1 /* 2 * P2P - generic helper functions 3 * Copyright (c) 2009, Atheros Communications 4 * 5 * This software may be distributed under the terms of the BSD license. 6 * See README for more details. 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 } 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 } 266