2 * BIRD -- BGP Attributes
4 * (c) 2000 Martin Mares <mj@ucw.cz>
6 * Can be freely distributed and used under the terms of the GNU GPL.
13 #include "nest/bird.h"
14 #include "nest/iface.h"
15 #include "nest/protocol.h"
16 #include "nest/route.h"
17 #include "nest/attrs.h"
18 #include "conf/conf.h"
19 #include "lib/resource.h"
20 #include "lib/string.h"
21 #include "lib/unaligned.h"
26 * UPDATE message error handling
28 * All checks from RFC 4271 6.3 are done as specified with these exceptions:
29 * - The semantic check of an IP address from NEXT_HOP attribute is missing.
30 * - Checks of some optional attribute values are missing.
31 * - Syntactic and semantic checks of NLRIs (done in DECODE_PREFIX())
32 * are probably inadequate.
34 * Loop detection based on AS_PATH causes updates to be withdrawn. RFC
35 * 4271 does not explicitly specifiy the behavior in that case.
37 * Loop detection related to route reflection (based on ORIGINATOR_ID
38 * and CLUSTER_LIST) causes updates to be withdrawn. RFC 4456 8
39 * specifies that such updates should be ignored, but that is generally
42 * Error checking of optional transitive attributes is done according to
43 * draft-ietf-idr-optional-transitive-03, but errors are handled always
46 * Unexpected AS_CONFED_* segments in AS_PATH are logged and removed,
47 * but unknown segments cause a session drop with Malformed AS_PATH
48 * error (see validate_path()). The behavior in such case is not
49 * explicitly specified by RFC 4271. RFC 5065 specifies that
50 * inconsistent AS_CONFED_* segments should cause a session drop, but
51 * implementations that pass invalid AS_CONFED_* segments are
54 * Error handling of AS4_* attributes is done as specified by
55 * draft-ietf-idr-rfc4893bis-03. There are several possible
56 * inconsistencies between AGGREGATOR and AS4_AGGREGATOR that are not
57 * handled by that draft, these are logged and ignored (see
58 * bgp_reconstruct_4b_attrs()).
61 static byte bgp_mandatory_attrs
[] = { BA_ORIGIN
, BA_AS_PATH
73 int (*validate
)(struct bgp_proto
*p
, byte
*attr
, int len
);
74 void (*format
)(eattr
*ea
, byte
*buf
, int buflen
);
81 bgp_check_origin(struct bgp_proto
*p UNUSED
, byte
*a
, int len UNUSED
)
89 bgp_format_origin(eattr
*a
, byte
*buf
, int buflen UNUSED
)
91 static char *bgp_origin_names
[] = { "IGP", "EGP", "Incomplete" };
93 bsprintf(buf
, bgp_origin_names
[a
->u
.data
]);
97 path_segment_contains(byte
*p
, int bs
, u32 asn
)
105 u32 asn2
= (bs
== 4) ? get_u32(p
) : get_u16(p
);
114 /* Validates path attribute, removes AS_CONFED_* segments, and also returns path length */
116 validate_path(struct bgp_proto
*p
, int as_path
, int bs
, byte
*idata
, unsigned int *ilength
)
130 plen
= 2 + bs
* a
[1];
141 case AS_PATH_SEQUENCE
:
146 case AS_PATH_CONFED_SEQUENCE
:
147 case AS_PATH_CONFED_SET
:
148 if (as_path
&& path_segment_contains(a
, bs
, p
->remote_as
))
150 log(L_WARN
"%s: AS_CONFED_* segment with peer ASN found, misconfigured confederation?", p
->p
.name
);
154 log(L_WARN
"%s: %s_PATH attribute contains AS_CONFED_* segment, skipping segment",
155 p
->p
.name
, as_path
? "AS" : "AS4");
166 memmove(dst
, a
, plen
);
174 *ilength
= dst
- idata
;
179 validate_as_path(struct bgp_proto
*p
, byte
*a
, int *len
)
181 return validate_path(p
, 1, p
->as4_session
? 4 : 2, a
, len
);
185 validate_as4_path(struct bgp_proto
*p
, struct adata
*path
)
187 return validate_path(p
, 0, 4, path
->data
, &path
->length
);
191 bgp_check_next_hop(struct bgp_proto
*p UNUSED
, byte
*a
, int len
)
198 memcpy(&addr
, a
, len
);
200 if (ipa_classify(addr
) & IADDR_HOST
)
208 bgp_format_next_hop(eattr
*a
, byte
*buf
, int buflen UNUSED
)
210 ip_addr
*ipp
= (ip_addr
*) a
->u
.ptr
->data
;
212 /* in IPv6, we might have two addresses in NEXT HOP */
213 if ((a
->u
.ptr
->length
== NEXT_HOP_LENGTH
) && ipa_nonzero(ipp
[1]))
215 bsprintf(buf
, "%I %I", ipp
[0], ipp
[1]);
220 bsprintf(buf
, "%I", ipp
[0]);
224 bgp_check_aggregator(struct bgp_proto
*p
, byte
*a UNUSED
, int len
)
226 int exp_len
= p
->as4_session
? 8 : 6;
228 return (len
== exp_len
) ? 0 : WITHDRAW
;
232 bgp_format_aggregator(eattr
*a
, byte
*buf
, int buflen UNUSED
)
234 struct adata
*ad
= a
->u
.ptr
;
235 byte
*data
= ad
->data
;
241 bsprintf(buf
, "%d.%d.%d.%d AS%d", data
[0], data
[1], data
[2], data
[3], as
);
245 bgp_check_community(struct bgp_proto
*p UNUSED
, byte
*a UNUSED
, int len
)
247 return ((len
% 4) == 0) ? 0 : WITHDRAW
;
252 bgp_check_cluster_list(struct bgp_proto
*p UNUSED
, byte
*a UNUSED
, int len
)
254 return ((len
% 4) == 0) ? 0 : 5;
258 bgp_format_cluster_list(eattr
*a
, byte
*buf
, int buflen
)
260 /* Truncates cluster lists larger than buflen, probably not a problem */
261 int_set_format(a
->u
.ptr
, 0, -1, buf
, buflen
);
