summaryrefslogtreecommitdiffstats
path: root/net/wireless/wext-spy.c
blob: b379a03716539764e5c708f132dae17632bcc3e9 (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
/*
 * This file implement the Wireless Extensions spy API.
 *
 * Authors :	Jean Tourrilhes - HPL - <jt@hpl.hp.com>
 * Copyright (c) 1997-2007 Jean Tourrilhes, All Rights Reserved.
 *
 * (As all part of the Linux kernel, this file is GPL)
 */

#include <linux/wireless.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/export.h>
#include <net/iw_handler.h>
#include <net/arp.h>
#include <net/wext.h>

static inline struct iw_spy_data *get_spydata(struct net_device *dev)
{
	/* This is the new way */
	if (dev->wireless_data)
		return dev->wireless_data->spy_data;
	return NULL;
}

int iw_handler_set_spy(struct net_device *	dev,
		       struct iw_request_info *	info,
		       union iwreq_data *	wrqu,
		       char *			extra)
{
	struct iw_spy_data *	spydata = get_spydata(dev);
	struct sockaddr *	address = (struct sockaddr *) extra;

	/* Make sure driver is not buggy or using the old API */
	if (!spydata)
		return -EOPNOTSUPP;

	/* Disable spy collection while we copy the addresses.
	 * While we copy addresses, any call to wireless_spy_update()
	 * will NOP. This is OK, as anyway the addresses are changing. */
	spydata->spy_number = 0;

	/* We want to operate without locking, because wireless_spy_update()
	 * most likely will happen in the interrupt handler, and therefore
	 * have its own locking constraints and needs performance.
	 * The rtnl_lock() make sure we don't race with the other iw_handlers.
	 * This make sure wireless_spy_update() "see" that the spy list
	 * is temporarily disabled. */
	smp_wmb();

	/* Are there are addresses to copy? */
	if (wrqu->data.length > 0) {
		int i;

		/* Copy addresses */
		for (i = 0; i < wrqu->data.length; i++)
			memcpy(spydata->spy_address[i], address[i].sa_data,
			       ETH_ALEN);
		/* Reset stats */
		memset(spydata->spy_stat, 0,
		       sizeof(struct iw_quality) * IW_MAX_SPY);
	}

	/* Make sure above is updated before re-enabling */
	smp_wmb();

	/* Enable addresses */
	spydata->spy_number = wrqu->data.length;

	return 0;
}
EXPORT_SYMBOL(iw_handler_set_spy);

int iw_handler_get_spy(struct net_device *	dev,
		       struct iw_request_info *	info,
		       union iwreq_data *	wrqu,
		       char *			extra)
{
	struct iw_spy_data *	spydata = get_spydata(dev);
	struct sockaddr *	address = (struct sockaddr *) extra;
	int			i;

	/* Make sure driver is not buggy or using the old API */
	if (!spydata)
		return -EOPNOTSUPP;

	wrqu->data.length = spydata->spy_number;

	/* Copy addresses. */
	for (i = 0; i < spydata->spy_number; i++) 	{
		memcpy(address[i].sa_data, spydata->spy_address[i], ETH_ALEN);
		address[i].sa_family = AF_UNIX;
	}
	/* Copy stats to the user buffer (just after). */
	if (spydata->spy_number > 0)
		memcpy(extra  + (sizeof(struct sockaddr) *spydata->spy_number),
		       spydata->spy_stat,
		       sizeof(struct iw_quality) * spydata->spy_number);
	/* Reset updated flags. */
	for (i = 0; i < spydata->spy_number; i++)
		spydata->spy_stat[i].updated &= ~IW_QUAL_ALL_UPDATED;
	return 0;
}
EXPORT_SYMBOL(iw_handler_get_spy);

/*------------------------------------------------------------------*/
/*
 * Standard Wireless Handler : set spy threshold
 */
int iw_handler_set_thrspy(struct net_device *	dev,
			  struct iw_request_info *info,
			  union iwreq_data *	wrqu,
			  char *		extra)
{
	struct iw_spy_data *	spydata = get_spydata(dev);
	struct iw_thrspy *	threshold = (struct iw_thrspy *) extra;

