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>
14 #include <sys/socket.h>
23 #include "libnetlink.h"
25 void rtnl_close(struct rtnl_handle *rth)
30 int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions)
34 memset(rth, 0, sizeof(rth));
36 rth->fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
38 bb_perror_msg("Cannot open netlink socket");
42 memset(&rth->local, 0, sizeof(rth->local));
43 rth->local.nl_family = AF_NETLINK;
44 rth->local.nl_groups = subscriptions;
46 if (bind(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local)) < 0) {
47 bb_perror_msg("Cannot bind netlink socket");
50 addr_len = sizeof(rth->local);
51 if (getsockname(rth->fd, (struct sockaddr*)&rth->local, &addr_len) < 0) {
52 bb_perror_msg("Cannot getsockname");
55 if (addr_len != sizeof(rth->local)) {
56 bb_error_msg("Wrong address length %d", addr_len);
59 if (rth->local.nl_family != AF_NETLINK) {
60 bb_error_msg("Wrong address family %d", rth->local.nl_family);
63 rth->seq = time(NULL);
67 int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type)
73 struct sockaddr_nl nladdr;
75 memset(&nladdr, 0, sizeof(nladdr));
76 nladdr.nl_family = AF_NETLINK;
78 req.nlh.nlmsg_len = sizeof(req);
79 req.nlh.nlmsg_type = type;
80 req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
81 req.nlh.nlmsg_pid = 0;
82 req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
83 req.g.rtgen_family = family;
85 return sendto(rth->fd, (void*)&req, sizeof(req), 0, (struct sockaddr*)&nladdr, sizeof(nladdr));
88 int rtnl_send(struct rtnl_handle *rth, char *buf, int len)
90 struct sockaddr_nl nladdr;
92 memset(&nladdr, 0, sizeof(nladdr));
93 nladdr.nl_family = AF_NETLINK;
95 return sendto(rth->fd, buf, len, 0, (struct sockaddr*)&nladdr, sizeof(nladdr));
98 int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
101 struct sockaddr_nl nladdr;
102 struct iovec iov[2] = { { &nlh, sizeof(nlh) }, { req, len } };
103 struct msghdr msg = {
104 (void*)&nladdr, sizeof(nladdr),
110 memset(&nladdr, 0, sizeof(nladdr));
111 nladdr.nl_family = AF_NETLINK;
113 nlh.nlmsg_len = NLMSG_LENGTH(len);
114 nlh.nlmsg_type = type;
115 nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
117 nlh.nlmsg_seq = rth->dump = ++rth->seq;
119 return sendmsg(rth->fd, &msg, 0);
122 int rtnl_dump_filter(struct rtnl_handle *rth,
123 int (*filter)(struct sockaddr_nl *, struct nlmsghdr *n, void *),
125 int (*junk)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
129 struct sockaddr_nl nladdr;
130 struct iovec iov = { buf, sizeof(buf) };
136 struct msghdr msg = {
137 (void*)&nladdr, sizeof(nladdr),
143 status = recvmsg(rth->fd, &msg, 0);
148 bb_perror_msg("OVERRUN");
152 bb_error_msg("EOF on netlink");
155 if (msg.msg_namelen != sizeof(nladdr)) {
156 bb_error_msg_and_die("sender address length == %d", msg.msg_namelen);
159 h = (struct nlmsghdr*)buf;
160 while (NLMSG_OK(h, status)) {
163 if (nladdr.nl_pid != 0 ||
164 h->nlmsg_pid != rth->local.nl_pid ||
165 h->nlmsg_seq != rth->dump) {
167 err = junk(&nladdr, h, arg2);
175 if (h->nlmsg_type == NLMSG_DONE) {
178 if (h->nlmsg_type == NLMSG_ERROR) {
179 struct nlmsgerr *l_err = (struct nlmsgerr*)NLMSG_DATA(h);
180 if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
181 bb_error_msg("ERROR truncated");
183 errno = -l_err->error;
184 bb_perror_msg("RTNETLINK answers");
188 err = filter(&nladdr, h, arg1);
194 h = NLMSG_NEXT(h, status);
196 if (msg.msg_flags & MSG_TRUNC) {
197 bb_error_msg("Message truncated");
201 bb_error_msg_and_die("!!!Remnant of size %d", status);
