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- /* SIP extension for NAT alteration.
- *
- * (C) 2005 by Christian Hentschel <chentschel@arnet.com.ar>
- * based on RR's ip_nat_ftp.c and other modules.
- * (C) 2007 United Security Providers
- * (C) 2007, 2008, 2011, 2012 Patrick McHardy <kaber@trash.net>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
- #include <linux/module.h>
- #include <linux/skbuff.h>
- #include <linux/inet.h>
- #include <linux/udp.h>
- #include <linux/tcp.h>
- #include <net/netfilter/nf_nat.h>
- #include <net/netfilter/nf_nat_helper.h>
- #include <net/netfilter/nf_conntrack_helper.h>
- #include <net/netfilter/nf_conntrack_expect.h>
- #include <net/netfilter/nf_conntrack_seqadj.h>
- #include <linux/netfilter/nf_conntrack_sip.h>
- MODULE_LICENSE("GPL");
- MODULE_AUTHOR("Christian Hentschel <chentschel@arnet.com.ar>");
- MODULE_DESCRIPTION("SIP NAT helper");
- MODULE_ALIAS("ip_nat_sip");
- static unsigned int mangle_packet(struct sk_buff *skb, unsigned int protoff,
- unsigned int dataoff,
- const char **dptr, unsigned int *datalen,
- unsigned int matchoff, unsigned int matchlen,
- const char *buffer, unsigned int buflen)
- {
- enum ip_conntrack_info ctinfo;
- struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
- struct tcphdr *th;
- unsigned int baseoff;
- if (nf_ct_protonum(ct) == IPPROTO_TCP) {
- th = (struct tcphdr *)(skb->data + protoff);
- baseoff = protoff + th->doff * 4;
- matchoff += dataoff - baseoff;
- if (!__nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
- protoff, matchoff, matchlen,
- buffer, buflen, false))
- return 0;
- } else {
- baseoff = protoff + sizeof(struct udphdr);
- matchoff += dataoff - baseoff;
- if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo,
- protoff, matchoff, matchlen,
- buffer, buflen))
- return 0;
- }
- /* Reload data pointer and adjust datalen value */
- *dptr = skb->data + dataoff;
- *datalen += buflen - matchlen;
- return 1;
- }
- static int sip_sprintf_addr(const struct nf_conn *ct, char *buffer,
- const union nf_inet_addr *addr, bool delim)
- {
- if (nf_ct_l3num(ct) == NFPROTO_IPV4)
- return sprintf(buffer, "%pI4", &addr->ip);
- else {
- if (delim)
- return sprintf(buffer, "[%pI6c]", &addr->ip6);
- else
- return sprintf(buffer, "%pI6c", &addr->ip6);
- }
- }
- static int sip_sprintf_addr_port(const struct nf_conn *ct, char *buffer,
- const union nf_inet_addr *addr, u16 port)
- {
- if (nf_ct_l3num(ct) == NFPROTO_IPV4)
- return sprintf(buffer, "%pI4:%u", &addr->ip, port);
- else
- return sprintf(buffer, "[%pI6c]:%u", &addr->ip6, port);
- }
- static int map_addr(struct sk_buff *skb, unsigned int protoff,
- unsigned int dataoff,
- const char **dptr, unsigned int *datalen,
- unsigned int matchoff, unsigned int matchlen,
- union nf_inet_addr *addr, __be16 port)
- {
- enum ip_conntrack_info ctinfo;
- struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
- enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
- struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
- char buffer[INET6_ADDRSTRLEN + sizeof("[]:nnnnn")];
- unsigned int buflen;
- union nf_inet_addr newaddr;
- __be16 newport;
- if (nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.src.u3, addr) &&
- ct->tuplehash[dir].tuple.src.u.udp.port == port) {
- newaddr = ct->tuplehash[!dir].tuple.dst.u3;
