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Commit | Line | Data |
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c01e3741 MM |
1 | /* |
2 | * BIRD -- BGP Attributes | |
3 | * | |
4 | * (c) 2000 Martin Mares <mj@ucw.cz> | |
5 | * | |
6 | * Can be freely distributed and used under the terms of the GNU GPL. | |
7 | */ | |
8 | ||
85368cd4 | 9 | #undef LOCAL_DEBUG |
c00d31be | 10 | |
e3558ab1 MM |
11 | #include <stdlib.h> |
12 | ||
c01e3741 MM |
13 | #include "nest/bird.h" |
14 | #include "nest/iface.h" | |
15 | #include "nest/protocol.h" | |
16 | #include "nest/route.h" | |
c0668f36 | 17 | #include "nest/attrs.h" |
c01e3741 | 18 | #include "conf/conf.h" |
c00d31be MM |
19 | #include "lib/resource.h" |
20 | #include "lib/string.h" | |
21 | #include "lib/unaligned.h" | |
c01e3741 MM |
22 | |
23 | #include "bgp.h" | |
c00d31be | 24 | |
06fb60c4 OZ |
25 | /* |
26 | * UPDATE message error handling | |
27 | * | |
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. | |
33 | * | |
34 | * Loop detection based on AS_PATH causes updates to be withdrawn. RFC | |
35 | * 4271 does not explicitly specifiy the behavior in that case. | |
36 | * | |
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38 | * and CLUSTER_LIST) causes updates to be withdrawn.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 | |
40 | * a bad idea. | |
41 | * | |
42 | * Error checking of optional transitive attributes is done according to | |
43 | * draft-ietf-idr-optional-transitive-03, but errors are handled always | |
44 | * as withdraws. | |
45 | * | |
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 | |
52 | * widespread. | |
53 | * | |
4e379bde OZ |
54 | * Error handling of AS4_* attributes is done as specified by RFC 6793. There |
55 | * are several possible inconsistencies between AGGREGATOR and AS4_AGGREGATOR | |
56 | * that are not handled by that RFC, these are logged and ignored (see | |
06fb60c4 OZ |
57 | * bgp_reconstruct_4b_attrs()). |
58 | */ | |
59 | ||
e7d2ac44 | 60 | |
1c1da87b MM |
61 | static byte bgp_mandatory_attrs[] = { BA_ORIGIN, BA_AS_PATH |
62 | #ifndef IPV6 | |
63 | ,BA_NEXT_HOP | |
64 | #endif | |
65 | }; | |
ae8f5584 | 66 | |
ae8f5584 | 67 | struct attr_desc { |
99f70c78 | 68 | char *name; |
ae8f5584 MM |
69 | int expected_length; |
70 | int expected_flags; | |
71 | int type; | |
56a2bed4 | 72 | int allow_in_ebgp; |
ae8f5584 | 73 | int (*validate)(struct bgp_proto *p, byte *attr, int len); |
aebe06b4 | 74 | void (*format)(eattr *ea, byte *buf, int buflen); |
ae8f5584 MM |
75 | }; |
76 | ||
06fb60c4 OZ |
77 | #define IGNORE -1 |
78 | #define WITHDRAW -2 | |
79 | ||
f421cfdd | 80 | static int |
da95a7a7 | 81 | bgp_check_origin(struct bgp_proto *p UNUSED, byte *a, int len UNUSED) |
f421cfdd | 82 | { |
da95a7a7 | 83 | if (*a > 2) |
f421cfdd MM |
84 | return 6; |
85 | return 0; | |
86 | } | |
87 | ||
88 | static void | |
e81b440f | 89 | bgp_format_origin(eattr *a, byte *buf, int buflen UNUSED) |
f421cfdd MM |
90 | { |
91 | static char *bgp_origin_names[] = { "IGP", "EGP", "Incomplete" }; | |
92 | ||
93 | bsprintf(buf, bgp_origin_names[a->u.data]); | |
94 | } | |
95 | ||
96 | static int | |
29c430f8 | 97 | path_segment_contains(byte *p, int bs, u32 asn) |
f421cfdd | 98 | { |
29c430f8 OZ |
99 | int i; |
100 | int len = p[1]; | |
101 | p += 2; | |
102 | ||
103 | for(i=0; i<len; i++) | |
f421cfdd | 104 | { |
29c430f8 OZ |
105 | u32 asn2 = (bs == 4) ? get_u32(p) : get_u16(p); |
106 | if (asn2 == asn) | |
107 | return 1; | |
108 | p += bs; | |
f421cfdd | 109 | } |
29c430f8 | 110 | |
f421cfdd MM |
111 | return 0; |
112 | } | |
113 | ||
29c430f8 | 114 | /* Validates path attribute, removes AS_CONFED_* segments, and also returns path length */ |
11cb6202 | 115 | static int |
ae80a2de | 116 | validate_path(struct bgp_proto *p, int as_path, int bs, byte *idata, uint *ilength) |
29c430f8 OZ |
117 | { |
118 | int res = 0; | |
119 | u8 *a, *dst; | |
775a5a81 | 120 | int len, plen; |
29c430f8 OZ |
121 | |
122 | dst = a = idata; | |
123 | len = *ilength; | |
124 | ||
125 | while (len) | |
126 | { | |
127 | if (len < 2) | |
128 | return -1; | |
129 | ||
130 | plen = 2 + bs * a[1]; | |
131 | if (len < plen) | |
132 | return -1; | |
133 | ||
775a5a81 OZ |
134 | if (a[1] == 0) |
135 | { | |
136 | log(L_WARN "%s: %s_PATH attribute contains empty segment, skipping it", | |
137 | p->p.name, as_path ? "AS" : "AS4"); | |
138 | goto skip; | |
139 | } | |
140 | ||
29c430f8 OZ |
141 | switch (a[0]) |
142 | { | |
143 | case AS_PATH_SET: | |
29c430f8 OZ |
144 | res++; |
145 | break; | |
146 | ||
147 | case AS_PATH_SEQUENCE: | |
29c430f8 OZ |
148 | res += a[1]; |
149 | break; | |
150 | ||
151 | case AS_PATH_CONFED_SEQUENCE: | |
152 | case AS_PATH_CONFED_SET: | |
153 | if (as_path && path_segment_contains(a, bs, p->remote_as)) | |
154 | { | |
155 | log(L_WARN "%s: AS_CONFED_* segment with peer ASN found, misconfigured confederation?", p->p.name); | |
156 | return -1; | |
157 | } | |
158 | ||
159 | log(L_WARN "%s: %s_PATH attribute contains AS_CONFED_* segment, skipping segment", | |
160 | p->p.name, as_path ? "AS" : "AS4"); | |
775a5a81 | 161 | goto skip; |
29c430f8 OZ |
162 | |
163 | default: | |
164 | return -1; | |
165 | } | |
166 | ||
775a5a81 OZ |
167 | if (dst != a) |
168 | memmove(dst, a, plen); | |
169 | dst += plen; | |
29c430f8 | 170 | |
775a5a81 | 171 | skip: |
29c430f8 OZ |
172 | len -= plen; |
173 | a += plen; | |
174 | } | |
175 | ||
176 | *ilength = dst - idata; | |
177 | return res; | |
178 | } | |
179 | ||
180 | static inline int | |
181 | validate_as_path(struct bgp_proto *p, byte *a, int *len) | |
11cb6202 | 182 | { |
29c430f8 OZ |
183 | return validate_path(p, 1, p->as4_session ? 4 : 2, a, len); |
184 | } | |
185 | ||
186 | static inline int | |
187 | validate_as4_path(struct bgp_proto *p, struct adata *path) | |
188 | { | |
189 | return validate_path(p, 0, 4, path->data, &path->length); | |
11cb6202 OZ |
190 | } |
191 | ||
f421cfdd | 192 | static int |
3e236955 | 193 | bgp_check_next_hop(struct bgp_proto *p UNUSED, byte *a UNUSED6, int len UNUSED6) |
f421cfdd | 194 | { |
1c1da87b | 195 | #ifdef IPV6 |
06fb60c4 | 196 | return IGNORE; |
1c1da87b | 197 | #else |
f421cfdd MM |
198 | ip_addr addr; |
199 | ||
200 | memcpy(&addr, a, len); | |
201 | ipa_ntoh(addr); | |
202 | if (ipa_classify(addr) & IADDR_HOST) | |
203 | return 0; | |
204 | else | |
205 | return 8; | |
1c1da87b MM |
206 | #endif |
207 | } | |
208 | ||
d0e2d6d1 OZ |
209 | static void |
210 | bgp_format_next_hop(eattr *a, byte *buf, int buflen UNUSED) | |
211 | { | |
212 | ip_addr *ipp = (ip_addr *) a->u.ptr->data; | |
213 | #ifdef IPV6 | |
214 | /* in IPv6, we might have two addresses in NEXT HOP */ | |
215 | if ((a->u.ptr->length == NEXT_HOP_LENGTH) && ipa_nonzero(ipp[1])) | |
216 | { | |
217 | bsprintf(buf, "%I %I", ipp[0], ipp[1]); | |
218 | return; | |
219 | } | |
220 | #endif | |
221 | ||
222 | bsprintf(buf, "%I", ipp[0]); | |
223 | } | |
224 | ||
11cb6202 | 225 | static int |
aebe06b4 | 226 | bgp_check_aggregator(struct bgp_proto *p, byte *a UNUSED, int len) |
11cb6202 | 227 | { |
ba5ed6f3 | 228 | int exp_len = p->as4_session ? 8 : 6; |
11cb6202 | 229 | |
06fb60c4 | 230 | return (len == exp_len) ? 0 : WITHDRAW; |
11cb6202 OZ |
231 | } |
232 | ||
cd17c651 OZ |
233 | static void |
234 | bgp_format_aggregator(eattr *a, byte *buf, int buflen UNUSED) | |
235 | { | |
236 | struct adata *ad = a->u.ptr; | |
237 | byte *data = ad->data; | |
238 | u32 as; | |
239 | ||
43c1cecc OZ |
240 | as = get_u32(data); |
241 | data += 4; | |
cd17c651 | 242 | |
e16469bc | 243 | bsprintf(buf, "%d.%d.%d.%d AS%u", data[0], data[1], data[2], data[3], as); |
cd17c651 OZ |
244 | } |
245 | ||
06fb60c4 OZ |
246 | static int |
247 | bgp_check_community(struct bgp_proto *p UNUSED, byte *a UNUSED, int len) | |
248 | { | |
249 | return ((len % 4) == 0) ? 0 : WITHDRAW; | |
250 | } | |
251 | ||
4847a894 | 252 | static int |
aebe06b4 | 253 | bgp_check_cluster_list(struct bgp_proto *p UNUSED, byte *a UNUSED, int len) |
4847a894 OZ |
254 | { |
255 | return ((len % 4) == 0) ? 0 : 5; | |
256 | } | |
257 | ||
aebe06b4 | 258 | static void |
fdf16eb6 | 259 | bgp_format_cluster_list(eattr *a, byte *buf, int buflen) |
aebe06b4 | 260 | { |
fdf16eb6 OZ |
261 | /* Truncates cluster lists larger than buflen, probably not a problem */ |
262 | int_set_format(a->u.ptr, 0, -1, buf, buflen); | |
aebe06b4 OZ |
263 | } |
264 | ||
1c1da87b | 265 | static int |
e21423ba | 266 | bgp_check_reach_nlri(struct bgp_proto *p UNUSED, byte *a UNUSED, int len UNUSED) |
1c1da87b MM |
267 | { |
268 | #ifdef IPV6 | |
269 | p->mp_reach_start = a; | |
270 | p->mp_reach_len = len; | |
1c1da87b | 271 | #endif |
06fb60c4 | 272 | return IGNORE; |
1c1da87b MM |
273 | } |
274 | ||
275 | static int | |
e21423ba | 276 | bgp_check_unreach_nlri(struct bgp_proto *p UNUSED, byte *a UNUSED, int len UNUSED) |
1c1da87b MM |
277 | { |
278 | #ifdef IPV6 | |
279 | p->mp_unreach_start = a; | |
280 | p->mp_unreach_len = len; | |
1c1da87b | 281 | #endif |
06fb60c4 | 282 | return IGNORE; |
f421cfdd MM |
283 | } |
284 | ||
42a0c054 OZ |
285 | static int |
286 | bgp_check_ext_community(struct bgp_proto *p UNUSED, byte *a UNUSED, int len) | |
287 | { | |
288 | return ((len % 8) == 0) ? 0 : WITHDRAW; | |
289 | } | |
290 | ||
66dbdbd9 OZ |
291 | static int |
292 | bgp_check_large_community(struct bgp_proto *p UNUSED, byte *a UNUSED, int len) | |
293 | { | |
294 | return ((len % 12) == 0) ? 0 : WITHDRAW; | |
295 | } | |
296 | ||
42a0c054 | 297 | |
