if (b->dynamic) pcrs_free_joblist(joblist);
1579
1580 /* If this tagger matched */
1581 if (tag != header)
1582 {
1583 if (0 == size)
1584 {
1585 /*
1586 * There is no technical limitation which makes
1587 * it impossible to use empty tags, but I assume
1588 * no one would do it intentionally.
1589 */
1590 freez(tag);
1591 log_error(LOG_LEVEL_TAGGING,
1592 "Tagger \'%s\' created an empty tag. Ignored.", b->name);
1593 continue;
1594 }
1595
1596 if (list_contains_item(csp->action->multi[ACTION_MULTI_SUPPRESS_TAG], tag))
1597 {
1598 log_error(LOG_LEVEL_TAGGING,
1599 "Tagger \'%s\' didn't add tag \'%s\': suppressed",
1600 b->name, tag);
1601 freez(tag);
1602 continue;
1603 }
1604
1605 if (!list_contains_item(csp->tags, tag))
1606 {
1607 if (JB_ERR_OK != enlist(csp->tags, tag))
1608 {
1609 log_error(LOG_LEVEL_ERROR,
1610 "Insufficient memory to add tag \'%s\', "
1611 "based on tagger \'%s\' and header \'%s\'",
1612 tag, b->name, header);
1613 }
1614 else
1615 {
1616 char *action_message;
1617 /*
1618 * update the action bits right away, to make
1619 * tagging based on tags set by earlier taggers
1620 * of the same kind possible.
1621 */
1622 if (update_action_bits_for_tag(csp, tag))
1623 {
1624 action_message = "Action bits updated accordingly.";
1625 }
1626 else
1627 {
1628 action_message = "No action bits update necessary.";
1629 }
1630
1631 log_error(LOG_LEVEL_TAGGING,
1632 "Tagger \'%s\' added tag \'%s\'. %s",
1633 b->name, tag, action_message);
1634 }
1635 }
1636 else
1637 {
1638 /* XXX: Is this log-worthy? */
1639 log_error(LOG_LEVEL_TAGGING,
1640 "Tagger \'%s\' didn't add tag \'%s\'. Tag already present",
1641 b->name, tag);
1642 }
1643 freez(tag);
1644 }
1645 }
1646
1647 return JB_ERR_OK;
1648 }
1649
1650 /* here begins the family of parser functions that reformat header lines */
1651
1652 /*********************************************************************
1653 *
1654 * Function : filter_header
1655 *
1656 * Description : Executes all text substitutions from all applying
1657 * +(server|client)-header-filter actions on the header.
1658 * Most of the code was copied from pcrs_filter_response,
1659 * including the rather short variable names
1660 *
1661 * Parameters :
1662 * 1 : csp = Current client state (buffers, headers, etc...)
1663 * 2 : header = On input, pointer to header to modify.
1664 * On output, pointer to the modified header, or NULL
1665 * to remove the header. This function frees the
1666 * original string if necessary.
1667 *
1668 * Returns : JB_ERR_OK on success and always succeeds
1669 *
1670 *********************************************************************/
filter_header(struct client_state * csp,char ** header)1671 static jb_err filter_header(struct client_state *csp, char **header)
1672 {
1673 int hits=0;
1674 int matches;
1675 size_t size = strlen(*header);
1676
1677 char *newheader = NULL;
1678 pcrs_job *job;
1679
1680 struct re_filterfile_spec *b;
1681 struct list_entry *filtername;
1682
1683 enum filter_type wanted_filter_type;
1684 int multi_action_index;
1685
1686 if (csp->flags & CSP_FLAG_NO_FILTERING)
1687 {
1688 return JB_ERR_OK;
1689 }
1690
1691 if (csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
1692 {
1693 wanted_filter_type = FT_SERVER_HEADER_FILTER;
1694 multi_action_index = ACTION_MULTI_SERVER_HEADER_FILTER;
1695 }
1696 else
1697 {
1698 wanted_filter_type = FT_CLIENT_HEADER_FILTER;
1699 multi_action_index = ACTION_MULTI_CLIENT_HEADER_FILTER;
1700 }
1701
1702 if (list_is_empty(csp->action->multi[multi_action_index])
1703 || filters_available(csp) == FALSE)
1704 {
1705 /* Return early if no filters apply or if none are available. */
1706 return JB_ERR_OK;
1707 }
1708
1709 /* Execute all applying header filters */
1710 for (filtername = csp->action->multi[multi_action_index]->first;
1711 filtername != NULL; filtername = filtername->next)
1712 {
1713 int current_hits = 0;
1714 pcrs_job *joblist;
1715
1716 b = get_filter(csp, filtername->str, wanted_filter_type);
1717 if (b == NULL)
1718 {
1719 continue;
1720 }
1721
1722 joblist = b->joblist;
1723
1724 if (b->dynamic) joblist = compile_dynamic_pcrs_job_list(csp, b);
1725
1726 if (NULL == joblist)
1727 {
1728 log_error(LOG_LEVEL_RE_FILTER,
1729 "Filter %s has empty joblist. Nothing to do.", b->name);
1730 continue;
1731 }
1732
1733 log_error(LOG_LEVEL_RE_FILTER, "filtering \'%s\' (size %lu) with \'%s\' ...",
1734 *header, size, b->name);
1735
1736 /* Apply all jobs from the joblist */
1737 for (job = joblist; NULL != job; job = job->next)
1738 {
1739 matches = pcrs_execute(job, *header, size, &newheader, &size);
1740 if (0 < matches)
1741 {
1742 current_hits += matches;
1743 log_error(LOG_LEVEL_HEADER,
1744 "Transforming \"%s\" to \"%s\"", *header, newheader);
1745 freez(*header);
1746 *header = newheader;
1747 }
1748 else if (0 == matches)
1749 {
1750 /* Filter doesn't change header */
1751 freez(newheader);
1752 }
1753 else
1754 {
1755 /* RegEx failure */
1756 log_error(LOG_LEVEL_ERROR,
1757 "Filtering \'%s\' with \'%s\' didn't work out: %s",
1758 *header, b->name, pcrs_strerror(matches));
1759 if (newheader != NULL)
1760 {
1761 log_error(LOG_LEVEL_ERROR, "Freeing what's left: %s", newheader);
1762 freez(newheader);
1763 }
1764 }
1765 }
1766
1767 if (b->dynamic) pcrs_free_joblist(joblist);
1768
1769 log_error(LOG_LEVEL_RE_FILTER,
1770 "... produced %d hits (new size %lu).", current_hits, size);
1771 hits += current_hits;
1772 }
1773
1774 /*
1775 * Additionally checking for hits is important because if
1776 * the continue hack is triggered, server headers can
1777 * arrive empty to separate multiple heads from each other.
1778 */
1779 if ((0 == size) && hits)
1780 {
1781 log_error(LOG_LEVEL_HEADER, "Removing empty header %s", *header);
1782 freez(*header);
1783 }
1784
1785 return JB_ERR_OK;
1786 }
1787
1788
1789 /*********************************************************************
1790 *
1791 * Function : server_connection
1792 *
1793 * Description : Makes sure a proper "Connection:" header is
1794 * set and signals connection_header_adder to
1795 * do nothing.
1796 *
1797 * Parameters :
1798 * 1 : csp = Current client state (buffers, headers, etc...)
1799 * 2 : header = On input, pointer to header to modify.
1800 * On output, pointer to the modified header, or NULL
1801 * to remove the header. This function frees the
1802 * original string if necessary.
1803 *
1804 * Returns : JB_ERR_OK on success.
1805 *
1806 *********************************************************************/
server_connection(struct client_state * csp,char ** header)1807 static jb_err server_connection(struct client_state *csp, char **header)
1808 {
1809 if (!strcmpic(*header, "Connection: keep-alive")
1810 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1811 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
1812 #endif
1813 )
1814 {
1815 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1816 if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE))
1817 {
1818 csp->flags |= CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE;
1819 }
1820
1821 if ((csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE))
1822 {
1823 log_error(LOG_LEVEL_HEADER,
1824 "Keeping the server header '%s' around.", *header);
1825 }
1826 else
1827 #endif /* FEATURE_CONNECTION_KEEP_ALIVE */
1828 {
1829 char *old_header = *header;
1830
1831 *header = strdup_or_die("Connection: close");
1832 log_error(LOG_LEVEL_HEADER, "Replaced: \'%s\' with \'%s\'", old_header, *header);
1833 freez(old_header);
1834 }
1835 }
1836
1837 /* Signal server_connection_adder() to return early. */
1838 csp->flags |= CSP_FLAG_SERVER_CONNECTION_HEADER_SET;
1839
1840 return JB_ERR_OK;
1841 }
1842
1843
1844 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1845 /*********************************************************************
1846 *
1847 * Function : server_keep_alive
1848 *
1849 * Description : Stores the server's keep alive timeout.
1850 *
1851 * Parameters :
1852 * 1 : csp = Current client state (buffers, headers, etc...)
1853 * 2 : header = On input, pointer to header to modify.
1854 * On output, pointer to the modified header, or NULL
1855 * to remove the header. This function frees the
1856 * original string if necessary.
1857 *
1858 * Returns : JB_ERR_OK.
1859 *
1860 *********************************************************************/
server_keep_alive(struct client_state * csp,char ** header)1861 static jb_err server_keep_alive(struct client_state *csp, char **header)
1862 {
1863 unsigned int keep_alive_timeout;
1864 const char *timeout_position = strstr(*header, "timeout=");
1865
1866 if ((NULL == timeout_position)
1867 || (1 != sscanf(timeout_position, "timeout=%u", &keep_alive_timeout)))
1868 {
1869 log_error(LOG_LEVEL_ERROR, "Couldn't parse: %s", *header);
1870 }
1871 else
1872 {
1873 if (keep_alive_timeout < csp->server_connection.keep_alive_timeout)
1874 {
1875 log_error(LOG_LEVEL_HEADER,
1876 "Reducing keep-alive timeout from %u to %u.",
1877 csp->server_connection.keep_alive_timeout, keep_alive_timeout);
1878 csp->server_connection.keep_alive_timeout = keep_alive_timeout;
1879 }
1880 else
1881 {
1882 /* XXX: Is this log worthy? */
1883 log_error(LOG_LEVEL_HEADER,
1884 "Server keep-alive timeout is %u. Sticking with %u.",
1885 keep_alive_timeout, csp->server_connection.keep_alive_timeout);
1886 }
1887 csp->flags |= CSP_FLAG_SERVER_KEEP_ALIVE_TIMEOUT_SET;
1888 }
1889
1890 freez(*header);
1891
1892 return JB_ERR_OK;
1893 }
1894
1895
1896 /*********************************************************************
1897 *
1898 * Function : server_proxy_connection
1899 *
1900 * Description : Figures out whether or not we should add a
1901 * Proxy-Connection header.
1902 *
1903 * Parameters :
1904 * 1 : csp = Current client state (buffers, headers, etc...)
1905 * 2 : header = On input, pointer to header to modify.
1906 * On output, pointer to the modified header, or NULL
1907 * to remove the header. This function frees the
1908 * original string if necessary.
1909 *
1910 * Returns : JB_ERR_OK.
1911 *
1912 *********************************************************************/
server_proxy_connection(struct client_state * csp,char ** header)1913 static jb_err server_proxy_connection(struct client_state *csp, char **header)
1914 {
1915 csp->flags |= CSP_FLAG_SERVER_PROXY_CONNECTION_HEADER_SET;
1916 return JB_ERR_OK;
1917 }
1918 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
1919
1920
1921 /*********************************************************************
1922 *
1923 * Function : proxy_authentication
1924 *
1925 * Description : Removes headers that are relevant for proxy
1926 * authentication unless forwarding them has
1927 * been explicitly requested.
1928 *
1929 * Parameters :
1930 * 1 : csp = Current client state (buffers, headers, etc...)
1931 * 2 : header = On input, pointer to header to modify.
1932 * On output, pointer to the modified header, or NULL
1933 * to remove the header. This function frees the
1934 * original string if necessary.
1935 *
1936 * Returns : JB_ERR_OK.
1937 *
1938 *********************************************************************/
proxy_authentication(struct client_state * csp,char ** header)1939 static jb_err proxy_authentication(struct client_state *csp, char **header)
1940 {
1941 if ((csp->config->feature_flags &
1942 RUNTIME_FEATURE_FORWARD_PROXY_AUTHENTICATION_HEADERS) == 0) {
1943 log_error(LOG_LEVEL_HEADER,
1944 "Forwarding proxy authentication headers is disabled. Crunching: %s", *header);
1945 freez(*header);
1946 }
1947 return JB_ERR_OK;
1948 }
1949
1950
1951 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
1952 /*********************************************************************
1953 *
1954 * Function : client_keep_alive
1955 *
1956 * Description : Stores the client's keep alive timeout.
1957 *
1958 * Parameters :
1959 * 1 : csp = Current client state (buffers, headers, etc...)
1960 * 2 : header = On input, pointer to header to modify.
1961 * On output, pointer to the modified header, or NULL
1962 * to remove the header. This function frees the
1963 * original string if necessary.
1964 *
1965 * Returns : JB_ERR_OK.
1966 *
1967 *********************************************************************/
client_keep_alive(struct client_state * csp,char ** header)1968 static jb_err client_keep_alive(struct client_state *csp, char **header)
1969 {
1970 unsigned int keep_alive_timeout;
1971 char *timeout_position;
1972
1973 if (!(csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE))
1974 {
1975 log_error(LOG_LEVEL_HEADER,
1976 "keep-alive support is disabled. Crunching: %s.", *header);
1977 freez(*header);
1978 return JB_ERR_OK;
1979 }
1980
1981 /* Check for parameter-less format "Keep-Alive: 100" */
1982 timeout_position = strstr(*header, ": ");
1983 if ((NULL == timeout_position)
1984 || (1 != sscanf(timeout_position, ": %u", &keep_alive_timeout)))
1985 {
1986 /* Assume parameter format "Keep-Alive: timeout=100" */
1987 timeout_position = strstr(*header, "timeout=");
1988 if ((NULL == timeout_position)
1989 || (1 != sscanf(timeout_position, "timeout=%u", &keep_alive_timeout)))
1990 {
1991 log_error(LOG_LEVEL_HEADER,
1992 "Couldn't parse: '%s'. Using default timeout %u",
1993 *header, csp->config->keep_alive_timeout);
1994 freez(*header);
1995
1996 return JB_ERR_OK;
1997 }
1998 }
1999
2000 if (keep_alive_timeout < csp->config->keep_alive_timeout)
2001 {
2002 log_error(LOG_LEVEL_HEADER,
2003 "Reducing keep-alive timeout from %u to %u.",
2004 csp->config->keep_alive_timeout, keep_alive_timeout);
2005 csp->server_connection.keep_alive_timeout = keep_alive_timeout;
2006 }
2007 else
2008 {
2009 /* XXX: Is this log worthy? */
2010 log_error(LOG_LEVEL_HEADER,
2011 "Client keep-alive timeout is %u. Sticking with %u.",
2012 keep_alive_timeout, csp->config->keep_alive_timeout);
2013 freez(*header);
2014 }
2015
2016 return JB_ERR_OK;
2017 }
2018 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2019
2020
2021 /*********************************************************************
2022 *
2023 * Function : get_content_length
2024 *
2025 * Description : Gets the content length specified in a
2026 * Content-Length header.