- newport = ct->tuplehash[!dir].tuple.dst.u.udp.port;
- } else if (nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3, addr) &&
- ct->tuplehash[dir].tuple.dst.u.udp.port == port) {
- newaddr = ct->tuplehash[!dir].tuple.src.u3;
- newport = ct_sip_info->forced_dport ? :
- ct->tuplehash[!dir].tuple.src.u.udp.port;
- } else
- return 1;
- if (nf_inet_addr_cmp(&newaddr, addr) && newport == port)
- return 1;
- buflen = sip_sprintf_addr_port(ct, buffer, &newaddr, ntohs(newport));
- return mangle_packet(skb, protoff, dataoff, dptr, datalen,
- matchoff, matchlen, buffer, buflen);
- }
- static int map_sip_addr(struct sk_buff *skb, unsigned int protoff,
- unsigned int dataoff,
- const char **dptr, unsigned int *datalen,
- enum sip_header_types type)
- {
- enum ip_conntrack_info ctinfo;
- struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
- unsigned int matchlen, matchoff;
- union nf_inet_addr addr;
- __be16 port;
- if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen, type, NULL,
- &matchoff, &matchlen, &addr, &port) <= 0)
- return 1;
- return map_addr(skb, protoff, dataoff, dptr, datalen,
- matchoff, matchlen, &addr, port);
- }
- static unsigned int nf_nat_sip(struct sk_buff *skb, unsigned int protoff,
- unsigned int dataoff,
- const char **dptr, unsigned int *datalen)
- {
- enum ip_conntrack_info ctinfo;
- struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
- enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
- struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
- unsigned int coff, matchoff, matchlen;
- enum sip_header_types hdr;
- union nf_inet_addr addr;
- __be16 port;
- int request, in_header;
- /* Basic rules: requests and responses. */
- if (strncasecmp(*dptr, "SIP/2.0", strlen("SIP/2.0")) != 0) {
- if (ct_sip_parse_request(ct, *dptr, *datalen,
- &matchoff, &matchlen,
- &addr, &port) > 0 &&
- !map_addr(skb, protoff, dataoff, dptr, datalen,
- matchoff, matchlen, &addr, port)) {
- nf_ct_helper_log(skb, ct, "cannot mangle SIP message");
- return NF_DROP;
- }
- request = 1;
- } else
- request = 0;
- if (nf_ct_protonum(ct) == IPPROTO_TCP)
- hdr = SIP_HDR_VIA_TCP;
- else
- hdr = SIP_HDR_VIA_UDP;
- /* Translate topmost Via header and parameters */
- if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen,
- hdr, NULL, &matchoff, &matchlen,
- &addr, &port) > 0) {
- unsigned int olen, matchend, poff, plen, buflen, n;
- char buffer[INET6_ADDRSTRLEN + sizeof("[]:nnnnn")];
- /* We're only interested in headers related to this
- * connection */
- if (request) {
- if (!nf_inet_addr_cmp(&addr,
- &ct->tuplehash[dir].tuple.src.u3) ||
- port != ct->tuplehash[dir].tuple.src.u.udp.port)
- goto next;
- } else {
- if (!nf_inet_addr_cmp(&addr,
- &ct->tuplehash[dir].tuple.dst.u3) ||
- port != ct->tuplehash[dir].tuple.dst.u.udp.port)
- goto next;
- }
- olen = *datalen;
- if (!map_addr(skb, protoff, dataoff, dptr, datalen,
- matchoff, matchlen, &addr, port)) {
- nf_ct_helper_log(skb, ct, "cannot mangle Via header");
- return NF_DROP;
- }
- matchend = matchoff + matchlen + *datalen - olen;
- /* The maddr= parameter (RFC 2361) specifies where to send
- * the reply. */
- if (ct_sip_parse_address_param(ct, *dptr, matchend, *datalen,
- "maddr=", &poff, &plen,
- &addr, true) > 0 &&
- nf_inet_addr_cmp(&addr, &ct->tuplehash[dir].tuple.src.u3) &&
