* are probably inadequate.
*
* Loop detection based on AS_PATH causes updates to be withdrawn. RFC
- * 4271 does not explicitly specifiy the behavior in that case.
+ * 4271 does not explicitly specify the behavior in that case.
*
* Loop detection related to route reflection (based on ORIGINATOR_ID
* and CLUSTER_LIST) causes updates to be withdrawn. RFC 4456 8
}
+/*
+ * AIGP handling
+ */
+
+static int
+bgp_aigp_valid(byte *data, uint len, char *err, uint elen)
+{
+ byte *pos = data;
+ char *err_dsc = NULL;
+ uint err_val = 0;
+
+#define BAD(DSC,VAL) ({ err_dsc = DSC; err_val = VAL; goto bad; })
+ while (len)
+ {
+ if (len < 3)
+ BAD("TLV framing error", len);
+
+ /* Process one TLV */
+ uint ptype = pos[0];
+ uint plen = get_u16(pos + 1);
+
+ if (len < plen)
+ BAD("TLV framing error", plen);
+
+ if (plen < 3)
+ BAD("Bad TLV length", plen);
+
+ if ((ptype == BGP_AIGP_METRIC) && (plen != 11))
+ BAD("Bad AIGP TLV length", plen);
+
+ ADVANCE(pos, len, plen);
+ }
+#undef BAD
+
+ return 1;
+
+bad:
+ if (err)
+ if (bsnprintf(err, elen, "%s (%u) at %d", err_dsc, err_val, (int) (pos - data)) < 0)
+ err[0] = 0;
+
+ return 0;
+}
+
+static const byte *
+bgp_aigp_get_tlv(const struct adata *ad, uint type)
+{
+ if (!ad)
+ return NULL;
+
+ uint len = ad->length;
+ const byte *pos = ad->data;
+
+ while (len)
+ {
+ uint ptype = pos[0];
+ uint plen = get_u16(pos + 1);
+
+ if (ptype == type)
+ return pos;
+
+ ADVANCE(pos, len, plen);
+ }
+
+ return NULL;
+}
+
+static const struct adata *
+bgp_aigp_set_tlv(struct linpool *pool, const struct adata *ad, uint type, byte *data, uint dlen)
+{
+ uint len = ad ? ad->length : 0;
+ const byte *pos = ad ? ad->data : NULL;
+ struct adata *res = lp_alloc_adata(pool, len + 3 + dlen);
+ byte *dst = res->data;
+ byte *tlv = NULL;
+ int del = 0;
+
+ while (len)
+ {
+ uint ptype = pos[0];
+ uint plen = get_u16(pos + 1);
+
+ /* Find position for new TLV */
+ if ((ptype >= type) && !tlv)
+ {
+ tlv = dst;
+ dst += 3 + dlen;
+ }
+
+ /* Skip first matching TLV, copy others */
+ if ((ptype == type) && !del)
+ del = 1;
+ else
+ {
+ memcpy(dst, pos, plen);
+ dst += plen;
+ }
+
+ ADVANCE(pos, len, plen);
+ }
+
+ if (!tlv)
+ {
+ tlv = dst;
+ dst += 3 + dlen;
+ }
+
+ /* Store the TLD */
+ put_u8(tlv + 0, type);
+ put_u16(tlv + 1, 3 + dlen);
+ memcpy(tlv + 3, data, dlen);
+
+ /* Update length */
+ res->length = dst - res->data;
+
+ return res;
+}
+
+static u64 UNUSED
+bgp_aigp_get_metric(const struct adata *ad, u64 def)
+{
+ const byte *b = bgp_aigp_get_tlv(ad, BGP_AIGP_METRIC);
+ return b ? get_u64(b + 3) : def;
+}
+
+static const struct adata *
+bgp_aigp_set_metric(struct linpool *pool, const struct adata *ad, u64 metric)
+{
+ byte data[8];
+ put_u64(data, metric);
+ return bgp_aigp_set_tlv(pool, ad, BGP_AIGP_METRIC, data, 8);
+}
+
+int
+bgp_total_aigp_metric_(rte *e, u64 *metric, const struct adata **ad)
+{
+ eattr *a = ea_find(e->attrs->eattrs, EA_CODE(PROTOCOL_BGP, BA_AIGP));
+ if (!a)
+ return 0;
+
+ const byte *b = bgp_aigp_get_tlv(a->u.ptr, BGP_AIGP_METRIC);
+ if (!b)
+ return 0;
+
+ u64 aigp = get_u64(b + 3);
+ u64 step = e->attrs->igp_metric;
+
+ if (!rte_resolvable(e) || (step >= IGP_METRIC_UNKNOWN))
