isisd/isis_csm.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * IS-IS Rout(e)ing protocol - isis_csm.c
   4  *                             IS-IS circuit state machine
   5  * Copyright (C) 2001,2002    Sampo Saaristo
   6  *                            Tampere University of Technology
   7  *                            Institute of Communications Engineering
   8  */
   9
  10 #include <zebra.h>
  11
  12 #include "log.h"
  13 #include "memory.h"
  14 #include "if.h"
  15 #include "linklist.h"
  16 #include "command.h"
  17 #include "thread.h"
  18 #include "hash.h"
  19 #include "prefix.h"
  20 #include "stream.h"
  21
  22 #include "isisd/isis_constants.h"
  23 #include "isisd/isis_common.h"
  24 #include "isisd/isis_flags.h"
  25 #include "isisd/isis_circuit.h"
  26 #include "isisd/isis_lsp.h"
  27 #include "isisd/isis_pdu.h"
  28 #include "isisd/isis_network.h"
  29 #include "isisd/isis_misc.h"
  30 #include "isisd/isis_constants.h"
  31 #include "isisd/isis_adjacency.h"
  32 #include "isisd/isis_dr.h"
  33 #include "isisd/isisd.h"
  34 #include "isisd/isis_csm.h"
  35 #include "isisd/isis_events.h"
  36 #include "isisd/isis_errors.h"
  37
  38 static const char *const csm_statestr[] = {"C_STATE_NA", "C_STATE_INIT",
  39                                      "C_STATE_CONF", "C_STATE_UP"};
  40
  41 #define STATE2STR(S) csm_statestr[S]
  42
  43 static const char *const csm_eventstr[] = {
  44         "NO_STATE",     "ISIS_ENABLE",    "IF_UP_FROM_Z",
  45         "ISIS_DISABLE", "IF_DOWN_FROM_Z",
  46 };
  47
  48 #define EVENT2STR(E) csm_eventstr[E]
  49
  50 struct isis_circuit *isis_csm_state_change(enum isis_circuit_event event,
  51                                            struct isis_circuit *circuit,
  52                                            void *arg)
  53 {
  54         enum isis_circuit_state old_state;
  55         struct isis_area *area = NULL;
  56         struct interface *ifp;
  57
  58         assert(circuit);
  59
  60         old_state = circuit->state;
  61         if (IS_DEBUG_EVENTS)
  62                 zlog_debug("CSM_EVENT for %s: %s", circuit->interface->name,
  63                            EVENT2STR(event));
  64
  65         switch (old_state) {
  66         case C_STATE_NA:
  67                 switch (event) {
  68                 case ISIS_ENABLE:
  69                         area = arg;
  70
  71                         isis_circuit_configure(circuit, area);
  72                         circuit->state = C_STATE_CONF;
  73                         break;
  74                 case IF_UP_FROM_Z:
  75                         ifp = arg;
  76
  77                         isis_circuit_if_add(circuit, ifp);
  78                         circuit->state = C_STATE_INIT;
  79                         break;
  80                 case ISIS_DISABLE:
  81                         if (IS_DEBUG_EVENTS)
  82                                 zlog_debug("circuit %s already disabled",
  83                                            circuit->interface->name);
  84                         break;
  85                 case IF_DOWN_FROM_Z:
  86                         if (IS_DEBUG_EVENTS)
  87                                 zlog_debug("circuit %s already disconnected",
  88                                            circuit->interface->name);
  89                         break;
  90                 }
  91                 break;
  92         case C_STATE_INIT:
  93                 switch (event) {
  94                 case ISIS_ENABLE:
  95                         area = arg;
  96
  97                         isis_circuit_configure(circuit, area);
  98                         if (isis_circuit_up(circuit) != ISIS_OK) {
  99                                 isis_circuit_deconfigure(circuit, area);
 100                                 break;
 101                         }
 102                         circuit->state = C_STATE_UP;
 103                         isis_event_circuit_state_change(circuit, circuit->area,
 104                                                         1);
 105                         break;
 106                 case IF_UP_FROM_Z:
 107                         if (IS_DEBUG_EVENTS)
 108                                 zlog_debug("circuit %s already connected",
 109                                            circuit->interface->name);
 110                         break;
 111                 case ISIS_DISABLE:
 112                         if (IS_DEBUG_EVENTS)
 113                                 zlog_debug("circuit %s already disabled",
 114                                            circuit->interface->name);
 115                         break;
 116                 case IF_DOWN_FROM_Z:
 117                         ifp = arg;
 118
 119                         isis_circuit_if_del(circuit, ifp);
 120                         circuit->state = C_STATE_NA;
 121                         break;
 122                 }
 123                 break;
 124         case C_STATE_CONF:
 125                 switch (event) {
 126                 case ISIS_ENABLE:
 127                         if (IS_DEBUG_EVENTS)
 128                                 zlog_debug("circuit %s is already enabled",
 129                                            circuit->interface->name);
 130                         break;
 131                 case IF_UP_FROM_Z:
 132                         ifp = arg;
 133
 134                         isis_circuit_if_add(circuit, ifp);
 135                         if (isis_circuit_up(circuit) != ISIS_OK) {
 136                                 isis_circuit_if_del(circuit, ifp);
 137                                 flog_err(
 138                                         EC_ISIS_CONFIG,
 139                                         "Could not bring up %s because of invalid config.",
 140                                         circuit->interface->name);
 141                                 break;
 142                         }
 143                         circuit->state = C_STATE_UP;
 144                         isis_event_circuit_state_change(circuit, circuit->area,
 145                                                         1);
 146                         break;
 147                 case ISIS_DISABLE:
 148                         area = arg;
 149
 150                         isis_circuit_deconfigure(circuit, area);
 151                         circuit->state = C_STATE_NA;
 152                         break;
 153                 case IF_DOWN_FROM_Z:
 154                         if (IS_DEBUG_EVENTS)
 155                                 zlog_debug("circuit %s already disconnected",
 156                                            circuit->interface->name);
 157                         break;
 158                 }
 159                 break;
 160         case C_STATE_UP:
 161                 switch (event) {
 162                 case ISIS_ENABLE:
 163                         if (IS_DEBUG_EVENTS)
 164                                 zlog_debug("circuit %s already enabled",
 165                                            circuit->interface->name);
 166                         break;
 167                 case IF_UP_FROM_Z:
 168                         if (IS_DEBUG_EVENTS)
 169                                 zlog_debug("circuit %s already connected",
 170                                            circuit->interface->name);
 171                         break;
 172                 case ISIS_DISABLE:
 173                         area = arg;
 174
 175                         isis_circuit_down(circuit);
 176                         isis_circuit_deconfigure(circuit, area);
 177                         circuit->state = C_STATE_INIT;
 178                         isis_event_circuit_state_change(circuit, area, 0);
 179                         break;
 180                 case IF_DOWN_FROM_Z:
 181                         ifp = arg;
 182
 183                         isis_circuit_down(circuit);
 184                         isis_circuit_if_del(circuit, ifp);
 185                         circuit->state = C_STATE_CONF;
 186                         isis_event_circuit_state_change(circuit, circuit->area,
 187                                                         0);
 188                         break;
 189                 }
 190                 break;
 191         }
 192
 193         if (IS_DEBUG_EVENTS)
 194                 zlog_debug("CSM_STATE_CHANGE: %s -> %s ", STATE2STR(old_state),
 195                            STATE2STR(circuit->state));
 196
 197         return circuit;
 198 }