1
2
3
4
5
6
7
8
9
10
11#include <sys/socket.h>
12#include <sys/uio.h>
13
14#include "libbb.h"
15#include "libnetlink.h"
16
17void FAST_FUNC xrtnl_open(struct rtnl_handle *rth)
18{
19 socklen_t addr_len;
20
21 memset(rth, 0, sizeof(*rth));
22 rth->fd = xsocket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
23 rth->local.nl_family = AF_NETLINK;
24
25
26 xbind(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local));
27 addr_len = sizeof(rth->local);
28 getsockname(rth->fd, (struct sockaddr*)&rth->local, &addr_len);
29
30
31
32
33
34
35
36
37
38 rth->seq = time(NULL);
39}
40
41int FAST_FUNC xrtnl_wilddump_request(struct rtnl_handle *rth, int family, int type)
42{
43 struct {
44 struct nlmsghdr nlh;
45 struct rtgenmsg g;
46 } req;
47
48 req.nlh.nlmsg_len = sizeof(req);
49 req.nlh.nlmsg_type = type;
50 req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
51 req.nlh.nlmsg_pid = 0;
52 req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
53 req.g.rtgen_family = family;
54
55 return rtnl_send(rth, (void*)&req, sizeof(req));
56}
57
58
59int FAST_FUNC rtnl_send(struct rtnl_handle *rth, char *buf, int len)
60{
61 struct sockaddr_nl nladdr;
62
63 memset(&nladdr, 0, sizeof(nladdr));
64 nladdr.nl_family = AF_NETLINK;
65
66 return xsendto(rth->fd, buf, len, (struct sockaddr*)&nladdr, sizeof(nladdr));
67}
68
69int FAST_FUNC rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
70{
71 struct nlmsghdr nlh;
72 struct sockaddr_nl nladdr;
73 struct iovec iov[2] = { { &nlh, sizeof(nlh) }, { req, len } };
74
75 struct msghdr msg = {
76 .msg_name = (void*)&nladdr,
77 .msg_namelen = sizeof(nladdr),
78 .msg_iov = iov,
79 .msg_iovlen = 2,
80 .msg_control = NULL,
81 .msg_controllen = 0,
82 .msg_flags = 0
83 };
84
85 memset(&nladdr, 0, sizeof(nladdr));
86 nladdr.nl_family = AF_NETLINK;
87
88 nlh.nlmsg_len = NLMSG_LENGTH(len);
89 nlh.nlmsg_type = type;
90 nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
91 nlh.nlmsg_pid = 0;
92 nlh.nlmsg_seq = rth->dump = ++rth->seq;
93
94 return sendmsg(rth->fd, &msg, 0);
95}
96
97static int rtnl_dump_filter(struct rtnl_handle *rth,
98 int (*filter)(const struct sockaddr_nl *, struct nlmsghdr *n, void *) FAST_FUNC,
99 void *arg1
100
101)
102{
103 int retval = -1;
104 char *buf = xmalloc(8*1024);
105 struct sockaddr_nl nladdr;
106 struct iovec iov = { buf, 8*1024 };
107
108 while (1) {
109 int status;
110 struct nlmsghdr *h;
111
112 struct msghdr msg = {
113 .msg_name = (void*)&nladdr,
114 .msg_namelen = sizeof(nladdr),
115 .msg_iov = &iov,
116 .msg_iovlen = 1,
117 .msg_control = NULL,
118 .msg_controllen = 0,
119 .msg_flags = 0
120 };
121
122 status = recvmsg(rth->fd, &msg, 0);
123
124 if (status < 0) {
125 if (errno == EINTR)
126 continue;
127 bb_perror_msg("OVERRUN");
128 continue;
129 }
130 if (status == 0) {
131 bb_error_msg("EOF on netlink");
132 goto ret;
133 }
134 if (msg.msg_namelen != sizeof(nladdr)) {
135 bb_error_msg_and_die("sender address length == %d", msg.msg_namelen);
136 }
137
138 h = (struct nlmsghdr*)buf;
139 while (NLMSG_OK(h, status)) {
140 int err;
141
142 if (nladdr.nl_pid != 0 ||
143 h->nlmsg_pid != rth->local.nl_pid ||
