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>
24 #include <net/netfilter/nf_conntrack.h>
25 #include <net/netfilter/nf_conntrack_core.h>
26 #include <net/netfilter/nf_conntrack_expect.h>
27 #include <net/netfilter/nf_conntrack_helper.h>
28 #include <net/netfilter/nf_conntrack_zones.h>
29 #include <linux/netfilter/nf_conntrack_sip.h>
31 MODULE_LICENSE("GPL");
32 MODULE_AUTHOR("Christian Hentschel <chentschel@arnet.com.ar>");
33 MODULE_DESCRIPTION("SIP connection tracking helper");
34 MODULE_ALIAS("ip_conntrack_sip");
35 MODULE_ALIAS_NFCT_HELPER("sip");
38 static unsigned short ports
[MAX_PORTS
];
39 static unsigned int ports_c
;
40 module_param_array(ports
, ushort
, &ports_c
, 0400);
41 MODULE_PARM_DESC(ports
, "port numbers of SIP servers");
43 static unsigned int sip_timeout __read_mostly
= SIP_TIMEOUT
;
44 module_param(sip_timeout
, uint
, 0600);
45 MODULE_PARM_DESC(sip_timeout
, "timeout for the master SIP session");
47 static int sip_direct_signalling __read_mostly
= 1;
48 module_param(sip_direct_signalling
, int, 0600);
49 MODULE_PARM_DESC(sip_direct_signalling
, "expect incoming calls from registrar "
52 static int sip_direct_media __read_mostly
= 1;
53 module_param(sip_direct_media
, int, 0600);
54 MODULE_PARM_DESC(sip_direct_media
, "Expect Media streams between signalling "
55 "endpoints only (default 1)");
57 const struct nf_nat_sip_hooks
*nf_nat_sip_hooks
;
58 EXPORT_SYMBOL_GPL(nf_nat_sip_hooks
);
60 static int string_len(const struct nf_conn
*ct
, const char *dptr
,
61 const char *limit
, int *shift
)
65 while (dptr
< limit
&& isalpha(*dptr
)) {
72 static int digits_len(const struct nf_conn
*ct
, const char *dptr
,
73 const char *limit
, int *shift
)
76 while (dptr
< limit
&& isdigit(*dptr
)) {
83 static int iswordc(const char c
)
85 if (isalnum(c
) || c
== '!' || c
== '"' || c
== '%' ||
86 (c
>= '(' && c
<= '+') || c
== ':' || c
== '<' || c
== '>' ||
87 c
== '?' || (c
>= '[' && c
<= ']') || c
== '_' || c
== '`' ||
88 c
== '{' || c
== '}' || c
== '~' || (c
>= '-' && c
<= '/') ||
94 static int word_len(const char *dptr
, const char *limit
)
97 while (dptr
< limit
&& iswordc(*dptr
)) {
104 static int callid_len(const struct nf_conn
*ct
, const char *dptr
,
105 const char *limit
, int *shift
)
109 len
= word_len(dptr
, limit
);
111 if (!len
|| dptr
== limit
|| *dptr
!= '@')
116 domain_len
= word_len(dptr
, limit
);
119 return len
+ domain_len
;
122 /* get media type + port length */
123 static int media_len(const struct nf_conn
*ct
, const char *dptr
,
124 const char *limit
, int *shift
)
126 int len
= string_len(ct
, dptr
, limit
, shift
);
129 if (dptr
>= limit
|| *dptr
!= ' ')
134 return len
+ digits_len(ct
, dptr
, limit
, shift
);
137 static int sip_parse_addr(const struct nf_conn
*ct
, const char *cp
,
138 const char **endp
, union nf_inet_addr
*addr
,
139 const char *limit
, bool delim
)
147 memset(addr
, 0, sizeof(*addr
));
148 switch (nf_ct_l3num(ct
)) {
150 ret
= in4_pton(cp
, limit
- cp
, (u8
*)&addr
->ip
, -1, &end
);
155 if (cp
< limit
&& *cp
== '[')
160 ret
= in6_pton(cp
, limit
- cp
, (u8
*)&addr
->ip6
, -1, &end
);
164 if (end
< limit
&& *end
== ']')
178 /* skip ip address. returns its length. */
179 static int epaddr_len(const struct nf_conn
*ct
, const char *dptr
,
180 const char *limit
, int *shift
)
182 union nf_inet_addr addr
;
183 const char *aux
= dptr
;
185 if (!sip_parse_addr(ct
, dptr
, &dptr
, &addr
, limit
, true)) {
186 pr_debug("ip: %s parse failed.!\n", dptr
);
193 dptr
+= digits_len(ct
, dptr
, limit
, shift
);
198 /* get address length, skiping user info. */
199 static int skp_epaddr_len(const struct nf_conn
*ct
, const char *dptr
,
200 const char *limit
, int *shift
)
202 const char *start
= dptr
;
205 /* Search for @, but stop at the end of the line.
206 * We are inside a sip: URI, so we don't need to worry about
207 * continuation lines. */
208 while (dptr
< limit
&&
209 *dptr
!= '@' && *dptr
!= '\r' && *dptr
!= '\n') {
214 if (dptr
< limit
&& *dptr
== '@') {
222 return epaddr_len(ct
, dptr
, limit
, shift
);
225 /* Parse a SIP request line of the form:
227 * Request-Line = Method SP Request-URI SP SIP-Version CRLF
229 * and return the offset and length of the address contained in the Request-URI.
231 int ct_sip_parse_request(const struct nf_conn
*ct
,
232 const char *dptr
, unsigned int datalen
,
233 unsigned int *matchoff
, unsigned int *matchlen
,
234 union nf_inet_addr
*addr
, __be16
*port
)
236 const char *start
= dptr
, *limit
= dptr
+ datalen
, *end
;
241 /* Skip method and following whitespace */
242 mlen
= string_len(ct
, dptr
, limit
, NULL
);
250 for (; dptr
< limit
- strlen("sip:"); dptr
++) {
251 if (*dptr
== '\r' || *dptr
== '\n')
253 if (strncasecmp(dptr
, "sip:", strlen("sip:")) == 0) {
254 dptr
+= strlen("sip:");
258 if (!skp_epaddr_len(ct
, dptr
, limit
, &shift
))
262 if (!sip_parse_addr(ct
, dptr
, &end
, addr
, limit
, true))
264 if (end
< limit
&& *end
== ':') {
266 p
= simple_strtoul(end
, (char **)&end
, 10);
267 if (p
< 1024 || p
> 65535)
271 *port
= htons(SIP_PORT
);
275 *matchoff
= dptr
- start
;
276 *matchlen
= end
- dptr
;
279 EXPORT_SYMBOL_GPL(ct_sip_parse_request
);
281 /* SIP header parsing: SIP headers are located at the beginning of a line, but
282 * may span several lines, in which case the continuation lines begin with a
283 * whitespace character. RFC 2543 allows lines to be terminated with CR, LF or
284 * CRLF, RFC 3261 allows only CRLF, we support both.
