xref: /freebsd/sys/netlink/netlink_message_parser.c (revision 1dbc104148845434575d1931d47876ae0ca1542f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2022 Alexander V. Chernikov <melifaro@FreeBSD.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 #include "opt_inet.h"
30 #include "opt_inet6.h"
31 #include <sys/types.h>
32 #include <sys/malloc.h>
33 #include <sys/rmlock.h>
34 #include <sys/socket.h>
35 #include <sys/stdarg.h>
36 
37 #include <net/if.h>
38 #include <net/route.h>
39 #include <net/route/nhop.h>
40 
41 #include <net/route/route_ctl.h>
42 #include <netinet/in.h>
43 #include <netlink/netlink.h>
44 #include <netlink/netlink_ctl.h>
45 #include <netlink/netlink_var.h>
46 #include <netlink/netlink_route.h>
47 
48 #define	DEBUG_MOD_NAME	nl_parser
49 #define	DEBUG_MAX_LEVEL	LOG_DEBUG3
50 #include <netlink/netlink_debug.h>
51 _DECLARE_DEBUG(LOG_INFO);
52 
53 /*
54  * Some applications try to provide only the non-zero part of the required
55  * message header instead of a full one.  It happens when fetching routes or
56  * interface addresses, where the first header byte is the family.
57  * This behavior is "illegal" under the "strict" Netlink socket option, however
58  * there are many applications out there doing things in the "old" way.
59  * Support this usecase by copying the provided bytes into the temporary
60  * zero-filled header and running the parser on this header instead.
61  */
62 struct nlmsghdr *
nl_alloc_compat_hdr(struct nlmsghdr * hdr,uint32_t len,struct nl_pstate * npt)63 nl_alloc_compat_hdr(struct nlmsghdr *hdr, uint32_t len, struct nl_pstate *npt)
64 {
65 	struct nlmsghdr *tmp;
66 
67 	MPASS(hdr->nlmsg_len < sizeof(struct nlmsghdr) + len);
68 
69 	len += sizeof(struct nlmsghdr);
70 	if (npt->strict) {
71 		nlmsg_report_err_msg(npt,
72 		    "header too short: expected %d, got %d",
73 		     len, hdr->nlmsg_len);
74 		return (NULL);
75 	}
76 	tmp = npt_alloc(npt, len);
77 	if (tmp == NULL)
78 		return (NULL);
79 	memcpy(tmp, hdr, hdr->nlmsg_len);
80 	tmp->nlmsg_len = len;
81 
82 	return (tmp);
83 }
84 
85 bool
nlmsg_report_err_msg(struct nl_pstate * npt,const char * fmt,...)86 nlmsg_report_err_msg(struct nl_pstate *npt, const char *fmt, ...)
87 {
88 	va_list ap;
89 
90 	if (npt->err_msg != NULL)
91 		return (false);
92 	char *buf = npt_alloc(npt, NL_MAX_ERROR_BUF);
93 	if (buf == NULL)
94 		return (false);
95 	va_start(ap, fmt);
96 	vsnprintf(buf, NL_MAX_ERROR_BUF, fmt, ap);
97 	va_end(ap);
98 
99 	npt->err_msg = buf;
100 	return (true);
101 }
102 
103 bool
nlmsg_report_err_offset(struct nl_pstate * npt,uint32_t off)104 nlmsg_report_err_offset(struct nl_pstate *npt, uint32_t off)
105 {
106 	if (npt->err_off != 0)
107 		return (false);
108 	npt->err_off = off;
109 	return (true);
110 }
111 
112 void
nlmsg_report_cookie(struct nl_pstate * npt,struct nlattr * nla)113 nlmsg_report_cookie(struct nl_pstate *npt, struct nlattr *nla)
114 {
115 	MPASS(nla->nla_type == NLMSGERR_ATTR_COOKIE);
116 	MPASS(nla->nla_len >= sizeof(struct nlattr));
117 	npt->cookie = nla;
118 }
119 
120 void