265 bgp_check_reach_nlri(struct bgp_proto
*p UNUSED
, byte
*a UNUSED
, int len UNUSED
)
268 p
->mp_reach_start
= a
;
269 p
->mp_reach_len
= len
;
275 bgp_check_unreach_nlri(struct bgp_proto
*p UNUSED
, byte
*a UNUSED
, int len UNUSED
)
278 p
->mp_unreach_start
= a
;
279 p
->mp_unreach_len
= len
;
284 static struct attr_desc bgp_attr_table
[] = {
285 { NULL
, -1, 0, 0, 0, /* Undefined */
287 { "origin", 1, BAF_TRANSITIVE
, EAF_TYPE_INT
, 1, /* BA_ORIGIN */
288 bgp_check_origin
, bgp_format_origin
},
289 { "as_path", -1, BAF_TRANSITIVE
, EAF_TYPE_AS_PATH
, 1, /* BA_AS_PATH */
290 NULL
, NULL
}, /* is checked by validate_as_path() as a special case */
291 { "next_hop", 4, BAF_TRANSITIVE
, EAF_TYPE_IP_ADDRESS
, 1, /* BA_NEXT_HOP */
292 bgp_check_next_hop
, bgp_format_next_hop
},
293 { "med", 4, BAF_OPTIONAL
, EAF_TYPE_INT
, 1, /* BA_MULTI_EXIT_DISC */
295 { "local_pref", 4, BAF_TRANSITIVE
, EAF_TYPE_INT
, 0, /* BA_LOCAL_PREF */
297 { "atomic_aggr", 0, BAF_TRANSITIVE
, EAF_TYPE_OPAQUE
, 1, /* BA_ATOMIC_AGGR */
299 { "aggregator", -1, BAF_OPTIONAL
| BAF_TRANSITIVE
, EAF_TYPE_OPAQUE
, 1, /* BA_AGGREGATOR */
300 bgp_check_aggregator
, bgp_format_aggregator
},
301 { "community", -1, BAF_OPTIONAL
| BAF_TRANSITIVE
, EAF_TYPE_INT_SET
, 1, /* BA_COMMUNITY */
302 bgp_check_community
, NULL
},
303 { "originator_id", 4, BAF_OPTIONAL
, EAF_TYPE_ROUTER_ID
, 0, /* BA_ORIGINATOR_ID */
305 { "cluster_list", -1, BAF_OPTIONAL
, EAF_TYPE_INT_SET
, 0, /* BA_CLUSTER_LIST */
306 bgp_check_cluster_list
, bgp_format_cluster_list
},
307 { .name
= NULL
}, /* BA_DPA */
308 { .name
= NULL
}, /* BA_ADVERTISER */
309 { .name
= NULL
}, /* BA_RCID_PATH */
310 { "mp_reach_nlri", -1, BAF_OPTIONAL
, EAF_TYPE_OPAQUE
, 1, /* BA_MP_REACH_NLRI */
311 bgp_check_reach_nlri
, NULL
},
312 { "mp_unreach_nlri", -1, BAF_OPTIONAL
, EAF_TYPE_OPAQUE
, 1, /* BA_MP_UNREACH_NLRI */
313 bgp_check_unreach_nlri
, NULL
},
314 { .name
= NULL
}, /* BA_EXTENDED_COMM */
315 { "as4_path", -1, BAF_OPTIONAL
| BAF_TRANSITIVE
, EAF_TYPE_OPAQUE
, 1, /* BA_AS4_PATH */
317 { "as4_aggregator", -1, BAF_OPTIONAL
| BAF_TRANSITIVE
, EAF_TYPE_OPAQUE
, 1, /* BA_AS4_PATH */
321 /* BA_AS4_PATH is type EAF_TYPE_OPAQUE and not type EAF_TYPE_AS_PATH.
322 * It does not matter as this attribute does not appear on routes in the routing table.
325 #define ATTR_KNOWN(code) ((code) < ARRAY_SIZE(bgp_attr_table) && bgp_attr_table[code].name)
327 static inline struct adata
*
328 bgp_alloc_adata(struct linpool
*pool
, unsigned len
)
330 struct adata
*ad
= lp_alloc(pool
, sizeof(struct adata
) + len
);
336 bgp_set_attr(eattr
*e
, unsigned attr
, uintptr_t val
)
338 ASSERT(ATTR_KNOWN(attr
));
339 e
->id
= EA_CODE(EAP_BGP
, attr
);
340 e
->type
= bgp_attr_table
[attr
].type
;
341 e
->flags
= bgp_attr_table
[attr
].expected_flags
;
342 if (e
->type
& EAF_EMBEDDED
)
345 e
->u
.ptr
= (struct adata
*) val
;
349 bgp_set_attr_wa(eattr
*e
, struct linpool
*pool
, unsigned attr
, unsigned len
)
351 struct adata
*ad
= bgp_alloc_adata(pool
, len
);
352 bgp_set_attr(e
, attr
, (uintptr_t) ad
);
357 bgp_attach_attr(ea_list
**to
, struct linpool
*pool
, unsigned attr
, uintptr_t val
)
359 ea_list
*a
= lp_alloc(pool
, sizeof(ea_list
) + sizeof(eattr
));
362 a
->flags
= EALF_SORTED
;
364 bgp_set_attr(a
->attrs
, attr
, val
);
368 bgp_attach_attr_wa(ea_list
**to
, struct linpool
*pool
, unsigned attr
, unsigned len
)
370 struct adata
*ad
= bgp_alloc_adata(pool
, len
);
371 bgp_attach_attr(to
, pool
, attr
, (uintptr_t) ad
);
376 bgp_encode_attr_hdr(byte
*dst
, unsigned int flags
, unsigned code
, int len
)
380 DBG("\tAttribute %02x (%d bytes, flags %02x)\n", code
, len
, flags
);
391 *dst
++ = flags
| BAF_EXT_LEN
;
401 aggregator_convert_to_old(struct adata
*aggr
, byte
*dst
, int *new_used
)
403 byte
*src
= aggr
->data
;
406 u32 as
= get_u32(src
);
414 /* Copy IPv4 address */
415 memcpy(dst
+ 2, src
+ 4, 4);
419 aggregator_convert_to_new(struct adata
*aggr
, byte
*dst
)
421 byte
*src
= aggr
->data
;
423 u32 as
= get_u16(src
);
426 /* Copy IPv4 address */
427 memcpy(dst
+ 4, src
+ 2, 4);
431 bgp_get_attr_len(eattr
*a
)
434 if (ATTR_KNOWN(EA_ID(a
->id
)))
436 int code
= EA_ID(a
->id
);
437 struct attr_desc
*desc
= &bgp_attr_table
[code
];
438 len
= desc
->expected_length
;
441 ASSERT(!(a
->type
& EAF_EMBEDDED
));
442 len
= a
->u
.ptr
->length
;
447 ASSERT((a
->type
& EAF_TYPE_MASK
) == EAF_TYPE_OPAQUE
);
448 len
= a
->u
.ptr
->length
;
454 #define ADVANCE(w, r, l) do { r -= l; w += l; } while (0)
457 * bgp_encode_attrs - encode BGP attributes
460 * @attrs: a list of extended attributes
461 * @remains: remaining space in the buffer
463 * The bgp_encode_attrs() function takes a list of extended attributes
464 * and converts it to its BGP representation (a part of an Update message).
