1 /* AS path management routines.
2 * Copyright (C) 1996, 97, 98, 99 Kunihiro Ishiguro
3 * Copyright (C) 2005 Sun Microsystems, Inc.
5 * This file is part of GNU Zebra.
7 * GNU Zebra is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2, or (at your option) any
12 * GNU Zebra is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
17 * You should have received a copy of the GNU General Public License along
18 * with this program; see the file COPYING; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
34 #include "bgpd/bgpd.h"
35 #include "bgpd/bgp_aspath.h"
36 #include "bgpd/bgp_debug.h"
37 #include "bgpd/bgp_attr.h"
38 #include "bgpd/bgp_errors.h"
40 /* Attr. Flags and Attr. Type Code. */
41 #define AS_HEADER_SIZE 2
43 /* Now FOUR octets are used for AS value. */
44 #define AS_VALUE_SIZE sizeof(as_t)
45 /* This is the old one */
46 #define AS16_VALUE_SIZE sizeof(as16_t)
48 /* Maximum protocol segment length value */
49 #define AS_SEGMENT_MAX 255
51 /* The following length and size macros relate specifically to Quagga's
52 * internal representation of AS-Segments, not per se to the on-wire
53 * sizes and lengths. At present (200508) they sort of match, however
54 * the ONLY functions which should now about the on-wire syntax are
55 * aspath_put, assegment_put and assegment_parse.
57 * aspath_put returns bytes written, the only definitive record of
58 * size of wire-format attribute..
61 /* Calculated size in bytes of ASN segment data to hold N ASN's */
62 #define ASSEGMENT_DATA_SIZE(N, S) \
63 ((N) * ((S) ? AS_VALUE_SIZE : AS16_VALUE_SIZE))
65 /* Calculated size of segment struct to hold N ASN's */
66 #define ASSEGMENT_SIZE(N,S) (AS_HEADER_SIZE + ASSEGMENT_DATA_SIZE (N,S))
68 /* AS segment octet length. */
69 #define ASSEGMENT_LEN(X,S) ASSEGMENT_SIZE((X)->length,S)
71 /* AS_SEQUENCE segments can be packed together */
72 /* Can the types of X and Y be considered for packing? */
73 #define ASSEGMENT_TYPES_PACKABLE(X, Y) \
74 (((X)->type == (Y)->type) && ((X)->type == AS_SEQUENCE))
75 /* Types and length of X,Y suitable for packing? */
76 #define ASSEGMENTS_PACKABLE(X, Y) \
77 (ASSEGMENT_TYPES_PACKABLE((X), (Y)) \
78 && (((X)->length + (Y)->length) <= AS_SEGMENT_MAX))
80 /* As segment header - the on-wire representation
81 * NOT the internal representation!
83 struct assegment_header
{
88 /* Hash for aspath. This is the top level structure of AS path. */
89 static struct hash
*ashash
;
91 /* Stream for SNMP. See aspath_snmp_pathseg */
92 static struct stream
*snmp_stream
;
94 /* Callers are required to initialize the memory */
95 static as_t
*assegment_data_new(int num
)
97 return (XMALLOC(MTYPE_AS_SEG_DATA
, ASSEGMENT_DATA_SIZE(num
, 1)));
100 static void assegment_data_free(as_t
*asdata
)
102 XFREE(MTYPE_AS_SEG_DATA
, asdata
);
105 const char *const aspath_segment_type_str
[] = {
106 "as-invalid", "as-set", "as-sequence", "as-confed-sequence",
110 /* Get a new segment. Note that 0 is an allowed length,
111 * and will result in a segment with no allocated data segment.
112 * the caller should immediately assign data to the segment, as the segment
113 * otherwise is not generally valid
115 static struct assegment
*assegment_new(uint8_t type
, unsigned short length
)
117 struct assegment
*new;
119 new = XCALLOC(MTYPE_AS_SEG
, sizeof(struct assegment
));
122 new->as
= assegment_data_new(length
);
124 new->length
= length
;
130 static void assegment_free(struct assegment
*seg
)
135 assegment_data_free(seg
->as
);
136 memset(seg
, 0xfe, sizeof(struct assegment
));
137 XFREE(MTYPE_AS_SEG
, seg
);
142 /* free entire chain of segments */
143 static void assegment_free_all(struct assegment
*seg
)
145 struct assegment
*prev
;
150 assegment_free(prev
);
154 /* Duplicate just the given assegment and its data */
155 static struct assegment
*assegment_dup(struct assegment
*seg
)
157 struct assegment
*new;
159 new = assegment_new(seg
->type
, seg
->length
);
160 memcpy(new->as
, seg
->as
, ASSEGMENT_DATA_SIZE(new->length
, 1));
165 /* Duplicate entire chain of assegments, return the head */
166 static struct assegment
*assegment_dup_all(struct assegment
*seg
)
168 struct assegment
*new = NULL
;
169 struct assegment
*head
= NULL
;
173 new->next
= assegment_dup(seg
);
176 head
= new = assegment_dup(seg
);
183 /* prepend the as number to given segment, given num of times */
184 static struct assegment
*assegment_prepend_asns(struct assegment
*seg
,
193 if (num
>= AS_SEGMENT_MAX
)
194 return seg
; /* we don't do huge prepends */
196 newas
= assegment_data_new(seg
->length
+ num
);
200 for (i
= 0; i
< num
; i
++)
203 memcpy(newas
+ num
, seg
->as
, ASSEGMENT_DATA_SIZE(seg
->length
, 1));
204 assegment_data_free(seg
->as
);
211 /* append given array of as numbers to the segment */
212 static struct assegment
*assegment_append_asns(struct assegment
*seg
,
213 as_t
*asnos
, int num
)
220 newas
= XREALLOC(MTYPE_AS_SEG_DATA
, seg
->as
,
221 ASSEGMENT_DATA_SIZE(seg
->length
+ num
, 1));
224 memcpy(seg
->as
+ seg
->length
, asnos
,
225 ASSEGMENT_DATA_SIZE(num
, 1));
230 static int int_cmp(const void *p1
, const void *p2
)
232 const as_t
*as1
= p1
;
233 const as_t
*as2
= p2
;
235 return (*as1
== *as2
) ? 0 : ((*as1
> *as2
) ? 1 : -1);
238 /* normalise the segment.
239 * In particular, merge runs of AS_SEQUENCEs into one segment
240 * Internally, we do not care about the wire segment length limit, and
241 * we want each distinct AS_PATHs to have the exact same internal
242 * representation - eg, so that our hashing actually works..
