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1 /*
2  * libnetlink.c	RTnetlink service routines.
3  *
4  *		This program is free software; you can redistribute it and/or
5  *		modify it under the terms of the GNU General Public License
6  *		as published by the Free Software Foundation; either version
7  *		2 of the License, or (at your option) any later version.
8  *
9  * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10  *
11  */
12 
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <unistd.h>
16 #include <syslog.h>
17 #include <fcntl.h>
18 #include <net/if_arp.h>
19 #include <sys/socket.h>
20 #include <netinet/in.h>
21 #include <string.h>
22 #include <errno.h>
23 #include <time.h>
24 #include <sys/uio.h>
25 
26 #include "libnetlink.h"
27 
28 int rcvbuf = 1024 * 1024;
29 
rtnl_close(struct rtnl_handle * rth)30 void rtnl_close(struct rtnl_handle *rth)
31 {
32 	if (rth->fd >= 0) {
33 		close(rth->fd);
34 		rth->fd = -1;
35 	}
36 }
37 
rtnl_open_byproto(struct rtnl_handle * rth,unsigned subscriptions,int protocol)38 int rtnl_open_byproto(struct rtnl_handle *rth, unsigned subscriptions,
39 		      int protocol)
40 {
41 	socklen_t addr_len;
42 	int sndbuf = 32768;
43 
44 	memset(rth, 0, sizeof(*rth));
45 
46 	rth->fd = socket(AF_NETLINK, SOCK_RAW, protocol);
47 	if (rth->fd < 0) {
48 		perror("Cannot open netlink socket");
49 		return -1;
50 	}
51 
52 	if (setsockopt(rth->fd,SOL_SOCKET,SO_SNDBUF,&sndbuf,sizeof(sndbuf)) < 0) {
53 		perror("SO_SNDBUF");
54 		return -1;
55 	}
56 
57 	if (setsockopt(rth->fd,SOL_SOCKET,SO_RCVBUF,&rcvbuf,sizeof(rcvbuf)) < 0) {
58 		perror("SO_RCVBUF");
59 		return -1;
60 	}
61 
62 	memset(&rth->local, 0, sizeof(rth->local));
63 	rth->local.nl_family = AF_NETLINK;
64 	rth->local.nl_groups = subscriptions;
65 
66 	if (bind(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local)) < 0) {
67 		perror("Cannot bind netlink socket");
68 		return -1;
69 	}
70 	addr_len = sizeof(rth->local);
71 	if (getsockname(rth->fd, (struct sockaddr*)&rth->local, &addr_len) < 0) {
72 		perror("Cannot getsockname");
73 		return -1;
74 	}
75 	if (addr_len != sizeof(rth->local)) {
76 		fprintf(stderr, "Wrong address length %d\n", addr_len);
77 		return -1;
78 	}
79 	if (rth->local.nl_family != AF_NETLINK) {
80 		fprintf(stderr, "Wrong address family %d\n", rth->local.nl_family);
81 		return -1;
82 	}
83 	rth->seq = time(NULL);
84 	return 0;
85 }
86 
rtnl_open(struct rtnl_handle * rth,unsigned subscriptions)87 int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions)
88 {
89 	return rtnl_open_byproto(rth, subscriptions, NETLINK_ROUTE);
90 }
91 
rtnl_wilddump_request(struct rtnl_handle * rth,int family,int type)92 int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type)
93 {
94 	struct {
95 		struct nlmsghdr nlh;
96 		struct rtgenmsg g;
97 	} req;
98 
99 	memset(&req, 0, sizeof(req));
100 	req.nlh.nlmsg_len = sizeof(req);
101 	req.nlh.nlmsg_type = type;
102 	req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
103 	req.nlh.nlmsg_pid = 0;
104 	req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
105 	req.g.rtgen_family = family;
106 
107 	return send(rth->fd, (void*)&req, sizeof(req), 0);
108 }
109 
rtnl_send(struct rtnl_handle * rth,const char * buf,int len)110 int rtnl_send(struct rtnl_handle *rth, const char *buf, int len)
111 {
112 	return send(rth->fd, buf, len, 0);
113 }
