net/bluetooth/amp.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3    Copyright (c) 2011,2012 Intel Corp.
   4
   5 */
   6
   7 #include <net/bluetooth/bluetooth.h>
   8 #include <net/bluetooth/hci.h>
   9 #include <net/bluetooth/hci_core.h>
  10 #include <crypto/hash.h>
  11
  12 #include "hci_request.h"
  13 #include "a2mp.h"
  14 #include "amp.h"
  15
  16 /* Remote AMP Controllers interface */
  17 void amp_ctrl_get(struct amp_ctrl *ctrl)
  18 {
  19         BT_DBG("ctrl %p orig refcnt %d", ctrl,
  20                kref_read(&ctrl->kref));
  21
  22         kref_get(&ctrl->kref);
  23 }
  24
  25 static void amp_ctrl_destroy(struct kref *kref)
  26 {
  27         struct amp_ctrl *ctrl = container_of(kref, struct amp_ctrl, kref);
  28
  29         BT_DBG("ctrl %p", ctrl);
  30
  31         kfree(ctrl->assoc);
  32         kfree(ctrl);
  33 }
  34
  35 int amp_ctrl_put(struct amp_ctrl *ctrl)
  36 {
  37         BT_DBG("ctrl %p orig refcnt %d", ctrl,
  38                kref_read(&ctrl->kref));
  39
  40         return kref_put(&ctrl->kref, &amp_ctrl_destroy);
  41 }
  42
  43 struct amp_ctrl *amp_ctrl_add(struct amp_mgr *mgr, u8 id)
  44 {
  45         struct amp_ctrl *ctrl;
  46
  47         ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
  48         if (!ctrl)
  49                 return NULL;
  50
  51         kref_init(&ctrl->kref);
  52         ctrl->id = id;
  53
  54         mutex_lock(&mgr->amp_ctrls_lock);
  55         list_add(&ctrl->list, &mgr->amp_ctrls);
  56         mutex_unlock(&mgr->amp_ctrls_lock);
  57
  58         BT_DBG("mgr %p ctrl %p", mgr, ctrl);
  59
  60         return ctrl;
  61 }
  62
  63 void amp_ctrl_list_flush(struct amp_mgr *mgr)
  64 {
  65         struct amp_ctrl *ctrl, *n;
  66
  67         BT_DBG("mgr %p", mgr);
  68
  69         mutex_lock(&mgr->amp_ctrls_lock);
  70         list_for_each_entry_safe(ctrl, n, &mgr->amp_ctrls, list) {
  71                 list_del(&ctrl->list);
  72                 amp_ctrl_put(ctrl);
  73         }
  74         mutex_unlock(&mgr->amp_ctrls_lock);
  75 }
  76
  77 struct amp_ctrl *amp_ctrl_lookup(struct amp_mgr *mgr, u8 id)
  78 {
  79         struct amp_ctrl *ctrl;
  80
  81         BT_DBG("mgr %p id %d", mgr, id);
  82
  83         mutex_lock(&mgr->amp_ctrls_lock);
  84         list_for_each_entry(ctrl, &mgr->amp_ctrls, list) {
  85                 if (ctrl->id == id) {
  86                         amp_ctrl_get(ctrl);
  87                         mutex_unlock(&mgr->amp_ctrls_lock);
  88                         return ctrl;
  89                 }
  90         }
  91         mutex_unlock(&mgr->amp_ctrls_lock);
  92
  93         return NULL;
  94 }
  95
  96 /* Physical Link interface */
  97 static u8 __next_handle(struct amp_mgr *mgr)
  98 {
  99         if (++mgr->handle == 0)
 100                 mgr->handle = 1;
 101
 102         return mgr->handle;
 103 }
 104
 105 struct hci_conn *phylink_add(struct hci_dev *hdev, struct amp_mgr *mgr,
 106                              u8 remote_id, bool out)
 107 {
 108         bdaddr_t *dst = &mgr->l2cap_conn->hcon->dst;
 109         struct hci_conn *hcon;
 110         u8 role = out ? HCI_ROLE_MASTER : HCI_ROLE_SLAVE;
 111
 112         hcon = hci_conn_add(hdev, AMP_LINK, dst, role);
 113         if (!hcon)
 114                 return NULL;
 115
 116         BT_DBG("hcon %p dst %pMR", hcon, dst);
