mini_snmpd: 1.4-rc1 add git,autoconf,procd init script,uci validation - new upstream/openwrt maintainer

Makes use of all available runtime options that can be passed to mini_snmpd such as -I listen_on interface Run-tested on trunk on ar71xx. Please review the init script regarding procd monitoring interfaces, though everything else due to the conversion to procd should be and done properly, if not overkill compared to most other script bundled with openwrt. The main benefit of all this is now larger routers can run multiple instances of mini_snmpd on different ports, to get around the MIB hard coded 4 interface/mountpoint limits. Due to somewhat lacking dev / package maintainer docs except for http://wiki.prplfoundation.org/wiki/Procd_reference writing this script took longer than it should. You can see it's evolution here: https://github.com/hojuruku/openwrt-packages/blob/mini_snmpd/net/mini_snmpd/files/mini_snmpd.init If everything in it is found to be sane, please include it to the openwrt wiki on procd as an example. Due to procd / uci /sbin/validate_data cbi element datatype (uciname) being used to check uci config, the configuration file now only takes openwrt uci network names not physical network names as it did before. http://git.openwrt.org/?p=packages.git;a=commit;h=783e5578ad104d1ca3c31582add08fc8eb4ad083 Like busybox the package Makefile has depends for all runtime dependencies needed by the init script. mini_snmpd only depends on libc squashed commits: mini_snmpd: fix typo to fix procd triggers calling daemon binary directly instead of init script - misuse of $PROG var mini_snmpd: enable SSP & mini_snmpd to start by default and listen on lan mini_snmpd: disable RELRO blocker in Makefile after consulation mini_snmpd: add smarts to init script to detect if ubusd hasn't started yet mini_snmpd: fix init script - ubus -S doesn't print meaningful errors to give the user mini_snmpd: Makefile roll back Makefile PKG_RELEASE to 1 for feng shui
9 years ago · 82cf5ca5c6
--- a/net/mini_snmpd/Makefile
+++ b/net/mini_snmpd/Makefile
@ -1,5 +1,5 @@
 #
 # Copyright (C) 2009-2014 OpenWrt.org
 # Copyright (C) 2009-2016 OpenWrt.org
 #
 # This is free software, licensed under the GNU General Public License v2.
 # See /LICENSE for more information.
@ -8,54 +8,68 @@
 include $(TOPDIR)/rules.mk

 PKG_NAME:=mini_snmpd
 PKG_VERSION:=1.2b
 PKG_RELEASE:=8
 PKG_VERSION:=1.4-rc1
 PKG_RELEASE:=1
 PKG_MAINTAINER:=Luke McKee <hojuruku@gmail.com>
 PKG_LICENSE:=GPL-2.0
 PKG_LICENSE_FILES:=COPYING

 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL:=https://github.com/troglobit/mini-snmpd.git
 PKG_SOURCE_SUBDIR:=$(PKG_NAME)-$(PKG_VERSION)
 PKG_SOURCE_VERSION:=203d92e60ed09466d6676c6ad20ad6cb2ce08a5d
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=http://members.aon.at/linuxfreak/linux/
 PKG_MD5SUM:=9e432c50ba8216d7fab0983b11b7112a

 PKG_BUILD_DIR:=$(BUILD_DIR)/$(PKG_NAME)
 PKG_FIXUP:=autoreconf
 PKG_BUILD_DIR:=$(BUILD_DIR)/$(PKG_NAME)-$(PKG_VERSION)
 PKG_BUILD_PARALLEL:=1
 PKG_INSTALL:=1
 # As warned by upstream maintainer and binutils 
 # however compiler warnings can be ignored until next binutils release 
 # https://github.com/wongsyrone/openwrt-1/issues/67
 # PKG_SSP:=0
 # PKG_RELRO:=0

 include $(INCLUDE_DIR)/package.mk

 define Package/mini-snmpd
 define Package/mini_snmpd
  SECTION:=net
  CATEGORY:=Network
  TITLE:=SNMP server for embedded systems
  URL:=http://members.aon.at/linuxfreak/linux/mini_snmpd.html
  TITLE:=A tiny SNMP server for embedded systems 
  URL:=http://troglobit.github.io/mini-snmpd.html
 # uncomment if you just want the binary, not the init script
 # openwrt requires init script runtime dependencies be defined for make menuconfig 
 # (e.g busybox sysntpd)
  DEPENDS:=+jsonfilter +ubus +procd +ubox
 endef

 ifneq ($(CONFIG_IPV6),)
  TARGET_CFLAGS+= -D__IPV6__
 else
  TARGET_CFLAGS+= -D__IPV4__
 endif
 CONFIGURE_ARGS+= \
 	$(if $(CONFIG_IPV6),,--disable-ipv6)

