summaryrefslogtreecommitdiff
path: root/net/ipv4/af_inet.c
diff options
context:
space:
mode:
authorDavid S. Miller <davem@davemloft.net>2012-08-31 20:43:37 -0400
committerDavid S. Miller <davem@davemloft.net>2012-08-31 20:43:37 -0400
commit1bed966cc3bd4042110129f0fc51aeeb59c5b200 (patch)
tree0d5b9181b840c9b6b08b1452004f0746e8eebab8 /net/ipv4/af_inet.c
parent2a35cfa591ac63f17815c2d9432b799e37527980 (diff)
parent168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef (diff)
Merge branch 'tcp_fastopen_server'
Jerry Chu says: ==================== This patch series provides the server (passive open) side code for TCP Fast Open. Together with the earlier client side patches it completes the TCP Fast Open implementation. The server side Fast Open code accepts data carried in the SYN packet with a valid Fast Open cookie, and passes it to the application right away, allowing application to send back response data, all before TCP's 3-way handshake finishes. A simple cookie scheme together with capping the number of outstanding TFO requests (still in TCP_SYN_RECV state) to a limit per listener forms the main line of defense against spoofed SYN attacks. For more details about TCP Fast Open see our IETF internet draft at http://www.ietf.org/id/draft-ietf-tcpm-fastopen-01.txt and a research paper at http://conferences.sigcomm.org/co-next/2011/papers/1569470463.pdf A prototype implementation was first developed by Sivasankar Radhakrishnan (sivasankar@cs.ucsd.edu). A patch based on an older version of Linux kernel has been undergoing internal tests at Google for the past few months. Jerry Chu (3): tcp: TCP Fast Open Server - header & support functions tcp: TCP Fast Open Server - support TFO listeners tcp: TCP Fast Open Server - main code path ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/af_inet.c')
-rw-r--r--net/ipv4/af_inet.c28
1 files changed, 27 insertions, 1 deletions
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 6681ccf5c3ee..4f70ef0b946d 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -149,6 +149,11 @@ void inet_sock_destruct(struct sock *sk)
pr_err("Attempt to release alive inet socket %p\n", sk);
return;
}
+ if (sk->sk_type == SOCK_STREAM) {
+ struct fastopen_queue *fastopenq =
+ inet_csk(sk)->icsk_accept_queue.fastopenq;
+ kfree(fastopenq);
+ }
WARN_ON(atomic_read(&sk->sk_rmem_alloc));
WARN_ON(atomic_read(&sk->sk_wmem_alloc));
@@ -212,6 +217,26 @@ int inet_listen(struct socket *sock, int backlog)
* we can only allow the backlog to be adjusted.
*/
if (old_state != TCP_LISTEN) {
+ /* Check special setups for testing purpose to enable TFO w/o
+ * requiring TCP_FASTOPEN sockopt.
+ * Note that only TCP sockets (SOCK_STREAM) will reach here.
+ * Also fastopenq may already been allocated because this
+ * socket was in TCP_LISTEN state previously but was
+ * shutdown() (rather than close()).
+ */
+ if ((sysctl_tcp_fastopen & TFO_SERVER_ENABLE) != 0 &&
+ inet_csk(sk)->icsk_accept_queue.fastopenq == NULL) {
+ if ((sysctl_tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) != 0)
+ err = fastopen_init_queue(sk, backlog);
+ else if ((sysctl_tcp_fastopen &
+ TFO_SERVER_WO_SOCKOPT2) != 0)
+ err = fastopen_init_queue(sk,
+ ((uint)sysctl_tcp_fastopen) >> 16);
+ else
+ err = 0;
+ if (err)
+ goto out;
+ }
err = inet_csk_listen_start(sk, backlog);
if (err)
goto out;
@@ -701,7 +726,8 @@ int inet_accept(struct socket *sock, struct socket *newsock, int flags)
sock_rps_record_flow(sk2);
WARN_ON(!((1 << sk2->sk_state) &
- (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE)));
+ (TCPF_ESTABLISHED | TCPF_SYN_RECV |
+ TCPF_CLOSE_WAIT | TCPF_CLOSE)));
sock_graft(sk2, newsock);