diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 4351ca2cf0b8554eadd258295d44a93455f3e506..537731b3bcb3e5717769588e2f0768bc02ed8570 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -446,6 +446,28 @@ extern int sysctl_tcp_synack_retries; EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add); +/* Decide when to expire the request and when to resend SYN-ACK */ +static inline void syn_ack_recalc(struct request_sock *req, const int thresh, + const int max_retries, + const u8 rskq_defer_accept, + int *expire, int *resend) +{ + if (!rskq_defer_accept) { + *expire = req->retrans >= thresh; + *resend = 1; + return; + } + *expire = req->retrans >= thresh && + (!inet_rsk(req)->acked || req->retrans >= max_retries); + /* + * Do not resend while waiting for data after ACK, + * start to resend on end of deferring period to give + * last chance for data or ACK to create established socket. + */ + *resend = !inet_rsk(req)->acked || + req->retrans >= rskq_defer_accept - 1; +} + void inet_csk_reqsk_queue_prune(struct sock *parent, const unsigned long interval, const unsigned long timeout, @@ -501,9 +523,15 @@ void inet_csk_reqsk_queue_prune(struct sock *parent, reqp=&lopt->syn_table[i]; while ((req = *reqp) != NULL) { if (time_after_eq(now, req->expires)) { - if ((req->retrans < thresh || - (inet_rsk(req)->acked && req->retrans < max_retries)) - && !req->rsk_ops->rtx_syn_ack(parent, req)) { + int expire = 0, resend = 0; + + syn_ack_recalc(req, thresh, max_retries, + queue->rskq_defer_accept, + &expire, &resend); + if (!expire && + (!resend || + !req->rsk_ops->rtx_syn_ack(parent, req) || + inet_rsk(req)->acked)) { unsigned long timeo; if (req->retrans++ == 0)