[PATCH 06/14] netfilter: synproxy: fix erroneous tcp mss option
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: 2019-07-19 16:45:51
Also in:
netfilter-devel
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Fernando Fernandez Mancera <redacted>
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 <redacted>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
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(-)
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
--
2.11.0