Refactor startup and docker files

Dockerfile

@@ -8,19 +8,22 @@ RUN git clone https://gitea.osmocom.org/cellular-infrastructure/libgtpnl \
 
 FROM alpine:3.19
 
-WORKDIR /nf-gtp-gw
+WORKDIR /gw
 
 COPY --from=buildenv /libgtpnl/src/.libs/libgtpnl.so* /usr/lib/
-COPY --from=buildenv /libgtpnl/tools/.libs/* .
+COPY --from=buildenv /libgtpnl/tools/.libs/* /usr/bin/
 COPY ./startup.sh ./
 
-RUN apk add --no-cache libmnl iproute2 \
+RUN apk add --no-cache libmnl iproute2 tcpdump figlet \
 	&& ldconfig /
 
-ENV TEID_N3_GNB=100 \
+ENV UE_IP=10.10.10.1 \
+    TEID_N3_GNB=100 \
     TEID_N3_UPF=200 \
-    N3_UPF_IP=127.0.0.1 \
-    N6_APP_SERVER_IP=127.0.0.2 \
-    N6_APP_SERVER_SUBNET=127.0.0.0/8
+    N3_GNB_IP=127.0.0.2 \
+    N3_UPF_IP=127.0.0.3 \
+    N6_APP_SERVER_IP=127.0.0.4
 
-ENTRYPOINT ["./startup.sh"]
+EXPOSE 2152
+
+CMD ["/bin/sh"]

startup.sh

@@ -1,37 +1,108 @@
 #!/bin/sh
 
-# User defined variables
-#TEID_N3_UPF
-#TEID_N3_GNB
-#N3_UPF_IP
-#N6_APP_SERVER_IP
-#N6_APP_SERVER_SUBNET
-
-# Pre-defined variables
+set -e
+
+_authors="abousselmi and sofianinho"
+_license="LGPLv2"
+_version="v1.0.0"
+
 IP_VERSION="ip"
 MTU=1500
 GTP_DEV="ue-tun"
 
-function log {
-    echo -e "[INFO] $1"
-    sleep 1
+banner() {
+    figlet -f big "GTP-GW"
+    echo "version: $_version"
+    echo "authors: $_authors"
+    echo "license: $_license"
+    echo ""
 }
 
-function start {
-    log "create gtp devices (run in bg mode)"
-    ./gtp-link add $GTP_DEV $IP_VERSION &
+log() {
+    echo -e "$(date +%F-%T) [INFO] $1"
+}
+
+checks() {
+    if [ -z "$UE_IP" ]; then echo "UE_IP is not set.." && exit 1 ; fi
+    if [ -z "$N3_GNB_IP" ]; then echo "N3_GNB_IP is not set.." && exit 1 ; fi
+    if [ -z "$N3_UPF_IP" ]; then echo "N3_UPF_IP is not set.." && exit 1 ; fi
+    if [ -z "$TEID_N3_UPF" ]; then echo "TEID_N3_UPF is not set.." && exit 1 ; fi
+    if [ -z "$TEID_N3_GNB" ]; then echo "TEID_N3_GNB is not set.." && exit 1 ; fi
+    if [ -z "$N6_APP_SERVER_IP" ]; then echo "N6_APP_SERVER_IP is not set.." && exit 1 ; fi
+}
+
+start() {
+    log "starting gtp-gw.."
+
+    log "add UE ip [$UE_IP] to loopback interface"
+    ip addr add $UE_IP/32 dev lo
+
+    log "create [$GTP_DEV] gtp device"
+    gtp-link add $GTP_DEV $IP_VERSION > /dev/null 2>&1 &
+
+    echo $! > pid
+
+    sleep 1
 
-    log "configure mtu of gtp devices"
+    log "set [$GTP_DEV] mtu to [$MTU]"
     ip link set mtu $MTU dev $GTP_DEV
 
-    log "create gtp tunnel: [TEID_N3_GNB=$TEID_N3_GNB, TEID_N3_UPF=$TEID_N3_UPF, \
-        N3_UPF_IP=$N3_UPF_IP, N6_APP_SERVER_IP=$N6_APP_SERVER_IP]"
-    ./gtp-tunnel add $GTP_DEV v1 $TEID_N3_UPF $TEID_N3_GNB $N6_APP_SERVER_IP $N3_UPF_IP
-    log "$(./gtp-tunnel list)"
+    log "create gtp tunnel"
+    gtp-tunnel add $GTP_DEV v1 $TEID_N3_UPF $TEID_N3_GNB $UE_IP $N3_UPF_IP
+
+    sleep 1
 
     log "configure routes using gtp devices"
-    ip route add $N6_APP_SERVER_SUBNET dev $GTP_DEV
+    ip route add $N6_APP_SERVER_IP/32 dev $GTP_DEV
+
+    log "------------------------------------------------------------------------"
+    log "UE if: $GTP_DEV"
+    log "UE ip: $UE_IP"
+    log "APP server ip: $N6_APP_SERVER_IP"
+    log "N3 GNB ip: $N3_GNB_IP"
+    log "N3 UPF ip: $N3_UPF_IP"
+    log "GNB GTP TEID: $TEID_N3_GNB"
+    log "UPF GTP TEID: $TEID_N3_UPF"
+    log "------------------------------------------------------------------------"
+    log "$(gtp-tunnel list)"
+    log "------------------------------------------------------------------------"
+}
+
+stop() {
+    log "stopping gtp-gw.."
+
+    log "delete gtp-tunnel"
+    gtp-tunnel del $GTP_DEV v1 $TEID_N3_UPF $IP_VERSION
+
+    log "delete the gtp device"
+    gtp-link del $GTP_DEV
+
+    log "kill the gtp device process"
+    kill -9 $(cat pid)
+}
+
+usage() {
+    echo ""
+    echo "Usage: $0 <start|stop>"
+    echo ""
 }
 
-start
-sleep infinity
+case "$1" in
+    -h | --help | help)
+        usage
+	exit
+	;;
+    start | add | create)
+	banner
+	checks
+	start
+	;;
+    stop | delete | del)
+	checks
+	stop
+	;;
+    *)
+	usage
+	exit
+	;;
+esac