2027 *
2028 * Parameters :
2029 * 1 : header_value = The Content-Length header value.
2030 * 2 : length = Storage to return the value.
2031 *
2032 * Returns : JB_ERR_OK on success, or
2033 * JB_ERR_PARSE if no value is recognized.
2034 *
2035 *********************************************************************/
get_content_length(const char * header_value,unsigned long long * length)2036 static jb_err get_content_length(const char *header_value, unsigned long long *length)
2037 {
2038 #ifdef _WIN32
2039 #if SIZEOF_LONG_LONG < 8
2040 #error sizeof(unsigned long long) too small
2041 #endif
2042 if (1 != sscanf(header_value, "%I64u", length))
2043 #else
2044 if (1 != sscanf(header_value, "%llu", length))
2045 #endif
2046 {
2047 return JB_ERR_PARSE;
2048 }
2049
2050 return JB_ERR_OK;
2051 }
2052
2053
2054 /*********************************************************************
2055 *
2056 * Function : client_save_content_length
2057 *
2058 * Description : Save the Content-Length sent by the client.
2059 *
2060 * Parameters :
2061 * 1 : csp = Current client state (buffers, headers, etc...)
2062 * 2 : header = pointer to the Content-Length header
2063 *
2064 * Returns : JB_ERR_OK on success, or
2065 * JB_ERR_MEMORY on out-of-memory error.
2066 *
2067 *********************************************************************/
client_save_content_length(struct client_state * csp,char ** header)2068 static jb_err client_save_content_length(struct client_state *csp, char **header)
2069 {
2070 unsigned long long content_length = 0;
2071 const char *header_value;
2072
2073 assert(*(*header+14) == ':');
2074
2075 header_value = *header + 15;
2076 if (JB_ERR_OK != get_content_length(header_value, &content_length))
2077 {
2078 log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
2079 freez(*header);
2080 }
2081 else
2082 {
2083 csp->expected_client_content_length = content_length;
2084 }
2085
2086 return JB_ERR_OK;
2087 }
2088
2089
2090 /*********************************************************************
2091 *
2092 * Function : client_connection
2093 *
2094 * Description : Makes sure a proper "Connection:" header is
2095 * set and signals connection_header_adder
2096 * to do nothing.
2097 *
2098 * Parameters :
2099 * 1 : csp = Current client state (buffers, headers, etc...)
2100 * 2 : header = On input, pointer to header to modify.
2101 * On output, pointer to the modified header, or NULL
2102 * to remove the header. This function frees the
2103 * original string if necessary.
2104 *
2105 * Returns : JB_ERR_OK on success.
2106 *
2107 *********************************************************************/
client_connection(struct client_state * csp,char ** header)2108 static jb_err client_connection(struct client_state *csp, char **header)
2109 {
2110 static const char connection_close[] = "Connection: close";
2111
2112 if (!strcmpic(*header, connection_close))
2113 {
2114 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2115 if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
2116 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
2117 #ifdef FEATURE_HTTPS_INSPECTION
2118 && !client_use_ssl(csp)
2119 #endif
2120 )
2121 {
2122 if (!strcmpic(csp->http->version, "HTTP/1.1"))
2123 {
2124 log_error(LOG_LEVEL_HEADER,
2125 "Removing \'%s\' to imply keep-alive.", *header);
2126 freez(*header);
2127 /*
2128 * While we imply keep-alive to the server,
2129 * we have to remember that the client didn't.
2130 */
2131 csp->flags &= ~CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
2132 }
2133 else
2134 {
2135 char *old_header = *header;
2136
2137 *header = strdup_or_die("Connection: keep-alive");
2138 log_error(LOG_LEVEL_HEADER,
2139 "Replaced: \'%s\' with \'%s\'", old_header, *header);
2140 freez(old_header);
2141 }
2142 }
2143 else
2144 {
2145 log_error(LOG_LEVEL_HEADER,
2146 "Keeping the client header '%s' around. "
2147 "The connection will not be kept alive.",
2148 *header);
2149 csp->flags &= ~CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
2150 }
2151 }
2152 else if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
2153 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED))
2154 {
2155 log_error(LOG_LEVEL_HEADER,
2156 "Keeping the client header '%s' around. "
2157 "The server connection will be kept alive if possible.",
2158 *header);
2159 csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
2160 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2161 }
2162 else
2163 {
2164 char *old_header = *header;
2165
2166 *header = strdup_or_die(connection_close);
2167 log_error(LOG_LEVEL_HEADER,
2168 "Replaced: \'%s\' with \'%s\'", old_header, *header);
2169 freez(old_header);
2170 }
2171
2172 /* Signal client_connection_header_adder() to return early. */
2173 csp->flags |= CSP_FLAG_CLIENT_CONNECTION_HEADER_SET;
2174
2175 return JB_ERR_OK;
2176 }
2177
2178
2179 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2180 /*********************************************************************
2181 *
2182 * Function : client_proxy_connection
2183 *
2184 * Description : Sets the CLIENT_CONNECTION_KEEP_ALIVE flag when
2185 * appropriate and removes the Proxy-Connection
2186 * header.
2187 *
2188 * Parameters :
2189 * 1 : csp = Current client state (buffers, headers, etc...)
2190 * 2 : header = On input, pointer to header to modify.
2191 * On output, pointer to the modified header, or NULL
2192 * to remove the header. This function frees the
2193 * original string if necessary.
2194 *
2195 * Returns : JB_ERR_OK
2196 *
2197 *********************************************************************/
client_proxy_connection(struct client_state * csp,char ** header)2198 static jb_err client_proxy_connection(struct client_state *csp, char **header)
2199 {
2200 if (0 == (csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
2201 && (csp->http->ssl == 0)
2202 && (NULL == strstr(*header, "close")))
2203 {
2204 log_error(LOG_LEVEL_HEADER,
2205 "The client connection can be kept alive due to: %s", *header);
2206 csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
2207 }
2208 crumble(csp, header);
2209
2210 return JB_ERR_OK;
2211 }
2212 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2213
2214
2215 /*********************************************************************
2216 *
2217 * Function : client_transfer_encoding
2218 *
2219 * Description : Raise the CSP_FLAG_CHUNKED_CLIENT_BODY flag if
2220 * the request body is "chunked"
2221 *
2222 * XXX: Currently not called through sed() as we
2223 * need the flag earlier on. Should be fixed.
2224 *
2225 * Parameters :
2226 * 1 : csp = Current client state (buffers, headers, etc...)
2227 * 2 : header = On input, pointer to header to modify.
2228 * On output, pointer to the modified header, or NULL
2229 * to remove the header. This function frees the
2230 * original string if necessary.
2231 *
2232 * Returns : JB_ERR_OK on success, or
2233 *
2234 *********************************************************************/
client_transfer_encoding(struct client_state * csp,char ** header)2235 jb_err client_transfer_encoding(struct client_state *csp, char **header)
2236 {
2237 if (strstr(*header, "chunked"))
2238 {
2239 csp->flags |= CSP_FLAG_CHUNKED_CLIENT_BODY;
2240 log_error(LOG_LEVEL_HEADER, "Expecting chunked client body");
2241 }
2242
2243 return JB_ERR_OK;
2244 }
2245
2246
2247 /*********************************************************************
2248 *
2249 * Function : client_expect
2250 *
2251 * Description : Raise the CSP_FLAG_UNSUPPORTED_CLIENT_EXPECTATION
2252 * if the Expect header value is unsupported.
2253 *
2254 * Rejecting unsupported expectations is a RFC 7231 5.1.1
2255 * MAY and a RFC 2616 (obsolete) MUST.
2256 *
2257 * Parameters :
2258 * 1 : csp = Current client state (buffers, headers, etc...)
2259 * 2 : header = On input, pointer to header to modify.
2260 * On output, pointer to the modified header, or NULL
2261 * to remove the header. This function frees the
2262 * original string if necessary.
2263 *
2264 * Returns : JB_ERR_OK on success, or
2265 *
2266 *********************************************************************/
client_expect(struct client_state * csp,char ** header)2267 jb_err client_expect(struct client_state *csp, char **header)
2268 {
2269 if (0 != strcmpic(*header, "Expect: 100-continue"))
2270 {
2271 csp->flags |= CSP_FLAG_UNSUPPORTED_CLIENT_EXPECTATION;
2272 log_error(LOG_LEVEL_HEADER,
2273 "Unsupported client expectaction: %s", *header);
2274 }
2275
2276 return JB_ERR_OK;
2277
2278 }
2279
2280
2281 /*********************************************************************
2282 *
2283 * Function : crumble
2284 *
2285 * Description : This is called if a header matches a pattern to "crunch"
2286 *
2287 * Parameters :
2288 * 1 : csp = Current client state (buffers, headers, etc...)
2289 * 2 : header = On input, pointer to header to modify.
2290 * On output, pointer to the modified header, or NULL
2291 * to remove the header. This function frees the
2292 * original string if necessary.
2293 *
2294 * Returns : JB_ERR_OK on success, or
2295 * JB_ERR_MEMORY on out-of-memory error.
2296 *
2297 *********************************************************************/
crumble(struct client_state * csp,char ** header)2298 static jb_err crumble(struct client_state *csp, char **header)
2299 {
2300 (void)csp;
2301 log_error(LOG_LEVEL_HEADER, "crumble crunched: %s!", *header);
2302 freez(*header);
2303 return JB_ERR_OK;
2304 }
2305
2306
2307 /*********************************************************************
2308 *
2309 * Function : crunch_server_header
2310 *
2311 * Description : Crunch server header if it matches a string supplied by the
2312 * user. Called from `sed'.
2313 *
2314 * Parameters :
2315 * 1 : csp = Current client state (buffers, headers, etc...)
2316 * 2 : header = On input, pointer to header to modify.
2317 * On output, pointer to the modified header, or NULL
2318 * to remove the header. This function frees the
2319 * original string if necessary.
2320 *
2321 * Returns : JB_ERR_OK on success and always succeeds
2322 *
2323 *********************************************************************/
crunch_server_header(struct client_state * csp,char ** header)2324 static jb_err crunch_server_header(struct client_state *csp, char **header)
2325 {
2326 const char *crunch_pattern;
2327
2328 /* Do we feel like crunching? */
2329 if ((csp->action->flags & ACTION_CRUNCH_SERVER_HEADER))
2330 {
2331 crunch_pattern = csp->action->string[ACTION_STRING_SERVER_HEADER];
2332
2333 /* Is the current header the lucky one? */
2334 if (strstr(*header, crunch_pattern))
2335 {
2336 log_error(LOG_LEVEL_HEADER, "Crunching server header: %s (contains: %s)", *header, crunch_pattern);
2337 freez(*header);
2338 }
2339 }
2340
2341 return JB_ERR_OK;
2342 }
2343
2344
2345 /*********************************************************************
2346 *
2347 * Function : server_content_type
2348 *
2349 * Description : Set the content-type for filterable types (text/.*,
2350 * .*xml.*, .*script.* and image/gif) unless filtering has been
2351 * forbidden (CT_TABOO) while parsing earlier headers.
2352 * NOTE: Since text/plain is commonly used by web servers
2353 * for files whose correct type is unknown, we don't
2354 * set CT_TEXT for it.
2355 *
2356 * Parameters :
2357 * 1 : csp = Current client state (buffers, headers, etc...)
2358 * 2 : header = On input, pointer to header to modify.
2359 * On output, pointer to the modified header, or NULL
2360 * to remove the header. This function frees the
2361 * original string if necessary.
2362 *
2363 * Returns : JB_ERR_OK on success, or
2364 * JB_ERR_MEMORY on out-of-memory error.
2365 *
2366 *********************************************************************/
server_content_type(struct client_state * csp,char ** header)2367 static jb_err server_content_type(struct client_state *csp, char **header)
2368 {
2369 /* Remove header if it isn't the first Content-Type header */
2370 if ((csp->content_type & CT_DECLARED))
2371 {
2372 if (content_filters_enabled(csp->action))
2373 {
2374 /*
2375 * Making sure the client interprets the content the same way
2376 * Privoxy did is only relevant if Privoxy modified it.
2377 *
2378 * Checking for this is "hard" as it's not yet known when
2379 * this function is called, thus go shopping and and just
2380 * check if Privoxy could filter it.
2381 *
2382 * The main thing is that we don't mess with the headers
2383 * unless the user signalled that it's acceptable.
2384 */
2385 log_error(LOG_LEVEL_HEADER,
2386 "Multiple Content-Type headers detected. "
2387 "Removing and ignoring: %s",
2388 *header);
2389 freez(*header);
2390 }
2391 return JB_ERR_OK;
2392 }
2393
2394 /*
2395 * Signal that the Content-Type has been set.
2396 */
2397 csp->content_type |= CT_DECLARED;
2398
2399 if (!(csp->content_type & CT_TABOO))
2400 {
2401 /*
2402 * XXX: The assumption that text/plain is a sign of
2403 * binary data seems to be somewhat unreasonable nowadays
2404 * and should be dropped after 3.0.8 is out.
2405 */
2406 if ((strstr(*header, "text/") && !strstr(*header, "plain"))
2407 || strstr(*header, "xml")
2408 || strstr(*header, "script"))
2409 {
2410 csp->content_type |= CT_TEXT;
2411 }
2412 else if (strstr(*header, "image/gif"))
2413 {
2414 csp->content_type |= CT_GIF;
2415 }
2416 }
2417
2418 /*
2419 * Are we messing with the content type?
2420 */
2421 if (csp->action->flags & ACTION_CONTENT_TYPE_OVERWRITE)
2422 {
2423 /*
2424 * Make sure the user doesn't accidentally
2425 * change the content type of binary documents.
2426 */
2427 if ((csp->content_type & CT_TEXT) || (csp->action->flags & ACTION_FORCE_TEXT_MODE))
2428 {
2429 jb_err err;
2430 freez(*header);
2431 *header = strdup_or_die("Content-Type: ");
2432
2433 err = string_append(header, csp->action->string[ACTION_STRING_CONTENT_TYPE]);
2434 if (JB_ERR_OK != err)
2435 {
2436 log_error(LOG_LEVEL_HEADER, "Insufficient memory to replace Content-Type!");
2437 return JB_ERR_MEMORY;
2438 }
2439 log_error(LOG_LEVEL_HEADER, "Modified: %s!", *header);
2440 }
2441 else
2442 {
2443 log_error(LOG_LEVEL_HEADER, "%s not replaced. "
2444 "It doesn't look like a content type that should be filtered. "
2445 "Enable force-text-mode if you know what you're doing.", *header);
2446 }
2447 }
2448
2449 return JB_ERR_OK;
2450 }
2451
2452
2453 /*********************************************************************
2454 *
2455 * Function : server_transfer_coding
2456 *
2457 * Description : - Prohibit filtering (CT_TABOO) if transfer coding compresses
2458 * - Raise the CSP_FLAG_CHUNKED flag if coding is "chunked"
2459 * - Remove header if body was chunked but has been
2460 * de-chunked for filtering.
