isisd/isis_csm.c

   1 /*
   2  * IS-IS Rout(e)ing protocol - isis_csm.c
   3  *                             IS-IS circuit state machine
   4  * Copyright (C) 2001,2002    Sampo Saaristo
   5  *                            Tampere University of Technology
   6  *                            Institute of Communications Engineering
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public Licenseas published by the Free
  10  * Software Foundation; either version 2 of the License, or (at your option)
  11  * any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,but WITHOUT
  14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  16  * more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; if not, write to the Free Software Foundation, Inc.,
  20  * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21  */
  22
  23 #include <zebra.h>
  24
  25 #include "log.h"
  26 #include "memory.h"
  27 #include "if.h"
  28 #include "linklist.h"
  29 #include "command.h"
  30 #include "thread.h"
  31 #include "hash.h"
  32 #include "prefix.h"
  33 #include "stream.h"
  34
  35 #include "isisd/dict.h"
  36 #include "isisd/include-netbsd/iso.h"
  37 #include "isisd/isis_constants.h"
  38 #include "isisd/isis_common.h"
  39 #include "isisd/isis_circuit.h"
  40 #include "isisd/isis_tlv.h"
  41 #include "isisd/isis_lsp.h"
  42 #include "isisd/isis_pdu.h"
  43 #include "isisd/isis_network.h"
  44 #include "isisd/isis_misc.h"
  45 #include "isisd/isis_constants.h"
  46 #include "isisd/isis_adjacency.h"
  47 #include "isisd/isis_dr.h"
  48 #include "isisd/isis_flags.h"
  49 #include "isisd/isisd.h"
  50 #include "isisd/isis_csm.h"
  51 #include "isisd/isis_events.h"
  52
  53 extern struct isis *isis;
  54
  55 static const char *csm_statestr[] = {
  56   "C_STATE_NA",
  57   "C_STATE_INIT",
  58   "C_STATE_CONF",
  59   "C_STATE_UP"
  60 };
  61
  62 #define STATE2STR(S) csm_statestr[S]
  63
  64 static const char *csm_eventstr[] = {
  65   "NO_STATE",
  66   "ISIS_ENABLE",
  67   "IF_UP_FROM_Z",
  68   "ISIS_DISABLE",
  69   "IF_DOWN_FROM_Z",
  70 };
  71
  72 #define EVENT2STR(E) csm_eventstr[E]
  73
  74 struct isis_circuit *
  75 isis_csm_state_change (int event, struct isis_circuit *circuit, void *arg)
  76 {
  77   int old_state;
  78
  79   old_state = circuit ? circuit->state : C_STATE_NA;
  80   if (isis->debugs & DEBUG_EVENTS)
  81     zlog_debug ("CSM_EVENT: %s", EVENT2STR (event));
  82
  83   switch (old_state)
  84     {
  85     case C_STATE_NA:
  86       if (circuit)
  87         zlog_warn ("Non-null circuit while state C_STATE_NA");
  88       switch (event)
  89         {
  90         case ISIS_ENABLE:
  91           circuit = isis_circuit_new ();
  92           isis_circuit_configure (circuit, (struct isis_area *) arg);
  93           circuit->state = C_STATE_CONF;
  94           break;
  95         case IF_UP_FROM_Z:
  96           circuit = isis_circuit_new ();
  97           isis_circuit_if_add (circuit, (struct interface *) arg);
  98           listnode_add (isis->init_circ_list, circuit);
  99           circuit->state = C_STATE_INIT;
 100           break;
 101         case ISIS_DISABLE:
 102           zlog_warn ("circuit already disabled");
 103         case IF_DOWN_FROM_Z:
 104           zlog_warn ("circuit already disconnected");
 105           break;
 106         }
 107       break;
 108     case C_STATE_INIT:
 109       switch (event)
 110         {
 111         case ISIS_ENABLE:
 112           isis_circuit_configure (circuit, (struct isis_area *) arg);
 113           isis_circuit_up (circuit);
 114           circuit->state = C_STATE_UP;
 115           isis_event_circuit_state_change (circuit, 1);
 116           listnode_delete (isis->init_circ_list, circuit);
 117           break;
 118         case IF_UP_FROM_Z:
 119           zlog_warn ("circuit already connected");
 120           break;
 121         case ISIS_DISABLE:
 122           zlog_warn ("circuit already disabled");
 123           break;
 124         case IF_DOWN_FROM_Z:
 125           isis_circuit_if_del (circuit);
 126           listnode_delete (isis->init_circ_list, circuit);
 127           isis_circuit_del (circuit);
 128           circuit = NULL;
 129           break;
 130         }
 131       break;
 132     case C_STATE_CONF:
 133       switch (event)
 134         {
 135         case ISIS_ENABLE:
 136           zlog_warn ("circuit already enabled");
 137           break;
 138         case IF_UP_FROM_Z:
 139           isis_circuit_if_add (circuit, (struct interface *) arg);
 140           isis_circuit_up (circuit);
 141           circuit->state = C_STATE_UP;
 142           isis_event_circuit_state_change (circuit, 1);
 143           break;
 144         case ISIS_DISABLE:
 145           isis_circuit_deconfigure (circuit, (struct isis_area *) arg);
 146           isis_circuit_del (circuit);
 147           circuit = NULL;
 148           break;
 149         case IF_DOWN_FROM_Z:
 150           zlog_warn ("circuit already disconnected");
 151           break;
 152         }
 153       break;
 154     case C_STATE_UP:
 155       switch (event)
 156         {
 157         case ISIS_ENABLE:
 158           zlog_warn ("circuit already configured");
 159           break;
 160         case IF_UP_FROM_Z:
 161           zlog_warn ("circuit already connected");
 162           break;
 163         case ISIS_DISABLE:
 164           isis_circuit_deconfigure (circuit, (struct isis_area *) arg);
 165           listnode_add (isis->init_circ_list, circuit);
 166           circuit->state = C_STATE_INIT;
 167           isis_event_circuit_state_change (circuit, 0);
 168           break;
 169         case IF_DOWN_FROM_Z:
 170           isis_circuit_if_del (circuit);
 171           circuit->state = C_STATE_CONF;
 172           isis_event_circuit_state_change (circuit, 0);
 173           break;
 174         }
 175       break;
 176
 177     default:
 178       zlog_warn ("Invalid circuit state %d", old_state);
 179     }
 180
 181   if (isis->debugs & DEBUG_EVENTS)
 182     zlog_debug ("CSM_STATE_CHANGE: %s -> %s ", STATE2STR (old_state),
 183                 circuit ? STATE2STR (circuit->state) : STATE2STR (C_STATE_NA));
 184
 185   return circuit;
 186 }