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| author |   Jason A. Donenfeld <Jason@zx2c4.com> | 2025-05-21 23:03:08 +0200 |
|---|---|---|
| committer | Jason A. Donenfeld <Jason@zx2c4.com> | 2025-05-21 23:07:59 +0200 |
| commit | 5150cd647073be1f1c12688aef291bdf17970154 (patch) | |
| tree | 9b843e6603ad4dc10a128b90c2be640bfda03a71 | |
| parent | version: bump (diff) | |
| download | wireguard-tools-5150cd647073be1f1c12688aef291bdf17970154.tar.xz wireguard-tools-5150cd647073be1f1c12688aef291bdf17970154.zip | |
wg-quick: linux: use smallest mtu, not largest
By accident, this function was looking at the endpoint with the largest
MTU rather than the smallest one.
Reported-by: Ismael Bouya <ismael@bouya.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
| -rwxr-xr-x | src/wg-quick/linux.bash | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/src/wg-quick/linux.bash b/src/wg-quick/linux.bash index 93df80d..acb015d 100755 --- a/src/wg-quick/linux.bash +++ b/src/wg-quick/linux.bash @@ -123,7 +123,7 @@ add_addr() { } set_mtu_up() { - local mtu=0 endpoint output + local mtu=2147483647 endpoint output if [[ -n $MTU ]]; then cmd ip link set mtu "$MTU" up dev "$INTERFACE" return @@ -131,13 +131,13 @@ set_mtu_up() { while read -r _ endpoint; do [[ $endpoint =~ ^\[?([a-z0-9:.]+)\]?:[0-9]+$ ]] || continue output="$(ip route get "${BASH_REMATCH[1]}" || true)" - [[ ( $output =~ mtu\ ([0-9]+) || ( $output =~ dev\ ([^ ]+) && $(ip link show dev "${BASH_REMATCH[1]}") =~ mtu\ ([0-9]+) ) ) && ${BASH_REMATCH[1]} -gt $mtu ]] && mtu="${BASH_REMATCH[1]}" + [[ ( $output =~ mtu\ ([0-9]+) || ( $output =~ dev\ ([^ ]+) && $(ip link show dev "${BASH_REMATCH[1]}") =~ mtu\ ([0-9]+) ) ) && ${BASH_REMATCH[1]} -lt $mtu ]] && mtu="${BASH_REMATCH[1]}" done < <(wg show "$INTERFACE" endpoints) - if [[ $mtu -eq 0 ]]; then + if [[ $mtu -eq 2147483647 ]]; then read -r output < <(ip route show default || true) || true - [[ ( $output =~ mtu\ ([0-9]+) || ( $output =~ dev\ ([^ ]+) && $(ip link show dev "${BASH_REMATCH[1]}") =~ mtu\ ([0-9]+) ) ) && ${BASH_REMATCH[1]} -gt $mtu ]] && mtu="${BASH_REMATCH[1]}" + [[ ( $output =~ mtu\ ([0-9]+) || ( $output =~ dev\ ([^ ]+) && $(ip link show dev "${BASH_REMATCH[1]}") =~ mtu\ ([0-9]+) ) ) && ${BASH_REMATCH[1]} -lt $mtu ]] && mtu="${BASH_REMATCH[1]}" fi - [[ $mtu -gt 0 ]] || mtu=1500 + [[ $mtu -gt 0 && $mtu -lt 2147483647 ]] || mtu=1500 cmd ip link set mtu $(( mtu - 80 )) up dev "$INTERFACE" } |