286 * Headers are followed by (optionally) whitespace, a colon, again (optionally)
287 * whitespace and the values. Whitespace in this context means any amount of
288 * tabs, spaces and continuation lines, which are treated as a single whitespace
291 * Some headers may appear multiple times. A comma separated list of values is
292 * equivalent to multiple headers.
294 static const struct sip_header ct_sip_hdrs
[] = {
295 [SIP_HDR_CSEQ
] = SIP_HDR("CSeq", NULL
, NULL
, digits_len
),
296 [SIP_HDR_FROM
] = SIP_HDR("From", "f", "sip:", skp_epaddr_len
),
297 [SIP_HDR_TO
] = SIP_HDR("To", "t", "sip:", skp_epaddr_len
),
298 [SIP_HDR_CONTACT
] = SIP_HDR("Contact", "m", "sip:", skp_epaddr_len
),
299 [SIP_HDR_VIA_UDP
] = SIP_HDR("Via", "v", "UDP ", epaddr_len
),
300 [SIP_HDR_VIA_TCP
] = SIP_HDR("Via", "v", "TCP ", epaddr_len
),
301 [SIP_HDR_EXPIRES
] = SIP_HDR("Expires", NULL
, NULL
, digits_len
),
302 [SIP_HDR_CONTENT_LENGTH
] = SIP_HDR("Content-Length", "l", NULL
, digits_len
),
303 [SIP_HDR_CALL_ID
] = SIP_HDR("Call-Id", "i", NULL
, callid_len
),
306 static const char *sip_follow_continuation(const char *dptr
, const char *limit
)
308 /* Walk past newline */
312 /* Skip '\n' in CR LF */
313 if (*(dptr
- 1) == '\r' && *dptr
== '\n') {
318 /* Continuation line? */
319 if (*dptr
!= ' ' && *dptr
!= '\t')
322 /* skip leading whitespace */
323 for (; dptr
< limit
; dptr
++) {
324 if (*dptr
!= ' ' && *dptr
!= '\t')
330 static const char *sip_skip_whitespace(const char *dptr
, const char *limit
)
332 for (; dptr
< limit
; dptr
++) {
333 if (*dptr
== ' ' || *dptr
== '\t')
335 if (*dptr
!= '\r' && *dptr
!= '\n')
337 dptr
= sip_follow_continuation(dptr
, limit
);
343 /* Search within a SIP header value, dealing with continuation lines */
344 static const char *ct_sip_header_search(const char *dptr
, const char *limit
,
345 const char *needle
, unsigned int len
)
347 for (limit
-= len
; dptr
< limit
; dptr
++) {
348 if (*dptr
== '\r' || *dptr
== '\n') {
349 dptr
= sip_follow_continuation(dptr
, limit
);
355 if (strncasecmp(dptr
, needle
, len
) == 0)
361 int ct_sip_get_header(const struct nf_conn
*ct
, const char *dptr
,
362 unsigned int dataoff
, unsigned int datalen
,
363 enum sip_header_types type
,
364 unsigned int *matchoff
, unsigned int *matchlen
)
366 const struct sip_header
*hdr
= &ct_sip_hdrs
[type
];
367 const char *start
= dptr
, *limit
= dptr
+ datalen
;
370 for (dptr
+= dataoff
; dptr
< limit
; dptr
++) {
371 /* Find beginning of line */
372 if (*dptr
!= '\r' && *dptr
!= '\n')
376 if (*(dptr
- 1) == '\r' && *dptr
== '\n') {
381 /* Skip continuation lines */
382 if (*dptr
== ' ' || *dptr
== '\t')
385 /* Find header. Compact headers must be followed by a
386 * non-alphabetic character to avoid mismatches. */
387 if (limit
- dptr
>= hdr
->len
&&
388 strncasecmp(dptr
, hdr
->name
, hdr
->len
) == 0)
390 else if (hdr
->cname
&& limit
- dptr
>= hdr
->clen
+ 1 &&
391 strncasecmp(dptr
, hdr
->cname
, hdr
->clen
) == 0 &&
392 !isalpha(*(dptr
+ hdr
->clen
)))
397 /* Find and skip colon */
398 dptr
= sip_skip_whitespace(dptr
, limit
);
401 if (*dptr
!= ':' || ++dptr
>= limit
)
404 /* Skip whitespace after colon */
405 dptr
= sip_skip_whitespace(dptr
, limit
);
409 *matchoff
= dptr
- start
;
411 dptr
= ct_sip_header_search(dptr
, limit
, hdr
->search
,
418 *matchlen
= hdr
->match_len(ct
, dptr
, limit
, &shift
);
421 *matchoff
= dptr
- start
+ shift
;
426 EXPORT_SYMBOL_GPL(ct_sip_get_header
);
428 /* Get next header field in a list of comma separated values */
429 static int ct_sip_next_header(const struct nf_conn
*ct
, const char *dptr
,
430 unsigned int dataoff
, unsigned int datalen
,
431 enum sip_header_types type
,
432 unsigned int *matchoff
, unsigned int *matchlen
)
434 const struct sip_header
*hdr
= &ct_sip_hdrs
[type
];
435 const char *start
= dptr
, *limit
= dptr
+ datalen
;
440 dptr
= ct_sip_header_search(dptr
, limit
, ",", strlen(","));
444 dptr
= ct_sip_header_search(dptr
, limit
, hdr
->search
, hdr
->slen
);
449 *matchoff
= dptr
- start
;
450 *matchlen
= hdr
->match_len(ct
, dptr
, limit
, &shift
);
457 /* Walk through headers until a parsable one is found or no header of the
458 * given type is left. */
459 static int ct_sip_walk_headers(const struct nf_conn
*ct
, const char *dptr
,
460 unsigned int dataoff
, unsigned int datalen
,
461 enum sip_header_types type
, int *in_header
,
462 unsigned int *matchoff
, unsigned int *matchlen
)
466 if (in_header
&& *in_header
) {
468 ret
= ct_sip_next_header(ct
, dptr
, dataoff
, datalen
,
469 type
, matchoff
, matchlen
);
474 dataoff
+= *matchoff
;
480 ret
= ct_sip_get_header(ct
, dptr
, dataoff
, datalen
,
481 type
, matchoff
, matchlen
);
486 dataoff
+= *matchoff
;
494 /* Locate a SIP header, parse the URI and return the offset and length of
495 * the address as well as the address and port themselves. A stream of
496 * headers can be parsed by handing in a non-NULL datalen and in_header
499 int ct_sip_parse_header_uri(const struct nf_conn
*ct
, const char *dptr
,
500 unsigned int *dataoff
, unsigned int datalen
,
501 enum sip_header_types type
, int *in_header
,
502 unsigned int *matchoff
, unsigned int *matchlen
,
503 union nf_inet_addr
*addr
, __be16
*port
)
505 const char *c
, *limit
= dptr
+ datalen
;
509 ret
