1 /* SIP extension for IP connection tracking.
3 * (C) 2005 by Christian Hentschel <chentschel@arnet.com.ar>
4 * based on RR's ip_conntrack_ftp.c and other modules.
5 * (C) 2007 United Security Providers
6 * (C) 2007, 2008 Patrick McHardy <kaber@trash.net>
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.
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15 #include <linux/module.h>
16 #include <linux/ctype.h>
17 #include <linux/skbuff.h>
18 #include <linux/inet.h>
20 #include <linux/udp.h>
21 #include <linux/tcp.h>
22 #include <linux/netfilter.h>
23 #include <linux/netfilter_ipv4.h>
24 #include <linux/netfilter_ipv6.h>
26 #include <net/netfilter/nf_conntrack.h>
27 #include <net/netfilter/nf_conntrack_core.h>
28 #include <net/netfilter/nf_conntrack_expect.h>
29 #include <net/netfilter/nf_conntrack_helper.h>
30 #include <net/netfilter/nf_conntrack_zones.h>
31 #include <linux/netfilter/nf_conntrack_sip.h>
33 MODULE_LICENSE("GPL");
34 MODULE_AUTHOR("Christian Hentschel <chentschel@arnet.com.ar>");
35 MODULE_DESCRIPTION("SIP connection tracking helper");
36 MODULE_ALIAS("ip_conntrack_sip");
37 MODULE_ALIAS_NFCT_HELPER("sip");
40 static unsigned short ports[MAX_PORTS];
41 static unsigned int ports_c;
42 module_param_array(ports, ushort, &ports_c, 0400);
43 MODULE_PARM_DESC(ports, "port numbers of SIP servers");
45 static unsigned int sip_timeout __read_mostly = SIP_TIMEOUT;
46 module_param(sip_timeout, uint, 0600);
47 MODULE_PARM_DESC(sip_timeout, "timeout for the master SIP session");
49 static int sip_direct_signalling __read_mostly = 1;
50 module_param(sip_direct_signalling, int, 0600);
51 MODULE_PARM_DESC(sip_direct_signalling, "expect incoming calls from registrar "
54 static int sip_direct_media __read_mostly = 1;
55 module_param(sip_direct_media, int, 0600);
56 MODULE_PARM_DESC(sip_direct_media, "Expect Media streams between signalling "
57 "endpoints only (default 1)");
59 static int sip_external_media __read_mostly = 0;
60 module_param(sip_external_media, int, 0600);
61 MODULE_PARM_DESC(sip_external_media, "Expect Media streams between external "
62 "endpoints (default 0)");
64 const struct nf_nat_sip_hooks *nf_nat_sip_hooks;
65 EXPORT_SYMBOL_GPL(nf_nat_sip_hooks);
67 static int string_len(const struct nf_conn *ct, const char *dptr,
68 const char *limit, int *shift)
72 while (dptr < limit && isalpha(*dptr)) {
79 static int digits_len(const struct nf_conn *ct, const char *dptr,
80 const char *limit, int *shift)
83 while (dptr < limit && isdigit(*dptr)) {
90 static int iswordc(const char c)
92 if (isalnum(c) || c == '!' || c == '"' || c == '%' ||
93 (c >= '(' && c <= '+') || c == ':' || c == '<' || c == '>' ||
94 c == '?' || (c >= '[' && c <= ']') || c == '_' || c == '`' ||
95 c == '{' || c == '}' || c == '~' || (c >= '-' && c <= '/') ||
101 static int word_len(const char *dptr, const char *limit)
104 while (dptr < limit && iswordc(*dptr)) {
111 static int callid_len(const struct nf_conn *ct, const char *dptr,
112 const char *limit, int *shift)
116 len = word_len(dptr, limit);
118 if (!len || dptr == limit || *dptr != '@')
123 domain_len = word_len(dptr, limit);
126 return len + domain_len;
129 /* get media type + port length */
130 static int media_len(const struct nf_conn *ct, const char *dptr,
131 const char *limit, int *shift)
133 int len = string_len(ct, dptr, limit, shift);
136 if (dptr >= limit || *dptr != ' ')
141 return len + digits_len(ct, dptr, limit, shift);
144 static int sip_parse_addr(const struct nf_conn *ct, const char *cp,
145 const char **endp, union nf_inet_addr *addr,
146 const char *limit, bool delim)
154 memset(addr, 0, sizeof(*addr));
155 switch (nf_ct_l3num(ct)) {
157 ret = in4_pton(cp, limit - cp, (u8 *)&addr->ip, -1, &end);
162 if (cp < limit && *cp == '[')
167 ret = in6_pton(cp, limit - cp, (u8 *)&addr->ip6, -1, &end);
171 if (end < limit && *end == ']')
185 /* skip ip address. returns its length. */
186 static int epaddr_len(const struct nf_conn *ct, const char *dptr,
187 const char *limit, int *shift)
189 union nf_inet_addr addr;
190 const char *aux = dptr;
192 if (!sip_parse_addr(ct, dptr, &dptr, &addr, limit, true)) {
193 pr_debug("ip: %s parse failed.!\n", dptr);
200 dptr += digits_len(ct, dptr, limit, shift);
205 /* get address length, skiping user info. */
206 static int skp_epaddr_len(const struct nf_conn *ct, const char *dptr,
207 const char *limit, int *shift)
209 const char *start = dptr;
212 /* Search for @, but stop at the end of the line.
213 * We are inside a sip: URI, so we don't need to worry about
214 * continuation lines. */
215 while (dptr < limit &&
216 *dptr != '@' && *dptr != '\r' && *dptr != '\n') {
221 if (dptr < limit && *dptr == '@') {
229 return epaddr_len(ct, dptr, limit, shift);
232 /* Parse a SIP request line of the form:
234 * Request-Line = Method SP Request-URI SP SIP-Version CRLF
236 * and return the offset and length of the address contained in the Request-URI.