+ step = BGP_AIGP_MAX;
+
+ if (!step)
+ step = 1;
+
+ *ad = a->u.ptr;
+ *metric = aigp + step;
+ if (*metric < aigp)
+ *metric = BGP_AIGP_MAX;
+
+ return 1;
+}
+
+static inline int
+bgp_init_aigp_metric(rte *e, u64 *metric, const struct adata **ad)
+{
+ if (e->attrs->source == RTS_BGP)
+ return 0;
+
+ *metric = rt_get_igp_metric(e);
+ *ad = NULL;
+ return *metric < IGP_METRIC_UNKNOWN;
+}
+
+
/*
* Attribute hooks
*/
}
+static inline int
+bgp_as_path_first_as_equal(const byte *data, uint len, u32 asn)
+{
+ return (len >= 6) &&
+ ((data[0] == AS_PATH_SEQUENCE) || (data[0] == AS_PATH_CONFED_SEQUENCE)) &&
+ (data[1] > 0) &&
+ (get_u32(data+2) == asn);
+}
+
static int
bgp_encode_as_path(struct bgp_write_state *s, eattr *a, byte *buf, uint size)
{
{
struct bgp_proto *p = s->proto;
int as_length = s->as4_session ? 4 : 2;
+ int as_sets = p->cf->allow_as_sets;
int as_confed = p->cf->confederation && p->is_interior;
char err[128];
- if (!as_path_valid(data, len, as_length, as_confed, err, sizeof(err)))
+ if (!as_path_valid(data, len, as_length, as_sets, as_confed, err, sizeof(err)))
WITHDRAW("Malformed AS_PATH attribute - %s", err);
- /* In some circumstances check for initial AS_CONFED_SEQUENCE; RFC 5065 5.0 */
- if (p->is_interior && !p->is_internal &&
- ((len < 2) || (data[0] != AS_PATH_CONFED_SEQUENCE)))
- WITHDRAW("Malformed AS_PATH attribute - %s", "missing initial AS_CONFED_SEQUENCE");
-
if (!s->as4_session)
{
/* Prepare 32-bit AS_PATH (from 16-bit one) in a temporary buffer */
len = as_path_16to32(data, src, len);
}
+ /* In some circumstances check for initial AS_CONFED_SEQUENCE; RFC 5065 5.0 */
+ if (p->is_interior && !p->is_internal &&
+ ((len < 2) || (data[0] != AS_PATH_CONFED_SEQUENCE)))
+ WITHDRAW("Malformed AS_PATH attribute - %s", "missing initial AS_CONFED_SEQUENCE");
+
+ /* Reject routes with first AS in AS_PATH not matching neighbor AS; RFC 4271 6.3 */
+ if (!p->is_internal && p->cf->enforce_first_as &&
+ !bgp_as_path_first_as_equal(data, len, p->remote_as))
+ WITHDRAW("Malformed AS_PATH attribute - %s", "First AS differs from neigbor AS");
+
bgp_set_attr_data(to, s->pool, BA_AS_PATH, flags, data, len);
}
static void
bgp_export_ext_community(struct bgp_export_state *s, eattr *a)
{
- struct adata *ad = ec_set_del_nontrans(s->pool, a->u.ptr);
+ if (!s->proto->is_interior)
+ {
+ struct adata *ad = ec_set_del_nontrans(s->pool, a->u.ptr);
- if (ad->length == 0)
- UNSET(a);
+ if (ad->length == 0)
+ UNSET(a);
+
+ ec_set_sort_x(ad);
+ a->u.ptr = ad;
+ }
+ else
+ {
+ if (a->u.ptr->length == 0)
+ UNSET(a);
- ec_set_sort_x(ad);
- a->u.ptr = ad;
+ a->u.ptr = ec_set_sort(s->pool, a->u.ptr);
+ }
}
static void
static void
bgp_decode_as4_path(struct bgp_parse_state *s, uint code UNUSED, uint flags, byte *data, uint len, ea_list **to)
{
+ struct bgp_proto *p = s->proto;
+ int sets = p->cf->allow_as_sets;
+
char err[128];
if (s->as4_session)
if (len < 6)
DISCARD(BAD_LENGTH, "AS4_PATH", len);
- if (!as_path_valid(data, len, 4, 1, err, sizeof(err)))
+ if (!as_path_valid(data, len, 4, sets, 1, err, sizeof(err)))
DISCARD("Malformed AS4_PATH attribute - %s", err);
struct adata *a = lp_alloc_adata(s->pool, len);
bgp_set_attr_ptr(to, s->pool, BA_AS4_PATH, flags, a);
