[202511] Backport PR #22486: sonic dhcp relay agent for IPv4

dockers/docker-dhcp-relay/Dockerfile.j2

@@ -14,7 +14,8 @@ RUN apt-get update
 
 RUN apt-get install -y libjsoncpp-dev \
                        python3-dev    \
-                       build-essential
+                       build-essential \
+                       libpcap-dev
 
 RUN pip3 install psutil
 
@@ -40,7 +41,7 @@ RUN apt-get remove -y build-essential     \
 
 COPY ["docker_init.sh", "start.sh", "/usr/bin/"]
 COPY ["docker-dhcp-relay.supervisord.conf.j2", "port-name-alias-map.txt.j2", "wait_for_intf.sh.j2", "/usr/share/sonic/templates/"]
-COPY ["dhcp-relay.programs.j2", "dhcpv4-relay.agents.j2", "dhcpv6-relay.agents.j2", "dhcp-relay.monitors.j2", "/usr/share/sonic/templates/"]
+COPY ["dhcp-relay.programs.j2", "dhcpv4-relay.agents.j2", "dhcpv4-sonic-relay.agents.j2", "dhcpv6-relay.agents.j2", "dhcp-relay.monitors.j2", "/usr/share/sonic/templates/"]
 COPY ["critical_processes", "/etc/supervisor"]
 COPY ["cli", "/cli/"]
 

dockers/docker-dhcp-relay/dhcp-relay.monitors.j2

@@ -49,6 +49,10 @@ stdout_syslog=true
 stderr_logfile=NONE
 stderr_syslog=true
 dependent_startup=true
+{% if 'has_sonic_dhcpv4_relay' in DEVICE_METADATA['localhost'] and DEVICE_METADATA['localhost']['has_sonic_dhcpv4_relay'] == 'True' %}
+dependent_startup_wait_for=dhcp4relay:running
+{% else %}
 dependent_startup_wait_for=isc-dhcpv4-relay-{{ vlan_name }}:running
+{% endif %}
 
 {% endfor %}

dockers/docker-dhcp-relay/dhcp-relay.programs.j2

@@ -1,5 +1,6 @@
 [group:dhcp-relay]
 programs=dhcprelayd
+{%- if 'has_sonic_dhcpv4_relay' in DEVICE_METADATA['localhost'] and DEVICE_METADATA['localhost']['has_sonic_dhcpv4_relay'] == 'True' %}
 {%- set relay_for_ipv6 = { 'flag': False } %}
 {%- set add_preceding_comma = { 'flag': True } %}
 {% for vlan_name in VLAN_INTERFACE %}
@@ -12,4 +13,25 @@ programs=dhcprelayd
 {% if add_preceding_comma.flag %},{% endif %}
 {% set _dummy = add_preceding_comma.update({'flag': True}) %}
 dhcp6relay
+{%- endif %}
+{# Create a program entry for sonic dhcpv4 relay agent #}
+{%- set add_preceding_comma = { 'flag': True } %}
+{# Append sonic DHCPv4 agent #}
+{% if add_preceding_comma.flag %},{% endif %}
+{% set _dummy = add_preceding_comma.update({'flag': True}) %}
+dhcp4relay
+{% else %}
+{%- set relay_for_ipv6 = { 'flag': False } %}
+{%- set add_preceding_comma = { 'flag': True } %}
+{% for vlan_name in VLAN_INTERFACE %}
+{% if DHCP_RELAY and vlan_name in DHCP_RELAY and DHCP_RELAY[vlan_name]['dhcpv6_servers']|length > 0 %}
+{% set _dummy = relay_for_ipv6.update({'flag': True})  %}
+{%- endif %}
+{% endfor %}
+{# Append DHCPv6 agents #}
+{% if relay_for_ipv6.flag %}
+{% if add_preceding_comma.flag %},{% endif %}
+{% set _dummy = add_preceding_comma.update({'flag': True}) %}
+dhcp6relay
+{% endif %}
 {% endif %}

