tcp: TCP Fast Open Server - support TFO listeners
This patch builds on top of the previous patch to add the support
for TFO listeners. This includes -
1. allocating, properly initializing, and managing the per listener
fastopen_queue structure when TFO is enabled
2. changes to the inet_csk_accept code to support TFO. E.g., the
request_sock can no longer be freed upon accept(), not until 3WHS
finishes
3. allowing a TCP_SYN_RECV socket to properly poll() and sendmsg()
if it's a TFO socket
4. properly closing a TFO listener, and a TFO socket before 3WHS
finishes
5. supporting TCP_FASTOPEN socket option
6. modifying tcp_check_req() to use to check a TFO socket as well
as request_sock
7. supporting TCP's TFO cookie option
8. adding a new SYN-ACK retransmit handler to use the timer directly
off the TFO socket rather than the listener socket. Note that TFO
server side will not retransmit anything other than SYN-ACK until
the 3WHS is completed.
The patch also contains an important function
"reqsk_fastopen_remove()" to manage the somewhat complex relation
between a listener, its request_sock, and the corresponding child
socket. See the comment above the function for the detail.
Signed-off-by: H.K. Jerry Chu <hkchu@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/request_sock.h b/include/net/request_sock.h
index c3cdd6c..b01d8dd 100644
--- a/include/net/request_sock.h
+++ b/include/net/request_sock.h
@@ -226,19 +226,6 @@
return req;
}
-static inline struct sock *reqsk_queue_get_child(struct request_sock_queue *queue,
- struct sock *parent)
-{
- struct request_sock *req = reqsk_queue_remove(queue);
- struct sock *child = req->sk;
-
- WARN_ON(child == NULL);
-
- sk_acceptq_removed(parent);
- __reqsk_free(req);
- return child;
-}
-
static inline int reqsk_queue_removed(struct request_sock_queue *queue,
struct request_sock *req)
{
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 9f8821e..1421b02 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -424,7 +424,8 @@
const struct tcphdr *th);
extern struct sock * tcp_check_req(struct sock *sk,struct sk_buff *skb,
struct request_sock *req,
- struct request_sock **prev);
+ struct request_sock **prev,
+ bool fastopen);
extern int tcp_child_process(struct sock *parent, struct sock *child,
struct sk_buff *skb);
extern bool tcp_use_frto(struct sock *sk);
@@ -478,7 +479,8 @@
extern int tcp_connect(struct sock *sk);
extern struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst,
struct request_sock *req,
- struct request_values *rvp);
+ struct request_values *rvp,
+ struct tcp_fastopen_cookie *foc);
extern int tcp_disconnect(struct sock *sk, int flags);
void tcp_connect_init(struct sock *sk);