2 * P2P - generic helper functions
3 * Copyright (c) 2009, Atheros Communications
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * Alternatively, this software may be distributed under the terms of BSD
12 * See README and COPYING for more details.
22 * p2p_random - Generate random string for SSID and passphrase
23 * @buf: Buffer for returning the result
24 * @len: Number of octets to write to the buffer
25 * Returns: 0 on success, -1 on failure
27 * This function generates a random string using the following character set:
28 * 'A'-'Z', 'a'-'z', '0'-'9'.
30 int p2p_random(char *buf, size_t len)
34 u8 letters = 'Z' - 'A' + 1;
37 if (os_get_random((unsigned char *) buf, len))
39 /* Character set: 'A'-'Z', 'a'-'z', '0'-'9' */
40 for (i = 0; i < len; i++) {
42 val %= 2 * letters + numbers;
45 else if (val < 2 * letters)
46 buf[i] = 'a' + (val - letters);
48 buf[i] = '0' + (val - 2 * letters);
55 static int p2p_channel_to_freq_j4(int reg_class, int channel)
57 /* Table J-4 in P802.11REVmb/D4.0 - Global operating classes */
58 /* TODO: more regulatory classes */
62 if (channel < 1 || channel > 13)
64 return 2407 + 5 * channel;
69 return 2414 + 5 * channel;
70 case 83: /* channels 1..9; 40 MHz */
71 case 84: /* channels 5..13; 40 MHz */
72 if (channel < 1 || channel > 13)
74 return 2407 + 5 * channel;
75 case 115: /* channels 36,40,44,48; indoor only */
76 case 118: /* channels 52,56,60,64; dfs */
77 if (channel < 36 || channel > 64)
79 return 5000 + 5 * channel;
80 case 124: /* channels 149,153,157,161 */
81 case 125: /* channels 149,153,157,161,165,169 */
82 if (channel < 149 || channel > 161)
84 return 5000 + 5 * channel;
85 case 116: /* channels 36,44; 40 MHz; indoor only */
86 case 117: /* channels 40,48; 40 MHz; indoor only */
87 case 119: /* channels 52,60; 40 MHz; dfs */
88 case 120: /* channels 56,64; 40 MHz; dfs */
89 if (channel < 36 || channel > 64)
91 return 5000 + 5 * channel;
92 case 126: /* channels 149,157; 40 MHz */
93 case 127: /* channels 153,161; 40 MHz */
94 if (channel < 149 || channel > 161)
96 return 5000 + 5 * channel;
103 * p2p_channel_to_freq - Convert channel info to frequency
104 * @country: Country code
105 * @reg_class: Regulatory class
106 * @channel: Channel number
107 * Returns: Frequency in MHz or -1 if the specified channel is unknown
109 int p2p_channel_to_freq(const char *country, int reg_class, int channel)
111 if (country[2] == 0x04)
112 return p2p_channel_to_freq_j4(reg_class, channel);
114 /* These are mainly for backwards compatibility; to be removed */
116 case 1: /* US/1, EU/1, JP/1 = 5 GHz, channels 36,40,44,48 */
117 if (channel < 36 || channel > 48)
119 return 5000 + 5 * channel;
120 case 3: /* US/3 = 5 GHz, channels 149,153,157,161 */
121 case 5: /* US/5 = 5 GHz, channels 149,153,157,161 */
122 if (channel < 149 || channel > 161)
124 return 5000 + 5 * channel;
125 case 4: /* EU/4 = 2.407 GHz, channels 1..13 */
126 case 12: /* US/12 = 2.407 GHz, channels 1..11 */
127 case 30: /* JP/30 = 2.407 GHz, channels 1..13 */
128 if (channel < 1 || channel > 13)
130 return 2407 + 5 * channel;
131 case 31: /* JP/31 = 2.414 GHz, channel 14 */
134 return 2414 + 5 * channel;
142 * p2p_freq_to_channel - Convert frequency into channel info
143 * @country: Country code
144 * @reg_class: Buffer for returning regulatory class
145 * @channel: Buffer for returning channel number
146 * Returns: 0 on success, -1 if the specified frequency is unknown
148 int p2p_freq_to_channel(const char *country, unsigned int freq, u8 *reg_class,
151 /* TODO: more operating classes */
152 if (freq >= 2412 && freq <= 2472) {
153 *reg_class = 81; /* 2.407 GHz, channels 1..13 */
154 *channel = (freq - 2407) / 5;
159 *reg_class = 82; /* channel 14 */
164 if (freq >= 5180 && freq <= 5240) {
165 *reg_class = 115; /* 5 GHz, channels 36..48 */
166 *channel = (freq - 5000) / 5;
170 if (freq >= 5745 && freq <= 5805) {
171 *reg_class = 124; /* 5 GHz, channels 149..161 */
172 *channel = (freq - 5000) / 5;
180 static void p2p_reg_class_intersect(const struct p2p_reg_class *a,
181 const struct p2p_reg_class *b,
182 struct p2p_reg_class *res)
186 res->reg_class = a->reg_class;
188 for (i = 0; i < a->channels; i++) {
189 for (j = 0; j < b->channels; j++) {
190 if (a->channel[i] != b->channel[j])
192 res->channel[res->channels] = a->channel[i];
194 if (res->channels == P2P_MAX_REG_CLASS_CHANNELS)
202 * p2p_channels_intersect - Intersection of supported channel lists
203 * @a: First set of supported channels
204 * @b: Second set of supported channels
205 * @res: Data structure for returning the intersection of support channels
207 * This function can be used to find a common set of supported channels. Both
208 * input channels sets are assumed to use the same country code. If different
209 * country codes are used, the regulatory class numbers may not be matched
210 * correctly and results are undefined.
212 void p2p_channels_intersect(const struct p2p_channels *a,
213 const struct p2p_channels *b,
214 struct p2p_channels *res)
218 os_memset(res, 0, sizeof(*res));
220 for (i = 0; i < a->reg_classes; i++) {
221 const struct p2p_reg_class *a_reg = &a->reg_class[i];
222 for (j = 0; j < b->reg_classes; j++) {
223 const struct p2p_reg_class *b_reg = &b->reg_class[j];
224 if (a_reg->reg_class != b_reg->reg_class)
226 p2p_reg_class_intersect(
228 &res->reg_class[res->reg_classes]);
229 if (res->reg_class[res->reg_classes].channels) {
231 if (res->reg_classes == P2P_MAX_REG_CLASSES)
240 * p2p_channels_includes - Check whether a channel is included in the list
241 * @channels: List of supported channels
242 * @reg_class: Regulatory class of the channel to search
243 * @channel: Channel number of the channel to search
244 * Returns: 1 if channel was found or 0 if not
246 int p2p_channels_includes(const struct p2p_channels *channels, u8 reg_class,
250 for (i = 0; i < channels->reg_classes; i++) {
251 const struct p2p_reg_class *reg = &channels->reg_class[i];
252 if (reg->reg_class != reg_class)
254 for (j = 0; j < reg->channels; j++) {
255 if (reg->channel[j] == channel)