- !nf_inet_addr_cmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3)) {
- buflen = sip_sprintf_addr(ct, buffer,
- &ct->tuplehash[!dir].tuple.dst.u3,
- true);
- if (!mangle_packet(skb, protoff, dataoff, dptr, datalen,
- poff, plen, buffer, buflen)) {
- nf_ct_helper_log(skb, ct, "cannot mangle maddr");
- return NF_DROP;
- }
- }
- /* The received= parameter (RFC 2361) contains the address
- * from which the server received the request. */
- if (ct_sip_parse_address_param(ct, *dptr, matchend, *datalen,
- "received=", &poff, &plen,
- &addr, false) > 0 &&
- nf_inet_addr_cmp(&addr, &ct->tuplehash[dir].tuple.dst.u3) &&
- !nf_inet_addr_cmp(&addr, &ct->tuplehash[!dir].tuple.src.u3)) {
- buflen = sip_sprintf_addr(ct, buffer,
- &ct->tuplehash[!dir].tuple.src.u3,
- false);
- if (!mangle_packet(skb, protoff, dataoff, dptr, datalen,
- poff, plen, buffer, buflen)) {
- nf_ct_helper_log(skb, ct, "cannot mangle received");
- return NF_DROP;
- }
- }
- /* The rport= parameter (RFC 3581) contains the port number
- * from which the server received the request. */
- if (ct_sip_parse_numerical_param(ct, *dptr, matchend, *datalen,
- "rport=", &poff, &plen,
- &n) > 0 &&
- htons(n) == ct->tuplehash[dir].tuple.dst.u.udp.port &&
- htons(n) != ct->tuplehash[!dir].tuple.src.u.udp.port) {
- __be16 p = ct->tuplehash[!dir].tuple.src.u.udp.port;
- buflen = sprintf(buffer, "%u", ntohs(p));
- if (!mangle_packet(skb, protoff, dataoff, dptr, datalen,
- poff, plen, buffer, buflen)) {
- nf_ct_helper_log(skb, ct, "cannot mangle rport");
- return NF_DROP;
- }
- }
- }
- next:
- /* Translate Contact headers */
- coff = 0;
- in_header = 0;
- while (ct_sip_parse_header_uri(ct, *dptr, &coff, *datalen,
- SIP_HDR_CONTACT, &in_header,
- &matchoff, &matchlen,
- &addr, &port) > 0) {
- if (!map_addr(skb, protoff, dataoff, dptr, datalen,
- matchoff, matchlen,
- &addr, port)) {
- nf_ct_helper_log(skb, ct, "cannot mangle contact");
- return NF_DROP;
- }
- }
- if (!map_sip_addr(skb, protoff, dataoff, dptr, datalen, SIP_HDR_FROM) ||
- !map_sip_addr(skb, protoff, dataoff, dptr, datalen, SIP_HDR_TO)) {
- nf_ct_helper_log(skb, ct, "cannot mangle SIP from/to");
- return NF_DROP;
- }
- /* Mangle destination port for Cisco phones, then fix up checksums */
- if (dir == IP_CT_DIR_REPLY && ct_sip_info->forced_dport) {
- struct udphdr *uh;
- if (!skb_make_writable(skb, skb->len)) {
- nf_ct_helper_log(skb, ct, "cannot mangle packet");
- return NF_DROP;
- }
- uh = (void *)skb->data + protoff;
- uh->dest = ct_sip_info->forced_dport;
- if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, protoff,
- 0, 0, NULL, 0)) {
- nf_ct_helper_log(skb, ct, "cannot mangle packet");
- return NF_DROP;
- }
- }
- return NF_ACCEPT;
- }
- static void nf_nat_sip_seq_adjust(struct sk_buff *skb, unsigned int protoff,
- s16 off)
- {
- enum ip_conntrack_info ctinfo;
- struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
- const struct tcphdr *th;
- if (nf_ct_protonum(ct) != IPPROTO_TCP || off == 0)
- return;
- th = (struct tcphdr *)(skb->data + protoff);
- nf_ct_seqadj_set(ct, ctinfo, th->seq, off);
- }
- /* Handles expected signalling connections and media streams */
- static void nf_nat_sip_expected(struct nf_conn *ct,
- struct nf_conntrack_expect *exp)
- {
- struct nf_nat_range range;
