iw.c revision 66f8ca457aa27222f79d97096dd34ec4b0719783 
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#ifndef CONFIG_LIBNL20
27/* libnl 2.0 compatibility code */
28
29static inline struct nl_handle *nl_socket_alloc(void)
30{
31	return nl_handle_alloc();
32}
33
34static inline void nl_socket_free(struct nl_sock *h)
35{
36	nl_handle_destroy(h);
37}
38
39static inline int __genl_ctrl_alloc_cache(struct nl_sock *h, struct nl_cache **cache)
40{
41	struct nl_cache *tmp = genl_ctrl_alloc_cache(h);
42	if (!tmp)
43		return -ENOMEM;
44	*cache = tmp;
45	return 0;
46}
47#define genl_ctrl_alloc_cache __genl_ctrl_alloc_cache
48#endif /* CONFIG_LIBNL20 */
49
50int iw_debug = 0;
51
52static int nl80211_init(struct nl80211_state *state)
53{
54	int err;
55
56	state->nl_sock = nl_socket_alloc();
57	if (!state->nl_sock) {
58		fprintf(stderr, "Failed to allocate netlink socket.\n");
59		return -ENOMEM;
60	}
61
62	if (genl_connect(state->nl_sock)) {
63		fprintf(stderr, "Failed to connect to generic netlink.\n");
64		err = -ENOLINK;
65		goto out_handle_destroy;
66	}
67
68	if (genl_ctrl_alloc_cache(state->nl_sock, &state->nl_cache)) {
69		fprintf(stderr, "Failed to allocate generic netlink cache.\n");
70		err = -ENOMEM;
71		goto out_handle_destroy;
72	}
73
74	state->nl80211 = genl_ctrl_search_by_name(state->nl_cache, "nl80211");
75	if (!state->nl80211) {
76		fprintf(stderr, "nl80211 not found.\n");
77		err = -ENOENT;
78		goto out_cache_free;
79	}
80
81	return 0;
82
83 out_cache_free:
84	nl_cache_free(state->nl_cache);
85 out_handle_destroy:
86	nl_socket_free(state->nl_sock);
87	return err;
88}
89
90static void nl80211_cleanup(struct nl80211_state *state)
91{
92	genl_family_put(state->nl80211);
93	nl_cache_free(state->nl_cache);
94	nl_socket_free(state->nl_sock);
95}
96
97__COMMAND(NULL, NULL, "", NULL, 0, 0, 0, CIB_NONE, NULL, NULL);
98__COMMAND(NULL, NULL, "", NULL, 1, 0, 0, CIB_NONE, NULL, NULL);
99
100static int cmd_size;
101
102static void __usage_cmd(struct cmd *cmd, char *indent, bool full)
103{
104	const char *start, *lend, *end;
105
106	fprintf(stderr, "%s", indent);
107
108	switch (cmd->idby) {
109	case CIB_NONE:
110		break;
111	case CIB_PHY:
112		fprintf(stderr, "phy <phyname> ");
113		break;
114	case CIB_NETDEV:
115		fprintf(stderr, "dev <devname> ");
116		break;
117	}
118	if (cmd->section)
119		fprintf(stderr, "%s ", cmd->section);
120	fprintf(stderr, "%s", cmd->name);
121	if (cmd->args)
122		fprintf(stderr, " %s", cmd->args);
123	fprintf(stderr, "\n");
124
125	if (!full || !cmd->help)
126		return;
127
128	/* hack */
129	if (strlen(indent))
130		indent = "\t\t";
131	else
132		fprintf(stderr, "\n");
133
134	/* print line by line */
135	start = cmd->help;
136	end = strchr(start, '\0');
137	do {
138		lend = strchr(start, '\n');
139		if (!lend)
140			lend = end;
141		fprintf(stderr, "%s", indent);
142		fprintf(stderr, "%.*s\n", (int)(lend - start), start);
143		start = lend + 1;
144	} while (end != lend);
145
146	fprintf(stderr, "\n");
147}
148
149static void usage_options(void)
150{
151	fprintf(stderr, "Options:\n");
152	fprintf(stderr, "\t--debug\t\tenable netlink debugging\n");
153}
154
155static const char *argv0;
156
157static void usage(bool full)
158{
159	struct cmd *cmd;
160
161	fprintf(stderr, "Usage:\t%s [options] command\n", argv0);
162	usage_options();
163	fprintf(stderr, "\t--version\tshow version (%s)\n", iw_version);
164	fprintf(stderr, "Commands:\n");
165	for (cmd = &__start___cmd; cmd < &__stop___cmd;
