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
 117         hcon = hci_conn_add(hdev, AMP_LINK, dst);
 118         if (!hcon)
 119                 return NULL;
 120
 121         BT_DBG("hcon %p dst %pMR", hcon, dst);
 122
 123         hcon->state = BT_CONNECT;
 124         hcon->attempt++;
 125         hcon->handle = __next_handle(mgr);
 126         hcon->remote_id = remote_id;
 127         hcon->amp_mgr = amp_mgr_get(mgr);
 128         hcon->out = out;
 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         int ret = 0;
 137         struct crypto_shash *tfm;
 138
 139         if (!ksize)
 140                 return -EINVAL;
 141
 142         tfm = crypto_alloc_shash("hmac(sha256)", 0, 0);
 143         if (IS_ERR(tfm)) {
 144                 BT_DBG("crypto_alloc_ahash failed: err %ld", PTR_ERR(tfm));
 145                 return PTR_ERR(tfm);
 146         }
 147
 148         ret = crypto_shash_setkey(tfm, key, ksize);
 149         if (ret) {
 150                 BT_DBG("crypto_ahash_setkey failed: err %d", ret);
 151         } else {
 152                 struct {
 153                         struct shash_desc shash;
 154                         char ctx[crypto_shash_descsize(tfm)];
 155                 } desc;
 156
 157                 desc.shash.tfm = tfm;
 158                 desc.shash.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 159
 160                 ret = crypto_shash_digest(&desc.shash, plaintext, psize,
 161                                           output);
 162         }
 163
 164         crypto_free_shash(tfm);
 165         return ret;
 166 }
 167
 168 int phylink_gen_key(struct hci_conn *conn, u8 *data, u8 *len, u8 *type)
 169 {
 170         struct hci_dev *hdev = conn->hdev;
 171         struct link_key *key;
 172         u8 keybuf[HCI_AMP_LINK_KEY_SIZE];
 173         u8 gamp_key[HCI_AMP_LINK_KEY_SIZE];
 174         int err;
 175
 176         if (!hci_conn_check_link_mode(conn))
 177                 return -EACCES;
 178
 179         BT_DBG("conn %p key_type %d", conn, conn->key_type);
 180
 181         /* Legacy key */
 182         if (conn->key_type < 3) {
 183                 BT_ERR("Legacy key type %d", conn->key_type);
 184                 return -EACCES;
 185         }
 186
 187         *type = conn->key_type;
 188         *len = HCI_AMP_LINK_KEY_SIZE;
 189
 190         key = hci_find_link_key(hdev, &conn->dst);
 191         if (!key) {
 192                 BT_DBG("No Link key for conn %p dst %pMR", conn, &conn->dst);
 193                 return -EACCES;
 194         }
 195
 196         /* BR/EDR Link Key concatenated together with itself */
 197         memcpy(&keybuf[0], key->val, HCI_LINK_KEY_SIZE);
 198         memcpy(&keybuf[HCI_LINK_KEY_SIZE], key->val, HCI_LINK_KEY_SIZE);
 199
 200         /* Derive Generic AMP Link Key (gamp) */
 201         err = hmac_sha256(keybuf, HCI_AMP_LINK_KEY_SIZE, "gamp", 4, gamp_key);
 202         if (err) {
 203                 BT_ERR("Could not derive Generic AMP Key: err %d", err);
 204                 return err;
 205         }
 206
 207         if (conn->key_type == HCI_LK_DEBUG_COMBINATION) {
 208                 BT_DBG("Use Generic AMP Key (gamp)");
 209                 memcpy(data, gamp_key, HCI_AMP_LINK_KEY_SIZE);
 210                 return err;
 211         }
 212
 213         /* Derive Dedicated AMP Link Key: "802b" is 802.11 PAL keyID */
 214         return hmac_sha256(gamp_key, HCI_AMP_LINK_KEY_SIZE, "802b", 4, data);
 215 }
 216
 217 void amp_read_loc_assoc_frag(struct hci_dev *hdev, u8 phy_handle)
 218 {
 219         struct hci_cp_read_local_amp_assoc cp;
 220         struct amp_assoc *loc_assoc = &hdev->loc_assoc;
 221
 222         BT_DBG("%s handle %d", hdev->name, phy_handle);
 223
 224         cp.phy_handle = phy_handle;
 225         cp.max_len = cpu_to_le16(hdev->amp_assoc_size);
 226         cp.len_so_far = cpu_to_le16(loc_assoc->offset);
 227
 228         hci_send_cmd(hdev, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
 229 }
 230
 231 void amp_read_loc_assoc(struct hci_dev *hdev, struct amp_mgr *mgr)
 232 {
 233         struct hci_cp_read_local_amp_assoc cp;
 234
