]> git.proxmox.com Git - mirror_frr.git/blame - isisd/isis_dr.c
2005-04-07 Paul Jakma <paul.jakma@sun.com>
[mirror_frr.git] / isisd / isis_dr.c
CommitLineData
eb5d44eb 1/*
2 * IS-IS Rout(e)ing protocol - isis_dr.c
3 * IS-IS designated router related routines
4 *
5 * Copyright (C) 2001,2002 Sampo Saaristo
6 * Tampere University of Technology
7 * Institute of Communications Engineering
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public Licenseas published by the Free
11 * Software Foundation; either version 2 of the License, or (at your option)
12 * any later version.
13 *
14 * This program is distributed in the hope that it will be useful,but WITHOUT
15 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
17 * more details.
18
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
22 */
23
24
25#include <zebra.h>
eb5d44eb 26
27#include "log.h"
28#include "hash.h"
29#include "thread.h"
30#include "linklist.h"
31#include "vty.h"
32#include "stream.h"
33#include "if.h"
34
35#include "isisd/dict.h"
36#include "isisd/isis_constants.h"
37#include "isisd/isis_common.h"
38#include "isisd/isis_misc.h"
39#include "isisd/isis_flags.h"
40#include "isisd/isis_circuit.h"
41#include "isisd/isisd.h"
42#include "isisd/isis_adjacency.h"
43#include "isisd/isis_constants.h"
44#include "isisd/isis_pdu.h"
45#include "isisd/isis_tlv.h"
46#include "isisd/isis_lsp.h"
47#include "isisd/isis_dr.h"
48#include "isisd/isis_events.h"
49
50extern struct isis *isis;
51extern struct thread_master *master;
52
1cd80845 53const char *
f390d2c7 54isis_disflag2string (int disflag)
55{
eb5d44eb 56
f390d2c7 57 switch (disflag)
58 {
eb5d44eb 59 case ISIS_IS_NOT_DIS:
60 return "is not DIS";
61 case ISIS_IS_DIS:
62 return "is DIS";
63 case ISIS_WAS_DIS:
64 return "was DIS";
f390d2c7 65 default:
66 return "unknown DIS state";
67 }
68 return NULL; /* not reached */
eb5d44eb 69}
70
eb5d44eb 71int
72isis_run_dr_l1 (struct thread *thread)
73{
74 struct isis_circuit *circuit;
f390d2c7 75
eb5d44eb 76 circuit = THREAD_ARG (thread);
77 assert (circuit);
78
79 if (circuit->u.bc.run_dr_elect[0])
80 zlog_warn ("isis_run_dr(): run_dr_elect already set for l1");
f390d2c7 81
efc1e725 82 circuit->u.bc.t_run_dr[0] = NULL;
eb5d44eb 83 circuit->u.bc.run_dr_elect[0] = 1;
f390d2c7 84
eb5d44eb 85 return ISIS_OK;
86}
87
88int
89isis_run_dr_l2 (struct thread *thread)
90{
91 struct isis_circuit *circuit;
f390d2c7 92
eb5d44eb 93 circuit = THREAD_ARG (thread);
94 assert (circuit);
95
96 if (circuit->u.bc.run_dr_elect[1])
97 zlog_warn ("isis_run_dr(): run_dr_elect already set for l2");
f390d2c7 98
99
100 circuit->u.bc.t_run_dr[1] = NULL;
eb5d44eb 101 circuit->u.bc.run_dr_elect[1] = 1;
f390d2c7 102
eb5d44eb 103 return ISIS_OK;
104}
105
92365889 106static int
