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bird/proto/ospf/neighbor.c
Ondrej Zajicek 70945cb645 Temporary integrated OSPF commit.
2014-06-26 11:58:57 +02:00

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/*
* BIRD -- OSPF
*
* (c) 1999--2004 Ondrej Filip <feela@network.cz>
* (c) 2009--2014 Ondrej Zajicek <santiago@crfreenet.org>
* (c) 2009--2014 CZ.NIC z.s.p.o.
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include "ospf.h"
char *ospf_ns[] = { " down",
" attempt",
" init",
" 2way",
" exstart",
"exchange",
" loading",
" full"
};
const char *ospf_inm[] =
{ "hello received", "neighbor start", "2-way received",
"negotiation done", "exstart done", "bad ls request", "load done",
"adjacency ok?", "sequence mismatch", "1-way received", "kill neighbor",
"inactivity timer", "line down"
};
static void neigh_chstate(struct ospf_neighbor *n, u8 state);
static void neighbor_timer_hook(timer * timer);
static void rxmt_timer_hook(timer * timer);
static void ackd_timer_hook(timer * t);
static void
init_lists(struct ospf_neighbor *n)
{
s_init_list(&(n->lsrql));
n->lsrqh = ospf_top_new(n->pool);
s_init_list(&(n->lsrtl));
n->lsrth = ospf_top_new(n->pool);
}
/* Resets LSA request and retransmit lists.
* We do not reset DB summary list iterator here,
* it is reset during entering EXCHANGE state.
*/
static void
reset_lists(struct ospf_neighbor *n)
{
ospf_top_free(n->lsrqh);
ospf_top_free(n->lsrth);
init_lists(n);
}
struct ospf_neighbor *
ospf_neighbor_new(struct ospf_iface *ifa)
{
struct ospf_proto *p = ifa->oa->po;
struct pool *pool = rp_new(p->p.pool, "OSPF Neighbor");
struct ospf_neighbor *n = mb_allocz(pool, sizeof(struct ospf_neighbor));
n->pool = pool;
n->ifa = ifa;
add_tail(&ifa->neigh_list, NODE n);
n->adj = 0;
n->csn = 0;
n->state = NEIGHBOR_DOWN;
init_lists(n);
s_init(&(n->dbsi), &(p->lsal));
n->inactim = tm_new(pool);
n->inactim->data = n;
n->inactim->randomize = 0;
n->inactim->hook = neighbor_timer_hook;
n->inactim->recurrent = 0;
DBG("%s: Installing inactivity timer.\n", p->p.name);
n->rxmt_timer = tm_new(pool);
n->rxmt_timer->data = n;
n->rxmt_timer->randomize = 0;
n->rxmt_timer->hook = rxmt_timer_hook;
n->rxmt_timer->recurrent = ifa->rxmtint;
tm_start(n->rxmt_timer, n->ifa->rxmtint);
DBG("%s: Installing rxmt timer.\n", p->p.name);
n->ackd_timer = tm_new(pool);
n->ackd_timer->data = n;
n->ackd_timer->randomize = 0;
n->ackd_timer->hook = ackd_timer_hook;
n->ackd_timer->recurrent = ifa->rxmtint / 2;
init_list(&n->ackl[ACKL_DIRECT]);
init_list(&n->ackl[ACKL_DELAY]);
tm_start(n->ackd_timer, n->ifa->rxmtint / 2);
DBG("%s: Installing ackd timer.\n", p->p.name);
return (n);
}
/**
* neigh_chstate - handles changes related to new or lod state of neighbor
* @n: OSPF neighbor
* @state: new state
*
* Many actions have to be taken acording to a change of state of a neighbor. It
* starts rxmt timers, call interface state machine etc.