f421cfdd | 298 | static struct attr_desc bgp_attr_table[] = { |
1c1da87b | 299 | { NULL, -1, 0, 0, 0, /* Undefined */ |
f421cfdd | 300 | NULL, NULL }, |
1c1da87b | 301 | { "origin", 1, BAF_TRANSITIVE, EAF_TYPE_INT, 1, /* BA_ORIGIN */ |
f421cfdd | 302 | bgp_check_origin, bgp_format_origin }, |
1c1da87b | 303 | { "as_path", -1, BAF_TRANSITIVE, EAF_TYPE_AS_PATH, 1, /* BA_AS_PATH */ |
29c430f8 | 304 | NULL, NULL }, /* is checked by validate_as_path() as a special case */ |
1c1da87b | 305 | { "next_hop", 4, BAF_TRANSITIVE, EAF_TYPE_IP_ADDRESS, 1, /* BA_NEXT_HOP */ |
d0e2d6d1 | 306 | bgp_check_next_hop, bgp_format_next_hop }, |
b6bf284a | 307 | { "med", 4, BAF_OPTIONAL, EAF_TYPE_INT, 1, /* BA_MULTI_EXIT_DISC */ |
f421cfdd | 308 | NULL, NULL }, |
1950a479 | 309 | { "local_pref", 4, BAF_TRANSITIVE, EAF_TYPE_INT, 1, /* BA_LOCAL_PREF */ |
f421cfdd | 310 | NULL, NULL }, |
1c1da87b | 311 | { "atomic_aggr", 0, BAF_TRANSITIVE, EAF_TYPE_OPAQUE, 1, /* BA_ATOMIC_AGGR */ |
f421cfdd | 312 | NULL, NULL }, |
11cb6202 | 313 | { "aggregator", -1, BAF_OPTIONAL | BAF_TRANSITIVE, EAF_TYPE_OPAQUE, 1, /* BA_AGGREGATOR */ |
cd17c651 | 314 | bgp_check_aggregator, bgp_format_aggregator }, |
1c1da87b | 315 | { "community", -1, BAF_OPTIONAL | BAF_TRANSITIVE, EAF_TYPE_INT_SET, 1, /* BA_COMMUNITY */ |
06fb60c4 | 316 | bgp_check_community, NULL }, |
aebe06b4 | 317 | { "originator_id", 4, BAF_OPTIONAL, EAF_TYPE_ROUTER_ID, 0, /* BA_ORIGINATOR_ID */ |
4847a894 OZ |
318 | NULL, NULL }, |
319 | { "cluster_list", -1, BAF_OPTIONAL, EAF_TYPE_INT_SET, 0, /* BA_CLUSTER_LIST */ | |
aebe06b4 | 320 | bgp_check_cluster_list, bgp_format_cluster_list }, |
e81b440f | 321 | { .name = NULL }, /* BA_DPA */ |
06fb60c4 OZ |
322 | { .name = NULL }, /* BA_ADVERTISER */ |
323 | { .name = NULL }, /* BA_RCID_PATH */ | |
1c1da87b MM |
324 | { "mp_reach_nlri", -1, BAF_OPTIONAL, EAF_TYPE_OPAQUE, 1, /* BA_MP_REACH_NLRI */ |
325 | bgp_check_reach_nlri, NULL }, | |
326 | { "mp_unreach_nlri", -1, BAF_OPTIONAL, EAF_TYPE_OPAQUE, 1, /* BA_MP_UNREACH_NLRI */ | |
327 | bgp_check_unreach_nlri, NULL }, | |
42a0c054 OZ |
328 | { "ext_community", -1, BAF_OPTIONAL | BAF_TRANSITIVE, EAF_TYPE_EC_SET, 1, /* BA_EXT_COMMUNITY */ |
329 | bgp_check_ext_community, NULL }, | |
11cb6202 | 330 | { "as4_path", -1, BAF_OPTIONAL | BAF_TRANSITIVE, EAF_TYPE_OPAQUE, 1, /* BA_AS4_PATH */ |
48d79d52 OZ |
331 | NULL, NULL }, |
332 | { "as4_aggregator", -1, BAF_OPTIONAL | BAF_TRANSITIVE, EAF_TYPE_OPAQUE, 1, /* BA_AS4_PATH */ | |
66dbdbd9 OZ |
333 | NULL, NULL }, |
334 | [BA_LARGE_COMMUNITY] = | |
335 | { "large_community", -1, BAF_OPTIONAL | BAF_TRANSITIVE, EAF_TYPE_LC_SET, 1, | |
336 | bgp_check_large_community, NULL } | |
f421cfdd MM |
337 | }; |
338 | ||
43c1cecc OZ |
339 | /* BA_AS4_PATH is type EAF_TYPE_OPAQUE and not type EAF_TYPE_AS_PATH. |
340 | * It does not matter as this attribute does not appear on routes in the routing table. | |
11cb6202 OZ |
341 | */ |
342 | ||
d1a74339 MM |
343 | #define ATTR_KNOWN(code) ((code) < ARRAY_SIZE(bgp_attr_table) && bgp_attr_table[code].name) |
344 | ||
4847a894 OZ |
345 | static inline struct adata * |
346 | bgp_alloc_adata(struct linpool *pool, unsigned len) | |
347 | { | |
348 | struct adata *ad = lp_alloc(pool, sizeof(struct adata) + len); | |
349 | ad->length = len; | |
350 | return ad; | |
351 | } | |
352 | ||
353 | static void | |
354 | bgp_set_attr(eattr *e, unsigned attr, uintptr_t val) | |
cf3d6470 MM |
355 | { |
356 | ASSERT(ATTR_KNOWN(attr)); | |
357 | e->id = EA_CODE(EAP_BGP, attr); | |
358 | e->type = bgp_attr_table[attr].type; | |
359 | e->flags = bgp_attr_table[attr].expected_flags; | |
360 | if (e->type & EAF_EMBEDDED) | |
4847a894 | 361 | e->u.data = val; |
cf3d6470 | 362 | else |
4847a894 | 363 | e->u.ptr = (struct adata *) val; |
cf3d6470 MM |
364 | } |
365 | ||
4847a894 OZ |
366 | static byte * |
367 | bgp_set_attr_wa(eattr *e, struct linpool *pool, unsigned attr, unsigned len) | |
368 | { | |
369 | struct adata *ad = bgp_alloc_adata(pool, len); | |
370 | bgp_set_attr(e, attr, (uintptr_t) ad); | |
371 | return ad->data; | |
372 | } | |
373 | ||
374 | void | |
375 | bgp_attach_attr(ea_list **to, struct linpool *pool, unsigned attr, uintptr_t val) | |
cf3d6470 MM |
376 | { |
377 | ea_list *a = lp_alloc(pool, sizeof(ea_list) + sizeof(eattr)); | |
378 | a->next = *to; | |
379 | *to = a; | |
380 | a->flags = EALF_SORTED; | |
381 | a->count = 1; | |
4847a894 OZ |
382 | bgp_set_attr(a->attrs, attr, val); |
383 | } | |
384 | ||
385 | byte * | |
386 | bgp_attach_attr_wa(ea_list **to, struct linpool *pool, unsigned attr, unsigned len) | |
387 | { | |
388 | struct adata *ad = bgp_alloc_adata(pool, len); | |
389 | bgp_attach_attr(to, pool, attr, (uintptr_t) ad); | |
390 | return ad->data; | |
cf3d6470 MM |
391 | } |
392 | ||
11cb6202 | 393 | static int |
ae80a2de | 394 | bgp_encode_attr_hdr(byte *dst, uint flags, unsigned code, int len) |
11cb6202 OZ |
395 | { |
396 | int wlen; | |
397 | ||
398 | DBG("\tAttribute %02x (%d bytes, flags %02x)\n", code, len, flags); | |
399 | ||
400 | if (len < 256) | |
401 | { | |
402 | *dst++ = flags; | |
403 | *dst++ = code; | |
404 | *dst++ = len; | |
405 | wlen = 3; | |
406 | } | |
407 | else | |
408 | { | |
409 | *dst++ = flags | BAF_EXT_LEN; | |
410 | *dst++ = code; | |
411 | put_u16(dst, len); | |
412 | wlen = 4; | |
413 | } | |
414 | ||
415 | return wlen; | |
416 | } | |
417 | ||
418 | static void | |
419 | aggregator_convert_to_old(struct adata *aggr, byte *dst, int *new_used) | |
420 | { | |
421 | byte *src = aggr->data; | |
422 | *new_used = 0; | |
423 | ||
424 | u32 as = get_u32(src); | |
425 | if (as > 0xFFFF) | |
426 | { | |
427 | as = AS_TRANS; | |
428 | *new_used = 1; | |
429 | } | |
430 | put_u16(dst, as); | |
431 | ||
432 | /* Copy IPv4 address */ | |
433 | memcpy(dst + 2, src + 4, 4); | |
434 | } | |
435 | ||
436 | static void | |
437 | aggregator_convert_to_new(struct adata *aggr, byte *dst) | |
438 | { | |
439 | byte *src = aggr->data; | |
440 | ||
441 | u32 as = get_u16(src); | |
442 | put_u32(dst, as); | |
443 | ||
444 | /* Copy IPv4 address */ | |
445 | memcpy(dst + 4, src + 2, 4); | |
446 | } | |
447 | ||
448 | static int | |
449 | bgp_get_attr_len(eattr *a) | |
450 | { | |
451 | int len; | |
452 | if (ATTR_KNOWN(EA_ID(a->id))) | |
453 | { | |
454 | int code = EA_ID(a->id); | |
455 | struct attr_desc *desc = &bgp_attr_table[code]; | |
456 | len = desc->expected_length; | |
457 | if (len < 0) | |
458 | { | |
459 | ASSERT(!(a->type & EAF_EMBEDDED)); | |
460 | len = a->u.ptr->length; | |
461 | } | |
462 | } | |
463 | else | |
464 | { | |
465 | ASSERT((a->type & EAF_TYPE_MASK) == EAF_TYPE_OPAQUE); | |
466 | len = a->u.ptr->length; | |
467 | } | |
468 | ||
469 | return len; | |
470 | } | |
471 | ||
54e55169 MM |
472 | /** |
473 | * bgp_encode_attrs - encode BGP attributes | |
11cb6202 | 474 | * @p: BGP instance |
54e55169 MM |
475 | * @w: buffer |
476 | * @attrs: a list of extended attributes | |
477 | * @remains: remaining space in the buffer | |
478 | * | |
479 | * The bgp_encode_attrs() function takes a list of extended attributes | |
480 | * and converts it to its BGP representation (a part of an Update message). | |
481 | * | |
82a79586 | 482 | * Result: Length of the attribute block generated or -1 if not enough space. |
54e55169 | 483 | */ |
ae80a2de | 484 | uint |
11cb6202 | 485 | bgp_encode_attrs(struct bgp_proto *p, byte *w, ea_list *attrs, int remains) |
f421cfdd | 486 | { |
ae80a2de | 487 | uint i, code, type, flags; |
f421cfdd | 488 | byte *start = w; |
11cb6202 | 489 | int len, rv; |
f421cfdd | 490 | |
cf3d6470 | 491 | for(i=0; i<attrs->count; i++) |
f421cfdd | 492 | { |
cf3d6470 | 493 | eattr *a = &attrs->attrs[i]; |
f421cfdd MM |
494 | ASSERT(EA_PROTO(a->id) == EAP_BGP); |
495 | code = EA_ID(a->id); | |
42a0c054 | 496 | |
cf3d6470 MM |
497 | #ifdef IPV6 |
498 | /* When talking multiprotocol BGP, the NEXT_HOP attributes are used only temporarily. */ | |
499 | if (code == BA_NEXT_HOP) | |
500 | continue; | |
501 | #endif | |
11cb6202 OZ |
502 | |
503 | /* When AS4-aware BGP speaker is talking to non-AS4-aware BGP speaker, | |
504 | * we have to convert our 4B AS_PATH to 2B AS_PATH and send our AS_PATH | |
505 | * as optional AS4_PATH attribute. | |
506 | */ | |
43c1cecc | 507 | if ((code == BA_AS_PATH) && (! p->as4_session)) |
f421cfdd | 508 | { |
f421cfdd | 509 | len = a->u.ptr->length; |
11cb6202 OZ |
510 | |
511 | if (remains < (len + 4)) | |
512 | goto err_no_buffer; | |
513 | ||
514 | /* Using temporary buffer because don't know a length of created attr | |
515 | * and therefore a length of a header. Perhaps i should better always | |
516 | * use BAF_EXT_LEN. */ | |
517 | ||
518 | byte buf[len]; | |
519 | int new_used; | |
520 | int nl = as_path_convert_to_old(a->u.ptr, buf, &new_used); | |
521 | ||
11b32d91 | 522 | DBG("BGP: Encoding old AS_PATH\n"); |
11cb6202 OZ |
523 | rv = bgp_encode_attr_hdr(w, BAF_TRANSITIVE, BA_AS_PATH, nl); |
524 | ADVANCE(w, remains, rv); | |
525 | memcpy(w, buf, nl); | |
526 | ADVANCE(w, remains, nl); | |
527 | ||
528 | if (! new_used) | |
529 | continue; | |
530 | ||
531 | if (remains < (len + 4)) | |
532 | goto err_no_buffer; | |
533 | ||
534 | /* We should discard AS_CONFED_SEQUENCE or AS_CONFED_SET path segments | |
535 | * here but we don't support confederations and such paths we already | |
536 | * discarded in bgp_check_as_path(). | |
537 | */ | |
538 | ||
11b32d91 | 539 | DBG("BGP: Encoding AS4_PATH\n"); |
11cb6202 OZ |
