X-Git-Url: https://iankelling.org/git/?p=distro-setup;a=blobdiff_plain;f=mail-route;h=332f1edbf592728bd916dedb2816c50b3c67c20a;hp=95cbf8d8ef7c1bf4be8efd3d0a069f6d1a077b66;hb=79b274fcd8bfa556133ab13270e84b40aebe8468;hpb=eb9b839bb5a91c60cc4f6eb9d7e38ffbf73f0e90

diff --git a/mail-route b/mail-route
index 95cbf8d..332f1ed 100755
--- a/mail-route
+++ b/mail-route
@@ -1,6 +1,5 @@
 #!/bin/bash
 # Copyright (C) 2016 Ian Kelling
-
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
@@ -13,107 +12,181 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-[[ $EUID == 0 ]] || exec sudo "$BASH_SOURCE" "$@"
+[[ $EUID == 0 ]] || exec sudo -E "${BASH_SOURCE[0]}" "$@"
 
-source /a/bin/errhandle/errcatch-function
-source /a/bin/errhandle/errallow-function
-source /a/bin/errhandle/bash-trace-function
-errcatch
+source /a/bin/errhandle/err
 
 usage() {
-    cat <<'EOF'
-Usage: mail-route start|stop|show
+  cat <<'EOF'
+Usage: mail-route up|down|show
+
+Marks tcp packets on port 25, 143 and 587 to be routed through
+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.
+
+
+todo: Need to give mail.iankelling.org an ipv6 dns address.
 
-Marks tcp packets on port 25 and 143 to be routed through
-a vpn ip.
 EOF
-    exit $1
+  exit $1
 }
 
-if (( $# != 1 )); then
-    usage 1
+if (( $# < 1 )); then
+  usage 1
 fi
 
-start() {
-    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.
+up() {
+  start=true
+  stop=false
+  iptables_op=-A
+  ip_op=add
+  timeout_secs=20
+  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 [[ $tun_dev == tun* ]]; then
-            found=true
-            break
-        fi
-        sleep 1
+    for ((i=1; i<=timeout_secs; i++)); do
+      tun_dev=$(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
+      echo "$0: error: timeout after $timeout_secs waiting for valid tun_dev, currently:$tun_dev"
+      exit 1
     fi
-    e() { "$@"; }
-    _errcatch_cleanup=stop
-    modify
+  fi
+  e() { echo "$0: $*"; "$@"; }
+  _errcatch_cleanup=stop
+  modify
+  # we leave it as is even when stopping, because we would like it to be default, but the only way
+  # 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.
+  val=$(sysctl -n net.ipv4.conf.$tun_dev.rp_filter)
+  if [[ $val != 2 ]]; then
+    echo "net.ipv4.conf.$tun_dev.rp_filter = $val"
+    e sysctl net.ipv4.conf.$tun_dev.rp_filter=2
+  fi
+
 }
-stop() {
-    iptables_op=-D
-    ip_op=del
-    tun_dev=$(iptables -t nat -S | sed -rn "s/^-A POSTROUTING -o (tun[[:digit:]]+) -m mark --mark 0x1 -j SNAT --to-source 10.8.0.4$/\1/p"|head -n1) || printf "failed to find tun device.\n"
-    e() { "$@" || printf "maybe ok failure: %s\n" "$*"; }
-    modify
+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
 }
 
 show() {
-    e() { printf "${0##*/}: %s\n" "$*"; "$@"; }
-    e iptables -t mangle -S
-    e iptables -t nat -S
-    e ip rule
-    e ip route show table 1
+  printf "$(tput setaf 5)█$(tput sgr0)%.0s" $(seq ${COLUMNS:-60});
+  echo
+  e() { printf "=================================\n# %s\n\n" "$*"; "$@"; }
+  e iptables -t mangle -S
+  e ip6tables -t mangle -S
+  e iptables -t nat -S
+  e ip rule
+  e ip -6 rule
+  e ip route show table 1
+  e ip -6 route show table 1
+  e ip -6 route show default
+
+  tun_dev=$(ip a show to 10.8.0.4/24 | sed -rn '1s/^\S+\s+([^:]+).*/\1/p')
+  if [[ $tun_dev == tun* ]]; then
+    e sysctl net.ipv4.conf.$tun_dev.rp_filter
+  else
+    echo "$0: note, no tun device found"
+  fi
+  exit 0
+}
 
-    tun_dev=$(ip a show to 10.8.0.4/24 | sed -rn '1s/^\S+\s+([^:]+).*/\1/p')
-    if [[ $tun_dev == tun* ]]; then
-        e sysctl net.ipv4.conf.$tun_dev.rp_filter
-    else
-        echo "$0: note, no tun device found"
-    fi
-    exit 0
+runtest() {
+  # debugging:
+  #echo start=$start stop=$stop exists=$exists
+  { $start && ! $exists; } || { $stop && $exists; }
 }
 
+iptmod() { #iptables modify
+  local cmd="$*"
+  local exists=true
+  ${cmd/-[AD]/-C} &>/dev/null || exists=false
+  if runtest; then e $cmd; fi
+}
 
