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Diffstat (limited to 'net/ipv4/tcp_fastopen.c')
-rw-r--r--net/ipv4/tcp_fastopen.c75
1 files changed, 34 insertions, 41 deletions
diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
index f9c0fb84e435..55be6ac70cff 100644
--- a/net/ipv4/tcp_fastopen.c
+++ b/net/ipv4/tcp_fastopen.c
@@ -124,27 +124,29 @@ static bool tcp_fastopen_cookie_gen(struct request_sock *req,
return false;
}
-static bool tcp_fastopen_create_child(struct sock *sk,
- struct sk_buff *skb,
- struct dst_entry *dst,
- struct request_sock *req)
+static struct sock *tcp_fastopen_create_child(struct sock *sk,
+ struct sk_buff *skb,
+ struct dst_entry *dst,
+ struct request_sock *req)
{
struct tcp_sock *tp;
struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
struct sock *child;
u32 end_seq;
+ bool own_req;
req->num_retrans = 0;
req->num_timeout = 0;
req->sk = NULL;
- child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL);
+ child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL,
+ NULL, &own_req);
if (!child)
- return false;
+ return NULL;
- spin_lock(&queue->fastopenq->lock);
- queue->fastopenq->qlen++;
- spin_unlock(&queue->fastopenq->lock);
+ spin_lock(&queue->fastopenq.lock);
+ queue->fastopenq.qlen++;
+ spin_unlock(&queue->fastopenq.lock);
/* Initialize the child socket. Have to fix some values to take
* into account the child is a Fast Open socket and is created
@@ -161,15 +163,13 @@ static bool tcp_fastopen_create_child(struct sock *sk,
tp->snd_wnd = ntohs(tcp_hdr(skb)->window);
/* Activate the retrans timer so that SYNACK can be retransmitted.
- * The request socket is not added to the SYN table of the parent
+ * The request socket is not added to the ehash
* because it's been added to the accept queue directly.
*/
inet_csk_reset_xmit_timer(child, ICSK_TIME_RETRANS,
TCP_TIMEOUT_INIT, TCP_RTO_MAX);
- atomic_set(&req->rsk_refcnt, 1);
- /* Add the child socket directly into the accept queue */
- inet_csk_reqsk_queue_add(sk, req, child);
+ atomic_set(&req->rsk_refcnt, 2);
/* Now finish processing the fastopen child socket. */
inet_csk(child)->icsk_af_ops->rebuild_header(child);
@@ -178,12 +178,10 @@ static bool tcp_fastopen_create_child(struct sock *sk,
tcp_init_metrics(child);
tcp_init_buffer_space(child);
- /* Queue the data carried in the SYN packet. We need to first
- * bump skb's refcnt because the caller will attempt to free it.
- * Note that IPv6 might also have used skb_get() trick
- * in tcp_v6_conn_request() to keep this SYN around (treq->pktopts)
- * So we need to eventually get a clone of the packet,
- * before inserting it in sk_receive_queue.
+ /* Queue the data carried in the SYN packet.
+ * We used to play tricky games with skb_get().
+ * With lockless listener, it is a dead end.
+ * Do not think about it.
*
* XXX (TFO) - we honor a zero-payload TFO request for now,
* (any reason not to?) but no need to queue the skb since
@@ -191,12 +189,7 @@ static bool tcp_fastopen_create_child(struct sock *sk,
*/
end_seq = TCP_SKB_CB(skb)->end_seq;
if (end_seq != TCP_SKB_CB(skb)->seq + 1) {
- struct sk_buff *skb2;
-
- if (unlikely(skb_shared(skb)))
- skb2 = skb_clone(skb, GFP_ATOMIC);
- else
- skb2 = skb_get(skb);
+ struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
if (likely(skb2)) {
skb_dst_drop(skb2);
@@ -214,11 +207,10 @@ static bool tcp_fastopen_create_child(struct sock *sk,
}
}
tcp_rsk(req)->rcv_nxt = tp->rcv_nxt = end_seq;
- sk->sk_data_ready(sk);
- bh_unlock_sock(child);
- sock_put(child);
- WARN_ON(!req->sk);
- return true;
+ /* tcp_conn_request() is sending the SYNACK,
+ * and queues the child into listener accept queue.
+ */
+ return child;
}
static bool tcp_fastopen_queue_check(struct sock *sk)
@@ -235,8 +227,8 @@ static bool tcp_fastopen_queue_check(struct sock *sk)
* between qlen overflow causing Fast Open to be disabled
* temporarily vs a server not supporting Fast Open at all.
*/
- fastopenq = inet_csk(sk)->icsk_accept_queue.fastopenq;
- if (!fastopenq || fastopenq->max_qlen == 0)
+ fastopenq = &inet_csk(sk)->icsk_accept_queue.fastopenq;
+ if (fastopenq->max_qlen == 0)
return false;
if (fastopenq->qlen >= fastopenq->max_qlen) {
@@ -261,13 +253,14 @@ static bool tcp_fastopen_queue_check(struct sock *sk)
* may be updated and return the client in the SYN-ACK later. E.g., Fast Open
* cookie request (foc->len == 0).
*/
-bool tcp_try_fastopen(struct sock *sk, struct sk_buff *skb,
- struct request_sock *req,
- struct tcp_fastopen_cookie *foc,
- struct dst_entry *dst)
+struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb,
+ struct request_sock *req,
+ struct tcp_fastopen_cookie *foc,
+ struct dst_entry *dst)
{
struct tcp_fastopen_cookie valid_foc = { .len = -1 };
bool syn_data = TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq + 1;
+ struct sock *child;
if (foc->len == 0) /* Client requests a cookie */
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPFASTOPENCOOKIEREQD);
@@ -276,7 +269,7 @@ bool tcp_try_fastopen(struct sock *sk, struct sk_buff *skb,
(syn_data || foc->len >= 0) &&
tcp_fastopen_queue_check(sk))) {
foc->len = -1;
- return false;
+ return NULL;
}
if (syn_data && (sysctl_tcp_fastopen & TFO_SERVER_COOKIE_NOT_REQD))
@@ -296,11 +289,12 @@ bool tcp_try_fastopen(struct sock *sk, struct sk_buff *skb,
* data in SYN_RECV state.
*/
fastopen:
- if (tcp_fastopen_create_child(sk, skb, dst, req)) {
+ child = tcp_fastopen_create_child(sk, skb, dst, req);
+ if (child) {
foc->len = -1;
NET_INC_STATS_BH(sock_net(sk),
LINUX_MIB_TCPFASTOPENPASSIVE);
- return true;
+ return child;
}
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPFASTOPENPASSIVEFAIL);
} else if (foc->len > 0) /* Client presents an invalid cookie */
@@ -308,6 +302,5 @@ fastopen:
valid_foc.exp = foc->exp;
*foc = valid_foc;
- return false;
+ return NULL;
}
-EXPORT_SYMBOL(tcp_try_fastopen);
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-21 13:25:28 +0300