nlmsg_report_cookie_u32(struct nl_pstate * npt,uint32_t val)121 nlmsg_report_cookie_u32(struct nl_pstate *npt, uint32_t val)
122 {
123 	struct nlattr *nla = npt_alloc(npt, sizeof(*nla) + sizeof(uint32_t));
124 
125 	if (nla == NULL)
126 		return;
127 	nla->nla_type = NLMSGERR_ATTR_COOKIE;
128 	nla->nla_len = sizeof(*nla) + sizeof(uint32_t);
129 	memcpy(nla + 1, &val, sizeof(uint32_t));
130 	nlmsg_report_cookie(npt, nla);
131 }
132 
133 static const struct nlattr_parser *
search_states(const struct nlattr_parser * ps,u_int pslen,int key)134 search_states(const struct nlattr_parser *ps, u_int pslen, int key)
135 {
136 	int left_i = 0, right_i = pslen - 1;
137 
138 	if (key < ps[0].type || key > ps[pslen - 1].type)
139 		return (NULL);
140 
141 	while (left_i + 1 < right_i) {
142 		int mid_i = (left_i + right_i) / 2;
143 		if (key < ps[mid_i].type)
144 			right_i = mid_i;
145 		else if (key > ps[mid_i].type)
146 			left_i = mid_i + 1;
147 		else
148 			return (&ps[mid_i]);
149 	}
150 	if (ps[left_i].type == key)
151 		return (&ps[left_i]);
152 	else if (ps[right_i].type == key)
153 		return (&ps[right_i]);
154 	return (NULL);
155 }
156 
157 int
nl_parse_attrs_raw(struct nlattr * nla_head,uint16_t len,const struct nlattr_parser * ps,u_int pslen,struct nl_pstate * npt,void * target)158 nl_parse_attrs_raw(struct nlattr *nla_head, uint16_t len,
159     const struct nlattr_parser *ps, u_int pslen, struct nl_pstate *npt,
160     void *target)
161 {
162 	const struct nlattr_parser *s;
163 	struct nlattr *nla;
164 	uint16_t orig_len, off;
165 	int error = 0;
166 
167 	NL_LOG(LOG_DEBUG3, "parse %p remaining_len %d", nla_head, len);
168 	orig_len = len;
169 	NLA_FOREACH(nla, nla_head, len) {
170 		NL_LOG(LOG_DEBUG3, ">> parsing %p attr_type %u len %u (rem %u)",
171 		    nla, nla->nla_type, nla->nla_len, len);
172 		if (nla->nla_len < sizeof(struct nlattr)) {
173 			NLMSG_REPORT_ERR_MSG(npt,
174 			    "Invalid attr %p type %u len: %u",
175 			    nla, nla->nla_type, nla->nla_len);
176 			off = (char *)nla - (char *)npt->hdr;
177 			nlmsg_report_err_offset(npt, off);
178 			return (EINVAL);
179 		}
180 
181 		s = search_states(ps, pslen, nla->nla_type & NLA_TYPE_MASK);
182 		if (s != NULL) {
183 			void *ptr;
184 
185 			ptr = (void *)((char *)target + s->off);
186 			error = s->cb(nla, npt, s->arg, ptr);
187 			if (error != 0) {
188 				off = (char *)nla - (char *)npt->hdr;
189 				nlmsg_report_err_offset(npt, off);
190 				NL_LOG(LOG_DEBUG3,
191 				    "parse failed at offset %u", off);
192 				return (error);
193 			}
194 		} else {
195 			/* Ignore non-specified attributes */
196 			NL_LOG(LOG_DEBUG3, "ignoring attr %u", nla->nla_type);
197 		}
198 	}
199 	if (len >= sizeof(struct nlattr)) {
200 		nla = (struct nlattr *)((char *)nla_head + (orig_len - len));
201 		NL_LOG(LOG_DEBUG3, " >>> end %p attr_type %u len %u", nla,
202 		    nla->nla_type, nla->nla_len);
203 	}
204 	NL_LOG(LOG_DEBUG3, "end parse: %p remaining_len %u", nla, len);
205 
206 	return (0);
207 }
208 
209 void
nl_get_attrs_bmask_raw(struct nlattr * nla_head,uint32_t len,struct nlattr_bmask * bm)210 nl_get_attrs_bmask_raw(struct nlattr *nla_head, uint32_t len,
