wg-quick: linux: support older nft(8)

Older nft(8), such as that on Ubuntu, does not accept the - parameter to
the -f argument and doesn't accept symbolic priority names. So instead
use the canonical numeric priority forms and use <(echo) instead of -.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

diff --git a/src/wg-quick/linux.bash b/src/wg-quick/linux.bash
index dde02951289f0cb33d4fa335ee5a95306b714d13..d52bad306957f7372b2fadb8db70e65a0fabe90e 100755 (executable)
--- a/src/wg-quick/linux.bash
+++ b/src/wg-quick/linux.bash
@@ -187,7 +187,7 @@ remove_firewall() {
                while read -r table; do
                        [[ $table == *" wg-quick-$INTERFACE" ]] && printf -v nftcmd '%sdelete %s\n' "$nftcmd" "$table"
                done < <(nft list tables 2>/dev/null)
-               [[ -z $nftcmd ]] || echo -n "$nftcmd" | cmd nft -f -
+               [[ -z $nftcmd ]] || cmd nft -f <(echo -n "$nftcmd")
        else
                local line iptables found restore
                for iptables in iptables ip6tables; do
@@ -220,9 +220,9 @@ add_default() {
 
        local marker="-m comment --comment \"wg-quick(8) rule for $INTERFACE\"" restore=$'*raw\n' nftable="wg-quick-$INTERFACE" nftcmd 
        printf -v nftcmd '%sadd table %s %s\n' "$nftcmd" "$pf" "$nftable"
-       printf -v nftcmd '%sadd chain %s %s preraw { type filter hook prerouting priority raw; }\n' "$nftcmd" "$pf" "$nftable"
-       printf -v nftcmd '%sadd chain %s %s premangle { type filter hook prerouting priority mangle; }\n' "$nftcmd" "$pf" "$nftable"
-       printf -v nftcmd '%sadd chain %s %s postmangle { type filter hook postrouting priority mangle; }\n' "$nftcmd" "$pf" "$nftable"
+       printf -v nftcmd '%sadd chain %s %s preraw { type filter hook prerouting priority -300; }\n' "$nftcmd" "$pf" "$nftable"
+       printf -v nftcmd '%sadd chain %s %s premangle { type filter hook prerouting priority -150; }\n' "$nftcmd" "$pf" "$nftable"
+       printf -v nftcmd '%sadd chain %s %s postmangle { type filter hook postrouting priority -150; }\n' "$nftcmd" "$pf" "$nftable"
        for i in "${ADDRESSES[@]}"; do
                [[ ( $proto == -4 && $i != *:* ) || ( $proto == -6 && $i == *:* ) ]] || continue
                printf -v restore '%s-I PREROUTING ! -i %s -d %s -m addrtype ! --src-type LOCAL -j DROP %s\n' "$restore" "$INTERFACE" "${i%/*}" "$marker"
@@ -233,7 +233,7 @@ add_default() {
        printf -v nftcmd '%sadd rule %s %s premangle meta l4proto udp meta mark set ct mark \n' "$nftcmd" "$pf" "$nftable"
        [[ $proto == -4 ]] && cmd sysctl -q net.ipv4.conf.all.src_valid_mark=1
        if type -p nft >/dev/null; then
-               echo -n "$nftcmd" | cmd nft -f -
+               cmd nft -f <(echo -n "$nftcmd")
        else
                echo -n "$restore" | cmd $iptables-restore -n
        fi