466 * Result: Length of the attribute block generated or -1 if not enough space.
469 bgp_encode_attrs(struct bgp_proto
*p
, byte
*w
, ea_list
*attrs
, int remains
)
471 unsigned int i
, code
, flags
;
475 for(i
=0; i
<attrs
->count
; i
++)
477 eattr
*a
= &attrs
->attrs
[i
];
478 ASSERT(EA_PROTO(a
->id
) == EAP_BGP
);
481 /* When talking multiprotocol BGP, the NEXT_HOP attributes are used only temporarily. */
482 if (code
== BA_NEXT_HOP
)
486 /* When AS4-aware BGP speaker is talking to non-AS4-aware BGP speaker,
487 * we have to convert our 4B AS_PATH to 2B AS_PATH and send our AS_PATH
488 * as optional AS4_PATH attribute.
490 if ((code
== BA_AS_PATH
) && (! p
->as4_session
))
492 len
= a
->u
.ptr
->length
;
494 if (remains
< (len
+ 4))
497 /* Using temporary buffer because don't know a length of created attr
498 * and therefore a length of a header. Perhaps i should better always
499 * use BAF_EXT_LEN. */
503 int nl
= as_path_convert_to_old(a
->u
.ptr
, buf
, &new_used
);
505 DBG("BGP: Encoding old AS_PATH\n");
506 rv
= bgp_encode_attr_hdr(w
, BAF_TRANSITIVE
, BA_AS_PATH
, nl
);
507 ADVANCE(w
, remains
, rv
);
509 ADVANCE(w
, remains
, nl
);
514 if (remains
< (len
+ 4))
517 /* We should discard AS_CONFED_SEQUENCE or AS_CONFED_SET path segments
518 * here but we don't support confederations and such paths we already
519 * discarded in bgp_check_as_path().
522 DBG("BGP: Encoding AS4_PATH\n");
523 rv
= bgp_encode_attr_hdr(w
, BAF_OPTIONAL
| BAF_TRANSITIVE
, BA_AS4_PATH
, len
);
524 ADVANCE(w
, remains
, rv
);
525 memcpy(w
, a
->u
.ptr
->data
, len
);
526 ADVANCE(w
, remains
, len
);
531 /* The same issue with AGGREGATOR attribute */
532 if ((code
== BA_AGGREGATOR
) && (! p
->as4_session
))
537 if (remains
< (len
+ 3))
540 rv
= bgp_encode_attr_hdr(w
, BAF_OPTIONAL
| BAF_TRANSITIVE
, BA_AGGREGATOR
, len
);
541 ADVANCE(w
, remains
, rv
);
542 aggregator_convert_to_old(a
->u
.ptr
, w
, &new_used
);
543 ADVANCE(w
, remains
, len
);
549 if (remains
< (len
+ 3))
552 rv
= bgp_encode_attr_hdr(w
, BAF_OPTIONAL
| BAF_TRANSITIVE
, BA_AS4_AGGREGATOR
, len
);
553 ADVANCE(w
, remains
, rv
);
554 memcpy(w
, a
->u
.ptr
->data
, len
);
555 ADVANCE(w
, remains
, len
);
560 /* Standard path continues here ... */
562 flags
= a
->flags
& (BAF_OPTIONAL
| BAF_TRANSITIVE
| BAF_PARTIAL
);
563 len
= bgp_get_attr_len(a
);
565 /* Skip empty int sets */
566 if (((a
->type
& EAF_TYPE_MASK
) == EAF_TYPE_INT_SET
) && (len
== 0))
569 if (remains
< len
+ 4)
572 rv
= bgp_encode_attr_hdr(w
, flags
, code
, len
);
573 ADVANCE(w
, remains
, rv
);
575 switch (a
->type
& EAF_TYPE_MASK
)
578 case EAF_TYPE_ROUTER_ID
:
580 put_u32(w
, a
->u
.data
);
584 case EAF_TYPE_IP_ADDRESS
:
586 ip_addr ip
= *(ip_addr
*)a
->u
.ptr
->data
;
591 case EAF_TYPE_INT_SET
:
593 u32
*z
= (u32
*)a
->u
.ptr
->data
;
595 for(i
=0; i
<len
; i
+=4)
599 case EAF_TYPE_OPAQUE
:
600 case EAF_TYPE_AS_PATH
:
601 memcpy(w
, a
->u
.ptr
->data
, len
);
604 bug("bgp_encode_attrs: unknown attribute type %02x", a
->type
);
606 ADVANCE(w
, remains
, len
);
615 bgp_init_prefix(struct fib_node
*N
)
617 struct bgp_prefix
*p
= (struct bgp_prefix
*) N
;
618 p
->bucket_node
.next
= NULL
;
622 bgp_compare_u32(const u32
*x
, const u32
*y
)
624 return (*x
< *y
) ? -1 : (*x
> *y
) ? 1 : 0;
628 bgp_normalize_set(u32
*dest
, u32
*src
, unsigned cnt
)
630 memcpy(dest
, src
, sizeof(u32
) * cnt
);
631 qsort(dest
, cnt
, sizeof(u32
), (int(*)(const void *, const void *)) bgp_compare_u32
);
635 bgp_rehash_buckets(struct bgp_proto
*p
)
637 struct bgp_bucket
**old
= p
->bucket_hash
;
638 struct bgp_bucket
**new;
639 unsigned oldn
= p
->hash_size
;
641 struct bgp_bucket
*b
;
643 p
->hash_size
= p
->hash_limit
;
644 DBG("BGP: Rehashing bucket table from %d to %d\n", oldn
, p
->hash_size
);
646 if (p
->hash_limit
>= 65536)
648 new = p
->bucket_hash
= mb_allocz(p
->p
.pool
, p
->hash_size
* sizeof(struct bgp_bucket
*));
649 mask
= p
->hash_size
- 1;
650 for (i
=0; i
<oldn
; i
++)
653 old
[i
] = b
->hash_next
;
655 b
->hash_next
= new[e
];
657 b
->hash_next
->hash_prev
= b
;
664 static struct bgp_bucket
*
665 bgp_new_bucket(struct bgp_proto
*p
, ea_list
*new, unsigned hash
)
667 struct bgp_bucket
*b
;
668 unsigned ea_size
= sizeof(ea_list
) + new->count
* sizeof(eattr
);
669 unsigned ea_size_aligned
= BIRD_ALIGN(ea_size
, CPU_STRUCT_ALIGN
);
670 unsigned size
= sizeof(struct bgp_bucket
) + ea_size
;
673 unsigned index
= hash
& (p
->hash_size
- 1);
675 /* Gather total size of non-inline attributes */
676 for (i
=0; i
<new->count
; i
++)
678 eattr
*a
= &new->attrs
[i
];
679 if (!(a
->type
& EAF_EMBEDDED
))
680 size
+= BIRD_ALIGN(sizeof(struct adata
) + a
->u
.ptr
->length