244 static struct assegment
*assegment_normalise(struct assegment
*head
)
246 struct assegment
*seg
= head
, *pin
;
247 struct assegment
*tmp
;
255 /* Sort values SET segments, for determinism in paths to aid
256 * creation of hash values / path comparisons
257 * and because it helps other lesser implementations ;)
259 if (seg
->type
== AS_SET
|| seg
->type
== AS_CONFED_SET
) {
263 qsort(seg
->as
, seg
->length
, sizeof(as_t
), int_cmp
);
266 for (i
= 1; i
< seg
->length
; i
++) {
267 if (seg
->as
[tail
] == seg
->as
[i
])
272 seg
->as
[tail
] = seg
->as
[i
];
274 /* seg->length can be 0.. */
276 seg
->length
= tail
+ 1;
279 /* read ahead from the current, pinned segment while the
281 * are packable/mergeable. Append all following packable
283 * to the segment we have pinned and remove these appended
286 while (pin
->next
&& ASSEGMENT_TYPES_PACKABLE(pin
, pin
->next
)) {
290 /* append the next sequence to the pinned sequence */
291 pin
= assegment_append_asns(pin
, seg
->as
, seg
->length
);
293 /* bypass the next sequence */
294 pin
->next
= seg
->next
;
296 /* get rid of the now referenceless segment */
305 static struct aspath
*aspath_new(void)
307 return XCALLOC(MTYPE_AS_PATH
, sizeof(struct aspath
));
310 /* Free AS path structure. */
311 void aspath_free(struct aspath
*aspath
)
315 if (aspath
->segments
)
316 assegment_free_all(aspath
->segments
);
317 XFREE(MTYPE_AS_STR
, aspath
->str
);
320 json_object_free(aspath
->json
);
324 XFREE(MTYPE_AS_PATH
, aspath
);
327 /* Unintern aspath from AS path bucket. */
328 void aspath_unintern(struct aspath
**aspath
)
341 if (asp
->refcnt
== 0) {
342 /* This aspath must exist in aspath hash table. */
343 ret
= hash_release(ashash
, asp
);
350 /* Return the start or end delimiters for a particular Segment type */
351 #define AS_SEG_START 0
353 static char aspath_delimiter_char(uint8_t type
, uint8_t which
)
360 } aspath_delim_char
[] = {{AS_SET
, '{', '}'},
361 {AS_CONFED_SET
, '[', ']'},
362 {AS_CONFED_SEQUENCE
, '(', ')'},
365 for (i
= 0; aspath_delim_char
[i
].type
!= 0; i
++) {
366 if (aspath_delim_char
[i
].type
== type
) {
367 if (which
== AS_SEG_START
)
368 return aspath_delim_char
[i
].start
;
369 else if (which
== AS_SEG_END
)
370 return aspath_delim_char
[i
].end
;
376 /* countup asns from this segment and index onward */
377 static int assegment_count_asns(struct assegment
*seg
, int from
)
382 count
+= seg
->length
;
384 count
+= (seg
->length
- from
);
392 unsigned int aspath_count_confeds(struct aspath
*aspath
)
395 struct assegment
*seg
= aspath
->segments
;
398 if (seg
->type
== AS_CONFED_SEQUENCE
)
399 count
+= seg
->length
;
400 else if (seg
->type
== AS_CONFED_SET
)
408 unsigned int aspath_count_hops(const struct aspath
*aspath
)
411 struct assegment
*seg
= aspath
->segments
;
414 if (seg
->type
== AS_SEQUENCE
)
415 count
+= seg
->length
;
416 else if (seg
->type
== AS_SET
)
424 /* Check if aspath has AS_SET or AS_CONFED_SET */
425 bool aspath_check_as_sets(struct aspath
*aspath
)
427 struct assegment
*seg
= aspath
->segments
;
430 if (seg
->type
== AS_SET
|| seg
->type
== AS_CONFED_SET
)
437 /* Check if aspath has BGP_AS_ZERO */
438 bool aspath_check_as_zero(struct aspath
*aspath
)
440 struct assegment
*seg
= aspath
->segments
;
444 for (i
= 0; i
< seg
->length
; i
++)
445 if (seg
->as
[i
] == BGP_AS_ZERO
)
453 /* Estimate size aspath /might/ take if encoded into an
456 * This is a quick estimate, not definitive! aspath_put()
457 * may return a different number!!
459 unsigned int aspath_size(struct aspath
*aspath
)
462 struct assegment
*seg
= aspath
->segments
;
465 size
+= ASSEGMENT_SIZE(seg
->length
, 1);
471 /* Return highest public ASN in path */
472 as_t
aspath_highest(struct aspath
*aspath
)
474 struct assegment
*seg
= aspath
->segments
;
479 for (i
= 0; i
< seg
->length
; i
++)
480 if (seg
->as
[i
] > highest
481 && !BGP_AS_IS_PRIVATE(seg
->as
[i
]))
482 highest
= seg
->as
[i
];
488 /* Return the left-most ASN in path */
489 as_t
aspath_leftmost(struct aspath
*aspath
)
491 struct assegment
*seg
= aspath
->segments
;
494 if (seg
&& seg
->length
&& seg
->type
== AS_SEQUENCE
)
495 leftmost
= seg
->as
[0];
500 /* Return 1 if there are any 4-byte ASes in the path */
501 bool aspath_has_as4(struct aspath
*aspath
)
503 struct assegment
*seg
= aspath
->segments
;
507 for (i
= 0; i
< seg
->length
; i
++)
508 if (seg
->as
[i
] > BGP_AS_MAX
)
515 /* Convert aspath structure to string expression. */
516 static void aspath_make_str_count(struct aspath
*as
, bool make_json
)
518 struct assegment
*seg
;
522 json_object
*jaspath_segments
= NULL
;
523 json_object
*jseg
= NULL
;
524 json_object
*jseg_list
= NULL
;
527 as
->json
= json_object_new_object();
528 jaspath_segments
= json_object_new_array();
534 json_object_string_add(as
->json
, "string", "Local");
535 json_object_object_add(as
->json
, "segments",
537 json_object_int_add(as
->json
, "length", 0);
539 as
->str
= XMALLOC(MTYPE_AS_STR
, 1);
547 /* ASN takes 5 to 10 chars plus separator, see below.
548 * If there is one differing segment type, we need an additional
549 * 2 chars for segment delimiters, and the final '\0'.
550 * Hopefully this is large enough to avoid hitting the realloc
551 * code below for most common sequences.
553 * This was changed to 10 after the well-known BGP assertion, which
554 * had hit some parts of the Internet in May of 2009.
556 #define ASN_STR_LEN (10 + 1)
557 str_size
= MAX(assegment_count_asns(seg
, 0) * ASN_STR_LEN
+ 2 + 1,
558 ASPATH_STR_DEFAULT_LEN
);
559 str_buf
= XMALLOC(MTYPE_AS_STR
, str_size
);
565 /* Check AS type validity. Set separator for segment */
572 case AS_CONFED_SEQUENCE
:
576 XFREE(MTYPE_AS_STR
, str_buf
);
579 json_object_free(as
->json
);
585 /* We might need to increase str_buf, particularly if path has
586 * differing segments types, our initial guesstimate above will
587 * have been wrong. Need 10 chars for ASN, a separator each and
588 * potentially two segment delimiters, plus a space between each
589 * segment and trailing zero.
