From d29245692a44d71d5e2e0770463184a693696232 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 27 May 2020 17:34:58 -0700 Subject: [PATCH] tcp: ipv6: support RFC 6069 (TCP-LD) Make tcp_ld_RTO_revert() helper available to IPv6, and implement RFC 6069 : Quoting this RFC : 3. Connectivity Disruption Indication For Internet Protocol version 6 (IPv6) [RFC2460], the counterpart of the ICMP destination unreachable message of code 0 (net unreachable) and of code 1 (host unreachable) is the ICMPv6 destination unreachable message of code 0 (no route to destination) [RFC4443]. As with IPv4, a router should generate an ICMPv6 destination unreachable message of code 0 in response to a packet that cannot be delivered to its destination address because it lacks a matching entry in its routing table. Signed-off-by: Eric Dumazet Acked-by: Yuchung Cheng Acked-by: Neal Cardwell Signed-off-by: David S. Miller --- include/net/tcp.h | 1 + net/ipv4/tcp_ipv4.c | 3 ++- net/ipv6/tcp_ipv6.c | 9 +++++++++ 3 files changed, 12 insertions(+), 1 deletion(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index b681338a8320..66e4b8331850 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -437,6 +437,7 @@ u16 tcp_get_syncookie_mss(struct request_sock_ops *rsk_ops, void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb); void tcp_v4_mtu_reduced(struct sock *sk); void tcp_req_err(struct sock *sk, u32 seq, bool abort); +void tcp_ld_RTO_revert(struct sock *sk, u32 seq); int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb); struct sock *tcp_create_openreq_child(const struct sock *sk, struct request_sock *req, diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 4eef5b84fff1..ad6435ba6d72 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -404,7 +404,7 @@ void tcp_req_err(struct sock *sk, u32 seq, bool abort) EXPORT_SYMBOL(tcp_req_err); /* TCP-LD (RFC 6069) logic */ -static void tcp_ld_RTO_revert(struct sock *sk, u32 seq) +void tcp_ld_RTO_revert(struct sock *sk, u32 seq) { struct inet_connection_sock *icsk = inet_csk(sk); struct tcp_sock *tp = tcp_sk(sk); @@ -441,6 +441,7 @@ static void tcp_ld_RTO_revert(struct sock *sk, u32 seq) tcp_retransmit_timer(sk); } } +EXPORT_SYMBOL(tcp_ld_RTO_revert); /* * This routine is called by the ICMP module when it gets some diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 01a6f5111a77..b7415ca75c2d 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -473,6 +473,15 @@ static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, } else sk->sk_err_soft = err; goto out; + case TCP_LISTEN: + break; + default: + /* check if this ICMP message allows revert of backoff. + * (see RFC 6069) + */ + if (!fastopen && type == ICMPV6_DEST_UNREACH && + code == ICMPV6_NOROUTE) + tcp_ld_RTO_revert(sk, seq); } if (!sock_owned_by_user(sk) && np->recverr) {