diff options
| -rw-r--r-- | proto/babel/babel.c | 44 |
1 files changed, 18 insertions, 26 deletions
diff --git a/proto/babel/babel.c b/proto/babel/babel.c index 54b31c22..0b7ab91b 100644 --- a/proto/babel/babel.c +++ b/proto/babel/babel.c @@ -721,28 +721,24 @@ babel_send_seqno_request(struct babel_entry *e) } static void -babel_unicast_seqno_request(struct babel_route *r) +babel_unicast_seqno_request(struct babel_entry *e, struct babel_source *s, struct babel_neighbor *nbr) { - struct babel_entry *e = r->e; struct babel_proto *p = e->proto; - struct babel_iface *ifa = r->neigh->ifa; - 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)) + 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, r->router_id, s->seqno + 1); + e->n.addr, s->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.router_id = s->router_id; net_copy(&msg.seqno_request.net, e->n.addr); - babel_send_unicast(&msg, ifa, r->neigh->addr); + babel_send_unicast(&msg, nbr->ifa, nbr->addr); } /** @@ -1088,9 +1084,9 @@ babel_handle_update(union babel_msg *m, struct babel_iface *ifa) struct babel_neighbor *nbr; struct babel_entry *e; struct babel_source *s; - struct babel_route *r; + struct babel_route *r, *best; node *n; - int feasible; + int feasible, metric; if (msg->wildcard) TRACE(D_PACKETS, "Handling wildcard retraction", msg->seqno); @@ -1192,6 +1188,13 @@ babel_handle_update(union babel_msg *m, struct babel_iface *ifa) r = babel_find_route(e, nbr); /* the route entry indexed by neighbour */ s = babel_find_source(e, msg->router_id); /* for feasibility */ feasible = babel_is_feasible(s, msg->seqno, msg->metric); + metric = babel_compute_metric(nbr, msg->metric); + best = e->selected_in; + + /* 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(e, s, nbr); if (!r) { @@ -1201,18 +1204,13 @@ babel_handle_update(union babel_msg *m, struct babel_iface *ifa) r = babel_get_route(e, nbr); r->advert_metric = msg->metric; r->router_id = msg->router_id; - r->metric = babel_compute_metric(nbr, msg->metric); + r->metric = metric; r->next_hop = msg->next_hop; r->seqno = msg->seqno; } - else if (r == r->e->selected_in && !feasible) + else if (r == best && !feasible) { - /* - * Route is installed and update is infeasible - we may lose the route, - * so send a unicast seqno request (section 3.8.2.2 second paragraph). - */ - babel_unicast_seqno_request(r); - + /* Penultimate paragraph above - ignore or retract */ if (msg->router_id == r->router_id) return; @@ -1223,7 +1221,7 @@ babel_handle_update(union babel_msg *m, struct babel_iface *ifa) { /* Last paragraph above - update the entry */ r->advert_metric = msg->metric; - r->metric = babel_compute_metric(nbr, msg->metric); + r->metric = metric; r->next_hop = msg->next_hop; r->router_id = msg->router_id; @@ -1233,12 +1231,6 @@ 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 the route is not feasible at this point, it means it is from another - neighbour than the one currently selected; so send a unicast seqno - request to try to get a better route (section 3.8.2.2 last paragraph). */ - if (!feasible) - babel_unicast_seqno_request(r); } babel_select_route(e); |