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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 | */ | |
ac4d0be5 | 47 | static inline const char *addr_to_a(u_char af, void *addr) |
5adc2528 | 48 | { |
ac4d0be5 | 49 | if (!addr) |
50 | return "<No address>"; | |
51 | ||
52 | switch (af) { | |
53 | ||
54 | case AF_INET: | |
55 | return inet_ntoa(*((struct in_addr *)addr)); | |
56 | break; | |
57 | case AF_INET6: | |
58 | return inet6_ntoa(*((struct in6_addr *)addr)); | |
59 | break; | |
60 | default: | |
61 | return "<Addr in unknown AF>"; | |
62 | break; | |
63 | } | |
5adc2528 AS |
64 | } |
65 | ||
66 | /* | |
67 | * prefix_addr_to_a | |
68 | * | |
69 | * Convience wrapper that returns a human-readable string for the | |
70 | * address in a prefix. | |
71 | */ | |
ac4d0be5 | 72 | static const char *prefix_addr_to_a(struct prefix *prefix) |
5adc2528 | 73 | { |
ac4d0be5 | 74 | if (!prefix) |
75 | return "<No address>"; | |
5adc2528 | 76 | |
ac4d0be5 | 77 | return addr_to_a(prefix->family, &prefix->u.prefix); |
5adc2528 AS |
78 | } |
79 | ||
80 | /* | |
81 | * af_addr_size | |
82 | * | |
83 | * The size of an address in a given address family. | |
84 | */ | |
ac4d0be5 | 85 | static size_t af_addr_size(u_char af) |
5adc2528 | 86 | { |
ac4d0be5 | 87 | switch (af) { |
88 | ||
89 | case AF_INET: | |
90 | return 4; | |
91 | break; | |
92 | case AF_INET6: | |
93 | return 16; | |
94 | break; | |
95 | default: | |
96 | assert(0); | |
97 | return 16; | |
98 | } | |
5adc2528 AS |
99 | } |
100 | ||
101 | /* | |
102 | * netlink_nh_info_t | |
103 | * | |
104 | * Holds information about a single nexthop for netlink. These info | |
105 | * structures are transient and may contain pointers into rib | |
106 | * data structures for convenience. | |
107 | */ | |
ac4d0be5 | 108 | typedef struct netlink_nh_info_t_ { |
109 | uint32_t if_index; | |
110 | union g_addr *gateway; | |
111 | ||
112 | /* | |
113 | * Information from the struct nexthop from which this nh was | |
114 | * derived. For debug purposes only. | |
115 | */ | |
116 | int recursive; | |
117 | enum nexthop_types_t type; | |
5adc2528 AS |
118 | } netlink_nh_info_t; |
119 | ||
120 | /* | |
121 | * netlink_route_info_t | |
122 | * | |
123 | * A structure for holding information for a netlink route message. | |
124 | */ | |
ac4d0be5 | 125 | typedef struct netlink_route_info_t_ { |
126 | uint16_t nlmsg_type; | |
127 | u_char rtm_type; | |
128 | uint32_t rtm_table; | |
129 | u_char rtm_protocol; | |
130 | u_char af; | |
131 | struct prefix *prefix; | |
132 | uint32_t *metric; | |
133 | unsigned int num_nhs; | |
134 | ||
135 | /* | |
136 | * Nexthop structures | |
137 | */ | |
138 | netlink_nh_info_t nhs[MULTIPATH_NUM]; | |
139 | union g_addr *pref_src; | |
5adc2528 AS |
140 | } netlink_route_info_t; |
141 | ||
142 | /* | |
143 | * netlink_route_info_add_nh | |
144 | * | |
145 | * Add information about the given nexthop to the given route info | |
146 | * structure. | |
147 | * | |
148 | * Returns TRUE if a nexthop was added, FALSE otherwise. | |
149 | */ | |
ac4d0be5 | 150 | static int netlink_route_info_add_nh(netlink_route_info_t *ri, |
151 | struct nexthop *nexthop, int recursive) | |
5adc2528 | 152 | { |
ac4d0be5 | 153 | netlink_nh_info_t nhi; |
154 | union g_addr *src; | |
155 | ||
