wg-quick: linux: some iptables don't like empty lines

Reported-by: Kenneth R. Crudup <kenny@panix.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

diff --git a/src/wg-quick/linux.bash b/src/wg-quick/linux.bash
index fc90e55b123d85641fad222b432fc61247f0f684..d2c2ba93ec2b30d9edda4d74d149e986dcf76fff 100755 (executable)
--- a/src/wg-quick/linux.bash
+++ b/src/wg-quick/linux.bash
@@ -188,9 +188,9 @@ remove_iptables() {
                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" "${line/#-A/-D}"
+                       printf -v restore '%s%s\n' "$restore" "${line/#-A/-D}"
                done < <($iptables-save)
-               [[ $found -ne 1 ]] || echo "$restore" | cmd $iptables-restore -n
+               [[ $found -ne 1 ]] || echo -n "$restore" | cmd $iptables-restore -n
        done
 }
 
@@ -210,14 +210,14 @@ add_default() {
        cmd ip $proto rule add not fwmark $table table $table
        cmd ip $proto rule add table main suppress_prefixlength 0
 
-       local marker="-m comment --comment \"wg-quick(8) rule for $INTERFACE\"" restore="*raw"
+       local marker="-m comment --comment \"wg-quick(8) rule for $INTERFACE\"" restore=$'*raw\n'
        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%/*}" "$marker"
+               printf -v restore '%s-I PREROUTING ! -i %s -d %s -m addrtype ! --src-type LOCAL -j DROP %s\n' "$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" "$marker"
+       printf -v restore '%sCOMMIT\n*mangle\n-I POSTROUTING -m mark --mark %d -p udp -j CONNMARK --save-mark %s\n-I PREROUTING -p udp -j CONNMARK --restore-mark %s\nCOMMIT\n' "$restore" $table "$marker" "$marker"
        [[ $proto == -4 ]] && cmd sysctl -q net.ipv4.conf.all.src_valid_mark=1
-       echo "$restore" | cmd $iptables-restore -n
+       echo -n "$restore" | cmd $iptables-restore -n
        HAVE_SET_IPTABLES=1
        return 0
 }