114 
rtnl_send_check(struct rtnl_handle * rth,const char * buf,int len)115 int rtnl_send_check(struct rtnl_handle *rth, const char *buf, int len)
116 {
117 	struct nlmsghdr *h;
118 	int status;
119 	char resp[1024];
120 
121 	status = send(rth->fd, buf, len, 0);
122 	if (status < 0)
123 		return status;
124 
125 	/* Check for immediate errors */
126 	status = recv(rth->fd, resp, sizeof(resp), MSG_DONTWAIT|MSG_PEEK);
127 	if (status < 0) {
128 		if (errno == EAGAIN)
129 			return 0;
130 		return -1;
131 	}
132 
133 	for (h = (struct nlmsghdr *)resp; NLMSG_OK(h, status);
134 	     h = NLMSG_NEXT(h, status)) {
135 		if (h->nlmsg_type == NLMSG_ERROR) {
136 			struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
137 			if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr)))
138 				fprintf(stderr, "ERROR truncated\n");
139 			else
140 				errno = -err->error;
141 			return -1;
142 		}
143 	}
144 
145 	return 0;
146 }
147 
rtnl_dump_request(struct rtnl_handle * rth,int type,void * req,int len)148 int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
149 {
150 	struct nlmsghdr nlh;
151 	struct sockaddr_nl nladdr;
152 	struct iovec iov[2] = {
153 		{ .iov_base = &nlh, .iov_len = sizeof(nlh) },
154 		{ .iov_base = req, .iov_len = len }
155 	};
156 	struct msghdr msg = {
157 		.msg_name = &nladdr,
158 		.msg_namelen = 	sizeof(nladdr),
159 		.msg_iov = iov,
160 		.msg_iovlen = 2,
161 	};
162 
163 	memset(&nladdr, 0, sizeof(nladdr));
164 	nladdr.nl_family = AF_NETLINK;
165 
166 	nlh.nlmsg_len = NLMSG_LENGTH(len);
167 	nlh.nlmsg_type = type;
168 	nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
169 	nlh.nlmsg_pid = 0;
170 	nlh.nlmsg_seq = rth->dump = ++rth->seq;
171 
172 	return sendmsg(rth->fd, &msg, 0);
173 }
174 
rtnl_dump_filter_l(struct rtnl_handle * rth,const struct rtnl_dump_filter_arg * arg)175 int rtnl_dump_filter_l(struct rtnl_handle *rth,
176 		       const struct rtnl_dump_filter_arg *arg)
177 {
178 	struct sockaddr_nl nladdr;
179 	struct iovec iov;
180 	struct msghdr msg = {
181 		.msg_name = &nladdr,
182 		.msg_namelen = sizeof(nladdr),
183 		.msg_iov = &iov,
184 		.msg_iovlen = 1,
185 	};
186 	char buf[16384];
187 
188 	iov.iov_base = buf;
189 	while (1) {
190 		int status;
191 		const struct rtnl_dump_filter_arg *a;
192 
193 		iov.iov_len = sizeof(buf);
194 		status = recvmsg(rth->fd, &msg, 0);
195 
196 		if (status < 0) {
197 			if (errno == EINTR || errno == EAGAIN)
198 				continue;
199 			fprintf(stderr, "netlink receive error %s (%d)\n",
200 				strerror(errno), errno);
201 			return -1;
202 		}
203 
204 		if (status == 0) {
205 			fprintf(stderr, "EOF on netlink\n");
206 			return -1;
207 		}
208 
209 		for (a = arg; a->filter; a++) {
210 			struct nlmsghdr *h = (struct nlmsghdr*)buf;
211 
212 			while (NLMSG_OK(h, status)) {
213 				int err;
214 
215 				if (nladdr.nl_pid != 0 ||
216 				    h->nlmsg_pid != rth->local.nl_pid ||
217 				    h->nlmsg_seq != rth->dump) {
218 					if (a->junk) {
219 						err = a->junk(&nladdr, h,
220 							      a->arg2);
221 						if (err < 0)
222 							return err;
223 					}
224 					goto skip_it;
225 				}
226 
227 				if (h->nlmsg_type == NLMSG_DONE)
228 					return 0;
229 				if (h->nlmsg_type == NLMSG_ERROR) {
230 					struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
231 					if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
