kernel/linux.git/net/ipv6/udp_offload.c, branch linux-7.1.y

udp: Don't pass udptable to IPv6 socket lookup functions.

2026-03-14T01:57:46+00:00

Since UDP and UDP-Lite had dedicated socket hash tables for each, we have had to pass the pointer down to many socket lookup functions. UDP-Lite gone, and we do not need to do that. Let's fetch net->ipv4.udp_table only where needed in IPv6 stack: __udp6_lib_lookup() and __udp6_lib_mcast_deliver(). __udp6_lib_err() is renamed to udpv6_err() as its wrapper is no longer needed. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20260311052020.1213705-14-kuniyu@google.com Signed-off-by: Jakub Kicinski

gro: inline tcp6_gro_complete()

2026-01-22T03:28:32+00:00

Remove one function call from GRO stack for native IPv6 + TCP packets. $ scripts/bloat-o-meter -t vmlinux.2 vmlinux.3 add/remove: 0/0 grow/shrink: 1/1 up/down: 298/-5 (293) Function old new delta ipv6_gro_complete 435 733 +298 tcp6_gro_complete 311 306 -5 Total: Before=22593532, After=22593825, chg +0.00% Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20260120164903.1912995-4-edumazet@google.com Signed-off-by: Jakub Kicinski

gro: inline tcp6_gro_receive()

2026-01-22T03:28:32+00:00

FDO/LTO are unable to inline tcp6_gro_receive() from ipv6_gro_receive() Make sure tcp6_check_fraglist_gro() is only called only when needed, so that compiler can leave it out-of-line. $ scripts/bloat-o-meter -t vmlinux.1 vmlinux.2 add/remove: 2/0 grow/shrink: 3/1 up/down: 1123/-253 (870) Function old new delta ipv6_gro_receive 1069 1846 +777 tcp6_check_fraglist_gro - 272 +272 ipv6_offload_init 218 274 +56 __pfx_tcp6_check_fraglist_gro - 16 +16 ipv6_gro_complete 433 435 +2 tcp6_gro_receive 959 706 -253 Total: Before=22592662, After=22593532, chg +0.00% Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20260120164903.1912995-3-edumazet@google.com Signed-off-by: Jakub Kicinski

net: gro: remove is_ipv6 from napi_gro_cb

2025-09-25T10:42:49+00:00

Remove is_ipv6 from napi_gro_cb and use sk->sk_family instead. This frees up space for another ip_fixedid bit that will be added in the next commit. udp_sock_create always creates either a AF_INET or a AF_INET6 socket, so using sk->sk_family is reliable. In IPv6-FOU, cfg->ipv6_v6only is always enabled. Signed-off-by: Richard Gobert Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20250923085908.4687-2-richardbgobert@gmail.com Signed-off-by: Paolo Abeni

udp_tunnel: create a fastpath GRO lookup.

2025-04-09T01:19:41+00:00

Most UDP tunnels bind a socket to a local port, with ANY address, no peer and no interface index specified. Additionally it's quite common to have a single tunnel device per namespace. Track in each namespace the UDP tunnel socket respecting the above. When only a single one is present, store a reference in the netns. When such reference is not NULL, UDP tunnel GRO lookup just need to match the incoming packet destination port vs the socket local port. The tunnel socket never sets the reuse[port] flag[s]. When bound to no address and interface, no other socket can exist in the same netns matching the specified local port. Matching packets with non-local destination addresses will be aggregated, and eventually segmented as needed - no behavior changes intended. Restrict the optimization to kernel sockets only: it covers all the relevant use-cases, and user-space owned sockets could be disconnected and rebound after setup_udp_tunnel_sock(), breaking the uniqueness assumption Note that the UDP tunnel socket reference is stored into struct netns_ipv4 for both IPv4 and IPv6 tunnels. That is intentional to keep all the fastpath-related netns fields in the same struct and allow cacheline-based optimization. Currently both the IPv4 and IPv6 socket pointer share the same cacheline as the `udp_table` field. Signed-off-by: Paolo Abeni Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/41d16bc8d1257d567f9344c445b4ae0b4a91ede4.1744040675.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski

Revert "udp_tunnel: GRO optimizations"

2025-03-25T16:15:07+00:00

Revert "udp_tunnel: use static call for GRO hooks when possible" This reverts commit 311b36574ceaccfa3f91b74054a09cd4bb877702. Revert "udp_tunnel: create a fastpath GRO lookup." This reverts commit 8d4880db378350f8ed8969feea13bdc164564fc1. There are multiple small issues with the series. In the interest of unblocking the merge window let's opt for a revert. Link: https://lore.kernel.org/cover.1742557254.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski

udp_tunnel: create a fastpath GRO lookup.

