gbproxy: Properly capture HDLC/FR traffic in addition to ethernet

We cannot use "-i all" but must list each interface separately,
which is only supported by dumpcap.  We also must write pcapng
files.

Change-Id: Id412af3bb6bcad5e0f2cf40a6dc497d7e4f3d948
This commit is contained in:
Harald Welte 2020-12-11 15:30:56 +01:00
parent dc805c00eb
commit 7c29536975
3 changed files with 152 additions and 0 deletions

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@ -1,3 +1,7 @@
[DEFINE]
TCPDUMP_START := $TTCN3_HACKS_PATH"/ttcn3-dumpcap-start.sh"
TCPDUMP_STOP := $TTCN3_HACKS_PATH"/ttcn3-dumpcap-stop.sh"
[LOGGING]
FileMask := LOG_ALL | TTCN_MATCHING;

96
ttcn3-dumpcap-start.sh Executable file
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#!/bin/bash
#
# contrary to ttcn3-tcpdump-start.sh, this version is dumpcap-only and
# needed when we want to capture from interfaces of different link
# types. It will also store the results as pcap-ng, not plain old pcap.
PIDFILE_PCAP=/tmp/pcap.pid
DUMPCAP=/usr/bin/dumpcap
PIDFILE_NETCAT=/tmp/netcat.pid
NETCAT=/bin/nc
GSMTAP_PORT=4729
TESTCASE=$1
kill_rm_pidfile() {
if [ -e $1 ]; then
kill "$(cat "$1")"
rm $1
fi
}
echo "------ $TESTCASE ------"
date
if [ "z$TTCN3_PCAP_PATH" = "z" ]; then
TTCN3_PCAP_PATH=/tmp
fi
kill_rm_pidfile $PIDFILE_NETCAT
kill_rm_pidfile $PIDFILE_PCAP
if [ -x $DUMPCAP ]; then
CAP_ERR="1"
if [ -x /sbin/setcap ]; then
# N. B: this check requires libcap2-bin package
/sbin/setcap -q -v 'cap_net_admin,cap_net_raw=pie' $DUMPCAP
CAP_ERR="$?"
fi
if [ -u $DUMPCAP -o "$CAP_ERR" = "0" ]; then
CMD="$DUMPCAP -q"
else
echo "NOTE: unable to use dumpcap due to missing capabilities or suid bit"
exit 32
fi
fi
# Create a dummy sink for GSMTAP packets
$NETCAT -l -u -k -p $GSMTAP_PORT >/dev/null 2>$TESTCASE.netcat.stderr &
PID=$!
echo $PID > $PIDFILE_NETCAT
# generate the list of interface arguments. For capturing from
# interfaces of different link-layer types, we cannot use "-i all"
# but must use dumpcap with each individual interface name. We also
# must write pcapng files, as only those can record the interface of
# each packet
ADDL_ARGS=""
for f in /sys/class/net/*; do
DEV=`basename $f`
if [[ "$DEV" == "hdlcnet"* ]]; then
# skip these as we only want the hdlcX devices, avoid capturing twice on both sides
continue
elif [[ "$DEV" == "hdlc"* ]]; then
# these are the user-side of the FR links, which is
# what we interface with from our test suite, emulating
# a BSS.
ADDL_ARGS="${ADDL_ARGS} -i ${DEV}"
elif [[ "$DEV" == "eth"* ]]; then
# we blindly assume that "normal" docker network devices
# are called ethXXX
ADDL_ARGS="${ADDL_ARGS} -i ${DEV}"
fi
done
$CMD -s 1500 -n ${ADDL_ARGS} -w "$TTCN3_PCAP_PATH/$TESTCASE.pcapng" >$TTCN3_PCAP_PATH/$TESTCASE.pcapng.stdout 2>&1 &
PID=$!
echo $PID > $PIDFILE_PCAP
# Wait until packet dumper creates the pcap file and starts recording.
# We generate some traffic until we see packet dumper catches it.
# Timeout is 10 seconds.
ping 127.0.0.1 >/dev/null 2>&1 &
PID=$!
i=0
while [ ! -f "$TTCN3_PCAP_PATH/$TESTCASE.pcapng" ] ||
[ "$(stat -c '%s' "$TTCN3_PCAP_PATH/$TESTCASE.pcapng")" -eq 32 ]
do
echo "Waiting for packet dumper to start... $i"
sleep 1
i=$((i+1))
if [ $i -eq 10 ]; then
break
fi
done
kill $PID

52
ttcn3-dumpcap-stop.sh Executable file
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#!/bin/sh
PIDFILE_PCAP=/tmp/pcap.pid
PIDFILE_NETCAT=/tmp/netcat.pid
TESTCASE=$1
VERDICT="$2"
kill_rm_pidfile() {
if [ -e $1 ]; then
PSNAME="$(ps -q "$(cat "$1")" -o comm=)"
if [ "$PSNAME" != "sudo" ]; then
kill "$(cat "$1")"
else
# NOTE: This requires you to be root or something like
# "laforge ALL=NOPASSWD: /usr/sbin/tcpdump, /bin/kill" in your sudoers file
sudo kill "$(cat "$1")"
fi
rm $1
fi
}
date
if [ x"$VERDICT" = x"pass" ]; then
echo -e "\033[1;32m====== $TESTCASE $VERDICT ======\033[0m"
else
echo -e "\033[1;31m------ $TESTCASE $VERDICT ------\033[0m"
fi
echo
if [ "z$TTCN3_PCAP_PATH" = "z" ]; then
TTCN3_PCAP_PATH=/tmp
fi
# Wait for up to 2 seconds if we keep receiving traffinc from packet dumper,
# otherwise we might lose last packets from test.
i=0
prev_count=-1
count=$(stat --format="%s" "$TTCN3_PCAP_PATH/$TESTCASE.pcapng")
while [ $count -gt $prev_count ] && [ $i -lt 2 ]
do
echo "Waiting for packet dumper to finish... $i (prev_count=$prev_count, count=$count)"
sleep 1
prev_count=$count
count=$(stat --format="%s" "$TTCN3_PCAP_PATH/$TESTCASE.pcapng")
i=$((i+1))
done
kill_rm_pidfile "$PIDFILE_PCAP"
kill_rm_pidfile "$PIDFILE_NETCAT"
gzip -f "$TTCN3_PCAP_PATH/$TESTCASE.pcapng"