1 /*
2 * nl80211 userspace tool
3 *
4 * Copyright 2007, 2008 Johannes Berg <johannes@sipsolutions.net>
5 */
6
7 #include <errno.h>
8 #include <stdio.h>
9 #include <string.h>
10 #include <net/if.h>
11 #include <sys/types.h>
12 #include <sys/stat.h>
13 #include <fcntl.h>
14 #include <unistd.h>
15 #include <stdbool.h>
16
17 #include <netlink/genl/genl.h>
18 #include <netlink/genl/family.h>
19 #include <netlink/genl/ctrl.h>
20 #include <netlink/msg.h>
21 #include <netlink/attr.h>
22
23 #include "nl80211.h"
24 #include "iw.h"
25
26 /* libnl 1.x compatibility code */
27 #if !defined(CONFIG_LIBNL20) && !defined(CONFIG_LIBNL30)
nl_socket_alloc(void)28 static inline struct nl_handle *nl_socket_alloc(void)
29 {
30 return nl_handle_alloc();
31 }
32
nl_socket_free(struct nl_sock * h)33 static inline void nl_socket_free(struct nl_sock *h)
34 {
35 nl_handle_destroy(h);
36 }
37
nl_socket_set_buffer_size(struct nl_sock * sk,int rxbuf,int txbuf)38 static inline int nl_socket_set_buffer_size(struct nl_sock *sk,
39 int rxbuf, int txbuf)
40 {
41 return nl_set_buffer_size(sk, rxbuf, txbuf);
42 }
43 #endif /* CONFIG_LIBNL20 && CONFIG_LIBNL30 */
44
45 int iw_debug = 0;
46
nl80211_init(struct nl80211_state * state)47 static int nl80211_init(struct nl80211_state *state)
48 {
49 int err;
50
51 state->nl_sock = nl_socket_alloc();
52 if (!state->nl_sock) {
53 fprintf(stderr, "Failed to allocate netlink socket.\n");
54 return -ENOMEM;
55 }
56
57 nl_socket_set_buffer_size(state->nl_sock, 8192, 8192);
58
59 if (genl_connect(state->nl_sock)) {
60 fprintf(stderr, "Failed to connect to generic netlink.\n");
61 err = -ENOLINK;
62 goto out_handle_destroy;
63 }
64
65 state->nl80211_id = genl_ctrl_resolve(state->nl_sock, "nl80211");
66 if (state->nl80211_id < 0) {
67 fprintf(stderr, "nl80211 not found.\n");
68 err = -ENOENT;
69 goto out_handle_destroy;
70 }
71
72 return 0;
73
74 out_handle_destroy:
75 nl_socket_free(state->nl_sock);
76 return err;
77 }
78
nl80211_cleanup(struct nl80211_state * state)79 static void nl80211_cleanup(struct nl80211_state *state)
80 {
81 nl_socket_free(state->nl_sock);
82 }
83
84 static int cmd_size;
85
86 extern struct cmd __start___cmd;
87 extern struct cmd __stop___cmd;
88
89 #define for_each_cmd(_cmd) \
90 for (_cmd = &__start___cmd; _cmd < &__stop___cmd; \
91 _cmd = (const struct cmd *)((char *)_cmd + cmd_size))
92
93
__usage_cmd(const struct cmd * cmd,char * indent,bool full)94 static void __usage_cmd(const struct cmd *cmd, char *indent, bool full)
95 {
96 const char *start, *lend, *end;
97
98 printf("%s", indent);
99
100 switch (cmd->idby) {
101 case CIB_NONE:
102 break;
103 case CIB_PHY:
104 printf("phy <phyname> ");
105 break;
106 case CIB_NETDEV:
107 printf("dev <devname> ");
108 break;
109 case CIB_WDEV:
110 printf("wdev <idx> ");
111 break;
112 }
113 if (cmd->parent && cmd->parent->name)
114 printf("%s ", cmd->parent->name);
115 printf("%s", cmd->name);
116
117 if (cmd->args) {
118 /* print line by line */
119 start = cmd->args;
120 end = strchr(start, '\0');
121 printf(" ");
122 do {
123 lend = strchr(start, '\n');
124 if (!lend)
125 lend = end;
126 if (start != cmd->args) {
127 printf("\t");
128 switch (cmd->idby) {
129 case CIB_NONE:
130 break;
131 case CIB_PHY:
132 printf("phy <phyname> ");
133 break;
134 case CIB_NETDEV:
135 printf("dev <devname> ");
136 break;
137 case CIB_WDEV:
138 printf("wdev <idx> ");
139 break;
140 }
141 if (cmd->parent && cmd->parent->name)
142 printf("%s ", cmd->parent->name);
