diff options
Diffstat (limited to 'net/bluetooth/hci_request.c')
| -rw-r--r-- | net/bluetooth/hci_request.c | 568 |
1 files changed, 568 insertions, 0 deletions
diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c new file mode 100644 index 000000000..d6025d6e6 --- /dev/null +++ b/net/bluetooth/hci_request.c @@ -0,0 +1,568 @@ +/* + BlueZ - Bluetooth protocol stack for Linux + + Copyright (C) 2014 Intel Corporation + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License version 2 as + published by the Free Software Foundation; + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. + IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY + CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES + WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + + ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS, + COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS + SOFTWARE IS DISCLAIMED. +*/ + +#include <net/bluetooth/bluetooth.h> +#include <net/bluetooth/hci_core.h> + +#include "smp.h" +#include "hci_request.h" + +void hci_req_init(struct hci_request *req, struct hci_dev *hdev) +{ + skb_queue_head_init(&req->cmd_q); + req->hdev = hdev; + req->err = 0; +} + +static int req_run(struct hci_request *req, hci_req_complete_t complete, + hci_req_complete_skb_t complete_skb) +{ + struct hci_dev *hdev = req->hdev; + struct sk_buff *skb; + unsigned long flags; + + BT_DBG("length %u", skb_queue_len(&req->cmd_q)); + + /* If an error occurred during request building, remove all HCI + * commands queued on the HCI request queue. + */ + if (req->err) { + skb_queue_purge(&req->cmd_q); + return req->err; + } + + /* Do not allow empty requests */ + if (skb_queue_empty(&req->cmd_q)) + return -ENODATA; + + skb = skb_peek_tail(&req->cmd_q); + bt_cb(skb)->req.complete = complete; + bt_cb(skb)->req.complete_skb = complete_skb; + + spin_lock_irqsave(&hdev->cmd_q.lock, flags); + skb_queue_splice_tail(&req->cmd_q, &hdev->cmd_q); + spin_unlock_irqrestore(&hdev->cmd_q.lock, flags); + + queue_work(hdev->workqueue, &hdev->cmd_work); + + return 0; +} + +int hci_req_run(struct hci_request *req, hci_req_complete_t complete) +{ + return req_run(req, complete, NULL); +} + +int hci_req_run_skb(struct hci_request *req, hci_req_complete_skb_t complete) +{ + return req_run(req, NULL, complete); +} + +struct sk_buff *hci_prepare_cmd(struct hci_dev *hdev, u16 opcode, u32 plen, + const void *param) +{ + int len = HCI_COMMAND_HDR_SIZE + plen; + struct hci_command_hdr *hdr; + struct sk_buff *skb; + + skb = bt_skb_alloc(len, GFP_ATOMIC); + if (!skb) + return NULL; + + hdr = (struct hci_command_hdr *) skb_put(skb, HCI_COMMAND_HDR_SIZE); + hdr->opcode = cpu_to_le16(opcode); + hdr->plen = plen; + + if (plen) + memcpy(skb_put(skb, plen), param, plen); + + BT_DBG("skb len %d", skb->len); + + bt_cb(skb)->pkt_type = HCI_COMMAND_PKT; + bt_cb(skb)->opcode = opcode; + + return skb; +} + +/* Queue a command to an asynchronous HCI request */ +void hci_req_add_ev(struct hci_request *req, u16 opcode, u32 plen, + const void *param, u8 event) +{ + struct hci_dev *hdev = req->hdev; + struct sk_buff *skb; + + BT_DBG("%s opcode 0x%4.4x plen %d", hdev->name, opcode, plen); + + /* If an error occurred during request building, there is no point in + * queueing the HCI command. We can simply return. + */ + if (req->err) + return; + + skb = hci_prepare_cmd(hdev, opcode, plen, param); + if (!skb) { + BT_ERR("%s no memory for command (opcode 0x%4.4x)", + hdev->name, opcode); + req->err = -ENOMEM; + return; + } + + if (skb_queue_empty(&req->cmd_q)) + bt_cb(skb)->req.start = true; + + bt_cb(skb)->req.event = event; + + skb_queue_tail(&req->cmd_q, skb); +} + +void