package/wireguard-go
1
0
Fork 0
mirror of https://git.zx2c4.com/wireguard-go synced 2025-10-05 08:36:57 +08:00
Code Issues Packages Projects Releases Wiki Activity

tun: use correct IP header comparisons in tcpGRO() and tcpPacketsCanCoalesce()

Browse Source 
tcpGRO() was using an incorrect IPv4 more fragments bit mask.

tcpPacketsCanCoalesce() was not distinguishing tcp6 from tcp4, and TTL
values were not compared. TTL values should be equal at the IP layer,
otherwise the packets should not coalesce. This tracks with the kernel.

Reviewed-by: Denton Gentry <dgentry@tailscale.com>
Signed-off-by: Jordan Whited <jordan@tailscale.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
Jordan Whited
2023-03-24 16:23:42 -07:00
committed by Jason A. Donenfeld
parent aad7fca9c5
commit 052af4a807
2 changed files with 119 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

35
tun/tcp_offload_linux.go
View File

@@ -189,14 +189,29 @@ func tcpPacketsCanCoalesce(pkt []byte, iphLen, tcphLen uint8, seq uint32, pshSet
return coalesceUnavailable
}
}
if pkt[1] != pktTarget[1] {
// cannot coalesce with unequal ToS values
return coalesceUnavailable
}
if pkt[6]>>5 != pktTarget[6]>>5 {
// cannot coalesce with unequal DF or reserved bits. MF is checked
// further up the stack.
return coalesceUnavailable
if pkt[0]>>4 == 6 {
if pkt[0] != pktTarget[0] || pkt[1]>>4 != pktTarget[1]>>4 {
// cannot coalesce with unequal Traffic class values
return coalesceUnavailable
}
if pkt[7] != pktTarget[7] {
// cannot coalesce with unequal Hop limit values
return coalesceUnavailable
}
} else {
if pkt[1] != pktTarget[1] {
// cannot coalesce with unequal ToS values
return coalesceUnavailable
}
if pkt[6]>>5 != pktTarget[6]>>5 {
// cannot coalesce with unequal DF or reserved bits. MF is checked
// further up the stack.
return coalesceUnavailable
}
if pkt[8] != pktTarget[8] {
// cannot coalesce with unequal TTL values
return coalesceUnavailable
}
}
// seq adjacency
lhsLen := item.gsoSize
@@ -366,7 +381,7 @@ func coalesceTCPPackets(mode canCoalesce, pkt []byte, pktBuffsIndex int, gsoSize
}
const (
ipv4FlagMoreFragments = 0x80
ipv4FlagMoreFragments uint8 = 0x20
)
const (
@@ -409,7 +424,7 @@ func tcpGRO(bufs [][]byte, offset int, pktI int, table *tcpGROTable, isV6 bool)
return false
}
if !isV6 {
if pkt[6]&ipv4FlagMoreFragments != 0 || (pkt[6]<<3 != 0 || pkt[7] != 0) {
if pkt[6]&ipv4FlagMoreFragments != 0 || pkt[6]<<3 != 0 || pkt[7] != 0 {
// no GRO support for fragmented segments for now
return false
}