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 #include "isisd/isis_errors.h"
  51
  52 extern struct isis *isis;
  53
  54 static const char *csm_statestr[] = {"C_STATE_NA", "C_STATE_INIT",
  55                                      "C_STATE_CONF", "C_STATE_UP"};
  56
  57 #define STATE2STR(S) csm_statestr[S]
  58
  59 static const char *csm_eventstr[] = {
  60         "NO_STATE",     "ISIS_ENABLE",    "IF_UP_FROM_Z",
  61         "ISIS_DISABLE", "IF_DOWN_FROM_Z",
  62 };
  63
  64 #define EVENT2STR(E) csm_eventstr[E]
  65
  66 struct isis_circuit *
  67 isis_csm_state_change(int event, struct isis_circuit *circuit, void *arg)
  68 {
  69         int old_state;
  70
  71         old_state = circuit ? circuit->state : C_STATE_NA;
  72         if (isis->debugs & DEBUG_EVENTS)
  73                 zlog_debug("CSM_EVENT: %s", EVENT2STR(event));
  74
  75         switch (old_state) {
  76         case C_STATE_NA:
  77                 if (circuit)
  78                         zlog_warn("Non-null circuit while state C_STATE_NA");
  79                 assert(circuit == NULL);
  80                 switch (event) {
  81                 case ISIS_ENABLE:
  82                         circuit = isis_circuit_new();
  83                         isis_circuit_configure(circuit,
  84                                                (struct isis_area *)arg);
  85                         circuit->state = C_STATE_CONF;
  86                         break;
  87                 case IF_UP_FROM_Z:
  88                         circuit = isis_circuit_new();
  89                         isis_circuit_if_add(circuit, (struct interface *)arg);
  90                         listnode_add(isis->init_circ_list, circuit);
  91                         circuit->state = C_STATE_INIT;
  92                         break;
  93                 case ISIS_DISABLE:
  94                         zlog_warn("circuit already disabled");
  95                         break;
  96                 case IF_DOWN_FROM_Z:
  97                         zlog_warn("circuit already disconnected");
  98                         break;
  99                 }
 100                 break;
 101         case C_STATE_INIT:
 102                 assert(circuit);
 103                 switch (event) {
 104                 case ISIS_ENABLE:
 105                         isis_circuit_configure(circuit,
 106                                                (struct isis_area *)arg);
 107                         if (isis_circuit_up(circuit) != ISIS_OK) {
 108                                 isis_circuit_deconfigure(
 109                                         circuit, (struct isis_area *)arg);
 110                                 break;
 111                         }
 112                         circuit->state = C_STATE_UP;
 113                         isis_event_circuit_state_change(circuit, circuit->area,
 114                                                         1);
 115                         listnode_delete(isis->init_circ_list, circuit);
 116                         break;
 117                 case IF_UP_FROM_Z:
 118                         assert(circuit);
 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, (struct interface *)arg);
 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                 assert(circuit);
 134                 switch (event) {
 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                         if (isis_circuit_up(circuit) != ISIS_OK) {
 141                                 flog_err(
 142                                         EC_ISIS_CONFIG,
 143                                         "Could not bring up %s because of invalid config.",
 144                                         circuit->interface->name);
 145                                 flog_err(
 146                                         EC_ISIS_CONFIG,
 147                                         "Clearing config for %s. Please re-examine it.",
 148                                         circuit->interface->name);
 149                                 if (circuit->ip_router) {
 150                                         circuit->ip_router = 0;
 151                                         circuit->area->ip_circuits--;
 152                                 }
 153                                 if (circuit->ipv6_router) {
 154                                         circuit->ipv6_router = 0;
 155                                         circuit->area->ipv6_circuits--;
 156                                 }
 157                                 circuit_update_nlpids(circuit);
 158                                 isis_circuit_deconfigure(circuit,
 159                                                          circuit->area);
 160                                 listnode_add(isis->init_circ_list, circuit);
 161                                 circuit->state = C_STATE_INIT;
 162                                 break;
 163                         }
 164                         circuit->state = C_STATE_UP;
 165                         isis_event_circuit_state_change(circuit, circuit->area,
 166                                                         1);
 167                         break;
 168                 case ISIS_DISABLE:
 169                         isis_circuit_deconfigure(circuit,
 170                                                  (struct isis_area *)arg);
 171                         isis_circuit_del(circuit);
 172                         circuit = NULL;
 173                         break;
 174                 case IF_DOWN_FROM_Z:
 175                         zlog_warn("circuit already disconnected");
 176                         break;
 177                 }
 178                 break;
 179         case C_STATE_UP:
 180                 assert(circuit);
 181                 switch (event) {
 182                 case ISIS_ENABLE:
 183                         zlog_warn("circuit already configured");
 184                         break;
 185                 case IF_UP_FROM_Z:
 186                         zlog_warn("circuit already connected");
 187                         break;
 188                 case ISIS_DISABLE:
 189                         isis_circuit_down(circuit);
 190                         isis_circuit_deconfigure(circuit,
 191                                                  (struct isis_area *)arg);
 192                         circuit->state = C_STATE_INIT;
 193                         isis_event_circuit_state_change(
 194                                 circuit, (struct isis_area *)arg, 0);
 195                         listnode_add(isis->init_circ_list, circuit);
 196                         break;
 197                 case IF_DOWN_FROM_Z:
 198                         isis_circuit_down(circuit);
 199                         isis_circuit_if_del(circuit, (struct interface *)arg);
 200                         circuit->state = C_STATE_CONF;
 201                         isis_event_circuit_state_change(circuit, circuit->area,
 202                                                         0);
 203                         break;
 204                 }
 205                 break;
 206
 207         default:
 208                 zlog_warn("Invalid circuit state %d", old_state);
 209         }
 210
 211         if (isis->debugs & DEBUG_EVENTS)
 212                 zlog_debug("CSM_STATE_CHANGE: %s -> %s ", STATE2STR(old_state),
 213                            circuit ? STATE2STR(circuit->state)
 214                                    : STATE2STR(C_STATE_NA));
 215
 216         return circuit;
 217 }