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pim_msdp.c
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* IP MSDP for Quagga
* Copyright (C) 2016 Cumulus Networks, Inc.
*/
#include <zebra.h>
#include <lib/hash.h>
#include <lib/jhash.h>
#include <lib/log.h>
#include <lib/prefix.h>
#include <lib/sockunion.h>
#include <lib/stream.h>
#include <frrevent.h>
#include <lib/vty.h>
#include <lib/plist.h>
#include <lib/lib_errors.h>
#include "pimd.h"
#include "pim_memory.h"
#include "pim_instance.h"
#include "pim_iface.h"
#include "pim_rp.h"
#include "pim_str.h"
#include "pim_time.h"
#include "pim_upstream.h"
#include "pim_oil.h"
#include "pim_msdp.h"
#include "pim_msdp_packet.h"
#include "pim_msdp_socket.h"
// struct pim_msdp pim_msdp, *msdp = &pim_msdp;
static void pim_msdp_peer_listen(struct pim_msdp_peer *mp);
static void pim_msdp_peer_cr_timer_setup(struct pim_msdp_peer *mp, bool start);
static void pim_msdp_peer_ka_timer_setup(struct pim_msdp_peer *mp, bool start);
static void pim_msdp_peer_hold_timer_setup(struct pim_msdp_peer *mp,
bool start);
static void pim_msdp_peer_free(struct pim_msdp_peer *mp);
static void pim_msdp_enable(struct pim_instance *pim);
static void pim_msdp_sa_adv_timer_setup(struct pim_instance *pim, bool start);
static void pim_msdp_sa_deref(struct pim_msdp_sa *sa,
enum pim_msdp_sa_flags flags);
static int pim_msdp_mg_mbr_comp(const void *p1, const void *p2);
static void pim_msdp_mg_mbr_free(struct pim_msdp_mg_mbr *mbr);
/************************ SA cache management ******************************/
static void pim_msdp_sa_timer_expiry_log(struct pim_msdp_sa *sa,
const char *timer_str)
{
zlog_debug("MSDP SA %s %s timer expired", sa->sg_str, timer_str);
}
/* RFC-3618:Sec-5.1 - global active source advertisement timer */
static void pim_msdp_sa_adv_timer_cb(struct event *t)
{
struct pim_instance *pim = EVENT_ARG(t);
if (PIM_DEBUG_MSDP_EVENTS) {
zlog_debug("MSDP SA advertisement timer expired");
}
pim_msdp_sa_adv_timer_setup(pim, true /* start */);
pim_msdp_pkt_sa_tx(pim);
}
static void pim_msdp_sa_adv_timer_setup(struct pim_instance *pim, bool start)
{
EVENT_OFF(pim->msdp.sa_adv_timer);
if (start) {
event_add_timer(pim->msdp.master, pim_msdp_sa_adv_timer_cb, pim,
PIM_MSDP_SA_ADVERTISMENT_TIME,
&pim->msdp.sa_adv_timer);
}
}
/* RFC-3618:Sec-5.3 - SA cache state timer */
static void pim_msdp_sa_state_timer_cb(struct event *t)
{
struct pim_msdp_sa *sa;
sa = EVENT_ARG(t);
if (PIM_DEBUG_MSDP_EVENTS) {
pim_msdp_sa_timer_expiry_log(sa, "state");
}
pim_msdp_sa_deref(sa, PIM_MSDP_SAF_PEER);
}
static void pim_msdp_sa_state_timer_setup(struct pim_msdp_sa *sa, bool start)
{
EVENT_OFF(sa->sa_state_timer);
if (start) {
event_add_timer(sa->pim->msdp.master,
pim_msdp_sa_state_timer_cb, sa,
PIM_MSDP_SA_HOLD_TIME, &sa->sa_state_timer);
}
}
static void pim_msdp_sa_upstream_del(struct pim_msdp_sa *sa)
{
struct pim_upstream *up = sa->up;
if (!up) {
return;
}
sa->up = NULL;
if (PIM_UPSTREAM_FLAG_TEST_SRC_MSDP(up->flags)) {
PIM_UPSTREAM_FLAG_UNSET_SRC_MSDP(up->flags);
sa->flags |= PIM_MSDP_SAF_UP_DEL_IN_PROG;
up = pim_upstream_del(sa->pim, up, __func__);