, CPU_STRUCT_ALIGN
);
683 /* Create the bucket and hash it */
684 b
= mb_alloc(p
->p
.pool
, size
);
685 b
->hash_next
= p
->bucket_hash
[index
];
687 b
->hash_next
->hash_prev
= b
;
688 p
->bucket_hash
[index
] = b
;
691 add_tail(&p
->bucket_queue
, &b
->send_node
);
692 init_list(&b
->prefixes
);
693 memcpy(b
->eattrs
, new, ea_size
);
694 dest
= ((byte
*)b
->eattrs
) + ea_size_aligned
;
696 /* Copy values of non-inline attributes */
697 for (i
=0; i
<new->count
; i
++)
699 eattr
*a
= &b
->eattrs
->attrs
[i
];
700 if (!(a
->type
& EAF_EMBEDDED
))
702 struct adata
*oa
= a
->u
.ptr
;
703 struct adata
*na
= (struct adata
*) dest
;
704 memcpy(na
, oa
, sizeof(struct adata
) + oa
->length
);
706 dest
+= BIRD_ALIGN(sizeof(struct adata
) + na
->length
, CPU_STRUCT_ALIGN
);
710 /* If needed, rehash */
712 if (p
->hash_count
> p
->hash_limit
)
713 bgp_rehash_buckets(p
);
718 static struct bgp_bucket
*
719 bgp_get_bucket(struct bgp_proto
*p
, net
*n
, ea_list
*attrs
, int originate
)
722 unsigned i
, cnt
, hash
, code
;
725 struct bgp_bucket
*b
;
727 /* Merge the attribute list */
728 new = alloca(ea_scan(attrs
));
729 ea_merge(attrs
, new);
732 /* Normalize attributes */
739 if (EA_PROTO(a
->id
) != EAP_BGP
)
742 if (ATTR_KNOWN(code
))
744 if (!bgp_attr_table
[code
].allow_in_ebgp
&& !p
->is_internal
)
746 /* The flags might have been zero if the attr was added by filters */
747 a
->flags
= (a
->flags
& BAF_PARTIAL
) | bgp_attr_table
[code
].expected_flags
;
753 /* Don't re-export unknown non-transitive attributes */
754 if (!(a
->flags
& BAF_TRANSITIVE
))
758 if ((d
->type
& EAF_ORIGINATED
) && !originate
&& (d
->flags
& BAF_TRANSITIVE
) && (d
->flags
& BAF_OPTIONAL
))
759 d
->flags
|= BAF_PARTIAL
;
760 switch (d
->type
& EAF_TYPE_MASK
)
762 case EAF_TYPE_INT_SET
:
764 struct adata
*z
= alloca(sizeof(struct adata
) + d
->u
.ptr
->length
);
765 z
->length
= d
->u
.ptr
->length
;
766 bgp_normalize_set((u32
*) z
->data
, (u32
*) d
->u
.ptr
->data
, z
->length
/ 4);
778 for(b
=p
->bucket_hash
[hash
& (p
->hash_size
- 1)]; b
; b
=b
->hash_next
)
779 if (b
->hash
== hash
&& ea_same(b
->eattrs
, new))
781 DBG("Found bucket.\n");
785 /* Ensure that there are all mandatory attributes */
786 for(i
=0; i
<ARRAY_SIZE(bgp_mandatory_attrs
); i
++)
787 if (!(seen
& (1 << bgp_mandatory_attrs
[i
])))
789 log(L_ERR
"%s: Mandatory attribute %s missing in route %I/%d", p
->p
.name
, bgp_attr_table
[bgp_mandatory_attrs
[i
]].name
, n
->n
.prefix
, n
->n
.pxlen
);
793 /* Check if next hop is valid */
794 a
= ea_find(new, EA_CODE(EAP_BGP
, BA_NEXT_HOP
));
795 if (!a
|| ipa_equal(p
->cf
->remote_ip
, *(ip_addr
*)a
->u
.ptr
->data
))
797 log(L_ERR
"%s: Invalid NEXT_HOP attribute in route %I/%d", p
->p
.name
, n
->n
.prefix
, n
->n
.pxlen
);
801 /* Create new bucket */
802 DBG("Creating bucket.\n");
803 return bgp_new_bucket(p
, new, hash
);
807 bgp_free_bucket(struct bgp_proto
*p
, struct bgp_bucket
*buck
)
810 buck
->hash_next
->hash_prev
= buck
->hash_prev
;
812 buck
->hash_prev
->hash_next
= buck
->hash_next
;
814 p
->bucket_hash
[buck
->hash
& (p
->hash_size
-1)] = buck
->hash_next
;
819 bgp_rt_notify(struct proto
*P
, rtable
*tbl UNUSED
, net
*n
, rte
*new, rte
*old UNUSED
, ea_list
*attrs
)
821 struct bgp_proto
*p
= (struct bgp_proto
*) P
;
822 struct bgp_bucket
*buck
;
823 struct bgp_prefix
*px
;
825 DBG("BGP: Got route %I/%d %s\n", n
->n
.prefix
, n
->n
.pxlen
, new ? "up" : "down");
829 buck
= bgp_get_bucket(p
, n
, attrs
, new->attrs
->source
!= RTS_BGP
);
830 if (!buck
) /* Inconsistent attribute list */
835 if (!(buck
= p
->withdraw_bucket
))
837 buck
= p
->withdraw_bucket
= mb_alloc(P
->pool
, sizeof(struct bgp_bucket
));
838 init_list(&buck
->prefixes
);
841 px
= fib_get(&p
->prefix_fib
, &n
->n
.prefix
, n
->n
.pxlen
);
842 if (px
->bucket_node
.next
)
844 DBG("\tRemoving old entry.\n");
845 rem_node(&px
->bucket_node
);
847 add_tail(&buck
->prefixes
, &px
->bucket_node
);
848 bgp_schedule_packet(p
->conn
, PKT_UPDATE
);
852 bgp_create_attrs(struct bgp_proto
*p
, rte
*e
, ea_list
**attrs
, struct linpool
*pool
)
854 ea_list
*ea
= lp_alloc(pool
, sizeof(ea_list
) + 4*sizeof(eattr
));
860 ea
->flags
= EALF_SORTED
;
863 bgp_set_attr(ea
->attrs
, BA_ORIGIN
,
864 ((rta
->source
== RTS_OSPF_EXT1
) || (rta
->source
== RTS_OSPF_EXT2
)) ? ORIGIN_INCOMPLETE
: ORIGIN_IGP
);
867 bgp_set_attr_wa(ea
->attrs
+1, pool
, BA_AS_PATH
, 0);
870 z
= bgp_set_attr_wa(ea
->attrs
+1, pool
, BA_AS_PATH
, 6);
871 z
[0] = AS_PATH_SEQUENCE
;
873 put_u32(z
+2, p
->local_as
);
876 /* iBGP -> use gw, eBGP multi-hop -> use source_addr,
877 eBGP single-hop -> use gw if on the same iface */
878 z
= bgp_set_attr_wa(ea
