From patchwork Fri Jan 25 13:54:33 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 215692 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 370C72C0085 for ; Sat, 26 Jan 2013 00:55:19 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932431Ab3AYNzP (ORCPT ); Fri, 25 Jan 2013 08:55:15 -0500 Received: from mail.us.es ([193.147.175.20]:60256 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932346Ab3AYNzJ (ORCPT ); Fri, 25 Jan 2013 08:55:09 -0500 Received: (qmail 21601 invoked from network); 25 Jan 2013 14:55:07 +0100 Received: from unknown (HELO us.es) (192.168.2.11) by us.es with SMTP; 25 Jan 2013 14:55:07 +0100 Received: (qmail 24932 invoked by uid 507); 25 Jan 2013 13:55:07 -0000 X-Qmail-Scanner-Diagnostics: from 127.0.0.1 by antivirus1 (envelope-from , uid 501) with qmail-scanner-2.10 (clamdscan: 0.97.6/16567. spamassassin: 3.3.2. 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Processed in 6.479197 secs); 25 Jan 2013 13:55:07 -0000 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on antivirus1 X-Spam-Level: X-Spam-Status: No, score=-98.4 required=7.5 tests=BAYES_50,RCVD_IN_PBL, RDNS_DYNAMIC,USER_IN_WHITELIST autolearn=disabled version=3.3.2 X-Envelope-From: pablo@netfilter.org Received: from unknown (HELO antivirus1) (127.0.0.1) by us.es with SMTP; 25 Jan 2013 13:55:00 -0000 Received: from 192.168.1.13 (192.168.1.13) by antivirus1 (F-Secure/fsigk_smtp/407/antivirus1); Fri, 25 Jan 2013 14:55:00 +0100 (CET) X-Virus-Status: clean(F-Secure/fsigk_smtp/407/antivirus1) Received: (qmail 15409 invoked from network); 25 Jan 2013 14:55:00 +0100 Received: from 187.94.78.188.dynamic.jazztel.es (HELO localhost.localdomain) (pneira@us.es@188.78.94.187) by us.es with SMTP; 25 Jan 2013 14:55:00 +0100 From: pablo@netfilter.org To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org Subject: [PATCH 01/21] netfilter: nf_ct_sip: support Cisco 7941/7945 IP phones Date: Fri, 25 Jan 2013 14:54:33 +0100 Message-Id: <1359122093-3404-2-git-send-email-pablo@netfilter.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1359122093-3404-1-git-send-email-pablo@netfilter.org> References: <1359122093-3404-1-git-send-email-pablo@netfilter.org> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Kevin Cernekee Most SIP devices use a source port of 5060/udp on SIP requests, so the response automatically comes back to port 5060: phone_ip:5060 -> proxy_ip:5060 REGISTER proxy_ip:5060 -> phone_ip:5060 100 Trying The newer Cisco IP phones, however, use a randomly chosen high source port for the SIP request but expect the response on port 5060: phone_ip:49173 -> proxy_ip:5060 REGISTER proxy_ip:5060 -> phone_ip:5060 100 Trying Standard Linux NAT, with or without nf_nat_sip, will send the reply back to port 49173, not 5060: phone_ip:49173 -> proxy_ip:5060 REGISTER proxy_ip:5060 -> phone_ip:49173 100 Trying But the phone is not listening on 49173, so it will never see the reply. This patch modifies nf_*_sip to work around this quirk by extracting the SIP response port from the Via: header, iff the source IP in the packet header matches the source IP in the SIP request. Signed-off-by: Kevin Cernekee Acked-by: Eric Dumazet Cc: Patrick McHardy Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter/nf_conntrack_sip.h | 3 +++ net/netfilter/nf_conntrack_sip.c | 17 +++++++++++++++++ net/netfilter/nf_nat_sip.c | 27 ++++++++++++++++++++++++--- 3 files changed, 44 insertions(+), 3 deletions(-) diff --git a/include/linux/netfilter/nf_conntrack_sip.h b/include/linux/netfilter/nf_conntrack_sip.h index 387bdd0..ba7f571 100644 --- a/include/linux/netfilter/nf_conntrack_sip.h +++ b/include/linux/netfilter/nf_conntrack_sip.h @@ -4,12 +4,15 @@ #include +#include + #define SIP_PORT 5060 #define SIP_TIMEOUT 3600 struct nf_ct_sip_master { unsigned int register_cseq; unsigned int invite_cseq; + __be16 forced_dport; }; enum sip_expectation_classes { diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c index df8f4f2..72a67bb 100644 --- a/net/netfilter/nf_conntrack_sip.c +++ b/net/netfilter/nf_conntrack_sip.c @@ -1440,8 +1440,25 @@ static int process_sip_request(struct sk_buff *skb, unsigned int protoff, { enum ip_conntrack_info ctinfo; struct nf_conn *ct = nf_ct_get(skb, &ctinfo); + struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); + enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); unsigned int matchoff, matchlen; unsigned int cseq, i; + union nf_inet_addr addr; + __be16 port; + + /* Many Cisco IP phones use a high source port for SIP requests, but + * listen for the response on port 5060. If we are the local + * router for one of these phones, save the port number from the + * Via: header so that nf_nat_sip can redirect the responses to + * the correct port. + */ + if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen, + SIP_HDR_VIA_UDP, NULL, &matchoff, + &matchlen, &addr, &port) > 0 && + port != ct->tuplehash[dir].tuple.src.u.udp.port && + nf_inet_addr_cmp(&addr, &ct->tuplehash[dir].tuple.src.u3)) + ct_sip_info->forced_dport = port; for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) { const struct sip_handler *handler; diff --git a/net/netfilter/nf_nat_sip.c b/net/netfilter/nf_nat_sip.c index 16303c7..5951146e 100644 --- a/net/netfilter/nf_nat_sip.c +++ b/net/netfilter/nf_nat_sip.c @@ -95,6 +95,7 @@ static int map_addr(struct sk_buff *skb, unsigned int protoff, 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; @@ -107,7 +108,8 @@ static int map_addr(struct sk_buff *skb, unsigned int protoff, } 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->tuplehash[!dir].tuple.src.u.udp.port; + newport = ct_sip_info->forced_dport ? : + ct->tuplehash[!dir].tuple.src.u.udp.port; } else return 1; @@ -144,6 +146,7 @@ static unsigned int nf_nat_sip(struct sk_buff *skb, unsigned int protoff, 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; @@ -258,6 +261,21 @@ next: !map_sip_addr(skb, protoff, dataoff, dptr, datalen, SIP_HDR_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)) + 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)) + return NF_DROP; + } + return NF_ACCEPT; } @@ -311,8 +329,10 @@ static unsigned int nf_nat_sip_expect(struct sk_buff *skb, unsigned int protoff, 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; @@ -326,8 +346,9 @@ static unsigned int nf_nat_sip_expect(struct sk_buff *skb, unsigned int protoff, /* 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) + 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);