net/mini_snmpd/files/mini_snmpd.init

   1 #!/bin/sh /etc/rc.common
   2 # Copyright (C) 2009-2016 OpenWrt.org
   3 # Copyright (C) 2016 Luke McKee <hojuruku@gmail.com>
   4 # Procd init script reference: http://wiki.prplfoundation.org/wiki/Procd_reference
   5
   6 START=98
   7 USE_PROCD=1
   8 PROG=/usr/bin/mini_snmpd
   9 NAME=mini_snmpd
  10
  11 global_respawn_threshold=
  12 global_respawn_timeout=
  13 global_respawn_retry=
  14
  15 _log() {
  16         logger -p daemon.info -t mini_snmpd "$@"
  17 }
  18
  19 _err() {
  20         logger -p daemon.err -t mini_snmpd "$@"
  21 }
  22
  23
  24 # mini_snmpd 1.3+ now starts later in the game. Expects filesystems monitored to be already mounted, or wont pass args to mini_snmpd
  25 # and at least configuration entry for network physical interface defined in /etc/config/network
  26 # It handles network interfaces not yet present (e.g. ppp) but will statfs() the root/wrong filesystem if device not mounted
  27 # Tip: complex scripts run faster without in openwrt if you stop busybox forking and searching for applets. Faster bootups
  28 #       CONFIG_BUSYBOX_CONFIG_FEATURE_SH_NOFORK
  29 #       CONFIG_BUSYBOX_CONFIG_FEATURE_PREFER_APPLETS
  30 #       BUSYBOX_CONFIG_ASH_OPTIMIZE_FOR_SIZE [=n]
  31 #       CONFIG_BUSYBOX_CONFIG_ASH_CMDCMD
  32
  33 mini_snmpd_validation="enabled:bool:0 \
  34                 ipv6:bool:0 \
  35                 debug:bool:0 \
  36                 auth:bool:1 \
  37                 community:rangelength(1,32):public \
  38                 contact:maxlength(255) \
  39                 description:maxlength(255) \
  40                 location:maxlength(255) \
  41                 listen_interface:uciname \
  42                 udp_port:port \
  43                 tcp_port:port \
  44                 vendor_oid:string \
  45                 mib_timeout:and(min(1),uinteger) \
  46                 disks:list(directory) \
  47                 interfaces:list(uciname) \
  48                 respawn_threshold:uinteger respawn_timeout:uinteger respawn_retry:uinteger"
  49 # busybox ash has no array variable support, when put validations in a string be careful to have no spaces in each validate constraint
  50 # this makes it very difficult to use the 'or(uciname, "all")' test, so listen_interface '' or undefined now meands bind to "all".
  51 # 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
  52 # in syslog
  53
  54 append_disk() {
  55         local disk="$1" disk_count
  56         [ -z $disk_count ] && disk_count=0
  57         if grep -qF "$disk" /proc/mounts; then
  58                 # check the fileystem is mountpoint, and directory search permissions available for statfs()
  59                 # presence as a directory -d test done is already done by uci_validate_section()
  60                 [ -x "$disk" ] || {
  61                         _err "$cfg: mountpoint $disk for snmp monitoring EACCES error. Check permissions, ignoring"
  62                         return 1
  63                 }
  64                 if [ $disk_count -lt 4 ]; then
  65                         append disks_arg "$disk" ','
  66                         disk_count=$((disk_count++))
  67                 else
  68                         _err "$cfg: more than 4 mountpoints defined in uci. Disc $disk ignored."
  69                 fi
  70         else
  71                 _err "$cfg: mountpoint $disk for snmp monitoring not mounted, ignoring."
