0
0
mirror of https://gitlab.nic.cz/labs/bird.git synced 2024-12-22 17:51:53 +00:00
bird/proto/rip/rip.c

1289 lines
32 KiB
C
Raw Normal View History

/*
* BIRD -- Routing Information Protocol (RIP)
*
* (c) 1998--1999 Pavel Machek <pavel@ucw.cz>
* (c) 2004--2013 Ondrej Filip <feela@network.cz>
* (c) 2009--2015 Ondrej Zajicek <santiago@crfreenet.org>
* (c) 2009--2015 CZ.NIC z.s.p.o.
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
/**
* DOC: Routing Information Protocol (RIP)
*
* The RIP protocol is implemented in two files: |rip.c| containing the protocol
* logic, route management and the protocol glue with BIRD core, and |packets.c|
* handling RIP packet processing, RX, TX and protocol sockets.
*
* Each instance of RIP is described by a structure &rip_proto, which contains
* an internal RIP routing table, a list of protocol interfaces and the main
* timer responsible for RIP routing table cleanup.
*
* RIP internal routing table contains incoming and outgoing routes. For each
* network (represented by structure &rip_entry) there is one outgoing route
* stored directly in &rip_entry and an one-way linked list of incoming routes
* (structures &rip_rte). The list contains incoming routes from different RIP
* neighbors, but only routes with the lowest metric are stored (i.e., all
* stored incoming routes have the same metric).
*
* Note that RIP itself does not select outgoing route, that is done by the core
* routing table. When a new incoming route is received, it is propagated to the
* RIP table by rip_update_rte() and possibly stored in the list of incoming
* routes. Then the change may be propagated to the core by rip_announce_rte().
* The core selects the best route and propagate it to RIP by rip_rt_notify(),
* which updates outgoing route part of &rip_entry and possibly triggers route
* propagation by rip_trigger_update().
*
* RIP interfaces are represented by structures &rip_iface. A RIP interface
* contains a per-interface socket, a list of associated neighbors, interface
* configuration, and state information related to scheduled interface events
* and running update sessions. RIP interfaces are added and removed based on
* core interface notifications.
*
* There are two RIP interface events - regular updates and triggered updates.
* Both are managed from the RIP interface timer (rip_iface_timer()). Regular
* updates are called at fixed interval and propagate the whole routing table,
* while triggered updates are scheduled by rip_trigger_update() due to some
* routing table change and propagate only the routes modified since the time
* they were scheduled. There are also unicast-destined requested updates, but
* these are sent directly as a reaction to received RIP request message. The
* update session is started by rip_send_table(). There may be at most one
* active update session per interface, as the associated state (including the
* fib iterator) is stored directly in &rip_iface structure.
2000-06-07 13:25:53 +00:00
*
* RIP neighbors are represented by structures &rip_neighbor. Compared to
* neighbor handling in other routing protocols, RIP does not have explicit
* neighbor discovery and adjacency maintenance, which makes the &rip_neighbor
* related code a bit peculiar. RIP neighbors are interlinked with core neighbor
* structures (&neighbor) and use core neighbor notifications to ensure that RIP
* neighbors are timely removed. RIP neighbors are added based on received route
* notifications and removed based on core neighbor and RIP interface events.
*
* RIP neighbors are linked by RIP routes and use counter to track the number of
* associated routes, but when these RIP routes timeout, associated RIP neighbor
* is still alive (with zero counter). When RIP neighbor is removed but still
* has some associated routes, it is not freed, just changed to detached state
* (core neighbors and RIP ifaces are unlinked), then during the main timer
* cleanup phase the associated routes are removed and the &rip_neighbor
* structure is finally freed.
*
* Supported standards:
* - RFC 1058 - RIPv1
* - RFC 2453 - RIPv2
* - RFC 2080 - RIPng
* - RFC 4822 - RIP cryptographic authentication
*/
#include <stdlib.h>
#include "rip.h"
static inline void rip_lock_neighbor(struct rip_neighbor *n);
static inline void rip_unlock_neighbor(struct rip_neighbor *n);
static inline int rip_iface_link_up(struct rip_iface *ifa);
static inline void rip_kick_timer(struct rip_proto *p);
static inline void rip_iface_kick_timer(struct rip_iface *ifa);
static void rip_iface_timer(timer *timer);
static void rip_trigger_update(struct rip_proto *p);
/*
* RIP routes
*/
static void
rip_init_entry(struct fib_node *fn)
{
// struct rip_entry *en = (void) *fn;
const uint offset = OFFSETOF(struct rip_entry, routes);
memset((byte *)fn + offset, 0, sizeof(struct rip_entry) - offset);
}
static struct rip_rte *
rip_add_rte(struct rip_proto *p, struct rip_rte **rp, struct rip_rte *src)
{
struct rip_rte *rt = sl_alloc(p->rte_slab);
memcpy(rt, src, sizeof(struct rip_rte));
rt->next = *rp;
*rp = rt;
2000-06-07 13:58:49 +00:00
rip_lock_neighbor(rt->from);
2000-04-26 11:07:57 +00:00
return rt;
}
static inline void
rip_remove_rte(struct rip_proto *p, struct rip_rte **rp)
{
struct rip_rte *rt = *rp;
rip_unlock_neighbor(rt->from);
*rp = rt->next;
sl_free(p->rte_slab, rt);
}
static inline int rip_same_rte(struct rip_rte *a, struct rip_rte *b)
{ return a->metric == b->metric && a->tag == b->tag && ipa_equal(a->next_hop, b->next_hop); }
static inline int rip_valid_rte(struct rip_rte *rt)
{ return rt->from->ifa != NULL; }
/**
* rip_announce_rte - announce route from RIP routing table to the core
* @p: RIP instance
* @en: related network
*
* The function takes a list of incoming routes from @en, prepare appropriate
* &rte for the core and propagate it by rte_update().
