kernel/net/ipv6/ip6_offload.c, branch linux-6.2.y

IPv6/GRO: generic helper to remove temporary HBH/jumbo header in driver

2022-12-12T23:41:44Z

IPv6/TCP and GRO stacks can build big TCP packets with an added temporary Hop By Hop header. Is GSO is not involved, then the temporary header needs to be removed in the driver. This patch provides a generic helper for drivers that need to modify their headers in place. Tested: Compiled and ran with ethtool -K eth1 tso off Could send Big TCP packets Signed-off-by: Coco Li Link: https://lore.kernel.org/r/20221210041646.3587757-1-lixiaoyan@google.com Signed-off-by: Jakub Kicinski

net-next: skbuff: refactor pskb_pull

2022-09-30T11:31:46Z

pskb_may_pull already contains all of the checks performed by pskb_pull. Use pskb_may_pull for validation in pskb_pull, eliminating the duplication and making __pskb_pull obsolete. Replace __pskb_pull with pskb_pull where applicable. Signed-off-by: Richard Gobert Signed-off-by: David S. Miller

net-next: gro: Fix use of skb_gro_header_slow

2022-09-20T09:47:25Z

In the cited commit, the function ipv6_gro_receive was accidentally changed to use skb_gro_header_slow, without attempting the fast path. Fix it. Fixes: 35ffb6654729 ("net: gro: skb_gro_header helper function") Signed-off-by: Richard Gobert Link: https://lore.kernel.org/r/20220911184835.GA105063@debian Signed-off-by: Paolo Abeni

net: gro: skb_gro_header helper function

2022-08-25T08:33:21Z

Introduce a simple helper function to replace a common pattern. When accessing the GRO header, we fetch the pointer from frag0, then test its validity and fetch it from the skb when necessary. This leads to the pattern skb_gro_header_fast -> skb_gro_header_hard -> skb_gro_header_slow recurring many times throughout GRO code. This patch replaces these patterns with a single inlined function call, improving code readability. Signed-off-by: Richard Gobert Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20220823071034.GA56142@debian Signed-off-by: Paolo Abeni

ipv6/gro: insert temporary HBH/jumbo header

2022-05-16T09:18:56Z

Following patch will add GRO_IPV6_MAX_SIZE, allowing gro to build BIG TCP ipv6 packets (bigger than 64K). This patch changes ipv6_gro_complete() to insert a HBH/jumbo header so that resulting packet can go through IPv6/TCP stacks. Signed-off-by: Eric Dumazet Acked-by: Alexander Duyck Signed-off-by: David S. Miller

ipv6/gso: remove temporary HBH/jumbo header

2022-05-16T09:18:56Z

ipv6 tcp and gro stacks will soon be able to build big TCP packets, with an added temporary Hop By Hop header. If GSO is involved for these large packets, we need to remove the temporary HBH header before segmentation happens. v2: perform HBH removal from ipv6_gso_segment() instead of skb_segment() (Alexander feedback) Signed-off-by: Eric Dumazet Acked-by: Alexander Duyck Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2022-02-25T01:54:25Z

tools/testing/selftests/net/mptcp/mptcp_join.sh 34aa6e3bccd8 ("selftests: mptcp: add ip mptcp wrappers") 857898eb4b28 ("selftests: mptcp: add missing join check") 6ef84b1517e0 ("selftests: mptcp: more robust signal race test") https://lore.kernel.org/all/20220221131842.468893-1-broonie@kernel.org/ drivers/net/ethernet/mellanox/mlx5/core/en/tc/act/act.h drivers/net/ethernet/mellanox/mlx5/core/en/tc/act/ct.c fb7e76ea3f3b6 ("net/mlx5e: TC, Skip redundant ct clear actions") c63741b426e11 ("net/mlx5e: Fix MPLSoUDP encap to use MPLS action information") 09bf97923224f ("net/mlx5e: TC, Move pedit_headers_action to parse_attr") 84ba8062e383 ("net/mlx5e: Test CT and SAMPLE on flow attr") efe6f961cd2e ("net/mlx5e: CT, Don't set flow flag CT for ct clear flow") 3b49a7edec1d ("net/mlx5e: TC, Reject rules with multiple CT actions") Signed-off-by: Jakub Kicinski

gso: do not skip outer ip header in case of ipip and net_failover

2022-02-21T11:41:30Z

We encounter a tcp drop issue in our cloud environment. Packet GROed in host forwards to a VM virtio_net nic with net_failover enabled. VM acts as a IPVS LB with ipip encapsulation. The full path like: host gro -> vm virtio_net rx -> net_failover rx -> ipvs fullnat -> ipip encap -> net_failover tx -> virtio_net tx When net_failover transmits a ipip pkt (gso_type = 0x0103, which means SKB_GSO_TCPV4, SKB_GSO_DODGY and SKB_GSO_IPXIP4), there is no gso did because it supports TSO and GSO_IPXIP4. But network_header points to inner ip header. Call Trace: tcp4_gso_segment ------> return NULL inet_gso_segment ------> inner iph, network_header points to ipip_gso_segment inet_gso_segment ------> outer iph skb_mac_gso_segment Afterwards virtio_net transmits the pkt, only inner ip header is modified. And the outer one just keeps unchanged. The pkt will be dropped in remote host. Call Trace: inet_gso_segment ------> inner iph, outer iph is skipped skb_mac_gso_segment __skb_gso_segment validate_xmit_skb validate_xmit_skb_list sch_direct_xmit __qdisc_run __dev_queue_xmit ------> virtio_net dev_hard_start_xmit __dev_queue_xmit ------> net_failover ip_finish_output2 ip_output iptunnel_xmit ip_tunnel_xmit ipip_tunnel_xmit ------> ipip dev_hard_start_xmit __dev_queue_xmit ip_finish_output2 ip_output ip_forward ip_rcv __netif_receive_skb_one_core netif_receive_skb_internal napi_gro_receive receive_buf virtnet_poll net_rx_action The root cause of this issue is specific with the rare combination of SKB_GSO_DODGY and a tunnel device that adds an SKB_GSO_ tunnel option. SKB_GSO_DODGY is set from external virtio_net. We need to reset network header when callbacks.gso_segment() returns NULL. This patch also includes ipv6_gso_segment(), considering SIT, etc. Fixes: cb32f511a70b ("ipip: add GSO/TSO support") Signed-off-by: Tao Liu Reviewed-by: Willem de Bruijn Signed-off-by: David S. Miller

ipv6: gro: flush instead of assuming different flows on hop_limit mismatch

2022-01-25T13:05:11Z

IPv6 GRO considers packets to belong to different flows when their hop_limit is different. This seems counter-intuitive, the flow is the same. hop_limit may vary because of various bugs or hacks but that doesn't mean it's okay for GRO to reorder packets. Practical impact of this problem on overall TCP performance is unclear, but TCP itself detects this reordering and bumps TCPSACKReorder resulting in user complaints. Eric warns that there may be performance regressions in setups which do packet spraying across links with similar RTT but different hop count. To be safe let's target -next and not treat this as a fix. If the packet spraying is using flow label there should be no difference in behavior as flow label is checked first. Note that the code plays an easy to miss trick by upcasting next_hdr to a u16 pointer and compares next_hdr and hop_limit in one go. Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2021-12-02T19:44:56Z

Signed-off-by: Jakub Kicinski