  72         fi
  73 }
  74
  75 append_interface() {
  76         local name="$1" netdev netdev_count
  77         [ -z $netdev_count ] && netdev_count=0
  78         # for the purposes of snmp monitoring it doesn't need to be up, it just needs to exist in /proc/net/dev
  79         network_get_device netdev "$name"
  80         if [ -n "$netdev" ] && grep -qF "$netdev" /proc/net/dev; then
  81                 [ $netdev_count -ge 8 ] && {
  82                         _err "$cfg: too many network interfaces configured, ignoring $name"
  83                         return
  84                 }
  85                 netdev_count=$((netdev_count++))
  86                 if [ -n "$interfaces_arg" ]; then
  87                         append interfaces_arg "$netdev" ','
  88                 else
  89                         append interfaces_arg "$netdev"
  90                 fi
  91         else
  92                  _log "$cfg: physical interface for network $name not found in uci or kernel so not monitoring"
  93         fi
  94 }
  95
  96 append_arg() {
  97         local var="$2"
  98         local opt="$1"
  99         [ -n "$var" ] && procd_append_param command $opt "$var"
 100 }
 101
 102 watch_interfaces() {
 103         local cfg="$1"
 104         local enabled listen_interface # listen_interface_up
 105         config_get_bool enabled "$cfg" "enabled" '1'
 106         [ "$enabled" -gt 0 ] || return 0
 107         config_get listen_interface "$cfg" listen_interface
 108         # 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
 109         # Regardless of ubus knowing about an interface (in the case it's not yet configured)
 110         [ -n "$listen_interface" ] && trigger_interfaces="$listen_interface $trigger_interfaces"
 111         # Restart daemon if one of monitored interfaces changes
 112         config_get reload_interfaces "$cfg" interfaces
 113 }
 114
 115 validate_mini_snmpd_section() {
 116         # validate a mini_snmpd instance in uci config file mini_snmpd
 117         # http://luci.subsignal.org/trac/wiki/Documentation/Datatypes ubox/validate/validate.c
 118         uci_load_validate mini_snmpd mini_snmpd "$1" "$2" $mini_snmpd_validation
 119 }
 120
 121
 122 service_triggers() {
 123         config_load 'mini_snmpd'
 124         procd_open_trigger
 125         procd_add_config_trigger "config.change" "mini_snmpd" /etc/init.d/mini_snmpd reload
 126         config_foreach watch_interfaces 'mini_snmpd'
 127         # this only watches interfaces for which there is no running instance due to interface down / not in ubus
 128         # hence start not reload, this trigger will not affect running instances as another start will not change their procd command arguments
 129         # or stop the already running process
 130         [ -n "$trigger_interfaces" ] && {
 131                 for n in $trigger_interfaces; do
 132                         procd_add_interface_trigger "interface.*" $n /etc/init.d/mini_snmpd start
 133                 done
 134         }
 135         [ -n "$reload_interfaces" ] && {
 136                 for n in $reload_interfaces; do
 137                         procd_add_reload_interface_trigger $n
 138                 done
 139         }
 140         procd_close_trigger
 141         procd_add_validation validate_mini_snmpd_section
 142 }
 143
 144
 145 start_instance() {
 146         local cfg validation_failed validation_err disks_arg interfaces_arg
 147         cfg="$1"
 148         [ "$2" = 0 ] || validation_failed=1
 149         [ "$enabled" == 1 ] || {
 150                 _log "instance:$cfg disabled not starting"
 151                  return 1
 152         }
 153
 154         local listen_interface_json listen_interface_ip listen_interface_device listen_interface_up
 155         [ -n "$listen_interface" ] && {
 156                 if [ "$ipv6" = 1 ]; then
 157                         network_get_ipaddrs6 listen_interface_ip "$listen_interface"
 158                 else
 159                         network_get_ipaddrs listen_interface_ip "$listen_interface"
 160                 fi
 161                 network_is_up "$listen_interface" && [ -n "$listen_interface_ip" ] || {
 162                         _log "$cfg:listen interface $listen_interface not up yet / not configured properly"
 163                         _log "$cfg:procd will try again when interface state changes"
