Commit | Line | Data |
---|---|---|
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 | ||
13 | #include <linux/module.h> | |
14 | #include <linux/ctype.h> | |
15 | #include <linux/skbuff.h> | |
16 | #include <linux/inet.h> | |
17 | #include <linux/in.h> | |
18 | #include <linux/udp.h> | |
f5b321bd | 19 | #include <linux/tcp.h> |
1863f096 | 20 | #include <linux/netfilter.h> |
9fafcd7b PM |
21 | |
22 | #include <net/netfilter/nf_conntrack.h> | |
9467ee38 | 23 | #include <net/netfilter/nf_conntrack_core.h> |
9fafcd7b PM |
24 | #include <net/netfilter/nf_conntrack_expect.h> |
25 | #include <net/netfilter/nf_conntrack_helper.h> | |
5d0aa2cc | 26 | #include <net/netfilter/nf_conntrack_zones.h> |
9fafcd7b PM |
27 | #include <linux/netfilter/nf_conntrack_sip.h> |
28 | ||
9fafcd7b PM |
29 | MODULE_LICENSE("GPL"); |
30 | MODULE_AUTHOR("Christian Hentschel <chentschel@arnet.com.ar>"); | |
31 | MODULE_DESCRIPTION("SIP connection tracking helper"); | |
32 | MODULE_ALIAS("ip_conntrack_sip"); | |
4dc06f96 | 33 | MODULE_ALIAS_NFCT_HELPER("sip"); |
9fafcd7b PM |
34 | |
35 | #define MAX_PORTS 8 | |
36 | static unsigned short ports[MAX_PORTS]; | |
2f0d2f10 | 37 | static unsigned int ports_c; |
9fafcd7b PM |
38 | module_param_array(ports, ushort, &ports_c, 0400); |
39 | MODULE_PARM_DESC(ports, "port numbers of SIP servers"); | |
40 | ||
41 | static unsigned int sip_timeout __read_mostly = SIP_TIMEOUT; | |
42 | module_param(sip_timeout, uint, 0600); | |
43 | MODULE_PARM_DESC(sip_timeout, "timeout for the master SIP session"); | |
44 | ||
0f32a40f PM |
45 | static int sip_direct_signalling __read_mostly = 1; |
46 | module_param(sip_direct_signalling, int, 0600); | |
47 | MODULE_PARM_DESC(sip_direct_signalling, "expect incoming calls from registrar " | |
48 | "only (default 1)"); | |
49 | ||
d901a936 PM |
50 | static int sip_direct_media __read_mostly = 1; |
51 | module_param(sip_direct_media, int, 0600); | |
52 | MODULE_PARM_DESC(sip_direct_media, "Expect Media streams between signalling " | |
53 | "endpoints only (default 1)"); | |
54 | ||
180cf72f | 55 | const struct nf_nat_sip_hooks *nf_nat_sip_hooks; |
56 | EXPORT_SYMBOL_GPL(nf_nat_sip_hooks); | |
9fafcd7b | 57 | |
ac367740 PM |
58 | static int string_len(const struct nf_conn *ct, const char *dptr, |
59 | const char *limit, int *shift) | |
60 | { | |
61 | int len = 0; | |
62 | ||
63 | while (dptr < limit && isalpha(*dptr)) { | |
64 | dptr++; | |
65 | len++; | |
66 | } | |
67 | return len; | |
68 | } | |
69 | ||
13f7d63c | 70 | static int digits_len(const struct nf_conn *ct, const char *dptr, |
9fafcd7b PM |
71 | const char *limit, int *shift) |
72 | { | |
73 | int len = 0; | |
b1ec488b | 74 | while (dptr < limit && isdigit(*dptr)) { |
9fafcd7b PM |
75 | dptr++; |
76 | len++; | |
77 | } | |
78 | return len; | |
79 | } | |
80 | ||
001985b2 SH |
81 | static int iswordc(const char c) |
82 | { | |
83 | if (isalnum(c) || c == '!' || c == '"' || c == '%' || | |
84 | (c >= '(' && c <= '/') || c == ':' || c == '<' || c == '>' || | |
85 | c == '?' || (c >= '[' && c <= ']') || c == '_' || c == '`' || | |
86 | c == '{' || c == '}' || c == '~') | |
87 | return 1; | |
88 | return 0; | |
89 | } | |
90 | ||
91 | static int word_len(const char *dptr, const char *limit) | |
92 | { | |
93 | int len = 0; | |
94 | while (dptr < limit && iswordc(*dptr)) { | |
95 | dptr++; | |
96 | len++; | |
97 | } | |
98 | return len; | |
99 | } | |
100 | ||
101 | static int callid_len(const struct nf_conn *ct, const char *dptr, | |
102 | const char *limit, int *shift) | |
103 | { | |
104 | int len, domain_len; | |
105 | ||
106 | len = word_len(dptr, limit); | |
107 | dptr += len; | |
108 | if (!len || dptr == limit || *dptr != '@') | |
109 | return len; | |
110 | dptr++; | |
111 | len++; | |
112 | ||
113 | domain_len = word_len(dptr, limit); | |
114 | if (!domain_len) | |
115 | return 0; | |
116 | return len + domain_len; | |
117 | } | |
118 | ||
0d0ab037 PM |
119 | /* get media type + port length */ |
120 | static int media_len(const struct nf_conn *ct, const char *dptr, | |
121 | const char *limit, int *shift) | |
122 | { | |
123 | int len = string_len(ct, dptr, limit, shift); | |
124 | ||
125 | dptr += len; | |
126 | if (dptr >= limit || *dptr != ' ') | |
127 | return 0; | |
128 | len++; | |
129 | dptr++; | |
130 | ||
131 | return len + digits_len(ct, dptr, limit, shift); | |
132 | } | |
133 | ||
02b69cbd PM |
134 | static int sip_parse_addr(const struct nf_conn *ct, const char *cp, |
135 | const char **endp, union nf_inet_addr *addr, | |
136 | const char *limit, bool delim) | |
9fafcd7b PM |
137 | { |
138 | const char *end; | |
02b69cbd | 139 | int ret; |
9fafcd7b | 140 | |
5adbb9fb SH |
141 | if (!ct) |
142 | return 0; | |
143 | ||
fa913ddf | 144 | memset(addr, 0, sizeof(*addr)); |
5e8fbe2a | 145 | switch (nf_ct_l3num(ct)) { |
9fafcd7b PM |
146 | case AF_INET: |
147 | ret = in4_pton(cp, limit - cp, (u8 *)&addr->ip, -1, &end); | |
02b69cbd PM |
148 | if (ret == 0) |
149 | return 0; | |
9fafcd7b PM |
150 | break; |
151 | case AF_INET6: | |
02b69cbd PM |
152 | if (cp < limit && *cp == '[') |
153 | cp++; | |
154 | else if (delim) | |
155 | return 0; | |
156 | ||
9fafcd7b | 157 | ret = in6_pton(cp, limit - cp, (u8 *)&addr->ip6, -1, &end); |
02b69cbd PM |
158 | if (ret == 0) |
159 | return 0; | |
160 | ||
161 | if (end < limit && *end == ']') | |
162 | end++; | |
163 | else if (delim) | |
164 | return 0; | |
9fafcd7b PM |
165 | break; |
166 | default: | |
167 | BUG(); | |
168 | } | |
169 | ||
9fafcd7b PM |
170 | if (endp) |
171 | *endp = end; | |
172 | return 1; | |
173 | } | |
174 | ||
175 | /* skip ip address. returns its length. */ | |
13f7d63c | 176 | static int epaddr_len(const struct nf_conn *ct, const char *dptr, |
9fafcd7b PM |
177 | const char *limit, int *shift) |
178 | { | |
643a2c15 | 179 | union nf_inet_addr addr; |
9fafcd7b PM |
180 | const char *aux = dptr; |
181 | ||
02b69cbd | 182 | if (!sip_parse_addr(ct, dptr, &dptr, &addr, limit, true)) { |
0d53778e | 183 | pr_debug("ip: %s parse failed.!\n", dptr); |
9fafcd7b PM |
184 | return 0; |
185 | } | |
186 | ||
187 | /* Port number */ | |
188 | if (*dptr == ':') { | |
189 | dptr++; | |
190 | dptr += digits_len(ct, dptr, limit, shift); | |
191 | } | |
192 | return dptr - aux; | |
193 | } | |
194 | ||
195 | /* get address length, skiping user info. */ | |
13f7d63c | 196 | static int skp_epaddr_len(const struct nf_conn *ct, const char *dptr, |
9fafcd7b PM |
197 | const char *limit, int *shift) |
198 | { | |
aa584eda | 199 | const char *start = dptr; |
9fafcd7b PM |
200 | int s = *shift; |
201 | ||
7da5bfbb LI |
202 | /* Search for @, but stop at the end of the line. |
203 | * We are inside a sip: URI, so we don't need to worry about | |
204 | * continuation lines. */ | |
b1ec488b | 205 | while (dptr < limit && |
7da5bfbb | 206 | *dptr != '@' && *dptr != '\r' && *dptr != '\n') { |
9fafcd7b | 207 | (*shift)++; |
7da5bfbb LI |
208 | dptr++; |
209 | } | |
9fafcd7b | 210 | |
b1ec488b | 211 | if (dptr < limit && *dptr == '@') { |
9fafcd7b PM |
212 | dptr++; |
213 | (*shift)++; | |
aa584eda PM |
214 | } else { |
215 | dptr = start; | |
9fafcd7b | 216 | *shift = s; |
aa584eda | 217 | } |
9fafcd7b PM |
218 | |
219 | return epaddr_len(ct, dptr, limit, shift); | |
220 | } | |
221 | ||
ac367740 PM |
222 | /* Parse a SIP request line of the form: |
223 | * | |
224 | * Request-Line = Method SP Request-URI SP SIP-Version CRLF | |
225 | * | |
226 | * and return the offset and length of the address contained in the Request-URI. | |
227 | */ | |
228 | int ct_sip_parse_request(const struct nf_conn *ct, | |
229 | const char *dptr, unsigned int datalen, | |
624f8b7b PM |
230 | unsigned int *matchoff, unsigned int *matchlen, |
231 | union nf_inet_addr *addr, __be16 *port) | |
ac367740 | 232 | { |
624f8b7b | 233 | const char *start = dptr, *limit = dptr + datalen, *end; |
ac367740 | 234 | unsigned int mlen; |
624f8b7b | 235 | unsigned int p; |
ac367740 PM |
236 | int shift = 0; |
237 | ||
238 | /* Skip method and following whitespace */ | |
239 | mlen = string_len(ct, dptr, limit, NULL); | |
240 | if (!mlen) | |