eb5d44eb 107isis_check_dr_change (struct isis_adjacency *adj, int level)
108{
109 int i;
110
f390d2c7 111 if (adj->dis_record[level - 1].dis !=
112 adj->dis_record[(1 * ISIS_LEVELS) + level - 1].dis)
113 /* was there a DIS state transition ? */
eb5d44eb 114 {
f390d2c7 115 adj->dischanges[level - 1]++;
eb5d44eb 116 /* ok rotate the history list through */
f390d2c7 117 for (i = DIS_RECORDS - 1; i > 0; i--)
eb5d44eb 118 {
f390d2c7 119 adj->dis_record[(i * ISIS_LEVELS) + level - 1].dis =
120 adj->dis_record[((i - 1) * ISIS_LEVELS) + level - 1].dis;
121 adj->dis_record[(i * ISIS_LEVELS) + level - 1].last_dis_change =
122 adj->dis_record[((i - 1) * ISIS_LEVELS) + level -
123 1].last_dis_change;
eb5d44eb 124 }
125 }
126 return ISIS_OK;
127}
128
f390d2c7 129int
eb5d44eb 130isis_dr_elect (struct isis_circuit *circuit, int level)
131{
132 struct list *adjdb;
1eb8ef25 133 struct listnode *node, *nnode;
eb5d44eb 134 struct isis_adjacency *adj, *adj_dr = NULL;
135 struct list *list = list_new ();
136 u_char own_prio;
137 int biggest_prio = -1;
138 int cmp_res, retval = ISIS_OK;
f390d2c7 139
eb5d44eb 140 own_prio = circuit->u.bc.priority[level - 1];
141 adjdb = circuit->u.bc.adjdb[level - 1];
142
f390d2c7 143 if (!adjdb)
144 {
145 zlog_warn ("isis_dr_elect() adjdb == NULL");
146 retval = ISIS_WARNING;
147 list_delete (list);
148 goto out;
149 }
eb5d44eb 150 isis_adj_build_up_list (adjdb, list);
151
152 /*
153 * Loop the adjacencies and find the one with the biggest priority
154 */
1eb8ef25 155 for (ALL_LIST_ELEMENTS (list, node, nnode, adj))
f390d2c7 156 {
f390d2c7 157 /* clear flag for show output */
158 adj->dis_record[level - 1].dis = ISIS_IS_NOT_DIS;
159 adj->dis_record[level - 1].last_dis_change = time (NULL);
160
161 if (adj->prio[level - 1] > biggest_prio)
162 {
163 biggest_prio = adj->prio[level - 1];
164 adj_dr = adj;
165 }
166 else if (adj->prio[level - 1] == biggest_prio)
167 {
168 /*
169 * Comparison of MACs breaks a tie
170 */
171 if (adj_dr)
172 {
173 cmp_res = memcmp (adj_dr->snpa, adj->snpa, ETH_ALEN);
174 if (cmp_res < 0)
175 {
176 adj_dr = adj;
177 }
178 if (cmp_res == 0)
179 zlog_warn
180 ("isis_dr_elect(): multiple adjacencies with same SNPA");
181 }
182 else
183 {
184 adj_dr = adj;
185 }
186 }
187 }
188
189 if (!adj_dr)
190 {
eb5d44eb 191 /*
f390d2c7 192 * Could not find the DR - means we are alone and thus the DR
eb5d44eb 193 */
f390d2c7 194 if (!circuit->u.bc.is_dr[level - 1])
195 {
196 list_delete (list);
197 list = NULL;
198 return isis_dr_commence (circuit, level);
eb5d44eb 199 }
f390d2c7 200 goto out;
eb5d44eb 201 }
eb5d44eb 202
203 /*
204 * Now we have the DR adjacency, compare it to self
205 */
f390d2c7 206 if (adj_dr->prio[level - 1] < own_prio
207 || (adj_dr->prio[level - 1] == own_prio
