diff options
Diffstat (limited to 'net/bluetooth/amp.c')
-rw-r--r-- | net/bluetooth/amp.c | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/net/bluetooth/amp.c b/net/bluetooth/amp.c new file mode 100644 index 000000000000..231d7ef53ecb --- /dev/null +++ b/net/bluetooth/amp.c @@ -0,0 +1,374 @@ +/* + Copyright (c) 2011,2012 Intel Corp. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License version 2 and + only version 2 as published by the Free Software Foundation. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. +*/ + +#include <net/bluetooth/bluetooth.h> +#include <net/bluetooth/hci.h> +#include <net/bluetooth/hci_core.h> +#include <net/bluetooth/a2mp.h> +#include <net/bluetooth/amp.h> +#include <crypto/hash.h> + +/* Remote AMP Controllers interface */ +void amp_ctrl_get(struct amp_ctrl *ctrl) +{ + BT_DBG("ctrl %p orig refcnt %d", ctrl, + atomic_read(&ctrl->kref.refcount)); + + kref_get(&ctrl->kref); +} + +static void amp_ctrl_destroy(struct kref *kref) +{ + struct amp_ctrl *ctrl = container_of(kref, struct amp_ctrl, kref); + + BT_DBG("ctrl %p", ctrl); + + kfree(ctrl->assoc); + kfree(ctrl); +} + +int amp_ctrl_put(struct amp_ctrl *ctrl) +{ + BT_DBG("ctrl %p orig refcnt %d", ctrl, + atomic_read(&ctrl->kref.refcount)); + + return kref_put(&ctrl->kref, &_ctrl_destroy); +} + +struct amp_ctrl *amp_ctrl_add(struct amp_mgr *mgr, u8 id) +{ + struct amp_ctrl *ctrl; + + ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL); + if (!ctrl) + return NULL; + + kref_init(&ctrl->kref); + ctrl->id = id; + + mutex_lock(&mgr->amp_ctrls_lock); + list_add(&ctrl->list, &mgr->amp_ctrls); + mutex_unlock(&mgr->amp_ctrls_lock); + + BT_DBG("mgr %p ctrl %p", mgr, ctrl); + + return ctrl; +} + +void amp_ctrl_list_flush(struct amp_mgr *mgr) +{ + struct amp_ctrl *ctrl, *n; + + BT_DBG("mgr %p", mgr); + + mutex_lock(&mgr->amp_ctrls_lock); + list_for_each_entry_safe(ctrl, n, &mgr->amp_ctrls, list) { + list_del(&ctrl->list); + amp_ctrl_put(ctrl); + } + mutex_unlock(&mgr->amp_ctrls_lock); +} + +struct amp_ctrl *amp_ctrl_lookup(struct amp_mgr *mgr, u8 id) +{ + struct amp_ctrl *ctrl; + + BT_DBG("mgr %p id %d", mgr, id); + + mutex_lock(&mgr->amp_ctrls_lock); + list_for_each_entry(ctrl, &mgr->amp_ctrls, list) { + if (ctrl->id == id) { + amp_ctrl_get(ctrl); + mutex_unlock(&mgr->amp_ctrls_lock); + return ctrl; + } + } + mutex_unlock(&mgr->amp_ctrls_lock); + + return NULL; +} + +/* Physical Link interface */ +static u8 __next_handle(struct amp_mgr *mgr) +{ + if (++mgr->handle == 0) + mgr->handle = 1; + + return mgr->handle; +} + +struct hci_conn *phylink_add(struct hci_dev *hdev, struct amp_mgr *mgr, + u8 remote_id, bool out) +{ + bdaddr_t *dst = mgr->l2cap_conn->dst; + struct hci_conn *hcon; + + hcon = hci_conn_add(hdev, AMP_LINK, dst); + if (!hcon) + return NULL; + + BT_DBG("hcon %p dst %pMR", hcon, dst); + + hcon->state = BT_CONNECT; + hcon->attempt++; + hcon->handle = __next_handle(mgr); + hcon->remote_id = remote_id; + hcon->amp_mgr = amp_mgr_get(mgr); + hcon->out = out; + + return hcon; +} + +/* AMP crypto key generation interface */ +static int hmac_sha256(u8 *key, u8 ksize, char *plaintext, u8 psize, u8 *output) +{ + int ret = 0; + struct crypto_shash *tfm; + + if (!ksize) + return -EINVAL; + + tfm = crypto_alloc_shash("hmac(sha256)", 0, 0); + if (IS_ERR(tfm)) { + BT_DBG("crypto_alloc_ahash failed: err %ld", PTR_ERR(tfm)); + return PTR_ERR(tfm); + } + + ret = crypto_shash_setkey(tfm, key, ksize); + if (ret) { + BT_DBG("crypto_ahash_setkey failed: err %d", ret); + } else { + struct { + struct shash_desc shash; + char ctx[crypto_shash_descsize(tfm)]; + } desc; + + desc.shash.tfm = tfm; + desc.shash.flags = CRYPTO_TFM_REQ_MAY_SLEEP; + + ret = crypto_shash_digest(&desc.shash, plaintext, psize, + output); + } + + crypto_free_shash(tfm); + return ret; +} + +int phylink_gen_key(struct hci_conn *conn, u8 *data, u8 *len, u8 *type) +{ + struct hci_dev *hdev = conn->hdev; + struct link_key *key; + u8 keybuf[HCI_AMP_LINK_KEY_SIZE]; + u8 gamp_key[HCI_AMP_LINK_KEY_SIZE]; + int err; + + if (!hci_conn_check_link_mode(conn)) + return -EACCES; + + BT_DBG("conn %p key_type %d", conn, conn->key_type); + + /* Legacy key */ + if (conn->key_type < 3) { + BT_ERR("Legacy key type %d", conn->key_type); + return -EACCES; + } + + *type = conn->key_type; + *len = HCI_AMP_LINK_KEY_SIZE; + + key = hci_find_link_key(hdev, &conn->dst); + if (!key) { + BT_DBG("No Link key for conn %p dst %pMR", conn, &conn->dst); + return -EACCES; + } + + /* BR/EDR Link Key concatenated together with itself */ + memcpy(&keybuf[0], key->val, HCI_LINK_KEY_SIZE); + memcpy(&keybuf[HCI_LINK_KEY_SIZE], key->val, HCI_LINK_KEY_SIZE); + + /* Derive Generic AMP Link Key (gamp) */ + err = hmac_sha256(keybuf, HCI_AMP_LINK_KEY_SIZE, "gamp", 4, gamp_key); + if (err) { + BT_ERR("Could not derive Generic AMP Key: err %d", err); + return err; + } + + if (conn->key_type == HCI_LK_DEBUG_COMBINATION) { + BT_DBG("Use Generic AMP Key (gamp)"); + memcpy(data, gamp_key, HCI_AMP_LINK_KEY_SIZE); + return err; + } + + /* Derive Dedicated AMP Link Key: "802b" is 802.11 PAL keyID */ + return hmac_sha256(gamp_key, HCI_AMP_LINK_KEY_SIZE, "802b", 4, data); +} + +void amp_read_loc_assoc_frag(struct hci_dev *hdev, u8 phy_handle) +{ + struct hci_cp_read_local_amp_assoc cp; + struct amp_assoc *loc_assoc = &hdev->loc_assoc; + + BT_DBG("%s handle %d", hdev->name, phy_handle); + + cp.phy_handle = phy_handle; + cp.max_len = cpu_to_le16(hdev->amp_assoc_size); + cp.len_so_far = cpu_to_le16(loc_assoc->offset); + + hci_send_cmd(hdev, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp); +} + +void amp_read_loc_assoc(struct hci_dev *hdev, struct amp_mgr *mgr) +{ + struct hci_cp_read_local_amp_assoc cp; + + memset(&hdev->loc_assoc, 0, sizeof(struct amp_assoc)); + memset(&cp, 0, sizeof(cp)); + + cp.max_len = cpu_to_le16(hdev->amp_assoc_size); + + mgr->state = READ_LOC_AMP_ASSOC; + hci_send_cmd(hdev, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp); +} + +void amp_read_loc_assoc_final_data(struct hci_dev *hdev, + struct hci_conn *hcon) +{ + struct hci_cp_read_local_amp_assoc cp; + struct amp_mgr *mgr = hcon->amp_mgr; + + cp.phy_handle = hcon->handle; + cp.len_so_far = cpu_to_le16(0); + cp.max_len = cpu_to_le16(hdev->amp_assoc_size); + + mgr->state = READ_LOC_AMP_ASSOC_FINAL; + + /* Read Local AMP Assoc final link information data */ + hci_send_cmd(hdev, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp); +} + +/* Write AMP Assoc data fragments, returns true with last fragment written*/ +static bool amp_write_rem_assoc_frag(struct hci_dev *hdev, + struct hci_conn *hcon) +{ + struct hci_cp_write_remote_amp_assoc *cp; + struct amp_mgr *mgr = hcon->amp_mgr; + struct amp_ctrl *ctrl; + u16 frag_len, len; + + ctrl = amp_ctrl_lookup(mgr, hcon->remote_id); + if (!ctrl) + return false; + + if (!ctrl->assoc_rem_len) { + BT_DBG("all fragments are written"); + ctrl->assoc_rem_len = ctrl->assoc_len; + ctrl->assoc_len_so_far = 0; + + amp_ctrl_put(ctrl); + return true; + } + + frag_len = min_t(u16, 248, ctrl->assoc_rem_len); + len = frag_len + sizeof(*cp); + + cp = kzalloc(len, GFP_KERNEL); + if (!cp) { + amp_ctrl_put(ctrl); + return false; + } + + BT_DBG("hcon %p ctrl %p frag_len %u assoc_len %u rem_len %u", + hcon, ctrl, frag_len, ctrl->assoc_len, ctrl->assoc_rem_len); + + cp->phy_handle = hcon->handle; + cp->len_so_far = cpu_to_le16(ctrl->assoc_len_so_far); + cp->rem_len = cpu_to_le16(ctrl->assoc_rem_len); + memcpy(cp->frag, ctrl->assoc, frag_len); + + ctrl->assoc_len_so_far += frag_len; + ctrl->assoc_rem_len -= frag_len; + + amp_ctrl_put(ctrl); + + hci_send_cmd(hdev, HCI_OP_WRITE_REMOTE_AMP_ASSOC, len, cp); + + kfree(cp); + + return false; +} + +void amp_write_rem_assoc_continue(struct hci_dev *hdev, u8 handle) +{ + struct hci_conn *hcon; + + BT_DBG("%s phy handle 0x%2.2x", hdev->name, handle); + + hcon = hci_conn_hash_lookup_handle(hdev, handle); + if (!hcon) + return; + + amp_write_rem_assoc_frag(hdev, hcon); +} + +void amp_write_remote_assoc(struct hci_dev *hdev, u8 handle) +{ + struct hci_conn *hcon; + + BT_DBG("%s phy handle 0x%2.2x", hdev->name, handle); + + hcon = hci_conn_hash_lookup_handle(hdev, handle); + if (!hcon) + return; + + BT_DBG("%s phy handle 0x%2.2x hcon %p", hdev->name, handle, hcon); + + amp_write_rem_assoc_frag(hdev, hcon); +} + +void amp_create_phylink(struct hci_dev *hdev, struct amp_mgr *mgr, + struct hci_conn *hcon) +{ + struct hci_cp_create_phy_link cp; + + cp.phy_handle = hcon->handle; + + BT_DBG("%s hcon %p phy handle 0x%2.2x", hdev->name, hcon, + hcon->handle); + + if (phylink_gen_key(mgr->l2cap_conn->hcon, cp.key, &cp.key_len, + &cp.key_type)) { + BT_DBG("Cannot create link key"); + return; + } + + hci_send_cmd(hdev, HCI_OP_CREATE_PHY_LINK, sizeof(cp), &cp); +} + +void amp_accept_phylink(struct hci_dev *hdev, struct amp_mgr *mgr, + struct hci_conn *hcon) +{ + struct hci_cp_accept_phy_link cp; + + cp.phy_handle = hcon->handle; + + BT_DBG("%s hcon %p phy handle 0x%2.2x", hdev->name, hcon, + hcon->handle); + + if (phylink_gen_key(mgr->l2cap_conn->hcon, cp.key, &cp.key_len, + &cp.key_type)) { + BT_DBG("Cannot create link key"); + return; + } + + hci_send_cmd(hdev, HCI_OP_ACCEPT_PHY_LINK, sizeof(cp), &cp); +} |