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>
14 #include <sys/socket.h>
18 #include "libnetlink.h"
20 void rtnl_close(struct rtnl_handle *rth)
25 int xrtnl_open(struct rtnl_handle *rth/*, unsigned subscriptions*/)
29 memset(rth, 0, sizeof(rth));
31 rth->fd = xsocket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
33 memset(&rth->local, 0, sizeof(rth->local));
34 rth->local.nl_family = AF_NETLINK;
35 /*rth->local.nl_groups = subscriptions;*/
37 xbind(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local));
38 addr_len = sizeof(rth->local);
39 if (getsockname(rth->fd, (struct sockaddr*)&rth->local, &addr_len) < 0)
40 bb_perror_msg_and_die("cannot getsockname");
41 if (addr_len != sizeof(rth->local))
42 bb_error_msg_and_die("wrong address length %d", addr_len);
43 if (rth->local.nl_family != AF_NETLINK)
44 bb_error_msg_and_die("wrong address family %d", rth->local.nl_family);
45 rth->seq = time(NULL);
49 int xrtnl_wilddump_request(struct rtnl_handle *rth, int family, int type)
55 struct sockaddr_nl nladdr;
57 memset(&nladdr, 0, sizeof(nladdr));
58 nladdr.nl_family = AF_NETLINK;
60 req.nlh.nlmsg_len = sizeof(req);
61 req.nlh.nlmsg_type = type;
62 req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
63 req.nlh.nlmsg_pid = 0;
64 req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
65 req.g.rtgen_family = family;
67 return xsendto(rth->fd, (void*)&req, sizeof(req),
68 (struct sockaddr*)&nladdr, sizeof(nladdr));
71 int rtnl_send(struct rtnl_handle *rth, char *buf, int len)
73 struct sockaddr_nl nladdr;
75 memset(&nladdr, 0, sizeof(nladdr));
76 nladdr.nl_family = AF_NETLINK;
78 return xsendto(rth->fd, buf, len, (struct sockaddr*)&nladdr, sizeof(nladdr));
81 int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
84 struct sockaddr_nl nladdr;
85 struct iovec iov[2] = { { &nlh, sizeof(nlh) }, { req, len } };
87 (void*)&nladdr, sizeof(nladdr),
93 memset(&nladdr, 0, sizeof(nladdr));
94 nladdr.nl_family = AF_NETLINK;
96 nlh.nlmsg_len = NLMSG_LENGTH(len);
97 nlh.nlmsg_type = type;
98 nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
100 nlh.nlmsg_seq = rth->dump = ++rth->seq;
102 return sendmsg(rth->fd, &msg, 0);
105 static int rtnl_dump_filter(struct rtnl_handle *rth,
106 int (*filter)(struct sockaddr_nl *, struct nlmsghdr *n, void *),
108 int (*junk)(struct sockaddr_nl *, struct nlmsghdr *n, void *),
112 struct sockaddr_nl nladdr;
113 struct iovec iov = { buf, sizeof(buf) };
119 struct msghdr msg = {
120 (void*)&nladdr, sizeof(nladdr),
126 status = recvmsg(rth->fd, &msg, 0);
131 bb_perror_msg("OVERRUN");
135 bb_error_msg("EOF on netlink");
138 if (msg.msg_namelen != sizeof(nladdr)) {
139 bb_error_msg_and_die("sender address length == %d", msg.msg_namelen);
142 h = (struct nlmsghdr*)buf;
143 while (NLMSG_OK(h, status)) {
146 if (nladdr.nl_pid != 0 ||
147 h->nlmsg_pid != rth->local.nl_pid ||
148 h->nlmsg_seq != rth->dump) {
150 err = junk(&nladdr, h, arg2);
157 if (h->nlmsg_type == NLMSG_DONE) {
160 if (h->nlmsg_type == NLMSG_ERROR) {
161 struct nlmsgerr *l_err = (struct nlmsgerr*)NLMSG_DATA(h);
162 if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
163 bb_error_msg("ERROR truncated");
165 errno = -l_err->error;
166 bb_perror_msg("RTNETLINK answers");
170 err = filter(&nladdr, h, arg1);
175 h = NLMSG_NEXT(h, status);
177 if (msg.msg_flags & MSG_TRUNC) {
178 bb_error_msg("message truncated");
182 bb_error_msg_and_die("remnant of size %d!", status);
187 int xrtnl_dump_filter(struct rtnl_handle *rth,
188 int (*filter)(struct sockaddr_nl *, struct nlmsghdr *n, void *),
191 int ret = rtnl_dump_filter(rth, filter, arg1/*, NULL, NULL*/);
193 bb_error_msg_and_die("dump terminated");
