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 | ||
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 | ||
051966c0 PM |
55 | unsigned int (*nf_nat_sip_hook)(struct sk_buff *skb, unsigned int protoff, |
56 | unsigned int dataoff, const char **dptr, | |
2a6cfb22 | 57 | unsigned int *datalen) __read_mostly; |
9fafcd7b PM |
58 | EXPORT_SYMBOL_GPL(nf_nat_sip_hook); |
59 | ||
9a664821 PM |
60 | void (*nf_nat_sip_seq_adjust_hook)(struct sk_buff *skb, unsigned int protoff, |
61 | s16 off) __read_mostly; | |
48f8ac26 PM |
62 | EXPORT_SYMBOL_GPL(nf_nat_sip_seq_adjust_hook); |
63 | ||
0f32a40f | 64 | unsigned int (*nf_nat_sip_expect_hook)(struct sk_buff *skb, |
051966c0 | 65 | unsigned int protoff, |
3b6b9fab | 66 | unsigned int dataoff, |
0f32a40f PM |
67 | const char **dptr, |
68 | unsigned int *datalen, | |
69 | struct nf_conntrack_expect *exp, | |
70 | unsigned int matchoff, | |
71 | unsigned int matchlen) __read_mostly; | |
72 | EXPORT_SYMBOL_GPL(nf_nat_sip_expect_hook); | |
73 | ||
051966c0 PM |
74 | unsigned int (*nf_nat_sdp_addr_hook)(struct sk_buff *skb, unsigned int protoff, |
75 | unsigned int dataoff, | |
4ab9e64e | 76 | const char **dptr, |
4ab9e64e | 77 | unsigned int *datalen, |
3b6b9fab | 78 | unsigned int sdpoff, |
4ab9e64e PM |
79 | enum sdp_header_types type, |
80 | enum sdp_header_types term, | |
81 | const union nf_inet_addr *addr) | |
82 | __read_mostly; | |
83 | EXPORT_SYMBOL_GPL(nf_nat_sdp_addr_hook); | |
84 | ||
051966c0 PM |
85 | unsigned int (*nf_nat_sdp_port_hook)(struct sk_buff *skb, unsigned int protoff, |
86 | unsigned int dataoff, | |
c7f485ab PM |
87 | const char **dptr, |
88 | unsigned int *datalen, | |
89 | unsigned int matchoff, | |
90 | unsigned int matchlen, | |
91 | u_int16_t port) __read_mostly; | |
92 | EXPORT_SYMBOL_GPL(nf_nat_sdp_port_hook); | |
93 | ||
4ab9e64e | 94 | unsigned int (*nf_nat_sdp_session_hook)(struct sk_buff *skb, |
051966c0 | 95 | unsigned int protoff, |
4ab9e64e | 96 | unsigned int dataoff, |
3b6b9fab | 97 | const char **dptr, |
4ab9e64e | 98 | unsigned int *datalen, |
3b6b9fab | 99 | unsigned int sdpoff, |
4ab9e64e PM |
100 | const union nf_inet_addr *addr) |
101 | __read_mostly; | |
102 | EXPORT_SYMBOL_GPL(nf_nat_sdp_session_hook); | |
103 | ||
051966c0 PM |
104 | unsigned int (*nf_nat_sdp_media_hook)(struct sk_buff *skb, unsigned int protoff, |
105 | unsigned int dataoff, | |
4ab9e64e PM |
106 | const char **dptr, |
107 | unsigned int *datalen, | |
108 | struct nf_conntrack_expect *rtp_exp, | |
109 | struct nf_conntrack_expect *rtcp_exp, | |
110 | unsigned int mediaoff, | |
111 | unsigned int medialen, | |
112 | union nf_inet_addr *rtp_addr) | |
113 | __read_mostly; | |
114 | EXPORT_SYMBOL_GPL(nf_nat_sdp_media_hook); | |
9fafcd7b | 115 | |
ac367740 PM |
116 | static int string_len(const struct nf_conn *ct, const char *dptr, |
117 | const char *limit, int *shift) | |
118 | { | |
119 | int len = 0; | |
120 | ||
121 | while (dptr < limit && isalpha(*dptr)) { | |
122 | dptr++; | |
123 | len++; | |
124 | } | |
125 | return len; | |
126 | } | |
127 | ||
13f7d63c | 128 | static int digits_len(const struct nf_conn *ct, const char *dptr, |
9fafcd7b PM |
129 | const char *limit, int *shift) |
130 | { | |
131 | int len = 0; | |
b1ec488b | 132 | while (dptr < limit && isdigit(*dptr)) { |
9fafcd7b PM |
133 | dptr++; |
134 | len++; | |
135 | } | |
136 | return len; | |
137 | } | |
138 | ||
001985b2 SH |
139 | static int iswordc(const char c) |
140 | { | |
141 | if (isalnum(c) || c == '!' || c == '"' || c == '%' || | |
142 | (c >= '(' && c <= '/') || c == ':' || c == '<' || c == '>' || | |
143 | c == '?' || (c >= '[' && c <= ']') || c == '_' || c == '`' || | |
144 | c == '{' || c == '}' || c == '~') | |
145 | return 1; | |
146 | return 0; | |
147 | } | |
148 | ||
149 | static int word_len(const char *dptr, const char *limit) | |
150 | { | |
151 | int len = 0; | |
152 | while (dptr < limit && iswordc(*dptr)) { | |
153 | dptr++; | |
154 | len++; | |
155 | } | |
156 | return len; | |
157 | } | |
158 | ||
159 | static int callid_len(const struct nf_conn *ct, const char *dptr, | |
160 | const char *limit, int *shift) | |
161 | { | |
162 | int len, domain_len; | |
163 | ||
164 | len = word_len(dptr, limit); | |
165 | dptr += len; | |
166 | if (!len || dptr == limit || *dptr != '@') | |
167 | return len; | |
168 | dptr++; | |
169 | len++; | |
170 | ||
171 | domain_len = word_len(dptr, limit); | |
172 | if (!domain_len) | |
173 | return 0; | |
174 | return len + domain_len; | |
175 | } | |
176 | ||
0d0ab037 PM |
177 | /* get media type + port length */ |
178 | static int media_len(const struct nf_conn *ct, const char *dptr, | |
179 | const char *limit, int *shift) | |
180 | { | |
181 | int len = string_len(ct, dptr, limit, shift); | |
182 | ||
183 | dptr += len; | |
184 | if (dptr >= limit || *dptr != ' ') | |
185 | return 0; | |
186 | len++; | |
187 | dptr++; | |
188 | ||
189 | return len + digits_len(ct, dptr, limit, shift); | |
190 | } | |
191 | ||
02b69cbd PM |
192 | static int sip_parse_addr(const struct nf_conn *ct, const char *cp, |
193 | const char **endp, union nf_inet_addr *addr, | |
194 | const char *limit, bool delim) | |
9fafcd7b PM |
195 | { |
196 | const char *end; | |
02b69cbd | 197 | int ret; |
9fafcd7b | 198 | |
5adbb9fb SH |
199 | if (!ct) |
200 | return 0; | |
201 | ||
fa913ddf | 202 | memset(addr, 0, sizeof(*addr)); |
5e8fbe2a | 203 | switch (nf_ct_l3num(ct)) { |
9fafcd7b PM |
204 | case AF_INET: |
205 | ret = in4_pton(cp, limit - cp, (u8 *)&addr->ip, -1, &end); | |
02b69cbd PM |
206 | if (ret == 0) |
207 | return 0; | |
9fafcd7b PM |
208 | break; |
209 | case AF_INET6: | |
02b69cbd PM |
210 | if (cp < limit && *cp == '[') |
211 | cp++; | |
212 | else if (delim) | |
213 | return 0; | |
214 | ||
9fafcd7b | 215 | ret = in6_pton(cp, limit - cp, (u8 *)&addr->ip6, -1, &end); |
02b69cbd PM |
216 | if (ret == 0) |
217 | return 0; | |
218 | ||
219 | if (end < limit && *end == ']') | |
220 | end++; | |
221 | else if (delim) | |
222 | return 0; | |
9fafcd7b PM |
223 | break; |
224 | default: | |
225 | BUG(); | |
226 | } | |
227 | ||
9fafcd7b PM |
228 | if (endp) |
229 | *endp = end; | |
230 | return 1; | |
231 | } | |
232 | ||
233 | /* skip ip address. returns its length. */ | |
13f7d63c | 234 | static int epaddr_len(const struct nf_conn *ct, const char *dptr, |
9fafcd7b PM |
235 | const char *limit, int *shift) |
236 | { | |
643a2c15 | 237 | union nf_inet_addr addr; |
9fafcd7b PM |
238 | const char *aux = dptr; |
239 | ||
02b69cbd | 240 | if (!sip_parse_addr(ct, dptr, &dptr, &addr, limit, true)) { |
0d53778e | 241 | pr_debug("ip: %s parse failed.!\n", dptr); |
9fafcd7b PM |
242 | return 0; |
243 | } | |
244 | ||
245 | /* Port number */ | |
246 | if (*dptr == ':') { | |
247 | dptr++; | |
248 | dptr += digits_len(ct, dptr, limit, shift); | |
249 | } | |
250 | return dptr - aux; | |
251 | } | |
252 | ||
253 | /* get address length, skiping user info. */ | |
13f7d63c | 254 | static int skp_epaddr_len(const struct nf_conn *ct, const char *dptr, |
9fafcd7b PM |
255 | const char *limit, int *shift) |
256 | { | |
aa584eda | 257 | const char *start = dptr; |
9fafcd7b PM |
258 | int s = *shift; |
259 | ||
7da5bfbb LI |
260 | /* Search for @, but stop at the end of the line. |
261 | * We are inside a sip: URI, so we don't need to worry about | |
262 | * continuation lines. */ | |
b1ec488b | 263 | while (dptr < limit && |
7da5bfbb | 264 | *dptr != '@' && *dptr != '\r' && *dptr != '\n') { |
9fafcd7b | 265 | (*shift)++; |
7da5bfbb LI |
266 | dptr++; |
267 | } | |
9fafcd7b | 268 | |
b1ec488b | 269 | if (dptr < limit && *dptr == '@') { |
9fafcd7b PM |
270 | dptr++; |
271 | (*shift)++; | |
aa584eda PM |
272 | } else { |
273 | dptr = start; | |
9fafcd7b | 274 | *shift = s; |
aa584eda | 275 | } |
9fafcd7b PM |
276 | |
277 | return epaddr_len(ct, dptr, limit, shift); | |
278 | } | |
279 | ||
