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5adc2528 AS |
1 | /* |
2 | * Code for encoding/decoding FPM messages that are in netlink format. | |
3 | * | |
4 | * Copyright (C) 1997, 98, 99 Kunihiro Ishiguro | |
5 | * Copyright (C) 2012 by Open Source Routing. | |
6 | * Copyright (C) 2012 by Internet Systems Consortium, Inc. ("ISC") | |
7 | * | |
8 | * This file is part of GNU Zebra. | |
9 | * | |
10 | * GNU Zebra is free software; you can redistribute it and/or modify it | |
11 | * under the terms of the GNU General Public License as published by the | |
12 | * Free Software Foundation; either version 2, or (at your option) any | |
13 | * later version. | |
14 | * | |
15 | * GNU Zebra is distributed in the hope that it will be useful, but | |
16 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
18 | * General Public License for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU General Public License | |
21 | * along with GNU Zebra; see the file COPYING. If not, write to the Free | |
22 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA | |
23 | * 02111-1307, USA. | |
24 | */ | |
25 | ||
26 | #include <zebra.h> | |
27 | ||
28 | #include "log.h" | |
29 | #include "rib.h" | |
82f97584 | 30 | #include "vty.h" |
e3be0432 | 31 | #include "prefix.h" |
5adc2528 | 32 | |
1fdc9eae | 33 | #include "zebra/zserv.h" |
34 | #include "zebra/zebra_ns.h" | |
35 | #include "zebra/zebra_vrf.h" | |
36 | #include "zebra/kernel_netlink.h" | |
37 | #include "zebra/rt_netlink.h" | |
fb018d25 | 38 | #include "nexthop.h" |
5adc2528 | 39 | |
1fdc9eae | 40 | #include "zebra/zebra_fpm_private.h" |
5adc2528 AS |
41 | |
42 | /* | |
43 | * addr_to_a | |
44 | * | |
45 | * Returns string representation of an address of the given AF. | |
46 | */ | |
47 | static inline const char * | |
48 | addr_to_a (u_char af, void *addr) | |
49 | { | |
50 | if (!addr) | |
51 | return "<No address>"; | |
52 | ||
53 | switch (af) | |
54 | { | |
55 | ||
56 | case AF_INET: | |
57 | return inet_ntoa (*((struct in_addr *) addr)); | |
58 | ||
59 | #ifdef HAVE_IPV6 | |
60 | case AF_INET6: | |
61 | return inet6_ntoa (*((struct in6_addr *) addr)); | |
62 | #endif | |
63 | ||
64 | default: | |
65 | return "<Addr in unknown AF>"; | |
66 | } | |
67 | } | |
68 | ||
69 | /* | |
70 | * prefix_addr_to_a | |
71 | * | |
72 | * Convience wrapper that returns a human-readable string for the | |
73 | * address in a prefix. | |
74 | */ | |
75 | static const char * | |
76 | prefix_addr_to_a (struct prefix *prefix) | |
77 | { | |
78 | if (!prefix) | |
79 | return "<No address>"; | |
80 | ||
81 | return addr_to_a (prefix->family, &prefix->u.prefix); | |
82 | } | |
83 | ||
84 | /* | |
85 | * af_addr_size | |
86 | * | |
87 | * The size of an address in a given address family. | |
88 | */ | |
89 | static size_t | |
90 | af_addr_size (u_char af) | |
91 | { | |
92 | switch (af) | |
93 | { | |
94 | ||
95 | case AF_INET: | |
96 | return 4; | |