540 | rv = bgp_encode_attr_hdr(w, BAF_OPTIONAL | BAF_TRANSITIVE, BA_AS4_PATH, len); |
541 | ADVANCE(w, remains, rv); | |
542 | memcpy(w, a->u.ptr->data, len); | |
543 | ADVANCE(w, remains, len); | |
544 | ||
545 | continue; | |
f421cfdd | 546 | } |
11cb6202 OZ |
547 | |
548 | /* The same issue with AGGREGATOR attribute */ | |
43c1cecc | 549 | if ((code == BA_AGGREGATOR) && (! p->as4_session)) |
f421cfdd | 550 | { |
11cb6202 OZ |
551 | int new_used; |
552 | ||
553 | len = 6; | |
554 | if (remains < (len + 3)) | |
555 | goto err_no_buffer; | |
556 | ||
557 | rv = bgp_encode_attr_hdr(w, BAF_OPTIONAL | BAF_TRANSITIVE, BA_AGGREGATOR, len); | |
558 | ADVANCE(w, remains, rv); | |
559 | aggregator_convert_to_old(a->u.ptr, w, &new_used); | |
560 | ADVANCE(w, remains, len); | |
561 | ||
562 | if (! new_used) | |
563 | continue; | |
564 | ||
565 | len = 8; | |
566 | if (remains < (len + 3)) | |
567 | goto err_no_buffer; | |
568 | ||
569 | rv = bgp_encode_attr_hdr(w, BAF_OPTIONAL | BAF_TRANSITIVE, BA_AS4_AGGREGATOR, len); | |
570 | ADVANCE(w, remains, rv); | |
571 | memcpy(w, a->u.ptr->data, len); | |
572 | ADVANCE(w, remains, len); | |
573 | ||
574 | continue; | |
f421cfdd | 575 | } |
11cb6202 OZ |
576 | |
577 | /* Standard path continues here ... */ | |
578 | ||
42a0c054 | 579 | type = a->type & EAF_TYPE_MASK; |
11cb6202 OZ |
580 | flags = a->flags & (BAF_OPTIONAL | BAF_TRANSITIVE | BAF_PARTIAL); |
581 | len = bgp_get_attr_len(a); | |
582 | ||
42a0c054 | 583 | /* Skip empty sets */ |
66dbdbd9 | 584 | if (((type == EAF_TYPE_INT_SET) || (type == EAF_TYPE_EC_SET) || (type == EAF_TYPE_LC_SET)) && (len == 0)) |
6b5a8649 OZ |
585 | continue; |
586 | ||
11cb6202 OZ |
587 | if (remains < len + 4) |
588 | goto err_no_buffer; | |
589 | ||
590 | rv = bgp_encode_attr_hdr(w, flags, code, len); | |
591 | ADVANCE(w, remains, rv); | |
592 | ||
42a0c054 | 593 | switch (type) |
f421cfdd MM |
594 | { |
595 | case EAF_TYPE_INT: | |
596 | case EAF_TYPE_ROUTER_ID: | |
597 | if (len == 4) | |
598 | put_u32(w, a->u.data); | |
599 | else | |
600 | *w = a->u.data; | |
601 | break; | |
602 | case EAF_TYPE_IP_ADDRESS: | |
603 | { | |
604 | ip_addr ip = *(ip_addr *)a->u.ptr->data; | |
605 | ipa_hton(ip); | |
606 | memcpy(w, &ip, len); | |
607 | break; | |
608 | } | |
1ed2fe96 | 609 | case EAF_TYPE_INT_SET: |
66dbdbd9 | 610 | case EAF_TYPE_LC_SET: |
42a0c054 | 611 | case EAF_TYPE_EC_SET: |
1ed2fe96 | 612 | { |
42a0c054 | 613 | u32 *z = int_set_get_data(a->u.ptr); |
1ed2fe96 MM |
614 | int i; |
615 | for(i=0; i<len; i+=4) | |
616 | put_u32(w+i, *z++); | |
617 | break; | |
618 | } | |
f421cfdd MM |
619 | case EAF_TYPE_OPAQUE: |
620 | case EAF_TYPE_AS_PATH: | |
f421cfdd MM |
621 | memcpy(w, a->u.ptr->data, len); |
622 | break; | |
623 | default: | |
624 | bug("bgp_encode_attrs: unknown attribute type %02x", a->type); | |
625 | } | |
11cb6202 | 626 | ADVANCE(w, remains, len); |
f421cfdd | 627 | } |
cf3d6470 | 628 | return w - start; |
11cb6202 OZ |
629 | |
630 | err_no_buffer: | |
82a79586 | 631 | return -1; |
f421cfdd | 632 | } |
ae8f5584 | 633 | |
094d2bdb | 634 | /* |
c2b28c99 MM |
635 | static void |
636 | bgp_init_prefix(struct fib_node *N) | |
637 | { | |
638 | struct bgp_prefix *p = (struct bgp_prefix *) N; | |
f421cfdd | 639 | p->bucket_node.next = NULL; |
c2b28c99 | 640 | } |
094d2bdb | 641 | */ |
c2b28c99 | 642 | |
e3558ab1 MM |
643 | static int |
644 | bgp_compare_u32(const u32 *x, const u32 *y) | |
645 | { | |
646 | return (*x < *y) ? -1 : (*x > *y) ? 1 : 0; | |
647 | } | |
648 | ||
42a0c054 OZ |
649 | static inline void |
650 | bgp_normalize_int_set(u32 *dest, u32 *src, unsigned cnt) | |
ae8f5584 MM |
651 | { |
652 | memcpy(dest, src, sizeof(u32) * cnt); | |
e3558ab1 | 653 | qsort(dest, cnt, sizeof(u32), (int(*)(const void *, const void *)) bgp_compare_u32); |
ae8f5584 MM |
654 | } |
655 | ||
42a0c054 OZ |
656 | static int |
657 | bgp_compare_ec(const u32 *xp, const u32 *yp) | |
658 | { | |
659 | u64 x = ec_get(xp, 0); | |
660 | u64 y = ec_get(yp, 0); | |
661 | return (x < y) ? -1 : (x > y) ? 1 : 0; | |
662 | } | |
663 | ||
664 | static inline void | |
665 | bgp_normalize_ec_set(struct adata *ad, u32 *src, int internal) | |
666 | { | |
667 | u32 *dst = int_set_get_data(ad); | |
668 | ||
669 | /* Remove non-transitive communities (EC_TBIT active) on external sessions */ | |
670 | if (! internal) | |
671 | { | |
672 | int len = int_set_get_size(ad); | |
673 | u32 *t = dst; | |
674 | int i; | |
675 | ||
676 | for (i=0; i < len; i += 2) | |
677 | { | |
678 | if (src[i] & EC_TBIT) | |
679 | continue; | |
680 | ||
681 | *t++ = src[i]; | |
682 | *t++ = src[i+1]; | |
683 | } | |
684 | ||
685 | ad->length = (t - dst) * 4; | |
686 | } | |
687 | else | |
688 | memcpy(dst, src, ad->length); | |
689 | ||
690 | qsort(dst, ad->length / 8, 8, (int(*)(const void *, const void *)) bgp_compare_ec); | |
691 | } | |
692 | ||
66dbdbd9 OZ |
693 | static int |
694 | bgp_compare_lc(const u32 *x, const u32 *y) | |
695 | { | |
696 | if (x[0] != y[0]) | |
697 | return (x[0] > y[0]) ? 1 : -1; | |
698 | if (x[1] != y[1]) | |
699 | return (x[1] > y[1]) ? 1 : -1; | |
700 | if (x[2] != y[2]) | |
701 | return (x[2] > y[2]) ? 1 : -1; | |
702 | return 0; | |
703 | } | |
704 | ||
705 | static inline void | |
706 | bgp_normalize_lc_set(u32 *dest, u32 *src, unsigned cnt) | |
707 | { | |
708 | memcpy(dest, src, LCOMM_LENGTH * cnt); | |
709 | qsort(dest, cnt, LCOMM_LENGTH, (int(*)(const void *, const void *)) bgp_compare_lc); | |
710 | } | |
711 | ||
ae8f5584 MM |
712 | static void |
713 | bgp_rehash_buckets(struct bgp_proto *p) | |
714 | { | |
c2b28c99 | 715 | struct bgp_bucket **old = p->bucket_hash; |
ae8f5584 MM |
716 | struct bgp_bucket **new; |
717 | unsigned oldn = p->hash_size; | |
718 | unsigned i, e, mask; | |
719 | struct bgp_bucket *b; | |
720 | ||
721 | p->hash_size = p->hash_limit; | |
722 | DBG("BGP: Rehashing bucket table from %d to %d\n", oldn, p->hash_size); | |
723 | p->hash_limit *= 4; | |
724 | if (p->hash_limit >= 65536) | |
725 | p->hash_limit = ~0; | |
c2b28c99 | 726 | new = p->bucket_hash = mb_allocz(p->p.pool, p->hash_size * sizeof(struct bgp_bucket *)); |
ae8f5584 MM |
727 | mask = p->hash_size - 1; |
728 | for (i=0; i<oldn; i++) | |
729 | while (b = old[i]) | |
730 | { | |
c2b28c99 | 731 | old[i] = b->hash_next; |
ae8f5584 | 732 | e = b->hash & mask; |
c2b28c99 MM |
733 | b->hash_next = new[e]; |
734 | if (b->hash_next) | |
735 | b->hash_next->hash_prev = b; | |
736 | b->hash_prev = NULL; | |
ae8f5584 MM |
737 | new[e] = b; |
738 | } | |
739 | mb_free(old); | |
740 | } | |
741 | ||
742 | static struct bgp_bucket * | |
743 | bgp_new_bucket(struct bgp_proto *p, ea_list *new, unsigned hash) | |
744 | { | |
745 | struct bgp_bucket *b; | |
746 | unsigned ea_size = sizeof(ea_list) + new->count * sizeof(eattr); | |
7fdd338c | 747 | unsigned ea_size_aligned = BIRD_ALIGN(ea_size, CPU_STRUCT_ALIGN); |
dfc7a6c6 | 748 | unsigned size = sizeof(struct bgp_bucket) + ea_size_aligned; |
ae8f5584 MM |
749 | unsigned i; |
750 | byte *dest; | |
751 | unsigned index = hash & (p->hash_size - 1); | |
752 | ||
753 | /* Gather total size of non-inline attributes */ | |
754 | for (i=0; i<new->count; i++) | |
755 | { | |
756 | eattr *a = &new->attrs[i]; | |
757 | if (!(a->type & EAF_EMBEDDED)) | |
7fdd338c | 758 | size += BIRD_ALIGN(sizeof(struct adata) + a->u.ptr->length, CPU_STRUCT_ALIGN); |
ae8f5584 MM |
759 | } |
760 | ||
761 | /* Create the bucket and hash it */ | |
762 | b = mb_alloc(p->p.pool, size); | |
c2b28c99 MM |
763 | b->hash_next = p->bucket_hash[index]; |
764 | if (b->hash_next) | |
765 | b->hash_next->hash_prev = b; | |
766 | p->bucket_hash[index] = b; | |
767 | b->hash_prev = NULL; | |
ae8f5584 | 768 | b->hash = hash; |
f421cfdd MM |
769 | add_tail(&p->bucket_queue, &b->send_node); |
770 | init_list(&b->prefixes); | |
ae8f5584 MM |
771 | memcpy(b->eattrs, new, ea_size); |
772 | dest = ((byte *)b->eattrs) + ea_size_aligned; | |
773 | ||
774 | /* Copy values of non-inline attributes */ | |
775 | for (i=0; i<new->count; i++) | |
776 | { | |
85368cd4 | 777 | eattr *a = &b->eattrs->attrs[i]; |
ae8f5584 MM |
778 | if (!(a->type & EAF_EMBEDDED)) |
779 | { | |
780 | struct adata *oa = a->u.ptr; | |
781 | struct adata *na = (struct adata *) dest; | |
782 | memcpy(na, oa, sizeof(struct adata) + oa->length); | |
783 | a->u.ptr = na; | |
7fdd338c | 784 | dest += BIRD_ALIGN(sizeof(struct adata) + na->length, CPU_STRUCT_ALIGN); |
ae8f5584 MM |
785 | } |
786 | } | |
787 | ||
788 | /* If needed, rehash */ | |
789 | p->hash_count++; | |
790 | if (p->hash_count > p->hash_limit) | |
791 | bgp_rehash_buckets(p); | |
792 | ||
793 | return b; | |
794 | } | |
795 | ||
796 | static struct bgp_bucket * | |
6cb8f742 | 797 | bgp_get_bucket(struct bgp_proto *p, net *n, ea_list *attrs, int originate) |
ae8f5584 | 798 | { |
e21423ba | 799 | ea_list *new; |
56a2bed4 | 800 | unsigned i, cnt, hash, code; |
ae8f5584 MM |
801 | eattr *a, *d; |
802 | u32 seen = 0; | |
ae8f5584 MM |
803 | struct bgp_bucket *b; |
804 | ||
02bd064a MM |
805 | /* Merge the attribute list */ |
806 | new = alloca(ea_scan(attrs)); | |
807 | ea_merge(attrs, new); | |
8b258e4e | 808 | ea_sort(new); |
ae8f5584 MM |
809 | |
810 | /* Normalize attributes */ | |
811 | d = new->attrs; | |
812 | cnt = new->count; | |
813 | new->count = 0; | |
814 | for(i=0; i<cnt; i++) | |
815 | { | |
816 | a = &new->attrs[i]; | |
ae8f5584 MM |
817 | if (EA_PROTO(a->id) != EAP_BGP) |
818 | continue; | |
56a2bed4 | 819 | code = EA_ID(a->id); |
