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Commit | Line | Data |
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9fafcd7b PM |
1 | /* SIP extension for IP connection tracking. |
2 | * | |
3 | * (C) 2005 by Christian Hentschel <chentschel@arnet.com.ar> | |
4 | * based on RR's ip_conntrack_ftp.c and other modules. | |
f49e1aa1 PM |
5 | * (C) 2007 United Security Providers |
6 | * (C) 2007, 2008 Patrick McHardy <kaber@trash.net> | |
9fafcd7b PM |
7 | * |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | */ | |
12 | ||
ad6d9503 PNA |
13 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
14 | ||
9fafcd7b PM |
15 | #include <linux/module.h> |
16 | #include <linux/ctype.h> | |
17 | #include <linux/skbuff.h> | |
18 | #include <linux/inet.h> | |
19 | #include <linux/in.h> | |
20 | #include <linux/udp.h> | |
f5b321bd | 21 | #include <linux/tcp.h> |
1863f096 | 22 | #include <linux/netfilter.h> |
9fafcd7b PM |
23 | |
24 | #include <net/netfilter/nf_conntrack.h> | |
9467ee38 | 25 | #include <net/netfilter/nf_conntrack_core.h> |
9fafcd7b PM |
26 | #include <net/netfilter/nf_conntrack_expect.h> |
27 | #include <net/netfilter/nf_conntrack_helper.h> | |
5d0aa2cc | 28 | #include <net/netfilter/nf_conntrack_zones.h> |
9fafcd7b PM |
29 | #include <linux/netfilter/nf_conntrack_sip.h> |
30 | ||
9fafcd7b PM |
31 | MODULE_LICENSE("GPL"); |
32 | MODULE_AUTHOR("Christian Hentschel <chentschel@arnet.com.ar>"); | |
33 | MODULE_DESCRIPTION("SIP connection tracking helper"); | |
34 | MODULE_ALIAS("ip_conntrack_sip"); | |
4dc06f96 | 35 | MODULE_ALIAS_NFCT_HELPER("sip"); |
9fafcd7b PM |
36 | |
37 | #define MAX_PORTS 8 | |
38 | static unsigned short ports[MAX_PORTS]; | |
2f0d2f10 | 39 | static unsigned int ports_c; |
9fafcd7b PM |
40 | module_param_array(ports, ushort, &ports_c, 0400); |
41 | MODULE_PARM_DESC(ports, "port numbers of SIP servers"); | |
42 | ||
43 | static unsigned int sip_timeout __read_mostly = SIP_TIMEOUT; | |
44 | module_param(sip_timeout, uint, 0600); | |
45 | MODULE_PARM_DESC(sip_timeout, "timeout for the master SIP session"); | |
46 | ||
0f32a40f PM |
47 | static int sip_direct_signalling __read_mostly = 1; |
48 | module_param(sip_direct_signalling, int, 0600); | |
49 | MODULE_PARM_DESC(sip_direct_signalling, "expect incoming calls from registrar " | |
50 | "only (default 1)"); | |
51 | ||
d901a936 PM |
52 | static int sip_direct_media __read_mostly = 1; |
53 | module_param(sip_direct_media, int, 0600); | |
54 | MODULE_PARM_DESC(sip_direct_media, "Expect Media streams between signalling " | |
55 | "endpoints only (default 1)"); | |
56 | ||
180cf72f | 57 | const struct nf_nat_sip_hooks *nf_nat_sip_hooks; |
58 | EXPORT_SYMBOL_GPL(nf_nat_sip_hooks); | |
9fafcd7b | 59 | |
ac367740 PM |
60 | static int string_len(const struct nf_conn *ct, const char *dptr, |
61 | const char *limit, int *shift) | |
62 | { | |
63 | int len = 0; | |
64 | ||
65 | while (dptr < limit && isalpha(*dptr)) { | |
66 | dptr++; | |
67 | len++; | |
68 | } | |
69 | return len; | |
70 | } | |
71 | ||
13f7d63c | 72 | static int digits_len(const struct nf_conn *ct, const char *dptr, |
9fafcd7b PM |
73 | const char *limit, int *shift) |
74 | { | |
75 | int len = 0; | |
b1ec488b | 76 | while (dptr < limit && isdigit(*dptr)) { |
9fafcd7b PM |
77 | dptr++; |
78 | len++; | |
79 | } | |
80 | return len; | |
81 | } | |
82 | ||
001985b2 SH |
83 | static int iswordc(const char c) |
84 | { | |
85 | if (isalnum(c) || c == '!' || c == '"' || c == '%' || | |
f0608cea | 86 | (c >= '(' && c <= '+') || c == ':' || c == '<' || c == '>' || |
001985b2 | 87 | c == '?' || (c >= '[' && c <= ']') || c == '_' || c == '`' || |
f0608cea MA |
88 | c == '{' || c == '}' || c == '~' || (c >= '-' && c <= '/') || |
89 | c == '\'') | |
001985b2 SH |
90 | return 1; |
91 | return 0; | |
92 | } | |
93 | ||
94 | static int word_len(const char *dptr, const char *limit) | |
95 | { | |
96 | int len = 0; | |
97 | while (dptr < limit && iswordc(*dptr)) { | |
98 | dptr++; | |
99 | len++; | |
100 | } | |
101 | return len; | |
102 | } | |
103 | ||
104 | static int callid_len(const struct nf_conn *ct, const char *dptr, | |
105 | const char *limit, int *shift) | |
106 | { | |
107 | int len, domain_len; | |
108 | ||
109 | len = word_len(dptr, limit); | |
110 | dptr += len; | |
111 | if (!len || dptr == limit || *dptr != '@') | |
112 | return len; | |
113 | dptr++; | |
114 | len++; | |
115 | ||
116 | domain_len = word_len(dptr, limit); | |
117 | if (!domain_len) | |
118 | return 0; | |
119 | return len + domain_len; | |
120 | } | |
121 | ||
0d0ab037 PM |
122 | /* get media type + port length */ |
123 | static int media_len(const struct nf_conn *ct, const char *dptr, | |
124 | const char *limit, int *shift) | |
125 | { | |
126 | int len = string_len(ct, dptr, limit, shift); | |
127 | ||
128 | dptr += len; | |
129 | if (dptr >= limit || *dptr != ' ') | |
130 | return 0; | |
131 | len++; | |
132 | dptr++; | |
133 | ||
134 | return len + digits_len(ct, dptr, limit, shift); | |
135 | } | |
136 | ||
02b69cbd PM |
137 | static int sip_parse_addr(const struct nf_conn *ct, const char *cp, |
138 | const char **endp, union nf_inet_addr *addr, | |
139 | const char *limit, bool delim) | |
9fafcd7b PM |
140 | { |
141 | const char *end; | |
02b69cbd | 142 | int ret; |
9fafcd7b | 143 | |
5adbb9fb SH |
144 | if (!ct) |
145 | return 0; | |
146 | ||
fa913ddf | 147 | memset(addr, 0, sizeof(*addr)); |
5e8fbe2a | 148 | switch (nf_ct_l3num(ct)) { |
9fafcd7b PM |
149 | case AF_INET: |
150 | ret = in4_pton(cp, limit - cp, (u8 *)&addr->ip, -1, &end); | |
02b69cbd PM |
151 | if (ret == 0) |
152 | return 0; | |
9fafcd7b PM |
153 | break; |
154 | case AF_INET6: | |
02b69cbd PM |
155 | if (cp < limit && *cp == '[') |
156 | cp++; | |
157 | else if (delim) | |
158 | return 0; | |
159 | ||
9fafcd7b | 160 | ret = in6_pton(cp, limit - cp, (u8 *)&addr->ip6, -1, &end); |
02b69cbd PM |
161 | if (ret == 0) |
162 | return 0; | |
163 | ||
164 | if (end < limit && *end == ']') | |
165 | end++; | |
166 | else if (delim) | |
167 | return 0; | |
9fafcd7b PM |
168 | break; |
169 | default: | |
170 | BUG(); | |
171 | } | |
172 | ||
9fafcd7b PM |
173 | if (endp) |
174 | *endp = end; | |
175 | return 1; | |
176 | } | |
177 | ||
178 | /* skip ip address. returns its length. */ | |
13f7d63c | 179 | static int epaddr_len(const struct nf_conn *ct, const char *dptr, |
9fafcd7b PM |
180 | const char *limit, int *shift) |
181 | { | |
643a2c15 | 182 | union nf_inet_addr addr; |
9fafcd7b PM |
183 | const char *aux = dptr; |
184 | ||
02b69cbd | 185 | if (!sip_parse_addr(ct, dptr, &dptr, &addr, limit, true)) { |
0d53778e | 186 | pr_debug("ip: %s parse failed.!\n", dptr); |
9fafcd7b PM |
187 | return 0; |
188 | } | |
189 | ||
190 | /* Port number */ | |
191 | if (*dptr == ':') { | |
192 | dptr++; | |
193 | dptr += digits_len(ct, dptr, limit, shift); | |
194 | } | |
195 | return dptr - aux; | |
196 | } | |
197 | ||
198 | /* get address length, skiping user info. */ | |
13f7d63c | 199 | static int skp_epaddr_len(const struct nf_conn *ct, const char *dptr, |
9fafcd7b PM |
200 | const char *limit, int *shift) |
201 | { | |
aa584eda | 202 | const char *start = dptr; |
9fafcd7b PM |
203 | int s = *shift; |
204 | ||
7da5bfbb LI |
205 | /* Search for @, but stop at the end of the line. |
206 | * We are inside a sip: URI, so we don't need to worry about | |
207 | * continuation lines. */ | |
b1ec488b | 208 | while (dptr < limit && |
7da5bfbb | 209 | *dptr != '@' && *dptr != '\r' && *dptr != '\n') { |
9fafcd7b | 210 | (*shift)++; |
7da5bfbb LI |
211 | dptr++; |
212 | } | |
9fafcd7b | 213 | |
b1ec488b | 214 | if (dptr < limit && *dptr == '@') { |
9fafcd7b PM |
215 | dptr++; |
216 | (*shift)++; | |
aa584eda PM |
217 | } else { |
218 | dptr = start; | |
9fafcd7b | 219 | *shift = s; |
aa584eda | 220 | } |
9fafcd7b PM |
221 | |
222 | return epaddr_len(ct, dptr, limit, shift); | |
223 | } | |
224 | ||
ac367740 PM |
225 | /* Parse a SIP request line of the form: |
226 | * | |
227 | * Request-Line = Method SP Request-URI SP SIP-Version CRLF | |
228 | * | |
229 | * and return the offset and length of the address contained in the Request-URI. | |
230 | */ | |