241 | return 0; | |
242 | dptr += mlen; | |
243 | if (++dptr >= limit) | |
244 | return 0; | |
245 | ||
246 | /* Find SIP URI */ | |
54101f4f | 247 | for (; dptr < limit - strlen("sip:"); dptr++) { |
ac367740 PM |
248 | if (*dptr == '\r' || *dptr == '\n') |
249 | return -1; | |
18082746 | 250 | if (strncasecmp(dptr, "sip:", strlen("sip:")) == 0) { |
54101f4f | 251 | dptr += strlen("sip:"); |
ac367740 | 252 | break; |
54101f4f | 253 | } |
ac367740 | 254 | } |
624f8b7b | 255 | if (!skp_epaddr_len(ct, dptr, limit, &shift)) |
ac367740 | 256 | return 0; |
624f8b7b PM |
257 | dptr += shift; |
258 | ||
02b69cbd | 259 | if (!sip_parse_addr(ct, dptr, &end, addr, limit, true)) |
624f8b7b PM |
260 | return -1; |
261 | if (end < limit && *end == ':') { | |
262 | end++; | |
263 | p = simple_strtoul(end, (char **)&end, 10); | |
264 | if (p < 1024 || p > 65535) | |
265 | return -1; | |
266 | *port = htons(p); | |
267 | } else | |
268 | *port = htons(SIP_PORT); | |
269 | ||
270 | if (end == dptr) | |
271 | return 0; | |
272 | *matchoff = dptr - start; | |
273 | *matchlen = end - dptr; | |
ac367740 PM |
274 | return 1; |
275 | } | |
276 | EXPORT_SYMBOL_GPL(ct_sip_parse_request); | |
277 | ||
ea45f12a PM |
278 | /* SIP header parsing: SIP headers are located at the beginning of a line, but |
279 | * may span several lines, in which case the continuation lines begin with a | |
280 | * whitespace character. RFC 2543 allows lines to be terminated with CR, LF or | |
281 | * CRLF, RFC 3261 allows only CRLF, we support both. | |
282 | * | |
283 | * Headers are followed by (optionally) whitespace, a colon, again (optionally) | |
284 | * whitespace and the values. Whitespace in this context means any amount of | |
285 | * tabs, spaces and continuation lines, which are treated as a single whitespace | |
286 | * character. | |
05e3ced2 | 287 | * |
3ad2f3fb | 288 | * Some headers may appear multiple times. A comma separated list of values is |
05e3ced2 | 289 | * equivalent to multiple headers. |
ea45f12a PM |
290 | */ |
291 | static const struct sip_header ct_sip_hdrs[] = { | |
30f33e6d | 292 | [SIP_HDR_CSEQ] = SIP_HDR("CSeq", NULL, NULL, digits_len), |
ea45f12a PM |
293 | [SIP_HDR_FROM] = SIP_HDR("From", "f", "sip:", skp_epaddr_len), |
294 | [SIP_HDR_TO] = SIP_HDR("To", "t", "sip:", skp_epaddr_len), | |
295 | [SIP_HDR_CONTACT] = SIP_HDR("Contact", "m", "sip:", skp_epaddr_len), | |
f5b321bd PM |
296 | [SIP_HDR_VIA_UDP] = SIP_HDR("Via", "v", "UDP ", epaddr_len), |
297 | [SIP_HDR_VIA_TCP] = SIP_HDR("Via", "v", "TCP ", epaddr_len), | |
0f32a40f | 298 | [SIP_HDR_EXPIRES] = SIP_HDR("Expires", NULL, NULL, digits_len), |
ea45f12a | 299 | [SIP_HDR_CONTENT_LENGTH] = SIP_HDR("Content-Length", "l", NULL, digits_len), |
001985b2 | 300 | [SIP_HDR_CALL_ID] = SIP_HDR("Call-Id", "i", NULL, callid_len), |
ea45f12a PM |
301 | }; |
302 | ||
303 | static const char *sip_follow_continuation(const char *dptr, const char *limit) | |
9fafcd7b | 304 | { |
ea45f12a PM |
305 | /* Walk past newline */ |
306 | if (++dptr >= limit) | |
307 | return NULL; | |
308 | ||
309 | /* Skip '\n' in CR LF */ | |
310 | if (*(dptr - 1) == '\r' && *dptr == '\n') { | |
311 | if (++dptr >= limit) | |
312 | return NULL; | |
313 | } | |
9fafcd7b | 314 | |
ea45f12a PM |
315 | /* Continuation line? */ |
316 | if (*dptr != ' ' && *dptr != '\t') | |
317 | return NULL; | |
9fafcd7b | 318 | |
ea45f12a PM |
319 | /* skip leading whitespace */ |
320 | for (; dptr < limit; dptr++) { | |
321 | if (*dptr != ' ' && *dptr != '\t') | |
322 | break; | |
323 | } | |
324 | return dptr; | |
325 | } | |
326 | ||
327 | static const char *sip_skip_whitespace(const char *dptr, const char *limit) | |
328 | { | |
329 | for (; dptr < limit; dptr++) { | |
330 | if (*dptr == ' ') | |
331 | continue; | |
332 | if (*dptr != '\r' && *dptr != '\n') | |
333 | break; | |
334 | dptr = sip_follow_continuation(dptr, limit); | |
335 | if (dptr == NULL) | |
336 | return NULL; | |
337 | } | |
338 | return dptr; | |
339 | } | |
340 | ||
341 | /* Search within a SIP header value, dealing with continuation lines */ | |
342 | static const char *ct_sip_header_search(const char *dptr, const char *limit, | |
343 | const char *needle, unsigned int len) | |
344 | { | |
345 | for (limit -= len; dptr < limit; dptr++) { | |
346 | if (*dptr == '\r' || *dptr == '\n') { | |
347 | dptr = sip_follow_continuation(dptr, limit); | |
348 | if (dptr == NULL) | |
349 | break; | |
9fafcd7b PM |
350 | continue; |
351 | } | |
ea45f12a | 352 | |
18082746 | 353 | if (strncasecmp(dptr, needle, len) == 0) |
ea45f12a PM |
354 | return dptr; |
355 | } | |
356 | return NULL; | |
357 | } | |
358 | ||
359 | int ct_sip_get_header(const struct nf_conn *ct, const char *dptr, | |
360 | unsigned int dataoff, unsigned int datalen, | |
361 | enum sip_header_types type, | |
362 | unsigned int *matchoff, unsigned int *matchlen) | |
363 | { | |
364 | const struct sip_header *hdr = &ct_sip_hdrs[type]; | |
365 | const char *start = dptr, *limit = dptr + datalen; | |
366 | int shift = 0; | |
367 | ||
368 | for (dptr += dataoff; dptr < limit; dptr++) { | |
369 | /* Find beginning of line */ | |
370 | if (*dptr != '\r' && *dptr != '\n') | |
371 | continue; | |
372 | if (++dptr >= limit) | |
373 | break; | |
374 | if (*(dptr - 1) == '\r' && *dptr == '\n') { | |
375 | if (++dptr >= limit) | |
376 | break; | |
9fafcd7b | 377 | } |
9fafcd7b | 378 | |
ea45f12a PM |
379 | /* Skip continuation lines */ |
380 | if (*dptr == ' ' || *dptr == '\t') | |
381 | continue; | |
9fafcd7b | 382 | |
ea45f12a PM |
383 | /* Find header. Compact headers must be followed by a |
384 | * non-alphabetic character to avoid mismatches. */ | |
385 | if (limit - dptr >= hdr->len && | |
18082746 | 386 | strncasecmp(dptr, hdr->name, hdr->len) == 0) |
ea45f12a PM |
387 | dptr += hdr->len; |
388 | else if (hdr->cname && limit - dptr >= hdr->clen + 1 && | |
18082746 | 389 | strncasecmp(dptr, hdr->cname, hdr->clen) == 0 && |
135d0189 | 390 | !isalpha(*(dptr + hdr->clen))) |
ea45f12a PM |
391 | dptr += hdr->clen; |
392 | else | |
393 | continue; | |
9fafcd7b | 394 | |
ea45f12a PM |
395 | /* Find and skip colon */ |
396 | dptr = sip_skip_whitespace(dptr, limit); | |
397 | if (dptr == NULL) | |
398 | break; | |
399 | if (*dptr != ':' || ++dptr >= limit) | |
400 | break; | |
401 | ||
402 | /* Skip whitespace after colon */ | |
403 | dptr = sip_skip_whitespace(dptr, limit); | |
404 | if (dptr == NULL) | |
405 | break; | |
406 | ||
407 | *matchoff = dptr - start; | |
408 | if (hdr->search) { | |
409 | dptr = ct_sip_header_search(dptr, limit, hdr->search, | |
410 | hdr->slen); | |
411 | if (!dptr) | |
412 | return -1; | |
413 | dptr += hdr->slen; | |
414 | } | |
415 | ||
416 | *matchlen = hdr->match_len(ct, dptr, limit, &shift); | |
417 | if (!*matchlen) | |
418 | return -1; | |
419 | *matchoff = dptr - start + shift; | |
9fafcd7b PM |
420 | return 1; |
421 | } | |
9fafcd7b PM |
422 | return 0; |
423 | } | |
ea45f12a | 424 | EXPORT_SYMBOL_GPL(ct_sip_get_header); |
9fafcd7b | 425 | |
3ad2f3fb | 426 | /* Get next header field in a list of comma separated values */ |
05e3ced2 PM |
427 | static int ct_sip_next_header(const struct nf_conn *ct, const char *dptr, |
428 | unsigned int dataoff, unsigned int datalen, | |
429 | enum sip_header_types type, | |
430 | unsigned int *matchoff, unsigned int *matchlen) | |
431 | { | |
432 | const struct sip_header *hdr = &ct_sip_hdrs[type]; | |
433 | const char *start = dptr, *limit = dptr + datalen; | |
434 | int shift = 0; | |
435 | ||
436 | dptr += dataoff; | |
437 | ||
438 | dptr = ct_sip_header_search(dptr, limit, ",", strlen(",")); | |
439 | if (!dptr) | |
440 | return 0; | |
441 | ||
442 | dptr = ct_sip_header_search(dptr, limit, hdr->search, hdr->slen); | |
443 | if (!dptr) | |
444 | return 0; | |
445 | dptr += hdr->slen; | |
446 | ||
447 | *matchoff = dptr - start; | |
448 | *matchlen = hdr->match_len(ct, dptr, limit, &shift); | |
449 | if (!*matchlen) | |
450 | return -1; | |
451 | *matchoff += shift; | |
452 | return 1; | |
453 | } | |
454 | ||
455 | /* Walk through headers until a parsable one is found or no header of the | |
