2 * libnetlink.c RTnetlink service routines.
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.
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
18 #include <net/if_arp.h>
19 #include <sys/socket.h>
20 #include <netinet/in.h>
26 #include "libnetlink.h"
28 void rtnl_close(struct rtnl_handle *rth)
36 int rtnl_open_byproto(struct rtnl_handle *rth, unsigned subscriptions,
43 memset(rth, 0, sizeof(*rth));
45 rth->fd = socket(AF_NETLINK, SOCK_RAW, protocol);
47 perror("Cannot open netlink socket");
51 if (setsockopt(rth->fd,SOL_SOCKET,SO_SNDBUF,&sndbuf,sizeof(sndbuf)) < 0) {
56 if (setsockopt(rth->fd,SOL_SOCKET,SO_RCVBUF,&rcvbuf,sizeof(rcvbuf)) < 0) {
61 memset(&rth->local, 0, sizeof(rth->local));
62 rth->local.nl_family = AF_NETLINK;
63 rth->local.nl_groups = subscriptions;
65 if (bind(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local)) < 0) {
66 perror("Cannot bind netlink socket");
69 addr_len = sizeof(rth->local);
70 if (getsockname(rth->fd, (struct sockaddr*)&rth->local, &addr_len) < 0) {
71 perror("Cannot getsockname");
74 if (addr_len != sizeof(rth->local)) {
75 fprintf(stderr, "Wrong address length %d\n", addr_len);
78 if (rth->local.nl_family != AF_NETLINK) {
79 fprintf(stderr, "Wrong address family %d\n", rth->local.nl_family);
82 rth->seq = time(NULL);
86 int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions)
88 return rtnl_open_byproto(rth, subscriptions, NETLINK_ROUTE);
91 int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type)
98 memset(&req, 0, sizeof(req));
99 req.nlh.nlmsg_len = sizeof(req);
100 req.nlh.nlmsg_type = type;
101 req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
102 req.nlh.nlmsg_pid = 0;
103 req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
104 req.g.rtgen_family = family;
106 return send(rth->fd, (void*)&req, sizeof(req), 0);
109 int rtnl_send(struct rtnl_handle *rth, const char *buf, int len)
111 return send(rth->fd, buf, len, 0);
114 int rtnl_send_check(struct rtnl_handle *rth, const char *buf, int len)
120 status = send(rth->fd, buf, len, 0);
124 /* Check for errors */
125 status = recv(rth->fd, resp, sizeof(resp), MSG_DONTWAIT);
132 for (h = (struct nlmsghdr *)resp; NLMSG_OK(h, status);
133 h = NLMSG_NEXT(h, status)) {
134 if (h->nlmsg_type == NLMSG_ERROR) {
135 struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
136 if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr)))
137 fprintf(stderr, "ERROR truncated\n");
147 int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
150 struct sockaddr_nl nladdr;
151 struct iovec iov[2] = {
152 { .iov_base = &nlh, .iov_len = sizeof(nlh) },
153 { .iov_base = req, .iov_len = len }
155 struct msghdr msg = {
157 .msg_namelen = sizeof(nladdr),
162 memset(&nladdr, 0, sizeof(nladdr));
163 nladdr.nl_family = AF_NETLINK;
165 nlh.nlmsg_len = NLMSG_LENGTH(len);
166 nlh.nlmsg_type = type;
167 nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
169 nlh.nlmsg_seq = rth->dump = ++rth->seq;
171 return sendmsg(rth->fd, &msg, 0);
174 int rtnl_dump_filter(struct rtnl_handle *rth,
175 rtnl_filter_t filter,
180 struct sockaddr_nl nladdr;
182 struct msghdr msg = {
184 .msg_namelen = sizeof(nladdr),
195 iov.iov_len = sizeof(buf);
196 status = recvmsg(rth->fd, &msg, 0);
199 if (errno == EINTR || errno == EAGAIN)
201 fprintf(stderr, "netlink receive error %s (%d)\n",
202 strerror(errno), errno);
207 fprintf(stderr, "EOF on netlink\n");
211 h = (struct nlmsghdr*)buf;
212 while (NLMSG_OK(h, status)) {
215 if (nladdr.nl_pid != 0 ||
216 h->nlmsg_pid != rth->local.nl_pid ||
217 h->nlmsg_seq != rth->dump) {
219 err = junk(&nladdr, h, arg2);
226 if (h->nlmsg_type == NLMSG_DONE)
228 if (h->nlmsg_type == NLMSG_ERROR) {
229 struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
230 if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
231 fprintf(stderr, "ERROR truncated\n");
234 perror("RTNETLINK answers");
238 err = filter(&nladdr, h, arg1);
