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 _log() {
  12         logger -p daemon.info -t mini_snmpd "$@"
  13 }
  14
  15 _err() {
  16         logger -p daemon.err -t mini_snmpd "$@"
  17 }
  18
  19
  20 # mini_snmpd 1.3+ now starts later in the game. Expects filesystems monitored to be already mounted, or wont pass args to mini_snmpd
  21 # and at least configuration entry for network physical interface defined in /etc/config/network
  22 # It handles network interfaces not yet present (e.g. ppp) but will statfs() the root/wrong filesystem if device not mounted
  23 # Tip: complex scripts run faster without in openwrt if you stop busybox forking and searching for applets. Faster bootups
  24 #       CONFIG_BUSYBOX_CONFIG_FEATURE_SH_NOFORK
  25 #       CONFIG_BUSYBOX_CONFIG_FEATURE_PREFER_APPLETS
  26 #       BUSYBOX_CONFIG_ASH_OPTIMIZE_FOR_SIZE [=n]
  27 #       CONFIG_BUSYBOX_CONFIG_ASH_CMDCMD
  28
  29 mini_snmpd_validation="enabled:bool:0 \
  30                 ipv6:bool:0 \
  31                 debug:bool:0 \
  32                 auth:bool:1 \
  33                 community:rangelength(1,32):public \
  34                 contact:maxlength(255) \
  35                 location:maxlength(255) \
  36                 listen_interface:uciname \
  37                 udp_port:port \
  38                 tcp_port:port \
  39                 vendor_oid:string \
  40                 mib_timeout:and(min(1),uinteger) \
  41                 disks:list(directory) \
  42                 interfaces:list(uciname) \
  43                 respawn_threshold:uinteger respawn_timeout:uinteger respawn_retry:uinteger"
  44 # busybox ash has no array variable support, when put validations in a string be careful to have no spaces in each validate constraint
  45 # this makes it very difficult to use the 'or(uciname, "all")' test, so listen_interface '' or undefined now meands bind to "all".
  46 # 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
  47 # in syslog
  48
  49 append_disk() {
  50         local disk="$1" disk_count
  51         [ -z $disk_count ] && disk_count=0
  52         if grep -qF "$disk" /proc/mounts ; then
  53                 # check the fileystem is mountpoint, and directory search permissions available for statfs()
  54                 # presence as a directory -d test done is already done by uci_validate_section()
  55                 [ -x "$disk" ] || {
  56                         _err "$cfg: mountpoint $disk for snmp monitoring EACCES error. Check permissions, ignoring"
  57                         return 1
  58                 }
  59                 if [ $disk_count -lt 4 ] ;  then
  60                         append disks_arg "$disk" ','
  61                         disk_count=$((disk_count++))
  62                 else
  63                         _err "$cfg: more than 4 mountpoints defined in uci. Disc $disk ignored."
  64                 fi
  65         else
  66                 _err "$cfg: mountpoint $disk for snmp monitoring not mounted, ignoring."
  67         fi
  68 }
  69
  70 append_interface() {
  71         local name="$1" netdev netdev_count
  72         [ -z $netdev_count ] && netdev_count=0
  73         # for the purposes of snmp monitoring it doesn't need to be up, it just needs to exist in /proc/net/dev
  74         netdev=$(ubus -S call network.interface dump|jsonfilter -e "@.interface[@.interface=\"$name\"].l3_device")
  75         if [ -n "$netdev" ] && grep -qF "$netdev" /proc/net/dev ]; then
  76                 [ $netdev_count -ge 4 ] && {
  77                         _err "$cfg: too many network interfaces configured, ignoring $name"
  78                         return
  79                 }
  80                 netdev_count=$((netdev_count++))
  81                 if [ -n "$interfaces_arg" ]; then
  82                         append interfaces_arg "$netdev" ','
  83                 else
  84                         append interfaces_arg "$netdev"
  85                 fi
  86         else
  87                  _err "$cfg: physical interface for network $name not found in uci or kernel so not monitoring"
  88         fi
  89 }
  90
  91 append_arg() {
  92         local var="$2"
  93         local opt="$1"
  94         [ -n "$var" ] && procd_append_param command $opt "$var"
  95 }
  96
  97 watch_interfaces() {
  98         local cfg="$1"
  99         local enabled listen_interface # listen_interface_up
 100         config_get_bool enabled "$cfg" "enabled" '1'
 101         [ "$enabled" -gt 0 ] || return 0
 102         config_get listen_interface "$cfg" listen_interface
 103         # listen_interface_up=$(ubus -S call network.interface dump | jsonfilter -e "@.interface[@.interface=\"$listen_interface\"].up")
 104         # 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
 105         # Regardless of ubus knowing about an interface (in the case it's not yet configured)
 106         [ -n "$listen_interface" ] && trigger_interfaces="${listen_interface} ${trigger_interfaces} "
 107 }
 108
 109 validate_mini_snmpd_section() {
 110         # validate a mini_snmpd instance in uci config file mini_snmpd
 111         # http://luci.subsignal.org/trac/wiki/Documentation/Datatypes ubox/validate/validate.c
 112         uci_validate_section mini_snmpd mini_snmpd "${1}" $mini_snmpd_validation
 113 }
 114
 115
 116 service_triggers() {
 117         config_load 'mini_snmpd'
 118         procd_open_trigger
 119         procd_add_config_trigger "config.change" "mini_snmpd" /etc/init.d/mini_snmpd reload
 120         config_foreach watch_interfaces 'mini_snmpd'
 121         # this only watches interfaces for which there is no running instance due to interface down / not in ubus
 122         # hence start not reload, this trigger will not affect running instances as another start will not change their procd command arguments
 123         # or stop the already running process
 124         [ -n "$trigger_interfaces" ] & {
 125                 for n in $trigger_interfaces ; do
 126                         procd_add_interface_trigger "interface.*" $n /etc/init.d/mini_snmpd start
 127                 done
 128         }
 129         procd_close_trigger
 130         procd_add_validation validate_mini_snmpd_section
 131 }
 132
 133
 134 start_instance() {
 135         local cfg validation_failed validation_err disks_arg interfaces_arg
 136         cfg="$1"
 137         #uci_validate_section should unset undefined variables from other instances
 138         #however defining uci variables as local will scope them to this instance
 139         #"local variables are also visible to functions called by the parent function" so it's good practice
 140         local enabled ipv6 debug auth community contact location listen_interface \
 141                 udp_port tcp_port vendor_oid mib_timeout
 142         local disks="" interfaces=""
 143         validate_mini_snmpd_section "$cfg" 2>/dev/null || validation_failed=1
 144         [ "$enabled" == 1 ] || {
 145                 _log "instance:$cfg disabled not starting"
 146                  return 1
 147         }
 148
 149         local listen_interface_json listen_interface_ip listen_interface_device listen_interface_up ubus_exit ubus_err
 150         [ -n "$listen_interface" ] && {
 151                 listen_interface_json=$(ubus -S call network.interface.$listen_interface status)
 152                 ubus_exit=$?