211     struct nlattr_bmask *bm)
212 {
213 	struct nlattr *nla = NULL;
214 	uint16_t nla_type;
215 
216 	BIT_ZERO(NL_ATTR_BMASK_SIZE, bm);
217 
218 	NLA_FOREACH(nla, nla_head, len) {
219 		if (nla->nla_len < sizeof(struct nlattr))
220 			return;
221 		nla_type = nla->nla_type & NLA_TYPE_MASK;
222 		if (nla_type < NL_ATTR_BMASK_SIZE)
223 			BIT_SET(NL_ATTR_BMASK_SIZE, nla_type, bm);
224 		else
225 			NL_LOG(LOG_DEBUG2,
226 			    "Skipping type %u in the mask: too short",
227 			    nla_type);
228 	}
229 }
230 
231 bool
nl_has_attr(const struct nlattr_bmask * bm,uint16_t nla_type)232 nl_has_attr(const struct nlattr_bmask *bm, uint16_t nla_type)
233 {
234 	MPASS(nla_type < NL_ATTR_BMASK_SIZE);
235 
236 	return (BIT_ISSET(NL_ATTR_BMASK_SIZE, nla_type, bm));
237 }
238 
239 int
nlattr_get_flag(struct nlattr * nla,struct nl_pstate * npt,const void * arg,void * target)240 nlattr_get_flag(struct nlattr *nla, struct nl_pstate *npt, const void *arg,
241     void *target)
242 {
243 	if (__predict_false(NLA_DATA_LEN(nla) != 0)) {
244 		NLMSG_REPORT_ERR_MSG(npt, "nla type %d size(%u) is not a flag",
245 		    nla->nla_type, NLA_DATA_LEN(nla));
246 		return (EINVAL);
247 	}
248 
249 	*((uint8_t *)target) = 1;
250 	return (0);
251 }
252 
253 static struct sockaddr *
parse_rta_ip4(void * rta_data,struct nl_pstate * npt,int * perror)254 parse_rta_ip4(void *rta_data, struct nl_pstate *npt, int *perror)
255 {
256 	struct sockaddr_in *sin;
257 
258 	sin = (struct sockaddr_in *)npt_alloc_sockaddr(npt,
259 	    sizeof(struct sockaddr_in));
260 	if (__predict_false(sin == NULL)) {
261 		*perror = ENOBUFS;
262 		return (NULL);
263 	}
264 	sin->sin_len = sizeof(struct sockaddr_in);
265 	sin->sin_family = AF_INET;
266 	memcpy(&sin->sin_addr, rta_data, sizeof(struct in_addr));
267 	return ((struct sockaddr *)sin);
268 }
269 
270 static struct sockaddr *
parse_rta_ip6(void * rta_data,struct nl_pstate * npt,int * perror)271 parse_rta_ip6(void *rta_data, struct nl_pstate *npt, int *perror)
272 {
273 	struct sockaddr_in6 *sin6;
274 
275 	sin6 = (struct sockaddr_in6 *)npt_alloc_sockaddr(npt,
276 	    sizeof(struct sockaddr_in6));
277 	if (__predict_false(sin6 == NULL)) {
278 		*perror = ENOBUFS;
279 		return (NULL);
280 	}
281 	sin6->sin6_len = sizeof(struct sockaddr_in6);
282 	sin6->sin6_family = AF_INET6;
283 	memcpy(&sin6->sin6_addr, rta_data, sizeof(struct in6_addr));
284 	return ((struct sockaddr *)sin6);
285 }
286 
287 static struct sockaddr *
parse_rta_ip(struct rtattr * rta,struct nl_pstate * npt,int * perror)288 parse_rta_ip(struct rtattr *rta, struct nl_pstate *npt, int *perror)
289 {
290 	void *rta_data = NL_RTA_DATA(rta);
291 	int rta_len = NL_RTA_DATA_LEN(rta);
292 
293 	if (rta_len == sizeof(struct in_addr)) {
294 		return (parse_rta_ip4(rta_data, npt, perror));
295 	} else if (rta_len == sizeof(struct in6_addr)) {
296 		return (parse_rta_ip6(rta_data, npt, perror));
297 	} else {
298 		NLMSG_REPORT_ERR_MSG(npt, "unknown IP len: %d for rta type %d",
299 		    rta_len, rta->rta_type);
300 		*perror = ENOTSUP;
301 		return (NULL);
302 	}
