source: MondoRescue/trunk/mindi-busybox/networking/libiproute/libnetlink.c@ 1075

Last change on this file since 1075 was 821, checked in by Bruno Cornec, 19 years ago

Addition of busybox 1.2.1 as a mindi-busybox new package
This should avoid delivering binary files in mindi not built there (Fedora and Debian are quite serious about that)
File size: 8.9 KB
Line 
1/*
2 * libnetlink.c RTnetlink service routines.
3 *
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.
8 *
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 *
11 */
12
13#include "libbb.h"
14#include <sys/socket.h>
15
16#include <errno.h>
17#include <string.h>
18#include <time.h>
19#include <unistd.h>
20
21#include <sys/uio.h>
22
23#include "libnetlink.h"
24
25void rtnl_close(struct rtnl_handle *rth)
26{
27 close(rth->fd);
28}
29
30int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions)
31{
32 socklen_t addr_len;
33
34 memset(rth, 0, sizeof(rth));
35
36 rth->fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
37 if (rth->fd < 0) {
38 bb_perror_msg("Cannot open netlink socket");
39 return -1;
40 }
41
42 memset(&rth->local, 0, sizeof(rth->local));
43 rth->local.nl_family = AF_NETLINK;
44 rth->local.nl_groups = subscriptions;
45
46 if (bind(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local)) < 0) {
47 bb_perror_msg("Cannot bind netlink socket");
48 return -1;
49 }
50 addr_len = sizeof(rth->local);
51 if (getsockname(rth->fd, (struct sockaddr*)&rth->local, &addr_len) < 0) {
52 bb_perror_msg("Cannot getsockname");
53 return -1;
54 }
55 if (addr_len != sizeof(rth->local)) {
56 bb_error_msg("Wrong address length %d", addr_len);
57 return -1;
58 }
59 if (rth->local.nl_family != AF_NETLINK) {
60 bb_error_msg("Wrong address family %d", rth->local.nl_family);
61 return -1;
62 }
63 rth->seq = time(NULL);
64 return 0;
65}
66
67int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type)
68{
69 struct {
70 struct nlmsghdr nlh;
71 struct rtgenmsg g;
72 } req;
73 struct sockaddr_nl nladdr;
74
75 memset(&nladdr, 0, sizeof(nladdr));
76 nladdr.nl_family = AF_NETLINK;
77
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;
84
85 return sendto(rth->fd, (void*)&req, sizeof(req), 0, (struct sockaddr*)&nladdr, sizeof(nladdr));
86}
87
88int rtnl_send(struct rtnl_handle *rth, char *buf, int len)
89{
90 struct sockaddr_nl nladdr;
91
92 memset(&nladdr, 0, sizeof(nladdr));
93 nladdr.nl_family = AF_NETLINK;
94
95 return sendto(rth->fd, buf, len, 0, (struct sockaddr*)&nladdr, sizeof(nladdr));
96}
97
98int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
99{
100 struct nlmsghdr nlh;
101 struct sockaddr_nl nladdr;
102 struct iovec iov[2] = { { &nlh, sizeof(nlh) }, { req, len } };
103 struct msghdr msg = {
104 (void*)&nladdr, sizeof(nladdr),
105 iov, 2,
106 NULL, 0,
107 0
108 };
109
110 memset(&nladdr, 0, sizeof(nladdr));
111 nladdr.nl_family = AF_NETLINK;
112
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;
116 nlh.nlmsg_pid = 0;
117 nlh.nlmsg_seq = rth->dump = ++rth->seq;
118
119 return sendmsg(rth->fd, &msg, 0);
120}
121
122int rtnl_dump_filter(struct rtnl_handle *rth,
123 int (*filter)(struct sockaddr_nl *, struct nlmsghdr *n, void *),
124 void *arg1,
125 int (*junk)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
126 void *arg2)
127{
128 char buf[8192];
129 struct sockaddr_nl nladdr;
130 struct iovec iov = { buf, sizeof(buf) };
131
132 while (1) {
133 int status;
134 struct nlmsghdr *h;
135
136 struct msghdr msg = {
137 (void*)&nladdr, sizeof(nladdr),
138 &iov, 1,
139 NULL, 0,
140 0
141 };
142
143 status = recvmsg(rth->fd, &msg, 0);
144
145 if (status < 0) {
146 if (errno == EINTR)
147 continue;
148 bb_perror_msg("OVERRUN");
149 continue;
150 }
151 if (status == 0) {
152 bb_error_msg("EOF on netlink");
153 return -1;
154 }
155 if (msg.msg_namelen != sizeof(nladdr)) {
156 bb_error_msg_and_die("sender address length == %d", msg.msg_namelen);
157 }
158
159 h = (struct nlmsghdr*)buf;
160 while (NLMSG_OK(h, status)) {
161 int err;
162
163 if (nladdr.nl_pid != 0 ||
164 h->nlmsg_pid != rth->local.nl_pid ||
165 h->nlmsg_seq != rth->dump) {
166 if (junk) {
167 err = junk(&nladdr, h, arg2);
168 if (err < 0) {
169 return err;
170 }
171 }
172 goto skip_it;
173 }
174
175 if (h->nlmsg_type == NLMSG_DONE) {
176 return 0;
177 }
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");
182 } else {
183 errno = -l_err->error;
184 bb_perror_msg("RTNETLINK answers");
185 }
186 return -1;
187 }
188 err = filter(&nladdr, h, arg1);
189 if (err < 0) {
190 return err;
191 }