->attrs
+2, pool
, BA_NEXT_HOP
, NEXT_HOP_LENGTH
);
879 if (p
->cf
->next_hop_self
||
880 rta
->dest
!= RTD_ROUTER
||
881 ipa_equal(rta
->gw
, IPA_NONE
) ||
882 ipa_has_link_scope(rta
->gw
) ||
883 (!p
->is_internal
&& (!p
->neigh
|| (rta
->iface
!= p
->neigh
->iface
))))
884 set_next_hop(z
, p
->source_addr
);
886 set_next_hop(z
, rta
->gw
);
888 bgp_set_attr(ea
->attrs
+3, BA_LOCAL_PREF
, p
->cf
->default_local_pref
);
890 return 0; /* Leave decision to the filters */
895 bgp_as_path_loopy(struct bgp_proto
*p
, rta
*a
)
897 eattr
*e
= ea_find(a
->eattrs
, EA_CODE(EAP_BGP
, BA_AS_PATH
));
898 return (e
&& as_path_is_member(e
->u
.ptr
, p
->local_as
));
902 bgp_originator_id_loopy(struct bgp_proto
*p
, rta
*a
)
904 eattr
*e
= ea_find(a
->eattrs
, EA_CODE(EAP_BGP
, BA_ORIGINATOR_ID
));
905 return (e
&& (e
->u
.data
== p
->local_id
));
909 bgp_cluster_list_loopy(struct bgp_proto
*p
, rta
*a
)
911 eattr
*e
= ea_find(a
->eattrs
, EA_CODE(EAP_BGP
, BA_CLUSTER_LIST
));
912 return (e
&& p
->rr_client
&& int_set_contains(e
->u
.ptr
, p
->rr_cluster_id
));
917 bgp_path_prepend(rte
*e
, ea_list
**attrs
, struct linpool
*pool
, u32 as
)
919 eattr
*a
= ea_find(e
->attrs
->eattrs
, EA_CODE(EAP_BGP
, BA_AS_PATH
));
920 bgp_attach_attr(attrs
, pool
, BA_AS_PATH
, (uintptr_t) as_path_prepend(pool
, a
->u
.ptr
, as
));
924 bgp_cluster_list_prepend(rte
*e
, ea_list
**attrs
, struct linpool
*pool
, u32 cid
)
926 eattr
*a
= ea_find(e
->attrs
->eattrs
, EA_CODE(EAP_BGP
, BA_CLUSTER_LIST
));
927 bgp_attach_attr(attrs
, pool
, BA_CLUSTER_LIST
, (uintptr_t) int_set_add(pool
, a
? a
->u
.ptr
: NULL
, cid
));
931 bgp_update_attrs(struct bgp_proto
*p
, rte
*e
, ea_list
**attrs
, struct linpool
*pool
, int rr
)
935 if (!p
->is_internal
&& !p
->rs_client
)
937 bgp_path_prepend(e
, attrs
, pool
, p
->local_as
);
939 /* The MULTI_EXIT_DISC attribute received from a neighboring AS MUST NOT be
940 * propagated to other neighboring ASes.
941 * Perhaps it would be better to undefine it.
943 a
= ea_find(e
->attrs
->eattrs
, EA_CODE(EAP_BGP
, BA_MULTI_EXIT_DISC
));
945 bgp_attach_attr(attrs
, pool
, BA_MULTI_EXIT_DISC
, 0);
948 /* iBGP -> keep next_hop, eBGP multi-hop -> use source_addr,
949 eBGP single-hop -> keep next_hop if on the same iface */
950 a
= ea_find(e
->attrs
->eattrs
, EA_CODE(EAP_BGP
, BA_NEXT_HOP
));
951 if (a
&& !p
->cf
->next_hop_self
&&
952 (p
->is_internal
|| (p
->neigh
&& (e
->attrs
->iface
== p
->neigh
->iface
))))
954 /* Leave the original next hop attribute, will check later where does it point */
958 /* Need to create new one */
959 byte
*b
= bgp_attach_attr_wa(attrs
, pool
, BA_NEXT_HOP
, NEXT_HOP_LENGTH
);
960 set_next_hop(b
, p
->source_addr
);
965 /* Handling route reflection, RFC 4456 */
966 struct bgp_proto
*src
= (struct bgp_proto
*) e
->attrs
->proto
;
968 a
= ea_find(e
->attrs
->eattrs
, EA_CODE(EAP_BGP
, BA_ORIGINATOR_ID
));
970 bgp_attach_attr(attrs
, pool
, BA_ORIGINATOR_ID
, src
->remote_id
);
972 /* We attach proper cluster ID according to whether the route is entering or leaving the cluster */
973 bgp_cluster_list_prepend(e
, attrs
, pool
, src
->rr_client
? src
->rr_cluster_id
: p
->rr_cluster_id
);
975 /* Two RR clients with different cluster ID, hmmm */
976 if (src
->rr_client
&& p
->rr_client
&& (src
->rr_cluster_id
!= p
->rr_cluster_id
))
977 bgp_cluster_list_prepend(e
, attrs
, pool
, p
->rr_cluster_id
);
980 return 0; /* Leave decision to the filters */
984 bgp_community_filter(struct bgp_proto
*p
, rte
*e
)
989 /* Check if we aren't forbidden to export the route by communities */
990 a
= ea_find(e
->attrs
->eattrs
, EA_CODE(EAP_BGP
, BA_COMMUNITY
));
994 if (int_set_contains(d
, BGP_COMM_NO_ADVERTISE
))
996 DBG("\tNO_ADVERTISE\n");
999 if (!p
->is_internal
&&
1000 (int_set_contains(d
, BGP_COMM_NO_EXPORT
) ||
1001 int_set_contains(d
, BGP_COMM_NO_EXPORT_SUBCONFED
)))
1003 DBG("\tNO_EXPORT\n");
1012 bgp_import_control(struct proto
*P
, rte
**new, ea_list
**attrs
, struct linpool
*pool
)
1015 struct bgp_proto
*p
= (struct bgp_proto
*) P
;
1016 struct bgp_proto
*new_bgp
= (e
->attrs
->proto
->proto
== &proto_bgp
) ? (struct bgp_proto
*) e
->attrs
->proto
: NULL
;
1018 if (p
== new_bgp
) /* Poison reverse updates */
1022 /* We should check here for cluster list loop, because the receiving BGP instance
1023 might have different cluster ID */
1024 if (bgp_cluster_list_loopy(p
, e
->attrs
))
1027 if (p
->cf
->interpret_communities
&& bgp_community_filter(p
, e
))
1030 if (p
->local_as
== new_bgp
->local_as
&& p
->is_internal
&& new_bgp
->is_internal
)
1032 /* Redistribution of internal routes with IBGP */
1033 if (p
->rr_client
|| new_bgp
->rr_client