303 	return (NULL);
304 }
305 
306 int
nlattr_get_ip(struct nlattr * nla,struct nl_pstate * npt,const void * arg,void * target)307 nlattr_get_ip(struct nlattr *nla, struct nl_pstate *npt, const void *arg,
308     void *target)
309 {
310 	int error = 0;
311 
312 	struct sockaddr *sa = parse_rta_ip((struct rtattr *)nla, npt, &error);
313 
314 	*((struct sockaddr **)target) = sa;
315 	return (error);
316 }
317 
318 static struct sockaddr *
parse_rta_via(struct rtattr * rta,struct nl_pstate * npt,int * perror)319 parse_rta_via(struct rtattr *rta, struct nl_pstate *npt, int *perror)
320 {
321 	struct rtvia *via = NL_RTA_DATA(rta);
322 	int data_len = NL_RTA_DATA_LEN(rta);
323 
324 	if (__predict_false(data_len) < sizeof(struct rtvia)) {
325 		NLMSG_REPORT_ERR_MSG(npt, "undersized RTA_VIA(%d) attr: len %d",
326 		    rta->rta_type, data_len);
327 		*perror = EINVAL;
328 		return (NULL);
329 	}
330 	data_len -= offsetof(struct rtvia, rtvia_addr);
331 
332 	switch (via->rtvia_family) {
333 	case AF_INET:
334 		if (__predict_false(data_len < sizeof(struct in_addr))) {
335 			*perror = EINVAL;
336 			return (NULL);
337 		}
338 		return (parse_rta_ip4(via->rtvia_addr, npt, perror));
339 	case AF_INET6:
340 		if (__predict_false(data_len < sizeof(struct in6_addr))) {
341 			*perror = EINVAL;
342 			return (NULL);
343 		}
344 		return (parse_rta_ip6(via->rtvia_addr, npt, perror));
345 	default:
346 		*perror = ENOTSUP;
347 		return (NULL);
348 	}
349 }
350 
351 int
nlattr_get_ipvia(struct nlattr * nla,struct nl_pstate * npt,const void * arg,void * target)352 nlattr_get_ipvia(struct nlattr *nla, struct nl_pstate *npt, const void *arg,
353     void *target)
354 {
355 	int error = 0;
356 
357 	struct sockaddr *sa = parse_rta_via((struct rtattr *)nla, npt, &error);
358 
359 	*((struct sockaddr **)target) = sa;
360 	return (error);
361 }
362 
363 int
nlattr_get_bool(struct nlattr * nla,struct nl_pstate * npt,const void * arg,void * target)364 nlattr_get_bool(struct nlattr *nla, struct nl_pstate *npt, const void *arg,
365     void *target)
366 {
367 	if (__predict_false(NLA_DATA_LEN(nla) != sizeof(bool))) {
368 		NLMSG_REPORT_ERR_MSG(npt, "nla type %d size(%u) is not bool",
369 		    nla->nla_type, NLA_DATA_LEN(nla));
370 		return (EINVAL);
371 	}
372 	*((bool *)target) = *((const bool *)NL_RTA_DATA_CONST(nla));
373 	return (0);
374 }
375 
376 int
nlattr_get_uint8(struct nlattr * nla,struct nl_pstate * npt,const void * arg,void * target)377 nlattr_get_uint8(struct nlattr *nla, struct nl_pstate *npt, const void *arg,
378     void *target)
379 {
380 	if (__predict_false(NLA_DATA_LEN(nla) != sizeof(uint8_t))) {
381 		NLMSG_REPORT_ERR_MSG(npt, "nla type %d size(%u) is not uint8",
382 		    nla->nla_type, NLA_DATA_LEN(nla));
383 		return (EINVAL);
384 	}
385 	*((uint8_t *)target) = *((const uint8_t *)NL_RTA_DATA_CONST(nla));
386 	return (0);
387 }
388 
389 int
nlattr_get_uint16(struct nlattr * nla,struct nl_pstate * npt,const void * arg,void * target)390 nlattr_get_uint16(struct nlattr *nla, struct nl_pstate *npt, const void *arg,
391     void *target)
392 {
