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