- /* This must be a fresh one. */
- BUG_ON(ct->status & IPS_NAT_DONE_MASK);
- /* For DST manip, map port here to where it's expected. */
- range.flags = (NF_NAT_RANGE_MAP_IPS | NF_NAT_RANGE_PROTO_SPECIFIED);
- range.min_proto = range.max_proto = exp->saved_proto;
- range.min_addr = range.max_addr = exp->saved_addr;
- nf_nat_setup_info(ct, &range, NF_NAT_MANIP_DST);
- /* Change src to where master sends to, but only if the connection
- * actually came from the same source. */
- if (nf_inet_addr_cmp(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3,
- &ct->master->tuplehash[exp->dir].tuple.src.u3)) {
- range.flags = NF_NAT_RANGE_MAP_IPS;
- range.min_addr = range.max_addr
- = ct->master->tuplehash[!exp->dir].tuple.dst.u3;
- nf_nat_setup_info(ct, &range, NF_NAT_MANIP_SRC);
- }
- }
- static unsigned int nf_nat_sip_expect(struct sk_buff *skb, unsigned int protoff,
- unsigned int dataoff,
- const char **dptr, unsigned int *datalen,
- struct nf_conntrack_expect *exp,
- unsigned int matchoff,
- unsigned int matchlen)
- {
- enum ip_conntrack_info ctinfo;
- struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
- enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
- struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
- union nf_inet_addr newaddr;
- u_int16_t port;
- __be16 srcport;
- char buffer[INET6_ADDRSTRLEN + sizeof("[]:nnnnn")];
- unsigned int buflen;
- /* Connection will come from reply */
- if (nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.src.u3,
- &ct->tuplehash[!dir].tuple.dst.u3))
- newaddr = exp->tuple.dst.u3;
- else
- newaddr = ct->tuplehash[!dir].tuple.dst.u3;
- /* If the signalling port matches the connection's source port in the
- * original direction, try to use the destination port in the opposite
- * direction. */
- srcport = ct_sip_info->forced_dport ? :
- ct->tuplehash[dir].tuple.src.u.udp.port;
- if (exp->tuple.dst.u.udp.port == srcport)
- port = ntohs(ct->tuplehash[!dir].tuple.dst.u.udp.port);
- else
- port = ntohs(exp->tuple.dst.u.udp.port);
- exp->saved_addr = exp->tuple.dst.u3;
- exp->tuple.dst.u3 = newaddr;
- exp->saved_proto.udp.port = exp->tuple.dst.u.udp.port;
- exp->dir = !dir;
- exp->expectfn = nf_nat_sip_expected;
- for (; port != 0; port++) {
- int ret;
- exp->tuple.dst.u.udp.port = htons(port);
- ret = nf_ct_expect_related(exp);
- if (ret == 0)
- break;
- else if (ret != -EBUSY) {
- port = 0;
- break;
- }
- }
- if (port == 0) {
- nf_ct_helper_log(skb, ct, "all ports in use for SIP");
- return NF_DROP;
- }
- if (!nf_inet_addr_cmp(&exp->tuple.dst.u3, &exp->saved_addr) ||
- exp->tuple.dst.u.udp.port != exp->saved_proto.udp.port) {
- buflen = sip_sprintf_addr_port(ct, buffer, &newaddr, port);
- if (!mangle_packet(skb, protoff, dataoff, dptr, datalen,
- matchoff, matchlen, buffer, buflen)) {
- nf_ct_helper_log(skb, ct, "cannot mangle packet");
- goto err;
- }
- }
- return NF_ACCEPT;
- err:
- nf_ct_unexpect_related(exp);
- return NF_DROP;
- }
- static int mangle_content_len(struct sk_buff *skb, unsigned int protoff,
- unsigned int dataoff,
- const char **dptr, unsigned int *datalen)
- {
- enum ip_conntrack_info ctinfo;
- struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
- unsigned int matchoff, matchlen;
- char buffer[sizeof("65536")];
- int buflen, c_len;
- /* Get actual SDP length */