238 int ct_sip_parse_request(const struct nf_conn *ct,
239 const char *dptr, unsigned int datalen,
240 unsigned int *matchoff, unsigned int *matchlen,
241 union nf_inet_addr *addr, __be16 *port)
243 const char *start = dptr, *limit = dptr + datalen, *end;
248 /* Skip method and following whitespace */
249 mlen = string_len(ct, dptr, limit, NULL);
257 for (; dptr < limit - strlen("sip:"); dptr++) {
258 if (*dptr == '\r' || *dptr == '\n')
260 if (strncasecmp(dptr, "sip:", strlen("sip:")) == 0) {
261 dptr += strlen("sip:");
265 if (!skp_epaddr_len(ct, dptr, limit, &shift))
269 if (!sip_parse_addr(ct, dptr, &end, addr, limit, true))
271 if (end < limit && *end == ':') {
273 p = simple_strtoul(end, (char **)&end, 10);
274 if (p < 1024 || p > 65535)
278 *port = htons(SIP_PORT);
282 *matchoff = dptr - start;
283 *matchlen = end - dptr;
286 EXPORT_SYMBOL_GPL(ct_sip_parse_request);
288 /* SIP header parsing: SIP headers are located at the beginning of a line, but
289 * may span several lines, in which case the continuation lines begin with a
290 * whitespace character. RFC 2543 allows lines to be terminated with CR, LF or
291 * CRLF, RFC 3261 allows only CRLF, we support both.
293 * Headers are followed by (optionally) whitespace, a colon, again (optionally)
294 * whitespace and the values. Whitespace in this context means any amount of
295 * tabs, spaces and continuation lines, which are treated as a single whitespace
298 * Some headers may appear multiple times. A comma separated list of values is
299 * equivalent to multiple headers.
301 static const struct sip_header ct_sip_hdrs[] = {
302 [SIP_HDR_CSEQ] = SIP_HDR("CSeq", NULL, NULL, digits_len),
303 [SIP_HDR_FROM] = SIP_HDR("From", "f", "sip:", skp_epaddr_len),
304 [SIP_HDR_TO] = SIP_HDR("To", "t", "sip:", skp_epaddr_len),
305 [SIP_HDR_CONTACT] = SIP_HDR("Contact", "m", "sip:", skp_epaddr_len),
306 [SIP_HDR_VIA_UDP] = SIP_HDR("Via", "v", "UDP ", epaddr_len),
307 [SIP_HDR_VIA_TCP] = SIP_HDR("Via", "v", "TCP ", epaddr_len),
308 [SIP_HDR_EXPIRES] = SIP_HDR("Expires", NULL, NULL, digits_len),
309 [SIP_HDR_CONTENT_LENGTH] = SIP_HDR("Content-Length", "l", NULL, digits_len),
310 [SIP_HDR_CALL_ID] = SIP_HDR("Call-Id", "i", NULL, callid_len),
313 static const char *sip_follow_continuation(const char *dptr, const char *limit)
315 /* Walk past newline */
319 /* Skip '\n' in CR LF */
320 if (*(dptr - 1) == '\r' && *dptr == '\n') {
325 /* Continuation line? */
326 if (*dptr != ' ' && *dptr != '\t')
329 /* skip leading whitespace */
330 for (; dptr < limit; dptr++) {
331 if (*dptr != ' ' && *dptr != '\t')
337 static const char *sip_skip_whitespace(const char *dptr, const char *limit)
339 for (; dptr < limit; dptr++) {
340 if (*dptr == ' ' || *dptr == '\t')
342 if (*dptr != '\r' && *dptr != '\n')
344 dptr = sip_follow_continuation(dptr, limit);
350 /* Search within a SIP header value, dealing with continuation lines */
351 static const char *ct_sip_header_search(const char *dptr, const char *limit,
352 const char *needle, unsigned int len)
354 for (limit -= len; dptr < limit; dptr++) {
355 if (*dptr == '\r' || *dptr == '\n') {
356 dptr = sip_follow_continuation(dptr, limit);
362 if (strncasecmp(dptr, needle, len) == 0)
368 int ct_sip_get_header(const struct nf_conn *ct, const char *dptr,
369 unsigned int dataoff, unsigned int datalen,
370 enum sip_header_types type,
371 unsigned int *matchoff, unsigned int *matchlen)
373 const struct sip_header *hdr = &ct_sip_hdrs[type];
374 const char *start = dptr, *limit = dptr + datalen;
377 for (dptr += dataoff; dptr < limit; dptr++) {
378 /* Find beginning of line */
379 if (*dptr != '\r' && *dptr != '\n')
383 if (*(dptr - 1) == '\r' && *dptr == '\n') {
388 /* Skip continuation lines */
389 if (*dptr == ' ' || *dptr == '\t')
392 /* Find header. Compact headers must be followed by a
393 * non-alphabetic character to avoid mismatches. */
394 if (limit - dptr >= hdr->len &&
395 strncasecmp(dptr, hdr->name, hdr->len) == 0)
397 else if (hdr->cname && limit - dptr >= hdr->clen + 1 &&
398 strncasecmp(dptr, hdr->cname, hdr->clen) == 0 &&
399 !isalpha(*(dptr + hdr->clen)))
404 /* Find and skip colon */
405 dptr = sip_skip_whitespace(dptr, limit);
408 if (*dptr != ':' || ++dptr >= limit)
411 /* Skip whitespace after colon */
412 dptr = sip_skip_whitespace(dptr, limit);
416 *matchoff = dptr - start;
418 dptr = ct_sip_header_search(dptr, limit, hdr->search,
425 *matchlen = hdr->match_len(ct, dptr, limit, &shift);
428 *matchoff = dptr - start + shift;
433 EXPORT_SYMBOL_GPL(ct_sip_get_header);
435 /* Get next header field in a list of comma separated values */
436 static int ct_sip_next_header(const struct nf_conn *ct, const char *dptr,
437 unsigned int dataoff, unsigned int datalen,
438 enum sip_header_types type,
439 unsigned int *matchoff, unsigned int *matchlen)
441 const struct sip_header *hdr = &ct_sip_hdrs[type];
442 const char *start = dptr, *limit = dptr + datalen;
447 dptr = ct_sip_header_search(dptr, limit, ",", strlen(","));
451 dptr = ct_sip_header_search(dptr, limit, hdr->search, hdr->slen);
456 *matchoff = dptr - start;
457 *matchlen = hdr->match_len(ct, dptr, limit, &shift);
464 /* Walk through headers until a parsable one is found or no header of the
465 * given type is left. */
466 static int ct_sip_walk_headers(const struct nf_conn *ct, const char *dptr,
467 unsigned int dataoff, unsigned int datalen,
468 enum sip_header_types type, int *in_header,
469 unsigned int *matchoff, unsigned int *matchlen)
473 if (in_header && *in_header) {
475 ret = ct_sip_next_header(ct, dptr, dataoff, datalen,
476 type, matchoff, matchlen);
481 dataoff += *matchoff;
487 ret = ct_sip_get_header(ct, dptr, dataoff, datalen,
