[NET] Generalise tcp_listen_opt
This chunks out the accept_queue and tcp_listen_opt code and moves
them to net/core/request_sock.c and include/net/request_sock.h, to
make it useful for other transport protocols, DCCP being the first one
to use it.
Next patches will rename tcp_listen_opt to accept_sock and remove the
inline tcp functions that just call a reqsk_queue_ function.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 1c29feb..b85a46d 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -316,7 +316,7 @@
static __inline__ unsigned int tcp_listen_poll(struct sock *sk,
poll_table *wait)
{
- return tcp_sk(sk)->accept_queue ? (POLLIN | POLLRDNORM) : 0;
+ return !reqsk_queue_empty(&tcp_sk(sk)->accept_queue) ? (POLLIN | POLLRDNORM) : 0;
}
/*
@@ -462,28 +462,15 @@
{
struct inet_sock *inet = inet_sk(sk);
struct tcp_sock *tp = tcp_sk(sk);
- struct tcp_listen_opt *lopt;
+ int rc = reqsk_queue_alloc(&tp->accept_queue, TCP_SYNQ_HSIZE);
+
+ if (rc != 0)
+ return rc;
sk->sk_max_ack_backlog = 0;
sk->sk_ack_backlog = 0;
- tp->accept_queue = tp->accept_queue_tail = NULL;
- rwlock_init(&tp->syn_wait_lock);
tcp_delack_init(tp);
- lopt = kmalloc(sizeof(struct tcp_listen_opt), GFP_KERNEL);
- if (!lopt)
- return -ENOMEM;
-
- memset(lopt, 0, sizeof(struct tcp_listen_opt));
- for (lopt->max_qlen_log = 6; ; lopt->max_qlen_log++)
- if ((1 << lopt->max_qlen_log) >= sysctl_max_syn_backlog)
- break;
- get_random_bytes(&lopt->hash_rnd, 4);
-
- write_lock_bh(&tp->syn_wait_lock);
- tp->listen_opt = lopt;
- write_unlock_bh(&tp->syn_wait_lock);
-
/* There is race window here: we announce ourselves listening,
* but this transition is still not validated by get_port().
* It is OK, because this socket enters to hash table only
@@ -500,10 +487,7 @@
}
sk->sk_state = TCP_CLOSE;
- write_lock_bh(&tp->syn_wait_lock);
- tp->listen_opt = NULL;
- write_unlock_bh(&tp->syn_wait_lock);
- kfree(lopt);
+ reqsk_queue_destroy(&tp->accept_queue);
return -EADDRINUSE;
}
@@ -515,18 +499,16 @@
static void tcp_listen_stop (struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
- struct tcp_listen_opt *lopt = tp->listen_opt;
- struct request_sock *acc_req = tp->accept_queue;
+ struct tcp_listen_opt *lopt;
+ struct request_sock *acc_req;
struct request_sock *req;
int i;
tcp_delete_keepalive_timer(sk);
/* make all the listen_opt local to us */
- write_lock_bh(&tp->syn_wait_lock);
- tp->listen_opt = NULL;
- write_unlock_bh(&tp->syn_wait_lock);
- tp->accept_queue = tp->accept_queue_tail = NULL;
+ lopt = reqsk_queue_yank_listen_sk(&tp->accept_queue);
+ acc_req = reqsk_queue_yank_acceptq(&tp->accept_queue);
if (lopt->qlen) {
for (i = 0; i < TCP_SYNQ_HSIZE; i++) {
@@ -1867,11 +1849,11 @@
prepare_to_wait_exclusive(sk->sk_sleep, &wait,
TASK_INTERRUPTIBLE);
release_sock(sk);
- if (!tp->accept_queue)
+ if (reqsk_queue_empty(&tp->accept_queue))
timeo = schedule_timeout(timeo);
lock_sock(sk);
err = 0;
- if (tp->accept_queue)
+ if (!reqsk_queue_empty(&tp->accept_queue))
break;
err = -EINVAL;
if (sk->sk_state != TCP_LISTEN)
@@ -1894,7 +1876,6 @@
struct sock *tcp_accept(struct sock *sk, int flags, int *err)
{
struct tcp_sock *tp = tcp_sk(sk);
- struct request_sock *req;
struct sock *newsk;
int error;
@@ -1905,37 +1886,31 @@
*/
error = -EINVAL;
if (sk->sk_state != TCP_LISTEN)
- goto out;
+ goto out_err;
/* Find already established connection */
- if (!tp->accept_queue) {
+ if (reqsk_queue_empty(&tp->accept_queue)) {
long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
/* If this is a non blocking socket don't sleep */
error = -EAGAIN;
if (!timeo)
- goto out;
+ goto out_err;
error = wait_for_connect(sk, timeo);
if (error)
- goto out;
+ goto out_err;
}
- req = tp->accept_queue;
- if ((tp->accept_queue = req->dl_next) == NULL)
- tp->accept_queue_tail = NULL;
-
- newsk = req->sk;
- sk_acceptq_removed(sk);
- __reqsk_free(req);
+ newsk = reqsk_queue_get_child(&tp->accept_queue, sk);
BUG_TRAP(newsk->sk_state != TCP_SYN_RECV);
- release_sock(sk);
- return newsk;
-
out:
release_sock(sk);
+ return newsk;
+out_err:
+ newsk = NULL;
*err = error;
- return NULL;
+ goto out;
}
/*