 TARGET_CFLAGS+= -DSYSLOG
 # Configure weirdness - Disabled by default, explicitately disabling turns feature on!
 #     --disable-debug \
 #	--disable-demo - Upstream Github Issue #4 Fixed 20160707

 MAKE_FLAGS+= \
 	OFLAGS="$(TARGET_CFLAGS)" \
 # We make sure that only openwrt buildroot does the stripping as per user request via make menuconfig
 CONFIGURE_VARS+= LD="$(TARGET_CC)" \
 	STRIP="/bin/true" \
 	INSTALL_ROOT="$(PKG_INSTALL_DIR)"
 	CFLAGS="$(TARGET_CFLAGS)"
 MAKE_FLAGS+= STRIP="/bin/true" 

 define Build/Compile
 	$(call Build/Compile/Default,mini_snmpd)
 endef
 # FYI upstream suggested stripping options
 #	STRIP="strip -S --strip-unneeded --remove-section=.note.gnu.gold-version --remove-section=.comment --remove-section=.note --remove-section=.note.gnu.build-id --remove-section=.note.ABI-tag mini_snmpd" 

 define Package/mini-snmpd/install
 define Package/mini_snmpd/install
 	$(INSTALL_DIR) $(1)/usr/bin
 	$(CP) $(PKG_INSTALL_DIR)/sbin/mini_snmpd $(1)/usr/bin/
 	$(CP) $(PKG_INSTALL_DIR)/usr/bin/mini_snmpd $(1)/usr/bin/
 	$(INSTALL_DIR) $(1)/etc/config
 	$(INSTALL_CONF) ./files/mini_snmpd.config $(1)/etc/config/mini_snmpd
 	$(INSTALL_DIR) $(1)/etc/init.d
 	$(INSTALL_BIN) ./files/mini_snmpd.init $(1)/etc/init.d/mini_snmpd
 endef

 define Package/mini-snmpd/conffiles
 define Package/mini_snmpd/conffiles
 /etc/config/mini_snmpd
 endef

 $(eval $(call BuildPackage,mini-snmpd))
 $(eval $(call BuildPackage,mini_snmpd))
--- a/net/mini_snmpd/files/mini_snmpd.config
+++ b/net/mini_snmpd/files/mini_snmpd.config
@ -1,16 +1,26 @@
 config mini_snmpd
 	option enabled 0
 # you may add more than the 'default' mini_snmpd instances provided they all bind to different ports/interfaces
 # to get around max 4 interface or mountpoint limit constrained by mini_snmpd's mib
 config mini_snmpd 'default'
 	option enabled 1
 	option ipv6 0
 	# Verbose flag given to mini_snmpd, extra verbose is only possible with compile time config flags
 	option debug 0
 	# Turn on community authentication (snmp agent must use community name)
 	option auth 0
 	option community 'public'
 	option contact ''
 	option location ''

 	option contact 'OpenWRT router <openwrt@openwrt.org>'
 	option location 'Undisclosed'
 	# to listen on all interfaces you need to set option listen_interface ''
 	option listen_interface 'lan'
 	#option udp_port '161'
 	#option tcp_port '161'
 	#option vendor_oid ''
 	option mib_timeout 1
 	# enable basic disk usage statistics on specified mountpoint
 	list disks '/jffs'
 	list disks '/overlay'
 	list disks '/tmp'

 	# enable basic network statistics on specified interface
 	# 4 interfaces maximum, as named in /etc/config/network
 	list interfaces 'loopback'
 	# 4 interfaces maximum per instance, as named in /etc/config/network and luci
 	# not physical device names
 	list interfaces 'lan'
 	list interfaces 'wan'
--- a/net/mini_snmpd/files/mini_snmpd.init
+++ b/net/mini_snmpd/files/mini_snmpd.init
@ -1,65 +1,240 @@
 #!/bin/sh /etc/rc.common
 # Copyright (C) 2009-2012 OpenWrt.org
 # Copyright (C) 2009-2016 OpenWrt.org
 # Copyright (C) 2016 Luke McKee <hojuruku@gmail.com>
 # Procd init script reference: http://wiki.prplfoundation.org/wiki/Procd_reference

