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)
97 struct sockaddr_nl nladdr;
99 memset(&nladdr, 0, sizeof(nladdr));
100 nladdr.nl_family = AF_NETLINK;
102 memset(&req, 0, sizeof(req));
103 req.nlh.nlmsg_len = sizeof(req);
104 req.nlh.nlmsg_type = type;
105 req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
106 req.nlh.nlmsg_pid = 0;
107 req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
108 req.g.rtgen_family = family;
110 return sendto(rth->fd, (void*)&req, sizeof(req), 0,
111 (struct sockaddr*)&nladdr, sizeof(nladdr));
114 int rtnl_send(struct rtnl_handle *rth, const char *buf, int len)
116 struct sockaddr_nl nladdr;
118 memset(&nladdr, 0, sizeof(nladdr));
119 nladdr.nl_family = AF_NETLINK;
121 return sendto(rth->fd, buf, len, 0, (struct sockaddr*)&nladdr, sizeof(nladdr));
124 int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
127 struct sockaddr_nl nladdr;
128 struct iovec iov[2] = {
129 { .iov_base = &nlh, .iov_len = sizeof(nlh) },
130 { .iov_base = req, .iov_len = len }
132 struct msghdr msg = {
134 .msg_namelen = sizeof(nladdr),
139 memset(&nladdr, 0, sizeof(nladdr));
140 nladdr.nl_family = AF_NETLINK;
142 nlh.nlmsg_len = NLMSG_LENGTH(len);
143 nlh.nlmsg_type = type;
144 nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
146 nlh.nlmsg_seq = rth->dump = ++rth->seq;
148 return sendmsg(rth->fd, &msg, 0);
151 int rtnl_dump_filter(struct rtnl_handle *rth,
152 rtnl_filter_t filter,
157 struct sockaddr_nl nladdr;
159 struct msghdr msg = {
161 .msg_namelen = sizeof(nladdr),
172 iov.iov_len = sizeof(buf);
173 status = recvmsg(rth->fd, &msg, 0);
183 fprintf(stderr, "EOF on netlink\n");
187 h = (struct nlmsghdr*)buf;
188 while (NLMSG_OK(h, status)) {
191 if (nladdr.nl_pid != 0 ||
192 h->nlmsg_pid != rth->local.nl_pid ||
193 h->nlmsg_seq != rth->dump) {
195 err = junk(&nladdr, h, arg2);
202 if (h->nlmsg_type == NLMSG_DONE)
204 if (h->nlmsg_type == NLMSG_ERROR) {
205 struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
206 if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
207 fprintf(stderr, "ERROR truncated\n");
210 perror("RTNETLINK answers");
214 err = filter(&nladdr, h, arg1);
219 h = NLMSG_NEXT(h, status);
221 if (msg.msg_flags & MSG_TRUNC) {
222 fprintf(stderr, "Message truncated\n");
226 fprintf(stderr, "!!!Remnant of size %d\n", status);
232 int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
233 unsigned groups, struct nlmsghdr *answer,
240 struct sockaddr_nl nladdr;
242 .iov_base = (void*) n,
243 .iov_len = n->nlmsg_len
245 struct msghdr msg = {
247 .msg_namelen = sizeof(nladdr),
253 memset(&nladdr, 0, sizeof(nladdr));
254 nladdr.nl_family = AF_NETLINK;
255 nladdr.nl_pid = peer;
256 nladdr.nl_groups = groups;
258 n->nlmsg_seq = seq = ++rtnl->seq;
261 n->nlmsg_flags |= NLM_F_ACK;
263 status = sendmsg(rtnl->fd, &msg, 0);
266 perror("Cannot talk to rtnetlink");
270 memset(buf,0,sizeof(buf));
275 iov.iov_len = sizeof(buf);
276 status = recvmsg(rtnl->fd, &msg, 0);
285 fprintf(stderr, "EOF on netlink\n");
288 if (msg.msg_namelen != sizeof(nladdr)) {
289 fprintf(stderr, "sender address length == %d\n", msg.msg_namelen);
292 for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
294 int len = h->nlmsg_len;
295 int l = len - sizeof(*h);