2461 *
2462 * Parameters :
2463 * 1 : csp = Current client state (buffers, headers, etc...)
2464 * 2 : header = On input, pointer to header to modify.
2465 * On output, pointer to the modified header, or NULL
2466 * to remove the header. This function frees the
2467 * original string if necessary.
2468 *
2469 * Returns : JB_ERR_OK on success, or
2470 * JB_ERR_MEMORY on out-of-memory error.
2471 *
2472 *********************************************************************/
server_transfer_coding(struct client_state * csp,char ** header)2473 static jb_err server_transfer_coding(struct client_state *csp, char **header)
2474 {
2475 /*
2476 * Turn off pcrs and gif filtering if body compressed
2477 */
2478 if (strstr(*header, "gzip") || strstr(*header, "compress") || strstr(*header, "deflate"))
2479 {
2480 #ifdef FEATURE_ZLIB
2481 /*
2482 * XXX: Added to test if we could use CT_GZIP and CT_DEFLATE here.
2483 */
2484 log_error(LOG_LEVEL_INFO, "Marking content type for %s as CT_TABOO because of %s.",
2485 csp->http->cmd, *header);
2486 #endif /* def FEATURE_ZLIB */
2487 csp->content_type = CT_TABOO;
2488 }
2489
2490 /*
2491 * Raise flag if body chunked
2492 */
2493 if (strstr(*header, "chunked"))
2494 {
2495 csp->flags |= CSP_FLAG_CHUNKED;
2496
2497 /*
2498 * If the body was modified, it has been de-chunked first
2499 * and the header must be removed.
2500 *
2501 * FIXME: If there is more than one transfer encoding,
2502 * only the "chunked" part should be removed here.
2503 */
2504 if (csp->flags & CSP_FLAG_MODIFIED)
2505 {
2506 log_error(LOG_LEVEL_HEADER, "Removing: %s", *header);
2507 freez(*header);
2508 }
2509 }
2510
2511 return JB_ERR_OK;
2512 }
2513
2514
2515 /*********************************************************************
2516 *
2517 * Function : server_content_encoding
2518 *
2519 * Description : Used to check if the content is compressed, and if
2520 * FEATURE_ZLIB is disabled, filtering is disabled as
2521 * well.
2522 *
2523 * If FEATURE_ZLIB is enabled and the compression type
2524 * supported, the content is marked for decompression.
2525 *
2526 * XXX: Doesn't properly deal with multiple or with
2527 * unsupported but unknown encodings.
2528 * Is case-sensitive but shouldn't be.
2529 *
2530 * Parameters :
2531 * 1 : csp = Current client state (buffers, headers, etc...)
2532 * 2 : header = On input, pointer to header to modify.
2533 * On output, pointer to the modified header, or NULL
2534 * to remove the header. This function frees the
2535 * original string if necessary.
2536 *
2537 * Returns : JB_ERR_OK on success, or
2538 * JB_ERR_MEMORY on out-of-memory error.
2539 *
2540 *********************************************************************/
server_content_encoding(struct client_state * csp,char ** header)2541 static jb_err server_content_encoding(struct client_state *csp, char **header)
2542 {
2543 #ifdef FEATURE_ZLIB
2544 if (strstr(*header, "sdch"))
2545 {
2546 /*
2547 * Shared Dictionary Compression over HTTP isn't supported,
2548 * filtering it anyway is pretty much guaranteed to mess up
2549 * the encoding.
2550 */
2551 csp->content_type |= CT_TABOO;
2552
2553 /*
2554 * Log a warning if the user expects the content to be filtered.
2555 */
2556 if (content_filters_enabled(csp->action))
2557 {
2558 log_error(LOG_LEVEL_INFO,
2559 "SDCH-compressed content detected, content filtering disabled. "
2560 "Consider suppressing SDCH offers made by the client.");
2561 }
2562 }
2563 else if (strstr(*header, "gzip"))
2564 {
2565 /* Mark for gzip decompression */
2566 csp->content_type |= CT_GZIP;
2567 }
2568 else if (strstr(*header, "deflate"))
2569 {
2570 /* Mark for zlib decompression */
2571 csp->content_type |= CT_DEFLATE;
2572 }
2573 else if (strstr(*header, "br"))
2574 {
2575 #ifdef FEATURE_BROTLI
2576 /* Mark for Brotli decompression */
2577 csp->content_type |= CT_BROTLI;
2578 #else
2579 csp->content_type |= CT_TABOO;
2580 #endif
2581 }
2582 else if (strstr(*header, "compress"))
2583 {
2584 /*
2585 * We can't decompress this; therefore we can't filter
2586 * it either.
2587 */
2588 csp->content_type |= CT_TABOO;
2589 }
2590 #else /* !defined(FEATURE_ZLIB) */
2591 /*
2592 * XXX: Using a black list here isn't the right approach.
2593 *
2594 * In case of SDCH, building with zlib support isn't
2595 * going to help.
2596 */
2597 if (strstr(*header, "gzip") ||
2598 strstr(*header, "compress") ||
2599 strstr(*header, "deflate") ||
2600 strstr(*header, "sdch"))
2601 {
2602 /*
2603 * Body is compressed, turn off pcrs and gif filtering.
2604 */
2605 csp->content_type |= CT_TABOO;
2606
2607 /*
2608 * Log a warning if the user expects the content to be filtered.
2609 */
2610 if (content_filters_enabled(csp->action))
2611 {
2612 log_error(LOG_LEVEL_INFO,
2613 "Compressed content detected, content filtering disabled. "
2614 "Consider recompiling Privoxy with zlib support or "
2615 "enable the prevent-compression action.");
2616 }
2617 }
2618 #endif /* defined(FEATURE_ZLIB) */
2619
2620 return JB_ERR_OK;
2621
2622 }
2623
2624
2625 #ifdef FEATURE_ZLIB
2626 /*********************************************************************
2627 *
2628 * Function : server_adjust_content_encoding
2629 *
2630 * Description : Remove the Content-Encoding header if the
2631 * decompression was successful and the content
2632 * has been modified.
2633 *
2634 * Parameters :
2635 * 1 : csp = Current client state (buffers, headers, etc...)
2636 * 2 : header = On input, pointer to header to modify.
2637 * On output, pointer to the modified header, or NULL
2638 * to remove the header. This function frees the
2639 * original string if necessary.
2640 *
2641 * Returns : JB_ERR_OK on success, or
2642 * JB_ERR_MEMORY on out-of-memory error.
2643 *
2644 *********************************************************************/
server_adjust_content_encoding(struct client_state * csp,char ** header)2645 static jb_err server_adjust_content_encoding(struct client_state *csp, char **header)
2646 {
2647 if ((csp->flags & CSP_FLAG_MODIFIED)
2648 && ((csp->content_type & (CT_GZIP | CT_DEFLATE))
2649 #ifdef FEATURE_BROTLI
2650 || (csp->content_type & CT_BROTLI)
2651 #endif
2652 )
2653 )
2654 {
2655 /*
2656 * We successfully decompressed the content,
2657 * and have to clean the header now, so the
2658 * client no longer expects compressed data.
2659 *
2660 * XXX: There is a difference between cleaning
2661 * and removing it completely.
2662 */
2663 log_error(LOG_LEVEL_HEADER, "Crunching: %s", *header);
2664 freez(*header);
2665 }
2666
2667 return JB_ERR_OK;
2668
2669 }
2670 #endif /* defined(FEATURE_ZLIB) */
2671
2672
2673 /*********************************************************************
2674 *
2675 * Function : header_adjust_content_length
2676 *
2677 * Description : Replace given header with new Content-Length header.
2678 *
2679 * Parameters :
2680 * 1 : header = On input, pointer to header to modify.
2681 * On output, pointer to the modified header, or NULL
2682 * to remove the header. This function frees the
2683 * original string if necessary.
2684 * 2 : content_length = content length value to set
2685 *
2686 * Returns : JB_ERR_OK on success, or
2687 * JB_ERR_MEMORY on out-of-memory error.
2688 *
2689 *********************************************************************/
header_adjust_content_length(char ** header,size_t content_length)2690 jb_err header_adjust_content_length(char **header, size_t content_length)
2691 {
2692 const size_t header_length = 50;
2693 freez(*header);
2694 *header = malloc(header_length);
2695 if (*header == NULL)
2696 {
2697 return JB_ERR_MEMORY;
2698 }
2699 create_content_length_header(content_length, *header, header_length);
2700 return JB_ERR_OK;
2701 }
2702
2703
2704 /*********************************************************************
2705 *
2706 * Function : server_adjust_content_length
2707 *
2708 * Description : Adjust Content-Length header if we modified
2709 * the body.
2710 *
2711 * Parameters :
2712 * 1 : csp = Current client state (buffers, headers, etc...)
2713 * 2 : header = On input, pointer to header to modify.
2714 * On output, pointer to the modified header, or NULL
2715 * to remove the header. This function frees the
2716 * original string if necessary.
2717 *
2718 * Returns : JB_ERR_OK on success, or
2719 * JB_ERR_MEMORY on out-of-memory error.
2720 *
2721 *********************************************************************/
server_adjust_content_length(struct client_state * csp,char ** header)2722 static jb_err server_adjust_content_length(struct client_state *csp, char **header)
2723 {
2724 /* Regenerate header if the content was modified. */
2725 if (csp->flags & CSP_FLAG_MODIFIED)
2726 {
2727 if (JB_ERR_OK != header_adjust_content_length(header, csp->content_length))
2728 {
2729 return JB_ERR_MEMORY;
2730 }
2731 log_error(LOG_LEVEL_HEADER,
2732 "Adjusted Content-Length to %llu", csp->content_length);
2733 }
2734
2735 return JB_ERR_OK;
2736 }
2737
2738
2739 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
2740 /*********************************************************************
2741 *
2742 * Function : server_save_content_length
2743 *
2744 * Description : Save the Content-Length sent by the server.
2745 *
2746 * Parameters :
2747 * 1 : csp = Current client state (buffers, headers, etc...)
2748 * 2 : header = On input, pointer to header to modify.
2749 * On output, pointer to the modified header, or NULL
2750 * to remove the header. This function frees the
2751 * original string if necessary.
2752 *
2753 * Returns : JB_ERR_OK on success, or
2754 * JB_ERR_MEMORY on out-of-memory error.
2755 *
2756 *********************************************************************/
server_save_content_length(struct client_state * csp,char ** header)2757 static jb_err server_save_content_length(struct client_state *csp, char **header)
2758 {
2759 unsigned long long content_length = 0;
2760 const char *header_value;
2761
2762 assert(*(*header+14) == ':');
2763
2764 header_value = *header + 15;
2765 if (JB_ERR_OK != get_content_length(header_value, &content_length))
2766 {
2767 log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
2768 freez(*header);
2769 }
2770 else
2771 {
2772 csp->expected_content_length = content_length;
2773 csp->flags |= CSP_FLAG_SERVER_CONTENT_LENGTH_SET;
2774 csp->flags |= CSP_FLAG_CONTENT_LENGTH_SET;
2775 }
2776
2777 return JB_ERR_OK;
2778 }
2779 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
2780
2781
2782 /*********************************************************************
2783 *
2784 * Function : server_content_md5
2785 *
2786 * Description : Crumble any Content-MD5 headers if the document was
2787 * modified. FIXME: Should we re-compute instead?
2788 *
2789 * Parameters :
2790 * 1 : csp = Current client state (buffers, headers, etc...)
2791 * 2 : header = On input, pointer to header to modify.
2792 * On output, pointer to the modified header, or NULL
2793 * to remove the header. This function frees the
2794 * original string if necessary.
2795 *
2796 * Returns : JB_ERR_OK on success, or
2797 * JB_ERR_MEMORY on out-of-memory error.
2798 *
2799 *********************************************************************/
server_content_md5(struct client_state * csp,char ** header)2800 static jb_err server_content_md5(struct client_state *csp, char **header)
2801 {
2802 if (csp->flags & CSP_FLAG_MODIFIED)
2803 {
2804 log_error(LOG_LEVEL_HEADER, "Crunching Content-MD5");
2805 freez(*header);
2806 }
2807
2808 return JB_ERR_OK;
2809 }
2810
2811
2812 /*********************************************************************
2813 *
2814 * Function : server_content_disposition
2815 *
2816 * Description : If enabled, blocks or modifies the "Content-Disposition" header.
2817 * Called from `sed'.
2818 *
2819 * Parameters :
2820 * 1 : csp = Current client state (buffers, headers, etc...)
2821 * 2 : header = On input, pointer to header to modify.
2822 * On output, pointer to the modified header, or NULL
2823 * to remove the header. This function frees the
2824 * original string if necessary.
2825 *
2826 * Returns : JB_ERR_OK on success, or
2827 * JB_ERR_MEMORY on out-of-memory error.
2828 *
2829 *********************************************************************/
server_content_disposition(struct client_state * csp,char ** header)2830 static jb_err server_content_disposition(struct client_state *csp, char **header)
2831 {
2832 const char *newval;
2833
2834 /*
2835 * Are we messing with the Content-Disposition header?
2836 */
2837 if ((csp->action->flags & ACTION_HIDE_CONTENT_DISPOSITION) == 0)
2838 {
2839 /* Me tinks not */
2840 return JB_ERR_OK;
2841 }
2842
2843 newval = csp->action->string[ACTION_STRING_CONTENT_DISPOSITION];
2844
2845 if ((newval == NULL) || (0 == strcmpic(newval, "block")))
2846 {
2847 /*
2848 * Blocking content-disposition header
2849 */
2850 log_error(LOG_LEVEL_HEADER, "Crunching %s!", *header);
2851 freez(*header);
2852 return JB_ERR_OK;
2853 }
2854 else
2855 {
2856 /*
2857 * Replacing Content-Disposition header
2858 */
2859 freez(*header);
2860 *header = strdup("Content-Disposition: ");
2861 string_append(header, newval);
2862
2863 if (*header != NULL)
2864 {
2865 log_error(LOG_LEVEL_HEADER,
2866 "Content-Disposition header crunched and replaced with: %s", *header);
2867 }
2868 }
2869 return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
2870 }
2871
2872
2873 /*********************************************************************
2874 *
2875 * Function : server_last_modified
2876 *
2877 * Description : Changes Last-Modified header to the actual date
2878 * to help hide-if-modified-since.
2879 * Called from `sed'.
2880 *
2881 * Parameters :
2882 * 1 : csp = Current client state (buffers, headers, etc...)