97 | ||
98 | #ifdef HAVE_IPV6 | |
99 | case AF_INET6: | |
100 | return 16; | |
101 | #endif | |
102 | ||
103 | default: | |
104 | assert(0); | |
105 | return 16; | |
106 | } | |
107 | } | |
108 | ||
109 | /* | |
110 | * netlink_nh_info_t | |
111 | * | |
112 | * Holds information about a single nexthop for netlink. These info | |
113 | * structures are transient and may contain pointers into rib | |
114 | * data structures for convenience. | |
115 | */ | |
116 | typedef struct netlink_nh_info_t_ | |
117 | { | |
118 | uint32_t if_index; | |
119 | union g_addr *gateway; | |
120 | ||
121 | /* | |
122 | * Information from the struct nexthop from which this nh was | |
123 | * derived. For debug purposes only. | |
124 | */ | |
125 | int recursive; | |
126 | enum nexthop_types_t type; | |
127 | } netlink_nh_info_t; | |
128 | ||
129 | /* | |
130 | * netlink_route_info_t | |
131 | * | |
132 | * A structure for holding information for a netlink route message. | |
133 | */ | |
134 | typedef struct netlink_route_info_t_ | |
135 | { | |
136 | uint16_t nlmsg_type; | |
137 | u_char rtm_type; | |
138 | uint32_t rtm_table; | |
139 | u_char rtm_protocol; | |
140 | u_char af; | |
141 | struct prefix *prefix; | |
142 | uint32_t *metric; | |
143 | int num_nhs; | |
144 | ||
145 | /* | |
7c5d2b76 | 146 | * Nexthop structures |
5adc2528 | 147 | */ |
7c5d2b76 | 148 | netlink_nh_info_t nhs[MULTIPATH_NUM]; |
5adc2528 AS |
149 | union g_addr *pref_src; |
150 | } netlink_route_info_t; | |
151 | ||
152 | /* | |
153 | * netlink_route_info_add_nh | |
154 | * | |
155 | * Add information about the given nexthop to the given route info | |
156 | * structure. | |
157 | * | |
158 | * Returns TRUE if a nexthop was added, FALSE otherwise. | |
159 | */ | |
160 | static int | |
fa713d9e CF |
161 | netlink_route_info_add_nh (netlink_route_info_t *ri, struct nexthop *nexthop, |
162 | int recursive) | |
5adc2528 AS |
163 | { |
164 | netlink_nh_info_t nhi; | |
165 | union g_addr *src; | |
166 | ||
167 | memset (&nhi, 0, sizeof (nhi)); | |
168 | src = NULL; | |
169 | ||
170 | if (ri->num_nhs >= (int) ZEBRA_NUM_OF (ri->nhs)) | |
171 | return 0; | |
172 | ||
fa713d9e | 173 | nhi.recursive = recursive; |
5adc2528 | 174 | nhi.type = nexthop->type; |
324ed1f8 | 175 | nhi.if_index = nexthop->ifindex; |
5adc2528 AS |
176 | |
177 | if (nexthop->type == NEXTHOP_TYPE_IPV4 | |
178 | || nexthop->type == NEXTHOP_TYPE_IPV4_IFINDEX) | |
179 | { | |
180 | nhi.gateway = &nexthop->gate; | |
181 | if (nexthop->src.ipv4.s_addr) | |
182 | src = &nexthop->src; | |
183 | } | |
184 | ||
5adc2528 | 185 | if (nexthop->type == NEXTHOP_TYPE_IPV6 |
5adc2528 AS |
186 | || nexthop->type == NEXTHOP_TYPE_IPV6_IFINDEX) |
187 | { | |
188 | nhi.gateway = &nexthop->gate; | |
189 | } | |
324ed1f8 | 190 | |
3ee39b5b | 191 | if (nexthop->type == NEXTHOP_TYPE_IFINDEX) |
5adc2528 | 192 | { |
5adc2528 AS |
193 | if (nexthop->src.ipv4.s_addr) |
194 | src = &nexthop->src; | |
