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 natgw_check_config ()
  18 {
  19     [ -r "$CTDB_NATGW_NODES" ] || \
  20         die "error: CTDB_NATGW_NODES=${CTDB_NATGW_NODES} unreadable"
  21     [ -n "$CTDB_NATGW_PUBLIC_IP" ] || \
  22         die "Invalid configuration: CTDB_NATGW_PUBLIC_IP not set"
  23     [ -n "$CTDB_NATGW_PUBLIC_IFACE" ] || \
  24         die "Invalid configuration: CTDB_NATGW_PUBLIC_IFACE not set"
  25     [ -n "$CTDB_NATGW_PRIVATE_NETWORK" ] || \
  26         die "Invalid configuration: CTDB_NATGW_PRIVATE_NETWORK not set"
  27 }
  28
  29 natgw_set_capability ()
  30 {
  31     # Set NATGW capability depending on configuration
  32     if [ "$CTDB_NATGW_SLAVE_ONLY" = "yes" ] ; then
  33         ctdb setnatgwstate off
  34     else
  35         ctdb setnatgwstate on
  36     fi
  37 }
  38
  39 natgw_clear ()
  40 {
  41         _ip="${CTDB_NATGW_PUBLIC_IP%/*}"
  42         _maskbits="${CTDB_NATGW_PUBLIC_IP#*/}"
  43
  44         delete_ip_from_iface $CTDB_NATGW_PUBLIC_IFACE $_ip $_maskbits >/dev/null 2>&1
  45         ip route del 0.0.0.0/0 metric 10 >/dev/null 2>/dev/null
  46
  47         # Delete the masquerading setup from a previous iteration where we
  48         # were the NAT-GW
  49         iptables -D POSTROUTING -t nat -s $CTDB_NATGW_PRIVATE_NETWORK ! -d $CTDB_NATGW_PRIVATE_NETWORK -j MASQUERADE >/dev/null 2>/dev/null
  50
  51         # remove any iptables rule we may have on this address
  52         iptables -D INPUT -p tcp --syn -d $_ip/32 -j REJECT 2>/dev/null
  53 }
  54
  55 natgw_set_master ()
  56 {
  57     set_proc sys/net/ipv4/ip_forward 1
  58     iptables -A POSTROUTING -t nat \
  59         -s $CTDB_NATGW_PRIVATE_NETWORK ! -d $CTDB_NATGW_PRIVATE_NETWORK \
  60         -j MASQUERADE
  61
  62     # block all incoming connections to the NATGW IP address
  63     ctdb_natgw_public_ip_host="${CTDB_NATGW_PUBLIC_IP%/*}/32"
  64     iptables -D INPUT -p tcp --syn \
  65         -d $ctdb_natgw_public_ip_host -j REJECT 2>/dev/null
  66     iptables -I INPUT -p tcp --syn \
  67         -d $ctdb_natgw_public_ip_host -j REJECT 2>/dev/null
  68
  69     ip addr add $CTDB_NATGW_PUBLIC_IP dev $CTDB_NATGW_PUBLIC_IFACE
  70     ip route add 0.0.0.0/0 metric 10 via $CTDB_NATGW_DEFAULT_GATEWAY >/dev/null 2>/dev/null
  71 }
  72
  73 natgw_set_slave ()
  74 {
  75     _natgwip="$1"
  76
  77     ip route add 0.0.0.0/0 via "$_natgwip" metric 10
  78
  79     # Make sure winbindd does not stay bound to this address if we are
  80     # no longer NATGW master
  81     smbcontrol winbindd ip-dropped $CTDB_NATGW_PUBLIC_IP >/dev/null 2>&1
  82 }
  83
  84 natgw_ensure_master ()
  85 {
  86     _event="$1"
  87
  88     set -- $(ctdb natgwlist)
  89     natgwmaster="${1:--1}" # Default is -1 if natgwlist fails
  90     natgwip="$2"
  91
  92     if [ "$natgwmaster" = "-1" ]; then
  93         # Fail...
  94         die "There is no NATGW master node"
  95     fi
  96 }
  97
  98 case "$1" in
  99     setup)
 100         natgw_check_config
 101         natgw_set_capability
 102         ;;
 103
 104     startup)
 105         natgw_check_config
 106
 107         # Error if CTDB_NATGW_PUBLIC_IP is listed in public addresses
 108         grep -q "^$CTDB_NATGW_PUBLIC_IP[[:space:]]" "${CTDB_PUBLIC_ADDRESSES:-/etc/ctdb/public_addresses}" && \
 109             die "ERROR: NATGW configured to use a public address. NATGW must not use a public address."
 110
 111         # do not send out arp requests from loopback addresses
 112         set_proc sys/net/ipv4/conf/all/arp_announce 2
 113         ;;
 114
 115     updatenatgw|ipreallocated)
 116         natgw_check_config
 117
 118         mypnn=$(ctdb pnn | cut -d: -f2)
 119
 120         natgw_set_capability
 121         natgw_ensure_master "$1"
 122
 123         natgw_clear
 124
 125         if [ "$mypnn" = "$natgwmaster" ]; then
 126             natgw_set_master
 127         else
 128             natgw_set_slave "$natgwip"
 129         fi
 130
 131         # flush our route cache
 132         set_proc sys/net/ipv4/route/flush 1
 133         ;;
 134
 135     shutdown|removenatgw)
 136         natgw_check_config
 137         natgw_clear
 138         ;;
 139
 140     monitor)
 141         natgw_check_config
 142         natgw_set_capability
 143         natgw_ensure_master "$1"
 144         ;;
 145
 146     *)
 147         ctdb_standard_event_handler "@"
 148         ;;
 149 esac
 150
 151 exit 0