ac367740 PM |
280 | /* Parse a SIP request line of the form: |
281 | * | |
282 | * Request-Line = Method SP Request-URI SP SIP-Version CRLF | |
283 | * | |
284 | * and return the offset and length of the address contained in the Request-URI. | |
285 | */ | |
286 | int ct_sip_parse_request(const struct nf_conn *ct, | |
287 | const char *dptr, unsigned int datalen, | |
624f8b7b PM |
288 | unsigned int *matchoff, unsigned int *matchlen, |
289 | union nf_inet_addr *addr, __be16 *port) | |
ac367740 | 290 | { |
624f8b7b | 291 | const char *start = dptr, *limit = dptr + datalen, *end; |
ac367740 | 292 | unsigned int mlen; |
624f8b7b | 293 | unsigned int p; |
ac367740 PM |
294 | int shift = 0; |
295 | ||
296 | /* Skip method and following whitespace */ | |
297 | mlen = string_len(ct, dptr, limit, NULL); | |
298 | if (!mlen) | |
299 | return 0; | |
300 | dptr += mlen; | |
301 | if (++dptr >= limit) | |
302 | return 0; | |
303 | ||
304 | /* Find SIP URI */ | |
54101f4f | 305 | for (; dptr < limit - strlen("sip:"); dptr++) { |
ac367740 PM |
306 | if (*dptr == '\r' || *dptr == '\n') |
307 | return -1; | |
54101f4f PM |
308 | if (strnicmp(dptr, "sip:", strlen("sip:")) == 0) { |
309 | dptr += strlen("sip:"); | |
ac367740 | 310 | break; |
54101f4f | 311 | } |
ac367740 | 312 | } |
624f8b7b | 313 | if (!skp_epaddr_len(ct, dptr, limit, &shift)) |
ac367740 | 314 | return 0; |
624f8b7b PM |
315 | dptr += shift; |
316 | ||
02b69cbd | 317 | if (!sip_parse_addr(ct, dptr, &end, addr, limit, true)) |
624f8b7b PM |
318 | return -1; |
319 | if (end < limit && *end == ':') { | |
320 | end++; | |
321 | p = simple_strtoul(end, (char **)&end, 10); | |
322 | if (p < 1024 || p > 65535) | |
323 | return -1; | |
324 | *port = htons(p); | |
325 | } else | |
326 | *port = htons(SIP_PORT); | |
327 | ||
328 | if (end == dptr) | |
329 | return 0; | |
330 | *matchoff = dptr - start; | |
331 | *matchlen = end - dptr; | |
ac367740 PM |
332 | return 1; |
333 | } | |
334 | EXPORT_SYMBOL_GPL(ct_sip_parse_request); | |
335 | ||
ea45f12a PM |
336 | /* SIP header parsing: SIP headers are located at the beginning of a line, but |
337 | * may span several lines, in which case the continuation lines begin with a | |
338 | * whitespace character. RFC 2543 allows lines to be terminated with CR, LF or | |
339 | * CRLF, RFC 3261 allows only CRLF, we support both. | |
340 | * | |
341 | * Headers are followed by (optionally) whitespace, a colon, again (optionally) | |
342 | * whitespace and the values. Whitespace in this context means any amount of | |
343 | * tabs, spaces and continuation lines, which are treated as a single whitespace | |
344 | * character. | |
05e3ced2 | 345 | * |
3ad2f3fb | 346 | * Some headers may appear multiple times. A comma separated list of values is |
05e3ced2 | 347 | * equivalent to multiple headers. |
ea45f12a PM |
348 | */ |
349 | static const struct sip_header ct_sip_hdrs[] = { | |
30f33e6d | 350 | [SIP_HDR_CSEQ] = SIP_HDR("CSeq", NULL, NULL, digits_len), |
ea45f12a PM |
351 | [SIP_HDR_FROM] = SIP_HDR("From", "f", "sip:", skp_epaddr_len), |
352 | [SIP_HDR_TO] = SIP_HDR("To", "t", "sip:", skp_epaddr_len), | |
353 | [SIP_HDR_CONTACT] = SIP_HDR("Contact", "m", "sip:", skp_epaddr_len), | |
f5b321bd PM |
354 | [SIP_HDR_VIA_UDP] = SIP_HDR("Via", "v", "UDP ", epaddr_len), |
355 | [SIP_HDR_VIA_TCP] = SIP_HDR("Via", "v", "TCP ", epaddr_len), | |
0f32a40f | 356 | [SIP_HDR_EXPIRES] = SIP_HDR("Expires", NULL, NULL, digits_len), |
ea45f12a | 357 | [SIP_HDR_CONTENT_LENGTH] = SIP_HDR("Content-Length", "l", NULL, digits_len), |
001985b2 | 358 | [SIP_HDR_CALL_ID] = SIP_HDR("Call-Id", "i", NULL, callid_len), |
ea45f12a PM |
359 | }; |
360 | ||
361 | static const char *sip_follow_continuation(const char *dptr, const char *limit) | |
9fafcd7b | 362 | { |
ea45f12a PM |
363 | /* Walk past newline */ |
364 | if (++dptr >= limit) | |
365 | return NULL; | |
366 | ||
367 | /* Skip '\n' in CR LF */ | |
368 | if (*(dptr - 1) == '\r' && *dptr == '\n') { | |
369 | if (++dptr >= limit) | |
370 | return NULL; | |
371 | } | |
9fafcd7b | 372 | |
ea45f12a PM |
373 | /* Continuation line? */ |
374 | if (*dptr != ' ' && *dptr != '\t') | |
375 | return NULL; | |
9fafcd7b | 376 | |
ea45f12a PM |
377 | /* skip leading whitespace */ |
378 | for (; dptr < limit; dptr++) { | |
379 | if (*dptr != ' ' && *dptr != '\t') | |
380 | break; | |
381 | } | |
382 | return dptr; | |
383 | } | |
384 | ||
385 | static const char *sip_skip_whitespace(const char *dptr, const char *limit) | |
386 | { | |
387 | for (; dptr < limit; dptr++) { | |
388 | if (*dptr == ' ') | |
389 | continue; | |
390 | if (*dptr != '\r' && *dptr != '\n') | |
391 | break; | |
392 | dptr = sip_follow_continuation(dptr, limit); | |
393 | if (dptr == NULL) | |
394 | return NULL; | |
395 | } | |
396 | return dptr; | |
397 | } | |
398 | ||
399 | /* Search within a SIP header value, dealing with continuation lines */ | |
400 | static const char *ct_sip_header_search(const char *dptr, const char *limit, | |
401 | const char *needle, unsigned int len) | |
402 | { | |
403 | for (limit -= len; dptr < limit; dptr++) { | |
404 | if (*dptr == '\r' || *dptr == '\n') { | |
405 | dptr = sip_follow_continuation(dptr, limit); | |
406 | if (dptr == NULL) | |
407 | break; | |
9fafcd7b PM |
408 | continue; |
409 | } | |
ea45f12a PM |
410 | |
411 | if (strnicmp(dptr, needle, len) == 0) | |
412 | return dptr; | |
413 | } | |
414 | return NULL; | |
415 | } | |
416 | ||
417 | int ct_sip_get_header(const struct nf_conn *ct, const char *dptr, | |
418 | unsigned int dataoff, unsigned int datalen, | |
419 | enum sip_header_types type, | |
420 | unsigned int *matchoff, unsigned int *matchlen) | |
421 | { | |
422 | const struct sip_header *hdr = &ct_sip_hdrs[type]; | |
423 | const char *start = dptr, *limit = dptr + datalen; | |
424 | int shift = 0; | |
425 | ||
426 | for (dptr += dataoff; dptr < limit; dptr++) { | |
427 | /* Find beginning of line */ | |
428 | if (*dptr != '\r' && *dptr != '\n') | |
429 | continue; | |
430 | if (++dptr >= limit) | |
431 | break; | |
432 | if (*(dptr - 1) == '\r' && *dptr == '\n') { | |
433 | if (++dptr >= limit) | |
434 | break; | |
9fafcd7b | 435 | } |
9fafcd7b | 436 | |
ea45f12a PM |
437 | /* Skip continuation lines */ |
438 | if (*dptr == ' ' || *dptr == '\t') | |
439 | continue; | |
9fafcd7b | 440 | |
ea45f12a PM |
441 | /* Find header. Compact headers must be followed by a |
442 | * non-alphabetic character to avoid mismatches. */ | |
443 | if (limit - dptr >= hdr->len && | |
444 | strnicmp(dptr, hdr->name, hdr->len) == 0) | |
445 | dptr += hdr->len; | |
446 | else if (hdr->cname && limit - dptr >= hdr->clen + 1 && | |
447 | strnicmp(dptr, hdr->cname, hdr->clen) == 0 && | |
135d0189 | 448 | !isalpha(*(dptr + hdr->clen))) |
ea45f12a PM |
449 | dptr += hdr->clen; |
450 | else | |
451 | continue; | |
9fafcd7b | 452 | |
ea45f12a PM |
453 | /* Find and skip colon */ |
454 | dptr = sip_skip_whitespace(dptr, limit); | |
455 | if (dptr == NULL) | |
456 | break; | |
457 | if (*dptr != ':' || ++dptr >= limit) | |
458 | break; | |
459 | ||
460 | /* Skip whitespace after colon */ | |
461 | dptr = sip_skip_whitespace(dptr, limit); | |
462 | if (dptr == NULL) | |
463 | break; | |
464 | ||
465 | *matchoff = dptr - start; | |
466 | if (hdr->search) { | |
467 | dptr = ct_sip_header_search(dptr, limit, hdr->search, | |
468 | hdr->slen); | |
469 | if (!dptr) | |
470 | return -1; | |
471 | dptr += hdr->slen; | |
472 | } | |
473 | ||
474 | *matchlen = hdr->match_len(ct, dptr, limit, &shift); | |
475 | if (!*matchlen) | |
476 | return -1; | |
477 | *matchoff = dptr - start + shift; | |
9fafcd7b PM |
478 | return 1; |
479 | } | |
9fafcd7b PM |
480 | return 0; |
481 | } | |
ea45f12a | 482 | EXPORT_SYMBOL_GPL(ct_sip_get_header); |
9fafcd7b | 483 | |
3ad2f3fb | 484 | /* Get next header field in a list of comma separated values */ |
05e3ced2 PM |