 153                 [ $ubus_exit = 4 ] && {
 154                         _err "$cfg: listen_interface $listen_interface not properly configured in ubus network.interface.* not starting this instance "
 155                         return 1
 156                 }
 157                 [ $ubus_exit = 255 -a -z "$listen_interface_json" ] && {
 158                         _log "$cfg: ubusd not yet up, will try to start mini_snmpd shorlty when procd detects $listen_interface comes up"
 159                         return 1
 160                 }
 161                 [ -z "$listen_interface_json" ] && {
 162                         ubus_err=`ubus call network.interface.$listen_interface status 2>&1 >/dev/null`
 163                         _err "$cfg: unknown ubus error. exit: $ubus_exit errormsg: $ubus_err "
 164                         return 1
 165                 }
 166                 listen_interface_up=$(jsonfilter -s "$listen_interface_json" -e '@.up')
 167                 if [ "$ipv6" = 1 ]; then
 168                         listen_interface_ip=$(jsonfilter -s "$listen_interface_json" -e "@['ipv6-address'][0].address")
 169                 else
 170                         listen_interface_ip=$(jsonfilter -s "$listen_interface_json" -e "@['ipv4-address'][0].address")
 171                 fi
 172                 [ -n "$listen_interface_ip" -a "$listen_interface_up" = 'true' ] || {
 173                         _log "$cfg:listen interface $listen_interface not up yet / not configured properly"
 174                         _log "$cfg:procd will try again when interface state changes"
 175                         return 1
 176                 }
 177                 listen_interface_device=$(jsonfilter -s "$listen_interface_json" -e '@.l3_device')
 178         }
 179
 180         [ $validation_failed ] && {
 181                 _err "validation of $NAME configuration for $cfg instance failed, all tests should be within constraints"
 182                 _err "please edit the configuration values below using [l]uci "
 183                 validation_err=`/sbin/validate_data mini_snmpd mini_snmpd "$cfg" $mini_snmpd_validation 2>&1 | sed '/with\ false$/!d;s/validates\ as\ /needs\ to\ be\ /;s/with\ false//' `
 184                 _err "${validation_err}"
 185                 return 1
 186         }
 187         config_list_foreach "$cfg" 'disks' append_disk
 188         config_list_foreach "$cfg" 'interfaces' append_interface
 189         # test if variables are unset or zero length
 190         [ -z "${disks_arg:+1}" -a -z "${interfaces_arg:+1}" ] && {
 191                 _err "$cfg: you haven't sucessfully configured any mountpoints or disks for this instance, not starting"
 192                 return 1
 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 left 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 "-p" $udp_port
 217         append_arg "-P" $tcp_port
 218         append_arg "-V" "${vendor_oid}"
 219         append_arg "-t" $mib_timeout
 220
 221         [ "$ipv6" = 1  ] && procd_append_param command "-6"
 222         [ "$debug" = 1 ] && procd_append_param command "-v"
 223         # uci_validate_section() aka /sbin/validate_data can only cast default values not defined in /etc/config/* to string
 224         # e.g. ="1" however it sets bools defined in /etc/config/* to =1 / =0
 225         [ "$auth" = 1 -o "$auth" = "1" ] && procd_append_param command "-a"
 226         [ -n "$disks_arg" ] && procd_append_param command "-d $disks_arg"
 227         [ -n "$interfaces_arg" ] && procd_append_param command "-i $interfaces_arg"
 228         [ -n "$listen_interface_device" ] && {
 229                  procd_append_param command "-I" "$listen_interface_device"
 230                  # and this monitors the hardware device for changes outside of ubus - just a guess
 231                  procd_set_param netdev $listen_interface_device
 232         }
 233         procd_close_instance
 234 }
 235
 236 start_service() {
 237         config_load 'mini_snmpd'
 238         config_foreach start_instance 'mini_snmpd'
 239 }
 240