/* re-eval joinDesired; clearing peer-msdp-sa flag can
* cause JD to change
*/
if (up)
pim_upstream_update_join_desired(sa->pim, up);
sa->flags &= ~PIM_MSDP_SAF_UP_DEL_IN_PROG;
}
if (PIM_DEBUG_MSDP_EVENTS) {
zlog_debug("MSDP SA %s de-referenced SPT", sa->sg_str);
}
}
static bool pim_msdp_sa_upstream_add_ok(struct pim_msdp_sa *sa,
struct pim_upstream *xg_up)
{
if (!(sa->flags & PIM_MSDP_SAF_PEER)) {
/* SA should have been rxed from a peer */
return false;
}
/* check if we are RP */
if (!I_am_RP(sa->pim, sa->sg.grp)) {
return false;
}
/* check if we have a (*, G) with a non-empty immediate OIL */
if (!xg_up) {
pim_sgaddr sg;
memset(&sg, 0, sizeof(sg));
sg.grp = sa->sg.grp;
xg_up = pim_upstream_find(sa->pim, &sg);
}
if (!xg_up || (xg_up->join_state != PIM_UPSTREAM_JOINED)) {
/* join desired will be true for such (*, G) entries so we will
* just look at join_state and let the PIM state machine do the
* rest of
* the magic */
return false;
}
return true;
}
/* Upstream add evaluation needs to happen everytime -
* 1. Peer reference is added or removed.
* 2. The RP for a group changes.
* 3. joinDesired for the associated (*, G) changes
* 4. associated (*, G) is removed - this seems like a bit redundant
* (considering #4); but just in case an entry gets nuked without
* upstream state transition
* */
static void pim_msdp_sa_upstream_update(struct pim_msdp_sa *sa,
struct pim_upstream *xg_up,
const char *ctx)
{
struct pim_upstream *up;
if (!pim_msdp_sa_upstream_add_ok(sa, xg_up)) {
pim_msdp_sa_upstream_del(sa);
return;
}
if (sa->up) {
/* nothing to do */
return;
}
up = pim_upstream_find(sa->pim, &sa->sg);
if (up && (PIM_UPSTREAM_FLAG_TEST_SRC_MSDP(up->flags))) {
/* somehow we lost track of the upstream ptr? best log it */
sa->up = up;
if (PIM_DEBUG_MSDP_EVENTS) {
zlog_debug("MSDP SA %s SPT reference missing",
sa->sg_str);
}
return;
}
/* RFC3618: "RP triggers a (S, G) join event towards the data source
* as if a JP message was rxed addressed to the RP itself." */
up = pim_upstream_add(sa->pim, &sa->sg, NULL /* iif */,
PIM_UPSTREAM_FLAG_MASK_SRC_MSDP, __func__, NULL);
sa->up = up;
if (up) {
/* update inherited oil */
pim_upstream_inherited_olist(sa->pim, up);
/* should we also start the kat in parallel? we will need it
* when the
* SA ages out */
if (PIM_DEBUG_MSDP_EVENTS) {
zlog_debug("MSDP SA %s referenced SPT", sa->sg_str);
}
} else {
if (PIM_DEBUG_MSDP_EVENTS) {
zlog_debug("MSDP SA %s SPT reference failed",
sa->sg_str);
}
}
}
/* release all mem associated with a sa */
static void pim_msdp_sa_free(struct pim_msdp_sa *sa)
{
pim_msdp_sa_state_timer_setup(sa, false);
XFREE(MTYPE_PIM_MSDP_SA, sa);
}
static struct pim_msdp_sa *pim_msdp_sa_new(struct pim_instance *pim,
pim_sgaddr *sg, struct in_addr rp)
{
struct pim_msdp_sa *sa;
sa = XCALLOC(MTYPE_PIM_MSDP_SA, sizeof(*sa));
sa->pim = pim;
sa->sg = *sg;
snprintfrr(sa->sg_str, sizeof(sa->sg_str), "%pSG", sg);
sa->rp = rp;
sa->uptime = pim_time_monotonic_sec();
/* insert into misc tables for easy access */
sa = hash_get(pim->msdp.sa_hash, sa, hash_alloc_intern);
listnode_add_sort(pim->msdp.sa_list, sa);