456 | * given type is left. */ | |
457 | static int ct_sip_walk_headers(const struct nf_conn *ct, const char *dptr, | |
458 | unsigned int dataoff, unsigned int datalen, | |
459 | enum sip_header_types type, int *in_header, | |
460 | unsigned int *matchoff, unsigned int *matchlen) | |
461 | { | |
462 | int ret; | |
463 | ||
464 | if (in_header && *in_header) { | |
465 | while (1) { | |
466 | ret = ct_sip_next_header(ct, dptr, dataoff, datalen, | |
467 | type, matchoff, matchlen); | |
468 | if (ret > 0) | |
469 | return ret; | |
470 | if (ret == 0) | |
471 | break; | |
472 | dataoff += *matchoff; | |
473 | } | |
474 | *in_header = 0; | |
475 | } | |
476 | ||
477 | while (1) { | |
478 | ret = ct_sip_get_header(ct, dptr, dataoff, datalen, | |
479 | type, matchoff, matchlen); | |
480 | if (ret > 0) | |
481 | break; | |
482 | if (ret == 0) | |
483 | return ret; | |
484 | dataoff += *matchoff; | |
485 | } | |
486 | ||
487 | if (in_header) | |
488 | *in_header = 1; | |
489 | return 1; | |
490 | } | |
491 | ||
492 | /* Locate a SIP header, parse the URI and return the offset and length of | |
493 | * the address as well as the address and port themselves. A stream of | |
494 | * headers can be parsed by handing in a non-NULL datalen and in_header | |
495 | * pointer. | |
496 | */ | |
497 | int ct_sip_parse_header_uri(const struct nf_conn *ct, const char *dptr, | |
498 | unsigned int *dataoff, unsigned int datalen, | |
499 | enum sip_header_types type, int *in_header, | |
500 | unsigned int *matchoff, unsigned int *matchlen, | |
501 | union nf_inet_addr *addr, __be16 *port) | |
502 | { | |
503 | const char *c, *limit = dptr + datalen; | |
504 | unsigned int p; | |
505 | int ret; | |
506 | ||
507 | ret = ct_sip_walk_headers(ct, dptr, dataoff ? *dataoff : 0, datalen, | |
508 | type, in_header, matchoff, matchlen); | |
509 | WARN_ON(ret < 0); | |
510 | if (ret == 0) | |
511 | return ret; | |
512 | ||
02b69cbd | 513 | if (!sip_parse_addr(ct, dptr + *matchoff, &c, addr, limit, true)) |
05e3ced2 PM |
514 | return -1; |
515 | if (*c == ':') { | |
516 | c++; | |
517 | p = simple_strtoul(c, (char **)&c, 10); | |
518 | if (p < 1024 || p > 65535) | |
519 | return -1; | |
520 | *port = htons(p); | |
521 | } else | |
522 | *port = htons(SIP_PORT); | |
523 | ||
524 | if (dataoff) | |
525 | *dataoff = c - dptr; | |
526 | return 1; | |
527 | } | |
528 | EXPORT_SYMBOL_GPL(ct_sip_parse_header_uri); | |
529 | ||
f5b321bd PM |
530 | static int ct_sip_parse_param(const struct nf_conn *ct, const char *dptr, |
531 | unsigned int dataoff, unsigned int datalen, | |
532 | const char *name, | |
533 | unsigned int *matchoff, unsigned int *matchlen) | |
534 | { | |
535 | const char *limit = dptr + datalen; | |
536 | const char *start; | |
537 | const char *end; | |
538 | ||
539 | limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(",")); | |
540 | if (!limit) | |
541 | limit = dptr + datalen; | |
542 | ||
543 | start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name)); | |
544 | if (!start) | |
545 | return 0; | |
546 | start += strlen(name); | |
547 | ||
548 | end = ct_sip_header_search(start, limit, ";", strlen(";")); | |
549 | if (!end) | |
550 | end = limit; | |
551 | ||
552 | *matchoff = start - dptr; | |
553 | *matchlen = end - start; | |
554 | return 1; | |
555 | } | |
556 | ||
2bbb2116 PM |
557 | /* Parse address from header parameter and return address, offset and length */ |
558 | int ct_sip_parse_address_param(const struct nf_conn *ct, const char *dptr, | |
559 | unsigned int dataoff, unsigned int datalen, | |
560 | const char *name, | |
561 | unsigned int *matchoff, unsigned int *matchlen, | |
02b69cbd | 562 | union nf_inet_addr *addr, bool delim) |
2bbb2116 PM |
563 | { |
564 | const char *limit = dptr + datalen; | |
565 | const char *start, *end; | |
566 | ||
567 | limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(",")); | |
568 | if (!limit) | |
569 | limit = dptr + datalen; | |
570 | ||
571 | start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name)); | |
572 | if (!start) | |
573 | return 0; | |
574 | ||
575 | start += strlen(name); | |
02b69cbd | 576 | if (!sip_parse_addr(ct, start, &end, addr, limit, delim)) |
2bbb2116 PM |
577 | return 0; |
578 | *matchoff = start - dptr; | |
579 | *matchlen = end - start; | |
580 | return 1; | |
581 | } | |
582 | EXPORT_SYMBOL_GPL(ct_sip_parse_address_param); | |
583 | ||
584 | /* Parse numerical header parameter and return value, offset and length */ | |
585 | int ct_sip_parse_numerical_param(const struct nf_conn *ct, const char *dptr, | |
586 | unsigned int dataoff, unsigned int datalen, | |
587 | const char *name, | |
588 | unsigned int *matchoff, unsigned int *matchlen, | |
589 | unsigned int *val) | |
590 | { | |
591 | const char *limit = dptr + datalen; | |
592 | const char *start; | |
593 | char *end; | |
594 | ||
595 | limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(",")); | |
596 | if (!limit) | |
597 | limit = dptr + datalen; | |
598 | ||
599 | start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name)); | |
600 | if (!start) | |
601 | return 0; | |
602 | ||
603 | start += strlen(name); | |
604 | *val = simple_strtoul(start, &end, 0); | |
605 | if (start == end) | |
606 | return 0; | |
607 | if (matchoff && matchlen) { | |
608 | *matchoff = start - dptr; | |
609 | *matchlen = end - start; | |
610 | } | |
611 | return 1; | |
612 | } | |
613 | EXPORT_SYMBOL_GPL(ct_sip_parse_numerical_param); | |
614 | ||
f5b321bd PM |
615 | static int ct_sip_parse_transport(struct nf_conn *ct, const char *dptr, |
616 | unsigned int dataoff, unsigned int datalen, | |
617 | u8 *proto) | |
618 | { | |
619 | unsigned int matchoff, matchlen; | |
620 | ||
621 | if (ct_sip_parse_param(ct, dptr, dataoff, datalen, "transport=", | |
622 | &matchoff, &matchlen)) { | |
18082746 | 623 | if (!strncasecmp(dptr + matchoff, "TCP", strlen("TCP"))) |
f5b321bd | 624 | *proto = IPPROTO_TCP; |
18082746 | 625 | else if (!strncasecmp(dptr + matchoff, "UDP", strlen("UDP"))) |
f5b321bd PM |
626 | *proto = IPPROTO_UDP; |
627 | else | |
628 | return 0; | |
629 | ||
630 | if (*proto != nf_ct_protonum(ct)) | |
631 | return 0; | |
632 | } else | |
633 | *proto = nf_ct_protonum(ct); | |
634 | ||
635 | return 1; | |
636 | } | |
637 | ||
02b69cbd PM |
638 | static int sdp_parse_addr(const struct nf_conn *ct, const char *cp, |
639 | const char **endp, union nf_inet_addr *addr, | |
640 | const char *limit) | |
641 | { | |
642 | const char *end; | |
643 | int ret; | |
644 | ||
645 | memset(addr, 0, sizeof(*addr)); | |
646 | switch (nf_ct_l3num(ct)) { | |
647 | case AF_INET: | |
648 | ret = in4_pton(cp, limit - cp, (u8 *)&addr->ip, -1, &end); | |
649 | break; | |
650 | case AF_INET6: | |
651 | ret = in6_pton(cp, limit - cp, (u8 *)&addr->ip6, -1, &end); | |
652 | break; | |
653 | default: | |
654 | BUG(); | |
655 | } | |
656 | ||
657 | if (ret == 0) | |
658 | return 0; | |
659 | if (endp) | |
660 | *endp = end; | |
661 | return 1; | |
662 | } | |
663 | ||
664 | /* skip ip address. returns its length. */ | |
665 | static int sdp_addr_len(const struct nf_conn *ct, const char *dptr, | |
666 | const char *limit, int *shift) | |
667 | { | |
668 | union nf_inet_addr addr; | |
669 | const char *aux = dptr; | |
670 | ||
671 | if (!sdp_parse_addr(ct, dptr, &dptr, &addr, limit)) { | |
672 | pr_debug("ip: %s parse failed.!\n", dptr); | |
673 | return 0; | |
674 | } | |
675 | ||
676 | return dptr - aux; | |
677 | } | |
678 | ||
3e9b4600 PM |
679 | /* SDP header parsing: a SDP session description contains an ordered set of |
680 | * headers, starting with a section containing general session parameters, | |
681 | * optionally followed by multiple media descriptions. | |
682 | * | |
683 | * SDP headers always start at the beginning of a line. According to RFC 2327: | |
684 | * "The sequence CRLF (0x0d0a) is used to end a record, although parsers should | |
685 | * be tolerant and also accept records terminated with a single newline | |
686 | * character". We handle both cases. | |
687 | */ | |
9a664821 PM |
688 | static const struct sip_header ct_sdp_hdrs_v4[] = { |