195 | } | |
5adc2528 | 196 | |
5adc2528 AS |
197 | if (!nhi.gateway && nhi.if_index == 0) |
198 | return 0; | |
199 | ||
200 | /* | |
201 | * We have a valid nhi. Copy the structure over to the route_info. | |
202 | */ | |
203 | ri->nhs[ri->num_nhs] = nhi; | |
204 | ri->num_nhs++; | |
205 | ||
206 | if (src && !ri->pref_src) | |
207 | ri->pref_src = src; | |
208 | ||
209 | return 1; | |
210 | } | |
211 | ||
212 | /* | |
213 | * netlink_proto_from_route_type | |
214 | */ | |
215 | static u_char | |
216 | netlink_proto_from_route_type (int type) | |
217 | { | |
218 | switch (type) | |
219 | { | |
220 | case ZEBRA_ROUTE_KERNEL: | |
221 | case ZEBRA_ROUTE_CONNECT: | |
222 | return RTPROT_KERNEL; | |
223 | ||
224 | default: | |
225 | return RTPROT_ZEBRA; | |
226 | } | |
227 | } | |
228 | ||
229 | /* | |
230 | * netlink_route_info_fill | |
231 | * | |
232 | * Fill out the route information object from the given route. | |
233 | * | |
234 | * Returns TRUE on success and FALSE on failure. | |
235 | */ | |
236 | static int | |
237 | netlink_route_info_fill (netlink_route_info_t *ri, int cmd, | |
238 | rib_dest_t *dest, struct rib *rib) | |
239 | { | |
fa713d9e CF |
240 | struct nexthop *nexthop, *tnexthop; |
241 | int recursing; | |
5adc2528 AS |
242 | int discard; |
243 | ||
244 | memset (ri, 0, sizeof (*ri)); | |
245 | ||
246 | ri->prefix = rib_dest_prefix (dest); | |
247 | ri->af = rib_dest_af (dest); | |
248 | ||
249 | ri->nlmsg_type = cmd; | |
661512bf | 250 | ri->rtm_table = zvrf_id (rib_dest_vrf (dest)); |
5adc2528 AS |
251 | ri->rtm_protocol = RTPROT_UNSPEC; |
252 | ||
253 | /* | |
254 | * An RTM_DELROUTE need not be accompanied by any nexthops, | |
255 | * particularly in our communication with the FPM. | |
256 | */ | |
257 | if (cmd == RTM_DELROUTE && !rib) | |
258 | goto skip; | |
259 | ||
260 | if (rib) | |
261 | ri->rtm_protocol = netlink_proto_from_route_type (rib->type); | |
262 | ||
263 | if ((rib->flags & ZEBRA_FLAG_BLACKHOLE) || (rib->flags & ZEBRA_FLAG_REJECT)) | |
264 | discard = 1; | |
265 | else | |
266 | discard = 0; | |
267 | ||
268 | if (cmd == RTM_NEWROUTE) | |
269 | { | |
270 | if (discard) | |
271 | { | |
272 | if (rib->flags & ZEBRA_FLAG_BLACKHOLE) | |
273 | ri->rtm_type = RTN_BLACKHOLE; | |
274 | else if (rib->flags & ZEBRA_FLAG_REJECT) | |
275 | ri->rtm_type = RTN_UNREACHABLE; | |
276 | else | |
277 | assert (0); | |
278 | } | |
279 | else | |
280 | ri->rtm_type = RTN_UNICAST; | |
281 | } | |
282 | ||
283 | ri->metric = &rib->metric; | |
284 | ||
285 | if (discard) | |
286 | { | |
287 | goto skip; | |
288 | } | |
289 | ||
fa713d9e | 290 | for (ALL_NEXTHOPS_RO(rib->nexthop, nexthop, tnexthop, recursing)) |
5adc2528 | 291 | { |
7c5d2b76 | 292 | if (ri->num_nhs >= MULTIPATH_NUM) |
fa713d9e | 293 | break; |
5adc2528 | 294 | |
fa713d9e CF |
295 | if (CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_RECURSIVE)) |
296 | continue; | |
297 | ||
