kernel/linux.git/net/ipv4/udp_offload.c, branch linux-7.1.y

udp: Fix UDP length on last GSO_PARTIAL segment

2026-05-20T22:03:47+00:00

Following the cited commit, __udp_gso_segment() writes single MSS length in the UDP header. The cited patch doesn't account for the fact that the last segment could be a GSO skb by itself. This could happen when the size of the packet is a multiple of MSS, hence the first segment is also the last one (there is no need for a remainder skb). When the post-loop segment is a GSO skb, assign the single MSS length in the UDP header. Fixes: b10b446ce7ad ("udp: gso: Use single MSS length in UDP header for GSO_PARTIAL") Reported-by: Matthew Schwartz Closes: https://lore.kernel.org/all/6c3fb15e-711d-4b8d-b152-e03d9b05293f@linux.dev/ Tested-by: Matthew Schwartz Reviewed-by: Dragos Tatulea Signed-off-by: Gal Pressman Link: https://patch.msgid.link/20260518062250.3019914-3-gal@nvidia.com Signed-off-by: Jakub Kicinski

udp: gso: Fix handling checksum in __udp_gso_segment

2026-05-20T22:02:47+00:00

The cited commit started using msslen for uh->len, but still uses newlen to adjust uh->check. Although the checksum is ignored in most cases due to the hardware offload, __udp_gso_segment attempts to maintain the correct one. Fix uh->check and adjust it by the right value. Additionally, after the fix, newlen becomes assigned and unused before the loop. The code can be simplified a bit if mss adjustment is dropped, so that newlen becomes equal to msslen before the loop, and msslen can be also dropped, saving a few lines of code. This brings us back to one variable, drops an unneeded arithmetic for mss, and fixes the UDP checksum. Fixes: b10b446ce7ad ("udp: gso: Use single MSS length in UDP header for GSO_PARTIAL") Signed-off-by: Alice Mikityanska Reviewed-by: Willem de Bruijn Signed-off-by: Gal Pressman Link: https://patch.msgid.link/20260518062250.3019914-2-gal@nvidia.com Signed-off-by: Jakub Kicinski

inet: remove leftover EXPORT_SYMBOL()

2026-04-03T22:07:46+00:00

IPv6 is no longer a module, we no longer need to export these symbols. Signed-off-by: Eric Dumazet Reviewed-by: Fernando Fernandez Mancera Link: https://patch.msgid.link/20260402174430.2462800-1-edumazet@google.com Signed-off-by: Jakub Kicinski

udp: Don't pass udptable to IPv4 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 IPv4 stack: __udp4_lib_lookup(), __udp4_lib_mcast_deliver(), and udp_diag_dump(). Some functions are renamed as the wrapper functions are no longer needed. __udp4_lib_err() -> udp_err() __udp_diag_destroy() -> udp_diag_destroy() udp_dump_one() -> udp_diag_dump_one() udp_dump() -> udp_diag_dump() Signed-off-by: Kuniyuki Iwashima Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20260311052020.1213705-15-kuniyu@google.com Signed-off-by: Jakub Kicinski

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

2026-01-30T01:28:54+00:00

Cross-merge networking fixes after downstream PR (net-6.19-rc8). No adjacent changes, conflicts: drivers/net/ethernet/spacemit/k1_emac.c 2c84959167d64 ("net: spacemit: Check for netif_carrier_ok() in emac_stats_update()") f66086798f91f ("net: spacemit: Remove broken flow control support") https://lore.kernel.org/aXjAqZA3iEWD_DGM@sirena.org.uk Signed-off-by: Jakub Kicinski

