/**
* DOC: Router Advertisements
*
- * The RAdv protocol is implemented in two files: |radv.c| containing
- * the interface with BIRD core and the protocol logic and |packets.c|
- * handling low level protocol stuff (RX, TX and packet formats).
- * The protocol does not export any routes.
+ * The RAdv protocol is implemented in two files: |radv.c| containing the
+ * interface with BIRD core and the protocol logic and |packets.c| handling low
+ * level protocol stuff (RX, TX and packet formats). The protocol does not
+ * export any routes.
*
- * The RAdv is structured in the usual way - for each handled interface
- * there is a structure &radv_iface that contains a state related to
- * that interface together with its resources (a socket, a timer).
- * There is also a prepared RA stored in a TX buffer of the socket
- * associated with an iface. These iface structures are created
- * and removed according to iface events from BIRD core handled by
- * radv_if_notify() callback.
+ * The RAdv is structured in the usual way - for each handled interface there is
+ * a structure &radv_iface that contains a state related to that interface
+ * together with its resources (a socket, a timer). There is also a prepared RA
+ * stored in a TX buffer of the socket associated with an iface. These iface
+ * structures are created and removed according to iface events from BIRD core
+ * handled by radv_if_notify() callback.
*
- * The main logic of RAdv consists of two functions:
- * radv_iface_notify(), which processes asynchronous events (specified
- * by RA_EV_* codes), and radv_timer(), which triggers sending RAs and
- * computes the next timeout.
+ * The main logic of RAdv consists of two functions: radv_iface_notify(), which
+ * processes asynchronous events (specified by RA_EV_* codes), and radv_timer(),
+ * which triggers sending RAs and computes the next timeout.
*
- * The RAdv protocol could receive routes (through
- * radv_import_control() and radv_rt_notify()), but only the
- * configured trigger route is tracked (in &active var). When a radv
- * protocol is reconfigured, the connected routing table is examined
- * (in radv_check_active()) to have proper &active value in case of
- * the specified trigger prefix was changed.
+ * The RAdv protocol could receive routes (through radv_import_control() and
+ * radv_rt_notify()), but only the configured trigger route is tracked (in
+ * &active var). When a radv protocol is reconfigured, the connected routing
+ * table is examined (in radv_check_active()) to have proper &active value in
+ * case of the specified trigger prefix was changed.
*
* Supported standards:
* - RFC 4861 - main RA standard
+ * - RFC 4191 - Default Router Preferences and More-Specific Routes
* - RFC 6106 - DNS extensions (RDDNS, DNSSL)
- * - RFC 4191 (partial) - Default Router Preference
*/
+static void radv_prune_prefixes(struct radv_iface *ifa);
+static void radv_prune_routes(struct radv_proto *p);
+
+/* Invalidate cached RA packet */
+static inline void radv_invalidate(struct radv_iface *ifa)
+{ ifa->plen = 0; }
+
static void
radv_timer(timer *tm)
{
struct radv_iface *ifa = tm->data;
struct radv_proto *p = ifa->ra;
+ btime now = current_time();
RADV_TRACE(D_EVENTS, "Timer fired on %s", ifa->iface->name);
- /*
- * If some dead prefixes expired, regenerate the prefix list and the packet.
- * We do so by pretending there was a change on the interface.
- *
- * This sets the timer, but we replace it just at the end of this function
- * (replacing a timer is fine).