)
1034 /* Route reflection, RFC 4456 */
1035 return bgp_update_attrs(p
, e
, attrs
, pool
, 1);
1040 return bgp_update_attrs(p
, e
, attrs
, pool
, 0);
1043 return bgp_create_attrs(p
, e
, attrs
, pool
);
1047 bgp_get_neighbor(rte
*r
)
1049 eattr
*e
= ea_find(r
->attrs
->eattrs
, EA_CODE(EAP_BGP
, BA_AS_PATH
));
1052 if (e
&& as_path_get_first(e
->u
.ptr
, &as
))
1055 return ((struct bgp_proto
*) r
->attrs
->proto
)->remote_as
;
1059 rte_resolvable(rte
*rt
)
1061 int rd
= rt
->attrs
->dest
;
1062 return (rd
== RTD_ROUTER
) || (rd
== RTD_DEVICE
) || (rd
== RTD_MULTIPATH
);
1066 bgp_rte_better(rte
*new, rte
*old
)
1068 struct bgp_proto
*new_bgp
= (struct bgp_proto
*) new->attrs
->proto
;
1069 struct bgp_proto
*old_bgp
= (struct bgp_proto
*) old
->attrs
->proto
;
1073 /* RFC 4271 9.1.2.1. Route resolvability test */
1074 n
= rte_resolvable(new);
1075 o
= rte_resolvable(old
);
1081 /* Start with local preferences */
1082 x
= ea_find(new->attrs
->eattrs
, EA_CODE(EAP_BGP
, BA_LOCAL_PREF
));
1083 y
= ea_find(old
->attrs
->eattrs
, EA_CODE(EAP_BGP
, BA_LOCAL_PREF
));
1084 n
= x
? x
->u
.data
: new_bgp
->cf
->default_local_pref
;
1085 o
= y
? y
->u
.data
: old_bgp
->cf
->default_local_pref
;
1091 /* RFC 4271 9.1.2.2. a) Use AS path lengths */
1092 if (new_bgp
->cf
->compare_path_lengths
|| old_bgp
->cf
->compare_path_lengths
)
1094 x
= ea_find(new->attrs
->eattrs
, EA_CODE(EAP_BGP
, BA_AS_PATH
));
1095 y
= ea_find(old
->attrs
->eattrs
, EA_CODE(EAP_BGP
, BA_AS_PATH
));
1096 n
= x
? as_path_getlen(x
->u
.ptr
) : AS_PATH_MAXLEN
;
1097 o
= y
? as_path_getlen(y
->u
.ptr
) : AS_PATH_MAXLEN
;
1104 /* RFC 4271 9.1.2.2. b) Use origins */
1105 x
= ea_find(new->attrs
->eattrs
, EA_CODE(EAP_BGP
, BA_ORIGIN
));
1106 y
= ea_find(old
->attrs
->eattrs
, EA_CODE(EAP_BGP
, BA_ORIGIN
));
1107 n
= x
? x
->u
.data
: ORIGIN_INCOMPLETE
;
1108 o
= y
? y
->u
.data
: ORIGIN_INCOMPLETE
;
1114 /* RFC 4271 9.1.2.2. c) Compare MED's */
1115 /* This is noncompliant. Proper RFC 4271 path selection cannot be
1116 * interpreted as finding the best path in some ordering.
1117 * Therefore, it cannot be implemented in BIRD without some ugly
1118 * hacks. This is just an approximation, which in specific
1119 * situations may lead to persistent routing loops, because it is
1120 * nondeterministic - it depends on the order in which routes
1121 * appeared. But it is also the same behavior as used by default in
1122 * Cisco routers, so it is probably not a big issue.
1124 if (new_bgp
->cf
->med_metric
|| old_bgp
->cf
->med_metric
||
1125 (bgp_get_neighbor(new) == bgp_get_neighbor(old
)))
1127 x
= ea_find(new->attrs
->eattrs
, EA_CODE(EAP_BGP
, BA_MULTI_EXIT_DISC
));
1128 y
= ea_find(old
->attrs
->eattrs
, EA_CODE(EAP_BGP
, BA_MULTI_EXIT_DISC
));
1129 n
= x
? x
->u
.data
: new_bgp
->cf
->default_med
;
1130 o
= y
? y
->u
.data
: old_bgp
->cf
->default_med
;
1137 /* RFC 4271 9.1.2.2. d) Prefer external peers */
1138 if (new_bgp
->is_internal
> old_bgp
->is_internal
)
1140 if (new_bgp
->is_internal
< old_bgp
->is_internal
)
1143 /* RFC 4271 9.1.2.2. e) Compare IGP metrics */
1144 n
= new_bgp
->cf
->igp_metric
? new->attrs
->igp_metric
: 0;
1145 o
= old_bgp
->cf
->igp_metric
? old
->attrs
->igp_metric
: 0;
1151 /* RFC 4271 9.1.2.2. f) Compare BGP identifiers */
1152 /* RFC 4456 9. a) Use ORIGINATOR_ID instead of local neighor ID */
1153 x
= ea_find(new->attrs
->eattrs
, EA_CODE(EAP_BGP
, BA_ORIGINATOR_ID
));
1154 y
= ea_find(old
->attrs
->eattrs
, EA_CODE(EAP_BGP
, BA_ORIGINATOR_ID
));
1155 n
= x
? x
->u
.data
: new_bgp
->remote_id
;
1156 o
= y
? y
->u
.data
: old_bgp
->remote_id
;
1158 /* RFC 5004 - prefer older routes */
1159 /* (if both are external and from different peer) */
1160 if ((new_bgp
->cf
->prefer_older
|| old_bgp
->cf
->prefer_older
) &&
1161 !new_bgp
->is_internal
&& n
!= o
)
1164 /* rest of RFC 4271 9.1.2.2. f) */
1170 /* RFC 4456 9. b) Compare cluster list lengths */
1171 x
= ea_find(new->attrs
->eattrs
, EA_CODE(EAP_BGP
, BA_CLUSTER_LIST
));
1172 y
= ea_find(old
->attrs
->eattrs
, EA_CODE(EAP_BGP
, BA_CLUSTER_LIST
));
1173 n
= x
? int_set_get_size(x
->u
.ptr
) : 0;
1174 o
= y
? int_set_get_size(y
->u
.ptr
) : 0;
1180 /* RFC 4271 9.1.2.2. g) Compare peer IP adresses */
1181 return (ipa_compare(new_bgp
->cf
->remote_ip
, old_bgp
->cf
->remote_ip
) < 0);
1184 static struct adata
*
1185 bgp_aggregator_convert_to_new(struct adata
*old
, struct linpool
*pool
)
1187 struct adata
*newa
= lp_alloc(pool
, sizeof(struct adata
) + 8);
1189 aggregator_convert_to_new(old
, newa
->data
);
1194 /* Take last req_as ASNs from path old2 (in 2B format), convert to 4B format
1195 * and append path old4 (in 4B format).
