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)
33 int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions)
37 memset(rth, 0, sizeof(rth));
39 rth->fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
41 perror("Cannot open netlink socket");
45 memset(&rth->local, 0, sizeof(rth->local));
46 rth->local.nl_family = AF_NETLINK;
47 rth->local.nl_groups = subscriptions;
49 if (bind(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local)) < 0) {
50 perror("Cannot bind netlink socket");
53 addr_len = sizeof(rth->local);
54 if (getsockname(rth->fd, (struct sockaddr*)&rth->local, &addr_len) < 0) {
55 perror("Cannot getsockname");
58 if (addr_len != sizeof(rth->local)) {
59 fprintf(stderr, "Wrong address length %d\n", addr_len);
62 if (rth->local.nl_family != AF_NETLINK) {
63 fprintf(stderr, "Wrong address family %d\n", rth->local.nl_family);
66 rth->seq = time(NULL);
70 int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type)
76 struct sockaddr_nl nladdr;
78 memset(&nladdr, 0, sizeof(nladdr));
79 nladdr.nl_family = AF_NETLINK;
81 req.nlh.nlmsg_len = sizeof(req);
82 req.nlh.nlmsg_type = type;
83 req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
84 req.nlh.nlmsg_pid = 0;
85 req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
86 req.g.rtgen_family = family;
88 return sendto(rth->fd, (void*)&req, sizeof(req), 0, (struct sockaddr*)&nladdr, sizeof(nladdr));
91 int rtnl_send(struct rtnl_handle *rth, char *buf, int len)
93 struct sockaddr_nl nladdr;
95 memset(&nladdr, 0, sizeof(nladdr));
96 nladdr.nl_family = AF_NETLINK;
98 return sendto(rth->fd, buf, len, 0, (struct sockaddr*)&nladdr, sizeof(nladdr));
101 int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
104 struct sockaddr_nl nladdr;
105 struct iovec iov[2] = { { &nlh, sizeof(nlh) }, { req, len } };
106 struct msghdr msg = {
107 (void*)&nladdr, sizeof(nladdr),
113 memset(&nladdr, 0, sizeof(nladdr));
114 nladdr.nl_family = AF_NETLINK;
116 nlh.nlmsg_len = NLMSG_LENGTH(len);
117 nlh.nlmsg_type = type;
118 nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
120 nlh.nlmsg_seq = rth->dump = ++rth->seq;
122 return sendmsg(rth->fd, &msg, 0);
125 int rtnl_dump_filter(struct rtnl_handle *rth,
126 int (*filter)(struct sockaddr_nl *, struct nlmsghdr *n, void *),
128 int (*junk)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
132 struct sockaddr_nl nladdr;
133 struct iovec iov = { buf, sizeof(buf) };
139 struct msghdr msg = {
140 (void*)&nladdr, sizeof(nladdr),
146 status = recvmsg(rth->fd, &msg, 0);
155 fprintf(stderr, "EOF on netlink\n");
158 if (msg.msg_namelen != sizeof(nladdr)) {
159 fprintf(stderr, "sender address length == %d\n", msg.msg_namelen);
163 h = (struct nlmsghdr*)buf;
164 while (NLMSG_OK(h, status)) {
167 if (h->nlmsg_pid != rth->local.nl_pid ||
168 h->nlmsg_seq != rth->dump) {
170 err = junk(&nladdr, h, arg2);
177 if (h->nlmsg_type == NLMSG_DONE)
179 if (h->nlmsg_type == NLMSG_ERROR) {
180 struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
181 if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
182 fprintf(stderr, "ERROR truncated\n");
185 perror("RTNETLINK answers");
189 err = filter(&nladdr, h, arg1);
194 h = NLMSG_NEXT(h, status);
196 if (msg.msg_flags & MSG_TRUNC) {
197 fprintf(stderr, "Message truncated\n");
201 fprintf(stderr, "!!!Remnant of size %d\n", status);
207 int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
208 unsigned groups, struct nlmsghdr *answer,
209 int (*junk)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
215 struct sockaddr_nl nladdr;
216 struct iovec iov = { (void*)n, n->nlmsg_len };
218 struct msghdr msg = {
219 (void*)&nladdr, sizeof(nladdr),
225 memset(&nladdr, 0, sizeof(nladdr));
226 nladdr.nl_family = AF_NETLINK;
227 nladdr.nl_pid = peer;
228 nladdr.nl_groups = groups;
230 n->nlmsg_seq = seq = ++rtnl->seq;
232 n->nlmsg_flags |= NLM_F_ACK;
234 status = sendmsg(rtnl->fd, &msg, 0);
237 perror("Cannot talk to rtnetlink");
244 iov.iov_len = sizeof(buf);
245 status = recvmsg(rtnl->fd, &msg, 0);
254 fprintf(stderr, "EOF on netlink\n");
257 if (msg.msg_namelen != sizeof(nladdr)) {
258 fprintf(stderr, "sender address length == %d\n", msg.msg_namelen);
261 for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
263 int len = h->nlmsg_len;
264 int l = len - sizeof(*h);
266 if (l<0 || len>status) {