488 type, matchoff, matchlen);
493 dataoff += *matchoff;
501 /* Locate a SIP header, parse the URI and return the offset and length of
502 * the address as well as the address and port themselves. A stream of
503 * headers can be parsed by handing in a non-NULL datalen and in_header
506 int ct_sip_parse_header_uri(const struct nf_conn *ct, const char *dptr,
507 unsigned int *dataoff, unsigned int datalen,
508 enum sip_header_types type, int *in_header,
509 unsigned int *matchoff, unsigned int *matchlen,
510 union nf_inet_addr *addr, __be16 *port)
512 const char *c, *limit = dptr + datalen;
516 ret = ct_sip_walk_headers(ct, dptr, dataoff ? *dataoff : 0, datalen,
517 type, in_header, matchoff, matchlen);
522 if (!sip_parse_addr(ct, dptr + *matchoff, &c, addr, limit, true))
526 p = simple_strtoul(c, (char **)&c, 10);
527 if (p < 1024 || p > 65535)
531 *port = htons(SIP_PORT);
537 EXPORT_SYMBOL_GPL(ct_sip_parse_header_uri);
539 static int ct_sip_parse_param(const struct nf_conn *ct, const char *dptr,
540 unsigned int dataoff, unsigned int datalen,
542 unsigned int *matchoff, unsigned int *matchlen)
544 const char *limit = dptr + datalen;
548 limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(","));
550 limit = dptr + datalen;
552 start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name));
555 start += strlen(name);
557 end = ct_sip_header_search(start, limit, ";", strlen(";"));
561 *matchoff = start - dptr;
562 *matchlen = end - start;
566 /* Parse address from header parameter and return address, offset and length */
567 int ct_sip_parse_address_param(const struct nf_conn *ct, const char *dptr,
568 unsigned int dataoff, unsigned int datalen,
570 unsigned int *matchoff, unsigned int *matchlen,
571 union nf_inet_addr *addr, bool delim)
573 const char *limit = dptr + datalen;
574 const char *start, *end;
576 limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(","));
578 limit = dptr + datalen;
580 start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name));
584 start += strlen(name);
585 if (!sip_parse_addr(ct, start, &end, addr, limit, delim))
587 *matchoff = start - dptr;
588 *matchlen = end - start;
591 EXPORT_SYMBOL_GPL(ct_sip_parse_address_param);
593 /* Parse numerical header parameter and return value, offset and length */
594 int ct_sip_parse_numerical_param(const struct nf_conn *ct, const char *dptr,
595 unsigned int dataoff, unsigned int datalen,
597 unsigned int *matchoff, unsigned int *matchlen,
600 const char *limit = dptr + datalen;
604 limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(","));
606 limit = dptr + datalen;
608 start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name));
612 start += strlen(name);
613 *val = simple_strtoul(start, &end, 0);
616 if (matchoff && matchlen) {
617 *matchoff = start - dptr;
618 *matchlen = end - start;
622 EXPORT_SYMBOL_GPL(ct_sip_parse_numerical_param);
624 static int ct_sip_parse_transport(struct nf_conn *ct, const char *dptr,
625 unsigned int dataoff, unsigned int datalen,
628 unsigned int matchoff, matchlen;
630 if (ct_sip_parse_param(ct, dptr, dataoff, datalen, "transport=",
631 &matchoff, &matchlen)) {
632 if (!strncasecmp(dptr + matchoff, "TCP", strlen("TCP")))
633 *proto = IPPROTO_TCP;
634 else if (!strncasecmp(dptr + matchoff, "UDP", strlen("UDP")))
635 *proto = IPPROTO_UDP;
639 if (*proto != nf_ct_protonum(ct))
642 *proto = nf_ct_protonum(ct);
647 static int sdp_parse_addr(const struct nf_conn *ct, const char *cp,
648 const char **endp, union nf_inet_addr *addr,
654 memset(addr, 0, sizeof(*addr));
655 switch (nf_ct_l3num(ct)) {
657 ret = in4_pton(cp, limit - cp, (u8 *)&addr->ip, -1, &end);
660 ret = in6_pton(cp, limit - cp, (u8 *)&addr->ip6, -1, &end);
673 /* skip ip address. returns its length. */
674 static int sdp_addr_len(const struct nf_conn *ct, const char *dptr,
675 const char *limit, int *shift)
677 union nf_inet_addr addr;
678 const char *aux = dptr;
680 if (!sdp_parse_addr(ct, dptr, &dptr, &addr, limit)) {
681 pr_debug("ip: %s parse failed.!\n", dptr);
688 /* SDP header parsing: a SDP session description contains an ordered set of
689 * headers, starting with a section containing general session parameters,
690 * optionally followed by multiple media descriptions.
692 * SDP headers always start at the beginning of a line. According to RFC 2327:
693 * "The sequence CRLF (0x0d0a) is used to end a record, although parsers should
694 * be tolerant and also accept records terminated with a single newline
695 * character". We handle both cases.
697 static const struct sip_header ct_sdp_hdrs_v4[] = {
698 [SDP_HDR_VERSION] = SDP_HDR("v=", NULL, digits_len),
699 [SDP_HDR_OWNER] = SDP_HDR("o=", "IN IP4 ", sdp_addr_len),
700 [SDP_HDR_CONNECTION] = SDP_HDR("c=", "IN IP4 ", sdp_addr_len),
701 [SDP_HDR_MEDIA] = SDP_HDR("m=", NULL, media_len),
704 static const struct sip_header ct_sdp_hdrs_v6[] = {
705 [SDP_HDR_VERSION] = SDP_HDR("v=", NULL, digits_len),
706 [SDP_HDR_OWNER] = SDP_HDR("o=", "IN IP6 ", sdp_addr_len),
707 [SDP_HDR_CONNECTION] = SDP_HDR("c=", "IN IP6 ", sdp_addr_len),
708 [SDP_HDR_MEDIA] = SDP_HDR("m=", NULL, media_len),
711 /* Linear string search within SDP header values */
712 static const char *ct_sdp_header_search(const char *dptr, const char *limit,
713 const char *needle, unsigned int len)
715 for (limit -= len; dptr < limit; dptr++) {
716 if (*dptr == '\r' || *dptr == '\n')
718 if (strncmp(dptr, needle, len) == 0)
724 /* Locate a SDP header (optionally a substring within the header value),
725 * optionally stopping at the first occurrence of the term header, parse
726 * it and return the offset and length of the data we're interested in.