591 * This definitely didn't work with the value of 5 bytes and
594 #define SEGMENT_STR_LEN(X) (((X)->length * ASN_STR_LEN) + 2 + 1 + 1)
595 if ((len
+ SEGMENT_STR_LEN(seg
)) > str_size
) {
596 str_size
= len
+ SEGMENT_STR_LEN(seg
);
597 str_buf
= XREALLOC(MTYPE_AS_STR
, str_buf
, str_size
);
600 #undef SEGMENT_STR_LEN
602 if (seg
->type
!= AS_SEQUENCE
)
604 str_buf
+ len
, str_size
- len
, "%c",
605 aspath_delimiter_char(seg
->type
, AS_SEG_START
));
608 jseg_list
= json_object_new_array();
610 /* write out the ASNs, with their separators, bar the last one*/
611 for (i
= 0; i
< seg
->length
; i
++) {
613 json_object_array_add(
615 json_object_new_int64(seg
->as
[i
]));
617 len
+= snprintf(str_buf
+ len
, str_size
- len
, "%u",
620 if (i
< (seg
->length
- 1))
621 len
+= snprintf(str_buf
+ len
, str_size
- len
,
626 jseg
= json_object_new_object();
627 json_object_string_add(
629 aspath_segment_type_str
[seg
->type
]);
630 json_object_object_add(jseg
, "list", jseg_list
);
631 json_object_array_add(jaspath_segments
, jseg
);
634 if (seg
->type
!= AS_SEQUENCE
)
636 str_buf
+ len
, str_size
- len
, "%c",
637 aspath_delimiter_char(seg
->type
, AS_SEG_END
));
639 len
+= snprintf(str_buf
+ len
, str_size
- len
, " ");
644 assert(len
< str_size
);
651 json_object_string_add(as
->json
, "string", str_buf
);
652 json_object_object_add(as
->json
, "segments", jaspath_segments
);
653 json_object_int_add(as
->json
, "length", aspath_count_hops(as
));
659 void aspath_str_update(struct aspath
*as
, bool make_json
)
661 XFREE(MTYPE_AS_STR
, as
->str
);
664 json_object_free(as
->json
);
668 aspath_make_str_count(as
, make_json
);
671 /* Intern allocated AS path. */
672 struct aspath
*aspath_intern(struct aspath
*aspath
)
676 /* Assert this AS path structure is not interned and has the string
677 representation built. */
678 assert(aspath
->refcnt
== 0);
681 /* Check AS path hash. */
682 find
= hash_get(ashash
, aspath
, hash_alloc_intern
);
691 /* Duplicate aspath structure. Created same aspath structure but
692 reference count and AS path string is cleared. */
693 struct aspath
*aspath_dup(struct aspath
*aspath
)
695 unsigned short buflen
= aspath
->str_len
+ 1;
698 new = XCALLOC(MTYPE_AS_PATH
, sizeof(struct aspath
));
701 if (aspath
->segments
)
702 new->segments
= assegment_dup_all(aspath
->segments
);
707 new->str
= XMALLOC(MTYPE_AS_STR
, buflen
);
708 new->str_len
= aspath
->str_len
;
710 /* copy the string data */
711 if (aspath
->str_len
> 0)
712 memcpy(new->str
, aspath
->str
, buflen
);
719 static void *aspath_hash_alloc(void *arg
)
721 const struct aspath
*aspath
= arg
;
724 /* Malformed AS path value. */
727 /* New aspath structure is needed. */
728 new = XMALLOC(MTYPE_AS_PATH
, sizeof(struct aspath
));
730 /* Reuse segments and string representation */
732 new->segments
= aspath
->segments
;
733 new->str
= aspath
->str
;
734 new->str_len
= aspath
->str_len
;
735 new->json
= aspath
->json
;
740 /* parse as-segment byte stream in struct assegment */
741 static int assegments_parse(struct stream
*s
, size_t length
,
742 struct assegment
**result
, int use32bit
)
744 struct assegment_header segh
;
745 struct assegment
*seg
, *prev
= NULL
, *head
= NULL
;
748 /* empty aspath (ie iBGP or somesuch) */
752 if (BGP_DEBUG(as4
, AS4_SEGMENT
))
754 "[AS4SEG] Parse aspath segment: got total byte length %lu",
755 (unsigned long)length
);
757 if ((STREAM_READABLE(s
) < length
)
758 || (STREAM_READABLE(s
) < AS_HEADER_SIZE
)
759 || (length
% AS16_VALUE_SIZE
))
762 while (bytes
< length
) {
766 if ((length
- bytes
) <= AS_HEADER_SIZE
) {
768 assegment_free_all(head
);
772 /* softly softly, get the header first on its own */
773 segh
.type
= stream_getc(s
);
774 segh
.length
= stream_getc(s
);
776 seg_size
= ASSEGMENT_SIZE(segh
.length
, use32bit
);
778 if (BGP_DEBUG(as4
, AS4_SEGMENT
))
780 "[AS4SEG] Parse aspath segment: got type %d, length %d",
781 segh
.type
, segh
.length
);
784 if (((bytes
+ seg_size
) > length
)
785 /* 1771bis 4.3b: seg length contains one or more */
786 || (segh
.length
== 0)
787 /* Paranoia in case someone changes type of segment length.
788 * Shift both values by 0x10 to make the comparison operate
789 * on more, than 8 bits (otherwise it's a warning, bug
792 || ((sizeof(segh
.length
) > 1)
793 && (0x10 + segh
.length
> 0x10 + AS_SEGMENT_MAX
))) {
795 assegment_free_all(head
);
802 case AS_CONFED_SEQUENCE
:
807 assegment_free_all(head
);
811 /* now its safe to trust lengths */
812 seg
= assegment_new(segh
.type
, segh
.length
);
816 else /* it's the first segment */
819 for (i
= 0; i
< segh
.length
; i
++)
821 (use32bit
) ? stream_getl(s
) : stream_getw(s
);
825 if (BGP_DEBUG(as4
, AS4_SEGMENT
))
827 "[AS4SEG] Parse aspath segment: Bytes now: %lu",
828 (unsigned long)bytes
);
833 *result
= assegment_normalise(head
);
837 /* AS path parse function. pnt is a pointer to byte stream and length
838 is length of byte stream. If there is same AS path in the the AS
839 path hash then return it else make new AS path structure.
841 On error NULL is returned.
843 struct aspath
*aspath_parse(struct stream
*s
, size_t length
, int use32bit
)
848 /* If length is odd it's malformed AS path. */
849 /* Nit-picking: if (use32bit == 0) it is malformed if odd,
850 * otherwise its malformed when length is larger than 2 and (length-2)
851 * is not dividable by 4.
852 * But... this time we're lazy
854 if (length
% AS16_VALUE_SIZE
)
857 memset(&as
, 0, sizeof(as
));
858 if (assegments_parse(s
, length
, &as
.segments
, use32bit
) < 0)
861 /* If already same aspath exist then return it. */
862 find
= hash_get(ashash
, &as
, aspath_hash_alloc
);
864 /* if the aspath was already hashed free temporary memory. */
866 assegment_free_all(as
.segments
);
867 /* aspath_key_make() always updates the string */
868 XFREE(MTYPE_AS_STR
, as
.str
);
870 json_object_free(as
.json
);
880 static void assegment_data_put(struct stream
*s
, as_t
*as
, int num
,
884 assert(num
<= AS_SEGMENT_MAX
);
886 for (i
= 0; i
< num
; i
++)
888 stream_putl(s
, as
[i
]);
890 if (as
[i
] <= BGP_AS_MAX
)
891 stream_putw(s
, as
[i
]);
893 stream_putw(s
, BGP_AS_TRANS
);
897 static size_t assegment_header_put(struct stream
*s
, uint8_t type
, int length
)
900 assert(length
<= AS_SEGMENT_MAX
);
901 stream_putc(s
, type
);
902 lenp
= stream_get_endp(s
);
903 stream_putc(s
, length
);
907 /* write aspath data to stream */
908 size_t aspath_put(struct stream
*s
, struct aspath
*as
, int use32bit
)
910 struct assegment
*seg
= as
->segments
;
913 if (!seg
|| seg
->length
== 0)
917 * Hey, what do we do when we have > STREAM_WRITABLE(s) here?
