[thirdparty/hostap.git] / src / p2p / p2p_utils.c

/*
 * P2P - generic helper functions
 * Copyright (c) 2009, Atheros Communications
 *
 * This software may be distributed under the terms of the BSD license.
 * See README for more details.
 */

#include "includes.h"

#include "common.h"
#include "p2p_i.h"


/**
 * p2p_random - Generate random string for SSID and passphrase
 * @buf: Buffer for returning the result
 * @len: Number of octets to write to the buffer
 * Returns: 0 on success, -1 on failure
 *
 * This function generates a random string using the following character set:
 * 'A'-'Z', 'a'-'z', '0'-'9'.
 */
int p2p_random(char *buf, size_t len)
{
	u8 val;
	size_t i;
	u8 letters = 'Z' - 'A' + 1;
	u8 numbers = 10;

	if (os_get_random((unsigned char *) buf, len))
		return -1;
	/* Character set: 'A'-'Z', 'a'-'z', '0'-'9' */
	for (i = 0; i < len; i++) {
		val = buf[i];
		val %= 2 * letters + numbers;
		if (val < letters)
			buf[i] = 'A' + val;
		else if (val < 2 * letters)
			buf[i] = 'a' + (val - letters);
		else
			buf[i] = '0' + (val - 2 * letters);
	}

	return 0;
}


static int p2p_channel_to_freq_j4(int reg_class, int channel)
{
	/* Table J-4 in P802.11REVmb/D4.0 - Global operating classes */
	/* TODO: more regulatory classes */
	switch (reg_class) {
	case 81:
		/* channels 1..13 */
		if (channel < 1 || channel > 13)
			return -1;
		return 2407 + 5 * channel;
	case 82:
		/* channel 14 */
		if (channel != 14)
			return -1;
		return 2414 + 5 * channel;
	case 83: /* channels 1..9; 40 MHz */
	case 84: /* channels 5..13; 40 MHz */
		if (channel < 1 || channel > 13)
			return -1;
		return 2407 + 5 * channel;
	case 115: /* channels 36,40,44,48; indoor only */
	case 118: /* channels 52,56,60,64; dfs */
		if (channel < 36 || channel > 64)
			return -1;
		return 5000 + 5 * channel;
	case 124: /* channels 149,153,157,161 */
	case 125: /* channels 149,153,157,161,165,169 */
		if (channel < 149 || channel > 161)
			return -1;
		return 5000 + 5 * channel;
	case 116: /* channels 36,44; 40 MHz; indoor only */
	case 117: /* channels 40,48; 40 MHz; indoor only */
	case 119: /* channels 52,60; 40 MHz; dfs */
	case 120: /* channels 56,64; 40 MHz; dfs */
		if (channel < 36 || channel > 64)
			return -1;
		return 5000 + 5 * channel;
	case 126: /* channels 149,157; 40 MHz */
	case 127: /* channels 153,161; 40 MHz */
		if (channel < 149 || channel > 161)
			return -1;
		return 5000 + 5 * channel;
	}
	return -1;
}


/**
 * p2p_channel_to_freq - Convert channel info to frequency
 * @country: Country code
 * @reg_class: Regulatory class
 * @channel: Channel number
 * Returns: Frequency in MHz or -1 if the specified channel is unknown
 */
int p2p_channel_to_freq(const char *country, int reg_class, int channel)
{
	if (country[2] == 0x04)
		return p2p_channel_to_freq_j4(reg_class, channel);

	/* These are mainly for backwards compatibility; to be removed */
	switch (reg_class) {
	case 1: /* US/1, EU/1, JP/1 = 5 GHz, channels 36,40,44,48 */
		if (channel < 36 || channel > 48)
			return -1;
		return 5000 + 5 * channel;
	case 3: /* US/3 = 5 GHz, channels 149,153,157,161 */
	case 5: /* US/5 = 5 GHz, channels 149,153,157,161 */
		if (channel < 149 || channel > 161)
			return -1;
		return 5000 + 5 * channel;
	case 4: /* EU/4 = 2.407 GHz, channels 1..13 */
	case 12: /* US/12 = 2.407 GHz, channels 1..11 */
	case 30: /* JP/30 = 2.407 GHz, channels 1..13 */
		if (channel < 1 || channel > 13)
			return -1;
		return 2407 + 5 * channel;
	case 31: /* JP/31 = 2.414 GHz, channel 14 */
		if (channel != 14)
			return -1;
		return 2414 + 5 * channel;
	}

