fixup mail route going down, and switch mail with no internet

[distro-setup] / mail-route

diff --git a/mail-route b/mail-route
index 2e08a83309a7481a8989b23e62805aadb5e142b4..81a3ccb73dcc7b1f797353df5c6ea56ba546aa09 100755 (executable)
--- a/mail-route
+++ b/mail-route
@@ -22,37 +22,41 @@ errcatch
 
 usage() {
     cat <<'EOF'
-Usage: mail-route start|stop|show
+Usage: mail-route up|down|show
 
 Marks tcp packets on port 25 and 143 to be routed through
-a vpn ip. Is idempotent.
+a vpn ip. If called from --up/--down in openvpn, (we have multiple args) $1 is the
+tun_dev, and action is from $script_type.
+
+Is idempotent.
 EOF
     exit $1
 }
 
-if (( $# != 1 )); then
+if (( $# < 1 )); then
     usage 1
 fi
 
-start() {
+up() {
     start=true
     stop=false
     iptables_op=-A
     ip_op=add
-    # systemd around stretch release time, would wait until openvpn actually connected,
-    # so this was unnecessary, but now it returns immediately.
-    found=false
-    for ((i=1; i<=30; i++)); do
-        tun_dev=$(ip a show to 10.8.0.4/24 | sed -rn '1s/^\S+\s+([^:]+).*/\1/p')
-        if [[ $tun_dev == tun* ]]; then
-            found=true
-            break
+    if [[ ! $tun_dev ]]; then
+        # delays because I was running this outside of openvpn before
+        found=false
+        for ((i=1; i<=30; i++)); do
+            tun_dev=$(ip a show to 10.8.0.4/24 | sed -rn '1s/^\S+\s+([^:]+).*/\1/p')
+            if [[ $tun_dev == tun* ]]; then
+                found=true
+                break
+            fi
+            sleep 1
+        done
+        if ! $found; then
+            echo "$0: error: timeout waiting for valid tun_dev, currently:$tun_dev"
+            exit 1
         fi
-        sleep 1
-    done
-    if ! $found; then
-        echo "$0: error: timeout waiting for valid tun_dev, currently:$tun_dev"
-        exit 1
     fi
     e() { echo "$0: $*"; "$@"; }
     _errcatch_cleanup=stop
@@ -61,12 +65,17 @@ start() {
     # to change the default is for every device, and I want to avoid that, even though I wouldn't mind, others users of this script might.
     e sysctl net.ipv4.conf.$tun_dev.rp_filter=2
 }
-stop() {
+down() {
     start=false
     stop=true
     iptables_op=-D
     ip_op=del
+    # note, this is not going to work if the interface has been deleted.
+    # we could also check for an iptable rule that on some tun interface like the one
+    # we use, but meh, the way I'm using the script now, tun_dev is supplied by openvpn
+    if [[ ! tun_dev ]]; then
     tun_dev=$(ip a show to 10.8.0.4/24 | sed -rn '1s/^\S+\s+([^:]+).*/\1/p')
+    fi
     e() { echo "$0: $*"; "$@" || printf "maybe ok failure: %s\n" "$*"; }
     modify
 }
@@ -113,7 +122,7 @@ modify() {
 
     if [[ $tun_dev ]]; then
         # when $tun_dev goes away, so does this rul
-    iptmod iptables -t nat $iptables_op POSTROUTING -o $tun_dev -m mark --mark 0x1 -j SNAT --to-source 10.8.0.4
+        iptmod iptables -t nat $iptables_op POSTROUTING -o $tun_dev -m mark --mark 0x1 -j SNAT --to-source 10.8.0.4
     fi
 
 
@@ -130,13 +139,21 @@ modify() {
     # so, eh, might as well. some rhel docs recommend using it.
 
 
-    exit 0
 }
 
-case $1 in
-    start|stop|show) $1 ;;
-    *) usage 1 ;;
-esac
+if (( $# > 1 )); then
+tun_dev=$1
+$script_type
+else
+    case $1 in
+        up|down|show) $1 ;;
+        *) usage 1 ;;
+    esac
+fi
+
+
+
+exit 0
 
 
 # background: something like this does not work for packets which