231 | int ct_sip_parse_request(const struct nf_conn *ct, | |
232 | const char *dptr, unsigned int datalen, | |
624f8b7b PM |
233 | unsigned int *matchoff, unsigned int *matchlen, |
234 | union nf_inet_addr *addr, __be16 *port) | |
ac367740 | 235 | { |
624f8b7b | 236 | const char *start = dptr, *limit = dptr + datalen, *end; |
ac367740 | 237 | unsigned int mlen; |
624f8b7b | 238 | unsigned int p; |
ac367740 PM |
239 | int shift = 0; |
240 | ||
241 | /* Skip method and following whitespace */ | |
242 | mlen = string_len(ct, dptr, limit, NULL); | |
243 | if (!mlen) | |
244 | return 0; | |
245 | dptr += mlen; | |
246 | if (++dptr >= limit) | |
247 | return 0; | |
248 | ||
249 | /* Find SIP URI */ | |
54101f4f | 250 | for (; dptr < limit - strlen("sip:"); dptr++) { |
ac367740 PM |
251 | if (*dptr == '\r' || *dptr == '\n') |
252 | return -1; | |
18082746 | 253 | if (strncasecmp(dptr, "sip:", strlen("sip:")) == 0) { |
54101f4f | 254 | dptr += strlen("sip:"); |
ac367740 | 255 | break; |
54101f4f | 256 | } |
ac367740 | 257 | } |
624f8b7b | 258 | if (!skp_epaddr_len(ct, dptr, limit, &shift)) |
ac367740 | 259 | return 0; |
624f8b7b PM |
260 | dptr += shift; |
261 | ||
02b69cbd | 262 | if (!sip_parse_addr(ct, dptr, &end, addr, limit, true)) |
624f8b7b PM |
263 | return -1; |
264 | if (end < limit && *end == ':') { | |
265 | end++; | |
266 | p = simple_strtoul(end, (char **)&end, 10); | |
267 | if (p < 1024 || p > 65535) | |
268 | return -1; | |
269 | *port = htons(p); | |
270 | } else | |
271 | *port = htons(SIP_PORT); | |
272 | ||
273 | if (end == dptr) | |
274 | return 0; | |
275 | *matchoff = dptr - start; | |
276 | *matchlen = end - dptr; | |
ac367740 PM |
277 | return 1; |
278 | } | |
279 | EXPORT_SYMBOL_GPL(ct_sip_parse_request); | |
280 | ||
ea45f12a PM |
281 | /* SIP header parsing: SIP headers are located at the beginning of a line, but |
282 | * may span several lines, in which case the continuation lines begin with a | |
283 | * whitespace character. RFC 2543 allows lines to be terminated with CR, LF or | |
284 | * CRLF, RFC 3261 allows only CRLF, we support both. | |
285 | * | |
286 | * Headers are followed by (optionally) whitespace, a colon, again (optionally) | |
287 | * whitespace and the values. Whitespace in this context means any amount of | |
288 | * tabs, spaces and continuation lines, which are treated as a single whitespace | |
289 | * character. | |
05e3ced2 | 290 | * |
3ad2f3fb | 291 | * Some headers may appear multiple times. A comma separated list of values is |
05e3ced2 | 292 | * equivalent to multiple headers. |
ea45f12a PM |
293 | */ |
294 | static const struct sip_header ct_sip_hdrs[] = { | |
30f33e6d | 295 | [SIP_HDR_CSEQ] = SIP_HDR("CSeq", NULL, NULL, digits_len), |
ea45f12a PM |
296 | [SIP_HDR_FROM] = SIP_HDR("From", "f", "sip:", skp_epaddr_len), |
297 | [SIP_HDR_TO] = SIP_HDR("To", "t", "sip:", skp_epaddr_len), | |
298 | [SIP_HDR_CONTACT] = SIP_HDR("Contact", "m", "sip:", skp_epaddr_len), | |
f5b321bd PM |
299 | [SIP_HDR_VIA_UDP] = SIP_HDR("Via", "v", "UDP ", epaddr_len), |
300 | [SIP_HDR_VIA_TCP] = SIP_HDR("Via", "v", "TCP ", epaddr_len), | |
0f32a40f | 301 | [SIP_HDR_EXPIRES] = SIP_HDR("Expires", NULL, NULL, digits_len), |
ea45f12a | 302 | [SIP_HDR_CONTENT_LENGTH] = SIP_HDR("Content-Length", "l", NULL, digits_len), |
001985b2 | 303 | [SIP_HDR_CALL_ID] = SIP_HDR("Call-Id", "i", NULL, callid_len), |
ea45f12a PM |
304 | }; |
305 | ||
306 | static const char *sip_follow_continuation(const char *dptr, const char *limit) | |
9fafcd7b | 307 | { |
ea45f12a PM |
308 | /* Walk past newline */ |
309 | if (++dptr >= limit) | |
310 | return NULL; | |
311 | ||
312 | /* Skip '\n' in CR LF */ | |
313 | if (*(dptr - 1) == '\r' && *dptr == '\n') { | |
314 | if (++dptr >= limit) | |
315 | return NULL; | |
316 | } | |
9fafcd7b | 317 | |
ea45f12a PM |
318 | /* Continuation line? */ |
319 | if (*dptr != ' ' && *dptr != '\t') | |
320 | return NULL; | |
9fafcd7b | 321 | |
ea45f12a PM |
322 | /* skip leading whitespace */ |
323 | for (; dptr < limit; dptr++) { | |
324 | if (*dptr != ' ' && *dptr != '\t') | |
325 | break; | |
326 | } | |
327 | return dptr; | |
328 | } | |
329 | ||
330 | static const char *sip_skip_whitespace(const char *dptr, const char *limit) | |
331 | { | |
332 | for (; dptr < limit; dptr++) { | |
1bcabc81 | 333 | if (*dptr == ' ' || *dptr == '\t') |
ea45f12a PM |
334 | continue; |
335 | if (*dptr != '\r' && *dptr != '\n') | |
336 | break; | |
337 | dptr = sip_follow_continuation(dptr, limit); | |
68cb9fe4 | 338 | break; |
ea45f12a PM |
339 | } |
340 | return dptr; | |
341 | } | |
342 | ||
343 | /* Search within a SIP header value, dealing with continuation lines */ | |
344 | static const char *ct_sip_header_search(const char *dptr, const char *limit, | |
345 | const char *needle, unsigned int len) | |
346 | { | |
347 | for (limit -= len; dptr < limit; dptr++) { | |
348 | if (*dptr == '\r' || *dptr == '\n') { | |
349 | dptr = sip_follow_continuation(dptr, limit); | |
350 | if (dptr == NULL) | |
351 | break; | |
9fafcd7b PM |
352 | continue; |
353 | } | |
ea45f12a | 354 | |
18082746 | 355 | if (strncasecmp(dptr, needle, len) == 0) |
ea45f12a PM |
356 | return dptr; |
357 | } | |
358 | return NULL; | |
359 | } | |
360 | ||
361 | int ct_sip_get_header(const struct nf_conn *ct, const char *dptr, | |
362 | unsigned int dataoff, unsigned int datalen, | |
363 | enum sip_header_types type, | |
364 | unsigned int *matchoff, unsigned int *matchlen) | |
365 | { | |
366 | const struct sip_header *hdr = &ct_sip_hdrs[type]; | |
367 | const char *start = dptr, *limit = dptr + datalen; | |
368 | int shift = 0; | |
369 | ||
370 | for (dptr += dataoff; dptr < limit; dptr++) { | |
371 | /* Find beginning of line */ | |
372 | if (*dptr != '\r' && *dptr != '\n') | |
373 | continue; | |
374 | if (++dptr >= limit) | |
375 | break; | |
376 | if (*(dptr - 1) == '\r' && *dptr == '\n') { | |
377 | if (++dptr >= limit) | |
378 | break; | |
9fafcd7b | 379 | } |
9fafcd7b | 380 | |
ea45f12a PM |
381 | /* Skip continuation lines */ |
382 | if (*dptr == ' ' || *dptr == '\t') | |
383 | continue; | |
9fafcd7b | 384 | |
ea45f12a PM |
385 | /* Find header. Compact headers must be followed by a |
386 | * non-alphabetic character to avoid mismatches. */ | |
387 | if (limit - dptr >= hdr->len && | |
18082746 | 388 | strncasecmp(dptr, hdr->name, hdr->len) == 0) |
ea45f12a PM |
389 | dptr += hdr->len; |
390 | else if (hdr->cname && limit - dptr >= hdr->clen + 1 && | |
18082746 | 391 | strncasecmp(dptr, hdr->cname, hdr->clen) == 0 && |
135d0189 | 392 | !isalpha(*(dptr + hdr->clen))) |
ea45f12a PM |
393 | dptr += hdr->clen; |
394 | else | |
395 | continue; | |
9fafcd7b | 396 | |
ea45f12a PM |
397 | /* Find and skip colon */ |
398 | dptr = sip_skip_whitespace(dptr, limit); | |
399 | if (dptr == NULL) | |
400 | break; | |
401 | if (*dptr != ':' || ++dptr >= limit) | |
402 | break; | |
403 | ||
404 | /* Skip whitespace after colon */ | |
405 | dptr = sip_skip_whitespace(dptr, limit); | |
406 | if (dptr == NULL) | |
407 | break; | |
408 | ||
409 | *matchoff = dptr - start; | |
410 | if (hdr->search) { | |
411 | dptr = ct_sip_header_search(dptr, limit, hdr->search, | |
412 | hdr->slen); | |
413 | if (!dptr) | |
414 | return -1; | |
415 | dptr += hdr->slen; | |
416 | } | |
417 | ||
418 | *matchlen = hdr->match_len(ct, dptr, limit, &shift); | |
419 | if (!*matchlen) | |
420 | return -1; | |
421 | *matchoff = dptr - start + shift; | |
9fafcd7b PM |
422 | return 1; |
423 | } | |
9fafcd7b PM |
424 | return 0; |
425 | } | |
ea45f12a | 426 | EXPORT_SYMBOL_GPL(ct_sip_get_header); |
9fafcd7b | 427 | |
3ad2f3fb | 428 | /* Get next header field in a list of comma separated values */ |
05e3ced2 PM |
429 | static int ct_sip_next_header(const struct nf_conn *ct, const char *dptr, |
430 | unsigned int dataoff, unsigned int datalen, | |
431 | enum sip_header_types type, | |
432 | unsigned int *matchoff, unsigned int *matchlen) | |
433 | { | |
434 | const struct sip_header *hdr = &ct_sip_hdrs[type]; | |
435 | const char *start = dptr, *limit = dptr + datalen; | |
436 | int shift = 0; | |
437 | ||
438 | dptr += dataoff; | |
439 | ||
440 | dptr = ct_sip_header_search(dptr, limit, ",", strlen(",")); | |