*/
static void
neigh_chstate(struct ospf_neighbor *n, u8 state)
{
struct ospf_iface *ifa = n->ifa;
struct ospf_proto *p = ifa->oa->po;
u8 old_state = n->state;
int old_fadj = ifa->fadj;
if (state == old_state)
return;
OSPF_TRACE(D_EVENTS, "Neighbor %I changes state from %s to %s",
n->ip, ospf_ns[old_state], ospf_ns[state]);
n->state = state;
if ((state == NEIGHBOR_2WAY) && (old_state < NEIGHBOR_2WAY))
ospf_iface_sm(ifa, ISM_NEICH);
if ((state < NEIGHBOR_2WAY) && (old_state >= NEIGHBOR_2WAY))
ospf_iface_sm(ifa, ISM_NEICH);
/* Increase number of partial adjacencies */
if ((state == NEIGHBOR_EXCHANGE) || (state == NEIGHBOR_LOADING))
p->padj++;
/* Decrease number of partial adjacencies */
if ((old_state == NEIGHBOR_EXCHANGE) || (old_state == NEIGHBOR_LOADING))
p->padj--;
/* Increase number of full adjacencies */
if (state == NEIGHBOR_FULL)
ifa->fadj++;
/* Decrease number of full adjacencies */
if (old_state == NEIGHBOR_FULL)
ifa->fadj--;
if (ifa->fadj != old_fadj)
{
/* RFC 2328 12.4 Event 4 - neighbor enters/leaves Full state */
ospf_notify_rt_lsa(ifa->oa);
ospf_notify_net_lsa(ifa);
/* RFC 2328 12.4 Event 8 - vlink state change */
if (ifa->type == OSPF_IT_VLINK)
ospf_notify_rt_lsa(ifa->voa);
}
if (state == NEIGHBOR_EXSTART)
{
/* First time adjacency */
if (n->adj == 0)
n->dds = random_u32();
n->dds++;
n->myimms = DBDES_IMMS;
}
if (state > NEIGHBOR_EXSTART)
n->myimms &= ~DBDES_I;
}
static inline u32 neigh_get_id(struct ospf_proto *p, struct ospf_neighbor *n)
{ return ospf_is_v2(p) ? ipa_to_u32(n->ip) : n->rid; }
static struct ospf_neighbor *
elect_bdr(struct ospf_proto *p, list nl)
{
struct ospf_neighbor *neigh, *n1, *n2;
u32 nid;
n1 = NULL;
n2 = NULL;
WALK_LIST(neigh, nl) /* First try those decl. themselves */
{
nid = neigh_get_id(p, neigh);
if (neigh->state >= NEIGHBOR_2WAY) /* Higher than 2WAY */
if (neigh->priority > 0) /* Eligible */
if (neigh->dr != nid) /* And not decl. itself DR */
{
if (neigh->bdr == nid) /* Declaring BDR */
{
if (n1 != NULL)
{
if (neigh->priority > n1->priority)
n1 = neigh;
else if (neigh->priority == n1->priority)
if (neigh->rid > n1->rid)
n1 = neigh;
}
else
{
n1 = neigh;
}
}
else /* And NOT declaring BDR */
{
if (n2 != NULL)
{
if (neigh->priority > n2->priority)
n2 = neigh;
else if (neigh->priority == n2->priority)
if (neigh->rid > n2->rid)
n2 = neigh;
}
else
{
n2 = neigh;
}
}
}
}
if (n1 == NULL)
n1 = n2;
return (n1);
}
static struct ospf_neighbor *
elect_dr(struct ospf_proto *p, list nl)
{
struct ospf_neighbor *neigh, *n;
u32 nid;
n = NULL;
WALK_LIST(neigh, nl) /* And now DR */
{
nid = neigh_get_id(p, neigh);
if (neigh->state >= NEIGHBOR_2WAY) /* Higher than 2WAY */
if (neigh->priority > 0) /* Eligible */
if (neigh->dr == nid) /* And declaring itself DR */
{
if (n != NULL)
{
if (neigh->priority > n->priority)
n = neigh;
else if (neigh->priority == n->priority)
if (neigh->rid > n->rid)
n = neigh;
}
else
{
n = neigh;
}
}
}
return (n);
}
static int
can_do_adj(struct ospf_neighbor *n)
{
struct ospf_iface *ifa = n->ifa;
struct ospf_proto *p = ifa->oa->po;
int i = 0;
switch (ifa->type)
{
case OSPF_IT_PTP:
