static int on_neighbor_timer(struct thread *t)
{
struct pim_neighbor *neigh;
struct interface *ifp;
char msg[100];
zassert(t);
neigh = THREAD_ARG(t);
zassert(neigh);
ifp = neigh->interface;
if (PIM_DEBUG_PIM_TRACE) {
char src_str[100];
pim_inet4_dump("<src?>", neigh->source_addr, src_str, sizeof(src_str));
zlog_debug("Expired %d sec holdtime for neighbor %s on interface %s",
neigh->holdtime, src_str, ifp->name);
}
neigh->t_expire_timer = 0;
snprintf(msg, sizeof(msg), "%d-sec holdtime expired", neigh->holdtime);
pim_neighbor_delete(ifp, neigh, msg);
/*
RFC 4601: 4.3.2. DR Election
A router's idea of the current DR on an interface can change when a
PIM Hello message is received, when a neighbor times out, or when a
router's own DR Priority changes.
*/
pim_if_dr_election(ifp); // neighbor times out
return 0;
}
static void pim_addr_change(struct interface *ifp)
{
struct pim_interface *pim_ifp;
pim_ifp = ifp->info;
zassert(pim_ifp);
pim_if_dr_election(ifp); /* router's own DR Priority (addr) changes -- Done TODO T30 */
pim_if_update_join_desired(pim_ifp); /* depends on DR */
pim_if_update_could_assert(ifp); /* depends on DR */
pim_if_update_my_assert_metric(ifp); /* depends on could_assert */
pim_if_update_assert_tracking_desired(ifp); /* depends on DR, join_desired */
/*
RFC 4601: 4.3.1. Sending Hello Messages
1) Before an interface goes down or changes primary IP address, a
Hello message with a zero HoldTime should be sent immediately
(with the old IP address if the IP address changed).
-- FIXME See CAVEAT C13
2) After an interface has changed its IP address, it MUST send a
Hello message with its new IP address.
-- DONE below
3) If an interface changes one of its secondary IP addresses, a
Hello message with an updated Address_List option and a non-zero
HoldTime should be sent immediately.
-- FIXME See TODO T31
*/
pim_ifp->pim_ifstat_hello_sent = 0; /* reset hello counter */
if (pim_ifp->pim_sock_fd < 0)
return;
pim_hello_restart_now(ifp); /* send hello and restart timer */
}
static void update_dr_priority(struct pim_neighbor *neigh,
pim_hello_options hello_options,
uint32_t dr_priority)
{
pim_hello_options will_set_pri; /* boolean */
pim_hello_options bit_flip; /* boolean */
pim_hello_options pri_change; /* boolean */
will_set_pri = PIM_OPTION_IS_SET(hello_options,
PIM_OPTION_MASK_DR_PRIORITY);
bit_flip =
(
will_set_pri !=
PIM_OPTION_IS_SET(neigh->hello_options, PIM_OPTION_MASK_DR_PRIORITY)
);
if (bit_flip) {
struct pim_interface *pim_ifp = neigh->interface->info;
/* update num. of neighbors without dr_pri */
if (will_set_pri) {
--pim_ifp->pim_dr_num_nondrpri_neighbors;
}
else {
++pim_ifp->pim_dr_num_nondrpri_neighbors;
}
}
pri_change =
(
bit_flip
||
(neigh->dr_priority != dr_priority)
);
if (will_set_pri) {
neigh->dr_priority = dr_priority;
}
else {
neigh->dr_priority = 0; /* cosmetic unset */
}
if (pri_change) {
/*
RFC 4601: 4.3.2. DR Election
A router's idea of the current DR on an interface can change when a
PIM Hello message is received, when a neighbor times out, or when a
router's own DR Priority changes.
*/
pim_if_dr_election(neigh->interface); // router's own DR Priority changes
}
}
struct pim_neighbor *pim_neighbor_add(struct interface *ifp,
struct in_addr source_addr,
pim_hello_options hello_options,
uint16_t holdtime,
uint16_t propagation_delay,
uint16_t override_interval,
uint32_t dr_priority,
uint32_t generation_id,
struct list *addr_list)
{
struct pim_interface *pim_ifp;
struct pim_neighbor *neigh;
neigh = pim_neighbor_new(ifp, source_addr,
hello_options,
holdtime,
propagation_delay,
override_interval,
dr_priority,
generation_id,
addr_list);
if (!neigh) {
return 0;
}
pim_ifp = ifp->info;
zassert(pim_ifp);
listnode_add(pim_ifp->pim_neighbor_list, neigh);
/*
RFC 4601: 4.3.2. DR Election
A router's idea of the current DR on an interface can change when a
PIM Hello message is received, when a neighbor times out, or when a
router's own DR Priority changes.
*/
pim_if_dr_election(neigh->interface); // new neighbor -- should not trigger dr election...
/*
RFC 4601: 4.3.1. Sending Hello Messages
To allow new or rebooting routers to learn of PIM neighbors quickly,
when a Hello message is received from a new neighbor, or a Hello
message with a new GenID is received from an existing neighbor, a
new Hello message should be sent on this interface after a
randomized delay between 0 and Triggered_Hello_Delay.
*/
pim_hello_restart_triggered(neigh->interface);
return neigh;
}