689 | [SDP_HDR_VERSION] = SDP_HDR("v=", NULL, digits_len), | |
690 | [SDP_HDR_OWNER] = SDP_HDR("o=", "IN IP4 ", sdp_addr_len), | |
691 | [SDP_HDR_CONNECTION] = SDP_HDR("c=", "IN IP4 ", sdp_addr_len), | |
692 | [SDP_HDR_MEDIA] = SDP_HDR("m=", NULL, media_len), | |
693 | }; | |
694 | ||
695 | static const struct sip_header ct_sdp_hdrs_v6[] = { | |
696 | [SDP_HDR_VERSION] = SDP_HDR("v=", NULL, digits_len), | |
697 | [SDP_HDR_OWNER] = SDP_HDR("o=", "IN IP6 ", sdp_addr_len), | |
698 | [SDP_HDR_CONNECTION] = SDP_HDR("c=", "IN IP6 ", sdp_addr_len), | |
699 | [SDP_HDR_MEDIA] = SDP_HDR("m=", NULL, media_len), | |
3e9b4600 PM |
700 | }; |
701 | ||
702 | /* Linear string search within SDP header values */ | |
703 | static const char *ct_sdp_header_search(const char *dptr, const char *limit, | |
704 | const char *needle, unsigned int len) | |
705 | { | |
706 | for (limit -= len; dptr < limit; dptr++) { | |
707 | if (*dptr == '\r' || *dptr == '\n') | |
708 | break; | |
709 | if (strncmp(dptr, needle, len) == 0) | |
710 | return dptr; | |
711 | } | |
712 | return NULL; | |
713 | } | |
714 | ||
715 | /* Locate a SDP header (optionally a substring within the header value), | |
25985edc | 716 | * optionally stopping at the first occurrence of the term header, parse |
3e9b4600 PM |
717 | * it and return the offset and length of the data we're interested in. |
718 | */ | |
719 | int ct_sip_get_sdp_header(const struct nf_conn *ct, const char *dptr, | |
720 | unsigned int dataoff, unsigned int datalen, | |
721 | enum sdp_header_types type, | |
722 | enum sdp_header_types term, | |
723 | unsigned int *matchoff, unsigned int *matchlen) | |
724 | { | |
9a664821 | 725 | const struct sip_header *hdrs, *hdr, *thdr; |
3e9b4600 PM |
726 | const char *start = dptr, *limit = dptr + datalen; |
727 | int shift = 0; | |
728 | ||
9a664821 PM |
729 | hdrs = nf_ct_l3num(ct) == NFPROTO_IPV4 ? ct_sdp_hdrs_v4 : ct_sdp_hdrs_v6; |
730 | hdr = &hdrs[type]; | |
731 | thdr = &hdrs[term]; | |
732 | ||
3e9b4600 PM |
733 | for (dptr += dataoff; dptr < limit; dptr++) { |
734 | /* Find beginning of line */ | |
735 | if (*dptr != '\r' && *dptr != '\n') | |
736 | continue; | |
737 | if (++dptr >= limit) | |
738 | break; | |
739 | if (*(dptr - 1) == '\r' && *dptr == '\n') { | |
740 | if (++dptr >= limit) | |
741 | break; | |
742 | } | |
743 | ||
744 | if (term != SDP_HDR_UNSPEC && | |
745 | limit - dptr >= thdr->len && | |
18082746 | 746 | strncasecmp(dptr, thdr->name, thdr->len) == 0) |
3e9b4600 PM |
747 | break; |
748 | else if (limit - dptr >= hdr->len && | |
18082746 | 749 | strncasecmp(dptr, hdr->name, hdr->len) == 0) |
3e9b4600 PM |
750 | dptr += hdr->len; |
751 | else | |
752 | continue; | |
753 | ||
754 | *matchoff = dptr - start; | |
755 | if (hdr->search) { | |
756 | dptr = ct_sdp_header_search(dptr, limit, hdr->search, | |
757 | hdr->slen); | |
758 | if (!dptr) | |
759 | return -1; | |
760 | dptr += hdr->slen; | |
761 | } | |
762 | ||
763 | *matchlen = hdr->match_len(ct, dptr, limit, &shift); | |
764 | if (!*matchlen) | |
765 | return -1; | |
766 | *matchoff = dptr - start + shift; | |
767 | return 1; | |
768 | } | |
769 | return 0; | |
770 | } | |
771 | EXPORT_SYMBOL_GPL(ct_sip_get_sdp_header); | |
772 | ||
4ab9e64e PM |
773 | static int ct_sip_parse_sdp_addr(const struct nf_conn *ct, const char *dptr, |
774 | unsigned int dataoff, unsigned int datalen, | |
775 | enum sdp_header_types type, | |
776 | enum sdp_header_types term, | |
777 | unsigned int *matchoff, unsigned int *matchlen, | |
778 | union nf_inet_addr *addr) | |
779 | { | |
780 | int ret; | |
781 | ||
782 | ret = ct_sip_get_sdp_header(ct, dptr, dataoff, datalen, type, term, | |
783 | matchoff, matchlen); | |
784 | if (ret <= 0) | |
785 | return ret; | |
786 | ||
02b69cbd PM |
787 | if (!sdp_parse_addr(ct, dptr + *matchoff, NULL, addr, |
788 | dptr + *matchoff + *matchlen)) | |
4ab9e64e PM |
789 | return -1; |
790 | return 1; | |
791 | } | |
792 | ||
0f32a40f PM |
793 | static int refresh_signalling_expectation(struct nf_conn *ct, |
794 | union nf_inet_addr *addr, | |
f5b321bd | 795 | u8 proto, __be16 port, |
0f32a40f | 796 | unsigned int expires) |
9467ee38 PM |
797 | { |
798 | struct nf_conn_help *help = nfct_help(ct); | |
799 | struct nf_conntrack_expect *exp; | |
b67bfe0d | 800 | struct hlist_node *next; |
0f32a40f | 801 | int found = 0; |
9467ee38 | 802 | |
ca7433df | 803 | spin_lock_bh(&nf_conntrack_expect_lock); |
b67bfe0d | 804 | hlist_for_each_entry_safe(exp, next, &help->expectations, lnode) { |
0f32a40f PM |
805 | if (exp->class != SIP_EXPECT_SIGNALLING || |
806 | !nf_inet_addr_cmp(&exp->tuple.dst.u3, addr) || | |
f5b321bd | 807 | exp->tuple.dst.protonum != proto || |
0f32a40f PM |
808 | exp->tuple.dst.u.udp.port != port) |
809 | continue; | |
810 | if (!del_timer(&exp->timeout)) | |
811 | continue; | |
812 | exp->flags &= ~NF_CT_EXPECT_INACTIVE; | |
813 | exp->timeout.expires = jiffies + expires * HZ; | |
814 | add_timer(&exp->timeout); | |
815 | found = 1; | |
816 | break; | |
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; | |
9467ee38 PM |
832 | if (!del_timer(&exp->timeout)) |
833 | continue; | |
834 | nf_ct_unlink_expect(exp); | |
835 | nf_ct_expect_put(exp); | |
0f32a40f PM |
836 | if (!media) |
837 | break; | |
9467ee38 | 838 | } |
ca7433df | 839 | spin_unlock_bh(&nf_conntrack_expect_lock); |
9467ee38 PM |
840 | } |
841 | ||
051966c0 PM |
842 | static int set_expected_rtp_rtcp(struct sk_buff *skb, unsigned int protoff, |
843 | unsigned int dataoff, | |
a9c1d359 | 844 | const char **dptr, unsigned int *datalen, |
4ab9e64e | 845 | union nf_inet_addr *daddr, __be16 port, |
0d0ab037 | 846 | enum sip_expectation_classes class, |
4ab9e64e | 847 | unsigned int mediaoff, unsigned int medialen) |
9fafcd7b | 848 | { |
a9c1d359 | 849 | struct nf_conntrack_expect *exp, *rtp_exp, *rtcp_exp; |
212440a7 PM |
850 | enum ip_conntrack_info ctinfo; |
851 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
a5c3a800 | 852 | struct net *net = nf_ct_net(ct); |
9fafcd7b | 853 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
d901a936 PM |
854 | union nf_inet_addr *saddr; |
855 | struct nf_conntrack_tuple tuple; | |
c7f485ab | 856 | int direct_rtp = 0, skip_expect = 0, ret = NF_DROP; |
a9c1d359 PM |
857 | u_int16_t base_port; |
858 | __be16 rtp_port, rtcp_port; | |
180cf72f | 859 | const struct nf_nat_sip_hooks *hooks; |
9fafcd7b | 860 | |
d901a936 PM |
861 | saddr = NULL; |
862 | if (sip_direct_media) { | |
863 | if (!nf_inet_addr_cmp(daddr, &ct->tuplehash[dir].tuple.src.u3)) | |
864 | return NF_ACCEPT; | |
865 | saddr = &ct->tuplehash[!dir].tuple.src.u3; | |
866 | } | |
867 | ||
868 | /* We need to check whether the registration exists before attempting | |
869 | * to register it since we can see the same media description multiple | |
870 | * times on different connections in case multiple endpoints receive | |
871 | * the same call. | |
c7f485ab PM |
872 | * |
873 | * RTP optimization: if we find a matching media channel expectation | |
874 | * and both the expectation and this connection are SNATed, we assume | |
875 | * both sides can reach each other directly and use the final | |
876 | * destination address from the expectation. We still need to keep | |
877 | * the NATed expectations for media that might arrive from the | |
878 | * outside, and additionally need to expect the direct RTP stream | |
879 | * in case it passes through us even without NAT. | |
d901a936 PM |
880 | */ |
881 | memset(&tuple, 0, sizeof(tuple)); | |
882 | if (saddr) | |
883 | tuple.src.u3 = *saddr; | |
5e8fbe2a | 884 | tuple.src.l3num = nf_ct_l3num(ct); |
d901a936 PM |
885 | tuple.dst.protonum = IPPROTO_UDP; |
886 | tuple.dst.u3 = *daddr; | |
887 | tuple.dst.u.udp.port = port; | |
888 | ||
889 | rcu_read_lock(); | |
c7f485ab | 890 | do { |
5d0aa2cc | 891 | exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple); |
d901a936 | 892 | |
c7f485ab PM |
893 | if (!exp || exp->master == ct || |
894 | nfct_help(exp->master)->helper != nfct_help(ct)->helper || | |
895 | exp->class != class) | |
896 | break; | |
e1f9a464 | 897 | #ifdef CONFIG_NF_NAT_NEEDED |
