fix: double offset bug in ip address calculation for pseudo headers#101
Merged
vnt-dev merged 1 commit intotun-rs:mainfrom Dec 22, 2025
Merged
fix: double offset bug in ip address calculation for pseudo headers#101vnt-dev merged 1 commit intotun-rs:mainfrom
vnt-dev merged 1 commit intotun-rs:mainfrom
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Fixes a critical bug in `apply_tcp_coalesce_accounting` and `apply_udp_coalesce_accounting` where the buffer offset was added twice when calculating the source and destination address positions. The packet buffer slice (`pkt`) was already offset by `offset` (i.e. VIRTIO_NET_HDR_LEN), but the code added `offset` again to `addr_offset`. This caused the pseudo-header checksum to be calculated using garbage data (often bytes from the Transport header) instead of the correct Source and Destination IP addresses. This resulted in invalid TCP/UDP checksum seeds, causing dropped packets.
Contributor
Author
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Any advice on how to deal with the failing checks? They don't seem to be related to my changes |
Collaborator
Let's ignore this problem, I'll handle it. |
Collaborator
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This issue is caused by an update in libc. You can refer to nix-rust/nix#2709 |
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Fixes a critical bug in
apply_tcp_coalesce_accountingandapply_udp_coalesce_accountingwhere the buffer offset was added twice when calculating the source and destination address positions.The packet buffer slice (
pkt) was already offset byoffset(i.e. VIRTIO_NET_HDR_LEN), but the code addedoffsetagain toaddr_offset. This caused the pseudo-header checksum to be calculated using garbage data (often bytes from the Transport header) instead of the correct Source and Destination IP addresses.This resulted in invalid TCP/UDP checksum seeds, causing dropped packets.