232 						fprintf(stderr,
233 							"ERROR truncated\n");
234 					} else {
235 						errno = -err->error;
236 						perror("RTNETLINK answers");
237 					}
238 					return -1;
239 				}
240 				err = a->filter(&nladdr, h, a->arg1);
241 				if (err < 0)
242 					return err;
243 
244 skip_it:
245 				h = NLMSG_NEXT(h, status);
246 			}
247 		} while (0);
248 		if (msg.msg_flags & MSG_TRUNC) {
249 			fprintf(stderr, "Message truncated\n");
250 			continue;
251 		}
252 		if (status) {
253 			fprintf(stderr, "!!!Remnant of size %d\n", status);
254 			exit(1);
255 		}
256 	}
257 }
258 
rtnl_dump_filter(struct rtnl_handle * rth,rtnl_filter_t filter,void * arg1,rtnl_filter_t junk,void * arg2)259 int rtnl_dump_filter(struct rtnl_handle *rth,
260 		     rtnl_filter_t filter,
261 		     void *arg1,
262 		     rtnl_filter_t junk,
263 		     void *arg2)
264 {
265 	const struct rtnl_dump_filter_arg a[2] = {
266 		{ .filter = filter, .arg1 = arg1, .junk = junk, .arg2 = arg2 },
267 		{ .filter = NULL,   .arg1 = NULL, .junk = NULL, .arg2 = NULL }
268 	};
269 
270 	return rtnl_dump_filter_l(rth, a);
271 }
272 
rtnl_talk(struct rtnl_handle * rtnl,struct nlmsghdr * n,pid_t peer,unsigned groups,struct nlmsghdr * answer,rtnl_filter_t junk,void * jarg)273 int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
274 	      unsigned groups, struct nlmsghdr *answer,
275 	      rtnl_filter_t junk,
276 	      void *jarg)
277 {
278 	int status;
279 	unsigned seq;
280 	struct nlmsghdr *h;
281 	struct sockaddr_nl nladdr;
282 	struct iovec iov = {
283 		.iov_base = (void*) n,
284 		.iov_len = n->nlmsg_len
285 	};
286 	struct msghdr msg = {
287 		.msg_name = &nladdr,
288 		.msg_namelen = sizeof(nladdr),
289 		.msg_iov = &iov,
290 		.msg_iovlen = 1,
291 	};
292 	char   buf[16384];
293 
294 	memset(&nladdr, 0, sizeof(nladdr));
295 	nladdr.nl_family = AF_NETLINK;
296 	nladdr.nl_pid = peer;
297 	nladdr.nl_groups = groups;
298 
299 	n->nlmsg_seq = seq = ++rtnl->seq;
300 
301 	if (answer == NULL)
302 		n->nlmsg_flags |= NLM_F_ACK;
303 
304 	status = sendmsg(rtnl->fd, &msg, 0);
305 
306 	if (status < 0) {
307 		perror("Cannot talk to rtnetlink");
308 		return -1;
309 	}
310 
311 	memset(buf,0,sizeof(buf));
312 
313 	iov.iov_base = buf;
314 
315 	while (1) {
316 		iov.iov_len = sizeof(buf);
317 		status = recvmsg(rtnl->fd, &msg, 0);
318 
319 		if (status < 0) {
320 			if (errno == EINTR || errno == EAGAIN)
321 				continue;
322 			fprintf(stderr, "netlink receive error %s (%d)\n",
323 				strerror(errno), errno);
324 			return -1;
325 		}
326 		if (status == 0) {
327 			fprintf(stderr, "EOF on netlink\n");
328 			return -1;
329 		}
330 		if (msg.msg_namelen != sizeof(nladdr)) {
331 			fprintf(stderr, "sender address length == %d\n", msg.msg_namelen);
332 			exit(1);
333 		}
334 		for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
335 			int err;
336 			int len = h->nlmsg_len;
337 			int l = len - sizeof(*h);
338 
339 			if (l<0 || len>status) {
340 				if (msg.msg_flags & MSG_TRUNC) {
341 					fprintf(stderr, "Truncated message\n");
342 					return -1;
343 				}
344 				fprintf(stderr, "!!!malformed message: len=%d\n", len);
345 				exit(1);
346 			}
347 
348 			if (nladdr.nl_pid != peer ||
349 			    h->nlmsg_pid != rtnl->local.nl_pid ||
350 			    h->nlmsg_seq != seq) {
351 				if (junk) {
352 					err = junk(&nladdr, h, jarg);
353 					if (err < 0)