case OSPF_IT_PTMP:
case OSPF_IT_VLINK:
i = 1;
break;
case OSPF_IT_BCAST:
case OSPF_IT_NBMA:
switch (ifa->state)
{
case OSPF_IS_DOWN:
case OSPF_IS_LOOP:
bug("%s: Iface %s in down state?", p->p.name, ifa->ifname);
break;
case OSPF_IS_WAITING:
DBG("%s: Neighbor? on iface %s\n", p->p.name, ifa->ifname);
break;
case OSPF_IS_DROTHER:
if (((n->rid == ifa->drid) || (n->rid == ifa->bdrid))
&& (n->state >= NEIGHBOR_2WAY))
i = 1;
break;
case OSPF_IS_PTP:
case OSPF_IS_BACKUP:
case OSPF_IS_DR:
if (n->state >= NEIGHBOR_2WAY)
i = 1;
break;
default:
bug("%s: Iface %s in unknown state?", p->p.name, ifa->ifname);
break;
}
break;
default:
bug("%s: Iface %s is unknown type?", p->p.name, ifa->ifname);
break;
}
DBG("%s: Iface %s can_do_adj=%d\n", p->p.name, ifa->ifname, i);
return i;
}
/**
* ospf_neigh_sm - ospf neighbor state machine
* @n: neighor
* @event: actual event
*
* This part implements the neighbor state machine as described in 10.3 of
* RFC 2328. The only difference is that state %NEIGHBOR_ATTEMPT is not
* used. We discover neighbors on nonbroadcast networks in the
* same way as on broadcast networks. The only difference is in
* sending hello packets. These are sent to IPs listed in
* @ospf_iface->nbma_list .
*/
void
ospf_neigh_sm(struct ospf_neighbor *n, int event)
{
struct ospf_proto *p = n->ifa->oa->po;
DBG("Neighbor state machine for neighbor %I, event '%s'\n", n->ip,
ospf_inm[event]);
switch (event)
{
case INM_START:
neigh_chstate(n, NEIGHBOR_ATTEMPT);
/* NBMA are used different way */
break;
case INM_HELLOREC:
if ((n->state == NEIGHBOR_DOWN) ||
(n->state == NEIGHBOR_ATTEMPT))
neigh_chstate(n, NEIGHBOR_INIT);
/* Restart inactivity timer */
tm_start(n->inactim, n->ifa->deadint);
break;
case INM_2WAYREC:
if (n->state < NEIGHBOR_2WAY)
neigh_chstate(n, NEIGHBOR_2WAY);
if ((n->state == NEIGHBOR_2WAY) && can_do_adj(n))
neigh_chstate(n, NEIGHBOR_EXSTART);
break;
case INM_NEGDONE:
if (n->state == NEIGHBOR_EXSTART)
{
neigh_chstate(n, NEIGHBOR_EXCHANGE);
/* Reset DB summary list iterator */
s_get(&(n->dbsi));
s_init(&(n->dbsi), &p->lsal);
ospf_reset_lsack_queue(n);
}
else
bug("NEGDONE and I'm not in EXSTART?");
break;
case INM_EXDONE:
neigh_chstate(n, NEIGHBOR_LOADING);
break;
case INM_LOADDONE:
neigh_chstate(n, NEIGHBOR_FULL);
break;
case INM_ADJOK:
switch (n->state)
{
case NEIGHBOR_2WAY:
/* Can In build adjacency? */
if (can_do_adj(n))
{
neigh_chstate(n, NEIGHBOR_EXSTART);
}
break;
default:
if (n->state >= NEIGHBOR_EXSTART)
if (!can_do_adj(n))
{
reset_lists(n);
neigh_chstate(n, NEIGHBOR_2WAY);
}
break;
}
break;
case INM_SEQMIS:
case INM_BADLSREQ:
if (n->state >= NEIGHBOR_EXCHANGE)
{
reset_lists(n);
neigh_chstate(n, NEIGHBOR_EXSTART);
}
break;
case INM_KILLNBR:
case INM_LLDOWN:
case INM_INACTTIM:
reset_lists(n);
neigh_chstate(n, NEIGHBOR_DOWN);
break;
case INM_1WAYREC:
reset_lists(n);
neigh_chstate(n, NEIGHBOR_INIT);
break;
default:
bug("%s: INM - Unknown event?", p->p.name);
break;
}
}
/**
* ospf_dr_election - (Backup) Designed Router election
* @ifa: actual interface
*
* When the wait timer fires, it is time to elect (Backup) Designated Router.
