From 9a664821068739dbc8eac13770e28167b46a0c0f Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Sun, 26 Aug 2012 19:14:25 +0200 Subject: netfilter: nf_nat: support IPv6 in SIP NAT helper Add IPv6 support to the SIP NAT helper. There are no functional differences to IPv4 NAT, just different formats for addresses. Signed-off-by: Patrick McHardy --- net/ipv4/netfilter/Kconfig | 5 - net/ipv4/netfilter/Makefile | 1 - net/ipv4/netfilter/nf_nat_sip.c | 580 ---------------------------------------- 3 files changed, 586 deletions(-) delete mode 100644 net/ipv4/netfilter/nf_nat_sip.c (limited to 'net/ipv4/netfilter') diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig index 52c4a87..30197f8 100644 --- a/net/ipv4/netfilter/Kconfig +++ b/net/ipv4/netfilter/Kconfig @@ -242,11 +242,6 @@ config NF_NAT_H323 depends on NF_CONNTRACK && NF_NAT_IPV4 default NF_NAT_IPV4 && NF_CONNTRACK_H323 -config NF_NAT_SIP - tristate - depends on NF_CONNTRACK && NF_NAT_IPV4 - default NF_NAT_IPV4 && NF_CONNTRACK_SIP - # mangle + specific targets config IP_NF_MANGLE tristate "Packet mangling" diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile index 8baa496..8914abf 100644 --- a/net/ipv4/netfilter/Makefile +++ b/net/ipv4/netfilter/Makefile @@ -23,7 +23,6 @@ obj-$(CONFIG_NF_DEFRAG_IPV4) += nf_defrag_ipv4.o obj-$(CONFIG_NF_NAT_H323) += nf_nat_h323.o obj-$(CONFIG_NF_NAT_IRC) += nf_nat_irc.o obj-$(CONFIG_NF_NAT_PPTP) += nf_nat_pptp.o -obj-$(CONFIG_NF_NAT_SIP) += nf_nat_sip.o obj-$(CONFIG_NF_NAT_SNMP_BASIC) += nf_nat_snmp_basic.o obj-$(CONFIG_NF_NAT_TFTP) += nf_nat_tftp.o diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c deleted file mode 100644 index 47a4718..0000000 --- a/net/ipv4/netfilter/nf_nat_sip.c +++ /dev/null @@ -1,580 +0,0 @@ -/* SIP extension for NAT alteration. - * - * (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 - * published by the Free Software Foundation. - */ - -#include -#include -#include -#include -#include -#include - -#include -#include -#include -#include -#include - -MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Christian Hentschel "); -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 + ip_hdrlen(skb)); - baseoff = ip_hdrlen(skb) + 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 = ip_hdrlen(skb) + 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 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); - 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 (newaddr == addr->ip && newport == port) - return 1; - - buflen = sprintf(buffer, "%pI4:%u", &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 ip_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); - 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 (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, protoff, dataoff, dptr, datalen, - matchoff, matchlen, &addr, port)) - 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[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; - } - - olen = *datalen; - if (!map_addr(skb, protoff, dataoff, dptr, datalen, - matchoff, matchlen, &addr, port)) - 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 && - addr.ip == ct->tuplehash[dir].tuple.src.u3.ip && - addr.ip != ct->tuplehash[!dir].tuple.dst.u3.ip) { - buflen = sprintf(buffer, "%pI4", - &ct->tuplehash[!dir].tuple.dst.u3.ip); - if (!mangle_packet(skb, protoff, dataoff, 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, false) > 0 && - addr.ip == ct->tuplehash[dir].tuple.dst.u3.ip && - addr.ip != ct->tuplehash[!dir].tuple.src.u3.ip) { - buflen = sprintf(buffer, "%pI4", - &ct->tuplehash[!dir].tuple.src.u3.ip); - if (!mangle_packet(skb, protoff, dataoff, 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, protoff, dataoff, dptr, datalen, - poff, plen, buffer, buflen)) - 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)) - 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)) - return NF_DROP; - - return NF_ACCEPT; -} - -static void ip_nat_sip_seq_adjust(struct sk_buff *skb, 