wg-quick: linux: filter bogus injected packets and don't disable rpfilter

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
Jason A. Donenfeld 2019-11-21 11:19:43 +01:00
parent a59aa6c404
commit ebcf1ef8b1
1 changed files with 29 additions and 8 deletions

View File

@ -95,6 +95,7 @@ add_if() {
del_if() {
local table
[[ $HAVE_SET_DNS -eq 0 ]] || unset_dns
[[ $HAVE_SET_IPTABLES -eq 0 ]] || remove_iptables
if [[ -z $TABLE || $TABLE == auto ]] && get_fwmark table && [[ $(wg show "$INTERFACE" allowed-ips) =~ /0(\ |$'\n'|$) ]]; then
while [[ $(ip -4 rule show) == *"lookup $table"* ]]; do
cmd ip -4 rule delete table $table
@ -180,8 +181,22 @@ get_fwmark() {
return 0
}
remove_iptables() {
local line iptables found restore
for iptables in iptables ip6tables; do
restore="" found=0
while read -r line; do
[[ $line == "*"* || $line == COMMIT || $line == "-A "*"-m comment --comment \"wg-quick(8) rule for $INTERFACE\""* ]] || continue
[[ $line == "-A"* ]] && found=1
printf -v restore '%s\n%s' "$restore" "${line/#-A/-D}"
done < <($iptables-save)
[[ $found -eq 1 ]] && echo "$restore" | cmd $iptables-restore -nw
done
}
HAVE_SET_IPTABLES=0
add_default() {
local table proto key value
local table proto i iptables
if ! get_fwmark table; then
table=51820
while [[ -n $(ip -4 route show table $table) || -n $(ip -6 route show table $table) ]]; do
@ -189,16 +204,21 @@ add_default() {
done
cmd wg set "$INTERFACE" fwmark $table
fi
proto=-4
[[ $1 == *:* ]] && proto=-6
proto=-4 iptables=iptables
[[ $1 == *:* ]] && proto=-6 iptables=ip6tables
cmd ip $proto route add "$1" dev "$INTERFACE" table $table
cmd ip $proto rule add not fwmark $table table $table
cmd ip $proto rule add table main suppress_prefixlength 0
if [[ $proto == -4 ]]; then
while read -r key _ value; do
[[ $value -eq 1 ]] && sysctl -q "$key=2"
done < <(sysctl -a -r '^net\.ipv4.conf\.[^ .=]+\.rp_filter$')
fi
local marker="-m comment --comment \"wg-quick(8) rule for $INTERFACE\"" restore="*raw"
for i in "${ADDRESSES[@]}"; do
[[ ( $proto == -4 && $i != *:* ) || ( $proto == -6 && $i == *:* ) ]] || continue
printf -v restore '%s\n-I PREROUTING ! -i %s -d %s -m addrtype ! --src-type LOCAL -j DROP %s\n' "$restore" "$INTERFACE" "${i%/*}" "$marker"
done
printf -v restore '%s\nCOMMIT\n*mangle\n-I POSTROUTING -m mark --mark %d -p udp -j CONNMARK --save-mark %s\n-I PREROUTING -p udp -j CONNMARK --restore-mark %s\nCOMMIT\n' "$restore" $table "$marker" "$marker"
[[ $proto == -4 ]] && cmd sysctl -q net.ipv4.conf.all.src_valid_mark=1
echo "$restore" | cmd $iptables-restore -nw
HAVE_SET_IPTABLES=1
return 0
}
@ -303,6 +323,7 @@ cmd_down() {
[[ $SAVE_CONFIG -eq 0 ]] || save_config
del_if
unset_dns
remove_iptables
execute_hooks "${POST_DOWN[@]}"
}