net/l2tpv3tun/files/l2tp.sh

   1 # l2tp.sh - L2TPv3 tunnel backend
   2 # Copyright (c) 2010 OpenWrt.org
   3
   4 l2tp_next_tunnel_id() {
   5         local max=0
   6         local val
   7         for val in $(
   8                 local l
   9                 l2tpv3tun show tunnel | while read l; do
  10                         case "$l" in
  11                                 Tunnel*,*encap*) l="${l#Tunnel }"; echo "${l%%,*}";;
  12                         esac
  13                 done
  14         ); do
  15                 [ "$val" -gt "$max" ] && max="$val"
  16         done
  17         echo $((max + 1))
  18 }
  19
  20 l2tp_next_session_id() {
  21         local tunnel="$1"
  22         local max=0
  23         local val
  24         for val in $(
  25                 local l
  26                 l2tpv3tun show session${tunnel:+ tunnel_id "$tunnel"} | while read l; do
  27                         case "$l" in
  28                                 Session*in*) l="${l#Session }"; echo "${l%% *}";;
  29                         esac
  30                 done
  31         ); do
  32                 [ "$val" -gt "$max" ] && max="$val"
  33         done
  34         echo $((max + 1))
  35 }
  36
  37 l2tp_tunnel_exists() {
  38         test -n "$(l2tpv3tun show tunnel tunnel_id "$1" 2>/dev/null)"
  39 }
  40
  41 l2tp_session_exists() {
  42         test -n "$(l2tpv3tun show session tunnel_id "$1" session_id "$2" 2>/dev/null)"
  43 }
  44
  45 l2tp_ifname() {
  46         l2tpv3tun show session tunnel_id "$1" session_id "$2" 2>/dev/null | \
  47                 sed -ne 's/^.*interface name: //p'
  48 }
  49
  50 l2tp_lock() {
  51         lock /var/lock/l2tp-setup
  52 }
  53
  54 l2tp_unlock() {
  55         lock -u /var/lock/l2tp-setup
  56 }
  57
  58 l2tp_log() {
  59         logger -t "ifup-l2tp" "$@"
  60 }
  61
  62
  63 # Hook into scan_interfaces() to synthesize a .device option
  64 # This is needed for /sbin/ifup to properly dispatch control
  65 # to setup_interface_l2tp() even if no .ifname is set in
  66 # the configuration.
  67 scan_l2tp() {
  68         local dev
  69         config_get dev "$1" device
  70         config_set "$1" device "${dev:+$dev }l2tp-$1"
  71 }
  72
  73 coldplug_interface_l2tp() {
  74         setup_interface_l2tp "l2tp-$1" "$1"
  75 }
  76
  77 setup_interface_l2tp() {
  78         local iface="$1"
  79         local cfg="$2"
  80         local link="l2tp-$cfg"
  81
  82         l2tp_lock
  83
  84         # prevent recursion
  85         local up="$(uci_get_state network "$cfg" up 0)"
  86         [ "$up" = 0 ] || {
  87                 l2tp_unlock
  88                 return 0
  89         }
  90
  91         local tunnel_id
  92         config_get tunnel_id "$cfg" tunnel_id
  93         [ -n "$tunnel_id" ] || {
  94                 tunnel_id="$(l2tp_next_tunnel_id)"
  95                 uci_set_state network "$cfg" tunnel_id "$tunnel_id"
  96                 l2tp_log "No tunnel ID specified, assuming $tunnel_id"
  97         }
  98
  99         local peer_tunnel_id
 100         config_get peer_tunnel_id "$cfg" peer_tunnel_id
 101         [ -n "$peer_tunnel_id" ] || {
 102                 peer_tunnel_id="$tunnel_id"
 103                 uci_set_state network "$cfg" peer_tunnel_id "$peer_tunnel_id"
 104                 l2tp_log "No peer tunnel ID specified, assuming $peer_tunnel_id"
 105         }
 106
 107         local encap
 108         config_get encap "$cfg" encap udp
 109
 110         local sport dport
 111         [ "$encap" = udp ] && {
 112                 config_get sport "$cfg" sport 1701
 113                 config_get dport "$cfg" dport 1701
 114         }
 115
 116         local peeraddr
 117         config_get peeraddr "$cfg" peeraddr
 118         [ -z "$peeraddr" ] && config_get peeraddr "$cfg" peer6addr
 119
 120         local localaddr