1197 static struct adata
*
1198 bgp_merge_as_paths(struct adata
*old2
, struct adata
*old4
, int req_as
, struct linpool
*pool
)
1200 byte buf
[old2
->length
* 2];
1202 int ol
= as_path_convert_to_new(old2
, buf
, req_as
);
1203 int nl
= ol
+ (old4
? old4
->length
: 0);
1205 struct adata
*newa
= lp_alloc(pool
, sizeof(struct adata
) + nl
);
1207 memcpy(newa
->data
, buf
, ol
);
1208 if (old4
) memcpy(newa
->data
+ ol
, old4
->data
, old4
->length
);
1214 as4_aggregator_valid(struct adata
*aggr
)
1216 return aggr
->length
== 8;
1220 /* Reconstruct 4B AS_PATH and AGGREGATOR according to RFC 4893 4.2.3 */
1222 bgp_reconstruct_4b_atts(struct bgp_proto
*p
, rta
*a
, struct linpool
*pool
)
1224 eattr
*p2
=ea_find(a
->eattrs
, EA_CODE(EAP_BGP
, BA_AS_PATH
));
1225 eattr
*p4
=ea_find(a
->eattrs
, EA_CODE(EAP_BGP
, BA_AS4_PATH
));
1226 eattr
*a2
=ea_find(a
->eattrs
, EA_CODE(EAP_BGP
, BA_AGGREGATOR
));
1227 eattr
*a4
=ea_find(a
->eattrs
, EA_CODE(EAP_BGP
, BA_AS4_AGGREGATOR
));
1230 if (a4
&& !as4_aggregator_valid(a4
->u
.ptr
))
1232 log(L_WARN
"%s: AS4_AGGREGATOR attribute is invalid, skipping attribute", p
->p
.name
);
1239 u32 a2_as
= get_u16(a2
->u
.ptr
->data
);
1243 if (a2_as
!= AS_TRANS
)
1245 /* Routes were aggregated by old router and therefore AS4_PATH
1246 * and AS4_AGGREGATOR is invalid
1248 * Convert AS_PATH and AGGREGATOR to 4B format and finish.
1251 a2
->u
.ptr
= bgp_aggregator_convert_to_new(a2
->u
.ptr
, pool
);
1252 p2
->u
.ptr
= bgp_merge_as_paths(p2
->u
.ptr
, NULL
, AS_PATH_MAXLEN
, pool
);
1258 /* Common case, use AS4_AGGREGATOR attribute */
1259 a2
->u
.ptr
= a4
->u
.ptr
;
1264 /* Common case, use old AGGREGATOR attribute */
1265 a2
->u
.ptr
= bgp_aggregator_convert_to_new(a2
->u
.ptr
, pool
);
1267 if ((a2_as
== AS_TRANS
) && !a4_removed
)
1268 log(L_WARN
"%s: AGGREGATOR attribute contain AS_TRANS, but AS4_AGGREGATOR is missing", p
->p
.name
);
1273 log(L_WARN
"%s: AS4_AGGREGATOR attribute received, but AGGREGATOR attribute is missing", p
->p
.name
);
1275 int p2_len
= as_path_getlen_int(p2
->u
.ptr
, 2);
1276 int p4_len
= p4
? validate_as4_path(p
, p4
->u
.ptr
) : -1;
1278 if (p4
&& (p4_len
< 0))
1279 log(L_WARN
"%s: AS4_PATH attribute is malformed, skipping attribute", p
->p
.name
);
1281 if ((p4_len
<= 0) || (p2_len
< p4_len
))
1282 p2
->u
.ptr
= bgp_merge_as_paths(p2
->u
.ptr
, NULL
, AS_PATH_MAXLEN
, pool
);
1284 p2
->u
.ptr
= bgp_merge_as_paths(p2
->u
.ptr
, p4
->u
.ptr
, p2_len
- p4_len
, pool
);
1288 bgp_remove_as4_attrs(struct bgp_proto
*p
, rta
*a
)
1290 unsigned id1
= EA_CODE(EAP_BGP
, BA_AS4_PATH
);
1291 unsigned id2
= EA_CODE(EAP_BGP
, BA_AS4_AGGREGATOR
);
1292 ea_list
**el
= &(a
->eattrs
);
1294 /* We know that ea_lists constructed in bgp_decode attrs have one attribute per ea_list struct */
1297 unsigned fid
= (*el
)->attrs
[0].id
;
1299 if ((fid
== id1
) || (fid
== id2
))
1303 log(L_WARN
"%s: Unexpected AS4_* attributes received", p
->p
.name
);
1306 el
= &((*el
)->next
);
1311 * bgp_decode_attrs - check and decode BGP attributes
1313 * @attr: start of attribute block
1314 * @len: length of attribute block
1315 * @pool: linear pool to make all the allocations in
1316 * @mandatory: 1 iff presence of mandatory attributes has to be checked
1318 * This function takes a BGP attribute block (a part of an Update message), checks
1319 * its consistency and converts it to a list of BIRD route attributes represented
1323 bgp_decode_attrs(struct bgp_conn
*conn
, byte
*attr
, unsigned int len
, struct linpool
*pool
, int mandatory
)
1325 struct bgp_proto
*bgp
= conn
->bgp
;
1326 rta
*a
= lp_alloc(pool
, sizeof(struct rta
));
1327 unsigned int flags
, code
, l
, i
, type
;
1329 byte
*z
, *attr_start
;
1335 bzero(a
, sizeof(rta
));
1337 a
->source
= RTS_BGP
;
1338 a
->scope
= SCOPE_UNIVERSE
;
1339 a
->cast
= RTC_UNICAST
;
1340 /* a->dest = RTD_ROUTER; -- set in bgp_set_next_hop() */
1341 a
->from
= bgp
->cf
->remote_ip
;
1343 /* Parse the attributes */
1344 bzero(seen
, sizeof(seen
));
1345 DBG("BGP: Parsing attributes\n");
1354 if (flags
& BAF_EXT_LEN
)
1374 DBG("Attr %02x %02x %d\n", code
, flags
, l
);
1375 if (seen
[code
/8] & (1 << (code
%8)))
1377 if (ATTR_KNOWN(code
))
1379 struct attr_desc
*desc
= &bgp_attr_table
[code
];
1380 if (desc