	/* Make sure driver is not buggy or using the old API */
	if (!spydata)
		return -EOPNOTSUPP;

	/* Just do it */
	spydata->spy_thr_low = threshold->low;
	spydata->spy_thr_high = threshold->high;

	/* Clear flag */
	memset(spydata->spy_thr_under, '\0', sizeof(spydata->spy_thr_under));

	return 0;
}
EXPORT_SYMBOL(iw_handler_set_thrspy);

/*------------------------------------------------------------------*/
/*
 * Standard Wireless Handler : get spy threshold
 */
int iw_handler_get_thrspy(struct net_device *	dev,
			  struct iw_request_info *info,
			  union iwreq_data *	wrqu,
			  char *		extra)
{
	struct iw_spy_data *	spydata = get_spydata(dev);
	struct iw_thrspy *	threshold = (struct iw_thrspy *) extra;

	/* Make sure driver is not buggy or using the old API */
	if (!spydata)
		return -EOPNOTSUPP;

	/* Just do it */
	threshold->low = spydata->spy_thr_low;
	threshold->high = spydata->spy_thr_high;

	return 0;
}
EXPORT_SYMBOL(iw_handler_get_thrspy);

/*------------------------------------------------------------------*/
/*
 * Prepare and send a Spy Threshold event
 */
static void iw_send_thrspy_event(struct net_device *	dev,
				 struct iw_spy_data *	spydata,
				 unsigned char *	address,
				 struct iw_quality *	wstats)
{
	union iwreq_data	wrqu;
	struct iw_thrspy	threshold;

	/* Init */
	wrqu.data.length = 1;
	wrqu.data.flags = 0;
	/* Copy address */
	memcpy(threshold.addr.sa_data, address, ETH_ALEN);
	threshold.addr.sa_family = ARPHRD_ETHER;
	/* Copy stats */
	threshold.qual = *wstats;
	/* Copy also thresholds */
	threshold.low = spydata->spy_thr_low;
	threshold.high = spydata->spy_thr_high;

	/* Send event to user space */
	wireless_send_event(dev, SIOCGIWTHRSPY, &wrqu, (char *) &threshold);
}

/* ---------------------------------------------------------------- */
/*
 * Call for the driver to update the spy data.
 * For now, the spy data is a simple array. As the size of the array is
 * small, this is good enough. If we wanted to support larger number of
 * spy addresses, we should use something more efficient...
 */
void wireless_spy_update(struct net_device *	dev,
			 unsigned char *	address,
			 struct iw_quality *	wstats)
{
	struct iw_spy_data *	spydata = get_spydata(dev);
	int			i;
	int			match = -1;

	/* Make sure driver is not buggy or using the old API */
	if (!spydata)
		return;

	/* Update all records that match */
	for (i = 0; i < spydata->spy_number; i++)
		if (ether_addr_equal(address, spydata->spy_address[i])) {
			memcpy(&(spydata->spy_stat[i]), wstats,
			       sizeof(struct iw_quality));
			match = i;
		}

	/* Generate an event if we cross the spy threshold.
	 * To avoid event storms, we have a simple hysteresis : we generate
	 * event only when we go under the low threshold or above the
	 * high threshold. */
	if (match >= 0) {
		if (spydata->spy_thr_under[match]) {
			if (wstats->level > spydata->spy_thr_high.level) {
				spydata->spy_thr_under[match] = 0;
				iw_send_thrspy_event(dev, spydata,
						     address, wstats);
			}
		} else {
			if (wstats->level < spydata->spy_thr_low.level) {
				spydata->spy_thr_under[match] = 1;
				iw_send_thrspy_event(dev, spydata,
						     address, wstats);
			}
		}
	}
}
EXPORT_SYMBOL(wireless_spy_update);