 235         memset(&hdev->loc_assoc, 0, sizeof(struct amp_assoc));
 236         memset(&cp, 0, sizeof(cp));
 237
 238         cp.max_len = cpu_to_le16(hdev->amp_assoc_size);
 239
 240         set_bit(READ_LOC_AMP_ASSOC, &mgr->state);
 241         hci_send_cmd(hdev, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
 242 }
 243
 244 void amp_read_loc_assoc_final_data(struct hci_dev *hdev,
 245                                    struct hci_conn *hcon)
 246 {
 247         struct hci_cp_read_local_amp_assoc cp;
 248         struct amp_mgr *mgr = hcon->amp_mgr;
 249
 250         cp.phy_handle = hcon->handle;
 251         cp.len_so_far = cpu_to_le16(0);
 252         cp.max_len = cpu_to_le16(hdev->amp_assoc_size);
 253
 254         set_bit(READ_LOC_AMP_ASSOC_FINAL, &mgr->state);
 255
 256         /* Read Local AMP Assoc final link information data */
 257         hci_send_cmd(hdev, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
 258 }
 259
 260 /* Write AMP Assoc data fragments, returns true with last fragment written*/
 261 static bool amp_write_rem_assoc_frag(struct hci_dev *hdev,
 262                                      struct hci_conn *hcon)
 263 {
 264         struct hci_cp_write_remote_amp_assoc *cp;
 265         struct amp_mgr *mgr = hcon->amp_mgr;
 266         struct amp_ctrl *ctrl;
 267         u16 frag_len, len;
 268
 269         ctrl = amp_ctrl_lookup(mgr, hcon->remote_id);
 270         if (!ctrl)
 271                 return false;
 272
 273         if (!ctrl->assoc_rem_len) {
 274                 BT_DBG("all fragments are written");
 275                 ctrl->assoc_rem_len = ctrl->assoc_len;
 276                 ctrl->assoc_len_so_far = 0;
 277
 278                 amp_ctrl_put(ctrl);
 279                 return true;
 280         }
 281
 282         frag_len = min_t(u16, 248, ctrl->assoc_rem_len);
 283         len = frag_len + sizeof(*cp);
 284
 285         cp = kzalloc(len, GFP_KERNEL);
 286         if (!cp) {
 287                 amp_ctrl_put(ctrl);
 288                 return false;
 289         }
 290
 291         BT_DBG("hcon %p ctrl %p frag_len %u assoc_len %u rem_len %u",
 292                hcon, ctrl, frag_len, ctrl->assoc_len, ctrl->assoc_rem_len);
 293
 294         cp->phy_handle = hcon->handle;
 295         cp->len_so_far = cpu_to_le16(ctrl->assoc_len_so_far);
 296         cp->rem_len = cpu_to_le16(ctrl->assoc_rem_len);
 297         memcpy(cp->frag, ctrl->assoc, frag_len);
 298
 299         ctrl->assoc_len_so_far += frag_len;
 300         ctrl->assoc_rem_len -= frag_len;
 301
 302         amp_ctrl_put(ctrl);
 303
 304         hci_send_cmd(hdev, HCI_OP_WRITE_REMOTE_AMP_ASSOC, len, cp);
 305
 306         kfree(cp);
 307
 308         return false;
 309 }
 310
 311 void amp_write_rem_assoc_continue(struct hci_dev *hdev, u8 handle)
 312 {
 313         struct hci_conn *hcon;
 314
 315         BT_DBG("%s phy handle 0x%2.2x", hdev->name, handle);
 316
 317         hcon = hci_conn_hash_lookup_handle(hdev, handle);
 318         if (!hcon)
 319                 return;
 320
 321         /* Send A2MP create phylink rsp when all fragments are written */
 322         if (amp_write_rem_assoc_frag(hdev, hcon))
 323                 a2mp_send_create_phy_link_rsp(hdev, 0);
 324 }
 325
 326 void amp_write_remote_assoc(struct hci_dev *hdev, u8 handle)
 327 {
 328         struct hci_conn *hcon;
 329
 330         BT_DBG("%s phy handle 0x%2.2x", hdev->name, handle);
 331
 332         hcon = hci_conn_hash_lookup_handle(hdev, handle);
 333         if (!hcon)
 334                 return;
 335
 336         BT_DBG("%s phy handle 0x%2.2x hcon %p", hdev->name, handle, hcon);
 337
 338         amp_write_rem_assoc_frag(hdev, hcon);
 339 }
 340
 341 void amp_create_phylink(struct hci_dev *hdev, struct amp_mgr *mgr,
 342                         struct hci_conn *hcon)
 343 {
 344         struct hci_cp_create_phy_link cp;
 345
 346         cp.phy_handle = hcon->handle;
 347
 348         BT_DBG("%s hcon %p phy handle 0x%2.2x", hdev->name, hcon,
 349                hcon->handle);
 350
 351         if (phylink_gen_key(mgr->l2cap_conn->hcon, cp.key, &cp.key_len,
 352                             &cp.key_type)) {
