From e2dc2f30efd65cf3da4db150fae695978388e247 Mon Sep 17 00:00:00 2001 From: Martin Mares Date: Mon, 5 Apr 1999 20:25:03 +0000 Subject: Routing table core changes to support full route filtering: o Introduced rte_cow() which should be used for copying on write the rte's in filters. Each rte now carries a flag saying whether it's a real route (possessing table linkage and other insignia) or a local copy. This function can be expected to be fast since its fast-path is inlined. o Introduced rte_update_pool which is a linear memory pool used for all temporary data during rte_update. You should not reference it directly -- instead use a pool pointer passed to all related functions. o Split rte_update to three functions: rte_update The front end: handles all checking, inbound filtering and calls rte_recalculate() for the final version of the route. rte_recalculate Update the table according to already filtered route. rte_announce Announce routing table changes to all protocols, passing them through export filters and so on. The interface has _not_ changed -- still call rte_update() and it will do the rest for you automagically. o Use new filtering semantics to be explained in a separate mail. --- nest/rt-table.c | 128 +++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 103 insertions(+), 25 deletions(-) (limited to 'nest/rt-table.c') diff --git a/nest/rt-table.c b/nest/rt-table.c index 8a5c593..47b4bb7 100644 --- a/nest/rt-table.c +++ b/nest/rt-table.c @@ -19,6 +19,7 @@ rtable master_table; static slab *rte_slab; +static linpool *rte_update_pool; #define RT_GC_MIN_TIME 5 /* FIXME: Make configurable */ #define RT_GC_MIN_COUNT 100 @@ -95,6 +96,17 @@ rte_get_temp(rta *a) return e; } +rte * +rte_do_cow(rte *r) +{ + rte *e = sl_alloc(rte_slab); + + memcpy(e, r, sizeof(rte)); + e->attrs = rta_clone(r->attrs); + e->flags = 0; + return e; +} + static int /* Actually better or at least as good as */ rte_better(rte *new, rte *old) { @@ -114,21 +126,42 @@ rte_better(rte *new, rte *old) } static inline void -do_rte_announce(struct proto *p, net *net, rte *new, rte *old) +do_rte_announce(struct proto *p, net *net, rte *new, rte *old, ea_list *tmpa) { - if (p->out_filter) + rte *new0 = new; + rte *old0 = old; + if (new) { - if (old && f_run(p->out_filter, old, NULL) != F_ACCEPT) - old = NULL; - if (new && f_run(p->out_filter, new, NULL) != F_ACCEPT) + int ok = p->import_control ? p->import_control(p, &new, &tmpa, rte_update_pool) : 0; + if (ok < 0 || + (!ok && (p->out_filter == FILTER_REJECT || + p->out_filter && f_run(p->out_filter, &new, &tmpa, rte_update_pool) > F_MODIFY) + ) + ) new = NULL; } + if (old && p->out_filter) + { + /* FIXME: Do we really need to filter old routes? */ + if (p->out_filter == FILTER_REJECT) + old = NULL; + else + { + ea_list *tmpb = p->make_tmp_attrs ? p->make_tmp_attrs(old, rte_update_pool) : NULL; + if (f_run(p->out_filter, &old, &tmpb, rte_update_pool) > F_MODIFY) + old = NULL; + } + } if (new || old) p->rt_notify(p, net, new, old); + if (new && new != new0) /* Discard temporary rte's */ + rte_free(new); + if (old && old != old0) + rte_free(old); } -void -rte_announce(net *net, rte *new, rte *old) +static void +rte_announce(net *net, rte *new, rte *old, ea_list *tmpa) { struct proto *p; @@ -136,7 +169,7 @@ rte_announce(net *net, rte *new, rte *old) { ASSERT(p->core_state == FS_HAPPY); if (p->rt_notify) - do_rte_announce(p, net, new, old); + do_rte_announce(p, net, new, old, tmpa); } } @@ -155,7 +188,12 @@ rt_feed_baby(struct proto *p) net *n = (net *) fn; rte *e; for(e=n->routes; e; e=e->next) - do_rte_announce(p, n, e, NULL); + { + struct proto *q = e->attrs->proto; + ea_list *tmpa = q->make_tmp_attrs ? q->make_tmp_attrs(e, rte_update_pool) : NULL; + do_rte_announce(p, n, e, NULL, tmpa); + lp_flush(rte_update_pool); + } } FIB_WALK_END; t = t->sibling; @@ -209,24 +247,13 @@ rte_free_quick(rte *e) sl_free(rte_slab, e); } -void -rte_update(net *net, struct proto *p, rte *new) +static void +rte_recalculate(net *net, struct proto *p, rte *new, ea_list *tmpa) { rte *old_best = net->routes; rte *old = NULL; rte **k, *r, *s; - if (new) - { - if (!rte_validate(new) || p->in_filter && f_run(p->in_filter, new, NULL) != F_ACCEPT) - { - rte_free(new); - return; - } - if (!(new->attrs->aflags & RTAF_CACHED)) /* Need to copy attributes */ - new->attrs = rta_lookup(new->attrs); - } - k = &net->routes; /* Find and remove original route from the same protocol */ while (old = *k) { @@ -240,7 +267,7 @@ rte_update(net *net, struct proto *p, rte *new) if (new && rte_better(new, old_best)) /* It's a new optimal route => announce and relink it */ { - rte_announce(net, new, old_best); + rte_announce(net, new, old_best, tmpa); new->next = net->routes; net->routes = new; } @@ -252,7 +279,7 @@ rte_update(net *net, struct proto *p, rte *new) for(s=net->routes; s; s=s->next) if (rte_better(s, r)) r = s; - rte_announce(net, r, old_best); + rte_announce(net, r, old_best, tmpa); if (r) /* Re-link the new optimal route */ { k = &net->routes; @@ -291,10 +318,60 @@ rte_update(net *net, struct proto *p, rte *new) } } +static int rte_update_nest_cnt; /* Nesting counter to allow recursive updates */ + +static inline void +rte_update_lock(void) +{ + rte_update_nest_cnt++; +} + +static inline void +rte_update_unlock(void) +{ + if (!--rte_update_nest_cnt) + lp_flush(rte_update_pool); +} + +void +rte_update(net *net, struct proto *p, rte *new) +{ + ea_list *tmpa = NULL; + + rte_update_lock(); + if (new) + { + if (!rte_validate(new) || p->in_filter == FILTER_REJECT) + goto drop; + if (p->make_tmp_attrs) + tmpa = p->make_tmp_attrs(new, rte_update_pool); + if (p->in_filter) + { + int fr = f_run(p->in_filter, &new, &tmpa, rte_update_pool); + if (fr > F_MODIFY) + goto drop; + if (fr == F_MODIFY && p->store_tmp_attrs) + p->store_tmp_attrs(new, tmpa); + } + if (!(new->attrs->aflags & RTAF_CACHED)) /* Need to copy attributes */ + new->attrs = rta_lookup(new->attrs); + new->flags |= REF_COW; + } + rte_recalculate(net, p, new, tmpa); + rte_update_unlock(); + return; + +drop: + rte_free(new); + rte_update_unlock(); +} + void rte_discard(rte *old) /* Non-filtered route deletion, used during garbage collection */ { - rte_update(old->net, old->attrs->proto, NULL); + rte_update_lock(); + rte_recalculate(old->net, old->attrs->proto, NULL, NULL); + rte_update_unlock(); } void @@ -357,6 +434,7 @@ rt_init(void) { rta_init(); rt_table_pool = rp_new(&root_pool, "Routing tables"); + rte_update_pool = lp_new(rt_table_pool, 4080); rt_setup(rt_table_pool, &master_table, "master"); rte_slab = sl_new(rt_table_pool, sizeof(rte)); rt_last_gc = now; -- cgit v1.2.3