aboutsummaryrefslogtreecommitdiffstats
path: root/package/wprobe/src/user/wprobe.c
blob: 1f8df6c7e99e4503eefd6648d58cbf2f930d5926 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
/*
 * wprobe.c: Wireless probe user space library
 * Copyright (C) 2008-2009 Felix Fietkau <nbd@openwrt.org>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <getopt.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <math.h>
#include <linux/wprobe.h>
#include <netlink/netlink.h>
#include <netlink/genl/genl.h>
#include <netlink/genl/ctrl.h>
#include <netlink/genl/family.h>
#include "wprobe.h"

#define DEBUG 1
#ifdef DEBUG
#define DPRINTF(fmt, ...) fprintf(stderr, "%s(%d): " fmt, __func__, __LINE__, ##__VA_ARGS__)
#else
#define DPRINTF(fmt, ...) do {} while (0)
#endif

static struct nl_sock *handle = NULL;
static struct nl_cache *cache = NULL;
static struct genl_family *family = NULL;
static struct nlattr *tb[WPROBE_ATTR_LAST+1];
static struct nla_policy attribute_policy[WPROBE_ATTR_LAST+1] = {
	[WPROBE_ATTR_ID] = { .type = NLA_U32 },
	[WPROBE_ATTR_MAC] = { .type = NLA_UNSPEC, .minlen = 6, .maxlen = 6 },
	[WPROBE_ATTR_NAME] = { .type = NLA_STRING },
	[WPROBE_ATTR_FLAGS] = { .type = NLA_U32 },
	[WPROBE_ATTR_TYPE] = { .type = NLA_U8 },
	[WPROBE_VAL_S8] = { .type = NLA_U8 },
	[WPROBE_VAL_S16] = { .type = NLA_U16 },
	[WPROBE_VAL_S32] = { .type = NLA_U32 },
	[WPROBE_VAL_S64] = { .type = NLA_U64 },
	[WPROBE_VAL_U8] = { .type = NLA_U8 },
	[WPROBE_VAL_U16] = { .type = NLA_U16 },
	[WPROBE_VAL_U32] = { .type = NLA_U32 },
	[WPROBE_VAL_U64] = { .type = NLA_U64 },
	[WPROBE_VAL_SUM] = { .type = NLA_U64 },
	[WPROBE_VAL_SUM_SQ] = { .type = NLA_U64 },
	[WPROBE_VAL_SAMPLES] = { .type = NLA_U32 },
};

static int
error_handler(struct sockaddr_nl *nla, struct nlmsgerr *err, void *arg)
{
	int *ret = arg;
	*ret = err->error;
	return NL_STOP;
}

static int
finish_handler(struct nl_msg *msg, void *arg)
{
	int *ret = arg;
	*ret = 0;
	return NL_SKIP;
}

static int
ack_handler(struct nl_msg *msg, void *arg)
{
	int *ret = arg;
	*ret = 0;
	return NL_STOP;
}


void
wprobe_free(void)
{
	if (cache)
		nl_cache_free(cache);
	if (handle)
		nl_socket_free(handle);
	handle = NULL;
	cache = NULL;
}

int
wprobe_init(void)
{
	int ret;

	handle = nl_socket_alloc();
	if (!handle) {
		DPRINTF("Failed to create handle\n");
		goto err;
	}

	if (genl_connect(handle)) {
		DPRINTF("Failed to connect to generic netlink\n");
		goto err;
	}

	ret = genl_ctrl_alloc_cache(handle, &cache);
	if (ret < 0) {
		DPRINTF("Failed to allocate netlink cache\n");
		goto err;
	}

	family = genl_ctrl_search_by_name(cache, "wprobe");
	if (!family) {
		DPRINTF("wprobe API not present\n");
		goto err;
	}
	return 0;

err:
	wprobe_free();
	return -EINVAL;
}


static struct nl_msg *
wprobe_new_msg(const char *ifname, int cmd, bool dump)
{
	struct nl_msg *msg;
	uint32_t flags = 0;

	msg = nlmsg_alloc();
	if (!msg)
		return NULL;

	if (dump)
		flags |= NLM_F_DUMP;

	genlmsg_put(msg, 0, 0, genl_family_get_id(family),
			0, flags, cmd, 0);

