1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * BlueZ - Bluetooth protocol stack for Linux 4 * 5 * Copyright (C) 2021 Intel Corporation 6 */ 7 8 #include <net/bluetooth/bluetooth.h> 9 #include <net/bluetooth/hci_core.h> 10 #include <net/bluetooth/mgmt.h> 11 12 #include "eir.h" 13 14 #define PNP_INFO_SVCLASS_ID 0x1200 15 16 static u8 eir_append_name(u8 *eir, u16 eir_len, u8 type, u8 *data, u8 data_len) 17 { 18 u8 name[HCI_MAX_SHORT_NAME_LENGTH + 1]; 19 20 /* If data is already NULL terminated just pass it directly */ 21 if (data[data_len - 1] == '\0') 22 return eir_append_data(eir, eir_len, type, data, data_len); 23 24 memcpy(name, data, HCI_MAX_SHORT_NAME_LENGTH); 25 name[HCI_MAX_SHORT_NAME_LENGTH] = '\0'; 26 27 return eir_append_data(eir, eir_len, type, name, sizeof(name)); 28 } 29 30 u8 eir_append_local_name(struct hci_dev *hdev, u8 *ptr, u8 ad_len) 31 { 32 size_t short_len; 33 size_t complete_len; 34 35 /* no space left for name (+ NULL + type + len) */ 36 if ((max_adv_len(hdev) - ad_len) < HCI_MAX_SHORT_NAME_LENGTH + 3) 37 return ad_len; 38 39 /* use complete name if present and fits */ 40 complete_len = strnlen(hdev->dev_name, sizeof(hdev->dev_name)); 41 if (complete_len && complete_len <= HCI_MAX_SHORT_NAME_LENGTH) 42 return eir_append_name(ptr, ad_len, EIR_NAME_COMPLETE, 43 hdev->dev_name, complete_len + 1); 44 45 /* use short name if present */ 46 short_len = strnlen(hdev->short_name, sizeof(hdev->short_name)); 47 if (short_len) 48 return eir_append_name(ptr, ad_len, EIR_NAME_SHORT, 49 hdev->short_name, 50 short_len == HCI_MAX_SHORT_NAME_LENGTH ? 51 short_len : short_len + 1); 52 53 /* use shortened full name if present, we already know that name 54 * is longer then HCI_MAX_SHORT_NAME_LENGTH 55 */ 56 if (complete_len) 57 return eir_append_name(ptr, ad_len, EIR_NAME_SHORT, 58 hdev->dev_name, 59 HCI_MAX_SHORT_NAME_LENGTH); 60 61 return ad_len; 62 } 63 64 u8 eir_append_appearance(struct hci_dev *hdev, u8 *ptr, u8 ad_len) 65 { 66 return eir_append_le16(ptr, ad_len, EIR_APPEARANCE, hdev->appearance); 67 } 68 69 u8 eir_append_service_data(u8 *eir, u16 eir_len, u16 uuid, u8 *data, 70 u8 data_len) 71 { 72 eir[eir_len++] = sizeof(u8) + sizeof(uuid) + data_len; 73 eir[eir_len++] = EIR_SERVICE_DATA; 74 put_unaligned_le16(uuid, &eir[eir_len]); 75 eir_len += sizeof(uuid); 76 memcpy(&eir[eir_len], data, data_len); 77 eir_len += data_len; 78 79 return eir_len; 80 } 81 82 static u8 *create_uuid16_list(struct hci_dev *hdev, u8 *data, ptrdiff_t len) 83 { 84 u8 *ptr = data, *uuids_start = NULL; 85 struct bt_uuid *uuid; 86 87 if (len < 4) 88 return ptr; 89 90 list_for_each_entry(uuid, &hdev->uuids, list) { 91 u16 uuid16; 92 93 if (uuid->size != 16) 94 continue; 95 96 uuid16 = get_unaligned_le16(&uuid->uuid[12]); 97 if (uuid16 < 0x1100) 98 continue; 99 100 if (uuid16 == PNP_INFO_SVCLASS_ID) 101 continue; 102 103 if (!uuids_start) { 104 uuids_start = ptr; 105 uuids_start[0] = 1; 106 uuids_start[1] = EIR_UUID16_ALL; 107 ptr += 2; 108 } 109 110 /* Stop if not enough space to put next UUID */ 111 if ((ptr - data) + sizeof(u16) > len) { 112 uuids_start[1] = EIR_UUID16_SOME; 113 break; 114 } 115 116 *ptr++ = (uuid16 & 0x00ff); 117 *ptr++ = (uuid16 & 0xff00) >> 8; 118 uuids_start[0] += sizeof(uuid16); 119 } 120 121 return ptr; 122 } 123 