*/
static void
rip_announce_rte(struct rip_proto *p, struct rip_entry *en)
{
struct rip_rte *rt = en->routes;
/* Find first valid rte */
while (rt && !rip_valid_rte(rt))
rt = rt->next;
if (rt)
{
/* Update */
net *n = net_get(p->p.table, en->n.prefix, en->n.pxlen);
rta a0 = {
.src = p->p.main_source,
.source = RTS_RIP,
.scope = SCOPE_UNIVERSE,
.cast = RTC_UNICAST
};
u8 rt_metric = rt->metric;
u16 rt_tag = rt->tag;
struct rip_rte *rt2 = rt->next;
/* Find second valid rte */
while (rt2 && !rip_valid_rte(rt2))
rt2 = rt2->next;
if (p->ecmp && rt2)
{
/* ECMP route */
struct mpnh *nhs = NULL;
struct mpnh **nhp = &nhs;
int num = 0;
for (rt = en->routes; rt && (num < p->ecmp); rt = rt->next)
{
if (!rip_valid_rte(rt))
continue;
struct mpnh *nh = alloca(sizeof(struct mpnh));
nh->gw = rt->next_hop;
nh->iface = rt->from->nbr->iface;
nh->weight = rt->from->ifa->cf->ecmp_weight;
nh->next = NULL;
*nhp = nh;
nhp = &(nh->next);
num++;
if (rt->tag != rt_tag)
rt_tag = 0;
}
a0.dest = RTD_MULTIPATH;
a0.nexthops = nhs;
2000-01-26 14:12:18 +00:00
}
else
{
/* Unipath route */
a0.dest = RTD_ROUTER;
a0.gw = rt->next_hop;
a0.iface = rt->from->nbr->iface;
a0.from = rt->from->nbr->addr;
}
rta *a = rta_lookup(&a0);
rte *e = rte_get_temp(a);
e->u.rip.from = a0.iface;
e->u.rip.metric = rt_metric;
e->u.rip.tag = rt_tag;
e->net = n;
e->pflags = 0;
rte_update(&p->p, n, e);
}
else
{
/* Withdraw */
net *n = net_find(p->p.table, en->n.prefix, en->n.pxlen);
rte_update(&p->p, n, NULL);
}
}
/**
* rip_update_rte - enter a route update to RIP routing table
* @p: RIP instance
* @prefix: network prefix
* @pxlen: network prefix length
* @new: a &rip_rte representing the new route
*
* The function is called by the RIP packet processing code whenever it receives
* a reachable route. The appropriate routing table entry is found and the list
* of incoming routes is updated. Eventually, the change is also propagated to
* the core by rip_announce_rte(). Note that for unreachable routes,
* rip_withdraw_rte() should be called instead of rip_update_rte().
*/
void
rip_update_rte(struct rip_proto *p, ip_addr *prefix, int pxlen, struct rip_rte *new)
{
struct rip_entry *en = fib_get(&p->rtable, prefix, pxlen);
struct rip_rte *rt, **rp;
int changed = 0;
/* If the new route is better, remove all current routes */
if (en->routes && new->metric < en->routes->metric)
while (en->routes)
rip_remove_rte(p, &en->routes);
/* Find the old route (also set rp for later) */
for (rp = &en->routes; rt = *rp; rp = &rt->next)
if (rt->from == new->from)
{
if (rip_same_rte(rt, new))
{
rt->expires = new->expires;
return;
}
1998-12-09 20:08:57 +00:00
/* Remove the old route */
rip_remove_rte(p, rp);
changed = 1;
break;
}
/* If the new route is optimal, add it to the list */
if (!en->routes || new->metric == en->routes->metric)
{
rt = rip_add_rte(p, rp, new);
changed = 1;
}
/* Announce change if on relevant position (the first or any for ECMP) */
if (changed && (rp == &en->routes || p->ecmp))
rip_announce_rte(p, en);
}
/**
* rip_withdraw_rte - enter a route withdraw to RIP routing table
* @p: RIP instance
* @prefix: network prefix
* @pxlen: network prefix length
* @from: a &rip_neighbor propagating the withdraw
*
* The function is called by the RIP packet processing code whenever it receives
* an unreachable route. The incoming route for given network from nbr @from is
* removed. Eventually, the change is also propagated by rip_announce_rte().