243 h = NLMSG_NEXT(h, status);
245 if (msg.msg_flags & MSG_TRUNC) {
246 fprintf(stderr, "Message truncated\n");
250 fprintf(stderr, "!!!Remnant of size %d\n", status);
256 int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
257 unsigned groups, struct nlmsghdr *answer,
264 struct sockaddr_nl nladdr;
266 .iov_base = (void*) n,
267 .iov_len = n->nlmsg_len
269 struct msghdr msg = {
271 .msg_namelen = sizeof(nladdr),
277 memset(&nladdr, 0, sizeof(nladdr));
278 nladdr.nl_family = AF_NETLINK;
279 nladdr.nl_pid = peer;
280 nladdr.nl_groups = groups;
282 n->nlmsg_seq = seq = ++rtnl->seq;
285 n->nlmsg_flags |= NLM_F_ACK;
287 status = sendmsg(rtnl->fd, &msg, 0);
290 perror("Cannot talk to rtnetlink");
294 memset(buf,0,sizeof(buf));
299 iov.iov_len = sizeof(buf);
300 status = recvmsg(rtnl->fd, &msg, 0);
303 if (errno == EINTR || errno == EAGAIN)
305 fprintf(stderr, "netlink receive error %s (%d)\n",
306 strerror(errno), errno);
310 fprintf(stderr, "EOF on netlink\n");
313 if (msg.msg_namelen != sizeof(nladdr)) {
314 fprintf(stderr, "sender address length == %d\n", msg.msg_namelen);
317 for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
319 int len = h->nlmsg_len;
320 int l = len - sizeof(*h);
322 if (l<0 || len>status) {
323 if (msg.msg_flags & MSG_TRUNC) {
324 fprintf(stderr, "Truncated message\n");
327 fprintf(stderr, "!!!malformed message: len=%d\n", len);
331 if (nladdr.nl_pid != peer ||
332 h->nlmsg_pid != rtnl->local.nl_pid ||
333 h->nlmsg_seq != seq) {
335 err = junk(&nladdr, h, jarg);
339 /* Don't forget to skip that message. */
340 status -= NLMSG_ALIGN(len);
341 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
345 if (h->nlmsg_type == NLMSG_ERROR) {
346 struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
347 if (l < sizeof(struct nlmsgerr)) {
348 fprintf(stderr, "ERROR truncated\n");
353 memcpy(answer, h, h->nlmsg_len);
356 perror("RTNETLINK answers");
361 memcpy(answer, h, h->nlmsg_len);
365 fprintf(stderr, "Unexpected reply!!!\n");
367 status -= NLMSG_ALIGN(len);
368 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
370 if (msg.msg_flags & MSG_TRUNC) {
371 fprintf(stderr, "Message truncated\n");
375 fprintf(stderr, "!!!Remnant of size %d\n", status);
381 int rtnl_listen(struct rtnl_handle *rtnl,
382 rtnl_filter_t handler,
387 struct sockaddr_nl nladdr;
389 struct msghdr msg = {
391 .msg_namelen = sizeof(nladdr),
397 memset(&nladdr, 0, sizeof(nladdr));
398 nladdr.nl_family = AF_NETLINK;
400 nladdr.nl_groups = 0;
404 iov.iov_len = sizeof(buf);
405 status = recvmsg(rtnl->fd, &msg, 0);
408 if (errno == EINTR || errno == EAGAIN)
410 fprintf(stderr, "netlink receive error %s (%d)\n",
411 strerror(errno), errno);
415 fprintf(stderr, "EOF on netlink\n");
418 if (msg.msg_namelen != sizeof(nladdr)) {
419 fprintf(stderr, "Sender address length == %d\n", msg.msg_namelen);
422 for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
424 int len = h->nlmsg_len;
425 int l = len - sizeof(*h);
427 if (l<0 || len>status) {
428 if (msg.msg_flags & MSG_TRUNC) {
429 fprintf(stderr, "Truncated message\n");
432 fprintf(stderr, "!!!malformed message: len=%d\n", len);
436 err = handler(&nladdr, h, jarg);
440 status -= NLMSG_ALIGN(len);
441 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
443 if (msg.msg_flags & MSG_TRUNC) {
444 fprintf(stderr, "Message truncated\n");
448 fprintf(stderr, "!!!Remnant of size %d\n", status);
454 int rtnl_from_file(FILE *rtnl, rtnl_filter_t handler,
458 struct sockaddr_nl nladdr;
460 struct nlmsghdr *h = (void*)buf;
462 memset(&nladdr, 0, sizeof(nladdr));
463 nladdr.nl_family = AF_NETLINK;
465 nladdr.nl_groups = 0;
471 status = fread(&buf, 1, sizeof(*h), rtnl);
476 perror("rtnl_from_file: fread");
484 l = len - sizeof(*h);
486 if (l<0 || len>sizeof(buf)) {
487 fprintf(stderr, "!!!malformed message: len=%d @%lu\n",
492 status = fread(NLMSG_DATA(h), 1, NLMSG_ALIGN(l), rtnl);
495 perror("rtnl_from_file: fread");