= ct_sip_walk_headers(ct
, dptr
, dataoff
? *dataoff
: 0, datalen
,
510 type
, in_header
, matchoff
, matchlen
);
515 if (!sip_parse_addr(ct
, dptr
+ *matchoff
, &c
, addr
, limit
, true))
519 p
= simple_strtoul(c
, (char **)&c
, 10);
520 if (p
< 1024 || p
> 65535)
524 *port
= htons(SIP_PORT
);
530 EXPORT_SYMBOL_GPL(ct_sip_parse_header_uri
);
532 static int ct_sip_parse_param(const struct nf_conn
*ct
, const char *dptr
,
533 unsigned int dataoff
, unsigned int datalen
,
535 unsigned int *matchoff
, unsigned int *matchlen
)
537 const char *limit
= dptr
+ datalen
;
541 limit
= ct_sip_header_search(dptr
+ dataoff
, limit
, ",", strlen(","));
543 limit
= dptr
+ datalen
;
545 start
= ct_sip_header_search(dptr
+ dataoff
, limit
, name
, strlen(name
));
548 start
+= strlen(name
);
550 end
= ct_sip_header_search(start
, limit
, ";", strlen(";"));
554 *matchoff
= start
- dptr
;
555 *matchlen
= end
- start
;
559 /* Parse address from header parameter and return address, offset and length */
560 int ct_sip_parse_address_param(const struct nf_conn
*ct
, const char *dptr
,
561 unsigned int dataoff
, unsigned int datalen
,
563 unsigned int *matchoff
, unsigned int *matchlen
,
564 union nf_inet_addr
*addr
, bool delim
)
566 const char *limit
= dptr
+ datalen
;
567 const char *start
, *end
;
569 limit
= ct_sip_header_search(dptr
+ dataoff
, limit
, ",", strlen(","));
571 limit
= dptr
+ datalen
;
573 start
= ct_sip_header_search(dptr
+ dataoff
, limit
, name
, strlen(name
));
577 start
+= strlen(name
);
578 if (!sip_parse_addr(ct
, start
, &end
, addr
, limit
, delim
))
580 *matchoff
= start
- dptr
;
581 *matchlen
= end
- start
;
584 EXPORT_SYMBOL_GPL(ct_sip_parse_address_param
);
586 /* Parse numerical header parameter and return value, offset and length */
587 int ct_sip_parse_numerical_param(const struct nf_conn
*ct
, const char *dptr
,
588 unsigned int dataoff
, unsigned int datalen
,
590 unsigned int *matchoff
, unsigned int *matchlen
,
593 const char *limit
= dptr
+ datalen
;
597 limit
= ct_sip_header_search(dptr
+ dataoff
, limit
, ",", strlen(","));
599 limit
= dptr
+ datalen
;
601 start
= ct_sip_header_search(dptr
+ dataoff
, limit
, name
, strlen(name
));
605 start
+= strlen(name
);
606 *val
= simple_strtoul(start
, &end
, 0);
609 if (matchoff
&& matchlen
) {
610 *matchoff
= start
- dptr
;
611 *matchlen
= end
- start
;
615 EXPORT_SYMBOL_GPL(ct_sip_parse_numerical_param
);
617 static int ct_sip_parse_transport(struct nf_conn
*ct
, const char *dptr
,
618 unsigned int dataoff
, unsigned int datalen
,
621 unsigned int matchoff
, matchlen
;
623 if (ct_sip_parse_param(ct
, dptr
, dataoff
, datalen
, "transport=",
624 &matchoff
, &matchlen
)) {
625 if (!strncasecmp(dptr
+ matchoff
, "TCP", strlen("TCP")))
626 *proto
= IPPROTO_TCP
;
627 else if (!strncasecmp(dptr
+ matchoff
, "UDP", strlen("UDP")))
628 *proto
= IPPROTO_UDP
;
632 if (*proto
!= nf_ct_protonum(ct
))
635 *proto
= nf_ct_protonum(ct
);
640 static int sdp_parse_addr(const struct nf_conn
*ct
, const char *cp
,
641 const char **endp
, union nf_inet_addr
*addr
,
647 memset(addr
, 0, sizeof(*addr
));
648 switch (nf_ct_l3num(ct
)) {
650 ret
= in4_pton(cp
, limit
- cp
, (u8
*)&addr
->ip
, -1, &end
);
653 ret
= in6_pton(cp
, limit
- cp
, (u8
*)&addr
->ip6
, -1, &end
);
666 /* skip ip address. returns its length. */
667 static int sdp_addr_len(const struct nf_conn
*ct
, const char *dptr
,
668 const char *limit
, int *shift
)
670 union nf_inet_addr addr
;
671 const char *aux
= dptr
;
673 if (!sdp_parse_addr(ct
, dptr
, &dptr
, &addr
, limit
)) {
674 pr_debug("ip: %s parse failed.!\n", dptr
);
681 /* SDP header parsing: a SDP session description contains an ordered set of
682 * headers, starting with a section containing general session parameters,
683 * optionally followed by multiple media descriptions.
685 * SDP headers always start at the beginning of a line. According to RFC 2327:
686 * "The sequence CRLF (0x0d0a) is used to end a record, although parsers should
687 * be tolerant and also accept records terminated with a single newline
688 * character". We handle both cases.
690 static const struct sip_header ct_sdp_hdrs_v4
[] = {
691 [SDP_HDR_VERSION
] = SDP_HDR("v=", NULL
, digits_len
),
692 [SDP_HDR_OWNER
] = SDP_HDR("o=", "IN IP4 ", sdp_addr_len
),
693 [SDP_HDR_CONNECTION
] = SDP_HDR("c=", "IN IP4 ", sdp_addr_len
),
694 [SDP_HDR_MEDIA
] = SDP_HDR("m=", NULL
, media_len
),
697 static const struct sip_header ct_sdp_hdrs_v6
[] = {
698 [SDP_HDR_VERSION
] = SDP_HDR("v=", NULL
, digits_len
),
699 [SDP_HDR_OWNER
] = SDP_HDR("o=", "IN IP6 ", sdp_addr_len
),
700 [SDP_HDR_CONNECTION
] = SDP_HDR("c=", "IN IP6 ", sdp_addr_len
),
701 [SDP_HDR_MEDIA
] = SDP_HDR("m=", NULL
, media_len
),
704 /* Linear string search within SDP header values */
705 static const char *ct_sdp_header_search(const char *dptr
, const char *limit
,
706 const char *needle
, unsigned int len
)
708 for (limit
-= len
; dptr
< limit
; dptr
++) {
709 if (*dptr
== '\r' || *dptr
== '\n')
711 if (strncmp(dptr
, needle
, len
) == 0)
717 /* Locate a SDP header (optionally a substring within the header value),
718 * optionally stopping at the first occurrence of the term header, parse
719 * it and return the offset and length of the data we're interested in.