d1a74339 | 820 | if (ATTR_KNOWN(code)) |
56a2bed4 | 821 | { |
1950a479 OZ |
822 | if (!p->is_internal) |
823 | { | |
824 | if (!bgp_attr_table[code].allow_in_ebgp) | |
825 | continue; | |
826 | if ((code == BA_LOCAL_PREF) && !p->cf->allow_local_pref) | |
827 | continue; | |
828 | } | |
684c25d9 MM |
829 | /* The flags might have been zero if the attr was added by filters */ |
830 | a->flags = (a->flags & BAF_PARTIAL) | bgp_attr_table[code].expected_flags; | |
d1a74339 MM |
831 | if (code < 32) |
832 | seen |= 1 << code; | |
833 | } | |
834 | else | |
835 | { | |
836 | /* Don't re-export unknown non-transitive attributes */ | |
837 | if (!(a->flags & BAF_TRANSITIVE)) | |
838 | continue; | |
56a2bed4 | 839 | } |
ae8f5584 | 840 | *d = *a; |
e3558ab1 MM |
841 | if ((d->type & EAF_ORIGINATED) && !originate && (d->flags & BAF_TRANSITIVE) && (d->flags & BAF_OPTIONAL)) |
842 | d->flags |= BAF_PARTIAL; | |
ae8f5584 MM |
843 | switch (d->type & EAF_TYPE_MASK) |
844 | { | |
e3558ab1 | 845 | case EAF_TYPE_INT_SET: |
ae8f5584 MM |
846 | { |
847 | struct adata *z = alloca(sizeof(struct adata) + d->u.ptr->length); | |
848 | z->length = d->u.ptr->length; | |
42a0c054 OZ |
849 | bgp_normalize_int_set((u32 *) z->data, (u32 *) d->u.ptr->data, z->length / 4); |
850 | d->u.ptr = z; | |
851 | break; | |
852 | } | |
853 | case EAF_TYPE_EC_SET: | |
854 | { | |
855 | struct adata *z = alloca(sizeof(struct adata) + d->u.ptr->length); | |
856 | z->length = d->u.ptr->length; | |
857 | bgp_normalize_ec_set(z, (u32 *) d->u.ptr->data, p->is_internal); | |
ae8f5584 MM |
858 | d->u.ptr = z; |
859 | break; | |
860 | } | |
66dbdbd9 OZ |
861 | case EAF_TYPE_LC_SET: |
862 | { | |
863 | struct adata *z = alloca(sizeof(struct adata) + d->u.ptr->length); | |
864 | z->length = d->u.ptr->length; | |
865 | bgp_normalize_lc_set((u32 *) z->data, (u32 *) d->u.ptr->data, z->length / LCOMM_LENGTH); | |
866 | d->u.ptr = z; | |
867 | break; | |
868 | } | |
de10a974 | 869 | default: ; |
ae8f5584 MM |
870 | } |
871 | d++; | |
872 | new->count++; | |
873 | } | |
874 | ||
875 | /* Hash */ | |
876 | hash = ea_hash(new); | |
c2b28c99 | 877 | for(b=p->bucket_hash[hash & (p->hash_size - 1)]; b; b=b->hash_next) |
ae8f5584 MM |
878 | if (b->hash == hash && ea_same(b->eattrs, new)) |
879 | { | |
880 | DBG("Found bucket.\n"); | |
881 | return b; | |
882 | } | |
883 | ||
884 | /* Ensure that there are all mandatory attributes */ | |
77506349 | 885 | for(i=0; i<ARRAY_SIZE(bgp_mandatory_attrs); i++) |
ae8f5584 MM |
886 | if (!(seen & (1 << bgp_mandatory_attrs[i]))) |
887 | { | |
6cb8f742 | 888 | 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); |
ae8f5584 MM |
889 | return NULL; |
890 | } | |
891 | ||
6cb8f742 OZ |
892 | /* Check if next hop is valid */ |
893 | a = ea_find(new, EA_CODE(EAP_BGP, BA_NEXT_HOP)); | |
9be9a264 | 894 | if (!a || ipa_equal(p->cf->remote_ip, *(ip_addr *)a->u.ptr->data)) |
6cb8f742 OZ |
895 | { |
896 | log(L_ERR "%s: Invalid NEXT_HOP attribute in route %I/%d", p->p.name, n->n.prefix, n->n.pxlen); | |
897 | return NULL; | |
898 | } | |
f421cfdd | 899 | |
ae8f5584 MM |
900 | /* Create new bucket */ |
901 | DBG("Creating bucket.\n"); | |
902 | return bgp_new_bucket(p, new, hash); | |
903 | } | |
904 | ||
f421cfdd MM |
905 | void |
906 | bgp_free_bucket(struct bgp_proto *p, struct bgp_bucket *buck) | |
907 | { | |
908 | if (buck->hash_next) | |
909 | buck->hash_next->hash_prev = buck->hash_prev; | |
910 | if (buck->hash_prev) | |
911 | buck->hash_prev->hash_next = buck->hash_next; | |
912 | else | |
913 | p->bucket_hash[buck->hash & (p->hash_size-1)] = buck->hash_next; | |
914 | mb_free(buck); | |
915 | } | |
916 | ||
094d2bdb OZ |
917 | |
918 | /* Prefix hash table */ | |
919 | ||
e7d2ac44 OZ |
920 | #define PXH_KEY(n1) n1->n.prefix, n1->n.pxlen, n1->path_id |
921 | #define PXH_NEXT(n) n->next | |
922 | #define PXH_EQ(p1,l1,i1,p2,l2,i2) ipa_equal(p1, p2) && l1 == l2 && i1 == i2 | |
923 | #define PXH_FN(p,l,i) ipa_hash32(p) ^ u32_hash((l << 16) ^ i) | |
924 | ||
925 | #define PXH_REHASH bgp_pxh_rehash | |
926 | #define PXH_PARAMS /8, *2, 2, 2, 8, 20 | |
927 | ||
094d2bdb | 928 | |
e7d2ac44 | 929 | HASH_DEFINE_REHASH_FN(PXH, struct bgp_prefix) |
094d2bdb OZ |
930 | |
931 | void | |
932 | bgp_init_prefix_table(struct bgp_proto *p, u32 order) | |
933 | { | |
e7d2ac44 | 934 | HASH_INIT(p->prefix_hash, p->p.pool, order); |
094d2bdb | 935 | |
e7d2ac44 | 936 | p->prefix_slab = sl_new(p->p.pool, sizeof(struct bgp_prefix)); |
094d2bdb OZ |
937 | } |
938 | ||
ed1a908e OZ |
939 | void |
940 | bgp_free_prefix_table(struct bgp_proto *p) | |
941 | { | |
942 | HASH_FREE(p->prefix_hash); | |
943 | ||
944 | rfree(p->prefix_slab); | |
945 | p->prefix_slab = NULL; | |
946 | } | |
947 | ||
094d2bdb OZ |
948 | static struct bgp_prefix * |
949 | bgp_get_prefix(struct bgp_proto *p, ip_addr prefix, int pxlen, u32 path_id) | |
950 | { | |
e7d2ac44 | 951 | struct bgp_prefix *bp = HASH_FIND(p->prefix_hash, PXH, prefix, pxlen, path_id); |
094d2bdb | 952 | |
e7d2ac44 OZ |
953 | if (bp) |
954 | return bp; | |
094d2bdb OZ |
955 | |
956 | bp = sl_alloc(p->prefix_slab); | |
957 | bp->n.prefix = prefix; | |
958 | bp->n.pxlen = pxlen; | |
959 | bp->path_id = path_id; | |
094d2bdb OZ |
960 | bp->bucket_node.next = NULL; |
961 | ||
e7d2ac44 | 962 | HASH_INSERT2(p->prefix_hash, PXH, p->p.pool, bp); |
094d2bdb OZ |
963 | |
964 | return bp; | |
965 | } | |
966 | ||
967 | void | |
968 | bgp_free_prefix(struct bgp_proto *p, struct bgp_prefix *bp) | |
969 | { | |
e7d2ac44 | 970 | HASH_REMOVE2(p->prefix_hash, PXH, p->p.pool, bp); |
094d2bdb | 971 | sl_free(p->prefix_slab, bp); |
094d2bdb OZ |
972 | } |
973 | ||
974 | ||
ef2c708d | 975 | void |
dca75fd7 | 976 | bgp_rt_notify(struct proto *P, rtable *tbl UNUSED, net *n, rte *new, rte *old UNUSED, ea_list *attrs) |
ef2c708d | 977 | { |
ae8f5584 | 978 | struct bgp_proto *p = (struct bgp_proto *) P; |
f421cfdd MM |
979 | struct bgp_bucket *buck; |
980 | struct bgp_prefix *px; | |
094d2bdb OZ |
981 | rte *key; |
982 | u32 path_id; | |
ae8f5584 | 983 | |
f421cfdd | 984 | DBG("BGP: Got route %I/%d %s\n", n->n.prefix, n->n.pxlen, new ? "up" : "down"); |
ae8f5584 MM |
985 | |
986 | if (new) | |
987 | { | |
094d2bdb | 988 | key = new; |
6cb8f742 | 989 | buck = bgp_get_bucket(p, n, attrs, new->attrs->source != RTS_BGP); |
ae8f5584 MM |
990 | if (!buck) /* Inconsistent attribute list */ |
991 | return; | |
992 | } | |
f421cfdd MM |
993 | else |
994 | { | |
094d2bdb | 995 | key = old; |
f421cfdd MM |
996 | if (!(buck = p->withdraw_bucket)) |
997 | { | |
998 | buck = p->withdraw_bucket = mb_alloc(P->pool, sizeof(struct bgp_bucket)); | |
999 | init_list(&buck->prefixes); | |
1000 | } | |
1001 | } | |
094d2bdb OZ |
1002 | path_id = p->add_path_tx ? key->attrs->src->global_id : 0; |
1003 | px = bgp_get_prefix(p, n->n.prefix, n->n.pxlen, path_id); | |
f421cfdd MM |
1004 | if (px->bucket_node.next) |
1005 | { | |
1006 | DBG("\tRemoving old entry.\n"); | |
1007 | rem_node(&px->bucket_node); | |
1008 | } | |
1009 | add_tail(&buck->prefixes, &px->bucket_node); | |
1010 | bgp_schedule_packet(p->conn, PKT_UPDATE); | |
ef2c708d MM |
1011 | } |
1012 | ||
48e842cc MM |
1013 | static int |
1014 | bgp_create_attrs(struct bgp_proto *p, rte *e, ea_list **attrs, struct linpool *pool) | |
ef2c708d | 1015 | { |
8b258e4e | 1016 | ea_list *ea = lp_alloc(pool, sizeof(ea_list) + 4*sizeof(eattr)); |
ef2c708d | 1017 | rta *rta = e->attrs; |
cf3d6470 | 1018 | byte *z; |
ef2c708d | 1019 | |
48e842cc MM |
1020 | ea->next = *attrs; |
1021 | *attrs = ea; | |
ef2c708d | 1022 | ea->flags = EALF_SORTED; |
8b258e4e | 1023 | ea->count = 4; |
ef2c708d | 1024 | |
4847a894 | 1025 | bgp_set_attr(ea->attrs, BA_ORIGIN, |
98ac6176 | 1026 | ((rta->source == RTS_OSPF_EXT1) || (rta->source == RTS_OSPF_EXT2)) ? ORIGIN_INCOMPLETE : ORIGIN_IGP); |
ef2c708d | 1027 | |
ef2c708d | 1028 | if (p->is_internal) |
4847a894 | 1029 | bgp_set_attr_wa(ea->attrs+1, pool, BA_AS_PATH, 0); |
ef2c708d MM |
1030 | else |
1031 | { | |
43c1cecc | 1032 | z = bgp_set_attr_wa(ea->attrs+1, pool, BA_AS_PATH, 6); |
8b258e4e | 1033 | z[0] = AS_PATH_SEQUENCE; |
ef2c708d | 1034 | z[1] = 1; /* 1 AS */ |
43c1cecc | 1035 | put_u32(z+2, p->local_as); |
ef2c708d MM |
1036 | } |
1037 | ||
9be9a264 OZ |
1038 | /* iBGP -> use gw, eBGP multi-hop -> use source_addr, |
1039 | eBGP single-hop -> use gw if on the same iface */ | |
4827b69f | 1040 | z = bgp_set_attr_wa(ea->attrs+2, pool, BA_NEXT_HOP, NEXT_HOP_LENGTH); |
48e842cc | 1041 | if (p->cf->next_hop_self || |
b7a735ea | 1042 | rta->dest != RTD_ROUTER || |
9be9a264 | 1043 | ipa_equal(rta->gw, IPA_NONE) || |
88a183c6 | 1044 | ipa_is_link_local(rta->gw) || |
48bc232f OZ |
1045 | (!p->is_internal && !p->cf->next_hop_keep && |
1046 | (!p->neigh || (rta->iface != p->neigh->iface)))) | |
4827b69f | 1047 | set_next_hop(z, p->source_addr); |
ef2c708d | 1048 | else |
f2d7da74 | 1049 | set_next_hop(z, rta->gw); |
8b258e4e | 1050 | |
fbcb7d5f | 1051 | bgp_set_attr(ea->attrs+3, BA_LOCAL_PREF, p->cf->default_local_pref); |
ef2c708d | 1052 | |
48e842cc | 1053 | return 0; /* Leave decision to the filters */ |
ef2c708d MM |
1054 | } |
1055 | ||
4847a894 OZ |
1056 | |
1057 | static inline int | |
1058 | bgp_as_path_loopy(struct bgp_proto *p, rta *a) | |
1059 | { | |
a15dab76 | 1060 | int num = p->cf->allow_local_as + 1; |
4847a894 | 1061 | eattr *e = ea_find(a->eattrs, EA_CODE(EAP_BGP, BA_AS_PATH)); |
a15dab76 | 1062 | return (e && (num > 0) && as_path_contains(e->u.ptr, p->local_as, num)); |
4847a894 OZ |