->expected_length
>= 0 && desc
->expected_length
!= (int) l
)
1381 { errcode
= 5; goto err
; }
1382 if ((desc
->expected_flags
^ flags
) & (BAF_OPTIONAL
| BAF_TRANSITIVE
))
1383 { errcode
= 4; goto err
; }
1384 if (!desc
->allow_in_ebgp
&& !bgp
->is_internal
)
1388 errcode
= desc
->validate(bgp
, z
, l
);
1391 if (errcode
== IGNORE
)
1393 if (errcode
<= WITHDRAW
)
1395 log(L_WARN
"%s: Attribute %s is malformed, withdrawing update",
1396 bgp
->p
.name
, desc
->name
);
1400 else if (code
== BA_AS_PATH
)
1402 /* Special case as it might also trim the attribute */
1403 if (validate_as_path(bgp
, z
, &l
) < 0)
1404 { errcode
= 11; goto err
; }
1408 else /* Unknown attribute */
1410 if (!(flags
& BAF_OPTIONAL
))
1411 { errcode
= 2; goto err
; }
1412 type
= EAF_TYPE_OPAQUE
;
1415 // Only OPTIONAL and TRANSITIVE attributes may have non-zero PARTIAL flag
1416 // if (!((flags & BAF_OPTIONAL) && (flags & BAF_TRANSITIVE)) && (flags & BAF_PARTIAL))
1417 // { errcode = 4; goto err; }
1419 seen
[code
/8] |= (1 << (code
%8));
1420 ea
= lp_alloc(pool
, sizeof(ea_list
) + sizeof(eattr
));
1421 ea
->next
= a
->eattrs
;
1425 ea
->attrs
[0].id
= EA_CODE(EAP_BGP
, code
);
1426 ea
->attrs
[0].flags
= flags
;
1427 ea
->attrs
[0].type
= type
;
1428 if (type
& EAF_EMBEDDED
)
1432 ad
= lp_alloc(pool
, sizeof(struct adata
) + l
);
1433 ea
->attrs
[0].u
.ptr
= ad
;
1435 memcpy(ad
->data
, z
, l
);
1439 case EAF_TYPE_ROUTER_ID
:
1442 ea
->attrs
[0].u
.data
= *z
;
1444 ea
->attrs
[0].u
.data
= get_u32(z
);
1446 case EAF_TYPE_IP_ADDRESS
:
1447 ipa_ntoh(*(ip_addr
*)ad
->data
);
1449 case EAF_TYPE_INT_SET
:
1451 u32
*z
= (u32
*) ad
->data
;
1452 for(i
=0; i
<ad
->length
/4; i
++)
1463 /* If we received MP_REACH_NLRI we should check mandatory attributes */
1464 if (bgp
->mp_reach_len
!= 0)
1468 /* If there is no (reachability) NLRI, we should exit now */
1472 /* Check if all mandatory attributes are present */
1473 for(i
=0; i
< ARRAY_SIZE(bgp_mandatory_attrs
); i
++)
1475 code
= bgp_mandatory_attrs
[i
];
1476 if (!(seen
[code
/8] & (1 << (code
%8))))
1478 bgp_error(conn
, 3, 3, &bgp_mandatory_attrs
[i
], 1);
1483 /* When receiving attributes from non-AS4-aware BGP speaker,
1484 * we have to reconstruct 4B AS_PATH and AGGREGATOR attributes
1486 if (! bgp
->as4_session
)
1487 bgp_reconstruct_4b_atts(bgp
, a
, pool
);
1489 bgp_remove_as4_attrs(bgp
, a
);
1491 /* If the AS path attribute contains our AS, reject the routes */
1492 if (bgp_as_path_loopy(bgp
, a
))
1495 /* Two checks for IBGP loops caused by route reflection, RFC 4456 */
1496 if (bgp_originator_id_loopy(bgp
, a
) ||
1497 bgp_cluster_list_loopy(bgp
, a
))
1500 /* If there's no local preference, define one */
1501 if (!(seen
[0] & (1 << BA_LOCAL_PREF
)))
1502 bgp_attach_attr(&a
->eattrs
, pool
, BA_LOCAL_PREF
, bgp
->cf
->default_local_pref
);
1510 bgp_error(conn
, 3, 1, NULL
, 0);
1514 bgp_error(conn
, 3, errcode
, attr_start
, z
+l
-attr_start
);
1519 bgp_get_attr(eattr
*a
, byte
*buf
, int buflen
)
1521 unsigned int i
= EA_ID(a
->id
);
1522 struct attr_desc
*d
;
1526 d
= &bgp_attr_table
[i
];
1527 buf
+= bsprintf(buf
, "%s", d
->name
);
1532 d
->format(a
, buf
, buflen
);
1537 bsprintf(buf
, "%02x%s", i
, (a
->flags
& BAF_TRANSITIVE
) ? " [t]" : "");
1542 bgp_attr_init(struct bgp_proto
*p
)
1545 p
->hash_limit
= p
->hash_size
* 4;
1546 p
->bucket_hash
= mb_allocz(p
->p
.pool
, p
->hash_size
* sizeof(struct bgp_bucket
*));
1547 init_list(&p
->bucket_queue
);
1548 p
->withdraw_bucket
= NULL
;
1549 fib_init(&p
->prefix_fib
, p
->p
.pool
, sizeof(struct bgp_prefix
), 0, bgp_init_prefix
);
1553 bgp_get_route_info(rte
*e
, byte
*buf
, ea_list
*attrs
)
1555 eattr
*p
= ea_find(attrs
, EA_CODE(EAP_BGP
, BA_AS_PATH
));
1556 eattr
*o
= ea_find(attrs
, EA_CODE(EAP_BGP
, BA_ORIGIN
));
1559 buf
+= bsprintf(buf
, " (%d", e
->pref
);
1560 if (e
->attrs
->hostentry
)
1562 if (!rte_resolvable(e
))
1563 buf
+= bsprintf(buf
, "/-");
1564 else if (e
->attrs
->igp_metric
>= IGP_METRIC_UNKNOWN
)
1565 buf
+= bsprintf(buf
, "/?");
1567 buf
+= bsprintf(buf
, "/%d", e
->attrs
->igp_metric
);
1569 buf
+= bsprintf(buf
, ") [");
1571 if (p
&& as_path_get_last(p
->u
.ptr
, &origas
))
1572 buf
+= bsprintf(buf
, "AS%u", origas
);
1574 buf
+= bsprintf(buf
, "%c", "ie?"[o
->u
.data
]);