918 * At the moment, we would write out a partial aspath, and our
920 * will complain and drop the session :-/
922 * The general assumption here is that many things tested will
923 * never happen. And, in real live, up to now, they have not.
925 while (seg
&& (ASSEGMENT_LEN(seg
, use32bit
) <= STREAM_WRITEABLE(s
))) {
926 struct assegment
*next
= seg
->next
;
931 /* Overlength segments have to be split up */
932 while ((seg
->length
- written
) > AS_SEGMENT_MAX
) {
933 assegment_header_put(s
, seg
->type
, AS_SEGMENT_MAX
);
934 assegment_data_put(s
, (seg
->as
+ written
),
935 AS_SEGMENT_MAX
, use32bit
);
936 written
+= AS_SEGMENT_MAX
;
937 bytes
+= ASSEGMENT_SIZE(AS_SEGMENT_MAX
, use32bit
);
940 /* write the final segment, probably is also the first
942 lenp
= assegment_header_put(s
, seg
->type
,
943 seg
->length
- written
);
944 assegment_data_put(s
, (seg
->as
+ written
),
945 seg
->length
- written
, use32bit
);
947 /* Sequence-type segments can be 'packed' together
948 * Case of a segment which was overlength and split up
949 * will be missed here, but that doesn't matter.
951 while (next
&& ASSEGMENTS_PACKABLE(seg
, next
)) {
952 /* NB: We should never normally get here given
954 * normalise aspath data when parse them.
956 * safe than sorry. We potentially could call
957 * assegment_normalise here instead, but it's
959 * easier to do it on the fly here rather than
961 * the segment list twice every time we write
966 /* Next segment's data can fit in this one */
967 assegment_data_put(s
, next
->as
, next
->length
, use32bit
);
969 /* update the length of the segment header */
970 stream_putc_at(s
, lenp
,
971 seg
->length
- written
+ next
->length
);
972 asns_packed
+= next
->length
;
977 bytes
+= ASSEGMENT_SIZE(seg
->length
- written
+ asns_packed
,
984 /* This is for SNMP BGP4PATHATTRASPATHSEGMENT
985 * We have no way to manage the storage, so we use a static stream
986 * wrapper around aspath_put.
988 uint8_t *aspath_snmp_pathseg(struct aspath
*as
, size_t *varlen
)
990 #define SNMP_PATHSEG_MAX 1024
993 snmp_stream
= stream_new(SNMP_PATHSEG_MAX
);
995 stream_reset(snmp_stream
);
1001 aspath_put(snmp_stream
, as
, 0); /* use 16 bit for now here */
1003 *varlen
= stream_get_endp(snmp_stream
);
1004 return stream_pnt(snmp_stream
);
1007 static struct assegment
*aspath_aggregate_as_set_add(struct aspath
*aspath
,
1008 struct assegment
*asset
,
1013 /* If this is first AS set member, create new as-set segment. */
1014 if (asset
== NULL
) {
1015 asset
= assegment_new(AS_SET
, 1);
1016 if (!aspath
->segments
)
1017 aspath
->segments
= asset
;
1019 struct assegment
*seg
= aspath
->segments
;
1024 asset
->type
= AS_SET
;
1028 /* Check this AS value already exists or not. */
1029 for (i
= 0; i
< asset
->length
; i
++)
1030 if (asset
->as
[i
] == as
)
1034 asset
->as
= XREALLOC(MTYPE_AS_SEG_DATA
, asset
->as
,
1035 asset
->length
* AS_VALUE_SIZE
);
1036 asset
->as
[asset
->length
- 1] = as
;
1043 /* Modify as1 using as2 for aggregation. */
1044 struct aspath
*aspath_aggregate(struct aspath
*as1
, struct aspath
*as2
)
1050 struct assegment
*seg1
= as1
->segments
;
1051 struct assegment
*seg2
= as2
->segments
;
1052 struct aspath
*aspath
= NULL
;
1053 struct assegment
*asset
= NULL
;
1054 struct assegment
*prevseg
= NULL
;
1056 /* First of all check common leading sequence. */
1057 while (seg1
&& seg2
) {
1058 /* Check segment type. */
1059 if (seg1
->type
!= seg2
->type
)
1062 /* Minimum segment length. */
1063 minlen
= MIN(seg1
->length
, seg2
->length
);
1065 for (match
= 0; match
< minlen
; match
++)
1066 if (seg1
->as
[match
] != seg2
->as
[match
])
1070 struct assegment
*seg
= assegment_new(seg1
->type
, 0);
1072 seg
= assegment_append_asns(seg
, seg1
->as
, match
);
1075 aspath
= aspath_new();
1076 aspath
->segments
= seg
;
1078 prevseg
->next
= seg
;
1083 if (match
!= minlen
|| match
!= seg1
->length
1084 || seg1
->length
!= seg2
->length
)
1086 /* We are moving on to the next segment to reset match */
1095 aspath
= aspath_new();
1097 /* Make as-set using rest of all information. */
1100 for (i
= from
; i
< seg1
->length
; i
++)
1101 asset
= aspath_aggregate_as_set_add(aspath
, asset
,
1110 for (i
= from
; i
< seg2
->length
; i
++)
1111 asset
= aspath_aggregate_as_set_add(aspath
, asset
,
1118 assegment_normalise(aspath
->segments
);
1119 aspath_str_update(aspath
, false);
1123 /* When a BGP router receives an UPDATE with an MP_REACH_NLRI
1124 attribute, check the leftmost AS number in the AS_PATH attribute is
1125 or not the peer's AS number. */
1126 bool aspath_firstas_check(struct aspath
*aspath
, as_t asno
)
1128 if ((aspath
== NULL
) || (aspath
->segments
== NULL
))
1131 if (aspath
->segments
&& (aspath
->segments
->type
== AS_SEQUENCE
)
1132 && (aspath
->segments
->as
[0] == asno
))
1138 unsigned int aspath_get_first_as(struct aspath
*aspath
)
1140 if (aspath
== NULL
|| aspath
->segments
== NULL
)
1143 return aspath
->segments
->as
[0];
1146 unsigned int aspath_get_last_as(struct aspath
*aspath
)
1149 unsigned int last_as
= 0;
1150 const struct assegment
*seg
;
1152 if (aspath
== NULL
|| aspath
->segments
== NULL
)
1155 seg
= aspath
->segments
;
1158 if (seg
->type
== AS_SEQUENCE
|| seg
->type
== AS_CONFED_SEQUENCE
)
1159 for (i
= 0; i
< seg
->length
; i
++)
1160 last_as
= seg
->as
[i
];
1167 /* AS path loop check. If aspath contains asno then return >= 1. */
1168 int aspath_loop_check(struct aspath
*aspath
, as_t asno
)
1170 struct assegment
*seg
;
1173 if ((aspath
== NULL
) || (aspath
->segments
== NULL
))
1176 seg
= aspath
->segments
;
1181 for (i
= 0; i
< seg
->length
; i
++)
1182 if (seg
->as
[i
] == asno
)
1190 /* When all of AS path is private AS return 1. */
1191 bool aspath_private_as_check(struct aspath
*aspath
)
1193 struct assegment
*seg
;
1195 if (!(aspath
&& aspath
->segments
))
1198 seg
= aspath
->segments
;
1203 for (i
= 0; i
< seg
->length
; i
++) {
1204 if (!BGP_AS_IS_PRIVATE(seg
->as
[i
]))
1212 /* Replace all instances of the target ASN with our own ASN */
1213 struct aspath
*aspath_replace_specific_asn(struct aspath
*aspath
,
1214 as_t target_asn
, as_t our_asn
)
1217 struct assegment
*seg
;
1219 new = aspath_dup(aspath
);
1220 seg
= new->segments