485 | static int ct_sip_next_header(const struct nf_conn *ct, const char *dptr, |
486 | unsigned int dataoff, unsigned int datalen, | |
487 | enum sip_header_types type, | |
488 | unsigned int *matchoff, unsigned int *matchlen) | |
489 | { | |
490 | const struct sip_header *hdr = &ct_sip_hdrs[type]; | |
491 | const char *start = dptr, *limit = dptr + datalen; | |
492 | int shift = 0; | |
493 | ||
494 | dptr += dataoff; | |
495 | ||
496 | dptr = ct_sip_header_search(dptr, limit, ",", strlen(",")); | |
497 | if (!dptr) | |
498 | return 0; | |
499 | ||
500 | dptr = ct_sip_header_search(dptr, limit, hdr->search, hdr->slen); | |
501 | if (!dptr) | |
502 | return 0; | |
503 | dptr += hdr->slen; | |
504 | ||
505 | *matchoff = dptr - start; | |
506 | *matchlen = hdr->match_len(ct, dptr, limit, &shift); | |
507 | if (!*matchlen) | |
508 | return -1; | |
509 | *matchoff += shift; | |
510 | return 1; | |
511 | } | |
512 | ||
513 | /* Walk through headers until a parsable one is found or no header of the | |
514 | * given type is left. */ | |
515 | static int ct_sip_walk_headers(const struct nf_conn *ct, const char *dptr, | |
516 | unsigned int dataoff, unsigned int datalen, | |
517 | enum sip_header_types type, int *in_header, | |
518 | unsigned int *matchoff, unsigned int *matchlen) | |
519 | { | |
520 | int ret; | |
521 | ||
522 | if (in_header && *in_header) { | |
523 | while (1) { | |
524 | ret = ct_sip_next_header(ct, dptr, dataoff, datalen, | |
525 | type, matchoff, matchlen); | |
526 | if (ret > 0) | |
527 | return ret; | |
528 | if (ret == 0) | |
529 | break; | |
530 | dataoff += *matchoff; | |
531 | } | |
532 | *in_header = 0; | |
533 | } | |
534 | ||
535 | while (1) { | |
536 | ret = ct_sip_get_header(ct, dptr, dataoff, datalen, | |
537 | type, matchoff, matchlen); | |
538 | if (ret > 0) | |
539 | break; | |
540 | if (ret == 0) | |
541 | return ret; | |
542 | dataoff += *matchoff; | |
543 | } | |
544 | ||
545 | if (in_header) | |
546 | *in_header = 1; | |
547 | return 1; | |
548 | } | |
549 | ||
550 | /* Locate a SIP header, parse the URI and return the offset and length of | |
551 | * the address as well as the address and port themselves. A stream of | |
552 | * headers can be parsed by handing in a non-NULL datalen and in_header | |
553 | * pointer. | |
554 | */ | |
555 | int ct_sip_parse_header_uri(const struct nf_conn *ct, const char *dptr, | |
556 | unsigned int *dataoff, unsigned int datalen, | |
557 | enum sip_header_types type, int *in_header, | |
558 | unsigned int *matchoff, unsigned int *matchlen, | |
559 | union nf_inet_addr *addr, __be16 *port) | |
560 | { | |
561 | const char *c, *limit = dptr + datalen; | |
562 | unsigned int p; | |
563 | int ret; | |
564 | ||
565 | ret = ct_sip_walk_headers(ct, dptr, dataoff ? *dataoff : 0, datalen, | |
566 | type, in_header, matchoff, matchlen); | |
567 | WARN_ON(ret < 0); | |
568 | if (ret == 0) | |
569 | return ret; | |
570 | ||
02b69cbd | 571 | if (!sip_parse_addr(ct, dptr + *matchoff, &c, addr, limit, true)) |
05e3ced2 PM |
572 | return -1; |
573 | if (*c == ':') { | |
574 | c++; | |
575 | p = simple_strtoul(c, (char **)&c, 10); | |
576 | if (p < 1024 || p > 65535) | |
577 | return -1; | |
578 | *port = htons(p); | |
579 | } else | |
580 | *port = htons(SIP_PORT); | |
581 | ||
582 | if (dataoff) | |
583 | *dataoff = c - dptr; | |
584 | return 1; | |
585 | } | |
586 | EXPORT_SYMBOL_GPL(ct_sip_parse_header_uri); | |
587 | ||
f5b321bd PM |
588 | static int ct_sip_parse_param(const struct nf_conn *ct, const char *dptr, |
589 | unsigned int dataoff, unsigned int datalen, | |
590 | const char *name, | |
591 | unsigned int *matchoff, unsigned int *matchlen) | |
592 | { | |
593 | const char *limit = dptr + datalen; | |
594 | const char *start; | |
595 | const 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 | start += strlen(name); | |
605 | ||
606 | end = ct_sip_header_search(start, limit, ";", strlen(";")); | |
607 | if (!end) | |
608 | end = limit; | |
609 | ||
610 | *matchoff = start - dptr; | |
611 | *matchlen = end - start; | |
612 | return 1; | |
613 | } | |
614 | ||
2bbb2116 PM |
615 | /* Parse address from header parameter and return address, offset and length */ |
616 | int ct_sip_parse_address_param(const struct nf_conn *ct, const char *dptr, | |
617 | unsigned int dataoff, unsigned int datalen, | |
618 | const char *name, | |
619 | unsigned int *matchoff, unsigned int *matchlen, | |
02b69cbd | 620 | union nf_inet_addr *addr, bool delim) |
2bbb2116 PM |
621 | { |
622 | const char *limit = dptr + datalen; | |
623 | const char *start, *end; | |
624 | ||
625 | limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(",")); | |
626 | if (!limit) | |
627 | limit = dptr + datalen; | |
628 | ||
629 | start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name)); | |
630 | if (!start) | |
631 | return 0; | |
632 | ||
633 | start += strlen(name); | |
02b69cbd | 634 | if (!sip_parse_addr(ct, start, &end, addr, limit, delim)) |
2bbb2116 PM |
635 | return 0; |
636 | *matchoff = start - dptr; | |
637 | *matchlen = end - start; | |
638 | return 1; | |
639 | } | |
640 | EXPORT_SYMBOL_GPL(ct_sip_parse_address_param); | |
641 | ||
642 | /* Parse numerical header parameter and return value, offset and length */ | |
643 | int ct_sip_parse_numerical_param(const struct nf_conn *ct, const char *dptr, | |
644 | unsigned int dataoff, unsigned int datalen, | |
645 | const char *name, | |
646 | unsigned int *matchoff, unsigned int *matchlen, | |
647 | unsigned int *val) | |
648 | { | |
649 | const char *limit = dptr + datalen; | |
650 | const char *start; | |
651 | char *end; | |
652 | ||
653 | limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(",")); | |
654 | if (!limit) | |
655 | limit = dptr + datalen; | |
656 | ||
657 | start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name)); | |
658 | if (!start) | |
659 | return 0; | |
660 | ||
661 | start += strlen(name); | |
662 | *val = simple_strtoul(start, &end, 0); | |
663 | if (start == end) | |
664 | return 0; | |
665 | if (matchoff && matchlen) { | |
666 | *matchoff = start - dptr; | |
667 | *matchlen = end - start; | |
668 | } | |
669 | return 1; | |
670 | } | |
671 | EXPORT_SYMBOL_GPL(ct_sip_parse_numerical_param); | |
672 | ||
f5b321bd PM |
673 | static int ct_sip_parse_transport(struct nf_conn *ct, const char *dptr, |
674 | unsigned int dataoff, unsigned int datalen, | |
675 | u8 *proto) | |
676 | { | |
677 | unsigned int matchoff, matchlen; | |
678 | ||
679 | if (ct_sip_parse_param(ct, dptr, dataoff, datalen, "transport=", | |
680 | &matchoff, &matchlen)) { | |
681 | if (!strnicmp(dptr + matchoff, "TCP", strlen("TCP"))) | |
682 | *proto = IPPROTO_TCP; | |
683 | else if (!strnicmp(dptr + matchoff, "UDP", strlen("UDP"))) | |
684 | *proto = IPPROTO_UDP; | |
685 | else | |
686 | return 0; | |
687 | ||
688 | if (*proto != nf_ct_protonum(ct)) | |
689 | return 0; | |
690 | } else | |
691 | *proto = nf_ct_protonum(ct); | |
692 | ||
693 | return 1; | |
694 | } | |
695 | ||
02b69cbd PM |
696 | static int sdp_parse_addr(const struct nf_conn *ct, const char *cp, |
697 | const char **endp, union nf_inet_addr *addr, | |
698 | const char *limit) | |
699 | { | |
700 | const char *end; | |
701 | int ret; | |
702 | ||
703 | memset(addr, 0, sizeof(*addr)); | |
704 | switch (nf_ct_l3num(ct)) { | |
705 | case AF_INET: | |
706 | ret = in4_pton(cp, limit - cp, (u8 *)&addr->ip, -1, &end); | |
707 | break; | |
708 | case AF_INET6: | |
709 | ret = in6_pton(cp, limit - cp, (u8 *)&addr->ip6, -1, &end); | |
710 | break; | |
711 | default: | |
712 | BUG(); | |
713 | } | |
714 | ||
715 | if (ret == 0) | |
716 | return 0; | |
717 | if (endp) | |
718 | *endp = end; | |
719 | return 1; | |
720 | } | |
721 | ||
722 | /* skip ip address. returns its length. */ | |
723 | static int sdp_addr_len(const struct nf_conn *ct, const char *dptr, | |
