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>
13 #include <sys/socket.h>
23 #include "libnetlink.h"
26 void rtnl_close(struct rtnl_handle *rth)
31 int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions)
35 memset(rth, 0, sizeof(rth));
37 rth->fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
39 bb_perror_msg("Cannot open netlink socket");
43 memset(&rth->local, 0, sizeof(rth->local));
44 rth->local.nl_family = AF_NETLINK;
45 rth->local.nl_groups = subscriptions;
47 if (bind(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local)) < 0) {
48 bb_perror_msg("Cannot bind netlink socket");
51 addr_len = sizeof(rth->local);
52 if (getsockname(rth->fd, (struct sockaddr*)&rth->local, &addr_len) < 0) {
53 bb_perror_msg("Cannot getsockname");
56 if (addr_len != sizeof(rth->local)) {
57 bb_error_msg("Wrong address length %d", addr_len);
60 if (rth->local.nl_family != AF_NETLINK) {
61 bb_error_msg("Wrong address family %d", rth->local.nl_family);
64 rth->seq = time(NULL);
68 int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type)
74 struct sockaddr_nl nladdr;
76 memset(&nladdr, 0, sizeof(nladdr));
77 nladdr.nl_family = AF_NETLINK;
79 req.nlh.nlmsg_len = sizeof(req);
80 req.nlh.nlmsg_type = type;
81 req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
82 req.nlh.nlmsg_pid = 0;
83 req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
84 req.g.rtgen_family = family;
86 return sendto(rth->fd, (void*)&req, sizeof(req), 0, (struct sockaddr*)&nladdr, sizeof(nladdr));
89 int rtnl_send(struct rtnl_handle *rth, char *buf, int len)
91 struct sockaddr_nl nladdr;
93 memset(&nladdr, 0, sizeof(nladdr));
94 nladdr.nl_family = AF_NETLINK;
96 return sendto(rth->fd, buf, len, 0, (struct sockaddr*)&nladdr, sizeof(nladdr));
99 int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
102 struct sockaddr_nl nladdr;
103 struct iovec iov[2] = { { &nlh, sizeof(nlh) }, { req, len } };
104 struct msghdr msg = {
105 (void*)&nladdr, sizeof(nladdr),
111 memset(&nladdr, 0, sizeof(nladdr));
112 nladdr.nl_family = AF_NETLINK;
114 nlh.nlmsg_len = NLMSG_LENGTH(len);
115 nlh.nlmsg_type = type;
116 nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
118 nlh.nlmsg_seq = rth->dump = ++rth->seq;
120 return sendmsg(rth->fd, &msg, 0);
123 int rtnl_dump_filter(struct rtnl_handle *rth,
124 int (*filter)(struct sockaddr_nl *, struct nlmsghdr *n, void *),
126 int (*junk)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
130 struct sockaddr_nl nladdr;
131 struct iovec iov = { buf, sizeof(buf) };
137 struct msghdr msg = {
138 (void*)&nladdr, sizeof(nladdr),
144 status = recvmsg(rth->fd, &msg, 0);
149 bb_perror_msg("OVERRUN");
153 bb_error_msg("EOF on netlink");
156 if (msg.msg_namelen != sizeof(nladdr)) {
157 bb_error_msg_and_die("sender address length == %d", msg.msg_namelen);
160 h = (struct nlmsghdr*)buf;
161 while (NLMSG_OK(h, status)) {
164 if (nladdr.nl_pid != 0 ||
165 h->nlmsg_pid != rth->local.nl_pid ||
166 h->nlmsg_seq != rth->dump) {
168 err = junk(&nladdr, h, arg2);
176 if (h->nlmsg_type == NLMSG_DONE) {
179 if (h->nlmsg_type == NLMSG_ERROR) {
180 struct nlmsgerr *l_err = (struct nlmsgerr*)NLMSG_DATA(h);
181 if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
182 bb_error_msg("ERROR truncated");
184 errno = -l_err->error;
185 bb_perror_msg("RTNETLINK answers");
189 err = filter(&nladdr, h, arg1);
195 h = NLMSG_NEXT(h, status);
197 if (msg.msg_flags & MSG_TRUNC) {
198 bb_error_msg("Message truncated");
202 bb_error_msg_and_die("!!!Remnant of size %d", 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;
231 if (answer == NULL) {
232 n->nlmsg_flags |= NLM_F_ACK;
234 status = sendmsg(rtnl->fd, &msg, 0);
237 bb_perror_msg("Cannot talk to rtnetlink");
244 iov.iov_len = sizeof(buf);
245 status = recvmsg(rtnl->fd, &msg, 0);
248 if (errno == EINTR) {
251 bb_perror_msg("OVERRUN");
