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/*
* IS-IS Rout(e)ing protocol - isis_dr.c
* IS-IS designated router related routines
*
* Copyright (C) 2001,2002 Sampo Saaristo
* Tampere University of Technology
* Institute of Communications Engineering
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public Licenseas published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; see the file COPYING; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <zebra.h>
#include "log.h"
#include "hash.h"
#include "thread.h"
#include "linklist.h"
#include "vty.h"
#include "stream.h"
#include "if.h"
#include "isisd/dict.h"
#include "isisd/isis_constants.h"
#include "isisd/isis_common.h"
#include "isisd/isis_misc.h"
#include "isisd/isis_flags.h"
#include "isisd/isis_circuit.h"
#include "isisd/isisd.h"
#include "isisd/isis_adjacency.h"
#include "isisd/isis_constants.h"
#include "isisd/isis_pdu.h"
#include "isisd/isis_lsp.h"
#include "isisd/isis_dr.h"
#include "isisd/isis_events.h"
const char *isis_disflag2string(int disflag)
{
switch (disflag) {
case ISIS_IS_NOT_DIS:
return "is not DIS";
case ISIS_IS_DIS:
return "is DIS";
case ISIS_WAS_DIS:
return "was DIS";
default:
return "unknown DIS state";
}
return NULL; /* not reached */
}
int isis_run_dr_l1(struct thread *thread)
{
struct isis_circuit *circuit;
circuit = THREAD_ARG(thread);
assert(circuit);
if (circuit->u.bc.run_dr_elect[0])
zlog_warn("isis_run_dr(): run_dr_elect already set for l1");
circuit->u.bc.t_run_dr[0] = NULL;
circuit->u.bc.run_dr_elect[0] = 1;
return ISIS_OK;
}
int isis_run_dr_l2(struct thread *thread)
{
struct isis_circuit *circuit;
circuit = THREAD_ARG(thread);
assert(circuit);
if (circuit->u.bc.run_dr_elect[1])
zlog_warn("isis_run_dr(): run_dr_elect already set for l2");
circuit->u.bc.t_run_dr[1] = NULL;
circuit->u.bc.run_dr_elect[1] = 1;
return ISIS_OK;
}
static int isis_check_dr_change(struct isis_adjacency *adj, int level)
{
int i;
if (adj->dis_record[level - 1].dis
!= adj->dis_record[(1 * ISIS_LEVELS) + level - 1].dis)
/* was there a DIS state transition ? */
{
adj->dischanges[level - 1]++;
/* ok rotate the history list through */
for (i = DIS_RECORDS - 1; i > 0; i--) {
adj->dis_record[(i * ISIS_LEVELS) + level - 1].dis =
adj->dis_record[((i - 1) * ISIS_LEVELS) + level
- 1]
.dis;
adj->dis_record[(i * ISIS_LEVELS) + level - 1]
.last_dis_change =
adj->dis_record[((i - 1) * ISIS_LEVELS) + level
- 1]
.last_dis_change;
}
}
return ISIS_OK;
}
int isis_dr_elect(struct isis_circuit *circuit, int level)
{
struct list *adjdb;
struct listnode *node;
struct isis_adjacency *adj, *adj_dr = NULL;
struct list *list = list_new();
uint8_t own_prio;
int biggest_prio = -1;
int cmp_res, retval = ISIS_OK;
own_prio = circuit->priority[level - 1];
adjdb = circuit->u.bc.adjdb[level - 1];
if (!adjdb) {
zlog_warn("isis_dr_elect() adjdb == NULL");
list_delete(&list);
return ISIS_WARNING;
}
isis_adj_build_up_list(adjdb, list);
/*
* Loop the adjacencies and find the one with the biggest priority
*/
for (ALL_LIST_ELEMENTS_RO(list, node, adj)) {
/* clear flag for show output */
adj->dis_record[level - 1].dis = ISIS_IS_NOT_DIS;
adj->dis_record[level - 1].last_dis_change = time(NULL);
if (adj->prio[level - 1] > biggest_prio) {
biggest_prio = adj->prio[level - 1];
adj_dr = adj;
} else if (adj->prio[level - 1] == biggest_prio) {
/*
* Comparison of MACs breaks a tie
*/
if (adj_dr) {
cmp_res = memcmp(adj_dr->snpa, adj->snpa,
ETH_ALEN);
if (cmp_res < 0) {
adj_dr = adj;
}
if (cmp_res == 0)
zlog_warn(
"isis_dr_elect(): multiple adjacencies with same SNPA");
} else {
adj_dr = adj;
}
}
}
if (!adj_dr) {
/*
* Could not find the DR - means we are alone. Resign if we were
* DR.