 121         case "$peeraddr" in
 122                 *:*) config_get localaddr "$cfg" local6addr ;;
 123                 *)   config_get localaddr "$cfg" localaddr  ;;
 124         esac
 125
 126         [ -n "$localaddr" -a -n "$peeraddr" ] || {
 127                 l2tp_log "Missing local or peer address for tunnel $cfg - skipping"
 128                 return 1
 129         }
 130
 131         (
 132                 while ! l2tp_tunnel_exists "$tunnel_id"; do
 133                         [ -n "$sport" ] && l2tpv3tun show tunnel 2>/dev/null | grep -q "ports: $sport/" && {
 134                                 l2tp_log "There already is a tunnel with src port $sport - skipping"
 135                                 l2tp_unlock
 136                                 return 1
 137                         }
 138
 139                         l2tpv3tun add tunnel tunnel_id "$tunnel_id" peer_tunnel_id "$peer_tunnel_id" \
 140                                 encap "$encap" local "$localaddr" remote "$peeraddr" \
 141                                 ${sport:+udp_sport "$sport"} ${dport:+udp_dport "$dport"}
 142
 143                         # Wait for tunnel
 144                         sleep 1
 145                 done
 146
 147
 148                 local session_id
 149                 config_get session_id "$cfg" session_id
 150                 [ -n "$session_id" ] || {
 151                         session_id="$(l2tp_next_session_id "$tunnel_id")"
 152                         uci_set_state network "$cfg" session_id "$session_id"
 153                         l2tp_log "No session ID specified, assuming $session_id"
 154                 }
 155
 156                 local peer_session_id
 157                 config_get peer_session_id "$cfg" peer_session_id
 158                 [ -n "$peer_session_id" ] || {
 159                         peer_session_id="$session_id"
 160                         uci_set_state network "$cfg" peer_session_id "$peer_session_id"
 161                         l2tp_log "No peer session ID specified, assuming $peer_session_id"
 162                 }
 163
 164
 165                 while ! l2tp_session_exists "$tunnel_id" "$session_id"; do
 166                         l2tpv3tun add session ifname "$link" tunnel_id "$tunnel_id" \
 167                                 session_id "$session_id" peer_session_id "$peer_session_id"
 168
 169                         # Wait for session
 170                         sleep 1
 171                 done
 172
 173
 174                 local dev
 175                 config_get dev "$cfg" device
 176
 177                 local ifn
 178                 config_get ifn "$cfg" ifname
 179
 180                 uci_set_state network "$cfg" ifname "${ifn:-$dev}"
 181                 uci_set_state network "$cfg" device "$dev"
 182
 183                 local mtu
 184                 config_get mtu "$cfg" mtu 1462
 185
 186                 local ttl
 187                 config_get ttl "$cfg" ttl
 188
 189                 ip link set mtu "$mtu" ${ttl:+ ttl "$ttl"} dev "$link"
 190
 191                 # IP setup inherited from proto static
 192                 prepare_interface "$link" "$cfg"
 193                 setup_interface_static "${ifn:-$dev}" "$cfg"
 194
 195                 ip link set up dev "$link"
 196
 197                 uci_set_state network "$cfg" up 1
 198                 l2tp_unlock
 199         ) &
 200 }
 201
 202 stop_interface_l2tp() {
 203         local cfg="$1"
 204         local link="l2tp-$cfg"
 205
 206         local tunnel=$(uci_get_state network "$cfg" tunnel_id)
 207         local session=$(uci_get_state network "$cfg" session_id)
 208
 209         [ -n "$tunnel" ] && [ -n "$session" ] && {
 210                 l2tpv3tun del session tunnel_id "$tunnel" session_id "$session"
 211                 l2tpv3tun del tunnel tunnel_id "$tunnel"
 212         }
 213 }