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 + ip_hdrlen(skb)); - nf_nat_set_seq_adjust(ct, ctinfo, th->seq, off); -} - -/* Handles expected signalling connections and media streams */ -static void ip_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 (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip == - ct->master->tuplehash[exp->dir].tuple.src.u3.ip) { - 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 ip_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); - __be32 newip; - u_int16_t port; - char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")]; - unsigned int 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_addr = exp->tuple.dst.u3; - 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++) { - 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) - return NF_DROP; - - if (exp->tuple.dst.u3.ip != exp->saved_addr.ip || - exp->tuple.dst.u.udp.port != exp->saved_proto.udp.port) { - buflen = sprintf(buffer, "%pI4:%u", &newip, port); - if (!mangle_packet(skb, protoff, dataoff, 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, 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 ip_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) -{ - char buffer[sizeof("nnn.nnn.nnn.nnn")]; - unsigned int buflen; - - buflen = sprintf(buffer, "%pI4", &addr->ip); - 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 ip_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 ip_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) -{ - char buffer[sizeof("nnn.nnn.nnn.nnn")]; - unsigned int buflen; - - /* Mangle session description owner and contact addresses */ - buflen = sprintf(buffer, "%pI4", &addr->ip); - if (mangle_sdp_packet(skb, protoff, dataoff, dptr, datalen, sdpoff, - SDP_HDR_OWNER_IP4, SDP_HDR_MEDIA, - buffer, buflen)) - return 0; - - switch (mangle_sdp_packet(skb, protoff, dataoff, dptr, datalen, sdpoff, - SDP_HDR_CONNECTION_IP4, 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 ip_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 (ct->tuplehash[dir].tuple.src.u3.ip == - ct->tuplehash[!dir].tuple.dst.u3.ip) - rtp_addr->ip = rtp_exp->tuple.dst.u3.ip; - else - rtp_addr->ip = ct->tuplehash[!dir].tuple.dst.u3.ip; - - rtp_exp->saved_addr = rtp_exp->tuple.dst.u3; - 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_addr = rtcp_exp->tuple.dst.u3; - 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) { - 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); - port = 0; - break; - } - } - - if (port == 0) - goto err1; - - /* Update media port. */ - if (rtp_exp->tuple.dst.u.udp.port != rtp_exp->saved_proto.udp.port && - !ip_nat_sdp_port(skb, protoff, dataoff, dptr, datalen, - mediaoff, medialen, port)) - 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 = ip_nat_sip_expected, -}; - -static void __exit nf_nat_sip_fini(void) -{ - RCU_INIT_POINTER(nf_nat_sip_hook, NULL); - RCU_INIT_POINTER(nf_nat_sip_seq_adjust_hook, NULL); - RCU_INIT_POINTER(nf_nat_sip_expect_hook, NULL); - RCU_INIT_POINTER(nf_nat_sdp_addr_hook, NULL); - RCU_INIT_POINTER(nf_nat_sdp_port_hook, NULL); - RCU_INIT_POINTER(nf_nat_sdp_session_hook, NULL); - RCU_INIT_POINTER(nf_nat_sdp_media_hook, NULL); - nf_ct_helper_expectfn_unregister(&sip_nat); - synchronize_rcu(); -} - -static int __init nf_nat_sip_init(void) -{ - BUG_ON(nf_nat_sip_hook != NULL); - BUG_ON(nf_nat_sip_seq_adjust_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_INIT_POINTER(nf_nat_sip_hook, ip_nat_sip); - RCU_INIT_POINTER(nf_nat_sip_seq_adjust_hook, ip_nat_sip_seq_adjust); - RCU_INIT_POINTER(nf_nat_sip_expect_hook, ip_nat_sip_expect); - RCU_INIT_POINTER(nf_nat_sdp_addr_hook, ip_nat_sdp_addr); - RCU_INIT_POINTER(nf_nat_sdp_port_hook, ip_nat_sdp_port); - RCU_INIT_POINTER(nf_nat_sdp_session_hook, ip_nat_sdp_session); - RCU_INIT_POINTER(nf_nat_sdp_media_hook, ip_nat_sdp_media); - nf_ct_helper_expectfn_register(&sip_nat); - return 0; -} - -module_init(nf_nat_sip_init); -module_exit(nf_nat_sip_fini); -- cgit v1.1