 117
 118         hcon->state = BT_CONNECT;
 119         hcon->attempt++;
 120         hcon->handle = __next_handle(mgr);
 121         hcon->remote_id = remote_id;
 122         hcon->amp_mgr = amp_mgr_get(mgr);
 123
 124         return hcon;
 125 }
 126
 127 /* AMP crypto key generation interface */
 128 static int hmac_sha256(u8 *key, u8 ksize, char *plaintext, u8 psize, u8 *output)
 129 {
 130         struct crypto_shash *tfm;
 131         struct shash_desc *shash;
 132         int ret;
 133
 134         if (!ksize)
 135                 return -EINVAL;
 136
 137         tfm = crypto_alloc_shash("hmac(sha256)", 0, 0);
 138         if (IS_ERR(tfm)) {
 139                 BT_DBG("crypto_alloc_ahash failed: err %ld", PTR_ERR(tfm));
 140                 return PTR_ERR(tfm);
 141         }
 142
 143         ret = crypto_shash_setkey(tfm, key, ksize);
 144         if (ret) {
 145                 BT_DBG("crypto_ahash_setkey failed: err %d", ret);
 146                 goto failed;
 147         }
 148
 149         shash = kzalloc(sizeof(*shash) + crypto_shash_descsize(tfm),
 150                         GFP_KERNEL);
 151         if (!shash) {
 152                 ret = -ENOMEM;
 153                 goto failed;
 154         }
 155
 156         shash->tfm = tfm;
 157
 158         ret = crypto_shash_digest(shash, plaintext, psize, output);
 159
 160         kfree(shash);
 161
 162 failed:
 163         crypto_free_shash(tfm);
 164         return ret;
 165 }
 166
 167 int phylink_gen_key(struct hci_conn *conn, u8 *data, u8 *len, u8 *type)
 168 {
 169         struct hci_dev *hdev = conn->hdev;
 170         struct link_key *key;
 171         u8 keybuf[HCI_AMP_LINK_KEY_SIZE];
 172         u8 gamp_key[HCI_AMP_LINK_KEY_SIZE];
 173         int err;
 174
 175         if (!hci_conn_check_link_mode(conn))
 176                 return -EACCES;
 177
 178         BT_DBG("conn %p key_type %d", conn, conn->key_type);
 179
 180         /* Legacy key */
 181         if (conn->key_type < 3) {
 182                 bt_dev_err(hdev, "legacy key type %d", conn->key_type);
 183                 return -EACCES;
 184         }
 185
 186         *type = conn->key_type;
 187         *len = HCI_AMP_LINK_KEY_SIZE;
 188
 189         key = hci_find_link_key(hdev, &conn->dst);
 190         if (!key) {
 191                 BT_DBG("No Link key for conn %p dst %pMR", conn, &conn->dst);
 192                 return -EACCES;
 193         }
 194
 195         /* BR/EDR Link Key concatenated together with itself */
 196         memcpy(&keybuf[0], key->val, HCI_LINK_KEY_SIZE);
 197         memcpy(&keybuf[HCI_LINK_KEY_SIZE], key->val, HCI_LINK_KEY_SIZE);
 198
 199         /* Derive Generic AMP Link Key (gamp) */
 200         err = hmac_sha256(keybuf, HCI_AMP_LINK_KEY_SIZE, "gamp", 4, gamp_key);
 201         if (err) {
 202                 bt_dev_err(hdev, "could not derive Generic AMP Key: err %d", err);
 203                 return err;
 204         }
 205
 206         if (conn->key_type == HCI_LK_DEBUG_COMBINATION) {
 207                 BT_DBG("Use Generic AMP Key (gamp)");
 208                 memcpy(data, gamp_key, HCI_AMP_LINK_KEY_SIZE);
 209                 return err;
 210         }
 211
 212         /* Derive Dedicated AMP Link Key: "802b" is 802.11 PAL keyID */
 213         return hmac_sha256(gamp_key, HCI_AMP_LINK_KEY_SIZE, "802b", 4, data);
 214 }