441 | if (!dptr) | |
442 | return 0; | |
443 | ||
444 | dptr = ct_sip_header_search(dptr, limit, hdr->search, hdr->slen); | |
445 | if (!dptr) | |
446 | return 0; | |
447 | dptr += hdr->slen; | |
448 | ||
449 | *matchoff = dptr - start; | |
450 | *matchlen = hdr->match_len(ct, dptr, limit, &shift); | |
451 | if (!*matchlen) | |
452 | return -1; | |
453 | *matchoff += shift; | |
454 | return 1; | |
455 | } | |
456 | ||
457 | /* Walk through headers until a parsable one is found or no header of the | |
458 | * given type is left. */ | |
459 | static int ct_sip_walk_headers(const struct nf_conn *ct, const char *dptr, | |
460 | unsigned int dataoff, unsigned int datalen, | |
461 | enum sip_header_types type, int *in_header, | |
462 | unsigned int *matchoff, unsigned int *matchlen) | |
463 | { | |
464 | int ret; | |
465 | ||
466 | if (in_header && *in_header) { | |
467 | while (1) { | |
468 | ret = ct_sip_next_header(ct, dptr, dataoff, datalen, | |
469 | type, matchoff, matchlen); | |
470 | if (ret > 0) | |
471 | return ret; | |
472 | if (ret == 0) | |
473 | break; | |
474 | dataoff += *matchoff; | |
475 | } | |
476 | *in_header = 0; | |
477 | } | |
478 | ||
479 | while (1) { | |
480 | ret = ct_sip_get_header(ct, dptr, dataoff, datalen, | |
481 | type, matchoff, matchlen); | |
482 | if (ret > 0) | |
483 | break; | |
484 | if (ret == 0) | |
485 | return ret; | |
486 | dataoff += *matchoff; | |
487 | } | |
488 | ||
489 | if (in_header) | |
490 | *in_header = 1; | |
491 | return 1; | |
492 | } | |
493 | ||
494 | /* Locate a SIP header, parse the URI and return the offset and length of | |
495 | * the address as well as the address and port themselves. A stream of | |
496 | * headers can be parsed by handing in a non-NULL datalen and in_header | |
497 | * pointer. | |
498 | */ | |
499 | int ct_sip_parse_header_uri(const struct nf_conn *ct, const char *dptr, | |
500 | unsigned int *dataoff, unsigned int datalen, | |
501 | enum sip_header_types type, int *in_header, | |
502 | unsigned int *matchoff, unsigned int *matchlen, | |
503 | union nf_inet_addr *addr, __be16 *port) | |
504 | { | |
505 | const char *c, *limit = dptr + datalen; | |
506 | unsigned int p; | |
507 | int ret; | |
508 | ||
509 | ret = ct_sip_walk_headers(ct, dptr, dataoff ? *dataoff : 0, datalen, | |
510 | type, in_header, matchoff, matchlen); | |
511 | WARN_ON(ret < 0); | |
512 | if (ret == 0) | |
513 | return ret; | |
514 | ||
02b69cbd | 515 | if (!sip_parse_addr(ct, dptr + *matchoff, &c, addr, limit, true)) |
05e3ced2 PM |
516 | return -1; |
517 | if (*c == ':') { | |
518 | c++; | |
519 | p = simple_strtoul(c, (char **)&c, 10); | |
520 | if (p < 1024 || p > 65535) | |
521 | return -1; | |
522 | *port = htons(p); | |
523 | } else | |
524 | *port = htons(SIP_PORT); | |
525 | ||
526 | if (dataoff) | |
527 | *dataoff = c - dptr; | |
528 | return 1; | |
529 | } | |
530 | EXPORT_SYMBOL_GPL(ct_sip_parse_header_uri); | |
531 | ||
f5b321bd PM |
532 | static int ct_sip_parse_param(const struct nf_conn *ct, const char *dptr, |
533 | unsigned int dataoff, unsigned int datalen, | |
534 | const char *name, | |
535 | unsigned int *matchoff, unsigned int *matchlen) | |
536 | { | |
537 | const char *limit = dptr + datalen; | |
538 | const char *start; | |
539 | const char *end; | |
540 | ||
541 | limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(",")); | |
542 | if (!limit) | |
543 | limit = dptr + datalen; | |
544 | ||
545 | start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name)); | |
546 | if (!start) | |
547 | return 0; | |
548 | start += strlen(name); | |
549 | ||
550 | end = ct_sip_header_search(start, limit, ";", strlen(";")); | |
551 | if (!end) | |
552 | end = limit; | |
553 | ||
554 | *matchoff = start - dptr; | |
555 | *matchlen = end - start; | |
556 | return 1; | |
557 | } | |
558 | ||
2bbb2116 PM |
559 | /* Parse address from header parameter and return address, offset and length */ |
560 | int ct_sip_parse_address_param(const struct nf_conn *ct, const char *dptr, | |
561 | unsigned int dataoff, unsigned int datalen, | |
562 | const char *name, | |
563 | unsigned int *matchoff, unsigned int *matchlen, | |
02b69cbd | 564 | union nf_inet_addr *addr, bool delim) |
2bbb2116 PM |
565 | { |
566 | const char *limit = dptr + datalen; | |
567 | const char *start, *end; | |
568 | ||
569 | limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(",")); | |
570 | if (!limit) | |
571 | limit = dptr + datalen; | |
572 | ||
573 | start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name)); | |
574 | if (!start) | |
575 | return 0; | |
576 | ||
577 | start += strlen(name); | |
02b69cbd | 578 | if (!sip_parse_addr(ct, start, &end, addr, limit, delim)) |
2bbb2116 PM |
579 | return 0; |
580 | *matchoff = start - dptr; | |
581 | *matchlen = end - start; | |
582 | return 1; | |
583 | } | |
584 | EXPORT_SYMBOL_GPL(ct_sip_parse_address_param); | |
585 | ||
586 | /* Parse numerical header parameter and return value, offset and length */ | |
587 | int ct_sip_parse_numerical_param(const struct nf_conn *ct, const char *dptr, | |
588 | unsigned int dataoff, unsigned int datalen, | |
589 | const char *name, | |
590 | unsigned int *matchoff, unsigned int *matchlen, | |
591 | unsigned int *val) | |
592 | { | |
593 | const char *limit = dptr + datalen; | |
594 | const char *start; | |
595 | char *end; | |
596 | ||
597 | limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(",")); | |
598 | if (!limit) | |
599 | limit = dptr + datalen; | |
600 | ||
601 | start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name)); | |
602 | if (!start) | |
603 | return 0; | |
604 | ||
605 | start += strlen(name); | |
606 | *val = simple_strtoul(start, &end, 0); | |
607 | if (start == end) | |
608 | return 0; | |
609 | if (matchoff && matchlen) { | |
610 | *matchoff = start - dptr; | |
611 | *matchlen = end - start; | |
612 | } | |
613 | return 1; | |
614 | } | |
615 | EXPORT_SYMBOL_GPL(ct_sip_parse_numerical_param); | |
616 | ||
f5b321bd PM |
617 | static int ct_sip_parse_transport(struct nf_conn *ct, const char *dptr, |
618 | unsigned int dataoff, unsigned int datalen, | |
619 | u8 *proto) | |
620 | { | |
621 | unsigned int matchoff, matchlen; | |
622 | ||
623 | if (ct_sip_parse_param(ct, dptr, dataoff, datalen, "transport=", | |
624 | &matchoff, &matchlen)) { | |
18082746 | 625 | if (!strncasecmp(dptr + matchoff, "TCP", strlen("TCP"))) |
f5b321bd | 626 | *proto = IPPROTO_TCP; |
18082746 | 627 | else if (!strncasecmp(dptr + matchoff, "UDP", strlen("UDP"))) |
f5b321bd PM |
628 | *proto = IPPROTO_UDP; |
629 | else | |
630 | return 0; | |
631 | ||
632 | if (*proto != nf_ct_protonum(ct)) | |
633 | return 0; | |
634 | } else | |
635 | *proto = nf_ct_protonum(ct); | |
636 | ||
637 | return 1; | |
638 | } | |
639 | ||
02b69cbd PM |
640 | static int sdp_parse_addr(const struct nf_conn *ct, const char *cp, |
641 | const char **endp, union nf_inet_addr *addr, | |
642 | const char *limit) | |
643 | { | |
644 | const char *end; | |
645 | int ret; | |
646 | ||
647 | memset(addr, 0, sizeof(*addr)); | |
648 | switch (nf_ct_l3num(ct)) { | |
649 | case AF_INET: | |
650 | ret = in4_pton(cp, limit - cp, (u8 *)&addr->ip, -1, &end); | |
651 | break; | |
652 | case AF_INET6: | |
653 | ret = in6_pton(cp, limit - cp, (u8 *)&addr->ip6, -1, &end); | |
654 | break; | |
655 | default: | |
656 | BUG(); | |
657 | } | |
658 | ||
659 | if (ret == 0) | |
660 | return 0; | |
661 | if (endp) | |
662 | *endp = end; | |
663 | return 1; | |
664 | } | |
665 | ||
666 | /* skip ip address. returns its length. */ | |
667 | static int sdp_addr_len(const struct nf_conn *ct, const char *dptr, | |
668 | const char *limit, int *shift) | |
669 | { | |
670 | union nf_inet_addr addr; | |
671 | const char *aux = dptr; | |
672 | ||
673 | if (!sdp_parse_addr(ct, dptr, &dptr, &addr, limit)) { | |
674 | pr_debug("ip: %s parse failed.!\n", dptr); | |
675 | return 0; | |
676 | } | |
677 | ||
678 | return dptr - aux; | |
679 | } | |
680 | ||
3e9b4600 PM |
681 | /* SDP header parsing: a SDP session description contains an ordered set of |
682 | * headers, starting with a section containing general session parameters, | |
683 | * optionally followed by multiple media descriptions. | |
