net/bluetooth/amp.c

   1 /*
   2    Copyright (c) 2011,2012 Intel Corp.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License version 2 and
   6    only version 2 as published by the Free Software Foundation.
   7
   8    This program is distributed in the hope that it will be useful,
   9    but WITHOUT ANY WARRANTY; without even the implied warranty of
  10    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11    GNU General Public License for more details.
  12 */
  13
  14 #include <net/bluetooth/bluetooth.h>
  15 #include <net/bluetooth/hci.h>
  16 #include <net/bluetooth/hci_core.h>
  17 #include <net/bluetooth/a2mp.h>
  18 #include <net/bluetooth/amp.h>
  19 #include <crypto/hash.h>
  20
  21 /* Remote AMP Controllers interface */
  22 void amp_ctrl_get(struct amp_ctrl *ctrl)
  23 {
  24         BT_DBG("ctrl %p orig refcnt %d", ctrl,
  25                atomic_read(&ctrl->kref.refcount));
  26
  27         kref_get(&ctrl->kref);
  28 }
  29
  30 static void amp_ctrl_destroy(struct kref *kref)
  31 {
  32         struct amp_ctrl *ctrl = container_of(kref, struct amp_ctrl, kref);
  33
  34         BT_DBG("ctrl %p", ctrl);
  35
  36         kfree(ctrl->assoc);
  37         kfree(ctrl);
  38 }
  39
  40 int amp_ctrl_put(struct amp_ctrl *ctrl)
  41 {
  42         BT_DBG("ctrl %p orig refcnt %d", ctrl,
  43                atomic_read(&ctrl->kref.refcount));
  44
  45         return kref_put(&ctrl->kref, &amp_ctrl_destroy);
  46 }
  47
  48 struct amp_ctrl *amp_ctrl_add(struct amp_mgr *mgr, u8 id)
  49 {
  50         struct amp_ctrl *ctrl;
  51
  52         ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
  53         if (!ctrl)
  54                 return NULL;
  55
  56         kref_init(&ctrl->kref);
  57         ctrl->id = id;
  58
  59         mutex_lock(&mgr->amp_ctrls_lock);
  60         list_add(&ctrl->list, &mgr->amp_ctrls);
  61         mutex_unlock(&mgr->amp_ctrls_lock);
  62
  63         BT_DBG("mgr %p ctrl %p", mgr, ctrl);
  64
  65         return ctrl;
  66 }
  67
  68 void amp_ctrl_list_flush(struct amp_mgr *mgr)
  69 {
  70         struct amp_ctrl *ctrl, *n;
  71
  72         BT_DBG("mgr %p", mgr);
  73
  74         mutex_lock(&mgr->amp_ctrls_lock);
  75         list_for_each_entry_safe(ctrl, n, &mgr->amp_ctrls, list) {
  76                 list_del(&ctrl->list);
  77                 amp_ctrl_put(ctrl);
  78         }
  79         mutex_unlock(&mgr->amp_ctrls_lock);
  80 }
  81
  82 struct amp_ctrl *amp_ctrl_lookup(struct amp_mgr *mgr, u8 id)
  83 {
  84         struct amp_ctrl *ctrl;
  85
  86         BT_DBG("mgr %p id %d", mgr, id);
  87
  88         mutex_lock(&mgr->amp_ctrls_lock);
  89         list_for_each_entry(ctrl, &mgr->amp_ctrls, list) {
  90                 if (ctrl->id == id) {
  91                         amp_ctrl_get(ctrl);
  92                         mutex_unlock(&mgr->amp_ctrls_lock);
  93                         return ctrl;
  94                 }
  95         }
  96         mutex_unlock(&mgr->amp_ctrls_lock);
  97
  98         return NULL;
  99 }
 100
 101 /* Physical Link interface */
 102 static u8 __next_handle(struct amp_mgr *mgr)
 103 {
 104         if (++mgr->handle == 0)
 105                 mgr->handle = 1;
 106
 107         return mgr->handle;
 108 }
 109
 110 struct hci_conn *phylink_add(struct hci_dev *hdev, struct amp_mgr *mgr,
 111                              u8 remote_id, bool out)
 112 {
 113         bdaddr_t *dst = mgr->l2cap_conn->dst;
 114         struct hci_conn *hcon;
 115
 116         hcon = hci_conn_add(hdev, AMP_LINK, dst);