721 int ct_sip_get_sdp_header(const struct nf_conn
*ct
, const char *dptr
,
722 unsigned int dataoff
, unsigned int datalen
,
723 enum sdp_header_types type
,
724 enum sdp_header_types term
,
725 unsigned int *matchoff
, unsigned int *matchlen
)
727 const struct sip_header
*hdrs
, *hdr
, *thdr
;
728 const char *start
= dptr
, *limit
= dptr
+ datalen
;
731 hdrs
= nf_ct_l3num(ct
) == NFPROTO_IPV4
? ct_sdp_hdrs_v4
: ct_sdp_hdrs_v6
;
735 for (dptr
+= dataoff
; dptr
< limit
; dptr
++) {
736 /* Find beginning of line */
737 if (*dptr
!= '\r' && *dptr
!= '\n')
741 if (*(dptr
- 1) == '\r' && *dptr
== '\n') {
746 if (term
!= SDP_HDR_UNSPEC
&&
747 limit
- dptr
>= thdr
->len
&&
748 strncasecmp(dptr
, thdr
->name
, thdr
->len
) == 0)
750 else if (limit
- dptr
>= hdr
->len
&&
751 strncasecmp(dptr
, hdr
->name
, hdr
->len
) == 0)
756 *matchoff
= dptr
- start
;
758 dptr
= ct_sdp_header_search(dptr
, limit
, hdr
->search
,
765 *matchlen
= hdr
->match_len(ct
, dptr
, limit
, &shift
);
768 *matchoff
= dptr
- start
+ shift
;
773 EXPORT_SYMBOL_GPL(ct_sip_get_sdp_header
);
775 static int ct_sip_parse_sdp_addr(const struct nf_conn
*ct
, const char *dptr
,
776 unsigned int dataoff
, unsigned int datalen
,
777 enum sdp_header_types type
,
778 enum sdp_header_types term
,
779 unsigned int *matchoff
, unsigned int *matchlen
,
780 union nf_inet_addr
*addr
)
784 ret
= ct_sip_get_sdp_header(ct
, dptr
, dataoff
, datalen
, type
, term
,
789 if (!sdp_parse_addr(ct
, dptr
+ *matchoff
, NULL
, addr
,
790 dptr
+ *matchoff
+ *matchlen
))
795 static int refresh_signalling_expectation(struct nf_conn
*ct
,
796 union nf_inet_addr
*addr
,
797 u8 proto
, __be16 port
,
798 unsigned int expires
)
800 struct nf_conn_help
*help
= nfct_help(ct
);
801 struct nf_conntrack_expect
*exp
;
802 struct hlist_node
*next
;
805 spin_lock_bh(&nf_conntrack_expect_lock
);
806 hlist_for_each_entry_safe(exp
, next
, &help
->expectations
, lnode
) {
807 if (exp
->class != SIP_EXPECT_SIGNALLING
||
808 !nf_inet_addr_cmp(&exp
->tuple
.dst
.u3
, addr
) ||
809 exp
->tuple
.dst
.protonum
!= proto
||
810 exp
->tuple
.dst
.u
.udp
.port
!= port
)
812 if (mod_timer_pending(&exp
->timeout
, jiffies
+ expires
* HZ
)) {
813 exp
->flags
&= ~NF_CT_EXPECT_INACTIVE
;
818 spin_unlock_bh(&nf_conntrack_expect_lock
);
822 static void flush_expectations(struct nf_conn
*ct
, bool media
)
824 struct nf_conn_help
*help
= nfct_help(ct
);
825 struct nf_conntrack_expect
*exp
;
826 struct hlist_node
*next
;
828 spin_lock_bh(&nf_conntrack_expect_lock
);
829 hlist_for_each_entry_safe(exp
, next
, &help
->expectations
, lnode
) {
830 if ((exp
->class != SIP_EXPECT_SIGNALLING
) ^ media
)
832 if (!nf_ct_remove_expect(exp
))
837 spin_unlock_bh(&nf_conntrack_expect_lock
);
840 static int set_expected_rtp_rtcp(struct sk_buff
*skb
, unsigned int protoff
,
841 unsigned int dataoff
,
842 const char **dptr
, unsigned int *datalen
,
843 union nf_inet_addr
*daddr
, __be16 port
,
844 enum sip_expectation_classes
class,
845 unsigned int mediaoff
, unsigned int medialen
)
847 struct nf_conntrack_expect
*exp
, *rtp_exp
, *rtcp_exp
;
848 enum ip_conntrack_info ctinfo
;
849 struct nf_conn
*ct
= nf_ct_get(skb
, &ctinfo
);
850 struct net
*net
= nf_ct_net(ct
);
851 enum ip_conntrack_dir dir
= CTINFO2DIR(ctinfo
);
852 union nf_inet_addr
*saddr
;
853 struct nf_conntrack_tuple tuple
;
854 int direct_rtp
= 0, skip_expect
= 0, ret
= NF_DROP
;
856 __be16 rtp_port
, rtcp_port
;
857 const struct nf_nat_sip_hooks
*hooks
;
860 if (sip_direct_media
) {
861 if (!nf_inet_addr_cmp(daddr
, &ct
->tuplehash
[dir
].tuple
.src
.u3
))
863 saddr
= &ct
->tuplehash
[!dir
].tuple
.src
.u3
;
866 /* We need to check whether the registration exists before attempting
867 * to register it since we can see the same media description multiple
868 * times on different connections in case multiple endpoints receive
871 * RTP optimization: if we find a matching media channel expectation
872 * and both the expectation and this connection are SNATed, we assume
873 * both sides can reach each other directly and use the final
874 * destination address from the expectation. We still need to keep
875 * the NATed expectations for media that might arrive from the
876 * outside, and additionally need to expect the direct RTP stream
877 * in case it passes through us even without NAT.