- if (ct_sip_get_sdp_header(ct, *dptr, 0, *datalen,
- SDP_HDR_VERSION, SDP_HDR_UNSPEC,
- &matchoff, &matchlen) <= 0)
- return 0;
- c_len = *datalen - matchoff + strlen("v=");
- /* Now, update SDP length */
- if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CONTENT_LENGTH,
- &matchoff, &matchlen) <= 0)
- return 0;
- buflen = sprintf(buffer, "%u", c_len);
- return mangle_packet(skb, protoff, dataoff, dptr, datalen,
- matchoff, matchlen, buffer, buflen);
- }
- static int mangle_sdp_packet(struct sk_buff *skb, unsigned int protoff,
- unsigned int dataoff,
- const char **dptr, unsigned int *datalen,
- unsigned int sdpoff,
- enum sdp_header_types type,
- enum sdp_header_types term,
- char *buffer, int buflen)
- {
- enum ip_conntrack_info ctinfo;
- struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
- unsigned int matchlen, matchoff;
- if (ct_sip_get_sdp_header(ct, *dptr, sdpoff, *datalen, type, term,
- &matchoff, &matchlen) <= 0)
- return -ENOENT;
- return mangle_packet(skb, protoff, dataoff, dptr, datalen,
- matchoff, matchlen, buffer, buflen) ? 0 : -EINVAL;
- }
- static unsigned int nf_nat_sdp_addr(struct sk_buff *skb, unsigned int protoff,
- unsigned int dataoff,
- const char **dptr, unsigned int *datalen,
- unsigned int sdpoff,
- enum sdp_header_types type,
- enum sdp_header_types term,
- const union nf_inet_addr *addr)
- {
- enum ip_conntrack_info ctinfo;
- struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
- char buffer[INET6_ADDRSTRLEN];
- unsigned int buflen;
- buflen = sip_sprintf_addr(ct, buffer, addr, false);
- if (mangle_sdp_packet(skb, protoff, dataoff, dptr, datalen,
- sdpoff, type, term, buffer, buflen))
- return 0;
- return mangle_content_len(skb, protoff, dataoff, dptr, datalen);
- }
- static unsigned int nf_nat_sdp_port(struct sk_buff *skb, unsigned int protoff,
- unsigned int dataoff,
- const char **dptr, unsigned int *datalen,
- unsigned int matchoff,
- unsigned int matchlen,
- u_int16_t port)
- {
- char buffer[sizeof("nnnnn")];
- unsigned int buflen;
- buflen = sprintf(buffer, "%u", port);
- if (!mangle_packet(skb, protoff, dataoff, dptr, datalen,
- matchoff, matchlen, buffer, buflen))
- return 0;
- return mangle_content_len(skb, protoff, dataoff, dptr, datalen);
- }
- static unsigned int nf_nat_sdp_session(struct sk_buff *skb, unsigned int protoff,
- unsigned int dataoff,
- const char **dptr, unsigned int *datalen,
- unsigned int sdpoff,
- const union nf_inet_addr *addr)
- {
- enum ip_conntrack_info ctinfo;
- struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
- char buffer[INET6_ADDRSTRLEN];
- unsigned int buflen;
- /* Mangle session description owner and contact addresses */
- buflen = sip_sprintf_addr(ct, buffer, addr, false);
- if (mangle_sdp_packet(skb, protoff, dataoff, dptr, datalen, sdpoff,
- SDP_HDR_OWNER, SDP_HDR_MEDIA, buffer, buflen))
- return 0;
- switch (mangle_sdp_packet(skb, protoff, dataoff, dptr, datalen, sdpoff,
- SDP_HDR_CONNECTION, SDP_HDR_MEDIA,
- buffer, buflen)) {
- case 0:
- /*
- * RFC 2327:
- *
- * Session description
- *
- * c=* (connection information - not required if included in all media)
- */
- case -ENOENT:
- break;
- default:
- return 0;
- }
- return mangle_content_len(skb, protoff, dataoff, dptr, datalen);
- }
- /* So, this packet has hit the connection tracking matching code.
