From 3c00fb0bf0e0f061715c04ad609de93ddc046aa1 Mon Sep 17 00:00:00 2001 From: xiao ruizhu Date: Thu, 4 Jul 2019 11:31:13 +0800 Subject: netfilter: nf_conntrack_sip: fix expectation clash When conntracks change during a dialog, SDP messages may be sent from different conntracks to establish expects with identical tuples. In this case expects conflict may be detected for the 2nd SDP message and end up with a process failure. The fixing here is to reuse an existing expect who has the same tuple for a different conntrack if any. Here are two scenarios for the case. 1) SERVER CPE | INVITE SDP | 5060 |<----------------------|5060 | 100 Trying | 5060 |---------------------->|5060 | 183 SDP | 5060 |---------------------->|5060 ===> Conntrack 1 | PRACK | 50601 |<----------------------|5060 | 200 OK (PRACK) | 50601 |---------------------->|5060 | 200 OK (INVITE) | 5060 |---------------------->|5060 | ACK | 50601 |<----------------------|5060 | | |<--- RTP stream ------>| | | | INVITE SDP (t38) | 50601 |---------------------->|5060 ===> Conntrack 2 With a certain configuration in the CPE, SIP messages "183 with SDP" and "re-INVITE with SDP t38" will go through the sip helper to create expects for RTP and RTCP. It is okay to create RTP and RTCP expects for "183", whose master connection source port is 5060, and destination port is 5060. In the "183" message, port in Contact header changes to 50601 (from the original 5060). So the following requests e.g. PRACK and ACK are sent to port 50601. It is a different conntrack (let call Conntrack 2) from the original INVITE (let call Conntrack 1) due to the port difference. In this example, after the call is established, there is RTP stream but no RTCP stream for Conntrack 1, so the RTP expect created upon "183" is cleared, and RTCP expect created for Conntrack 1 retains. When "re-INVITE with SDP t38" arrives to create RTP&RTCP expects, current ALG implementation will call nf_ct_expect_related() for RTP and RTCP. The expects tuples are identical to those for Conntrack 1. RTP expect for Conntrack 2 succeeds in creation as the one for Conntrack 1 has been removed. RTCP expect for Conntrack 2 fails in creation because it has idential tuples and 'conflict' with the one retained for Conntrack 1. And then result in a failure in processing of the re-INVITE. 2) SERVER A CPE | REGISTER | 5060 |<------------------| 5060 ==> CT1 | 200 | 5060 |------------------>| 5060 | | | INVITE SDP(1) | 5060 |<------------------| 5060 | 300(multi choice) | 5060 |------------------>| 5060 SERVER B | ACK | 5060 |<------------------| 5060 | INVITE SDP(2) | 5060 |-------------------->| 5060 ==> CT2 | 100 | 5060 |<--------------------| 5060 | 200(contact changes)| 5060 |<--------------------| 5060 | ACK | 5060 |-------------------->| 50601 ==> CT3 | | |<--- RTP stream ---->| | | | BYE | 5060 |<--------------------| 50601 | 200 | 5060 |-------------------->| 50601 | INVITE SDP(3) | 5060 |<------------------| 5060 ==> CT1 CPE sends an INVITE request(1) to Server A, and creates a RTP&RTCP expect pair for this Conntrack 1 (CT1). Server A responds 300 to redirect to Server B. The RTP&RTCP expect pairs created on CT1 are removed upon 300 response. CPE sends the INVITE request(2) to Server B, and creates an expect pair for the new conntrack (due to destination address difference), let call CT2. Server B changes the port to 50601 in 200 OK response, and the following requests ACK and BYE from CPE are sent to 50601. The call is established. There is RTP stream and no RTCP stream. So RTP expect is removed and RTCP expect for CT2 retains. As BYE request is sent from port 50601, it is another conntrack, let call CT3, different from CT2 due to the port difference. So the BYE request will not remove the RTCP expect for CT2. Then another outgoing call is made, with the same RTP port being