X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=net%2Fipv4%2Fnetfilter%2Fnf_nat_sip.c;h=4334d5cabc5b17b1eb6ab6a8ec9873ee623c3bc4;hb=584015727a3b88b46602b20077b46cd04f8b4ab3;hp=3ca98971a1e92c3385e7398fffb87168ad900c46;hpb=86533e80e0a20ed1a676f9eeb2dde0fa5ff23276;p=linux-2.6 diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c index 3ca98971a1..4334d5cabc 100644 --- a/net/ipv4/netfilter/nf_nat_sip.c +++ b/net/ipv4/netfilter/nf_nat_sip.c @@ -2,6 +2,8 @@ * * (C) 2005 by Christian Hentschel * based on RR's ip_nat_ftp.c and other modules. + * (C) 2007 United Security Providers + * (C) 2007, 2008 Patrick McHardy * * 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 @@ -26,277 +28,461 @@ MODULE_AUTHOR("Christian Hentschel "); MODULE_DESCRIPTION("SIP NAT helper"); MODULE_ALIAS("ip_nat_sip"); -struct addr_map { - struct { - char src[sizeof("nnn.nnn.nnn.nnn:nnnnn")]; - char dst[sizeof("nnn.nnn.nnn.nnn:nnnnn")]; - unsigned int srclen, srciplen; - unsigned int dstlen, dstiplen; - } addr[IP_CT_DIR_MAX]; -}; -static void addr_map_init(struct nf_conn *ct, struct addr_map *map) +static unsigned int mangle_packet(struct sk_buff *skb, + const char **dptr, unsigned int *datalen, + unsigned int matchoff, unsigned int matchlen, + const char *buffer, unsigned int buflen) { - struct nf_conntrack_tuple *t; - enum ip_conntrack_dir dir; - unsigned int n; - - for (dir = 0; dir < IP_CT_DIR_MAX; dir++) { - t = &ct->tuplehash[dir].tuple; - - n = sprintf(map->addr[dir].src, "%u.%u.%u.%u", - NIPQUAD(t->src.u3.ip)); - map->addr[dir].srciplen = n; - n += sprintf(map->addr[dir].src + n, ":%u", - ntohs(t->src.u.udp.port)); - map->addr[dir].srclen = n; - - n = sprintf(map->addr[dir].dst, "%u.%u.%u.%u", - NIPQUAD(t->dst.u3.ip)); - map->addr[dir].dstiplen = n; - n += sprintf(map->addr[dir].dst + n, ":%u", - ntohs(t->dst.u.udp.port)); - map->addr[dir].dstlen = n; - } + enum ip_conntrack_info ctinfo; + struct nf_conn *ct = nf_ct_get(skb, &ctinfo); + + if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, matchoff, matchlen, + buffer, buflen)) + return 0; + + /* Reload data pointer and adjust datalen value */ + *dptr = skb->data + ip_hdrlen(skb) + sizeof(struct udphdr); + *datalen += buflen - matchlen; + return 1; } -static int map_sip_addr(struct sk_buff *skb, enum ip_conntrack_info ctinfo, - struct nf_conn *ct, const char **dptr, size_t dlen, - enum sip_header_pos pos, struct addr_map *map) +static int map_addr(struct sk_buff *skb, + 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); - unsigned int matchlen, matchoff, addrlen; - char *addr; - - if (ct_sip_get_info(ct, *dptr, dlen, &matchoff, &matchlen, pos) <= 0) + char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")]; + unsigned int buflen; + __be32 newaddr; + __be16 newport; + + if (ct->tuplehash[dir].tuple.src.u3.ip == addr->ip && + ct->tuplehash[dir].tuple.src.u.udp.port == port) { + newaddr = ct->tuplehash[!dir].tuple.dst.u3.ip; + newport = ct->tuplehash[!dir].tuple.dst.u.udp.port; + } else if (ct->tuplehash[dir].tuple.dst.u3.ip == addr->ip && + ct->tuplehash[dir].tuple.dst.u.udp.port == port) { + newaddr = ct->tuplehash[!dir].tuple.src.u3.ip; + newport = ct->tuplehash[!dir].tuple.src.u.udp.port; + } else return 1; - if ((matchlen == map->addr[dir].srciplen || - matchlen == map->addr[dir].srclen) && - memcmp(*dptr + matchoff, map->addr[dir].src, matchlen) == 0) { - addr = map->addr[!dir].dst; - addrlen = map->addr[!dir].dstlen; - } else if ((matchlen == map->addr[dir].dstiplen || - matchlen == map->addr[dir].dstlen) && - memcmp(*dptr + matchoff, map->addr[dir].dst, matchlen) == 0) { - addr = map->addr[!dir].src; - addrlen = map->addr[!dir].srclen; - } else + if (newaddr == addr->ip && newport == port) return 1; - if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, - matchoff, matchlen, addr, addrlen)) - return 0; - *dptr = skb->data + ip_hdrlen(skb) + sizeof(struct udphdr); - return 1; + buflen = sprintf(buffer, "%u.%u.%u.%u:%u", + NIPQUAD(newaddr), ntohs(newport)); + return mangle_packet(skb, dptr, datalen, matchoff, matchlen, + buffer, buflen); } -static unsigned int ip_nat_sip(struct sk_buff *skb, - enum ip_conntrack_info ctinfo, - struct nf_conn *ct, - const char **dptr) +static int map_sip_addr(struct sk_buff *skb, + const char **dptr, unsigned int *datalen, + enum sip_header_types type) { - enum sip_header_pos pos; - struct addr_map map; - int dataoff, datalen; + 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; - dataoff = ip_hdrlen(skb) + sizeof(struct udphdr); - datalen = skb->len - dataoff; - if (datalen < sizeof("SIP/2.0") - 1) - return NF_ACCEPT; + if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen, type, NULL, + &matchoff, &matchlen, &addr, &port) <= 0) + return 1; + return map_addr(skb, dptr, datalen, matchoff, matchlen, &addr, port); +} - addr_map_init(ct, &map); +static unsigned int ip_nat_sip(struct sk_buff *skb, + 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); + unsigned int dataoff, matchoff, matchlen; + union nf_inet_addr addr; + __be16 port; + int request, in_header; /* Basic rules: requests and responses. */ - if (strncmp(*dptr, "SIP/2.0", sizeof("SIP/2.0") - 1) != 0) { - /* 10.2: Constructing the REGISTER Request: - * - * The "userinfo" and "@" components of the SIP URI MUST NOT - * be present. - */ - if (datalen >= sizeof("REGISTER") - 1 && - strncmp(*dptr, "REGISTER", sizeof("REGISTER") - 1) == 0) - pos = POS_REG_REQ_URI; - else - pos = POS_REQ_URI; - - if (!map_sip_addr(skb, ctinfo, ct, dptr, datalen, pos, &map)) + if (strnicmp(*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, dptr, datalen, matchoff, matchlen, + &addr, port)) return NF_DROP; + request = 1; + } else + request = 0; + + /* Translate topmost Via header and parameters */ + if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen, + SIP_HDR_VIA, NULL, &matchoff, &matchlen, + &addr, &port) > 0) { + unsigned int matchend, poff, plen, buflen, n; + char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")]; + + /* We're only interested in headers related to this + * connection */ + if (request) { + if (addr.ip != ct->tuplehash[dir].tuple.src.u3.ip || + port != ct->tuplehash[dir].tuple.src.u.udp.port) + goto next; + } else { + if (addr.ip != ct->tuplehash[dir].tuple.dst.u3.ip || + port != ct->tuplehash[dir].tuple.dst.u.udp.port) + goto next; + } + + if (!map_addr(skb, dptr, datalen, matchoff, matchlen, + &addr, port)) + return NF_DROP; + + matchend = matchoff + matchlen; + + /* 