144 h->nlmsg_seq != rth->dump
145 ) {
146
147
148
149
150
151
152
153 goto skip_it;
154 }
155
156 if (h->nlmsg_type == NLMSG_DONE) {
157 goto ret_0;
158 }
159 if (h->nlmsg_type == NLMSG_ERROR) {
160 struct nlmsgerr *l_err = (struct nlmsgerr*)NLMSG_DATA(h);
161 if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
162 bb_error_msg("ERROR truncated");
163 } else {
164 errno = -l_err->error;
165 bb_perror_msg("RTNETLINK answers");
166 }
167 goto ret;
168 }
169 err = filter(&nladdr, h, arg1);
170 if (err < 0) {
171 retval = err;
172 goto ret;
173 }
174
175 skip_it:
176 h = NLMSG_NEXT(h, status);
177 }
178 if (msg.msg_flags & MSG_TRUNC) {
179 bb_error_msg("message truncated");
180 continue;
181 }
182 if (status) {
183 bb_error_msg_and_die("remnant of size %d!", status);
184 }
185 }
186 ret_0:
187 retval++;
188 ret:
189 free(buf);
190 return retval;
191}
192
193int FAST_FUNC xrtnl_dump_filter(struct rtnl_handle *rth,
194 int (*filter)(const struct sockaddr_nl *, struct nlmsghdr *, void *) FAST_FUNC,
195 void *arg1)
196{
197 int ret = rtnl_dump_filter(rth, filter, arg1);
198 if (ret < 0)
199 bb_error_msg_and_die("dump terminated");
200 return ret;
201}
202
203int FAST_FUNC rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
204 pid_t peer, unsigned groups,
205 struct nlmsghdr *answer,
206 int (*junk)(struct sockaddr_nl *, struct nlmsghdr *, void *),
207 void *jarg)
208{
209
210#define peer 0
211#define groups 0
212#define junk NULL
213#define jarg NULL
214 int retval = -1;
215 int status;
216 unsigned seq;
217 struct nlmsghdr *h;
218 struct sockaddr_nl nladdr;
219 struct iovec iov = { (void*)n, n->nlmsg_len };
220 char *buf = xmalloc(8*1024);
221
222 struct msghdr msg = {
223 .msg_name = (void*)&nladdr,
224 .msg_namelen = sizeof(nladdr),
225 .msg_iov = &iov,
226 .msg_iovlen = 1,
227 .msg_control = NULL,
228 .msg_controllen = 0,
229 .msg_flags = 0
230 };
231
232 memset(&nladdr, 0, sizeof(nladdr));
233 nladdr.nl_family = AF_NETLINK;
234
235
236
237 n->nlmsg_seq = seq = ++rtnl->seq;
238 if (answer == NULL) {
239 n->nlmsg_flags |= NLM_F_ACK;
240 }
241 status = sendmsg(rtnl->fd, &msg, 0);
242
243 if (status < 0) {
244 bb_perror_msg("can't talk to rtnetlink");
245 goto ret;
246 }
247
248 iov.iov_base = buf;
249
250 while (1) {
251 iov.iov_len = 8*1024;
252 status = recvmsg(rtnl->fd, &msg, 0);
253
254 if (status < 0) {
255 if (errno == EINTR) {
256 continue;
257 }
258 bb_perror_msg("OVERRUN");
259 continue;
260 }
261 if (status == 0) {
262 bb_error_msg("EOF on netlink");
263 goto ret;
264 }
265 if (msg.msg_namelen != sizeof(nladdr)) {
266 bb_error_msg_and_die("sender address length == %d", msg.msg_namelen);
267 }
268 for (h = (struct nlmsghdr*)buf; status >= (int)sizeof(*h); ) {
269
270 int len = h->nlmsg_len;
271 int l = len - sizeof(*h);
272
273 if (l < 0 || len > status) {
274 if (msg.msg_flags & MSG_TRUNC) {
275 bb_error_msg("truncated message");
276 goto ret;
277 }
278 bb_error_msg_and_die("malformed message: len=%d!", len);
279 }
280
281 if (nladdr.nl_pid != peer ||
282 h->nlmsg_pid != rtnl->local.nl_pid ||
283 h->nlmsg_seq != seq
284 ) {
285
286
287
288