if (PIM_DEBUG_MSDP_EVENTS) {
zlog_debug("MSDP SA %s created", sa->sg_str);
}
return sa;
}
static struct pim_msdp_sa *pim_msdp_sa_find(struct pim_instance *pim,
pim_sgaddr *sg)
{
struct pim_msdp_sa lookup;
lookup.sg = *sg;
return hash_lookup(pim->msdp.sa_hash, &lookup);
}
static struct pim_msdp_sa *pim_msdp_sa_add(struct pim_instance *pim,
pim_sgaddr *sg, struct in_addr rp)
{
struct pim_msdp_sa *sa;
sa = pim_msdp_sa_find(pim, sg);
if (sa) {
return sa;
}
return pim_msdp_sa_new(pim, sg, rp);
}
static void pim_msdp_sa_del(struct pim_msdp_sa *sa)
{
/* this is somewhat redundant - still want to be careful not to leave
* stale upstream references */
pim_msdp_sa_upstream_del(sa);
/* stop timers */
pim_msdp_sa_state_timer_setup(sa, false /* start */);
/* remove the entry from various tables */
listnode_delete(sa->pim->msdp.sa_list, sa);
hash_release(sa->pim->msdp.sa_hash, sa);
if (PIM_DEBUG_MSDP_EVENTS) {
zlog_debug("MSDP SA %s deleted", sa->sg_str);
}
/* free up any associated memory */
pim_msdp_sa_free(sa);
}
static void pim_msdp_sa_peer_ip_set(struct pim_msdp_sa *sa,
struct pim_msdp_peer *mp, struct in_addr rp)
{
struct pim_msdp_peer *old_mp;
/* optimize the "no change" case as it will happen
* frequently/periodically */
if (mp && (sa->peer.s_addr == mp->peer.s_addr)) {
return;
}
/* any time the peer ip changes also update the rp address */
if (sa->peer.s_addr != INADDR_ANY) {
old_mp = pim_msdp_peer_find(sa->pim, sa->peer);
if (old_mp && old_mp->sa_cnt) {
--old_mp->sa_cnt;
}
}
if (mp) {
++mp->sa_cnt;
sa->peer = mp->peer;
} else {
sa->peer.s_addr = PIM_NET_INADDR_ANY;
}
sa->rp = rp;
}
/* When a local active-source is removed there is no way to withdraw the
* source from peers. We will simply remove it from the SA cache so it will
* not be sent in supsequent SA updates. Peers will consequently timeout the
* SA.
* Similarly a "peer-added" SA is never explicitly deleted. It is simply
* aged out overtime if not seen in the SA updates from the peers.
* XXX: should we provide a knob to drop entries learnt from a peer when the
* peer goes down? */
static void pim_msdp_sa_deref(struct pim_msdp_sa *sa,
enum pim_msdp_sa_flags flags)
{
bool update_up = false;
if ((sa->flags & PIM_MSDP_SAF_LOCAL)) {
if (flags & PIM_MSDP_SAF_LOCAL) {
if (PIM_DEBUG_MSDP_EVENTS) {
zlog_debug("MSDP SA %s local reference removed",
sa->sg_str);
}
if (sa->pim->msdp.local_cnt)
--sa->pim->msdp.local_cnt;
}
}
if ((sa->flags & PIM_MSDP_SAF_PEER)) {
if (flags & PIM_MSDP_SAF_PEER) {
struct in_addr rp;
if (PIM_DEBUG_MSDP_EVENTS) {
zlog_debug("MSDP SA %s peer reference removed",
sa->sg_str);
}
pim_msdp_sa_state_timer_setup(sa, false /* start */);
rp.s_addr = INADDR_ANY;
pim_msdp_sa_peer_ip_set(sa, NULL /* mp */, rp);
/* if peer ref was removed we need to remove the msdp
* reference on the
* msdp entry */
update_up = true;
}
}
sa->flags &= ~flags;
if (update_up) {
pim_msdp_sa_upstream_update(sa, NULL /* xg_up */, "sa-deref");
}
if (!(sa->flags & PIM_MSDP_SAF_REF)) {
pim_msdp_sa_del(sa);
}
}
void pim_msdp_sa_ref(struct pim_instance *pim, struct pim_msdp_peer *mp,
