1 /* vi: set sw=4 ts=4: */
3 * libnetlink.c RTnetlink service routines.
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version
8 * 2 of the License, or (at your option) any later version.
10 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
15 #include <sys/socket.h>
24 #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 addattr32(struct nlmsghdr *n, int maxlen, int type, uint32_t data)
324 int len = RTA_LENGTH(4);
326 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen)
328 rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len));
329 rta->rta_type = type;
331 memcpy(RTA_DATA(rta), &data, 4);
332 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
336 int addattr_l(struct nlmsghdr *n, int maxlen, int type, void *data, int alen)
338 int len = RTA_LENGTH(alen);
341 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen)
343 rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len));
344 rta->rta_type = type;
346 memcpy(RTA_DATA(rta), data, alen);
347 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
351 int rta_addattr32(struct rtattr *rta, int maxlen, int type, uint32_t data)
353 int len = RTA_LENGTH(4);
354 struct rtattr *subrta;
356 if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
359 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
360 subrta->rta_type = type;
361 subrta->rta_len = len;
362 memcpy(RTA_DATA(subrta), &data, 4);
363 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
367 int rta_addattr_l(struct rtattr *rta, int maxlen, int type, void *data, int alen)
369 struct rtattr *subrta;
370 int len = RTA_LENGTH(alen);
372 if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
375 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
376 subrta->rta_type = type;
377 subrta->rta_len = len;
378 memcpy(RTA_DATA(subrta), data, alen);
379 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
384 int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
386 while (RTA_OK(rta, len)) {
387 if (rta->rta_type <= max) {
388 tb[rta->rta_type] = rta;
390 rta = RTA_NEXT(rta,len);
393 bb_error_msg("deficit %d, rta_len=%d!", len, rta->rta_len);