9a664821 PM |
898 | if (!direct_rtp && |
899 | (!nf_inet_addr_cmp(&exp->saved_addr, &exp->tuple.dst.u3) || | |
c7f485ab PM |
900 | exp->saved_proto.udp.port != exp->tuple.dst.u.udp.port) && |
901 | ct->status & IPS_NAT_MASK) { | |
9a664821 PM |
902 | *daddr = exp->saved_addr; |
903 | tuple.dst.u3 = exp->saved_addr; | |
c7f485ab PM |
904 | tuple.dst.u.udp.port = exp->saved_proto.udp.port; |
905 | direct_rtp = 1; | |
906 | } else | |
e1f9a464 | 907 | #endif |
c7f485ab PM |
908 | skip_expect = 1; |
909 | } while (!skip_expect); | |
d901a936 | 910 | |
a9c1d359 PM |
911 | base_port = ntohs(tuple.dst.u.udp.port) & ~1; |
912 | rtp_port = htons(base_port); | |
913 | rtcp_port = htons(base_port + 1); | |
914 | ||
c7f485ab | 915 | if (direct_rtp) { |
180cf72f | 916 | hooks = rcu_dereference(nf_nat_sip_hooks); |
917 | if (hooks && | |
918 | !hooks->sdp_port(skb, protoff, dataoff, dptr, datalen, | |
c7f485ab PM |
919 | mediaoff, medialen, ntohs(rtp_port))) |
920 | goto err1; | |
921 | } | |
922 | ||
b21613ae | 923 | if (skip_expect) { |
924 | rcu_read_unlock(); | |
c7f485ab | 925 | return NF_ACCEPT; |
b21613ae | 926 | } |
c7f485ab | 927 | |
a9c1d359 PM |
928 | rtp_exp = nf_ct_expect_alloc(ct); |
929 | if (rtp_exp == NULL) | |
930 | goto err1; | |
5e8fbe2a | 931 | nf_ct_expect_init(rtp_exp, class, nf_ct_l3num(ct), saddr, daddr, |
a9c1d359 PM |
932 | IPPROTO_UDP, NULL, &rtp_port); |
933 | ||
934 | rtcp_exp = nf_ct_expect_alloc(ct); | |
935 | if (rtcp_exp == NULL) | |
936 | goto err2; | |
5e8fbe2a | 937 | nf_ct_expect_init(rtcp_exp, class, nf_ct_l3num(ct), saddr, daddr, |
a9c1d359 | 938 | IPPROTO_UDP, NULL, &rtcp_port); |
9fafcd7b | 939 | |
180cf72f | 940 | hooks = rcu_dereference(nf_nat_sip_hooks); |
941 | if (hooks && ct->status & IPS_NAT_MASK && !direct_rtp) | |
942 | ret = hooks->sdp_media(skb, protoff, dataoff, dptr, | |
943 | datalen, rtp_exp, rtcp_exp, | |
4ab9e64e | 944 | mediaoff, medialen, daddr); |
9fafcd7b | 945 | else { |
a9c1d359 PM |
946 | if (nf_ct_expect_related(rtp_exp) == 0) { |
947 | if (nf_ct_expect_related(rtcp_exp) != 0) | |
948 | nf_ct_unexpect_related(rtp_exp); | |
949 | else | |
950 | ret = NF_ACCEPT; | |
951 | } | |
9fafcd7b | 952 | } |
a9c1d359 PM |
953 | nf_ct_expect_put(rtcp_exp); |
954 | err2: | |
955 | nf_ct_expect_put(rtp_exp); | |
956 | err1: | |
b21613ae | 957 | rcu_read_unlock(); |
9fafcd7b PM |
958 | return ret; |
959 | } | |
960 | ||
0d0ab037 PM |
961 | static const struct sdp_media_type sdp_media_types[] = { |
962 | SDP_MEDIA_TYPE("audio ", SIP_EXPECT_AUDIO), | |
963 | SDP_MEDIA_TYPE("video ", SIP_EXPECT_VIDEO), | |
9d288dff | 964 | SDP_MEDIA_TYPE("image ", SIP_EXPECT_IMAGE), |
0d0ab037 PM |
965 | }; |
966 | ||
967 | static const struct sdp_media_type *sdp_media_type(const char *dptr, | |
968 | unsigned int matchoff, | |
969 | unsigned int matchlen) | |
970 | { | |
971 | const struct sdp_media_type *t; | |
972 | unsigned int i; | |
973 | ||
974 | for (i = 0; i < ARRAY_SIZE(sdp_media_types); i++) { | |
975 | t = &sdp_media_types[i]; | |
976 | if (matchlen < t->len || | |
977 | strncmp(dptr + matchoff, t->name, t->len)) | |
978 | continue; | |
979 | return t; | |
980 | } | |
981 | return NULL; | |
982 | } | |
983 | ||
051966c0 PM |
984 | static int process_sdp(struct sk_buff *skb, unsigned int protoff, |
985 | unsigned int dataoff, | |
30f33e6d PM |
986 | const char **dptr, unsigned int *datalen, |
987 | unsigned int cseq) | |
7d3dd043 PM |
988 | { |
989 | enum ip_conntrack_info ctinfo; | |
990 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
7d3dd043 | 991 | unsigned int matchoff, matchlen; |
4ab9e64e PM |
992 | unsigned int mediaoff, medialen; |
993 | unsigned int sdpoff; | |
994 | unsigned int caddr_len, maddr_len; | |
0d0ab037 | 995 | unsigned int i; |
4ab9e64e | 996 | union nf_inet_addr caddr, maddr, rtp_addr; |
180cf72f | 997 | const struct nf_nat_sip_hooks *hooks; |
7d3dd043 | 998 | unsigned int port; |
0d0ab037 PM |
999 | const struct sdp_media_type *t; |
1000 | int ret = NF_ACCEPT; | |
7d3dd043 | 1001 | |
180cf72f | 1002 | hooks = rcu_dereference(nf_nat_sip_hooks); |
7d3dd043 | 1003 | |
4ab9e64e | 1004 | /* Find beginning of session description */ |
7d3dd043 | 1005 | if (ct_sip_get_sdp_header(ct, *dptr, 0, *datalen, |
4ab9e64e | 1006 | SDP_HDR_VERSION, SDP_HDR_UNSPEC, |
7d3dd043 PM |
1007 | &matchoff, &matchlen) <= 0) |
1008 | return NF_ACCEPT; | |
4ab9e64e PM |
1009 | sdpoff = matchoff; |
1010 | ||
1011 | /* The connection information is contained in the session description | |
1012 | * and/or once per media description. The first media description marks | |
1013 | * the end of the session description. */ | |
1014 | caddr_len = 0; | |
1015 | if (ct_sip_parse_sdp_addr(ct, *dptr, sdpoff, *datalen, | |
9a664821 | 1016 | SDP_HDR_CONNECTION, SDP_HDR_MEDIA, |
4ab9e64e PM |
1017 | &matchoff, &matchlen, &caddr) > 0) |
1018 | caddr_len = matchlen; | |
1019 | ||
0d0ab037 PM |
1020 | mediaoff = sdpoff; |
1021 | for (i = 0; i < ARRAY_SIZE(sdp_media_types); ) { | |
1022 | if (ct_sip_get_sdp_header(ct, *dptr, mediaoff, *datalen, | |
1023 | SDP_HDR_MEDIA, SDP_HDR_UNSPEC, | |
1024 | &mediaoff, &medialen) <= 0) | |
1025 | break; | |
7d3dd043 | 1026 | |
0d0ab037 PM |
1027 | /* Get media type and port number. A media port value of zero |
1028 | * indicates an inactive stream. */ | |
1029 | t = sdp_media_type(*dptr, mediaoff, medialen); | |
1030 | if (!t) { | |
1031 | mediaoff += medialen; | |
1032 | continue; | |
1033 | } | |
1034 | mediaoff += t->len; | |
1035 | medialen -= t->len; | |
7d3dd043 | 1036 | |
0d0ab037 PM |
1037 | port = simple_strtoul(*dptr + mediaoff, NULL, 10); |
1038 | if (port == 0) | |
1039 | continue; | |
b20ab9cc PNA |
1040 | if (port < 1024 || port > 65535) { |
1041 | nf_ct_helper_log(skb, ct, "wrong port %u", port); | |
0d0ab037 | 1042 | return NF_DROP; |
b20ab9cc | 1043 | } |
4ab9e64e | 1044 | |
0d0ab037 PM |
1045 | /* The media description overrides the session description. */ |
1046 | maddr_len = 0; | |
1047 | if (ct_sip_parse_sdp_addr(ct, *dptr, mediaoff, *datalen, | |
9a664821 | 1048 | SDP_HDR_CONNECTION, SDP_HDR_MEDIA, |
0d0ab037 PM |
1049 | &matchoff, &matchlen, &maddr) > 0) { |
1050 | maddr_len = matchlen; | |
1051 | memcpy(&rtp_addr, &maddr, sizeof(rtp_addr)); | |
1052 | } else if (caddr_len) | |
1053 | memcpy(&rtp_addr, &caddr, sizeof(rtp_addr)); | |
b20ab9cc PNA |
1054 | else { |
1055 | nf_ct_helper_log(skb, ct, "cannot parse SDP message"); | |
0d0ab037 | 1056 | return NF_DROP; |
b20ab9cc | 1057 | } |
0d0ab037 | 1058 | |
051966c0 PM |
1059 | ret = set_expected_rtp_rtcp(skb, protoff, dataoff, |
1060 | dptr, datalen, | |
0d0ab037 PM |
1061 | &rtp_addr, htons(port), t->class, |
1062 | mediaoff, medialen); | |
b20ab9cc PNA |
1063 | if (ret != NF_ACCEPT) { |
1064 | nf_ct_helper_log(skb, ct, | |
1065 | "cannot add expectation for voice"); | |
0d0ab037 | 1066 | return ret; |
b20ab9cc | 1067 | } |
4ab9e64e | 1068 | |
0d0ab037 | 1069 | /* Update media connection address if present */ |
180cf72f | 1070 | if (maddr_len && hooks && ct->status & IPS_NAT_MASK) { |
1071 | ret = hooks->sdp_addr(skb, protoff, dataoff, | |
9a664821 | 1072 | dptr, datalen, mediaoff, |
180cf72f | 1073 | SDP_HDR_CONNECTION, |
1074 | SDP_HDR_MEDIA, | |
3b6b9fab | 1075 | &rtp_addr); |
b20ab9cc PNA |
1076 | if (ret != NF_ACCEPT) { |
1077 | nf_ct_helper_log(skb, ct, "cannot mangle SDP"); | |
4ab9e64e | 1078 | return ret; |
b20ab9cc | 1079 | } |
4ab9e64e | 1080 | } |
0d0ab037 | 1081 | i++; |
4ab9e64e PM |
1082 | } |
1083 | ||
1084 | /* Update session connection and owner addresses */ | |
180cf72f | 1085 | hooks = rcu_dereference(nf_nat_sip_hooks); |
1086 | if (hooks && ct->status & IPS_NAT_MASK) | |
1087 | ret = hooks->sdp_session(skb, protoff, dataoff, | |
1088 | dptr, datalen, sdpoff, | |
1089 | &rtp_addr); | |
4ab9e64e PM |
1090 | |
1091 | return ret; | |
7d3dd043 | 1092 | } |
051966c0 PM |
1093 | static int process_invite_response(struct sk_buff *skb, unsigned int protoff, |
1094 | unsigned int dataoff, | |
30f33e6d PM |
1095 | const char **dptr, unsigned int *datalen, |
1096 | unsigned int cseq, unsigned int code) | |