354 						return err;
355 				}
356 				/* Don't forget to skip that message. */
357 				status -= NLMSG_ALIGN(len);
358 				h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
359 				continue;
360 			}
361 
362 			if (h->nlmsg_type == NLMSG_ERROR) {
363 				struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
364 				if (l < sizeof(struct nlmsgerr)) {
365 					fprintf(stderr, "ERROR truncated\n");
366 				} else {
367 					errno = -err->error;
368 					if (errno == 0) {
369 						if (answer)
370 							memcpy(answer, h, h->nlmsg_len);
371 						return 0;
372 					}
373 					perror("RTNETLINK answers");
374 				}
375 				return -1;
376 			}
377 			if (answer) {
378 				memcpy(answer, h, h->nlmsg_len);
379 				return 0;
380 			}
381 
382 			fprintf(stderr, "Unexpected reply!!!\n");
383 
384 			status -= NLMSG_ALIGN(len);
385 			h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
386 		}
387 		if (msg.msg_flags & MSG_TRUNC) {
388 			fprintf(stderr, "Message truncated\n");
389 			continue;
390 		}
391 		if (status) {
392 			fprintf(stderr, "!!!Remnant of size %d\n", status);
393 			exit(1);
394 		}
395 	}
396 }
397 
rtnl_listen(struct rtnl_handle * rtnl,rtnl_filter_t handler,void * jarg)398 int rtnl_listen(struct rtnl_handle *rtnl,
399 		rtnl_filter_t handler,
400 		void *jarg)
401 {
402 	int status;
403 	struct nlmsghdr *h;
404 	struct sockaddr_nl nladdr;
405 	struct iovec iov;
406 	struct msghdr msg = {
407 		.msg_name = &nladdr,
408 		.msg_namelen = sizeof(nladdr),
409 		.msg_iov = &iov,
410 		.msg_iovlen = 1,
411 	};
412 	char   buf[8192];
413 
414 	memset(&nladdr, 0, sizeof(nladdr));
415 	nladdr.nl_family = AF_NETLINK;
416 	nladdr.nl_pid = 0;
417 	nladdr.nl_groups = 0;
418 
419 	iov.iov_base = buf;
420 	while (1) {
421 		iov.iov_len = sizeof(buf);
422 		status = recvmsg(rtnl->fd, &msg, 0);
423 
424 		if (status < 0) {
425 			if (errno == EINTR || errno == EAGAIN)
426 				continue;
427 			fprintf(stderr, "netlink receive error %s (%d)\n",
428 				strerror(errno), errno);
429 			if (errno == ENOBUFS)
430 				continue;
431 			return -1;
432 		}
433 		if (status == 0) {
434 			fprintf(stderr, "EOF on netlink\n");
435 			return -1;
436 		}
437 		if (msg.msg_namelen != sizeof(nladdr)) {
438 			fprintf(stderr, "Sender address length == %d\n", msg.msg_namelen);
439 			exit(1);
440 		}
441 		for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
442 			int err;
443 			int len = h->nlmsg_len;
444 			int l = len - sizeof(*h);
445 
446 			if (l<0 || len>status) {
447 				if (msg.msg_flags & MSG_TRUNC) {
448 					fprintf(stderr, "Truncated message\n");
449 					return -1;
450 				}
451 				fprintf(stderr, "!!!malformed message: len=%d\n", len);
452 				exit(1);
453 			}
454 
455 			err = handler(&nladdr, h, jarg);
456 			if (err < 0)
457 				return err;
458 
459 			status -= NLMSG_ALIGN(len);
460 			h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
461 		}
462 		if (msg.msg_flags & MSG_TRUNC) {
463 			fprintf(stderr, "Message truncated\n");
464 			continue;
465 		}
466 		if (status) {
467 			fprintf(stderr, "!!!Remnant of size %d\n", status);
468 			exit(1);
469 		}
470 	}
471 }
472 
rtnl_from_file(FILE * rtnl,rtnl_filter_t handler,void * jarg)473 int rtnl_from_file(FILE *rtnl, rtnl_filter_t handler,
474 		   void *jarg)
475 {
476 	int status;
477 	struct sockaddr_nl nladdr;
478 	char   buf[8192];
