ctdb/config/events.d/11.natgw

   1 #!/bin/sh
   2 # Script to set up one of the nodes as a NAT gateway for all other nodes.
   3 # This is used to ensure that all nodes in the cluster can still originate
   4 # traffic to the external network even if there are no public addresses
   5 # available.
   6 #
   7
   8 [ -n "$CTDB_BASE" ] || \
   9     export CTDB_BASE=$(cd -P $(dirname "$0") ; dirname "$PWD")
  10
  11 . $CTDB_BASE/functions
  12 loadconfig
  13
  14 [ -n "$CTDB_NATGW_NODES" ] || exit 0
  15 export CTDB_NATGW_NODES
  16
  17 set_natgw_capability ()
  18 {
  19     # Set NATGW capability depending on configuration
  20     if [ "$CTDB_NATGW_SLAVE_ONLY" = "yes" ] ; then
  21         ctdb setnatgwstate off
  22     else
  23         ctdb setnatgwstate on
  24     fi
  25 }
  26
  27 delete_all() {
  28         _ip="${CTDB_NATGW_PUBLIC_IP%/*}"
  29         _maskbits="${CTDB_NATGW_PUBLIC_IP#*/}"
  30
  31         [ -z "$CTDB_NATGW_PUBLIC_IFACE" ] || {
  32             delete_ip_from_iface $CTDB_NATGW_PUBLIC_IFACE $_ip $_maskbits >/dev/null 2>&1
  33         }
  34         ip route del 0.0.0.0/0 metric 10 >/dev/null 2>/dev/null
  35
  36         # Delete the masquerading setup from a previous iteration where we
  37         # were the NAT-GW
  38         iptables -D POSTROUTING -t nat -s $CTDB_NATGW_PRIVATE_NETWORK ! -d $CTDB_NATGW_PRIVATE_NETWORK -j MASQUERADE >/dev/null 2>/dev/null
  39
  40         # remove any iptables rule we may have on this address
  41         iptables -D INPUT -p tcp --syn -d $_ip/32 -j REJECT 2>/dev/null
  42 }
  43
  44 ensure_natgwmaster ()
  45 {
  46     _event="$1"
  47
  48     set -- $(ctdb natgwlist)
  49     natgwmaster="${1:--1}" # Default is -1 if natgwlist fails
  50     natgwip="$2"
  51
  52     if [ "$natgwmaster" = "-1" ]; then
  53         # Fail...
  54         die "There is no NATGW master node"
  55     fi
  56 }
  57
  58 case "$1" in
  59     setup)
  60         set_natgw_capability
  61         ;;
  62
  63     startup)
  64         # Error if CTDB_NATGW_PUBLIC_IP is listed in public addresses
  65         grep -q "^$CTDB_NATGW_PUBLIC_IP[[:space:]]" "${CTDB_PUBLIC_ADDRESSES:-/etc/ctdb/public_addresses}" && \
  66             die "ERROR: NATGW configured to use a public address. NATGW must not use a public address."
  67
  68         # do not send out arp requests from loopback addresses
  69         echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce
  70         ;;
  71
  72     updatenatgw|ipreallocated)
  73         mypnn=$(ctdb pnn | cut -d: -f2)
  74
  75         set_natgw_capability
  76         ensure_natgwmaster "$1"
  77
  78         delete_all
  79
  80         if [ "$mypnn" = "$natgwmaster" ]; then
  81                 # This is the NAT GW
  82                 echo 1 >/proc/sys/net/ipv4/ip_forward
  83                 iptables -A POSTROUTING -t nat -s $CTDB_NATGW_PRIVATE_NETWORK ! -d $CTDB_NATGW_PRIVATE_NETWORK -j MASQUERADE
  84
  85                 # block all incoming connections to the natgw address
  86                 ctdb_natgw_public_ip_host="${CTDB_NATGW_PUBLIC_IP%/*}/32"
  87                 iptables -D INPUT -p tcp --syn -d $ctdb_natgw_public_ip_host -j REJECT 2>/dev/null
  88                 iptables -I INPUT -p tcp --syn -d $ctdb_natgw_public_ip_host -j REJECT 2>/dev/null
  89
  90                 ip addr add $CTDB_NATGW_PUBLIC_IP dev $CTDB_NATGW_PUBLIC_IFACE
  91                 ip route add 0.0.0.0/0 metric 10 via $CTDB_NATGW_DEFAULT_GATEWAY >/dev/null 2>/dev/null
  92         else
  93                 # This is NOT the NAT GW
  94                 ip route add 0.0.0.0/0 via $natgwip metric 10
  95                 # Make sure winbindd does not stay bound to this address
  96                 # if we are no longer natgwmaster
  97                 smbcontrol winbindd ip-dropped $CTDB_NATGW_PUBLIC_IP >/dev/null 2>/dev/null
  98         fi
  99
 100         # flush our route cache
 101         echo 1 > /proc/sys/net/ipv4/route/flush
 102         ;;
 103
 104     shutdown|removenatgw)
 105         delete_all
 106         ;;
 107
 108     monitor)
 109         set_natgw_capability
 110         ensure_natgwmaster "$1"
 111         ;;
 112
 113     *)
 114         ctdb_standard_event_handler "@"
 115         ;;
 116 esac
 117
 118 exit 0