1063 | } |
1064 | ||
1065 | static inline int | |
1066 | bgp_originator_id_loopy(struct bgp_proto *p, rta *a) | |
0a40e973 | 1067 | { |
4847a894 OZ |
1068 | eattr *e = ea_find(a->eattrs, EA_CODE(EAP_BGP, BA_ORIGINATOR_ID)); |
1069 | return (e && (e->u.data == p->local_id)); | |
1070 | } | |
1071 | ||
1072 | static inline int | |
1073 | bgp_cluster_list_loopy(struct bgp_proto *p, rta *a) | |
1074 | { | |
1075 | eattr *e = ea_find(a->eattrs, EA_CODE(EAP_BGP, BA_CLUSTER_LIST)); | |
1076 | return (e && p->rr_client && int_set_contains(e->u.ptr, p->rr_cluster_id)); | |
1077 | } | |
1078 | ||
1079 | ||
1080 | static inline void | |
1081 | bgp_path_prepend(rte *e, ea_list **attrs, struct linpool *pool, u32 as) | |
1082 | { | |
1083 | eattr *a = ea_find(e->attrs->eattrs, EA_CODE(EAP_BGP, BA_AS_PATH)); | |
1084 | bgp_attach_attr(attrs, pool, BA_AS_PATH, (uintptr_t) as_path_prepend(pool, a->u.ptr, as)); | |
1085 | } | |
1086 | ||
1087 | static inline void | |
1088 | bgp_cluster_list_prepend(rte *e, ea_list **attrs, struct linpool *pool, u32 cid) | |
1089 | { | |
1090 | eattr *a = ea_find(e->attrs->eattrs, EA_CODE(EAP_BGP, BA_CLUSTER_LIST)); | |
261816b0 | 1091 | bgp_attach_attr(attrs, pool, BA_CLUSTER_LIST, (uintptr_t) int_set_prepend(pool, a ? a->u.ptr : NULL, cid)); |
ef2c708d MM |
1092 | } |
1093 | ||
48e842cc | 1094 | static int |
4847a894 | 1095 | bgp_update_attrs(struct bgp_proto *p, rte *e, ea_list **attrs, struct linpool *pool, int rr) |
ef2c708d | 1096 | { |
48e842cc MM |
1097 | eattr *a; |
1098 | ||
a92fe607 | 1099 | if (!p->is_internal && !p->rs_client) |
b6bf284a OZ |
1100 | { |
1101 | bgp_path_prepend(e, attrs, pool, p->local_as); | |
1102 | ||
1103 | /* The MULTI_EXIT_DISC attribute received from a neighboring AS MUST NOT be | |
1104 | * propagated to other neighboring ASes. | |
1105 | * Perhaps it would be better to undefine it. | |
1106 | */ | |
1107 | a = ea_find(e->attrs->eattrs, EA_CODE(EAP_BGP, BA_MULTI_EXIT_DISC)); | |
1108 | if (a) | |
1109 | bgp_attach_attr(attrs, pool, BA_MULTI_EXIT_DISC, 0); | |
1110 | } | |
ef2c708d | 1111 | |
9be9a264 | 1112 | /* iBGP -> keep next_hop, eBGP multi-hop -> use source_addr, |
53ffbff3 OZ |
1113 | * eBGP single-hop -> keep next_hop if on the same iface. |
1114 | * If the next_hop is zero (i.e. link-local), keep only if on the same iface. | |
48bc232f OZ |
1115 | * |
1116 | * Note that same-iface-check uses iface from route, which is based on gw. | |
53ffbff3 | 1117 | */ |
48e842cc | 1118 | a = ea_find(e->attrs->eattrs, EA_CODE(EAP_BGP, BA_NEXT_HOP)); |
9be9a264 | 1119 | if (a && !p->cf->next_hop_self && |
48bc232f OZ |
1120 | (p->cf->next_hop_keep || |
1121 | (p->is_internal && ipa_nonzero(*((ip_addr *) a->u.ptr->data))) || | |
53ffbff3 | 1122 | (p->neigh && (e->attrs->iface == p->neigh->iface)))) |
48e842cc MM |
1123 | { |
1124 | /* Leave the original next hop attribute, will check later where does it point */ | |
1125 | } | |
1126 | else | |
1127 | { | |
1128 | /* Need to create new one */ | |
4827b69f OZ |
1129 | byte *b = bgp_attach_attr_wa(attrs, pool, BA_NEXT_HOP, NEXT_HOP_LENGTH); |
1130 | set_next_hop(b, p->source_addr); | |
4847a894 OZ |
1131 | } |
1132 | ||
1133 | if (rr) | |
1134 | { | |
1135 | /* Handling route reflection, RFC 4456 */ | |
094d2bdb | 1136 | struct bgp_proto *src = (struct bgp_proto *) e->attrs->src->proto; |
4847a894 OZ |
1137 | |
1138 | a = ea_find(e->attrs->eattrs, EA_CODE(EAP_BGP, BA_ORIGINATOR_ID)); | |
1139 | if (!a) | |
1140 | bgp_attach_attr(attrs, pool, BA_ORIGINATOR_ID, src->remote_id); | |
1141 | ||
1142 | /* We attach proper cluster ID according to whether the route is entering or leaving the cluster */ | |
1143 | bgp_cluster_list_prepend(e, attrs, pool, src->rr_client ? src->rr_cluster_id : p->rr_cluster_id); | |
1144 | ||
1145 | /* Two RR clients with different cluster ID, hmmm */ | |
1146 | if (src->rr_client && p->rr_client && (src->rr_cluster_id != p->rr_cluster_id)) | |
1147 | bgp_cluster_list_prepend(e, attrs, pool, p->rr_cluster_id); | |
48e842cc | 1148 | } |
ef2c708d | 1149 | |
48e842cc | 1150 | return 0; /* Leave decision to the filters */ |
ef2c708d MM |
1151 | } |
1152 | ||
6cb8f742 OZ |
1153 | static int |
1154 | bgp_community_filter(struct bgp_proto *p, rte *e) | |
1155 | { | |
1156 | eattr *a; | |
1157 | struct adata *d; | |
1158 | ||
1159 | /* Check if we aren't forbidden to export the route by communities */ | |
1160 | a = ea_find(e->attrs->eattrs, EA_CODE(EAP_BGP, BA_COMMUNITY)); | |
1161 | if (a) | |
1162 | { | |
1163 | d = a->u.ptr; | |
1164 | if (int_set_contains(d, BGP_COMM_NO_ADVERTISE)) | |
1165 | { | |
1166 | DBG("\tNO_ADVERTISE\n"); | |
1167 | return 1; | |
1168 | } | |
1169 | if (!p->is_internal && | |
1170 | (int_set_contains(d, BGP_COMM_NO_EXPORT) || | |
1171 | int_set_contains(d, BGP_COMM_NO_EXPORT_SUBCONFED))) | |
1172 | { | |
1173 | DBG("\tNO_EXPORT\n"); | |
1174 | return 1; | |
1175 | } | |
1176 | } | |
1177 | ||
1178 | return 0; | |
1179 | } | |
1180 | ||
ef2c708d MM |
1181 | int |
1182 | bgp_import_control(struct proto *P, rte **new, ea_list **attrs, struct linpool *pool) | |
1183 | { | |
1184 | rte *e = *new; | |
1185 | struct bgp_proto *p = (struct bgp_proto *) P; | |
094d2bdb OZ |
1186 | struct bgp_proto *new_bgp = (e->attrs->src->proto->proto == &proto_bgp) ? |
1187 | (struct bgp_proto *) e->attrs->src->proto : NULL; | |
ef2c708d | 1188 | |
48e842cc | 1189 | if (p == new_bgp) /* Poison reverse updates */ |
ef2c708d MM |
1190 | return -1; |
1191 | if (new_bgp) | |
1192 | { | |
4847a894 OZ |
1193 | /* We should check here for cluster list loop, because the receiving BGP instance |
1194 | might have different cluster ID */ | |
1195 | if (bgp_cluster_list_loopy(p, e->attrs)) | |
1196 | return -1; | |
1197 | ||
41677025 | 1198 | if (p->cf->interpret_communities && bgp_community_filter(p, e)) |
6cb8f742 OZ |
1199 | return -1; |
1200 | ||
ef2c708d | 1201 | if (p->local_as == new_bgp->local_as && p->is_internal && new_bgp->is_internal) |
4847a894 OZ |
1202 | { |
1203 | /* Redistribution of internal routes with IBGP */ | |
1204 | if (p->rr_client || new_bgp->rr_client) | |
1205 | /* Route reflection, RFC 4456 */ | |
1206 | return bgp_update_attrs(p, e, attrs, pool, 1); | |
1207 | else | |
1208 | return -1; | |
1209 | } | |
1210 | else | |
1211 | return bgp_update_attrs(p, e, attrs, pool, 0); | |
ef2c708d MM |
1212 | } |
1213 | else | |
48e842cc | 1214 | return bgp_create_attrs(p, e, attrs, pool); |
ef2c708d MM |
1215 | } |
1216 | ||
b6bf284a OZ |
1217 | static inline u32 |
1218 | bgp_get_neighbor(rte *r) | |
1219 | { | |
1220 | eattr *e = ea_find(r->attrs->eattrs, EA_CODE(EAP_BGP, BA_AS_PATH)); | |
1221 | u32 as; | |
1222 | ||
52b9b2a1 | 1223 | if (e && as_path_get_first(e->u.ptr, &as)) |
b6bf284a OZ |
1224 | return as; |
1225 | else | |
094d2bdb | 1226 | return ((struct bgp_proto *) r->attrs->src->proto)->remote_as; |
b6bf284a OZ |
1227 | } |
1228 | ||
7e95c05d OZ |
1229 | static inline int |
1230 | rte_resolvable(rte *rt) | |
1231 | { | |
1232 | int rd = rt->attrs->dest; | |
1233 | return (rd == RTD_ROUTER) || (rd == RTD_DEVICE) || (rd == RTD_MULTIPATH); | |
1234 | } | |
1235 | ||
ef2c708d MM |
1236 | int |
1237 | bgp_rte_better(rte *new, rte *old) | |
1238 | { | |
094d2bdb OZ |
1239 | struct bgp_proto *new_bgp = (struct bgp_proto *) new->attrs->src->proto; |
1240 | struct bgp_proto *old_bgp = (struct bgp_proto *) old->attrs->src->proto; | |
56a2bed4 MM |
1241 | eattr *x, *y; |
1242 | u32 n, o; | |
ef2c708d | 1243 | |
be4cd99a OZ |
1244 | /* Skip suppressed routes (see bgp_rte_recalculate()) */ |
1245 | n = new->u.bgp.suppressed; | |
1246 | o = old->u.bgp.suppressed; | |
1247 | if (n > o) | |
1248 | return 0; | |
1249 | if (n < o) | |
1250 | return 1; | |
1251 | ||
ac3ac49a | 1252 | /* RFC 4271 9.1.2.1. Route resolvability test */ |
7e95c05d OZ |
1253 | n = rte_resolvable(new); |
1254 | o = rte_resolvable(old); | |
ac3ac49a OZ |
1255 | if (n > o) |
1256 | return 1; | |
1257 | if (n < o) | |
1258 | return 0; | |
1259 | ||
ef2c708d | 1260 | /* Start with local preferences */ |
56a2bed4 MM |
1261 | x = ea_find(new->attrs->eattrs, EA_CODE(EAP_BGP, BA_LOCAL_PREF)); |
1262 | y = ea_find(old->attrs->eattrs, EA_CODE(EAP_BGP, BA_LOCAL_PREF)); | |
1263 | n = x ? x->u.data : new_bgp->cf->default_local_pref; | |
1264 | o = y ? y->u.data : old_bgp->cf->default_local_pref; | |
1265 | if (n > o) | |
1266 | return 1; | |
1267 | if (n < o) | |
1268 | return 0; | |
1269 | ||
4847a894 | 1270 | /* RFC 4271 9.1.2.2. a) Use AS path lengths */ |
56a2bed4 | 1271 | if (new_bgp->cf->compare_path_lengths || old_bgp->cf->compare_path_lengths) |
ef2c708d | 1272 | { |
56a2bed4 MM |
1273 | x = ea_find(new->attrs->eattrs, EA_CODE(EAP_BGP, BA_AS_PATH)); |
1274 | y = ea_find(old->attrs->eattrs, EA_CODE(EAP_BGP, BA_AS_PATH)); | |
11cb6202 OZ |
1275 | n = x ? as_path_getlen(x->u.ptr) : AS_PATH_MAXLEN; |
1276 | o = y ? as_path_getlen(y->u.ptr) : AS_PATH_MAXLEN; | |
56a2bed4 | 1277 | if (n < o) |
ef2c708d | 1278 | return 1; |
56a2bed4 | 1279 | if (n > o) |
ef2c708d MM |
1280 | return 0; |
1281 | } | |
1282 | ||
4847a894 | 1283 | /* RFC 4271 9.1.2.2. b) Use origins */ |
56a2bed4 MM |
1284 | x = ea_find(new->attrs->eattrs, EA_CODE(EAP_BGP, BA_ORIGIN)); |
1285 | y = ea_find(old->attrs->eattrs, EA_CODE(EAP_BGP, BA_ORIGIN)); | |
cea63664 MM |
1286 | n = x ? x->u.data : ORIGIN_INCOMPLETE; |
1287 | o = y ? y->u.data : ORIGIN_INCOMPLETE; | |
56a2bed4 MM |
1288 | if (n < o) |
1289 | return 1; | |
1290 | if (n > o) | |
1291 | return 0; | |