479 	struct nlmsghdr *h = (void*)buf;
480 
481 	memset(&nladdr, 0, sizeof(nladdr));
482 	nladdr.nl_family = AF_NETLINK;
483 	nladdr.nl_pid = 0;
484 	nladdr.nl_groups = 0;
485 
486 	while (1) {
487 		int err, len, type;
488 		int l;
489 
490 		status = fread(&buf, 1, sizeof(*h), rtnl);
491 
492 		if (status < 0) {
493 			if (errno == EINTR)
494 				continue;
495 			perror("rtnl_from_file: fread");
496 			return -1;
497 		}
498 		if (status == 0)
499 			return 0;
500 
501 		len = h->nlmsg_len;
502 		type= h->nlmsg_type;
503 		l = len - sizeof(*h);
504 
505 		if (l<0 || len>sizeof(buf)) {
506 			fprintf(stderr, "!!!malformed message: len=%d @%lu\n",
507 				len, ftell(rtnl));
508 			return -1;
509 		}
510 
511 		status = fread(NLMSG_DATA(h), 1, NLMSG_ALIGN(l), rtnl);
512 
513 		if (status < 0) {
514 			perror("rtnl_from_file: fread");
515 			return -1;
516 		}
517 		if (status < l) {
518 			fprintf(stderr, "rtnl-from_file: truncated message\n");
519 			return -1;
520 		}
521 
522 		err = handler(&nladdr, h, jarg);
523 		if (err < 0)
524 			return err;
525 	}
526 }
527 
addattr32(struct nlmsghdr * n,int maxlen,int type,__u32 data)528 int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
529 {
530 	int len = RTA_LENGTH(4);
531 	struct rtattr *rta;
532 	if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen) {
533 		fprintf(stderr,"addattr32: Error! max allowed bound %d exceeded\n",maxlen);
534 		return -1;
535 	}
536 	rta = NLMSG_TAIL(n);
537 	rta->rta_type = type;
538 	rta->rta_len = len;
539 	memcpy(RTA_DATA(rta), &data, 4);
540 	n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
541 	return 0;
542 }
543 
addattr_l(struct nlmsghdr * n,int maxlen,int type,const void * data,int alen)544 int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data,
545 	      int alen)
546 {
547 	int len = RTA_LENGTH(alen);
548 	struct rtattr *rta;
549 
550 	if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) {
551 		fprintf(stderr, "addattr_l ERROR: message exceeded bound of %d\n",maxlen);
552 		return -1;
553 	}
554 	rta = NLMSG_TAIL(n);
555 	rta->rta_type = type;
556 	rta->rta_len = len;
557 	memcpy(RTA_DATA(rta), data, alen);
558 	n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
559 	return 0;
560 }
561 
addraw_l(struct nlmsghdr * n,int maxlen,const void * data,int len)562 int addraw_l(struct nlmsghdr *n, int maxlen, const void *data, int len)
563 {
564 	if (NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len) > maxlen) {
565 		fprintf(stderr, "addraw_l ERROR: message exceeded bound of %d\n",maxlen);
566 		return -1;
567 	}
568 
569 	memcpy(NLMSG_TAIL(n), data, len);
570 	memset((void *) NLMSG_TAIL(n) + len, 0, NLMSG_ALIGN(len) - len);
571 	n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len);
572 	return 0;
573 }
574 
addattr_nest(struct nlmsghdr * n,int maxlen,int type)575 struct rtattr *addattr_nest(struct nlmsghdr *n, int maxlen, int type)
576 {
577 	struct rtattr *nest = NLMSG_TAIL(n);
578 
579 	addattr_l(n, maxlen, type, NULL, 0);
580 	return nest;
581 }
582 
addattr_nest_end(struct nlmsghdr * n,struct rtattr * nest)583 int addattr_nest_end(struct nlmsghdr *n, struct rtattr *nest)
584 {
585 	nest->rta_len = (void *)NLMSG_TAIL(n) - (void *)nest;
586 	return n->nlmsg_len;
587 }
588 
addattr_nest_compat(struct nlmsghdr * n,int maxlen,int type,const void * data,int len)589 struct rtattr *addattr_nest_compat(struct nlmsghdr *n, int maxlen, int type,
