[dhcp-relay]: Add DHCP Relay Monitor

.gitignore

@@ -23,6 +23,11 @@ target/
 # Subdirectories in src
 src/bash/*
 !src/bash/Makefile
+src/dhcpmon/debian/*
+!src/dhcpmon/debian/changelog 
+!src/dhcpmon/debian/compat 
+!src/dhcpmon/debian/control
+!src/dhcpmon/debian/rules 
 src/ixgbe/*
 !src/ixgbe/Makefile
 src/isc-dhcp/*
@@ -106,6 +111,7 @@ src/thrift/*
 # Autogenerated Dockerfiles
 sonic-slave/Dockerfile
 sonic-slave-stretch/Dockerfile
+sonic-slave-jessie/Dockerfile
 dockers/docker-base/Dockerfile
 dockers/docker-base-stretch/Dockerfile
 dockers/docker-config-engine/Dockerfile

dockers/docker-dhcp-relay/docker-dhcp-relay.supervisord.conf.j2

@@ -85,5 +85,53 @@ stderr_logfile=syslog
 {% endif %}
 {% endif %}
 {% endfor %}
+
+[group:dhcpmon]
+programs=
+{%- set add_preceding_comma = { 'flag': False } %}
+{% for vlan_name in VLAN %}
+{% if VLAN[vlan_name]['dhcp_servers'] %}
+{% if add_preceding_comma.flag %},{% endif %}
+{% set _dummy = add_preceding_comma.update({'flag': True}) %}
+dhcpmon-{{ vlan_name }}
+{%- endif %}
+{% endfor %}
+
+
+{# Create a program entry for each DHCP MONitor instance #}
+{% set relay_for_ipv4 = { 'flag': False } %}
+{% for vlan_name in VLAN %}
+{% if VLAN[vlan_name]['dhcp_servers'] %}
+{% for dhcp_server in VLAN[vlan_name]['dhcp_servers'] %}
+{% if dhcp_server | ipv4 %}
+{% set _dummy = relay_for_ipv4.update({'flag': True}) %}
+{% endif %}
+{% endfor %}
+{% if relay_for_ipv4.flag %}
+{% set _dummy = relay_for_ipv4.update({'flag': False}) %}
+[program:dhcpmon-{{ vlan_name }}]
+{# We treat this VLAN as a downstream interface (-id), as we only want to listen for requests #}
+command=/usr/sbin/dhcpmon -id {{ vlan_name }}
+{#- We treat all other interfaces as upstream interfaces (-iu), as we only want to listen for replies #}
+{% for (name, prefix) in VLAN_INTERFACE|pfx_filter %}
+{% if prefix | ipv4 and name != vlan_name %} -iu {{ name }}{% endif -%}
+{% endfor %}
+{% for (name, prefix) in INTERFACE|pfx_filter %}
+{% if prefix | ipv4 %} -iu {{ name }}{% endif -%}
+{% endfor %}
+{% for (name, prefix) in PORTCHANNEL_INTERFACE|pfx_filter %}
+{% if prefix | ipv4 %} -iu {{ name }}{% endif -%}
+{% endfor %}
+
+priority=4
+autostart=false
+autorestart=false
+stdout_logfile=syslog
+stderr_logfile=syslog
+
+{% endif %}
+{% endif %}
+{% endfor %}
+
 {% endif %}
 {% endif %}

dockers/docker-dhcp-relay/start.sh

@@ -19,3 +19,9 @@ if [ $(supervisorctl status | grep -c "^isc-dhcp-relay:") -gt 0 ]; then
     # Start all DHCP relay agent(s)
     supervisorctl start isc-dhcp-relay:*
 fi
+
+# If our supervisor config has entries in the "dhcpmon" group...
+if [ $(supervisorctl status | grep -c "^dhcpmon:") -gt 0 ]; then
+    # Start all DHCP Monitor daemon(s)
+    supervisorctl start dhcpmon:*
+fi

rules/dhcpmon.mk

@@ -0,0 +1,8 @@
+# SONiC DHCP MONitor package
+
+SONIC_DHCPMON_VERSION = 1.0.0-0
+SONIC_DHCPMON_PKG_NAME = dhcpmon
+
+SONIC_DHCPMON = sonic-$(SONIC_DHCPMON_PKG_NAME)_$(SONIC_DHCPMON_VERSION)_$(CONFIGURED_ARCH).deb
+$(SONIC_DHCPMON)_SRC_PATH = $(SRC_PATH)/$(SONIC_DHCPMON_PKG_NAME)
+SONIC_DPKG_DEBS += $(SONIC_DHCPMON)

rules/docker-dhcp-relay.mk

@@ -6,7 +6,7 @@ DOCKER_DHCP_RELAY_DBG = $(DOCKER_DHCP_RELAY_STEM)-$(DBG_IMAGE_MARK).gz
 
 $(DOCKER_DHCP_RELAY)_PATH = $(DOCKERS_PATH)/$(DOCKER_DHCP_RELAY_STEM)
 