255 bb_error_msg("EOF on netlink");
258 if (msg.msg_namelen != sizeof(nladdr)) {
259 bb_error_msg_and_die("sender address length == %d", 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 bb_error_msg("Truncated message");
271 bb_error_msg_and_die("!!!malformed message: len=%d", len);
274 if (nladdr.nl_pid != peer ||
275 h->nlmsg_pid != rtnl->local.nl_pid ||
276 h->nlmsg_seq != seq) {
278 l_err = junk(&nladdr, h, jarg);
286 if (h->nlmsg_type == NLMSG_ERROR) {
287 struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
288 if (l < sizeof(struct nlmsgerr)) {
289 bb_error_msg("ERROR truncated");
294 memcpy(answer, h, h->nlmsg_len);
298 bb_perror_msg("RTNETLINK answers");
303 memcpy(answer, h, h->nlmsg_len);
307 bb_error_msg("Unexpected reply!!!");
309 status -= NLMSG_ALIGN(len);
310 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
312 if (msg.msg_flags & MSG_TRUNC) {
313 bb_error_msg("Message truncated");
317 bb_error_msg_and_die("!!!Remnant of size %d", status);
322 int rtnl_listen(struct rtnl_handle *rtnl,
323 int (*handler)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
328 struct sockaddr_nl nladdr;
331 struct msghdr msg = {
332 (void*)&nladdr, sizeof(nladdr),
338 memset(&nladdr, 0, sizeof(nladdr));
339 nladdr.nl_family = AF_NETLINK;
341 nladdr.nl_groups = 0;
347 iov.iov_len = sizeof(buf);
348 status = recvmsg(rtnl->fd, &msg, 0);
353 bb_perror_msg("OVERRUN");
357 bb_error_msg("EOF on netlink");
360 if (msg.msg_namelen != sizeof(nladdr)) {
361 bb_error_msg_and_die("Sender address length == %d", 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 bb_error_msg("Truncated message");
373 bb_error_msg_and_die("!!!malformed message: len=%d", len);
376 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 bb_error_msg("Message truncated");
389 bb_error_msg_and_die("!!!Remnant of size %d", status);
394 int rtnl_from_file(FILE *rtnl,
395 int (*handler)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
399 struct sockaddr_nl nladdr;
401 struct nlmsghdr *h = (void*)buf;
403 memset(&nladdr, 0, sizeof(nladdr));
404 nladdr.nl_family = AF_NETLINK;
406 nladdr.nl_groups = 0;
412 status = fread(&buf, 1, sizeof(*h), rtnl);
417 bb_perror_msg("rtnl_from_file: fread");
425 l = len - sizeof(*h);
427 if (l<0 || len>sizeof(buf)) {
428 bb_error_msg("!!!malformed message: len=%d @%lu",
433 status = fread(NLMSG_DATA(h), 1, NLMSG_ALIGN(l), rtnl);
436 bb_perror_msg("rtnl_from_file: fread");
440 bb_error_msg("rtnl-from_file: truncated message");
444 err = handler(&nladdr, h, jarg);
450 int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
452 int len = RTA_LENGTH(4);
454 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen)
456 rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len));
457 rta->rta_type = type;
459 memcpy(RTA_DATA(rta), &data, 4);
460 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
464 int addattr_l(struct nlmsghdr *n, int maxlen, int type, void *data, int alen)
466 int len = RTA_LENGTH(alen);
469 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen)
471 rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len));
472 rta->rta_type = type;
474 memcpy(RTA_DATA(rta), data, alen);
475 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
479 int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data)
481 int len = RTA_LENGTH(4);
482 struct rtattr *subrta;
484 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) {
503 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
504 subrta->rta_type = type;
505 subrta->rta_len = len;
506 memcpy(RTA_DATA(subrta), data, alen);
507 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
512 int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
514 while (RTA_OK(rta, len)) {
515 if (rta->rta_type <= max) {
516 tb[rta->rta_type] = rta;
518 rta = RTA_NEXT(rta,len);
521 bb_error_msg("!!!Deficit %d, rta_len=%d", len, rta->rta_len);