used (not definitely but possibly). CPE firstly sends the INVITE request(3) to Server A, and tries to create a RTP&RTCP expect pairs for this CT1. In current ALG implementation, the RTCP expect for CT1 fails in creation because it 'conflicts' with the residual one for CT2. As a result the INVITE request fails to send. Signed-off-by: xiao ruizhu Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_conntrack_expect.h | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/net/netfilter/nf_conntrack_expect.h b/include/net/netfilter/nf_conntrack_expect.h index 93ce6b0daaba..573429be4d59 100644 --- a/include/net/netfilter/nf_conntrack_expect.h +++ b/include/net/netfilter/nf_conntrack_expect.h @@ -76,6 +76,11 @@ struct nf_conntrack_expect_policy { #define NF_CT_EXPECT_CLASS_DEFAULT 0 #define NF_CT_EXPECT_MAX_CNT 255 +/* Allow to reuse expectations with the same tuples from different master + * conntracks. + */ +#define NF_CT_EXP_F_SKIP_MASTER 0x1 + int nf_conntrack_expect_pernet_init(struct net *net); void nf_conntrack_expect_pernet_fini(struct net *net); @@ -122,10 +127,11 @@ void nf_ct_expect_init(struct nf_conntrack_expect *, unsigned int, u_int8_t, u_int8_t, const __be16 *, const __be16 *); void nf_ct_expect_put(struct nf_conntrack_expect *exp); int nf_ct_expect_related_report(struct nf_conntrack_expect *expect, - u32 portid, int report); -static inline int nf_ct_expect_related(struct nf_conntrack_expect *expect) + u32 portid, int report, unsigned int flags); +static inline int nf_ct_expect_related(struct nf_conntrack_expect *expect, + unsigned int flags) { - return nf_ct_expect_related_report(expect, 0, 0); + return nf_ct_expect_related_report(expect, 0, 0, flags); } #endif /*_NF_CONNTRACK_EXPECT_H*/ -- cgit v1.2.3 From 05ba4c895363db795f3d54f2da0de56d6520e52d Mon Sep 17 00:00:00 2001 From: Yonatan Goldschmidt Date: Mon, 8 Jul 2019 15:57:09 -0700 Subject: netfilter: Update obsolete comments referring to ip_conntrack In 9fb9cbb1082d ("[NETFILTER]: Add nf_conntrack subsystem.") the new generic nf_conntrack was introduced, and it came to supersede the old ip_conntrack. This change updates (some) of the obsolete comments referring to old file/function names of the ip_conntrack mechanism, as well as removes a few self-referencing comments that we shouldn't maintain anymore. I did not update any comments referring to historical actions (e.g, comments like "this file was derived from ..." were left untouched, even if the referenced file is no longer here). Signed-off-by: Yonatan Goldschmidt Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter/nf_conntrack_h323_asn1.h | 3 +-- net/ipv4/netfilter/ipt_CLUSTERIP.c | 4 ++-- net/netfilter/Kconfig | 6 ++---- net/netfilter/nf_conntrack_core.c | 4 +--- net/netfilter/nf_conntrack_h323_asn1.c | 5 ++--- net/netfilter/nf_conntrack_proto_gre.c | 2 -- net/netfilter/nf_conntrack_proto_icmp.c | 2 +- net/netfilter/nf_nat_core.c | 2 +- 8 files changed, 10 insertions(+), 18 deletions(-) (limited to 'include') diff --git a/include/linux/netfilter/nf_conntrack_h323_asn1.h b/include/linux/netfilter/nf_conntrack_h323_asn1.h index 91d6275292a5..19df78341fb3 100644 --- a/include/linux/netfilter/nf_conntrack_h323_asn1.h +++ b/include/linux/netfilter/nf_conntrack_h323_asn1.h @@ -1,7 +1,6 @@ /* SPDX-License-Identifier: GPL-2.0-only */ /**************************************************************************** - * ip_conntrack_h323_asn1.h - BER and PER decoding library for H.323 - * conntrack/NAT module. + * BER and PER decoding library for H.323 conntrack/NAT module. * * Copyright (c) 2006 by Jing Min Zhao * diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c index 4d6bf7ac0792..6bdb1ab8af61 100644 --- a/net/ipv4/netfilter/ipt_CLUSTERIP.c +++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c @@ -416,8 +416,8 @@ clusterip_tg(struct sk_buff *skb, const