2 Copyright (c) 2011,2012 Intel Corp.
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.
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.
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>
21 /* Remote AMP Controllers interface */
22 static void amp_ctrl_get(struct amp_ctrl *ctrl)
24 BT_DBG("ctrl %p orig refcnt %d", ctrl,
25 atomic_read(&ctrl->kref.refcount));
27 kref_get(&ctrl->kref);
30 static void amp_ctrl_destroy(struct kref *kref)
32 struct amp_ctrl *ctrl = container_of(kref, struct amp_ctrl, kref);
34 BT_DBG("ctrl %p", ctrl);
40 int amp_ctrl_put(struct amp_ctrl *ctrl)
42 BT_DBG("ctrl %p orig refcnt %d", ctrl,
43 atomic_read(&ctrl->kref.refcount));
45 return kref_put(&ctrl->kref, &_ctrl_destroy);
48 struct amp_ctrl *amp_ctrl_add(struct amp_mgr *mgr)
50 struct amp_ctrl *ctrl;
52 ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
56 mutex_lock(&mgr->amp_ctrls_lock);
57 list_add(&ctrl->list, &mgr->amp_ctrls);
58 mutex_unlock(&mgr->amp_ctrls_lock);
60 kref_init(&ctrl->kref);
62 BT_DBG("mgr %p ctrl %p", mgr, ctrl);
67 void amp_ctrl_list_flush(struct amp_mgr *mgr)
69 struct amp_ctrl *ctrl, *n;
71 BT_DBG("mgr %p", mgr);
73 mutex_lock(&mgr->amp_ctrls_lock);
74 list_for_each_entry_safe(ctrl, n, &mgr->amp_ctrls, list) {
75 list_del(&ctrl->list);
78 mutex_unlock(&mgr->amp_ctrls_lock);
81 struct amp_ctrl *amp_ctrl_lookup(struct amp_mgr *mgr, u8 id)
83 struct amp_ctrl *ctrl;
85 BT_DBG("mgr %p id %d", mgr, id);
87 mutex_lock(&mgr->amp_ctrls_lock);
88 list_for_each_entry(ctrl, &mgr->amp_ctrls, list) {
91 mutex_unlock(&mgr->amp_ctrls_lock);
95 mutex_unlock(&mgr->amp_ctrls_lock);
100 /* Physical Link interface */
101 static u8 __next_handle(struct amp_mgr *mgr)
103 if (++mgr->handle == 0)
109 struct hci_conn *phylink_add(struct hci_dev *hdev, struct amp_mgr *mgr,
112 bdaddr_t *dst = mgr->l2cap_conn->dst;
113 struct hci_conn *hcon;
115 hcon = hci_conn_add(hdev, AMP_LINK, dst);
119 hcon->state = BT_CONNECT;
122 hcon->handle = __next_handle(mgr);
123 hcon->remote_id = remote_id;
129 /* AMP crypto key generation interface */
130 static int hmac_sha256(u8 *key, u8 ksize, char *plaintext, u8 psize, u8 *output)
133 struct crypto_shash *tfm;
138 tfm = crypto_alloc_shash("hmac(sha256)", 0, 0);
140 BT_DBG("crypto_alloc_ahash failed: err %ld", PTR_ERR(tfm));
144 ret = crypto_shash_setkey(tfm, key, ksize);
146 BT_DBG("crypto_ahash_setkey failed: err %d", ret);
149 struct shash_desc shash;
150 char ctx[crypto_shash_descsize(tfm)];
153 desc.shash.tfm = tfm;
154 desc.shash.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
156 ret = crypto_shash_digest(&desc.shash, plaintext, psize,
160 crypto_free_shash(tfm);
164 int phylink_gen_key(struct hci_conn *conn, u8 *data, u8 *len, u8 *type)
166 struct hci_dev *hdev = conn->hdev;
167 struct link_key *key;
168 u8 keybuf[HCI_AMP_LINK_KEY_SIZE];
169 u8 gamp_key[HCI_AMP_LINK_KEY_SIZE];
172 if (!hci_conn_check_link_mode(conn))
175 BT_DBG("conn %p key_type %d", conn, conn->key_type);
178 if (conn->key_type < 3) {
179 BT_ERR("Legacy key type %d", conn->key_type);
183 *type = conn->key_type;
184 *len = HCI_AMP_LINK_KEY_SIZE;
186 key = hci_find_link_key(hdev, &conn->dst);
188 /* BR/EDR Link Key concatenated together with itself */
189 memcpy(&keybuf[0], key->val, HCI_LINK_KEY_SIZE);
190 memcpy(&keybuf[HCI_LINK_KEY_SIZE], key->val, HCI_LINK_KEY_SIZE);
192 /* Derive Generic AMP Link Key (gamp) */
193 err = hmac_sha256(keybuf, HCI_AMP_LINK_KEY_SIZE, "gamp", 4, gamp_key);
195 BT_ERR("Could not derive Generic AMP Key: err %d", err);
199 if (conn->key_type == HCI_LK_DEBUG_COMBINATION) {
