static inline net *net_find_valid(rtable *tab, const net_addr *addr)
{ net *n = net_find(tab, addr); return (n && rte_is_valid(n->routes)) ? n : NULL; }
static inline net *net_get(rtable *tab, const net_addr *addr) { return (net *) fib_get(&tab->fib, addr); }
-void *net_route(rtable *tab, const net_addr *n);
+net *net_get(rtable *tab, const net_addr *addr);
+net *net_route(rtable *tab, const net_addr *n);
int net_roa_check(rtable *tab, const net_addr *n, u32 asn);
rte *rte_find(net *net, struct rte_src *src);
- rte *rte_get_temp(struct rta *);
+ rte *rte_get_temp(struct rta *, struct rte_src *src);
void rte_update2(struct channel *c, const net_addr *n, rte *new, struct rte_src *src);
/* rte_update() moved to protocol.h to avoid dependency conflicts */
int rt_examine(rtable *t, net_addr *a, struct proto *p, const struct filter *filter);
return e;
}
- struct bgp_proto *p = (void *) r->attrs->src->proto;
+
+#ifdef CONFIG_BGP
+
+static inline int
+net_flow_has_dst_prefix(const net_addr *n)
+{
+ ASSUME(net_is_flow(n));
+
+ if (n->pxlen)
+ return 1;
+
+ if (n->type == NET_FLOW4)
+ {
+ const net_addr_flow4 *n4 = (void *) n;
+ return (n4->length > sizeof(net_addr_flow4)) && (n4->data[0] == FLOW_TYPE_DST_PREFIX);
+ }
+ else
+ {
+ const net_addr_flow6 *n6 = (void *) n;
+ return (n6->length > sizeof(net_addr_flow6)) && (n6->data[0] == FLOW_TYPE_DST_PREFIX);
+ }
+}
+
+static inline int
+rta_as_path_is_empty(rta *a)
+{
+ eattr *e = ea_find(a->eattrs, EA_CODE(PROTOCOL_BGP, BA_AS_PATH));
+ return !e || (as_path_getlen(e->u.ptr) == 0);
+}
+
+static inline u32
+rta_get_first_asn(rta *a)
+{
+ eattr *e = ea_find(a->eattrs, EA_CODE(PROTOCOL_BGP, BA_AS_PATH));
+ u32 asn;
+
+ return (e && as_path_get_first_regular(e->u.ptr, &asn)) ? asn : 0;
+}
+
+int
+rt_flowspec_check(rtable *tab_ip, rtable *tab_flow, const net_addr *n, rta *a, int interior)
+{
+ ASSERT(rt_is_ip(tab_ip));
+ ASSERT(rt_is_flow(tab_flow));
+ ASSERT(tab_ip->trie);
+
+ /* RFC 8955 6. a) Flowspec has defined dst prefix */
+ if (!net_flow_has_dst_prefix(n))
+ return 0;
+
+ /* RFC 9117 4.1. Accept AS_PATH is empty (fr */
+ if (interior && rta_as_path_is_empty(a))
+ return 1;
+
+
+ /* RFC 8955 6. b) Flowspec and its best-match route have the same originator */
+
+ /* Find flowspec dst prefix */
+ net_addr dst;
+ if (n->type == NET_FLOW4)
+ net_fill_ip4(&dst, net4_prefix(n), net4_pxlen(n));
+ else
+ net_fill_ip6(&dst, net6_prefix(n), net6_pxlen(n));
+
+ /* Find best-match BGP unicast route for flowspec dst prefix */
+ net *nb = net_route(tab_ip, &dst);
+ rte *rb = nb ? nb->routes : NULL;
+
+ /* Register prefix to trie for tracking further changes */
+ int max_pxlen = (n->type == NET_FLOW4) ? IP4_MAX_PREFIX_LENGTH : IP6_MAX_PREFIX_LENGTH;
+ trie_add_prefix(tab_flow->flowspec_trie, &dst, (nb ? nb->n.addr->pxlen : 0), max_pxlen);
+
+ /* No best-match BGP route -> no flowspec */
+ if (!rb || (rb->attrs->source != RTS_BGP))
+ return 0;
+
+ /* Find ORIGINATOR_ID values */
+ u32 orig_a = ea_get_int(a->eattrs, EA_CODE(PROTOCOL_BGP, BA_ORIGINATOR_ID), 0);
+ u32 orig_b = ea_get_int(rb->attrs->eattrs, EA_CODE(PROTOCOL_BGP, BA_ORIGINATOR_ID), 0);
+
+ /* Originator is either ORIGINATOR_ID (if present), or BGP neighbor address (if not) */
+ if ((orig_a != orig_b) || (!orig_a && !orig_b && !ipa_equal(a->from, rb->attrs->from)))
+ return 0;
+
+
+ /* Find ASN of the best-match route, for use in next checks */
+ u32 asn_b = rta_get_first_asn(rb->attrs);
+ if (!asn_b)
+ return 0;
+
+ /* RFC 9117 4.2. For EBGP, flowspec and its best-match route are from the same AS */
+ if (!interior && (rta_get_first_asn(a) != asn_b))
+ return 0;
+
+ /* RFC 8955 6. c) More-specific routes are from the same AS as the best-match route */
+ TRIE_WALK(tab_ip->trie, subnet, &dst)
+ {
+ net *nc = net_find_valid(tab_ip, &subnet);
+ if (!nc)
+ continue;
+
+ rte *rc = nc->routes;
+ if (rc->attrs->source != RTS_BGP)
+ return 0;
+
+ if (rta_get_first_asn(rc->attrs) != asn_b)
+ return 0;
+ }
+ TRIE_WALK_END;
+
+ return 1;
+}
+
+#endif /* CONFIG_BGP */
+
+static rte *
+rt_flowspec_update_rte(rtable *tab, rte *r)
+{
+#ifdef CONFIG_BGP
+ if ((r->attrs->source != RTS_BGP) || !r->u.bgp.base_table)
+ return NULL;
+
+ const net_addr *n = r->net->n.addr;
- a->aflags = 0;
++ struct bgp_proto *p = (void *) r->src->proto;
+ int valid = rt_flowspec_check(r->u.bgp.base_table, tab, n, r->attrs, p->is_interior);
+ int dest = valid ? RTD_NONE : RTD_UNREACHABLE;
+
+ if (dest == r->attrs->dest)
+ return NULL;
+
+ rta *a = alloca(RTA_MAX_SIZE);
+ memcpy(a, r->attrs, rta_size(r->attrs));
+ a->dest = dest;
++ a->cached = 0;
+
+ rte *new = sl_alloc(rte_slab);
+ memcpy(new, r, sizeof(rte));
+ new->attrs = rta_lookup(a);
+
+ return new;
+#else
+ return NULL;
+#endif
+}
+
+
static inline int
rt_next_hop_update_net(rtable *tab, net *n)
{