1097 | { | |
9467ee38 PM |
1098 | enum ip_conntrack_info ctinfo; |
1099 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
1afc5679 | 1100 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
9467ee38 | 1101 | |
30f33e6d PM |
1102 | if ((code >= 100 && code <= 199) || |
1103 | (code >= 200 && code <= 299)) | |
051966c0 | 1104 | return process_sdp(skb, protoff, dataoff, dptr, datalen, cseq); |
1afc5679 | 1105 | else if (ct_sip_info->invite_cseq == cseq) |
0f32a40f | 1106 | flush_expectations(ct, true); |
ef75d49f | 1107 | return NF_ACCEPT; |
30f33e6d PM |
1108 | } |
1109 | ||
051966c0 PM |
1110 | static int process_update_response(struct sk_buff *skb, unsigned int protoff, |
1111 | unsigned int dataoff, | |
30f33e6d PM |
1112 | const char **dptr, unsigned int *datalen, |
1113 | unsigned int cseq, unsigned int code) | |
1114 | { | |
9467ee38 PM |
1115 | enum ip_conntrack_info ctinfo; |
1116 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
1afc5679 | 1117 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
9467ee38 | 1118 | |
30f33e6d PM |
1119 | if ((code >= 100 && code <= 199) || |
1120 | (code >= 200 && code <= 299)) | |
051966c0 | 1121 | return process_sdp(skb, protoff, dataoff, dptr, datalen, cseq); |
1afc5679 | 1122 | else if (ct_sip_info->invite_cseq == cseq) |
0f32a40f | 1123 | flush_expectations(ct, true); |
ef75d49f | 1124 | return NF_ACCEPT; |
30f33e6d PM |
1125 | } |
1126 | ||
051966c0 PM |
1127 | static int process_prack_response(struct sk_buff *skb, unsigned int protoff, |
1128 | unsigned int dataoff, | |
595a8ecb PM |
1129 | const char **dptr, unsigned int *datalen, |
1130 | unsigned int cseq, unsigned int code) | |
1131 | { | |
9467ee38 PM |
1132 | enum ip_conntrack_info ctinfo; |
1133 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
1afc5679 | 1134 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
9467ee38 | 1135 | |
595a8ecb PM |
1136 | if ((code >= 100 && code <= 199) || |
1137 | (code >= 200 && code <= 299)) | |
051966c0 | 1138 | return process_sdp(skb, protoff, dataoff, dptr, datalen, cseq); |
1afc5679 | 1139 | else if (ct_sip_info->invite_cseq == cseq) |
0f32a40f | 1140 | flush_expectations(ct, true); |
ef75d49f | 1141 | return NF_ACCEPT; |
9467ee38 PM |
1142 | } |
1143 | ||
051966c0 PM |
1144 | static int process_invite_request(struct sk_buff *skb, unsigned int protoff, |
1145 | unsigned int dataoff, | |
9d288dff PM |
1146 | const char **dptr, unsigned int *datalen, |
1147 | unsigned int cseq) | |
1148 | { | |
1149 | enum ip_conntrack_info ctinfo; | |
1150 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
1afc5679 | 1151 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
9d288dff PM |
1152 | unsigned int ret; |
1153 | ||
1154 | flush_expectations(ct, true); | |
051966c0 | 1155 | ret = process_sdp(skb, protoff, dataoff, dptr, datalen, cseq); |
9d288dff | 1156 | if (ret == NF_ACCEPT) |
1afc5679 | 1157 | ct_sip_info->invite_cseq = cseq; |
9d288dff PM |
1158 | return ret; |
1159 | } | |
1160 | ||
051966c0 PM |
1161 | static int process_bye_request(struct sk_buff *skb, unsigned int protoff, |
1162 | unsigned int dataoff, | |
9467ee38 PM |
1163 | const char **dptr, unsigned int *datalen, |
1164 | unsigned int cseq) | |
1165 | { | |
1166 | enum ip_conntrack_info ctinfo; | |
1167 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
595a8ecb | 1168 | |
0f32a40f PM |
1169 | flush_expectations(ct, true); |
1170 | return NF_ACCEPT; | |
1171 | } | |
1172 | ||
1173 | /* Parse a REGISTER request and create a permanent expectation for incoming | |
1174 | * signalling connections. The expectation is marked inactive and is activated | |
1175 | * when receiving a response indicating success from the registrar. | |
1176 | */ | |
051966c0 PM |
1177 | static int process_register_request(struct sk_buff *skb, unsigned int protoff, |
1178 | unsigned int dataoff, | |
0f32a40f PM |
1179 | const char **dptr, unsigned int *datalen, |
1180 | unsigned int cseq) | |
1181 | { | |
1182 | enum ip_conntrack_info ctinfo; | |
1183 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
1afc5679 | 1184 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
0f32a40f | 1185 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
0f32a40f PM |
1186 | unsigned int matchoff, matchlen; |
1187 | struct nf_conntrack_expect *exp; | |
1188 | union nf_inet_addr *saddr, daddr; | |
180cf72f | 1189 | const struct nf_nat_sip_hooks *hooks; |
0f32a40f | 1190 | __be16 port; |
f5b321bd | 1191 | u8 proto; |
0f32a40f PM |
1192 | unsigned int expires = 0; |
1193 | int ret; | |
0f32a40f PM |
1194 | |
1195 | /* Expected connections can not register again. */ | |
1196 | if (ct->status & IPS_EXPECTED) | |
1197 | return NF_ACCEPT; | |
1198 | ||
1199 | /* We must check the expiration time: a value of zero signals the | |
1200 | * registrar to release the binding. We'll remove our expectation | |
1201 | * when receiving the new bindings in the response, but we don't | |
1202 | * want to create new ones. | |
1203 | * | |
1204 | * The expiration time may be contained in Expires: header, the | |
1205 | * Contact: header parameters or the URI parameters. | |
1206 | */ | |
1207 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_EXPIRES, | |
1208 | &matchoff, &matchlen) > 0) | |
1209 | expires = simple_strtoul(*dptr + matchoff, NULL, 10); | |
1210 | ||
1211 | ret = ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen, | |
1212 | SIP_HDR_CONTACT, NULL, | |
1213 | &matchoff, &matchlen, &daddr, &port); | |
b20ab9cc PNA |
1214 | if (ret < 0) { |
1215 | nf_ct_helper_log(skb, ct, "cannot parse contact"); | |
0f32a40f | 1216 | return NF_DROP; |
b20ab9cc | 1217 | } else if (ret == 0) |
0f32a40f PM |
1218 | return NF_ACCEPT; |
1219 | ||
1220 | /* We don't support third-party registrations */ | |
1221 | if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.src.u3, &daddr)) | |
1222 | return NF_ACCEPT; | |
1223 | ||
f5b321bd PM |
1224 | if (ct_sip_parse_transport(ct, *dptr, matchoff + matchlen, *datalen, |
1225 | &proto) == 0) | |
1226 | return NF_ACCEPT; | |
1227 | ||
0f32a40f PM |
1228 | if (ct_sip_parse_numerical_param(ct, *dptr, |
1229 | matchoff + matchlen, *datalen, | |
b20ab9cc PNA |
1230 | "expires=", NULL, NULL, &expires) < 0) { |
1231 | nf_ct_helper_log(skb, ct, "cannot parse expires"); | |
0f32a40f | 1232 | return NF_DROP; |
b20ab9cc | 1233 | } |
0f32a40f PM |
1234 | |
1235 | if (expires == 0) { | |
1236 | ret = NF_ACCEPT; | |
1237 | goto store_cseq; | |
1238 | } | |
1239 | ||
1240 | exp = nf_ct_expect_alloc(ct); | |
b20ab9cc PNA |
1241 | if (!exp) { |
1242 | nf_ct_helper_log(skb, ct, "cannot alloc expectation"); | |
0f32a40f | 1243 | return NF_DROP; |
b20ab9cc | 1244 | } |
0f32a40f PM |
1245 | |
1246 | saddr = NULL; | |
1247 | if (sip_direct_signalling) | |
1248 | saddr = &ct->tuplehash[!dir].tuple.src.u3; | |
1249 | ||
5e8fbe2a | 1250 | nf_ct_expect_init(exp, SIP_EXPECT_SIGNALLING, nf_ct_l3num(ct), |
f5b321bd | 1251 | saddr, &daddr, proto, NULL, &port); |
0f32a40f PM |
1252 | exp->timeout.expires = sip_timeout * HZ; |
1253 | exp->helper = nfct_help(ct)->helper; | |
1254 | exp->flags = NF_CT_EXPECT_PERMANENT | NF_CT_EXPECT_INACTIVE; | |
1255 | ||
180cf72f | 1256 | hooks = rcu_dereference(nf_nat_sip_hooks); |
1257 | if (hooks && ct->status & IPS_NAT_MASK) | |
1258 | ret = hooks->expect(skb, protoff, dataoff, dptr, datalen, | |
1259 | exp, matchoff, matchlen); | |
0f32a40f | 1260 | else { |
b20ab9cc PNA |
1261 | if (nf_ct_expect_related(exp) != 0) { |
1262 | nf_ct_helper_log(skb, ct, "cannot add expectation"); | |
0f32a40f | 1263 | ret = NF_DROP; |
b20ab9cc | 1264 | } else |
0f32a40f PM |
1265 | ret = NF_ACCEPT; |
1266 | } | |
1267 | nf_ct_expect_put(exp); | |
1268 | ||
1269 | store_cseq: | |
1270 | if (ret == NF_ACCEPT) | |
1afc5679 | 1271 | ct_sip_info->register_cseq = cseq; |
0f32a40f PM |
1272 | return ret; |
1273 | } | |
1274 | ||
051966c0 PM |
1275 | static int process_register_response(struct sk_buff *skb, unsigned int protoff, |
1276 | unsigned int dataoff, | |
0f32a40f PM |
1277 | const char **dptr, unsigned int *datalen, |
1278 | unsigned int cseq, unsigned int code) | |