2883 * 2 : header = On input, pointer to header to modify.
2884 * On output, pointer to the modified header, or NULL
2885 * to remove the header. This function frees the
2886 * original string if necessary.
2887 *
2888 * Returns : JB_ERR_OK on success, or
2889 * JB_ERR_MEMORY on out-of-memory error.
2890 *
2891 *********************************************************************/
server_last_modified(struct client_state * csp,char ** header)2892 static jb_err server_last_modified(struct client_state *csp, char **header)
2893 {
2894 const char *newval;
2895 time_t last_modified;
2896 char newheader[50];
2897
2898 /*
2899 * Are we messing with the Last-Modified header?
2900 */
2901 if ((csp->action->flags & ACTION_OVERWRITE_LAST_MODIFIED) == 0)
2902 {
2903 /*Nope*/
2904 return JB_ERR_OK;
2905 }
2906
2907 newval = csp->action->string[ACTION_STRING_LAST_MODIFIED];
2908
2909 if (0 == strcmpic(newval, "block"))
2910 {
2911 /*
2912 * Blocking Last-Modified header. Useless but why not.
2913 */
2914 log_error(LOG_LEVEL_HEADER, "Crunching %s!", *header);
2915 freez(*header);
2916 return JB_ERR_OK;
2917 }
2918 else if (0 == strcmpic(newval, "reset-to-request-time"))
2919 {
2920 /*
2921 * Setting Last-Modified Header to now.
2922 */
2923 char buf[30];
2924 get_http_time(0, buf, sizeof(buf));
2925 freez(*header);
2926 *header = strdup("Last-Modified: ");
2927 string_append(header, buf);
2928
2929 if (*header == NULL)
2930 {
2931 log_error(LOG_LEVEL_HEADER, "Insufficient memory. Last-Modified header got lost, boohoo.");
2932 }
2933 else
2934 {
2935 log_error(LOG_LEVEL_HEADER, "Reset to present time: %s", *header);
2936 }
2937 }
2938 else if (0 == strcmpic(newval, "randomize"))
2939 {
2940 log_error(LOG_LEVEL_HEADER, "Randomizing: %s", *header);
2941
2942 if (JB_ERR_OK != parse_time_header(*header, &last_modified))
2943 {
2944 log_error(LOG_LEVEL_HEADER,
2945 "Couldn't parse time in %s (crunching!)", *header);
2946 freez(*header);
2947 }
2948 else
2949 {
2950 time_t now;
2951 struct tm *timeptr = NULL;
2952 long int rtime;
2953 struct tm gmt;
2954
2955 now = time(NULL);
2956 rtime = (long int)difftime(now, last_modified);
2957 if (rtime)
2958 {
2959 long int days, hours, minutes, seconds;
2960 const int negative_delta = (rtime < 0);
2961
2962 if (negative_delta)
2963 {
2964 rtime *= -1;
2965 log_error(LOG_LEVEL_HEADER, "Server time in the future.");
2966 }
2967 rtime = pick_from_range(rtime);
2968 if (negative_delta)
2969 {
2970 rtime *= -1;
2971 }
2972 last_modified += rtime;
2973 timeptr = privoxy_gmtime_r(&last_modified, &gmt);
2974 if ((NULL == timeptr) || !strftime(newheader,
2975 sizeof(newheader), "%a, %d %b %Y %H:%M:%S GMT", timeptr))
2976 {
2977 log_error(LOG_LEVEL_ERROR,
2978 "Randomizing '%s' failed. Crunching the header without replacement.",
2979 *header);
2980 freez(*header);
2981 return JB_ERR_OK;
2982 }
2983 freez(*header);
2984 *header = strdup("Last-Modified: ");
2985 string_append(header, newheader);
2986
2987 if (*header == NULL)
2988 {
2989 log_error(LOG_LEVEL_ERROR, "Insufficient memory, header crunched without replacement.");
2990 return JB_ERR_MEMORY;
2991 }
2992
2993 days = rtime / (3600 * 24);
2994 hours = rtime / 3600 % 24;
2995 minutes = rtime / 60 % 60;
2996 seconds = rtime % 60;
2997
2998 log_error(LOG_LEVEL_HEADER,
2999 "Randomized: %s (added %ld da%s %ld hou%s %ld minut%s %ld second%s",
3000 *header, days, (days == 1) ? "y" : "ys", hours, (hours == 1) ? "r" : "rs",
3001 minutes, (minutes == 1) ? "e" : "es", seconds, (seconds == 1) ? ")" : "s)");
3002 }
3003 else
3004 {
3005 log_error(LOG_LEVEL_HEADER, "Randomized ... or not. No time difference to work with.");
3006 }
3007 }
3008 }
3009
3010 return JB_ERR_OK;
3011 }
3012
3013
3014 /*********************************************************************
3015 *
3016 * Function : client_accept_encoding
3017 *
3018 * Description : Rewrite the client's Accept-Encoding header so that
3019 * if doesn't allow compression, if the action applies.
3020 * Note: For HTTP/1.0 the absence of the header is enough.
3021 *
3022 * Parameters :
3023 * 1 : csp = Current client state (buffers, headers, etc...)
3024 * 2 : header = On input, pointer to header to modify.
3025 * On output, pointer to the modified header, or NULL
3026 * to remove the header. This function frees the
3027 * original string if necessary.
3028 *
3029 * Returns : JB_ERR_OK on success, or
3030 * JB_ERR_MEMORY on out-of-memory error.
3031 *
3032 *********************************************************************/
client_accept_encoding(struct client_state * csp,char ** header)3033 static jb_err client_accept_encoding(struct client_state *csp, char **header)
3034 {
3035 #ifdef FEATURE_COMPRESSION
3036 if ((csp->config->feature_flags & RUNTIME_FEATURE_COMPRESSION)
3037 && strstr(*header, "deflate"))
3038 {
3039 csp->flags |= CSP_FLAG_CLIENT_SUPPORTS_DEFLATE;
3040 }
3041 #endif
3042 if ((csp->action->flags & ACTION_NO_COMPRESSION) != 0)
3043 {
3044 log_error(LOG_LEVEL_HEADER, "Suppressed offer to compress content");
3045 freez(*header);
3046 }
3047
3048 return JB_ERR_OK;
3049 }
3050
3051
3052 /*********************************************************************
3053 *
3054 * Function : client_te
3055 *
3056 * Description : Rewrite the client's TE header so that
3057 * if doesn't allow compression, if the action applies.
3058 *
3059 * Parameters :
3060 * 1 : csp = Current client state (buffers, headers, etc...)
3061 * 2 : header = On input, pointer to header to modify.
3062 * On output, pointer to the modified header, or NULL
3063 * to remove the header. This function frees the
3064 * original string if necessary.
3065 *
3066 * Returns : JB_ERR_OK on success, or
3067 * JB_ERR_MEMORY on out-of-memory error.
3068 *
3069 *********************************************************************/
client_te(struct client_state * csp,char ** header)3070 static jb_err client_te(struct client_state *csp, char **header)
3071 {
3072 if ((csp->action->flags & ACTION_NO_COMPRESSION) != 0)
3073 {
3074 freez(*header);
3075 log_error(LOG_LEVEL_HEADER, "Suppressed offer to compress transfer");
3076 }
3077
3078 return JB_ERR_OK;
3079 }
3080
3081
3082 /*********************************************************************
3083 *
3084 * Function : client_referrer
3085 *
3086 * Description : Handle the "referer" config setting properly.
3087 * Called from `sed'.
3088 *
3089 * Parameters :
3090 * 1 : csp = Current client state (buffers, headers, etc...)
3091 * 2 : header = On input, pointer to header to modify.
3092 * On output, pointer to the modified header, or NULL
3093 * to remove the header. This function frees the
3094 * original string if necessary.
3095 *
3096 * Returns : JB_ERR_OK on success, or
3097 * JB_ERR_MEMORY on out-of-memory error.
3098 *
3099 *********************************************************************/
client_referrer(struct client_state * csp,char ** header)3100 static jb_err client_referrer(struct client_state *csp, char **header)
3101 {
3102 const char *parameter;
3103 /* booleans for parameters we have to check multiple times */
3104 int parameter_conditional_block;
3105 int parameter_conditional_forge;
3106
3107 #ifdef FEATURE_FORCE_LOAD
3108 /*
3109 * Since the referrer can include the prefix even
3110 * if the request itself is non-forced, we must
3111 * clean it unconditionally.
3112 *
3113 * XXX: strclean is too broad
3114 */
3115 strclean(*header, FORCE_PREFIX);
3116 #endif /* def FEATURE_FORCE_LOAD */
3117
3118 if ((csp->action->flags & ACTION_HIDE_REFERER) == 0)
3119 {
3120 /* Nothing left to do */
3121 return JB_ERR_OK;
3122 }
3123
3124 parameter = csp->action->string[ACTION_STRING_REFERER];
3125 assert(parameter != NULL);
3126 parameter_conditional_block = (0 == strcmpic(parameter, "conditional-block"));
3127 parameter_conditional_forge = (0 == strcmpic(parameter, "conditional-forge"));
3128
3129 if (!parameter_conditional_block && !parameter_conditional_forge)
3130 {
3131 /*
3132 * As conditional-block and conditional-forge are the only
3133 * parameters that rely on the original referrer, we can
3134 * remove it now for all the others.
3135 */
3136 freez(*header);
3137 }
3138
3139 if (0 == strcmpic(parameter, "block"))
3140 {
3141 log_error(LOG_LEVEL_HEADER, "Referer crunched!");
3142 return JB_ERR_OK;
3143 }
3144 else if (parameter_conditional_block || parameter_conditional_forge)
3145 {
3146 return handle_conditional_hide_referrer_parameter(header,
3147 csp->http->hostport, parameter_conditional_block);
3148 }
3149 else if (0 == strcmpic(parameter, "forge"))
3150 {
3151 return create_forged_referrer(header, csp->http->hostport);
3152 }
3153 else
3154 {
3155 /* interpret parameter as user-supplied referer to fake */
3156 return create_fake_referrer(header, parameter);
3157 }
3158 }
3159
3160
3161 /*********************************************************************
3162 *
3163 * Function : client_accept_language
3164 *
3165 * Description : Handle the "Accept-Language" config setting properly.
3166 * Called from `sed'.
3167 *
3168 * Parameters :
3169 * 1 : csp = Current client state (buffers, headers, etc...)
3170 * 2 : header = On input, pointer to header to modify.
3171 * On output, pointer to the modified header, or NULL
3172 * to remove the header. This function frees the
3173 * original string if necessary.
3174 *
3175 * Returns : JB_ERR_OK on success, or
3176 * JB_ERR_MEMORY on out-of-memory error.
3177 *
3178 *********************************************************************/
client_accept_language(struct client_state * csp,char ** header)3179 static jb_err client_accept_language(struct client_state *csp, char **header)
3180 {
3181 const char *newval;
3182
3183 /*
3184 * Are we messing with the Accept-Language?
3185 */
3186 if ((csp->action->flags & ACTION_HIDE_ACCEPT_LANGUAGE) == 0)
3187 {
3188 /*I don't think so*/
3189 return JB_ERR_OK;
3190 }
3191
3192 newval = csp->action->string[ACTION_STRING_LANGUAGE];
3193
3194 if ((newval == NULL) || (0 == strcmpic(newval, "block")))
3195 {
3196 /*
3197 * Blocking Accept-Language header
3198 */
3199 log_error(LOG_LEVEL_HEADER, "Crunching Accept-Language!");
3200 freez(*header);
3201 return JB_ERR_OK;
3202 }
3203 else
3204 {
3205 /*
3206 * Replacing Accept-Language header
3207 */
3208 freez(*header);
3209 *header = strdup("Accept-Language: ");
3210 string_append(header, newval);
3211
3212 if (*header == NULL)
3213 {
3214 log_error(LOG_LEVEL_ERROR,
3215 "Insufficient memory. Accept-Language header crunched without replacement.");
3216 }
3217 else
3218 {
3219 log_error(LOG_LEVEL_HEADER,
3220 "Accept-Language header crunched and replaced with: %s", *header);
3221 }
3222 }
3223 return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
3224 }
3225
3226
3227 /*********************************************************************
3228 *
3229 * Function : crunch_client_header
3230 *
3231 * Description : Crunch client header if it matches a string supplied by the
3232 * user. Called from `sed'.
3233 *
3234 * Parameters :
3235 * 1 : csp = Current client state (buffers, headers, etc...)
3236 * 2 : header = On input, pointer to header to modify.
3237 * On output, pointer to the modified header, or NULL
3238 * to remove the header. This function frees the
3239 * original string if necessary.
3240 *
3241 * Returns : JB_ERR_OK on success and always succeeds
3242 *
3243 *********************************************************************/
crunch_client_header(struct client_state * csp,char ** header)3244 static jb_err crunch_client_header(struct client_state *csp, char **header)
3245 {
3246 const char *crunch_pattern;
3247
3248 /* Do we feel like crunching? */
3249 if ((csp->action->flags & ACTION_CRUNCH_CLIENT_HEADER))
3250 {
3251 crunch_pattern = csp->action->string[ACTION_STRING_CLIENT_HEADER];
3252
3253 /* Is the current header the lucky one? */
3254 if (strstr(*header, crunch_pattern))
3255 {
3256 log_error(LOG_LEVEL_HEADER, "Crunching client header: %s (contains: %s)", *header, crunch_pattern);
3257 freez(*header);
3258 }
3259 }
3260 return JB_ERR_OK;
3261 }
3262
3263
3264 /*********************************************************************
3265 *
3266 * Function : client_uagent
3267 *
3268 * Description : Handle the "user-agent" config setting properly
3269 * and remember its original value to enable browser
3270 * bug workarounds. Called from `sed'.
3271 *
3272 * Parameters :
3273 * 1 : csp = Current client state (buffers, headers, etc...)
3274 * 2 : header = On input, pointer to header to modify.
3275 * On output, pointer to the modified header, or NULL
3276 * to remove the header. This function frees the
3277 * original string if necessary.
3278 *
3279 * Returns : JB_ERR_OK on success, or
3280 * JB_ERR_MEMORY on out-of-memory error.
3281 *
3282 *********************************************************************/
client_uagent(struct client_state * csp,char ** header)3283 static jb_err client_uagent(struct client_state *csp, char **header)
3284 {
3285 const char *newval;
3286
3287 if ((csp->action->flags & ACTION_HIDE_USER_AGENT) == 0)
3288 {
3289 return JB_ERR_OK;
3290 }
3291
3292 newval = csp->action->string[ACTION_STRING_USER_AGENT];
3293 if (newval == NULL)
3294 {
3295 return JB_ERR_OK;
3296 }
3297
3298 freez(*header);
3299 *header = strdup("User-Agent: ");
3300 string_append(header, newval);
3301
3302 log_error(LOG_LEVEL_HEADER, "Modified: %s", *header);
3303
3304 return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
3305 }
3306
3307
3308 /*********************************************************************
3309 *
3310 * Function : client_ua
3311 *
3312 * Description : Handle "ua-" headers properly. Called from `sed'.
