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-rw-r--r--proto/babel/babel.c305
-rw-r--r--proto/babel/babel.h24
2 files changed, 187 insertions, 142 deletions
diff --git a/proto/babel/babel.c b/proto/babel/babel.c
index f5aef492..68b32e8f 100644
--- a/proto/babel/babel.c
+++ b/proto/babel/babel.c
@@ -48,19 +48,20 @@
static inline int ge_mod64k(uint a, uint b)
{ return (u16)(a - b) < 0x8000; }
-static void babel_dump_entry(struct babel_entry *e);
-static void babel_dump_route(struct babel_route *r);
+static void babel_expire_requests(struct babel_proto *p, struct babel_entry *e);
static void babel_select_route(struct babel_proto *p, struct babel_entry *e);
static void babel_send_route_request(struct babel_proto *p, struct babel_entry *e, struct babel_neighbor *n);
-static void babel_send_wildcard_request(struct babel_iface *ifa);
-static int babel_cache_seqno_request(struct babel_proto *p, net_addr *n, u64 router_id, u16 seqno);
-static void babel_trigger_iface_update(struct babel_iface *ifa);
-static void babel_trigger_update(struct babel_proto *p);
-static void babel_send_seqno_request(struct babel_proto *p, struct babel_entry *e);
+static void babel_send_seqno_request(struct babel_proto *p, struct babel_entry *e, struct babel_seqno_request *sr);
static void babel_update_cost(struct babel_neighbor *n);
static inline void babel_kick_timer(struct babel_proto *p);
static inline void babel_iface_kick_timer(struct babel_iface *ifa);
+static inline void babel_lock_neighbor(struct babel_neighbor *nbr)
+{ if (nbr) nbr->uc++; }
+
+static inline void babel_unlock_neighbor(struct babel_neighbor *nbr)
+{ if (nbr && !--nbr->uc) mb_free(nbr); }
+
/*
* Functions to maintain data structures
@@ -72,6 +73,7 @@ babel_init_entry(void *E)
struct babel_entry *e = E;
e->updated = current_time();
+ init_list(&e->requests);
init_list(&e->sources);
init_list(&e->routes);
}
@@ -260,9 +262,10 @@ loop:
}
babel_expire_sources(p, e);
+ babel_expire_requests(p, e);
/* Remove empty entries */
- if (EMPTY_LIST(e->sources) && EMPTY_LIST(e->routes))
+ if (EMPTY_LIST(e->sources) && EMPTY_LIST(e->routes) && EMPTY_LIST(e->requests))
{
FIB_ITERATE_PUT(&fit);
fib_delete(rtable, e);
@@ -279,6 +282,110 @@ babel_expire_routes(struct babel_proto *p)
babel_expire_routes_(p, &p->ip6_rtable);
}
+static inline int seqno_request_valid(struct babel_seqno_request *sr)
+{ return !sr->nbr || sr->nbr->ifa; }
+
+/*
+ * Add seqno request to the table of pending requests (RFC 6216 3.2.6) and send
+ * it to network. Do nothing if it is already in the table.