 164                         return 1
 165                 }
 166                 network_get_physdev listen_interface_device "$listen_interface"
 167         }
 168
 169         [ $validation_failed ] && {
 170                 _err "validation of $NAME configuration for $cfg instance failed, all tests should be within constraints"
 171                 _err "please edit the configuration values below using [l]uci "
 172                 validation_err=`/sbin/validate_data mini_snmpd mini_snmpd "$cfg" $mini_snmpd_validation 2>&1 | sed '/with\ false$/!d;s/validates\ as\ /needs\ to\ be\ /;s/with\ false//' `
 173                 _err "$validation_err"
 174                 return 1
 175         }
 176         config_list_foreach "$cfg" 'disks' append_disk
 177         config_list_foreach "$cfg" 'interfaces' append_interface
 178         # test if variables are unset or zero length
 179         [ -z "${disks_arg:+1}" -a -z "${interfaces_arg:+1}" ] && {
 180                 _err "$cfg: you haven't sucessfully configured any mountpoints or disks for this instance, not starting"
 181                 return 1
 182         }
 183
 184         [ -z "$respawn_threshold$respawn_timeout$respawn_retry" ] && {
 185                 respawn_threshold=$global_respawn_threshold
 186                 respawn_timeout=$global_respawn_timeout
 187                 respawn_retry=$global_respawn_retry
 188         }
 189         [ -z "$global_respawn_threshold$global_respawn_timeout$global_respawn_retry" ] && {
 190                 global_respawn_threshold=$respawn_threshold
 191                 global_respawn_timeout=$respawn_timeout
 192                 global_respawn_retry=$respawn_retry
 193         }
 194
 195         procd_open_instance
 196
 197         procd_set_param command "$PROG" -n
 198         procd_set_param stdout "1"
 199         procd_set_param stderr "1"
 200         # don't the like default respawn values? you can override through uci.
 201         # vars saved as global so you only need to do it in the first mini_snmpd instance
 202         procd_set_param respawn ${respawn_threshold:-3600} ${respawn_timeout:-10} ${respawn_retry:-1}
 203         # this monitors ubus changes
 204         [ -n "$listen_interface" ] && {
 205                  #procd_open_trigger
 206                  #procd_add_interface_trigger "interface.*" $listen_interface /etc/init.d/mini_snmpd reload
 207                  #procd_close_trigger
 208                  procd_add_reload_interface_trigger $listen_interface #or use shorthand of above
 209         }
 210         # this re-starts the daemon if a properly configured network interface is changed whilst it is already running
 211         # igmpproxy has this as well as "procd_set_param netdev"
 212
 213         append_arg "-c" "$community"
 214         append_arg "-L" "$location"
 215         append_arg "-C" "$contact"
 216         append_arg "-D" "$description"
 217         append_arg "-p" $udp_port
 218         append_arg "-P" $tcp_port
 219         append_arg "-V" "$vendor_oid"
 220         append_arg "-t" $mib_timeout
 221
 222         [ "$ipv6" = 1 ] && procd_append_param command "-6"
 223         [ "$debug" = 1 ] && procd_append_param command "-v"
 224         # uci_validate_section() aka /sbin/validate_data can only cast default values not defined in /etc/config/* to string
 225         # e.g. ="1" however it sets bools defined in /etc/config/* to =1 / =0
 226         [ "$auth" = 1 -o "$auth" = "1" ] && procd_append_param command "-a"
 227         [ -n "$disks_arg" ] && procd_append_param command "-d" "$disks_arg"
 228         [ -n "$interfaces_arg" ] && {
 229                 procd_append_param netdev ${interfaces_arg//,/ }
 230                 procd_append_param command "-i" "$interfaces_arg"
 231         }
 232         [ -n "$listen_interface_device" ] && {
 233                  procd_append_param command "-I" "$listen_interface_device"
 234                  # and this monitors the hardware device for changes outside of ubus - just a guess
 235                  procd_append_param netdev $listen_interface_device
 236         }
 237         procd_close_instance
 238 }
 239
 240 start_service() {
 241         . /lib/functions.sh
 242         . /lib/functions/network.sh
 243
 244         config_load 'mini_snmpd'
 245         config_foreach validate_mini_snmpd_section 'mini_snmpd' start_instance
 246 }