 215
 216 static void read_local_amp_assoc_complete(struct hci_dev *hdev, u8 status,
 217                                           u16 opcode, struct sk_buff *skb)
 218 {
 219         struct hci_rp_read_local_amp_assoc *rp = (void *)skb->data;
 220         struct amp_assoc *assoc = &hdev->loc_assoc;
 221         size_t rem_len, frag_len;
 222
 223         BT_DBG("%s status 0x%2.2x", hdev->name, rp->status);
 224
 225         if (rp->status)
 226                 goto send_rsp;
 227
 228         frag_len = skb->len - sizeof(*rp);
 229         rem_len = __le16_to_cpu(rp->rem_len);
 230
 231         if (rem_len > frag_len) {
 232                 BT_DBG("frag_len %zu rem_len %zu", frag_len, rem_len);
 233
 234                 memcpy(assoc->data + assoc->offset, rp->frag, frag_len);
 235                 assoc->offset += frag_len;
 236
 237                 /* Read other fragments */
 238                 amp_read_loc_assoc_frag(hdev, rp->phy_handle);
 239
 240                 return;
 241         }
 242
 243         memcpy(assoc->data + assoc->offset, rp->frag, rem_len);
 244         assoc->len = assoc->offset + rem_len;
 245         assoc->offset = 0;
 246
 247 send_rsp:
 248         /* Send A2MP Rsp when all fragments are received */
 249         a2mp_send_getampassoc_rsp(hdev, rp->status);
 250         a2mp_send_create_phy_link_req(hdev, rp->status);
 251 }
 252
 253 void amp_read_loc_assoc_frag(struct hci_dev *hdev, u8 phy_handle)
 254 {
 255         struct hci_cp_read_local_amp_assoc cp;
 256         struct amp_assoc *loc_assoc = &hdev->loc_assoc;
 257         struct hci_request req;
 258         int err;
 259
 260         BT_DBG("%s handle %d", hdev->name, phy_handle);
 261
 262         cp.phy_handle = phy_handle;
 263         cp.max_len = cpu_to_le16(hdev->amp_assoc_size);
 264         cp.len_so_far = cpu_to_le16(loc_assoc->offset);
 265
 266         hci_req_init(&req, hdev);
 267         hci_req_add(&req, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
 268         err = hci_req_run_skb(&req, read_local_amp_assoc_complete);
 269         if (err < 0)
 270                 a2mp_send_getampassoc_rsp(hdev, A2MP_STATUS_INVALID_CTRL_ID);
 271 }
 272
 273 void amp_read_loc_assoc(struct hci_dev *hdev, struct amp_mgr *mgr)
 274 {
 275         struct hci_cp_read_local_amp_assoc cp;
 276         struct hci_request req;
 277         int err;
 278
 279         memset(&hdev->loc_assoc, 0, sizeof(struct amp_assoc));
 280         memset(&cp, 0, sizeof(cp));
 281
 282         cp.max_len = cpu_to_le16(hdev->amp_assoc_size);
 283
 284         set_bit(READ_LOC_AMP_ASSOC, &mgr->state);
 285         hci_req_init(&req, hdev);
 286         hci_req_add(&req, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
 287         err = hci_req_run_skb(&req, read_local_amp_assoc_complete);
 288         if (err < 0)
 289                 a2mp_send_getampassoc_rsp(hdev, A2MP_STATUS_INVALID_CTRL_ID);
 290 }
 291
 292 void amp_read_loc_assoc_final_data(struct hci_dev *hdev,
 293                                    struct hci_conn *hcon)
 294 {
 295         struct hci_cp_read_local_amp_assoc cp;
 296         struct amp_mgr *mgr = hcon->amp_mgr;
 297         struct hci_request req;
 298         int err;
 299
 300         cp.phy_handle = hcon->handle;
 301         cp.len_so_far = cpu_to_le16(0);
 302         cp.max_len = cpu_to_le16(hdev->amp_assoc_size);