 START=50
 START=98
 USE_PROCD=1
 PROG=/usr/bin/mini_snmpd
 NAME=mini_snmpd

 SERVICE_DAEMONIZE=1
 SERVICE_WRITE_PID=1
 _log() {
        logger -p daemon.info -t mini_snmpd "$@"
 }

 _err() {
        logger -p daemon.err -t mini_snmpd "$@"
 }


 # mini_snmpd 1.3+ now starts later in the game. Expects filesystems monitored to be already mounted, or wont pass args to mini_snmpd 
 # and at least configuration entry for network physical interface defined in /etc/config/network
 # It handles network interfaces not yet present (e.g. ppp) but will statfs() the root/wrong filesystem if device not mounted
 # Tip: complex scripts run faster without in openwrt if you stop busybox forking and searching for applets. Faster bootups
 #	CONFIG_BUSYBOX_CONFIG_FEATURE_SH_NOFORK
 # 	CONFIG_BUSYBOX_CONFIG_FEATURE_PREFER_APPLETS
 # 	BUSYBOX_CONFIG_ASH_OPTIMIZE_FOR_SIZE [=n]
 #	CONFIG_BUSYBOX_CONFIG_ASH_CMDCMD

 mini_snmpd_validation="enabled:bool:0 \
 		ipv6:bool:0 \
 		debug:bool:0 \
 		auth:bool:1 \
 		community:rangelength(1,32):public \
 		contact:maxlength(255) \
 		location:maxlength(255) \
 		listen_interface:uciname \
 		udp_port:port \
 		tcp_port:port \
 		vendor_oid:string \
 		mib_timeout:and(min(1),uinteger) \
 		disks:list(directory) \
 		interfaces:list(uciname) \
 		respawn_threshold:uinteger respawn_timeout:uinteger respawn_retry:uinteger"
 # busybox ash has no array variable support, when put validations in a string be careful to have no spaces in each validate constraint
 # this makes it very difficult to use the 'or(uciname, "all")' test, so listen_interface '' or undefined now meands bind to "all".
 # this is the sarafice you have to make to avoid typing it all in twice in this script so we can give feedback to user on what's misconfigered
 # in syslog

 append_disk() {
 	local disk="$1"
 	append disks "$disk" ','
 	local disk="$1" disk_count
 	[ -z $disk_count ] && disk_count=0
 	if grep -qF "$disk" /proc/mounts ; then
 		# check the fileystem is mountpoint, and directory search permissions available for statfs()
 		# presence as a directory -d test done is already done by uci_validate_section()
 		[ -x "$disk" ] || {
 			_err "$cfg: mountpoint $disk for snmp monitoring EACCES error. Check permissions, ignoring"
 			return 1
 		}
 		if [ $disk_count -lt 4 ] ;  then  
 			append disks_arg "$disk" ','
 			disk_count=$((disk_count++))
 		else
 			_err "$cfg: more than 4 mountpoints defined in uci. Disc $disk ignored."
 		fi
 	else
 		_err "$cfg: mountpoint $disk for snmp monitoring not mounted, ignoring."
 	fi
 }

 append_interface() {
 	local name="$1"
 	local device
 	network_get_device device "$name"
 	append interfaces "${device:-$name}" ','
 	local name="$1" netdev netdev_count
 	[ -z $netdev_count ] && netdev_count=0
 	# for the purposes of snmp monitoring it doesn't need to be up, it just needs to exist in /proc/net/dev
 	netdev=$(ubus -S call network.interface dump|jsonfilter -e "@.interface[@.interface=\"$name\"].device")  
 	if [ -n "$netdev" ] && grep -qF "$netdev" /proc/net/dev ]; then 
 		[ $netdev_count -ge 4 ] && {
 			_err "$cfg: too many network interfaces configured, ignoring $name"
 			return
 		}
 		netdev_count=$((netdev_count++))	
 		if [ -n "$interfaces_arg" ]; then	
 			append interfaces_arg "$netdev" ','
 		else	
 			append interfaces_arg "$netdev"
 		fi
 	else
 		 _err "$cfg: physical interface for network $name not found in uci or kernel so not monitoring"
 	fi
 }

