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