*/
void
rip_withdraw_rte(struct rip_proto *p, ip_addr *prefix, int pxlen, struct rip_neighbor *from)
{
struct rip_entry *en = fib_find(&p->rtable, prefix, pxlen);
struct rip_rte *rt, **rp;
if (!en)
return;
/* Find the old route */
for (rp = &en->routes; rt = *rp; rp = &rt->next)
if (rt->from == from)
break;
if (!rt)
return;
/* Remove the old route */
rip_remove_rte(p, rp);
/* Announce change if on relevant position */
if (rp == &en->routes || p->ecmp)
rip_announce_rte(p, en);
}
/*
* rip_rt_notify - core tells us about new route, so store
* it into our data structures.
*/
static void
rip_rt_notify(struct proto *P, struct rtable *table UNUSED, struct network *net, struct rte *new,
struct rte *old UNUSED, struct ea_list *attrs)
{
struct rip_proto *p = (struct rip_proto *) P;
struct rip_entry *en;
int old_metric;
if (new)
{
/* Update */
u32 rt_metric = ea_get_int(attrs, EA_RIP_METRIC, 1);
u32 rt_tag = ea_get_int(attrs, EA_RIP_TAG, 0);
if (rt_metric > p->infinity)
{
log(L_WARN "%s: Invalid rip_metric value %u for route %I/%d",
p->p.name, rt_metric, net->n.prefix, net->n.pxlen);
rt_metric = p->infinity;
}
if (rt_tag > 0xffff)
{
log(L_WARN "%s: Invalid rip_tag value %u for route %I/%d",
p->p.name, rt_tag, net->n.prefix, net->n.pxlen);
rt_metric = p->infinity;
rt_tag = 0;
}
/*
* Note that we accept exported routes with infinity metric (this could
* happen if rip_metric is modified in filters). Such entry has infinity
* metric but is RIP_ENTRY_VALID and therefore is not subject to garbage
* collection.
*/
en = fib_get(&p->rtable, &net->n.prefix, net->n.pxlen);
old_metric = en->valid ? en->metric : -1;
en->valid = RIP_ENTRY_VALID;
en->metric = rt_metric;
en->tag = rt_tag;
en->from = (new->attrs->src->proto == P) ? new->u.rip.from : NULL;
en->iface = new->attrs->iface;
en->next_hop = new->attrs->gw;
}
else
{
/* Withdraw */
en = fib_find(&p->rtable, &net->n.prefix, net->n.pxlen);
1998-10-20 16:12:43 +00:00
if (!en || en->valid != RIP_ENTRY_VALID)
return;
old_metric = en->metric;
en->valid = RIP_ENTRY_STALE;
en->metric = p->infinity;
en->tag = 0;
en->from = NULL;
en->iface = NULL;
en->next_hop = IPA_NONE;
1998-12-09 20:08:57 +00:00
}
/* Activate triggered updates */
if (en->metric != old_metric)
{
en->changed = now;
rip_trigger_update(p);
1999-03-17 10:20:23 +00:00
}
}
/*
* RIP neighbors
*/
struct rip_neighbor *
rip_get_neighbor(struct rip_proto *p, ip_addr *a, struct rip_iface *ifa)
{
neighbor *nbr = neigh_find2(&p->p, a, ifa->iface, 0);
if (!nbr || (nbr->scope == SCOPE_HOST) || !rip_iface_link_up(ifa))
return NULL;
if (nbr->data)
return nbr->data;
TRACE(D_EVENTS, "New neighbor %I on %s", *a, ifa->iface->name);
struct rip_neighbor *n = mb_allocz(p->p.pool, sizeof(struct rip_neighbor));
n->ifa = ifa;
n->nbr = nbr;
nbr->data = n;
n->csn = nbr->aux;
add_tail(&ifa->neigh_list, NODE n);
return n;
}
static void
rip_remove_neighbor(struct rip_proto *p, struct rip_neighbor *n)
{
neighbor *nbr = n->nbr;
TRACE(D_EVENTS, "Removing neighbor %I on %s", nbr->addr, nbr->iface->name);
rem_node(NODE n);
n->ifa = NULL;
n->nbr = NULL;
nbr->data = NULL;
nbr->aux = n->csn;
rfree(n->bfd_req);
n->bfd_req = NULL;
n->last_seen = 0;
if (!n->uc)
mb_free(n);
/* Related routes are removed in rip_timer() */
rip_kick_timer(p);
}
static inline void
rip_lock_neighbor(struct rip_neighbor *n)
{
n->uc++;
}
static inline void
rip_unlock_neighbor(struct rip_neighbor *n)
{
n->uc--;
if (!n->nbr && !n->uc)
mb_free(n);
}
static void
rip_neigh_notify(struct neighbor *nbr)
{
struct rip_proto *p = (struct rip_proto *) nbr->proto;
struct rip_neighbor *n = nbr->data;
if (!n)
return;
/*
* We assume that rip_neigh_notify() is called before rip_if_notify() for
* IF_CHANGE_DOWN and therefore n->ifa is still valid. We have no such
* ordering assumption for IF_CHANGE_LINK, so we test link state of the
* underlying iface instead of just rip_iface state.