393 	if (__predict_false(NLA_DATA_LEN(nla) != sizeof(uint16_t))) {
394 		NLMSG_REPORT_ERR_MSG(npt, "nla type %d size(%u) is not uint16",
395 		    nla->nla_type, NLA_DATA_LEN(nla));
396 		return (EINVAL);
397 	}
398 	*((uint16_t *)target) = *((const uint16_t *)NL_RTA_DATA_CONST(nla));
399 	return (0);
400 }
401 
402 int
nlattr_get_uint32(struct nlattr * nla,struct nl_pstate * npt,const void * arg,void * target)403 nlattr_get_uint32(struct nlattr *nla, struct nl_pstate *npt, const void *arg,
404     void *target)
405 {
406 	if (__predict_false(NLA_DATA_LEN(nla) != sizeof(uint32_t))) {
407 		NLMSG_REPORT_ERR_MSG(npt, "nla type %d size(%u) is not uint32",
408 		    nla->nla_type, NLA_DATA_LEN(nla));
409 		return (EINVAL);
410 	}
411 	*((uint32_t *)target) = *((const uint32_t *)NL_RTA_DATA_CONST(nla));
412 	return (0);
413 }
414 
415 int
nlattr_get_uint64(struct nlattr * nla,struct nl_pstate * npt,const void * arg,void * target)416 nlattr_get_uint64(struct nlattr *nla, struct nl_pstate *npt, const void *arg,
417     void *target)
418 {
419 	if (__predict_false(NLA_DATA_LEN(nla) != sizeof(uint64_t))) {
420 		NLMSG_REPORT_ERR_MSG(npt, "nla type %d size(%u) is not uint64",
421 		    nla->nla_type, NLA_DATA_LEN(nla));
422 		return (EINVAL);
423 	}
424 	memcpy(target, NL_RTA_DATA_CONST(nla), sizeof(uint64_t));
425 	return (0);
426 }
427 
428 int
nlattr_get_in_addr(struct nlattr * nla,struct nl_pstate * npt,const void * arg,void * target)429 nlattr_get_in_addr(struct nlattr *nla, struct nl_pstate *npt, const void *arg,
430     void *target)
431 {
432 	if (__predict_false(NLA_DATA_LEN(nla) != sizeof(in_addr_t))) {
433 		NLMSG_REPORT_ERR_MSG(npt,
434 		    "nla type %d size(%u) is not in_addr_t",
435 		    nla->nla_type, NLA_DATA_LEN(nla));
436 		return (EINVAL);
437 	}
438 	memcpy(target, NLA_DATA_CONST(nla), sizeof(in_addr_t));
439 	return (0);
440 }
441 
442 int
nlattr_get_in6_addr(struct nlattr * nla,struct nl_pstate * npt,const void * arg,void * target)443 nlattr_get_in6_addr(struct nlattr *nla, struct nl_pstate *npt, const void *arg,
444     void *target)
445 {
446 	if (__predict_false(NLA_DATA_LEN(nla) != sizeof(struct in6_addr))) {
447 		NLMSG_REPORT_ERR_MSG(npt,
448 		    "nla type %d size(%u) is not struct in6_addr",
449 		    nla->nla_type, NLA_DATA_LEN(nla));
450 		return (EINVAL);
451 	}
452 	memcpy(target, NLA_DATA_CONST(nla), sizeof(struct in6_addr));
453 	return (0);
454 }
455 
456 static int
nlattr_get_ifp_internal(struct nlattr * nla,struct nl_pstate * npt,void * target,bool zero_ok)457 nlattr_get_ifp_internal(struct nlattr *nla, struct nl_pstate *npt,
458     void *target, bool zero_ok)
459 {
460 	struct ifnet *ifp;
461 	u_int ifindex;
462 
463 	if (__predict_false(NLA_DATA_LEN(nla) != sizeof(uint32_t))) {
464 		NLMSG_REPORT_ERR_MSG(npt, "nla type %d size(%u) is not uint32",
465 		    nla->nla_type, NLA_DATA_LEN(nla));
466 		return (EINVAL);
467 	}
468 	ifindex = *((const u_int *)NLA_DATA_CONST(nla));
469 
470 	if (ifindex == 0 && zero_ok) {
471 		*((struct ifnet **)target) = NULL;
472 		return (0);
473 	}
474 
475 	NET_EPOCH_ASSERT();
476 