+ */
+
+static void
+babel_add_seqno_request(struct babel_proto *p, struct babel_entry *e,
+ u64 router_id, u16 seqno, u8 hop_count,
+ struct babel_neighbor *nbr)
+{
+ struct babel_seqno_request *sr;
+
+ WALK_LIST(sr, e->requests)
+ if (sr->router_id == router_id)
+ {
+ /* Found matching or newer */
+ if (ge_mod64k(sr->seqno, seqno) && seqno_request_valid(sr))
+ return;
+
+ /* Found older */
+ babel_unlock_neighbor(sr->nbr);
+ rem_node(NODE sr);
+ goto found;
+ }
+
+ /* No entries found */
+ sr = sl_alloc(p->seqno_slab);
+
+found:
+ sr->router_id = router_id;
+ sr->seqno = seqno;
+ sr->hop_count = hop_count;
+ sr->count = 0;
+ sr->expires = current_time() + BABEL_SEQNO_REQUEST_EXPIRY;
+ babel_lock_neighbor(sr->nbr = nbr);
+ add_tail(&e->requests, NODE sr);
+
+ babel_send_seqno_request(p, e, sr);
+}
+
+static void
+babel_remove_seqno_request(struct babel_proto *p, struct babel_seqno_request *sr)
+{
+ babel_unlock_neighbor(sr->nbr);
+ rem_node(NODE sr);
+ sl_free(p->seqno_slab, sr);
+}
+
+static int
+babel_satisfy_seqno_request(struct babel_proto *p, struct babel_entry *e,
+ u64 router_id, u16 seqno)
+{
+ struct babel_seqno_request *sr;
+
+ WALK_LIST(sr, e->requests)
+ if ((sr->router_id == router_id) && ge_mod64k(seqno, sr->seqno))
+ {
+ /* Found the request, remove it */
+ babel_remove_seqno_request(p, sr);
+ return 1;
+ }
+
+ return 0;
+}
+
+static void
+babel_expire_requests(struct babel_proto *p, struct babel_entry *e)
+{
+ struct babel_seqno_request *sr, *srx;
+ btime now_ = current_time();
+
+ WALK_LIST_DELSAFE(sr, srx, e->requests)
+ {
+ /* Remove seqno requests sent to dead neighbors */
+ if (!seqno_request_valid(sr))
+ {
+ babel_remove_seqno_request(p, sr);
+ continue;
+ }
+
+ /* Handle expired requests - resend or remove */
+ if (sr->expires && sr->expires <= now_)
+ {
+ if (sr->count < BABEL_SEQNO_REQUEST_RETRY)
+ {
+ sr->count++;
+ sr->expires += (BABEL_SEQNO_REQUEST_EXPIRY << sr->count);
+ babel_send_seqno_request(p, e, sr);
+ }
+ else
+ {
+ TRACE(D_EVENTS, "Seqno request for %N router-id %lR expired",
+ e->n.addr, sr->router_id);
+
+ babel_remove_seqno_request(p, sr);
+ continue;
+ }
+ }
+ }
+}
+
static struct babel_neighbor *
babel_find_neighbor(struct babel_iface *ifa, ip_addr addr)
{
@@ -309,6 +416,7 @@ babel_get_neighbor(struct babel_iface *ifa, ip_addr addr)
nbr->txcost = BABEL_INFINITY;
nbr->cost = BABEL_INFINITY;
init_list(&nbr->routes);
+ babel_lock_neighbor(nbr);
add_tail(&ifa->neigh_list, NODE nbr);
return nbr;
@@ -333,8 +441,9 @@ babel_flush_neighbor(struct babel_proto *p, struct babel_neighbor *nbr)
babel_select_route(p, e);
}
+ nbr->ifa = NULL;
rem_node(NODE nbr);
- mb_free(nbr);
+ babel_unlock_neighbor(nbr);
}
static void
@@ -588,14 +697,14 @@ babel_select_route(struct babel_proto *p, struct babel_entry *e)
(as unreachable), then send a seqno request.
babel_build_rte() will set the unreachable flag if the metric is BABEL_INFINITY.*/
- if (e->selected_in)
+ if (best)
{
TRACE(D_EVENTS, "Lost feasible route for prefix %N", e->n.addr);
- e->selected_in->metric = e->selected_in->advert_metric = BABEL_INFINITY;
+ best->metric = best->advert_metric = BABEL_INFINITY;
e->updated = current_time();
- babel_send_seqno_request(p, e);
+ babel_add_seqno_request(p, e, best->router_id, best->seqno + 1, 0, NULL);
babel_announce_rte(p, e);
/* Section 3.6 of the RFC forbids an infeasible from being selected. This