 303
 304         set_bit(READ_LOC_AMP_ASSOC_FINAL, &mgr->state);
 305
 306         /* Read Local AMP Assoc final link information data */
 307         hci_req_init(&req, hdev);
 308         hci_req_add(&req, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
 309         err = hci_req_run_skb(&req, read_local_amp_assoc_complete);
 310         if (err < 0)
 311                 a2mp_send_getampassoc_rsp(hdev, A2MP_STATUS_INVALID_CTRL_ID);
 312 }
 313
 314 static void write_remote_amp_assoc_complete(struct hci_dev *hdev, u8 status,
 315                                             u16 opcode, struct sk_buff *skb)
 316 {
 317         struct hci_rp_write_remote_amp_assoc *rp = (void *)skb->data;
 318
 319         BT_DBG("%s status 0x%2.2x phy_handle 0x%2.2x",
 320                hdev->name, rp->status, rp->phy_handle);
 321
 322         if (rp->status)
 323                 return;
 324
 325         amp_write_rem_assoc_continue(hdev, rp->phy_handle);
 326 }
 327
 328 /* Write AMP Assoc data fragments, returns true with last fragment written*/
 329 static bool amp_write_rem_assoc_frag(struct hci_dev *hdev,
 330                                      struct hci_conn *hcon)
 331 {
 332         struct hci_cp_write_remote_amp_assoc *cp;
 333         struct amp_mgr *mgr = hcon->amp_mgr;
 334         struct amp_ctrl *ctrl;
 335         struct hci_request req;
 336         u16 frag_len, len;
 337
 338         ctrl = amp_ctrl_lookup(mgr, hcon->remote_id);
 339         if (!ctrl)
 340                 return false;
 341
 342         if (!ctrl->assoc_rem_len) {
 343                 BT_DBG("all fragments are written");
 344                 ctrl->assoc_rem_len = ctrl->assoc_len;
 345                 ctrl->assoc_len_so_far = 0;
 346
 347                 amp_ctrl_put(ctrl);
 348                 return true;
 349         }
 350
 351         frag_len = min_t(u16, 248, ctrl->assoc_rem_len);
 352         len = frag_len + sizeof(*cp);
 353
 354         cp = kzalloc(len, GFP_KERNEL);
 355         if (!cp) {
 356                 amp_ctrl_put(ctrl);
 357                 return false;
 358         }
 359
 360         BT_DBG("hcon %p ctrl %p frag_len %u assoc_len %u rem_len %u",
 361                hcon, ctrl, frag_len, ctrl->assoc_len, ctrl->assoc_rem_len);
 362
 363         cp->phy_handle = hcon->handle;
 364         cp->len_so_far = cpu_to_le16(ctrl->assoc_len_so_far);
 365         cp->rem_len = cpu_to_le16(ctrl->assoc_rem_len);
 366         memcpy(cp->frag, ctrl->assoc, frag_len);
 367
 368         ctrl->assoc_len_so_far += frag_len;
 369         ctrl->assoc_rem_len -= frag_len;
 370
 371         amp_ctrl_put(ctrl);
 372
 373         hci_req_init(&req, hdev);
 374         hci_req_add(&req, HCI_OP_WRITE_REMOTE_AMP_ASSOC, len, cp);
 375         hci_req_run_skb(&req, write_remote_amp_assoc_complete);
 376
 377         kfree(cp);
 378
 379         return false;
 380 }
 381
 382 void amp_write_rem_assoc_continue(struct hci_dev *hdev, u8 handle)
 383 {
 384         struct hci_conn *hcon;
 385
 386         BT_DBG("%s phy handle 0x%2.2x", hdev->name, handle);
 387
 388         hcon = hci_conn_hash_lookup_handle(hdev, handle);
 389         if (!hcon)
 390                 return;
 391
 392         /* Send A2MP create phylink rsp when all fragments are written */
 393         if (amp_write_rem_assoc_frag(hdev, hcon))