* Structure describing me is added to this list so every electing router
* has the same list. Backup Designated Router is elected before Designated
* Router. This process is described in 9.4 of RFC 2328.
*/
void
ospf_dr_election(struct ospf_iface *ifa)
{
struct ospf_proto *p = ifa->oa->po;
struct ospf_neighbor *neigh, *ndr, *nbdr, me;
u32 myid = p->router_id;
DBG("(B)DR election.\n");
me.state = NEIGHBOR_2WAY;
me.rid = myid;
me.priority = ifa->priority;
me.ip = ifa->addr->ip;
me.dr = ospf_is_v2(p) ? ipa_to_u32(ifa->drip) : ifa->drid;
me.bdr = ospf_is_v2(p) ? ipa_to_u32(ifa->bdrip) : ifa->bdrid;
me.iface_id = ifa->iface_id;
add_tail(&ifa->neigh_list, NODE & me);
nbdr = elect_bdr(p, ifa->neigh_list);
ndr = elect_dr(p, ifa->neigh_list);
if (ndr == NULL)
ndr = nbdr;
/* 9.4. (4) */
if (((ifa->drid == myid) && (ndr != &me))
|| ((ifa->drid != myid) && (ndr == &me))
|| ((ifa->bdrid == myid) && (nbdr != &me))
|| ((ifa->bdrid != myid) && (nbdr == &me)))
{
me.dr = ndr ? neigh_get_id(p, ndr) : 0;
me.bdr = nbdr ? neigh_get_id(p, nbdr) : 0;
nbdr = elect_bdr(p, ifa->neigh_list);
ndr = elect_dr(p, ifa->neigh_list);
if (ndr == NULL)
ndr = nbdr;
}
rem_node(NODE & me);
u32 old_drid = ifa->drid;
u32 old_bdrid = ifa->bdrid;
ifa->drid = ndr ? ndr->rid : 0;
ifa->drip = ndr ? ndr->ip : IPA_NONE;
ifa->dr_iface_id = ndr ? ndr->iface_id : 0;
ifa->bdrid = nbdr ? nbdr->rid : 0;
ifa->bdrip = nbdr ? nbdr->ip : IPA_NONE;
DBG("DR=%R, BDR=%R\n", ifa->drid, ifa->bdrid);
if (ifa->drid == myid)
ospf_iface_chstate(ifa, OSPF_IS_DR);
else if (ifa->bdrid == myid)
ospf_iface_chstate(ifa, OSPF_IS_BACKUP);
else
ospf_iface_chstate(ifa, OSPF_IS_DROTHER);
/* Review neighbor adjacencies if DR or BDR changed */
if ((ifa->drid != old_drid) || (ifa->bdrid != old_bdrid))
WALK_LIST(neigh, ifa->neigh_list)
if (neigh->state >= NEIGHBOR_2WAY)
ospf_neigh_sm(neigh, INM_ADJOK);
/* RFC 2328 12.4 Event 3 - DR change */
if (ifa->drid != old_drid)
ospf_notify_rt_lsa(ifa->oa);
}
struct ospf_neighbor *
find_neigh(struct ospf_iface *ifa, u32 rid)
{
struct ospf_neighbor *n;
WALK_LIST(n, ifa->neigh_list)
if (n->rid == rid)
return n;
return NULL;
}
struct ospf_neighbor *
find_neigh_by_ip(struct ospf_iface *ifa, ip_addr ip)
{
struct ospf_neighbor *n;
WALK_LIST(n, ifa->neigh_list)
if (ipa_equal(n->ip, ip))
return n;
return NULL;
}
/* Neighbor is inactive for a long time. Remove it. */
static void
neighbor_timer_hook(timer * timer)
{
struct ospf_neighbor *n = (struct ospf_neighbor *) timer->data;