724 | const char *limit, int *shift) | |
725 | { | |
726 | union nf_inet_addr addr; | |
727 | const char *aux = dptr; | |
728 | ||
729 | if (!sdp_parse_addr(ct, dptr, &dptr, &addr, limit)) { | |
730 | pr_debug("ip: %s parse failed.!\n", dptr); | |
731 | return 0; | |
732 | } | |
733 | ||
734 | return dptr - aux; | |
735 | } | |
736 | ||
3e9b4600 PM |
737 | /* SDP header parsing: a SDP session description contains an ordered set of |
738 | * headers, starting with a section containing general session parameters, | |
739 | * optionally followed by multiple media descriptions. | |
740 | * | |
741 | * SDP headers always start at the beginning of a line. According to RFC 2327: | |
742 | * "The sequence CRLF (0x0d0a) is used to end a record, although parsers should | |
743 | * be tolerant and also accept records terminated with a single newline | |
744 | * character". We handle both cases. | |
745 | */ | |
9a664821 PM |
746 | static const struct sip_header ct_sdp_hdrs_v4[] = { |
747 | [SDP_HDR_VERSION] = SDP_HDR("v=", NULL, digits_len), | |
748 | [SDP_HDR_OWNER] = SDP_HDR("o=", "IN IP4 ", sdp_addr_len), | |
749 | [SDP_HDR_CONNECTION] = SDP_HDR("c=", "IN IP4 ", sdp_addr_len), | |
750 | [SDP_HDR_MEDIA] = SDP_HDR("m=", NULL, media_len), | |
751 | }; | |
752 | ||
753 | static const struct sip_header ct_sdp_hdrs_v6[] = { | |
754 | [SDP_HDR_VERSION] = SDP_HDR("v=", NULL, digits_len), | |
755 | [SDP_HDR_OWNER] = SDP_HDR("o=", "IN IP6 ", sdp_addr_len), | |
756 | [SDP_HDR_CONNECTION] = SDP_HDR("c=", "IN IP6 ", sdp_addr_len), | |
757 | [SDP_HDR_MEDIA] = SDP_HDR("m=", NULL, media_len), | |
3e9b4600 PM |
758 | }; |
759 | ||
760 | /* Linear string search within SDP header values */ | |
761 | static const char *ct_sdp_header_search(const char *dptr, const char *limit, | |
762 | const char *needle, unsigned int len) | |
763 | { | |
764 | for (limit -= len; dptr < limit; dptr++) { | |
765 | if (*dptr == '\r' || *dptr == '\n') | |
766 | break; | |
767 | if (strncmp(dptr, needle, len) == 0) | |
768 | return dptr; | |
769 | } | |
770 | return NULL; | |
771 | } | |
772 | ||
773 | /* Locate a SDP header (optionally a substring within the header value), | |
25985edc | 774 | * optionally stopping at the first occurrence of the term header, parse |
3e9b4600 PM |
775 | * it and return the offset and length of the data we're interested in. |
776 | */ | |
777 | int ct_sip_get_sdp_header(const struct nf_conn *ct, const char *dptr, | |
778 | unsigned int dataoff, unsigned int datalen, | |
779 | enum sdp_header_types type, | |
780 | enum sdp_header_types term, | |
781 | unsigned int *matchoff, unsigned int *matchlen) | |
782 | { | |
9a664821 | 783 | const struct sip_header *hdrs, *hdr, *thdr; |
3e9b4600 PM |
784 | const char *start = dptr, *limit = dptr + datalen; |
785 | int shift = 0; | |
786 | ||
9a664821 PM |
787 | hdrs = nf_ct_l3num(ct) == NFPROTO_IPV4 ? ct_sdp_hdrs_v4 : ct_sdp_hdrs_v6; |
788 | hdr = &hdrs[type]; | |
789 | thdr = &hdrs[term]; | |
790 | ||
3e9b4600 PM |
791 | for (dptr += dataoff; dptr < limit; dptr++) { |
792 | /* Find beginning of line */ | |
793 | if (*dptr != '\r' && *dptr != '\n') | |
794 | continue; | |
795 | if (++dptr >= limit) | |
796 | break; | |
797 | if (*(dptr - 1) == '\r' && *dptr == '\n') { | |
798 | if (++dptr >= limit) | |
799 | break; | |
800 | } | |
801 | ||
802 | if (term != SDP_HDR_UNSPEC && | |
803 | limit - dptr >= thdr->len && | |
804 | strnicmp(dptr, thdr->name, thdr->len) == 0) | |
805 | break; | |
806 | else if (limit - dptr >= hdr->len && | |
807 | strnicmp(dptr, hdr->name, hdr->len) == 0) | |
808 | dptr += hdr->len; | |
809 | else | |
810 | continue; | |
811 | ||
812 | *matchoff = dptr - start; | |
813 | if (hdr->search) { | |
814 | dptr = ct_sdp_header_search(dptr, limit, hdr->search, | |
815 | hdr->slen); | |
816 | if (!dptr) | |
817 | return -1; | |
818 | dptr += hdr->slen; | |
819 | } | |
820 | ||
821 | *matchlen = hdr->match_len(ct, dptr, limit, &shift); | |
822 | if (!*matchlen) | |
823 | return -1; | |
824 | *matchoff = dptr - start + shift; | |
825 | return 1; | |
826 | } | |
827 | return 0; | |
828 | } | |
829 | EXPORT_SYMBOL_GPL(ct_sip_get_sdp_header); | |
830 | ||
4ab9e64e PM |
831 | static int ct_sip_parse_sdp_addr(const struct nf_conn *ct, const char *dptr, |
832 | unsigned int dataoff, unsigned int datalen, | |
833 | enum sdp_header_types type, | |
834 | enum sdp_header_types term, | |
835 | unsigned int *matchoff, unsigned int *matchlen, | |
836 | union nf_inet_addr *addr) | |
837 | { | |
838 | int ret; | |
839 | ||
840 | ret = ct_sip_get_sdp_header(ct, dptr, dataoff, datalen, type, term, | |
841 | matchoff, matchlen); | |
842 | if (ret <= 0) | |
843 | return ret; | |
844 | ||
02b69cbd PM |
845 | if (!sdp_parse_addr(ct, dptr + *matchoff, NULL, addr, |
846 | dptr + *matchoff + *matchlen)) | |
4ab9e64e PM |
847 | return -1; |
848 | return 1; | |
849 | } | |
850 | ||
0f32a40f PM |
851 | static int refresh_signalling_expectation(struct nf_conn *ct, |
852 | union nf_inet_addr *addr, | |
f5b321bd | 853 | u8 proto, __be16 port, |
0f32a40f | 854 | unsigned int expires) |
9467ee38 PM |
855 | { |
856 | struct nf_conn_help *help = nfct_help(ct); | |
857 | struct nf_conntrack_expect *exp; | |
858 | struct hlist_node *n, *next; | |
0f32a40f | 859 | int found = 0; |
9467ee38 PM |
860 | |
861 | spin_lock_bh(&nf_conntrack_lock); | |
862 | hlist_for_each_entry_safe(exp, n, next, &help->expectations, lnode) { | |
0f32a40f PM |
863 | if (exp->class != SIP_EXPECT_SIGNALLING || |
864 | !nf_inet_addr_cmp(&exp->tuple.dst.u3, addr) || | |
f5b321bd | 865 | exp->tuple.dst.protonum != proto || |
0f32a40f PM |
866 | exp->tuple.dst.u.udp.port != port) |
867 | continue; | |
868 | if (!del_timer(&exp->timeout)) | |
869 | continue; | |
870 | exp->flags &= ~NF_CT_EXPECT_INACTIVE; | |
871 | exp->timeout.expires = jiffies + expires * HZ; | |
872 | add_timer(&exp->timeout); | |
873 | found = 1; | |
874 | break; | |
875 | } | |
876 | spin_unlock_bh(&nf_conntrack_lock); | |
877 | return found; | |
878 | } | |
879 | ||
880 | static void flush_expectations(struct nf_conn *ct, bool media) | |
881 | { | |
882 | struct nf_conn_help *help = nfct_help(ct); | |
883 | struct nf_conntrack_expect *exp; | |
884 | struct hlist_node *n, *next; | |
885 | ||
886 | spin_lock_bh(&nf_conntrack_lock); | |
887 | hlist_for_each_entry_safe(exp, n, next, &help->expectations, lnode) { | |
888 | if ((exp->class != SIP_EXPECT_SIGNALLING) ^ media) | |
889 | continue; | |
9467ee38 PM |
890 | if (!del_timer(&exp->timeout)) |
891 | continue; | |
892 | nf_ct_unlink_expect(exp); | |
893 | nf_ct_expect_put(exp); | |
0f32a40f PM |
894 | if (!media) |
895 | break; | |
9467ee38 PM |
896 | } |
897 | spin_unlock_bh(&nf_conntrack_lock); | |
898 | } | |
899 | ||
051966c0 PM |
900 | static int set_expected_rtp_rtcp(struct sk_buff *skb, unsigned int protoff, |
901 | unsigned int dataoff, | |
a9c1d359 | 902 | const char **dptr, unsigned int *datalen, |
4ab9e64e | 903 | union nf_inet_addr *daddr, __be16 port, |
0d0ab037 | 904 | enum sip_expectation_classes class, |
4ab9e64e | 905 | unsigned int mediaoff, unsigned int medialen) |
9fafcd7b | 906 | { |
a9c1d359 | 907 | struct nf_conntrack_expect *exp, *rtp_exp, *rtcp_exp; |
212440a7 PM |
908 | enum ip_conntrack_info ctinfo; |
909 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
a5c3a800 | 910 | struct net *net = nf_ct_net(ct); |
9fafcd7b | 911 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
d901a936 PM |
912 | union nf_inet_addr *saddr; |
913 | struct nf_conntrack_tuple tuple; | |
c7f485ab | 914 | int direct_rtp = 0, skip_expect = 0, ret = NF_DROP; |
a9c1d359 PM |
915 | u_int16_t base_port; |
916 | __be16 rtp_port, rtcp_port; | |
c7f485ab | 917 | typeof(nf_nat_sdp_port_hook) nf_nat_sdp_port; |
4ab9e64e | 918 | typeof(nf_nat_sdp_media_hook) nf_nat_sdp_media; |
9fafcd7b | 919 | |
d901a936 PM |
920 | saddr = NULL; |