298 | if ((cmd == RTM_NEWROUTE | |
299 | && CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE)) | |
300 | || (cmd == RTM_DELROUTE | |
301 | && CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB))) | |
5adc2528 | 302 | { |
fa713d9e | 303 | netlink_route_info_add_nh (ri, nexthop, recursing); |
5adc2528 AS |
304 | } |
305 | } | |
306 | ||
307 | /* If there is no useful nexthop then return. */ | |
308 | if (ri->num_nhs == 0) | |
309 | { | |
310 | zfpm_debug ("netlink_encode_route(): No useful nexthop."); | |
311 | return 0; | |
312 | } | |
313 | ||
314 | skip: | |
315 | return 1; | |
316 | } | |
317 | ||
318 | /* | |
319 | * netlink_route_info_encode | |
320 | * | |
321 | * Returns the number of bytes written to the buffer. 0 or a negative | |
322 | * value indicates an error. | |
323 | */ | |
324 | static int | |
325 | netlink_route_info_encode (netlink_route_info_t *ri, char *in_buf, | |
326 | size_t in_buf_len) | |
327 | { | |
c7450f9a | 328 | size_t bytelen; |
5adc2528 AS |
329 | int nexthop_num = 0; |
330 | size_t buf_offset; | |
331 | netlink_nh_info_t *nhi; | |
332 | ||
333 | struct | |
334 | { | |
335 | struct nlmsghdr n; | |
336 | struct rtmsg r; | |
337 | char buf[1]; | |
338 | } *req; | |
339 | ||
340 | req = (void *) in_buf; | |
341 | ||
342 | buf_offset = ((char *) req->buf) - ((char *) req); | |
343 | ||
344 | if (in_buf_len < buf_offset) { | |
345 | assert(0); | |
346 | return 0; | |
347 | } | |
348 | ||
349 | memset (req, 0, buf_offset); | |
350 | ||
351 | bytelen = af_addr_size (ri->af); | |
352 | ||
353 | req->n.nlmsg_len = NLMSG_LENGTH (sizeof (struct rtmsg)); | |
354 | req->n.nlmsg_flags = NLM_F_CREATE | NLM_F_REQUEST; | |
355 | req->n.nlmsg_type = ri->nlmsg_type; | |
356 | req->r.rtm_family = ri->af; | |
357 | req->r.rtm_table = ri->rtm_table; | |
358 | req->r.rtm_dst_len = ri->prefix->prefixlen; | |
359 | req->r.rtm_protocol = ri->rtm_protocol; | |
360 | req->r.rtm_scope = RT_SCOPE_UNIVERSE; | |
361 | ||
362 | addattr_l (&req->n, in_buf_len, RTA_DST, &ri->prefix->u.prefix, bytelen); | |
363 | ||
364 | req->r.rtm_type = ri->rtm_type; | |
365 | ||
366 | /* Metric. */ | |
367 | if (ri->metric) | |
368 | addattr32 (&req->n, in_buf_len, RTA_PRIORITY, *ri->metric); | |
369 | ||
370 | if (ri->num_nhs == 0) | |
371 | goto done; | |
372 | ||
373 | if (ri->num_nhs == 1) | |
374 | { | |
375 | nhi = &ri->nhs[0]; | |
376 | ||
377 | if (nhi->gateway) | |
378 | { | |
379 | addattr_l (&req->n, in_buf_len, RTA_GATEWAY, nhi->gateway, | |
380 | bytelen); | |
381 | } | |
382 | ||
383 | if (nhi->if_index) | |
384 | { | |
385 | addattr32 (&req->n, in_buf_len, RTA_OIF, nhi->if_index); | |
386 | } | |
387 | ||
388 | goto done; | |
389 | ||
390 | } | |
391 | ||
392 | /* | |
393 | * Multipath case. | |
394 | */ | |
395 | char buf[NL_PKT_BUF_SIZE]; | |
396 | struct rtattr *rta = (void *) buf; | |
397 | struct rtnexthop *rtnh; | |
398 | ||
399 | rta->rta_type = RTA_MULTIPATH; | |