3313 *
3314 * Parameters :
3315 * 1 : csp = Current client state (buffers, headers, etc...)
3316 * 2 : header = On input, pointer to header to modify.
3317 * On output, pointer to the modified header, or NULL
3318 * to remove the header. This function frees the
3319 * original string if necessary.
3320 *
3321 * Returns : JB_ERR_OK on success, or
3322 * JB_ERR_MEMORY on out-of-memory error.
3323 *
3324 *********************************************************************/
client_ua(struct client_state * csp,char ** header)3325 static jb_err client_ua(struct client_state *csp, char **header)
3326 {
3327 if ((csp->action->flags & ACTION_HIDE_USER_AGENT) != 0)
3328 {
3329 log_error(LOG_LEVEL_HEADER, "crunched User-Agent!");
3330 freez(*header);
3331 }
3332
3333 return JB_ERR_OK;
3334 }
3335
3336
3337 /*********************************************************************
3338 *
3339 * Function : client_from
3340 *
3341 * Description : Handle the "from" config setting properly.
3342 * Called from `sed'.
3343 *
3344 * Parameters :
3345 * 1 : csp = Current client state (buffers, headers, etc...)
3346 * 2 : header = On input, pointer to header to modify.
3347 * On output, pointer to the modified header, or NULL
3348 * to remove the header. This function frees the
3349 * original string if necessary.
3350 *
3351 * Returns : JB_ERR_OK on success, or
3352 * JB_ERR_MEMORY on out-of-memory error.
3353 *
3354 *********************************************************************/
client_from(struct client_state * csp,char ** header)3355 static jb_err client_from(struct client_state *csp, char **header)
3356 {
3357 const char *newval;
3358
3359 if ((csp->action->flags & ACTION_HIDE_FROM) == 0)
3360 {
3361 return JB_ERR_OK;
3362 }
3363
3364 freez(*header);
3365
3366 newval = csp->action->string[ACTION_STRING_FROM];
3367
3368 /*
3369 * Are we blocking the e-mail address?
3370 */
3371 if ((newval == NULL) || (0 == strcmpic(newval, "block")))
3372 {
3373 log_error(LOG_LEVEL_HEADER, "crunched From!");
3374 return JB_ERR_OK;
3375 }
3376
3377 log_error(LOG_LEVEL_HEADER, " modified");
3378
3379 *header = strdup("From: ");
3380 string_append(header, newval);
3381
3382 return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
3383 }
3384
3385
3386 /*********************************************************************
3387 *
3388 * Function : client_send_cookie
3389 *
3390 * Description : Crunches the "cookie" header if necessary.
3391 * Called from `sed'.
3392 *
3393 * XXX: Stupid name, doesn't send squat.
3394 *
3395 * Parameters :
3396 * 1 : csp = Current client state (buffers, headers, etc...)
3397 * 2 : header = On input, pointer to header to modify.
3398 * On output, pointer to the modified header, or NULL
3399 * to remove the header. This function frees the
3400 * original string if necessary.
3401 *
3402 * Returns : JB_ERR_OK on success, or
3403 * JB_ERR_MEMORY on out-of-memory error.
3404 *
3405 *********************************************************************/
client_send_cookie(struct client_state * csp,char ** header)3406 static jb_err client_send_cookie(struct client_state *csp, char **header)
3407 {
3408 if (csp->action->flags & ACTION_CRUNCH_OUTGOING_COOKIES)
3409 {
3410 log_error(LOG_LEVEL_HEADER, "Crunched outgoing cookie: %s", *header);
3411 freez(*header);
3412 }
3413
3414 return JB_ERR_OK;
3415 }
3416
3417
3418 /*********************************************************************
3419 *
3420 * Function : client_x_forwarded
3421 *
3422 * Description : Handle the "x-forwarded-for" config setting properly,
3423 * also used in the add_client_headers list. Called from `sed'.
3424 *
3425 * Parameters :
3426 * 1 : csp = Current client state (buffers, headers, etc...)
3427 * 2 : header = On input, pointer to header to modify.
3428 * On output, pointer to the modified header, or NULL
3429 * to remove the header. This function frees the
3430 * original string if necessary.
3431 *
3432 * Returns : JB_ERR_OK on success, or
3433 * JB_ERR_MEMORY on out-of-memory error.
3434 *
3435 *********************************************************************/
client_x_forwarded(struct client_state * csp,char ** header)3436 jb_err client_x_forwarded(struct client_state *csp, char **header)
3437 {
3438 if (0 != (csp->action->flags & ACTION_CHANGE_X_FORWARDED_FOR))
3439 {
3440 const char *parameter = csp->action->string[ACTION_STRING_CHANGE_X_FORWARDED_FOR];
3441
3442 if (0 == strcmpic(parameter, "block"))
3443 {
3444 freez(*header);
3445 log_error(LOG_LEVEL_HEADER, "crunched x-forwarded-for!");
3446 }
3447 else if (0 == strcmpic(parameter, "add"))
3448 {
3449 string_append(header, ", ");
3450 string_append(header, csp->ip_addr_str);
3451
3452 if (*header == NULL)
3453 {
3454 return JB_ERR_MEMORY;
3455 }
3456 log_error(LOG_LEVEL_HEADER,
3457 "Appended client IP address to %s", *header);
3458 csp->flags |= CSP_FLAG_X_FORWARDED_FOR_APPENDED;
3459 }
3460 else
3461 {
3462 log_error(LOG_LEVEL_FATAL,
3463 "Invalid change-x-forwarded-for parameter: '%s'", parameter);
3464 }
3465 }
3466
3467 return JB_ERR_OK;
3468 }
3469
3470
3471 /*********************************************************************
3472 *
3473 * Function : client_max_forwards
3474 *
3475 * Description : If the HTTP method is OPTIONS or TRACE, subtract one
3476 * from the value of the Max-Forwards header field.
3477 *
3478 * Parameters :
3479 * 1 : csp = Current client state (buffers, headers, etc...)
3480 * 2 : header = On input, pointer to header to modify.
3481 * On output, pointer to the modified header, or NULL
3482 * to remove the header. This function frees the
3483 * original string if necessary.
3484 *
3485 * Returns : JB_ERR_OK on success, or
3486 * JB_ERR_MEMORY on out-of-memory error.
3487 *
3488 *********************************************************************/
client_max_forwards(struct client_state * csp,char ** header)3489 static jb_err client_max_forwards(struct client_state *csp, char **header)
3490 {
3491 int max_forwards;
3492
3493 if ((0 == strcmpic(csp->http->gpc, "trace")) ||
3494 (0 == strcmpic(csp->http->gpc, "options")))
3495 {
3496 assert(*(*header+12) == ':');
3497 if (1 == sscanf(*header+12, ": %d", &max_forwards))
3498 {
3499 if (max_forwards > 0)
3500 {
3501 snprintf(*header, strlen(*header)+1, "Max-Forwards: %d", --max_forwards);
3502 log_error(LOG_LEVEL_HEADER,
3503 "Max-Forwards value for %s request reduced to %d.",
3504 csp->http->gpc, max_forwards);
3505 }
3506 else if (max_forwards < 0)
3507 {
3508 log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
3509 freez(*header);
3510 }
3511 }
3512 else
3513 {
3514 log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
3515 freez(*header);
3516 }
3517 }
3518
3519 return JB_ERR_OK;
3520 }
3521
3522
3523 /*********************************************************************
3524 *
3525 * Function : client_host
3526 *
3527 * Description : If the request URI did not contain host and
3528 * port information, parse and evaluate the Host
3529 * header field.
3530 *
3531 * Parameters :
3532 * 1 : csp = Current client state (buffers, headers, etc...)
3533 * 2 : header = On input, pointer to header to modify.
3534 * On output, pointer to the modified header, or NULL
3535 * to remove the header. This function frees the
3536 * original string if necessary.
3537 *
3538 * Returns : JB_ERR_OK on success, or
3539 * JB_ERR_MEMORY on out-of-memory error.
3540 *
3541 *********************************************************************/
client_host(struct client_state * csp,char ** header)3542 static jb_err client_host(struct client_state *csp, char **header)
3543 {
3544 char *p, *q;
3545
3546 if (strlen(*header) < 7)
3547 {
3548 log_error(LOG_LEVEL_HEADER, "Removing empty Host header");
3549 freez(*header);
3550 return JB_ERR_OK;
3551 }
3552
3553 if (!csp->http->hostport || (*csp->http->hostport == '*') ||
3554 *csp->http->hostport == ' ' || *csp->http->hostport == '\0')
3555 {
3556
3557 p = strdup_or_die((*header)+6);
3558 chomp(p);
3559 q = strdup_or_die(p);
3560
3561 freez(csp->http->hostport);
3562 csp->http->hostport = p;
3563 freez(csp->http->host);
3564 csp->http->host = q;
3565 q = strchr(csp->http->host, ':');
3566 if (q != NULL)
3567 {
3568 /* Terminate hostname and evaluate port string */
3569 *q++ = '\0';
3570 csp->http->port = atoi(q);
3571 }
3572 else
3573 {
3574 csp->http->port = csp->http->ssl ? 443 : 80;
3575 }
3576
3577 log_error(LOG_LEVEL_HEADER, "New host and port from Host field: %s = %s:%d",
3578 csp->http->hostport, csp->http->host, csp->http->port);
3579 }
3580
3581 /* Signal client_host_adder() to return right away */
3582 csp->flags |= CSP_FLAG_HOST_HEADER_IS_SET;
3583
3584 return JB_ERR_OK;
3585 }
3586
3587
3588 /*********************************************************************
3589 *
3590 * Function : client_if_modified_since
3591 *
3592 * Description : Remove or modify the If-Modified-Since header.
3593 *
3594 * Parameters :
3595 * 1 : csp = Current client state (buffers, headers, etc...)
3596 * 2 : header = On input, pointer to header to modify.
3597 * On output, pointer to the modified header, or NULL
3598 * to remove the header. This function frees the
3599 * original string if necessary.
3600 *
3601 * Returns : JB_ERR_OK on success, or
3602 * JB_ERR_MEMORY on out-of-memory error.
3603 *
3604 *********************************************************************/
client_if_modified_since(struct client_state * csp,char ** header)3605 static jb_err client_if_modified_since(struct client_state *csp, char **header)
3606 {
3607 char newheader[50];
3608 struct tm gmt;
3609 struct tm *timeptr = NULL;
3610 time_t tm = 0;
3611 const char *newval;
3612 char * endptr;
3613
3614 if (0 == strcmpic(*header, "If-Modified-Since: Wed, 08 Jun 1955 12:00:00 GMT"))
3615 {
3616 /*
3617 * The client got an error message because of a temporary problem,
3618 * the problem is gone and the client now tries to revalidate our
3619 * error message on the real server. The revalidation would always
3620 * end with the transmission of the whole document and there is
3621 * no need to expose the bogus If-Modified-Since header.
3622 */
3623 log_error(LOG_LEVEL_HEADER, "Crunching useless If-Modified-Since header.");
3624 freez(*header);
3625 }
3626 else if (csp->action->flags & ACTION_HIDE_IF_MODIFIED_SINCE)
3627 {
3628 newval = csp->action->string[ACTION_STRING_IF_MODIFIED_SINCE];
3629
3630 if ((0 == strcmpic(newval, "block")))
3631 {
3632 log_error(LOG_LEVEL_HEADER, "Crunching %s", *header);
3633 freez(*header);
3634 }
3635 else /* add random value */
3636 {
3637 if (JB_ERR_OK != parse_time_header(*header, &tm))
3638 {
3639 log_error(LOG_LEVEL_HEADER,
3640 "Couldn't parse time in %s (crunching!)", *header);
3641 freez(*header);
3642 }
3643 else
3644 {
3645 long int hours, minutes, seconds;
3646 long int rtime = strtol(newval, &endptr, 0);
3647 const int negative_range = (rtime < 0);
3648
3649 if (rtime)
3650 {
3651 log_error(LOG_LEVEL_HEADER, "Randomizing: %s (random range: %ld minut%s)",
3652 *header, rtime, (rtime == 1 || rtime == -1) ? "e": "es");
3653 if (negative_range)
3654 {
3655 rtime *= -1;
3656 }
3657 rtime *= 60;
3658 rtime = pick_from_range(rtime);
3659 }
3660 else
3661 {
3662 log_error(LOG_LEVEL_ERROR,
3663 "Random range is 0. Assuming time transformation test.");
3664 }
3665 tm += rtime * (negative_range ? -1 : 1);
3666 timeptr = privoxy_gmtime_r(&tm, &gmt);
3667 if ((NULL == timeptr) || !strftime(newheader,
3668 sizeof(newheader), "%a, %d %b %Y %H:%M:%S GMT", timeptr))
3669 {
3670 log_error(LOG_LEVEL_ERROR,
3671 "Randomizing '%s' failed. Crunching the header without replacement.",
3672 *header);
3673 freez(*header);
3674 return JB_ERR_OK;
3675 }
3676 freez(*header);
3677 *header = strdup("If-Modified-Since: ");
3678 string_append(header, newheader);
3679
3680 if (*header == NULL)
3681 {
3682 log_error(LOG_LEVEL_HEADER, "Insufficient memory, header crunched without replacement.");
3683 return JB_ERR_MEMORY;
3684 }
3685
3686 hours = rtime / 3600;
3687 minutes = rtime / 60 % 60;
3688 seconds = rtime % 60;
3689
3690 log_error(LOG_LEVEL_HEADER,
3691 "Randomized: %s (%s %ld hou%s %ld minut%s %ld second%s",
3692 *header, (negative_range) ? "subtracted" : "added", hours,
3693 (hours == 1) ? "r" : "rs", minutes, (minutes == 1) ? "e" : "es",
3694 seconds, (seconds == 1) ? ")" : "s)");
3695 }
3696 }
3697 }
3698
3699 return JB_ERR_OK;
3700 }
3701
3702
3703 /*********************************************************************
3704 *
3705 * Function : client_if_none_match
3706 *
3707 * Description : Remove the If-None-Match header.
3708 *
3709 * Parameters :
3710 * 1 : csp = Current client state (buffers, headers, etc...)
3711 * 2 : header = On input, pointer to header to modify.
3712 * On output, pointer to the modified header, or NULL
3713 * to remove the header. This function frees the
3714 * original string if necessary.
3715 *
3716 * Returns : JB_ERR_OK on success, or
3717 * JB_ERR_MEMORY on out-of-memory error.