477 	ifp = ifnet_byindex(ifindex);
478 	if (__predict_false(ifp == NULL)) {
479 		NLMSG_REPORT_ERR_MSG(npt, "nla type %d: ifindex %u invalid",
480 		    nla->nla_type, ifindex);
481 		return (ENOENT);
482 	}
483 	*((struct ifnet **)target) = ifp;
484 	NL_LOG(LOG_DEBUG3, "nla type %d: ifindex %u -> %s", nla->nla_type,
485 	    ifindex, if_name(ifp));
486 
487 	return (0);
488 }
489 
490 int
nlattr_get_ifp(struct nlattr * nla,struct nl_pstate * npt,const void * arg,void * target)491 nlattr_get_ifp(struct nlattr *nla, struct nl_pstate *npt, const void *arg,
492     void *target)
493 {
494 	return (nlattr_get_ifp_internal(nla, npt, target, false));
495 }
496 
497 int
nlattr_get_ifpz(struct nlattr * nla,struct nl_pstate * npt,const void * arg,void * target)498 nlattr_get_ifpz(struct nlattr *nla, struct nl_pstate *npt, const void *arg,
499     void *target)
500 {
501 	return (nlattr_get_ifp_internal(nla, npt, target, true));
502 }
503 
504 int
nlattr_get_chara(struct nlattr * nla,struct nl_pstate * npt,const void * arg,void * target)505 nlattr_get_chara(struct nlattr *nla, struct nl_pstate *npt, const void *arg,
506     void *target)
507 {
508 	int maxlen = NLA_DATA_LEN(nla);
509 	int target_size = (size_t)arg;
510 	int len = strnlen((char *)NLA_DATA(nla), maxlen);
511 
512 	if (__predict_false(len >= maxlen) ||
513 	    __predict_false(len >= target_size)) {
514 		NLMSG_REPORT_ERR_MSG(npt, "nla type %d size(%u) is not "
515 		    "NULL-terminated or longer than %u",
516 		    nla->nla_type, maxlen, target_size);
517 		return (EINVAL);
518 	}
519 
520 	strncpy((char *)target, (char *)NLA_DATA(nla), target_size);
521 	return (0);
522 }
523 
524 int
nlattr_get_string(struct nlattr * nla,struct nl_pstate * npt,const void * arg,void * target)525 nlattr_get_string(struct nlattr *nla, struct nl_pstate *npt, const void *arg,
526     void *target)
527 {
528 	int maxlen = NLA_DATA_LEN(nla);
529 
530 	if (__predict_false(strnlen((char *)NLA_DATA(nla), maxlen) >= maxlen)) {
531 		NLMSG_REPORT_ERR_MSG(npt,
532 		    "nla type %d size(%u) is not NULL-terminated",
533 		    nla->nla_type, maxlen);
534 		return (EINVAL);
535 	}
536 
537 	*((char **)target) = (char *)NLA_DATA(nla);
538 	return (0);
539 }
540 
541 int
nlattr_get_stringn(struct nlattr * nla,struct nl_pstate * npt,const void * arg,void * target)542 nlattr_get_stringn(struct nlattr *nla, struct nl_pstate *npt, const void *arg,
543     void *target)
544 {
545 	int maxlen = NLA_DATA_LEN(nla);
546 
547 	char *buf = npt_alloc(npt, maxlen + 1);
548 	if (buf == NULL)
549 		return (ENOMEM);
550 	buf[maxlen] = '\0';
551 	memcpy(buf, NLA_DATA(nla), maxlen);
552 
553 	*((char **)target) = buf;
554 	return (0);
555 }
556 
557 int
nlattr_get_bytes(struct nlattr * nla,struct nl_pstate * npt,const void * arg,void * target)558 nlattr_get_bytes(struct nlattr *nla, struct nl_pstate *npt, const void *arg,
559     void *target)
560 {
561 	size_t size = (size_t)arg;
562 
563 	if (NLA_DATA_LEN(nla) != size)
564 		return (EINVAL);
565 
566 	memcpy(target, NLA_DATA(nla), size);
567 
568 	return (0);
569 }
570 
571 int