	NLA_PUT_STRING(msg, WPROBE_ATTR_INTERFACE, ifname);
nla_put_failure:
	return msg;
}

static int
wprobe_send_msg(struct nl_msg *msg, void *callback, void *arg)
{
	struct nl_cb *cb;
	int err = 0;

	cb = nl_cb_alloc(NL_CB_DEFAULT);
	if (!cb)
		goto out_no_cb;

	if (callback)
		nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, callback, arg);

	err = nl_send_auto_complete(handle, msg);
	if (err < 0)
		goto out;

	err = 1;

	nl_cb_err(cb, NL_CB_CUSTOM, error_handler, &err);
	nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, finish_handler, &err);
	nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, ack_handler, &err);

	while (err > 0)
		nl_recvmsgs(handle, cb);

out:
	nl_cb_put(cb);
out_no_cb:
	nlmsg_free(msg);
	return err;
}

struct wprobe_attr_cb {
	struct list_head *list;
	char *addr;
};

static int
save_attribute_handler(struct nl_msg *msg, void *arg)
{
	struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
	const char *name = "N/A";
	struct wprobe_attribute *attr;
	int type = 0;
	struct wprobe_attr_cb *cb = arg;

	nla_parse(tb, WPROBE_ATTR_LAST, genlmsg_attrdata(gnlh, 0),
			genlmsg_attrlen(gnlh, 0), attribute_policy);

	if (tb[WPROBE_ATTR_NAME])
		name = nla_data(tb[WPROBE_ATTR_NAME]);

	attr = malloc(sizeof(struct wprobe_attribute) + strlen(name) + 1);
	if (!attr)
		return -1;

	memset(attr, 0, sizeof(struct wprobe_attribute));

	if (tb[WPROBE_ATTR_ID])
		attr->id = nla_get_u32(tb[WPROBE_ATTR_ID]);

	if (tb[WPROBE_ATTR_MAC] && cb->addr)
		memcpy(cb->addr, nla_data(tb[WPROBE_ATTR_MAC]), 6);

	if (tb[WPROBE_ATTR_FLAGS])
		attr->flags = nla_get_u32(tb[WPROBE_ATTR_FLAGS]);

	if (tb[WPROBE_ATTR_TYPE])
		type = nla_get_u8(tb[WPROBE_ATTR_TYPE]);

	if ((type < WPROBE_VAL_STRING) ||
		(type > WPROBE_VAL_U64))
		type = 0;

	attr->type = type;
	strcpy(attr->name, name);
	INIT_LIST_HEAD(&attr->list);
	list_add(&attr->list, cb->list);
	return 0;
}


int
wprobe_dump_attributes(const char *ifname, bool link, struct list_head *list, char *addr)
{
	struct nl_msg *msg;
	struct wprobe_attr_cb cb;

	cb.list = list;
	cb.addr = addr;
	msg = wprobe_new_msg(ifname, WPROBE_CMD_GET_LIST, true);
	if (!msg)
		return -ENOMEM;

	if (link)
		NLA_PUT(msg, WPROBE_ATTR_MAC, 6, "\x00\x00\x00\x00\x00\x00");

	return wprobe_send_msg(msg, save_attribute_handler, &cb);

nla_put_failure:
	nlmsg_free(msg);
	return -EINVAL;
}

static struct wprobe_link *
get_link(struct list_head *list, const char *addr)
{
	struct wprobe_link *l;

	list_for_each_entry(l, list, list) {
		if (!memcmp(l->addr, addr, 6)) {
			list_del_init(&l->list);
			goto out;
		}
	}

	/* no previous link found, allocate a new one */
	l = malloc(sizeof(struct wprobe_link));
	if (!l)
		goto out;

	memset(l, 0, sizeof(struct wprobe_link));
	memcpy(l->addr, addr, sizeof(l->addr));
	INIT_LIST_HEAD(&l->list);

out:
	return l;
}

struct wprobe_save_cb {
	struct list_head *list;
	struct list_head old_list;
};

static int
save_link_handler(struct nl_msg *msg, void *arg)
{
	struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
	struct wprobe_link *link;
	struct wprobe_save_cb *cb = arg;
	const char *addr;

	nla_parse(tb, WPROBE_ATTR_LAST, genlmsg_attrdata(gnlh, 0),
			genlmsg_attrlen(gnlh, 0), attribute_policy);

	if (!tb[WPROBE_ATTR_MAC] || (nla_len(tb[WPROBE_ATTR_MAC]) != 6))
		return -1;

	addr = nla_data(tb[WPROBE_ATTR_MAC]);
	link = get_link(&cb->old_list, addr);
	if (!link)
		return -1;

	if (tb[WPROBE_ATTR_FLAGS])
		link->flags = nla_get_u32(tb[WPROBE_ATTR_FLAGS]);

	list_add_tail(&link->list, cb->list);
	return 0;
}


int
wprobe_update_links(const char *ifname, struct list_head *list)
{
	struct wprobe_link *l, *tmp;
	struct nl_msg *msg;
	struct wprobe_save_cb cb;
	int err;