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) > 0 && + addr.ip == ct->tuplehash[dir].tuple.src.u3.ip && + addr.ip != ct->tuplehash[!dir].tuple.dst.u3.ip) { + __be32 ip = ct->tuplehash[!dir].tuple.dst.u3.ip; + buflen = sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(ip)); + if (!mangle_packet(skb, dptr, datalen, poff, plen, + buffer, buflen)) + 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) > 0 && + addr.ip == ct->tuplehash[dir].tuple.dst.u3.ip && + addr.ip != ct->tuplehash[!dir].tuple.src.u3.ip) { + __be32 ip = ct->tuplehash[!dir].tuple.src.u3.ip; + buflen = sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(ip)); + if (!mangle_packet(skb, dptr, datalen, poff, plen, + buffer, buflen)) + 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, dptr, datalen, poff, plen, + buffer, buflen)) + return NF_DROP; + } } - if (!map_sip_addr(skb, ctinfo, ct, dptr, datalen, POS_FROM, &map) || - !map_sip_addr(skb, ctinfo, ct, dptr, datalen, POS_TO, &map) || - !map_sip_addr(skb, ctinfo, ct, dptr, datalen, POS_VIA, &map) || - !map_sip_addr(skb, ctinfo, ct, dptr, datalen, POS_CONTACT, &map)) +next: + /* Translate Contact headers */ + dataoff = 0; + in_header = 0; + while (ct_sip_parse_header_uri(ct, *dptr, &dataoff, *datalen, + SIP_HDR_CONTACT, &in_header, + &matchoff, &matchlen, + &addr, &port) > 0) { + if (!map_addr(skb, dptr, datalen, matchoff, matchlen, + &addr, port)) + return NF_DROP; + } + + if (!map_sip_addr(skb, dptr, datalen, SIP_HDR_FROM) || + !map_sip_addr(skb, dptr, datalen, SIP_HDR_TO)) return NF_DROP; return NF_ACCEPT; } -static unsigned int mangle_sip_packet(struct sk_buff *skb, - enum ip_conntrack_info ctinfo, - struct nf_conn *ct, - const char **dptr, size_t dlen, - char *buffer, int bufflen, - enum sip_header_pos pos) +/* Handles expected signalling connections and media streams */ +static void ip_nat_sip_expected(struct nf_conn *ct, + struct nf_conntrack_expect *exp) { - unsigned int matchlen, matchoff; + struct nf_nat_range range; - if (ct_sip_get_info(ct, *dptr, dlen, &matchoff, &matchlen, pos) <= 0) - return 0; + /* This must be a fresh one. */ + BUG_ON(ct->status & IPS_NAT_DONE_MASK); - if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, - matchoff, matchlen, buffer, bufflen)) - return 0; + /* For DST manip, map port here to where it's expected. */ + range.flags = (IP_NAT_RANGE_MAP_IPS | IP_NAT_RANGE_PROTO_SPECIFIED); + range.min = range.max = exp->saved_proto; + range.min_ip = range.max_ip = exp->saved_ip; + nf_nat_setup_info(ct, &range, IP_NAT_MANIP_DST); + + /* Change src to where master sends to, but only if the connection + * actually came from the same source. */ + if (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip == + ct->master->tuplehash[exp->dir].tuple.src.u3.ip) { + range.flags = IP_NAT_RANGE_MAP_IPS; + range.min_ip = range.max_ip + = ct->master->tuplehash[!exp->dir].tuple.dst.u3.ip; + nf_nat_setup_info(ct, &range, IP_NAT_MANIP_SRC); + } +} - /* We need to reload this. Thanks Patrick. */ - *dptr = skb->data + ip_hdrlen(skb) + sizeof(struct udphdr); - return 1; +static unsigned int ip_nat_sip_expect(struct sk_buff *skb, + 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); + __be32 newip; + u_int16_t