156 | memset(&nhi, 0, sizeof(nhi)); | |
157 | src = NULL; | |
158 | ||
159 | if (ri->num_nhs >= (int)ZEBRA_NUM_OF(ri->nhs)) | |
160 | return 0; | |
161 | ||
162 | nhi.recursive = recursive; | |
163 | nhi.type = nexthop->type; | |
164 | nhi.if_index = nexthop->ifindex; | |
165 | ||
166 | if (nexthop->type == NEXTHOP_TYPE_IPV4 | |
167 | || nexthop->type == NEXTHOP_TYPE_IPV4_IFINDEX) { | |
168 | nhi.gateway = &nexthop->gate; | |
169 | if (nexthop->src.ipv4.s_addr) | |
170 | src = &nexthop->src; | |
171 | } | |
172 | ||
173 | if (nexthop->type == NEXTHOP_TYPE_IPV6 | |
174 | || nexthop->type == NEXTHOP_TYPE_IPV6_IFINDEX) { | |
175 | nhi.gateway = &nexthop->gate; | |
176 | } | |
177 | ||
178 | if (nexthop->type == NEXTHOP_TYPE_IFINDEX) { | |
179 | if (nexthop->src.ipv4.s_addr) | |
180 | src = &nexthop->src; | |
181 | } | |
182 | ||
183 | if (!nhi.gateway && nhi.if_index == 0) | |
184 | return 0; | |
185 | ||
186 | /* | |
187 | * We have a valid nhi. Copy the structure over to the route_info. | |
188 | */ | |
189 | ri->nhs[ri->num_nhs] = nhi; | |
190 | ri->num_nhs++; | |
191 | ||
192 | if (src && !ri->pref_src) | |
193 | ri->pref_src = src; | |
194 | ||
195 | return 1; | |
5adc2528 AS |
196 | } |
197 | ||
198 | /* | |
199 | * netlink_proto_from_route_type | |
200 | */ | |
ac4d0be5 | 201 | static u_char netlink_proto_from_route_type(int type) |
5adc2528 | 202 | { |
ac4d0be5 | 203 | switch (type) { |
204 | case ZEBRA_ROUTE_KERNEL: | |
205 | case ZEBRA_ROUTE_CONNECT: | |
206 | return RTPROT_KERNEL; | |
207 | ||
208 | default: | |
209 | return RTPROT_ZEBRA; | |
210 | } | |
5adc2528 AS |
211 | } |
212 | ||
213 | /* | |
214 | * netlink_route_info_fill | |
215 | * | |
216 | * Fill out the route information object from the given route. | |
217 | * | |
218 | * Returns TRUE on success and FALSE on failure. | |
219 | */ | |
ac4d0be5 | 220 | static int netlink_route_info_fill(netlink_route_info_t *ri, int cmd, |
221 | rib_dest_t *dest, struct rib *rib) | |
5adc2528 | 222 | { |
ac4d0be5 | 223 | struct nexthop *nexthop, *tnexthop; |
224 | int recursing; | |
225 | int discard; | |
226 | ||
227 | memset(ri, 0, sizeof(*ri)); | |
228 | ||
229 | ri->prefix = rib_dest_prefix(dest); | |
230 | ri->af = rib_dest_af(dest); | |
231 | ||
232 | ri->nlmsg_type = cmd; | |
233 | ri->rtm_table = zvrf_id(rib_dest_vrf(dest)); | |
234 | ri->rtm_protocol = RTPROT_UNSPEC; | |
235 | ||
236 | /* | |
237 | * An RTM_DELROUTE need not be accompanied by any nexthops, | |
238 | * particularly in our communication with the FPM. | |
239 | */ | |
240 | if (cmd == RTM_DELROUTE && !rib) | |
241 | return 1; | |
242 | ||
243 | if (!rib) { | |
244 | zfpm_debug("%s: Expected non-NULL rib pointer", | |
245 | __PRETTY_FUNCTION__); | |
246 | return 0; | |
247 | } | |
248 | ||
249 | ri->rtm_protocol = netlink_proto_from_route_type(rib->type); | |
250 | ||
251 | if ((rib->flags & ZEBRA_FLAG_BLACKHOLE) | |
252 | || (rib->flags & ZEBRA_FLAG_REJECT)) | |
253 | discard = 1; | |
254 | else | |
255 | discard = 0; | |
256 | ||
257 | if (cmd == RTM_NEWROUTE) { | |
258 | if (discard) { | |
259 | if (rib->flags & ZEBRA_FLAG_BLACKHOLE) | |
260 | ri->rtm_type = RTN_BLACKHOLE; | |
261 | else if (rib->flags & ZEBRA_FLAG_REJECT) | |
262 | ri->rtm_type = RTN_UNREACHABLE; | |
263 | else | |
264 | assert(0); | |
265 | } else | |
266 | ri->rtm_type = RTN_UNICAST; | |
