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; see the file COPYING; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 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_lsp.h"
  41 #include "isisd/isis_pdu.h"
  42 #include "isisd/isis_network.h"
  43 #include "isisd/isis_misc.h"
  44 #include "isisd/isis_constants.h"
  45 #include "isisd/isis_adjacency.h"
  46 #include "isisd/isis_dr.h"
  47 #include "isisd/isisd.h"
  48 #include "isisd/isis_csm.h"
  49 #include "isisd/isis_events.h"
  50
  51 extern struct isis *isis;
  52
  53 static const char *csm_statestr[] = {"C_STATE_NA", "C_STATE_INIT",
  54                                      "C_STATE_CONF", "C_STATE_UP"};
  55
  56 #define STATE2STR(S) csm_statestr[S]
  57
  58 static const char *csm_eventstr[] = {
  59         "NO_STATE",     "ISIS_ENABLE",    "IF_UP_FROM_Z",
  60         "ISIS_DISABLE", "IF_DOWN_FROM_Z",
  61 };
  62
  63 #define EVENT2STR(E) csm_eventstr[E]
  64
  65 struct isis_circuit *
  66 isis_csm_state_change(int event, struct isis_circuit *circuit, void *arg)
  67 {
  68         int old_state;
  69
  70         old_state = circuit ? circuit->state : C_STATE_NA;
  71         if (isis->debugs & DEBUG_EVENTS)
  72                 zlog_debug("CSM_EVENT: %s", EVENT2STR(event));
  73
  74         switch (old_state) {
  75         case C_STATE_NA:
  76                 if (circuit)
  77                         zlog_warn("Non-null circuit while state C_STATE_NA");
  78                 assert(circuit == NULL);
  79                 switch (event) {
  80                 case ISIS_ENABLE:
  81                         circuit = isis_circuit_new();
  82                         isis_circuit_configure(circuit,
  83                                                (struct isis_area *)arg);
  84                         circuit->state = C_STATE_CONF;
  85                         break;
  86                 case IF_UP_FROM_Z:
  87                         circuit = isis_circuit_new();
  88                         isis_circuit_if_add(circuit, (struct interface *)arg);
  89                         if (!circuit->circuit_id) {
  90                                 isis_circuit_if_del(circuit,
  91                                                     (struct interface *)arg);
  92                                 isis_circuit_del(circuit);
  93                                 circuit = NULL;
  94                                 break;
  95                         }
  96                         listnode_add(isis->init_circ_list, circuit);
  97                         circuit->state = C_STATE_INIT;
  98                         break;
  99                 case ISIS_DISABLE:
 100                         zlog_warn("circuit already disabled");
 101                         break;
 102                 case IF_DOWN_FROM_Z:
 103                         zlog_warn("circuit already disconnected");
 104                         break;
 105                 }
 106                 break;
 107         case C_STATE_INIT:
 108                 assert(circuit);
 109                 switch (event) {
 110                 case ISIS_ENABLE:
 111                         isis_circuit_configure(circuit,
 112                                                (struct isis_area *)arg);
 113                         if (isis_circuit_up(circuit) != ISIS_OK) {
 114                                 isis_circuit_deconfigure(
 115                                         circuit, (struct isis_area *)arg);
 116                                 break;
 117                         }
 118                         circuit->state = C_STATE_UP;
 119                         isis_event_circuit_state_change(circuit, circuit->area,
 120                                                         1);
 121                         listnode_delete(isis->init_circ_list, circuit);
 122                         break;
 123                 case IF_UP_FROM_Z:
 124                         assert(circuit);
 125                         zlog_warn("circuit already connected");
 126                         break;
 127                 case ISIS_DISABLE:
 128                         zlog_warn("circuit already disabled");
 129                         break;
 130                 case IF_DOWN_FROM_Z:
 131                         isis_circuit_if_del(circuit, (struct interface *)arg);
 132                         listnode_delete(isis->init_circ_list, circuit);
 133                         isis_circuit_del(circuit);
 134                         circuit = NULL;
 135                         break;
 136                 }
 137                 break;
 138         case C_STATE_CONF:
 139                 assert(circuit);
 140                 switch (event) {
 141                 case ISIS_ENABLE:
 142                         zlog_warn("circuit already enabled");
 143                         break;
 144                 case IF_UP_FROM_Z:
 145                         isis_circuit_if_add(circuit, (struct interface *)arg);
 146                         if (!circuit->circuit_id)
 147                                 break;
 148                         if (isis_circuit_up(circuit) != ISIS_OK) {
 149                                 zlog_err(
 150                                         "Could not bring up %s because of invalid config.",
 151                                         circuit->interface->name);
 152                                 zlog_err(
 153                                         "Clearing config for %s. Please re-examine it.",
 154                                         circuit->interface->name);
 155                                 if (circuit->ip_router) {
 156                                         circuit->ip_router = 0;
 157                                         circuit->area->ip_circuits--;
 158                                 }
 159                                 if (circuit->ipv6_router) {
 160                                         circuit->ipv6_router = 0;
 161                                         circuit->area->ipv6_circuits--;
 162                                 }
 163                                 circuit_update_nlpids(circuit);
 164                                 isis_circuit_deconfigure(circuit,
 165                                                          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,
 172                                                         1);
 173                         break;
 174                 case ISIS_DISABLE:
 175                         isis_circuit_deconfigure(circuit,
 176                                                  (struct isis_area *)arg);
 177                         isis_circuit_del(circuit);
 178                         circuit = NULL;
 179                         break;
 180                 case IF_DOWN_FROM_Z:
 181                         zlog_warn("circuit already disconnected");
 182                         break;
 183                 }
 184                 break;
 185         case C_STATE_UP:
 186                 assert(circuit);
 187                 switch (event) {
 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,
 197                                                  (struct isis_area *)arg);
 198                         circuit->state = C_STATE_INIT;
 199                         isis_event_circuit_state_change(
 200                                 circuit, (struct isis_area *)arg, 0);
 201                         listnode_add(isis->init_circ_list, circuit);
 202                         break;
 203                 case IF_DOWN_FROM_Z:
 204                         isis_circuit_down(circuit);
 205                         isis_circuit_if_del(circuit, (struct interface *)arg);
 206                         circuit->state = C_STATE_CONF;
 207                         isis_event_circuit_state_change(circuit, circuit->area,
 208                                                         0);
 209                         break;
 210                 }
 211                 break;
 212
 213         default:
 214                 zlog_warn("Invalid circuit state %d", old_state);
 215         }
 216
 217         if (isis->debugs & DEBUG_EVENTS)
 218                 zlog_debug("CSM_STATE_CHANGE: %s -> %s ", STATE2STR(old_state),
 219                            circuit ? STATE2STR(circuit->state)
 220                                    : STATE2STR(C_STATE_NA));
 221
 222         return circuit;
 223 }