400 | rta->rta_len = RTA_LENGTH (0); | |
401 | rtnh = RTA_DATA (rta); | |
402 | ||
403 | for (nexthop_num = 0; nexthop_num < ri->num_nhs; nexthop_num++) | |
404 | { | |
405 | nhi = &ri->nhs[nexthop_num]; | |
406 | ||
407 | rtnh->rtnh_len = sizeof (*rtnh); | |
408 | rtnh->rtnh_flags = 0; | |
409 | rtnh->rtnh_hops = 0; | |
410 | rtnh->rtnh_ifindex = 0; | |
411 | rta->rta_len += rtnh->rtnh_len; | |
412 | ||
413 | if (nhi->gateway) | |
414 | { | |
415 | rta_addattr_l (rta, sizeof (buf), RTA_GATEWAY, nhi->gateway, bytelen); | |
416 | rtnh->rtnh_len += sizeof (struct rtattr) + bytelen; | |
417 | } | |
418 | ||
419 | if (nhi->if_index) | |
420 | { | |
421 | rtnh->rtnh_ifindex = nhi->if_index; | |
422 | } | |
423 | ||
424 | rtnh = RTNH_NEXT (rtnh); | |
425 | } | |
426 | ||
427 | assert (rta->rta_len > RTA_LENGTH (0)); | |
428 | addattr_l (&req->n, in_buf_len, RTA_MULTIPATH, RTA_DATA (rta), | |
429 | RTA_PAYLOAD (rta)); | |
430 | ||
431 | done: | |
432 | ||
433 | if (ri->pref_src) | |
434 | { | |
435 | addattr_l (&req->n, in_buf_len, RTA_PREFSRC, &ri->pref_src, bytelen); | |
436 | } | |
437 | ||
438 | assert (req->n.nlmsg_len < in_buf_len); | |
439 | return req->n.nlmsg_len; | |
440 | } | |
441 | ||
442 | /* | |
443 | * zfpm_log_route_info | |
444 | * | |
445 | * Helper function to log the information in a route_info structure. | |
446 | */ | |
447 | static void | |
448 | zfpm_log_route_info (netlink_route_info_t *ri, const char *label) | |
449 | { | |
450 | netlink_nh_info_t *nhi; | |
451 | int i; | |
452 | ||
453 | zfpm_debug ("%s : %s %s/%d, Proto: %s, Metric: %u", label, | |
454 | nl_msg_type_to_str (ri->nlmsg_type), | |
455 | prefix_addr_to_a (ri->prefix), ri->prefix->prefixlen, | |
456 | nl_rtproto_to_str (ri->rtm_protocol), | |
457 | ri->metric ? *ri->metric : 0); | |
458 | ||
459 | for (i = 0; i < ri->num_nhs; i++) | |
460 | { | |
461 | nhi = &ri->nhs[i]; | |
462 | zfpm_debug(" Intf: %u, Gateway: %s, Recursive: %s, Type: %s", | |
463 | nhi->if_index, addr_to_a (ri->af, nhi->gateway), | |
464 | nhi->recursive ? "yes" : "no", | |
465 | nexthop_type_to_str (nhi->type)); | |
466 | } | |
467 | } | |
468 | ||
469 | /* | |
470 | * zfpm_netlink_encode_route | |
471 | * | |
472 | * Create a netlink message corresponding to the given route in the | |
473 | * given buffer space. | |
474 | * | |
475 | * Returns the number of bytes written to the buffer. 0 or a negative | |
476 | * value indicates an error. | |
477 | */ | |
478 | int | |
479 | zfpm_netlink_encode_route (int cmd, rib_dest_t *dest, struct rib *rib, | |
480 | char *in_buf, size_t in_buf_len) | |
481 | { | |
482 | netlink_route_info_t ri_space, *ri; | |
483 | ||
484 | ri = &ri_space; | |
485 | ||
486 | if (!netlink_route_info_fill (ri, cmd, dest, rib)) | |
487 | return 0; | |
488 | ||
489 | zfpm_log_route_info (ri, __FUNCTION__); | |
490 | ||
491 | return netlink_route_info_encode (ri, in_buf, in_buf_len); | |
492 | } |