- */
- if (ifa->prefix_expires && (ifa->prefix_expires <= now))
- radv_iface_notify(ifa, RA_EV_GC);
+ if (ifa->valid_time <= now)
+ radv_invalidate(ifa);
- radv_send_ra(ifa, 0);
+ if (ifa->prune_time <= now)
+ radv_prune_prefixes(ifa);
+
+ if (p->prune_time <= now)
+ radv_prune_routes(p);
+
+ radv_send_ra(ifa);
/* Update timer */
ifa->last = now;
- unsigned after = ifa->cf->min_ra_int;
- after += random() % (ifa->cf->max_ra_int - ifa->cf->min_ra_int + 1);
+ btime t = ifa->cf->min_ra_int S;
+ btime r = (ifa->cf->max_ra_int - ifa->cf->min_ra_int) S;
+ t += random() % (r + 1);
if (ifa->initial)
+ {
+ t = MIN(t, MAX_INITIAL_RTR_ADVERT_INTERVAL);
ifa->initial--;
+ }
- if (ifa->initial)
- after = MIN(after, MAX_INITIAL_RTR_ADVERT_INTERVAL);
-
- tm_start(ifa->timer, after);
+ tm_start(ifa->timer, t);
}
static struct radv_prefix_config default_prefix = {
/* Find a corresponding config for the given prefix */
static struct radv_prefix_config *
-radv_prefix_match(struct radv_iface *ifa, struct ifa *a)
+radv_prefix_match(struct radv_iface *ifa, net_addr_ip6 *px)
{
struct radv_proto *p = ifa->ra;
struct radv_config *cf = (struct radv_config *) (p->p.cf);
struct radv_prefix_config *pc;
- if (a->scope <= SCOPE_LINK)
- return NULL;
-
WALK_LIST(pc, ifa->cf->pref_list)
- if ((a->pxlen >= pc->pxlen) && ipa_in_net(a->prefix, pc->prefix, pc->pxlen))
+ if (net_in_net_ip6(px, &pc->prefix))
return pc;
WALK_LIST(pc, cf->pref_list)
- if ((a->pxlen >= pc->pxlen) && ipa_in_net(a->prefix, pc->prefix, pc->pxlen))
+ if (net_in_net_ip6(px, &pc->prefix))
return pc;
return &default_prefix;
radv_prepare_prefixes(struct radv_iface *ifa)
{
struct radv_proto *p = ifa->ra;
- struct radv_iface_config *cf = ifa->cf;
- struct radv_prefix *pfx;
+ struct radv_prefix *pfx, *next;
+ btime now = current_time();
/* First mark all the prefixes as unused */
WALK_LIST(pfx, ifa->prefixes)
struct ifa *addr;
WALK_LIST(addr, ifa->iface->addrs)
{
- struct radv_prefix_config *pc = radv_prefix_match(ifa, addr);
+ if ((addr->prefix.type != NET_IP6) ||
+ (addr->scope <= SCOPE_LINK))
+ continue;
+
+ net_addr_ip6 *prefix = (void *) &addr->prefix;
+ struct radv_prefix_config *pc = radv_prefix_match(ifa, prefix);
if (!pc || pc->skip)
continue;
/* Do we have it already? */
struct radv_prefix *existing = NULL;
WALK_LIST(pfx, ifa->prefixes)
- if ((pfx->len == addr->pxlen) && ipa_equal(pfx->prefix, addr->prefix))
+ if (net_equal_ip6(&pfx->prefix, prefix))
{
existing = pfx;
break;
if (!existing)
{
- RADV_TRACE(D_EVENTS, "Adding new prefix %I/%d on %s",
- addr->prefix, addr->pxlen, ifa->iface->name);
+ RADV_TRACE(D_EVENTS, "Adding new prefix %N on %s",
+ prefix, ifa->iface->name);
existing = mb_allocz(ifa->pool, sizeof *existing);
- existing->prefix = addr->prefix;
- existing->len = addr->pxlen;
+ net_copy_ip6(&existing->prefix, prefix);
add_tail(&ifa->prefixes, NODE existing);
}
* Update the information (it may have changed, or even bring a prefix back
* to life).
*/
- existing->alive = 1;
+ existing->valid = 1;
+ existing->changed = now;
existing->mark = 1;
existing->cf = pc;
}
- /*
- * Garbage-collect the prefixes. If something isn't used, it dies (but isn't
- * dropped just yet). If something is dead and rots there for long enough,
- * clean it up.