921 | if (sip_direct_media) { | |
922 | if (!nf_inet_addr_cmp(daddr, &ct->tuplehash[dir].tuple.src.u3)) | |
923 | return NF_ACCEPT; | |
924 | saddr = &ct->tuplehash[!dir].tuple.src.u3; | |
925 | } | |
926 | ||
927 | /* We need to check whether the registration exists before attempting | |
928 | * to register it since we can see the same media description multiple | |
929 | * times on different connections in case multiple endpoints receive | |
930 | * the same call. | |
c7f485ab PM |
931 | * |
932 | * RTP optimization: if we find a matching media channel expectation | |
933 | * and both the expectation and this connection are SNATed, we assume | |
934 | * both sides can reach each other directly and use the final | |
935 | * destination address from the expectation. We still need to keep | |
936 | * the NATed expectations for media that might arrive from the | |
937 | * outside, and additionally need to expect the direct RTP stream | |
938 | * in case it passes through us even without NAT. | |
d901a936 PM |
939 | */ |
940 | memset(&tuple, 0, sizeof(tuple)); | |
941 | if (saddr) | |
942 | tuple.src.u3 = *saddr; | |
5e8fbe2a | 943 | tuple.src.l3num = nf_ct_l3num(ct); |
d901a936 PM |
944 | tuple.dst.protonum = IPPROTO_UDP; |
945 | tuple.dst.u3 = *daddr; | |
946 | tuple.dst.u.udp.port = port; | |
947 | ||
948 | rcu_read_lock(); | |
c7f485ab | 949 | do { |
5d0aa2cc | 950 | exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple); |
d901a936 | 951 | |
c7f485ab PM |
952 | if (!exp || exp->master == ct || |
953 | nfct_help(exp->master)->helper != nfct_help(ct)->helper || | |
954 | exp->class != class) | |
955 | break; | |
e1f9a464 | 956 | #ifdef CONFIG_NF_NAT_NEEDED |
9a664821 PM |
957 | if (!direct_rtp && |
958 | (!nf_inet_addr_cmp(&exp->saved_addr, &exp->tuple.dst.u3) || | |
c7f485ab PM |
959 | exp->saved_proto.udp.port != exp->tuple.dst.u.udp.port) && |
960 | ct->status & IPS_NAT_MASK) { | |
9a664821 PM |
961 | *daddr = exp->saved_addr; |
962 | tuple.dst.u3 = exp->saved_addr; | |
c7f485ab PM |
963 | tuple.dst.u.udp.port = exp->saved_proto.udp.port; |
964 | direct_rtp = 1; | |
965 | } else | |
e1f9a464 | 966 | #endif |
c7f485ab PM |
967 | skip_expect = 1; |
968 | } while (!skip_expect); | |
969 | rcu_read_unlock(); | |
d901a936 | 970 | |
a9c1d359 PM |
971 | base_port = ntohs(tuple.dst.u.udp.port) & ~1; |
972 | rtp_port = htons(base_port); | |
973 | rtcp_port = htons(base_port + 1); | |
974 | ||
c7f485ab PM |
975 | if (direct_rtp) { |
976 | nf_nat_sdp_port = rcu_dereference(nf_nat_sdp_port_hook); | |
977 | if (nf_nat_sdp_port && | |
051966c0 | 978 | !nf_nat_sdp_port(skb, protoff, dataoff, dptr, datalen, |
c7f485ab PM |
979 | mediaoff, medialen, ntohs(rtp_port))) |
980 | goto err1; | |
981 | } | |
982 | ||
983 | if (skip_expect) | |
984 | return NF_ACCEPT; | |
985 | ||
a9c1d359 PM |
986 | rtp_exp = nf_ct_expect_alloc(ct); |
987 | if (rtp_exp == NULL) | |
988 | goto err1; | |
5e8fbe2a | 989 | nf_ct_expect_init(rtp_exp, class, nf_ct_l3num(ct), saddr, daddr, |
a9c1d359 PM |
990 | IPPROTO_UDP, NULL, &rtp_port); |
991 | ||
992 | rtcp_exp = nf_ct_expect_alloc(ct); | |
993 | if (rtcp_exp == NULL) | |
994 | goto err2; | |
5e8fbe2a | 995 | nf_ct_expect_init(rtcp_exp, class, nf_ct_l3num(ct), saddr, daddr, |
a9c1d359 | 996 | IPPROTO_UDP, NULL, &rtcp_port); |
9fafcd7b | 997 | |
4ab9e64e | 998 | nf_nat_sdp_media = rcu_dereference(nf_nat_sdp_media_hook); |
9a664821 | 999 | if (nf_nat_sdp_media && ct->status & IPS_NAT_MASK && !direct_rtp) |
051966c0 | 1000 | ret = nf_nat_sdp_media(skb, protoff, dataoff, dptr, datalen, |
3b6b9fab | 1001 | rtp_exp, rtcp_exp, |
4ab9e64e | 1002 | mediaoff, medialen, daddr); |
9fafcd7b | 1003 | else { |
a9c1d359 PM |
1004 | if (nf_ct_expect_related(rtp_exp) == 0) { |
1005 | if (nf_ct_expect_related(rtcp_exp) != 0) | |
1006 | nf_ct_unexpect_related(rtp_exp); | |
1007 | else | |
1008 | ret = NF_ACCEPT; | |
1009 | } | |
9fafcd7b | 1010 | } |
a9c1d359 PM |
1011 | nf_ct_expect_put(rtcp_exp); |
1012 | err2: | |
1013 | nf_ct_expect_put(rtp_exp); | |
1014 | err1: | |
9fafcd7b PM |
1015 | return ret; |
1016 | } | |
1017 | ||
0d0ab037 PM |
1018 | static const struct sdp_media_type sdp_media_types[] = { |
1019 | SDP_MEDIA_TYPE("audio ", SIP_EXPECT_AUDIO), | |
1020 | SDP_MEDIA_TYPE("video ", SIP_EXPECT_VIDEO), | |
9d288dff | 1021 | SDP_MEDIA_TYPE("image ", SIP_EXPECT_IMAGE), |
0d0ab037 PM |
1022 | }; |
1023 | ||
1024 | static const struct sdp_media_type *sdp_media_type(const char *dptr, | |
1025 | unsigned int matchoff, | |
1026 | unsigned int matchlen) | |
1027 | { | |
1028 | const struct sdp_media_type *t; | |
1029 | unsigned int i; | |
1030 | ||
1031 | for (i = 0; i < ARRAY_SIZE(sdp_media_types); i++) { | |
1032 | t = &sdp_media_types[i]; | |
1033 | if (matchlen < t->len || | |
1034 | strncmp(dptr + matchoff, t->name, t->len)) | |
1035 | continue; | |
1036 | return t; | |
1037 | } | |
1038 | return NULL; | |
1039 | } | |
1040 | ||
051966c0 PM |
1041 | static int process_sdp(struct sk_buff *skb, unsigned int protoff, |
1042 | unsigned int dataoff, | |
30f33e6d PM |
1043 | const char **dptr, unsigned int *datalen, |
1044 | unsigned int cseq) | |
7d3dd043 PM |
1045 | { |
1046 | enum ip_conntrack_info ctinfo; | |
1047 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
7d3dd043 | 1048 | unsigned int matchoff, matchlen; |
4ab9e64e PM |
1049 | unsigned int mediaoff, medialen; |
1050 | unsigned int sdpoff; | |
1051 | unsigned int caddr_len, maddr_len; | |
0d0ab037 | 1052 | unsigned int i; |
4ab9e64e | 1053 | union nf_inet_addr caddr, maddr, rtp_addr; |
7d3dd043 | 1054 | unsigned int port; |
0d0ab037 PM |
1055 | const struct sdp_media_type *t; |
1056 | int ret = NF_ACCEPT; | |
4ab9e64e PM |
1057 | typeof(nf_nat_sdp_addr_hook) nf_nat_sdp_addr; |
1058 | typeof(nf_nat_sdp_session_hook) nf_nat_sdp_session; | |
7d3dd043 | 1059 | |
0d0ab037 | 1060 | nf_nat_sdp_addr = rcu_dereference(nf_nat_sdp_addr_hook); |
7d3dd043 | 1061 | |
4ab9e64e | 1062 | /* Find beginning of session description */ |
7d3dd043 | 1063 | if (ct_sip_get_sdp_header(ct, *dptr, 0, *datalen, |
4ab9e64e | 1064 | SDP_HDR_VERSION, SDP_HDR_UNSPEC, |
7d3dd043 PM |
1065 | &matchoff, &matchlen) <= 0) |
1066 | return NF_ACCEPT; | |
4ab9e64e PM |
1067 | sdpoff = matchoff; |
1068 | ||
1069 | /* The connection information is contained in the session description | |
1070 | * and/or once per media description. The first media description marks | |
1071 | * the end of the session description. */ | |
1072 | caddr_len = 0; | |
1073 | if (ct_sip_parse_sdp_addr(ct, *dptr, sdpoff, *datalen, | |
9a664821 | 1074 | SDP_HDR_CONNECTION, SDP_HDR_MEDIA, |
4ab9e64e PM |
1075 | &matchoff, &matchlen, &caddr) > 0) |
1076 | caddr_len = matchlen; | |
1077 | ||
0d0ab037 PM |
1078 | mediaoff = sdpoff; |
1079 | for (i = 0; i < ARRAY_SIZE(sdp_media_types); ) { | |
1080 | if (ct_sip_get_sdp_header(ct, *dptr, mediaoff, *datalen, | |
1081 | SDP_HDR_MEDIA, SDP_HDR_UNSPEC, | |
1082 | &mediaoff, &medialen) <= 0) | |
1083 | break; | |
7d3dd043 | 1084 | |
0d0ab037 PM |
1085 | /* Get media type and port number. A media port value of zero |
1086 | * indicates an inactive stream. */ | |
1087 | t = sdp_media_type(*dptr, mediaoff, medialen); | |
1088 | if (!t) { | |
1089 | mediaoff += medialen; | |
1090 | continue; | |
1091 | } | |
1092 | mediaoff += t->len; | |
1093 | medialen -= t->len; | |
7d3dd043 | 1094 | |
0d0ab037 PM |
1095 | port = simple_strtoul(*dptr + mediaoff, NULL, 10); |
1096 | if (port == 0) | |
1097 | continue; | |
1098 | if (port < 1024 || port > 65535) | |
1099 | return NF_DROP; | |
4ab9e64e | 1100 | |
0d0ab037 PM |
1101 | /* The media description overrides the session description. */ |
1102 | maddr_len = 0; | |
1103 | if (ct_sip_parse_sdp_addr(ct, *dptr, mediaoff, *datalen, | |
9a664821 | 1104 | SDP_HDR_CONNECTION, SDP_HDR_MEDIA, |
0d0ab037 PM |
1105 | &matchoff, &matchlen, &maddr) > 0) { |
1106 | maddr_len = matchlen; | |