 394                 a2mp_send_create_phy_link_rsp(hdev, 0);
 395 }
 396
 397 void amp_write_remote_assoc(struct hci_dev *hdev, u8 handle)
 398 {
 399         struct hci_conn *hcon;
 400
 401         BT_DBG("%s phy handle 0x%2.2x", hdev->name, handle);
 402
 403         hcon = hci_conn_hash_lookup_handle(hdev, handle);
 404         if (!hcon)
 405                 return;
 406
 407         BT_DBG("%s phy handle 0x%2.2x hcon %p", hdev->name, handle, hcon);
 408
 409         amp_write_rem_assoc_frag(hdev, hcon);
 410 }
 411
 412 static void create_phylink_complete(struct hci_dev *hdev, u8 status,
 413                                     u16 opcode)
 414 {
 415         struct hci_cp_create_phy_link *cp;
 416
 417         BT_DBG("%s status 0x%2.2x", hdev->name, status);
 418
 419         cp = hci_sent_cmd_data(hdev, HCI_OP_CREATE_PHY_LINK);
 420         if (!cp)
 421                 return;
 422
 423         hci_dev_lock(hdev);
 424
 425         if (status) {
 426                 struct hci_conn *hcon;
 427
 428                 hcon = hci_conn_hash_lookup_handle(hdev, cp->phy_handle);
 429                 if (hcon)
 430                         hci_conn_del(hcon);
 431         } else {
 432                 amp_write_remote_assoc(hdev, cp->phy_handle);
 433         }
 434
 435         hci_dev_unlock(hdev);
 436 }
 437
 438 void amp_create_phylink(struct hci_dev *hdev, struct amp_mgr *mgr,
 439                         struct hci_conn *hcon)
 440 {
 441         struct hci_cp_create_phy_link cp;
 442         struct hci_request req;
 443
 444         cp.phy_handle = hcon->handle;
 445
 446         BT_DBG("%s hcon %p phy handle 0x%2.2x", hdev->name, hcon,
 447                hcon->handle);
 448
 449         if (phylink_gen_key(mgr->l2cap_conn->hcon, cp.key, &cp.key_len,
 450                             &cp.key_type)) {
 451                 BT_DBG("Cannot create link key");
 452                 return;
 453         }
 454
 455         hci_req_init(&req, hdev);
 456         hci_req_add(&req, HCI_OP_CREATE_PHY_LINK, sizeof(cp), &cp);
 457         hci_req_run(&req, create_phylink_complete);
 458 }
 459
 460 static void accept_phylink_complete(struct hci_dev *hdev, u8 status,
 461                                     u16 opcode)
 462 {
 463         struct hci_cp_accept_phy_link *cp;
 464
 465         BT_DBG("%s status 0x%2.2x", hdev->name, status);
 466
 467         if (status)
 468                 return;
 469
 470         cp = hci_sent_cmd_data(hdev, HCI_OP_ACCEPT_PHY_LINK);
 471         if (!cp)
 472                 return;
 473
 474         amp_write_remote_assoc(hdev, cp->phy_handle);
 475 }
 476
 477 void amp_accept_phylink(struct hci_dev *hdev, struct amp_mgr *mgr,
 478                         struct hci_conn *hcon)
 479 {
 480         struct hci_cp_accept_phy_link cp;
 481         struct hci_request req;
 482
 483         cp.phy_handle = hcon->handle;
 484
 485         BT_DBG("%s hcon %p phy handle 0x%2.2x", hdev->name, hcon,
 486                hcon->handle);
 487
 488         if (phylink_gen_key(mgr->l2cap_conn->hcon, cp.key, &cp.key_len,
 489                             &cp.key_type)) {
 490                 BT_DBG("Cannot create link key");
 491                 return;
 492         }
 493
 494         hci_req_init(&req, hdev);
 495         hci_req_add(&req, HCI_OP_ACCEPT_PHY_LINK, sizeof(cp), &cp);
 496         hci_req_run(&req, accept_phylink_complete);