124 static u8 *create_uuid32_list(struct hci_dev *hdev, u8 *data, ptrdiff_t len) 125 { 126 u8 *ptr = data, *uuids_start = NULL; 127 struct bt_uuid *uuid; 128 129 if (len < 6) 130 return ptr; 131 132 list_for_each_entry(uuid, &hdev->uuids, list) { 133 if (uuid->size != 32) 134 continue; 135 136 if (!uuids_start) { 137 uuids_start = ptr; 138 uuids_start[0] = 1; 139 uuids_start[1] = EIR_UUID32_ALL; 140 ptr += 2; 141 } 142 143 /* Stop if not enough space to put next UUID */ 144 if ((ptr - data) + sizeof(u32) > len) { 145 uuids_start[1] = EIR_UUID32_SOME; 146 break; 147 } 148 149 memcpy(ptr, &uuid->uuid[12], sizeof(u32)); 150 ptr += sizeof(u32); 151 uuids_start[0] += sizeof(u32); 152 } 153 154 return ptr; 155 } 156 157 static u8 *create_uuid128_list(struct hci_dev *hdev, u8 *data, ptrdiff_t len) 158 { 159 u8 *ptr = data, *uuids_start = NULL; 160 struct bt_uuid *uuid; 161 162 if (len < 18) 163 return ptr; 164 165 list_for_each_entry(uuid, &hdev->uuids, list) { 166 if (uuid->size != 128) 167 continue; 168 169 if (!uuids_start) { 170 uuids_start = ptr; 171 uuids_start[0] = 1; 172 uuids_start[1] = EIR_UUID128_ALL; 173 ptr += 2; 174 } 175 176 /* Stop if not enough space to put next UUID */ 177 if ((ptr - data) + 16 > len) { 178 uuids_start[1] = EIR_UUID128_SOME; 179 break; 180 } 181 182 memcpy(ptr, uuid->uuid, 16); 183 ptr += 16; 184 uuids_start[0] += 16; 185 } 186 187 return ptr; 188 } 189 190 void eir_create(struct hci_dev *hdev, u8 *data) 191 { 192 u8 *ptr = data; 193 size_t name_len; 194 195 name_len = strnlen(hdev->dev_name, sizeof(hdev->dev_name)); 196 197 if (name_len > 0) { 198 /* EIR Data type */ 199 if (name_len > 48) { 200 name_len = 48; 201 ptr[1] = EIR_NAME_SHORT; 202 } else { 203 ptr[1] = EIR_NAME_COMPLETE; 204 } 205 206 /* EIR Data length */ 207 ptr[0] = name_len + 1; 208 209 memcpy(ptr + 2, hdev->dev_name, name_len); 210 211 ptr += (name_len + 2); 212 } 213 214 if (hdev->inq_tx_power != HCI_TX_POWER_INVALID) { 215 ptr[0] = 2; 216 ptr[1] = EIR_TX_POWER; 217 ptr[2] = (u8)hdev->inq_tx_power; 218 219 ptr += 3; 220 } 221 222 if (hdev->devid_source > 0) { 223 ptr[0] = 9; 224 ptr[1] = EIR_DEVICE_ID; 225 226 put_unaligned_le16(hdev->devid_source, ptr + 2); 227 put_unaligned_le16(hdev->devid_vendor, ptr + 4); 228 put_unaligned_le16(hdev->devid_product, ptr + 6); 229 put_unaligned_le16(hdev->devid_version, ptr + 8); 230 231 ptr += 10; 232 } 233 234 ptr = create_uuid16_list(hdev, ptr, HCI_MAX_EIR_LENGTH - (ptr - data)); 235 ptr = create_uuid32_list(hdev, ptr, HCI_MAX_EIR_LENGTH - (ptr - data)); 236 ptr = create_uuid128_list(hdev, ptr, HCI_MAX_EIR_LENGTH - (ptr - data)); 237 } 238 239 u8 eir_create_per_adv_data(struct hci_dev *hdev, u8 instance, u8 *ptr) 240 { 241 struct adv_info *adv = NULL; 242 u8 ad_len = 0; 243 244 /* Return 0 when the current instance identifier is invalid. */ 245 if (instance) { 246 adv = hci_find_adv_instance(hdev, instance); 247 if (!adv) 248 return 0; 249 } 250 251 if (adv) { 252 memcpy(ptr, adv->per_adv_data, adv->per_adv_data_len); 253 ad_len += adv->per_adv_data_len; 254 ptr += adv->per_adv_data_len; 255 } 256 257 return ad_len; 258 } 259 260 u8 eir_create_adv_data(struct hci_dev *hdev, u8 instance, u8 *ptr) 261 { 262 struct adv_info *adv = NULL; 263 u8 ad_len = 0, flags = 0; 264 u32 instance_flags; 265 266 /* Return 0 when the current instance identifier is invalid. */ 267 if (instance) { 268 adv = hci_find_adv_instance(hdev, instance); 269 if (!adv) 270 return 0; 271 } 272 273 instance_flags = hci_adv_instance_flags(hdev, instance); 274 275 /* If instance already has the flags set skip adding it once 276 * again. 