1107 | memcpy(&rtp_addr, &maddr, sizeof(rtp_addr)); | |
1108 | } else if (caddr_len) | |
1109 | memcpy(&rtp_addr, &caddr, sizeof(rtp_addr)); | |
1110 | else | |
1111 | return NF_DROP; | |
1112 | ||
051966c0 PM |
1113 | ret = set_expected_rtp_rtcp(skb, protoff, dataoff, |
1114 | dptr, datalen, | |
0d0ab037 PM |
1115 | &rtp_addr, htons(port), t->class, |
1116 | mediaoff, medialen); | |
1117 | if (ret != NF_ACCEPT) | |
1118 | return ret; | |
4ab9e64e | 1119 | |
0d0ab037 | 1120 | /* Update media connection address if present */ |
9a664821 | 1121 | if (maddr_len && nf_nat_sdp_addr && ct->status & IPS_NAT_MASK) { |
051966c0 | 1122 | ret = nf_nat_sdp_addr(skb, protoff, dataoff, |
9a664821 PM |
1123 | dptr, datalen, mediaoff, |
1124 | SDP_HDR_CONNECTION, SDP_HDR_MEDIA, | |
3b6b9fab | 1125 | &rtp_addr); |
4ab9e64e PM |
1126 | if (ret != NF_ACCEPT) |
1127 | return ret; | |
1128 | } | |
0d0ab037 | 1129 | i++; |
4ab9e64e PM |
1130 | } |
1131 | ||
1132 | /* Update session connection and owner addresses */ | |
1133 | nf_nat_sdp_session = rcu_dereference(nf_nat_sdp_session_hook); | |
9a664821 | 1134 | if (nf_nat_sdp_session && ct->status & IPS_NAT_MASK) |
051966c0 PM |
1135 | ret = nf_nat_sdp_session(skb, protoff, dataoff, |
1136 | dptr, datalen, sdpoff, &rtp_addr); | |
4ab9e64e PM |
1137 | |
1138 | return ret; | |
7d3dd043 | 1139 | } |
051966c0 PM |
1140 | static int process_invite_response(struct sk_buff *skb, unsigned int protoff, |
1141 | unsigned int dataoff, | |
30f33e6d PM |
1142 | const char **dptr, unsigned int *datalen, |
1143 | unsigned int cseq, unsigned int code) | |
1144 | { | |
9467ee38 PM |
1145 | enum ip_conntrack_info ctinfo; |
1146 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
1afc5679 | 1147 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
9467ee38 | 1148 | |
30f33e6d PM |
1149 | if ((code >= 100 && code <= 199) || |
1150 | (code >= 200 && code <= 299)) | |
051966c0 | 1151 | return process_sdp(skb, protoff, dataoff, dptr, datalen, cseq); |
1afc5679 | 1152 | else if (ct_sip_info->invite_cseq == cseq) |
0f32a40f | 1153 | flush_expectations(ct, true); |
ef75d49f | 1154 | return NF_ACCEPT; |
30f33e6d PM |
1155 | } |
1156 | ||
051966c0 PM |
1157 | static int process_update_response(struct sk_buff *skb, unsigned int protoff, |
1158 | unsigned int dataoff, | |
30f33e6d PM |
1159 | const char **dptr, unsigned int *datalen, |
1160 | unsigned int cseq, unsigned int code) | |
1161 | { | |
9467ee38 PM |
1162 | enum ip_conntrack_info ctinfo; |
1163 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
1afc5679 | 1164 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
9467ee38 | 1165 | |
30f33e6d PM |
1166 | if ((code >= 100 && code <= 199) || |
1167 | (code >= 200 && code <= 299)) | |
051966c0 | 1168 | return process_sdp(skb, protoff, dataoff, dptr, datalen, cseq); |
1afc5679 | 1169 | else if (ct_sip_info->invite_cseq == cseq) |
0f32a40f | 1170 | flush_expectations(ct, true); |
ef75d49f | 1171 | return NF_ACCEPT; |
30f33e6d PM |
1172 | } |
1173 | ||
051966c0 PM |
1174 | static int process_prack_response(struct sk_buff *skb, unsigned int protoff, |
1175 | unsigned int dataoff, | |
595a8ecb PM |
1176 | const char **dptr, unsigned int *datalen, |
1177 | unsigned int cseq, unsigned int code) | |
1178 | { | |
9467ee38 PM |
1179 | enum ip_conntrack_info ctinfo; |
1180 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
1afc5679 | 1181 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
9467ee38 | 1182 | |
595a8ecb PM |
1183 | if ((code >= 100 && code <= 199) || |
1184 | (code >= 200 && code <= 299)) | |
051966c0 | 1185 | return process_sdp(skb, protoff, dataoff, dptr, datalen, cseq); |
1afc5679 | 1186 | else if (ct_sip_info->invite_cseq == cseq) |
0f32a40f | 1187 | flush_expectations(ct, true); |
ef75d49f | 1188 | return NF_ACCEPT; |
9467ee38 PM |
1189 | } |
1190 | ||
051966c0 PM |
1191 | static int process_invite_request(struct sk_buff *skb, unsigned int protoff, |
1192 | unsigned int dataoff, | |
9d288dff PM |
1193 | const char **dptr, unsigned int *datalen, |
1194 | unsigned int cseq) | |
1195 | { | |
1196 | enum ip_conntrack_info ctinfo; | |
1197 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
1afc5679 | 1198 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
9d288dff PM |
1199 | unsigned int ret; |
1200 | ||
1201 | flush_expectations(ct, true); | |
051966c0 | 1202 | ret = process_sdp(skb, protoff, dataoff, dptr, datalen, cseq); |
9d288dff | 1203 | if (ret == NF_ACCEPT) |
1afc5679 | 1204 | ct_sip_info->invite_cseq = cseq; |
9d288dff PM |
1205 | return ret; |
1206 | } | |
1207 | ||
051966c0 PM |
1208 | static int process_bye_request(struct sk_buff *skb, unsigned int protoff, |
1209 | unsigned int dataoff, | |
9467ee38 PM |
1210 | const char **dptr, unsigned int *datalen, |
1211 | unsigned int cseq) | |
1212 | { | |
1213 | enum ip_conntrack_info ctinfo; | |
1214 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
595a8ecb | 1215 | |
0f32a40f PM |
1216 | flush_expectations(ct, true); |
1217 | return NF_ACCEPT; | |
1218 | } | |
1219 | ||
1220 | /* Parse a REGISTER request and create a permanent expectation for incoming | |
1221 | * signalling connections. The expectation is marked inactive and is activated | |
1222 | * when receiving a response indicating success from the registrar. | |
1223 | */ | |
051966c0 PM |
1224 | static int process_register_request(struct sk_buff *skb, unsigned int protoff, |
1225 | unsigned int dataoff, | |
0f32a40f PM |
1226 | const char **dptr, unsigned int *datalen, |
1227 | unsigned int cseq) | |
1228 | { | |
1229 | enum ip_conntrack_info ctinfo; | |
1230 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
1afc5679 | 1231 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
0f32a40f | 1232 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
0f32a40f PM |
1233 | unsigned int matchoff, matchlen; |
1234 | struct nf_conntrack_expect *exp; | |
1235 | union nf_inet_addr *saddr, daddr; | |
1236 | __be16 port; | |
f5b321bd | 1237 | u8 proto; |
0f32a40f PM |
1238 | unsigned int expires = 0; |
1239 | int ret; | |
1240 | typeof(nf_nat_sip_expect_hook) nf_nat_sip_expect; | |
1241 | ||
1242 | /* Expected connections can not register again. */ | |
1243 | if (ct->status & IPS_EXPECTED) | |
1244 | return NF_ACCEPT; | |
1245 | ||
1246 | /* We must check the expiration time: a value of zero signals the | |
1247 | * registrar to release the binding. We'll remove our expectation | |
1248 | * when receiving the new bindings in the response, but we don't | |
1249 | * want to create new ones. | |
1250 | * | |
1251 | * The expiration time may be contained in Expires: header, the | |
1252 | * Contact: header parameters or the URI parameters. | |
1253 | */ | |
1254 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_EXPIRES, | |
1255 | &matchoff, &matchlen) > 0) | |
1256 | expires = simple_strtoul(*dptr + matchoff, NULL, 10); | |
1257 | ||
1258 | ret = ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen, | |
1259 | SIP_HDR_CONTACT, NULL, | |
1260 | &matchoff, &matchlen, &daddr, &port); | |
1261 | if (ret < 0) | |
1262 | return NF_DROP; | |
1263 | else if (ret == 0) | |
1264 | return NF_ACCEPT; | |
1265 | ||
1266 | /* We don't support third-party registrations */ | |
1267 | if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.src.u3, &daddr)) | |
1268 | return NF_ACCEPT; | |
1269 | ||
f5b321bd PM |
1270 | if (ct_sip_parse_transport(ct, *dptr, matchoff + matchlen, *datalen, |
1271 | &proto) == 0) | |
1272 | return NF_ACCEPT; | |
1273 | ||
0f32a40f PM |
1274 | if (ct_sip_parse_numerical_param(ct, *dptr, |
1275 | matchoff + matchlen, *datalen, | |
1276 | "expires=", NULL, NULL, &expires) < 0) | |
1277 | return NF_DROP; | |
1278 | ||
1279 | if (expires == 0) { | |
1280 | ret = NF_ACCEPT; | |
1281 | goto store_cseq; | |
1282 | } | |
1283 | ||
1284 | exp = nf_ct_expect_alloc(ct); | |