143 printf("%s ", cmd->name);
144 }
145 printf("%.*s\n", (int)(lend - start), start);
146 start = lend + 1;
147 } while (end != lend);
148 } else
149 printf("\n");
150
151 if (!full || !cmd->help)
152 return;
153
154 /* hack */
155 if (strlen(indent))
156 indent = "\t\t";
157 else
158 printf("\n");
159
160 /* print line by line */
161 start = cmd->help;
162 end = strchr(start, '\0');
163 do {
164 lend = strchr(start, '\n');
165 if (!lend)
166 lend = end;
167 printf("%s", indent);
168 printf("%.*s\n", (int)(lend - start), start);
169 start = lend + 1;
170 } while (end != lend);
171
172 printf("\n");
173 }
174
usage_options(void)175 static void usage_options(void)
176 {
177 printf("Options:\n");
178 printf("\t--debug\t\tenable netlink debugging\n");
179 }
180
181 static const char *argv0;
182
usage(int argc,char ** argv)183 static void usage(int argc, char **argv)
184 {
185 const struct cmd *section, *cmd;
186 bool full = argc >= 0;
187 const char *sect_filt = NULL;
188 const char *cmd_filt = NULL;
189
190 if (argc > 0)
191 sect_filt = argv[0];
192
193 if (argc > 1)
194 cmd_filt = argv[1];
195
196 printf("Usage:\t%s [options] command\n", argv0);
197 usage_options();
198 printf("\t--version\tshow version (%s)\n", iw_version);
199 printf("Commands:\n");
200 for_each_cmd(section) {
201 if (section->parent)
202 continue;
203
204 if (sect_filt && strcmp(section->name, sect_filt))
205 continue;
206
207 if (section->handler && !section->hidden)
208 __usage_cmd(section, "\t", full);
209
210 for_each_cmd(cmd) {
211 if (section != cmd->parent)
212 continue;
213 if (!cmd->handler || cmd->hidden)
214 continue;
215 if (cmd_filt && strcmp(cmd->name, cmd_filt))
216 continue;
217 __usage_cmd(cmd, "\t", full);
218 }
219 }
220 printf("\nCommands that use the netdev ('dev') can also be given the\n"
221 "'wdev' instead to identify the device.\n");
222 printf("\nYou can omit the 'phy' or 'dev' if "
223 "the identification is unique,\n"
224 "e.g. \"iw wlan0 info\" or \"iw phy0 info\". "
225 "(Don't when scripting.)\n\n"
226 "Do NOT screenscrape this tool, we don't "
227 "consider its output stable.\n\n");
228 }
229
print_help(struct nl80211_state * state,struct nl_cb * cb,struct nl_msg * msg,int argc,char ** argv,enum id_input id)230 static int print_help(struct nl80211_state *state,
231 struct nl_cb *cb,
232 struct nl_msg *msg,
233 int argc, char **argv,
234 enum id_input id)
235 {
236 exit(3);
237 }
238 TOPLEVEL(help, "[command]", 0, 0, CIB_NONE, print_help,
239 "Print usage for all or a specific command, e.g.\n"
240 "\"help wowlan\" or \"help wowlan enable\".");
241
usage_cmd(const struct cmd * cmd)242 static void usage_cmd(const struct cmd *cmd)
243 {
244 printf("Usage:\t%s [options] ", argv0);
245 __usage_cmd(cmd, "", true);
246 usage_options();
247 }
248
version(void)249 static void version(void)
250 {
251 printf("iw version %s\n", iw_version);
252 }
253
phy_lookup(char * name)254 static int phy_lookup(char *name)
255 {
256 char buf[200];
257 int fd, pos;
258
259 snprintf(buf, sizeof(buf), "/sys/class/ieee80211/%s/index", name);
260
261 fd = open(buf, O_RDONLY);
262 if (fd < 0)
263 return -1;
264 pos = read(fd, buf, sizeof(buf) - 1);
265 if (pos < 0) {
266 close(fd);
267 return -1;
268 }
269 buf[pos] = '\0';
270 close(fd);
271 return atoi(buf);
272 }
273
error_handler(struct sockaddr_nl * nla,struct nlmsgerr * err,void * arg)274 static int error_handler(struct sockaddr_nl *nla, struct nlmsgerr *err,