1292 | ||
4847a894 | 1293 | /* RFC 4271 9.1.2.2. c) Compare MED's */ |
be4cd99a OZ |
1294 | /* Proper RFC 4271 path selection cannot be interpreted as finding |
1295 | * the best path in some ordering. It is implemented partially in | |
1296 | * bgp_rte_recalculate() when deterministic_med option is | |
1297 | * active. Without that option, the behavior is just an | |
1298 | * approximation, which in specific situations may lead to | |
1299 | * persistent routing loops, because it is nondeterministic - it | |
1300 | * depends on the order in which routes appeared. But it is also the | |
1301 | * same behavior as used by default in Cisco routers, so it is | |
1302 | * probably not a big issue. | |
73272f04 OZ |
1303 | */ |
1304 | if (new_bgp->cf->med_metric || old_bgp->cf->med_metric || | |
1305 | (bgp_get_neighbor(new) == bgp_get_neighbor(old))) | |
b6bf284a OZ |
1306 | { |
1307 | x = ea_find(new->attrs->eattrs, EA_CODE(EAP_BGP, BA_MULTI_EXIT_DISC)); | |
1308 | y = ea_find(old->attrs->eattrs, EA_CODE(EAP_BGP, BA_MULTI_EXIT_DISC)); | |
1309 | n = x ? x->u.data : new_bgp->cf->default_med; | |
1310 | o = y ? y->u.data : old_bgp->cf->default_med; | |
1311 | if (n < o) | |
1312 | return 1; | |
1313 | if (n > o) | |
1314 | return 0; | |
1315 | } | |
56a2bed4 | 1316 | |
4847a894 | 1317 | /* RFC 4271 9.1.2.2. d) Prefer external peers */ |
ef2c708d MM |
1318 | if (new_bgp->is_internal > old_bgp->is_internal) |
1319 | return 0; | |
1320 | if (new_bgp->is_internal < old_bgp->is_internal) | |
1321 | return 1; | |
ef2c708d | 1322 | |
d1e146f2 OZ |
1323 | /* RFC 4271 9.1.2.2. e) Compare IGP metrics */ |
1324 | n = new_bgp->cf->igp_metric ? new->attrs->igp_metric : 0; | |
1325 | o = old_bgp->cf->igp_metric ? old->attrs->igp_metric : 0; | |
1326 | if (n < o) | |
1327 | return 1; | |
1328 | if (n > o) | |
1329 | return 0; | |
4847a894 | 1330 | |
4847a894 OZ |
1331 | /* RFC 4271 9.1.2.2. f) Compare BGP identifiers */ |
1332 | /* RFC 4456 9. a) Use ORIGINATOR_ID instead of local neighor ID */ | |
1333 | x = ea_find(new->attrs->eattrs, EA_CODE(EAP_BGP, BA_ORIGINATOR_ID)); | |
1334 | y = ea_find(old->attrs->eattrs, EA_CODE(EAP_BGP, BA_ORIGINATOR_ID)); | |
1335 | n = x ? x->u.data : new_bgp->remote_id; | |
1336 | o = y ? y->u.data : old_bgp->remote_id; | |
3228c72c OZ |
1337 | |
1338 | /* RFC 5004 - prefer older routes */ | |
1339 | /* (if both are external and from different peer) */ | |
1340 | if ((new_bgp->cf->prefer_older || old_bgp->cf->prefer_older) && | |
1341 | !new_bgp->is_internal && n != o) | |
1342 | return 0; | |
1343 | ||
1344 | /* rest of RFC 4271 9.1.2.2. f) */ | |
4847a894 OZ |
1345 | if (n < o) |
1346 | return 1; | |
1347 | if (n > o) | |
1348 | return 0; | |
11cb6202 | 1349 | |
3075824d OZ |
1350 | /* RFC 4456 9. b) Compare cluster list lengths */ |
1351 | x = ea_find(new->attrs->eattrs, EA_CODE(EAP_BGP, BA_CLUSTER_LIST)); | |
1352 | y = ea_find(old->attrs->eattrs, EA_CODE(EAP_BGP, BA_CLUSTER_LIST)); | |
1353 | n = x ? int_set_get_size(x->u.ptr) : 0; | |
1354 | o = y ? int_set_get_size(y->u.ptr) : 0; | |
1355 | if (n < o) | |
1356 | return 1; | |
1357 | if (n > o) | |
1358 | return 0; | |
1359 | ||
4847a894 OZ |
1360 | /* RFC 4271 9.1.2.2. g) Compare peer IP adresses */ |
1361 | return (ipa_compare(new_bgp->cf->remote_ip, old_bgp->cf->remote_ip) < 0); | |
1362 | } | |
1363 | ||
be4cd99a | 1364 | |
8d9eef17 OZ |
1365 | int |
1366 | bgp_rte_mergable(rte *pri, rte *sec) | |
1367 | { | |
1368 | struct bgp_proto *pri_bgp = (struct bgp_proto *) pri->attrs->src->proto; | |
1369 | struct bgp_proto *sec_bgp = (struct bgp_proto *) sec->attrs->src->proto; | |
1370 | eattr *x, *y; | |
1371 | u32 p, s; | |
1372 | ||
1373 | /* Skip suppressed routes (see bgp_rte_recalculate()) */ | |
1374 | if (pri->u.bgp.suppressed != sec->u.bgp.suppressed) | |
1375 | return 0; | |
1376 | ||
1377 | /* RFC 4271 9.1.2.1. Route resolvability test */ | |
1378 | if (!rte_resolvable(sec)) | |
1379 | return 0; | |
1380 | ||
1381 | /* Start with local preferences */ | |
1382 | x = ea_find(pri->attrs->eattrs, EA_CODE(EAP_BGP, BA_LOCAL_PREF)); | |
1383 | y = ea_find(sec->attrs->eattrs, EA_CODE(EAP_BGP, BA_LOCAL_PREF)); | |
1384 | p = x ? x->u.data : pri_bgp->cf->default_local_pref; | |
1385 | s = y ? y->u.data : sec_bgp->cf->default_local_pref; | |
1386 | if (p != s) | |
1387 | return 0; | |
1388 | ||
1389 | /* RFC 4271 9.1.2.2. a) Use AS path lengths */ | |
1390 | if (pri_bgp->cf->compare_path_lengths || sec_bgp->cf->compare_path_lengths) | |
1391 | { | |
1392 | x = ea_find(pri->attrs->eattrs, EA_CODE(EAP_BGP, BA_AS_PATH)); | |
1393 | y = ea_find(sec->attrs->eattrs, EA_CODE(EAP_BGP, BA_AS_PATH)); | |
1394 | p = x ? as_path_getlen(x->u.ptr) : AS_PATH_MAXLEN; | |
1395 | s = y ? as_path_getlen(y->u.ptr) : AS_PATH_MAXLEN; | |
1396 | ||
1397 | if (p != s) | |
1398 | return 0; | |
1399 | ||
1400 | // if (DELTA(p, s) > pri_bgp->cf->relax_multipath) | |
1401 | // return 0; | |
1402 | } | |
1403 | ||
1404 | /* RFC 4271 9.1.2.2. b) Use origins */ | |
1405 | x = ea_find(pri->attrs->eattrs, EA_CODE(EAP_BGP, BA_ORIGIN)); | |
1406 | y = ea_find(sec->attrs->eattrs, EA_CODE(EAP_BGP, BA_ORIGIN)); | |
1407 | p = x ? x->u.data : ORIGIN_INCOMPLETE; | |
1408 | s = y ? y->u.data : ORIGIN_INCOMPLETE; | |
1409 | if (p != s) | |
1410 | return 0; | |
1411 | ||
1412 | /* RFC 4271 9.1.2.2. c) Compare MED's */ | |
1413 | if (pri_bgp->cf->med_metric || sec_bgp->cf->med_metric || | |
1414 | (bgp_get_neighbor(pri) == bgp_get_neighbor(sec))) | |
1415 | { | |
1416 | x = ea_find(pri->attrs->eattrs, EA_CODE(EAP_BGP, BA_MULTI_EXIT_DISC)); | |
1417 | y = ea_find(sec->attrs->eattrs, EA_CODE(EAP_BGP, BA_MULTI_EXIT_DISC)); | |
1418 | p = x ? x->u.data : pri_bgp->cf->default_med; | |
1419 | s = y ? y->u.data : sec_bgp->cf->default_med; | |
1420 | if (p != s) | |
1421 | return 0; | |
1422 | } | |
1423 | ||
1424 | /* RFC 4271 9.1.2.2. d) Prefer external peers */ | |
1425 | if (pri_bgp->is_internal != sec_bgp->is_internal) | |
1426 | return 0; | |
1427 | ||
1428 | /* RFC 4271 9.1.2.2. e) Compare IGP metrics */ | |
1429 | p = pri_bgp->cf->igp_metric ? pri->attrs->igp_metric : 0; | |
1430 | s = sec_bgp->cf->igp_metric ? sec->attrs->igp_metric : 0; | |
1431 | if (p != s) | |
1432 | return 0; | |
1433 | ||
1434 | /* Remaining criteria are ignored */ | |
1435 | ||
1436 | return 1; | |
1437 | } | |
1438 | ||
1439 | ||
1440 | ||
be4cd99a OZ |
1441 | static inline int |
1442 | same_group(rte *r, u32 lpref, u32 lasn) | |
1443 | { | |
1444 | return (r->pref == lpref) && (bgp_get_neighbor(r) == lasn); | |
1445 | } | |
1446 | ||
1447 | static inline int | |
1448 | use_deterministic_med(rte *r) | |
1449 | { | |
094d2bdb | 1450 | struct proto *P = r->attrs->src->proto; |
26822d8f | 1451 | return (P->proto == &proto_bgp) && ((struct bgp_proto *) P)->cf->deterministic_med; |
be4cd99a OZ |
1452 | } |
1453 | ||
1454 | int | |
1455 | bgp_rte_recalculate(rtable *table, net *net, rte *new, rte *old, rte *old_best) | |
1456 | { | |
1457 | rte *r, *s; | |
1458 | rte *key = new ? new : old; | |
1459 | u32 lpref = key->pref; | |
1460 | u32 lasn = bgp_get_neighbor(key); | |
1461 | int old_is_group_best = 0; | |
1462 | ||
1463 | /* | |
1464 | * Proper RFC 4271 path selection is a bit complicated, it cannot be | |
1465 | * implemented just by rte_better(), because it is not a linear | |
1466 | * ordering. But it can be splitted to two levels, where the lower | |
1467 | * level chooses the best routes in each group of routes from the | |
1468 | * same neighboring AS and higher level chooses the best route (with | |
1469 | * a slightly different ordering) between the best-in-group routes. | |
1470 | * | |
1471 | * When deterministic_med is disabled, we just ignore this issue and | |
1472 | * choose the best route by bgp_rte_better() alone. If enabled, the | |
1473 | * lower level of the route selection is done here (for the group | |
1474 | * to which the changed route belongs), all routes in group are | |
1475 | * marked as suppressed, just chosen best-in-group is not. | |
1476 | * | |
1477 | * Global best route selection then implements higher level by | |
1478 | * choosing between non-suppressed routes (as they are always | |
1479 | * preferred over suppressed routes). Routes from BGP protocols | |
1480 | * that do not set deterministic_med are just never suppressed. As | |
1481 | * they do not participate in the lower level selection, it is OK | |
1482 | * that this fn is not called for them. | |
1483 | * | |
1484 | * The idea is simple, the implementation is more problematic, | |
1485 | * mostly because of optimizations in rte_recalculate() that | |
1486 | * avoids full recalculation in most cases. | |
1487 | * | |
1488 | * We can assume that at least one of new, old is non-NULL and both | |
1489 | * are from the same protocol with enabled deterministic_med. We | |
1490 | * group routes by both neighbor AS (lasn) and preference (lpref), | |
1491 | * because bgp_rte_better() does not handle preference itself. | |
1492 | */ | |
1493 | ||
1494 | /* If new and old are from different groups, we just process that | |
1495 | as two independent events */ | |
1496 | if (new && old && !same_group(old, lpref, lasn)) | |
1497 | { | |
1498 | int i1, i2; | |
1499 | i1 = bgp_rte_recalculate(table, net, NULL, old, old_best); | |
1500 | i2 = bgp_rte_recalculate(table, net, new, NULL, old_best); | |
1501 | return i1 || i2; | |
1502 | } | |
1503 | ||
1504 | /* | |
1505 | * We could find the best-in-group and then make some shortcuts like | |