499 fprintf(stderr, "rtnl-from_file: truncated message\n");
503 err = handler(&nladdr, h, jarg);
509 int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
511 int len = RTA_LENGTH(4);
513 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen) {
514 fprintf(stderr,"addattr32: Error! max allowed bound %d exceeded\n",maxlen);
518 rta->rta_type = type;
520 memcpy(RTA_DATA(rta), &data, 4);
521 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
525 int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data,
528 int len = RTA_LENGTH(alen);
531 if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) {
532 fprintf(stderr, "addattr_l ERROR: message exceeded bound of %d\n",maxlen);
536 rta->rta_type = type;
538 memcpy(RTA_DATA(rta), data, alen);
539 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
543 int addraw_l(struct nlmsghdr *n, int maxlen, const void *data, int len)
545 if (NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len) > maxlen) {
546 fprintf(stderr, "addraw_l ERROR: message exceeded bound of %d\n",maxlen);
550 memcpy(NLMSG_TAIL(n), data, len);
551 memset((void *) NLMSG_TAIL(n) + len, 0, NLMSG_ALIGN(len) - len);
552 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len);
556 struct rtattr *addattr_nest(struct nlmsghdr *n, int maxlen, int type)
558 struct rtattr *nest = NLMSG_TAIL(n);
560 addattr_l(n, maxlen, type, NULL, 0);
564 int addattr_nest_end(struct nlmsghdr *n, struct rtattr *nest)
566 nest->rta_len = (void *)NLMSG_TAIL(n) - (void *)nest;
570 struct rtattr *addattr_nest_compat(struct nlmsghdr *n, int maxlen, int type,
571 const void *data, int len)
573 struct rtattr *start = NLMSG_TAIL(n);
575 addattr_l(n, maxlen, type, data, len);
576 addattr_nest(n, maxlen, type);
580 int addattr_nest_compat_end(struct nlmsghdr *n, struct rtattr *start)
582 struct rtattr *nest = (void *)start + NLMSG_ALIGN(start->rta_len);
584 start->rta_len = (void *)NLMSG_TAIL(n) - (void *)start;
585 addattr_nest_end(n, nest);
589 int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data)
591 int len = RTA_LENGTH(4);
592 struct rtattr *subrta;
594 if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
595 fprintf(stderr,"rta_addattr32: Error! max allowed bound %d exceeded\n",maxlen);
598 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
599 subrta->rta_type = type;
600 subrta->rta_len = len;
601 memcpy(RTA_DATA(subrta), &data, 4);
602 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
606 int rta_addattr_l(struct rtattr *rta, int maxlen, int type,
607 const void *data, int alen)
609 struct rtattr *subrta;
610 int len = RTA_LENGTH(alen);
612 if (RTA_ALIGN(rta->rta_len) + RTA_ALIGN(len) > maxlen) {
613 fprintf(stderr,"rta_addattr_l: Error! max allowed bound %d exceeded\n",maxlen);
616 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
617 subrta->rta_type = type;
618 subrta->rta_len = len;
619 memcpy(RTA_DATA(subrta), data, alen);
620 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + RTA_ALIGN(len);
624 int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
626 memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
627 while (RTA_OK(rta, len)) {
628 if (rta->rta_type <= max)
629 tb[rta->rta_type] = rta;
630 rta = RTA_NEXT(rta,len);
633 fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len);
637 int parse_rtattr_byindex(struct rtattr *tb[], int max, struct rtattr *rta, int len)
641 memset(tb, 0, sizeof(struct rtattr *) * max);
642 while (RTA_OK(rta, len)) {
643 if (rta->rta_type <= max && i < max)
645 rta = RTA_NEXT(rta,len);
648 fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len);
652 int __parse_rtattr_nested_compat(struct rtattr *tb[], int max, struct rtattr *rta,
655 if (RTA_PAYLOAD(rta) < len)
657 if (RTA_PAYLOAD(rta) >= RTA_ALIGN(len) + sizeof(struct rtattr)) {
658 rta = RTA_DATA(rta) + RTA_ALIGN(len);
659 return parse_rtattr_nested(tb, max, rta);
661 memset(tb, 0, sizeof(struct rtattr *) * (max + 1));