267 | } | |
268 | ||
269 | ri->metric = &rib->metric; | |
270 | ||
271 | if (discard) | |
272 | return 1; | |
273 | ||
274 | for (ALL_NEXTHOPS_RO(rib->nexthop, nexthop, tnexthop, recursing)) { | |
275 | if (ri->num_nhs >= multipath_num) | |
276 | break; | |
277 | ||
278 | if (CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_RECURSIVE)) | |
279 | continue; | |
280 | ||
281 | if ((cmd == RTM_NEWROUTE | |
282 | && CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_ACTIVE)) | |
283 | || (cmd == RTM_DELROUTE | |
284 | && CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_FIB))) { | |
285 | netlink_route_info_add_nh(ri, nexthop, recursing); | |
286 | } | |
287 | } | |
288 | ||
289 | /* If there is no useful nexthop then return. */ | |
290 | if (ri->num_nhs == 0) { | |
291 | zfpm_debug("netlink_encode_route(): No useful nexthop."); | |
292 | return 0; | |
293 | } | |
294 | ||
295 | return 1; | |
5adc2528 AS |
296 | } |
297 | ||
298 | /* | |
299 | * netlink_route_info_encode | |
300 | * | |
301 | * Returns the number of bytes written to the buffer. 0 or a negative | |
302 | * value indicates an error. | |
303 | */ | |
ac4d0be5 | 304 | static int netlink_route_info_encode(netlink_route_info_t *ri, char *in_buf, |
305 | size_t in_buf_len) | |
5adc2528 | 306 | { |
ac4d0be5 | 307 | size_t bytelen; |
308 | unsigned int nexthop_num = 0; | |
309 | size_t buf_offset; | |
310 | netlink_nh_info_t *nhi; | |
5adc2528 | 311 | |
ac4d0be5 | 312 | struct { |
313 | struct nlmsghdr n; | |
314 | struct rtmsg r; | |
315 | char buf[1]; | |
316 | } * req; | |
5adc2528 | 317 | |
ac4d0be5 | 318 | req = (void *)in_buf; |
5adc2528 | 319 | |
ac4d0be5 | 320 | buf_offset = ((char *)req->buf) - ((char *)req); |
5adc2528 | 321 | |
ac4d0be5 | 322 | if (in_buf_len < buf_offset) { |
323 | assert(0); | |
324 | return 0; | |
325 | } | |
5adc2528 | 326 | |
ac4d0be5 | 327 | memset(req, 0, buf_offset); |
5adc2528 | 328 | |
ac4d0be5 | 329 | bytelen = af_addr_size(ri->af); |
5adc2528 | 330 | |
ac4d0be5 | 331 | req->n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg)); |
332 | req->n.nlmsg_flags = NLM_F_CREATE | NLM_F_REQUEST; | |
333 | req->n.nlmsg_type = ri->nlmsg_type; | |
334 | req->r.rtm_family = ri->af; | |
335 | req->r.rtm_table = ri->rtm_table; | |
336 | req->r.rtm_dst_len = ri->prefix->prefixlen; | |
337 | req->r.rtm_protocol = ri->rtm_protocol; | |
338 | req->r.rtm_scope = RT_SCOPE_UNIVERSE; | |
5adc2528 | 339 | |
ac4d0be5 | 340 | addattr_l(&req->n, in_buf_len, RTA_DST, &ri->prefix->u.prefix, bytelen); |
5adc2528 | 341 | |
ac4d0be5 | 342 | req->r.rtm_type = ri->rtm_type; |
5adc2528 | 343 | |
ac4d0be5 | 344 | /* Metric. */ |
345 | if (ri->metric) | |
346 | addattr32(&req->n, in_buf_len, RTA_PRIORITY, *ri->metric); | |
5adc2528 | 347 | |
ac4d0be5 | 348 | if (ri->num_nhs == 0) |
349 | goto done; | |
5adc2528 | 350 | |
ac4d0be5 | 351 | if (ri->num_nhs == 1) { |
352 | nhi = &ri->nhs[0]; | |
5adc2528 | 353 | |
ac4d0be5 | 354 | if (nhi->gateway) { |
355 | addattr_l(&req->n, in_buf_len, RTA_GATEWAY, | |
356 | nhi->gateway, bytelen); | |
357 | } | |
5adc2528 | 358 | |
ac4d0be5 | 359 | if (nhi->if_index) { |
360 | addattr32(&req->n, in_buf_len, RTA_OIF, nhi->if_index); | |
361 | } | |
5adc2528 | 362 | |
ac4d0be5 | 363 | goto done; |
5adc2528 AS |
364 | } |
365 | ||