 497 }
 498
 499 void amp_physical_cfm(struct hci_conn *bredr_hcon, struct hci_conn *hs_hcon)
 500 {
 501         struct hci_dev *bredr_hdev = hci_dev_hold(bredr_hcon->hdev);
 502         struct amp_mgr *mgr = hs_hcon->amp_mgr;
 503         struct l2cap_chan *bredr_chan;
 504
 505         BT_DBG("bredr_hcon %p hs_hcon %p mgr %p", bredr_hcon, hs_hcon, mgr);
 506
 507         if (!bredr_hdev || !mgr || !mgr->bredr_chan)
 508                 return;
 509
 510         bredr_chan = mgr->bredr_chan;
 511
 512         l2cap_chan_lock(bredr_chan);
 513
 514         set_bit(FLAG_EFS_ENABLE, &bredr_chan->flags);
 515         bredr_chan->remote_amp_id = hs_hcon->remote_id;
 516         bredr_chan->local_amp_id = hs_hcon->hdev->id;
 517         bredr_chan->hs_hcon = hs_hcon;
 518         bredr_chan->conn->mtu = hs_hcon->hdev->block_mtu;
 519
 520         __l2cap_physical_cfm(bredr_chan, 0);
 521
 522         l2cap_chan_unlock(bredr_chan);
 523
 524         hci_dev_put(bredr_hdev);
 525 }
 526
 527 void amp_create_logical_link(struct l2cap_chan *chan)
 528 {
 529         struct hci_conn *hs_hcon = chan->hs_hcon;
 530         struct hci_cp_create_accept_logical_link cp;
 531         struct hci_dev *hdev;
 532
 533         BT_DBG("chan %p hs_hcon %p dst %pMR", chan, hs_hcon,
 534                &chan->conn->hcon->dst);
 535
 536         if (!hs_hcon)
 537                 return;
 538
 539         hdev = hci_dev_hold(chan->hs_hcon->hdev);
 540         if (!hdev)
 541                 return;
 542
 543         cp.phy_handle = hs_hcon->handle;
 544
 545         cp.tx_flow_spec.id = chan->local_id;
 546         cp.tx_flow_spec.stype = chan->local_stype;
 547         cp.tx_flow_spec.msdu = cpu_to_le16(chan->local_msdu);
 548         cp.tx_flow_spec.sdu_itime = cpu_to_le32(chan->local_sdu_itime);
 549         cp.tx_flow_spec.acc_lat = cpu_to_le32(chan->local_acc_lat);
 550         cp.tx_flow_spec.flush_to = cpu_to_le32(chan->local_flush_to);
 551
 552         cp.rx_flow_spec.id = chan->remote_id;
 553         cp.rx_flow_spec.stype = chan->remote_stype;
 554         cp.rx_flow_spec.msdu = cpu_to_le16(chan->remote_msdu);
 555         cp.rx_flow_spec.sdu_itime = cpu_to_le32(chan->remote_sdu_itime);
 556         cp.rx_flow_spec.acc_lat = cpu_to_le32(chan->remote_acc_lat);
 557         cp.rx_flow_spec.flush_to = cpu_to_le32(chan->remote_flush_to);
 558
 559         if (hs_hcon->out)
 560                 hci_send_cmd(hdev, HCI_OP_CREATE_LOGICAL_LINK, sizeof(cp),
 561                              &cp);
 562         else
 563                 hci_send_cmd(hdev, HCI_OP_ACCEPT_LOGICAL_LINK, sizeof(cp),
 564                              &cp);
 565
 566         hci_dev_put(hdev);
 567 }
 568
 569 void amp_disconnect_logical_link(struct hci_chan *hchan)
 570 {
 571         struct hci_conn *hcon = hchan->conn;
 572         struct hci_cp_disconn_logical_link cp;
 573
 574         if (hcon->state != BT_CONNECTED) {
 575                 BT_DBG("hchan %p not connected", hchan);
 576                 return;
 577         }
 578
 579         cp.log_handle = cpu_to_le16(hchan->handle);
 580         hci_send_cmd(hcon->hdev, HCI_OP_DISCONN_LOGICAL_LINK, sizeof(cp), &cp);
 581 }
 582
 583 void amp_destroy_logical_link(struct hci_chan *hchan, u8 reason)
 584 {
 585         BT_DBG("hchan %p", hchan);
 586
 587         hci_chan_del(hchan);
 588 }