pim_sgaddr *sg, struct in_addr rp)
{
struct pim_msdp_sa *sa;
struct rp_info *rp_info;
struct prefix grp;
sa = pim_msdp_sa_add(pim, sg, rp);
if (!sa) {
return;
}
/* reference it */
if (mp) {
if (!(sa->flags & PIM_MSDP_SAF_PEER)) {
sa->flags |= PIM_MSDP_SAF_PEER;
if (PIM_DEBUG_MSDP_EVENTS) {
zlog_debug("MSDP SA %s added by peer",
sa->sg_str);
}
}
pim_msdp_sa_peer_ip_set(sa, mp, rp);
/* start/re-start the state timer to prevent cache expiry */
pim_msdp_sa_state_timer_setup(sa, true /* start */);
/* We re-evaluate SA "SPT-trigger" everytime we hear abt it from
* a
* peer. XXX: If this becomes too much of a periodic overhead we
* can make it event based */
pim_msdp_sa_upstream_update(sa, NULL /* xg_up */, "peer-ref");
} else {
if (!(sa->flags & PIM_MSDP_SAF_LOCAL)) {
sa->flags |= PIM_MSDP_SAF_LOCAL;
++sa->pim->msdp.local_cnt;
if (PIM_DEBUG_MSDP_EVENTS) {
zlog_debug("MSDP SA %s added locally",
sa->sg_str);
}
/* send an immediate SA update to peers */
pim_addr_to_prefix(&grp, sa->sg.grp);
rp_info = pim_rp_find_match_group(pim, &grp);
if (rp_info) {
sa->rp = rp_info->rp.rpf_addr;
} else {
sa->rp = pim->msdp.originator_id;
}
pim_msdp_pkt_sa_tx_one(sa);
}
sa->flags &= ~PIM_MSDP_SAF_STALE;
}
}
/* The following criteria must be met to originate an SA from the MSDP
* speaker -
* 1. KAT must be running i.e. source is active.
* 2. We must be RP for the group.
* 3. Source must be registrable to the RP (this is where the RFC is vague
* and especially ambiguous in CLOS networks; with anycast RP all sources
* are potentially registrable to all RPs in the domain). We assume #3 is
* satisfied if -
* a. We are also the FHR-DR for the source (OR)
* b. We rxed a pim register (null or data encapsulated) within the last
* (3 * (1.5 * register_suppression_timer))).
*/
static bool pim_msdp_sa_local_add_ok(struct pim_upstream *up)
{
struct pim_instance *pim = up->channel_oil->pim;
if (!(pim->msdp.flags & PIM_MSDPF_ENABLE)) {
return false;
}
if (!pim_upstream_is_kat_running(up))
/* stream is not active */
return false;
if (!I_am_RP(pim, up->sg.grp)) {
/* we are not RP for the group */
return false;
}
/* we are the FHR-DR for this stream or we are RP and have seen
* registers
* from a FHR for this source */
if (PIM_UPSTREAM_FLAG_TEST_FHR(up->flags) || up->t_msdp_reg_timer) {
return true;
}
return false;
}
static void pim_msdp_sa_local_add(struct pim_instance *pim, pim_sgaddr *sg)
{
struct in_addr rp;
rp.s_addr = INADDR_ANY;
pim_msdp_sa_ref(pim, NULL /* mp */, sg, rp);
}
void pim_msdp_sa_local_del(struct pim_instance *pim, pim_sgaddr *sg)
{
struct pim_msdp_sa *sa;
sa = pim_msdp_sa_find(pim, sg);
if (sa) {
pim_msdp_sa_deref(sa, PIM_MSDP_SAF_LOCAL);
}
}
/* we need to be very cautious with this API as SA del too can trigger an
* upstream del and we will get stuck in a simple loop */
static void pim_msdp_sa_local_del_on_up_del(struct pim_instance *pim,
pim_sgaddr *sg)
{
struct pim_msdp_sa *sa;
sa = pim_msdp_sa_find(pim, sg);
if (sa) {
if (PIM_DEBUG_MSDP_INTERNAL) {
zlog_debug("MSDP local sa %s del on up del",
sa->sg_str);
}
/* if there is no local reference escape */
if (!(sa->flags & PIM_MSDP_SAF_LOCAL)) {