struct xt_action_param *par) ctinfo == IP_CT_RELATED_REPLY)) return XT_CONTINUE; - /* ip_conntrack_icmp guarantees us that we only have ICMP_ECHO, - * TIMESTAMP, INFO_REQUEST or ADDRESS type icmp packets from here + /* nf_conntrack_proto_icmp guarantees us that we only have ICMP_ECHO, + * TIMESTAMP, INFO_REQUEST or ICMP_ADDRESS type icmp packets from here * on, which all have an ID field [relevant for hashing]. */ hash = clusterip_hashfn(skb, cipinfo->config); diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index 32a45c03786e..0d65f4d39494 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -223,8 +223,6 @@ config NF_CONNTRACK_FTP of Network Address Translation on them. This is FTP support on Layer 3 independent connection tracking. - Layer 3 independent connection tracking is experimental scheme - which generalize ip_conntrack to support other layer 3 protocols. To compile it as a module, choose M here. If unsure, say N. @@ -338,7 +336,7 @@ config NF_CONNTRACK_SIP help SIP is an application-layer control protocol that can establish, modify, and terminate multimedia sessions (conferences) such as - Internet telephony calls. With the ip_conntrack_sip and + Internet telephony calls. With the nf_conntrack_sip and the nf_nat_sip modules you can support the protocol on a connection tracking/NATing firewall. @@ -1313,7 +1311,7 @@ config NETFILTER_XT_MATCH_HELPER depends on NETFILTER_ADVANCED help Helper matching allows you to match packets in dynamic connections - tracked by a conntrack-helper, ie. ip_conntrack_ftp + tracked by a conntrack-helper, ie. nf_conntrack_ftp To compile it as a module, choose M here. If unsure, say Y. diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index bdfeacee0817..a542761e90d1 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -1817,9 +1817,7 @@ EXPORT_SYMBOL_GPL(nf_ct_kill_acct); #include #include -/* Generic function for tcp/udp/sctp/dccp and alike. This needs to be - * in ip_conntrack_core, since we don't want the protocols to autoload - * or depend on ctnetlink */ +/* Generic function for tcp/udp/sctp/dccp and alike. */ int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb, const struct nf_conntrack_tuple *tuple) { diff --git a/net/netfilter/nf_conntrack_h323_asn1.c b/net/netfilter/nf_conntrack_h323_asn1.c index 8f6ba8162f0b..573cb4481481 100644 --- a/net/netfilter/nf_conntrack_h323_asn1.c +++ b/net/netfilter/nf_conntrack_h323_asn1.c @@ -1,11 +1,10 @@ // SPDX-License-Identifier: GPL-2.0-only /* - * ip_conntrack_helper_h323_asn1.c - BER and PER decoding library for H.323 - * conntrack/NAT module. + * BER and PER decoding library for H.323 conntrack/NAT module. * * Copyright (c) 2006 by Jing Min Zhao * - * See ip_conntrack_helper_h323_asn1.h for details. + * See nf_conntrack_helper_h323_asn1.h for details. */ #ifdef __KERNEL__ diff --git a/net/netfilter/nf_conntrack_proto_gre.c b/net/netfilter/nf_conntrack_proto_gre.c index c2eb365f1723..5b05487a60d2 100644 --- a/net/netfilter/nf_conntrack_proto_gre.c +++ b/net/netfilter/nf_conntrack_proto_gre.c @@ -1,7 +1,5 @@ // SPDX-License-Identifier: GPL-2.0-only /* - * ip_conntrack_proto_gre.c - Version 3.0 - * * Connection tracking protocol helper module for GRE. * * GRE is a generic encapsulation protocol, which is generally not very diff --git a/net/netfilter/nf_conntrack_proto_icmp.c b/net/netfilter/nf_conntrack_proto_icmp.c index dd53e2b20f6b..097deba7441a 100644 --- a/net/netfilter/nf_conntrack_proto_icmp.c +++ b/net/netfilter/nf_conntrack_proto_icmp.c @@ -215,7 +215,7 @@ int nf_conntrack_icmpv4_error(struct nf_conn *tmpl, return -NF_ACCEPT; } - /* See ip_conntrack_proto_tcp.c */ + /* See nf_conntrack_proto_tcp.c */ if (state->net->ct.sysctl_checksum && state->hook == NF_INET_PRE_ROUTING && nf_ip_checksum(skb, state->hook, dataoff, IPPROTO_ICMP)) { diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c