 append_string() {
 	local section="$1"
 	local option="$2"
 	local value="$3"
 	local _val
 	config_get _val "$section" "$option"
 	[ -n "$_val" ] && append args "$3 $_val"
 append_arg() {
 	local var="$2"
 	local opt="$1"
 	[ -n "$var" ] && procd_append_param command $opt "$var"
 }

 start_instance() {
 watch_interfaces() {
 	local cfg="$1"
 	local args=""
 	local disks=""
 	local interfaces=""
 	local ipv6
 	local enabled listen_interface # listen_interface_up
 	config_get_bool enabled "$cfg" "enabled" '1'
 	[ "$enabled" -gt 0 ] || return 0
 	config_get listen_interface "$cfg" listen_interface
 	# listen_interface_up=$(ubus -S call network.interface dump | jsonfilter -e "@.interface[@.interface=\"$listen_interface\"].up")
 	# If the interface is up & instance is running we'll watch at the instance level and only restart that instance if it's bound interface changes
 	# Regardless of ubus knowing about an interface (in the case it's not yet configured)
 	[ -n "$listen_interface" ] && trigger_interfaces="${listen_interface} ${trigger_interfaces} "
 }

 	append_string "$cfg" community "-c"
 	append_string "$cfg" location "-L"
 	append_string "$cfg" contact "-C"
 validate_mini_snmpd_section() {
 	# validate a mini_snmpd instance in uci config file mini_snmpd
 	# http://luci.subsignal.org/trac/wiki/Documentation/Datatypes ubox/validate/validate.c
 	uci_validate_section mini_snmpd mini_snmpd "${1}" $mini_snmpd_validation
 }

 	config_get_bool ipv6 "$cfg" "ipv6" '0'
 	[ "$ipv6" -gt 0 ] && append args "-6"

 	config_get_bool enabled "$cfg" "enabled" '1'
 	[ "$enabled" -gt 0 ] || return 1
 service_triggers() {
        config_load 'mini_snmpd'
        procd_open_trigger
        procd_add_config_trigger "config.change" "mini_snmpd" /etc/init.d/mini_snmpd reload
        config_foreach watch_interfaces 'mini_snmpd' 
 	# this only watches interfaces for which there is no running instance due to interface down / not in ubus
 	# hence start not reload, this trigger will not affect running instances as another start will not change their procd command arguments
 	# or stop the already running process
        [ -n "$trigger_interfaces" ] & {
                for n in $trigger_interfaces ; do
 			procd_add_interface_trigger "interface.*" $n /etc/init.d/mini_snmpd start
                done
        }
        procd_close_trigger
 	procd_add_validation validate_mini_snmpd_section
 }


 	config_list_foreach "$section" 'disks' append_disk
 	args="${args}${disks:+ -d $disks}"
 start_instance() {
 	local cfg validation_failed validation_err disks_arg interfaces_arg
 	cfg="$1"	
 	#uci_validate_section should unset undefined variables from other instances
 	#however defining uci variables as local will scope them to this instance
 	#"local variables are also visible to functions called by the parent function" so it's good practice
 	local enabled ipv6 debug auth community contact location listen_interface \
 		udp_port tcp_port vendor_oid mib_timeout
 	local disks="" interfaces=""
 	validate_mini_snmpd_section "$cfg" 2>/dev/null || validation_failed=1
 	[ "$enabled" == 1 ] || { 
 		_log "instance:$cfg disabled not starting" 
 		 return 1
 	}
 	