dockers/docker-dhcp-relay/dhcpv4-sonic-relay.agents.j2

@@ -0,0 +1,15 @@
+{# Append DHCPv4 sonic agent #}
+[program:dhcp4relay]
+command=/usr/sbin/dhcp4relay{% if 'subtype' in DEVICE_METADATA['localhost'] and DEVICE_METADATA['localhost']['subtype'] == 'DualToR' %} -u Loopback0{% endif %}
+
+priority=3
+autostart=false
+autorestart=false
+stdout_logfile=NONE
+stdout_syslog=true
+stderr_logfile=NONE
+stderr_syslog=true
+dependent_startup=true
+dependent_startup_wait_for=start:exited
+
+

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

@@ -48,6 +48,9 @@ dependent_startup_wait_for=rsyslogd:running
 {# Count how many VLANs require a DHCP relay agent... #}
 {% set ipv4_num_relays = { 'count': 0 } %}
 {% set ipv6_num_relays = { 'count': 0 } %}
+{% if 'has_sonic_dhcpv4_relay' in DEVICE_METADATA['localhost'] and DEVICE_METADATA['localhost']['has_sonic_dhcpv4_relay'] == 'True' %}
+{% set _dummy = ipv4_num_relays.update({'count': ipv4_num_relays.count + 1}) %}
+{% endif %}
 {% for vlan_name in VLAN_INTERFACE %}
 {% if VLAN and vlan_name in VLAN and 'dhcp_servers' in VLAN[vlan_name] and VLAN[vlan_name]['dhcp_servers']|length > 0 %}
 {% set _dummy = ipv4_num_relays.update({'count': ipv4_num_relays.count + 1}) %}
@@ -63,6 +66,12 @@ dependent_startup_wait_for=rsyslogd:running
 {# Create a program entry for each DHCP relay agent instance #}
 {% set relay_for_ipv4 = { 'flag': False } %}
 {% set relay_for_ipv6 = { 'flag': False } %}
+{# Decide the dhcpv4 relay agent based on the feature config #}
+{% if 'has_sonic_dhcpv4_relay' in DEVICE_METADATA['localhost'] and DEVICE_METADATA['localhost']['has_sonic_dhcpv4_relay'] == 'True' %}
+{% include 'dhcpv4-sonic-relay.agents.j2' %}
+{% include 'dhcpv6-relay.agents.j2' %}
+{% include 'dhcp-relay.monitors.j2' %}
+{% else %}
 {% set added_vlan = []%}
 {% for (vlan_name, prefix) in VLAN_INTERFACE|pfx_filter %}
     {%- if prefix | ipv4 and vlan_name not in added_vlan %}
@@ -75,6 +84,11 @@ dependent_startup_wait_for=rsyslogd:running
 {% include 'dhcp-relay.monitors.j2' %}
 {% endif %}
 {% endif %}
+{% else %}
+{% if 'has_sonic_dhcpv4_relay' in DEVICE_METADATA['localhost'] and DEVICE_METADATA['localhost']['has_sonic_dhcpv4_relay'] == 'True' %}
+{% include 'dhcpv4-sonic-relay.agents.j2' %}
+{% endif %}
+{% endif %}
 [program:dhcprelayd]
 command=/usr/local/bin/dhcprelayd
 priority=3

rules/dhcp4relay.dep

@@ -0,0 +1,11 @@
+
+SPATH       := $($(SONIC_DHCP4RELAY)_SRC_PATH)
+DEP_FILES   := $(SONIC_COMMON_FILES_LIST) rules/dhcp4relay.mk rules/dhcp4relay.dep
+DEP_FILES   += $(SONIC_COMMON_BASE_FILES_LIST)
+SMDEP_FILES := $(addprefix $(SPATH)/,$(shell cd $(SPATH) && git ls-files --recurse-submodules))
+
+$(SONIC_DHCP4RELAY)_CACHE_MODE  := GIT_CONTENT_SHA 
+$(SONIC_DHCP4RELAY)_DEP_FLAGS   := $(SONIC_COMMON_FLAGS_LIST)
+$(SONIC_DHCP4RELAY)_DEP_FILES   := $(DEP_FILES)
+$(SONIC_DHCP4RELAY)_SMDEP_FILES := $(SMDEP_FILES)
+$(SONIC_DHCP4RELAY)_SMDEP_PATHS := $(SPATH)