277 */ 278 if (adv && eir_get_data(adv->adv_data, adv->adv_data_len, EIR_FLAGS, 279 NULL)) 280 goto skip_flags; 281 282 /* The Add Advertising command allows userspace to set both the general 283 * and limited discoverable flags. 284 */ 285 if (instance_flags & MGMT_ADV_FLAG_DISCOV) 286 flags |= LE_AD_GENERAL; 287 288 if (instance_flags & MGMT_ADV_FLAG_LIMITED_DISCOV) 289 flags |= LE_AD_LIMITED; 290 291 if (!hci_dev_test_flag(hdev, HCI_BREDR_ENABLED)) 292 flags |= LE_AD_NO_BREDR; 293 294 if (flags || (instance_flags & MGMT_ADV_FLAG_MANAGED_FLAGS)) { 295 /* If a discovery flag wasn't provided, simply use the global 296 * settings. 297 */ 298 if (!flags) 299 flags |= mgmt_get_adv_discov_flags(hdev); 300 301 /* If flags would still be empty, then there is no need to 302 * include the "Flags" AD field". 303 */ 304 if (flags) { 305 ptr[0] = 0x02; 306 ptr[1] = EIR_FLAGS; 307 ptr[2] = flags; 308 309 ad_len += 3; 310 ptr += 3; 311 } 312 } 313 314 skip_flags: 315 if (adv) { 316 memcpy(ptr, adv->adv_data, adv->adv_data_len); 317 ad_len += adv->adv_data_len; 318 ptr += adv->adv_data_len; 319 } 320 321 if (instance_flags & MGMT_ADV_FLAG_TX_POWER) { 322 s8 adv_tx_power; 323 324 if (ext_adv_capable(hdev)) { 325 if (adv) 326 adv_tx_power = adv->tx_power; 327 else 328 adv_tx_power = hdev->adv_tx_power; 329 } else { 330 adv_tx_power = hdev->adv_tx_power; 331 } 332 333 /* Provide Tx Power only if we can provide a valid value for it */ 334 if (adv_tx_power != HCI_TX_POWER_INVALID) { 335 ptr[0] = 0x02; 336 ptr[1] = EIR_TX_POWER; 337 ptr[2] = (u8)adv_tx_power; 338 339 ad_len += 3; 340 ptr += 3; 341 } 342 } 343 344 return ad_len; 345 } 346 347 static u8 create_default_scan_rsp(struct hci_dev *hdev, u8 *ptr) 348 { 349 u8 scan_rsp_len = 0; 350 351 if (hdev->appearance) 352 scan_rsp_len = eir_append_appearance(hdev, ptr, scan_rsp_len); 353 354 return eir_append_local_name(hdev, ptr, scan_rsp_len); 355 } 356 357 u8 eir_create_scan_rsp(struct hci_dev *hdev, u8 instance, u8 *ptr) 358 { 359 struct adv_info *adv; 360 u8 scan_rsp_len = 0; 361 362 if (!instance) 363 return create_default_scan_rsp(hdev, ptr); 364 365 adv = hci_find_adv_instance(hdev, instance); 366 if (!adv) 367 return 0; 368 369 if ((adv->flags & MGMT_ADV_FLAG_APPEARANCE) && hdev->appearance) 370 scan_rsp_len = eir_append_appearance(hdev, ptr, scan_rsp_len); 371 372 memcpy(&ptr[scan_rsp_len], adv->scan_rsp_data, adv->scan_rsp_len); 373 374 scan_rsp_len += adv->scan_rsp_len; 375 376 if (adv->flags & MGMT_ADV_FLAG_LOCAL_NAME) 377 scan_rsp_len = eir_append_local_name(hdev, ptr, scan_rsp_len); 378 379 return scan_rsp_len; 380 } 381 382 void *eir_get_service_data(u8 *eir, size_t eir_len, u16 uuid, size_t *len) 383 { 384 while ((eir = eir_get_data(eir, eir_len, EIR_SERVICE_DATA, len))) { 385 u16 value = get_unaligned_le16(eir); 386 387 if (uuid == value) { 388 if (len) 389 *len -= 2; 390 return &eir[2]; 391 } 392 393 eir += *len; 394 eir_len -= *len; 395 } 396 397 return NULL; 398 } 399