1506 | * in rte_recalculate, but as we would have to walk through all | |
1507 | * net->routes just to find it, it is probably not worth. So we | |
1508 | * just have two simpler fast cases that use just the old route. | |
1509 | * We also set suppressed flag to avoid using it in bgp_rte_better(). | |
1510 | */ | |
1511 | ||
1512 | if (new) | |
1513 | new->u.bgp.suppressed = 1; | |
1514 | ||
1515 | if (old) | |
1516 | { | |
1517 | old_is_group_best = !old->u.bgp.suppressed; | |
1518 | old->u.bgp.suppressed = 1; | |
1519 | int new_is_better = new && bgp_rte_better(new, old); | |
1520 | ||
1521 | /* The first case - replace not best with worse (or remove not best) */ | |
1522 | if (!old_is_group_best && !new_is_better) | |
1523 | return 0; | |
1524 | ||
1525 | /* The second case - replace the best with better */ | |
1526 | if (old_is_group_best && new_is_better) | |
1527 | { | |
1528 | /* new is best-in-group, the see discussion below - this is | |
1529 | a special variant of NBG && OBG. From OBG we can deduce | |
1530 | that same_group(old_best) iff (old == old_best) */ | |
1531 | new->u.bgp.suppressed = 0; | |
1532 | return (old == old_best); | |
1533 | } | |
1534 | } | |
1535 | ||
1536 | /* The default case - find a new best-in-group route */ | |
1537 | r = new; /* new may not be in the list */ | |
cf98be7b | 1538 | for (s=net->routes; rte_is_valid(s); s=s->next) |
be4cd99a OZ |
1539 | if (use_deterministic_med(s) && same_group(s, lpref, lasn)) |
1540 | { | |
1541 | s->u.bgp.suppressed = 1; | |
1542 | if (!r || bgp_rte_better(s, r)) | |
1543 | r = s; | |
1544 | } | |
1545 | ||
1546 | /* Simple case - the last route in group disappears */ | |
1547 | if (!r) | |
1548 | return 0; | |
1549 | ||
1550 | /* Found best-in-group */ | |
1551 | r->u.bgp.suppressed = 0; | |
1552 | ||
1553 | /* | |
1554 | * There are generally two reasons why we have to force | |
1555 | * recalculation (return 1): First, the new route may be wrongfully | |
1556 | * chosen to be the best in the first case check in | |
1557 | * rte_recalculate(), this may happen only if old_best is from the | |
1558 | * same group. Second, another (different than new route) | |
1559 | * best-in-group is chosen and that may be the proper best (although | |
1560 | * rte_recalculate() without ignore that possibility). | |
1561 | * | |
1562 | * There are three possible cases according to whether the old route | |
1563 | * was the best in group (OBG, stored in old_is_group_best) and | |
1564 | * whether the new route is the best in group (NBG, tested by r == new). | |
1565 | * These cases work even if old or new is NULL. | |
1566 | * | |
1567 | * NBG -> new is a possible candidate for the best route, so we just | |
1568 | * check for the first reason using same_group(). | |
1569 | * | |
1570 | * !NBG && OBG -> Second reason applies, return 1 | |
1571 | * | |
1572 | * !NBG && !OBG -> Best in group does not change, old != old_best, | |
1573 | * rte_better(new, old_best) is false and therefore | |
1574 | * the first reason does not apply, return 0 | |
1575 | */ | |
1576 | ||
1577 | if (r == new) | |
1578 | return old_best && same_group(old_best, lpref, lasn); | |
1579 | else | |
1580 | return old_is_group_best; | |
1581 | } | |
1582 | ||
11cb6202 OZ |
1583 | static struct adata * |
1584 | bgp_aggregator_convert_to_new(struct adata *old, struct linpool *pool) | |
1585 | { | |
1586 | struct adata *newa = lp_alloc(pool, sizeof(struct adata) + 8); | |
1587 | newa->length = 8; | |
1588 | aggregator_convert_to_new(old, newa->data); | |
1589 | return newa; | |
1590 | } | |
1591 | ||
1592 | ||
1593 | /* Take last req_as ASNs from path old2 (in 2B format), convert to 4B format | |
1594 | * and append path old4 (in 4B format). | |
1595 | */ | |
1596 | static struct adata * | |
1597 | bgp_merge_as_paths(struct adata *old2, struct adata *old4, int req_as, struct linpool *pool) | |
1598 | { | |
1599 | byte buf[old2->length * 2]; | |
1600 | ||
1601 | int ol = as_path_convert_to_new(old2, buf, req_as); | |
1602 | int nl = ol + (old4 ? old4->length : 0); | |
ef2c708d | 1603 | |
11cb6202 OZ |
1604 | struct adata *newa = lp_alloc(pool, sizeof(struct adata) + nl); |
1605 | newa->length = nl; | |
1606 | memcpy(newa->data, buf, ol); | |
1607 | if (old4) memcpy(newa->data + ol, old4->data, old4->length); | |
1608 | ||
1609 | return newa; | |
1610 | } | |
1611 | ||
48d79d52 OZ |
1612 | static int |
1613 | as4_aggregator_valid(struct adata *aggr) | |
1614 | { | |
06fb60c4 | 1615 | return aggr->length == 8; |
48d79d52 OZ |
1616 | } |
1617 | ||
11cb6202 | 1618 | |
4847a894 | 1619 | /* Reconstruct 4B AS_PATH and AGGREGATOR according to RFC 4893 4.2.3 */ |
11cb6202 OZ |
1620 | static void |
1621 | bgp_reconstruct_4b_atts(struct bgp_proto *p, rta *a, struct linpool *pool) | |
1622 | { | |
1623 | eattr *p2 =ea_find(a->eattrs, EA_CODE(EAP_BGP, BA_AS_PATH)); | |
1624 | eattr *p4 =ea_find(a->eattrs, EA_CODE(EAP_BGP, BA_AS4_PATH)); | |
1625 | eattr *a2 =ea_find(a->eattrs, EA_CODE(EAP_BGP, BA_AGGREGATOR)); | |
1626 | eattr *a4 =ea_find(a->eattrs, EA_CODE(EAP_BGP, BA_AS4_AGGREGATOR)); | |
48d79d52 OZ |
1627 | int a4_removed = 0; |
1628 | ||
1629 | if (a4 && !as4_aggregator_valid(a4->u.ptr)) | |
1630 | { | |
29c430f8 | 1631 | log(L_WARN "%s: AS4_AGGREGATOR attribute is invalid, skipping attribute", p->p.name); |
48d79d52 OZ |
1632 | a4 = NULL; |
1633 | a4_removed = 1; | |
1634 | } | |
11cb6202 OZ |
1635 | |
1636 | if (a2) | |
ef2c708d | 1637 | { |
11cb6202 OZ |
1638 | u32 a2_as = get_u16(a2->u.ptr->data); |
1639 | ||
1640 | if (a4) | |
ef2c708d | 1641 | { |
11cb6202 OZ |
1642 | if (a2_as != AS_TRANS) |
1643 | { | |
1644 | /* Routes were aggregated by old router and therefore AS4_PATH | |
1645 | * and AS4_AGGREGATOR is invalid | |
1646 | * | |
1647 | * Convert AS_PATH and AGGREGATOR to 4B format and finish. | |
1648 | */ | |
1649 | ||
1650 | a2->u.ptr = bgp_aggregator_convert_to_new(a2->u.ptr, pool); | |
1651 | p2->u.ptr = bgp_merge_as_paths(p2->u.ptr, NULL, AS_PATH_MAXLEN, pool); | |
1652 | ||
1653 | return; | |
1654 | } | |
1655 | else | |
1656 | { | |
1657 | /* Common case, use AS4_AGGREGATOR attribute */ | |
1658 | a2->u.ptr = a4->u.ptr; | |
1659 | } | |
1660 | } | |
1661 | else | |
1662 | { | |
1663 | /* Common case, use old AGGREGATOR attribute */ | |
1664 | a2->u.ptr = bgp_aggregator_convert_to_new(a2->u.ptr, pool); | |
1665 | ||
48d79d52 | 1666 | if ((a2_as == AS_TRANS) && !a4_removed) |
29c430f8 | 1667 | log(L_WARN "%s: AGGREGATOR attribute contain AS_TRANS, but AS4_AGGREGATOR is missing", p->p.name); |
ef2c708d MM |
1668 | } |
1669 | } | |
11cb6202 OZ |
1670 | else |
1671 | if (a4) | |
29c430f8 | 1672 | log(L_WARN "%s: AS4_AGGREGATOR attribute received, but AGGREGATOR attribute is missing", p->p.name); |
11cb6202 | 1673 | |
949bd34e | 1674 | int p2_len = as_path_getlen_int(p2->u.ptr, 2); |
29c430f8 OZ |
1675 | int p4_len = p4 ? validate_as4_path(p, p4->u.ptr) : -1; |
1676 | ||
1677 | if (p4 && (p4_len < 0)) | |
1678 | log(L_WARN "%s: AS4_PATH attribute is malformed, skipping attribute", p->p.name); | |
11cb6202 | 1679 | |
48d79d52 | 1680 | if ((p4_len <= 0) || (p2_len < p4_len)) |
11cb6202 OZ |
1681 | p2->u.ptr = bgp_merge_as_paths(p2->u.ptr, NULL, AS_PATH_MAXLEN, pool); |
1682 | else | |
1683 | p2->u.ptr = bgp_merge_as_paths(p2->u.ptr, p4->u.ptr, p2_len - p4_len, pool); | |
11cb6202 OZ |
1684 | } |
1685 | ||
1686 | static void | |
1687 | bgp_remove_as4_attrs(struct bgp_proto *p, rta *a) | |
1688 | { | |
1689 | unsigned id1 = EA_CODE(EAP_BGP, BA_AS4_PATH); | |
1690 | unsigned id2 = EA_CODE(EAP_BGP, BA_AS4_AGGREGATOR); | |
1691 | ea_list **el = &(a->eattrs); | |
1692 | ||
29c430f8 | 1693 | /* We know that ea_lists constructed in bgp_decode attrs have one attribute per ea_list struct */ |
11cb6202 OZ |
1694 | while (*el != NULL) |
1695 | { | |
1696 | unsigned fid = (*el)->attrs[0].id; | |
1697 | ||
1698 | if ((fid == id1) || (fid == id2)) | |
1699 | { | |
1700 | *el = (*el)->next; | |
ba5ed6f3 | 1701 | if (p->as4_session) |
06fb60c4 | 1702 | log(L_WARN "%s: Unexpected AS4_* attributes received", p->p.name); |
11cb6202 OZ |
1703 | } |
1704 | else | |
1705 | el = &((*el)->next); | |
1706 | } | |
ef2c708d MM |
1707 | } |
1708 | ||
54e55169 MM |
1709 | /** |
1710 | * bgp_decode_attrs - check and decode BGP attributes | |
1711 | * @conn: connection | |
1712 | * @attr: start of attribute block | |
1713 | * @len: length of attribute block | |
1714 | * @pool: linear pool to make all the allocations in | |
1715 | * @mandatory: 1 iff presence of mandatory attributes has to be checked | |
1716 | * | |
1717 | * This function takes a BGP attribute block (a part of an Update message), checks | |
1718 | * its consistency and converts it to a list of BIRD route attributes represented | |
1719 | * by a &rta. | |
1720 | */ | |
c00d31be | 1721 | struct rta * |
ae80a2de | 1722 | bgp_decode_attrs(struct bgp_conn *conn, byte *attr, uint len, struct linpool *pool, int mandatory) |
c00d31be MM |
1723 | { |
1724 | struct bgp_proto *bgp = conn->bgp; | |
1725 | rta *a = lp_alloc(pool, sizeof(struct rta)); | |
ae80a2de | 1726 | uint flags, code, l, i, type; |
ef2c708d | 1727 | int errcode; |
c00d31be MM |
1728 | byte *z, *attr_start; |
1729 | byte seen[256/8]; | |
c00d31be MM |
1730 | ea_list *ea; |
1731 | struct adata *ad; | |
06fb60c4 | 1732 | int withdraw = 0; |
c00d31be | 1733 | |
cfe34a31 | 1734 | bzero(a, sizeof(rta)); |
c00d31be MM |
1735 | a->source = RTS_BGP; |
1736 | a->scope = SCOPE_UNIVERSE; | |
