diff options
| author | Patrick McHardy <kaber@trash.net> | 2013-08-27 08:50:14 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2013-08-28 00:27:54 +0200 |
| commit | 48b1de4c110a7afa4b85862f6c75af817db26fad (patch) | |
| tree | 9d5af0462fdfda02e8eba53018f3e9e577c657f2 /include/net/netfilter/nf_conntrack_seqadj.h | |
| parent | 0198230b7705eb2386e53778d944e307eef0cc71 (diff) | |
netfilter: add SYNPROXY core/target
Add a SYNPROXY for netfilter. The code is split into two parts, the synproxy
core with common functions and an address family specific target.
The SYNPROXY receives the connection request from the client, responds with
a SYN/ACK containing a SYN cookie and announcing a zero window and checks
whether the final ACK from the client contains a valid cookie.
It then establishes a connection to the original destination and, if
successful, sends a window update to the client with the window size
announced by the server.
Support for timestamps, SACK, window scaling and MSS options can be
statically configured as target parameters if the features of the server
are known. If timestamps are used, the timestamp value sent back to
the client in the SYN/ACK will be different from the real timestamp of
the server. In order to now break PAWS, the timestamps are translated in
the direction server->client.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Tested-by: Martin Topholm <mph@one.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'include/net/netfilter/nf_conntrack_seqadj.h')
| -rw-r--r-- | include/net/netfilter/nf_conntrack_seqadj.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/net/netfilter/nf_conntrack_seqadj.h b/include/net/netfilter/nf_conntrack_seqadj.h index 30bfbbed9f47..f6177a5fe0ca 100644 --- a/include/net/netfilter/nf_conntrack_seqadj.h +++ b/include/net/netfilter/nf_conntrack_seqadj.h @@ -30,6 +30,8 @@ static inline struct nf_conn_seqadj *nfct_seqadj_ext_add(struct nf_conn *ct) return nf_ct_ext_add(ct, NF_CT_EXT_SEQADJ, GFP_ATOMIC); } +extern int nf_ct_seqadj_init(struct nf_conn *ct, enum ip_conntrack_info ctinfo, + s32 off); extern int nf_ct_seqadj_set(struct nf_conn *ct, enum ip_conntrack_info ctinfo, __be32 seq, s32 off); extern void nf_ct_tcp_seqadj_set(struct sk_buff *skb, |