879 memset(&tuple
, 0, sizeof(tuple
));
881 tuple
.src
.u3
= *saddr
;
882 tuple
.src
.l3num
= nf_ct_l3num(ct
);
883 tuple
.dst
.protonum
= IPPROTO_UDP
;
884 tuple
.dst
.u3
= *daddr
;
885 tuple
.dst
.u
.udp
.port
= port
;
888 exp
= __nf_ct_expect_find(net
, nf_ct_zone(ct
), &tuple
);
890 if (!exp
|| exp
->master
== ct
||
891 nfct_help(exp
->master
)->helper
!= nfct_help(ct
)->helper
||
894 #ifdef CONFIG_NF_NAT_NEEDED
896 (!nf_inet_addr_cmp(&exp
->saved_addr
, &exp
->tuple
.dst
.u3
) ||
897 exp
->saved_proto
.udp
.port
!= exp
->tuple
.dst
.u
.udp
.port
) &&
898 ct
->status
& IPS_NAT_MASK
) {
899 *daddr
= exp
->saved_addr
;
900 tuple
.dst
.u3
= exp
->saved_addr
;
901 tuple
.dst
.u
.udp
.port
= exp
->saved_proto
.udp
.port
;
906 } while (!skip_expect
);
908 base_port
= ntohs(tuple
.dst
.u
.udp
.port
) & ~1;
909 rtp_port
= htons(base_port
);
910 rtcp_port
= htons(base_port
+ 1);
913 hooks
= rcu_dereference(nf_nat_sip_hooks
);
915 !hooks
->sdp_port(skb
, protoff
, dataoff
, dptr
, datalen
,
916 mediaoff
, medialen
, ntohs(rtp_port
)))
923 rtp_exp
= nf_ct_expect_alloc(ct
);
926 nf_ct_expect_init(rtp_exp
, class, nf_ct_l3num(ct
), saddr
, daddr
,
927 IPPROTO_UDP
, NULL
, &rtp_port
);
929 rtcp_exp
= nf_ct_expect_alloc(ct
);
930 if (rtcp_exp
== NULL
)
932 nf_ct_expect_init(rtcp_exp
, class, nf_ct_l3num(ct
), saddr
, daddr
,
933 IPPROTO_UDP
, NULL
, &rtcp_port
);
935 hooks
= rcu_dereference(nf_nat_sip_hooks
);
936 if (hooks
&& ct
->status
& IPS_NAT_MASK
&& !direct_rtp
)
937 ret
= hooks
->sdp_media(skb
, protoff
, dataoff
, dptr
,
938 datalen
, rtp_exp
, rtcp_exp
,
939 mediaoff
, medialen
, daddr
);
941 if (nf_ct_expect_related(rtp_exp
) == 0) {
942 if (nf_ct_expect_related(rtcp_exp
) != 0)
943 nf_ct_unexpect_related(rtp_exp
);
948 nf_ct_expect_put(rtcp_exp
);
950 nf_ct_expect_put(rtp_exp
);
955 static const struct sdp_media_type sdp_media_types
[] = {
956 SDP_MEDIA_TYPE("audio ", SIP_EXPECT_AUDIO
),
957 SDP_MEDIA_TYPE("video ", SIP_EXPECT_VIDEO
),
958 SDP_MEDIA_TYPE("image ", SIP_EXPECT_IMAGE
),
961 static const struct sdp_media_type
*sdp_media_type(const char *dptr
,
962 unsigned int matchoff
,
963 unsigned int matchlen
)
965 const struct sdp_media_type
*t
;
968 for (i
= 0; i
< ARRAY_SIZE(sdp_media_types
); i
++) {
969 t
= &sdp_media_types
[i
];
970 if (matchlen
< t
->len
||
971 strncmp(dptr
+ matchoff
, t
->name
, t
->len
))
978 static int process_sdp(struct sk_buff
*skb
, unsigned int protoff
,
979 unsigned int dataoff
,
980 const char **dptr
, unsigned int *datalen
,
983 enum ip_conntrack_info ctinfo
;
984 struct nf_conn
*ct
= nf_ct_get(skb
, &ctinfo
);
985 unsigned int matchoff
, matchlen
;
986 unsigned int mediaoff
, medialen
;
988 unsigned int caddr_len
, maddr_len
;
990 union nf_inet_addr caddr
, maddr
, rtp_addr
;
991 const struct nf_nat_sip_hooks
*hooks
;
993 const struct sdp_media_type
*t
;
996 hooks
= rcu_dereference(nf_nat_sip_hooks
);
998 /* Find beginning of session description */
999 if (ct_sip_get_sdp_header(ct
, *dptr
, 0, *datalen
,
1000 SDP_HDR_VERSION
, SDP_HDR_UNSPEC
,
1001 &matchoff
, &matchlen
) <= 0)
1005 /* The connection information is contained in the session description
1006 * and/or once per media description. The first media description marks
1007 * the end of the session description. */
1009 if (ct_sip_parse_sdp_addr(ct
, *dptr
, sdpoff
, *datalen
,
1010 SDP_HDR_CONNECTION
, SDP_HDR_MEDIA
,
1011 &matchoff
, &matchlen
, &caddr
) > 0)
1012 caddr_len
= matchlen
;
1015 for (i
= 0; i
< ARRAY_SIZE(sdp_media_types
); ) {
1016 if (ct_sip_get_sdp_header(ct
, *dptr
, mediaoff
, *datalen
,
1017 SDP_HDR_MEDIA
, SDP_HDR_UNSPEC
,
1018 &mediaoff
, &medialen
) <= 0)
1021 /* Get media type and port number. A media port value of zero
1022 * indicates an inactive stream. */
1023 t
= sdp_media_type(*dptr
, mediaoff
, medialen
);
1025 mediaoff
+= medialen
;
1031 port
= simple_strtoul(*dptr
+ mediaoff
, NULL
, 10);
1034 if (port
< 1024 || port
> 65535) {
1035 nf_ct_helper_log(skb
, ct
, "wrong port %u", port
);
1039 /* The media description overrides the session description. */
1041 if (ct_sip_parse_sdp_addr(ct
, *dptr
, mediaoff
, *datalen
,
1042 SDP_HDR_CONNECTION
, SDP_HDR_MEDIA
,
1043 &matchoff
, &matchlen
, &maddr
) > 0) {
1044 maddr_len
= matchlen
;
1045 memcpy(&rtp_addr
, &maddr
, sizeof(rtp_addr
));
1046 } else if (caddr_len
)
1047 memcpy(&rtp_addr
, &caddr
, sizeof(rtp_addr
));
1049 nf_ct_helper_log(skb
, ct
, "cannot parse SDP message");
1053 ret
= set_expected_rtp_rtcp(skb
, protoff
, dataoff
,
1055 &rtp_addr
, htons(port
), t
->class,
1056 mediaoff
, medialen
);
1057 if (ret
!= NF_ACCEPT
) {
1058 nf_ct_helper_log(skb
, ct
,
1059 "cannot add expectation for voice");
1063 /* Update media connection address if present */
1064 if (maddr_len
&& hooks
&& ct
->status
& IPS_NAT_MASK
) {
1065 ret
= hooks
->sdp_addr(skb
, protoff
, dataoff
,
1066 dptr
, datalen
, mediaoff
,
1070 if (ret
!= NF_ACCEPT
) {
1071 nf_ct_helper_log(skb
, ct
, "cannot mangle SDP");
1078 /* Update session connection and owner addresses */
1079 hooks
= rcu_dereference(nf_nat_sip_hooks
);
1080 if (hooks
&& ct
->status
& IPS_NAT_MASK
)
1081 ret
= hooks
->sdp_session(skb
, protoff
, dataoff
,
1082 dptr
, datalen
, sdpoff
,
1087 static int process_invite_response(struct sk_buff
*skb
, unsigned int protoff
,
1088 unsigned int dataoff
,
1089 const char **dptr
, unsigned int *datalen
,
1090 unsigned int cseq
, unsigned int code
)
1092 enum ip_conntrack_info ctinfo
;
1093 struct nf_conn
*ct
= nf_ct_get(skb
, &ctinfo
);
1094 struct nf_ct_sip_master
*ct_sip_info
= nfct_help_data(ct
);
1096 if ((code
>= 100 && code
<= 199) ||
1097 (code
>= 200 && code
<= 299))
1098 return process_sdp(skb
, protoff
, dataoff
, dptr
, datalen
, cseq
);
1099 else if (ct_sip_info