208 && memcmp (adj_dr->snpa, circuit->u.bc.snpa, ETH_ALEN) < 0))
209 {
210 if (!circuit->u.bc.is_dr[level - 1])
211 {
212 /*
d9c427b2 213 * We are the DR
f390d2c7 214 */
d9c427b2 215
216 /* rotate the history log */
1eb8ef25 217 for (ALL_LIST_ELEMENTS (list, node, nnode, adj))
218 isis_check_dr_change (adj, level);
d9c427b2 219
220 /* commence */
f390d2c7 221 list_delete (list);
222 return isis_dr_commence (circuit, level);
223 }
eb5d44eb 224 }
f390d2c7 225 else
226 {
eb5d44eb 227
f390d2c7 228 /* ok we have found the DIS - lets mark the adjacency */
229 /* set flag for show output */
230 adj_dr->dis_record[level - 1].dis = ISIS_IS_DIS;
231 adj_dr->dis_record[level - 1].last_dis_change = time (NULL);
eb5d44eb 232
f390d2c7 233 /* now loop through a second time to check if there has been a DIS change
234 * if yes rotate the history log
235 */
eb5d44eb 236
1eb8ef25 237 for (ALL_LIST_ELEMENTS (list, node, nnode, adj))
238 isis_check_dr_change (adj, level);
eb5d44eb 239
f390d2c7 240 /*
241 * We are not DR - if we were -> resign
242 */
eb5d44eb 243
f390d2c7 244 if (circuit->u.bc.is_dr[level - 1])
245 {
246 list_delete (list);
247 return isis_dr_resign (circuit, level);
248 }
eb5d44eb 249 }
f390d2c7 250out:
eb5d44eb 251 if (list)
252 list_delete (list);
253 return retval;
254}
255
f390d2c7 256int
eb5d44eb 257isis_dr_resign (struct isis_circuit *circuit, int level)
258{
259 u_char id[ISIS_SYS_ID_LEN + 2];
f390d2c7 260
529d65b3 261 zlog_debug ("isis_dr_resign l%d", level);
eb5d44eb 262
263 circuit->u.bc.is_dr[level - 1] = 0;
f390d2c7 264 circuit->u.bc.run_dr_elect[level - 1] = 0;
265 THREAD_TIMER_OFF (circuit->u.bc.t_run_dr[level - 1]);
266 THREAD_TIMER_OFF (circuit->u.bc.t_refresh_pseudo_lsp[level - 1]);
267
eb5d44eb 268 memcpy (id, isis->sysid, ISIS_SYS_ID_LEN);
f390d2c7 269 LSP_PSEUDO_ID (id) = circuit->circuit_id;
270 LSP_FRAGMENT (id) = 0;
eb5d44eb 271 lsp_purge_dr (id, circuit, level);
272
f390d2c7 273 if (level == 1)
274 {
275 memset (circuit->u.bc.l1_desig_is, 0, ISIS_SYS_ID_LEN + 1);
276
277 THREAD_TIMER_OFF (circuit->t_send_csnp[0]);
278
279 THREAD_TIMER_ON (master, circuit->u.bc.t_run_dr[0], isis_run_dr_l1,
280 circuit, 2 * circuit->hello_interval[1]);
281
282 THREAD_TIMER_ON (master, circuit->t_send_psnp[0], send_l1_psnp, circuit,
283 isis_jitter (circuit->psnp_interval[level - 1],
284 PSNP_JITTER));
285 }
286 else
287 {
288 memset (circuit->u.bc.l2_desig_is, 0, ISIS_SYS_ID_LEN + 1);
289
290 THREAD_TIMER_OFF (circuit->t_send_csnp[1]);
291
292 THREAD_TIMER_ON (master, circuit->u.bc.t_run_dr[1], isis_run_dr_l2,
293 circuit, 2 * circuit->hello_interval[1]);
294
295 THREAD_TIMER_ON (master, circuit->t_send_psnp[1], send_l2_psnp, circuit,
296 isis_jitter (circuit->psnp_interval[level - 1],
297 PSNP_JITTER));
298 }
299