728 int ct_sip_get_sdp_header(const struct nf_conn *ct, const char *dptr,
729 unsigned int dataoff, unsigned int datalen,
730 enum sdp_header_types type,
731 enum sdp_header_types term,
732 unsigned int *matchoff, unsigned int *matchlen)
734 const struct sip_header *hdrs, *hdr, *thdr;
735 const char *start = dptr, *limit = dptr + datalen;
738 hdrs = nf_ct_l3num(ct) == NFPROTO_IPV4 ? ct_sdp_hdrs_v4 : ct_sdp_hdrs_v6;
742 for (dptr += dataoff; dptr < limit; dptr++) {
743 /* Find beginning of line */
744 if (*dptr != '\r' && *dptr != '\n')
748 if (*(dptr - 1) == '\r' && *dptr == '\n') {
753 if (term != SDP_HDR_UNSPEC &&
754 limit - dptr >= thdr->len &&
755 strncasecmp(dptr, thdr->name, thdr->len) == 0)
757 else if (limit - dptr >= hdr->len &&
758 strncasecmp(dptr, hdr->name, hdr->len) == 0)
763 *matchoff = dptr - start;
765 dptr = ct_sdp_header_search(dptr, limit, hdr->search,
772 *matchlen = hdr->match_len(ct, dptr, limit, &shift);
775 *matchoff = dptr - start + shift;
780 EXPORT_SYMBOL_GPL(ct_sip_get_sdp_header);
782 static int ct_sip_parse_sdp_addr(const struct nf_conn *ct, const char *dptr,
783 unsigned int dataoff, unsigned int datalen,
784 enum sdp_header_types type,
785 enum sdp_header_types term,
786 unsigned int *matchoff, unsigned int *matchlen,
787 union nf_inet_addr *addr)
791 ret = ct_sip_get_sdp_header(ct, dptr, dataoff, datalen, type, term,
796 if (!sdp_parse_addr(ct, dptr + *matchoff, NULL, addr,
797 dptr + *matchoff + *matchlen))
802 static int refresh_signalling_expectation(struct nf_conn *ct,
803 union nf_inet_addr *addr,
804 u8 proto, __be16 port,
805 unsigned int expires)
807 struct nf_conn_help *help = nfct_help(ct);
808 struct nf_conntrack_expect *exp;
809 struct hlist_node *next;
812 spin_lock_bh(&nf_conntrack_expect_lock);
813 hlist_for_each_entry_safe(exp, next, &help->expectations, lnode) {
814 if (exp->class != SIP_EXPECT_SIGNALLING ||
815 !nf_inet_addr_cmp(&exp->tuple.dst.u3, addr) ||
816 exp->tuple.dst.protonum != proto ||
817 exp->tuple.dst.u.udp.port != port)
819 if (mod_timer_pending(&exp->timeout, jiffies + expires * HZ)) {
820 exp->flags &= ~NF_CT_EXPECT_INACTIVE;
825 spin_unlock_bh(&nf_conntrack_expect_lock);
829 static void flush_expectations(struct nf_conn *ct, bool media)
831 struct nf_conn_help *help = nfct_help(ct);
832 struct nf_conntrack_expect *exp;
833 struct hlist_node *next;
835 spin_lock_bh(&nf_conntrack_expect_lock);
836 hlist_for_each_entry_safe(exp, next, &help->expectations, lnode) {
837 if ((exp->class != SIP_EXPECT_SIGNALLING) ^ media)
839 if (!nf_ct_remove_expect(exp))
844 spin_unlock_bh(&nf_conntrack_expect_lock);
847 static int set_expected_rtp_rtcp(struct sk_buff *skb, unsigned int protoff,
848 unsigned int dataoff,
849 const char **dptr, unsigned int *datalen,
850 union nf_inet_addr *daddr, __be16 port,
851 enum sip_expectation_classes class,
852 unsigned int mediaoff, unsigned int medialen)
854 struct nf_conntrack_expect *exp, *rtp_exp, *rtcp_exp;
855 enum ip_conntrack_info ctinfo;
856 struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
857 struct net *net = nf_ct_net(ct);
858 enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
859 union nf_inet_addr *saddr;
860 struct nf_conntrack_tuple tuple;
861 int direct_rtp = 0, skip_expect = 0, ret = NF_DROP;
863 __be16 rtp_port, rtcp_port;
864 const struct nf_nat_sip_hooks *hooks;
867 if (sip_direct_media) {
868 if (!nf_inet_addr_cmp(daddr, &ct->tuplehash[dir].tuple.src.u3))
870 saddr = &ct->tuplehash[!dir].tuple.src.u3;
871 } else if (sip_external_media) {
872 struct net_device *dev = skb_dst(skb)->dev;
873 struct net *net = dev_net(dev);
875 struct dst_entry *dst = NULL;
877 memset(&fl, 0, sizeof(fl));
879 switch (nf_ct_l3num(ct)) {
881 fl.u.ip4.daddr = daddr->ip;
882 nf_ip_route(net, &dst, &fl, false);
886 fl.u.ip6.daddr = daddr->in6;
887 nf_ip6_route(net, &dst, &fl, false);
891 /* Don't predict any conntracks when media endpoint is reachable
892 * through the same interface as the signalling peer.
895 bool external_media = (dst->dev == dev);
903 /* We need to check whether the registration exists before attempting
904 * to register it since we can see the same media description multiple
905 * times on different connections in case multiple endpoints receive
908 * RTP optimization: if we find a matching media channel expectation
909 * and both the expectation and this connection are SNATed, we assume
910 * both sides can reach each other directly and use the final
911 * destination address from the expectation. We still need to keep
912 * the NATed expectations for media that might arrive from the
913 * outside, and additionally need to expect the direct RTP stream
914 * in case it passes through us even without NAT.