->invite_cseq
== cseq
)
1100 flush_expectations(ct
, true);
1104 static int process_update_response(struct sk_buff
*skb
, unsigned int protoff
,
1105 unsigned int dataoff
,
1106 const char **dptr
, unsigned int *datalen
,
1107 unsigned int cseq
, unsigned int code
)
1109 enum ip_conntrack_info ctinfo
;
1110 struct nf_conn
*ct
= nf_ct_get(skb
, &ctinfo
);
1111 struct nf_ct_sip_master
*ct_sip_info
= nfct_help_data(ct
);
1113 if ((code
>= 100 && code
<= 199) ||
1114 (code
>= 200 && code
<= 299))
1115 return process_sdp(skb
, protoff
, dataoff
, dptr
, datalen
, cseq
);
1116 else if (ct_sip_info
->invite_cseq
== cseq
)
1117 flush_expectations(ct
, true);
1121 static int process_prack_response(struct sk_buff
*skb
, unsigned int protoff
,
1122 unsigned int dataoff
,
1123 const char **dptr
, unsigned int *datalen
,
1124 unsigned int cseq
, unsigned int code
)
1126 enum ip_conntrack_info ctinfo
;
1127 struct nf_conn
*ct
= nf_ct_get(skb
, &ctinfo
);
1128 struct nf_ct_sip_master
*ct_sip_info
= nfct_help_data(ct
);
1130 if ((code
>= 100 && code
<= 199) ||
1131 (code
>= 200 && code
<= 299))
1132 return process_sdp(skb
, protoff
, dataoff
, dptr
, datalen
, cseq
);
1133 else if (ct_sip_info
->invite_cseq
== cseq
)
1134 flush_expectations(ct
, true);
1138 static int process_invite_request(struct sk_buff
*skb
, unsigned int protoff
,
1139 unsigned int dataoff
,
1140 const char **dptr
, unsigned int *datalen
,
1143 enum ip_conntrack_info ctinfo
;
1144 struct nf_conn
*ct
= nf_ct_get(skb
, &ctinfo
);
1145 struct nf_ct_sip_master
*ct_sip_info
= nfct_help_data(ct
);
1148 flush_expectations(ct
, true);
1149 ret
= process_sdp(skb
, protoff
, dataoff
, dptr
, datalen
, cseq
);
1150 if (ret
== NF_ACCEPT
)
1151 ct_sip_info
->invite_cseq
= cseq
;
1155 static int process_bye_request(struct sk_buff
*skb
, unsigned int protoff
,
1156 unsigned int dataoff
,
1157 const char **dptr
, unsigned int *datalen
,
1160 enum ip_conntrack_info ctinfo
;
1161 struct nf_conn
*ct
= nf_ct_get(skb
, &ctinfo
);
1163 flush_expectations(ct
, true);
1167 /* Parse a REGISTER request and create a permanent expectation for incoming
1168 * signalling connections. The expectation is marked inactive and is activated
1169 * when receiving a response indicating success from the registrar.
1171 static int process_register_request(struct sk_buff
*skb
, unsigned int protoff
,
1172 unsigned int dataoff
,
1173 const char **dptr
, unsigned int *datalen
,
1176 enum ip_conntrack_info ctinfo
;
1177 struct nf_conn
*ct
= nf_ct_get(skb
, &ctinfo
);
1178 struct nf_ct_sip_master
*ct_sip_info
= nfct_help_data(ct
);
1179 enum ip_conntrack_dir dir
= CTINFO2DIR(ctinfo
);
1180 unsigned int matchoff
, matchlen
;
1181 struct nf_conntrack_expect
*exp
;
1182 union nf_inet_addr
*saddr
, daddr
;
1183 const struct nf_nat_sip_hooks
*hooks
;
1186 unsigned int expires
= 0;
1189 /* Expected connections can not register again. */
1190 if (ct
->status
& IPS_EXPECTED
)
1193 /* We must check the expiration time: a value of zero signals the
1194 * registrar to release the binding. We'll remove our expectation
1195 * when receiving the new bindings in the response, but we don't
1196 * want to create new ones.
1198 * The expiration time may be contained in Expires: header, the
1199 * Contact: header parameters or the URI parameters.
1201 if (ct_sip_get_header(ct
, *dptr
, 0, *datalen
, SIP_HDR_EXPIRES
,
1202 &matchoff
, &matchlen
) > 0)
1203 expires
= simple_strtoul(*dptr
+ matchoff
, NULL
, 10);
1205 ret
= ct_sip_parse_header_uri(ct
, *dptr
, NULL
, *datalen
,
1206 SIP_HDR_CONTACT
, NULL
,
1207 &matchoff
, &matchlen
, &daddr
, &port
);
1209 nf_ct_helper_log(skb
, ct
, "cannot parse contact");
1211 } else if (ret
== 0)
1214 /* We don't support third-party registrations */
1215 if (!nf_inet_addr_cmp(&ct
->tuplehash
[dir
].tuple
.src
.u3
, &daddr
))
1218 if (ct_sip_parse_transport(ct
, *dptr
, matchoff
+ matchlen
, *datalen
,
1222 if (ct_sip_parse_numerical_param(ct
, *dptr
,
1223 matchoff
+ matchlen
, *datalen
,
1224 "expires=", NULL
, NULL
, &expires
) < 0) {
1225 nf_ct_helper_log(skb
, ct
, "cannot parse expires");
1234 exp
= nf_ct_expect_alloc(ct
);
1236 nf_ct_helper_log(skb
, ct
, "cannot alloc expectation");
1241 if (sip_direct_signalling
)
1242 saddr
= &ct
->tuplehash
[!dir
].tuple
.src
.u3
;
1244 nf_ct_expect_init(exp
, SIP_EXPECT_SIGNALLING
, nf_ct_l3num(ct
),
1245 saddr
, &daddr
, proto
, NULL
, &port
);
1246 exp
->timeout
.expires
= sip_timeout
* HZ
;
1247 exp
->helper
= nfct_help(ct
)->helper
;
1248 exp
->flags
= NF_CT_EXPECT_PERMANENT
| NF_CT_EXPECT_INACTIVE
;
1250 hooks
= rcu_dereference(nf_nat_sip_hooks
);
1251 if (hooks
&& ct
->status
& IPS_NAT_MASK
)
1252 ret
= hooks
->expect(skb
, protoff
, dataoff
, dptr
, datalen
,
1253 exp
, matchoff
, matchlen
);
1255 if (nf_ct_expect_related(exp
) != 0) {
1256 nf_ct_helper_log(skb
, ct
, "cannot add expectation");
1261 nf_ct_expect_put(exp
);
1264 if (ret
== NF_ACCEPT
)
1265 ct_sip_info
->register_cseq
= cseq
;
1269 static int process_register_response(struct sk_buff
*skb
, unsigned int protoff
,
1270 unsigned int dataoff
,
1271 const char **dptr
, unsigned int *datalen
,
1272 unsigned int cseq
, unsigned int code
)
1274 enum ip_conntrack_info ctinfo
;
1275 struct nf_conn
*ct
= nf_ct_get(skb
, &ctinfo
);
1276 struct nf_ct_sip_master
*ct_sip_info
= nfct_help_data(ct
);
1277 enum ip_conntrack_dir dir
= CTINFO2DIR(ctinfo
);
1278 union nf_inet_addr addr
;
1281 unsigned int matchoff
, matchlen
, coff
= 0;
1282 unsigned int expires
= 0;
1283 int in_contact
= 0, ret
;
1285 /* According to RFC 3261, "UAs MUST NOT send a new registration until
1286 * they have received a final response from the registrar for the
1287 * previous one or the previous REGISTER request has timed out".
