/etc/ppp/ip-up.d/snort is in snort 2.9.7.0-5.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 | #!/bin/sh -e
test $DEBIAN_SCRIPT_DEBUG && set -v -x
# Initial configuration :)
DAEMON=/usr/sbin/snort
NAME=snort
DESC="Network Intrusion Detection System"
CONFIG=/etc/snort/snort.debian.conf
if [ -r /etc/snort/snort.common.parameters ] ; then
COMMON=`cat /etc/snort/snort.common.parameters`
elif [ -r /etc/default/snort ] ; then
# Only read this if the old configuration is not present
. /etc/default/snort
COMMON="$PARAMS -l $LOGDIR -u $SNORTUSER -g $SNORTGROUP"
fi
test -x $DAEMON || exit 0
test -f $CONFIG && . $CONFIG
test "$DEBIAN_SNORT_STARTUP" = "dialup" || exit 0
# These are the cases in which this script can run:
# 1) with ppp environment set
# 1.1) from ppp/ip-up
# 1.2) from itself recursive
# 2) without ppp environment set
# 2.1) with saved ppp environment
# 2.1.1) with pppd running: saved ppp environment is valid
# 2.1.2) without pppd running: saved ppp environment is stale
# 2.2) without saved ppp environment
# 2.2.1) with pppd running
# 2.2.2) without pppd running
#
# Behaviour:
# 1.1, 1.2)
# We just trust the environment, assume snort isn't already running,
# overwrite any existing saved ppp environment with a new one
# and leave it at that.
# 2.1.1)
# We start snort with the values from the saved ppp environment.
# 2.1.2)
# We remove the stale saved ppp environment and fall back to 2.2).
# 2.2.1)
# We try to figure out the values that are correct and try
# to start snort.
# 2.2.2)
# We warn and won't start.
check_log_dir() {
# Does the logging directory belong to Snort?
# If we cannot determine the logdir return without error
# (we will not check it)
# This will only be used by people using /etc/default/snort
[ -n "$LOGDIR" ] || return 0
[ -n "$SNORTUSER" ] || return 0
if [ ! -e "$LOGDIR" ] ; then
echo -n "ERR: logging directory $LOGDIR does not exist"
return 1
elif [ ! -d "$LOGDIR" ] ; then
echo -n "ERR: logging directory $LOGDIR does not exist"
return 1
else
real_log_user=`stat -c %U $LOGDIR`
# An alternative way is to check if the snort user can create
# a file there...
if [ "$real_log_user" != "$SNORTUSER" ] ; then
echo -n "ERR: logging directory $LOGDIR does not belong to the snort user $SNORTUSER"
return 1
fi
fi
return 0
}
if ! check_log_dir; then
echo "Cannot start $DESC!"
exit 1
fi
if ! [ "$DEBIAN_SNORT_RECURSIVE" ]; then
# Acquire lock...
trap 'rm -f /var/run/snort.ppp.lock' 0
for tries in $(seq 1 10); do
mkfifo /var/run/snort.ppp.lock 2>/dev/null && break
sleep 1
done
# Now it's locked or timed out.
# In the latter case we assume stale lock.
fi
# If we are started with ppp environment set...
if [ "$PPPD_PID" -a "$PPP_IFACE" -a "$PPP_LOCAL" ]; then
echo -n "Starting $DESC: $NAME($PPP_IFACE)"
PIDFILE=/var/run/snort_$PPP_IFACE.pid
ENVFILE=/var/run/snort_$PPP_IFACE.env
fail="failed (check /var/log/daemon.log)"
/sbin/start-stop-daemon --stop --signal 0 --quiet \
--pidfile "$PIDFILE" --exec $DAEMON >/dev/null &&
fail="already running"
cd /etc/snort
CONFIGFILE=/etc/snort/snort.$PPP_IFACE.conf
if [ ! -e $CONFIGFILE ]; then
echo "No /etc/snort/snort.$PPP_IFACE.conf, defaulting to snort.conf"
CONFIGFILE=/etc/snort/snort.conf
fi
# We intentionally set +e here, thus (new) environment is even
# saved, if startup fails - for further startup attempts
set +e
/sbin/start-stop-daemon --start --quiet --pidfile "$PIDFILE" \
--exec $DAEMON -- $COMMON $DEBIAN_SNORT_OPTIONS \
-c $CONFIGFILE \
-S "HOME_NET=[$PPP_LOCAL/32]" \
-i $PPP_IFACE >/dev/null
ret=$?
set -e
case "$ret" in
0)
echo "."
;;
*)
echo "...$fail."
;;
esac
echo "PPPD_PID=$PPPD_PID" > "$ENVFILE"
echo "PPP_IFACE=$PPP_IFACE" >> "$ENVFILE"
echo "PPP_LOCAL=$PPP_LOCAL" >> "$ENVFILE"
exit $ret
fi
# Else, we are started without ppp environment set...
DEBIAN_SNORT_RECURSIVE=1
export DEBIAN_SNORT_RECURSIVE
# If we have saved environments, check and probably start them...
envpattern=/var/run/snort_*.env
# If we are requested to start one special environment...
test "$1" -a -z "$2" && envpattern=/var/run/snort_"$1".env
myret=0
got_instance=0
for env in $envpattern; do
# This check is also needed, if the above pattern doesn't match
test -f "$env" || continue;
. "$env"
# Prevent endless recursion because of damaged environments
# Check, if the environment is still valid...
if [ "$PPPD_PID" -a "$PPP_IFACE" -a "$PPP_LOCAL" ] &&
kill -0 $PPPD_PID 2>/dev/null &&
ps -p $PPPD_PID | grep -q pppd; then
got_instance=1
export PPPD_PID PPP_IFACE PPP_LOCAL
# Because the starup of this particular environment could
# fail, we guard it
set +e
$0 "$@"
ret=$?
set -e
case "$ret" in
0)
;;
*)
myret=$(expr "$myret" + 1)
;;
esac
else
rm -f "$env"
fi
done
# If we found no saved environments, we don't need to start anything
if [ "$got_instance" = 0 ]; then
echo "No snort instance found to be started!" >&2
exit 1
fi
exit $myret
|