 353                 BT_DBG("Cannot create link key");
 354                 return;
 355         }
 356
 357         hci_send_cmd(hdev, HCI_OP_CREATE_PHY_LINK, sizeof(cp), &cp);
 358 }
 359
 360 void amp_accept_phylink(struct hci_dev *hdev, struct amp_mgr *mgr,
 361                         struct hci_conn *hcon)
 362 {
 363         struct hci_cp_accept_phy_link cp;
 364
 365         cp.phy_handle = hcon->handle;
 366
 367         BT_DBG("%s hcon %p phy handle 0x%2.2x", hdev->name, hcon,
 368                hcon->handle);
 369
 370         if (phylink_gen_key(mgr->l2cap_conn->hcon, cp.key, &cp.key_len,
 371                             &cp.key_type)) {
 372                 BT_DBG("Cannot create link key");
 373                 return;
 374         }
 375
 376         hci_send_cmd(hdev, HCI_OP_ACCEPT_PHY_LINK, sizeof(cp), &cp);
 377 }
 378
 379 void amp_physical_cfm(struct hci_conn *bredr_hcon, struct hci_conn *hs_hcon)
 380 {
 381         struct hci_dev *bredr_hdev = hci_dev_hold(bredr_hcon->hdev);
 382         struct amp_mgr *mgr = hs_hcon->amp_mgr;
 383         struct l2cap_chan *bredr_chan;
 384
 385         BT_DBG("bredr_hcon %p hs_hcon %p mgr %p", bredr_hcon, hs_hcon, mgr);
 386
 387         if (!bredr_hdev || !mgr || !mgr->bredr_chan)
 388                 return;
 389
 390         bredr_chan = mgr->bredr_chan;
 391
 392         l2cap_chan_lock(bredr_chan);
 393
 394         set_bit(FLAG_EFS_ENABLE, &bredr_chan->flags);
 395         bredr_chan->remote_amp_id = hs_hcon->remote_id;
 396         bredr_chan->local_amp_id = hs_hcon->hdev->id;
 397         bredr_chan->hs_hcon = hs_hcon;
 398         bredr_chan->conn->mtu = hs_hcon->hdev->block_mtu;
 399
 400         __l2cap_physical_cfm(bredr_chan, 0);
 401
 402         l2cap_chan_unlock(bredr_chan);
 403
 404         hci_dev_put(bredr_hdev);
 405 }
 406
 407 void amp_create_logical_link(struct l2cap_chan *chan)
 408 {
 409         struct hci_conn *hs_hcon = chan->hs_hcon;
 410         struct hci_cp_create_accept_logical_link cp;
 411         struct hci_dev *hdev;
 412
 413         BT_DBG("chan %p hs_hcon %p dst %pMR", chan, hs_hcon,
 414                &chan->conn->hcon->dst);
 415
 416         if (!hs_hcon)
 417                 return;
 418
 419         hdev = hci_dev_hold(chan->hs_hcon->hdev);
 420         if (!hdev)
 421                 return;
 422
 423         cp.phy_handle = hs_hcon->handle;
 424
 425         cp.tx_flow_spec.id = chan->local_id;
 426         cp.tx_flow_spec.stype = chan->local_stype;
 427         cp.tx_flow_spec.msdu = cpu_to_le16(chan->local_msdu);
 428         cp.tx_flow_spec.sdu_itime = cpu_to_le32(chan->local_sdu_itime);
 429         cp.tx_flow_spec.acc_lat = cpu_to_le32(chan->local_acc_lat);
 430         cp.tx_flow_spec.flush_to = cpu_to_le32(chan->local_flush_to);
 431
 432         cp.rx_flow_spec.id = chan->remote_id;
 433         cp.rx_flow_spec.stype = chan->remote_stype;
 434         cp.rx_flow_spec.msdu = cpu_to_le16(chan->remote_msdu);
 435         cp.rx_flow_spec.sdu_itime = cpu_to_le32(chan->remote_sdu_itime);
 436         cp.rx_flow_spec.acc_lat = cpu_to_le32(chan->remote_acc_lat);
 437         cp.rx_flow_spec.flush_to = cpu_to_le32(chan->remote_flush_to);
 438
 439         if (hs_hcon->out)
 440                 hci_send_cmd(hdev, HCI_OP_CREATE_LOGICAL_LINK, sizeof(cp),
 441                              &cp);
 442         else
 443                 hci_send_cmd(hdev, HCI_OP_ACCEPT_LOGICAL_LINK, sizeof(cp),
 444                              &cp);
 445
 446         hci_dev_put(hdev);
 447 }
 448
 449 void amp_disconnect_logical_link(struct hci_chan *hchan)
 450 {
 451         struct hci_conn *hcon = hchan->conn;
 452         struct hci_cp_disconn_logical_link cp;
 453
 454         if (hcon->state != BT_CONNECTED) {
 455                 BT_DBG("hchan %p not connected", hchan);
 456                 return;
 457         }
 458
 459         cp.log_handle = cpu_to_le16(hchan->handle);
 460         hci_send_cmd(hcon->hdev, HCI_OP_DISCONN_LOGICAL_LINK, sizeof(cp), &cp);
 461 }
 462
 463 void amp_destroy_logical_link(struct hci_chan *hchan, u8 reason)
 464 {
 465         BT_DBG("hchan %p", hchan);
 466
 467         hci_chan_del(hchan);
 468 }