if (PIM_DEBUG_MSDP_INTERNAL) {
zlog_debug("MSDP local sa %s del; no local ref",
sa->sg_str);
}
return;
}
if (sa->flags & PIM_MSDP_SAF_UP_DEL_IN_PROG) {
/* MSDP is the one that triggered the upstream del. if
* this happens
* we most certainly have a bug in the PIM upstream
* state machine. We
* will not have a local reference unless the KAT is
* running. And if the
* KAT is running there MUST be an additional
* source-stream reference to
* the flow. Accounting for such cases requires lot of
* changes; perhaps
* address this in the next release? - XXX */
flog_err(
EC_LIB_DEVELOPMENT,
"MSDP sa %s SPT teardown is causing the local entry to be removed",
sa->sg_str);
return;
}
/* we are dropping the sa on upstream del we should not have an
* upstream reference */
if (sa->up) {
if (PIM_DEBUG_MSDP_INTERNAL) {
zlog_debug("MSDP local sa %s del; up non-NULL",
sa->sg_str);
}
sa->up = NULL;
}
pim_msdp_sa_deref(sa, PIM_MSDP_SAF_LOCAL);
}
}
/* Local SA qualification needs to be re-evaluated when -
* 1. KAT is started or stopped
* 2. on RP changes
* 3. Whenever FHR status changes for a (S,G) - XXX - currently there
* is no clear path to transition an entry out of "MASK_FHR" need
* to discuss this with Donald. May result in some strangeness if the
* FHR is also the RP.
* 4. When msdp_reg timer is started or stopped
*/
void pim_msdp_sa_local_update(struct pim_upstream *up)
{
struct pim_instance *pim = up->channel_oil->pim;
if (pim_msdp_sa_local_add_ok(up)) {
pim_msdp_sa_local_add(pim, &up->sg);
} else {
pim_msdp_sa_local_del(pim, &up->sg);
}
}
static void pim_msdp_sa_local_setup(struct pim_instance *pim)
{
struct pim_upstream *up;
frr_each (rb_pim_upstream, &pim->upstream_head, up)
pim_msdp_sa_local_update(up);
}
/* whenever the RP changes we need to re-evaluate the "local" SA-cache */
/* XXX: needs to be tested */
void pim_msdp_i_am_rp_changed(struct pim_instance *pim)
{
struct listnode *sanode;
struct listnode *nextnode;
struct pim_msdp_sa *sa;
if (!(pim->msdp.flags & PIM_MSDPF_ENABLE)) {
/* if the feature is not enabled do nothing */
return;
}
if (PIM_DEBUG_MSDP_INTERNAL) {
zlog_debug("MSDP i_am_rp changed");
}
/* mark all local entries as stale */
for (ALL_LIST_ELEMENTS_RO(pim->msdp.sa_list, sanode, sa)) {
if (sa->flags & PIM_MSDP_SAF_LOCAL) {
sa->flags |= PIM_MSDP_SAF_STALE;
}
}
/* re-setup local SA entries */
pim_msdp_sa_local_setup(pim);
for (ALL_LIST_ELEMENTS(pim->msdp.sa_list, sanode, nextnode, sa)) {
/* purge stale SA entries */
if (sa->flags & PIM_MSDP_SAF_STALE) {
/* clear the stale flag; the entry may be kept even
* after
* "local-deref" */
sa->flags &= ~PIM_MSDP_SAF_STALE;
/* sa_deref can end up freeing the sa; so don't access
* contents after */
pim_msdp_sa_deref(sa, PIM_MSDP_SAF_LOCAL);
} else {
/* if the souce is still active check if we can
* influence SPT */
pim_msdp_sa_upstream_update(sa, NULL /* xg_up */,
"rp-change");
}
}
}
/* We track the join state of (*, G) entries. If G has sources in the SA-cache
* we need to setup or teardown SPT when the JoinDesired status changes for
* (*, G) */
void pim_msdp_up_join_state_changed(struct pim_instance *pim,