*/
if ((nbr->scope <= 0) || !rip_iface_link_up(n->ifa))
rip_remove_neighbor(p, n);
}
static void
rip_bfd_notify(struct bfd_request *req)
{
struct rip_neighbor *n = req->data;
struct rip_proto *p = n->ifa->rip;
if (req->down)
{
TRACE(D_EVENTS, "BFD session down for nbr %I on %s",
n->nbr->addr, n->ifa->iface->name);
rip_remove_neighbor(p, n);
}
}
void
rip_update_bfd(struct rip_proto *p, struct rip_neighbor *n)
{
int use_bfd = n->ifa->cf->bfd && n->last_seen;
if (use_bfd && !n->bfd_req)
{
/*
* For RIPv2, use the same address as rip_open_socket(). For RIPng, neighbor
* should contain an address from the same prefix, thus also link-local. It
* may cause problems if two link-local addresses are assigned to one iface.
*/
ip_addr saddr = rip_is_v2(p) ? n->ifa->sk->saddr : n->nbr->ifa->ip;
n->bfd_req = bfd_request_session(p->p.pool, n->nbr->addr, saddr,
n->nbr->iface, rip_bfd_notify, n);
}
if (!use_bfd && n->bfd_req)
{
rfree(n->bfd_req);
n->bfd_req = NULL;
}
}
/*
* RIP interfaces
*/
static void
rip_iface_start(struct rip_iface *ifa)
{
struct rip_proto *p = ifa->rip;
TRACE(D_EVENTS, "Starting interface %s", ifa->iface->name);
ifa->next_regular = now + (random() % ifa->cf->update_time) + 1;
ifa->next_triggered = now; /* Available immediately */
ifa->want_triggered = 1; /* All routes in triggered update */
tm_start(ifa->timer, 1); /* Or 100 ms */
ifa->up = 1;
if (!ifa->cf->passive)
rip_send_request(ifa->rip, ifa);
}
static void
rip_iface_stop(struct rip_iface *ifa)
{
struct rip_proto *p = ifa->rip;
struct rip_neighbor *n;
TRACE(D_EVENTS, "Stopping interface %s", ifa->iface->name);
rip_reset_tx_session(p, ifa);
WALK_LIST_FIRST(n, ifa->neigh_list)
rip_remove_neighbor(p, n);
2000-05-10 12:46:47 +00:00
tm_stop(ifa->timer);
ifa->up = 0;
}
static inline int
rip_iface_link_up(struct rip_iface *ifa)
{
return !ifa->cf->check_link || (ifa->iface->flags & IF_LINK_UP);
}
static void
rip_iface_update_state(struct rip_iface *ifa)
{
int up = ifa->sk && rip_iface_link_up(ifa);
if (up == ifa->up)
return;
if (up)
rip_iface_start(ifa);
else
rip_iface_stop(ifa);
}
static void
rip_iface_update_buffers(struct rip_iface *ifa)
{
if (!ifa->sk)
return;
uint rbsize = ifa->cf->rx_buffer ?: ifa->iface->mtu;
uint tbsize = ifa->cf->tx_length ?: ifa->iface->mtu;
rbsize = MAX(rbsize, tbsize);
2013-02-26 13:13:11 +00:00
sk_set_rbsize(ifa->sk, rbsize);
sk_set_tbsize(ifa->sk, tbsize);
2013-02-26 13:13:11 +00:00
uint headers = (rip_is_v2(ifa->rip) ? IP4_HEADER_LENGTH : IP6_HEADER_LENGTH) + UDP_HEADER_LENGTH;
ifa->tx_plen = tbsize - headers;
1998-10-20 16:12:43 +00:00
if (ifa->cf->auth_type == RIP_AUTH_CRYPTO)
ifa->tx_plen -= RIP_AUTH_TAIL_LENGTH;
}
static inline void
rip_iface_update_bfd(struct rip_iface *ifa)
{
struct rip_proto *p = ifa->rip;
struct rip_neighbor *n;
WALK_LIST(n, ifa->neigh_list)
rip_update_bfd(p, n);
}
static void
rip_iface_locked(struct object_lock *lock)
{
struct rip_iface *ifa = lock->data;
struct rip_proto *p = ifa->rip;
if (!rip_open_socket(ifa))
1998-10-20 16:12:43 +00:00
{
log(L_ERR "%s: Cannot open socket for %s", p->p.name, ifa->iface->name);
return;
}
2013-02-23 23:43:08 +00:00
rip_iface_update_buffers(ifa);
rip_iface_update_state(ifa);
}
2013-02-23 23:43:08 +00:00
static struct rip_iface *
rip_find_iface(struct rip_proto *p, struct iface *what)
{
struct rip_iface *ifa;
1998-10-20 16:12:43 +00:00
WALK_LIST(ifa, p->iface_list)
if (ifa->iface == what)
return ifa;
return NULL;
}
static void
rip_add_iface(struct rip_proto *p, struct iface *iface, struct rip_iface_config *ic)
{
struct rip_iface *ifa;