}
+
+static void
+bgp_export_aigp(struct bgp_export_state *s, eattr *a)
+{
+ if (!s->channel->cf->aigp)
+ UNSET(a);
+}
+
+static void
+bgp_decode_aigp(struct bgp_parse_state *s, uint code UNUSED, uint flags, byte *data, uint len, ea_list **to)
+{
+ char err[128];
+
+ /* Acceptability test postponed to bgp_finish_attrs() */
+
+ if ((flags ^ bgp_attr_table[BA_AIGP].flags) & (BAF_OPTIONAL | BAF_TRANSITIVE))
+ DISCARD("Malformed AIGP attribute - conflicting flags (%02x)", flags);
+
+ if (!bgp_aigp_valid(data, len, err, sizeof(err)))
+ DISCARD("Malformed AIGP attribute - %s", err);
+
+ bgp_set_attr_data(to, s->pool, BA_AIGP, flags, data, len);
+}
+
+static void
+bgp_format_aigp(eattr *a, byte *buf, uint size UNUSED)
+{
+ const byte *b = bgp_aigp_get_tlv(a->u.ptr, BGP_AIGP_METRIC);
+
+ if (!b)
+ bsprintf(buf, "?");
+ else
+ bsprintf(buf, "%lu", get_u64(b + 3));
+}
+
+
static void
bgp_export_large_community(struct bgp_export_state *s, eattr *a)
{
.decode = bgp_decode_as4_aggregator,
.format = bgp_format_aggregator,
},
+ [BA_AIGP] = {
+ .name = "aigp",
+ .type = EAF_TYPE_OPAQUE,
+ .flags = BAF_OPTIONAL | BAF_DECODE_FLAGS,
+ .export = bgp_export_aigp,
+ .encode = bgp_encode_raw,
+ .decode = bgp_decode_aigp,
+ .format = bgp_format_aigp,
+ },
[BA_LARGE_COMMUNITY] = {
.name = "large_community",
.type = EAF_TYPE_LC_SET,
const struct bgp_attr_desc *desc = &bgp_attr_table[code];
/* Handle conflicting flags; RFC 7606 3 (c) */
- if ((flags ^ desc->flags) & (BAF_OPTIONAL | BAF_TRANSITIVE))
+ if (((flags ^ desc->flags) & (BAF_OPTIONAL | BAF_TRANSITIVE)) &&
+ !(desc->flags & BAF_DECODE_FLAGS))
WITHDRAW("Malformed %s attribute - conflicting flags (%02x)", desc->name, flags);
desc->decode(s, code, flags, data, len, to);
return NULL;
}
+void
+bgp_finish_attrs(struct bgp_parse_state *s, rta *a)
+{
+ /* AIGP test here instead of in bgp_decode_aigp() - we need to know channel */
+ if (BIT32_TEST(s->attrs_seen, BA_AIGP) && !s->channel->cf->aigp)
+ {
+ REPORT("Discarding AIGP attribute received on non-AIGP session");
+ bgp_unset_attr(&a->eattrs, s->pool, BA_AIGP);
+ }
+}
+
/*
* Route bucket hash table
if (p->is_interior && ! bgp_find_attr(attrs0, BA_LOCAL_PREF))
bgp_set_attr_u32(&attrs, pool, BA_LOCAL_PREF, 0, p->cf->default_local_pref);
+ /* AIGP attribute - accumulate local metric or originate new one */
+ u64 metric;
+ if (s.local_next_hop &&
+ (bgp_total_aigp_metric_(e, &metric, &ad) ||
+ (c->cf->aigp_originate && bgp_init_aigp_metric(e, &metric, &ad))))
+ {
+ ad = bgp_aigp_set_metric(pool, ad, metric);
+ bgp_set_attr_ptr(&attrs, pool, BA_AIGP, 0, ad);
+ }
+
/* IBGP route reflection, RFC 4456 */
if (src && src->is_internal && p->is_internal && (src->local_as == p->local_as))
{
return p->cf->confederation ?: p->local_as;
}
-static inline int
-rte_resolvable(rte *rt)
-{
- return rt->attrs->dest == RTD_UNICAST;
-}
-
static inline int
rte_stale(rte *r)
{
if (n < o)
return 0;
+ /* RFC 7311 4.1 - Apply AIGP metric */
+ u64 n2 = bgp_total_aigp_metric(new);
+ u64 o2 = bgp_total_aigp_metric(old);
+ if (n2 < o2)
+ return 1;
+ if (n2 > o2)
+ return 0;
+
/* RFC 4271 9.1.2.2. a) Use AS path lengths */
if (new_bgp->cf->compare_path_lengths || old_bgp->cf->compare_path_lengths)