- */
- bird_clock_t expires = now + cf->linger_time;
- bird_clock_t expires_min = 0;
- struct radv_prefix *next;
WALK_LIST_DELSAFE(pfx, next, ifa->prefixes)
{
- if (pfx->alive && !pfx->mark)
+ if (pfx->valid && !pfx->mark)
{
- RADV_TRACE(D_EVENTS, "Marking prefix %I/$d on %s as dead",
- pfx->prefix, pfx->len, ifa->iface->name);
+ RADV_TRACE(D_EVENTS, "Invalidating prefix %N on %s",
+ &pfx->prefix, ifa->iface->name);
- pfx->alive = 0;
- pfx->expires = expires;
+ pfx->valid = 0;
+ pfx->changed = now;
pfx->cf = &dead_prefix;
}
+ }
+}
- if (!pfx->alive)
+static void
+radv_prune_prefixes(struct radv_iface *ifa)
+{
+ struct radv_proto *p = ifa->ra;
+ btime now = current_time();
+ btime next = TIME_INFINITY;
+ btime expires = 0;
+
+ struct radv_prefix *px, *pxn;
+ WALK_LIST_DELSAFE(px, pxn, ifa->prefixes)
+ {
+ if (!px->valid)
{
- if (pfx->expires <= now)
+ expires = px->changed + ifa->cf->prefix_linger_time S;
+
+ if (expires <= now)
{
- RADV_TRACE(D_EVENTS, "Removing prefix %I/%d on %s",
- pfx->prefix, pfx->len, ifa->iface->name);
+ RADV_TRACE(D_EVENTS, "Removing prefix %N on %s",
+ &px->prefix, ifa->iface->name);
- rem_node(NODE pfx);
- mb_free(pfx);
+ rem_node(NODE px);
+ mb_free(px);
}
else
- {
- /* Find minimum expiration time */
- if (!expires_min || (pfx->expires < expires_min))
- expires_min = pfx->expires;
- }
+ next = MIN(next, expires);
}
}
- ifa->prefix_expires = expires_min;
+ ifa->prune_time = next;
}
-static char* ev_name[] = { NULL, "Init", "Change", "RS", "Garbage collect" };
+static char* ev_name[] = { NULL, "Init", "Change", "RS" };
void
radv_iface_notify(struct radv_iface *ifa, int event)
switch (event)
{
case RA_EV_CHANGE:
- case RA_EV_GC:
- ifa->plen = 0;
+ radv_invalidate(ifa);
+ /* fallthrough */
case RA_EV_INIT:
ifa->initial = MAX_INITIAL_RTR_ADVERTISEMENTS;
+ radv_prepare_prefixes(ifa);
+ radv_prune_prefixes(ifa);
break;
case RA_EV_RS:
break;
}
- radv_prepare_prefixes(ifa);
-
/* Update timer */
- unsigned delta = now - ifa->last;
- unsigned after = 0;
-
- if (delta < ifa->cf->min_delay)
- after = ifa->cf->min_delay - delta;
-
- tm_start(ifa->timer, after);
+ btime t = ifa->last + ifa->cf->min_delay S - current_time();
+ tm_start(ifa->timer, t);
}
static void
radv_iface_notify(ifa, event);
}
-
static struct radv_iface *
radv_iface_find(struct radv_proto *p, struct iface *what)
{
radv_iface_notify(ifa, RA_EV_INIT);
}
-static inline struct ifa *
-find_lladdr(struct iface *iface)
-{
- struct ifa *a;
- WALK_LIST(a, iface->addrs)
- if (a->scope == SCOPE_LINK)
- return a;
-
- return NULL;
-}
-
static void
radv_iface_new(struct radv_proto *p, struct iface *iface, struct radv_iface_config *cf)
{
ifa->ra = p;
ifa->cf = cf;
ifa->iface = iface;
