diff options
| -rw-r--r-- | include/net/tcp.h | 12 | ||||
| -rw-r--r-- | net/ipv4/tcp_input.c | 5 | ||||
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 37 | ||||
| -rw-r--r-- | net/ipv4/tcp_timer.c | 2 |
4 files changed, 52 insertions, 4 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index cbb2a4889fc9..54f212ce8aaf 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -469,6 +469,7 @@ extern void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, int nonagle); extern int tcp_may_send_now(struct sock *sk); extern int tcp_retransmit_skb(struct sock *, struct sk_buff *); +extern void tcp_retransmit_timer(struct sock *sk); extern void tcp_xmit_retransmit_queue(struct sock *); extern void tcp_simple_retransmit(struct sock *); extern int tcp_trim_head(struct sock *, struct sk_buff *, u32); @@ -521,6 +522,17 @@ extern int tcp_mtu_to_mss(struct sock *sk, int pmtu); extern int tcp_mss_to_mtu(struct sock *sk, int mss); extern void tcp_mtup_init(struct sock *sk); +static inline void tcp_bound_rto(const struct sock *sk) +{ + if (inet_csk(sk)->icsk_rto > TCP_RTO_MAX) + inet_csk(sk)->icsk_rto = TCP_RTO_MAX; +} + +static inline u32 __tcp_set_rto(const struct tcp_sock *tp) +{ + return (tp->srtt >> 3) + tp->rttvar; +} + static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd) { tp->pred_flags = htonl((tp->tcp_header_len << 26) | diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 2bdb0da237e6..af6d6fa00db1 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -685,7 +685,7 @@ static inline void tcp_set_rto(struct sock *sk) * is invisible. Actually, Linux-2.4 also generates erratic * ACKs in some circumstances. */ - inet_csk(sk)->icsk_rto = (tp->srtt >> 3) + tp->rttvar; + inet_csk(sk)->icsk_rto = __tcp_set_rto(tp); /* 2. Fixups made earlier cannot be right. * If we do not estimate RTO correctly without them, @@ -696,8 +696,7 @@ static inline void tcp_set_rto(struct sock *sk) /* NOTE: clamping at TCP_RTO_MIN is not required, current algo * guarantees that rto is higher. */ - if (inet_csk(sk)->icsk_rto > TCP_RTO_MAX) - inet_csk(sk)->icsk_rto = TCP_RTO_MAX; + tcp_bound_rto(sk); } /* Save metrics learned by this TCP session. diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 6ca1bc8c3025..6755e29a6dd3 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -332,12 +332,15 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info) { struct iphdr *iph = (struct iphdr *)icmp_skb->data; struct tcphdr *th = (struct tcphdr *)(icmp_skb->data + (iph->ihl << 2)); + struct inet_connection_sock *icsk; struct tcp_sock *tp; struct inet_sock *inet; const int type = icmp_hdr(icmp_skb)->type; const int code = icmp_hdr(icmp_skb)->code; struct sock *sk; + struct sk_buff *skb; __u32 seq; + __u32 remaining; int err; struct net *net = dev_net(icmp_skb->dev); @@ -367,6 +370,7 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info) if (sk->sk_state == TCP_CLOSE) goto out; + icsk = inet_csk(sk); tp = tcp_sk(sk); seq = ntohl(th->seq); if (sk->sk_state != TCP_LISTEN && @@ -393,6 +397,39 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info) } err = icmp_err_convert[code].errno; + /* check if icmp_skb allows revert of backoff + * (see draft-zimmermann-tcp-lcd) */ + if (code != ICMP_NET_UNREACH && code != ICMP_HOST_UNREACH) + break; + if (seq != tp->snd_una || !icsk->icsk_retransmits || + !icsk->icsk_backoff) + break; + + icsk->icsk_backoff--; + inet_csk(sk)->icsk_rto = __tcp_set_rto(tp) << + icsk->icsk_backoff; + tcp_bound_rto(sk); + + skb = tcp_write_queue_head(sk); + BUG_ON(!skb); + + remaining = icsk->icsk_rto - min(icsk->icsk_rto, + tcp_time_stamp - TCP_SKB_CB(skb)->when); + + if (remaining) { + inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, + remaining, TCP_RTO_MAX); + } else if (sock_owned_by_user(sk)) { + /* RTO revert clocked out retransmission, + * but socket is locked. Will defer. */ + inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, + HZ/20, TCP_RTO_MAX); + } else { + /* RTO revert clocked out retransmission. + * Will retransmit now */ + tcp_retransmit_timer(sk); + } + break; case ICMP_TIME_EXCEEDED: err = EHOSTUNREACH; diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index c520fb6e06d9..408fa4b7b9ba 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -279,7 +279,7 @@ static void tcp_probe_timer(struct sock *sk) * The TCP retransmit timer. */ -static void tcp_retransmit_timer(struct sock *sk) +void tcp_retransmit_timer(struct sock *sk) { struct tcp_sock *tp = tcp_sk(sk); struct inet_connection_sock *icsk = inet_csk(sk); |