1289 * However, some servers fail to detect retransmissions and send late
1290 * responses, so we store the sequence number of the last valid
1291 * request and compare it here.
1293 if (ct_sip_info
->register_cseq
!= cseq
)
1296 if (code
>= 100 && code
<= 199)
1298 if (code
< 200 || code
> 299)
1301 if (ct_sip_get_header(ct
, *dptr
, 0, *datalen
, SIP_HDR_EXPIRES
,
1302 &matchoff
, &matchlen
) > 0)
1303 expires
= simple_strtoul(*dptr
+ matchoff
, NULL
, 10);
1306 unsigned int c_expires
= expires
;
1308 ret
= ct_sip_parse_header_uri(ct
, *dptr
, &coff
, *datalen
,
1309 SIP_HDR_CONTACT
, &in_contact
,
1310 &matchoff
, &matchlen
,
1313 nf_ct_helper_log(skb
, ct
, "cannot parse contact");
1315 } else if (ret
== 0)
1318 /* We don't support third-party registrations */
1319 if (!nf_inet_addr_cmp(&ct
->tuplehash
[dir
].tuple
.dst
.u3
, &addr
))
1322 if (ct_sip_parse_transport(ct
, *dptr
, matchoff
+ matchlen
,
1323 *datalen
, &proto
) == 0)
1326 ret
= ct_sip_parse_numerical_param(ct
, *dptr
,
1327 matchoff
+ matchlen
,
1328 *datalen
, "expires=",
1329 NULL
, NULL
, &c_expires
);
1331 nf_ct_helper_log(skb
, ct
, "cannot parse expires");
1336 if (refresh_signalling_expectation(ct
, &addr
, proto
, port
,
1342 flush_expectations(ct
, false);
1346 static const struct sip_handler sip_handlers
[] = {
1347 SIP_HANDLER("INVITE", process_invite_request
, process_invite_response
),
1348 SIP_HANDLER("UPDATE", process_sdp
, process_update_response
),
1349 SIP_HANDLER("ACK", process_sdp
, NULL
),
1350 SIP_HANDLER("PRACK", process_sdp
, process_prack_response
),
1351 SIP_HANDLER("BYE", process_bye_request
, NULL
),
1352 SIP_HANDLER("REGISTER", process_register_request
, process_register_response
),
1355 static int process_sip_response(struct sk_buff
*skb
, unsigned int protoff
,
1356 unsigned int dataoff
,
1357 const char **dptr
, unsigned int *datalen
)
1359 enum ip_conntrack_info ctinfo
;
1360 struct nf_conn
*ct
= nf_ct_get(skb
, &ctinfo
);
1361 unsigned int matchoff
, matchlen
, matchend
;
1362 unsigned int code
, cseq
, i
;
1364 if (*datalen
< strlen("SIP/2.0 200"))
1366 code
= simple_strtoul(*dptr
+ strlen("SIP/2.0 "), NULL
, 10);
1368 nf_ct_helper_log(skb
, ct
, "cannot get code");
1372 if (ct_sip_get_header(ct
, *dptr
, 0, *datalen
, SIP_HDR_CSEQ
,
1373 &matchoff
, &matchlen
) <= 0) {
1374 nf_ct_helper_log(skb
, ct
, "cannot parse cseq");
1377 cseq
= simple_strtoul(*dptr
+ matchoff
, NULL
, 10);
1378 if (!cseq
&& *(*dptr
+ matchoff
) != '0') {
1379 nf_ct_helper_log(skb
, ct
, "cannot get cseq");
1382 matchend
= matchoff
+ matchlen
+ 1;
1384 for (i
= 0; i
< ARRAY_SIZE(sip_handlers
); i
++) {
1385 const struct sip_handler
*handler
;
1387 handler
= &sip_handlers
[i
];
1388 if (handler
->response
== NULL
)
1390 if (*datalen
< matchend
+ handler
->len
||
1391 strncasecmp(*dptr
+ matchend
, handler
->method
, handler
->len
))
1393 return handler
->response(skb
, protoff
, dataoff
, dptr
, datalen
,
1399 static int process_sip_request(struct sk_buff
*skb
, unsigned int protoff
,
1400 unsigned int dataoff
,
1401 const char **dptr
, unsigned int *datalen
)
1403 enum ip_conntrack_info ctinfo
;
1404 struct nf_conn
*ct
= nf_ct_get(skb
, &ctinfo
);
1405 struct nf_ct_sip_master
*ct_sip_info
= nfct_help_data(ct
);
1406 enum ip_conntrack_dir dir
= CTINFO2DIR(ctinfo
);
1407 unsigned int matchoff
, matchlen
;
1408 unsigned int cseq
, i
;
1409 union nf_inet_addr addr
;
1412 /* Many Cisco IP phones use a high source port for SIP requests, but
1413 * listen for the response on port 5060. If we are the local
1414 * router for one of these phones, save the port number from the
1415 * Via: header so that nf_nat_sip can redirect the responses to
1418 if (ct_sip_parse_header_uri(ct
, *dptr
, NULL
, *datalen
,
1419 SIP_HDR_VIA_UDP
, NULL
, &matchoff
,
1420 &matchlen
, &addr
, &port
) > 0 &&
1421 port
!= ct
->tuplehash
[dir
].tuple
.src
.u
.udp
.port
&&
1422 nf_inet_addr_cmp(&addr
, &ct
->tuplehash
[dir
].tuple
.src
.u3
))
1423 ct_sip_info
->forced_dport
= port
;
1425 for (i
= 0; i
< ARRAY_SIZE(sip_handlers
); i
++) {
1426 const struct sip_handler
*handler
;
1428 handler
= &sip_handlers
[i
];
1429 if (handler
->request
== NULL
)
1431 if (*datalen
< handler
->len
+ 2 ||
1432 strncasecmp(*dptr
, handler
->method
, handler
->len
))
1434 if ((*dptr
)[handler
->len
] != ' ' ||
1435 !isalpha((*dptr
)[handler
->len
+1]))
1438 if (ct_sip_get_header(ct
, *dptr
, 0, *datalen
, SIP_HDR_CSEQ
,
1439 &matchoff
, &matchlen
) <= 0) {
1440 nf_ct_helper_log(skb
, ct
, "cannot parse cseq");
1443 cseq
= simple_strtoul(*dptr
+ matchoff
, NULL
, 10);
1444 if (!cseq
&& *(*dptr