struct pim_upstream *xg_up)
{
struct listnode *sanode;
struct pim_msdp_sa *sa;
if (PIM_DEBUG_MSDP_INTERNAL) {
zlog_debug("MSDP join state changed for %s", xg_up->sg_str);
}
/* If this is not really an XG entry just move on */
if (!pim_addr_is_any(xg_up->sg.src) || pim_addr_is_any(xg_up->sg.grp)) {
return;
}
/* XXX: Need to maintain SAs per-group to avoid all this unnecessary
* walking */
for (ALL_LIST_ELEMENTS_RO(pim->msdp.sa_list, sanode, sa)) {
if (pim_addr_cmp(sa->sg.grp, xg_up->sg.grp)) {
continue;
}
pim_msdp_sa_upstream_update(sa, xg_up, "up-jp-change");
}
}
static void pim_msdp_up_xg_del(struct pim_instance *pim, pim_sgaddr *sg)
{
struct listnode *sanode;
struct pim_msdp_sa *sa;
if (PIM_DEBUG_MSDP_INTERNAL) {
zlog_debug("MSDP %pSG del", sg);
}
/* If this is not really an XG entry just move on */
if (!pim_addr_is_any(sg->src) || pim_addr_is_any(sg->grp)) {
return;
}
/* XXX: Need to maintain SAs per-group to avoid all this unnecessary
* walking */
for (ALL_LIST_ELEMENTS_RO(pim->msdp.sa_list, sanode, sa)) {
if (pim_addr_cmp(sa->sg.grp, sg->grp)) {
continue;
}
pim_msdp_sa_upstream_update(sa, NULL /* xg */, "up-jp-change");
}
}
void pim_msdp_up_del(struct pim_instance *pim, pim_sgaddr *sg)
{
if (PIM_DEBUG_MSDP_INTERNAL) {
zlog_debug("MSDP up %pSG del", sg);
}
if (pim_addr_is_any(sg->src)) {
pim_msdp_up_xg_del(pim, sg);
} else {
pim_msdp_sa_local_del_on_up_del(pim, sg);
}
}
/* sa hash and peer list helpers */
static unsigned int pim_msdp_sa_hash_key_make(const void *p)
{
const struct pim_msdp_sa *sa = p;
return pim_sgaddr_hash(sa->sg, 0);
}
static bool pim_msdp_sa_hash_eq(const void *p1, const void *p2)
{
const struct pim_msdp_sa *sa1 = p1;
const struct pim_msdp_sa *sa2 = p2;
return !pim_sgaddr_cmp(sa1->sg, sa2->sg);
}
static int pim_msdp_sa_comp(const void *p1, const void *p2)
{
const struct pim_msdp_sa *sa1 = p1;
const struct pim_msdp_sa *sa2 = p2;
return pim_sgaddr_cmp(sa1->sg, sa2->sg);
}
/* RFC-3618:Sec-10.1.3 - Peer-RPF forwarding */
/* XXX: this can use a bit of refining and extensions */
bool pim_msdp_peer_rpf_check(struct pim_msdp_peer *mp, struct in_addr rp)
{
struct pim_nexthop nexthop = {0};
if (mp->peer.s_addr == rp.s_addr) {
return true;
}
/* check if the MSDP peer is the nexthop for the RP */
if (pim_nexthop_lookup(mp->pim, &nexthop, rp, 0) &&
nexthop.mrib_nexthop_addr.s_addr == mp->peer.s_addr) {
return true;
}
return false;
}
/************************ Peer session management **************************/
char *pim_msdp_state_dump(enum pim_msdp_peer_state state, char *buf,
int buf_size)
{
switch (state) {
case PIM_MSDP_DISABLED:
snprintf(buf, buf_size, "%s", "disabled");
break;
case PIM_MSDP_INACTIVE:
snprintf(buf, buf_size, "%s", "inactive");
break;
case PIM_MSDP_LISTEN:
snprintf(buf, buf_size, "%s", "listen");
break;
case PIM_MSDP_CONNECTING:
snprintf(buf, buf_size, "%s", "connecting");
break;
case PIM_MSDP_ESTABLISHED:
snprintf(buf, buf_size, "%s", "established");
break;
default:
snprintf(buf, buf_size, "unk-%d", state);
}
return buf;
}
static void pim_msdp_peer_state_chg_log(struct pim_msdp_peer *mp)
