linux/net/ipv4/ip_output.c, branch v4.9

ipv4: Set skb->protocol properly for local output

2016-12-02T17:34:22Z

When xfrm is applied to TSO/GSO packets, it follows this path: xfrm_output() -> xfrm_output_gso() -> skb_gso_segment() where skb_gso_segment() relies on skb->protocol to function properly. This patch sets skb->protocol to ETH_P_IP before dst_output() is called, fixing a bug where GSO packets sent through a sit tunnel are dropped when xfrm is involved. Cc: stable@vger.kernel.org Signed-off-by: Eli Cooper Signed-off-by: David S. Miller

ipv4: update comment to document GSO fragmentation cases.

2016-11-10T17:01:54Z

This is a follow-up to commit 9ee6c5dc816a ("ipv4: allow local fragmentation in ip_finish_output_gso()"), updating the comment documenting cases in which fragmentation is needed for egress GSO packets. Suggested-by: Shmulik Ladkani Reviewed-by: Shmulik Ladkani Signed-off-by: Lance Richardson Signed-off-by: David S. Miller

net: tcp response should set oif only if it is L3 master

2016-11-10T03:32:10Z

Lorenzo noted an Android unit test failed due to e0d56fdd7342: "The expectation in the test was that the RST replying to a SYN sent to a closed port should be generated with oif=0. In other words it should not prefer the interface where the SYN came in on, but instead should follow whatever the routing table says it should do." Revert the change to ip_send_unicast_reply and tcp_v6_send_response such that the oif in the flow is set to the skb_iif only if skb_iif is an L3 master. Fixes: e0d56fdd7342 ("net: l3mdev: remove redundant calls") Reported-by: Lorenzo Colitti Signed-off-by: David Ahern Tested-by: Lorenzo Colitti Acked-by: Lorenzo Colitti Signed-off-by: David S. Miller

ipv4: allow local fragmentation in ip_finish_output_gso()

2016-11-03T20:10:26Z

Some configurations (e.g. geneve interface with default MTU of 1500 over an ethernet interface with 1500 MTU) result in the transmission of packets that exceed the configured MTU. While this should be considered to be a "bad" configuration, it is still allowed and should not result in the sending of packets that exceed the configured MTU. Fix by dropping the assumption in ip_finish_output_gso() that locally originated gso packets will never need fragmentation. Basic testing using iperf (observing CPU usage and bandwidth) have shown no measurable performance impact for traffic not requiring fragmentation. Fixes: c7ba65d7b649 ("net: ip: push gso skb forwarding handling down the stack") Reported-by: Jan Tluka Signed-off-by: Lance Richardson Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller

ipv4: Remove unused but set variable

2016-10-18T14:30:28Z

Remove the unused but set variable dev in ip_do_fragment to fix the following GCC warning when building with 'W=1': net/ipv4/ip_output.c: In function ‘ip_do_fragment’: net/ipv4/ip_output.c:541:21: warning: variable ‘dev’ set but not used [-Wunused-but-set-variable] Signed-off-by: Tobias Klauser Signed-off-by: David S. Miller

net: l3mdev: remove redundant calls

2016-09-11T06:12:52Z

A previous patch added l3mdev flow update making these hooks redundant. Remove them. Signed-off-by: David Ahern Signed-off-by: David S. Miller

net: l3mdev: Add hook to output path

2016-09-11T06:12:52Z

This patch adds the infrastructure to the output path to pass an skb to an l3mdev device if it has a hook registered. This is the Tx parallel to l3mdev_ip{6}_rcv in the receive path and is the basis for removing the existing hook that returns the vrf dst on the fib lookup. Signed-off-by: David Ahern Signed-off-by: David S. Miller

ipv4: use IS_ENABLED() instead of checking for built-in or module

2016-09-11T04:19:10Z

The IS_ENABLED() macro checks if a Kconfig symbol has been enabled either built-in or as a module, use that macro instead of open coding the same. Using the macro makes the code more readable by helping abstract away some of the Kconfig built-in and module enable details. Signed-off-by: Javier Martinez Canillas Signed-off-by: David S. Miller

net: lwtunnel: Handle fragmentation

2016-08-31T05:27:18Z

Today mpls iptunnel lwtunnel_output redirect expects the tunnel output function to handle fragmentation. This is ok but can be avoided if we did not do the mpls output redirect too early. ie we could wait until ip fragmentation is done and then call mpls output for each ip fragment. To make this work we will need, 1) the lwtunnel state to carry encap headroom 2) and do the redirect to the encap output handler on the ip fragment (essentially do the output redirect after fragmentation) This patch adds tunnel headroom in lwtstate to make sure we account for tunnel data in mtu calculations during fragmentation and adds new xmit redirect handler to redirect to lwtunnel xmit func after ip fragmentation. This includes IPV6 and some mtu fixes and testing from David Ahern. Signed-off-by: Roopa Prabhu Signed-off-by: David Ahern Signed-off-by: David S. Miller

net/ipv4: Introduce IPSKB_FRAG_SEGS bit to inet_skb_parm.flags

2016-07-19T23:40:22Z

This flag indicates whether fragmentation of segments is allowed. Formerly this policy was hardcoded according to IPSKB_FORWARDED (set by either ip_forward or ipmr_forward). Cc: Hannes Frederic Sowa Cc: Florian Westphal Signed-off-by: Shmulik Ladkani Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller