iw.c revision 4a972f80a40584eb0f119a204f0eb6568b3368f2 
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
16#include <netlink/genl/genl.h>
17#include <netlink/genl/family.h>
18#include <netlink/genl/ctrl.h>
19#include <netlink/msg.h>
20#include <netlink/attr.h>
21#include <linux/nl80211.h>
22
23#include "iw.h"
24#include "version.h"
25
26int debug = 0;
27
28static int nl80211_init(struct nl80211_state *state)
29{
30	int err;
31
32	state->nl_handle = nl_handle_alloc();
33	if (!state->nl_handle) {
34		fprintf(stderr, "Failed to allocate netlink handle.\n");
35		return -ENOMEM;
36	}
37
38	if (genl_connect(state->nl_handle)) {
39		fprintf(stderr, "Failed to connect to generic netlink.\n");
40		err = -ENOLINK;
41		goto out_handle_destroy;
42	}
43
44	state->nl_cache = genl_ctrl_alloc_cache(state->nl_handle);
45	if (!state->nl_cache) {
46		fprintf(stderr, "Failed to allocate generic netlink cache.\n");
47		err = -ENOMEM;
48		goto out_handle_destroy;
49	}
50
51	state->nl80211 = genl_ctrl_search_by_name(state->nl_cache, "nl80211");
52	if (!state->nl80211) {
53		fprintf(stderr, "nl80211 not found.\n");
54		err = -ENOENT;
55		goto out_cache_free;
56	}
57
58	return 0;
59
60 out_cache_free:
61	nl_cache_free(state->nl_cache);
62 out_handle_destroy:
63	nl_handle_destroy(state->nl_handle);
64	return err;
65}
66
67static void nl80211_cleanup(struct nl80211_state *state)
68{
69	genl_family_put(state->nl80211);
70	nl_cache_free(state->nl_cache);
71	nl_handle_destroy(state->nl_handle);
72}
73
74static void usage(const char *argv0)
75{
76	struct cmd *cmd;
77
78	fprintf(stderr, "Usage:\t%s [options] command\n", argv0);
79	fprintf(stderr, "Options:\n");
80	fprintf(stderr, "\t--debug\t\tenable netlink debugging\n");
81	fprintf(stderr, "\t--version\tshow version\n");
82	fprintf(stderr, "Commands:\n");
83	for (cmd = &__start___cmd; cmd < &__stop___cmd; cmd++) {
84		switch (cmd->idby) {
85		case CIB_NONE:
86			fprintf(stderr, "\t");
87			/* fall through */
88		case CIB_PHY:
89			if (cmd->idby == CIB_PHY)
90				fprintf(stderr, "\tphy <phyname> ");
91			/* fall through */
92		case CIB_NETDEV:
93			if (cmd->idby == CIB_NETDEV)
94				fprintf(stderr, "\tdev <devname> ");
95			if (cmd->section)
96				fprintf(stderr, "%s ", cmd->section);
97			fprintf(stderr, "%s", cmd->name);
98			if (cmd->args)
99				fprintf(stderr, " %s", cmd->args);
100			fprintf(stderr, "\n");
101			break;
102		}
103	}
104}
105
106static void version(void)
107{
108	printf("iw version " IW_VERSION "\n");
109}
110
111static int phy_lookup(char *name)
112{
113	char buf[200];
114	int fd, pos;
115
116	snprintf(buf, sizeof(buf), "/sys/class/ieee80211/%s/index", name);
117
118	fd = open(buf, O_RDONLY);
119	pos = read(fd, buf, sizeof(buf) - 1);
120	if (pos < 0)
121		return -1;
122	buf[pos] = '\0';
123	return atoi(buf);
124}
125
126static int error_handler(struct sockaddr_nl *nla, struct nlmsgerr *err,
127			 void *arg)
128{
129	int *ret = arg;
130	*ret = err->error;
131	return NL_STOP;
132}
133
134static int finish_handler(struct nl_msg *msg, void *arg)
135{
136	return NL_SKIP;
137}
138
139static int ack_handler(struct nl_msg *msg, void *arg)
140{
141	int *ret = arg;
142	*ret = 0;
143	return NL_STOP;
144}
145
146static int handle_cmd(struct nl80211_state *state,
147		      enum command_identify_by idby,
148		      int argc, char **argv)
149{
150	struct cmd *cmd;
151	struct nl_cb *cb = NULL;