port; + char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")]; + unsigned buflen; + + /* Connection will come from reply */ + if (ct->tuplehash[dir].tuple.src.u3.ip == ct->tuplehash[!dir].tuple.dst.u3.ip) + newip = exp->tuple.dst.u3.ip; + else + newip = ct->tuplehash[!dir].tuple.dst.u3.ip; + + /* If the signalling port matches the connection's source port in the + * original direction, try to use the destination port in the opposite + * direction. */ + if (exp->tuple.dst.u.udp.port == + ct->tuplehash[dir].tuple.src.u.udp.port) + port = ntohs(ct->tuplehash[!dir].tuple.dst.u.udp.port); + else + port = ntohs(exp->tuple.dst.u.udp.port); + + exp->saved_ip = exp->tuple.dst.u3.ip; + exp->tuple.dst.u3.ip = newip; + exp->saved_proto.udp.port = exp->tuple.dst.u.udp.port; + exp->dir = !dir; + exp->expectfn = ip_nat_sip_expected; + + for (; port != 0; port++) { + exp->tuple.dst.u.udp.port = htons(port); + if (nf_ct_expect_related(exp) == 0) + break; + } + + if (port == 0) + return NF_DROP; + + if (exp->tuple.dst.u3.ip != exp->saved_ip || + exp->tuple.dst.u.udp.port != exp->saved_proto.udp.port) { + buflen = sprintf(buffer, "%u.%u.%u.%u:%u", + NIPQUAD(newip), port); + if (!mangle_packet(skb, dptr, datalen, matchoff, matchlen, + buffer, buflen)) + goto err; + } + return NF_ACCEPT; + +err: + nf_ct_unexpect_related(exp); + return NF_DROP; } static int mangle_content_len(struct sk_buff *skb, - enum ip_conntrack_info ctinfo, - struct nf_conn *ct, - const char *dptr) + const char **dptr, unsigned int *datalen) { - unsigned int dataoff, matchoff, matchlen; + enum ip_conntrack_info ctinfo; + struct nf_conn *ct = nf_ct_get(skb, &ctinfo); + unsigned int matchoff, matchlen; char buffer[sizeof("65536")]; - int bufflen; + int buflen, c_len; - dataoff = ip_hdrlen(skb) + sizeof(struct udphdr); + /* 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="); - /* Get actual SDP lenght */ - if (ct_sip_get_info(ct, dptr, skb->len - dataoff, &matchoff, - &matchlen, POS_SDP_HEADER) > 0) { + /* Now, update SDP length */ + if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CONTENT_LENGTH, + &matchoff, &matchlen) <= 0) + return 0; - /* since ct_sip_get_info() give us a pointer passing 'v=' - we need to add 2 bytes in this count. */ - int c_len = skb->len - dataoff - matchoff + 2; + buflen = sprintf(buffer, "%u", c_len); + return mangle_packet(skb, dptr, datalen, matchoff, matchlen, + buffer, buflen); +} - /* Now, update SDP length */ - if (ct_sip_get_info(ct, dptr, skb->len - dataoff, &matchoff, - &matchlen, POS_CONTENT) > 0) { +static unsigned mangle_sdp_packet(struct sk_buff *skb, const char **dptr, + unsigned int dataoff, unsigned int *datalen, + 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; - bufflen = sprintf(buffer, "%u", c_len); - return nf_nat_mangle_udp_packet(skb, ct, ctinfo, - matchoff, matchlen, - buffer, bufflen); - } - } - return 0; + if (ct_sip_get_sdp_header(ct, *dptr, dataoff, *datalen, type, term, + &matchoff, &matchlen) <= 0) + return 0; + return mangle_packet(skb, dptr, datalen, matchoff, matchlen, + buffer, buflen); } -static unsigned int mangle_sdp(struct sk_buff *skb, - enum ip_conntrack_info ctinfo, - struct nf_conn *ct, - __be32 newip, u_int16_t port, - const char *dptr) +static unsigned int ip_nat_sdp_addr(struct sk_buff *skb, const char **dptr, + unsigned int dataoff, + unsigned int *datalen, + enum sdp_header_types type, + enum sdp_header_types term, + const union nf_inet_addr *addr) { char buffer[sizeof("nnn.nnn.nnn.nnn")]; - unsigned int dataoff, bufflen; + unsigned int buflen; - dataoff = ip_hdrlen(skb) + sizeof(struct udphdr); - - /* Mangle owner and contact info. */ - bufflen = sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(newip)); - if (!mangle_sip_packet(skb, ctinfo, ct, &dptr, skb->len - dataoff, - buffer, bufflen, POS_OWNER_IP4)) + buflen = sprintf(buffer, NIPQUAD_FMT, NIPQUAD(addr->ip)); + if (!mangle_sdp_packet(skb, dptr, dataoff, datalen, type, term, + buffer, buflen)) return 0; - if (!mangle_sip_packet(skb, ctinfo, ct, &dptr, skb->len - dataoff, - buffer, bufflen, POS_CONNECTION_IP4)) - return 0; + return mangle_content_len(skb, dptr, datalen); +} - /* Mangle media port. */ - bufflen = sprintf(buffer, "%u", port); - if (!mangle_sip_packet(skb, ctinfo, ct, &dptr, skb->len - dataoff, - buffer, bufflen, POS_MEDIA)) +static unsigned int ip_nat_sdp_port(struct sk_buff *skb, + 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, dptr, datalen, matchoff, matchlen, + buffer, buflen)) return 0; - return mangle_content_len(skb, ctinfo, ct, dptr); + return mangle_content_len(skb, dptr, datalen); } -static void ip_nat_sdp_expect(struct nf_conn *ct, - struct nf_conntrack_expect *exp) +static unsigned int ip_nat_sdp_session(struct sk_buff *skb, const char **dptr, + unsigned int dataoff, + unsigned int *datalen, + const union nf_inet_addr *addr) { - struct nf_nat_range range; + char buffer[sizeof("nnn.nnn.nnn.nnn")]; + unsigned int buflen; - /* This must be a fresh one. */ - BUG_ON(ct->status & IPS_NAT_DONE_MASK); + /* Mangle session description owner and contact addresses */ + buflen = sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(addr->ip)); + if (!mangle_sdp_packet(skb, dptr, dataoff, datalen, + SDP_HDR_OWNER_IP4, SDP_HDR_MEDIA, + buffer, buflen)) + return 0; - /* Change src to where master sends to */ - range.flags = IP_NAT_RANGE_MAP_IPS; - range.min_ip = range.max_ip - = ct->master->tuplehash[!exp->dir].tuple.dst.u3.ip; - /* hook doesn't matter, but it has to do source manip */ - nf_nat_setup_info(ct, &range, NF_IP_POST_ROUTING); + if (!mangle_sdp_packet(skb, dptr, dataoff, datalen, + SDP_HDR_CONNECTION_IP4, SDP_HDR_MEDIA, + buffer, buflen)) + return 0; - /* For DST manip, map port here to where it's expected. */ - range.flags = (IP_NAT_RANGE_MAP_IPS | IP_NAT_RANGE_PROTO_SPECIFIED); - range.min = range.max = exp->saved_proto; - range.min_ip = range.max_ip = exp->saved_ip; - /* hook doesn't matter, but it has to do destination manip */ - nf_nat_setup_info(ct, &range, NF_IP_PRE_ROUTING); + return mangle_content_len(skb, 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 ip_nat_sdp(struct sk_buff *skb, - enum ip_conntrack_info ctinfo, - struct nf_conntrack_expect *exp, - const char *dptr) +static unsigned int ip_nat_sdp_media(struct sk_buff *skb, + 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) { - struct nf_conn *ct = exp->master; + enum ip_conntrack_info ctinfo; + struct nf_conn *ct = nf_ct_get(skb, &ctinfo); enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); - __be32 newip; u_int16_t port; /* Connection will come from reply */ if (ct->tuplehash[dir].tuple.src.u3.ip == ct->tuplehash[!dir].tuple.dst.u3.ip) - newip = exp->tuple.dst.u3.ip; + rtp_addr->ip = rtp_exp->tuple.dst.u3.ip; else - newip = ct->tuplehash[!dir].tuple.dst.u3.ip; - - exp->saved_ip = exp->tuple.dst.u3.ip; - exp->tuple.dst.u3.ip = newip; - exp->saved_proto.udp.port = exp->tuple.dst.u.udp.port; - exp->dir = !dir; - - /* When you see the packet, we need to NAT it the same as the - this one. */ - exp->expectfn = ip_nat_sdp_expect; - - /* Try to get same port: if not, try to change it. */ - for (port = ntohs(exp->saved_proto.udp.port); port != 0; port++) { - exp->tuple.dst.u.udp.port = htons(port); - if (nf_ct_expect_related(exp) == 0) + rtp_addr->ip = ct->tuplehash[!dir].tuple.dst.u3.ip; + + rtp_exp->saved_ip = rtp_exp->tuple.dst.u3.ip; + rtp_exp->tuple.dst.u3.ip = rtp_addr->ip; + rtp_exp->saved_proto.udp.port = rtp_exp->tuple.dst.u.udp.port; + rtp_exp->dir = !dir; + rtp_exp->expectfn = ip_nat_sip_expected; + + rtcp_exp->saved_ip = rtcp_exp->tuple.dst.u3.ip; + rtcp_exp->tuple.dst.u3.ip = rtp_addr->ip; + rtcp_exp->saved_proto.udp.port = rtcp_exp->tuple.dst.u.udp.port; + rtcp_exp->dir = !dir; + rtcp_exp->expectfn = ip_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) { + rtp_exp->tuple.dst.u.udp.port = htons(port); + if (nf_ct_expect_related(rtp_exp) != 0) + continue; + rtcp_exp->tuple.dst.u.udp.port = htons(port + 1); + if (nf_ct_expect_related(rtcp_exp) == 0) break; + nf_ct_unexpect_related(rtp_exp); } if (port == 0) - return NF_DROP; + goto err1; + + /* Update media port. */ + if (rtp_exp->tuple.dst.u.udp.port != rtp_exp->saved_proto.udp.port && + !ip_nat_sdp_port(skb, dptr, datalen, mediaoff, medialen, port)) + goto err2; - if (!mangle_sdp(skb, ctinfo, ct, newip, port, dptr)) { - nf_ct_unexpect_related(exp); - return NF_DROP; - } return NF_ACCEPT; + +err2: + nf_ct_unexpect_related(rtp_exp); + nf_ct_unexpect_related(rtcp_exp); +err1: + return NF_DROP; } static void __exit nf_nat_sip_fini(void) { rcu_assign_pointer(nf_nat_sip_hook, NULL); - rcu_assign_pointer(nf_nat_sdp_hook, NULL); + rcu_assign_pointer(nf_nat_sip_expect_hook, NULL); + rcu_assign_pointer(nf_nat_sdp_addr_hook, NULL); + rcu_assign_pointer(nf_nat_sdp_port_hook, NULL); + rcu_assign_pointer(nf_nat_sdp_session_hook, NULL); + rcu_assign_pointer(nf_nat_sdp_media_hook, NULL); synchronize_rcu(); } static int __init nf_nat_sip_init(void) { BUG_ON(nf_nat_sip_hook != NULL); - BUG_ON(nf_nat_sdp_hook != NULL); + BUG_ON(nf_nat_sip_expect_hook != NULL); + BUG_ON(nf_nat_sdp_addr_hook != NULL); + BUG_ON(nf_nat_sdp_port_hook != NULL); + BUG_ON(nf_nat_sdp_session_hook != NULL); + BUG_ON(nf_nat_sdp_media_hook != NULL); rcu_assign_pointer(nf_nat_sip_hook, ip_nat_sip); - rcu_assign_pointer(nf_nat_sdp_hook, ip_nat_sdp); + rcu_assign_pointer(nf_nat_sip_expect_hook, ip_nat_sip_expect); + rcu_assign_pointer(nf_nat_sdp_addr_hook, ip_nat_sdp_addr); + rcu_assign_pointer(nf_nat_sdp_port_hook, ip_nat_sdp_port); + rcu_assign_pointer(nf_nat_sdp_session_hook, ip_nat_sdp_session); + rcu_assign_pointer(nf_nat_sdp_media_hook, ip_nat_sdp_media); return 0; }