TRACE(D_EVENTS, "Adding interface %s", iface->name);
ifa = mb_allocz(p->p.pool, sizeof(struct rip_iface));
ifa->rip = p;
ifa->iface = iface;
ifa->cf = ic;
if (ipa_nonzero(ic->address))
ifa->addr = ic->address;
else if (ic->mode == RIP_IM_MULTICAST)
ifa->addr = rip_is_v2(p) ? IP4_RIP_ROUTERS : IP6_RIP_ROUTERS;
else /* Broadcast */
ifa->addr = iface->addr->brd;
init_list(&ifa->neigh_list);
add_tail(&p->iface_list, NODE ifa);
ifa->timer = tm_new_set(p->p.pool, rip_iface_timer, ifa, 0, 0);
struct object_lock *lock = olock_new(p->p.pool);
lock->type = OBJLOCK_UDP;
lock->port = ic->port;
lock->iface = iface;
lock->data = ifa;
lock->hook = rip_iface_locked;
ifa->lock = lock;
olock_acquire(lock);
}
static void
rip_remove_iface(struct rip_proto *p, struct rip_iface *ifa)
{
rip_iface_stop(ifa);
TRACE(D_EVENTS, "Removing interface %s", ifa->iface->name);
rem_node(NODE ifa);
rfree(ifa->sk);
rfree(ifa->lock);
rfree(ifa->timer);
mb_free(ifa);
}
static int
rip_reconfigure_iface(struct rip_proto *p, struct rip_iface *ifa, struct rip_iface_config *new)
{
struct rip_iface_config *old = ifa->cf;
/* Change of these options would require to reset the iface socket */
if ((new->mode != old->mode) ||
(new->port != old->port) ||
(new->tx_tos != old->tx_tos) ||
(new->tx_priority != old->tx_priority) ||
(new->ttl_security != old->ttl_security))
return 0;
TRACE(D_EVENTS, "Reconfiguring interface %s", ifa->iface->name);
ifa->cf = new;
if (ifa->next_regular > (now + new->update_time))
ifa->next_regular = now + (random() % new->update_time) + 1;
if ((new->tx_length != old->tx_length) || (new->rx_buffer != old->rx_buffer))
rip_iface_update_buffers(ifa);
if (new->check_link != old->check_link)
rip_iface_update_state(ifa);
if (new->bfd != old->bfd)
rip_iface_update_bfd(ifa);
if (ifa->up)
rip_iface_kick_timer(ifa);
return 1;
}
static void
rip_reconfigure_ifaces(struct rip_proto *p, struct rip_config *cf)
{
struct iface *iface;
WALK_LIST(iface, iface_list)
{
if (! (iface->flags & IF_UP))
continue;
struct rip_iface *ifa = rip_find_iface(p, iface);
struct rip_iface_config *ic = (void *) iface_patt_find(&cf->patt_list, iface, NULL);
if (ifa && ic)
{
if (rip_reconfigure_iface(p, ifa, ic))
continue;
/* Hard restart */
log(L_INFO "%s: Restarting interface %s", p->p.name, ifa->iface->name);
rip_remove_iface(p, ifa);
rip_add_iface(p, iface, ic);
}
if (ifa && !ic)
rip_remove_iface(p, ifa);
if (!ifa && ic)
rip_add_iface(p, iface, ic);
}
}
static void
rip_if_notify(struct proto *P, unsigned flags, struct iface *iface)
{
struct rip_proto *p = (void *) P;
struct rip_config *cf = (void *) P->cf;
if (iface->flags & IF_IGNORE)
return;
if (flags & IF_CHANGE_UP)
{
struct rip_iface_config *ic = (void *) iface_patt_find(&cf->patt_list, iface, NULL);
if (ic)
rip_add_iface(p, iface, ic);
return;
}
struct rip_iface *ifa = rip_find_iface(p, iface);
if (!ifa)
return;
if (flags & IF_CHANGE_DOWN)
{
rip_remove_iface(p, ifa);
return;
}
if (flags & IF_CHANGE_MTU)
rip_iface_update_buffers(ifa);
if (flags & IF_CHANGE_LINK)
rip_iface_update_state(ifa);
}
/*
* RIP timer events
*/
2000-04-28 09:55:52 +00:00
/**
* rip_timer - RIP main timer hook
* @t: timer
*
* The RIP main timer is responsible for routing table maintenance. Invalid or
* expired routes (&rip_rte) are removed and garbage collection of stale routing
* table entries (&rip_entry) is done. Changes are propagated to core tables,
* route reload is also done here. Note that garbage collection uses a maximal
* GC time, while interfaces maintain an illusion of per-interface GC times in
* rip_send_response().