152	struct nl_msg *msg;
153	int devidx = 0;
154	int err;
155	const char *command, *section;
156
157	if (argc <= 1 && idby != CIB_NONE)
158		return 1;
159
160	switch (idby) {
161	case CIB_PHY:
162		devidx = phy_lookup(*argv);
163		argc--;
164		argv++;
165		break;
166	case CIB_NETDEV:
167		devidx = if_nametoindex(*argv);
168		argc--;
169		argv++;
170		break;
171	default:
172		break;
173	}
174
175	section = command = *argv;
176	argc--;
177	argv++;
178
179	for (cmd = &__start___cmd; cmd < &__stop___cmd; cmd++) {
180		if (cmd->idby != idby)
181			continue;
182		if (cmd->section) {
183			if (strcmp(cmd->section, section))
184				continue;
185			/* this is a bit icky ... */
186			if (command == section) {
187				if (argc <= 0)
188					return 1;
189				command = *argv;
190				argc--;
191				argv++;
192			}
193		} else if (section != command)
194			continue;
195		if (strcmp(cmd->name, command))
196			continue;
197		if (argc && !cmd->args)
198			continue;
199		break;
200	}
201
202	if (cmd == &__stop___cmd)
203		return 1;
204
205	msg = nlmsg_alloc();
206	if (!msg) {
207		fprintf(stderr, "failed to allocate netlink message\n");
208		return 2;
209	}
210
211	cb = nl_cb_alloc(debug ? NL_CB_DEBUG : NL_CB_DEFAULT);
212	if (!cb) {
213		fprintf(stderr, "failed to allocate netlink callbacks\n");
214		err = 2;
215		goto out_free_msg;
216	}
217
218	genlmsg_put(msg, 0, 0, genl_family_get_id(state->nl80211), 0,
219		    cmd->nl_msg_flags, cmd->cmd, 0);
220
221	switch (idby) {
222	case CIB_PHY:
223		NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, devidx);
224		break;
225	case CIB_NETDEV:
226		NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, devidx);
227		break;
228	default:
229		break;
230	}
231
232	err = cmd->handler(cb, msg, argc, argv);
233	if (err)
234		goto out;
235
236	err = nl_send_auto_complete(state->nl_handle, msg);
237	if (err < 0)
238		goto out;
239
240	nl_cb_err(cb, NL_CB_CUSTOM, error_handler, &err);
241	nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, finish_handler, NULL);
242	nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, ack_handler, &err);
243
244	nl_recvmsgs(state->nl_handle, cb);
245 out:
246	nl_cb_put(cb);
247 out_free_msg:
248	nlmsg_free(msg);
249	return err;
250 nla_put_failure:
251	fprintf(stderr, "building message failed\n");
252	return 2;
253}
254
255int main(int argc, char **argv)
256{
257	struct nl80211_state nlstate;
258	int err;
259	const char *argv0;
260
261	/* strip off self */
262	argc--;
263	argv0 = *argv++;
264
265	if (argc > 0 && strcmp(*argv, "--debug") == 0) {
266		debug = 1;
267		argc--;
268		argv++;
269	}
270
271	if (argc > 0 && strcmp(*argv, "--version") == 0) {
272		version();
273		return 0;
274	}
275
276	if (argc == 0 || strcmp(*argv, "help") == 0) {
277		usage(argv0);
278		return 0;
279	}
280
281	err = nl80211_init(&nlstate);
282	if (err)
283		return 1;
284
285	if (strcmp(*argv, "dev") == 0) {
286		argc--;
287		argv++;
288		err = handle_cmd(&nlstate, CIB_NETDEV, argc, argv);
289	} else if (strcmp(*argv, "phy") == 0) {
290		argc--;
291		argv++;
292		err = handle_cmd(&nlstate, CIB_PHY, argc, argv);
293	} else
294		err = handle_cmd(&nlstate, CIB_NONE, argc, argv);
295
296	if (err == 1)
297		usage(argv0);
298	if (err < 0)
299		fprintf(stderr, "command failed: %s (%d)\n", strerror(-err), err);
300
301	nl80211_cleanup(&nlstate);
302
303	return err;
304}
305