+ ifa->addr = iface->llv6;
init_list(&ifa->prefixes);
+ ifa->prune_time = TIME_INFINITY;
add_tail(&p->iface_list, NODE ifa);
- ifa->addr = find_lladdr(iface);
- if (!ifa->addr)
- {
- log(L_ERR "%s: Missing link-local address on interface %s", p->p.name, iface->name);
- return;
- }
-
- timer *tm = tm_new(pool);
- tm->hook = radv_timer;
- tm->data = ifa;
- tm->randomize = 0;
- tm->recurrent = 0;
- ifa->timer = tm;
+ ifa->timer = tm_new_init(pool, radv_timer, ifa, 0, 0);
struct object_lock *lock = olock_new(pool);
- lock->addr = IPA_NONE;
lock->type = OBJLOCK_IP;
lock->port = ICMPV6_PROTO;
lock->iface = iface;
if (flags & IF_CHANGE_UP)
{
- struct radv_iface_config *ic = (struct radv_iface_config *)
- iface_patt_find(&cf->patt_list, iface, NULL);
+ struct radv_iface_config *ic = (void *) iface_patt_find(&cf->patt_list, iface, NULL);
+
+ /* Ignore non-multicast ifaces */
+ if (!(iface->flags & IF_MULTICAST))
+ return;
+
+ /* Ignore ifaces without link-local address */
+ if (!iface->llv6)
+ return;
if (ic)
radv_iface_new(p, iface, ic);
radv_iface_notify(ifa, RA_EV_CHANGE);
}
-static inline int radv_net_match_trigger(struct radv_config *cf, net *n)
+static inline int
+radv_trigger_valid(struct radv_config *cf)
+{
+ return cf->trigger.type != 0;
+}
+
+static inline int
+radv_net_match_trigger(struct radv_config *cf, net *n)
{
- return cf->trigger_valid &&
- (n->n.pxlen == cf->trigger_pxlen) &&
- ipa_equal(n->n.prefix, cf->trigger_prefix);
+ return radv_trigger_valid(cf) && net_equal(n->n.addr, &cf->trigger);
}
int
-radv_import_control(struct proto *P, rte **new, ea_list **attrs UNUSED, struct linpool *pool UNUSED)
+radv_import_control(struct proto *P, rte **new, struct linpool *pool UNUSED)
{
// struct radv_proto *p = (struct radv_proto *) P;
struct radv_config *cf = (struct radv_config *) (P->cf);
if (radv_net_match_trigger(cf, (*new)->net))
return RIC_PROCESS;
- return RIC_DROP;
+ if (cf->propagate_routes)
+ return RIC_PROCESS;
+ else
+ return RIC_DROP;
}
static void
-radv_rt_notify(struct proto *P, rtable *tbl UNUSED, net *n, rte *new, rte *old UNUSED, ea_list *attrs UNUSED)
+radv_rt_notify(struct proto *P, struct channel *ch UNUSED, net *n, rte *new, rte *old UNUSED)
{
struct radv_proto *p = (struct radv_proto *) P;
struct radv_config *cf = (struct radv_config *) (P->cf);
+ struct radv_route *rt;
+ eattr *ea;
if (radv_net_match_trigger(cf, n))
{
RADV_TRACE(D_EVENTS, "Suppressed");
radv_iface_notify_all(p, RA_EV_CHANGE);
+ return;
+ }
+
+ if (!cf->propagate_routes)
+ return;
+
+ /*
+ * Some other route we want to send (or stop sending). Update the cache,
+ * with marking a removed one as dead or creating a new one as needed.
+ *
+ * And yes, we exclude the trigger route on purpose.