	return -1;
}


/**
 * p2p_freq_to_channel - Convert frequency into channel info
 * @country: Country code
 * @reg_class: Buffer for returning regulatory class
 * @channel: Buffer for returning channel number
 * Returns: 0 on success, -1 if the specified frequency is unknown
 */
int p2p_freq_to_channel(const char *country, unsigned int freq, u8 *reg_class,
			u8 *channel)
{
	/* TODO: more operating classes */
	if (freq >= 2412 && freq <= 2472) {
		*reg_class = 81; /* 2.407 GHz, channels 1..13 */
		*channel = (freq - 2407) / 5;
		return 0;
	}

	if (freq == 2484) {
		*reg_class = 82; /* channel 14 */
		*channel = 14;
		return 0;
	}

	if (freq >= 5180 && freq <= 5240) {
		*reg_class = 115; /* 5 GHz, channels 36..48 */
		*channel = (freq - 5000) / 5;
		return 0;
	}

	if (freq >= 5745 && freq <= 5805) {
		*reg_class = 124; /* 5 GHz, channels 149..161 */
		*channel = (freq - 5000) / 5;
		return 0;
	}

	return -1;
}


static void p2p_reg_class_intersect(const struct p2p_reg_class *a,
				    const struct p2p_reg_class *b,
				    struct p2p_reg_class *res)
{
	size_t i, j;

	res->reg_class = a->reg_class;

	for (i = 0; i < a->channels; i++) {
		for (j = 0; j < b->channels; j++) {
			if (a->channel[i] != b->channel[j])
				continue;
			res->channel[res->channels] = a->channel[i];
			res->channels++;
			if (res->channels == P2P_MAX_REG_CLASS_CHANNELS)
				return;
		}
	}
}


/**
 * p2p_channels_intersect - Intersection of supported channel lists
 * @a: First set of supported channels
 * @b: Second set of supported channels
 * @res: Data structure for returning the intersection of support channels
 *
 * This function can be used to find a common set of supported channels. Both
 * input channels sets are assumed to use the same country code. If different
 * country codes are used, the regulatory class numbers may not be matched
 * correctly and results are undefined.
 */
void p2p_channels_intersect(const struct p2p_channels *a,
			    const struct p2p_channels *b,
			    struct p2p_channels *res)
{
	size_t i, j;

	os_memset(res, 0, sizeof(*res));

	for (i = 0; i < a->reg_classes; i++) {
		const struct p2p_reg_class *a_reg = &a->reg_class[i];
		for (j = 0; j < b->reg_classes; j++) {
			const struct p2p_reg_class *b_reg = &b->reg_class[j];
			if (a_reg->reg_class != b_reg->reg_class)
				continue;
			p2p_reg_class_intersect(
				a_reg, b_reg,
				&res->reg_class[res->reg_classes]);
			if (res->reg_class[res->reg_classes].channels) {
				res->reg_classes++;
				if (res->reg_classes == P2P_MAX_REG_CLASSES)
					return;
			}
		}
	}
}


/**
 * p2p_channels_includes - Check whether a channel is included in the list
 * @channels: List of supported channels
 * @reg_class: Regulatory class of the channel to search
 * @channel: Channel number of the channel to search
 * Returns: 1 if channel was found or 0 if not
 */
int p2p_channels_includes(const struct p2p_channels *channels, u8 reg_class,
			  u8 channel)
{
	size_t i, j;
	for (i = 0; i < channels->reg_classes; i++) {
		const struct p2p_reg_class *reg = &channels->reg_class[i];
		if (reg->reg_class != reg_class)
			continue;
		for (j = 0; j < reg->channels; j++) {
			if (reg->channel[j] == channel)
				return 1;
		}
	}
	return 0;
}