166	     cmd = (struct cmd *)((char *)cmd + cmd_size)) {
167		if (!cmd->handler || cmd->hidden)
168			continue;
169		__usage_cmd(cmd, "\t", full);
170	}
171	fprintf(stderr, "\nYou can omit the 'phy' or 'dev' if "
172			"the identification is unique,\n"
173			"e.g. \"iw wlan0 info\" or \"iw phy0 info\". "
174			"(Don't when scripting.)\n\n");
175}
176
177static int print_help(struct nl80211_state *state,
178		      struct nl_cb *cb,
179		      struct nl_msg *msg,
180		      int argc, char **argv)
181{
182	exit(3);
183}
184TOPLEVEL(help, NULL, 0, 0, CIB_NONE, print_help,
185	 "Print usage for each command.");
186
187static void usage_cmd(struct cmd *cmd)
188{
189	fprintf(stderr, "Usage:\t%s [options] ", argv0);
190	__usage_cmd(cmd, "", true);
191	usage_options();
192}
193
194static void version(void)
195{
196	printf("iw version %s\n", iw_version);
197}
198
199static int phy_lookup(char *name)
200{
201	char buf[200];
202	int fd, pos;
203
204	snprintf(buf, sizeof(buf), "/sys/class/ieee80211/%s/index", name);
205
206	fd = open(buf, O_RDONLY);
207	if (fd < 0)
208		return -1;
209	pos = read(fd, buf, sizeof(buf) - 1);
210	if (pos < 0)
211		return -1;
212	buf[pos] = '\0';
213	return atoi(buf);
214}
215
216static int error_handler(struct sockaddr_nl *nla, struct nlmsgerr *err,
217			 void *arg)
218{
219	int *ret = arg;
220	*ret = err->error;
221	return NL_STOP;
222}
223
224static int finish_handler(struct nl_msg *msg, void *arg)
225{
226	int *ret = arg;
227	*ret = 0;
228	return NL_SKIP;
229}
230
231static int ack_handler(struct nl_msg *msg, void *arg)
232{
233	int *ret = arg;
234	*ret = 0;
235	return NL_STOP;
236}
237
238static int __handle_cmd(struct nl80211_state *state, enum id_input idby,
239			int argc, char **argv, struct cmd **cmdout)
240{
241	struct cmd *cmd, *match = NULL;
242	struct nl_cb *cb;
243	struct nl_msg *msg;
244	int devidx = 0;
245	int err, o_argc;
246	const char *command, *section;
247	char *tmp, **o_argv;
248	enum command_identify_by command_idby = CIB_NONE;
249
250	if (argc <= 1 && idby != II_NONE)
251		return 1;
252
253	o_argc = argc;
254	o_argv = argv;
255
256	switch (idby) {
257	case II_PHY_IDX:
258		command_idby = CIB_PHY;
259		devidx = strtoul(*argv + 4, &tmp, 0);
260		if (*tmp != '\0')
261			return 1;
262		argc--;
263		argv++;
264		break;
265	case II_PHY_NAME:
266		command_idby = CIB_PHY;
267		devidx = phy_lookup(*argv);
268		argc--;
269		argv++;
270		break;
271	case II_NETDEV:
272		command_idby = CIB_NETDEV;
273		devidx = if_nametoindex(*argv);
274		if (devidx == 0)
275			devidx = -1;
276		argc--;
277		argv++;
278		break;
279	default:
280		break;
281	}
282
283	if (devidx < 0)
284		return -errno;
285
286	section = command = *argv;
287	argc--;
288	argv++;
289
290	for (cmd = &__start___cmd; cmd < &__stop___cmd;
291	     cmd = (struct cmd *)((char *)cmd + cmd_size)) {
292		if (!cmd->handler)
293			continue;
294		if (cmd->idby != command_idby)
295			continue;
296		if (cmd->section) {
297			if (strcmp(cmd->section, section))
298				continue;
299			/* this is a bit icky ... */
300			if (command == section) {
301				if (argc <= 0) {
302					if (match)
303						break;
304					return 1;
305				}
306				command = *argv;
307				argc--;
308				argv++;
309			}
310		} else if (section != command)
311			continue;
312		if (strcmp(cmd->name, command))
313			continue;
314		if (argc && !cmd->args)
315			continue;
316
317		match = cmd;
318	}
319
320	cmd = match;
321
322	if (!cmd)
323		return 1;