+ matchoff
) != '0') {
1445 nf_ct_helper_log(skb
, ct
, "cannot get cseq");
1449 return handler
->request(skb
, protoff
, dataoff
, dptr
, datalen
,
1455 static int process_sip_msg(struct sk_buff
*skb
, struct nf_conn
*ct
,
1456 unsigned int protoff
, unsigned int dataoff
,
1457 const char **dptr
, unsigned int *datalen
)
1459 const struct nf_nat_sip_hooks
*hooks
;
1462 if (strncasecmp(*dptr
, "SIP/2.0 ", strlen("SIP/2.0 ")) != 0)
1463 ret
= process_sip_request(skb
, protoff
, dataoff
, dptr
, datalen
);
1465 ret
= process_sip_response(skb
, protoff
, dataoff
, dptr
, datalen
);
1467 if (ret
== NF_ACCEPT
&& ct
->status
& IPS_NAT_MASK
) {
1468 hooks
= rcu_dereference(nf_nat_sip_hooks
);
1469 if (hooks
&& !hooks
->msg(skb
, protoff
, dataoff
,
1471 nf_ct_helper_log(skb
, ct
, "cannot NAT SIP message");
1479 static int sip_help_tcp(struct sk_buff
*skb
, unsigned int protoff
,
1480 struct nf_conn
*ct
, enum ip_conntrack_info ctinfo
)
1482 struct tcphdr
*th
, _tcph
;
1483 unsigned int dataoff
, datalen
;
1484 unsigned int matchoff
, matchlen
, clen
;
1485 unsigned int msglen
, origlen
;
1486 const char *dptr
, *end
;
1487 s16 diff
, tdiff
= 0;
1488 int ret
= NF_ACCEPT
;
1491 if (ctinfo
!= IP_CT_ESTABLISHED
&&
1492 ctinfo
!= IP_CT_ESTABLISHED_REPLY
)
1496 th
= skb_header_pointer(skb
, protoff
, sizeof(_tcph
), &_tcph
);
1499 dataoff
= protoff
+ th
->doff
* 4;
1500 if (dataoff
>= skb
->len
)
1503 nf_ct_refresh(ct
, skb
, sip_timeout
* HZ
);
1505 if (unlikely(skb_linearize(skb
)))
1508 dptr
= skb
->data
+ dataoff
;
1509 datalen
= skb
->len
- dataoff
;
1510 if (datalen
< strlen("SIP/2.0 200"))
1514 if (ct_sip_get_header(ct
, dptr
, 0, datalen
,
1515 SIP_HDR_CONTENT_LENGTH
,
1516 &matchoff
, &matchlen
) <= 0)
1519 clen
= simple_strtoul(dptr
+ matchoff
, (char **)&end
, 10);
1520 if (dptr
+ matchoff
== end
)
1524 for (; end
+ strlen("\r\n\r\n") <= dptr
+ datalen
; end
++) {
1525 if (end
[0] == '\r' && end
[1] == '\n' &&
1526 end
[2] == '\r' && end
[3] == '\n') {
1533 end
+= strlen("\r\n\r\n") + clen
;
1535 msglen
= origlen
= end
- dptr
;
1536 if (msglen
> datalen
)
1539 ret
= process_sip_msg(skb
, ct
, protoff
, dataoff
,
1541 /* process_sip_* functions report why this packet is dropped */
1542 if (ret
!= NF_ACCEPT
)
1544 diff
= msglen
- origlen
;
1549 datalen
= datalen
+ diff
- msglen
;
1552 if (ret
== NF_ACCEPT
&& ct
->status
& IPS_NAT_MASK
) {
1553 const struct nf_nat_sip_hooks
*hooks
;
1555 hooks
= rcu_dereference(nf_nat_sip_hooks
);
1557 hooks
->seq_adjust(skb
, protoff
, tdiff
);
1563 static int sip_help_udp(struct sk_buff
*skb
, unsigned int protoff
,
1564 struct nf_conn
*ct
, enum ip_conntrack_info ctinfo
)
1566 unsigned int dataoff
, datalen
;
1570 dataoff
= protoff
+ sizeof(struct udphdr
);
1571 if (dataoff
>= skb
->len
)
1574 nf_ct_refresh(ct
, skb
, sip_timeout
* HZ
);
1576 if (unlikely(skb_linearize(skb
)))
1579 dptr
= skb
->data
+ dataoff
;
1580 datalen
= skb
->len
- dataoff
;
1581 if (datalen
< strlen("SIP/2.0 200"))
1584 return process_sip_msg(skb
, ct
, protoff
, dataoff
, &dptr
, &datalen
);
1587 static struct nf_conntrack_helper sip
[MAX_PORTS
* 4] __read_mostly
;
1589 static const struct nf_conntrack_expect_policy sip_exp_policy
[SIP_EXPECT_MAX
+ 1] = {
1590 [SIP_EXPECT_SIGNALLING
] = {
1591 .name
= "signalling",
1595 [SIP_EXPECT_AUDIO
] = {
1597 .max_expected
= 2 * IP_CT_DIR_MAX
,
1600 [SIP_EXPECT_VIDEO
] = {
1602 .max_expected
= 2 * IP_CT_DIR_MAX
,
1605 [SIP_EXPECT_IMAGE
] = {
1607 .max_expected
= IP_CT_DIR_MAX
,
1612 static void nf_conntrack_sip_fini(void)
1614 nf_conntrack_helpers_unregister(sip
, ports_c
* 4);
1617 static int __init
nf_conntrack_sip_init(void)
1621 NF_CT_HELPER_BUILD_BUG_ON(sizeof(struct nf_ct_sip_master
));
1624 ports
[ports_c
++] = SIP_PORT
;
1626 for (i
= 0; i
< ports_c
; i
++) {
1627 nf_ct_helper_init(&sip
[4 * i
], AF_INET
, IPPROTO_UDP
, "sip",
1628 SIP_PORT
, ports
[i
], i
, sip_exp_policy
,
1629 SIP_EXPECT_MAX
, sip_help_udp
,
1631 nf_ct_helper_init(&sip
[4 * i
+ 1], AF_INET
, IPPROTO_TCP
, "sip",
1632 SIP_PORT
, ports
[i
], i
, sip_exp_policy
,
1633 SIP_EXPECT_MAX
, sip_help_tcp
,
1635 nf_ct_helper_init(&sip
[4 * i
+ 2], AF_INET6
, IPPROTO_UDP
, "sip",
1636 SIP_PORT
, ports
[i
], i
, sip_exp_policy
,
1637 SIP_EXPECT_MAX
, sip_help_udp
,
1639 nf_ct_helper_init(&sip
[4 * i
+ 3], AF_INET6
, IPPROTO_TCP
, "sip",
1640 SIP_PORT
, ports
[i
], i
, sip_exp_policy
,
1641 SIP_EXPECT_MAX
, sip_help_tcp
,
1645 ret
= nf_conntrack_helpers_register(sip
, ports_c
* 4);
1647 pr_err("failed to register helpers\n");
1653 module_init(nf_conntrack_sip_init
);
1654 module_exit(nf_conntrack_sip_fini
);