 117         if (!hcon)
 118                 return NULL;
 119
 120         BT_DBG("hcon %p dst %pMR", hcon, dst);
 121
 122         hcon->state = BT_CONNECT;
 123         hcon->attempt++;
 124         hcon->handle = __next_handle(mgr);
 125         hcon->remote_id = remote_id;
 126         hcon->amp_mgr = amp_mgr_get(mgr);
 127         hcon->out = out;
 128
 129         return hcon;
 130 }
 131
 132 /* AMP crypto key generation interface */
 133 static int hmac_sha256(u8 *key, u8 ksize, char *plaintext, u8 psize, u8 *output)
 134 {
 135         int ret = 0;
 136         struct crypto_shash *tfm;
 137
 138         if (!ksize)
 139                 return -EINVAL;
 140
 141         tfm = crypto_alloc_shash("hmac(sha256)", 0, 0);
 142         if (IS_ERR(tfm)) {
 143                 BT_DBG("crypto_alloc_ahash failed: err %ld", PTR_ERR(tfm));
 144                 return PTR_ERR(tfm);
 145         }
 146
 147         ret = crypto_shash_setkey(tfm, key, ksize);
 148         if (ret) {
 149                 BT_DBG("crypto_ahash_setkey failed: err %d", ret);
 150         } else {
 151                 struct {
 152                         struct shash_desc shash;
 153                         char ctx[crypto_shash_descsize(tfm)];
 154                 } desc;
 155
 156                 desc.shash.tfm = tfm;
 157                 desc.shash.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 158
 159                 ret = crypto_shash_digest(&desc.shash, plaintext, psize,
 160                                           output);
 161         }
 162
 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_ERR("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_ERR("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 void amp_read_loc_assoc_frag(struct hci_dev *hdev, u8 phy_handle)
 217 {
 218         struct hci_cp_read_local_amp_assoc cp;
 219         struct amp_assoc *loc_assoc = &hdev->loc_assoc;
 220
 221         BT_DBG("%s handle %d", hdev->name, phy_handle);
 222
 223         cp.phy_handle = phy_handle;
 224         cp.max_len = cpu_to_le16(hdev->amp_assoc_size);
 225         cp.len_so_far = cpu_to_le16(loc_assoc->offset);
 226
 227         hci_send_cmd(hdev, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
 228 }
 229
 230 void amp_read_loc_assoc(struct hci_dev *hdev, struct amp_mgr *mgr)
 231 {
 232         struct hci_cp_read_local_amp_assoc cp;
 233
 234         memset(&hdev->loc_assoc, 0, sizeof(struct amp_assoc));
 235         memset(&cp, 0, sizeof(cp));
 236
 237         cp.max_len = cpu_to_le16(hdev->amp_assoc_size);
 238
 239         mgr->state = READ_LOC_AMP_ASSOC;
 240         hci_send_cmd(hdev, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
 241 }
 242
 243 void amp_read_loc_assoc_final_data(struct hci_dev *hdev,
 244                                    struct hci_conn *hcon)
 245 {
 246         struct hci_cp_read_local_amp_assoc cp;
 247         struct amp_mgr *mgr = hcon->amp_mgr;
 248
 249         cp.phy_handle = hcon->handle;
 250         cp.len_so_far = cpu_to_le16(0);
 251         cp.max_len = cpu_to_le16(hdev->amp_assoc_size);
 252
 253         mgr->state = READ_LOC_AMP_ASSOC_FINAL;
 254
 255         /* Read Local AMP Assoc final link information data */
 256         hci_send_cmd(hdev, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
 257 }
 258
 259 /* Write AMP Assoc data fragments, returns true with last fragment written*/
 260 static bool amp_write_rem_assoc_frag(struct hci_dev *hdev,
 261                                      struct hci_conn *hcon)
 262 {
 263         struct hci_cp_write_remote_amp_assoc *cp;