rules/dhcp4relay.mk

@@ -0,0 +1,12 @@
+# SONiC DHCPV4 RELAY Package
+
+SONIC_DHCP4RELAY_VERSION = 1.0.0-0
+SONIC_DHCP4RELAY_PKG_NAME = dhcp4relay
+
+SONIC_DHCP4RELAY = sonic-$(SONIC_DHCP4RELAY_PKG_NAME)_$(SONIC_DHCP4RELAY_VERSION)_$(CONFIGURED_ARCH).deb
+$(SONIC_DHCP4RELAY)_DEPENDS = $(LIBSWSSCOMMON) $(LIBSWSSCOMMON_DEV)
+$(SONIC_DHCP4RELAY)_SRC_PATH = $(SRC_PATH)/dhcprelay/dhcp4relay
+SONIC_DPKG_DEBS += $(SONIC_DHCP4RELAY)
+
+SONIC_DHCP4RELAY_DBG = sonic-$(SONIC_DHCP4RELAY_PKG_NAME)-dbgsym_$(SONIC_DHCP4RELAY_VERSION)_$(CONFIGURED_ARCH).deb
+$(eval $(call add_derived_package,$(SONIC_DHCP4RELAY),$(SONIC_DHCP4RELAY_DBG)))

rules/docker-dhcp-relay.dep

@@ -1,6 +1,6 @@
 
 DPATH       := $($(DOCKER_DHCP_RELAY)_PATH)
-DEP_FILES   := $(SONIC_COMMON_FILES_LIST) rules/docker-dhcp-relay.mk rules/docker-dhcp-relay.dep   
+DEP_FILES   := $(SONIC_COMMON_FILES_LIST) rules/docker-dhcp-relay.mk rules/docker-dhcp-relay.dep
 DEP_FILES   += $(SONIC_COMMON_BASE_FILES_LIST)
 DEP_FILES   += $(shell git ls-files $(DPATH))
 

rules/docker-dhcp-relay.mk

@@ -6,10 +6,10 @@ 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) $(SONIC_DHCPMON) $(SONIC_DHCPRELAY) $(LIBSWSSCOMMON)
+$(DOCKER_DHCP_RELAY)_DEPENDS += $(ISC_DHCP_RELAY) $(SONIC_DHCPMON) $(SONIC_DHCP4RELAY) $(SONIC_DHCPRELAY) $(LIBSWSSCOMMON)
 
 $(DOCKER_DHCP_RELAY)_DBG_DEPENDS = $($(DOCKER_CONFIG_ENGINE_BOOKWORM)_DBG_DEPENDS)
-$(DOCKER_DHCP_RELAY)_DBG_DEPENDS += $(ISC_DHCP_RELAY_DBG) $(SONIC_DHCPRELAY_DBG) $(SONIC_DHCPMON_DBG)
+$(DOCKER_DHCP_RELAY)_DBG_DEPENDS += $(ISC_DHCP_RELAY_DBG) $(SONIC_DHCP4RELAY_DBG) $(SONIC_DHCPRELAY_DBG) $(SONIC_DHCPMON_DBG)
 