;
1225 for (i
= 0; i
< seg
->length
; i
++) {
1226 if (seg
->as
[i
] == target_asn
)
1227 seg
->as
[i
] = our_asn
;
1232 aspath_str_update(new, false);
1236 /* Replace all ASNs with our own ASN */
1237 struct aspath
*aspath_replace_all_asn(struct aspath
*aspath
, as_t our_asn
)
1240 struct assegment
*seg
;
1242 new = aspath_dup(aspath
);
1243 seg
= new->segments
;
1248 for (i
= 0; i
< seg
->length
; i
++)
1249 seg
->as
[i
] = our_asn
;
1254 aspath_str_update(new, false);
1258 /* Replace all private ASNs with our own ASN */
1259 struct aspath
*aspath_replace_private_asns(struct aspath
*aspath
, as_t asn
,
1263 struct assegment
*seg
;
1265 new = aspath_dup(aspath
);
1266 seg
= new->segments
;
1271 for (i
= 0; i
< seg
->length
; i
++) {
1272 /* Don't replace if public ASN or peer's ASN */
1273 if (BGP_AS_IS_PRIVATE(seg
->as
[i
])
1274 && (seg
->as
[i
] != peer_asn
))
1280 aspath_str_update(new, false);
1284 /* Remove all private ASNs */
1285 struct aspath
*aspath_remove_private_asns(struct aspath
*aspath
, as_t peer_asn
)
1288 struct assegment
*seg
;
1289 struct assegment
*new_seg
;
1290 struct assegment
*last_new_seg
;
1296 new = XCALLOC(MTYPE_AS_PATH
, sizeof(struct aspath
));
1300 last_new_seg
= NULL
;
1301 seg
= aspath
->segments
;
1305 for (i
= 0; i
< seg
->length
; i
++) {
1307 if (!BGP_AS_IS_PRIVATE(seg
->as
[i
]))
1309 /* ASN matches peer's.
1310 * Don't double-count if peer_asn is public.
1312 else if (seg
->as
[i
] == peer_asn
)
1316 // The entire segment is public so copy it
1317 if (public == seg
->length
)
1318 new_seg
= assegment_dup(seg
);
1320 // The segment is a mix of public and private ASNs. Copy as many
1322 // there are public ASNs then come back and fill in only the
1325 /* length needs to account for all retained ASNs
1326 * (public or peer_asn), not just public
1328 new_seg
= assegment_new(seg
->type
, (public + peer
));
1330 for (i
= 0; i
< seg
->length
; i
++) {
1331 // keep ASN if public or matches peer's ASN
1332 if (!BGP_AS_IS_PRIVATE(seg
->as
[i
])
1333 || (seg
->as
[i
] == peer_asn
)) {
1334 new_seg
->as
[j
] = seg
->as
[i
];
1340 // This is the first segment so set the aspath segments pointer
1343 new->segments
= new_seg
;
1345 last_new_seg
->next
= new_seg
;
1347 last_new_seg
= new_seg
;
1351 aspath_str_update(new, false);
1355 /* AS path confed check. If aspath contains confed set or sequence then return
1357 bool aspath_confed_check(struct aspath
*aspath
)
1359 struct assegment
*seg
;
1361 if (!(aspath
&& aspath
->segments
))
1364 seg
= aspath
->segments
;
1367 if (seg
->type
== AS_CONFED_SET
1368 || seg
->type
== AS_CONFED_SEQUENCE
)
1375 /* Leftmost AS path segment confed check. If leftmost AS segment is of type
1376 AS_CONFED_SEQUENCE or AS_CONFED_SET then return 1. */
1377 bool aspath_left_confed_check(struct aspath
*aspath
)
1380 if (!(aspath
&& aspath
->segments
))
1383 if ((aspath
->segments
->type
== AS_CONFED_SEQUENCE
)
1384 || (aspath
->segments
->type
== AS_CONFED_SET
))
1390 /* Merge as1 to as2. as2 should be uninterned aspath. */
1391 static struct aspath
*aspath_merge(struct aspath
*as1
, struct aspath
*as2
)
1393 struct assegment
*last
, *new;
1398 last
= new = assegment_dup_all(as1
->segments
);
1400 /* find the last valid segment */
1401 while (last
&& last
->next
)
1405 last
->next
= as2
->segments
;
1406 as2
->segments
= new;
1407 aspath_str_update(as2
, false);
1411 /* Prepend as1 to as2. as2 should be uninterned aspath. */
1412 struct aspath
*aspath_prepend(struct aspath
*as1
, struct aspath
*as2
)
1414 struct assegment
*as1segtail
;
1415 struct assegment
*as2segtail
;
1416 struct assegment
*as2seghead
;
1421 /* If as2 is empty, only need to dupe as1's chain onto as2 */
1422 if (as2
->segments
== NULL
) {
1423 as2
->segments
= assegment_dup_all(as1
->segments
);
1424 aspath_str_update(as2
, false);
1428 /* If as1 is empty AS, no prepending to do. */
1429 if (as1
->segments
== NULL
)
1432 /* find the tail as1's segment chain. */
1433 as1segtail
= as1
->segments
;
1434 while (as1segtail
&& as1segtail
->next
)
1435 as1segtail
= as1segtail
->next
;
1437 /* Delete any AS_CONFED_SEQUENCE segment from as2. */
1438 if (as1segtail
->type
== AS_SEQUENCE
1439 && as2
->segments
->type
== AS_CONFED_SEQUENCE
)
1440 as2
= aspath_delete_confed_seq(as2
);
1442 if (!as2
->segments
) {
1443 as2
->segments
= assegment_dup_all(as1
->segments
);
1444 aspath_str_update(as2
, false);
1448 /* Compare last segment type of as1 and first segment type of as2. */
1449 if (as1segtail
->type
!= as2
->segments
->type
)
1450 return aspath_merge(as1
, as2
);
1452 if (as1segtail
->type
== AS_SEQUENCE
) {
1453 /* We have two chains of segments, as1->segments and seg2,
1454 * and we have to attach them together, merging the attaching
1455 * segments together into one.
1457 * 1. dupe as1->segments onto head of as2
1458 * 2. merge seg2's asns onto last segment of this new chain
1459 * 3. attach chain after seg2
1463 as2seghead
= as2
->segments
;
1465 /* dupe as1 onto as2's head */
1466 as2segtail
= as2
->segments
= assegment_dup_all(as1
->segments
);
1468 /* refind the tail of as2 */
1469 while (as2segtail
&& as2segtail
->next
)
1470 as2segtail
= as2segtail
->next
;
1472 /* merge the old head, seg2, into tail, seg1 */
1473 assegment_append_asns(as2segtail
, as2seghead
->as
,
1474 as2seghead
->length
);
1477 * bypass the merged seg2, and attach any chain after it
1478 * to chain descending from as2's head
1481 as2segtail
->next
= as2seghead
->next
;
1483 /* as2->segments is now referenceless and useless */
1484 assegment_free(as2seghead
);
1486 /* we've now prepended as1's segment chain to as2, merging
1487 * the inbetween AS_SEQUENCE of seg2 in the process
1489 aspath_str_update(as2
, false);
1492 /* AS_SET merge code is needed at here. */
1493 return aspath_merge(as1
, as2
);
1495 /* XXX: Ermmm, what if as1 has multiple segments?? */
1500 /* Iterate over AS_PATH segments and wipe all occurrences of the
1501 * listed AS numbers. Hence some segments may lose some or even
1502 * all data on the way, the operation is implemented as a smarter
1503 * version of aspath_dup(), which allocates memory to hold the new
1504 * data, not the original. The new AS path is returned.