916 memset(&tuple, 0, sizeof(tuple));
918 tuple.src.u3 = *saddr;
919 tuple.src.l3num = nf_ct_l3num(ct);
920 tuple.dst.protonum = IPPROTO_UDP;
921 tuple.dst.u3 = *daddr;
922 tuple.dst.u.udp.port = port;
925 exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple);
927 if (!exp || exp->master == ct ||
928 nfct_help(exp->master)->helper != nfct_help(ct)->helper ||
931 #ifdef CONFIG_NF_NAT_NEEDED
933 (!nf_inet_addr_cmp(&exp->saved_addr, &exp->tuple.dst.u3) ||
934 exp->saved_proto.udp.port != exp->tuple.dst.u.udp.port) &&
935 ct->status & IPS_NAT_MASK) {
936 *daddr = exp->saved_addr;
937 tuple.dst.u3 = exp->saved_addr;
938 tuple.dst.u.udp.port = exp->saved_proto.udp.port;
943 } while (!skip_expect);
945 base_port = ntohs(tuple.dst.u.udp.port) & ~1;
946 rtp_port = htons(base_port);
947 rtcp_port = htons(base_port + 1);
950 hooks = rcu_dereference(nf_nat_sip_hooks);
952 !hooks->sdp_port(skb, protoff, dataoff, dptr, datalen,
953 mediaoff, medialen, ntohs(rtp_port)))
960 rtp_exp = nf_ct_expect_alloc(ct);
963 nf_ct_expect_init(rtp_exp, class, nf_ct_l3num(ct), saddr, daddr,
964 IPPROTO_UDP, NULL, &rtp_port);
966 rtcp_exp = nf_ct_expect_alloc(ct);
967 if (rtcp_exp == NULL)
969 nf_ct_expect_init(rtcp_exp, class, nf_ct_l3num(ct), saddr, daddr,
970 IPPROTO_UDP, NULL, &rtcp_port);
972 hooks = rcu_dereference(nf_nat_sip_hooks);
973 if (hooks && ct->status & IPS_NAT_MASK && !direct_rtp)
974 ret = hooks->sdp_media(skb, protoff, dataoff, dptr,
975 datalen, rtp_exp, rtcp_exp,
976 mediaoff, medialen, daddr);
978 /* -EALREADY handling works around end-points that send
979 * SDP messages with identical port but different media type,
980 * we pretend expectation was set up.
982 int errp = nf_ct_expect_related(rtp_exp);
984 if (errp == 0 || errp == -EALREADY) {
985 int errcp = nf_ct_expect_related(rtcp_exp);
987 if (errcp == 0 || errcp == -EALREADY)
990 nf_ct_unexpect_related(rtp_exp);
993 nf_ct_expect_put(rtcp_exp);
995 nf_ct_expect_put(rtp_exp);
1000 static const struct sdp_media_type sdp_media_types[] = {
1001 SDP_MEDIA_TYPE("audio ", SIP_EXPECT_AUDIO),
1002 SDP_MEDIA_TYPE("video ", SIP_EXPECT_VIDEO),
1003 SDP_MEDIA_TYPE("image ", SIP_EXPECT_IMAGE),
1006 static const struct sdp_media_type *sdp_media_type(const char *dptr,
1007 unsigned int matchoff,
1008 unsigned int matchlen)
1010 const struct sdp_media_type *t;
1013 for (i = 0; i < ARRAY_SIZE(sdp_media_types); i++) {
1014 t = &sdp_media_types[i];
1015 if (matchlen < t->len ||
1016 strncmp(dptr + matchoff, t->name, t->len))
1023 static int process_sdp(struct sk_buff *skb, unsigned int protoff,
1024 unsigned int dataoff,
1025 const char **dptr, unsigned int *datalen,
1028 enum ip_conntrack_info ctinfo;
1029 struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
1030 unsigned int matchoff, matchlen;
1031 unsigned int mediaoff, medialen;
1032 unsigned int sdpoff;
1033 unsigned int caddr_len, maddr_len;
1035 union nf_inet_addr caddr, maddr, rtp_addr;
1036 const struct nf_nat_sip_hooks *hooks;
1038 const struct sdp_media_type *t;
1039 int ret = NF_ACCEPT;
1041 hooks = rcu_dereference(nf_nat_sip_hooks);
1043 /* Find beginning of session description */
1044 if (ct_sip_get_sdp_header(ct, *dptr, 0, *datalen,
1045 SDP_HDR_VERSION, SDP_HDR_UNSPEC,
1046 &matchoff, &matchlen) <= 0)
1050 /* The connection information is contained in the session description
1051 * and/or once per media description. The first media description marks
1052 * the end of the session description. */
1054 if (ct_sip_parse_sdp_addr(ct, *dptr, sdpoff, *datalen,
1055 SDP_HDR_CONNECTION, SDP_HDR_MEDIA,
1056 &matchoff, &matchlen, &caddr) > 0)
1057 caddr_len = matchlen;
1060 for (i = 0; i < ARRAY_SIZE(sdp_media_types); ) {
1061 if (ct_sip_get_sdp_header(ct, *dptr, mediaoff, *datalen,
1062 SDP_HDR_MEDIA, SDP_HDR_UNSPEC,
1063 &mediaoff, &medialen) <= 0)
1066 /* Get media type and port number. A media port value of zero
1067 * indicates an inactive stream. */
1068 t = sdp_media_type(*dptr, mediaoff, medialen);
1070 mediaoff += medialen;
1076 port = simple_strtoul(*dptr + mediaoff, NULL, 10);
1079 if (port < 1024 || port > 65535) {
1080 nf_ct_helper_log(skb, ct, "wrong port %u", port);
1084 /* The media description overrides the session description. */
1086 if (ct_sip_parse_sdp_addr(ct, *dptr, mediaoff, *datalen,
1087 SDP_HDR_CONNECTION, SDP_HDR_MEDIA,
1088 &matchoff, &matchlen, &maddr) > 0) {
1089 maddr_len = matchlen;
1090 memcpy(&rtp_addr, &maddr, sizeof(rtp_addr));
1091 } else if (caddr_len)
1092 memcpy(&rtp_addr, &caddr, sizeof(rtp_addr));
1094 nf_ct_helper_log(skb, ct, "cannot parse SDP message");