ac4d0be5 | 366 | /* |
367 | * Multipath case. | |
368 | */ | |
369 | char buf[NL_PKT_BUF_SIZE]; | |
370 | struct rtattr *rta = (void *)buf; | |
371 | struct rtnexthop *rtnh; | |
372 | ||
373 | rta->rta_type = RTA_MULTIPATH; | |
374 | rta->rta_len = RTA_LENGTH(0); | |
375 | rtnh = RTA_DATA(rta); | |
376 | ||
377 | for (nexthop_num = 0; nexthop_num < ri->num_nhs; nexthop_num++) { | |
378 | nhi = &ri->nhs[nexthop_num]; | |
379 | ||
380 | rtnh->rtnh_len = sizeof(*rtnh); | |
381 | rtnh->rtnh_flags = 0; | |
382 | rtnh->rtnh_hops = 0; | |
383 | rtnh->rtnh_ifindex = 0; | |
384 | rta->rta_len += rtnh->rtnh_len; | |
385 | ||
386 | if (nhi->gateway) { | |
387 | rta_addattr_l(rta, sizeof(buf), RTA_GATEWAY, | |
388 | nhi->gateway, bytelen); | |
389 | rtnh->rtnh_len += sizeof(struct rtattr) + bytelen; | |
390 | } | |
391 | ||
392 | if (nhi->if_index) { | |
393 | rtnh->rtnh_ifindex = nhi->if_index; | |
394 | } | |
395 | ||
396 | rtnh = RTNH_NEXT(rtnh); | |
5adc2528 AS |
397 | } |
398 | ||
ac4d0be5 | 399 | assert(rta->rta_len > RTA_LENGTH(0)); |
400 | addattr_l(&req->n, in_buf_len, RTA_MULTIPATH, RTA_DATA(rta), | |
401 | RTA_PAYLOAD(rta)); | |
5adc2528 AS |
402 | |
403 | done: | |
404 | ||
ac4d0be5 | 405 | if (ri->pref_src) { |
406 | addattr_l(&req->n, in_buf_len, RTA_PREFSRC, &ri->pref_src, | |
407 | bytelen); | |
408 | } | |
5adc2528 | 409 | |
ac4d0be5 | 410 | assert(req->n.nlmsg_len < in_buf_len); |
411 | return req->n.nlmsg_len; | |
5adc2528 AS |
412 | } |
413 | ||
414 | /* | |
415 | * zfpm_log_route_info | |
416 | * | |
417 | * Helper function to log the information in a route_info structure. | |
418 | */ | |
ac4d0be5 | 419 | static void zfpm_log_route_info(netlink_route_info_t *ri, const char *label) |
5adc2528 | 420 | { |
ac4d0be5 | 421 | netlink_nh_info_t *nhi; |
422 | unsigned int i; | |
423 | ||
424 | zfpm_debug("%s : %s %s/%d, Proto: %s, Metric: %u", label, | |
425 | nl_msg_type_to_str(ri->nlmsg_type), | |
426 | prefix_addr_to_a(ri->prefix), ri->prefix->prefixlen, | |
427 | nl_rtproto_to_str(ri->rtm_protocol), | |
428 | ri->metric ? *ri->metric : 0); | |
429 | ||
430 | for (i = 0; i < ri->num_nhs; i++) { | |
431 | nhi = &ri->nhs[i]; | |
432 | zfpm_debug(" Intf: %u, Gateway: %s, Recursive: %s, Type: %s", | |
433 | nhi->if_index, addr_to_a(ri->af, nhi->gateway), | |
434 | nhi->recursive ? "yes" : "no", | |
435 | nexthop_type_to_str(nhi->type)); | |
436 | } | |
5adc2528 AS |
437 | } |
438 | ||
439 | /* | |
440 | * zfpm_netlink_encode_route | |
441 | * | |
442 | * Create a netlink message corresponding to the given route in the | |
443 | * given buffer space. | |
444 | * | |
445 | * Returns the number of bytes written to the buffer. 0 or a negative | |
446 | * value indicates an error. | |
447 | */ | |
ac4d0be5 | 448 | int zfpm_netlink_encode_route(int cmd, rib_dest_t *dest, struct rib *rib, |
449 | char *in_buf, size_t in_buf_len) | |
5adc2528 | 450 | { |
ac4d0be5 | 451 | netlink_route_info_t ri_space, *ri; |
5adc2528 | 452 | |
ac4d0be5 | 453 | ri = &ri_space; |
5adc2528 | 454 | |
ac4d0be5 | 455 | if (!netlink_route_info_fill(ri, cmd, dest, rib)) |
456 | return 0; | |
5adc2528 | 457 | |
ac4d0be5 | 458 | zfpm_log_route_info(ri, __FUNCTION__); |
5adc2528 | 459 | |
ac4d0be5 | 460 | return netlink_route_info_encode(ri, in_buf, in_buf_len); |
5adc2528 | 461 | } |