TheArchive/tailscale
1
0
Fork 0
mirror of https://github.com/tailscale/tailscale.git synced 2025-12-27 04:46:40 +00:00
Code Issues Packages Projects Releases Wiki Activity

wgengine/magicsock: fix bpf fragmentation jump offsets (#16204)

Browse Source 
Fragmented datagrams would be processed instead of being dumped right
away. In reality, thse datagrams would be dropped anyway later so there
should functionally not be any change. Additionally, the feature is off
by default.

Closes #16203

Signed-off-by: Claus Lensbøl <claus@tailscale.com>
This commit is contained in:
Claus Lensbøl
2025-06-06 11:42:33 -04:00
committed by GitHub
parent 3e08eab21e
commit 3f7a9f82e3
2 changed files with 78 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
wgengine/magicsock/magicsock_linux.go
View File

@@ -66,10 +66,10 @@ var (
// fragmented, and we don't want to handle reassembly.
bpf.LoadAbsolute{Off: 6, Size: 2},
// More Fragments bit set means this is part of a fragmented packet.
bpf.JumpIf{Cond: bpf.JumpBitsSet, Val: 0x2000, SkipTrue: 7, SkipFalse: 0},
bpf.JumpIf{Cond: bpf.JumpBitsSet, Val: 0x2000, SkipTrue: 8, SkipFalse: 0},
// Non-zero fragment offset with MF=0 means this is the last
// fragment of packet.
bpf.JumpIf{Cond: bpf.JumpBitsSet, Val: 0x1fff, SkipTrue: 6, SkipFalse: 0},
bpf.JumpIf{Cond: bpf.JumpBitsSet, Val: 0x1fff, SkipTrue: 7, SkipFalse: 0},
// Load IP header length into X register.
bpf.LoadMemShift{Off: 0},