 264         struct amp_mgr *mgr = hcon->amp_mgr;
 265         struct amp_ctrl *ctrl;
 266         u16 frag_len, len;
 267
 268         ctrl = amp_ctrl_lookup(mgr, hcon->remote_id);
 269         if (!ctrl)
 270                 return false;
 271
 272         if (!ctrl->assoc_rem_len) {
 273                 BT_DBG("all fragments are written");
 274                 ctrl->assoc_rem_len = ctrl->assoc_len;
 275                 ctrl->assoc_len_so_far = 0;
 276
 277                 amp_ctrl_put(ctrl);
 278                 return true;
 279         }
 280
 281         frag_len = min_t(u16, 248, ctrl->assoc_rem_len);
 282         len = frag_len + sizeof(*cp);
 283
 284         cp = kzalloc(len, GFP_KERNEL);
 285         if (!cp) {
 286                 amp_ctrl_put(ctrl);
 287                 return false;
 288         }
 289
 290         BT_DBG("hcon %p ctrl %p frag_len %u assoc_len %u rem_len %u",
 291                hcon, ctrl, frag_len, ctrl->assoc_len, ctrl->assoc_rem_len);
 292
 293         cp->phy_handle = hcon->handle;
 294         cp->len_so_far = cpu_to_le16(ctrl->assoc_len_so_far);
 295         cp->rem_len = cpu_to_le16(ctrl->assoc_rem_len);
 296         memcpy(cp->frag, ctrl->assoc, frag_len);
 297
 298         ctrl->assoc_len_so_far += frag_len;
 299         ctrl->assoc_rem_len -= frag_len;
 300
 301         amp_ctrl_put(ctrl);
 302
 303         hci_send_cmd(hdev, HCI_OP_WRITE_REMOTE_AMP_ASSOC, len, cp);
 304
 305         kfree(cp);
 306
 307         return false;
 308 }
 309
 310 void amp_write_rem_assoc_continue(struct hci_dev *hdev, u8 handle)
 311 {
 312         struct hci_conn *hcon;
 313
 314         BT_DBG("%s phy handle 0x%2.2x", hdev->name, handle);
 315
 316         hcon = hci_conn_hash_lookup_handle(hdev, handle);
 317         if (!hcon)
 318                 return;
 319
 320         amp_write_rem_assoc_frag(hdev, hcon);
 321 }
 322
 323 void amp_write_remote_assoc(struct hci_dev *hdev, u8 handle)
 324 {
 325         struct hci_conn *hcon;
 326
 327         BT_DBG("%s phy handle 0x%2.2x", hdev->name, handle);
 328
 329         hcon = hci_conn_hash_lookup_handle(hdev, handle);
 330         if (!hcon)
 331                 return;
 332
 333         BT_DBG("%s phy handle 0x%2.2x hcon %p", hdev->name, handle, hcon);
 334
 335         amp_write_rem_assoc_frag(hdev, hcon);
 336 }
 337
 338 void amp_create_phylink(struct hci_dev *hdev, struct amp_mgr *mgr,
 339                         struct hci_conn *hcon)
 340 {
 341         struct hci_cp_create_phy_link cp;
 342
 343         cp.phy_handle = hcon->handle;
 344
 345         BT_DBG("%s hcon %p phy handle 0x%2.2x", hdev->name, hcon,
 346                hcon->handle);
 347
 348         if (phylink_gen_key(mgr->l2cap_conn->hcon, cp.key, &cp.key_len,
 349                             &cp.key_type)) {
 350                 BT_DBG("Cannot create link key");
 351                 return;
 352         }
 353
 354         hci_send_cmd(hdev, HCI_OP_CREATE_PHY_LINK, sizeof(cp), &cp);
 355 }
 356
 357 void amp_accept_phylink(struct hci_dev *hdev, struct amp_mgr *mgr,
 358                         struct hci_conn *hcon)
 359 {
 360         struct hci_cp_accept_phy_link cp;
 361
 362         cp.phy_handle = hcon->handle;
 363
 364         BT_DBG("%s hcon %p phy handle 0x%2.2x", hdev->name, hcon,
 365                hcon->handle);
 366
 367         if (phylink_gen_key(mgr->l2cap_conn->hcon, cp.key, &cp.key_len,
 368                             &cp.key_type)) {
 369                 BT_DBG("Cannot create link key");
 370                 return;