struct ospf_iface *ifa = n->ifa;
struct ospf_proto *p = ifa->oa->po;
OSPF_TRACE(D_EVENTS, "Inactivity timer fired on interface %s for neighbor %I",
ifa->ifname, n->ip);
ospf_neigh_remove(n);
}
void
ospf_neigh_remove(struct ospf_neighbor *n)
{
struct ospf_iface *ifa = n->ifa;
struct ospf_proto *p = ifa->oa->po;
if ((ifa->type == OSPF_IT_NBMA) || (ifa->type == OSPF_IT_PTMP))
{
struct nbma_node *nn = find_nbma_node(ifa, n->ip);
if (nn)
nn->found = 0;
}
s_get(&(n->dbsi));
neigh_chstate(n, NEIGHBOR_DOWN);
rem_node(NODE n);
rfree(n->pool);
OSPF_TRACE(D_EVENTS, "Deleting neigbor %R", n->rid);
}
static void
ospf_neigh_bfd_hook(struct bfd_request *req)
{
struct ospf_neighbor *n = req->data;
struct ospf_proto *p = n->ifa->oa->po;
if (req->down)
{
OSPF_TRACE(D_EVENTS, "BFD session down for %I on %s", n->ip, n->ifa->ifname);
ospf_neigh_remove(n);
}
}
void
ospf_neigh_update_bfd(struct ospf_neighbor *n, int use_bfd)
{
if (use_bfd && !n->bfd_req)
n->bfd_req = bfd_request_session(n->pool, n->ip, n->ifa->addr->ip, n->ifa->iface,
ospf_neigh_bfd_hook, n);
if (!use_bfd && n->bfd_req)
{
rfree(n->bfd_req);
n->bfd_req = NULL;
}
}
void
ospf_sh_neigh_info(struct ospf_neighbor *n)
{
struct ospf_iface *ifa = n->ifa;
char *pos = "other";
char etime[6];
int exp, sec, min;
exp = n->inactim->expires - now;
sec = exp % 60;
min = exp / 60;
if (min > 59)
{
bsprintf(etime, "-Inf-");
}
else
{
bsprintf(etime, "%02u:%02u", min, sec);
}
if (n->rid == ifa->drid)
pos = "dr ";
else if (n->rid == ifa->bdrid)
pos = "bdr ";
else if ((n->ifa->type == OSPF_IT_PTP) || (n->ifa->type == OSPF_IT_PTMP) ||
(n->ifa->type == OSPF_IT_VLINK))
pos = "ptp ";
cli_msg(-1013, "%-1R\t%3u\t%s/%s\t%-5s\t%-10s %-1I", n->rid, n->priority,
ospf_ns[n->state], pos, etime, ifa->ifname, n->ip);
}
static void
rxmt_timer_hook(timer * timer)
{
struct ospf_neighbor *n = (struct ospf_neighbor *) timer->data;
struct ospf_proto *p = n->ifa->oa->po;
DBG("%s: RXMT timer fired on interface %s for neigh %I\n",
p->p.name, n->ifa->ifname, n->ip);
switch (n->state)
{
case NEIGHBOR_EXSTART:
ospf_send_dbdes(n, 1);
return;
case NEIGHBOR_EXCHANGE:
if (n->myimms & DBDES_MS)
ospf_send_dbdes(n, 0);
case NEIGHBOR_LOADING:
ospf_send_lsreq(p, n);
return;
case NEIGHBOR_FULL:
/* LSA retransmissions */
if (!EMPTY_SLIST(n->lsrtl))
ospf_rxmt_lsupd(p, n);
return;
default:
return;
}
}
static void
ackd_timer_hook(timer * t)
{
struct ospf_neighbor *n = t->data;
ospf_lsack_send(n, ACKL_DELAY);
}
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