 	local listen_interface_json listen_interface_ip listen_interface_device listen_interface_up ubus_exit ubus_err
 	[ -n "$listen_interface" ] && {
 		listen_interface_json=$(ubus -S call network.interface.$listen_interface status)
 		ubus_exit=$?
 		[ $ubus_exit = 4 ] && {
 			_err "$cfg: listen_interface $listen_interface not properly configured in ubus network.interface.* not starting this instance "
 			return 1
 		}
 		[ $ubus_exit = 255 -a -z "$listen_interface_json" ] && { 
 			_log "$cfg: ubusd not yet up, will try to start mini_snmpd shorlty when procd detects $listen_interface comes up"
 			return 1
 		}
 		[ -z "$listen_interface_json" ] && { 
 			ubus_err=`ubus call network.interface.$listen_interface status 2>&1 >/dev/null`
 			_err "$cfg: unknown ubus error. exit: $ubus_exit errormsg: $ubus_err "
 			return 1
 		}
 		listen_interface_up=$(jsonfilter -s "$listen_interface_json" -e '@.up')
 		if [ "$ipv6" = 1 ]; then
 			listen_interface_ip=$(jsonfilter -s "$listen_interface_json" -e "@['ipv6-address'][0].address")
 		else
 			listen_interface_ip=$(jsonfilter -s "$listen_interface_json" -e "@['ipv4-address'][0].address")
 		fi
 		[ -n "$listen_interface_ip" -a "$listen_interface_up" = 'true' ] || {
 			_log "$cfg:listen interface $listen_interface not up yet / not configured properly"
 			_log "$cfg:procd will try again when interface state changes"
 			return 1
 		}
 		listen_interface_device=$(jsonfilter -s "$listen_interface_json" -e '@.l3_device')
 	}

 	config_list_foreach "$section" 'interfaces' append_interface
 	args="${args}${interfaces:+ -i $interfaces}"
 	[ $validation_failed ] && {  
 		_err "validation of $NAME configuration for $cfg instance failed, all tests should be within constraints"
 		_err "please edit the configuration values below using [l]uci "
 		validation_err=`/sbin/validate_data mini_snmpd mini_snmpd "$cfg" $mini_snmpd_validation 2>&1 | sed '/with\ false$/!d;s/validates\ as\ /needs\ to\ be\ /;s/with\ false//' `
 		_err "${validation_err}"
 		return 1
 	}
 	config_list_foreach "$cfg" 'disks' append_disk
 	config_list_foreach "$cfg" 'interfaces' append_interface
 	# test if variables are unset or zero length
 	[ -z "${disks_arg:+1}" -a -z "${interfaces_arg:+1}" ] && {
 		_err "$cfg: you haven't sucessfully configured any mountpoints or disks for this instance, not starting"
 		return 1
 	}
 	
 	procd_open_instance

 	service_start /usr/bin/mini_snmpd $args
 }
 	procd_set_param command "$PROG" -n
 	procd_set_param stdout "1"
 	procd_set_param stderr "1"
 	# don't the like default respawn values? you can override through uci.
 	# vars left as global so you only need to do it in the first mini_snmpd instance
 	procd_set_param respawn ${respawn_threshold:-3600} ${respawn_timeout:-10} ${respawn_retry:-1}
 	# this monitors ubus changes
 	[ -n "$listen_interface" ] && {
 		 #procd_open_trigger
 		 #procd_add_interface_trigger "interface.*" $listen_interface /etc/init.d/mini_snmpd reload 
 		 #procd_close_trigger
 		 procd_add_reload_interface_trigger $listen_interface #or use shorthand of above
 	}
 	# this re-starts the daemon if a properly configured network interface is changed whilst it is already running
 	# igmpproxy has this as well as "procd_set_param netdev" 

 start() {
 	. /lib/functions/network.sh
 	append_arg "-c" "$community" 
 	append_arg "-L" "${location}"
 	append_arg "-C" "${contact}" 
 	append_arg "-p" $udp_port  
 	append_arg "-P" $tcp_port  
 	append_arg "-V" "${vendor_oid}"  
 	append_arg "-t" $mib_timeout 
 	
 	[ "$ipv6" = 1  ] && procd_append_param command "-6"
 	[ "$debug" = 1 ] && procd_append_param command "-v"
 	# uci_validate_section() aka /sbin/validate_data can only cast default values not defined in /etc/config/* to string 
 	# e.g. ="1" however it sets bools defined in /etc/config/* to =1 / =0
 	[ "$auth" = 1 -o "$auth" = "1" ] && procd_append_param command "-a"
 	[ -n "$disks_arg" ] && procd_append_param command "-d $disks_arg" 
 	[ -n "$interfaces_arg" ] && procd_append_param command "-i $interfaces_arg"
 	[ -n "$listen_interface_device" ] && {
 		 procd_append_param command "-I" "$listen_interface_device"
 		 # and this monitors the hardware device for changes outside of ubus - just a guess
 		 procd_set_param netdev $listen_interface_device
 	}
 	procd_close_instance
 }

 start_service() {
 	config_load 'mini_snmpd'
 	config_foreach start_instance 'mini_snmpd'
 }

 stop() {
 	service_stop /usr/bin/mini_snmpd
 }
--- a/net/mini_snmpd/files/mini_snmpd.init-v2
+++ b/net/mini_snmpd/files/mini_snmpd.init-v2
@ -1,146 +0,0 @@
 #!/bin/sh /etc/rc.common
 # Copyright (C) 2009-2016 OpenWrt.org