275 void *arg)
276 {
277 int *ret = arg;
278 *ret = err->error;
279 return NL_STOP;
280 }
281
finish_handler(struct nl_msg * msg,void * arg)282 static int finish_handler(struct nl_msg *msg, void *arg)
283 {
284 int *ret = arg;
285 *ret = 0;
286 return NL_SKIP;
287 }
288
ack_handler(struct nl_msg * msg,void * arg)289 static int ack_handler(struct nl_msg *msg, void *arg)
290 {
291 int *ret = arg;
292 *ret = 0;
293 return NL_STOP;
294 }
295
__handle_cmd(struct nl80211_state * state,enum id_input idby,int argc,char ** argv,const struct cmd ** cmdout)296 static int __handle_cmd(struct nl80211_state *state, enum id_input idby,
297 int argc, char **argv, const struct cmd **cmdout)
298 {
299 const struct cmd *cmd, *match = NULL, *sectcmd;
300 struct nl_cb *cb;
301 struct nl_cb *s_cb;
302 struct nl_msg *msg;
303 signed long long devidx = 0;
304 int err, o_argc;
305 const char *command, *section;
306 char *tmp, **o_argv;
307 enum command_identify_by command_idby = CIB_NONE;
308
309 if (argc <= 1 && idby != II_NONE)
310 return 1;
311
312 o_argc = argc;
313 o_argv = argv;
314
315 switch (idby) {
316 case II_PHY_IDX:
317 command_idby = CIB_PHY;
318 devidx = strtoul(*argv + 4, &tmp, 0);
319 if (*tmp != '\0')
320 return 1;
321 argc--;
322 argv++;
323 break;
324 case II_PHY_NAME:
325 command_idby = CIB_PHY;
326 devidx = phy_lookup(*argv);
327 argc--;
328 argv++;
329 break;
330 case II_NETDEV:
331 command_idby = CIB_NETDEV;
332 devidx = if_nametoindex(*argv);
333 if (devidx == 0)
334 devidx = -1;
335 argc--;
336 argv++;
337 break;
338 case II_WDEV:
339 command_idby = CIB_WDEV;
340 devidx = strtoll(*argv, &tmp, 0);
341 if (*tmp != '\0')
342 return 1;
343 argc--;
344 argv++;
345 default:
346 break;
347 }
348
349 if (devidx < 0)
350 return -errno;
351
352 section = *argv;
353 argc--;
354 argv++;
355
356 for_each_cmd(sectcmd) {
357 if (sectcmd->parent)
358 continue;
359 /* ok ... bit of a hack for the dupe 'info' section */
360 if (match && sectcmd->idby != command_idby)
361 continue;
362 if (strcmp(sectcmd->name, section) == 0)
363 match = sectcmd;
364 }
365
366 sectcmd = match;
367 match = NULL;
368 if (!sectcmd)
369 return 1;
370
371 if (argc > 0) {
372 command = *argv;
373
374 for_each_cmd(cmd) {
375 if (!cmd->handler)
376 continue;
377 if (cmd->parent != sectcmd)
378 continue;
379 /*
380 * ignore mismatch id by, but allow WDEV
381 * in place of NETDEV
382 */
383 if (cmd->idby != command_idby &&
384 !(cmd->idby == CIB_NETDEV &&
385 command_idby == CIB_WDEV))
386 continue;
387 if (strcmp(cmd->name, command))
388 continue;
389 if (argc > 1 && !cmd->args)
390 continue;
391 match = cmd;
392 break;
393 }
394
395 if (match) {
396 argc--;
397 argv++;
398 }
399 }
400
401 if (match)
402 cmd = match;
403 else {
404 /* Use the section itself, if possible. */
405 cmd = sectcmd;
406 if (argc && !cmd->args)
407 return 1;
408 if (cmd->idby != command_idby &&
409 !(cmd->idby == CIB_NETDEV && command_idby == CIB_WDEV))
410 return 1;
411 if (!cmd->handler)
412 return 1;
413 }
414
415 if (cmd->selector) {
416 cmd = cmd->selector(argc, argv);
417 if (!cmd)
418 return 1;
419 }
420
421 if (cmdout)
422 *cmdout = cmd;
423
424 if (!cmd->cmd) {
425 argc = o_argc;
426 argv = o_argv;
427 return cmd->handler(state, NULL, NULL, argc, argv, idby);
428 }
429
430 msg = nlmsg_alloc();
431 if (!msg) {
432 fprintf(stderr, "failed to allocate netlink message\n");
433 return 2;
434 }
435
436 cb = nl_cb_alloc(iw_debug ? NL_CB_DEBUG : NL_CB_DEFAULT);
