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10#include <sys/socket.h>
11#include <sys/uio.h>
12
13#include "libbb.h"
14#include "libnetlink.h"
15
16void FAST_FUNC xrtnl_open(struct rtnl_handle *rth)
17{
18 memset(rth, 0, sizeof(*rth));
19 rth->fd = xsocket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
20 rth->local.nl_family = AF_NETLINK;
21
22
23 xbind(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local));
24 bb_getsockname(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local));
25
26
27
28
29
30
31
32
33
34 rth->seq = time(NULL);
35}
36
37void FAST_FUNC xrtnl_wilddump_request(struct rtnl_handle *rth, int family, int type)
38{
39 struct {
40 struct nlmsghdr nlh;
41 struct rtgenmsg g;
42 } req;
43
44 req.nlh.nlmsg_len = sizeof(req);
45 req.nlh.nlmsg_type = type;
46 req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
47 req.nlh.nlmsg_pid = 0;
48 req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
49 req.g.rtgen_family = family;
50
51 rtnl_send(rth, (void*)&req, sizeof(req));
52}
53
54
55
56
57int FAST_FUNC rtnl_send_check(struct rtnl_handle *rth, const void *buf, int len)
58{
59 struct nlmsghdr *h;
60 int status;
61 char resp[1024];
62
63 status = write(rth->fd, buf, len);
64 if (status < 0)
65 return status;
66
67
68 status = recv(rth->fd, resp, sizeof(resp), MSG_DONTWAIT|MSG_PEEK);
69 if (status < 0) {
70 if (errno == EAGAIN)
71 return 0;
72 return -1;
73 }
74
75 for (h = (struct nlmsghdr *)resp;
76 NLMSG_OK(h, status);
77 h = NLMSG_NEXT(h, status)
78 ) {
79 if (h->nlmsg_type == NLMSG_ERROR) {
80 struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
81 if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr)))
82 bb_simple_error_msg("ERROR truncated");
83 else
84 errno = -err->error;
85 return -1;
86 }
87 }
88
89 return 0;
90}
91
92int FAST_FUNC rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
93{
94 struct {
95 struct nlmsghdr nlh;
96 struct msghdr msg;
97 struct sockaddr_nl nladdr;
98 } s;
99 struct iovec iov[2] = { { &s.nlh, sizeof(s.nlh) }, { req, len } };
100
101 memset(&s, 0, sizeof(s));
102
103 s.msg.msg_name = (void*)&s.nladdr;
104 s.msg.msg_namelen = sizeof(s.nladdr);
105 s.msg.msg_iov = iov;
106 s.msg.msg_iovlen = 2;
107
108
109
110
111 s.nladdr.nl_family = AF_NETLINK;
112
113 s.nlh.nlmsg_len = NLMSG_LENGTH(len);
114 s.nlh.nlmsg_type = type;
115 s.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
116
117 s.nlh.nlmsg_seq = rth->dump = ++rth->seq;
118
119 return sendmsg(rth->fd, &s.msg, 0);
120}
121
122static int rtnl_dump_filter(struct rtnl_handle *rth,
123 int (*filter)(const struct sockaddr_nl *, struct nlmsghdr *n, void *) FAST_FUNC,
124 void *arg1
125
126)
127{
128 int retval = -1;
129 char *buf = xmalloc(8*1024);
130 struct sockaddr_nl nladdr;
131 struct iovec iov = { buf, 8*1024 };
132
133 while (1) {
134 int status;
135 struct nlmsghdr *h;
136
137 struct msghdr msg = {
138 .msg_name = (void*)&nladdr,
139 .msg_namelen = sizeof(nladdr),
140 .msg_iov = &iov,
141 .msg_iovlen = 1,
142 .msg_control = NULL,
143 .msg_controllen = 0,
144 .msg_flags = 0
145 };
146
147 status = recvmsg(rth->fd, &msg, 0);
148
149 if (status < 0) {
150 if (errno == EINTR)
151 continue;
152 bb_simple_perror_msg("OVERRUN");
153 continue;
154 }
155 if (status == 0) {
156 bb_simple_error_msg("EOF on netlink");
157 goto ret;