 START=95
 USE_PROCD=1
 PROCD_DEBUG=1
 PROG=/usr/bin/mini_snmpd
 NAME=mini_snmpd

 # mini_snmpd now starts later in the game. Expects filesystems monitored to be already mounted, 
 # and at least configuration entry for network physical interface defined in /etc/config/network
 # It handles network interfaces not yet present (e.g. ppp) but will statfs() the root/wrong filesystem if device not mounted

 append_disk() {
 	local disk="$1"
 	[ -z $disk_count ] && disk_count=1
 	if grep -qF "$disk" /proc/mounts ; then
 		if [ $disk_count -le 4 ] ;  then  
 			append disks "$disk" ','
 			disk_count=$((disk_count++))
 		else
 			logger -s -t mini_snmpd -p daemon.error "more than 4 mountpoints defined in uci. Disc $disk ignored."
 		fi
 	else
 		logger -s -t mini_snmpd -p daemon.error "mountpoint $disk for snmp monitoring not mounted, ignoring."
 	fi
 }

 append_interface() {
 	local name="$1"
 	local device
 	[ $(ubus -S call network.interface dump | jsonfilter -e "@.interface[@.interface=\"$name\"].device") ] && { 
 		append interfaces "${device:-$name}" ','
 	}
 }

 append_arg() {
        local cfg="$1"
        local var="$2"
        local opt="$3"
        local def="$4"
        local val
        config_get val "$cfg" "$var"
        [ -n "$val" -o -n "$def" ] && procd_append_param command $opt "${val:-$def}"
 }

 listen_interface_status() {
 	local cfg="$1"
 }

 watch_interfaces() {
 	local cfg="$1"
 	local enabled listen_interface
 	config_get_bool enabled "$cfg" "enabled" '1'
 	[ "$enabled" -gt 0 ] || return 0
 	config_get listen_interface "$cfg" listen_interface
 	[ "$listen_interface" = "all" ] && return 0
 	local listen_interface_up=$(ubus -S call network.interface dump | jsonfilter -e "@.interface[@.interface=\"$listen_interface\"].up")
 	# if ubus knows about it regardless if it's status we'll watch for changes.
 	[ -n "$listen_interface" -a -n "$listen_interface_up" ] && trigger_interfaces=" ${listen_interface} ${trigger_interfaces}"
 }

 service_triggers() {
        #procd_add_reload_trigger mini_snmpd
        procd_open_trigger
        procd_add_config_trigger "config.change" "mini_snmpd" /etc/init.d/mini_snmpd reload
        config_load 'mini_snmpd'
        config_foreach watch_interfaces 'mini_snmpd' 
        [ -n "${trigger_interfaces}" ] & {
                for n in $trigger_interfaces ; do
 			procd_add_interface_trigger "interface.*" $n /etc/init.d/mini_snmpd restart
                done
        }
        procd_close_trigger
        #procd_add_validation validate_section_mini_snmpd
 }


 start_instance() {
 	local cfg="$1" disks="" interfaces=""
 	local ipv6 debug auth