1098 ret = set_expected_rtp_rtcp(skb, protoff, dataoff,
1100 &rtp_addr, htons(port), t->class,
1101 mediaoff, medialen);
1102 if (ret != NF_ACCEPT) {
1103 nf_ct_helper_log(skb, ct,
1104 "cannot add expectation for voice");
1108 /* Update media connection address if present */
1109 if (maddr_len && hooks && ct->status & IPS_NAT_MASK) {
1110 ret = hooks->sdp_addr(skb, protoff, dataoff,
1111 dptr, datalen, mediaoff,
1115 if (ret != NF_ACCEPT) {
1116 nf_ct_helper_log(skb, ct, "cannot mangle SDP");
1123 /* Update session connection and owner addresses */
1124 hooks = rcu_dereference(nf_nat_sip_hooks);
1125 if (hooks && ct->status & IPS_NAT_MASK)
1126 ret = hooks->sdp_session(skb, protoff, dataoff,
1127 dptr, datalen, sdpoff,
1132 static int process_invite_response(struct sk_buff *skb, unsigned int protoff,
1133 unsigned int dataoff,
1134 const char **dptr, unsigned int *datalen,
1135 unsigned int cseq, unsigned int code)
1137 enum ip_conntrack_info ctinfo;
1138 struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
1139 struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
1141 if ((code >= 100 && code <= 199) ||
1142 (code >= 200 && code <= 299))
1143 return process_sdp(skb, protoff, dataoff, dptr, datalen, cseq);
1144 else if (ct_sip_info->invite_cseq == cseq)
1145 flush_expectations(ct, true);
1149 static int process_update_response(struct sk_buff *skb, unsigned int protoff,
1150 unsigned int dataoff,
1151 const char **dptr, unsigned int *datalen,
1152 unsigned int cseq, unsigned int code)
1154 enum ip_conntrack_info ctinfo;
1155 struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
1156 struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
1158 if ((code >= 100 && code <= 199) ||
1159 (code >= 200 && code <= 299))
1160 return process_sdp(skb, protoff, dataoff, dptr, datalen, cseq);
1161 else if (ct_sip_info->invite_cseq == cseq)
1162 flush_expectations(ct, true);
1166 static int process_prack_response(struct sk_buff *skb, unsigned int protoff,
1167 unsigned int dataoff,
1168 const char **dptr, unsigned int *datalen,
1169 unsigned int cseq, unsigned int code)
1171 enum ip_conntrack_info ctinfo;
1172 struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
1173 struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
1175 if ((code >= 100 && code <= 199) ||
1176 (code >= 200 && code <= 299))
1177 return process_sdp(skb, protoff, dataoff, dptr, datalen, cseq);
1178 else if (ct_sip_info->invite_cseq == cseq)
1179 flush_expectations(ct, true);
1183 static int process_invite_request(struct sk_buff *skb, unsigned int protoff,
1184 unsigned int dataoff,
1185 const char **dptr, unsigned int *datalen,
1188 enum ip_conntrack_info ctinfo;
1189 struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
1190 struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
1193 flush_expectations(ct, true);
1194 ret = process_sdp(skb, protoff, dataoff, dptr, datalen, cseq);
1195 if (ret == NF_ACCEPT)
1196 ct_sip_info->invite_cseq = cseq;
1200 static int process_bye_request(struct sk_buff *skb, unsigned int protoff,
1201 unsigned int dataoff,
1202 const char **dptr, unsigned int *datalen,
1205 enum ip_conntrack_info ctinfo;
1206 struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
1208 flush_expectations(ct, true);
1212 /* Parse a REGISTER request and create a permanent expectation for incoming
1213 * signalling connections. The expectation is marked inactive and is activated
1214 * when receiving a response indicating success from the registrar.
1216 static int process_register_request(struct sk_buff *skb, unsigned int protoff,
1217 unsigned int dataoff,
1218 const char **dptr, unsigned int *datalen,
1221 enum ip_conntrack_info ctinfo;
1222 struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
1223 struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
1224 enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
1225 unsigned int matchoff, matchlen;
1226 struct nf_conntrack_expect *exp;
1227 union nf_inet_addr *saddr, daddr;
1228 const struct nf_nat_sip_hooks *hooks;
1231 unsigned int expires = 0;
1234 /* Expected connections can not register again. */
1235 if (ct->status & IPS_EXPECTED)
1238 /* We must check the expiration time: a value of zero signals the
1239 * registrar to release the binding. We'll remove our expectation
1240 * when receiving the new bindings in the response, but we don't
1241 * want to create new ones.
1243 * The expiration time may be contained in Expires: header, the
1244 * Contact: header parameters or the URI parameters.