*
* Keeping incoming routes and the selected outgoing route are two independent
* functions, therefore after garbage collection some entries now considered
* invalid (RIP_ENTRY_DUMMY) still may have non-empty list of incoming routes,
* while some valid entries (representing an outgoing route) may have that list
* empty.
*
* The main timer is not scheduled periodically but it uses the time of the
* current next event and the minimal interval of any possible event to compute
* the time of the next run.
*/
static void
rip_timer(timer *t)
{
struct rip_proto *p = t->data;
struct rip_config *cf = (void *) (p->p.cf);
struct rip_iface *ifa;
struct rip_neighbor *n, *nn;
struct fib_iterator fit;
bird_clock_t next = now + MIN(cf->min_timeout_time, cf->max_garbage_time);
bird_clock_t expires = 0;
TRACE(D_EVENTS, "Main timer fired");
FIB_ITERATE_INIT(&fit, &p->rtable);
loop:
FIB_ITERATE_START(&p->rtable, &fit, node)
{
struct rip_entry *en = (struct rip_entry *) node;
struct rip_rte *rt, **rp;
int changed = 0;
/* Checking received routes for timeout and for dead neighbors */
for (rp = &en->routes; rt = *rp; /* rp = &rt->next */)
{
if (!rip_valid_rte(rt) || (rt->expires <= now))
{
rip_remove_rte(p, rp);
changed = 1;
continue;
}
next = MIN(next, rt->expires);
rp = &rt->next;
}
/* Propagating eventual change */
if (changed || p->rt_reload)
{
/*
* We have to restart the iteration because there may be a cascade of
* synchronous events rip_announce_rte() -> nest table change ->
* rip_rt_notify() -> p->rtable change, invalidating hidden variables.
*/
FIB_ITERATE_PUT_NEXT(&fit, &p->rtable, node);
rip_announce_rte(p, en);
goto loop;
}
/* Checking stale entries for garbage collection timeout */
if (en->valid == RIP_ENTRY_STALE)
{
expires = en->changed + cf->max_garbage_time;
if (expires <= now)
{
// TRACE(D_EVENTS, "entry is too old: %I/%d", en->n.prefix, en->n.pxlen);
en->valid = 0;
}
else
next = MIN(next, expires);
}
/* Remove empty nodes */
if (!en->valid && !en->routes)
{
FIB_ITERATE_PUT(&fit, node);
fib_delete(&p->rtable, node);
goto loop;
}
}
FIB_ITERATE_END(node);
p->rt_reload = 0;
/* Handling neighbor expiration */
WALK_LIST(ifa, p->iface_list)
WALK_LIST_DELSAFE(n, nn, ifa->neigh_list)
if (n->last_seen)
{
expires = n->last_seen + n->ifa->cf->timeout_time;
if (expires <= now)
rip_remove_neighbor(p, n);
else
next = MIN(next, expires);
}
tm_start(p->timer, MAX(next - now, 1));
}
static inline void
rip_kick_timer(struct rip_proto *p)
{
if (p->timer->expires > (now + 1))
tm_start(p->timer, 1); /* Or 100 ms */
}
/**
* rip_iface_timer - RIP interface timer hook
* @t: timer
*
* RIP interface timers are responsible for scheduling both regular and
* triggered updates. Fixed, delay-independent period is used for regular
* updates, while minimal separating interval is enforced for triggered updates.
* The function also ensures that a new update is not started when the old one
* is still running.