3718 *
3719 *********************************************************************/
client_if_none_match(struct client_state * csp,char ** header)3720 static jb_err client_if_none_match(struct client_state *csp, char **header)
3721 {
3722 if (csp->action->flags & ACTION_CRUNCH_IF_NONE_MATCH)
3723 {
3724 log_error(LOG_LEVEL_HEADER, "Crunching %s", *header);
3725 freez(*header);
3726 }
3727
3728 return JB_ERR_OK;
3729 }
3730
3731
3732 /*********************************************************************
3733 *
3734 * Function : client_x_filter
3735 *
3736 * Description : Disables filtering if the client set "X-Filter: No".
3737 * Called from `sed'.
3738 *
3739 * Parameters :
3740 * 1 : csp = Current client state (buffers, headers, etc...)
3741 * 2 : header = On input, pointer to header to modify.
3742 * On output, pointer to the modified header, or NULL
3743 * to remove the header. This function frees the
3744 * original string if necessary.
3745 *
3746 * Returns : JB_ERR_OK on success
3747 *
3748 *********************************************************************/
client_x_filter(struct client_state * csp,char ** header)3749 jb_err client_x_filter(struct client_state *csp, char **header)
3750 {
3751 if (0 == strcmpic(*header, "X-Filter: No"))
3752 {
3753 if (!(csp->config->feature_flags & RUNTIME_FEATURE_HTTP_TOGGLE))
3754 {
3755 log_error(LOG_LEVEL_INFO, "Ignored the client's request to fetch without filtering.");
3756 }
3757 else
3758 {
3759 if (csp->action->flags & ACTION_FORCE_TEXT_MODE)
3760 {
3761 log_error(LOG_LEVEL_HEADER,
3762 "force-text-mode overruled the client's request to fetch without filtering!");
3763 }
3764 else
3765 {
3766 csp->content_type = CT_TABOO; /* XXX: This hack shouldn't be necessary */
3767 csp->flags |= CSP_FLAG_NO_FILTERING;
3768 log_error(LOG_LEVEL_HEADER, "Accepted the client's request to fetch without filtering.");
3769 }
3770 log_error(LOG_LEVEL_HEADER, "Crunching %s", *header);
3771 freez(*header);
3772 }
3773 }
3774 return JB_ERR_OK;
3775 }
3776
3777
3778 /*********************************************************************
3779 *
3780 * Function : client_range
3781 *
3782 * Description : Removes Range, Request-Range and If-Range headers if
3783 * content filtering is enabled and the range doesn't
3784 * start at byte 0.
3785 *
3786 * If the client's version of the document has been
3787 * altered by Privoxy, the server could interpret the
3788 * range differently than the client intended in which
3789 * case the user could end up with corrupted content.
3790 *
3791 * If the range starts at byte 0 this isn't an issue
3792 * so the header can pass. Partial requests like this
3793 * are used to render preview images for videos without
3794 * downloading the whole video.
3795 *
3796 * While HTTP doesn't require that range requests are
3797 * honoured and the client could simply abort the download
3798 * after receiving a sufficient amount of data, various
3799 * clients don't handle complete responses to range
3800 * requests gracefully and emit misleading error messages
3801 * instead.
3802 *
3803 * Parameters :
3804 * 1 : csp = Current client state (buffers, headers, etc...)
3805 * 2 : header = On input, pointer to header to modify.
3806 * On output, pointer to the modified header, or NULL
3807 * to remove the header. This function frees the
3808 * original string if necessary.
3809 *
3810 * Returns : JB_ERR_OK
3811 *
3812 *********************************************************************/
client_range(struct client_state * csp,char ** header)3813 static jb_err client_range(struct client_state *csp, char **header)
3814 {
3815 if (content_filters_enabled(csp->action)
3816 && (0 != strncmpic(strstr(*header, ":"), ": bytes=0-", 10)))
3817 {
3818 log_error(LOG_LEVEL_HEADER, "Content filtering is enabled."
3819 " Crunching: \'%s\' to prevent range-mismatch problems.", *header);
3820 freez(*header);
3821 }
3822
3823 return JB_ERR_OK;
3824 }
3825
3826 /* the following functions add headers directly to the header list */
3827
3828 /*********************************************************************
3829 *
3830 * Function : client_host_adder
3831 *
3832 * Description : Adds the Host: header field if it is missing.
3833 * Called from `sed'.
3834 *
3835 * Parameters :
3836 * 1 : csp = Current client state (buffers, headers, etc...)
3837 *
3838 * Returns : JB_ERR_OK on success, or
3839 * JB_ERR_MEMORY on out-of-memory error.
3840 *
3841 *********************************************************************/
client_host_adder(struct client_state * csp)3842 static jb_err client_host_adder(struct client_state *csp)
3843 {
3844 char *p;
3845 jb_err err;
3846
3847 if (csp->flags & CSP_FLAG_HOST_HEADER_IS_SET)
3848 {
3849 /* Header already set by the client, nothing to do. */
3850 return JB_ERR_OK;
3851 }
3852
3853 if (!csp->http->hostport || !*(csp->http->hostport))
3854 {
3855 log_error(LOG_LEVEL_ERROR, "Destination host unknown.");
3856 return JB_ERR_PARSE;
3857 }
3858
3859 /*
3860 * remove 'user:pass@' from 'proto://user:pass@host'
3861 */
3862 if ((p = strchr( csp->http->hostport, '@')) != NULL)
3863 {
3864 p++;
3865 }
3866 else
3867 {
3868 p = csp->http->hostport;
3869 }
3870
3871 /* XXX: Just add it, we already made sure that it will be unique */
3872 log_error(LOG_LEVEL_HEADER, "addh-unique: Host: %s", p);
3873 err = enlist_unique_header(csp->headers, "Host", p);
3874 return err;
3875
3876 }
3877
3878
3879 /*********************************************************************
3880 *
3881 * Function : client_xtra_adder
3882 *
3883 * Description : Used in the add_client_headers list. Called from `sed'.
3884 *
3885 * Parameters :
3886 * 1 : csp = Current client state (buffers, headers, etc...)
3887 *
3888 * Returns : JB_ERR_OK on success, or
3889 * JB_ERR_MEMORY on out-of-memory error.
3890 *
3891 *********************************************************************/
client_xtra_adder(struct client_state * csp)3892 static jb_err client_xtra_adder(struct client_state *csp)
3893 {
3894 struct list_entry *lst;
3895 jb_err err;
3896
3897 for (lst = csp->action->multi[ACTION_MULTI_ADD_HEADER]->first;
3898 lst ; lst = lst->next)
3899 {
3900 log_error(LOG_LEVEL_HEADER, "addh: %s", lst->str);
3901 err = enlist(csp->headers, lst->str);
3902 if (err)
3903 {
3904 return err;
3905 }
3906
3907 }
3908
3909 return JB_ERR_OK;
3910 }
3911
3912
3913 /*********************************************************************
3914 *
3915 * Function : client_x_forwarded_for_adder
3916 *
3917 * Description : Used in the add_client_headers list. Called from `sed'.
3918 *
3919 * Parameters :
3920 * 1 : csp = Current client state (buffers, headers, etc...)
3921 *
3922 * Returns : JB_ERR_OK on success, or
3923 * JB_ERR_MEMORY on out-of-memory error.
3924 *
3925 *********************************************************************/
client_x_forwarded_for_adder(struct client_state * csp)3926 static jb_err client_x_forwarded_for_adder(struct client_state *csp)
3927 {
3928 char *header = NULL;
3929 jb_err err;
3930
3931 if (!((csp->action->flags & ACTION_CHANGE_X_FORWARDED_FOR)
3932 && (0 == strcmpic(csp->action->string[ACTION_STRING_CHANGE_X_FORWARDED_FOR], "add")))
3933 || (csp->flags & CSP_FLAG_X_FORWARDED_FOR_APPENDED))
3934 {
3935 /*
3936 * If we aren't adding X-Forwarded-For headers,
3937 * or we already appended an existing X-Forwarded-For
3938 * header, there's nothing left to do here.
3939 */
3940 return JB_ERR_OK;
3941 }
3942
3943 header = strdup("X-Forwarded-For: ");
3944 string_append(&header, csp->ip_addr_str);
3945
3946 if (header == NULL)
3947 {
3948 return JB_ERR_MEMORY;
3949 }
3950
3951 log_error(LOG_LEVEL_HEADER, "addh: %s", header);
3952 err = enlist(csp->headers, header);
3953 freez(header);
3954
3955 return err;
3956 }
3957
3958
3959 /*********************************************************************
3960 *
3961 * Function : server_connection_adder
3962 *
3963 * Description : Adds an appropriate "Connection:" header to csp->headers
3964 * unless the header was already present. Called from `sed'.
3965 *
3966 * Parameters :
3967 * 1 : csp = Current client state (buffers, headers, etc...)
3968 *
3969 * Returns : JB_ERR_OK on success, or
3970 * JB_ERR_MEMORY on out-of-memory error.
3971 *
3972 *********************************************************************/
server_connection_adder(struct client_state * csp)3973 static jb_err server_connection_adder(struct client_state *csp)
3974 {
3975 const unsigned int flags = csp->flags;
3976 const char *response_status_line = csp->headers->first->str;
3977 static const char connection_close[] = "Connection: close";
3978
3979 if ((flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
3980 && (flags & CSP_FLAG_SERVER_CONNECTION_HEADER_SET))
3981 {
3982 return JB_ERR_OK;
3983 }
3984
3985 /*
3986 * XXX: if we downgraded the response, this check will fail.
3987 */
3988 if ((csp->config->feature_flags &
3989 RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
3990 && (NULL != response_status_line)
3991 && !strncmpic(response_status_line, "HTTP/1.1", 8)
3992 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
3993 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
3994 #endif
3995 )
3996 {
3997 log_error(LOG_LEVEL_HEADER, "A HTTP/1.1 response "
3998 "without Connection header implies keep-alive.");
3999 csp->flags |= CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE;
4000 return JB_ERR_OK;
4001 }
4002
4003 log_error(LOG_LEVEL_HEADER, "Adding: %s", connection_close);
4004
4005 return enlist(csp->headers, connection_close);
4006 }
4007
4008
4009 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
4010 /*********************************************************************
4011 *
4012 * Function : server_proxy_connection_adder
4013 *
4014 * Description : Adds a "Proxy-Connection: keep-alive" header to
4015 * csp->headers when appropriate.
4016 *
4017 * Parameters :
4018 * 1 : csp = Current client state (buffers, headers, etc...)
4019 *
4020 * Returns : JB_ERR_OK on success, or
4021 * JB_ERR_MEMORY on out-of-memory error.
4022 *
4023 *********************************************************************/
server_proxy_connection_adder(struct client_state * csp)4024 static jb_err server_proxy_connection_adder(struct client_state *csp)
4025 {
4026 static const char proxy_connection_header[] = "Proxy-Connection: keep-alive";
4027 jb_err err = JB_ERR_OK;
4028
4029 if ((csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
4030 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
4031 && !(csp->flags & CSP_FLAG_SERVER_PROXY_CONNECTION_HEADER_SET)
4032 && ((csp->flags & CSP_FLAG_SERVER_CONTENT_LENGTH_SET)
4033 || (csp->flags & CSP_FLAG_CHUNKED))
4034 #ifdef FEATURE_HTTPS_INSPECTION
4035 && !client_use_ssl(csp)
4036 && !csp->http->ssl
4037 #endif
4038 )
4039 {
4040 log_error(LOG_LEVEL_HEADER, "Adding: %s", proxy_connection_header);
4041 err = enlist(csp->headers, proxy_connection_header);
4042 }
4043
4044 return err;
4045 }
4046 #endif /* FEATURE_CONNECTION_KEEP_ALIVE */
4047
4048
4049 /*********************************************************************
4050 *
4051 * Function : client_connection_header_adder
4052 *
4053 * Description : Adds a proper "Connection:" header to csp->headers
4054 * unless the header was already present or it's a
4055 * CONNECT request. Called from `sed'.
4056 *
4057 * Parameters :
4058 * 1 : csp = Current client state (buffers, headers, etc...)
4059 *
4060 * Returns : JB_ERR_OK on success, or
4061 * JB_ERR_MEMORY on out-of-memory error.
4062 *
4063 *********************************************************************/
client_connection_header_adder(struct client_state * csp)4064 static jb_err client_connection_header_adder(struct client_state *csp)
4065 {
4066 static const char connection_close[] = "Connection: close";
4067
4068 if (!(csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
4069 && (csp->flags & CSP_FLAG_CLIENT_CONNECTION_HEADER_SET))
4070 {
4071 return JB_ERR_OK;
4072 }
4073
4074 /*
4075 * In case of CONNECT requests "Connection: close" is implied,
4076 * but actually setting the header has been reported to cause
4077 * problems with some forwarding proxies that close the
4078 * connection prematurely.
4079 */
4080 if (csp->http->ssl != 0)
4081 {
4082 return JB_ERR_OK;
4083 }
4084
4085 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
4086 if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
4087 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
4088 && !strcmpic(csp->http->version, "HTTP/1.1"))
4089 {
4090 csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
4091 return JB_ERR_OK;
4092 }
4093 #endif /* FEATURE_CONNECTION_KEEP_ALIVE */
4094
4095 log_error(LOG_LEVEL_HEADER, "Adding: %s", connection_close);
4096
4097 return enlist(csp->headers, connection_close);
4098 }
4099
4100
4101 /*********************************************************************
4102 *
4103 * Function : server_http
4104 *
4105 * Description : - Save the HTTP Status into csp->http->status
4106 * - Set CT_TABOO to prevent filtering if the answer
4107 * is a partial range (HTTP status 206)
4108 * - Rewrite HTTP/1.1 answers to HTTP/1.0 if +downgrade
4109 * action applies.
4110 * - Normalize the HTTP-version.
4111 *
4112 * Parameters :
4113 * 1 : csp = Current client state (buffers, headers, etc...)
4114 * 2 : header = On input, pointer to header to modify.
4115 * On output, pointer to the modified header, or NULL
4116 * to remove the header. This function frees the
4117 * original string if necessary.
4118 *
4119 * Returns : JB_ERR_OK on success, or
4120 * JB_ERR_PARSE on fatal parse errors.
4121 *
4122 *********************************************************************/
server_http(struct client_state * csp,char ** header)4123 static jb_err server_http(struct client_state *csp, char **header)
4124 {
4125 char *reason_phrase = NULL;
4126 char *new_response_line;
4127 char *p;
4128 size_t length;
4129 unsigned int major_version;
4130 unsigned int minor_version;
4131
4132 /* Get the reason phrase which start after the second whitespace */
4133 p = strchr(*header, ' ');
4134 if (NULL != p)
4135 {
4136 p++;
4137 reason_phrase = strchr(p, ' ');
4138 }
4139
4140 if (reason_phrase != NULL)
4141 {
4142 reason_phrase++;
4143 }
4144 else
4145 {
4146 log_error(LOG_LEVEL_ERROR,
4147 "Response line lacks reason phrase: %s", *header);
4148 reason_phrase="";
4149 }
4150
4151 if (3 != sscanf(*header, "HTTP/%u.%u %d", &major_version,
4152 &minor_version, &(csp->http->status)))
4153 {
4154 log_error(LOG_LEVEL_ERROR,
4155 "Failed to parse the response line: %s", *header);
4156 return JB_ERR_PARSE;
4157 }
4158
4159 if (csp->http->status == 101 ||
4160 csp->http->status == 206)
4161 {
4162 csp->content_type = CT_TABOO;
4163 }
4164
4165 if (major_version != 1 || (minor_version != 0 && minor_version != 1))
4166 {
4167 /*
4168 * According to RFC 7230 2.6 intermediaries MUST send
4169 * their own HTTP-version in forwarded messages.