 	config_get_bool enabled "$cfg" "enabled" '1'
 	[ "$enabled" -gt 0 ] || return 1 

 	local listen_interface listen_interface_json listen_interface_ip listen_interface_device listen_interface_up
 	config_get_bool ipv6 "$cfg" "ipv6" '0'
 	config_get listen_interface "$cfg" listen_interface
 	[ -n "$listen_interface" -a "$listen_interface" != "all" ] && {
 		listen_interface_json=$(ubus -S call network.interface.$listen_interface status)
 		[ -z "$listen_interface_json" ] && { 
 			logger -s -t mini_snmpd -p daemon.error "interface configured to bind to is not configured in /etc/config/network"
 			return 1
 		}
 		listen_interface_up=$(jsonfilter -s "$listen_interface_json" -e '@.up')
 		if [ "$ipv6" -gt 0 ]; then
 			listen_interface_ip=$(jsonfilter -s "$listen_interface_json" -e "@['ipv6-address'][0].address")
 		else
 			listen_interface_ip=$(jsonfilter -s "$listen_interface_json" -e "@['ipv4-address'][0].address")
 		fi
 		[ -n "$listen_interface_ip" -a "$listen_interface_up" = 'true' ] || {
 			logger -s -t mini_snmpd -p daemon.debug "interface configured to bind to is not up yet, procd will try again later"
 			return 0
 		}
 		listen_interface_device=$(jsonfilter -s "$listen_interface_json" -e '@.l3_device')
 	}

 	procd_open_instance

 	procd_set_param command "$PROG" -n
 	procd_set_param stdout "1"
 	procd_set_param stderr "1"
 	procd_set_param respawn ${respawn_threshold:-3600} ${respawn_timeout:-5} ${respawn_retry:-5}

 	append_arg "$cfg" community "-c"
 	append_arg "$cfg" location "-L"
 	append_arg "$cfg" contact "-C"
 	append_arg "$cfg" udp_port "-p"
 	append_arg "$cfg" tcp_port "-P"
 	append_arg "$cfg" vendor_oid "-V"
 	append_arg "$cfg" mib_timeout "-t"

 	[ "$ipv6" -gt 0 ] && procd_append_param command "-6"
 	config_get_bool debug "$cfg" "debug" '0'
 	[ "$debug" -gt 0 ] && procd_append_param command "-v"
 	config_get_bool auth "$cfg" "auth" '0'
 	[ "$auth" -gt 0 ] && procd_append_param command "-a"
 	config_list_foreach "$cfg" 'disks' append_disk
 	[ -n "$disks" ] && procd_append_param command "-d $disks" 
 	config_list_foreach "$cfg" 'interfaces' append_interface
 	[ -n "$interfaces" ] && procd_append_param command "-i $interfaces"
 	# https://github.com/troglobit/mini-snmpd/issues/4 - yes I know there is no space after the -I
 	[ -n "$listen_interface_device" ] && procd_append_param command "-I$listen_interface_device"

 	procd_close_instance
 }

 start_service() {
 	config_load 'mini_snmpd'
 	config_foreach start_instance 'mini_snmpd'
 }

 reload_service() {
 	stop
        start
 }
--- a/net/mini_snmpd/files/mini_snmpd.init.orig
+++ b/net/mini_snmpd/files/mini_snmpd.init.orig
@ -1,65 +0,0 @@
 #!/bin/sh /etc/rc.common
 # Copyright (C) 2009-2012 OpenWrt.org

 START=50

 SERVICE_DAEMONIZE=1
 SERVICE_WRITE_PID=1

 append_disk() {
 	local disk="$1"
 	append disks "$disk" ','
 }

 append_interface() {
 	local name="$1"
 	local device
 	network_get_device device "$name"
 	append interfaces "${device:-$name}" ','
 }

 append_string() {
 	local section="$1"
 	local option="$2"
 	local value="$3"
 	local _val
 	config_get _val "$section" "$option"
 	[ -n "$_val" ] && append args "$3 $_val"
 }

 start_instance() {
 	local cfg="$1"
 	local args=""
 	local disks=""
 	local interfaces=""
 	local ipv6

 	append_string "$cfg" community "-c"
 	append_string "$cfg" location "-L"
 	append_string "$cfg" contact "-C"

 	config_get_bool ipv6 "$cfg" "ipv6" '0'
 	[ "$ipv6" -gt 0 ] && append args "-6"

 	config_get_bool enabled "$cfg" "enabled" '1'
 	[ "$enabled" -gt 0 ] || return 1

 	config_list_foreach "$section" 'disks' append_disk
 	args="${args}${disks:+ -d $disks}"

 	config_list_foreach "$section" 'interfaces' append_interface
 	args="${args}${interfaces:+ -i $interfaces}"

 	service_start /usr/bin/mini_snmpd $args
 }

 start() {
 	. /lib/functions/network.sh

 	config_load 'mini_snmpd'
 	config_foreach start_instance 'mini_snmpd'
 }

 stop() {
 	service_stop /usr/bin/mini_snmpd
 }