 371         }
 372
 373         hci_send_cmd(hdev, HCI_OP_ACCEPT_PHY_LINK, sizeof(cp), &cp);
 374 }
 375
 376 void amp_physical_cfm(struct hci_conn *bredr_hcon, struct hci_conn *hs_hcon)
 377 {
 378         struct hci_dev *bredr_hdev = hci_dev_hold(bredr_hcon->hdev);
 379         struct amp_mgr *mgr = hs_hcon->amp_mgr;
 380         struct l2cap_chan *bredr_chan;
 381
 382         BT_DBG("bredr_hcon %p hs_hcon %p mgr %p", bredr_hcon, hs_hcon, mgr);
 383
 384         if (!bredr_hdev || !mgr || !mgr->bredr_chan)
 385                 return;
 386
 387         bredr_chan = mgr->bredr_chan;
 388
 389         l2cap_chan_lock(bredr_chan);
 390
 391         set_bit(FLAG_EFS_ENABLE, &bredr_chan->flags);
 392         bredr_chan->remote_amp_id = hs_hcon->remote_id;
 393         bredr_chan->local_amp_id = hs_hcon->hdev->id;
 394         bredr_chan->hs_hcon = hs_hcon;
 395         bredr_chan->conn->mtu = hs_hcon->hdev->block_mtu;
 396
 397         __l2cap_physical_cfm(bredr_chan, 0);
 398
 399         l2cap_chan_unlock(bredr_chan);
 400
 401         hci_dev_put(bredr_hdev);
 402 }
 403
 404 void amp_create_logical_link(struct l2cap_chan *chan)
 405 {
 406         struct hci_cp_create_accept_logical_link cp;
 407         struct hci_conn *hcon;
 408         struct hci_dev *hdev;
 409
 410         BT_DBG("chan %p", chan);
 411
 412         if (!chan->hs_hcon)
 413                 return;
 414
 415         hdev = hci_dev_hold(chan->hs_hcon->hdev);
 416         if (!hdev)
 417                 return;
 418
 419         BT_DBG("chan %p dst %pMR", chan, chan->conn->dst);
 420
 421         hcon = hci_conn_hash_lookup_ba(hdev, AMP_LINK, chan->conn->dst);
 422         if (!hcon)
 423                 goto done;
 424
 425         cp.phy_handle = hcon->handle;
 426
 427         cp.tx_flow_spec.id = chan->local_id;
 428         cp.tx_flow_spec.stype = chan->local_stype;
 429         cp.tx_flow_spec.msdu = cpu_to_le16(chan->local_msdu);
 430         cp.tx_flow_spec.sdu_itime = cpu_to_le32(chan->local_sdu_itime);
 431         cp.tx_flow_spec.acc_lat = cpu_to_le32(chan->local_acc_lat);
 432         cp.tx_flow_spec.flush_to = cpu_to_le32(chan->local_flush_to);
 433
 434         cp.rx_flow_spec.id = chan->remote_id;
 435         cp.rx_flow_spec.stype = chan->remote_stype;
 436         cp.rx_flow_spec.msdu = cpu_to_le16(chan->remote_msdu);
 437         cp.rx_flow_spec.sdu_itime = cpu_to_le32(chan->remote_sdu_itime);
 438         cp.rx_flow_spec.acc_lat = cpu_to_le32(chan->remote_acc_lat);
 439         cp.rx_flow_spec.flush_to = cpu_to_le32(chan->remote_flush_to);
 440
 441         if (hcon->out)
 442                 hci_send_cmd(hdev, HCI_OP_CREATE_LOGICAL_LINK, sizeof(cp),
 443                              &cp);
 444         else
 445                 hci_send_cmd(hdev, HCI_OP_ACCEPT_LOGICAL_LINK, sizeof(cp),
 446                              &cp);
 447
 448 done:
 449         hci_dev_put(hdev);
 450 }
 451
 452 void amp_disconnect_logical_link(struct hci_chan *hchan)
 453 {
 454         struct hci_conn *hcon = hchan->conn;
 455         struct hci_cp_disconn_logical_link cp;
 456
 457         if (hcon->state != BT_CONNECTED) {
 458                 BT_DBG("hchan %p not connected", hchan);
 459                 return;
 460         }
 461
 462         cp.log_handle = cpu_to_le16(hchan->handle);
 463         hci_send_cmd(hcon->hdev, HCI_OP_DISCONN_LOGICAL_LINK, sizeof(cp), &cp);
 464 }
 465
 466 void amp_destroy_logical_link(struct hci_chan *hchan, u8 reason)
 467 {
 468         BT_DBG("hchan %p", hchan);
 469
 470         hci_chan_del(hchan);
 471 }