 $(DOCKER_DHCP_RELAY)_DBG_IMAGE_PACKAGES = $($(DOCKER_CONFIG_ENGINE_BOOKWORM)_DBG_IMAGE_PACKAGES)
 

src/sonic-config-engine/tests/dhcp-sonic-relay-disabled-sample.json

@@ -0,0 +1,27 @@
+{
+    "VLAN_INTERFACE": {
+        "Vlan1000|fc02:2000::2/24": {}
+    },
+    "FEATURE": {
+        "dhcp_server": {
+            "state": "disabled"
+        },
+        "dhcp_relay": {
+            "auto_restart": "disabled",
+            "check_up_status": "False",
+            "delayed": "False",
+            "has_global_scope": "True",
+            "has_per_asic_scope": "False",
+            "high_mem_alert": "disabled",
+            "set_owner": "local",
+            "state": "enabled",
+            "support_syslog_rate_limit": "True"
+        }
+
+    },
+    "DEVICE_METADATA": {
+        "localhost": {
+            "has_sonic_dhcpv4_relay": "False"
+        }
+    }
+}

src/sonic-config-engine/tests/dhcp-sonic-relay-enabled-sample.json

@@ -0,0 +1,26 @@
+{
+    "VLAN_INTERFACE": {
+        "Vlan1000|fc02:2000::2/24": {}
+    },
+    "FEATURE": {
+        "dhcp_server": {
+            "state": "disabled"
+        },
+        "dhcp_relay": {
+            "auto_restart": "disabled",
+            "check_up_status": "False",
+            "delayed": "False",
+            "has_global_scope": "True",
+            "has_per_asic_scope": "False",
+            "high_mem_alert": "disabled",
+            "set_owner": "local",
+            "state": "enabled",
+            "support_syslog_rate_limit": "True"
+        }
+    },
+    "DEVICE_METADATA": {
+        "localhost": {
+            "has_sonic_dhcpv4_relay": "True"
+        }
+    }
+}

src/sonic-config-engine/tests/sample_output/py2/docker-dhcp-relay-sonic-agent-no-relay-cfg.supervisord.conf

@@ -0,0 +1,74 @@
+[supervisord]
+logfile_maxbytes=1MB
+logfile_backups=2
+nodaemon=true
+
+[eventlistener:dependent-startup]
+command=python3 -m supervisord_dependent_startup
+autostart=true
+autorestart=unexpected
+startretries=0
+exitcodes=0,3
+events=PROCESS_STATE
+buffer_size=1024
+
+[eventlistener:supervisor-proc-exit-listener]
+command=/usr/bin/supervisor-proc-exit-listener-rs --container-name dhcp_relay
+events=PROCESS_STATE_EXITED,PROCESS_STATE_RUNNING
+autostart=true
+autorestart=unexpected
+buffer_size=1024
+
+[program:rsyslogd]
+command=/usr/sbin/rsyslogd -n -iNONE
+priority=1
+autostart=false
+autorestart=false
+stdout_logfile=NONE
+stdout_syslog=true
+stderr_logfile=NONE
+stderr_syslog=true
+dependent_startup=true
+
+[program:start]
+command=/usr/bin/start.sh
+priority=2
+autostart=false
+autorestart=false
+startsecs=0
+stdout_logfile=NONE
+stdout_syslog=true
+stderr_logfile=NONE
+stderr_syslog=true
+dependent_startup=true
+dependent_startup_wait_for=rsyslogd:running
+
+[group:dhcp-relay]
+programs=dhcprelayd,dhcp4relay
+
+[program:dhcp4relay]
+command=/usr/sbin/dhcp4relay
+priority=3
+autostart=false
+autorestart=false
+stdout_logfile=NONE
+stdout_syslog=true
+stderr_logfile=NONE
+stderr_syslog=true
+dependent_startup=true
+dependent_startup_wait_for=start:exited
+
+[group:dhcpmon]
+programs=
+
+[program:dhcprelayd]
+command=/usr/local/bin/dhcprelayd
+priority=3
+autostart=false
+autorestart=false
+stdout_logfile=NONE
+stdout_syslog=true
+stderr_logfile=NONE
+stderr_syslog=true
+dependent_startup=true
+dependent_startup_wait_for=start:exited