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_flags.h"
  40 #include "isisd/isis_circuit.h"
  41 #include "isisd/isis_tlv.h"
  42 #include "isisd/isis_lsp.h"
  43 #include "isisd/isis_pdu.h"
  44 #include "isisd/isis_network.h"
  45 #include "isisd/isis_misc.h"
  46 #include "isisd/isis_constants.h"
  47 #include "isisd/isis_adjacency.h"
  48 #include "isisd/isis_dr.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       assert (circuit == NULL);
  89       switch (event)
  90         {
  91         case ISIS_ENABLE:
  92           circuit = isis_circuit_new ();
  93           isis_circuit_configure (circuit, (struct isis_area *) arg);
  94           circuit->state = C_STATE_CONF;
  95           break;
  96         case IF_UP_FROM_Z:
  97           circuit = isis_circuit_new ();
  98           isis_circuit_if_add (circuit, (struct interface *) arg);
  99           listnode_add (isis->init_circ_list, circuit);
 100           circuit->state = C_STATE_INIT;
 101           break;
 102         case ISIS_DISABLE:
 103           zlog_warn ("circuit already disabled");
 104           break;
 105         case IF_DOWN_FROM_Z:
 106           zlog_warn ("circuit already disconnected");
 107           break;
 108         }
 109       break;
 110     case C_STATE_INIT:
 111       assert (circuit);
 112       switch (event)
 113         {
 114         case ISIS_ENABLE:
 115           isis_circuit_configure (circuit, (struct isis_area *) arg);
 116           if (isis_circuit_up (circuit) != ISIS_OK)
 117             {
 118               isis_circuit_deconfigure (circuit, (struct isis_area *) arg);
 119               break;
 120             }
 121           circuit->state = C_STATE_UP;
 122           isis_event_circuit_state_change (circuit, circuit->area, 1);
 123           listnode_delete (isis->init_circ_list, circuit);
 124           break;
 125         case IF_UP_FROM_Z:
 126           assert (circuit);
 127           zlog_warn ("circuit already connected");
 128           break;
 129         case ISIS_DISABLE:
 130           zlog_warn ("circuit already disabled");
 131           break;
 132         case IF_DOWN_FROM_Z:
 133           isis_circuit_if_del (circuit, (struct interface *) arg);
 134           listnode_delete (isis->init_circ_list, circuit);
 135           isis_circuit_del (circuit);
 136           circuit = NULL;
 137           break;
 138         }
 139       break;
 140     case C_STATE_CONF:
 141       assert (circuit);
 142       switch (event)
 143         {
 144         case ISIS_ENABLE:
 145           zlog_warn ("circuit already enabled");
 146           break;
 147         case IF_UP_FROM_Z:
 148           isis_circuit_if_add (circuit, (struct interface *) arg);
 149           if (isis_circuit_up (circuit) != ISIS_OK)
 150             {
 151               zlog_err("Could not bring up %s because of invalid config.",
 152                        circuit->interface->name);
 153               zlog_err("Clearing config for %s. Please re-examine it.",
 154                        circuit->interface->name);
 155               if (circuit->ip_router)
 156                 {
 157                   circuit->ip_router = 0;
 158                   circuit->area->ip_circuits--;
 159                 }
 160               if (circuit->ipv6_router)
 161                 {
 162                   circuit->ipv6_router = 0;
 163                   circuit->area->ipv6_circuits--;
 164                 }
 165               circuit_update_nlpids(circuit);
 166               isis_circuit_deconfigure(circuit, circuit->area);
 167               listnode_add (isis->init_circ_list, circuit);
 168               circuit->state = C_STATE_INIT;
 169               break;
 170             }
 171           circuit->state = C_STATE_UP;
 172           isis_event_circuit_state_change (circuit, circuit->area, 1);
 173           break;
 174         case ISIS_DISABLE:
 175           isis_circuit_deconfigure (circuit, (struct isis_area *) arg);
 176           isis_circuit_del (circuit);
 177           circuit = NULL;
 178           break;
 179         case IF_DOWN_FROM_Z:
 180           zlog_warn ("circuit already disconnected");
 181           break;
 182         }
 183       break;
 184     case C_STATE_UP:
 185       assert (circuit);
 186       switch (event)
 187         {
 188         case ISIS_ENABLE:
 189           zlog_warn ("circuit already configured");
 190           break;
 191         case IF_UP_FROM_Z:
 192           zlog_warn ("circuit already connected");
 193           break;
 194         case ISIS_DISABLE:
 195           isis_circuit_down (circuit);
 196           isis_circuit_deconfigure (circuit, (struct isis_area *) arg);
 197           circuit->state = C_STATE_INIT;
 198           isis_event_circuit_state_change (circuit,
 199                                            (struct isis_area *)arg, 0);
 200           listnode_add (isis->init_circ_list, circuit);
 201           break;
 202         case IF_DOWN_FROM_Z:
 203           isis_circuit_down (circuit);
 204           isis_circuit_if_del (circuit, (struct interface *) arg);
 205           circuit->state = C_STATE_CONF;
 206           isis_event_circuit_state_change (circuit, circuit->area, 0);
 207           break;
 208         }
 209       break;
 210
 211     default:
 212       zlog_warn ("Invalid circuit state %d", old_state);
 213     }
 214
 215   if (isis->debugs & DEBUG_EVENTS)
 216     zlog_debug ("CSM_STATE_CHANGE: %s -> %s ", STATE2STR (old_state),
 217                 circuit ? STATE2STR (circuit->state) : STATE2STR (C_STATE_NA));
 218
 219   return circuit;
 220 }