@@ -695,7 +804,6 @@ babel_send_hello(struct babel_iface *ifa)
static void
babel_send_route_request(struct babel_proto *p, struct babel_entry *e, struct babel_neighbor *n)
{
- struct babel_iface *ifa = n->ifa;
union babel_msg msg = {};
TRACE(D_PACKETS, "Sending route request for %N to %I",
@@ -704,7 +812,7 @@ babel_send_route_request(struct babel_proto *p, struct babel_entry *e, struct ba
msg.type = BABEL_TLV_ROUTE_REQUEST;
net_copy(&msg.route_request.net, e->n.addr);
- babel_send_unicast(&msg, ifa, n->addr);
+ babel_send_unicast(&msg, n->ifa, n->addr);
}
static void
@@ -723,48 +831,32 @@ babel_send_wildcard_request(struct babel_iface *ifa)
}
static void
-babel_send_seqno_request(struct babel_proto *p, struct babel_entry *e)
+babel_send_seqno_request(struct babel_proto *p, struct babel_entry *e, struct babel_seqno_request *sr)
{
- struct babel_route *r = e->selected_in;
- struct babel_iface *ifa = NULL;
- struct babel_source *s = NULL;
union babel_msg msg = {};
- s = babel_find_source(e, r->router_id);
- if (!s || !babel_cache_seqno_request(p, e->n.addr, r->router_id, s->seqno + 1))
- return;
-
- TRACE(D_PACKETS, "Sending seqno request for %N router-id %lR seqno %d",
- e->n.addr, r->router_id, s->seqno + 1);
-
msg.type = BABEL_TLV_SEQNO_REQUEST;
- msg.seqno_request.hop_count = BABEL_INITIAL_HOP_COUNT;
- msg.seqno_request.seqno = s->seqno + 1;
- msg.seqno_request.router_id = r->router_id;
+ msg.seqno_request.hop_count = sr->hop_count ?: BABEL_INITIAL_HOP_COUNT;
+ msg.seqno_request.seqno = sr->seqno;
+ msg.seqno_request.router_id = sr->router_id;
net_copy(&msg.seqno_request.net, e->n.addr);
- WALK_LIST(ifa, p->interfaces)
- babel_enqueue(&msg, ifa);
-}
-
-static void
-babel_unicast_seqno_request(struct babel_proto *p, struct babel_entry *e, struct babel_source *s, struct babel_neighbor *nbr)
-{
- union babel_msg msg = {};
-
- if (!s || !babel_cache_seqno_request(p, e->n.addr, s->router_id, s->seqno + 1))
- return;
-
- TRACE(D_PACKETS, "Sending seqno request for %N router-id %lR seqno %d",
- e->n.addr, s->router_id, s->seqno + 1);
+ if (sr->nbr)
+ {
+ TRACE(D_PACKETS, "Sending seqno request for %N router-id %lR seqno %d to %I on %s",
+ e->n.addr, sr->router_id, sr->seqno, sr->nbr->addr, sr->nbr->ifa->ifname);
- msg.type = BABEL_TLV_SEQNO_REQUEST;
- msg.seqno_request.hop_count = BABEL_INITIAL_HOP_COUNT;
- msg.seqno_request.seqno = s->seqno + 1;
- msg.seqno_request.router_id = s->router_id;
- net_copy(&msg.seqno_request.net, e->n.addr);
+ babel_send_unicast(&msg, sr->nbr->ifa, sr->nbr->addr);
+ }
+ else
+ {
+ TRACE(D_PACKETS, "Sending broadcast seqno request for %N router-id %lR seqno %d",
+ e->n.addr, sr->router_id, sr->seqno);
- babel_send_unicast(&msg, nbr->ifa, nbr->addr);
+ struct babel_iface *ifa;
+ WALK_LIST(ifa, p->interfaces)
+ babel_enqueue(&msg, ifa);
+ }
}
/**
@@ -966,81 +1058,6 @@ babel_update_hello_history(struct babel_neighbor *n, u16 seqno, uint interval)
n->last_hello_int = interval;
}
-static void
-babel_expire_seqno_requests(struct babel_proto *p)
-{
- btime now_ = current_time();
-
- struct babel_seqno_request *n, *nx;
- WALK_LIST_DELSAFE(n, nx, p->seqno_cache)
- {
- if ((n->updated + BABEL_SEQNO_REQUEST_EXPIRY) <= now_)
- {
- rem_node(NODE n);
- sl_free(p->seqno_slab, n);
- }
- }
-}
-
-/*
- * Checks the seqno request cache for a matching request and returns failure if
- * found. Otherwise, a new entry is stored in the cache.
