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/isis_constants.h"
  36 #include "isisd/isis_common.h"
  37 #include "isisd/isis_flags.h"
  38 #include "isisd/isis_circuit.h"
  39 #include "isisd/isis_lsp.h"
  40 #include "isisd/isis_pdu.h"
  41 #include "isisd/isis_network.h"
  42 #include "isisd/isis_misc.h"
  43 #include "isisd/isis_constants.h"
  44 #include "isisd/isis_adjacency.h"
  45 #include "isisd/isis_dr.h"
  46 #include "isisd/isisd.h"
  47 #include "isisd/isis_csm.h"
  48 #include "isisd/isis_events.h"
  49 #include "isisd/isis_errors.h"
  50
  51 extern struct isis *isis;
  52
  53 static const char *const 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 *const 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 (IS_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                         listnode_add(isis->init_circ_list, circuit);
  90                         circuit->state = C_STATE_INIT;
  91                         break;
  92                 case ISIS_DISABLE:
  93                         zlog_warn("circuit already disabled");
  94                         break;
  95                 case IF_DOWN_FROM_Z:
  96                         zlog_warn("circuit already disconnected");
  97                         break;
  98                 }
  99                 break;
 100         case C_STATE_INIT:
 101                 assert(circuit);
 102                 switch (event) {
 103                 case ISIS_ENABLE:
 104                         isis_circuit_configure(circuit,
 105                                                (struct isis_area *)arg);
 106                         if (isis_circuit_up(circuit) != ISIS_OK) {
 107                                 isis_circuit_deconfigure(
 108                                         circuit, (struct isis_area *)arg);
 109                                 break;
 110                         }
 111                         circuit->state = C_STATE_UP;
 112                         isis_event_circuit_state_change(circuit, circuit->area,
 113                                                         1);
 114                         listnode_delete(isis->init_circ_list, circuit);
 115                         break;
 116                 case IF_UP_FROM_Z:
 117                         assert(circuit);
 118                         zlog_warn("circuit already connected");
 119                         break;
 120                 case ISIS_DISABLE:
 121                         zlog_warn("circuit already disabled");
 122                         break;
 123                 case IF_DOWN_FROM_Z:
 124                         isis_circuit_if_del(circuit, (struct interface *)arg);
 125                         listnode_delete(isis->init_circ_list, circuit);
 126                         isis_circuit_del(circuit);
 127                         circuit = NULL;
 128                         break;
 129                 }
 130                 break;
 131         case C_STATE_CONF:
 132                 assert(circuit);
 133                 switch (event) {
 134                 case ISIS_ENABLE:
 135                         zlog_warn("circuit already enabled");
 136                         break;
 137                 case IF_UP_FROM_Z:
 138                         isis_circuit_if_add(circuit, (struct interface *)arg);
 139                         if (isis_circuit_up(circuit) != ISIS_OK) {
 140                                 flog_err(
 141                                         EC_ISIS_CONFIG,
 142                                         "Could not bring up %s because of invalid config.",
 143                                         circuit->interface->name);
 144                                 break;
 145                         }
 146                         circuit->state = C_STATE_UP;
 147                         isis_event_circuit_state_change(circuit, circuit->area,
 148                                                         1);
 149                         break;
 150                 case ISIS_DISABLE:
 151                         isis_circuit_deconfigure(circuit,
 152                                                  (struct isis_area *)arg);
 153                         isis_circuit_del(circuit);
 154                         circuit = NULL;
 155                         break;
 156                 case IF_DOWN_FROM_Z:
 157                         zlog_warn("circuit already disconnected");
 158                         break;
 159                 }
 160                 break;
 161         case C_STATE_UP:
 162                 assert(circuit);
 163                 switch (event) {
 164                 case ISIS_ENABLE:
 165                         zlog_warn("circuit already configured");
 166                         break;
 167                 case IF_UP_FROM_Z:
 168                         zlog_warn("circuit already connected");
 169                         break;
 170                 case ISIS_DISABLE:
 171                         isis_circuit_down(circuit);
 172                         isis_circuit_deconfigure(circuit,
 173                                                  (struct isis_area *)arg);
 174                         circuit->state = C_STATE_INIT;
 175                         isis_event_circuit_state_change(
 176                                 circuit, (struct isis_area *)arg, 0);
 177                         listnode_add(isis->init_circ_list, circuit);
 178                         break;
 179                 case IF_DOWN_FROM_Z:
 180                         isis_circuit_down(circuit);
 181                         isis_circuit_if_del(circuit, (struct interface *)arg);
 182                         circuit->state = C_STATE_CONF;
 183                         isis_event_circuit_state_change(circuit, circuit->area,
 184                                                         0);
 185                         break;
 186                 }
 187                 break;
 188
 189         default:
 190                 zlog_warn("Invalid circuit state %d", old_state);
 191         }
 192
 193         if (IS_DEBUG_EVENTS)
 194                 zlog_debug("CSM_STATE_CHANGE: %s -> %s ", STATE2STR(old_state),
 195                            circuit ? STATE2STR(circuit->state)
 196                                    : STATE2STR(C_STATE_NA));
 197
 198         return circuit;
 199 }