437 s_cb = nl_cb_alloc(iw_debug ? NL_CB_DEBUG : NL_CB_DEFAULT);
438 if (!cb || !s_cb) {
439 fprintf(stderr, "failed to allocate netlink callbacks\n");
440 err = 2;
441 goto out_free_msg;
442 }
443
444 genlmsg_put(msg, 0, 0, state->nl80211_id, 0,
445 cmd->nl_msg_flags, cmd->cmd, 0);
446
447 switch (command_idby) {
448 case CIB_PHY:
449 NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, devidx);
450 break;
451 case CIB_NETDEV:
452 NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, devidx);
453 break;
454 case CIB_WDEV:
455 NLA_PUT_U64(msg, NL80211_ATTR_WDEV, devidx);
456 break;
457 default:
458 break;
459 }
460
461 err = cmd->handler(state, cb, msg, argc, argv, idby);
462 if (err)
463 goto out;
464
465 nl_socket_set_cb(state->nl_sock, s_cb);
466
467 err = nl_send_auto_complete(state->nl_sock, msg);
468 if (err < 0)
469 goto out;
470
471 err = 1;
472
473 nl_cb_err(cb, NL_CB_CUSTOM, error_handler, &err);
474 nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, finish_handler, &err);
475 nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, ack_handler, &err);
476
477 while (err > 0)
478 nl_recvmsgs(state->nl_sock, cb);
479 out:
480 nl_cb_put(cb);
481 out_free_msg:
482 nlmsg_free(msg);
483 return err;
484 nla_put_failure:
485 fprintf(stderr, "building message failed\n");
486 return 2;
487 }
488
handle_cmd(struct nl80211_state * state,enum id_input idby,int argc,char ** argv)489 int handle_cmd(struct nl80211_state *state, enum id_input idby,
490 int argc, char **argv)
491 {
492 return __handle_cmd(state, idby, argc, argv, NULL);
493 }
494
main(int argc,char ** argv)495 int main(int argc, char **argv)
496 {
497 struct nl80211_state nlstate;
498 int err;
499 const struct cmd *cmd = NULL;
500
501 /* calculate command size including padding */
502 cmd_size = abs((long)&__section_set - (long)&__section_get);
503 /* strip off self */
504 argc--;
505 argv0 = *argv++;
506
507 if (argc > 0 && strcmp(*argv, "--debug") == 0) {
508 iw_debug = 1;
509 argc--;
510 argv++;
511 }
512
513 if (argc > 0 && strcmp(*argv, "--version") == 0) {
514 version();
515 return 0;
516 }
517
518 /* need to treat "help" command specially so it works w/o nl80211 */
519 if (argc == 0 || strcmp(*argv, "help") == 0) {
520 usage(argc - 1, argv + 1);
521 return 0;
522 }
523
524 err = nl80211_init(&nlstate);
525 if (err)
526 return 1;
527
528 if (strcmp(*argv, "dev") == 0 && argc > 1) {
529 argc--;
530 argv++;
531 err = __handle_cmd(&nlstate, II_NETDEV, argc, argv, &cmd);
532 } else if (strncmp(*argv, "phy", 3) == 0 && argc > 1) {
533 if (strlen(*argv) == 3) {
534 argc--;
535 argv++;
536 err = __handle_cmd(&nlstate, II_PHY_NAME, argc, argv, &cmd);
537 } else if (*(*argv + 3) == '#')
538 err = __handle_cmd(&nlstate, II_PHY_IDX, argc, argv, &cmd);
539 else
540 goto detect;
541 } else if (strcmp(*argv, "wdev") == 0 && argc > 1) {
542 argc--;
543 argv++;
544 err = __handle_cmd(&nlstate, II_WDEV, argc, argv, &cmd);
545 } else {
546 int idx;
547 enum id_input idby = II_NONE;
548 detect:
549 if ((idx = if_nametoindex(argv[0])) != 0)
550 idby = II_NETDEV;
551 else if ((idx = phy_lookup(argv[0])) >= 0)
552 idby = II_PHY_NAME;
553 err = __handle_cmd(&nlstate, idby, argc, argv, &cmd);
554 }
555
556 if (err == 1) {
557 if (cmd)
558 usage_cmd(cmd);
559 else
560 usage(0, NULL);
561 } else if (err < 0)
562 fprintf(stderr, "command failed: %s (%d)\n", strerror(-err), err);
563
564 nl80211_cleanup(&nlstate);
565
566 return err;
567 }
568