*/
if (circuit->u.bc.is_dr[level - 1])
retval = isis_dr_resign(circuit, level);
list_delete(&list);
return retval;
}
/*
* Now we have the DR adjacency, compare it to self
*/
if (adj_dr->prio[level - 1] < own_prio
|| (adj_dr->prio[level - 1] == own_prio
&& memcmp(adj_dr->snpa, circuit->u.bc.snpa, ETH_ALEN) < 0)) {
adj_dr->dis_record[level - 1].dis = ISIS_IS_NOT_DIS;
adj_dr->dis_record[level - 1].last_dis_change = time(NULL);
/* rotate the history log */
for (ALL_LIST_ELEMENTS_RO(list, node, adj))
isis_check_dr_change(adj, level);
/* We are the DR, commence DR */
if (circuit->u.bc.is_dr[level - 1] == 0 && listcount(list) > 0)
retval = isis_dr_commence(circuit, level);
} else {
/* ok we have found the DIS - lets mark the adjacency */
/* set flag for show output */
adj_dr->dis_record[level - 1].dis = ISIS_IS_DIS;
adj_dr->dis_record[level - 1].last_dis_change = time(NULL);
/* now loop through a second time to check if there has been a
* DIS change
* if yes rotate the history log
*/
for (ALL_LIST_ELEMENTS_RO(list, node, adj))
isis_check_dr_change(adj, level);
/*
* We are not DR - if we were -> resign
*/
if (circuit->u.bc.is_dr[level - 1])
retval = isis_dr_resign(circuit, level);
}
list_delete(&list);
return retval;
}
int isis_dr_resign(struct isis_circuit *circuit, int level)
{
uint8_t id[ISIS_SYS_ID_LEN + 2];
zlog_debug("isis_dr_resign l%d", level);
circuit->u.bc.is_dr[level - 1] = 0;
circuit->u.bc.run_dr_elect[level - 1] = 0;
THREAD_TIMER_OFF(circuit->u.bc.t_run_dr[level - 1]);
THREAD_TIMER_OFF(circuit->u.bc.t_refresh_pseudo_lsp[level - 1]);
circuit->lsp_regenerate_pending[level - 1] = 0;
memcpy(id, isis->sysid, ISIS_SYS_ID_LEN);
LSP_PSEUDO_ID(id) = circuit->circuit_id;
LSP_FRAGMENT(id) = 0;
lsp_purge_pseudo(id, circuit, level);
if (level == 1) {
memset(circuit->u.bc.l1_desig_is, 0, ISIS_SYS_ID_LEN + 1);
THREAD_TIMER_OFF(circuit->t_send_csnp[0]);
thread_add_timer(master, isis_run_dr_l1, circuit,
2 * circuit->hello_interval[0],
&circuit->u.bc.t_run_dr[0]);
thread_add_timer(master, send_l1_psnp, circuit,
isis_jitter(circuit->psnp_interval[level - 1],
PSNP_JITTER),
&circuit->t_send_psnp[0]);
} else {
memset(circuit->u.bc.l2_desig_is, 0, ISIS_SYS_ID_LEN + 1);
THREAD_TIMER_OFF(circuit->t_send_csnp[1]);
thread_add_timer(master, isis_run_dr_l2, circuit,
2 * circuit->hello_interval[1],
&circuit->u.bc.t_run_dr[1]);
thread_add_timer(master, send_l2_psnp, circuit,
isis_jitter(circuit->psnp_interval[level - 1],
