diff options
| author | Alice Mikityanska <alice@isovalent.com> | 2026-05-18 09:22:49 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-05-20 15:02:47 -0700 |
| commit | 5f17ae0f595aeb560155ce98edbe44d3eacc7e40 (patch) | |
| tree | 249c8bfa486a49febabc3a44aa114e08fcae3af1 | |
| parent | dc416e32baaeb620b9809e9e25fc7b30889686e9 (diff) | |
udp: gso: Fix handling checksum in __udp_gso_segment
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 <alice@isovalent.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Gal Pressman <gal@nvidia.com>
Link: https://patch.msgid.link/20260518062250.3019914-2-gal@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/ipv4/udp_offload.c | 13 |
1 files changed, 2 insertions, 11 deletions
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index a0813d425b71..2578aa7f9ff9 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -482,11 +482,11 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, struct sock *sk = gso_skb->sk; unsigned int sum_truesize = 0; struct sk_buff *segs, *seg; - __be16 newlen, msslen; struct udphdr *uh; unsigned int mss; bool copy_dtor; __sum16 check; + __be16 newlen; int ret = 0; mss = skb_shinfo(gso_skb)->gso_size; @@ -555,15 +555,6 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, return segs; } - msslen = htons(sizeof(*uh) + mss); - - /* GSO partial and frag_list segmentation only requires splitting - * the frame into an MSS multiple and possibly a remainder, both - * cases return a GSO skb. So update the mss now. - */ - if (skb_is_gso(segs)) - mss *= skb_shinfo(segs)->gso_segs; - seg = segs; uh = udp_hdr(seg); @@ -586,7 +577,7 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, if (!seg->next) break; - uh->len = msslen; + uh->len = newlen; uh->check = check; if (seg->ip_summed == CHECKSUM_PARTIAL) |