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/isis_constants.h"
  37 #include "isisd/isis_common.h"
  38 #include "isisd/isis_flags.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/isisd.h"
  49 #include "isisd/isis_csm.h"
  50 #include "isisd/isis_events.h"
  51
  52 extern struct isis *isis;
  53
  54 static const char *csm_statestr[] = {
  55   "C_STATE_NA",
  56   "C_STATE_INIT",
  57   "C_STATE_CONF",
  58   "C_STATE_UP"
  59 };
  60
  61 #define STATE2STR(S) csm_statestr[S]
  62
  63 static const char *csm_eventstr[] = {
  64   "NO_STATE",
  65   "ISIS_ENABLE",
  66   "IF_UP_FROM_Z",
  67   "ISIS_DISABLE",
  68   "IF_DOWN_FROM_Z",
  69 };
  70
  71 #define EVENT2STR(E) csm_eventstr[E]
  72
  73 struct isis_circuit *
  74 isis_csm_state_change (int event, struct isis_circuit *circuit, void *arg)
  75 {
  76   int old_state;
  77
  78   old_state = circuit ? circuit->state : C_STATE_NA;
  79   if (isis->debugs & DEBUG_EVENTS)
  80     zlog_debug ("CSM_EVENT: %s", EVENT2STR (event));
  81
  82   switch (old_state)
  83     {
  84     case C_STATE_NA:
  85       if (circuit)
  86         zlog_warn ("Non-null circuit while state C_STATE_NA");
  87       assert (circuit == NULL);
  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           break;
 104         case IF_DOWN_FROM_Z:
 105           zlog_warn ("circuit already disconnected");
 106           break;
 107         }
 108       break;
 109     case C_STATE_INIT:
 110       assert (circuit);
 111       switch (event)
 112         {
 113         case ISIS_ENABLE:
 114           isis_circuit_configure (circuit, (struct isis_area *) arg);
 115           if (isis_circuit_up (circuit) != ISIS_OK)
 116             {
 117               isis_circuit_deconfigure (circuit, (struct isis_area *) arg);
 118               break;
 119             }
 120           circuit->state = C_STATE_UP;
 121           isis_event_circuit_state_change (circuit, circuit->area, 1);
 122           listnode_delete (isis->init_circ_list, circuit);
 123           break;
 124         case IF_UP_FROM_Z:
 125           assert (circuit);
 126           zlog_warn ("circuit already connected");
 127           break;
 128         case ISIS_DISABLE:
 129           zlog_warn ("circuit already disabled");
 130           break;
 131         case IF_DOWN_FROM_Z:
 132           isis_circuit_if_del (circuit, (struct interface *) arg);
 133           listnode_delete (isis->init_circ_list, circuit);
 134           isis_circuit_del (circuit);
 135           circuit = NULL;
 136           break;
 137         }
 138       break;
 139     case C_STATE_CONF:
 140       assert (circuit);
 141       switch (event)
 142         {
 143         case ISIS_ENABLE:
 144           zlog_warn ("circuit already enabled");
 145           break;
 146         case IF_UP_FROM_Z:
 147           isis_circuit_if_add (circuit, (struct interface *) arg);
 148           if (isis_circuit_up (circuit) != ISIS_OK)
 149             {
 150               zlog_err("Could not bring up %s because of invalid config.",
 151                        circuit->interface->name);
 152               zlog_err("Clearing config for %s. Please re-examine it.",
 153                        circuit->interface->name);
 154               if (circuit->ip_router)
 155                 {
 156                   circuit->ip_router = 0;
 157                   circuit->area->ip_circuits--;
 158                 }
 159               if (circuit->ipv6_router)
 160                 {
 161                   circuit->ipv6_router = 0;
 162                   circuit->area->ipv6_circuits--;
 163                 }
 164               circuit_update_nlpids(circuit);
 165               isis_circuit_deconfigure(circuit, circuit->area);
 166               listnode_add (isis->init_circ_list, circuit);
 167               circuit->state = C_STATE_INIT;
 168               break;
 169             }
 170           circuit->state = C_STATE_UP;
 171           isis_event_circuit_state_change (circuit, circuit->area, 1);
 172           break;
 173         case ISIS_DISABLE:
 174           isis_circuit_deconfigure (circuit, (struct isis_area *) arg);
 175           isis_circuit_del (circuit);
 176           circuit = NULL;
 177           break;
 178         case IF_DOWN_FROM_Z:
 179           zlog_warn ("circuit already disconnected");
 180           break;
 181         }
 182       break;
 183     case C_STATE_UP:
 184       assert (circuit);
 185       switch (event)
 186         {
 187         case ISIS_ENABLE:
 188           zlog_warn ("circuit already configured");
 189           break;
 190         case IF_UP_FROM_Z:
 191           zlog_warn ("circuit already connected");
 192           break;
 193         case ISIS_DISABLE:
 194           isis_circuit_down (circuit);
 195           isis_circuit_deconfigure (circuit, (struct isis_area *) arg);
 196           circuit->state = C_STATE_INIT;
 197           isis_event_circuit_state_change (circuit,
 198                                            (struct isis_area *)arg, 0);
 199           listnode_add (isis->init_circ_list, circuit);
 200           break;
 201         case IF_DOWN_FROM_Z:
 202           isis_circuit_down (circuit);
 203           isis_circuit_if_del (circuit, (struct interface *) arg);
 204           circuit->state = C_STATE_CONF;
 205           isis_event_circuit_state_change (circuit, circuit->area, 0);
 206           break;
 207         }
 208       break;
 209
 210     default:
 211       zlog_warn ("Invalid circuit state %d", old_state);
 212     }
 213
 214   if (isis->debugs & DEBUG_EVENTS)
 215     zlog_debug ("CSM_STATE_CHANGE: %s -> %s ", STATE2STR (old_state),
 216                 circuit ? STATE2STR (circuit->state) : STATE2STR (C_STATE_NA));
 217
 218   return circuit;
 219 }