684 | * | |
685 | * SDP headers always start at the beginning of a line. According to RFC 2327: | |
686 | * "The sequence CRLF (0x0d0a) is used to end a record, although parsers should | |
687 | * be tolerant and also accept records terminated with a single newline | |
688 | * character". We handle both cases. | |
689 | */ | |
9a664821 PM |
690 | static const struct sip_header ct_sdp_hdrs_v4[] = { |
691 | [SDP_HDR_VERSION] = SDP_HDR("v=", NULL, digits_len), | |
692 | [SDP_HDR_OWNER] = SDP_HDR("o=", "IN IP4 ", sdp_addr_len), | |
693 | [SDP_HDR_CONNECTION] = SDP_HDR("c=", "IN IP4 ", sdp_addr_len), | |
694 | [SDP_HDR_MEDIA] = SDP_HDR("m=", NULL, media_len), | |
695 | }; | |
696 | ||
697 | static const struct sip_header ct_sdp_hdrs_v6[] = { | |
698 | [SDP_HDR_VERSION] = SDP_HDR("v=", NULL, digits_len), | |
699 | [SDP_HDR_OWNER] = SDP_HDR("o=", "IN IP6 ", sdp_addr_len), | |
700 | [SDP_HDR_CONNECTION] = SDP_HDR("c=", "IN IP6 ", sdp_addr_len), | |
701 | [SDP_HDR_MEDIA] = SDP_HDR("m=", NULL, media_len), | |
3e9b4600 PM |
702 | }; |
703 | ||
704 | /* Linear string search within SDP header values */ | |
705 | static const char *ct_sdp_header_search(const char *dptr, const char *limit, | |
706 | const char *needle, unsigned int len) | |
707 | { | |
708 | for (limit -= len; dptr < limit; dptr++) { | |
709 | if (*dptr == '\r' || *dptr == '\n') | |
710 | break; | |
711 | if (strncmp(dptr, needle, len) == 0) | |
712 | return dptr; | |
713 | } | |
714 | return NULL; | |
715 | } | |
716 | ||
717 | /* Locate a SDP header (optionally a substring within the header value), | |
25985edc | 718 | * optionally stopping at the first occurrence of the term header, parse |
3e9b4600 PM |
719 | * it and return the offset and length of the data we're interested in. |
720 | */ | |
721 | int ct_sip_get_sdp_header(const struct nf_conn *ct, const char *dptr, | |
722 | unsigned int dataoff, unsigned int datalen, | |
723 | enum sdp_header_types type, | |
724 | enum sdp_header_types term, | |
725 | unsigned int *matchoff, unsigned int *matchlen) | |
726 | { | |
9a664821 | 727 | const struct sip_header *hdrs, *hdr, *thdr; |
3e9b4600 PM |
728 | const char *start = dptr, *limit = dptr + datalen; |
729 | int shift = 0; | |
730 | ||
9a664821 PM |
731 | hdrs = nf_ct_l3num(ct) == NFPROTO_IPV4 ? ct_sdp_hdrs_v4 : ct_sdp_hdrs_v6; |
732 | hdr = &hdrs[type]; | |
733 | thdr = &hdrs[term]; | |
734 | ||
3e9b4600 PM |
735 | for (dptr += dataoff; dptr < limit; dptr++) { |
736 | /* Find beginning of line */ | |
737 | if (*dptr != '\r' && *dptr != '\n') | |
738 | continue; | |
739 | if (++dptr >= limit) | |
740 | break; | |
741 | if (*(dptr - 1) == '\r' && *dptr == '\n') { | |
742 | if (++dptr >= limit) | |
743 | break; | |
744 | } | |
745 | ||
746 | if (term != SDP_HDR_UNSPEC && | |
747 | limit - dptr >= thdr->len && | |
18082746 | 748 | strncasecmp(dptr, thdr->name, thdr->len) == 0) |
3e9b4600 PM |
749 | break; |
750 | else if (limit - dptr >= hdr->len && | |
18082746 | 751 | strncasecmp(dptr, hdr->name, hdr->len) == 0) |
3e9b4600 PM |
752 | dptr += hdr->len; |
753 | else | |
754 | continue; | |
755 | ||
756 | *matchoff = dptr - start; | |
757 | if (hdr->search) { | |
758 | dptr = ct_sdp_header_search(dptr, limit, hdr->search, | |
759 | hdr->slen); | |
760 | if (!dptr) | |
761 | return -1; | |
762 | dptr += hdr->slen; | |
763 | } | |
764 | ||
765 | *matchlen = hdr->match_len(ct, dptr, limit, &shift); | |
766 | if (!*matchlen) | |
767 | return -1; | |
768 | *matchoff = dptr - start + shift; | |
769 | return 1; | |
770 | } | |
771 | return 0; | |
772 | } | |
773 | EXPORT_SYMBOL_GPL(ct_sip_get_sdp_header); | |
774 | ||
4ab9e64e PM |
775 | static int ct_sip_parse_sdp_addr(const struct nf_conn *ct, const char *dptr, |
776 | unsigned int dataoff, unsigned int datalen, | |
777 | enum sdp_header_types type, | |
778 | enum sdp_header_types term, | |
779 | unsigned int *matchoff, unsigned int *matchlen, | |
780 | union nf_inet_addr *addr) | |
781 | { | |
782 | int ret; | |
783 | ||
784 | ret = ct_sip_get_sdp_header(ct, dptr, dataoff, datalen, type, term, | |
785 | matchoff, matchlen); | |
786 | if (ret <= 0) | |
787 | return ret; | |
788 | ||
02b69cbd PM |
789 | if (!sdp_parse_addr(ct, dptr + *matchoff, NULL, addr, |
790 | dptr + *matchoff + *matchlen)) | |
4ab9e64e PM |
791 | return -1; |
792 | return 1; | |
793 | } | |
794 | ||
0f32a40f PM |
795 | static int refresh_signalling_expectation(struct nf_conn *ct, |
796 | union nf_inet_addr *addr, | |
f5b321bd | 797 | u8 proto, __be16 port, |
0f32a40f | 798 | unsigned int expires) |
9467ee38 PM |
799 | { |
800 | struct nf_conn_help *help = nfct_help(ct); | |
801 | struct nf_conntrack_expect *exp; | |
b67bfe0d | 802 | struct hlist_node *next; |
0f32a40f | 803 | int found = 0; |
9467ee38 | 804 | |
ca7433df | 805 | spin_lock_bh(&nf_conntrack_expect_lock); |
b67bfe0d | 806 | hlist_for_each_entry_safe(exp, next, &help->expectations, lnode) { |
0f32a40f PM |
807 | if (exp->class != SIP_EXPECT_SIGNALLING || |
808 | !nf_inet_addr_cmp(&exp->tuple.dst.u3, addr) || | |
f5b321bd | 809 | exp->tuple.dst.protonum != proto || |
0f32a40f PM |
810 | exp->tuple.dst.u.udp.port != port) |
811 | continue; | |
a96e66e7 GF |
812 | if (mod_timer_pending(&exp->timeout, jiffies + expires * HZ)) { |
813 | exp->flags &= ~NF_CT_EXPECT_INACTIVE; | |
814 | found = 1; | |
815 | break; | |
816 | } | |
0f32a40f | 817 | } |
ca7433df | 818 | spin_unlock_bh(&nf_conntrack_expect_lock); |
0f32a40f PM |
819 | return found; |
820 | } | |
821 | ||
822 | static void flush_expectations(struct nf_conn *ct, bool media) | |
823 | { | |
824 | struct nf_conn_help *help = nfct_help(ct); | |
825 | struct nf_conntrack_expect *exp; | |
b67bfe0d | 826 | struct hlist_node *next; |
0f32a40f | 827 | |
ca7433df | 828 | spin_lock_bh(&nf_conntrack_expect_lock); |
b67bfe0d | 829 | hlist_for_each_entry_safe(exp, next, &help->expectations, lnode) { |
0f32a40f PM |
830 | if ((exp->class != SIP_EXPECT_SIGNALLING) ^ media) |
831 | continue; | |
ec0e3f01 | 832 | if (!nf_ct_remove_expect(exp)) |
9467ee38 | 833 | continue; |
0f32a40f PM |
834 | if (!media) |
835 | break; | |
9467ee38 | 836 | } |
ca7433df | 837 | spin_unlock_bh(&nf_conntrack_expect_lock); |
9467ee38 PM |
838 | } |
839 | ||
051966c0 PM |
840 | static int set_expected_rtp_rtcp(struct sk_buff *skb, unsigned int protoff, |
841 | unsigned int dataoff, | |
a9c1d359 | 842 | const char **dptr, unsigned int *datalen, |
4ab9e64e | 843 | union nf_inet_addr *daddr, __be16 port, |
0d0ab037 | 844 | enum sip_expectation_classes class, |
4ab9e64e | 845 | unsigned int mediaoff, unsigned int medialen) |
9fafcd7b | 846 | { |
a9c1d359 | 847 | struct nf_conntrack_expect *exp, *rtp_exp, *rtcp_exp; |
212440a7 PM |
848 | enum ip_conntrack_info ctinfo; |
849 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
a5c3a800 | 850 | struct net *net = nf_ct_net(ct); |
9fafcd7b | 851 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
d901a936 PM |
852 | union nf_inet_addr *saddr; |
853 | struct nf_conntrack_tuple tuple; | |
c7f485ab | 854 | int direct_rtp = 0, skip_expect = 0, ret = NF_DROP; |
a9c1d359 PM |
855 | u_int16_t base_port; |
856 | __be16 rtp_port, rtcp_port; | |
180cf72f | 857 | const struct nf_nat_sip_hooks *hooks; |
9fafcd7b | 858 | |
d901a936 PM |
859 | saddr = NULL; |
860 | if (sip_direct_media) { | |
861 | if (!nf_inet_addr_cmp(daddr, &ct->tuplehash[dir].tuple.src.u3)) | |
862 | return NF_ACCEPT; | |
863 | saddr = &ct->tuplehash[!dir].tuple.src.u3; | |
864 | } | |
865 | ||
866 | /* We need to check whether the registration exists before attempting | |
867 | * to register it since we can see the same media description multiple | |
868 | * times on different connections in case multiple endpoints receive | |
869 | * the same call. | |
c7f485ab PM |
870 | * |
871 | * RTP optimization: if we find a matching media channel expectation | |
872 | * and both the expectation and this connection are SNATed, we assume | |
873 | * both sides can reach each other directly and use the final | |
874 | * destination address from the expectation. We still need to keep | |
875 | * the NATed expectations for media that might arrive from the | |