590 				   const void *data, int len)
591 {
592 	struct rtattr *start = NLMSG_TAIL(n);
593 
594 	addattr_l(n, maxlen, type, data, len);
595 	addattr_nest(n, maxlen, type);
596 	return start;
597 }
598 
addattr_nest_compat_end(struct nlmsghdr * n,struct rtattr * start)599 int addattr_nest_compat_end(struct nlmsghdr *n, struct rtattr *start)
600 {
601 	struct rtattr *nest = (void *)start + NLMSG_ALIGN(start->rta_len);
602 
603 	start->rta_len = (void *)NLMSG_TAIL(n) - (void *)start;
604 	addattr_nest_end(n, nest);
605 	return n->nlmsg_len;
606 }
607 
rta_addattr32(struct rtattr * rta,int maxlen,int type,__u32 data)608 int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data)
609 {
610 	int len = RTA_LENGTH(4);
611 	struct rtattr *subrta;
612 
613 	if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
614 		fprintf(stderr,"rta_addattr32: Error! max allowed bound %d exceeded\n",maxlen);
615 		return -1;
616 	}
617 	subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
618 	subrta->rta_type = type;
619 	subrta->rta_len = len;
620 	memcpy(RTA_DATA(subrta), &data, 4);
621 	rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
622 	return 0;
623 }
624 
rta_addattr_l(struct rtattr * rta,int maxlen,int type,const void * data,int alen)625 int rta_addattr_l(struct rtattr *rta, int maxlen, int type,
626 		  const void *data, int alen)
627 {
628 	struct rtattr *subrta;
629 	int len = RTA_LENGTH(alen);
630 
631 	if (RTA_ALIGN(rta->rta_len) + RTA_ALIGN(len) > maxlen) {
632 		fprintf(stderr,"rta_addattr_l: Error! max allowed bound %d exceeded\n",maxlen);
633 		return -1;
634 	}
635 	subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
636 	subrta->rta_type = type;
637 	subrta->rta_len = len;
638 	memcpy(RTA_DATA(subrta), data, alen);
639 	rta->rta_len = NLMSG_ALIGN(rta->rta_len) + RTA_ALIGN(len);
640 	return 0;
641 }
642 
parse_rtattr(struct rtattr * tb[],int max,struct rtattr * rta,int len)643 int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
644 {
645 	memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
646 	while (RTA_OK(rta, len)) {
647 		if ((rta->rta_type <= max) && (!tb[rta->rta_type]))
648 			tb[rta->rta_type] = rta;
649 		rta = RTA_NEXT(rta,len);
650 	}
651 	if (len)
652 		fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len);
653 	return 0;
654 }
655 
parse_rtattr_byindex(struct rtattr * tb[],int max,struct rtattr * rta,int len)656 int parse_rtattr_byindex(struct rtattr *tb[], int max, struct rtattr *rta, int len)
657 {
658 	int i = 0;
659 
660 	memset(tb, 0, sizeof(struct rtattr *) * max);
661 	while (RTA_OK(rta, len)) {
662 		if (rta->rta_type <= max && i < max)
663 			tb[i++] = rta;
664 		rta = RTA_NEXT(rta,len);
665 	}
666 	if (len)
667 		fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len);
668 	return i;
669 }
670 
__parse_rtattr_nested_compat(struct rtattr * tb[],int max,struct rtattr * rta,int len)671 int __parse_rtattr_nested_compat(struct rtattr *tb[], int max, struct rtattr *rta,
672 			         int len)
673 {
674 	if (RTA_PAYLOAD(rta) < len)
675 		return -1;
676 	if (RTA_PAYLOAD(rta) >= RTA_ALIGN(len) + sizeof(struct rtattr)) {
677 		rta = RTA_DATA(rta) + RTA_ALIGN(len);
678 		return parse_rtattr_nested(tb, max, rta);
679 	}
680 	memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
681 	return 0;
682 }
683