- Mangle it, and change the expectation to match the new version. */
- static unsigned int nf_nat_sdp_media(struct sk_buff *skb, unsigned int protoff,
- unsigned int dataoff,
- const char **dptr, unsigned int *datalen,
- struct nf_conntrack_expect *rtp_exp,
- struct nf_conntrack_expect *rtcp_exp,
- unsigned int mediaoff,
- unsigned int medialen,
- union nf_inet_addr *rtp_addr)
- {
- enum ip_conntrack_info ctinfo;
- struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
- enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
- u_int16_t port;
- /* Connection will come from reply */
- if (nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.src.u3,
- &ct->tuplehash[!dir].tuple.dst.u3))
- *rtp_addr = rtp_exp->tuple.dst.u3;
- else
- *rtp_addr = ct->tuplehash[!dir].tuple.dst.u3;
- rtp_exp->saved_addr = rtp_exp->tuple.dst.u3;
- rtp_exp->tuple.dst.u3 = *rtp_addr;
- rtp_exp->saved_proto.udp.port = rtp_exp->tuple.dst.u.udp.port;
- rtp_exp->dir = !dir;
- rtp_exp->expectfn = nf_nat_sip_expected;
- rtcp_exp->saved_addr = rtcp_exp->tuple.dst.u3;
- rtcp_exp->tuple.dst.u3 = *rtp_addr;
- rtcp_exp->saved_proto.udp.port = rtcp_exp->tuple.dst.u.udp.port;
- rtcp_exp->dir = !dir;
- rtcp_exp->expectfn = nf_nat_sip_expected;
- /* Try to get same pair of ports: if not, try to change them. */
- for (port = ntohs(rtp_exp->tuple.dst.u.udp.port);
- port != 0; port += 2) {
- int ret;
- rtp_exp->tuple.dst.u.udp.port = htons(port);
- ret = nf_ct_expect_related(rtp_exp);
- if (ret == -EBUSY)
- continue;
- else if (ret < 0) {
- port = 0;
- break;
- }
- rtcp_exp->tuple.dst.u.udp.port = htons(port + 1);
- ret = nf_ct_expect_related(rtcp_exp);
- if (ret == 0)
- break;
- else if (ret == -EBUSY) {
- nf_ct_unexpect_related(rtp_exp);
- continue;
- } else if (ret < 0) {
- nf_ct_unexpect_related(rtp_exp);
- port = 0;
- break;
- }
- }
- if (port == 0) {
- nf_ct_helper_log(skb, ct, "all ports in use for SDP media");
- goto err1;
- }
- /* Update media port. */
- if (rtp_exp->tuple.dst.u.udp.port != rtp_exp->saved_proto.udp.port &&
- !nf_nat_sdp_port(skb, protoff, dataoff, dptr, datalen,
- mediaoff, medialen, port)) {
- nf_ct_helper_log(skb, ct, "cannot mangle SDP message");
- goto err2;
- }
- return NF_ACCEPT;
- err2:
- nf_ct_unexpect_related(rtp_exp);
- nf_ct_unexpect_related(rtcp_exp);
- err1:
- return NF_DROP;
- }
- static struct nf_ct_helper_expectfn sip_nat = {
- .name = "sip",
- .expectfn = nf_nat_sip_expected,
- };
- static void __exit nf_nat_sip_fini(void)
- {
- RCU_INIT_POINTER(nf_nat_sip_hooks, NULL);
- nf_ct_helper_expectfn_unregister(&sip_nat);
- synchronize_rcu();
- }
- static const struct nf_nat_sip_hooks sip_hooks = {
- .msg = nf_nat_sip,
- .seq_adjust = nf_nat_sip_seq_adjust,
- .expect = nf_nat_sip_expect,
- .sdp_addr = nf_nat_sdp_addr,
- .sdp_port = nf_nat_sdp_port,
- .sdp_session = nf_nat_sdp_session,
- .sdp_media = nf_nat_sdp_media,
- };
- static int __init nf_nat_sip_init(void)
- {
- BUG_ON(nf_nat_sip_hooks != NULL);
- RCU_INIT_POINTER(nf_nat_sip_hooks, &sip_hooks);
- nf_ct_helper_expectfn_register(&sip_nat);
- return 0;
- }
- module_init(nf_nat_sip_init);
- module_exit(nf_nat_sip_fini);
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