int p2p_supported_freq(struct p2p_data *p2p, unsigned int freq)
{
	u8 op_reg_class, op_channel;
	if (p2p_freq_to_channel(p2p->cfg->country, freq,
				&op_reg_class, &op_channel) < 0)
		return 0;
	return p2p_channels_includes(&p2p->cfg->channels, op_reg_class,
				     op_channel);
}
Commit	Line	Data
b22128ef JM	1	/*
	2	* P2P - generic helper functions
	3	* Copyright (c) 2009, Atheros Communications
	4	*
e22d4d95 JM	5	* This software may be distributed under the terms of the BSD license.
e22d4d95 JM	6	* See README for more details.
b22128ef JM	7	*/
	8
	9	#include "includes.h"
	10
	11	#include "common.h"
	12	#include "p2p_i.h"
	13
	14
	15	/**
	16	* p2p_random - Generate random string for SSID and passphrase
	17	* @buf: Buffer for returning the result
	18	* @len: Number of octets to write to the buffer
	19	* Returns: 0 on success, -1 on failure
	20	*
	21	* This function generates a random string using the following character set:
	22	* 'A'-'Z', 'a'-'z', '0'-'9'.
	23	*/
	24	int p2p_random(char *buf, size_t len)
	25	{
	26	u8 val;
	27	size_t i;
	28	u8 letters = 'Z' - 'A' + 1;
	29	u8 numbers = 10;
	30
	31	if (os_get_random((unsigned char *) buf, len))
	32	return -1;
	33	/* Character set: 'A'-'Z', 'a'-'z', '0'-'9' */
	34	for (i = 0; i < len; i++) {
	35	val = buf[i];
	36	val %= 2 * letters + numbers;
	37	if (val < letters)
	38	buf[i] = 'A' + val;
	39	else if (val < 2 * letters)
	40	buf[i] = 'a' + (val - letters);
	41	else
	42	buf[i] = '0' + (val - 2 * letters);
	43	}
	44
	45	return 0;
	46	}
	47
	48
	49	static int p2p_channel_to_freq_j4(int reg_class, int channel)
	50	{
	51	/* Table J-4 in P802.11REVmb/D4.0 - Global operating classes */
	52	/* TODO: more regulatory classes */
	53	switch (reg_class) {
	54	case 81:
	55	/* channels 1..13 */
	56	if (channel < 1 \|\| channel > 13)
	57	return -1;
	58	return 2407 + 5 * channel;
	59	case 82:
	60	/* channel 14 */
	61	if (channel != 14)
	62	return -1;
	63	return 2414 + 5 * channel;
	64	case 83: /* channels 1..9; 40 MHz */
	65	case 84: /* channels 5..13; 40 MHz */
	66	if (channel < 1 \|\| channel > 13)
	67	return -1;
	68	return 2407 + 5 * channel;
	69	case 115: /* channels 36,40,44,48; indoor only */
	70	case 118: /* channels 52,56,60,64; dfs */
71	if (channel < 36 \|\| channel > 64)
72	return -1;
73	return 5000 + 5 * channel;
74	case 124: /* channels 149,153,157,161 */
75	case 125: /* channels 149,153,157,161,165,169 */
76	if (channel < 149 \|\| channel > 161)
77	return -1;
78	return 5000 + 5 * channel;
79	case 116: /* channels 36,44; 40 MHz; indoor only */
80	case 117: /* channels 40,48; 40 MHz; indoor only */
81	case 119: /* channels 52,60; 40 MHz; dfs */
82	case 120: /* channels 56,64; 40 MHz; dfs */
83	if (channel < 36 \|\| channel > 64)
84	return -1;
85	return 5000 + 5 * channel;
86	case 126: /* channels 149,157; 40 MHz */
87	case 127: /* channels 153,161; 40 MHz */
88	if (channel < 149 \|\| channel > 161)
89	return -1;
90	return 5000 + 5 * channel;
91	}
92	return -1;
93	}
94
95
96	/**
97	* p2p_channel_to_freq - Convert channel info to frequency
98	* @country: Country code
99	* @reg_class: Regulatory class
100	* @channel: Channel number
101	* Returns: Frequency in MHz or -1 if the specified channel is unknown
102	*/
103	int p2p_channel_to_freq(const char *country, int reg_class, int channel)
104	{
105	if (country[2] == 0x04)
106	return p2p_channel_to_freq_j4(reg_class, channel);
107
108	/* These are mainly for backwards compatibility; to be removed */
109	switch (reg_class) {
110	case 1: /* US/1, EU/1, JP/1 = 5 GHz, channels 36,40,44,48 */
111	if (channel < 36 \|\| channel > 48)
112	return -1;
113	return 5000 + 5 * channel;
114	case 3: /* US/3 = 5 GHz, channels 149,153,157,161 */
115	case 5: /* US/5 = 5 GHz, channels 149,153,157,161 */
116	if (channel < 149 \|\| channel > 161)
117	return -1;
118	return 5000 + 5 * channel;
119	case 4: /* EU/4 = 2.407 GHz, channels 1..13 */
120	case 12: /* US/12 = 2.407 GHz, channels 1..11 */
121	case 30: /* JP/30 = 2.407 GHz, channels 1..13 */
122	if (channel < 1 \|\| channel > 13)