- */
-static int
-babel_cache_seqno_request(struct babel_proto *p, net_addr *n,
- u64 router_id, u16 seqno)
-{
- struct babel_seqno_request *r;
-
- WALK_LIST(r, p->seqno_cache)
- {
- if (net_equal(&r->net, n) && (r->router_id == router_id) && (r->seqno == seqno))
- return 0;
- }
-
- /* no entries found */
- r = sl_alloc(p->seqno_slab);
- net_copy(&r->net, n);
- r->router_id = router_id;
- r->seqno = seqno;
- r->updated = current_time();
- add_tail(&p->seqno_cache, NODE r);
-
- return 1;
-}
-
-static void
-babel_forward_seqno_request(struct babel_proto *p, struct babel_entry *e,
- struct babel_msg_seqno_request *in,
- ip_addr sender)
-{
- struct babel_route *r;
-
- TRACE(D_PACKETS, "Forwarding seqno request for %N router-id %lR seqno %d",
- e->n.addr, in->router_id, in->seqno);
-
- WALK_LIST(r, e->routes)
- {
- if ((r->router_id == in->router_id) &&
- !OUR_ROUTE(r) &&
- !ipa_equal(r->neigh->addr, sender))
- {
- if (!babel_cache_seqno_request(p, e->n.addr, in->router_id, in->seqno))
- return;
-
- union babel_msg msg = {};
- msg.type = BABEL_TLV_SEQNO_REQUEST;
- msg.seqno_request.hop_count = in->hop_count-1;
- msg.seqno_request.seqno = in->seqno;
- msg.seqno_request.router_id = in->router_id;
- net_copy(&msg.seqno_request.net, e->n.addr);
-
- babel_send_unicast(&msg, r->neigh->ifa, r->neigh->addr);
- return;
- }
- }
-}
-
/*
* TLV handlers
@@ -1227,7 +1244,7 @@ babel_handle_update(union babel_msg *m, struct babel_iface *ifa)
/* RFC section 3.8.2.2 - Dealing with unfeasible updates */
if (!feasible && (metric != BABEL_INFINITY) &&
(!best || (r == best) || (metric < best->metric)))
- babel_unicast_seqno_request(p, e, s, nbr);
+ babel_add_seqno_request(p, e, s->router_id, s->seqno + 1, 0, nbr);
if (!r)
{
@@ -1264,6 +1281,13 @@ babel_handle_update(union babel_msg *m, struct babel_iface *ifa)
r->expires = current_time() + r->expiry_interval;
if (r->expiry_interval > BABEL_ROUTE_REFRESH_INTERVAL)
r->refresh_time = current_time() + r->expiry_interval - BABEL_ROUTE_REFRESH_INTERVAL;
+
+ /* If received update satisfies seqno request, we send triggered updates */
+ if (babel_satisfy_seqno_request(p, e, msg->router_id, msg->seqno))
+ {
+ babel_trigger_update(p);
+ e->updated = current_time();
+ }
}
babel_select_route(p, e);
@@ -1301,7 +1325,6 @@ babel_handle_route_request(union babel_msg *m, struct babel_iface *ifa)
}
}
-
void
babel_handle_seqno_request(union babel_msg *m, struct babel_iface *ifa)
{
@@ -1335,11 +1358,31 @@ babel_handle_seqno_request(union babel_msg *m, struct babel_iface *ifa)
p->update_seqno_inc = 1;
babel_trigger_update(p);
}
- else
+ else if (msg->hop_count > 1)
{
/* Not ours; forward if TTL allows it */
- if (msg->hop_count > 1)
- babel_forward_seqno_request(p, e, msg, msg->sender);
+
+ /* Find best admissible route */
+ struct babel_route *r, *best1 = NULL, *best2 = NULL;
+ WALK_LIST(r, e->routes)
+ if ((r->router_id == msg->router_id) && r->neigh && !ipa_equal(r->neigh->addr, msg->sender))
+ {
+ /* Find best feasible route */
+ if (babel_is_feasible(babel_find_source(e, r->router_id), r->seqno, r->advert_metric) &&
+ (!best1 || r->metric < best1->metric))
+ best1 = r;
+
+ /* Find best not necessary feasible route */
+ if (!best2 || r->metric < best2->metric)
+ best2 = r;
+ }
+
+ /* If no route is found, do nothing */
+ r = best1 ?: best2;