PSNP_JITTER),
&circuit->t_send_psnp[1]);
}
thread_add_event(master, isis_event_dis_status_change, circuit, 0,
NULL);
return ISIS_OK;
}
int isis_dr_commence(struct isis_circuit *circuit, int level)
{
uint8_t old_dr[ISIS_SYS_ID_LEN + 2];
if (isis->debugs & DEBUG_EVENTS)
zlog_debug("isis_dr_commence l%d", level);
/* Lets keep a pause in DR election */
circuit->u.bc.run_dr_elect[level - 1] = 0;
if (level == 1)
thread_add_timer(master, isis_run_dr_l1, circuit,
2 * circuit->hello_interval[0],
&circuit->u.bc.t_run_dr[0]);
else
thread_add_timer(master, isis_run_dr_l2, circuit,
2 * circuit->hello_interval[1],
&circuit->u.bc.t_run_dr[1]);
circuit->u.bc.is_dr[level - 1] = 1;
if (level == 1) {
memcpy(old_dr, circuit->u.bc.l1_desig_is, ISIS_SYS_ID_LEN + 1);
LSP_FRAGMENT(old_dr) = 0;
if (LSP_PSEUDO_ID(old_dr)) {
/* there was a dr elected, purge its LSPs from the db */
lsp_purge_pseudo(old_dr, circuit, level);
}
memcpy(circuit->u.bc.l1_desig_is, isis->sysid, ISIS_SYS_ID_LEN);
*(circuit->u.bc.l1_desig_is + ISIS_SYS_ID_LEN) =
circuit->circuit_id;
assert(circuit->circuit_id); /* must be non-zero */
/* if (circuit->t_send_l1_psnp)
thread_cancel (circuit->t_send_l1_psnp); */
lsp_generate_pseudo(circuit, 1);
THREAD_TIMER_OFF(circuit->u.bc.t_run_dr[0]);
thread_add_timer(master, isis_run_dr_l1, circuit,
2 * circuit->hello_interval[0],
&circuit->u.bc.t_run_dr[0]);
thread_add_timer(master, send_l1_csnp, circuit,
isis_jitter(circuit->csnp_interval[level - 1],
CSNP_JITTER),
&circuit->t_send_csnp[0]);
} else {
memcpy(old_dr, circuit->u.bc.l2_desig_is, ISIS_SYS_ID_LEN + 1);
LSP_FRAGMENT(old_dr) = 0;
if (LSP_PSEUDO_ID(old_dr)) {
/* there was a dr elected, purge its LSPs from the db */
lsp_purge_pseudo(old_dr, circuit, level);
}
memcpy(circuit->u.bc.l2_desig_is, isis->sysid, ISIS_SYS_ID_LEN);
*(circuit->u.bc.l2_desig_is + ISIS_SYS_ID_LEN) =
circuit->circuit_id;
assert(circuit->circuit_id); /* must be non-zero */
/* if (circuit->t_send_l1_psnp)
thread_cancel (circuit->t_send_l1_psnp); */
lsp_generate_pseudo(circuit, 2);
THREAD_TIMER_OFF(circuit->u.bc.t_run_dr[1]);
thread_add_timer(master, isis_run_dr_l2, circuit,
2 * circuit->hello_interval[1],
&circuit->u.bc.t_run_dr[1]);
thread_add_timer(master, send_l2_csnp, circuit,
isis_jitter(circuit->csnp_interval[level - 1],
CSNP_JITTER),
&circuit->t_send_csnp[1]);
}
thread_add_event(master, isis_event_dis_status_change, circuit, 0,
NULL);
return ISIS_OK;
}
|