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_area *area = NULL;
  69         struct interface *ifp;
  70
  71         assert(circuit);
  72
  73         old_state = circuit->state;
  74         if (IS_DEBUG_EVENTS)
  75                 zlog_debug("CSM_EVENT for %s: %s", circuit->interface->name,
  76                            EVENT2STR(event));
  77
  78         switch (old_state) {
  79         case C_STATE_NA:
  80                 switch (event) {
  81                 case ISIS_ENABLE:
  82                         area = arg;
  83
  84                         isis_circuit_configure(circuit, area);
  85                         circuit->state = C_STATE_CONF;
  86                         break;
  87                 case IF_UP_FROM_Z:
  88                         ifp = arg;
  89
  90                         isis_circuit_if_add(circuit, ifp);
  91                         circuit->state = C_STATE_INIT;
  92                         break;
  93                 case ISIS_DISABLE:
  94                         if (IS_DEBUG_EVENTS)
  95                                 zlog_debug("circuit %s already disabled",
  96                                            circuit->interface->name);
  97                         break;
  98                 case IF_DOWN_FROM_Z:
  99                         if (IS_DEBUG_EVENTS)
 100                                 zlog_debug("circuit %s already disconnected",
 101                                            circuit->interface->name);
 102                         break;
 103                 }
 104                 break;
 105         case C_STATE_INIT:
 106                 switch (event) {
 107                 case ISIS_ENABLE:
 108                         area = arg;
 109
 110                         isis_circuit_configure(circuit, area);
 111                         if (isis_circuit_up(circuit) != ISIS_OK) {
 112                                 isis_circuit_deconfigure(circuit, area);
 113                                 break;
 114                         }
 115                         circuit->state = C_STATE_UP;
 116                         isis_event_circuit_state_change(circuit, circuit->area,
 117                                                         1);
 118                         break;
 119                 case IF_UP_FROM_Z:
 120                         if (IS_DEBUG_EVENTS)
 121                                 zlog_debug("circuit %s already connected",
 122                                            circuit->interface->name);
 123                         break;
 124                 case ISIS_DISABLE:
 125                         if (IS_DEBUG_EVENTS)
 126                                 zlog_debug("circuit %s already disabled",
 127                                            circuit->interface->name);
 128                         break;
 129                 case IF_DOWN_FROM_Z:
 130                         ifp = arg;
 131
 132                         isis_circuit_if_del(circuit, ifp);
 133                         circuit->state = C_STATE_NA;
 134                         break;
 135                 }
 136                 break;
 137         case C_STATE_CONF:
 138                 switch (event) {
 139                 case ISIS_ENABLE:
 140                         if (IS_DEBUG_EVENTS)
 141                                 zlog_debug("circuit %s is already enabled",
 142                                            circuit->interface->name);
 143                         break;
 144                 case IF_UP_FROM_Z:
 145                         ifp = arg;
 146
 147                         isis_circuit_if_add(circuit, ifp);
 148                         if (isis_circuit_up(circuit) != ISIS_OK) {
 149                                 isis_circuit_if_del(circuit, ifp);
 150                                 flog_err(
 151                                         EC_ISIS_CONFIG,
 152                                         "Could not bring up %s because of invalid config.",
 153                                         circuit->interface->name);
 154                                 break;
 155                         }
 156                         circuit->state = C_STATE_UP;
 157                         isis_event_circuit_state_change(circuit, circuit->area,
 158                                                         1);
 159                         break;
 160                 case ISIS_DISABLE:
 161                         area = arg;
 162
 163                         isis_circuit_deconfigure(circuit, area);
 164                         circuit->state = C_STATE_NA;
 165                         break;
 166                 case IF_DOWN_FROM_Z:
 167                         if (IS_DEBUG_EVENTS)
 168                                 zlog_debug("circuit %s already disconnected",
 169                                            circuit->interface->name);
 170                         break;
 171                 }
 172                 break;
 173         case C_STATE_UP:
 174                 switch (event) {
 175                 case ISIS_ENABLE:
 176                         if (IS_DEBUG_EVENTS)
 177                                 zlog_debug("circuit %s already enabled",
 178                                            circuit->interface->name);
 179                         break;
 180                 case IF_UP_FROM_Z:
 181                         if (IS_DEBUG_EVENTS)
 182                                 zlog_debug("circuit %s already connected",
 183                                            circuit->interface->name);
 184                         break;
 185                 case ISIS_DISABLE:
 186                         area = arg;
 187
 188                         isis_circuit_down(circuit);
 189                         isis_circuit_deconfigure(circuit, area);
 190                         circuit->state = C_STATE_INIT;
 191                         isis_event_circuit_state_change(circuit, area, 0);
 192                         break;
 193                 case IF_DOWN_FROM_Z:
 194                         ifp = arg;
 195
 196                         isis_circuit_down(circuit);
 197                         isis_circuit_if_del(circuit, ifp);
 198                         circuit->state = C_STATE_CONF;
 199                         isis_event_circuit_state_change(circuit, circuit->area,
 200                                                         0);
 201                         break;
 202                 }
 203                 break;
 204         }
 205
 206         if (IS_DEBUG_EVENTS)
 207                 zlog_debug("CSM_STATE_CHANGE: %s -> %s ", STATE2STR(old_state),
 208                            STATE2STR(circuit->state));
 209
 210         return circuit;
 211 }