eb5d44eb 300 thread_add_event (master, isis_event_dis_status_change, circuit, 0);
301
302 return ISIS_OK;
303}
304
f390d2c7 305int
eb5d44eb 306isis_dr_commence (struct isis_circuit *circuit, int level)
307{
308 u_char old_dr[ISIS_SYS_ID_LEN + 2];
f390d2c7 309
529d65b3 310 zlog_debug ("isis_dr_commence l%d", level);
eb5d44eb 311
312 /* Lets keep a pause in DR election */
313 circuit->u.bc.run_dr_elect[level - 1] = 0;
f390d2c7 314 if (level == 1)
315 THREAD_TIMER_ON (master, circuit->u.bc.t_run_dr[0], isis_run_dr_l1,
a211d65d 316 circuit, 2 * circuit->hello_interval[0]);
f390d2c7 317 else
318 THREAD_TIMER_ON (master, circuit->u.bc.t_run_dr[1], isis_run_dr_l2,
a211d65d 319 circuit, 2 * circuit->hello_interval[1]);
eb5d44eb 320 circuit->u.bc.is_dr[level - 1] = 1;
321
f390d2c7 322 if (level == 1)
323 {
324 memcpy (old_dr, circuit->u.bc.l1_desig_is, ISIS_SYS_ID_LEN + 1);
325 LSP_FRAGMENT (old_dr) = 0;
326 if (LSP_PSEUDO_ID (old_dr))
327 {
328 /* there was a dr elected, purge its LSPs from the db */
329 lsp_purge_dr (old_dr, circuit, level);
330 }
331 memcpy (circuit->u.bc.l1_desig_is, isis->sysid, ISIS_SYS_ID_LEN);
332 *(circuit->u.bc.l1_desig_is + ISIS_SYS_ID_LEN) = circuit->circuit_id;
333
334 assert (circuit->circuit_id); /* must be non-zero */
335 /* if (circuit->t_send_l1_psnp)
336 thread_cancel (circuit->t_send_l1_psnp); */
337 lsp_l1_pseudo_generate (circuit);
338
339 THREAD_TIMER_OFF (circuit->u.bc.t_run_dr[0]);
340 THREAD_TIMER_ON (master, circuit->u.bc.t_run_dr[0], isis_run_dr_l1,
341 circuit, 2 * circuit->hello_interval[0]);
342
343 THREAD_TIMER_ON (master, circuit->t_send_csnp[0], send_l1_csnp, circuit,
344 isis_jitter (circuit->csnp_interval[level - 1],
345 CSNP_JITTER));
346
eb5d44eb 347 }
f390d2c7 348 else
349 {
350 memcpy (old_dr, circuit->u.bc.l2_desig_is, ISIS_SYS_ID_LEN + 1);
351 LSP_FRAGMENT (old_dr) = 0;
352 if (LSP_PSEUDO_ID (old_dr))
353 {
354 /* there was a dr elected, purge its LSPs from the db */
355 lsp_purge_dr (old_dr, circuit, level);
356 }
357 memcpy (circuit->u.bc.l2_desig_is, isis->sysid, ISIS_SYS_ID_LEN);
358 *(circuit->u.bc.l2_desig_is + ISIS_SYS_ID_LEN) = circuit->circuit_id;
359
360 assert (circuit->circuit_id); /* must be non-zero */
361 /* if (circuit->t_send_l1_psnp)
362 thread_cancel (circuit->t_send_l1_psnp); */
363 lsp_l2_pseudo_generate (circuit);
364
365 THREAD_TIMER_OFF (circuit->u.bc.t_run_dr[1]);
366 THREAD_TIMER_ON (master, circuit->u.bc.t_run_dr[1], isis_run_dr_l2,
367 circuit, 2 * circuit->hello_interval[1]);
368
369 THREAD_TIMER_ON (master, circuit->t_send_csnp[1], send_l2_csnp, circuit,
370 isis_jitter (circuit->csnp_interval[level - 1],
371 CSNP_JITTER));
eb5d44eb 372 }
eb5d44eb 373
374 thread_add_event (master, isis_event_dis_status_change, circuit, 0);
f390d2c7 375
eb5d44eb 376 return ISIS_OK;
377}