net: fix segmentation of forwarding fraglist GRO

2026-01-29T13:40:12+00:00

This patch enhances GSO segment handling by properly checking the SKB_GSO_DODGY flag for frag_list GSO packets, addressing low throughput issues observed when a station accesses IPv4 servers via hotspots with an IPv6-only upstream interface. Specifically, it fixes a bug in GSO segmentation when forwarding GRO packets containing a frag_list. The function skb_segment_list cannot correctly process GRO skbs that have been converted by XLAT, since XLAT only translates the header of the head skb. Consequently, skbs in the frag_list may remain untranslated, resulting in protocol inconsistencies and reduced throughput. To address this, the patch explicitly sets the SKB_GSO_DODGY flag for GSO packets in XLAT's IPv4/IPv6 protocol translation helpers (bpf_skb_proto_4_to_6 and bpf_skb_proto_6_to_4). This marks GSO packets as potentially modified after protocol translation. As a result, GSO segmentation will avoid using skb_segment_list and instead falls back to skb_segment for packets with the SKB_GSO_DODGY flag. This ensures that only safe and fully translated frag_list packets are processed by skb_segment_list, resolving protocol inconsistencies and improving throughput when forwarding GRO packets converted by XLAT. Signed-off-by: Jibin Zhang Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260126152114.1211-1-jibin.zhang@mediatek.com Signed-off-by: Paolo Abeni

udp: gso: Use single MSS length in UDP header for GSO_PARTIAL

2026-01-28T01:30:51+00:00

In GSO_PARTIAL segmentation, set the UDP length field to the single segment size (gso_size + UDP header) instead of the large MSS size. This provides hardware with a template length value for final segmentation, similar to how tunnel GSO_PARTIAL handles outer headers in UDP tunnels. This will remove the need to manually adjust the UDP header length in the drivers, as can be seen in subsequent patches. This was suggested by Alex in 2018: https://lore.kernel.org/netdev/CAKgT0UcdnUWgr3KQ=RnLKigokkiUuYefmL-ePpDvJOBNpKScFA@mail.gmail.com/ Reviewed-by: Dragos Tatulea Signed-off-by: Gal Pressman Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20260125121649.778086-2-gal@nvidia.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: also consider secpath when evaluating ipsec use for checksumming

2025-08-07T06:07:15+00:00

Commit b40c5f4fde22 ("udp: disable inner UDP checksum offloads in IPsec case") tried to fix checksumming in UFO when the packets are going through IPsec, so that we can't rely on offloads because the UDP header and payload will be encrypted. But when doing a TCP test over VXLAN going through IPsec transport mode with GSO enabled (esp4_offload module loaded), I'm seeing broken UDP checksums on the encap after successful decryption. The skbs get to udp4_ufo_fragment/__skb_udp_tunnel_segment via __dev_queue_xmit -> validate_xmit_skb -> skb_gso_segment and at this point we've already dropped the dst (unless the device sets IFF_XMIT_DST_RELEASE, which is not common), so need_ipsec is false and we proceed with checksum offload. Make need_ipsec also check the secpath, which is not dropped on this callpath. Fixes: b40c5f4fde22 ("udp: disable inner UDP checksum offloads in IPsec case") Signed-off-by: Sabrina Dubroca Signed-off-by: Steffen Klassert

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

2025-07-17T18:00:33+00:00

Cross-merge networking fixes after downstream PR (net-6.16-rc7). Conflicts: Documentation/netlink/specs/ovpn.yaml 880d43ca9aa4 ("netlink: specs: clean up spaces in brackets") af52020fc599 ("ovpn: reject unexpected netlink attributes") drivers/net/phy/phy_device.c a44312d58e78 ("net: phy: Don't register LEDs for genphy") f0f2b992d818 ("net: phy: Don't register LEDs for genphy") https://lore.kernel.org/20250710114926.7ec3a64f@kernel.org drivers/net/wireless/intel/iwlwifi/fw/regulatory.c drivers/net/wireless/intel/iwlwifi/mld/regulatory.c 5fde0fcbd760 ("wifi: iwlwifi: mask reserved bits in chan_state_active_bitmap") ea045a0de3b9 ("wifi: iwlwifi: add support for accepting raw DSM tables by firmware") net/ipv6/mcast.c ae3264a25a46 ("ipv6: mcast: Delay put pmc->idev in mld_del_delrec()") a8594c956cc9 ("ipv6: mcast: Avoid a duplicate pointer check in mld_del_delrec()") https://lore.kernel.org/8cc52891-3653-4b03-a45e-05464fe495cf@kernel.org No adjacent changes. Signed-off-by: Jakub Kicinski