192
193skip_it:
194 h = NLMSG_NEXT(h, status);
195 }
196 if (msg.msg_flags & MSG_TRUNC) {
197 bb_error_msg("Message truncated");
198 continue;
199 }
200 if (status) {
201 bb_error_msg_and_die("!!!Remnant of size %d", status);
202 }
203 }
204}
205
206int 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 *),
209 void *jarg)
210{
211 int status;
212 unsigned seq;
213 struct nlmsghdr *h;
214 struct sockaddr_nl nladdr;
215 struct iovec iov = { (void*)n, n->nlmsg_len };
216 char buf[8192];
217 struct msghdr msg = {
218 (void*)&nladdr, sizeof(nladdr),
219 &iov, 1,
220 NULL, 0,
221 0
222 };
223
224 memset(&nladdr, 0, sizeof(nladdr));
225 nladdr.nl_family = AF_NETLINK;
226 nladdr.nl_pid = peer;
227 nladdr.nl_groups = groups;
228
229 n->nlmsg_seq = seq = ++rtnl->seq;
230 if (answer == NULL) {
231 n->nlmsg_flags |= NLM_F_ACK;
232 }
233 status = sendmsg(rtnl->fd, &msg, 0);
234
235 if (status < 0) {
236 bb_perror_msg("Cannot talk to rtnetlink");
237 return -1;
238 }
239
240 iov.iov_base = buf;
241
242 while (1) {
243 iov.iov_len = sizeof(buf);
244 status = recvmsg(rtnl->fd, &msg, 0);
245
246 if (status < 0) {
247 if (errno == EINTR) {
248 continue;
249 }
250 bb_perror_msg("OVERRUN");
251 continue;
252 }
253 if (status == 0) {
254 bb_error_msg("EOF on netlink");
255 return -1;
256 }
257 if (msg.msg_namelen != sizeof(nladdr)) {
258 bb_error_msg_and_die("sender address length == %d", msg.msg_namelen);
259 }
260 for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
261 int l_err;
262 int len = h->nlmsg_len;
263 int l = len - sizeof(*h);
264
265 if (l<0 || len>status) {
266 if (msg.msg_flags & MSG_TRUNC) {
267 bb_error_msg("Truncated message");
268 return -1;
269 }
270 bb_error_msg_and_die("!!!malformed message: len=%d", len);
271 }
272
273 if (nladdr.nl_pid != peer ||
274 h->nlmsg_pid != rtnl->local.nl_pid ||
275 h->nlmsg_seq != seq) {
276 if (junk) {
277 l_err = junk(&nladdr, h, jarg);
278 if (l_err < 0) {
279 return l_err;
280 }
281 }
282 continue;
283 }
284
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");
289 } else {
290 errno = -err->error;
291 if (errno == 0) {
292 if (answer) {
293 memcpy(answer, h, h->nlmsg_len);
294 }
295 return 0;
296 }
297 bb_perror_msg("RTNETLINK answers");
298 }
299 return -1;
300 }
301 if (answer) {
302 memcpy(answer, h, h->nlmsg_len);
303 return 0;
304 }
305
306 bb_error_msg("Unexpected reply!!!");
307
308 status -= NLMSG_ALIGN(len);
309 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
310 }
311 if (msg.msg_flags & MSG_TRUNC) {
312 bb_error_msg("Message truncated");
313 continue;
314 }
315 if (status) {
316 bb_error_msg_and_die("!!!Remnant of size %d", status);
317 }
318 }
319}
320
321int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
322{
323 int len = RTA_LENGTH(4);
324 struct rtattr *rta;
325 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen)
326 return -1;
327 rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len));
328 rta->rta_type = type;
329 rta->rta_len = len;
330 memcpy(RTA_DATA(rta), &data, 4);
331 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
332 return 0;
333}
334
335int addattr_l(struct nlmsghdr *n, int maxlen, int type, void *data, int alen)
336{
337 int len = RTA_LENGTH(alen);
338 struct rtattr *rta;
339
340 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen)
341 return -1;
342 rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len));
343 rta->rta_type = type;
344 rta->rta_len = len;
345 memcpy(RTA_DATA(rta), data, alen);
346 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
347 return 0;
348}
349
350int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data)
351{
352 int len = RTA_LENGTH(4);
353 struct rtattr *subrta;
354
355 if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
356 return -1;
357 }
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;
363 return 0;
364}
365
366int rta_addattr_l(struct rtattr *rta, int maxlen, int type, void *data, int alen)
367{
368 struct rtattr *subrta;
369 int len = RTA_LENGTH(alen);
370
371 if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
372 return -1;
373 }
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;
379 return 0;
380}
381
382
383int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
384{
385 while (RTA_OK(rta, len)) {
386 if (rta->rta_type <= max) {
387 tb[rta->rta_type] = rta;
388 }
389 rta = RTA_NEXT(rta,len);
390 }
391 if (len) {
392 bb_error_msg("!!!Deficit %d, rta_len=%d", len, rta->rta_len);
393 }
394 return 0;
395}
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