nlattr_get_nla(struct nlattr * nla,struct nl_pstate * npt,const void * arg,void * target)572 nlattr_get_nla(struct nlattr *nla, struct nl_pstate *npt, const void *arg,
573     void *target)
574 {
575 	NL_LOG(LOG_DEBUG3, "STORING %p len %d", nla, nla->nla_len);
576 	*((struct nlattr **)target) = nla;
577 	return (0);
578 }
579 
580 int
nlattr_get_nested(struct nlattr * nla,struct nl_pstate * npt,const void * arg,void * target)581 nlattr_get_nested(struct nlattr *nla, struct nl_pstate *npt, const void *arg,
582     void *target)
583 {
584 	const struct nlhdr_parser *p = (const struct nlhdr_parser *)arg;
585 
586 	/* Assumes target points to the beginning of the structure. */
587 	return (nl_parse_header(NLA_DATA(nla), NLA_DATA_LEN(nla), p, npt,
588 	    target));
589 }
590 
591 int
nlattr_get_nested_ptr(struct nlattr * nla,struct nl_pstate * npt,const void * arg,void * target)592 nlattr_get_nested_ptr(struct nlattr *nla, struct nl_pstate *npt,
593     const void *arg, void *target)
594 {
595 	const struct nlhdr_parser *p = (const struct nlhdr_parser *)arg;
596 
597 	/* Assumes target points to the beginning of the structure. */
598 	return (nl_parse_header(NLA_DATA(nla), NLA_DATA_LEN(nla), p, npt,
599 	    *(void **)target));
600 }
601 
602 int
nlf_get_ifp(void * src,struct nl_pstate * npt,void * target)603 nlf_get_ifp(void *src, struct nl_pstate *npt, void *target)
604 {
605 	struct ifnet *ifp;
606 	u_int ifindex;
607 
608 	NET_EPOCH_ASSERT();
609 
610 	ifindex = *((const u_int *)src);
611 	ifp = ifnet_byindex(ifindex);
612 	if (ifp == NULL) {
613 		NL_LOG(LOG_DEBUG, "ifindex %u invalid", ifindex);
614 		return (ENOENT);
615 	}
616 	*((struct ifnet **)target) = ifp;
617 
618 	return (0);
619 }
620 
621 int
nlf_get_ifpz(void * src,struct nl_pstate * npt,void * target)622 nlf_get_ifpz(void *src, struct nl_pstate *npt, void *target)
623 {
624 	struct ifnet *ifp;
625 	u_int ifindex;
626 
627 	NET_EPOCH_ASSERT();
628 
629 	ifindex = *((const u_int *)src);
630 	ifp = ifnet_byindex(ifindex);
631 	if (ifindex != 0 && ifp == NULL) {
632 		NL_LOG(LOG_DEBUG, "ifindex %u invalid", ifindex);
633 		return (ENOENT);
634 	}
635 	*((struct ifnet **)target) = ifp;
636 
637 	return (0);
638 }
639 
640 int
nlf_get_u8(void * src,struct nl_pstate * npt,void * target)641 nlf_get_u8(void *src, struct nl_pstate *npt, void *target)
642 {
643 	uint8_t val = *((const uint8_t *)src);
644 
645 	*((uint8_t *)target) = val;
646 
647 	return (0);
648 }
649 
650 int
nlf_get_u8_u32(void * src,struct nl_pstate * npt,void * target)651 nlf_get_u8_u32(void *src, struct nl_pstate *npt, void *target)
652 {
653 	*((uint32_t *)target) = *((const uint8_t *)src);
654 	return (0);
655 }
656 
657 int
nlf_get_u16(void * src,struct nl_pstate * npt,void * target)658 nlf_get_u16(void *src, struct nl_pstate *npt, void *target)
659 {
660 	*((uint16_t *)target) = *((const uint16_t *)src);
661 	return (0);
662 }
663 
664 int
nlf_get_u32(void * src,struct nl_pstate * npt,void * target)665 nlf_get_u32(void *src, struct nl_pstate *npt, void *target)
666 {
667 	*((uint32_t *)target) = *((const uint32_t *)src);
668 	return (0);
669 }
670