158 }
159 if (msg.msg_namelen != sizeof(nladdr)) {
160 bb_error_msg_and_die("sender address length == %d", msg.msg_namelen);
161 }
162
163 h = (struct nlmsghdr*)buf;
164 while (NLMSG_OK(h, status)) {
165 int err;
166
167 if (nladdr.nl_pid != 0 ||
168 h->nlmsg_pid != rth->local.nl_pid ||
169 h->nlmsg_seq != rth->dump
170 ) {
171
172
173
174
175
176
177
178 goto skip_it;
179 }
180
181 if (h->nlmsg_type == NLMSG_DONE) {
182 goto ret_0;
183 }
184 if (h->nlmsg_type == NLMSG_ERROR) {
185 struct nlmsgerr *l_err = (struct nlmsgerr*)NLMSG_DATA(h);
186 if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
187 bb_simple_error_msg("ERROR truncated");
188 } else {
189 errno = -l_err->error;
190 bb_simple_perror_msg("RTNETLINK answers");
191 }
192 goto ret;
193 }
194 err = filter(&nladdr, h, arg1);
195 if (err < 0) {
196 retval = err;
197 goto ret;
198 }
199
200 skip_it:
201 h = NLMSG_NEXT(h, status);
202 }
203 if (msg.msg_flags & MSG_TRUNC) {
204 bb_simple_error_msg("message truncated");
205 continue;
206 }
207 if (status) {
208 bb_error_msg_and_die("remnant of size %d!", status);
209 }
210 }
211 ret_0:
212 retval++;
213 ret:
214 free(buf);
215 return retval;
216}
217
218int FAST_FUNC xrtnl_dump_filter(struct rtnl_handle *rth,
219 int (*filter)(const struct sockaddr_nl *, struct nlmsghdr *, void *) FAST_FUNC,
220 void *arg1)
221{
222 int ret = rtnl_dump_filter(rth, filter, arg1);
223 if (ret < 0)
224 bb_simple_error_msg_and_die("dump terminated");
225 return ret;
226}
227
228int FAST_FUNC rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
229 pid_t peer, unsigned groups,
230 struct nlmsghdr *answer,
231 int (*junk)(struct sockaddr_nl *, struct nlmsghdr *, void *),
232 void *jarg)
233{
234
235#define peer 0
236#define groups 0
237#define junk NULL
238#define jarg NULL
239 int retval = -1;
240 int status;
241 unsigned seq;
242 struct nlmsghdr *h;
243 struct sockaddr_nl nladdr;
244 struct iovec iov = { (void*)n, n->nlmsg_len };
245 char *buf = xmalloc(8*1024);
246
247 struct msghdr msg = {
248 .msg_name = (void*)&nladdr,
249 .msg_namelen = sizeof(nladdr),
250 .msg_iov = &iov,
251 .msg_iovlen = 1,
252 .msg_control = NULL,
253 .msg_controllen = 0,
254 .msg_flags = 0
255 };
256
257 memset(&nladdr, 0, sizeof(nladdr));
258 nladdr.nl_family = AF_NETLINK;
259
260
261
262 n->nlmsg_seq = seq = ++rtnl->seq;
263 if (answer == NULL) {
264 n->nlmsg_flags |= NLM_F_ACK;
265 }
266 status = sendmsg(rtnl->fd, &msg, 0);
267
268 if (status < 0) {
269 bb_simple_perror_msg("can't talk to rtnetlink");
270 goto ret;
271 }
272
273 iov.iov_base = buf;
274
275 while (1) {
276 iov.iov_len = 8*1024;
277 status = recvmsg(rtnl->fd, &msg, 0);
278
279 if (status < 0) {
280 if (errno == EINTR) {
281 continue;
282 }
283 bb_simple_perror_msg("OVERRUN");
284 continue;
285 }
286 if (status == 0) {
287 bb_simple_error_msg("EOF on netlink");
288 goto ret;
289 }
290 if (msg.msg_namelen != sizeof(nladdr)) {
291 bb_error_msg_and_die("sender address length == %d", msg.msg_namelen);
292 }
293 for (h = (struct nlmsghdr*)buf; status >= (int)sizeof(*h); ) {
294
295 int len = h->nlmsg_len;
296 int l = len - sizeof(*h);
297
298 if (l < 0 || len > status) {
299 if (msg.msg_flags & MSG_TRUNC) {
300 bb_simple_error_msg("truncated message");
301 goto ret;
302 }
303 bb_error_msg_and_die("malformed message: len=%d!", len);