1737 | a->cast = RTC_UNICAST; | |
cfe34a31 | 1738 | /* a->dest = RTD_ROUTER; -- set in bgp_set_next_hop() */ |
c00d31be | 1739 | a->from = bgp->cf->remote_ip; |
c00d31be MM |
1740 | |
1741 | /* Parse the attributes */ | |
1742 | bzero(seen, sizeof(seen)); | |
1743 | DBG("BGP: Parsing attributes\n"); | |
1744 | while (len) | |
1745 | { | |
1746 | if (len < 2) | |
1747 | goto malformed; | |
1748 | attr_start = attr; | |
1749 | flags = *attr++; | |
1750 | code = *attr++; | |
1751 | len -= 2; | |
1752 | if (flags & BAF_EXT_LEN) | |
1753 | { | |
1754 | if (len < 2) | |
1755 | goto malformed; | |
1756 | l = get_u16(attr); | |
1757 | attr += 2; | |
1758 | len -= 2; | |
1759 | } | |
1760 | else | |
1761 | { | |
1762 | if (len < 1) | |
1763 | goto malformed; | |
1764 | l = *attr++; | |
1765 | len--; | |
1766 | } | |
1767 | if (l > len) | |
1768 | goto malformed; | |
1769 | len -= l; | |
1770 | z = attr; | |
1771 | attr += l; | |
1772 | DBG("Attr %02x %02x %d\n", code, flags, l); | |
1773 | if (seen[code/8] & (1 << (code%8))) | |
1774 | goto malformed; | |
d1a74339 | 1775 | if (ATTR_KNOWN(code)) |
c00d31be MM |
1776 | { |
1777 | struct attr_desc *desc = &bgp_attr_table[code]; | |
1778 | if (desc->expected_length >= 0 && desc->expected_length != (int) l) | |
1779 | { errcode = 5; goto err; } | |
1780 | if ((desc->expected_flags ^ flags) & (BAF_OPTIONAL | BAF_TRANSITIVE)) | |
1781 | { errcode = 4; goto err; } | |
1950a479 OZ |
1782 | if (!bgp->is_internal) |
1783 | { | |
1784 | if (!desc->allow_in_ebgp) | |
1785 | continue; | |
1786 | if ((code == BA_LOCAL_PREF) && !bgp->cf->allow_local_pref) | |
1787 | continue; | |
1788 | } | |
ef2c708d MM |
1789 | if (desc->validate) |
1790 | { | |
1791 | errcode = desc->validate(bgp, z, l); | |
1792 | if (errcode > 0) | |
1793 | goto err; | |
06fb60c4 | 1794 | if (errcode == IGNORE) |
ef2c708d | 1795 | continue; |
06fb60c4 OZ |
1796 | if (errcode <= WITHDRAW) |
1797 | { | |
1798 | log(L_WARN "%s: Attribute %s is malformed, withdrawing update", | |
1799 | bgp->p.name, desc->name); | |
1800 | withdraw = 1; | |
1801 | } | |
ef2c708d | 1802 | } |
29c430f8 OZ |
1803 | else if (code == BA_AS_PATH) |
1804 | { | |
1805 | /* Special case as it might also trim the attribute */ | |
1806 | if (validate_as_path(bgp, z, &l) < 0) | |
1807 | { errcode = 11; goto err; } | |
1808 | } | |
c00d31be MM |
1809 | type = desc->type; |
1810 | } | |
1811 | else /* Unknown attribute */ | |
e3558ab1 | 1812 | { |
c00d31be MM |
1813 | if (!(flags & BAF_OPTIONAL)) |
1814 | { errcode = 2; goto err; } | |
1815 | type = EAF_TYPE_OPAQUE; | |
1816 | } | |
29c430f8 OZ |
1817 | |
1818 | // Only OPTIONAL and TRANSITIVE attributes may have non-zero PARTIAL flag | |
1819 | // if (!((flags & BAF_OPTIONAL) && (flags & BAF_TRANSITIVE)) && (flags & BAF_PARTIAL)) | |
1820 | // { errcode = 4; goto err; } | |
1821 | ||
ef2c708d MM |
1822 | seen[code/8] |= (1 << (code%8)); |
1823 | ea = lp_alloc(pool, sizeof(ea_list) + sizeof(eattr)); | |
c00d31be MM |
1824 | ea->next = a->eattrs; |
1825 | a->eattrs = ea; | |
1826 | ea->flags = 0; | |
1827 | ea->count = 1; | |
1828 | ea->attrs[0].id = EA_CODE(EAP_BGP, code); | |
1829 | ea->attrs[0].flags = flags; | |
1830 | ea->attrs[0].type = type; | |
1831 | if (type & EAF_EMBEDDED) | |
1832 | ad = NULL; | |
1833 | else | |
1834 | { | |
1835 | ad = lp_alloc(pool, sizeof(struct adata) + l); | |
1836 | ea->attrs[0].u.ptr = ad; | |
1837 | ad->length = l; | |
1838 | memcpy(ad->data, z, l); | |
1839 | } | |
1840 | switch (type) | |
1841 | { | |
1842 | case EAF_TYPE_ROUTER_ID: | |
1843 | case EAF_TYPE_INT: | |
10be74da MM |
1844 | if (l == 1) |
1845 | ea->attrs[0].u.data = *z; | |
1846 | else | |
1847 | ea->attrs[0].u.data = get_u32(z); | |
c00d31be MM |
1848 | break; |
1849 | case EAF_TYPE_IP_ADDRESS: | |
f421cfdd | 1850 | ipa_ntoh(*(ip_addr *)ad->data); |
c00d31be | 1851 | break; |
1ed2fe96 | 1852 | case EAF_TYPE_INT_SET: |
66dbdbd9 | 1853 | case EAF_TYPE_LC_SET: |
42a0c054 | 1854 | case EAF_TYPE_EC_SET: |
1ed2fe96 MM |
1855 | { |
1856 | u32 *z = (u32 *) ad->data; | |
1857 | for(i=0; i<ad->length/4; i++) | |
1858 | z[i] = ntohl(z[i]); | |
1859 | break; | |
1860 | } | |
c00d31be MM |
1861 | } |
1862 | } | |
1863 | ||
06fb60c4 OZ |
1864 | if (withdraw) |
1865 | goto withdraw; | |
1866 | ||
1c1da87b | 1867 | #ifdef IPV6 |
f307842a OZ |
1868 | /* If we received MP_REACH_NLRI we should check mandatory attributes */ |
1869 | if (bgp->mp_reach_len != 0) | |
1c1da87b MM |
1870 | mandatory = 1; |
1871 | #endif | |
1872 | ||
b9539e78 OZ |
1873 | /* If there is no (reachability) NLRI, we should exit now */ |
1874 | if (! mandatory) | |
1875 | return a; | |
1876 | ||
c00d31be | 1877 | /* Check if all mandatory attributes are present */ |
b9539e78 | 1878 | for(i=0; i < ARRAY_SIZE(bgp_mandatory_attrs); i++) |
c00d31be | 1879 | { |
b9539e78 OZ |
1880 | code = bgp_mandatory_attrs[i]; |
1881 | if (!(seen[code/8] & (1 << (code%8)))) | |
c00d31be | 1882 | { |
b9539e78 OZ |
1883 | bgp_error(conn, 3, 3, &bgp_mandatory_attrs[i], 1); |
1884 | return NULL; | |
c00d31be MM |
1885 | } |
1886 | } | |
f307842a | 1887 | |
11cb6202 OZ |
1888 | /* When receiving attributes from non-AS4-aware BGP speaker, |
1889 | * we have to reconstruct 4B AS_PATH and AGGREGATOR attributes | |
1890 | */ | |
43c1cecc | 1891 | if (! bgp->as4_session) |
11cb6202 OZ |
1892 | bgp_reconstruct_4b_atts(bgp, a, pool); |
1893 | ||
43c1cecc | 1894 | bgp_remove_as4_attrs(bgp, a); |
c00d31be | 1895 | |
ef2c708d | 1896 | /* If the AS path attribute contains our AS, reject the routes */ |
4847a894 | 1897 | if (bgp_as_path_loopy(bgp, a)) |
06fb60c4 | 1898 | goto withdraw; |
4847a894 OZ |
1899 | |
1900 | /* Two checks for IBGP loops caused by route reflection, RFC 4456 */ | |
1901 | if (bgp_originator_id_loopy(bgp, a) || | |
1902 | bgp_cluster_list_loopy(bgp, a)) | |
06fb60c4 | 1903 | goto withdraw; |
ef2c708d | 1904 | |
8b258e4e | 1905 | /* If there's no local preference, define one */ |
4819c3e1 | 1906 | if (!(seen[0] & (1 << BA_LOCAL_PREF))) |
fbcb7d5f | 1907 | bgp_attach_attr(&a->eattrs, pool, BA_LOCAL_PREF, bgp->cf->default_local_pref); |
f307842a | 1908 | |
2a9e064d | 1909 | return a; |
c00d31be | 1910 | |
06fb60c4 | 1911 | withdraw: |
4847a894 OZ |
1912 | return NULL; |
1913 | ||
c00d31be | 1914 | malformed: |
efcece2d | 1915 | bgp_error(conn, 3, 1, NULL, 0); |
c00d31be MM |
1916 | return NULL; |
1917 | ||
1918 | err: | |
2138d3b4 | 1919 | bgp_error(conn, 3, errcode, attr_start, z+l-attr_start); |
c00d31be MM |
1920 | return NULL; |
1921 | } | |
10be74da MM |
1922 | |
1923 | int | |
aebe06b4 | 1924 | bgp_get_attr(eattr *a, byte *buf, int buflen) |
10be74da | 1925 | { |
ae80a2de | 1926 | uint i = EA_ID(a->id); |
10be74da | 1927 | struct attr_desc *d; |
6c4df703 | 1928 | int len; |
10be74da | 1929 | |
d1a74339 | 1930 | if (ATTR_KNOWN(i)) |
10be74da MM |
1931 | { |
1932 | d = &bgp_attr_table[i]; | |
6c4df703 OZ |
1933 | len = bsprintf(buf, "%s", d->name); |
1934 | buf += len; | |
10be74da MM |
1935 | if (d->format) |
1936 | { | |
1937 | *buf++ = ':'; | |
1938 | *buf++ = ' '; | |
6c4df703 | 1939 | d->format(a, buf, buflen - len - 2); |
10be74da MM |
1940 | return GA_FULL; |
1941 | } | |
1942 | return GA_NAME; | |
1943 | } | |
d1a74339 | 1944 | bsprintf(buf, "%02x%s", i, (a->flags & BAF_TRANSITIVE) ? " [t]" : ""); |
10be74da MM |
1945 | return GA_NAME; |
1946 | } | |
ae8f5584 MM |
1947 | |
1948 | void | |
094d2bdb | 1949 | bgp_init_bucket_table(struct bgp_proto *p) |
ae8f5584 MM |
1950 | { |
1951 | p->hash_size = 256; | |
1952 | p->hash_limit = p->hash_size * 4; | |
c2b28c99 MM |
1953 | p->bucket_hash = mb_allocz(p->p.pool, p->hash_size * sizeof(struct bgp_bucket *)); |
1954 | init_list(&p->bucket_queue); | |
1955 | p->withdraw_bucket = NULL; | |
094d2bdb | 1956 | // fib_init(&p->prefix_fib, p->p.pool, sizeof(struct bgp_prefix), 0, bgp_init_prefix); |
ae8f5584 | 1957 | } |
5e88d730 | 1958 | |
ed1a908e OZ |
1959 | void |
1960 | bgp_free_bucket_table(struct bgp_proto *p) | |
1961 | { | |
1962 | mb_free(p->bucket_hash); | |
1963 | p->bucket_hash = NULL; | |
1964 | ||
1965 | struct bgp_bucket *b; | |
1966 | WALK_LIST_FIRST(b, p->bucket_queue) | |
1967 | { | |
1968 | rem_node(&b->send_node); | |
1969 | mb_free(b); | |
1970 | } | |
1971 | ||
1972 | mb_free(p->withdraw_bucket); | |
1973 | p->withdraw_bucket = NULL; | |
1974 | } | |
1975 | ||
5e88d730 MM |
1976 | void |
1977 | bgp_get_route_info(rte *e, byte *buf, ea_list *attrs) | |
1978 | { | |
1979 | eattr *p = ea_find(attrs, EA_CODE(EAP_BGP, BA_AS_PATH)); | |
1980 | eattr *o = ea_find(attrs, EA_CODE(EAP_BGP, BA_ORIGIN)); | |
11cb6202 | 1981 | u32 origas; |
5e88d730 | 1982 | |
3ce17142 OZ |
1983 | buf += bsprintf(buf, " (%d", e->pref); |
1984 | ||
be4cd99a | 1985 | if (e->u.bgp.suppressed) |
3ce17142 | 1986 | buf += bsprintf(buf, "-"); |
be4cd99a | 1987 | |
d1e146f2 OZ |
1988 | if (e->attrs->hostentry) |
1989 | { | |
7e95c05d | 1990 | if (!rte_resolvable(e)) |
d1e146f2 OZ |
1991 | buf += bsprintf(buf, "/-"); |
1992 | else if (e->attrs->igp_metric >= IGP_METRIC_UNKNOWN) | |
1993 | buf += bsprintf(buf, "/?"); | |
1994 | else | |
1995 | buf += bsprintf(buf, "/%d", e->attrs->igp_metric); | |
1996 | } | |
1997 | buf += bsprintf(buf, ") ["); | |
1998 | ||
52b9b2a1 | 1999 | if (p && as_path_get_last(p->u.ptr, &origas)) |
11cb6202 | 2000 | buf += bsprintf(buf, "AS%u", origas); |
5e88d730 MM |
2001 | if (o) |
2002 | buf += bsprintf(buf, "%c", "ie?"[o->u.data]); | |
2003 | strcpy(buf, "]"); | |
2004 | } |