diff options
Diffstat (limited to 'net/ipv4/tcp_fastopen.c')
| -rw-r--r-- | net/ipv4/tcp_fastopen.c | 75 |
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); |