*/
static void
rip_iface_timer(timer *t)
{
struct rip_iface *ifa = t->data;
struct rip_proto *p = ifa->rip;
bird_clock_t period = ifa->cf->update_time;
if (ifa->cf->passive)
return;
TRACE(D_EVENTS, "Interface timer fired for %s", ifa->iface->name);
if (ifa->tx_active)
{
if (now < (ifa->next_regular + period))
{ tm_start(ifa->timer, 1); return; }
/* We are too late, reset is done by rip_send_table() */
log(L_WARN "%s: Too slow update on %s, resetting", p->p.name, ifa->iface->name);
}
if (now >= ifa->next_regular)
{
/* Send regular update, set timer for next period (or following one if necessay) */
TRACE(D_EVENTS, "Sending regular updates for %s", ifa->iface->name);
rip_send_table(p, ifa, ifa->addr, 0);
ifa->next_regular += period * (1 + ((now - ifa->next_regular) / period));
ifa->want_triggered = 0;
p->triggered = 0;
}
else if (ifa->want_triggered && (now >= ifa->next_triggered))
{
/* Send triggered update, enforce interval between triggered updates */
TRACE(D_EVENTS, "Sending triggered updates for %s", ifa->iface->name);
rip_send_table(p, ifa, ifa->addr, ifa->want_triggered);
ifa->next_triggered = now + MIN(5, period / 2 + 1);
ifa->want_triggered = 0;
p->triggered = 0;
}
tm_start(ifa->timer, ifa->want_triggered ? 1 : (ifa->next_regular - now));
}
static inline void
rip_iface_kick_timer(struct rip_iface *ifa)
{
if (ifa->timer->expires > (now + 1))
tm_start(ifa->timer, 1); /* Or 100 ms */
}
static void
rip_trigger_update(struct rip_proto *p)
{
if (p->triggered)
return;
struct rip_iface *ifa;
WALK_LIST(ifa, p->iface_list)
{
/* Interface not active */
if (! ifa->up)
continue;
/* Already scheduled */
if (ifa->want_triggered)
continue;
TRACE(D_EVENTS, "Scheduling triggered updates for %s", ifa->iface->name);
ifa->want_triggered = now;
rip_iface_kick_timer(ifa);
}
p->triggered = 1;
}
/*
* RIP protocol glue
*/
static struct ea_list *
rip_prepare_attrs(struct linpool *pool, ea_list *next, u8 metric, u16 tag)
{
struct ea_list *l = lp_alloc(pool, sizeof(struct ea_list) + 2 * sizeof(eattr));
l->next = next;
l->flags = EALF_SORTED;
l->count = 2;
l->attrs[0].id = EA_RIP_METRIC;
l->attrs[0].flags = 0;
l->attrs[0].type = EAF_TYPE_INT | EAF_TEMP;
l->attrs[0].u.data = metric;
l->attrs[1].id = EA_RIP_TAG;
l->attrs[1].flags = 0;
l->attrs[1].type = EAF_TYPE_INT | EAF_TEMP;
l->attrs[1].u.data = tag;
return l;
}
static int
rip_import_control(struct proto *P, struct rte **rt, struct ea_list **attrs, struct linpool *pool)
{
/* Prepare attributes with initial values */
if ((*rt)->attrs->source != RTS_RIP)
*attrs = rip_prepare_attrs(pool, *attrs, 1, 0);
return 0;
}
static int
rip_reload_routes(struct proto *P)
{
struct rip_proto *p = (struct rip_proto *) P;
if (p->rt_reload)
return 1;
TRACE(D_EVENTS, "Scheduling route reload");
p->rt_reload = 1;
rip_kick_timer(p);
return 1;
}
static struct ea_list *
rip_make_tmp_attrs(struct rte *rt, struct linpool *pool)
{
return rip_prepare_attrs(pool, NULL, rt->u.rip.metric, rt->u.rip.tag);
}
static void
rip_store_tmp_attrs(struct rte *rt, struct ea_list *attrs)
{
2000-05-10 06:56:42 +00:00
rt->u.rip.metric = ea_get_int(attrs, EA_RIP_METRIC, 1);
rt->u.rip.tag = ea_get_int(attrs, EA_RIP_TAG, 0);
}
static int
rip_rte_better(struct rte *new, struct rte *old)
{
return new->u.rip.metric < old->u.rip.metric;
}
static int
rip_rte_same(struct rte *new, struct rte *old)
{
return ((new->u.rip.metric == old->u.rip.metric) &&
(new->u.rip.tag == old->u.rip.tag) &&
(new->u.rip.from == old->u.rip.from));
}
static struct proto *
rip_init(struct proto_config *cfg)
{
struct proto *P = proto_new(cfg, sizeof(struct rip_proto));
P->accept_ra_types = RA_OPTIMAL;
P->if_notify = rip_if_notify;
P->rt_notify = rip_rt_notify;
P->neigh_notify = rip_neigh_notify;
P->import_control = rip_import_control;
P->reload_routes = rip_reload_routes;
P->make_tmp_attrs = rip_make_tmp_attrs;
P->store_tmp_attrs = rip_store_tmp_attrs;
P->rte_better = rip_rte_better;
P->rte_same = rip_rte_same;
return P;
}