{
char state_str[PIM_MSDP_STATE_STRLEN];
pim_msdp_state_dump(mp->state, state_str, sizeof(state_str));
zlog_debug("MSDP peer %s state chg to %s", mp->key_str, state_str);
}
/* MSDP Connection State Machine actions (defined in RFC-3618:Sec-11.2) */
/* 11.2.A2: active peer - start connect retry timer; when the timer fires
* a tcp connection will be made */
static void pim_msdp_peer_connect(struct pim_msdp_peer *mp)
{
mp->state = PIM_MSDP_CONNECTING;
if (PIM_DEBUG_MSDP_EVENTS) {
pim_msdp_peer_state_chg_log(mp);
}
pim_msdp_peer_cr_timer_setup(mp, true /* start */);
}
/* 11.2.A3: passive peer - just listen for connections */
static void pim_msdp_peer_listen(struct pim_msdp_peer *mp)
{
mp->state = PIM_MSDP_LISTEN;
if (PIM_DEBUG_MSDP_EVENTS) {
pim_msdp_peer_state_chg_log(mp);
}
/* this is interntionally asymmetric i.e. we set up listen-socket when
* the
* first listening peer is configured; but don't bother tearing it down
* when
* all the peers go down */
if (mp->auth_type == MSDP_AUTH_NONE)
pim_msdp_sock_listen(mp->pim);
else
pim_msdp_sock_auth_listen(mp);
}
/* 11.2.A4 and 11.2.A5: transition active or passive peer to
* established state */
void pim_msdp_peer_established(struct pim_msdp_peer *mp)
{
if (mp->state != PIM_MSDP_ESTABLISHED) {
++mp->est_flaps;
}
mp->state = PIM_MSDP_ESTABLISHED;
mp->uptime = pim_time_monotonic_sec();
if (PIM_DEBUG_MSDP_EVENTS) {
pim_msdp_peer_state_chg_log(mp);
}
/* stop retry timer on active peers */
pim_msdp_peer_cr_timer_setup(mp, false /* start */);
/* send KA; start KA and hold timers */
pim_msdp_pkt_ka_tx(mp);
pim_msdp_peer_ka_timer_setup(mp, true /* start */);
pim_msdp_peer_hold_timer_setup(mp, true /* start */);
pim_msdp_pkt_sa_tx_to_one_peer(mp);
PIM_MSDP_PEER_WRITE_ON(mp);
PIM_MSDP_PEER_READ_ON(mp);
}
/* 11.2.A6, 11.2.A7 and 11.2.A8: shutdown the peer tcp connection */
void pim_msdp_peer_stop_tcp_conn(struct pim_msdp_peer *mp, bool chg_state)
{
if (chg_state) {
if (mp->state == PIM_MSDP_ESTABLISHED) {
++mp->est_flaps;
}
mp->state = PIM_MSDP_INACTIVE;
if (PIM_DEBUG_MSDP_EVENTS) {
pim_msdp_peer_state_chg_log(mp);
}
}
if (PIM_DEBUG_MSDP_INTERNAL) {
zlog_debug("MSDP peer %s pim_msdp_peer_stop_tcp_conn",
mp->key_str);
}
/* stop read and write threads */
PIM_MSDP_PEER_READ_OFF(mp);
PIM_MSDP_PEER_WRITE_OFF(mp);
/* reset buffers */
mp->packet_size = 0;
if (mp->ibuf)
stream_reset(mp->ibuf);
if (mp->obuf)
stream_fifo_clean(mp->obuf);
/* stop all peer timers */
pim_msdp_peer_ka_timer_setup(mp, false /* start */);
pim_msdp_peer_cr_timer_setup(mp, false /* start */);
pim_msdp_peer_hold_timer_setup(mp, false /* start */);
/* close connection */
if (mp->fd >= 0) {
close(mp->fd);
mp->fd = -1;
}
}
/* RFC-3618:Sec-5.6 - stop the peer tcp connection and startover */
void pim_msdp_peer_reset_tcp_conn(struct pim_msdp_peer *mp, const char *rc_str)
{
if (PIM_DEBUG_EVENTS) {
zlog_debug("MSDP peer %s tcp reset %s", mp->key_str, rc_str);
snprintf(mp->last_reset, sizeof(mp->last_reset), "%s", rc_str);
}
/* close the connection and transition to listening or connecting */
pim_msdp_peer_stop_tcp_conn(mp, true /* chg_state */);