1285 | if (!exp) | |
1286 | return NF_DROP; | |
1287 | ||
1288 | saddr = NULL; | |
1289 | if (sip_direct_signalling) | |
1290 | saddr = &ct->tuplehash[!dir].tuple.src.u3; | |
1291 | ||
5e8fbe2a | 1292 | nf_ct_expect_init(exp, SIP_EXPECT_SIGNALLING, nf_ct_l3num(ct), |
f5b321bd | 1293 | saddr, &daddr, proto, NULL, &port); |
0f32a40f PM |
1294 | exp->timeout.expires = sip_timeout * HZ; |
1295 | exp->helper = nfct_help(ct)->helper; | |
1296 | exp->flags = NF_CT_EXPECT_PERMANENT | NF_CT_EXPECT_INACTIVE; | |
1297 | ||
1298 | nf_nat_sip_expect = rcu_dereference(nf_nat_sip_expect_hook); | |
9a664821 | 1299 | if (nf_nat_sip_expect && ct->status & IPS_NAT_MASK) |
051966c0 PM |
1300 | ret = nf_nat_sip_expect(skb, protoff, dataoff, dptr, datalen, |
1301 | exp, matchoff, matchlen); | |
0f32a40f PM |
1302 | else { |
1303 | if (nf_ct_expect_related(exp) != 0) | |
1304 | ret = NF_DROP; | |
1305 | else | |
1306 | ret = NF_ACCEPT; | |
1307 | } | |
1308 | nf_ct_expect_put(exp); | |
1309 | ||
1310 | store_cseq: | |
1311 | if (ret == NF_ACCEPT) | |
1afc5679 | 1312 | ct_sip_info->register_cseq = cseq; |
0f32a40f PM |
1313 | return ret; |
1314 | } | |
1315 | ||
051966c0 PM |
1316 | static int process_register_response(struct sk_buff *skb, unsigned int protoff, |
1317 | unsigned int dataoff, | |
0f32a40f PM |
1318 | const char **dptr, unsigned int *datalen, |
1319 | unsigned int cseq, unsigned int code) | |
1320 | { | |
1321 | enum ip_conntrack_info ctinfo; | |
1322 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
1afc5679 | 1323 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
0f32a40f PM |
1324 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
1325 | union nf_inet_addr addr; | |
1326 | __be16 port; | |
f5b321bd | 1327 | u8 proto; |
3b6b9fab | 1328 | unsigned int matchoff, matchlen, coff = 0; |
0f32a40f PM |
1329 | unsigned int expires = 0; |
1330 | int in_contact = 0, ret; | |
1331 | ||
1332 | /* According to RFC 3261, "UAs MUST NOT send a new registration until | |
1333 | * they have received a final response from the registrar for the | |
1334 | * previous one or the previous REGISTER request has timed out". | |
1335 | * | |
1336 | * However, some servers fail to detect retransmissions and send late | |
1337 | * responses, so we store the sequence number of the last valid | |
1338 | * request and compare it here. | |
1339 | */ | |
1afc5679 | 1340 | if (ct_sip_info->register_cseq != cseq) |
0f32a40f PM |
1341 | return NF_ACCEPT; |
1342 | ||
1343 | if (code >= 100 && code <= 199) | |
1344 | return NF_ACCEPT; | |
1345 | if (code < 200 || code > 299) | |
1346 | goto flush; | |
1347 | ||
1348 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_EXPIRES, | |
1349 | &matchoff, &matchlen) > 0) | |
1350 | expires = simple_strtoul(*dptr + matchoff, NULL, 10); | |
1351 | ||
1352 | while (1) { | |
1353 | unsigned int c_expires = expires; | |
1354 | ||
3b6b9fab | 1355 | ret = ct_sip_parse_header_uri(ct, *dptr, &coff, *datalen, |
0f32a40f PM |
1356 | SIP_HDR_CONTACT, &in_contact, |
1357 | &matchoff, &matchlen, | |
1358 | &addr, &port); | |
1359 | if (ret < 0) | |
1360 | return NF_DROP; | |
1361 | else if (ret == 0) | |
1362 | break; | |
1363 | ||
1364 | /* We don't support third-party registrations */ | |
1365 | if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3, &addr)) | |
1366 | continue; | |
1367 | ||
f5b321bd PM |
1368 | if (ct_sip_parse_transport(ct, *dptr, matchoff + matchlen, |
1369 | *datalen, &proto) == 0) | |
1370 | continue; | |
1371 | ||
0f32a40f PM |
1372 | ret = ct_sip_parse_numerical_param(ct, *dptr, |
1373 | matchoff + matchlen, | |
1374 | *datalen, "expires=", | |
1375 | NULL, NULL, &c_expires); | |
1376 | if (ret < 0) | |
1377 | return NF_DROP; | |
1378 | if (c_expires == 0) | |
1379 | break; | |
f5b321bd PM |
1380 | if (refresh_signalling_expectation(ct, &addr, proto, port, |
1381 | c_expires)) | |
0f32a40f PM |
1382 | return NF_ACCEPT; |
1383 | } | |
1384 | ||
1385 | flush: | |
1386 | flush_expectations(ct, false); | |
595a8ecb PM |
1387 | return NF_ACCEPT; |
1388 | } | |
1389 | ||
30f33e6d | 1390 | static const struct sip_handler sip_handlers[] = { |
9d288dff | 1391 | SIP_HANDLER("INVITE", process_invite_request, process_invite_response), |
30f33e6d | 1392 | SIP_HANDLER("UPDATE", process_sdp, process_update_response), |
595a8ecb PM |
1393 | SIP_HANDLER("ACK", process_sdp, NULL), |
1394 | SIP_HANDLER("PRACK", process_sdp, process_prack_response), | |
9467ee38 | 1395 | SIP_HANDLER("BYE", process_bye_request, NULL), |
0f32a40f | 1396 | SIP_HANDLER("REGISTER", process_register_request, process_register_response), |
30f33e6d PM |
1397 | }; |
1398 | ||
051966c0 PM |
1399 | static int process_sip_response(struct sk_buff *skb, unsigned int protoff, |
1400 | unsigned int dataoff, | |
30f33e6d PM |
1401 | const char **dptr, unsigned int *datalen) |
1402 | { | |
30f33e6d PM |
1403 | enum ip_conntrack_info ctinfo; |
1404 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
3b6b9fab PM |
1405 | unsigned int matchoff, matchlen, matchend; |
1406 | unsigned int code, cseq, i; | |
30f33e6d PM |
1407 | |
1408 | if (*datalen < strlen("SIP/2.0 200")) | |
1409 | return NF_ACCEPT; | |
1410 | code = simple_strtoul(*dptr + strlen("SIP/2.0 "), NULL, 10); | |
1411 | if (!code) | |
1412 | return NF_DROP; | |
1413 | ||
1414 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CSEQ, | |
1415 | &matchoff, &matchlen) <= 0) | |
1416 | return NF_DROP; | |
1417 | cseq = simple_strtoul(*dptr + matchoff, NULL, 10); | |
1418 | if (!cseq) | |
1419 | return NF_DROP; | |
3b6b9fab | 1420 | matchend = matchoff + matchlen + 1; |
30f33e6d PM |
1421 | |
1422 | for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) { | |
66bf7918 AD |
1423 | const struct sip_handler *handler; |
1424 | ||
30f33e6d PM |
1425 | handler = &sip_handlers[i]; |
1426 | if (handler->response == NULL) | |
1427 | continue; | |
3b6b9fab PM |
1428 | if (*datalen < matchend + handler->len || |
1429 | strnicmp(*dptr + matchend, handler->method, handler->len)) | |
30f33e6d | 1430 | continue; |
051966c0 | 1431 | return handler->response(skb, protoff, dataoff, dptr, datalen, |
3b6b9fab | 1432 | cseq, code); |
30f33e6d PM |
1433 | } |
1434 | return NF_ACCEPT; | |
1435 | } | |
1436 | ||
051966c0 PM |
1437 | static int process_sip_request(struct sk_buff *skb, unsigned int protoff, |
1438 | unsigned int dataoff, | |
30f33e6d PM |
1439 | const char **dptr, unsigned int *datalen) |
1440 | { | |
30f33e6d PM |
1441 | enum ip_conntrack_info ctinfo; |
1442 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
1443 | unsigned int matchoff, matchlen; | |
1444 | unsigned int cseq, i; | |
1445 | ||
1446 | for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) { | |
66bf7918 AD |
1447 | const struct sip_handler *handler; |
1448 | ||
30f33e6d PM |
1449 | handler = &sip_handlers[i]; |
1450 | if (handler->request == NULL) | |
1451 | continue; | |
1452 | if (*datalen < handler->len || | |
1453 | strnicmp(*dptr, handler->method, handler->len)) | |
1454 | continue; | |
1455 | ||
1456 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CSEQ, | |
1457 | &matchoff, &matchlen) <= 0) | |
1458 | return NF_DROP; | |
1459 | cseq = simple_strtoul(*dptr + matchoff, NULL, 10); | |
1460 | if (!cseq) | |
1461 | return NF_DROP; | |
1462 | ||
051966c0 PM |
1463 | return handler->request(skb, protoff, dataoff, dptr, datalen, |
1464 | cseq); | |
30f33e6d PM |
1465 | } |
1466 | return NF_ACCEPT; | |
1467 | } | |
7d3dd043 | 1468 | |
f5b321bd | 1469 | static int process_sip_msg(struct sk_buff *skb, struct nf_conn *ct, |
051966c0 PM |
1470 | unsigned int protoff, unsigned int dataoff, |
1471 | const char **dptr, unsigned int *datalen) | |
f5b321bd PM |
1472 | { |
1473 | typeof(nf_nat_sip_hook) nf_nat_sip; | |
1474 | int ret; | |
1475 | ||
1476 | if (strnicmp(*dptr, "SIP/2.0 ", strlen("SIP/2.0 ")) != 0) | |