297 if (l<0 || len>status) {
298 if (msg.msg_flags & MSG_TRUNC) {
299 fprintf(stderr, "Truncated message\n");
302 fprintf(stderr, "!!!malformed message: len=%d\n", len);
306 if (nladdr.nl_pid != peer ||
307 h->nlmsg_pid != rtnl->local.nl_pid ||
308 h->nlmsg_seq != seq) {
310 err = junk(&nladdr, h, jarg);
314 /* Don't forget to skip that message. */
315 status -= NLMSG_ALIGN(len);
316 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
320 if (h->nlmsg_type == NLMSG_ERROR) {
321 struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
322 if (l < sizeof(struct nlmsgerr)) {
323 fprintf(stderr, "ERROR truncated\n");
328 memcpy(answer, h, h->nlmsg_len);
331 perror("RTNETLINK answers");
336 memcpy(answer, h, h->nlmsg_len);
340 fprintf(stderr, "Unexpected reply!!!\n");
342 status -= NLMSG_ALIGN(len);
343 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
345 if (msg.msg_flags & MSG_TRUNC) {
346 fprintf(stderr, "Message truncated\n");
350 fprintf(stderr, "!!!Remnant of size %d\n", status);
356 int rtnl_listen(struct rtnl_handle *rtnl,
357 rtnl_filter_t handler,
362 struct sockaddr_nl nladdr;
364 struct msghdr msg = {
366 .msg_namelen = sizeof(nladdr),
372 memset(&nladdr, 0, sizeof(nladdr));
373 nladdr.nl_family = AF_NETLINK;
375 nladdr.nl_groups = 0;
379 iov.iov_len = sizeof(buf);
380 status = recvmsg(rtnl->fd, &msg, 0);
389 fprintf(stderr, "EOF on netlink\n");
392 if (msg.msg_namelen != sizeof(nladdr)) {
393 fprintf(stderr, "Sender address length == %d\n", msg.msg_namelen);
396 for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
398 int len = h->nlmsg_len;
399 int l = len - sizeof(*h);
401 if (l<0 || len>status) {
402 if (msg.msg_flags & MSG_TRUNC) {
403 fprintf(stderr, "Truncated message\n");
406 fprintf(stderr, "!!!malformed message: len=%d\n", len);
410 err = handler(&nladdr, h, jarg);
414 status -= NLMSG_ALIGN(len);
415 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
417 if (msg.msg_flags & MSG_TRUNC) {
418 fprintf(stderr, "Message truncated\n");
422 fprintf(stderr, "!!!Remnant of size %d\n", status);
428 int rtnl_from_file(FILE *rtnl, rtnl_filter_t handler,
432 struct sockaddr_nl nladdr;
434 struct nlmsghdr *h = (void*)buf;
436 memset(&nladdr, 0, sizeof(nladdr));
437 nladdr.nl_family = AF_NETLINK;
439 nladdr.nl_groups = 0;
445 status = fread(&buf, 1, sizeof(*h), rtnl);
450 perror("rtnl_from_file: fread");
458 l = len - sizeof(*h);
460 if (l<0 || len>sizeof(buf)) {
461 fprintf(stderr, "!!!malformed message: len=%d @%lu\n",
466 status = fread(NLMSG_DATA(h), 1, NLMSG_ALIGN(l), rtnl);
469 perror("rtnl_from_file: fread");
473 fprintf(stderr, "rtnl-from_file: truncated message\n");
477 err = handler(&nladdr, h, jarg);
483 int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
485 int len = RTA_LENGTH(4);
487 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen) {
488 fprintf(stderr,"addattr32: Error! max allowed bound %d exceeded\n",maxlen);
492 rta->rta_type = type;
494 memcpy(RTA_DATA(rta), &data, 4);
495 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
499 int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data,
502 int len = RTA_LENGTH(alen);
505 if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) {
506 fprintf(stderr, "addattr_l ERROR: message exceeded bound of %d\n",maxlen);