876 | * outside, and additionally need to expect the direct RTP stream | |
877 | * in case it passes through us even without NAT. | |
d901a936 PM |
878 | */ |
879 | memset(&tuple, 0, sizeof(tuple)); | |
880 | if (saddr) | |
881 | tuple.src.u3 = *saddr; | |
5e8fbe2a | 882 | tuple.src.l3num = nf_ct_l3num(ct); |
d901a936 PM |
883 | tuple.dst.protonum = IPPROTO_UDP; |
884 | tuple.dst.u3 = *daddr; | |
885 | tuple.dst.u.udp.port = port; | |
886 | ||
887 | rcu_read_lock(); | |
c7f485ab | 888 | do { |
5d0aa2cc | 889 | exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple); |
d901a936 | 890 | |
c7f485ab PM |
891 | if (!exp || exp->master == ct || |
892 | nfct_help(exp->master)->helper != nfct_help(ct)->helper || | |
893 | exp->class != class) | |
894 | break; | |
e1f9a464 | 895 | #ifdef CONFIG_NF_NAT_NEEDED |
9a664821 PM |
896 | if (!direct_rtp && |
897 | (!nf_inet_addr_cmp(&exp->saved_addr, &exp->tuple.dst.u3) || | |
c7f485ab PM |
898 | exp->saved_proto.udp.port != exp->tuple.dst.u.udp.port) && |
899 | ct->status & IPS_NAT_MASK) { | |
9a664821 PM |
900 | *daddr = exp->saved_addr; |
901 | tuple.dst.u3 = exp->saved_addr; | |
c7f485ab PM |
902 | tuple.dst.u.udp.port = exp->saved_proto.udp.port; |
903 | direct_rtp = 1; | |
904 | } else | |
e1f9a464 | 905 | #endif |
c7f485ab PM |
906 | skip_expect = 1; |
907 | } while (!skip_expect); | |
d901a936 | 908 | |
a9c1d359 PM |
909 | base_port = ntohs(tuple.dst.u.udp.port) & ~1; |
910 | rtp_port = htons(base_port); | |
911 | rtcp_port = htons(base_port + 1); | |
912 | ||
c7f485ab | 913 | if (direct_rtp) { |
180cf72f | 914 | hooks = rcu_dereference(nf_nat_sip_hooks); |
915 | if (hooks && | |
916 | !hooks->sdp_port(skb, protoff, dataoff, dptr, datalen, | |
c7f485ab PM |
917 | mediaoff, medialen, ntohs(rtp_port))) |
918 | goto err1; | |
919 | } | |
920 | ||
b21613ae | 921 | if (skip_expect) { |
922 | rcu_read_unlock(); | |
c7f485ab | 923 | return NF_ACCEPT; |
b21613ae | 924 | } |
c7f485ab | 925 | |
a9c1d359 PM |
926 | rtp_exp = nf_ct_expect_alloc(ct); |
927 | if (rtp_exp == NULL) | |
928 | goto err1; | |
5e8fbe2a | 929 | nf_ct_expect_init(rtp_exp, class, nf_ct_l3num(ct), saddr, daddr, |
a9c1d359 PM |
930 | IPPROTO_UDP, NULL, &rtp_port); |
931 | ||
932 | rtcp_exp = nf_ct_expect_alloc(ct); | |
933 | if (rtcp_exp == NULL) | |
934 | goto err2; | |
5e8fbe2a | 935 | nf_ct_expect_init(rtcp_exp, class, nf_ct_l3num(ct), saddr, daddr, |
a9c1d359 | 936 | IPPROTO_UDP, NULL, &rtcp_port); |
9fafcd7b | 937 | |
180cf72f | 938 | hooks = rcu_dereference(nf_nat_sip_hooks); |
939 | if (hooks && ct->status & IPS_NAT_MASK && !direct_rtp) | |
940 | ret = hooks->sdp_media(skb, protoff, dataoff, dptr, | |
941 | datalen, rtp_exp, rtcp_exp, | |
4ab9e64e | 942 | mediaoff, medialen, daddr); |
9fafcd7b | 943 | else { |
a9c1d359 PM |
944 | if (nf_ct_expect_related(rtp_exp) == 0) { |
945 | if (nf_ct_expect_related(rtcp_exp) != 0) | |
946 | nf_ct_unexpect_related(rtp_exp); | |
947 | else | |
948 | ret = NF_ACCEPT; | |
949 | } | |
9fafcd7b | 950 | } |
a9c1d359 PM |
951 | nf_ct_expect_put(rtcp_exp); |
952 | err2: | |
953 | nf_ct_expect_put(rtp_exp); | |
954 | err1: | |
b21613ae | 955 | rcu_read_unlock(); |
9fafcd7b PM |
956 | return ret; |
957 | } | |
958 | ||
0d0ab037 PM |
959 | static const struct sdp_media_type sdp_media_types[] = { |
960 | SDP_MEDIA_TYPE("audio ", SIP_EXPECT_AUDIO), | |
961 | SDP_MEDIA_TYPE("video ", SIP_EXPECT_VIDEO), | |
9d288dff | 962 | SDP_MEDIA_TYPE("image ", SIP_EXPECT_IMAGE), |
0d0ab037 PM |
963 | }; |
964 | ||
965 | static const struct sdp_media_type *sdp_media_type(const char *dptr, | |
966 | unsigned int matchoff, | |
967 | unsigned int matchlen) | |
968 | { | |
969 | const struct sdp_media_type *t; | |
970 | unsigned int i; | |
971 | ||
972 | for (i = 0; i < ARRAY_SIZE(sdp_media_types); i++) { | |
973 | t = &sdp_media_types[i]; | |
974 | if (matchlen < t->len || | |
975 | strncmp(dptr + matchoff, t->name, t->len)) | |
976 | continue; | |
977 | return t; | |
978 | } | |
979 | return NULL; | |
980 | } | |
981 | ||
051966c0 PM |
982 | static int process_sdp(struct sk_buff *skb, unsigned int protoff, |
983 | unsigned int dataoff, | |
30f33e6d PM |
984 | const char **dptr, unsigned int *datalen, |
985 | unsigned int cseq) | |
7d3dd043 PM |
986 | { |
987 | enum ip_conntrack_info ctinfo; | |
988 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
7d3dd043 | 989 | unsigned int matchoff, matchlen; |
4ab9e64e PM |
990 | unsigned int mediaoff, medialen; |
991 | unsigned int sdpoff; | |
992 | unsigned int caddr_len, maddr_len; | |
0d0ab037 | 993 | unsigned int i; |
4ab9e64e | 994 | union nf_inet_addr caddr, maddr, rtp_addr; |
180cf72f | 995 | const struct nf_nat_sip_hooks *hooks; |
7d3dd043 | 996 | unsigned int port; |
0d0ab037 PM |
997 | const struct sdp_media_type *t; |
998 | int ret = NF_ACCEPT; | |
7d3dd043 | 999 | |
180cf72f | 1000 | hooks = rcu_dereference(nf_nat_sip_hooks); |
7d3dd043 | 1001 | |
4ab9e64e | 1002 | /* Find beginning of session description */ |
7d3dd043 | 1003 | if (ct_sip_get_sdp_header(ct, *dptr, 0, *datalen, |
4ab9e64e | 1004 | SDP_HDR_VERSION, SDP_HDR_UNSPEC, |
7d3dd043 PM |
1005 | &matchoff, &matchlen) <= 0) |
1006 | return NF_ACCEPT; | |
4ab9e64e PM |
1007 | sdpoff = matchoff; |
1008 | ||
1009 | /* The connection information is contained in the session description | |
1010 | * and/or once per media description. The first media description marks | |
1011 | * the end of the session description. */ | |
1012 | caddr_len = 0; | |
1013 | if (ct_sip_parse_sdp_addr(ct, *dptr, sdpoff, *datalen, | |
9a664821 | 1014 | SDP_HDR_CONNECTION, SDP_HDR_MEDIA, |
4ab9e64e PM |
1015 | &matchoff, &matchlen, &caddr) > 0) |
1016 | caddr_len = matchlen; | |
1017 | ||
0d0ab037 PM |
1018 | mediaoff = sdpoff; |
1019 | for (i = 0; i < ARRAY_SIZE(sdp_media_types); ) { | |
1020 | if (ct_sip_get_sdp_header(ct, *dptr, mediaoff, *datalen, | |
1021 | SDP_HDR_MEDIA, SDP_HDR_UNSPEC, | |
1022 | &mediaoff, &medialen) <= 0) | |
1023 | break; | |
7d3dd043 | 1024 | |
0d0ab037 PM |
1025 | /* Get media type and port number. A media port value of zero |
1026 | * indicates an inactive stream. */ | |
1027 | t = sdp_media_type(*dptr, mediaoff, medialen); | |
1028 | if (!t) { | |
1029 | mediaoff += medialen; | |
1030 | continue; | |
1031 | } | |
1032 | mediaoff += t->len; | |
1033 | medialen -= t->len; | |
7d3dd043 | 1034 | |
0d0ab037 PM |
1035 | port = simple_strtoul(*dptr + mediaoff, NULL, 10); |
1036 | if (port == 0) | |
1037 | continue; | |
b20ab9cc PNA |
1038 | if (port < 1024 || port > 65535) { |
1039 | nf_ct_helper_log(skb, ct, "wrong port %u", port); | |
0d0ab037 | 1040 | return NF_DROP; |
b20ab9cc | 1041 | } |
4ab9e64e | 1042 | |
0d0ab037 PM |
1043 | /* The media description overrides the session description. */ |
1044 | maddr_len = 0; | |
1045 | if (ct_sip_parse_sdp_addr(ct, *dptr, mediaoff, *datalen, | |
9a664821 | 1046 | SDP_HDR_CONNECTION, SDP_HDR_MEDIA, |
0d0ab037 PM |
1047 | &matchoff, &matchlen, &maddr) > 0) { |
1048 | maddr_len = matchlen; | |
1049 | memcpy(&rtp_addr, &maddr, sizeof(rtp_addr)); | |
1050 | } else if (caddr_len) | |
1051 | memcpy(&rtp_addr, &caddr, sizeof(rtp_addr)); | |
b20ab9cc PNA |
1052 | else { |
1053 | nf_ct_helper_log(skb, ct, "cannot parse SDP message"); | |
0d0ab037 | 1054 | return NF_DROP; |
b20ab9cc | 1055 | } |
0d0ab037 | 1056 | |
051966c0 PM |
1057 | ret = set_expected_rtp_rtcp(skb, protoff, dataoff, |
1058 | dptr, datalen, | |
0d0ab037 PM |
1059 | &rtp_addr, htons(port), t->class, |
1060 | mediaoff, medialen); | |
b20ab9cc PNA |
1061 | if (ret != NF_ACCEPT) { |
1062 | nf_ct_helper_log(skb, ct, | |
1063 | "cannot add expectation for voice"); | |
0d0ab037 | 1064 | return ret; |
b20ab9cc | 1065 | } |
4ab9e64e | 1066 | |
0d0ab037 | 1067 | /* Update media connection address if present */ |
180cf72f | 1068 | if (maddr_len && hooks && ct->status & IPS_NAT_MASK) { |
1069 | ret = hooks->sdp_addr(skb, protoff, dataoff, | |
9a664821 | 1070 | dptr, datalen, mediaoff, |
180cf72f | 1071 | SDP_HDR_CONNECTION, |
1072 | SDP_HDR_MEDIA, | |
3b6b9fab | 1073 | &rtp_addr); |
b20ab9cc PNA |
1074 | if (ret != NF_ACCEPT) { |
1075 | nf_ct_helper_log(skb, ct, "cannot mangle SDP"); | |
4ab9e64e | 1076 | return ret; |
b20ab9cc | 1077 | } |