051966c0 | 1477 | ret = process_sip_request(skb, protoff, dataoff, dptr, datalen); |
f5b321bd | 1478 | else |
051966c0 | 1479 | ret = process_sip_response(skb, protoff, dataoff, dptr, datalen); |
f5b321bd | 1480 | |
9a664821 | 1481 | if (ret == NF_ACCEPT && ct->status & IPS_NAT_MASK) { |
f5b321bd | 1482 | nf_nat_sip = rcu_dereference(nf_nat_sip_hook); |
051966c0 PM |
1483 | if (nf_nat_sip && !nf_nat_sip(skb, protoff, dataoff, |
1484 | dptr, datalen)) | |
f5b321bd PM |
1485 | ret = NF_DROP; |
1486 | } | |
1487 | ||
1488 | return ret; | |
1489 | } | |
1490 | ||
1491 | static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff, | |
1492 | struct nf_conn *ct, enum ip_conntrack_info ctinfo) | |
9fafcd7b | 1493 | { |
f5b321bd | 1494 | struct tcphdr *th, _tcph; |
9fafcd7b | 1495 | unsigned int dataoff, datalen; |
f5b321bd PM |
1496 | unsigned int matchoff, matchlen, clen; |
1497 | unsigned int msglen, origlen; | |
1498 | const char *dptr, *end; | |
1499 | s16 diff, tdiff = 0; | |
7874896a | 1500 | int ret = NF_ACCEPT; |
e6e4d9ed | 1501 | bool term; |
48f8ac26 | 1502 | typeof(nf_nat_sip_seq_adjust_hook) nf_nat_sip_seq_adjust; |
f5b321bd PM |
1503 | |
1504 | if (ctinfo != IP_CT_ESTABLISHED && | |
fb048833 | 1505 | ctinfo != IP_CT_ESTABLISHED_REPLY) |
f5b321bd | 1506 | return NF_ACCEPT; |
9fafcd7b PM |
1507 | |
1508 | /* No Data ? */ | |
f5b321bd PM |
1509 | th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph); |
1510 | if (th == NULL) | |
1511 | return NF_ACCEPT; | |
1512 | dataoff = protoff + th->doff * 4; | |
3db05fea | 1513 | if (dataoff >= skb->len) |
9fafcd7b PM |
1514 | return NF_ACCEPT; |
1515 | ||
3db05fea | 1516 | nf_ct_refresh(ct, skb, sip_timeout * HZ); |
9fafcd7b | 1517 | |
a1d7c1b4 PM |
1518 | if (unlikely(skb_linearize(skb))) |
1519 | return NF_DROP; | |
9fafcd7b | 1520 | |
f5b321bd | 1521 | dptr = skb->data + dataoff; |
3db05fea | 1522 | datalen = skb->len - dataoff; |
779382eb | 1523 | if (datalen < strlen("SIP/2.0 200")) |
7d3dd043 | 1524 | return NF_ACCEPT; |
9fafcd7b | 1525 | |
f5b321bd PM |
1526 | while (1) { |
1527 | if (ct_sip_get_header(ct, dptr, 0, datalen, | |
1528 | SIP_HDR_CONTENT_LENGTH, | |
1529 | &matchoff, &matchlen) <= 0) | |
1530 | break; | |
33cb1e9a | 1531 | |
f5b321bd PM |
1532 | clen = simple_strtoul(dptr + matchoff, (char **)&end, 10); |
1533 | if (dptr + matchoff == end) | |
1534 | break; | |
1535 | ||
e6e4d9ed PM |
1536 | term = false; |
1537 | for (; end + strlen("\r\n\r\n") <= dptr + datalen; end++) { | |
1538 | if (end[0] == '\r' && end[1] == '\n' && | |
1539 | end[2] == '\r' && end[3] == '\n') { | |
1540 | term = true; | |
1541 | break; | |
1542 | } | |
1543 | } | |
1544 | if (!term) | |
f5b321bd PM |
1545 | break; |
1546 | end += strlen("\r\n\r\n") + clen; | |
1547 | ||
1548 | msglen = origlen = end - dptr; | |
274ea0e2 PM |
1549 | if (msglen > datalen) |
1550 | return NF_DROP; | |
f5b321bd | 1551 | |
051966c0 PM |
1552 | ret = process_sip_msg(skb, ct, protoff, dataoff, |
1553 | &dptr, &msglen); | |
f5b321bd PM |
1554 | if (ret != NF_ACCEPT) |
1555 | break; | |
1556 | diff = msglen - origlen; | |
1557 | tdiff += diff; | |
1558 | ||
1559 | dataoff += msglen; | |
1560 | dptr += msglen; | |
1561 | datalen = datalen + diff - msglen; | |
33cb1e9a PM |
1562 | } |
1563 | ||
9a664821 | 1564 | if (ret == NF_ACCEPT && ct->status & IPS_NAT_MASK) { |
48f8ac26 PM |
1565 | nf_nat_sip_seq_adjust = rcu_dereference(nf_nat_sip_seq_adjust_hook); |
1566 | if (nf_nat_sip_seq_adjust) | |
9a664821 | 1567 | nf_nat_sip_seq_adjust(skb, protoff, tdiff); |
48f8ac26 PM |
1568 | } |
1569 | ||
33cb1e9a | 1570 | return ret; |
9fafcd7b PM |
1571 | } |
1572 | ||
f5b321bd PM |
1573 | static int sip_help_udp(struct sk_buff *skb, unsigned int protoff, |
1574 | struct nf_conn *ct, enum ip_conntrack_info ctinfo) | |
1575 | { | |
1576 | unsigned int dataoff, datalen; | |
1577 | const char *dptr; | |
1578 | ||
1579 | /* No Data ? */ | |
1580 | dataoff = protoff + sizeof(struct udphdr); | |
1581 | if (dataoff >= skb->len) | |
1582 | return NF_ACCEPT; | |
1583 | ||
1584 | nf_ct_refresh(ct, skb, sip_timeout * HZ); | |
1585 | ||
a1d7c1b4 PM |
1586 | if (unlikely(skb_linearize(skb))) |
1587 | return NF_DROP; | |
f5b321bd PM |
1588 | |
1589 | dptr = skb->data + dataoff; | |
1590 | datalen = skb->len - dataoff; | |
1591 | if (datalen < strlen("SIP/2.0 200")) | |
1592 | return NF_ACCEPT; | |
1593 | ||
051966c0 | 1594 | return process_sip_msg(skb, ct, protoff, dataoff, &dptr, &datalen); |
f5b321bd PM |
1595 | } |
1596 | ||
1597 | static struct nf_conntrack_helper sip[MAX_PORTS][4] __read_mostly; | |
9fafcd7b | 1598 | |
0f32a40f PM |
1599 | static const struct nf_conntrack_expect_policy sip_exp_policy[SIP_EXPECT_MAX + 1] = { |
1600 | [SIP_EXPECT_SIGNALLING] = { | |
b87921bd | 1601 | .name = "signalling", |
0f32a40f PM |
1602 | .max_expected = 1, |
1603 | .timeout = 3 * 60, | |
1604 | }, | |
1605 | [SIP_EXPECT_AUDIO] = { | |
b87921bd | 1606 | .name = "audio", |
a9c1d359 | 1607 | .max_expected = 2 * IP_CT_DIR_MAX, |
0f32a40f PM |
1608 | .timeout = 3 * 60, |
1609 | }, | |
0d0ab037 | 1610 | [SIP_EXPECT_VIDEO] = { |
b87921bd | 1611 | .name = "video", |
0d0ab037 PM |
1612 | .max_expected = 2 * IP_CT_DIR_MAX, |
1613 | .timeout = 3 * 60, | |
1614 | }, | |
9d288dff PM |
1615 | [SIP_EXPECT_IMAGE] = { |
1616 | .name = "image", | |
1617 | .max_expected = IP_CT_DIR_MAX, | |
1618 | .timeout = 3 * 60, | |
1619 | }, | |
6002f266 PM |
1620 | }; |
1621 | ||
9fafcd7b PM |
1622 | static void nf_conntrack_sip_fini(void) |
1623 | { | |
1624 | int i, j; | |
1625 | ||
1626 | for (i = 0; i < ports_c; i++) { | |
f5b321bd | 1627 | for (j = 0; j < ARRAY_SIZE(sip[i]); j++) { |
9fafcd7b PM |
1628 | if (sip[i][j].me == NULL) |
1629 | continue; | |
1630 | nf_conntrack_helper_unregister(&sip[i][j]); | |
1631 | } | |
1632 | } | |
1633 | } | |
1634 | ||
1635 | static int __init nf_conntrack_sip_init(void) | |
1636 | { | |
1637 | int i, j, ret; | |
9fafcd7b PM |
1638 | |
1639 | if (ports_c == 0) | |
1640 | ports[ports_c++] = SIP_PORT; | |
1641 | ||
1642 | for (i = 0; i < ports_c; i++) { | |
1643 | memset(&sip[i], 0, sizeof(sip[i])); | |
1644 | ||
1645 | sip[i][0].tuple.src.l3num = AF_INET; | |
f5b321bd PM |
1646 | sip[i][0].tuple.dst.protonum = IPPROTO_UDP; |
1647 | sip[i][0].help = sip_help_udp; | |
1648 | sip[i][1].tuple.src.l3num = AF_INET; | |
1649 | sip[i][1].tuple.dst.protonum = IPPROTO_TCP; | |
1650 | sip[i][1].help = sip_help_tcp; | |
1651 | ||
1652 | sip[i][2].tuple.src.l3num = AF_INET6; | |
1653 | sip[i][2].tuple.dst.protonum = IPPROTO_UDP; | |
1654 | sip[i][2].help = sip_help_udp; | |
1655 | sip[i][3].tuple.src.l3num = AF_INET6; | |
1656 | sip[i][3].tuple.dst.protonum = IPPROTO_TCP; | |
1657 | sip[i][3].help = sip_help_tcp; | |
1658 | ||
1659 | for (j = 0; j < ARRAY_SIZE(sip[i]); j++) { | |
1afc5679 | 1660 | sip[i][j].data_len = sizeof(struct nf_ct_sip_master); |
9fafcd7b | 1661 | sip[i][j].tuple.src.u.udp.port = htons(ports[i]); |
0f32a40f PM |
1662 | sip[i][j].expect_policy = sip_exp_policy; |
1663 | sip[i][j].expect_class_max = SIP_EXPECT_MAX; | |
9fafcd7b | 1664 | sip[i][j].me = THIS_MODULE; |
9fafcd7b | 1665 | |
9fafcd7b | 1666 | if (ports[i] == SIP_PORT) |
e9324b2c | 1667 | sprintf(sip[i][j].name, "sip"); |
9fafcd7b | 1668 | else |
e9324b2c | 1669 | sprintf(sip[i][j].name, "sip-%u", i); |
9fafcd7b | 1670 | |
0d53778e | 1671 | pr_debug("port #%u: %u\n", i, ports[i]); |
9fafcd7b PM |
1672 | |
1673 | ret = nf_conntrack_helper_register(&sip[i][j]); | |
1674 | if (ret) { | |
654d0fbd SH |
1675 | printk(KERN_ERR "nf_ct_sip: failed to register" |
1676 | " helper for pf: %u port: %u\n", | |
9fafcd7b PM |
1677 | sip[i][j].tuple.src.l3num, ports[i]); |
1678 | nf_conntrack_sip_fini(); | |
1679 | return ret; | |
1680 | } | |
1681 | } | |
1682 | } | |
1683 | return 0; | |
1684 | } | |
1685 | ||
1686 | module_init(nf_conntrack_sip_init); | |
1687 | module_exit(nf_conntrack_sip_fini); |