510 rta->rta_type = type;
512 memcpy(RTA_DATA(rta), data, alen);
513 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
517 int addraw_l(struct nlmsghdr *n, int maxlen, const void *data, int len)
519 if (NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len) > maxlen) {
520 fprintf(stderr, "addraw_l ERROR: message exceeded bound of %d\n",maxlen);
524 memcpy(NLMSG_TAIL(n), data, len);
525 memset((void *) NLMSG_TAIL(n) + len, 0, NLMSG_ALIGN(len) - len);
526 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len);
530 struct rtattr *addattr_nest(struct nlmsghdr *n, int maxlen, int type)
532 struct rtattr *nest = NLMSG_TAIL(n);
534 addattr_l(n, maxlen, type, NULL, 0);
538 int addattr_nest_end(struct nlmsghdr *n, struct rtattr *nest)
540 nest->rta_len = (void *)NLMSG_TAIL(n) - (void *)nest;
544 struct rtattr *addattr_nest_compat(struct nlmsghdr *n, int maxlen, int type,
545 const void *data, int len)
547 struct rtattr *start = NLMSG_TAIL(n);
549 addattr_l(n, maxlen, type, data, len);
550 addattr_nest(n, maxlen, type);
554 int addattr_nest_compat_end(struct nlmsghdr *n, struct rtattr *start)
556 struct rtattr *nest = (void *)start + NLMSG_ALIGN(start->rta_len);
558 start->rta_len = (void *)NLMSG_TAIL(n) - (void *)start;
559 addattr_nest_end(n, nest);
563 int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data)
565 int len = RTA_LENGTH(4);
566 struct rtattr *subrta;
568 if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
569 fprintf(stderr,"rta_addattr32: Error! max allowed bound %d exceeded\n",maxlen);
572 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
573 subrta->rta_type = type;
574 subrta->rta_len = len;
575 memcpy(RTA_DATA(subrta), &data, 4);
576 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
580 int rta_addattr_l(struct rtattr *rta, int maxlen, int type,
581 const void *data, int alen)
583 struct rtattr *subrta;
584 int len = RTA_LENGTH(alen);
586 if (RTA_ALIGN(rta->rta_len) + RTA_ALIGN(len) > maxlen) {
587 fprintf(stderr,"rta_addattr_l: Error! max allowed bound %d exceeded\n",maxlen);
590 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
591 subrta->rta_type = type;
592 subrta->rta_len = len;
593 memcpy(RTA_DATA(subrta), data, alen);
594 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + RTA_ALIGN(len);
598 int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
600 memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
601 while (RTA_OK(rta, len)) {
602 if (rta->rta_type <= max)
603 tb[rta->rta_type] = rta;
604 rta = RTA_NEXT(rta,len);
607 fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len);
611 int parse_rtattr_byindex(struct rtattr *tb[], int max, struct rtattr *rta, int len)
615 memset(tb, 0, sizeof(struct rtattr *) * max);
616 while (RTA_OK(rta, len)) {
617 if (rta->rta_type <= max && i < max)
619 rta = RTA_NEXT(rta,len);
622 fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len);
626 int __parse_rtattr_nested_compat(struct rtattr *tb[], int max, struct rtattr *rta,
629 if (RTA_PAYLOAD(rta) < len)
631 if (RTA_PAYLOAD(rta) >= RTA_ALIGN(len) + sizeof(struct rtattr)) {
632 rta = RTA_DATA(rta) + RTA_ALIGN(len);
633 return parse_rtattr_nested(tb, max, rta);
635 memset(tb, 0, sizeof(struct rtattr *) * max);