+ */
+
+ if (new)
+ {
+ /* Update */
+
+ ea = ea_find(new->attrs->eattrs, EA_RA_PREFERENCE);
+ uint preference = ea ? ea->u.data : RA_PREF_MEDIUM;
+ uint preference_set = !!ea;
+
+ ea = ea_find(new->attrs->eattrs, EA_RA_LIFETIME);
+ uint lifetime = ea ? ea->u.data : 0;
+ uint lifetime_set = !!ea;
+
+ if ((preference != RA_PREF_LOW) &&
+ (preference != RA_PREF_MEDIUM) &&
+ (preference != RA_PREF_HIGH))
+ {
+ log(L_WARN "%s: Invalid ra_preference value %u on route %N",
+ p->p.name, preference, n->n.addr);
+ preference = RA_PREF_MEDIUM;
+ preference_set = 1;
+ lifetime = 0;
+ lifetime_set = 1;
+ }
+
+ rt = fib_get(&p->routes, n->n.addr);
+
+ /* Ignore update if nothing changed */
+ if (rt->valid &&
+ (rt->preference == preference) &&
+ (rt->preference_set == preference_set) &&
+ (rt->lifetime == lifetime) &&
+ (rt->lifetime_set == lifetime_set))
+ return;
+
+ if (p->routes.entries == 18)
+ log(L_WARN "%s: More than 17 routes exported to RAdv", p->p.name);
+
+ rt->valid = 1;
+ rt->changed = current_time();
+ rt->preference = preference;
+ rt->preference_set = preference_set;
+ rt->lifetime = lifetime;
+ rt->lifetime_set = lifetime_set;
+ }
+ else
+ {
+ /* Withdraw */
+ rt = fib_find(&p->routes, n->n.addr);
+
+ if (!rt || !rt->valid)
+ return;
+
+ /* Invalidate the route */
+ rt->valid = 0;
+ rt->changed = current_time();
+
+ /* Invalidated route will be pruned eventually */
+ btime expires = rt->changed + cf->max_linger_time S;
+ p->prune_time = MIN(p->prune_time, expires);
+ }
+
+ radv_iface_notify_all(p, RA_EV_CHANGE);
+}
+
+/*
+ * Cleans up all the dead routes that expired and schedules itself to be run
+ * again if there are more routes waiting for expiration.
+ */
+static void
+radv_prune_routes(struct radv_proto *p)
+{
+ struct radv_config *cf = (struct radv_config *) (p->p.cf);
+ btime now = current_time();
+ btime next = TIME_INFINITY;
+ btime expires = 0;
+
+ /* Should not happen */
+ if (!p->fib_up)
+ return;
+
+ struct fib_iterator fit;
+ FIB_ITERATE_INIT(&fit, &p->routes);
+
+again:
+ FIB_ITERATE_START(&p->routes, &fit, struct radv_route, rt)
+ {
+ if (!rt->valid)
+ {
+ expires = rt->changed + cf->max_linger_time S;
+
+ /* Delete expired nodes */
+ if (expires <= now)
+ {
+ FIB_ITERATE_PUT(&fit);
+ fib_delete(&p->routes, rt);
+ goto again;
+ }
+ else
+ next = MIN(next, expires);
+ }
}
+ FIB_ITERATE_END;
+
+ p->prune_time = next;
}
static int
{
struct radv_config *cf = (struct radv_config *) (p->p.cf);
- if (! cf->trigger_valid)
+ if (!radv_trigger_valid(cf))
return 1;
- return rt_examine(p->p.table, cf->trigger_prefix, cf->trigger_pxlen,
- &(p->p), p->p.cf->out_filter);
+ struct channel *c = p->p.main_channel;
+ return rt_examine(c->table, &cf->trigger, &p->p, c->out_filter);
+}
+
+static void
+radv_postconfig(struct proto_config *CF)
+{
+ // struct radv_config *cf = (void *) CF;
+
+ /* Define default channel */
+ if (EMPTY_LIST(CF->channels))
+ channel_config_new(NULL, net_label[NET_IP6], NET_IP6, CF);
}
static struct proto *
-radv_init(struct proto_config *c)
+radv_init(struct proto_config *CF)
{
- struct proto *P = proto_new(c, sizeof(struct radv_proto));
+ struct proto *P = proto_new(CF);
+
+ P->main_channel = proto_add_channel(P, proto_cf_main_channel(CF));
- P->accept_ra_types = RA_OPTIMAL;
P->import_control = radv_import_control;
P->rt_notify = radv_rt_notify;
P->if_notify = radv_if_notify;
return P;
}
+static void
+radv_set_fib(struct radv_proto *p, int up)
+{
+ if (up == p->fib_up)
+ return;
+
+ if (up)
+ fib_init(&p->routes, p->p.pool, NET_IP6, sizeof(struct radv_route),