200 BT_DBG("Use Generic AMP Key (gamp)");
201 memcpy(data, gamp_key, HCI_AMP_LINK_KEY_SIZE);
205 /* Derive Dedicated AMP Link Key: "802b" is 802.11 PAL keyID */
206 return hmac_sha256(gamp_key, HCI_AMP_LINK_KEY_SIZE, "802b", 4, data);
209 void amp_read_loc_assoc_frag(struct hci_dev *hdev, u8 phy_handle)
211 struct hci_cp_read_local_amp_assoc cp;
212 struct amp_assoc *loc_assoc = &hdev->loc_assoc;
214 BT_DBG("%s handle %d", hdev->name, phy_handle);
216 cp.phy_handle = phy_handle;
217 cp.max_len = cpu_to_le16(hdev->amp_assoc_size);
218 cp.len_so_far = cpu_to_le16(loc_assoc->offset);
220 hci_send_cmd(hdev, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
223 void amp_read_loc_assoc(struct hci_dev *hdev, struct amp_mgr *mgr)
225 struct hci_cp_read_local_amp_assoc cp;
227 memset(&hdev->loc_assoc, 0, sizeof(struct amp_assoc));
228 memset(&cp, 0, sizeof(cp));
230 cp.max_len = cpu_to_le16(hdev->amp_assoc_size);
232 mgr->state = READ_LOC_AMP_ASSOC;
233 hci_send_cmd(hdev, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
236 void amp_read_loc_assoc_final_data(struct hci_dev *hdev,
237 struct hci_conn *hcon)
239 struct hci_cp_read_local_amp_assoc cp;
240 struct amp_mgr *mgr = hcon->amp_mgr;
242 cp.phy_handle = hcon->handle;
243 cp.len_so_far = cpu_to_le16(0);
244 cp.max_len = cpu_to_le16(hdev->amp_assoc_size);
246 mgr->state = READ_LOC_AMP_ASSOC_FINAL;
248 /* Read Local AMP Assoc final link information data */
249 hci_send_cmd(hdev, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
252 /* Write AMP Assoc data fragments, returns true with last fragment written*/
253 static bool amp_write_rem_assoc_frag(struct hci_dev *hdev,
254 struct hci_conn *hcon)
256 struct hci_cp_write_remote_amp_assoc *cp;
257 struct amp_mgr *mgr = hcon->amp_mgr;
258 struct amp_ctrl *ctrl;
261 ctrl = amp_ctrl_lookup(mgr, hcon->remote_id);
265 if (!ctrl->assoc_rem_len) {
266 BT_DBG("all fragments are written");
267 ctrl->assoc_rem_len = ctrl->assoc_len;
268 ctrl->assoc_len_so_far = 0;
274 frag_len = min_t(u16, 248, ctrl->assoc_rem_len);
275 len = frag_len + sizeof(*cp);
277 cp = kzalloc(len, GFP_KERNEL);
283 BT_DBG("hcon %p ctrl %p frag_len %u assoc_len %u rem_len %u",
284 hcon, ctrl, frag_len, ctrl->assoc_len, ctrl->assoc_rem_len);
286 cp->phy_handle = hcon->handle;
287 cp->len_so_far = cpu_to_le16(ctrl->assoc_len_so_far);
288 cp->rem_len = cpu_to_le16(ctrl->assoc_rem_len);
289 memcpy(cp->frag, ctrl->assoc, frag_len);
291 ctrl->assoc_len_so_far += frag_len;
292 ctrl->assoc_rem_len -= frag_len;
296 hci_send_cmd(hdev, HCI_OP_WRITE_REMOTE_AMP_ASSOC, len, cp);
303 void amp_write_rem_assoc_continue(struct hci_dev *hdev, u8 handle)
305 struct hci_conn *hcon;
307 BT_DBG("%s phy handle 0x%2.2x", hdev->name, handle);
309 hcon = hci_conn_hash_lookup_handle(hdev, handle);
313 amp_write_rem_assoc_frag(hdev, hcon);
316 void amp_write_remote_assoc(struct hci_dev *hdev, u8 handle)
318 struct hci_conn *hcon;
320 BT_DBG("%s phy handle 0x%2.2x", hdev->name, handle);
322 hcon = hci_conn_hash_lookup_handle(hdev, handle);
326 BT_DBG("%s phy handle 0x%2.2x hcon %p", hdev->name, handle, hcon);
328 amp_write_rem_assoc_frag(hdev, hcon);
331 void amp_create_phylink(struct hci_dev *hdev, struct amp_mgr *mgr,
332 struct hci_conn *hcon)
334 struct hci_cp_create_phy_link cp;
336 cp.phy_handle = hcon->handle;
338 BT_DBG("%s hcon %p phy handle 0x%2.2x", hdev->name, hcon,
341 if (phylink_gen_key(mgr->l2cap_conn->hcon, cp.key, &cp.key_len,
343 BT_DBG("Cannot create link key");
347 hci_send_cmd(hdev, HCI_OP_CREATE_PHY_LINK, sizeof(cp), &cp);