diff options
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 19 | ||||
| -rw-r--r-- | net/ipv4/tcp_output.c | 6 | ||||
| -rw-r--r-- | net/ipv6/tcp_ipv6.c | 40 |
3 files changed, 44 insertions, 21 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 59110caeb07..bc5432e3c77 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -275,12 +275,15 @@ failure: EXPORT_SYMBOL(tcp_v4_connect); /* - * This routine does path mtu discovery as defined in RFC1191. + * This routine reacts to ICMP_FRAG_NEEDED mtu indications as defined in RFC1191. + * It can be called through tcp_release_cb() if socket was owned by user + * at the time tcp_v4_err() was called to handle ICMP message. */ -static void do_pmtu_discovery(struct sock *sk, const struct iphdr *iph, u32 mtu) +static void tcp_v4_mtu_reduced(struct sock *sk) { struct dst_entry *dst; struct inet_sock *inet = inet_sk(sk); + u32 mtu = tcp_sk(sk)->mtu_info; /* We are not interested in TCP_LISTEN and open_requests (SYN-ACKs * send out by Linux are always <576bytes so they should go through @@ -373,8 +376,12 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info) bh_lock_sock(sk); /* If too many ICMPs get dropped on busy * servers this needs to be solved differently. + * We do take care of PMTU discovery (RFC1191) special case : + * we can receive locally generated ICMP messages while socket is held. */ - if (sock_owned_by_user(sk)) + if (sock_owned_by_user(sk) && + type != ICMP_DEST_UNREACH && + code != ICMP_FRAG_NEEDED) NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS); if (sk->sk_state == TCP_CLOSE) @@ -409,8 +416,11 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info) goto out; if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */ + tp->mtu_info = info; if (!sock_owned_by_user(sk)) - do_pmtu_discovery(sk, iph, info); + tcp_v4_mtu_reduced(sk); + else + set_bit(TCP_MTU_REDUCED_DEFERRED, &tp->tsq_flags); goto out; } @@ -2596,6 +2606,7 @@ struct proto tcp_prot = { .sendpage = tcp_sendpage, .backlog_rcv = tcp_v4_do_rcv, .release_cb = tcp_release_cb, + .mtu_reduced = tcp_v4_mtu_reduced, .hash = inet_hash, .unhash = inet_unhash, .get_port = inet_csk_get_port, diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 950aebfd996..33cd065cfbd 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -885,7 +885,8 @@ static void tcp_tasklet_func(unsigned long data) #define TCP_DEFERRED_ALL ((1UL << TCP_TSQ_DEFERRED) | \ (1UL << TCP_WRITE_TIMER_DEFERRED) | \ - (1UL << TCP_DELACK_TIMER_DEFERRED)) + (1UL << TCP_DELACK_TIMER_DEFERRED) | \ + (1UL << TCP_MTU_REDUCED_DEFERRED)) /** * tcp_release_cb - tcp release_sock() callback * @sk: socket @@ -914,6 +915,9 @@ void tcp_release_cb(struct sock *sk) if (flags & (1UL << TCP_DELACK_TIMER_DEFERRED)) tcp_delack_timer_handler(sk); + + if (flags & (1UL << TCP_MTU_REDUCED_DEFERRED)) + sk->sk_prot->mtu_reduced(sk); } EXPORT_SYMBOL(tcp_release_cb); diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 0302ec3fecf..f49476e2d88 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -315,6 +315,23 @@ failure: return err; } +static void tcp_v6_mtu_reduced(struct sock *sk) +{ + struct dst_entry *dst; + + if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) + return; + + dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info); + if (!dst) + return; + + if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) { + tcp_sync_mss(sk, dst_mtu(dst)); + tcp_simple_retransmit(sk); + } +} + static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, u8 type, u8 code, int offset, __be32 info) { @@ -342,7 +359,7 @@ static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, } bh_lock_sock(sk); - if (sock_owned_by_user(sk)) + if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG) NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS); if (sk->sk_state == TCP_CLOSE) @@ -371,21 +388,11 @@ static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, } if (type == ICMPV6_PKT_TOOBIG) { - struct dst_entry *dst; - - if (sock_owned_by_user(sk)) - goto out; - if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) - goto out; - - dst = inet6_csk_update_pmtu(sk, ntohl(info)); - if (!dst) - goto out; - - if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) { - tcp_sync_mss(sk, dst_mtu(dst)); - tcp_simple_retransmit(sk); - } + tp->mtu_info = ntohl(info); + if (!sock_owned_by_user(sk)) + tcp_v6_mtu_reduced(sk); + else + set_bit(TCP_MTU_REDUCED_DEFERRED, &tp->tsq_flags); goto out; } @@ -1949,6 +1956,7 @@ struct proto tcpv6_prot = { .sendpage = tcp_sendpage, .backlog_rcv = tcp_v6_do_rcv, .release_cb = tcp_release_cb, + .mtu_reduced = tcp_v6_mtu_reduced, .hash = tcp_v6_hash, .unhash = inet_unhash, .get_port = inet_csk_get_port, |