{
return 0;
/* RFC 4271 9.1.2.1. Route resolvability test */
- if (!rte_resolvable(sec))
+ if (rte_resolvable(pri) != rte_resolvable(sec))
return 0;
/* LLGR draft - depreference stale routes */
rte *key = new ? new : old;
u32 lpref = key->pref;
u32 lasn = bgp_get_neighbor(key);
- int old_is_group_best = 0;
+ int old_suppressed = old ? old->u.bgp.suppressed : 0;
/*
* Proper RFC 4271 path selection is a bit complicated, it cannot be
* We could find the best-in-group and then make some shortcuts like
* in rte_recalculate, but as we would have to walk through all
* net->routes just to find it, it is probably not worth. So we
- * just have two simpler fast cases that use just the old route.
+ * just have one simple fast case that use just the old route.
* We also set suppressed flag to avoid using it in bgp_rte_better().
*/
if (old)
{
- old_is_group_best = !old->u.bgp.suppressed;
old->u.bgp.suppressed = 1;
- int new_is_better = new && bgp_rte_better(new, old);
- /* The first case - replace not best with worse (or remove not best) */
- if (!old_is_group_best && !new_is_better)
+ /* The fast case - replace not best with worse (or remove not best) */
+ if (old_suppressed && !(new && bgp_rte_better(new, old)))
return 0;
-
- /* The second case - replace the best with better */
- if (old_is_group_best && new_is_better)
- {
- /* new is best-in-group, the see discussion below - this is
- a special variant of NBG && OBG. From OBG we can deduce
- that same_group(old_best) iff (old == old_best) */
- new->u.bgp.suppressed = 0;
- return (old == old_best);
- }
}
/* The default case - find a new best-in-group route */
if (!r)
return 0;
+ /* Found if new is mergable with best-in-group */
+ if (new && (new != r) && bgp_rte_mergable(r, new))
+ new->u.bgp.suppressed = 0;
+
+ /* Found all existing routes mergable with best-in-group */
+ for (s=net->routes; rte_is_valid(s); s=s->next)
+ if (use_deterministic_med(s) && same_group(s, lpref, lasn))
+ if ((s != r) && bgp_rte_mergable(r, s))
+ s->u.bgp.suppressed = 0;
+
/* Found best-in-group */
r->u.bgp.suppressed = 0;
* rte_recalculate() without ignore that possibility).
*
* There are three possible cases according to whether the old route
- * was the best in group (OBG, stored in old_is_group_best) and
- * whether the new route is the best in group (NBG, tested by r == new).
- * These cases work even if old or new is NULL.
+ * was the best in group (OBG, i.e. !old_suppressed) and whether the
+ * new route is the best in group (NBG, tested by r == new). These
+ * cases work even if old or new is NULL.
*
* NBG -> new is a possible candidate for the best route, so we just
* check for the first reason using same_group().
if (r == new)
return old_best && same_group(old_best, lpref, lasn);
else
- return old_is_group_best;
+ return !old_suppressed;
}
struct rte *
if (rte_stale(e))
buf += bsprintf(buf, "s");
- if (e->attrs->hostentry)
+ u64 metric = bgp_total_aigp_metric(e);
+ if (metric < BGP_AIGP_MAX)
+ {
+ buf += bsprintf(buf, "/%lu", metric);
+ }
+ else if (e->attrs->igp_metric)
{
if (!rte_resolvable(e))
buf += bsprintf(buf, "/-");
projects / thirdparty / bird.git / blobdiff