	INIT_LIST_HEAD(&cb.old_list);
	list_splice_init(list, &cb.old_list);
	cb.list = list;

	msg = wprobe_new_msg(ifname, WPROBE_CMD_GET_LINKS, true);
	if (!msg)
		return -ENOMEM;

	err = wprobe_send_msg(msg, save_link_handler, &cb);
	if (err < 0)
		return err;

	list_for_each_entry_safe(l, tmp, &cb.old_list, list) {
		list_del(&l->list);
		free(l);
	}

	return 0;
}

void
wprobe_measure(const char *ifname)
{
	struct nl_msg *msg;

	msg = wprobe_new_msg(ifname, WPROBE_CMD_MEASURE, false);
	if (!msg)
		return;

	wprobe_send_msg(msg, NULL, NULL);
}

struct wprobe_request_cb {
	struct list_head *list;
	struct list_head old_list;
	char *addr;
};

static int
save_attrdata_handler(struct nl_msg *msg, void *arg)
{
	struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
	struct wprobe_request_cb *cb = arg;
	struct wprobe_attribute *attr;
	int type, id;

	nla_parse(tb, WPROBE_ATTR_LAST, genlmsg_attrdata(gnlh, 0),
			genlmsg_attrlen(gnlh, 0), attribute_policy);

	if (!tb[WPROBE_ATTR_ID])
		return -1;

	if (!tb[WPROBE_ATTR_TYPE])
		return -1;

	id = nla_get_u32(tb[WPROBE_ATTR_ID]);
	list_for_each_entry(attr, &cb->old_list, list) {
		if (attr->id == id)
			goto found;
	}
	/* not found */
	return -1;

found:
	list_del_init(&attr->list);

	type = nla_get_u8(tb[WPROBE_ATTR_TYPE]);
	if (type != attr->type) {
		DPRINTF("WARNING: type mismatch for %s attribute '%s' (%d != %d)\n",
			(cb->addr ? "link" : "global"),
			attr->name,
			type, attr->type);
		goto out;
	}

	if ((type < WPROBE_VAL_STRING) ||
		(type > WPROBE_VAL_U64))
		goto out;

	memset(&attr->val, 0, sizeof(attr->val));

#define HANDLE_INT_TYPE(_idx, _type) \
	case WPROBE_VAL_S##_type: \
	case WPROBE_VAL_U##_type: \
		attr->val.U##_type = nla_get_u##_type(tb[_idx]); \
		break

	switch(type) {
		HANDLE_INT_TYPE(type, 8);
		HANDLE_INT_TYPE(type, 16);
		HANDLE_INT_TYPE(type, 32);
		HANDLE_INT_TYPE(type, 64);
		case WPROBE_VAL_STRING:
			/* unimplemented */
			break;
	}
#undef HANDLE_TYPE

	if (attr->flags & WPROBE_F_KEEPSTAT) {
		if (tb[WPROBE_VAL_SUM])
			attr->val.s = nla_get_u64(tb[WPROBE_VAL_SUM]);

		if (tb[WPROBE_VAL_SUM_SQ])
			attr->val.ss = nla_get_u64(tb[WPROBE_VAL_SUM_SQ]);

		if (tb[WPROBE_VAL_SAMPLES])
			attr->val.n = nla_get_u32(tb[WPROBE_VAL_SAMPLES]);

		if (attr->val.n > 0) {
			float avg = ((float) attr->val.s) / attr->val.n;
			float stdev = sqrt((((float) attr->val.ss) / attr->val.n) - (avg * avg));
			attr->val.avg = avg;
			attr->val.stdev = stdev;
		}
	}

out:
	list_add_tail(&attr->list, cb->list);
	return 0;
}


int
wprobe_request_data(const char *ifname, struct list_head *attrs, const unsigned char *addr, int scale)
{
	struct wprobe_request_cb cb;
	struct nl_msg *msg;
	int err;

	msg = wprobe_new_msg(ifname, WPROBE_CMD_GET_INFO, true);
	if (!msg)
		return -ENOMEM;

	if (scale < 0)
		NLA_PUT_U32(msg, WPROBE_ATTR_FLAGS, WPROBE_F_RESET);
	else if (scale > 0)
		NLA_PUT_U32(msg, WPROBE_ATTR_SCALE, scale);

	if (addr)
		NLA_PUT(msg, WPROBE_ATTR_MAC, 6, addr);

nla_put_failure:
	INIT_LIST_HEAD(&cb.old_list);
	list_splice_init(attrs, &cb.old_list);
	cb.list = attrs;

	err = wprobe_send_msg(msg, save_attrdata_handler, &cb);
	list_splice(&cb.old_list, attrs->prev);
	return err;
}