Current TCP code relies on the local port of the listening socket
being the same as the destination address of the incoming
connection. Port redirection used by many transparent proxying
techniques obviously breaks this, so we have to store the original
destination port address.

This patch extends struct inet_request_sock and stores the incoming
destination port value there. It also modifies the handshake code to
use that value as the source port when sending reply packets.

Signed-off-by: KOVACS Krisztian <[EMAIL PROTECTED]>

---

 include/net/inet_sock.h         |    1 +
 include/net/tcp.h               |    1 +
 net/ipv4/inet_connection_sock.c |    2 ++
 net/ipv4/tcp_output.c           |    2 +-
 4 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index ce6da97..0bd167b 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -64,6 +64,7 @@ #if defined(CONFIG_IPV6) || defined(CONF
 #endif
        __be32                  loc_addr;
        __be32                  rmt_addr;
+       __be16                  loc_port;
        __be16                  rmt_port;
        u16                     snd_wscale : 4, 
                                rcv_wscale : 4, 
diff --git a/include/net/tcp.h b/include/net/tcp.h
index b7d8317..08ea8f3 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -983,6 +983,7 @@ static inline void tcp_openreq_init(stru
        ireq->acked = 0;
        ireq->ecn_ok = 0;
        ireq->rmt_port = skb->h.th->source;
+       ireq->loc_port = skb->h.th->dest;
 }
 
 extern void tcp_enter_memory_pressure(void);
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 9d68837..889a487 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -502,6 +502,8 @@ struct sock *inet_csk_clone(struct sock
                newicsk->icsk_bind_hash = NULL;
 
                inet_sk(newsk)->dport = inet_rsk(req)->rmt_port;
+               inet_sk(newsk)->num = ntohs(inet_rsk(req)->loc_port);
+               inet_sk(newsk)->sport = inet_rsk(req)->loc_port;
                newsk->sk_write_space = sk_stream_write_space;
 
                newicsk->icsk_retransmits = 0;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 32c1a97..bb37048 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2132,7 +2132,7 @@ #endif
        th->syn = 1;
        th->ack = 1;
        TCP_ECN_make_synack(req, th);
-       th->source = inet_sk(sk)->sport;
+       th->source = ireq->loc_port;
        th->dest = ireq->rmt_port;
        TCP_SKB_CB(skb)->seq = tcp_rsk(req)->snt_isn;
        TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(skb)->seq + 1;
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to