267 if (msg.msg_flags & MSG_TRUNC) {
268 fprintf(stderr, "Truncated message\n");
271 fprintf(stderr, "!!!malformed message: len=%d\n", len);
275 if (h->nlmsg_pid != rtnl->local.nl_pid ||
276 h->nlmsg_seq != seq) {
278 err = junk(&nladdr, h, jarg);
285 if (h->nlmsg_type == NLMSG_ERROR) {
286 struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
287 if (l < sizeof(struct nlmsgerr)) {
288 fprintf(stderr, "ERROR truncated\n");
293 memcpy(answer, h, h->nlmsg_len);
296 perror("RTNETLINK answers");
301 memcpy(answer, h, h->nlmsg_len);
305 fprintf(stderr, "Unexpected reply!!!\n");
307 status -= NLMSG_ALIGN(len);
308 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
310 if (msg.msg_flags & MSG_TRUNC) {
311 fprintf(stderr, "Message truncated\n");
315 fprintf(stderr, "!!!Remnant of size %d\n", status);
321 int rtnl_listen(struct rtnl_handle *rtnl,
322 int (*handler)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
327 struct sockaddr_nl nladdr;
330 struct msghdr msg = {
331 (void*)&nladdr, sizeof(nladdr),
337 memset(&nladdr, 0, sizeof(nladdr));
338 nladdr.nl_family = AF_NETLINK;
340 nladdr.nl_groups = 0;
346 iov.iov_len = sizeof(buf);
347 status = recvmsg(rtnl->fd, &msg, 0);
356 fprintf(stderr, "EOF on netlink\n");
359 if (msg.msg_namelen != sizeof(nladdr)) {
360 fprintf(stderr, "Sender address length == %d\n", msg.msg_namelen);
363 for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
365 int len = h->nlmsg_len;
366 int l = len - sizeof(*h);
368 if (l<0 || len>status) {
369 if (msg.msg_flags & MSG_TRUNC) {
370 fprintf(stderr, "Truncated message\n");
373 fprintf(stderr, "!!!malformed message: len=%d\n", len);
377 err = handler(&nladdr, h, jarg);
381 status -= NLMSG_ALIGN(len);
382 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
384 if (msg.msg_flags & MSG_TRUNC) {
385 fprintf(stderr, "Message truncated\n");
389 fprintf(stderr, "!!!Remnant of size %d\n", status);
395 int rtnl_from_file(FILE *rtnl,
396 int (*handler)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
400 struct sockaddr_nl nladdr;
402 struct nlmsghdr *h = (void*)buf;
404 memset(&nladdr, 0, sizeof(nladdr));
405 nladdr.nl_family = AF_NETLINK;
407 nladdr.nl_groups = 0;
413 status = fread(&buf, 1, sizeof(*h), rtnl);
418 perror("rtnl_from_file: fread");
426 l = len - sizeof(*h);
428 if (l<0 || len>sizeof(buf)) {
429 fprintf(stderr, "!!!malformed message: len=%d @%lu\n",
434 status = fread(NLMSG_DATA(h), 1, NLMSG_ALIGN(l), rtnl);
437 perror("rtnl_from_file: fread");
441 fprintf(stderr, "rtnl-from_file: truncated message\n");
445 err = handler(&nladdr, h, jarg);
451 int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
453 int len = RTA_LENGTH(4);
455 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen)
457 rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len));
458 rta->rta_type = type;
460 memcpy(RTA_DATA(rta), &data, 4);
461 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
465 int addattr_l(struct nlmsghdr *n, int maxlen, int type, void *data, int alen)
467 int len = RTA_LENGTH(alen);
470 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen)
472 rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len));
473 rta->rta_type = type;
475 memcpy(RTA_DATA(rta), data, alen);
476 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
480 int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data)
482 int len = RTA_LENGTH(4);
483 struct rtattr *subrta;
485 if (RTA_ALIGN(rta->rta_len) + len > maxlen)
487 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
488 subrta->rta_type = type;
489 subrta->rta_len = len;
490 memcpy(RTA_DATA(subrta), &data, 4);
491 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
495 int rta_addattr_l(struct rtattr *rta, int maxlen, int type, void *data, int alen)
497 struct rtattr *subrta;
498 int len = RTA_LENGTH(alen);
500 if (RTA_ALIGN(rta->rta_len) + len > maxlen)
502 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
503 subrta->rta_type = type;
504 subrta->rta_len = len;
505 memcpy(RTA_DATA(subrta), data, alen);
506 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
511 int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
513 while (RTA_OK(rta, len)) {
514 if (rta->rta_type <= max)
515 tb[rta->rta_type] = rta;
516 rta = RTA_NEXT(rta,len);
519 fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len);