| Message ID | 20190710100556.25307-2-ffmancera@riseup.net |
|---|---|
| State | Accepted |
| Delegated to: | Pablo Neira |
| Headers | show |
| Series | Fix mss value announced to the client | expand |
On Wed, Jul 10, 2019 at 12:05:57PM +0200, Fernando Fernandez Mancera wrote: > Now synproxy sends the mss value set by the user on client syn-ack packet > instead of the mss value that client announced. Applied to nf.git, thanks Fernando. Could you also make a backport of this patch? Use kernel 5.1 as reference, you should take Ibrahim's patch and adapt it to place the mss_encode in the synproxy_options.
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
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 <ffmancera@riseup.net> --- 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(-)