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