1506 struct aspath
*aspath_filter_exclude(struct aspath
*source
,
1507 struct aspath
*exclude_list
)
1509 struct assegment
*srcseg
, *exclseg
, *lastseg
;
1510 struct aspath
*newpath
;
1512 newpath
= aspath_new();
1515 for (srcseg
= source
->segments
; srcseg
; srcseg
= srcseg
->next
) {
1516 unsigned i
, y
, newlen
= 0, done
= 0, skip_as
;
1517 struct assegment
*newseg
;
1519 /* Find out, how much ASns are we going to pick from this
1521 * We can't perform filtering right inline, because the size of
1522 * the new segment isn't known at the moment yet.
1524 for (i
= 0; i
< srcseg
->length
; i
++) {
1526 for (exclseg
= exclude_list
->segments
;
1527 exclseg
&& !skip_as
; exclseg
= exclseg
->next
)
1528 for (y
= 0; y
< exclseg
->length
; y
++)
1529 if (srcseg
->as
[i
] == exclseg
->as
[y
]) {
1531 // There's no sense in testing
1532 // the rest of exclusion list,
1539 /* newlen is now the number of ASns to copy */
1543 /* Actual copying. Allocate memory and iterate once more,
1544 * performing filtering. */
1545 newseg
= assegment_new(srcseg
->type
, newlen
);
1546 for (i
= 0; i
< srcseg
->length
; i
++) {
1548 for (exclseg
= exclude_list
->segments
;
1549 exclseg
&& !skip_as
; exclseg
= exclseg
->next
)
1550 for (y
= 0; y
< exclseg
->length
; y
++)
1551 if (srcseg
->as
[i
] == exclseg
->as
[y
]) {
1557 newseg
->as
[done
++] = srcseg
->as
[i
];
1559 /* At his point newlen must be equal to done, and both must be
1561 * the filtered segment to the gross result. */
1563 newpath
->segments
= newseg
;
1565 lastseg
->next
= newseg
;
1568 aspath_str_update(newpath
, false);
1569 /* We are happy returning even an empty AS_PATH, because the
1571 * might expect this very behaviour. There's a mean to avoid this, if
1573 * by having a match rule against certain AS_PATH regexps in the
1576 aspath_free(source
);
1580 /* Add specified AS to the leftmost of aspath. */
1581 static struct aspath
*aspath_add_asns(struct aspath
*aspath
, as_t asno
,
1582 uint8_t type
, unsigned num
)
1584 struct assegment
*assegment
= aspath
->segments
;
1587 if (assegment
&& assegment
->type
== type
) {
1588 /* extend existing segment */
1590 assegment_prepend_asns(aspath
->segments
, asno
, num
);
1592 /* prepend with new segment */
1593 struct assegment
*newsegment
= assegment_new(type
, num
);
1594 for (i
= 0; i
< num
; i
++)
1595 newsegment
->as
[i
] = asno
;
1597 /* insert potentially replacing empty segment */
1598 if (assegment
&& assegment
->length
== 0) {
1599 newsegment
->next
= assegment
->next
;
1600 assegment_free(assegment
);
1602 newsegment
->next
= assegment
;
1603 aspath
->segments
= newsegment
;
1606 aspath_str_update(aspath
, false);
1610 /* Add specified AS to the leftmost of aspath num times. */
1611 struct aspath
*aspath_add_seq_n(struct aspath
*aspath
, as_t asno
, unsigned num
)
1613 return aspath_add_asns(aspath
, asno
, AS_SEQUENCE
, num
);
1616 /* Add specified AS to the leftmost of aspath. */
1617 struct aspath
*aspath_add_seq(struct aspath
*aspath
, as_t asno
)
1619 return aspath_add_asns(aspath
, asno
, AS_SEQUENCE
, 1);
1622 /* Compare leftmost AS value for MED check. If as1's leftmost AS and
1623 as2's leftmost AS is same return 1. */
1624 bool aspath_cmp_left(const struct aspath
*aspath1
, const struct aspath
*aspath2
)
1626 const struct assegment
*seg1
;
1627 const struct assegment
*seg2
;
1629 if (!(aspath1
&& aspath2
))
1632 seg1
= aspath1
->segments
;
1633 seg2
= aspath2
->segments
;
1635 /* If both paths are originated in this AS then we do want to compare
1640 /* find first non-confed segments for each */
1641 while (seg1
&& ((seg1
->type
== AS_CONFED_SEQUENCE
)
1642 || (seg1
->type
== AS_CONFED_SET
)))
1645 while (seg2
&& ((seg2
->type
== AS_CONFED_SEQUENCE
)
1646 || (seg2
->type
== AS_CONFED_SET
)))
1650 if (!(seg1
&& seg2
&& (seg1
->type
== AS_SEQUENCE
)
1651 && (seg2
->type
== AS_SEQUENCE
)))
1654 if (seg1
->as
[0] == seg2
->as
[0])
1660 /* Truncate an aspath after a number of hops, and put the hops remaining
1661 * at the front of another aspath. Needed for AS4 compat.
1663 * Returned aspath is a /new/ aspath, which should either by free'd or
1664 * interned by the caller, as desired.
1666 struct aspath
*aspath_reconcile_as4(struct aspath
*aspath
,
1667 struct aspath
*as4path
)
1669 struct assegment
*seg
, *newseg
, *prevseg
= NULL
;
1670 struct aspath
*newpath
= NULL
, *mergedpath
;
1671 int hops
, cpasns
= 0;
1673 if (!aspath
|| !as4path
)
1676 seg
= aspath
->segments
;
1678 /* CONFEDs should get reconciled too.. */
1679 hops
= (aspath_count_hops(aspath
) + aspath_count_confeds(aspath
))
1680 - aspath_count_hops(as4path
);
1683 if (BGP_DEBUG(as4
, AS4
))
1685 EC_BGP_ASPATH_FEWER_HOPS
,
1686 "[AS4] Fewer hops in AS_PATH than NEW_AS_PATH");
1687 /* Something's gone wrong. The RFC says we should now ignore
1689 * which is daft behaviour - it contains vital loop-detection
1690 * information which must have been removed from AS_PATH.
1692 hops
= aspath_count_hops(aspath
);
1696 newpath
= aspath_dup(as4path
);
1697 aspath_str_update(newpath
, false);
1701 if (BGP_DEBUG(as4
, AS4
))
1703 "[AS4] got AS_PATH %s and AS4_PATH %s synthesizing now",
1704 aspath
->str
, as4path
->str
);
1706 while (seg
&& hops
> 0) {
1707 switch (seg
->type
) {
1711 cpasns
= seg
->length
;
1713 case AS_CONFED_SEQUENCE
:
1714 /* Should never split a confed-sequence, if hop-count
1715 * suggests we must then something's gone wrong
1718 * Most important goal is to preserve AS_PATHs prime
1720 * as loop-detector, so we fudge the numbers so that the
1722 * confed-sequence is merged in.