4ab9e64e | 1078 | } |
0d0ab037 | 1079 | i++; |
4ab9e64e PM |
1080 | } |
1081 | ||
1082 | /* Update session connection and owner addresses */ | |
180cf72f | 1083 | hooks = rcu_dereference(nf_nat_sip_hooks); |
1084 | if (hooks && ct->status & IPS_NAT_MASK) | |
1085 | ret = hooks->sdp_session(skb, protoff, dataoff, | |
1086 | dptr, datalen, sdpoff, | |
1087 | &rtp_addr); | |
4ab9e64e PM |
1088 | |
1089 | return ret; | |
7d3dd043 | 1090 | } |
051966c0 PM |
1091 | static int process_invite_response(struct sk_buff *skb, unsigned int protoff, |
1092 | unsigned int dataoff, | |
30f33e6d PM |
1093 | const char **dptr, unsigned int *datalen, |
1094 | unsigned int cseq, unsigned int code) | |
1095 | { | |
9467ee38 PM |
1096 | enum ip_conntrack_info ctinfo; |
1097 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
1afc5679 | 1098 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
9467ee38 | 1099 | |
30f33e6d PM |
1100 | if ((code >= 100 && code <= 199) || |
1101 | (code >= 200 && code <= 299)) | |
051966c0 | 1102 | return process_sdp(skb, protoff, dataoff, dptr, datalen, cseq); |
1afc5679 | 1103 | else if (ct_sip_info->invite_cseq == cseq) |
0f32a40f | 1104 | flush_expectations(ct, true); |
ef75d49f | 1105 | return NF_ACCEPT; |
30f33e6d PM |
1106 | } |
1107 | ||
051966c0 PM |
1108 | static int process_update_response(struct sk_buff *skb, unsigned int protoff, |
1109 | unsigned int dataoff, | |
30f33e6d PM |
1110 | const char **dptr, unsigned int *datalen, |
1111 | unsigned int cseq, unsigned int code) | |
1112 | { | |
9467ee38 PM |
1113 | enum ip_conntrack_info ctinfo; |
1114 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
1afc5679 | 1115 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
9467ee38 | 1116 | |
30f33e6d PM |
1117 | if ((code >= 100 && code <= 199) || |
1118 | (code >= 200 && code <= 299)) | |
051966c0 | 1119 | return process_sdp(skb, protoff, dataoff, dptr, datalen, cseq); |
1afc5679 | 1120 | else if (ct_sip_info->invite_cseq == cseq) |
0f32a40f | 1121 | flush_expectations(ct, true); |
ef75d49f | 1122 | return NF_ACCEPT; |
30f33e6d PM |
1123 | } |
1124 | ||
051966c0 PM |
1125 | static int process_prack_response(struct sk_buff *skb, unsigned int protoff, |
1126 | unsigned int dataoff, | |
595a8ecb PM |
1127 | const char **dptr, unsigned int *datalen, |
1128 | unsigned int cseq, unsigned int code) | |
1129 | { | |
9467ee38 PM |
1130 | enum ip_conntrack_info ctinfo; |
1131 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
1afc5679 | 1132 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
9467ee38 | 1133 | |
595a8ecb PM |
1134 | if ((code >= 100 && code <= 199) || |
1135 | (code >= 200 && code <= 299)) | |
051966c0 | 1136 | return process_sdp(skb, protoff, dataoff, dptr, datalen, cseq); |
1afc5679 | 1137 | else if (ct_sip_info->invite_cseq == cseq) |
0f32a40f | 1138 | flush_expectations(ct, true); |
ef75d49f | 1139 | return NF_ACCEPT; |
9467ee38 PM |
1140 | } |
1141 | ||
051966c0 PM |
1142 | static int process_invite_request(struct sk_buff *skb, unsigned int protoff, |
1143 | unsigned int dataoff, | |
9d288dff PM |
1144 | const char **dptr, unsigned int *datalen, |
1145 | unsigned int cseq) | |
1146 | { | |
1147 | enum ip_conntrack_info ctinfo; | |
1148 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
1afc5679 | 1149 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
9d288dff PM |
1150 | unsigned int ret; |
1151 | ||
1152 | flush_expectations(ct, true); | |
051966c0 | 1153 | ret = process_sdp(skb, protoff, dataoff, dptr, datalen, cseq); |
9d288dff | 1154 | if (ret == NF_ACCEPT) |
1afc5679 | 1155 | ct_sip_info->invite_cseq = cseq; |
9d288dff PM |
1156 | return ret; |
1157 | } | |
1158 | ||
051966c0 PM |
1159 | static int process_bye_request(struct sk_buff *skb, unsigned int protoff, |
1160 | unsigned int dataoff, | |
9467ee38 PM |
1161 | const char **dptr, unsigned int *datalen, |
1162 | unsigned int cseq) | |
1163 | { | |
1164 | enum ip_conntrack_info ctinfo; | |
1165 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
595a8ecb | 1166 | |
0f32a40f PM |
1167 | flush_expectations(ct, true); |
1168 | return NF_ACCEPT; | |
1169 | } | |
1170 | ||
1171 | /* Parse a REGISTER request and create a permanent expectation for incoming | |
1172 | * signalling connections. The expectation is marked inactive and is activated | |
1173 | * when receiving a response indicating success from the registrar. | |
1174 | */ | |
051966c0 PM |
1175 | static int process_register_request(struct sk_buff *skb, unsigned int protoff, |
1176 | unsigned int dataoff, | |
0f32a40f PM |
1177 | const char **dptr, unsigned int *datalen, |
1178 | unsigned int cseq) | |
1179 | { | |
1180 | enum ip_conntrack_info ctinfo; | |
1181 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
1afc5679 | 1182 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
0f32a40f | 1183 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
0f32a40f PM |
1184 | unsigned int matchoff, matchlen; |
1185 | struct nf_conntrack_expect *exp; | |
1186 | union nf_inet_addr *saddr, daddr; | |
180cf72f | 1187 | const struct nf_nat_sip_hooks *hooks; |
0f32a40f | 1188 | __be16 port; |
f5b321bd | 1189 | u8 proto; |
0f32a40f PM |
1190 | unsigned int expires = 0; |
1191 | int ret; | |
0f32a40f PM |
1192 | |
1193 | /* Expected connections can not register again. */ | |
1194 | if (ct->status & IPS_EXPECTED) | |
1195 | return NF_ACCEPT; | |
1196 | ||
1197 | /* We must check the expiration time: a value of zero signals the | |
1198 | * registrar to release the binding. We'll remove our expectation | |
1199 | * when receiving the new bindings in the response, but we don't | |
1200 | * want to create new ones. | |
1201 | * | |
1202 | * The expiration time may be contained in Expires: header, the | |
1203 | * Contact: header parameters or the URI parameters. | |
1204 | */ | |
1205 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_EXPIRES, | |
1206 | &matchoff, &matchlen) > 0) | |
1207 | expires = simple_strtoul(*dptr + matchoff, NULL, 10); | |
1208 | ||
1209 | ret = ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen, | |
1210 | SIP_HDR_CONTACT, NULL, | |
1211 | &matchoff, &matchlen, &daddr, &port); | |
b20ab9cc PNA |
1212 | if (ret < 0) { |
1213 | nf_ct_helper_log(skb, ct, "cannot parse contact"); | |
0f32a40f | 1214 | return NF_DROP; |
b20ab9cc | 1215 | } else if (ret == 0) |
0f32a40f PM |
1216 | return NF_ACCEPT; |
1217 | ||
1218 | /* We don't support third-party registrations */ | |
1219 | if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.src.u3, &daddr)) | |
1220 | return NF_ACCEPT; | |
1221 | ||
f5b321bd PM |
1222 | if (ct_sip_parse_transport(ct, *dptr, matchoff + matchlen, *datalen, |
1223 | &proto) == 0) | |
1224 | return NF_ACCEPT; | |
1225 | ||
0f32a40f PM |
1226 | if (ct_sip_parse_numerical_param(ct, *dptr, |
1227 | matchoff + matchlen, *datalen, | |
b20ab9cc PNA |
1228 | "expires=", NULL, NULL, &expires) < 0) { |
1229 | nf_ct_helper_log(skb, ct, "cannot parse expires"); | |
0f32a40f | 1230 | return NF_DROP; |
b20ab9cc | 1231 | } |
0f32a40f PM |
1232 | |
1233 | if (expires == 0) { | |
1234 | ret = NF_ACCEPT; | |
1235 | goto store_cseq; | |
1236 | } | |
1237 | ||
1238 | exp = nf_ct_expect_alloc(ct); | |
b20ab9cc PNA |
1239 | if (!exp) { |
1240 | nf_ct_helper_log(skb, ct, "cannot alloc expectation"); | |
0f32a40f | 1241 | return NF_DROP; |
b20ab9cc | 1242 | } |
0f32a40f PM |
1243 | |
1244 | saddr = NULL; | |
1245 | if (sip_direct_signalling) | |
1246 | saddr = &ct->tuplehash[!dir].tuple.src.u3; | |
1247 | ||
5e8fbe2a | 1248 | nf_ct_expect_init(exp, SIP_EXPECT_SIGNALLING, nf_ct_l3num(ct), |
f5b321bd | 1249 | saddr, &daddr, proto, NULL, &port); |
0f32a40f PM |
1250 | exp->timeout.expires = sip_timeout * HZ; |
1251 | exp->helper = nfct_help(ct)->helper; | |
1252 | exp->flags = NF_CT_EXPECT_PERMANENT | NF_CT_EXPECT_INACTIVE; | |
1253 | ||
180cf72f | 1254 | hooks = rcu_dereference(nf_nat_sip_hooks); |
1255 | if (hooks && ct->status & IPS_NAT_MASK) | |
1256 | ret = hooks->expect(skb, protoff, dataoff, dptr, datalen, | |
1257 | exp, matchoff, matchlen); | |
0f32a40f | 1258 | else { |
b20ab9cc PNA |
1259 | if (nf_ct_expect_related(exp) != 0) { |