304 }
305
306 if (nladdr.nl_pid != peer ||
307 h->nlmsg_pid != rtnl->local.nl_pid ||
308 h->nlmsg_seq != seq
309 ) {
310
311
312
313
314
315
316
317 continue;
318 }
319
320 if (h->nlmsg_type == NLMSG_ERROR) {
321 struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
322 if (l < (int)sizeof(struct nlmsgerr)) {
323 bb_simple_error_msg("ERROR truncated");
324 } else {
325 errno = - err->error;
326 if (errno == 0) {
327 if (answer) {
328 memcpy(answer, h, h->nlmsg_len);
329 }
330 goto ret_0;
331 }
332 bb_simple_perror_msg("RTNETLINK answers");
333 }
334 goto ret;
335 }
336 if (answer) {
337 memcpy(answer, h, h->nlmsg_len);
338 goto ret_0;
339 }
340
341 bb_simple_error_msg("unexpected reply!");
342
343 status -= NLMSG_ALIGN(len);
344 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
345 }
346 if (msg.msg_flags & MSG_TRUNC) {
347 bb_simple_error_msg("message truncated");
348 continue;
349 }
350 if (status) {
351 bb_error_msg_and_die("remnant of size %d!", status);
352 }
353 }
354 ret_0:
355 retval++;
356 ret:
357 free(buf);
358 return retval;
359}
360
361int FAST_FUNC addattr32(struct nlmsghdr *n, int maxlen, int type, uint32_t data)
362{
363 int len = RTA_LENGTH(4);
364 struct rtattr *rta;
365
366 if ((int)(NLMSG_ALIGN(n->nlmsg_len + len)) > maxlen) {
367 return -1;
368 }
369 rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len));
370 rta->rta_type = type;
371 rta->rta_len = len;
372 move_to_unaligned32(RTA_DATA(rta), data);
373 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len + len);
374 return 0;
375}
376
377int FAST_FUNC addattr_l(struct nlmsghdr *n, int maxlen, int type, void *data, int alen)
378{
379 int len = RTA_LENGTH(alen);
380 struct rtattr *rta;
381
382 if ((int)(NLMSG_ALIGN(n->nlmsg_len + len)) > maxlen) {
383 return -1;
384 }
385 rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len));
386 rta->rta_type = type;
387 rta->rta_len = len;
388 memcpy(RTA_DATA(rta), data, alen);
389 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len + len);
390 return 0;
391}
392
393int FAST_FUNC rta_addattr32(struct rtattr *rta, int maxlen, int type, uint32_t data)
394{
395 int len = RTA_LENGTH(4);
396 struct rtattr *subrta;
397
398 if (RTA_ALIGN(rta->rta_len + len) > maxlen) {
399 return -1;
400 }
401 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
402 subrta->rta_type = type;
403 subrta->rta_len = len;
404 move_to_unaligned32(RTA_DATA(subrta), data);
405 rta->rta_len = NLMSG_ALIGN(rta->rta_len + len);
406 return 0;
407}
408
409int FAST_FUNC rta_addattr_l(struct rtattr *rta, int maxlen, int type, void *data, int alen)
410{
411 struct rtattr *subrta;
412 int len = RTA_LENGTH(alen);
413
414 if (RTA_ALIGN(rta->rta_len + len) > maxlen) {
415 return -1;
416 }
417 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
418 subrta->rta_type = type;
419 subrta->rta_len = len;
420 memcpy(RTA_DATA(subrta), data, alen);
421 rta->rta_len = NLMSG_ALIGN(rta->rta_len + len);
422 return 0;
423}
424
425
426void FAST_FUNC parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
427{
428 memset(tb, 0, (max + 1) * sizeof(tb[0]));
429
430 while (RTA_OK(rta, len)) {
431 if (rta->rta_type <= max) {
432 tb[rta->rta_type] = rta;
433 }
434 rta = RTA_NEXT(rta, len);
435 }
436 if (len) {
437 bb_error_msg("deficit %d, rta_len=%d!", len, rta->rta_len);
438 }
439}
440
