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| author | Pablo Neira Ayuso <pablo@netfilter.org> | 2018-03-20 12:33:51 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2018-03-20 14:39:31 +0100 |
| commit | 20710b3b81895c89e92bcc32ce85c0bede1171f8 (patch) | |
| tree | 5c30b92f59ca013c86a87f55fd4c01eb71cf1cfd /net/ipv4 | |
| parent | 5191d70f83fd1878c40029cffe69f6a2bf65fa0e (diff) | |
| download | linux-20710b3b81895c89e92bcc32ce85c0bede1171f8.tar.gz linux-20710b3b81895c89e92bcc32ce85c0bede1171f8.tar.bz2 linux-20710b3b81895c89e92bcc32ce85c0bede1171f8.zip | |
netfilter: ctnetlink: synproxy support
This patch exposes synproxy information per-conntrack. Moreover, send
sequence adjustment events once server sends us the SYN,ACK packet, so
we can synchronize the sequence adjustment too for packets going as
reply from the server, as part of the synproxy logic.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/netfilter/ipt_SYNPROXY.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/net/ipv4/netfilter/ipt_SYNPROXY.c b/net/ipv4/netfilter/ipt_SYNPROXY.c index f75fc6b53115..690b17ef6a44 100644 --- a/net/ipv4/netfilter/ipt_SYNPROXY.c +++ b/net/ipv4/netfilter/ipt_SYNPROXY.c @@ -16,6 +16,7 @@ #include <net/netfilter/nf_conntrack.h> #include <net/netfilter/nf_conntrack_seqadj.h> #include <net/netfilter/nf_conntrack_synproxy.h> +#include <net/netfilter/nf_conntrack_ecache.h> static struct iphdr * synproxy_build_ip(struct net *net, struct sk_buff *skb, __be32 saddr, @@ -384,6 +385,8 @@ static unsigned int ipv4_synproxy_hook(void *priv, synproxy->isn = ntohl(th->ack_seq); if (opts.options & XT_SYNPROXY_OPT_TIMESTAMP) synproxy->its = opts.tsecr; + + nf_conntrack_event_cache(IPCT_SYNPROXY, ct); break; case TCP_CONNTRACK_SYN_RECV: if (!th->syn || !th->ack) @@ -392,8 +395,10 @@ static unsigned int ipv4_synproxy_hook(void *priv, if (!synproxy_parse_options(skb, thoff, th, &opts)) return NF_DROP; - if (opts.options & XT_SYNPROXY_OPT_TIMESTAMP) + if (opts.options & XT_SYNPROXY_OPT_TIMESTAMP) { synproxy->tsoff = opts.tsval - synproxy->its; + nf_conntrack_event_cache(IPCT_SYNPROXY, ct); + } opts.options &= ~(XT_SYNPROXY_OPT_MSS | XT_SYNPROXY_OPT_WSCALE | @@ -403,6 +408,7 @@ static unsigned int ipv4_synproxy_hook(void *priv, synproxy_send_server_ack(net, state, skb, th, &opts); nf_ct_seqadj_init(ct, ctinfo, synproxy->isn - ntohl(th->seq)); + nf_conntrack_event_cache(IPCT_SEQADJ, ct); swap(opts.tsval, opts.tsecr); synproxy_send_client_ack(net, skb, th, &opts); |