 # code common to start and stop.
 modify() {
-    # match source or dest port. note, when we send to a port, it picks a random high port as
-    # the source.
-    for port in 25 143; do # smtp and imap.
-        e iptables -t mangle $iptables_op \
-          OUTPUT -m tcp -p tcp -m multiport --ports $port -j MARK --set-mark 0x1
-        e iptables -t mangle $iptables_op \
-          OUTPUT -m tcp -p tcp -m multiport --ports $port -j MARK --set-mark 0x0 \
-          -d 10.0.0.0/8,172.16.0.0/12,192.168.0.0/16
-        # note, we could have used a custom chain and returned instead of setting the mark again.
-        # in case anyone was ever curious, the inverse of private ips is:   #0.0.0.0/5,8.0.0.0/7,11.0.0.0/8,12.0.0.0/6,16.0.0.0/4,32.0.0.0/3,64.0.0.0/2,128.0.0.0/3,160.0.0.0/5,168.0.0.0/6,172.0.0.0/12,172.32.0.0/11,172.64.0.0/10,172.128.0.0/9,173.0.0.0/8,174.0.0.0/7,176.0.0.0/4,192.0.0.0/9,192.128.0.0/11,192.160.0.0/13,192.169.0.0/16,192.170.0.0/15,192.172.0.0/14,192.176.0.0/12,192.192.0.0/10,193.0.0.0/8,194.0.0.0/7,196.0.0.0/6,200.0.0.0/5,208.0.0.0/4,224.0.0.0/3
+  # match source or dest port. note, when we send to a port, it picks a random high port as
+  # the source.
+
+  iptcommon="OUTPUT -m tcp -p tcp -m multiport --ports 25,143,587 -j MARK --set-mark"
+  iptmod iptables -t mangle $iptables_op $iptcommon 0x1
+  iptmod iptables -t mangle $iptables_op $iptcommon 0x0 -d 10.0.0.0/8,172.16.0.0/12,192.168.0.0/16,127.0.0.0/8
+  # note, we could have used a custom chain and returned instead of setting the mark again.
+  # in case anyone was ever curious, the inverse of private ips is:   #0.0.0.0/5,8.0.0.0/7,11.0.0.0/8,12.0.0.0/6,16.0.0.0/4,32.0.0.0/3,64.0.0.0/2,128.0.0.0/3,160.0.0.0/5,168.0.0.0/6,172.0.0.0/12,172.32.0.0/11,172.64.0.0/10,172.128.0.0/9,173.0.0.0/8,174.0.0.0/7,176.0.0.0/4,192.0.0.0/9,192.128.0.0/11,192.160.0.0/13,192.169.0.0/16,192.170.0.0/15,192.172.0.0/14,192.176.0.0/12,192.192.0.0/10,193.0.0.0/8,194.0.0.0/7,196.0.0.0/6,200.0.0.0/5,208.0.0.0/4,224.0.0.0/3
+  iptmod ip6tables -t mangle $iptables_op $iptcommon 0x1 -d 2000::/3
+
+  if [[ $tun_dev ]]; then
+    # when $tun_dev goes away, so does this rule.
+    iptmod iptables -t nat $iptables_op POSTROUTING -o $tun_dev -m mark --mark 0x1 -j SNAT --to-source 10.8.0.4
+    iptmod ip6tables -t nat $iptables_op POSTROUTING -o $tun_dev -m mark --mark 0x1 -j SNAT --to-source 2600:3c00:e000:280::2
+
+  fi
+
+
+  iprulecmd="fwmark 1 table 1"
+  for v in -4 -6; do
+    exists=true; ip $v rule show $iprulecmd | grep . &>/dev/null || exists=false
+    if runtest; then e ip $v rule $ip_op $iprulecmd; fi
+  done
+
+  iproutecmd="default via 10.8.0.1 table 1"
+  exists=true; ip route show $iproutecmd | grep . &>/dev/null || exists=false
+  if runtest; then e ip route $ip_op $iproutecmd; fi
+  if [[ $tun_dev ]]; then
+    # when $tun_dev goes away, so does this route.
+    iproutecmd="default dev $tun_dev table 1"
+    exists=true; ip -6 route show $iproutecmd | grep . &>/dev/null || exists=false
+    if runtest; then e ip -6 route $ip_op $iproutecmd; fi
+
+    # We could only do this if we dont have a default route with [[ ! $(ip -6 r show default) ]] but
+    # metric seems to be perfectly good. 6000 because on my home comp,
+    # its about 6 times slower to ping google, than the default 1024 metric.
+    iproutecmd="default dev $tun_dev"
+    exists=true; ip -6 route show $iproutecmd | grep . &>/dev/null || exists=false
+    if runtest; then e ip -6 route $ip_op $iproutecmd metric 6000; fi
+  fi
+  # on debian this is 0 (no filter), on ubuntu it\'s 1, which is no good. 0 or 2 both work fine.
+  # 2 drops it if the packet is not routable, martian address, or my default route is screwed up,
+  # so, eh, might as well. some rhel docs recommend using it.
 
-    done
-    e iptables -t nat $iptables_op POSTROUTING -o $tun_dev -m mark --mark 0x1 -j SNAT --to-source 10.8.0.4
-    e ip rule $ip_op fwmark 1 table 1
-    # note, this rule does not persist when the tun interface is deleted
-    e ip route $ip_op default via 10.8.0.1 table 1
-
-    # on debian this is 0 (no filter), on ubuntu it\'s 1, which is no good. 0 or 2 both work fine.
-    # 2 drops it if the packet is not routable, martian address, or my default route is screwed up,
-    # so, eh, might as well. some rhel docs recommend using it.
-    e sysctl net.ipv4.conf.$tun_dev.rp_filter=2
 
-    exit 0
 }
 
-case $1 in
-    start|stop|show) $1 ;;
+if (( $# > 1 )); then
+  tun_dev=$1
+  $script_type
+else
+  case $1 in
+    up|down|show) $1 ;;
     *) usage 1 ;;
-esac
+  esac
+fi
+
+exit 0
 
 
 # background: something like this does not work for packets which
 # exim is replying to. I don't know why.
 #iptables -t mangle -A OUTPUT -m owner --uid-owner Debian-exim -j MARK --set-mark 0x1
+#
+# note: exim will misreport the I= interface for remote hosts that would
+# not use the default route. It still goes through the vpn, you can
+# verify with tcpdump.