+ if (!r)
+ return;
+
+ babel_add_seqno_request(p, e, msg->router_id, msg->seqno, msg->hop_count-1, r->neigh);
}
}
@@ -1396,7 +1439,7 @@ babel_iface_timer(timer *t)
{
TRACE(D_EVENTS, "Sending triggered updates on %s", ifa->ifname);
babel_send_update(ifa, ifa->want_triggered);
- ifa->next_triggered = now_ + MIN(5 S, update_period / 2);
+ ifa->next_triggered = now_ + MIN(1 S, update_period / 2);
ifa->want_triggered = 0;
p->triggered = 0;
}
@@ -1422,7 +1465,7 @@ babel_iface_start(struct babel_iface *ifa)
ifa->next_hello = current_time() + (random() % ifa->cf->hello_interval);
ifa->next_regular = current_time() + (random() % ifa->cf->update_interval);
- ifa->next_triggered = current_time() + MIN(5 S, ifa->cf->update_interval / 2);
+ ifa->next_triggered = current_time() + MIN(1 S, ifa->cf->update_interval / 2);
ifa->want_triggered = 0; /* We send an immediate update (below) */
tm2_start(ifa->timer, 100 MS);
ifa->up = 1;
@@ -1988,7 +2031,6 @@ babel_timer(timer *t)
struct babel_proto *p = t->data;
babel_expire_routes(p);
- babel_expire_seqno_requests(p);
babel_expire_neighbors(p);
}
@@ -2177,7 +2219,6 @@ babel_start(struct proto *P)
p->source_slab = sl_new(P->pool, sizeof(struct babel_source));
p->msg_slab = sl_new(P->pool, sizeof(struct babel_msg_node));
p->seqno_slab = sl_new(P->pool, sizeof(struct babel_seqno_request));
- init_list(&p->seqno_cache);
p->log_pkt_tbf = (struct tbf){ .rate = 1, .burst = 5 };
diff --git a/proto/babel/babel.h b/proto/babel/babel.h
index ccd3479e..3ea21269 100644
--- a/proto/babel/babel.h
+++ b/proto/babel/babel.h
@@ -42,7 +42,8 @@
#define BABEL_ROUTE_EXPIRY_FACTOR(X) ((btime)(X)*7/2) /* 3.5 */
#define BABEL_ROUTE_REFRESH_INTERVAL (2 S_) /* Time before route expiry to send route request */
#define BABEL_HOLD_TIME (10 S_) /* Expiry time for our own routes */
-#define BABEL_SEQNO_REQUEST_EXPIRY (60 S_)
+#define BABEL_SEQNO_REQUEST_RETRY 4
+#define BABEL_SEQNO_REQUEST_EXPIRY (2 S_)
#define BABEL_GARBAGE_INTERVAL (300 S_)
#define BABEL_RXCOST_WIRED 96
#define BABEL_RXCOST_WIRELESS 256
@@ -147,9 +148,7 @@ struct babel_proto {
slab *route_slab;
slab *source_slab;
slab *msg_slab;
-
slab *seqno_slab;
- list seqno_cache; /* Seqno requests in the cache (struct babel_seqno_request) */
struct tbf log_pkt_tbf; /* TBF for packet messages */
};
@@ -190,6 +189,7 @@ struct babel_neighbor {
struct babel_iface *ifa;
ip_addr addr;
+ uint uc; /* Reference counter for seqno requests */
u16 rxcost; /* Sent in last IHU */
u16 txcost; /* Received in last IHU */
u16 cost; /* Computed neighbor cost */
@@ -231,12 +231,23 @@ struct babel_route {
btime expiry_interval;
};
+struct babel_seqno_request {
+ node n;
+ u64 router_id;
+ u16 seqno;
+ u8 hop_count;
+ u8 count;
+ btime expires;
+ struct babel_neighbor *nbr;
+};
+
struct babel_entry {
struct babel_route *selected_in;
struct babel_route *selected_out;
btime updated;
+ list requests;
list sources; /* Source entries for this prefix (struct babel_source). */
list routes; /* Routes for this prefix (struct babel_route) */
@@ -244,13 +255,6 @@ struct babel_entry {
};
/* Stores forwarded seqno requests for duplicate suppression. */
-struct babel_seqno_request {
- node n;
- net_addr net;
- u64 router_id;
- u16 seqno;
- btime updated;
-};
/*
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-23 15:09:12 +0000