1246 if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_EXPIRES,
1247 &matchoff, &matchlen) > 0)
1248 expires = simple_strtoul(*dptr + matchoff, NULL, 10);
1250 ret = ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen,
1251 SIP_HDR_CONTACT, NULL,
1252 &matchoff, &matchlen, &daddr, &port);
1254 nf_ct_helper_log(skb, ct, "cannot parse contact");
1256 } else if (ret == 0)
1259 /* We don't support third-party registrations */
1260 if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.src.u3, &daddr))
1263 if (ct_sip_parse_transport(ct, *dptr, matchoff + matchlen, *datalen,
1267 if (ct_sip_parse_numerical_param(ct, *dptr,
1268 matchoff + matchlen, *datalen,
1269 "expires=", NULL, NULL, &expires) < 0) {
1270 nf_ct_helper_log(skb, ct, "cannot parse expires");
1279 exp = nf_ct_expect_alloc(ct);
1281 nf_ct_helper_log(skb, ct, "cannot alloc expectation");
1286 if (sip_direct_signalling)
1287 saddr = &ct->tuplehash[!dir].tuple.src.u3;
1289 nf_ct_expect_init(exp, SIP_EXPECT_SIGNALLING, nf_ct_l3num(ct),
1290 saddr, &daddr, proto, NULL, &port);
1291 exp->timeout.expires = sip_timeout * HZ;
1292 exp->helper = nfct_help(ct)->helper;
1293 exp->flags = NF_CT_EXPECT_PERMANENT | NF_CT_EXPECT_INACTIVE;
1295 hooks = rcu_dereference(nf_nat_sip_hooks);
1296 if (hooks && ct->status & IPS_NAT_MASK)
1297 ret = hooks->expect(skb, protoff, dataoff, dptr, datalen,
1298 exp, matchoff, matchlen);
1300 if (nf_ct_expect_related(exp) != 0) {
1301 nf_ct_helper_log(skb, ct, "cannot add expectation");
1306 nf_ct_expect_put(exp);
1309 if (ret == NF_ACCEPT)
1310 ct_sip_info->register_cseq = cseq;
1314 static int process_register_response(struct sk_buff *skb, unsigned int protoff,
1315 unsigned int dataoff,
1316 const char **dptr, unsigned int *datalen,
1317 unsigned int cseq, unsigned int code)
1319 enum ip_conntrack_info ctinfo;
1320 struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
1321 struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
1322 enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
1323 union nf_inet_addr addr;
1326 unsigned int matchoff, matchlen, coff = 0;
1327 unsigned int expires = 0;
1328 int in_contact = 0, ret;
1330 /* According to RFC 3261, "UAs MUST NOT send a new registration until
1331 * they have received a final response from the registrar for the
1332 * previous one or the previous REGISTER request has timed out".
1334 * However, some servers fail to detect retransmissions and send late
1335 * responses, so we store the sequence number of the last valid
1336 * request and compare it here.
1338 if (ct_sip_info->register_cseq != cseq)
1341 if (code >= 100 && code <= 199)
1343 if (code < 200 || code > 299)
1346 if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_EXPIRES,
1347 &matchoff, &matchlen) > 0)
1348 expires = simple_strtoul(*dptr + matchoff, NULL, 10);
1351 unsigned int c_expires = expires;
1353 ret = ct_sip_parse_header_uri(ct, *dptr, &coff, *datalen,
1354 SIP_HDR_CONTACT, &in_contact,
1355 &matchoff, &matchlen,
1358 nf_ct_helper_log(skb, ct, "cannot parse contact");
1360 } else if (ret == 0)
1363 /* We don't support third-party registrations */
1364 if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3, &addr))
1367 if (ct_sip_parse_transport(ct, *dptr, matchoff + matchlen,
1368 *datalen, &proto) == 0)
1371 ret = ct_sip_parse_numerical_param(ct, *dptr,
1372 matchoff + matchlen,
1373 *datalen, "expires=",
1374 NULL, NULL, &c_expires);
1376 nf_ct_helper_log(skb, ct, "cannot parse expires");
1381 if (refresh_signalling_expectation(ct, &addr, proto, port,
1387 flush_expectations(ct, false);
1391 static const struct sip_handler sip_handlers[] = {
1392 SIP_HANDLER("INVITE", process_invite_request, process_invite_response),
1393 SIP_HANDLER("UPDATE", process_sdp, process_update_response),
1394 SIP_HANDLER("ACK", process_sdp, NULL),
1395 SIP_HANDLER("PRACK", process_sdp, process_prack_response),
1396 SIP_HANDLER("BYE", process_bye_request, NULL),
1397 SIP_HANDLER("REGISTER", process_register_request, process_register_response),
1400 static int process_sip_response(struct sk_buff *skb, unsigned int protoff,
1401 unsigned int dataoff,
1402 const char **dptr, unsigned int *datalen)
1404 enum ip_conntrack_info ctinfo;
1405 struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
1406 unsigned int matchoff, matchlen, matchend;
1407 unsigned int code, cseq, i;
1409 if (*datalen < strlen("SIP/2.0 200"))
1411 code = simple_strtoul(*dptr + strlen("SIP/2.0 "), NULL, 10);
1413 nf_ct_helper_log(skb, ct, "cannot get code");
1417 if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CSEQ,
1418 &matchoff, &matchlen) <= 0) {
1419 nf_ct_helper_log(skb, ct, "cannot parse cseq");
1422 cseq = simple_strtoul(*dptr + matchoff, NULL, 10);
1423 if (!cseq && *(*dptr + matchoff) != '0') {
1424 nf_ct_helper_log(skb, ct, "cannot get cseq");
1427 matchend = matchoff + matchlen + 1;
1429 for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) {
1430 const struct sip_handler *handler;
1432 handler = &sip_handlers[i];
1433 if (handler->response == NULL)
1435 if (*datalen < matchend + handler->len ||
1436 strncasecmp(*dptr + matchend, handler->method, handler->len))
1438 return handler->response(skb, protoff, dataoff, dptr, datalen,
1444 static int process_sip_request(struct sk_buff *skb, unsigned int protoff,
1445 unsigned int dataoff,
1446 const char **dptr, unsigned int *datalen)
1448 enum ip_conntrack_info ctinfo;
1449 struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
1450 struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
1451 enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
1452 unsigned int matchoff, matchlen;
