When we expect an IPv6 dst, use dst6_mtu() instead of dst_mtu() to save some code space. Due to current dst6_mtu() implementation, only convert users in IPv6 stack. Signed-off-by: Eric Dumazet --- net/ipv6/ip6_gre.c | 2 +- net/ipv6/ip6_output.c | 6 +++--- net/ipv6/ip6_tunnel.c | 4 ++-- net/ipv6/ipv6_sockglue.c | 4 ++-- net/ipv6/route.c | 10 ++++++---- net/ipv6/tcp_ipv6.c | 9 +++++---- 6 files changed, 19 insertions(+), 16 deletions(-) diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c index d19d86ed43766bbc8ec052113be02ab231a5272c..dafcc0dcd77a5394857d6f339d83370826a25109 100644 --- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -1057,7 +1057,7 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb, /* TooBig packet may have updated dst->dev's mtu */ if (!t->parms.collect_md && dst) { mtu = READ_ONCE(dst_dev(dst)->mtu); - if (dst_mtu(dst) > mtu) + if (dst6_mtu(dst) > mtu) dst->ops->update_pmtu(dst, NULL, skb, mtu, false); } err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu, diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 4bb61265f1d8f870dbfd60bd22b8ab78828fb4cd..f110701d1eca1e5f763d9138a43e11e92c15412f 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -353,7 +353,7 @@ int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6, skb->priority = priority; skb->mark = mark; - mtu = dst_mtu(dst); + mtu = dst6_mtu(dst); if (likely((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb))) { IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS); @@ -1403,10 +1403,10 @@ static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork, v6_cork->dontfrag = ipc6->dontfrag; if (rt->dst.flags & DST_XFRM_TUNNEL) mtu = READ_ONCE(np->pmtudisc) >= IPV6_PMTUDISC_PROBE ? - READ_ONCE(rt->dst.dev->mtu) : dst_mtu(&rt->dst); + READ_ONCE(rt->dst.dev->mtu) : dst6_mtu(&rt->dst); else mtu = READ_ONCE(np->pmtudisc) >= IPV6_PMTUDISC_PROBE ? - READ_ONCE(rt->dst.dev->mtu) : dst_mtu(xfrm_dst_path(&rt->dst)); + READ_ONCE(rt->dst.dev->mtu) : dst6_mtu(xfrm_dst_path(&rt->dst)); frag_size = READ_ONCE(np->frag_size); if (frag_size && frag_size < mtu) diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index 6fca0868b5a237417eb4c013f713952e8922696d..4c29aa94e86eb9439458e4b23426bfda8b3b8922 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -638,7 +638,7 @@ ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, /* change mtu on this route */ if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) { - if (rel_info > dst_mtu(skb_dst(skb2))) + if (rel_info > dst6_mtu(skb_dst(skb2))) goto out; skb_dst_update_pmtu_no_confirm(skb2, rel_info); @@ -1187,7 +1187,7 @@ int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield, t->parms.name); goto tx_err_dst_release; } - mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen; + mtu = dst6_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen; if (encap_limit >= 0) { max_headroom += 8; mtu -= 8; diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c index a61e742794f9e67ff3743ddc31341d8647d5bcdc..d784a8644ff20e6008925b3d9b8e13c380318657 100644 --- a/net/ipv6/ipv6_sockglue.c +++ b/net/ipv6/ipv6_sockglue.c @@ -1184,7 +1184,7 @@ int do_ipv6_getsockopt(struct sock *sk, int level, int optname, rcu_read_lock(); dst = __sk_dst_get(sk); if (dst) - val = dst_mtu(dst); + val = dst6_mtu(dst); rcu_read_unlock(); if (!val) return -ENOTCONN; @@ -1283,7 +1283,7 @@ int do_ipv6_getsockopt(struct sock *sk, int level, int optname, rcu_read_lock(); dst = __sk_dst_get(sk); if (dst) - mtuinfo.ip6m_mtu = dst_mtu(dst); + mtuinfo.ip6m_mtu = dst6_mtu(dst); rcu_read_unlock(); if (!mtuinfo.ip6m_mtu) return -ENOTCONN; diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 3cfa7ae1294b59d14e030fb7a4ceabd4e9b673a8..c0350d97307e1ef6a3b500db32a311891d3c6e72 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -2049,6 +2049,8 @@ static void rt6_update_exception_stamp_rt(struct rt6_info *rt) static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev, struct rt6_info *rt, int mtu) { + u32 dmtu = dst6_mtu(&rt->dst); + /* If the new MTU is lower than the route PMTU, this new MTU will be the * lowest MTU in the path: always allow updating the route PMTU to * reflect PMTU decreases. @@ -2059,10 +2061,10 @@ static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev, * handle this. */ - if (dst_mtu(&rt->dst) >= mtu) + if (dmtu >= mtu) return true; - if (dst_mtu(&rt->dst) == idev->cnf.mtu6) + if (dmtu == idev->cnf.mtu6) return true; return false; @@ -2932,7 +2934,7 @@ static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk, if (mtu < IPV6_MIN_MTU) return; - if (mtu >= dst_mtu(dst)) + if (mtu >= dst6_mtu(dst)) return; if (!rt6_cache_allowed_for_pmtu(rt6)) { @@ -3248,7 +3250,7 @@ EXPORT_SYMBOL_GPL(ip6_sk_redirect); static unsigned int ip6_default_advmss(const struct dst_entry *dst) { - unsigned int mtu = dst_mtu(dst); + unsigned int mtu = dst6_mtu(dst); struct net *net; mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr); diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 4ae664b05fa9171ed996bf8f3b6e7b2aaa63d5c9..f154d8720e64908083032df7d8645289e801a59d 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -351,7 +351,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr_unsized *uaddr, static void tcp_v6_mtu_reduced(struct sock *sk) { struct dst_entry *dst; - u32 mtu; + u32 mtu, dmtu; if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) return; @@ -368,8 +368,9 @@ static void tcp_v6_mtu_reduced(struct sock *sk) if (!dst) return; - if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) { - tcp_sync_mss(sk, dst_mtu(dst)); + dmtu = dst6_mtu(dst); + if (inet_csk(sk)->icsk_pmtu_cookie > dmtu) { + tcp_sync_mss(sk, dmtu); tcp_simple_retransmit(sk); } } @@ -1467,7 +1468,7 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff * tcp_ca_openreq_child(newsk, dst); - tcp_sync_mss(newsk, dst_mtu(dst)); + tcp_sync_mss(newsk, dst6_mtu(dst)); newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst)); tcp_initialize_rcv_mss(newsk); -- 2.53.0.rc1.225.gd81095ad13-goog