289
290
291
292 continue;
293 }
294
295 if (h->nlmsg_type == NLMSG_ERROR) {
296 struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
297 if (l < (int)sizeof(struct nlmsgerr)) {
298 bb_error_msg("ERROR truncated");
299 } else {
300 errno = - err->error;
301 if (errno == 0) {
302 if (answer) {
303 memcpy(answer, h, h->nlmsg_len);
304 }
305 goto ret_0;
306 }
307 bb_perror_msg("RTNETLINK answers");
308 }
309 goto ret;
310 }
311 if (answer) {
312 memcpy(answer, h, h->nlmsg_len);
313 goto ret_0;
314 }
315
316 bb_error_msg("unexpected reply!");
317
318 status -= NLMSG_ALIGN(len);
319 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
320 }
321 if (msg.msg_flags & MSG_TRUNC) {
322 bb_error_msg("message truncated");
323 continue;
324 }
325 if (status) {
326 bb_error_msg_and_die("remnant of size %d!", status);
327 }
328 }
329 ret_0:
330 retval++;
331 ret:
332 free(buf);
333 return retval;
334}
335
336int FAST_FUNC addattr32(struct nlmsghdr *n, int maxlen, int type, uint32_t data)
337{
338 int len = RTA_LENGTH(4);
339 struct rtattr *rta;
340
341 if ((int)(NLMSG_ALIGN(n->nlmsg_len) + len) > maxlen) {
342 return -1;
343 }
344 rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len));
345 rta->rta_type = type;
346 rta->rta_len = len;
347 move_to_unaligned32(RTA_DATA(rta), data);
348 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
349 return 0;
350}
351
352int FAST_FUNC addattr_l(struct nlmsghdr *n, int maxlen, int type, void *data, int alen)
353{
354 int len = RTA_LENGTH(alen);
355 struct rtattr *rta;
356
357 if ((int)(NLMSG_ALIGN(n->nlmsg_len) + len) > maxlen) {
358 return -1;
359 }
360 rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len));
361 rta->rta_type = type;
362 rta->rta_len = len;
363 memcpy(RTA_DATA(rta), data, alen);
364 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
365 return 0;
366}
367
368int FAST_FUNC rta_addattr32(struct rtattr *rta, int maxlen, int type, uint32_t data)
369{
370 int len = RTA_LENGTH(4);
371 struct rtattr *subrta;
372
373 if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
374 return -1;
375 }
376 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
377 subrta->rta_type = type;
378 subrta->rta_len = len;
379 move_to_unaligned32(RTA_DATA(subrta), data);
380 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
381 return 0;
382}
383
384int FAST_FUNC rta_addattr_l(struct rtattr *rta, int maxlen, int type, void *data, int alen)
385{
386 struct rtattr *subrta;
387 int len = RTA_LENGTH(alen);
388
389 if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
390 return -1;
391 }
392 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
393 subrta->rta_type = type;
394 subrta->rta_len = len;
395 memcpy(RTA_DATA(subrta), data, alen);
396 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
397 return 0;
398}
399
400
401void FAST_FUNC parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
402{
403 while (RTA_OK(rta, len)) {
404 if (rta->rta_type <= max) {
405 tb[rta->rta_type] = rta;
406 }
407 rta = RTA_NEXT(rta, len);
408 }
409 if (len) {
410 bb_error_msg("deficit %d, rta_len=%d!", len, rta->rta_len);
411 }
412}
413
