diff options
Diffstat (limited to 'net/ipv4/tcp_ipv4.c')
-rw-r--r-- | net/ipv4/tcp_ipv4.c | 53 |
1 files changed, 45 insertions, 8 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 6d88219c5e2..6755e29a6dd 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -328,26 +328,29 @@ static void do_pmtu_discovery(struct sock *sk, struct iphdr *iph, u32 mtu) * */ -void tcp_v4_err(struct sk_buff *skb, u32 info) +void tcp_v4_err(struct sk_buff *icmp_skb, u32 info) { - struct iphdr *iph = (struct iphdr *)skb->data; - struct tcphdr *th = (struct tcphdr *)(skb->data + (iph->ihl << 2)); + 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(skb)->type; - const int code = icmp_hdr(skb)->code; + 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(skb->dev); + struct net *net = dev_net(icmp_skb->dev); - if (skb->len < (iph->ihl << 2) + 8) { + if (icmp_skb->len < (iph->ihl << 2) + 8) { ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); return; } sk = inet_lookup(net, &tcp_hashinfo, iph->daddr, th->dest, - iph->saddr, th->source, inet_iif(skb)); + iph->saddr, th->source, inet_iif(icmp_skb)); if (!sk) { ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); return; @@ -367,6 +370,7 @@ void tcp_v4_err(struct sk_buff *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 *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; |