324
325	if (cmdout)
326		*cmdout = cmd;
327
328	if (!cmd->cmd) {
329		argc = o_argc;
330		argv = o_argv;
331		return cmd->handler(state, NULL, NULL, argc, argv);
332	}
333
334	msg = nlmsg_alloc();
335	if (!msg) {
336		fprintf(stderr, "failed to allocate netlink message\n");
337		return 2;
338	}
339
340	cb = nl_cb_alloc(iw_debug ? NL_CB_DEBUG : NL_CB_DEFAULT);
341	if (!cb) {
342		fprintf(stderr, "failed to allocate netlink callbacks\n");
343		err = 2;
344		goto out_free_msg;
345	}
346
347	genlmsg_put(msg, 0, 0, genl_family_get_id(state->nl80211), 0,
348		    cmd->nl_msg_flags, cmd->cmd, 0);
349
350	switch (command_idby) {
351	case CIB_PHY:
352		NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, devidx);
353		break;
354	case CIB_NETDEV:
355		NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, devidx);
356		break;
357	default:
358		break;
359	}
360
361	err = cmd->handler(state, cb, msg, argc, argv);
362	if (err)
363		goto out;
364
365	err = nl_send_auto_complete(state->nl_sock, msg);
366	if (err < 0)
367		goto out;
368
369	err = 1;
370
371	nl_cb_err(cb, NL_CB_CUSTOM, error_handler, &err);
372	nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, finish_handler, &err);
373	nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, ack_handler, &err);
374
375	while (err > 0)
376		nl_recvmsgs(state->nl_sock, cb);
377 out:
378	nl_cb_put(cb);
379 out_free_msg:
380	nlmsg_free(msg);
381	return err;
382 nla_put_failure:
383	fprintf(stderr, "building message failed\n");
384	return 2;
385}
386
387int handle_cmd(struct nl80211_state *state, enum id_input idby,
388	       int argc, char **argv)
389{
390	return __handle_cmd(state, idby, argc, argv, NULL);
391}
392
393int main(int argc, char **argv)
394{
395	struct nl80211_state nlstate;
396	int err;
397	struct cmd *cmd = NULL;
398
399	/* calculate command size including padding */
400	cmd_size = abs((long)&__cmd_NULL_NULL_1_CIB_NONE_0
401	             - (long)&__cmd_NULL_NULL_0_CIB_NONE_0);
402	/* strip off self */
403	argc--;
404	argv0 = *argv++;
405
406	if (argc > 0 && strcmp(*argv, "--debug") == 0) {
407		iw_debug = 1;
408		argc--;
409		argv++;
410	}
411
412	if (argc > 0 && strcmp(*argv, "--version") == 0) {
413		version();
414		return 0;
415	}
416
417	/* need to treat "help" command specially so it works w/o nl80211 */
418	if (argc == 0 || strcmp(*argv, "help") == 0) {
419		usage(argc != 0);
420		return 0;
421	}
422
423	err = nl80211_init(&nlstate);
424	if (err)
425		return 1;
426
427	if (strcmp(*argv, "dev") == 0 && argc > 1) {
428		argc--;
429		argv++;
430		err = __handle_cmd(&nlstate, II_NETDEV, argc, argv, &cmd);
431	} else if (strncmp(*argv, "phy", 3) == 0 && argc > 1) {
432		if (strlen(*argv) == 3) {
433			argc--;
434			argv++;
435			err = __handle_cmd(&nlstate, II_PHY_NAME, argc, argv, &cmd);
436		} else if (*(*argv + 3) == '#')
437			err = __handle_cmd(&nlstate, II_PHY_IDX, argc, argv, &cmd);
438		else
439			goto detect;
440	} else {
441		int idx;
442		enum id_input idby = II_NONE;
443 detect:
444		if ((idx = if_nametoindex(argv[0])) != 0)
445			idby = II_NETDEV;
446		else if ((idx = phy_lookup(argv[0])) >= 0)
447			idby = II_PHY_NAME;
448		err = __handle_cmd(&nlstate, idby, argc, argv, &cmd);
449	}
450
451	if (err == 1) {
452		if (cmd)
453			usage_cmd(cmd);
454		else
455			usage(false);
456	} else if (err < 0)
457		fprintf(stderr, "command failed: %s (%d)\n", strerror(-err), err);
458
459	nl80211_cleanup(&nlstate);
460
461	return err;
462}
463