From d6af1a31cc72fbd558c7eddbc36f61bf09d1cf6a Mon Sep 17 00:00:00 2001 From: Steffen Klassert Date: Wed, 16 Mar 2016 10:17:37 +0100 Subject: vti: Add pmtu handling to vti_xmit. We currently rely on the PMTU discovery of xfrm. However if a packet is locally sent, the PMTU mechanism of xfrm tries to do local socket notification what might not work for applications like ping that don't check for this. So add pmtu handling to vti_xmit to report MTU changes immediately. Reported-by: Mark McKinstry Signed-off-by: Steffen Klassert --- net/ipv4/ip_vti.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'net/ipv4') diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c index 5cf10b777b7e..a917903d5e97 100644 --- a/net/ipv4/ip_vti.c +++ b/net/ipv4/ip_vti.c @@ -156,6 +156,7 @@ static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev, struct dst_entry *dst = skb_dst(skb); struct net_device *tdev; /* Device to other host */ int err; + int mtu; if (!dst) { dev->stats.tx_carrier_errors++; @@ -192,6 +193,23 @@ static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev, tunnel->err_count = 0; } + mtu = dst_mtu(dst); + if (skb->len > mtu) { + skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu); + if (skb->protocol == htons(ETH_P_IP)) { + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, + htonl(mtu)); + } else { + if (mtu < IPV6_MIN_MTU) + mtu = IPV6_MIN_MTU; + + icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); + } + + dst_release(dst); + goto tx_error; + } + skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev))); skb_dst_set(skb, dst); skb->dev = skb_dst(skb)->dev; -- cgit v1.2.3 From 43b8448cd7b42a4c39476c9a12c960c1408f1946 Mon Sep 17 00:00:00 2001 From: Jarno Rajahalme Date: Tue, 3 May 2016 16:10:20 -0700 Subject: udp_tunnel: Remove redundant udp_tunnel_gro_complete(). The setting of the UDP tunnel GSO type is already performed by udp[46]_gro_complete(). Signed-off-by: Jarno Rajahalme Signed-off-by: David S. Miller --- net/ipv4/fou.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c index a39068b4a4d9..305d9ac68bd9 100644 --- a/net/ipv4/fou.c +++ b/net/ipv4/fou.c @@ -228,8 +228,6 @@ static int fou_gro_complete(struct sk_buff *skb, int nhoff, int err = -ENOSYS; const struct net_offload **offloads; - udp_tunnel_gro_complete(skb, nhoff); - rcu_read_lock(); offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; ops = rcu_dereference(offloads[proto]); -- cgit v1.2.3 From 229740c63169462a838a8b8e16391ed000934631 Mon Sep 17 00:00:00 2001 From: Jarno Rajahalme Date: Tue, 3 May 2016 16:10:21 -0700 Subject: udp_offload: Set encapsulation before inner completes. UDP tunnel segmentation code relies on the inner offsets being set for an UDP tunnel GSO packet, but the inner *_complete() functions will set the inner offsets only if 'encapsulation' is set before calling them. Currently, udp_gro_complete() sets 'encapsulation' only after the inner *_complete() functions are done. This causes the inner offsets having invalid values after udp_gro_complete() returns, which in turn will make it impossible to properly segment the packet in case it needs to be forwarded, which would be visible to the user either as invalid packets being sent or as packet loss. This patch fixes this by setting skb's 'encapsulation' in udp_gro_complete() before calling into the inner complete functions, and by making each possible UDP tunnel gro_complete() callback set the inner_mac_header to the beginning of the tunnel payload. Signed-off-by: Jarno Rajahalme Reviewed-by: Alexander Duyck Signed-off-by: David S. Miller --- net/ipv4/fou.c | 4 ++++ net/ipv4/udp_offload.c | 8 +++++--- 2 files changed, 9 insertions(+), 3 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c index 305d9ac68bd9..a6962ccad98a 100644 --- a/net/ipv4/fou.c +++ b/net/ipv4/fou.c @@ -236,6 +236,8 @@ static int fou_gro_complete(struct sk_buff *skb, int nhoff, err = ops->callbacks.gro_complete(skb, nhoff); + skb_set_inner_mac_header(skb, nhoff); + out_unlock: rcu_read_unlock(); @@ -412,6 +414,8 @@ static int gue_gro_complete(struct sk_buff *skb, int nhoff, err = ops->callbacks.gro_complete(skb, nhoff + guehlen); + skb_set_inner_mac_header(skb, nhoff + guehlen); + out_unlock: rcu_read_unlock(); return err; diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index 0ed2dafb7cc4..e330c0e56b11 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -399,6 +399,11 @@ int udp_gro_complete(struct sk_buff *skb, int nhoff) uh->len = newlen; + /* Set encapsulation before calling into inner gro_complete() functions + * to make them set up the inner offsets. + */ + skb->encapsulation = 1; + rcu_read_lock(); uo_priv = rcu_dereference(udp_offload_base); @@ -421,9 +426,6 @@ int udp_gro_complete(struct sk_buff *skb, int nhoff) if (skb->remcsum_offload) skb_shinfo(skb)->gso_type |= SKB_GSO_TUNNEL_REMCSUM; - skb->encapsulation = 1; - skb_set_inner_mac_header(skb, nhoff + sizeof(struct udphdr)); - return err; } -- cgit v1.2.3