-$(DOCKER_DHCP_RELAY)_DEPENDS += $(ISC_DHCP_RELAY) $(REDIS_TOOLS)
+$(DOCKER_DHCP_RELAY)_DEPENDS += $(ISC_DHCP_RELAY) $(REDIS_TOOLS) $(SONIC_DHCPMON)
 $(DOCKER_DHCP_RELAY)_DBG_DEPENDS = $($(DOCKER_CONFIG_ENGINE_STRETCH)_DBG_DEPENDS)
 $(DOCKER_DHCP_RELAY)_DBG_DEPENDS += $(ISC_DHCP_RELAY_DBG)
 

sonic-slave-stretch/Dockerfile.j2

@@ -293,7 +293,10 @@ RUN apt-get update && apt-get install -y \
 # For kdump-tools
         liblzo2-dev \
 # For SAI3.7
-        libprotobuf-dev
+        libprotobuf-dev \
+# For DHCP Monitor tool
+        libexplain-dev \
+        libevent-dev
 
 ## Config dpkg
 ## install the configuration file if it’s currently missing

src/dhcpmon/Makefile

@@ -0,0 +1,44 @@
+RM := rm -rf
+DHCPMON_TARGET := dhcpmon
+CP := cp
+MKDIR := mkdir
+CC := gcc
+MV := mv
+
+# All of the sources participating in the build are defined here
+-include src/subdir.mk
+-include objects.mk
+
+ifneq ($(MAKECMDGOALS),clean)
+ifneq ($(strip $(C_DEPS)),)
+-include $(C_DEPS)
+endif
+endif
+
+# Add inputs and outputs from these tool invocations to the build variables 
+
+# All Target
+all: sonic-dhcpmon
+
+# Tool invocations
+sonic-dhcpmon: $(OBJS) $(USER_OBJS)
+	@echo 'Building target: $@'
+	@echo 'Invoking: GCC C Linker'
+	$(CC) -o "$(DHCPMON_TARGET)" $(OBJS) $(USER_OBJS) $(LIBS)
+	@echo 'Finished building target: $@'
+	@echo ' '
+
+# Other Targets
+install:
+	$(MKDIR) -p $(DESTDIR)/usr/sbin
+	$(MV) $(DHCPMON_TARGET) $(DESTDIR)/usr/sbin
+
+deinstall:
+	$(RM) $(DESTDIR)/usr/sbin/$(DHCPMON_TARGET)
+	$(RM) -rf $(DESTDIR)/usr/sbin
+
+clean:
+	-$(RM) $(EXECUTABLES)$(OBJS)$(C_DEPS) $(DHCPMON_TARGET)
+	-@echo ' '
+
+.PHONY: all clean dependents

src/dhcpmon/debian/changelog

@@ -0,0 +1,5 @@
+sonic-dhcpmon (1.0.0-0) UNRELEASED; urgency=medium
+
+  * Initial release.
+
+ -- Tamer Ahmed <tamer.ahmed@microsoft.com>  Mon, 09 Dec 2019 12:00:00 -0700

src/dhcpmon/debian/compat

@@ -0,0 +1 @@
+9

src/dhcpmon/debian/control

@@ -0,0 +1,16 @@
+Source: sonic-dhcpmon
+Section: devel
+Priority: optional
+Maintainer: Tamer Ahmed <tamer.ahmed@microsoft.com>
+Build-Depends: debhelper (>= 8.0.0),
+               dh-systemd
+Standards-Version: 3.9.3
+Homepage: https://github.com/Azure/sonic-buildimage
+XS-Go-Import-Path: github.com/Azure/sonic-buildimage
+
+Package: sonic-dhcpmon
+Architecture: any
+Built-Using: ${misc:Built-Using}
+Depends: libexplain51,
+         libevent-2.0-5
+Description: SONiC DHCP Monitor

src/dhcpmon/debian/rules

@@ -0,0 +1,3 @@
+#!/usr/bin/make -f
+%:
+	dh $@ --with systemd

src/dhcpmon/objects.mk

@@ -0,0 +1,4 @@
+USER_OBJS :=
+
+LIBS := -levent -lexplain
+