123	return -1;
124	return 2407 + 5 * channel;
125	case 31: /* JP/31 = 2.414 GHz, channel 14 */
126	if (channel != 14)
127	return -1;
128	return 2414 + 5 * channel;
129	}
130
131	return -1;
132	}
133
134
135	/**
136	* p2p_freq_to_channel - Convert frequency into channel info
137	* @country: Country code
138	* @reg_class: Buffer for returning regulatory class
139	* @channel: Buffer for returning channel number
140	* Returns: 0 on success, -1 if the specified frequency is unknown
141	*/
142	int p2p_freq_to_channel(const char country, unsigned int freq, u8 reg_class,
143	u8 *channel)
144	{
145	/* TODO: more operating classes */
146	if (freq >= 2412 && freq <= 2472) {
147	reg_class = 81; / 2.407 GHz, channels 1..13 */
148	*channel = (freq - 2407) / 5;
149	return 0;
150	}
151
152	if (freq == 2484) {
153	reg_class = 82; / channel 14 */
154	*channel = 14;
155	return 0;
156	}
157
158	if (freq >= 5180 && freq <= 5240) {
159	reg_class = 115; / 5 GHz, channels 36..48 */
160	*channel = (freq - 5000) / 5;
161	return 0;
162	}
163
164	if (freq >= 5745 && freq <= 5805) {
165	reg_class = 124; / 5 GHz, channels 149..161 */
166	*channel = (freq - 5000) / 5;
167	return 0;
168	}
169
170	return -1;
171	}
172
173
174	static void p2p_reg_class_intersect(const struct p2p_reg_class *a,
175	const struct p2p_reg_class *b,
176	struct p2p_reg_class *res)
177	{
178	size_t i, j;
179
180	res->reg_class = a->reg_class;
181
182	for (i = 0; i < a->channels; i++) {
183	for (j = 0; j < b->channels; j++) {
184	if (a->channel[i] != b->channel[j])
185	continue;
186	res->channel[res->channels] = a->channel[i];
187	res->channels++;
188	if (res->channels == P2P_MAX_REG_CLASS_CHANNELS)
189	return;
190	}
191	}
192	}
193
194
195	/**
196	* p2p_channels_intersect - Intersection of supported channel lists
197	* @a: First set of supported channels
198	* @b: Second set of supported channels
199	* @res: Data structure for returning the intersection of support channels
200	*
201	* This function can be used to find a common set of supported channels. Both
202	* input channels sets are assumed to use the same country code. If different
203	* country codes are used, the regulatory class numbers may not be matched
204	* correctly and results are undefined.
205	*/
206	void p2p_channels_intersect(const struct p2p_channels *a,
207	const struct p2p_channels *b,
208	struct p2p_channels *res)
209	{
210	size_t i, j;
211
212	os_memset(res, 0, sizeof(*res));
213
214	for (i = 0; i < a->reg_classes; i++) {
215	const struct p2p_reg_class *a_reg = &a->reg_class[i];
216	for (j = 0; j < b->reg_classes; j++) {
217	const struct p2p_reg_class *b_reg = &b->reg_class[j];
218	if (a_reg->reg_class != b_reg->reg_class)
219	continue;
220	p2p_reg_class_intersect(
221	a_reg, b_reg,
222	&res->reg_class[res->reg_classes]);
223	if (res->reg_class[res->reg_classes].channels) {
224	res->reg_classes++;
225	if (res->reg_classes == P2P_MAX_REG_CLASSES)
226	return;
227	}
228	}
229	}
230	}
231
232
233	/**
234	* p2p_channels_includes - Check whether a channel is included in the list
235	* @channels: List of supported channels
236	* @reg_class: Regulatory class of the channel to search
237	* @channel: Channel number of the channel to search
238	* Returns: 1 if channel was found or 0 if not
239	*/
240	int p2p_channels_includes(const struct p2p_channels *channels, u8 reg_class,
241	u8 channel)
242	{
243	size_t i, j;
244	for (i = 0; i < channels->reg_classes; i++) {
245	const struct p2p_reg_class *reg = &channels->reg_class[i];
246	if (reg->reg_class != reg_class)
247	continue;
248	for (j = 0; j < reg->channels; j++) {
249	if (reg->channel[j] == channel)
250	return 1;
251	}
252	}
253	return 0;
254	}
d054a462 JM	255
	256
	257	int p2p_supported_freq(struct p2p_data *p2p, unsigned int freq)
	258	{
	259	u8 op_reg_class, op_channel;
	260	if (p2p_freq_to_channel(p2p->cfg->country, freq,
	261	&op_reg_class, &op_channel) < 0)
	262	return 0;
	263	return p2p_channels_includes(&p2p->cfg->channels, op_reg_class,
	264	op_channel);
	265	}