1260 | nf_ct_helper_log(skb, ct, "cannot add expectation"); | |
0f32a40f | 1261 | ret = NF_DROP; |
b20ab9cc | 1262 | } else |
0f32a40f PM |
1263 | ret = NF_ACCEPT; |
1264 | } | |
1265 | nf_ct_expect_put(exp); | |
1266 | ||
1267 | store_cseq: | |
1268 | if (ret == NF_ACCEPT) | |
1afc5679 | 1269 | ct_sip_info->register_cseq = cseq; |
0f32a40f PM |
1270 | return ret; |
1271 | } | |
1272 | ||
051966c0 PM |
1273 | static int process_register_response(struct sk_buff *skb, unsigned int protoff, |
1274 | unsigned int dataoff, | |
0f32a40f PM |
1275 | const char **dptr, unsigned int *datalen, |
1276 | unsigned int cseq, unsigned int code) | |
1277 | { | |
1278 | enum ip_conntrack_info ctinfo; | |
1279 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
1afc5679 | 1280 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
0f32a40f PM |
1281 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
1282 | union nf_inet_addr addr; | |
1283 | __be16 port; | |
f5b321bd | 1284 | u8 proto; |
3b6b9fab | 1285 | unsigned int matchoff, matchlen, coff = 0; |
0f32a40f PM |
1286 | unsigned int expires = 0; |
1287 | int in_contact = 0, ret; | |
1288 | ||
1289 | /* According to RFC 3261, "UAs MUST NOT send a new registration until | |
1290 | * they have received a final response from the registrar for the | |
1291 | * previous one or the previous REGISTER request has timed out". | |
1292 | * | |
1293 | * However, some servers fail to detect retransmissions and send late | |
1294 | * responses, so we store the sequence number of the last valid | |
1295 | * request and compare it here. | |
1296 | */ | |
1afc5679 | 1297 | if (ct_sip_info->register_cseq != cseq) |
0f32a40f PM |
1298 | return NF_ACCEPT; |
1299 | ||
1300 | if (code >= 100 && code <= 199) | |
1301 | return NF_ACCEPT; | |
1302 | if (code < 200 || code > 299) | |
1303 | goto flush; | |
1304 | ||
1305 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_EXPIRES, | |
1306 | &matchoff, &matchlen) > 0) | |
1307 | expires = simple_strtoul(*dptr + matchoff, NULL, 10); | |
1308 | ||
1309 | while (1) { | |
1310 | unsigned int c_expires = expires; | |
1311 | ||
3b6b9fab | 1312 | ret = ct_sip_parse_header_uri(ct, *dptr, &coff, *datalen, |
0f32a40f PM |
1313 | SIP_HDR_CONTACT, &in_contact, |
1314 | &matchoff, &matchlen, | |
1315 | &addr, &port); | |
b20ab9cc PNA |
1316 | if (ret < 0) { |
1317 | nf_ct_helper_log(skb, ct, "cannot parse contact"); | |
0f32a40f | 1318 | return NF_DROP; |
b20ab9cc | 1319 | } else if (ret == 0) |
0f32a40f PM |
1320 | break; |
1321 | ||
1322 | /* We don't support third-party registrations */ | |
1323 | if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3, &addr)) | |
1324 | continue; | |
1325 | ||
f5b321bd PM |
1326 | if (ct_sip_parse_transport(ct, *dptr, matchoff + matchlen, |
1327 | *datalen, &proto) == 0) | |
1328 | continue; | |
1329 | ||
0f32a40f PM |
1330 | ret = ct_sip_parse_numerical_param(ct, *dptr, |
1331 | matchoff + matchlen, | |
1332 | *datalen, "expires=", | |
1333 | NULL, NULL, &c_expires); | |
b20ab9cc PNA |
1334 | if (ret < 0) { |
1335 | nf_ct_helper_log(skb, ct, "cannot parse expires"); | |
0f32a40f | 1336 | return NF_DROP; |
b20ab9cc | 1337 | } |
0f32a40f PM |
1338 | if (c_expires == 0) |
1339 | break; | |
f5b321bd PM |
1340 | if (refresh_signalling_expectation(ct, &addr, proto, port, |
1341 | c_expires)) | |
0f32a40f PM |
1342 | return NF_ACCEPT; |
1343 | } | |
1344 | ||
1345 | flush: | |
1346 | flush_expectations(ct, false); | |
595a8ecb PM |
1347 | return NF_ACCEPT; |
1348 | } | |
1349 | ||
30f33e6d | 1350 | static const struct sip_handler sip_handlers[] = { |
9d288dff | 1351 | SIP_HANDLER("INVITE", process_invite_request, process_invite_response), |
30f33e6d | 1352 | SIP_HANDLER("UPDATE", process_sdp, process_update_response), |
595a8ecb PM |
1353 | SIP_HANDLER("ACK", process_sdp, NULL), |
1354 | SIP_HANDLER("PRACK", process_sdp, process_prack_response), | |
9467ee38 | 1355 | SIP_HANDLER("BYE", process_bye_request, NULL), |
0f32a40f | 1356 | SIP_HANDLER("REGISTER", process_register_request, process_register_response), |
30f33e6d PM |
1357 | }; |
1358 | ||
051966c0 PM |
1359 | static int process_sip_response(struct sk_buff *skb, unsigned int protoff, |
1360 | unsigned int dataoff, | |
30f33e6d PM |
1361 | const char **dptr, unsigned int *datalen) |
1362 | { | |
30f33e6d PM |
1363 | enum ip_conntrack_info ctinfo; |
1364 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
3b6b9fab PM |
1365 | unsigned int matchoff, matchlen, matchend; |
1366 | unsigned int code, cseq, i; | |
30f33e6d PM |
1367 | |
1368 | if (*datalen < strlen("SIP/2.0 200")) | |
1369 | return NF_ACCEPT; | |
1370 | code = simple_strtoul(*dptr + strlen("SIP/2.0 "), NULL, 10); | |
b20ab9cc PNA |
1371 | if (!code) { |
1372 | nf_ct_helper_log(skb, ct, "cannot get code"); | |
30f33e6d | 1373 | return NF_DROP; |
b20ab9cc | 1374 | } |
30f33e6d PM |
1375 | |
1376 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CSEQ, | |
b20ab9cc PNA |
1377 | &matchoff, &matchlen) <= 0) { |
1378 | nf_ct_helper_log(skb, ct, "cannot parse cseq"); | |
30f33e6d | 1379 | return NF_DROP; |
b20ab9cc | 1380 | } |
30f33e6d | 1381 | cseq = simple_strtoul(*dptr + matchoff, NULL, 10); |
0d35d081 | 1382 | if (!cseq && *(*dptr + matchoff) != '0') { |
b20ab9cc | 1383 | nf_ct_helper_log(skb, ct, "cannot get cseq"); |
30f33e6d | 1384 | return NF_DROP; |
b20ab9cc | 1385 | } |
3b6b9fab | 1386 | matchend = matchoff + matchlen + 1; |
30f33e6d PM |
1387 | |
1388 | for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) { | |
66bf7918 AD |
1389 | const struct sip_handler *handler; |
1390 | ||
30f33e6d PM |
1391 | handler = &sip_handlers[i]; |
1392 | if (handler->response == NULL) | |
1393 | continue; | |
3b6b9fab | 1394 | if (*datalen < matchend + handler->len || |
18082746 | 1395 | strncasecmp(*dptr + matchend, handler->method, handler->len)) |
30f33e6d | 1396 | continue; |
051966c0 | 1397 | return handler->response(skb, protoff, dataoff, dptr, datalen, |
3b6b9fab | 1398 | cseq, code); |
30f33e6d PM |
1399 | } |
1400 | return NF_ACCEPT; | |
1401 | } | |
1402 | ||
051966c0 PM |
1403 | static int process_sip_request(struct sk_buff *skb, unsigned int protoff, |
1404 | unsigned int dataoff, | |
30f33e6d PM |
1405 | const char **dptr, unsigned int *datalen) |
1406 | { | |
30f33e6d PM |
1407 | enum ip_conntrack_info ctinfo; |
1408 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
7266507d KC |
1409 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
1410 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); | |
30f33e6d PM |
1411 | unsigned int matchoff, matchlen; |
1412 | unsigned int cseq, i; | |
7266507d KC |
1413 | union nf_inet_addr addr; |
1414 | __be16 port; | |
1415 | ||
1416 | /* Many Cisco IP phones use a high source port for SIP requests, but | |
1417 | * listen for the response on port 5060. If we are the local | |
1418 | * router for one of these phones, save the port number from the | |
1419 | * Via: header so that nf_nat_sip can redirect the responses to | |
1420 | * the correct port. | |
1421 | */ | |
1422 | if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen, | |
1423 | SIP_HDR_VIA_UDP, NULL, &matchoff, | |
1424 | &matchlen, &addr, &port) > 0 && | |
1425 | port != ct->tuplehash[dir].tuple.src.u.udp.port && | |
1426 | nf_inet_addr_cmp(&addr, &ct->tuplehash[dir].tuple.src.u3)) | |
1427 | ct_sip_info->forced_dport = port; | |
30f33e6d PM |
1428 | |
1429 | for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) { | |
66bf7918 AD |
1430 | const struct sip_handler *handler; |
1431 | ||
30f33e6d PM |
1432 | handler = &sip_handlers[i]; |
1433 | if (handler->request == NULL) | |
1434 | continue; | |
444f9017 | 1435 | if (*datalen < handler->len + 2 || |
18082746 | 1436 | strncasecmp(*dptr, handler->method, handler->len)) |
30f33e6d | 1437 | continue; |
444f9017 UW |
1438 | if ((*dptr)[handler->len] != ' ' || |
1439 | !isalpha((*dptr)[handler->len+1])) | |
1440 | continue; | |
30f33e6d PM |
1441 | |
1442 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CSEQ, | |
b20ab9cc PNA |
1443 | &matchoff, &matchlen) <= 0) { |
1444 | nf_ct_helper_log(skb, ct, "cannot parse cseq"); | |
30f33e6d | 1445 | return NF_DROP; |
b20ab9cc | 1446 | } |