if (PIM_MSDP_PEER_IS_LISTENER(mp)) {
pim_msdp_peer_listen(mp);
} else {
pim_msdp_peer_connect(mp);
}
}
static void pim_msdp_peer_timer_expiry_log(struct pim_msdp_peer *mp,
const char *timer_str)
{
zlog_debug("MSDP peer %s %s timer expired", mp->key_str, timer_str);
}
/* RFC-3618:Sec-5.4 - peer hold timer */
static void pim_msdp_peer_hold_timer_cb(struct event *t)
{
struct pim_msdp_peer *mp;
mp = EVENT_ARG(t);
if (PIM_DEBUG_MSDP_EVENTS) {
pim_msdp_peer_timer_expiry_log(mp, "hold");
}
if (mp->state != PIM_MSDP_ESTABLISHED) {
return;
}
if (PIM_DEBUG_MSDP_EVENTS) {
pim_msdp_peer_state_chg_log(mp);
}
pim_msdp_peer_reset_tcp_conn(mp, "ht-expired");
}
static void pim_msdp_peer_hold_timer_setup(struct pim_msdp_peer *mp, bool start)
{
struct pim_instance *pim = mp->pim;
EVENT_OFF(mp->hold_timer);
if (start) {
event_add_timer(pim->msdp.master, pim_msdp_peer_hold_timer_cb,
mp, pim->msdp.hold_time, &mp->hold_timer);
}
}
/* RFC-3618:Sec-5.5 - peer keepalive timer */
static void pim_msdp_peer_ka_timer_cb(struct event *t)
{
struct pim_msdp_peer *mp;
mp = EVENT_ARG(t);
if (PIM_DEBUG_MSDP_EVENTS) {
pim_msdp_peer_timer_expiry_log(mp, "ka");
}
pim_msdp_pkt_ka_tx(mp);
pim_msdp_peer_ka_timer_setup(mp, true /* start */);
}
static void pim_msdp_peer_ka_timer_setup(struct pim_msdp_peer *mp, bool start)
{
EVENT_OFF(mp->ka_timer);
if (start) {
event_add_timer(mp->pim->msdp.master, pim_msdp_peer_ka_timer_cb,
mp, mp->pim->msdp.keep_alive, &mp->ka_timer);
}
}
static void pim_msdp_peer_active_connect(struct pim_msdp_peer *mp)
{
int rc;
++mp->conn_attempts;
rc = pim_msdp_sock_connect(mp);
if (PIM_DEBUG_MSDP_INTERNAL) {
zlog_debug("MSDP peer %s pim_msdp_peer_active_connect: %d",
mp->key_str, rc);
}
switch (rc) {
case connect_error:
case -1:
/* connect failed restart the connect-retry timer */
pim_msdp_peer_cr_timer_setup(mp, true /* start */);
break;
case connect_success:
/* connect was sucessful move to established */
pim_msdp_peer_established(mp);
break;
case connect_in_progress:
/* for NB content we need to wait till sock is readable or
* writeable */
PIM_MSDP_PEER_WRITE_ON(mp);
PIM_MSDP_PEER_READ_ON(mp);
/* also restart connect-retry timer to reset the socket if
* connect is
* not sucessful */
pim_msdp_peer_cr_timer_setup(mp, true /* start */);
break;
}
}
/* RFC-3618:Sec-5.6 - connection retry on active peer */
static void pim_msdp_peer_cr_timer_cb(struct event *t)
{
struct pim_msdp_peer *mp;
mp = EVENT_ARG(t);
if (PIM_DEBUG_MSDP_EVENTS) {
pim_msdp_peer_timer_expiry_log(mp, "connect-retry");
}
if (mp->state != PIM_MSDP_CONNECTING || PIM_MSDP_PEER_IS_LISTENER(mp)) {
return;
}
pim_msdp_peer_active_connect(mp);
}
static void pim_msdp_peer_cr_timer_setup(struct pim_msdp_peer *mp, bool start)
{
EVENT_OFF(mp->cr_timer);
if (start) {
event_add_timer(mp->pim->msdp.master, pim_msdp_peer_cr_timer_cb,
mp, mp->pim->msdp.connection_retry,
&mp->cr_timer);
}
}
/* if a valid packet is rxed from the peer we can restart hold timer */
void pim_msdp_peer_pkt_rxed(struct pim_msdp_peer *mp)
{
if (mp->state == PIM_MSDP_ESTABLISHED) {
pim_msdp_peer_hold_timer_setup(mp, true /* start */);
}
}