1724 if (hops
< seg
->length
) {
1725 if (BGP_DEBUG(as4
, AS4
))
1727 "[AS4] AS4PATHmangle: AS_CONFED_SEQUENCE falls across 2/4 ASN boundary somewhere, broken..");
1732 cpasns
= MIN(seg
->length
, hops
);
1733 hops
-= seg
->length
;
1736 assert(cpasns
<= seg
->length
);
1738 newseg
= assegment_new(seg
->type
, 0);
1739 newseg
= assegment_append_asns(newseg
, seg
->as
, cpasns
);
1742 newpath
= aspath_new();
1743 newpath
->segments
= newseg
;
1745 prevseg
->next
= newseg
;
1751 /* We may be able to join some segments here, and we must
1752 * do this because... we want normalised aspaths in out hash
1753 * and we do not want to stumble in aspath_put.
1755 mergedpath
= aspath_merge(newpath
, aspath_dup(as4path
));
1756 aspath_free(newpath
);
1757 mergedpath
->segments
= assegment_normalise(mergedpath
->segments
);
1758 aspath_str_update(mergedpath
, false);
1760 if (BGP_DEBUG(as4
, AS4
))
1761 zlog_debug("[AS4] result of synthesizing is %s",
1767 /* Compare leftmost AS value for MED check. If as1's leftmost AS and
1768 as2's leftmost AS is same return 1. (confederation as-path
1770 bool aspath_cmp_left_confed(const struct aspath
*aspath1
,
1771 const struct aspath
*aspath2
)
1773 if (!(aspath1
&& aspath2
))
1776 if (!(aspath1
->segments
&& aspath2
->segments
))
1779 if ((aspath1
->segments
->type
!= AS_CONFED_SEQUENCE
)
1780 || (aspath2
->segments
->type
!= AS_CONFED_SEQUENCE
))
1783 if (aspath1
->segments
->as
[0] == aspath2
->segments
->as
[0])
1789 /* Delete all AS_CONFED_SEQUENCE/SET segments from aspath.
1790 * RFC 5065 section 4.1.c.1
1792 * 1) if any path segments of the AS_PATH are of the type
1793 * AS_CONFED_SEQUENCE or AS_CONFED_SET, those segments MUST be
1794 * removed from the AS_PATH attribute, leaving the sanitized
1795 * AS_PATH attribute to be operated on by steps 2, 3 or 4.
1797 struct aspath
*aspath_delete_confed_seq(struct aspath
*aspath
)
1799 struct assegment
*seg
, *prev
, *next
;
1800 char removed_confed_segment
;
1802 if (!(aspath
&& aspath
->segments
))
1805 seg
= aspath
->segments
;
1806 removed_confed_segment
= 0;
1813 if (seg
->type
== AS_CONFED_SEQUENCE
1814 || seg
->type
== AS_CONFED_SET
) {
1815 /* This is the first segment in the aspath */
1816 if (aspath
->segments
== seg
)
1817 aspath
->segments
= seg
->next
;
1819 prev
->next
= seg
->next
;
1821 assegment_free(seg
);
1822 removed_confed_segment
= 1;
1829 if (removed_confed_segment
)
1830 aspath_str_update(aspath
, false);
1835 /* Add new AS number to the leftmost part of the aspath as
1836 AS_CONFED_SEQUENCE. */
1837 struct aspath
*aspath_add_confed_seq(struct aspath
*aspath
, as_t asno
)
1839 return aspath_add_asns(aspath
, asno
, AS_CONFED_SEQUENCE
, 1);
1842 /* Add new as value to as path structure. */
1843 static void aspath_as_add(struct aspath
*as
, as_t asno
)
1845 struct assegment
*seg
= as
->segments
;
1850 /* Last segment search procedure. */
1854 assegment_append_asns(seg
, &asno
, 1);
1857 /* Add new as segment to the as path. */
1858 static void aspath_segment_add(struct aspath
*as
, int type
)
1860 struct assegment
*seg
= as
->segments
;
1861 struct assegment
*new = assegment_new(type
, 0);
1871 struct aspath
*aspath_empty(void)
1873 return aspath_parse(NULL
, 0, 1); /* 32Bit ;-) */
1876 struct aspath
*aspath_empty_get(void)
1878 struct aspath
*aspath
;
1880 aspath
= aspath_new();
1881 aspath_make_str_count(aspath
, false);
1885 unsigned long aspath_count(void)
1887 return ashash
->count
;
1891 Theoretically, one as path can have:
1893 One BGP packet size should be less than 4096.
1894 One BGP attribute size should be less than 4096 - BGP header size.
1895 One BGP aspath size should be less than 4096 - BGP header size -
1896 BGP mandantry attribute size.
1899 /* AS path string lexical token enum. */
1904 as_token_confed_seq_start
,
1905 as_token_confed_seq_end
,
1906 as_token_confed_set_start
,
1907 as_token_confed_set_end
,
1911 /* Return next token and point for string parse. */
1912 static const char *aspath_gettoken(const char *buf
, enum as_token
*token
,
1913 unsigned long *asno
)
1915 const char *p
= buf
;
1917 /* Skip separators (space for sequences, ',' for sets). */
1918 while (isspace((unsigned char)*p
) || *p
== ',')
1921 /* Check the end of the string and type specify characters
1927 *token
= as_token_set_start
;
1931 *token
= as_token_set_end
;
1935 *token
= as_token_confed_seq_start
;
1939 *token
= as_token_confed_seq_end
;
1943 *token
= as_token_confed_set_start
;
1947 *token
= as_token_confed_set_end
;
1952 /* Check actual AS value. */
1953 if (isdigit((unsigned char)*p
)) {
1956 *token
= as_token_asval
;
1960 while (isdigit((unsigned char)*p
)) {
1962 asval
+= (*p
- '0');
1969 /* There is no match then return unknown token. */
1970 *token
= as_token_unknown
;
1975 struct aspath
*aspath_str2aspath(const char *str
)
1977 enum as_token token
= as_token_unknown
;
1978 unsigned short as_type
;
1979 unsigned long asno
= 0;
1980 struct aspath
*aspath
;
1983 aspath
= aspath_new();
1985 /* We start default type as AS_SEQUENCE. */
1986 as_type
= AS_SEQUENCE
;
1989 while ((str
= aspath_gettoken(str
, &token
, &asno
)) != NULL
) {
1991 case as_token_asval
:
1993 aspath_segment_add(aspath
, as_type
);
1996 aspath_as_add(aspath
, asno
);
1998 case as_token_set_start
:
2000 aspath_segment_add(aspath
, as_type
);
2003 case as_token_set_end
:
2004 as_type
= AS_SEQUENCE
;
2007 case as_token_confed_seq_start
:
2008 as_type
= AS_CONFED_SEQUENCE
;
2009 aspath_segment_add(aspath
, as_type
);
2012 case as_token_confed_seq_end
:
2013 as_type
= AS_SEQUENCE
;
2016 case as_token_confed_set_start
:
2017 as_type
= AS_CONFED_SET
;
2018 aspath_segment_add(aspath
, as_type
);
2021 case as_token_confed_set_end
:
2022 as_type
= AS_SEQUENCE
;
2025 case as_token_unknown
:
2027 aspath_free(aspath
);
2032 aspath_make_str_count(aspath
, false);
2037 /* Make hash value by raw aspath data. */
2038 unsigned int aspath_key_make(const void *p
)
2040 const struct aspath
*aspath
= p
;
2041 unsigned int key
= 0;
2044 aspath_str_update((struct aspath
*)aspath
, false);
2046 key
= jhash(aspath
->str
, aspath
->str_len
, 2334325);
2051 /* If two aspath have same value then return 1 else return 0 */
2052 bool aspath_cmp(const void *arg1
, const void *arg2
)
2054 const struct assegment
*seg1
= ((const struct aspath
*)arg1
)->segments
;
2055 const struct assegment
*seg2
= ((const struct aspath
*)arg2
)->segments
;
2057 while (seg1
|| seg2
) {
2059 if ((!seg1
&& seg2
) || (seg1
&& !seg2
))
2061 if (seg1
->type
!= seg2
->type
)
2063 if (seg1
->length
!= seg2
->length
)
2065 for (i
= 0; i
< seg1
->length
; i
++)
2066 if (seg1
->as
[i
] != seg2
->as
[i
])
2074 /* AS path hash initialize. */
2075 void aspath_init(void)
2077 ashash
= hash_create_size(32768, aspath_key_make
, aspath_cmp
,
2081 void aspath_finish(void)
2083 hash_clean(ashash
, (void (*)(void *))aspath_free
);
2088 stream_free(snmp_stream
);
2091 /* return and as path value */
2092 const char *aspath_print(struct aspath
*as
)
2094 return (as
? as
->str
: NULL
);
2097 /* Printing functions */
2098 /* Feed the AS_PATH to the vty; the suffix string follows it only in case
2099 * AS_PATH wasn't empty.