197 int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
198 unsigned groups, struct nlmsghdr *answer,
199 int (*junk)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
205 struct sockaddr_nl nladdr;
206 struct iovec iov = { (void*)n, n->nlmsg_len };
208 struct msghdr msg = {
209 (void*)&nladdr, sizeof(nladdr),
215 memset(&nladdr, 0, sizeof(nladdr));
216 nladdr.nl_family = AF_NETLINK;
217 nladdr.nl_pid = peer;
218 nladdr.nl_groups = groups;
220 n->nlmsg_seq = seq = ++rtnl->seq;
221 if (answer == NULL) {
222 n->nlmsg_flags |= NLM_F_ACK;
224 status = sendmsg(rtnl->fd, &msg, 0);
227 bb_perror_msg("cannot talk to rtnetlink");
234 iov.iov_len = sizeof(buf);
235 status = recvmsg(rtnl->fd, &msg, 0);
238 if (errno == EINTR) {
241 bb_perror_msg("OVERRUN");
245 bb_error_msg("EOF on netlink");
248 if (msg.msg_namelen != sizeof(nladdr)) {
249 bb_error_msg_and_die("sender address length == %d", msg.msg_namelen);
251 for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
253 int len = h->nlmsg_len;
254 int l = len - sizeof(*h);
256 if (l<0 || len>status) {
257 if (msg.msg_flags & MSG_TRUNC) {
258 bb_error_msg("truncated message");
261 bb_error_msg_and_die("malformed message: len=%d!", len);
264 if (nladdr.nl_pid != peer ||
265 h->nlmsg_pid != rtnl->local.nl_pid ||
266 h->nlmsg_seq != seq) {
268 l_err = junk(&nladdr, h, jarg);
276 if (h->nlmsg_type == NLMSG_ERROR) {
277 struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
278 if (l < sizeof(struct nlmsgerr)) {
279 bb_error_msg("ERROR truncated");
284 memcpy(answer, h, h->nlmsg_len);
288 bb_perror_msg("RTNETLINK answers");
293 memcpy(answer, h, h->nlmsg_len);
297 bb_error_msg("unexpected reply!");
299 status -= NLMSG_ALIGN(len);
300 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
302 if (msg.msg_flags & MSG_TRUNC) {
303 bb_error_msg("message truncated");
307 bb_error_msg_and_die("remnant of size %d!", status);
312 int addattr32(struct nlmsghdr *n, int maxlen, int type, uint32_t data)
314 int len = RTA_LENGTH(4);
316 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen)
318 rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len));
319 rta->rta_type = type;
321 memcpy(RTA_DATA(rta), &data, 4);
322 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
326 int addattr_l(struct nlmsghdr *n, int maxlen, int type, void *data, int alen)
328 int len = RTA_LENGTH(alen);
331 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen)
333 rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len));
334 rta->rta_type = type;
336 memcpy(RTA_DATA(rta), data, alen);
337 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
341 int rta_addattr32(struct rtattr *rta, int maxlen, int type, uint32_t data)
343 int len = RTA_LENGTH(4);
344 struct rtattr *subrta;
346 if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
349 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
350 subrta->rta_type = type;
351 subrta->rta_len = len;
352 memcpy(RTA_DATA(subrta), &data, 4);
353 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
357 int rta_addattr_l(struct rtattr *rta, int maxlen, int type, void *data, int alen)
359 struct rtattr *subrta;
360 int len = RTA_LENGTH(alen);
362 if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
365 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
366 subrta->rta_type = type;
367 subrta->rta_len = len;
368 memcpy(RTA_DATA(subrta), data, alen);
369 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
374 int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
376 while (RTA_OK(rta, len)) {
377 if (rta->rta_type <= max) {
378 tb[rta->rta_type] = rta;
380 rta = RTA_NEXT(rta,len);
383 bb_error_msg("deficit %d, rta_len=%d!", len, rta->rta_len);