1279 | { | |
1280 | enum ip_conntrack_info ctinfo; | |
1281 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
1afc5679 | 1282 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
0f32a40f PM |
1283 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
1284 | union nf_inet_addr addr; | |
1285 | __be16 port; | |
f5b321bd | 1286 | u8 proto; |
3b6b9fab | 1287 | unsigned int matchoff, matchlen, coff = 0; |
0f32a40f PM |
1288 | unsigned int expires = 0; |
1289 | int in_contact = 0, ret; | |
1290 | ||
1291 | /* According to RFC 3261, "UAs MUST NOT send a new registration until | |
1292 | * they have received a final response from the registrar for the | |
1293 | * previous one or the previous REGISTER request has timed out". | |
1294 | * | |
1295 | * However, some servers fail to detect retransmissions and send late | |
1296 | * responses, so we store the sequence number of the last valid | |
1297 | * request and compare it here. | |
1298 | */ | |
1afc5679 | 1299 | if (ct_sip_info->register_cseq != cseq) |
0f32a40f PM |
1300 | return NF_ACCEPT; |
1301 | ||
1302 | if (code >= 100 && code <= 199) | |
1303 | return NF_ACCEPT; | |
1304 | if (code < 200 || code > 299) | |
1305 | goto flush; | |
1306 | ||
1307 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_EXPIRES, | |
1308 | &matchoff, &matchlen) > 0) | |
1309 | expires = simple_strtoul(*dptr + matchoff, NULL, 10); | |
1310 | ||
1311 | while (1) { | |
1312 | unsigned int c_expires = expires; | |
1313 | ||
3b6b9fab | 1314 | ret = ct_sip_parse_header_uri(ct, *dptr, &coff, *datalen, |
0f32a40f PM |
1315 | SIP_HDR_CONTACT, &in_contact, |
1316 | &matchoff, &matchlen, | |
1317 | &addr, &port); | |
b20ab9cc PNA |
1318 | if (ret < 0) { |
1319 | nf_ct_helper_log(skb, ct, "cannot parse contact"); | |
0f32a40f | 1320 | return NF_DROP; |
b20ab9cc | 1321 | } else if (ret == 0) |
0f32a40f PM |
1322 | break; |
1323 | ||
1324 | /* We don't support third-party registrations */ | |
1325 | if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3, &addr)) | |
1326 | continue; | |
1327 | ||
f5b321bd PM |
1328 | if (ct_sip_parse_transport(ct, *dptr, matchoff + matchlen, |
1329 | *datalen, &proto) == 0) | |
1330 | continue; | |
1331 | ||
0f32a40f PM |
1332 | ret = ct_sip_parse_numerical_param(ct, *dptr, |
1333 | matchoff + matchlen, | |
1334 | *datalen, "expires=", | |
1335 | NULL, NULL, &c_expires); | |
b20ab9cc PNA |
1336 | if (ret < 0) { |
1337 | nf_ct_helper_log(skb, ct, "cannot parse expires"); | |
0f32a40f | 1338 | return NF_DROP; |
b20ab9cc | 1339 | } |
0f32a40f PM |
1340 | if (c_expires == 0) |
1341 | break; | |
f5b321bd PM |
1342 | if (refresh_signalling_expectation(ct, &addr, proto, port, |
1343 | c_expires)) | |
0f32a40f PM |
1344 | return NF_ACCEPT; |
1345 | } | |
1346 | ||
1347 | flush: | |
1348 | flush_expectations(ct, false); | |
595a8ecb PM |
1349 | return NF_ACCEPT; |
1350 | } | |
1351 | ||
30f33e6d | 1352 | static const struct sip_handler sip_handlers[] = { |
9d288dff | 1353 | SIP_HANDLER("INVITE", process_invite_request, process_invite_response), |
30f33e6d | 1354 | SIP_HANDLER("UPDATE", process_sdp, process_update_response), |
595a8ecb PM |
1355 | SIP_HANDLER("ACK", process_sdp, NULL), |
1356 | SIP_HANDLER("PRACK", process_sdp, process_prack_response), | |
9467ee38 | 1357 | SIP_HANDLER("BYE", process_bye_request, NULL), |
0f32a40f | 1358 | SIP_HANDLER("REGISTER", process_register_request, process_register_response), |
30f33e6d PM |
1359 | }; |
1360 | ||
051966c0 PM |
1361 | static int process_sip_response(struct sk_buff *skb, unsigned int protoff, |
1362 | unsigned int dataoff, | |
30f33e6d PM |
1363 | const char **dptr, unsigned int *datalen) |
1364 | { | |
30f33e6d PM |
1365 | enum ip_conntrack_info ctinfo; |
1366 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
3b6b9fab PM |
1367 | unsigned int matchoff, matchlen, matchend; |
1368 | unsigned int code, cseq, i; | |
30f33e6d PM |
1369 | |
1370 | if (*datalen < strlen("SIP/2.0 200")) | |
1371 | return NF_ACCEPT; | |
1372 | code = simple_strtoul(*dptr + strlen("SIP/2.0 "), NULL, 10); | |
b20ab9cc PNA |
1373 | if (!code) { |
1374 | nf_ct_helper_log(skb, ct, "cannot get code"); | |
30f33e6d | 1375 | return NF_DROP; |
b20ab9cc | 1376 | } |
30f33e6d PM |
1377 | |
1378 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CSEQ, | |
b20ab9cc PNA |
1379 | &matchoff, &matchlen) <= 0) { |
1380 | nf_ct_helper_log(skb, ct, "cannot parse cseq"); | |
30f33e6d | 1381 | return NF_DROP; |
b20ab9cc | 1382 | } |
30f33e6d | 1383 | cseq = simple_strtoul(*dptr + matchoff, NULL, 10); |
b20ab9cc PNA |
1384 | if (!cseq) { |
1385 | nf_ct_helper_log(skb, ct, "cannot get cseq"); | |
30f33e6d | 1386 | return NF_DROP; |
b20ab9cc | 1387 | } |
3b6b9fab | 1388 | matchend = matchoff + matchlen + 1; |
30f33e6d PM |
1389 | |
1390 | for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) { | |
66bf7918 AD |
1391 | const struct sip_handler *handler; |
1392 | ||
30f33e6d PM |
1393 | handler = &sip_handlers[i]; |
1394 | if (handler->response == NULL) | |
1395 | continue; | |
3b6b9fab | 1396 | if (*datalen < matchend + handler->len || |
18082746 | 1397 | strncasecmp(*dptr + matchend, handler->method, handler->len)) |
30f33e6d | 1398 | continue; |
051966c0 | 1399 | return handler->response(skb, protoff, dataoff, dptr, datalen, |
3b6b9fab | 1400 | cseq, code); |
30f33e6d PM |
1401 | } |
1402 | return NF_ACCEPT; | |
1403 | } | |
1404 | ||
051966c0 PM |
1405 | static int process_sip_request(struct sk_buff *skb, unsigned int protoff, |
1406 | unsigned int dataoff, | |
30f33e6d PM |
1407 | const char **dptr, unsigned int *datalen) |
1408 | { | |
30f33e6d PM |
1409 | enum ip_conntrack_info ctinfo; |
1410 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
7266507d KC |
1411 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
1412 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); | |
30f33e6d PM |
1413 | unsigned int matchoff, matchlen; |
1414 | unsigned int cseq, i; | |
7266507d KC |
1415 | union nf_inet_addr addr; |
1416 | __be16 port; | |
1417 | ||
1418 | /* Many Cisco IP phones use a high source port for SIP requests, but | |
1419 | * listen for the response on port 5060. If we are the local | |
1420 | * router for one of these phones, save the port number from the | |
1421 | * Via: header so that nf_nat_sip can redirect the responses to | |
1422 | * the correct port. | |
1423 | */ | |
1424 | if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen, | |
1425 | SIP_HDR_VIA_UDP, NULL, &matchoff, | |
1426 | &matchlen, &addr, &port) > 0 && | |
1427 | port != ct->tuplehash[dir].tuple.src.u.udp.port && | |
1428 | nf_inet_addr_cmp(&addr, &ct->tuplehash[dir].tuple.src.u3)) | |
1429 | ct_sip_info->forced_dport = port; | |
30f33e6d PM |
1430 | |
1431 | for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) { | |
66bf7918 AD |
1432 | const struct sip_handler *handler; |
1433 | ||
30f33e6d PM |
1434 | handler = &sip_handlers[i]; |
1435 | if (handler->request == NULL) | |
1436 | continue; | |
1437 | if (*datalen < handler->len || | |
18082746 | 1438 | strncasecmp(*dptr, handler->method, handler->len)) |
30f33e6d PM |
1439 | continue; |
1440 | ||
1441 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CSEQ, | |
b20ab9cc PNA |
1442 | &matchoff, &matchlen) <= 0) { |
1443 | nf_ct_helper_log(skb, ct, "cannot parse cseq"); | |
30f33e6d | 1444 | return NF_DROP; |
b20ab9cc | 1445 | } |
30f33e6d | 1446 | cseq = simple_strtoul(*dptr + matchoff, NULL, 10); |
b20ab9cc PNA |
1447 | if (!cseq) { |
1448 | nf_ct_helper_log(skb, ct, "cannot get cseq"); | |
30f33e6d | 1449 | return NF_DROP; |
b20ab9cc | 1450 | } |
30f33e6d | 1451 | |
051966c0 PM |
1452 | return handler->request(skb, protoff, dataoff, dptr, datalen, |
1453 | cseq); | |
30f33e6d PM |
1454 | } |
1455 | return NF_ACCEPT; | |
1456 | } | |
7d3dd043 | 1457 | |
f5b321bd | 1458 | static int process_sip_msg(struct sk_buff *skb, struct nf_conn *ct, |
051966c0 PM |
1459 | unsigned int protoff, unsigned int dataoff, |
1460 | const char **dptr, unsigned int *datalen) | |
f5b321bd | 1461 | { |
180cf72f | 1462 | const struct nf_nat_sip_hooks *hooks; |