2101 void aspath_print_vty(struct vty
*vty
, const char *format
, struct aspath
*as
,
2105 vty_out(vty
, format
, as
->str
);
2106 if (as
->str_len
&& strlen(suffix
))
2107 vty_out(vty
, "%s", suffix
);
2110 static void aspath_show_all_iterator(struct hash_bucket
*bucket
,
2115 as
= (struct aspath
*)bucket
->data
;
2117 vty_out(vty
, "[%p:%u] (%ld) ", (void *)bucket
, bucket
->key
, as
->refcnt
);
2118 vty_out(vty
, "%s\n", as
->str
);
2121 /* Print all aspath and hash information. This function is used from
2122 `show [ip] bgp paths' command. */
2123 void aspath_print_all_vty(struct vty
*vty
)
2125 hash_iterate(ashash
, (void (*)(struct hash_bucket
*,
2126 void *))aspath_show_all_iterator
,
2130 static struct aspath
*bgp_aggr_aspath_lookup(struct bgp_aggregate
*aggregate
,
2131 struct aspath
*aspath
)
2133 return hash_lookup(aggregate
->aspath_hash
, aspath
);
2136 static void *bgp_aggr_aspath_hash_alloc(void *p
)
2138 struct aspath
*ref
= (struct aspath
*)p
;
2139 struct aspath
*aspath
= NULL
;
2141 aspath
= aspath_dup(ref
);
2145 static void bgp_aggr_aspath_prepare(struct hash_bucket
*hb
, void *arg
)
2147 struct aspath
*hb_aspath
= hb
->data
;
2148 struct aspath
**aggr_aspath
= arg
;
2151 *aggr_aspath
= aspath_aggregate(*aggr_aspath
, hb_aspath
);
2153 *aggr_aspath
= aspath_dup(hb_aspath
);
2156 void bgp_aggr_aspath_remove(void *arg
)
2158 struct aspath
*aspath
= arg
;
2160 aspath_free(aspath
);
2163 void bgp_compute_aggregate_aspath(struct bgp_aggregate
*aggregate
,
2164 struct aspath
*aspath
)
2166 bgp_compute_aggregate_aspath_hash(aggregate
, aspath
);
2168 bgp_compute_aggregate_aspath_val(aggregate
);
2172 void bgp_compute_aggregate_aspath_hash(struct bgp_aggregate
*aggregate
,
2173 struct aspath
*aspath
)
2175 struct aspath
*aggr_aspath
= NULL
;
2177 if ((aggregate
== NULL
) || (aspath
== NULL
))
2180 /* Create hash if not already created.
2182 if (aggregate
->aspath_hash
== NULL
)
2183 aggregate
->aspath_hash
= hash_create(
2184 aspath_key_make
, aspath_cmp
,
2185 "BGP Aggregator as-path hash");
2187 aggr_aspath
= bgp_aggr_aspath_lookup(aggregate
, aspath
);
2188 if (aggr_aspath
== NULL
) {
2189 /* Insert as-path into hash.
2191 aggr_aspath
= hash_get(aggregate
->aspath_hash
, aspath
,
2192 bgp_aggr_aspath_hash_alloc
);
2195 /* Increment reference counter.
2197 aggr_aspath
->refcnt
++;
2200 void bgp_compute_aggregate_aspath_val(struct bgp_aggregate
*aggregate
)
2202 if (aggregate
== NULL
)
2204 /* Re-compute aggregate's as-path.
2206 if (aggregate
->aspath
) {
2207 aspath_free(aggregate
->aspath
);
2208 aggregate
->aspath
= NULL
;
2210 if (aggregate
->aspath_hash
2211 && aggregate
->aspath_hash
->count
) {
2212 hash_iterate(aggregate
->aspath_hash
,
2213 bgp_aggr_aspath_prepare
,
2214 &aggregate
->aspath
);
2218 void bgp_remove_aspath_from_aggregate(struct bgp_aggregate
*aggregate
,
2219 struct aspath
*aspath
)
2221 struct aspath
*aggr_aspath
= NULL
;
2222 struct aspath
*ret_aspath
= NULL
;
2225 || (!aggregate
->aspath_hash
)
2229 /* Look-up the aspath in the hash.
2231 aggr_aspath
= bgp_aggr_aspath_lookup(aggregate
, aspath
);
2233 aggr_aspath
->refcnt
--;
2235 if (aggr_aspath
->refcnt
== 0) {
2236 ret_aspath
= hash_release(aggregate
->aspath_hash
,
2238 aspath_free(ret_aspath
);
2241 /* Remove aggregate's old as-path.
2243 aspath_free(aggregate
->aspath
);
2244 aggregate
->aspath
= NULL
;
2246 bgp_compute_aggregate_aspath_val(aggregate
);
2251 void bgp_remove_aspath_from_aggregate_hash(struct bgp_aggregate
*aggregate
,
2252 struct aspath
*aspath
)
2254 struct aspath
*aggr_aspath
= NULL
;
2255 struct aspath
*ret_aspath
= NULL
;
2258 || (!aggregate
->aspath_hash
)
2262 /* Look-up the aspath in the hash.
2264 aggr_aspath
= bgp_aggr_aspath_lookup(aggregate
, aspath
);
2266 aggr_aspath
->refcnt
--;
2268 if (aggr_aspath
->refcnt
== 0) {
2269 ret_aspath
= hash_release(aggregate
->aspath_hash
,
2271 aspath_free(ret_aspath
);