30f33e6d | 1447 | cseq = simple_strtoul(*dptr + matchoff, NULL, 10); |
0d35d081 | 1448 | if (!cseq && *(*dptr + matchoff) != '0') { |
b20ab9cc | 1449 | nf_ct_helper_log(skb, ct, "cannot get cseq"); |
30f33e6d | 1450 | return NF_DROP; |
b20ab9cc | 1451 | } |
30f33e6d | 1452 | |
051966c0 PM |
1453 | return handler->request(skb, protoff, dataoff, dptr, datalen, |
1454 | cseq); | |
30f33e6d PM |
1455 | } |
1456 | return NF_ACCEPT; | |
1457 | } | |
7d3dd043 | 1458 | |
f5b321bd | 1459 | static int process_sip_msg(struct sk_buff *skb, struct nf_conn *ct, |
051966c0 PM |
1460 | unsigned int protoff, unsigned int dataoff, |
1461 | const char **dptr, unsigned int *datalen) | |
f5b321bd | 1462 | { |
180cf72f | 1463 | const struct nf_nat_sip_hooks *hooks; |
f5b321bd PM |
1464 | int ret; |
1465 | ||
18082746 | 1466 | if (strncasecmp(*dptr, "SIP/2.0 ", strlen("SIP/2.0 ")) != 0) |
051966c0 | 1467 | ret = process_sip_request(skb, protoff, dataoff, dptr, datalen); |
f5b321bd | 1468 | else |
051966c0 | 1469 | ret = process_sip_response(skb, protoff, dataoff, dptr, datalen); |
f5b321bd | 1470 | |
9a664821 | 1471 | if (ret == NF_ACCEPT && ct->status & IPS_NAT_MASK) { |
180cf72f | 1472 | hooks = rcu_dereference(nf_nat_sip_hooks); |
1473 | if (hooks && !hooks->msg(skb, protoff, dataoff, | |
1474 | dptr, datalen)) { | |
b20ab9cc | 1475 | nf_ct_helper_log(skb, ct, "cannot NAT SIP message"); |
f5b321bd | 1476 | ret = NF_DROP; |
b20ab9cc | 1477 | } |
f5b321bd PM |
1478 | } |
1479 | ||
1480 | return ret; | |
1481 | } | |
1482 | ||
1483 | static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff, | |
1484 | struct nf_conn *ct, enum ip_conntrack_info ctinfo) | |
9fafcd7b | 1485 | { |
f5b321bd | 1486 | struct tcphdr *th, _tcph; |
9fafcd7b | 1487 | unsigned int dataoff, datalen; |
f5b321bd PM |
1488 | unsigned int matchoff, matchlen, clen; |
1489 | unsigned int msglen, origlen; | |
1490 | const char *dptr, *end; | |
1491 | s16 diff, tdiff = 0; | |
7874896a | 1492 | int ret = NF_ACCEPT; |
e6e4d9ed | 1493 | bool term; |
f5b321bd PM |
1494 | |
1495 | if (ctinfo != IP_CT_ESTABLISHED && | |
fb048833 | 1496 | ctinfo != IP_CT_ESTABLISHED_REPLY) |
f5b321bd | 1497 | return NF_ACCEPT; |
9fafcd7b PM |
1498 | |
1499 | /* No Data ? */ | |
f5b321bd PM |
1500 | th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph); |
1501 | if (th == NULL) | |
1502 | return NF_ACCEPT; | |
1503 | dataoff = protoff + th->doff * 4; | |
3db05fea | 1504 | if (dataoff >= skb->len) |
9fafcd7b PM |
1505 | return NF_ACCEPT; |
1506 | ||
3db05fea | 1507 | nf_ct_refresh(ct, skb, sip_timeout * HZ); |
9fafcd7b | 1508 | |
a1d7c1b4 PM |
1509 | if (unlikely(skb_linearize(skb))) |
1510 | return NF_DROP; | |
9fafcd7b | 1511 | |
f5b321bd | 1512 | dptr = skb->data + dataoff; |
3db05fea | 1513 | datalen = skb->len - dataoff; |
779382eb | 1514 | if (datalen < strlen("SIP/2.0 200")) |
7d3dd043 | 1515 | return NF_ACCEPT; |
9fafcd7b | 1516 | |
f5b321bd PM |
1517 | while (1) { |
1518 | if (ct_sip_get_header(ct, dptr, 0, datalen, | |
1519 | SIP_HDR_CONTENT_LENGTH, | |
1520 | &matchoff, &matchlen) <= 0) | |
1521 | break; | |
33cb1e9a | 1522 | |
f5b321bd PM |
1523 | clen = simple_strtoul(dptr + matchoff, (char **)&end, 10); |
1524 | if (dptr + matchoff == end) | |
1525 | break; | |
1526 | ||
e6e4d9ed PM |
1527 | term = false; |
1528 | for (; end + strlen("\r\n\r\n") <= dptr + datalen; end++) { | |
1529 | if (end[0] == '\r' && end[1] == '\n' && | |
1530 | end[2] == '\r' && end[3] == '\n') { | |
1531 | term = true; | |
1532 | break; | |
1533 | } | |
1534 | } | |
1535 | if (!term) | |
f5b321bd PM |
1536 | break; |
1537 | end += strlen("\r\n\r\n") + clen; | |
1538 | ||
1539 | msglen = origlen = end - dptr; | |
3a7b21ea PM |
1540 | if (msglen > datalen) |
1541 | return NF_ACCEPT; | |
f5b321bd | 1542 | |
051966c0 PM |
1543 | ret = process_sip_msg(skb, ct, protoff, dataoff, |
1544 | &dptr, &msglen); | |
b20ab9cc | 1545 | /* process_sip_* functions report why this packet is dropped */ |
f5b321bd PM |
1546 | if (ret != NF_ACCEPT) |
1547 | break; | |
1548 | diff = msglen - origlen; | |
1549 | tdiff += diff; | |
1550 | ||
1551 | dataoff += msglen; | |
1552 | dptr += msglen; | |
1553 | datalen = datalen + diff - msglen; | |
33cb1e9a PM |
1554 | } |
1555 | ||
9a664821 | 1556 | if (ret == NF_ACCEPT && ct->status & IPS_NAT_MASK) { |
180cf72f | 1557 | const struct nf_nat_sip_hooks *hooks; |
1558 | ||
1559 | hooks = rcu_dereference(nf_nat_sip_hooks); | |
1560 | if (hooks) | |
1561 | hooks->seq_adjust(skb, protoff, tdiff); | |
48f8ac26 PM |
1562 | } |
1563 | ||
33cb1e9a | 1564 | return ret; |
9fafcd7b PM |
1565 | } |
1566 | ||
f5b321bd PM |
1567 | static int sip_help_udp(struct sk_buff *skb, unsigned int protoff, |
1568 | struct nf_conn *ct, enum ip_conntrack_info ctinfo) | |
1569 | { | |
1570 | unsigned int dataoff, datalen; | |
1571 | const char *dptr; | |
1572 | ||
1573 | /* No Data ? */ | |
1574 | dataoff = protoff + sizeof(struct udphdr); | |
1575 | if (dataoff >= skb->len) | |
1576 | return NF_ACCEPT; | |
1577 | ||
1578 | nf_ct_refresh(ct, skb, sip_timeout * HZ); | |
1579 | ||
a1d7c1b4 PM |
1580 | if (unlikely(skb_linearize(skb))) |
1581 | return NF_DROP; | |
f5b321bd PM |
1582 | |
1583 | dptr = skb->data + dataoff; | |
1584 | datalen = skb->len - dataoff; | |
1585 | if (datalen < strlen("SIP/2.0 200")) | |
1586 | return NF_ACCEPT; | |
1587 | ||
051966c0 | 1588 | return process_sip_msg(skb, ct, protoff, dataoff, &dptr, &datalen); |
f5b321bd PM |
1589 | } |
1590 | ||
82de0be6 | 1591 | static struct nf_conntrack_helper sip[MAX_PORTS * 4] __read_mostly; |
9fafcd7b | 1592 | |
0f32a40f PM |
1593 | static const struct nf_conntrack_expect_policy sip_exp_policy[SIP_EXPECT_MAX + 1] = { |
1594 | [SIP_EXPECT_SIGNALLING] = { | |
b87921bd | 1595 | .name = "signalling", |
0f32a40f PM |
1596 | .max_expected = 1, |
1597 | .timeout = 3 * 60, | |
1598 | }, | |
1599 | [SIP_EXPECT_AUDIO] = { | |
b87921bd | 1600 | .name = "audio", |
a9c1d359 | 1601 | .max_expected = 2 * IP_CT_DIR_MAX, |
0f32a40f PM |
1602 | .timeout = 3 * 60, |
1603 | }, | |
0d0ab037 | 1604 | [SIP_EXPECT_VIDEO] = { |
b87921bd | 1605 | .name = "video", |
0d0ab037 PM |
1606 | .max_expected = 2 * IP_CT_DIR_MAX, |
1607 | .timeout = 3 * 60, | |
1608 | }, | |
9d288dff PM |
1609 | [SIP_EXPECT_IMAGE] = { |
1610 | .name = "image", | |
1611 | .max_expected = IP_CT_DIR_MAX, | |
1612 | .timeout = 3 * 60, | |
1613 | }, | |
6002f266 PM |
1614 | }; |
1615 | ||
9fafcd7b PM |
1616 | static void nf_conntrack_sip_fini(void) |
1617 | { | |
82de0be6 | 1618 | nf_conntrack_helpers_unregister(sip, ports_c * 4); |
9fafcd7b PM |
1619 | } |
1620 | ||
1621 | static int __init nf_conntrack_sip_init(void) | |
1622 | { | |
82de0be6 | 1623 | int i, ret; |
9fafcd7b | 1624 | |
dcf67740 FW |
1625 | NF_CT_HELPER_BUILD_BUG_ON(sizeof(struct nf_ct_sip_master)); |
1626 | ||
9fafcd7b PM |
1627 | if (ports_c == 0) |
1628 | ports[ports_c++] = SIP_PORT; | |
1629 | ||
1630 | for (i = 0; i < ports_c; i++) { | |
82de0be6 GF |
1631 | nf_ct_helper_init(&sip[4 * i], AF_INET, IPPROTO_UDP, "sip", |
1632 | SIP_PORT, ports[i], i, sip_exp_policy, | |
9f0f3ebe | 1633 | SIP_EXPECT_MAX, sip_help_udp, |
82de0be6 GF |
1634 | NULL, THIS_MODULE); |
1635 | nf_ct_helper_init(&sip[4 * i + 1], AF_INET, IPPROTO_TCP, "sip", | |
1636 | SIP_PORT, ports[i], i, sip_exp_policy, | |
9f0f3ebe | 1637 | SIP_EXPECT_MAX, sip_help_tcp, |
82de0be6 GF |
1638 | NULL, THIS_MODULE); |
1639 | nf_ct_helper_init(&sip[4 * i + 2], AF_INET6, IPPROTO_UDP, "sip", | |
1640 | SIP_PORT, ports[i], i, sip_exp_policy, | |
9f0f3ebe | 1641 | SIP_EXPECT_MAX, sip_help_udp, |
82de0be6 GF |
1642 | NULL, THIS_MODULE); |
1643 | nf_ct_helper_init(&sip[4 * i + 3], AF_INET6, IPPROTO_TCP, "sip", | |
1644 | SIP_PORT, ports[i], i, sip_exp_policy, | |
9f0f3ebe | 1645 | SIP_EXPECT_MAX, sip_help_tcp, |
82de0be6 GF |
1646 | NULL, THIS_MODULE); |
1647 | } | |
9fafcd7b | 1648 | |
82de0be6 GF |
1649 | ret = nf_conntrack_helpers_register(sip, ports_c * 4); |
1650 | if (ret < 0) { | |
1651 | pr_err("failed to register helpers\n"); | |
1652 | return ret; | |
9fafcd7b PM |
1653 | } |
1654 | return 0; | |
1655 | } | |
1656 | ||
1657 | module_init(nf_conntrack_sip_init); | |
1658 | module_exit(nf_conntrack_sip_fini); |