2 * P2P - generic helper functions
3 * Copyright (c) 2009, Atheros Communications
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
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
21 * This function generates a random string using the following character set:
22 * 'A'-'Z', 'a'-'z', '0'-'9'.
24 int p2p_random(char *buf, size_t len)
28 u8 letters = 'Z' - 'A' + 1;
31 if (os_get_random((unsigned char *) buf, len))
33 /* Character set: 'A'-'Z', 'a'-'z', '0'-'9' */
34 for (i = 0; i < len; i++) {
36 val %= 2 * letters + numbers;
39 else if (val < 2 * letters)
40 buf[i] = 'a' + (val - letters);
42 buf[i] = '0' + (val - 2 * letters);
50 * p2p_channel_to_freq - Convert channel info to frequency
51 * @op_class: Operating class
52 * @channel: Channel number
53 * Returns: Frequency in MHz or -1 if the specified channel is unknown
55 int p2p_channel_to_freq(int op_class, int channel)
57 /* Table E-4 in IEEE Std 802.11-2012 - Global operating classes */
58 /* TODO: more operating 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_freq_to_channel - Convert frequency into channel info
104 * @op_class: Buffer for returning operating class
105 * @channel: Buffer for returning channel number
106 * Returns: 0 on success, -1 if the specified frequency is unknown
108 int p2p_freq_to_channel(unsigned int freq, u8 *op_class, u8 *channel)
110 /* TODO: more operating classes */
111 if (freq >= 2412 && freq <= 2472) {
112 *op_class = 81; /* 2.407 GHz, channels 1..13 */
113 *channel = (freq - 2407) / 5;
118 *op_class = 82; /* channel 14 */
123 if (freq >= 5180 && freq <= 5240) {
124 *op_class = 115; /* 5 GHz, channels 36..48 */
125 *channel = (freq - 5000) / 5;
129 if (freq >= 5745 && freq <= 5805) {
130 *op_class = 124; /* 5 GHz, channels 149..161 */
131 *channel = (freq - 5000) / 5;
139 static void p2p_reg_class_intersect(const struct p2p_reg_class *a,
140 const struct p2p_reg_class *b,
141 struct p2p_reg_class *res)
145 res->reg_class = a->reg_class;
147 for (i = 0; i < a->channels; i++) {
148 for (j = 0; j < b->channels; j++) {
149 if (a->channel[i] != b->channel[j])
151 res->channel[res->channels] = a->channel[i];
153 if (res->channels == P2P_MAX_REG_CLASS_CHANNELS)
161 * p2p_channels_intersect - Intersection of supported channel lists
162 * @a: First set of supported channels
163 * @b: Second set of supported channels
164 * @res: Data structure for returning the intersection of support channels
166 * This function can be used to find a common set of supported channels. Both
167 * input channels sets are assumed to use the same country code. If different
168 * country codes are used, the regulatory class numbers may not be matched
169 * correctly and results are undefined.
171 void p2p_channels_intersect(const struct p2p_channels *a,
172 const struct p2p_channels *b,
173 struct p2p_channels *res)
177 os_memset(res, 0, sizeof(*res));
179 for (i = 0; i < a->reg_classes; i++) {
180 const struct p2p_reg_class *a_reg = &a->reg_class[i];
181 for (j = 0; j < b->reg_classes; j++) {
182 const struct p2p_reg_class *b_reg = &b->reg_class[j];
183 if (a_reg->reg_class != b_reg->reg_class)
185 p2p_reg_class_intersect(
187 &res->reg_class[res->reg_classes]);
188 if (res->reg_class[res->reg_classes].channels) {
190 if (res->reg_classes == P2P_MAX_REG_CLASSES)
199 * p2p_channels_includes - Check whether a channel is included in the list
200 * @channels: List of supported channels
201 * @reg_class: Regulatory class of the channel to search
202 * @channel: Channel number of the channel to search
203 * Returns: 1 if channel was found or 0 if not
205 int p2p_channels_includes(const struct p2p_channels *channels, u8 reg_class,
209 for (i = 0; i < channels->reg_classes; i++) {
210 const struct p2p_reg_class *reg = &channels->reg_class[i];
211 if (reg->reg_class != reg_class)
213 for (j = 0; j < reg->channels; j++) {
214 if (reg->channel[j] == channel)
222 int p2p_channels_includes_freq(const struct p2p_channels *channels,
226 for (i = 0; i < channels->reg_classes; i++) {
227 const struct p2p_reg_class *reg = &channels->reg_class[i];
228 for (j = 0; j < reg->channels; j++) {
229 if (p2p_channel_to_freq(reg->reg_class,
230 reg->channel[j]) == (int) freq)
238 int p2p_supported_freq(struct p2p_data *p2p, unsigned int freq)
240 u8 op_reg_class, op_channel;
241 if (p2p_freq_to_channel(freq, &op_reg_class, &op_channel) < 0)
243 return p2p_channels_includes(&p2p->cfg->channels, op_reg_class,
248 unsigned int p2p_get_pref_freq(struct p2p_data *p2p,
249 const struct p2p_channels *channels)
254 if (channels == NULL) {
255 if (p2p->cfg->num_pref_chan) {
256 freq = p2p_channel_to_freq(
257 p2p->cfg->pref_chan[0].op_class,
258 p2p->cfg->pref_chan[0].chan);
265 for (i = 0; p2p->cfg->pref_chan && i < p2p->cfg->num_pref_chan; i++) {
266 freq = p2p_channel_to_freq(p2p->cfg->pref_chan[i].op_class,
267 p2p->cfg->pref_chan[i].chan);
268 if (p2p_channels_includes_freq(channels, freq))