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Babel: Fix unicast seqno requests

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This commit is contained in:
Ondrej Zajicek (work) 2017-10-13 23:46:41 +02:00
parent 38f4721092
commit f00221fadb
1 changed files with 18 additions and 26 deletions
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44
proto/babel/babel.c
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@ -721,28 +721,24 @@ babel_send_seqno_request(struct babel_entry *e)
} }
static void 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_proto *p = e->proto;
struct babel_iface *ifa = r->neigh->ifa;
struct babel_source *s = NULL;
union babel_msg msg = {}; union babel_msg msg = {};
s = babel_find_source(e, r->router_id); if (!s || !babel_cache_seqno_request(p, e->n.addr, s->router_id, s->seqno + 1))
if (!s || !babel_cache_seqno_request(p, e->n.addr, r->router_id, s->seqno + 1))
return; return;
TRACE(D_PACKETS, "Sending seqno request for %N router-id %lR seqno %d", 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.type = BABEL_TLV_SEQNO_REQUEST;
msg.seqno_request.hop_count = BABEL_INITIAL_HOP_COUNT; msg.seqno_request.hop_count = BABEL_INITIAL_HOP_COUNT;
msg.seqno_request.seqno = s->seqno + 1; 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); 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_neighbor *nbr;
struct babel_entry *e; struct babel_entry *e;
struct babel_source *s; struct babel_source *s;
struct babel_route *r; struct babel_route *r, *best;
node *n; node *n;
int feasible; int feasible, metric;
if (msg->wildcard) if (msg->wildcard)
TRACE(D_PACKETS, "Handling wildcard retraction", msg->seqno); 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 */ r = babel_find_route(e, nbr); /* the route entry indexed by neighbour */
s = babel_find_source(e, msg->router_id); /* for feasibility */ s = babel_find_source(e, msg->router_id); /* for feasibility */
feasible = babel_is_feasible(s, msg->seqno, msg->metric); 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) if (!r)
{ {
@ -1201,18 +1204,13 @@ babel_handle_update(union babel_msg *m, struct babel_iface *ifa)
r = babel_get_route(e, nbr); r = babel_get_route(e, nbr);
r->advert_metric = msg->metric; r->advert_metric = msg->metric;
r->router_id = msg->router_id; r->router_id = msg->router_id;
r->metric = babel_compute_metric(nbr, msg->metric); r->metric = metric;
r->next_hop = msg->next_hop; r->next_hop = msg->next_hop;
r->seqno = msg->seqno; r->seqno = msg->seqno;
} }
else if (r == r->e->selected_in && !feasible) else if (r == best && !feasible)
{ {
/* /* Penultimate paragraph above - ignore or retract */
* 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);
if (msg->router_id == r->router_id) if (msg->router_id == r->router_id)
return; return;
@ -1223,7 +1221,7 @@ babel_handle_update(union babel_msg *m, struct babel_iface *ifa)
{ {
/* Last paragraph above - update the entry */ /* Last paragraph above - update the entry */
r->advert_metric = msg->metric; r->advert_metric = msg->metric;
r->metric = babel_compute_metric(nbr, msg->metric); r->metric = metric;
r->next_hop = msg->next_hop; r->next_hop = msg->next_hop;
r->router_id = msg->router_id; 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; r->expires = current_time() + r->expiry_interval;
if (r->expiry_interval > BABEL_ROUTE_REFRESH_INTERVAL) if (r->expiry_interval > BABEL_ROUTE_REFRESH_INTERVAL)
r->refresh_time = current_time() + 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); babel_select_route(e);