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Diffstat (limited to 'examples/scripts/wins_hook/dns_update')
| -rw-r--r-- | examples/scripts/wins_hook/dns_update | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/examples/scripts/wins_hook/dns_update b/examples/scripts/wins_hook/dns_update new file mode 100644 index 0000000..14fc1fe --- /dev/null +++ b/examples/scripts/wins_hook/dns_update @@ -0,0 +1,92 @@ +#!/bin/sh +# +# Example script for "wins hook". This attempts to update the DNS with +# new A records for the NETBIOS name that Samba passes us. We do this +# the simple way, by deleting all DNS records for the name and then +# re-adding all the expected 'A' records. +# +# Written by Stephen Rothwell <sfr@linuxcare.com> +# + +# +# Configurable things +# +# The domain in which to create names +# YOU MUST CHANGE THIS +# N.B. include the trailing dot +# +# It is a good idea to use a subdomain of your primary domain to ensure +# that rogue machines can't take over (or delete) important names on +# your network. +DOMAIN=wins.example.com. + +# +# The DNS TTL to give the records (in seconds) +# +TTL=3600 +# +# NETBIOS name types that we want to create DNS records for: +# 20 is server +# 00 is workstation +# 03 is user +# +USEFUL_TYPES="20 00 03" +# +# The name of a cache file to use to avoid continual updates +# of the same name and IP addresses. If you comment this out +# then the cache is not kept at all. +# +#CACHE_FILE=/usr/local/samba/var/wins_update.cache + +if [ $# -lt 4 ]; then + echo "Usage: $0 op name type ttl [ip_addr ...]" 1>&2 + echo " op is one of add, refresh, delete" 1>&2 + echo " name is the NETBIOS name" 1>&2 + echo " type is the NETBIOS name type" 1>&2 + echo " ttl is the NETBIOS time to live" 1>&2 + echo " ip_addr's are the remaining IP addresses for this name" 1>&2 + exit 1 +fi + +NSUPDATE=$(which nsupdate) +[ -x "$NSUPDATE" ] || NSUPDATE=/usr/bin/nsupdate +[ -x "$NSUPDATE" ] || NSUPDATE=/sbin/nsupdate +[ -x "$NSUPDATE" ] || NSUPDATE=/usr/sbin/nsupdate +[ -x "$NSUPDATE" ] || { + echo "Cannot find nsupdate." 1>&2 + exit 1 +} + +OP=$1 +NAME=$2 +TYPE=$3 +WINS_TTL=$4 +shift 4 +IP_ADDRS="$@" + +do_update=0 +for i in $USEFUL_TYPES; do + [ "$TYPE" = "$i" ] && do_update=1 +done +[ $do_update = 1 ] || exit 0 + +if [ -n "$CACHE_FILE" ]; then + if [ -r "$CACHE_FILE" ]; then + fgrep -q -x -i "$NAME $IP_ADDRS" "$CACHE_FILE" && + exit 0 + grep -v -i "^$NAME " "$CACHE_FILE" >"$CACHE_FILE".$$ + fi + echo "$NAME $IP_ADDRS" >>"$CACHE_FILE".$$ + mv "$CACHE_FILE" "$CACHE_FILE".old 2>/dev/null + mv "$CACHE_FILE".$$ "$CACHE_FILE" +fi + +{ + echo update delete $NAME.$DOMAIN + for i in $IP_ADDRS; do + echo update add $NAME.$DOMAIN $TTL A $i + done + echo +} 2>/dev/null | $NSUPDATE >/dev/null 2>&1 & + +exit 0 |