diff options
Diffstat (limited to 'proto')
| -rw-r--r-- | proto/babel/babel.c | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/proto/babel/babel.c b/proto/babel/babel.c index 4f3603e4..83a87d8f 100644 --- a/proto/babel/babel.c +++ b/proto/babel/babel.c @@ -50,6 +50,10 @@ static inline int ge_mod64k(uint a, uint b) { return (u16)(a - b) < 0x8000; } +/* Strict inequality version of the above */ +static inline int gt_mod64k(uint a, uint b) +{ return ge_mod64k(a, b) && a != b; } + 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, struct babel_route *mod); static inline void babel_announce_retraction(struct babel_proto *p, struct babel_entry *e); @@ -104,7 +108,8 @@ babel_find_source(struct babel_entry *e, u64 router_id) } static struct babel_source * -babel_get_source(struct babel_proto *p, struct babel_entry *e, u64 router_id) +babel_get_source(struct babel_proto *p, struct babel_entry *e, u64 router_id, + u16 initial_seqno) { struct babel_source *s = babel_find_source(e, router_id); @@ -114,7 +119,7 @@ babel_get_source(struct babel_proto *p, struct babel_entry *e, u64 router_id) s = sl_allocz(p->source_slab); s->router_id = router_id; s->expires = current_time() + BABEL_GARBAGE_INTERVAL; - s->seqno = 0; + s->seqno = initial_seqno; s->metric = BABEL_INFINITY; add_tail(&e->sources, NODE s); @@ -562,7 +567,7 @@ babel_is_feasible(struct babel_source *s, u16 seqno, u16 metric) { return !s || (metric == BABEL_INFINITY) || - (seqno > s->seqno) || + gt_mod64k(seqno, s->seqno) || ((seqno == s->seqno) && (metric < s->metric)); } @@ -1006,13 +1011,13 @@ babel_send_update_(struct babel_iface *ifa, btime changed, struct fib *rtable) babel_enqueue(&msg, ifa); - /* Update feasibility distance for redistributed routes */ + /* RFC 6126 3.7.3 - update feasibility distance for redistributed routes */ if (e->router_id != p->router_id) { - struct babel_source *s = babel_get_source(p, e, e->router_id); + struct babel_source *s = babel_get_source(p, e, e->router_id, msg.update.seqno); s->expires = current_time() + BABEL_GARBAGE_INTERVAL; - if ((msg.update.seqno > s->seqno) || + if (gt_mod64k(msg.update.seqno, s->seqno) || ((msg.update.seqno == s->seqno) && (msg.update.metric < s->metric))) { s->seqno = msg.update.seqno; @@ -1303,9 +1308,10 @@ babel_handle_update(union babel_msg *m, struct babel_iface *ifa) /* * RFC section 3.8.2.2 - Dealing with unfeasible updates. Generate a one-off - * (not retransmitted) unicast seqno request to the originator of this update + * (not retransmitted) unicast seqno request to the originator of this update. + * Note: !feasible -> s exists, check for 's' is just for clarity / safety. */ - if (!feasible && (metric != BABEL_INFINITY) && + if (!feasible && s && (metric != BABEL_INFINITY) && (!best || (r == best) || (metric < best->metric))) babel_generate_seqno_request(p, e, s->router_id, s->seqno + 1, nbr); |