1998-10-20 16:12:43 +00:00
static int
rip_start(struct proto *P)
{
struct rip_proto *p = (void *) P;
struct rip_config *cf = (void *) (P->cf);
2000-03-29 08:58:06 +00:00
init_list(&p->iface_list);
fib_init(&p->rtable, P->pool, sizeof(struct rip_entry), 0, rip_init_entry);
p->rte_slab = sl_new(P->pool, sizeof(struct rip_rte));
p->timer = tm_new_set(P->pool, rip_timer, p, 0, 0);
p->ecmp = cf->ecmp;
p->infinity = cf->infinity;
p->triggered = 0;
p->log_pkt_tbf = (struct tbf){ .rate = 1, .burst = 5 };
p->log_rte_tbf = (struct tbf){ .rate = 4, .burst = 20 };
tm_start(p->timer, MIN(cf->min_timeout_time, cf->max_garbage_time));
return PS_UP;
}
static int
rip_reconfigure(struct proto *P, struct proto_config *c)
1998-10-20 16:12:43 +00:00
{
struct rip_proto *p = (void *) P;
struct rip_config *new = (void *) c;
// struct rip_config *old = (void *) (P->cf);
1998-10-20 16:12:43 +00:00
if (new->infinity != p->infinity)
return 0;
1998-10-20 16:12:43 +00:00
TRACE(D_EVENTS, "Reconfiguring");
p->p.cf = c;
p->ecmp = new->ecmp;
rip_reconfigure_ifaces(p, new);
p->rt_reload = 1;
rip_kick_timer(p);
return 1;
}
static void
rip_get_route_info(rte *rte, byte *buf, ea_list *attrs)
{
buf += bsprintf(buf, " (%d/%d)", rte->pref, rte->u.rip.metric);
if (rte->u.rip.tag)
bsprintf(buf, " [%04x]", rte->u.rip.tag);
}
static int
rip_get_attr(eattr *a, byte *buf, int buflen UNUSED)
{
switch (a->id)
{
case EA_RIP_METRIC:
bsprintf(buf, "metric: %d", a->u.data);
return GA_FULL;
case EA_RIP_TAG:
bsprintf(buf, "tag: %04x", a->u.data);
return GA_FULL;
default:
return GA_UNKNOWN;
}
}
void
rip_show_interfaces(struct proto *P, char *iff)
{
struct rip_proto *p = (void *) P;
struct rip_iface *ifa = NULL;
struct rip_neighbor *n = NULL;
if (p->p.proto_state != PS_UP)
{
cli_msg(-1021, "%s: is not up", p->p.name);
cli_msg(0, "");
return;
}
cli_msg(-1021, "%s:", p->p.name);
cli_msg(-1021, "%-10s %-6s %6s %6s %6s",
"Interface", "State", "Metric", "Nbrs", "Timer");
WALK_LIST(ifa, p->iface_list)
{
if (iff && !patmatch(iff, ifa->iface->name))
continue;
int nbrs = 0;
WALK_LIST(n, ifa->neigh_list)
if (n->last_seen)
nbrs++;
int timer = MAX(ifa->next_regular - now, 0);
cli_msg(-1021, "%-10s %-6s %6u %6u %6u",
ifa->iface->name, (ifa->up ? "Up" : "Down"), ifa->cf->metric, nbrs, timer);
}
cli_msg(0, "");
}
void
rip_show_neighbors(struct proto *P, char *iff)
2000-05-10 12:32:45 +00:00
{
struct rip_proto *p = (void *) P;
struct rip_iface *ifa = NULL;
struct rip_neighbor *n = NULL;
2000-05-10 12:32:45 +00:00
if (p->p.proto_state != PS_UP)
{
cli_msg(-1022, "%s: is not up", p->p.name);
cli_msg(0, "");
return;
}
cli_msg(-1022, "%s:", p->p.name);
cli_msg(-1022, "%-25s %-10s %6s %6s %6s",
"IP address", "Interface", "Metric", "Routes", "Seen");
WALK_LIST(ifa, p->iface_list)
{
if (iff && !patmatch(iff, ifa->iface->name))
continue;
WALK_LIST(n, ifa->neigh_list)
{
if (!n->last_seen)
continue;
int timer = now - n->last_seen;
cli_msg(-1022, "%-25I %-10s %6u %6u %6u",
n->nbr->addr, ifa->iface->name, ifa->cf->metric, n->uc, timer);
}
}
cli_msg(0, "");
2000-05-10 12:32:45 +00:00
}
static void
rip_dump(struct proto *P)
{
struct rip_proto *p = (struct rip_proto *) P;
struct rip_iface *ifa;
int i;
i = 0;
FIB_WALK(&p->rtable, e)
{
struct rip_entry *en = (struct rip_entry *) e;
debug("RIP: entry #%d: %I/%d via %I dev %s valid %d metric %d age %d s\n",
i++, en->n.prefix, en->n.pxlen, en->next_hop, en->iface->name,
en->valid, en->metric, now - en->changed);
}
FIB_WALK_END;
i = 0;
WALK_LIST(ifa, p->iface_list)
{
debug("RIP: interface #%d: %s, %I, up = %d, busy = %d\n",
i++, ifa->iface->name, ifa->sk ? ifa->sk->daddr : IPA_NONE,
ifa->up, ifa->tx_active);
}
}
struct protocol proto_rip = {
.name = "RIP",
.template = "rip%d",
.attr_class = EAP_RIP,
.preference = DEF_PREF_RIP,
.config_size = sizeof(struct rip_config),
.init = rip_init,
.dump = rip_dump,
.start = rip_start,
.reconfigure = rip_reconfigure,
.get_route_info = rip_get_route_info,
.get_attr = rip_get_attr
};