1453 unsigned int cseq, i;
1454 union nf_inet_addr addr;
1457 /* Many Cisco IP phones use a high source port for SIP requests, but
1458 * listen for the response on port 5060. If we are the local
1459 * router for one of these phones, save the port number from the
1460 * Via: header so that nf_nat_sip can redirect the responses to
1463 if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen,
1464 SIP_HDR_VIA_UDP, NULL, &matchoff,
1465 &matchlen, &addr, &port) > 0 &&
1466 port != ct->tuplehash[dir].tuple.src.u.udp.port &&
1467 nf_inet_addr_cmp(&addr, &ct->tuplehash[dir].tuple.src.u3))
1468 ct_sip_info->forced_dport = port;
1470 for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) {
1471 const struct sip_handler *handler;
1473 handler = &sip_handlers[i];
1474 if (handler->request == NULL)
1476 if (*datalen < handler->len + 2 ||
1477 strncasecmp(*dptr, handler->method, handler->len))
1479 if ((*dptr)[handler->len] != ' ' ||
1480 !isalpha((*dptr)[handler->len+1]))
1483 if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CSEQ,
1484 &matchoff, &matchlen) <= 0) {
1485 nf_ct_helper_log(skb, ct, "cannot parse cseq");
1488 cseq = simple_strtoul(*dptr + matchoff, NULL, 10);
1489 if (!cseq && *(*dptr + matchoff) != '0') {
1490 nf_ct_helper_log(skb, ct, "cannot get cseq");
1494 return handler->request(skb, protoff, dataoff, dptr, datalen,
1500 static int process_sip_msg(struct sk_buff *skb, struct nf_conn *ct,
1501 unsigned int protoff, unsigned int dataoff,
1502 const char **dptr, unsigned int *datalen)
1504 const struct nf_nat_sip_hooks *hooks;
1507 if (strncasecmp(*dptr, "SIP/2.0 ", strlen("SIP/2.0 ")) != 0)
1508 ret = process_sip_request(skb, protoff, dataoff, dptr, datalen);
1510 ret = process_sip_response(skb, protoff, dataoff, dptr, datalen);
1512 if (ret == NF_ACCEPT && ct->status & IPS_NAT_MASK) {
1513 hooks = rcu_dereference(nf_nat_sip_hooks);
1514 if (hooks && !hooks->msg(skb, protoff, dataoff,
1516 nf_ct_helper_log(skb, ct, "cannot NAT SIP message");
1524 static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff,
1525 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1527 struct tcphdr *th, _tcph;
1528 unsigned int dataoff, datalen;
1529 unsigned int matchoff, matchlen, clen;
1530 unsigned int msglen, origlen;
1531 const char *dptr, *end;
1532 s16 diff, tdiff = 0;
1533 int ret = NF_ACCEPT;
1536 if (ctinfo != IP_CT_ESTABLISHED &&
1537 ctinfo != IP_CT_ESTABLISHED_REPLY)
1541 th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
1544 dataoff = protoff + th->doff * 4;
1545 if (dataoff >= skb->len)
1548 nf_ct_refresh(ct, skb, sip_timeout * HZ);
1550 if (unlikely(skb_linearize(skb)))
1553 dptr = skb->data + dataoff;
1554 datalen = skb->len - dataoff;
1555 if (datalen < strlen("SIP/2.0 200"))
1559 if (ct_sip_get_header(ct, dptr, 0, datalen,
1560 SIP_HDR_CONTENT_LENGTH,
1561 &matchoff, &matchlen) <= 0)
1564 clen = simple_strtoul(dptr + matchoff, (char **)&end, 10);
1565 if (dptr + matchoff == end)
1569 for (; end + strlen("\r\n\r\n") <= dptr + datalen; end++) {
1570 if (end[0] == '\r' && end[1] == '\n' &&
1571 end[2] == '\r' && end[3] == '\n') {
1578 end += strlen("\r\n\r\n") + clen;
1580 msglen = origlen = end - dptr;
1581 if (msglen > datalen)
1584 ret = process_sip_msg(skb, ct, protoff, dataoff,
1586 /* process_sip_* functions report why this packet is dropped */
1587 if (ret != NF_ACCEPT)
1589 diff = msglen - origlen;
1594 datalen = datalen + diff - msglen;
1597 if (ret == NF_ACCEPT && ct->status & IPS_NAT_MASK) {
1598 const struct nf_nat_sip_hooks *hooks;
1600 hooks = rcu_dereference(nf_nat_sip_hooks);
1602 hooks->seq_adjust(skb, protoff, tdiff);
1608 static int sip_help_udp(struct sk_buff *skb, unsigned int protoff,
1609 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1611 unsigned int dataoff, datalen;
1615 dataoff = protoff + sizeof(struct udphdr);
1616 if (dataoff >= skb->len)
1619 nf_ct_refresh(ct, skb, sip_timeout * HZ);
1621 if (unlikely(skb_linearize(skb)))
1624 dptr = skb->data + dataoff;
1625 datalen = skb->len - dataoff;
1626 if (datalen < strlen("SIP/2.0 200"))
1629 return process_sip_msg(skb, ct, protoff, dataoff, &dptr, &datalen);
1632 static struct nf_conntrack_helper sip[MAX_PORTS * 4] __read_mostly;
1634 static const struct nf_conntrack_expect_policy sip_exp_policy[SIP_EXPECT_MAX + 1] = {
1635 [SIP_EXPECT_SIGNALLING] = {
1636 .name = "signalling",
1640 [SIP_EXPECT_AUDIO] = {
1642 .max_expected = 2 * IP_CT_DIR_MAX,
1645 [SIP_EXPECT_VIDEO] = {
1647 .max_expected = 2 * IP_CT_DIR_MAX,
1650 [SIP_EXPECT_IMAGE] = {
1652 .max_expected = IP_CT_DIR_MAX,
1657 static void __exit nf_conntrack_sip_fini(void)
1659 nf_conntrack_helpers_unregister(sip, ports_c * 4);
1662 static int __init nf_conntrack_sip_init(void)
1666 NF_CT_HELPER_BUILD_BUG_ON(sizeof(struct nf_ct_sip_master));
1669 ports[ports_c++] = SIP_PORT;
1671 for (i = 0; i < ports_c; i++) {
1672 nf_ct_helper_init(&sip[4 * i], AF_INET, IPPROTO_UDP, "sip",
1673 SIP_PORT, ports[i], i, sip_exp_policy,
1674 SIP_EXPECT_MAX, sip_help_udp,
1676 nf_ct_helper_init(&sip[4 * i + 1], AF_INET, IPPROTO_TCP, "sip",
1677 SIP_PORT, ports[i], i, sip_exp_policy,
1678 SIP_EXPECT_MAX, sip_help_tcp,
1680 nf_ct_helper_init(&sip[4 * i + 2], AF_INET6, IPPROTO_UDP, "sip",
1681 SIP_PORT, ports[i], i, sip_exp_policy,
1682 SIP_EXPECT_MAX, sip_help_udp,
1684 nf_ct_helper_init(&sip[4 * i + 3], AF_INET6, IPPROTO_TCP, "sip",
1685 SIP_PORT, ports[i], i, sip_exp_policy,
1686 SIP_EXPECT_MAX, sip_help_tcp,
1690 ret = nf_conntrack_helpers_register(sip, ports_c * 4);
1692 pr_err("failed to register helpers\n");
1698 module_init(nf_conntrack_sip_init);
1699 module_exit(nf_conntrack_sip_fini);