4170 */
4171 log_error(LOG_LEVEL_ERROR,
4172 "Unsupported HTTP version. Downgrading to 1.1.");
4173 major_version = 1;
4174 minor_version = 1;
4175 }
4176
4177 if (((csp->action->flags & ACTION_DOWNGRADE) != 0) && (minor_version == 1))
4178 {
4179 log_error(LOG_LEVEL_HEADER, "Downgrading answer to HTTP/1.0");
4180 minor_version = 0;
4181 }
4182
4183 /* Rebuild response line. */
4184 length = sizeof("HTTP/1.1 200 ") + strlen(reason_phrase) + 1;
4185 new_response_line = malloc_or_die(length);
4186
4187 snprintf(new_response_line, length, "HTTP/%u.%u %d %s",
4188 major_version, minor_version, csp->http->status, reason_phrase);
4189
4190 if (0 != strcmp(*header, new_response_line))
4191 {
4192 log_error(LOG_LEVEL_HEADER, "Response line '%s' changed to '%s'",
4193 *header, new_response_line);
4194 }
4195
4196 freez(*header);
4197 *header = new_response_line;
4198
4199 return JB_ERR_OK;
4200 }
4201
4202 /*********************************************************************
4203 *
4204 * Function : add_cooky_expiry_date
4205 *
4206 * Description : Adds a cookie expiry date to a string.
4207 *
4208 * Parameters :
4209 * 1 : cookie = On input, pointer to cookie to modify.
4210 * On output, pointer to the modified header.
4211 * The original string is freed.
4212 * 2 : lifetime = Seconds the cookie should be valid
4213 *
4214 * Returns : N/A
4215 *
4216 *********************************************************************/
add_cookie_expiry_date(char ** cookie,time_t lifetime)4217 static void add_cookie_expiry_date(char **cookie, time_t lifetime)
4218 {
4219 char tmp[50];
4220 struct tm *timeptr = NULL;
4221 time_t expiry_date = time(NULL) + lifetime;
4222 struct tm gmt;
4223
4224 timeptr = privoxy_gmtime_r(&expiry_date, &gmt);
4225 if (NULL == timeptr)
4226 {
4227 log_error(LOG_LEVEL_FATAL,
4228 "Failed to get the time in add_cooky_expiry_date()");
4229 }
4230 strftime(tmp, sizeof(tmp), "; expires=%a, %d-%b-%Y %H:%M:%S GMT", timeptr);
4231 if (JB_ERR_OK != string_append(cookie, tmp))
4232 {
4233 log_error(LOG_LEVEL_FATAL, "Out of memory in add_cooky_expiry()");
4234 }
4235 }
4236
4237
4238 /*********************************************************************
4239 *
4240 * Function : server_set_cookie
4241 *
4242 * Description : Handle the server "cookie" header properly.
4243 * Crunch, accept or rewrite it to a session cookie.
4244 * Called from `sed'.
4245 *
4246 * Parameters :
4247 * 1 : csp = Current client state (buffers, headers, etc...)
4248 * 2 : header = On input, pointer to header to modify.
4249 * On output, pointer to the modified header, or NULL
4250 * to remove the header. This function frees the
4251 * original string if necessary.
4252 *
4253 * Returns : JB_ERR_OK on success, or
4254 * JB_ERR_MEMORY on out-of-memory error.
4255 *
4256 *********************************************************************/
server_set_cookie(struct client_state * csp,char ** header)4257 static jb_err server_set_cookie(struct client_state *csp, char **header)
4258 {
4259 if ((csp->action->flags & ACTION_CRUNCH_INCOMING_COOKIES) != 0)
4260 {
4261 log_error(LOG_LEVEL_HEADER, "Crunching incoming cookie: %s", *header);
4262 freez(*header);
4263 }
4264 else if ((0 != (csp->action->flags & ACTION_SESSION_COOKIES_ONLY))
4265 || (0 != (csp->action->flags & ACTION_LIMIT_COOKIE_LIFETIME)))
4266 {
4267 time_t now;
4268 time_t cookie_time;
4269 long cookie_lifetime = 0;
4270 enum
4271 {
4272 NO_EXPIRY_DATE_SPECIFIED,
4273 EXPIRY_DATE_ACCEPTABLE,
4274 EXPIRY_DATE_UNACCEPTABLE
4275 } expiry_date_status = NO_EXPIRY_DATE_SPECIFIED;
4276
4277 /* A variable to store the tag we're working on */
4278 char *cur_tag;
4279
4280 /* Skip "Set-Cookie:" (11 characters) in header */
4281 cur_tag = *header + 11;
4282
4283 /* skip whitespace between "Set-Cookie:" and value */
4284 while (*cur_tag && privoxy_isspace(*cur_tag))
4285 {
4286 cur_tag++;
4287 }
4288
4289 time(&now);
4290
4291 if ((csp->action->flags & ACTION_LIMIT_COOKIE_LIFETIME) != 0)
4292 {
4293 const char *param = csp->action->string[ACTION_STRING_LIMIT_COOKIE_LIFETIME];
4294
4295 cookie_lifetime = strtol(param, NULL, 0);
4296 if (cookie_lifetime < 0)
4297 {
4298 log_error(LOG_LEVEL_FATAL, "Invalid cookie lifetime limit: %s", param);
4299 }
4300 cookie_lifetime *= 60;
4301 }
4302
4303 /* Loop through each tag in the cookie */
4304 while (*cur_tag)
4305 {
4306 /* Find next tag */
4307 char *next_tag = strchr(cur_tag, ';');
4308 if (next_tag != NULL)
4309 {
4310 /* Skip the ';' character itself */
4311 next_tag++;
4312
4313 /* skip whitespace ";" and start of tag */
4314 while (*next_tag && privoxy_isspace(*next_tag))
4315 {
4316 next_tag++;
4317 }
4318 }
4319 else
4320 {
4321 /* "Next tag" is the end of the string */
4322 next_tag = cur_tag + strlen(cur_tag);
4323 }
4324
4325 /*
4326 * Check the expiration date to see
4327 * if the cookie is still valid, if yes,
4328 * rewrite it to a session cookie.
4329 */
4330 if ((strncmpic(cur_tag, "expires=", 8) == 0) && *(cur_tag + 8))
4331 {
4332 char *expiration_date = cur_tag + 8; /* Skip "[Ee]xpires=" */
4333
4334 if ((expiration_date[0] == '"')
4335 && (expiration_date[1] != '\0'))
4336 {
4337 /*
4338 * Skip quotation mark. RFC 2109 10.1.2 seems to hint
4339 * that the expiration date isn't supposed to be quoted,
4340 * but some servers do it anyway.
4341 */
4342 expiration_date++;
4343 }
4344
4345 /* Did we detect the date properly? */
4346 if (JB_ERR_OK != parse_header_time(expiration_date, &cookie_time))
4347 {
4348 /*
4349 * Nope, treat it as if it was still valid.
4350 *
4351 * XXX: Should we remove the whole cookie instead?
4352 */
4353 log_error(LOG_LEVEL_ERROR,
4354 "Can't parse \'%s\', send by %s. Unsupported time format?", cur_tag, csp->http->url);
4355 string_move(cur_tag, next_tag);
4356 expiry_date_status = EXPIRY_DATE_UNACCEPTABLE;
4357 }
4358 else
4359 {
4360 /*
4361 * Yes. Check if the cookie is still valid.
4362 *
4363 * If the cookie is already expired it's probably
4364 * a delete cookie and even if it isn't, the browser
4365 * will discard it anyway.
4366 */
4367
4368 /*
4369 * XXX: timegm() isn't available on some AmigaOS
4370 * versions and our replacement doesn't work.
4371 *
4372 * Our options are to either:
4373 *
4374 * - disable session-cookies-only completely if timegm
4375 * is missing,
4376 *
4377 * - to simply remove all expired tags, like it has
4378 * been done until Privoxy 3.0.6 and to live with
4379 * the consequence that it can cause login/logout
4380 * problems on servers that don't validate their
4381 * input properly, or
4382 *
4383 * - to replace it with mktime in which
4384 * case there is a slight chance of valid cookies
4385 * passing as already expired.
4386 *
4387 * This is the way it's currently done and it's not
4388 * as bad as it sounds. If the missing GMT offset is
4389 * enough to change the result of the expiration check
4390 * the cookie will be only valid for a few hours
4391 * anyway, which in many cases will be shorter
4392 * than a browser session.
4393 */
4394 if (cookie_time < now)
4395 {
4396 log_error(LOG_LEVEL_HEADER,
4397 "Cookie \'%s\' is already expired and can pass unmodified.", *header);
4398 /* Just in case some clown sets more then one expiration date */
4399 cur_tag = next_tag;
4400 expiry_date_status = EXPIRY_DATE_ACCEPTABLE;
4401 }
4402 else if ((cookie_lifetime != 0) && (cookie_time < (now + cookie_lifetime)))
4403 {
4404 log_error(LOG_LEVEL_HEADER, "Cookie \'%s\' can pass unmodified. "
4405 "Its lifetime is below the limit.", *header);
4406 /* Just in case some clown sets more then one expiration date */
4407 cur_tag = next_tag;
4408 expiry_date_status = EXPIRY_DATE_ACCEPTABLE;
4409 }
4410 else
4411 {
4412 /*
4413 * Still valid, delete expiration date by copying
4414 * the rest of the string over it.
4415 */
4416 string_move(cur_tag, next_tag);
4417
4418 /* That changed the header, need to issue a log message */
4419 expiry_date_status = EXPIRY_DATE_UNACCEPTABLE;
4420
4421 /*
4422 * Note that the next tag has now been moved to *cur_tag,
4423 * so we do not need to update the cur_tag pointer.
4424 */
4425 }
4426 }
4427
4428 }
4429 else
4430 {
4431 /* Move on to next cookie tag */
4432 cur_tag = next_tag;
4433 }
4434 }
4435
4436 if (expiry_date_status != EXPIRY_DATE_ACCEPTABLE)
4437 {
4438 assert(NULL != *header);
4439 if (cookie_lifetime != 0)
4440 {
4441 add_cookie_expiry_date(header, cookie_lifetime);
4442 log_error(LOG_LEVEL_HEADER, "Cookie rewritten to: %s", *header);
4443 }
4444 else if (expiry_date_status != NO_EXPIRY_DATE_SPECIFIED)
4445 {
4446 log_error(LOG_LEVEL_HEADER,
4447 "Cookie rewritten to a temporary one: %s", *header);
4448 }
4449 }
4450 }
4451
4452 return JB_ERR_OK;
4453 }
4454
4455
4456 #ifdef FEATURE_FORCE_LOAD
4457 /*********************************************************************
4458 *
4459 * Function : strclean
4460 *
4461 * Description : In-Situ-Eliminate all occurrences of substring in
4462 * string
4463 *
4464 * Parameters :
4465 * 1 : string = string to clean
4466 * 2 : substring = substring to eliminate
4467 *
4468 * Returns : Number of eliminations
4469 *
4470 *********************************************************************/
strclean(char * string,const char * substring)4471 int strclean(char *string, const char *substring)
4472 {
4473 int hits = 0;
4474 size_t len;
4475 char *pos, *p;
4476
4477 len = strlen(substring);
4478
4479 while((pos = strstr(string, substring)) != NULL)
4480 {
4481 p = pos + len;
4482 do
4483 {
4484 *(p - len) = *p;
4485 }
4486 while (*p++ != '\0');
4487
4488 hits++;
4489 }
4490
4491 return(hits);
4492 }
4493 #endif /* def FEATURE_FORCE_LOAD */
4494
4495
4496 /*********************************************************************
4497 *
4498 * Function : parse_header_time
4499 *
4500 * Description : Parses time formats used in HTTP header strings
4501 * to get the numerical respresentation.
4502 *
4503 * Parameters :
4504 * 1 : header_time = HTTP header time as string.
4505 * 2 : result = storage for header_time in seconds
4506 *
4507 * Returns : JB_ERR_OK if the time format was recognized, or
4508 * JB_ERR_PARSE otherwise.
4509 *
4510 *********************************************************************/
parse_header_time(const char * header_time,time_t * result)4511 static jb_err parse_header_time(const char *header_time, time_t *result)
4512 {
4513 struct tm gmt;
4514 /*
4515 * Checking for two-digit years first in an
4516 * attempt to work around GNU libc's strptime()
4517 * reporting negative year values when using %Y.
4518 */
4519 static const char time_formats[][22] = {
4520 /* Tue, 02-Jun-37 20:00:00 */
4521 "%a, %d-%b-%y %H:%M:%S",
4522 /* Tue, 02 Jun 2037 20:00:00 */
4523 "%a, %d %b %Y %H:%M:%S",
4524 /* Tue, 02-Jun-2037 20:00:00 */
4525 "%a, %d-%b-%Y %H:%M:%S",
4526 /* Tuesday, 02-Jun-2037 20:00:00 */
4527 "%A, %d-%b-%Y %H:%M:%S",
4528 /* Tuesday Jun 02 20:00:00 2037 */
4529 "%A %b %d %H:%M:%S %Y"
4530 };
4531 unsigned int i;
4532
4533 for (i = 0; i < SZ(time_formats); i++)
4534 {
4535 /*
4536 * Zero out gmt to prevent time zone offsets.
4537 * Documented to be required for GNU libc.
4538 */
4539 memset(&gmt, 0, sizeof(gmt));
4540
4541 if (NULL != strptime(header_time, time_formats[i], &gmt))
4542 {
4543 /* Sanity check for GNU libc. */
4544 if (gmt.tm_year < 0)
4545 {
4546 log_error(LOG_LEVEL_HEADER,
4547 "Failed to parse '%s' using '%s'. Moving on.",
4548 header_time, time_formats[i]);
4549 continue;
4550 }
4551 *result = timegm(&gmt);
4552
4553 #ifdef FEATURE_STRPTIME_SANITY_CHECKS
4554 /*
4555 * Verify that parsing the date recreated from the first
4556 * parse operation gets the previous result. If it doesn't,
4557 * either strptime() or strftime() are malfunctioning.
4558 *
4559 * We could string-compare the recreated date with the original
4560 * header date, but this leads to false positives as strptime()
4561 * may let %a accept all day formats while strftime() will only
4562 * create one.