f5b321bd PM |
1463 | int ret; |
1464 | ||
18082746 | 1465 | if (strncasecmp(*dptr, "SIP/2.0 ", strlen("SIP/2.0 ")) != 0) |
051966c0 | 1466 | ret = process_sip_request(skb, protoff, dataoff, dptr, datalen); |
f5b321bd | 1467 | else |
051966c0 | 1468 | ret = process_sip_response(skb, protoff, dataoff, dptr, datalen); |
f5b321bd | 1469 | |
9a664821 | 1470 | if (ret == NF_ACCEPT && ct->status & IPS_NAT_MASK) { |
180cf72f | 1471 | hooks = rcu_dereference(nf_nat_sip_hooks); |
1472 | if (hooks && !hooks->msg(skb, protoff, dataoff, | |
1473 | dptr, datalen)) { | |
b20ab9cc | 1474 | nf_ct_helper_log(skb, ct, "cannot NAT SIP message"); |
f5b321bd | 1475 | ret = NF_DROP; |
b20ab9cc | 1476 | } |
f5b321bd PM |
1477 | } |
1478 | ||
1479 | return ret; | |
1480 | } | |
1481 | ||
1482 | static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff, | |
1483 | struct nf_conn *ct, enum ip_conntrack_info ctinfo) | |
9fafcd7b | 1484 | { |
f5b321bd | 1485 | struct tcphdr *th, _tcph; |
9fafcd7b | 1486 | unsigned int dataoff, datalen; |
f5b321bd PM |
1487 | unsigned int matchoff, matchlen, clen; |
1488 | unsigned int msglen, origlen; | |
1489 | const char *dptr, *end; | |
1490 | s16 diff, tdiff = 0; | |
7874896a | 1491 | int ret = NF_ACCEPT; |
e6e4d9ed | 1492 | bool term; |
f5b321bd PM |
1493 | |
1494 | if (ctinfo != IP_CT_ESTABLISHED && | |
fb048833 | 1495 | ctinfo != IP_CT_ESTABLISHED_REPLY) |
f5b321bd | 1496 | return NF_ACCEPT; |
9fafcd7b PM |
1497 | |
1498 | /* No Data ? */ | |
f5b321bd PM |
1499 | th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph); |
1500 | if (th == NULL) | |
1501 | return NF_ACCEPT; | |
1502 | dataoff = protoff + th->doff * 4; | |
3db05fea | 1503 | if (dataoff >= skb->len) |
9fafcd7b PM |
1504 | return NF_ACCEPT; |
1505 | ||
3db05fea | 1506 | nf_ct_refresh(ct, skb, sip_timeout * HZ); |
9fafcd7b | 1507 | |
a1d7c1b4 PM |
1508 | if (unlikely(skb_linearize(skb))) |
1509 | return NF_DROP; | |
9fafcd7b | 1510 | |
f5b321bd | 1511 | dptr = skb->data + dataoff; |
3db05fea | 1512 | datalen = skb->len - dataoff; |
779382eb | 1513 | if (datalen < strlen("SIP/2.0 200")) |
7d3dd043 | 1514 | return NF_ACCEPT; |
9fafcd7b | 1515 | |
f5b321bd PM |
1516 | while (1) { |
1517 | if (ct_sip_get_header(ct, dptr, 0, datalen, | |
1518 | SIP_HDR_CONTENT_LENGTH, | |
1519 | &matchoff, &matchlen) <= 0) | |
1520 | break; | |
33cb1e9a | 1521 | |
f5b321bd PM |
1522 | clen = simple_strtoul(dptr + matchoff, (char **)&end, 10); |
1523 | if (dptr + matchoff == end) | |
1524 | break; | |
1525 | ||
e6e4d9ed PM |
1526 | term = false; |
1527 | for (; end + strlen("\r\n\r\n") <= dptr + datalen; end++) { | |
1528 | if (end[0] == '\r' && end[1] == '\n' && | |
1529 | end[2] == '\r' && end[3] == '\n') { | |
1530 | term = true; | |
1531 | break; | |
1532 | } | |
1533 | } | |
1534 | if (!term) | |
f5b321bd PM |
1535 | break; |
1536 | end += strlen("\r\n\r\n") + clen; | |
1537 | ||
1538 | msglen = origlen = end - dptr; | |
3a7b21ea PM |
1539 | if (msglen > datalen) |
1540 | return NF_ACCEPT; | |
f5b321bd | 1541 | |
051966c0 PM |
1542 | ret = process_sip_msg(skb, ct, protoff, dataoff, |
1543 | &dptr, &msglen); | |
b20ab9cc | 1544 | /* process_sip_* functions report why this packet is dropped */ |
f5b321bd PM |
1545 | if (ret != NF_ACCEPT) |
1546 | break; | |
1547 | diff = msglen - origlen; | |
1548 | tdiff += diff; | |
1549 | ||
1550 | dataoff += msglen; | |
1551 | dptr += msglen; | |
1552 | datalen = datalen + diff - msglen; | |
33cb1e9a PM |
1553 | } |
1554 | ||
9a664821 | 1555 | if (ret == NF_ACCEPT && ct->status & IPS_NAT_MASK) { |
180cf72f | 1556 | const struct nf_nat_sip_hooks *hooks; |
1557 | ||
1558 | hooks = rcu_dereference(nf_nat_sip_hooks); | |
1559 | if (hooks) | |
1560 | hooks->seq_adjust(skb, protoff, tdiff); | |
48f8ac26 PM |
1561 | } |
1562 | ||
33cb1e9a | 1563 | return ret; |
9fafcd7b PM |
1564 | } |
1565 | ||
f5b321bd PM |
1566 | static int sip_help_udp(struct sk_buff *skb, unsigned int protoff, |
1567 | struct nf_conn *ct, enum ip_conntrack_info ctinfo) | |
1568 | { | |
1569 | unsigned int dataoff, datalen; | |
1570 | const char *dptr; | |
1571 | ||
1572 | /* No Data ? */ | |
1573 | dataoff = protoff + sizeof(struct udphdr); | |
1574 | if (dataoff >= skb->len) | |
1575 | return NF_ACCEPT; | |
1576 | ||
1577 | nf_ct_refresh(ct, skb, sip_timeout * HZ); | |
1578 | ||
a1d7c1b4 PM |
1579 | if (unlikely(skb_linearize(skb))) |
1580 | return NF_DROP; | |
f5b321bd PM |
1581 | |
1582 | dptr = skb->data + dataoff; | |
1583 | datalen = skb->len - dataoff; | |
1584 | if (datalen < strlen("SIP/2.0 200")) | |
1585 | return NF_ACCEPT; | |
1586 | ||
051966c0 | 1587 | return process_sip_msg(skb, ct, protoff, dataoff, &dptr, &datalen); |
f5b321bd PM |
1588 | } |
1589 | ||
1590 | static struct nf_conntrack_helper sip[MAX_PORTS][4] __read_mostly; | |
9fafcd7b | 1591 | |
0f32a40f PM |
1592 | static const struct nf_conntrack_expect_policy sip_exp_policy[SIP_EXPECT_MAX + 1] = { |
1593 | [SIP_EXPECT_SIGNALLING] = { | |
b87921bd | 1594 | .name = "signalling", |
0f32a40f PM |
1595 | .max_expected = 1, |
1596 | .timeout = 3 * 60, | |
1597 | }, | |
1598 | [SIP_EXPECT_AUDIO] = { | |
b87921bd | 1599 | .name = "audio", |
a9c1d359 | 1600 | .max_expected = 2 * IP_CT_DIR_MAX, |
0f32a40f PM |
1601 | .timeout = 3 * 60, |
1602 | }, | |
0d0ab037 | 1603 | [SIP_EXPECT_VIDEO] = { |
b87921bd | 1604 | .name = "video", |
0d0ab037 PM |
1605 | .max_expected = 2 * IP_CT_DIR_MAX, |
1606 | .timeout = 3 * 60, | |
1607 | }, | |
9d288dff PM |
1608 | [SIP_EXPECT_IMAGE] = { |
1609 | .name = "image", | |
1610 | .max_expected = IP_CT_DIR_MAX, | |
1611 | .timeout = 3 * 60, | |
1612 | }, | |
6002f266 PM |
1613 | }; |
1614 | ||
9fafcd7b PM |
1615 | static void nf_conntrack_sip_fini(void) |
1616 | { | |
1617 | int i, j; | |
1618 | ||
1619 | for (i = 0; i < ports_c; i++) { | |
f5b321bd | 1620 | for (j = 0; j < ARRAY_SIZE(sip[i]); j++) { |
9fafcd7b PM |
1621 | if (sip[i][j].me == NULL) |
1622 | continue; | |
1623 | nf_conntrack_helper_unregister(&sip[i][j]); | |
1624 | } | |
1625 | } | |
1626 | } | |
1627 | ||
1628 | static int __init nf_conntrack_sip_init(void) | |
1629 | { | |
1630 | int i, j, ret; | |
9fafcd7b PM |
1631 | |
1632 | if (ports_c == 0) | |
1633 | ports[ports_c++] = SIP_PORT; | |
1634 | ||
1635 | for (i = 0; i < ports_c; i++) { | |
1636 | memset(&sip[i], 0, sizeof(sip[i])); | |
1637 | ||
1638 | sip[i][0].tuple.src.l3num = AF_INET; | |
f5b321bd PM |
1639 | sip[i][0].tuple.dst.protonum = IPPROTO_UDP; |
1640 | sip[i][0].help = sip_help_udp; | |
1641 | sip[i][1].tuple.src.l3num = AF_INET; | |
1642 | sip[i][1].tuple.dst.protonum = IPPROTO_TCP; | |
1643 | sip[i][1].help = sip_help_tcp; | |
1644 | ||
1645 | sip[i][2].tuple.src.l3num = AF_INET6; | |
1646 | sip[i][2].tuple.dst.protonum = IPPROTO_UDP; | |
1647 | sip[i][2].help = sip_help_udp; | |
1648 | sip[i][3].tuple.src.l3num = AF_INET6; | |
1649 | sip[i][3].tuple.dst.protonum = IPPROTO_TCP; | |
1650 | sip[i][3].help = sip_help_tcp; | |
1651 | ||
1652 | for (j = 0; j < ARRAY_SIZE(sip[i]); j++) { | |
1afc5679 | 1653 | sip[i][j].data_len = sizeof(struct nf_ct_sip_master); |
9fafcd7b | 1654 | sip[i][j].tuple.src.u.udp.port = htons(ports[i]); |
0f32a40f PM |
1655 | sip[i][j].expect_policy = sip_exp_policy; |
1656 | sip[i][j].expect_class_max = SIP_EXPECT_MAX; | |
9fafcd7b | 1657 | sip[i][j].me = THIS_MODULE; |
9fafcd7b | 1658 | |
9fafcd7b | 1659 | if (ports[i] == SIP_PORT) |
e9324b2c | 1660 | sprintf(sip[i][j].name, "sip"); |
9fafcd7b | 1661 | else |
e9324b2c | 1662 | sprintf(sip[i][j].name, "sip-%u", i); |
9fafcd7b | 1663 | |
0d53778e | 1664 | pr_debug("port #%u: %u\n", i, ports[i]); |
9fafcd7b PM |
1665 | |
1666 | ret = nf_conntrack_helper_register(&sip[i][j]); | |
1667 | if (ret) { | |
654d0fbd SH |
1668 | printk(KERN_ERR "nf_ct_sip: failed to register" |
1669 | " helper for pf: %u port: %u\n", | |
9fafcd7b PM |
1670 | sip[i][j].tuple.src.l3num, ports[i]); |
1671 | nf_conntrack_sip_fini(); | |
1672 | return ret; | |
1673 | } | |
1674 | } | |
1675 | } | |
1676 | return 0; | |
1677 | } | |
1678 | ||
1679 | module_init(nf_conntrack_sip_init); | |
1680 | module_exit(nf_conntrack_sip_fini); |