206 int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
207 unsigned groups, struct nlmsghdr *answer,
208 int (*junk)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
214 struct sockaddr_nl nladdr;
215 struct iovec iov = { (void*)n, n->nlmsg_len };
217 struct msghdr msg = {
218 (void*)&nladdr, sizeof(nladdr),
224 memset(&nladdr, 0, sizeof(nladdr));
225 nladdr.nl_family = AF_NETLINK;
226 nladdr.nl_pid = peer;
227 nladdr.nl_groups = groups;
229 n->nlmsg_seq = seq = ++rtnl->seq;
230 if (answer == NULL) {
231 n->nlmsg_flags |= NLM_F_ACK;
233 status = sendmsg(rtnl->fd, &msg, 0);
236 bb_perror_msg("Cannot talk to rtnetlink");
243 iov.iov_len = sizeof(buf);
244 status = recvmsg(rtnl->fd, &msg, 0);
247 if (errno == EINTR) {
250 bb_perror_msg("OVERRUN");
254 bb_error_msg("EOF on netlink");
257 if (msg.msg_namelen != sizeof(nladdr)) {
258 bb_error_msg_and_die("sender address length == %d", msg.msg_namelen);
260 for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
262 int len = h->nlmsg_len;
263 int l = len - sizeof(*h);
265 if (l<0 || len>status) {
266 if (msg.msg_flags & MSG_TRUNC) {
267 bb_error_msg("Truncated message");
270 bb_error_msg_and_die("!!!malformed message: len=%d", len);
273 if (nladdr.nl_pid != peer ||
274 h->nlmsg_pid != rtnl->local.nl_pid ||
275 h->nlmsg_seq != seq) {
277 l_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 bb_error_msg("ERROR truncated");
293 memcpy(answer, h, h->nlmsg_len);
297 bb_perror_msg("RTNETLINK answers");
302 memcpy(answer, h, h->nlmsg_len);
306 bb_error_msg("Unexpected reply!!!");
308 status -= NLMSG_ALIGN(len);
309 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
311 if (msg.msg_flags & MSG_TRUNC) {
312 bb_error_msg("Message truncated");
316 bb_error_msg_and_die("!!!Remnant of size %d", status);
321 int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
323 int len = RTA_LENGTH(4);
325 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen)
327 rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len));
328 rta->rta_type = type;
330 memcpy(RTA_DATA(rta), &data, 4);
331 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
335 int addattr_l(struct nlmsghdr *n, int maxlen, int type, void *data, int alen)
337 int len = RTA_LENGTH(alen);
340 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen)
342 rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len));
343 rta->rta_type = type;
345 memcpy(RTA_DATA(rta), data, alen);
346 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
350 int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data)
352 int len = RTA_LENGTH(4);
353 struct rtattr *subrta;
355 if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
358 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
359 subrta->rta_type = type;
360 subrta->rta_len = len;
361 memcpy(RTA_DATA(subrta), &data, 4);
362 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
366 int rta_addattr_l(struct rtattr *rta, int maxlen, int type, void *data, int alen)
368 struct rtattr *subrta;
369 int len = RTA_LENGTH(alen);
371 if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
374 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
375 subrta->rta_type = type;
376 subrta->rta_len = len;
377 memcpy(RTA_DATA(subrta), data, alen);
378 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
383 int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
385 while (RTA_OK(rta, len)) {
386 if (rta->rta_type <= max) {
387 tb[rta->rta_type] = rta;
389 rta = RTA_NEXT(rta,len);
392 bb_error_msg("!!!Deficit %d, rta_len=%d", len, rta->rta_len);