4563 */
4564 {
4565 char recreated_date[100];
4566 struct tm *tm;
4567 struct tm storage;
4568 time_t result2;
4569
4570 tm = privoxy_gmtime_r(result, &storage);
4571 if (!strftime(recreated_date, sizeof(recreated_date),
4572 time_formats[i], tm))
4573 {
4574 log_error(LOG_LEVEL_ERROR, "Failed to recreate date '%s' with '%s'.",
4575 header_time, time_formats[i]);
4576 continue;
4577 }
4578 memset(&gmt, 0, sizeof(gmt));
4579 if (NULL == strptime(recreated_date, time_formats[i], &gmt))
4580 {
4581 log_error(LOG_LEVEL_ERROR,
4582 "Failed to parse '%s' generated with '%s' to recreate '%s'.",
4583 recreated_date, time_formats[i], header_time);
4584 continue;
4585 }
4586 result2 = timegm(&gmt);
4587 if (*result != result2)
4588 {
4589 log_error(LOG_LEVEL_ERROR, "strftime() and strptime() disagree. "
4590 "Format: '%s'. In: '%s', out: '%s'. %ld != %ld. Rejecting.",
4591 time_formats[i], header_time, recreated_date, *result, result2);
4592 continue;
4593 }
4594 }
4595 #endif
4596
4597 return JB_ERR_OK;
4598 }
4599 }
4600
4601 return JB_ERR_PARSE;
4602
4603 }
4604
4605 /*********************************************************************
4606 *
4607 * Function : parse_time_header
4608 *
4609 * Description : Parses the time in an HTTP time header to get
4610 * the numerical respresentation.
4611 *
4612 * Parameters :
4613 * 1 : header = HTTP header with a time value
4614 * 2 : result = storage for header_time in seconds
4615 *
4616 * Returns : JB_ERR_OK if the time format was recognized, or
4617 * JB_ERR_PARSE otherwise.
4618 *
4619 *********************************************************************/
parse_time_header(const char * header,time_t * result)4620 static jb_err parse_time_header(const char *header, time_t *result)
4621 {
4622 const char *header_time;
4623
4624 header_time = strchr(header, ':');
4625
4626 /*
4627 * Currently this can't happen as all callers are called
4628 * through sed() which requires a header name followed by
4629 * a colon.
4630 */
4631 if (header_time == NULL)
4632 {
4633 return JB_ERR_PARSE;
4634 }
4635
4636 header_time++;
4637 if (*header_time == ' ')
4638 {
4639 header_time++;
4640 }
4641
4642 return parse_header_time(header_time, result);
4643
4644 }
4645
4646
4647 /*********************************************************************
4648 *
4649 * Function : get_destination_from_headers
4650 *
4651 * Description : Parse the "Host:" header to get the request's destination.
4652 * Only needed if the client's request was forcefully
4653 * redirected into Privoxy.
4654 *
4655 * Code mainly copied from client_host() which is currently
4656 * run too late for this purpose.
4657 *
4658 * Parameters :
4659 * 1 : headers = List of headers (one of them hopefully being
4660 * the "Host:" header)
4661 * 2 : http = storage for the result (host, port and hostport).
4662 *
4663 * Returns : JB_ERR_MEMORY (or terminates) in case of memory problems,
4664 * JB_ERR_PARSE if the host header couldn't be found,
4665 * JB_ERR_OK otherwise.
4666 *
4667 *********************************************************************/
get_destination_from_headers(const struct list * headers,struct http_request * http)4668 jb_err get_destination_from_headers(const struct list *headers, struct http_request *http)
4669 {
4670 char *q;
4671 char *p;
4672 char *host;
4673
4674 host = get_header_value(headers, "Host:");
4675
4676 if (NULL == host)
4677 {
4678 log_error(LOG_LEVEL_ERROR, "No \"Host:\" header found.");
4679 return JB_ERR_PARSE;
4680 }
4681
4682 p = string_tolower(host);
4683 if (p == NULL)
4684 {
4685 return JB_ERR_MEMORY;
4686 }
4687 chomp(p);
4688 q = strdup_or_die(p);
4689
4690 freez(http->hostport);
4691 http->hostport = p;
4692 freez(http->host);
4693 http->host = q;
4694 q = strchr(http->host, ':');
4695 if (q != NULL)
4696 {
4697 /* Terminate hostname and evaluate port string */
4698 *q++ = '\0';
4699 http->port = atoi(q);
4700 }
4701 else
4702 {
4703 http->port = 80;
4704 }
4705
4706 /* Rebuild request URL */
4707 freez(http->url);
4708 http->url = strdup("http://");
4709 string_append(&http->url, http->hostport);
4710 string_append(&http->url, http->path);
4711 if (http->url == NULL)
4712 {
4713 return JB_ERR_MEMORY;
4714 }
4715
4716 log_error(LOG_LEVEL_HEADER,
4717 "Destination extracted from \"Host\" header. New request URL: %s",
4718 http->url);
4719
4720 /*
4721 * Regenerate request line in "proxy format"
4722 * to make rewrites more convenient.
4723 */
4724 assert(http->cmd != NULL);
4725 freez(http->cmd);
4726 http->cmd = strdup_or_die(http->gpc);
4727 string_append(&http->cmd, " ");
4728 string_append(&http->cmd, http->url);
4729 string_append(&http->cmd, " ");
4730 string_append(&http->cmd, http->version);
4731 if (http->cmd == NULL)
4732 {
4733 return JB_ERR_MEMORY;
4734 }
4735
4736 return JB_ERR_OK;
4737
4738 }
4739
4740
4741 #ifdef FEATURE_HTTPS_INSPECTION
4742 /*********************************************************************
4743 *
4744 * Function : get_destination_from_https_headers
4745 *
4746 * Description : Parse the previously encrypted "Host:" header to
4747 * get the request's destination.
4748 *
4749 * Parameters :
4750 * 1 : headers = List of headers (one of them hopefully being
4751 * the "Host:" header)
4752 * 2 : http = storage for the result (host, port and hostport).
4753 *
4754 * Returns : JB_ERR_MEMORY (or terminates) in case of memory problems,
4755 * JB_ERR_PARSE if the host header couldn't be found,
4756 * JB_ERR_OK otherwise.
4757 *
4758 *********************************************************************/
get_destination_from_https_headers(const struct list * headers,struct http_request * http)4759 jb_err get_destination_from_https_headers(const struct list *headers, struct http_request *http)
4760 {
4761 char *q;
4762 char *p;
4763 char *host;
4764
4765 host = get_header_value(headers, "Host:");
4766
4767 if (NULL == host)
4768 {
4769 log_error(LOG_LEVEL_ERROR, "No \"Host:\" header found.");
4770 return JB_ERR_PARSE;
4771 }
4772
4773 p = string_tolower(host);
4774 if (p == NULL)
4775 {
4776 return JB_ERR_MEMORY;
4777 }
4778 chomp(p);
4779 q = strdup_or_die(p);
4780
4781 freez(http->hostport);
4782 http->hostport = p;
4783 freez(http->host);
4784 http->host = q;
4785 q = strchr(http->host, ':');
4786 if (q != NULL)
4787 {
4788 /* Terminate hostname and evaluate port string */
4789 *q++ = '\0';
4790 http->port = atoi(q);
4791 }
4792 else
4793 {
4794 http->port = 443;
4795 }
4796
4797 /* Rebuild request URL */
4798 freez(http->url);
4799 http->url = strdup_or_die(http->path);
4800
4801 log_error(LOG_LEVEL_HEADER,
4802 "Destination extracted from \"Host\" header. New request URL: %s",
4803 http->url);
4804
4805 /*
4806 * Regenerate request line in "proxy format"
4807 * to make rewrites more convenient.
4808 */
4809 assert(http->cmd != NULL);
4810 freez(http->cmd);
4811 http->cmd = strdup_or_die(http->gpc);
4812 string_append(&http->cmd, " ");
4813 string_append(&http->cmd, http->url);
4814 string_append(&http->cmd, " ");
4815 string_append(&http->cmd, http->version);
4816 if (http->cmd == NULL)
4817 {
4818 return JB_ERR_MEMORY;
4819 }
4820
4821 return JB_ERR_OK;
4822
4823 }
4824 #endif /* def FEATURE_HTTPS_INSPECTION */
4825
4826
4827 /*********************************************************************
4828 *
4829 * Function : create_forged_referrer
4830 *
4831 * Description : Helper for client_referrer to forge a referer as
4832 * 'http://hostname[:port]/' to fool stupid
4833 * checks for in-site links
4834 *
4835 * Parameters :
4836 * 1 : header = Pointer to header pointer
4837 * 2 : hostport = Host and optionally port as string
4838 *
4839 * Returns : JB_ERR_OK in case of success, or
4840 * JB_ERR_MEMORY in case of memory problems.
4841 *
4842 *********************************************************************/
create_forged_referrer(char ** header,const char * hostport)4843 static jb_err create_forged_referrer(char **header, const char *hostport)
4844 {
4845 assert(NULL == *header);
4846
4847 *header = strdup("Referer: http://");
4848 string_append(header, hostport);
4849 string_append(header, "/");
4850
4851 if (NULL == *header)
4852 {
4853 return JB_ERR_MEMORY;
4854 }
4855
4856 log_error(LOG_LEVEL_HEADER, "Referer forged to: %s", *header);
4857
4858 return JB_ERR_OK;
4859
4860 }
4861
4862
4863 /*********************************************************************
4864 *
4865 * Function : create_fake_referrer
4866 *
4867 * Description : Helper for client_referrer to create a fake referrer
4868 * based on a string supplied by the user.
4869 *
4870 * Parameters :
4871 * 1 : header = Pointer to header pointer
4872 * 2 : hosthost = Referrer to fake
4873 *
4874 * Returns : JB_ERR_OK in case of success, or
4875 * JB_ERR_MEMORY in case of memory problems.
4876 *
4877 *********************************************************************/
create_fake_referrer(char ** header,const char * fake_referrer)4878 static jb_err create_fake_referrer(char **header, const char *fake_referrer)
4879 {
4880 assert(NULL == *header);
4881
4882 if ((0 != strncmpic(fake_referrer, "http://", 7)) && (0 != strncmpic(fake_referrer, "https://", 8)))
4883 {
4884 log_error(LOG_LEVEL_HEADER,
4885 "Parameter: +hide-referrer{%s} is a bad idea, but I don't care.", fake_referrer);
4886 }
4887 *header = strdup("Referer: ");
4888 string_append(header, fake_referrer);
4889
4890 if (NULL == *header)
4891 {
4892 return JB_ERR_MEMORY;
4893 }
4894
4895 log_error(LOG_LEVEL_HEADER, "Referer replaced with: %s", *header);
4896
4897 return JB_ERR_OK;
4898
4899 }
4900
4901
4902 /*********************************************************************
4903 *
4904 * Function : handle_conditional_hide_referrer_parameter
4905 *
4906 * Description : Helper for client_referrer to crunch or forge
4907 * the referrer header if the host has changed.
4908 *
4909 * Parameters :
4910 * 1 : header = Pointer to header pointer
4911 * 2 : host = The target host (may include the port)
4912 * 3 : parameter_conditional_block = Boolean to signal
4913 * if we're in conditional-block mode. If not set,
4914 * we're in conditional-forge mode.
4915 *
4916 * Returns : JB_ERR_OK in case of success, or
4917 * JB_ERR_MEMORY in case of memory problems.
4918 *
4919 *********************************************************************/
handle_conditional_hide_referrer_parameter(char ** header,const char * host,const int parameter_conditional_block)4920 static jb_err handle_conditional_hide_referrer_parameter(char **header,
4921 const char *host, const int parameter_conditional_block)
4922 {
4923 char *referer = strdup_or_die(*header);
4924 const size_t hostlength = strlen(host);
4925 const char *referer_url = NULL;
4926
4927 /* referer begins with 'Referer: http[s]://' */
4928 if ((hostlength+17) < strlen(referer))
4929 {
4930 /*
4931 * Shorten referer to make sure the referer is blocked
4932 * if www.example.org/www.example.com-shall-see-the-referer/
4933 * links to www.example.com/
4934 */
4935 referer[hostlength+17] = '\0';
4936 }
4937 referer_url = strstr(referer, "http://");
4938 if (NULL == referer_url)
4939 {
4940 referer_url = strstr(referer, "https://");
4941 }
4942 if ((NULL == referer_url) || (NULL == strstr(referer_url, host)))
4943 {
4944 /* Host has changed, Referer is invalid or a https URL. */
4945 if (parameter_conditional_block)
4946 {
4947 log_error(LOG_LEVEL_HEADER, "New host is: %s. Crunching %s!", host, *header);
4948 freez(*header);
4949 }
4950 else
4951 {
4952 freez(*header);
4953 freez(referer);
4954 return create_forged_referrer(header, host);
4955 }
4956 }
4957 freez(referer);
4958
4959 return JB_ERR_OK;
4960
4961 }
4962
4963
4964 /*********************************************************************
4965 *
4966 * Function : create_content_length_header
4967 *
4968 * Description : Creates a Content-Length header.
4969 *
4970 * Parameters :
4971 * 1 : content_length = The content length to be used in the header.
4972 * 2 : header = Allocated space to safe the header.
4973 * 3 : buffer_length = The length of the allocated space.
4974 *
4975 * Returns : void
4976 *
4977 *********************************************************************/
create_content_length_header(unsigned long long content_length,char * header,size_t buffer_length)4978 static void create_content_length_header(unsigned long long content_length,
4979 char *header, size_t buffer_length)
4980 {
4981 #ifdef _WIN32
4982 #if SIZEOF_LONG_LONG < 8
4983 #error sizeof(unsigned long long) too small
4984 #endif
4985 snprintf(header, buffer_length, "Content-Length: %I64u", content_length);
4986 #else
4987 snprintf(header, buffer_length, "Content-Length: %llu", content_length);
4988 #endif
4989 }
4990
4991
4992 /*********************************************************************
4993 *
4994 * Function : get_expected_content_length
4995 *
4996 * Description : Figures out the content length from a list of headers.
4997 *
4998 * Parameters :
4999 * 1 : headers = List of headers
5000 *
5001 * Returns : Number of bytes to expect
5002 *
5003 *********************************************************************/
get_expected_content_length(struct list * headers)5004 unsigned long long get_expected_content_length(struct list *headers)
5005 {
5006 const char *content_length_header;
5007 unsigned long long content_length = 0;
5008
5009 content_length_header = get_header_value(headers, "Content-Length:");
5010 if (content_length_header != NULL)
5011 {
5012 if (JB_ERR_OK != get_content_length(content_length_header, &content_length))
5013 {
5014 log_error(LOG_LEVEL_ERROR,
5015 "Failed to get the Content-Length in %s", content_length_header);
5016 /* XXX: The header will be removed later on */
5017 return 0;
5018 }
5019 }
5020
5021 return content_length;
5022 }
5023
5024
5025 /*
5026 Local Variables:
5027 tab-width: 3
5028 end:
5029 */
5030