+ OFFSETOF(struct radv_route, n), 4, NULL);
+ else
+ fib_free(&p->routes);
+
+ p->fib_up = up;
+ p->prune_time = TIME_INFINITY;
+}
+
static int
radv_start(struct proto *P)
{
struct radv_config *cf = (struct radv_config *) (P->cf);
init_list(&(p->iface_list));
- p->active = !cf->trigger_valid;
+ p->valid = 1;
+ p->active = !radv_trigger_valid(cf);
+
+ p->fib_up = 0;
+ radv_set_fib(p, cf->propagate_routes);
+ p->prune_time = TIME_INFINITY;
return PS_UP;
}
radv_iface_shutdown(struct radv_iface *ifa)
{
if (ifa->sk)
- radv_send_ra(ifa, 1);
+ {
+ radv_invalidate(ifa);
+ radv_send_ra(ifa);
+ }
}
static int
{
struct radv_proto *p = (struct radv_proto *) P;
+ p->valid = 0;
+
struct radv_iface *ifa;
WALK_LIST(ifa, p->iface_list)
radv_iface_shutdown(ifa);
}
static int
-radv_reconfigure(struct proto *P, struct proto_config *c)
+radv_reconfigure(struct proto *P, struct proto_config *CF)
{
struct radv_proto *p = (struct radv_proto *) P;
- // struct radv_config *old = (struct radv_config *) (p->cf);
- struct radv_config *new = (struct radv_config *) c;
+ struct radv_config *old = (struct radv_config *) (P->cf);
+ struct radv_config *new = (struct radv_config *) CF;
- /*
- * The question is why there is a reconfigure function for RAdv if
- * it has almost none internal state so restarting the protocol
- * would probably suffice. One small reason is that restarting the
- * protocol would lead to sending a RA with Router Lifetime 0
- * causing nodes to temporary remove their default routes.
- */
+ if (!proto_configure_channel(P, &P->main_channel, proto_cf_main_channel(CF)))
+ return 0;
- P->cf = c; /* radv_check_active() requires proper P->cf */
+ P->cf = CF; /* radv_check_active() requires proper P->cf */
p->active = radv_check_active(p);
+ /* Allocate or free FIB */
+ radv_set_fib(p, new->propagate_routes);
+
+ /* We started to accept routes so we need to refeed them */
+ if (!old->propagate_routes && new->propagate_routes)
+ channel_request_feeding(p->p.main_channel);
+
struct iface *iface;
WALK_LIST(iface, iface_list)
{
+ if (!(iface->flags & IF_UP))
+ continue;
+
+ /* Ignore non-multicast ifaces */
+ if (!(iface->flags & IF_MULTICAST))
+ continue;
+
+ /* Ignore ifaces without link-local address */
+ if (!iface->llv6)
+ continue;
+
struct radv_iface *ifa = radv_iface_find(p, iface);
struct radv_iface_config *ic = (struct radv_iface_config *)
iface_patt_find(&new->patt_list, iface, NULL);
strcpy(buf, "Suppressed");
}
+static const char *
+radv_pref_str(u32 pref)
+{
+ switch (pref)
+ {
+ case RA_PREF_LOW:
+ return "low";
+ case RA_PREF_MEDIUM:
+ return "medium";
+ case RA_PREF_HIGH:
+ return "high";
+ default:
+ return "??";
+ }
+}
+
+/* The buffer has some minimal size */
+static int
+radv_get_attr(eattr *a, byte *buf, int buflen UNUSED)
+{
+ switch (a->id)
+ {
+ case EA_RA_PREFERENCE:
+ bsprintf(buf, "preference: %s", radv_pref_str(a->u.data));
+ return GA_FULL;
+ case EA_RA_LIFETIME:
+ bsprintf(buf, "lifetime");
+ return GA_NAME;
+ default:
+ return GA_UNKNOWN;
+ }
+}
+
struct protocol proto_radv = {
.name = "RAdv",
.template = "radv%d",
+ .class = PROTOCOL_RADV,
+ .channel_mask = NB_IP6,
+ .proto_size = sizeof(struct radv_proto),
.config_size = sizeof(struct radv_config),
+ .postconfig = radv_postconfig,
.init = radv_init,
.start = radv_start,
.shutdown = radv_shutdown,
.reconfigure = radv_reconfigure,
.copy_config = radv_copy_config,
- .get_status = radv_get_status
+ .get_status = radv_get_status,
+ .get_attr = radv_get_attr
};
projects / thirdparty / bird.git / blobdiff