2025-03-18T10:40:26+00:00

Most UDP tunnels bind a socket to a local port, with ANY address, no peer and no interface index specified. Additionally it's quite common to have a single tunnel device per namespace. Track in each namespace the UDP tunnel socket respecting the above. When only a single one is present, store a reference in the netns. When such reference is not NULL, UDP tunnel GRO lookup just need to match the incoming packet destination port vs the socket local port. The tunnel socket never sets the reuse[port] flag[s]. When bound to no address and interface, no other socket can exist in the same netns matching the specified local port. Matching packets with non-local destination addresses will be aggregated, and eventually segmented as needed - no behavior changes intended. Note that the UDP tunnel socket reference is stored into struct netns_ipv4 for both IPv4 and IPv6 tunnels. That is intentional to keep all the fastpath-related netns fields in the same struct and allow cacheline-based optimization. Currently both the IPv4 and IPv6 socket pointer share the same cacheline as the `udp_table` field. Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/4d5c319c4471161829f50cb8436841de81a5edae.1741718157.git.pabeni@redhat.com Signed-off-by: Paolo Abeni

net: gro: convert four dev_net() calls

2025-03-03T23:44:19+00:00

tcp4_check_fraglist_gro(), tcp6_check_fraglist_gro(), udp4_gro_lookup_skb() and udp6_gro_lookup_skb() assume RCU is held so that the net structure does not disappear. Use dev_net_rcu() instead of dev_net() to get LOCKDEP support. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250301201424.2046477-5-edumazet@google.com Signed-off-by: Jakub Kicinski

net: gro: fix udp bad offset in socket lookup by adding {inner_}network_offset to napi_gro_cb

2024-05-02T09:02:48+00:00

Commits a602456 ("udp: Add GRO functions to UDP socket") and 57c67ff ("udp: additional GRO support") introduce incorrect usage of {ip,ipv6}_hdr in the complete phase of gro. The functions always return skb->network_header, which in the case of encapsulated packets at the gro complete phase, is always set to the innermost L3 of the packet. That means that calling {ip,ipv6}_hdr for skbs which completed the GRO receive phase (both in gro_list and *_gro_complete) when parsing an encapsulated packet's _outer_ L3/L4 may return an unexpected value. This incorrect usage leads to a bug in GRO's UDP socket lookup. udp{4,6}_lib_lookup_skb functions use ip_hdr/ipv6_hdr respectively. These *_hdr functions return network_header which will point to the innermost L3, resulting in the wrong offset being used in __udp{4,6}_lib_lookup with encapsulated packets. This patch adds network_offset and inner_network_offset to napi_gro_cb, and makes sure both are set correctly. To fix the issue, network_offsets union is used inside napi_gro_cb, in which both the outer and the inner network offsets are saved. Reproduction example: Endpoint configuration example (fou + local address bind) # ip fou add port 6666 ipproto 4 # ip link add name tun1 type ipip remote 2.2.2.1 local 2.2.2.2 encap fou encap-dport 5555 encap-sport 6666 mode ipip # ip link set tun1 up # ip a add 1.1.1.2/24 dev tun1 Netperf TCP_STREAM result on net-next before patch is applied: net-next main, GRO enabled: $ netperf -H 1.1.1.2 -t TCP_STREAM -l 5 Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 131072 16384 16384 5.28 2.37 net-next main, GRO disabled: $ netperf -H 1.1.1.2 -t TCP_STREAM -l 5 Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 131072 16384 16384 5.01 2745.06 patch applied, GRO enabled: $ netperf -H 1.1.1.2 -t TCP_STREAM -l 5 Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 131072 16384 16384 5.01 2877.38 Fixes: a6024562ffd7 ("udp: Add GRO functions to UDP socket") Signed-off-by: Richard Gobert Reviewed-by: Eric Dumazet Reviewed-by: Willem de Bruijn Signed-off-by: Paolo Abeni

udp: do not transition UDP GRO fraglist partial checksums to unnecessary

2024-03-29T11:30:44+00:00

UDP GRO validates checksums and in udp4/6_gro_complete fraglist packets are converted to CHECKSUM_UNNECESSARY to avoid later checks. However this is an issue for CHECKSUM_PARTIAL packets as they can be looped in an egress path and then their partial checksums are not fixed. Different issues can be observed, from invalid checksum on packets to traces like: gen01: hw csum failure skb len=3008 headroom=160 headlen=1376 tailroom=0 mac=(106,14) net=(120,40) trans=160 shinfo(txflags=0 nr_frags=0 gso(size=0 type=0 segs=0)) csum(0xffff232e ip_summed=2 complete_sw=0 valid=0 level=0) hash(0x77e3d716 sw=1 l4=1) proto=0x86dd pkttype=0 iif=12 ... Fix this by only converting CHECKSUM_NONE packets to CHECKSUM_UNNECESSARY by reusing __skb_incr_checksum_unnecessary. All other checksum types are kept as-is, including CHECKSUM_COMPLETE as fraglist packets being segmented back would have their skb->csum valid. Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") Signed-off-by: Antoine Tenart Reviewed-by: Willem de Bruijn Signed-off-by: David S. Miller