index 9ab410455992..3f6023ed4966 100644 --- a/net/netfilter/nf_nat_core.c +++ b/net/netfilter/nf_nat_core.c @@ -519,7 +519,7 @@ another_round: * and NF_INET_LOCAL_OUT, we change the destination to map into the * range. It might not be possible to get a unique tuple, but we try. * At worst (or if we race), we will end up with a final duplicate in - * __ip_conntrack_confirm and drop the packet. */ + * __nf_conntrack_confirm and drop the packet. */ static void get_unique_tuple(struct nf_conntrack_tuple *tuple, const struct nf_conntrack_tuple *orig_tuple, -- cgit v1.2.3 From b83329fb473f29d34d85d642e3a3313bb2871fa9 Mon Sep 17 00:00:00 2001 From: Fernando Fernandez Mancera Date: Wed, 10 Jul 2019 12:05:57 +0200 Subject: netfilter: synproxy: fix erroneous tcp mss option Now synproxy sends the mss value set by the user on client syn-ack packet instead of the mss value that client announced. Fixes: 48b1de4c110a ("netfilter: add SYNPROXY core/target") Signed-off-by: Fernando Fernandez Mancera Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_conntrack_synproxy.h | 1 + net/ipv4/netfilter/ipt_SYNPROXY.c | 2 ++ net/ipv6/netfilter/ip6t_SYNPROXY.c | 2 ++ net/netfilter/nf_synproxy_core.c | 4 ++-- net/netfilter/nft_synproxy.c | 2 ++ 5 files changed, 9 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/net/netfilter/nf_conntrack_synproxy.h b/include/net/netfilter/nf_conntrack_synproxy.h index 8f00125b06f4..44513b93bd55 100644 --- a/include/net/netfilter/nf_conntrack_synproxy.h +++ b/include/net/netfilter/nf_conntrack_synproxy.h @@ -68,6 +68,7 @@ struct synproxy_options { u8 options; u8 wscale; u16 mss; + u16 mss_encode; u32 tsval; u32 tsecr; }; diff --git a/net/ipv4/netfilter/ipt_SYNPROXY.c b/net/ipv4/netfilter/ipt_SYNPROXY.c index 8e7f84ec783d..0e70f3f65f6f 100644 --- a/net/ipv4/netfilter/ipt_SYNPROXY.c +++ b/net/ipv4/netfilter/ipt_SYNPROXY.c @@ -36,6 +36,8 @@ synproxy_tg4(struct sk_buff *skb, const struct xt_action_param *par) opts.options |= XT_SYNPROXY_OPT_ECN; opts.options &= info->options; + opts.mss_encode = opts.mss; + opts.mss = info->mss; if (opts.options & XT_SYNPROXY_OPT_TIMESTAMP) synproxy_init_timestamp_cookie(info, &opts); else diff --git a/net/ipv6/netfilter/ip6t_SYNPROXY.c b/net/ipv6/netfilter/ip6t_SYNPROXY.c index e77ea1ed5edd..5cdb4a69d277 100644 --- a/net/ipv6/netfilter/ip6t_SYNPROXY.c +++ b/net/ipv6/netfilter/ip6t_SYNPROXY.c @@ -36,6 +36,8 @@ synproxy_tg6(struct sk_buff *skb, const struct xt_action_param *par) opts.options |= XT_SYNPROXY_OPT_ECN; opts.options &= info->options; + opts.mss_encode = opts.mss; + opts.mss = info->mss; if (opts.options & XT_SYNPROXY_OPT_TIMESTAMP) synproxy_init_timestamp_cookie(info, &opts); else diff --git a/net/netfilter/nf_synproxy_core.c b/net/netfilter/nf_synproxy_core.c index b101f187eda8..09718e5a9e41 100644 --- a/net/netfilter/nf_synproxy_core.c +++ b/net/netfilter/nf_synproxy_core.c @@ -470,7 +470,7 @@ synproxy_send_client_synack(struct net *net, struct iphdr *iph, *niph; struct tcphdr *nth; unsigned int tcp_hdr_size; - u16 mss = opts->mss; + u16 mss = opts->mss_encode; iph = ip_hdr(skb); @@ -884,7 +884,7 @@ synproxy_send_client_synack_ipv6(struct net *net, struct ipv6hdr *iph, *niph; struct tcphdr *nth; unsigned int tcp_hdr_size; - u16 mss = opts->mss; + u16 mss = opts->mss_encode; iph = ipv6_hdr(skb); diff --git a/net/netfilter/nft_synproxy.c b/net/netfilter/nft_synproxy.c index 80060ade8a5b..928e661d1517 100644 --- a/net/netfilter/nft_synproxy.c +++ b/net/netfilter/nft_synproxy.c @@ -31,6 +31,8 @@ static void nft_synproxy_tcp_options(struct synproxy_options *opts, opts->options |= NF_SYNPROXY_OPT_ECN; opts->options &= priv->info.options; + opts->mss_encode = opts->mss; + opts->mss = info->mss; if (opts->options & NF_SYNPROXY_OPT_TIMESTAMP) synproxy_init_timestamp_cookie(info, opts); else -- cgit v1.2.3