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 static const char *const csm_statestr[] = {"C_STATE_NA", "C_STATE_INIT",
  52                                      "C_STATE_CONF", "C_STATE_UP"};
  53
  54 #define STATE2STR(S) csm_statestr[S]
  55
  56 static const char *const csm_eventstr[] = {
  57         "NO_STATE",     "ISIS_ENABLE",    "IF_UP_FROM_Z",
  58         "ISIS_DISABLE", "IF_DOWN_FROM_Z",
  59 };
  60
  61 #define EVENT2STR(E) csm_eventstr[E]
  62
  63 struct isis_circuit *isis_csm_state_change(enum isis_circuit_event event,
  64                                            struct isis_circuit *circuit,
  65                                            void *arg)
  66 {
  67         enum isis_circuit_state old_state;
  68         struct isis *isis = NULL;
  69         struct isis_area *area = NULL;
  70         struct interface *ifp;
  71
  72         old_state = circuit ? circuit->state : C_STATE_NA;
  73         if (IS_DEBUG_EVENTS)
  74                 zlog_debug("CSM_EVENT: %s", EVENT2STR(event));
  75
  76         switch (old_state) {
  77         case C_STATE_NA:
  78                 if (circuit)
  79                         zlog_warn("Non-null circuit while state C_STATE_NA");
  80                 assert(circuit == NULL);
  81                 switch (event) {
  82                 case ISIS_ENABLE:
  83                         area = arg;
  84
  85                         circuit = isis_circuit_new(area->isis);
  86                         isis_circuit_configure(circuit, area);
  87                         circuit->state = C_STATE_CONF;
  88                         break;
  89                 case IF_UP_FROM_Z:
  90                         ifp = arg;
  91                         isis = isis_lookup_by_vrfid(ifp->vrf_id);
  92                         if (isis == NULL) {
  93                                 if (IS_DEBUG_EVENTS)
  94                                         zlog_debug(
  95                                                 " %s : ISIS routing instance not found when attempting to apply against interface %s",
  96                                                 __func__, ifp->name);
  97                                 break;
  98                         }
  99                         circuit = isis_circuit_new(isis);
 100                         isis_circuit_if_add(circuit, ifp);
 101                         listnode_add(isis->init_circ_list, circuit);
 102                         circuit->state = C_STATE_INIT;
 103                         break;
 104                 case ISIS_DISABLE:
 105                         if (IS_DEBUG_EVENTS)
 106                                 zlog_debug(
 107                                         "circuit disable event passed for a non existent circuit");
 108                         break;
 109                 case IF_DOWN_FROM_Z:
 110                         if (IS_DEBUG_EVENTS)
 111                                 zlog_debug(
 112                                         "circuit disconnect event passed for a non existent circuit");
 113                         break;
 114                 }
 115                 break;
 116         case C_STATE_INIT:
 117                 assert(circuit);
 118                 switch (event) {
 119                 case ISIS_ENABLE:
 120                         isis_circuit_configure(circuit,
 121                                                (struct isis_area *)arg);
 122                         if (isis_circuit_up(circuit) != ISIS_OK) {
 123                                 isis_circuit_deconfigure(
 124                                         circuit, (struct isis_area *)arg);
 125                                 break;
 126                         }
 127                         circuit->state = C_STATE_UP;
 128                         isis_event_circuit_state_change(circuit, circuit->area,
 129                                                         1);
 130                         listnode_delete(circuit->isis->init_circ_list,
 131                                         circuit);
 132                         break;
 133                 case IF_UP_FROM_Z:
 134                         if (IS_DEBUG_EVENTS)
 135                                 zlog_debug("circuit %s already connected",
 136                                            circuit->interface->name);
 137                         break;
 138                 case ISIS_DISABLE:
 139                         if (IS_DEBUG_EVENTS)
 140                                 zlog_debug("circuit %s already disabled",
 141                                            circuit->interface->name);
 142                         break;
 143                 case IF_DOWN_FROM_Z:
 144                         isis_circuit_if_del(circuit, (struct interface *)arg);
 145                         listnode_delete(circuit->isis->init_circ_list,
 146                                         circuit);
 147                         isis_circuit_del(circuit);
 148                         circuit = NULL;
 149                         break;
 150                 }
 151                 break;
 152         case C_STATE_CONF:
 153                 assert(circuit);
 154                 switch (event) {
 155                 case ISIS_ENABLE:
 156                         if (IS_DEBUG_EVENTS)
 157                                 zlog_debug("circuit %p is already enabled",
 158                                            circuit);
 159                         break;
 160                 case IF_UP_FROM_Z:
 161                         isis_circuit_if_add(circuit, (struct interface *)arg);
 162                         if (isis_circuit_up(circuit) != ISIS_OK) {
 163                                 isis_circuit_if_del(circuit, (struct interface *)arg);
 164                                 flog_err(
 165                                         EC_ISIS_CONFIG,
 166                                         "Could not bring up %s because of invalid config.",
 167                                         circuit->interface->name);
 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                         if (IS_DEBUG_EVENTS)
 182                                 zlog_debug("circuit %p already disconnected",
 183                                            circuit);
 184                         break;
 185                 }
 186                 break;
 187         case C_STATE_UP:
 188                 assert(circuit);
 189                 switch (event) {
 190                 case ISIS_ENABLE:
 191                         if (IS_DEBUG_EVENTS)
 192                                 zlog_debug("circuit %s already configured",
 193                                            circuit->interface->name);
 194                         break;
 195                 case IF_UP_FROM_Z:
 196                         if (IS_DEBUG_EVENTS)
 197                                 zlog_debug("circuit %s already connected",
 198                                            circuit->interface->name);
 199                         break;
 200                 case ISIS_DISABLE:
 201                         isis = circuit->isis;
 202                         isis_circuit_down(circuit);
 203                         isis_circuit_deconfigure(circuit,
 204                                                  (struct isis_area *)arg);
 205                         circuit->state = C_STATE_INIT;
 206                         isis_event_circuit_state_change(
 207                                 circuit, (struct isis_area *)arg, 0);
 208                         listnode_add(isis->init_circ_list, circuit);
 209                         break;
 210                 case IF_DOWN_FROM_Z:
 211                         isis_circuit_down(circuit);
 212                         isis_circuit_if_del(circuit, (struct interface *)arg);
 213                         circuit->state = C_STATE_CONF;
 214                         isis_event_circuit_state_change(circuit, circuit->area,
 215                                                         0);
 216                         break;
 217                 }
 218                 break;
 219         }
 220
 221         if (IS_DEBUG_EVENTS)
 222                 zlog_debug("CSM_STATE_CHANGE: %s -> %s ", STATE2STR(old_state),
 223                            circuit ? STATE2STR(circuit->state)
 224                                    : STATE2STR(C_STATE_NA));
 225
 226         return circuit;
 227 }