hci_req_add(struct hci_request *req, u16 opcode, u32 plen, + const void *param) +{ + hci_req_add_ev(req, opcode, plen, param, 0); +} + +void hci_req_add_le_scan_disable(struct hci_request *req) +{ + struct hci_cp_le_set_scan_enable cp; + + memset(&cp, 0, sizeof(cp)); + cp.enable = LE_SCAN_DISABLE; + hci_req_add(req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(cp), &cp); +} + +static void add_to_white_list(struct hci_request *req, + struct hci_conn_params *params) +{ + struct hci_cp_le_add_to_white_list cp; + + cp.bdaddr_type = params->addr_type; + bacpy(&cp.bdaddr, ¶ms->addr); + + hci_req_add(req, HCI_OP_LE_ADD_TO_WHITE_LIST, sizeof(cp), &cp); +} + +static u8 update_white_list(struct hci_request *req) +{ + struct hci_dev *hdev = req->hdev; + struct hci_conn_params *params; + struct bdaddr_list *b; + uint8_t white_list_entries = 0; + + /* Go through the current white list programmed into the + * controller one by one and check if that address is still + * in the list of pending connections or list of devices to + * report. If not present in either list, then queue the + * command to remove it from the controller. + */ + list_for_each_entry(b, &hdev->le_white_list, list) { + struct hci_cp_le_del_from_white_list cp; + + if (hci_pend_le_action_lookup(&hdev->pend_le_conns, + &b->bdaddr, b->bdaddr_type) || + hci_pend_le_action_lookup(&hdev->pend_le_reports, + &b->bdaddr, b->bdaddr_type)) { + white_list_entries++; + continue; + } + + cp.bdaddr_type = b->bdaddr_type; + bacpy(&cp.bdaddr, &b->bdaddr); + + hci_req_add(req, HCI_OP_LE_DEL_FROM_WHITE_LIST, + sizeof(cp), &cp); + } + + /* Since all no longer valid white list entries have been + * removed, walk through the list of pending connections + * and ensure that any new device gets programmed into + * the controller. + * + * If the list of the devices is larger than the list of + * available white list entries in the controller, then + * just abort and return filer policy value to not use the + * white list. + */ + list_for_each_entry(params, &hdev->pend_le_conns, action) { + if (hci_bdaddr_list_lookup(&hdev->le_white_list, + ¶ms->addr, params->addr_type)) + continue; + + if (white_list_entries >= hdev->le_white_list_size) { + /* Select filter policy to accept all advertising */ + return 0x00; + } + + if (hci_find_irk_by_addr(hdev, ¶ms->addr, + params->addr_type)) { + /* White list can not be used with RPAs */ + return 0x00; + } + + white_list_entries++; + add_to_white_list(req, params); + } + + /* After adding all new pending connections, walk through + * the list of pending reports and also add these to the + * white list if there is still space. + */ + list_for_each_entry(params, &hdev->pend_le_reports, action) { + if (hci_bdaddr_list_lookup(&hdev->le_white_list, + ¶ms->addr, params->addr_type)) + continue; + + if (white_list_entries >= hdev->le_white_list_size) { + /* Select filter policy to accept all advertising */ + return 0x00; + } + + if (hci_find_irk_by_addr(hdev, ¶ms->addr, + params->addr_type)) { + /* White list can not be used with RPAs */ + return 0x00; + } + + white_list_entries++; + add_to_white_list(req, params); + } + + /* Select filter policy to use white list */ + return 0x01; +} + +void hci_req_add_le_passive_scan(struct hci_request *req) +{ + struct hci_cp_le_set_scan_param param_cp; + struct hci_cp_le_set_scan_enable enable_cp; + struct hci_dev *hdev = req->hdev; + u8 own_addr_type; + u8 filter_policy; + + /* Set require_privacy to false since no SCAN_REQ are send + * during passive scanning. Not using an non-resolvable address + * here is important so that peer devices using direct + * advertising with our address will be correctly reported + * by the controller. + */ + if (hci_update_random_address(req, false, &own_addr_type)) + return; + + /* Adding or removing entries from the white list must + * happen before enabling scanning. The controller does + * not allow white list modification while scanning. + */ + filter_policy = update_white_list(req); + + /* When the controller is using random resolvable addresses and + * with that having LE privacy enabled, then controllers with + * Extended Scanner Filter Policies support can now enable support + * for handling directed advertising. + * + * So instead of using filter polices 0x00 (no whitelist) + * and 0x01 (whitelist enabled) use the new filter policies + * 0x02 (no whitelist) and 0x03 (whitelist enabled). + */ + if (hci_dev_test_flag(hdev, HCI_PRIVACY) && + (hdev->le_features[0] & HCI_LE_EXT_SCAN_POLICY)) + filter_policy |= 0x02; + + memset(¶m_cp, 0, sizeof(param_cp)); + param_cp.type = LE_SCAN_PASSIVE; + param_cp.interval = cpu_to_le16(hdev->le_scan_interval); + param_cp.window = cpu_to_le16(hdev->le_scan_window); + param_cp.own_address_type = own_addr_type; + param_cp.filter_policy = filter_policy; + hci_req_add(req, HCI_OP_LE_SET_SCAN_PARAM, sizeof(param_cp), + ¶m_cp); + + memset(&enable_cp, 0, sizeof(enable_cp)); + enable_cp.enable = LE_SCAN_ENABLE; + enable_cp.filter_dup = LE_SCAN_FILTER_DUP_ENABLE; + hci_req_add(req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(enable_cp), + &enable_cp); +} + +static void set_random_addr(struct hci_request *req, bdaddr_t *rpa) +{ + struct hci_dev *hdev = req->hdev; + + /* If we're advertising or initiating an LE connection we can't + * go ahead and change the random address at this time. This is + * because the eventual initiator address used for the + * subsequently created connection will be undefined (some + * controllers use the new address and others the one we had + * when the operation started). + * + * In this kind of scenario skip the update and let the random + * address be updated at the next cycle. + */ + if (hci_dev_test_flag(hdev, HCI_LE_ADV) || + hci_conn_hash_lookup_state(hdev, LE_LINK, BT_CONNECT)) { + BT_DBG("Deferring random address update"); + hci_dev_set_flag(hdev, HCI_RPA_EXPIRED); + return; + } + + hci_req_add(req, HCI_OP_LE_SET_RANDOM_ADDR, 6, rpa); +} + +int hci_update_random_address(struct hci_request *req, bool require_privacy, + u8 *own_addr_type) +{ + struct hci_dev *hdev = req->hdev; + int err; + + /* If privacy is enabled use a resolvable private address. If + * current RPA has expired or there is something else than + * the current RPA in use, then generate a new one. + */ + if (hci_dev_test_flag(hdev, HCI_PRIVACY)) { + int to; + + *own_addr_type = ADDR_LE_DEV_RANDOM; + + if (!hci_dev_test_and_clear_flag(hdev, HCI_RPA_EXPIRED) && + !bacmp(&hdev->random_addr, &hdev->rpa)) + return 0; + + err = smp_generate_rpa(hdev, hdev->irk, &hdev->rpa); + if (err < 0) { + BT_ERR("%s failed to generate new RPA", hdev->name); + return err; + } + + set_random_addr(req, &hdev->rpa); + + to = msecs_to_jiffies(hdev->rpa_timeout * 1000); + queue_delayed_work(hdev->workqueue, &hdev->rpa_expired, to); + + return 0; + } + + /* In case of required privacy without resolvable private address, + * use an non-resolvable private address. This is useful for active + * scanning and non-connectable advertising. + */ + if (require_privacy) { + bdaddr_t nrpa; + + while (true) { + /* The non-resolvable private address is generated + * from random six bytes with the two most significant + * bits cleared. + */ + get_random_bytes(&nrpa, 6); + nrpa.b[5] &= 0x3f; + + /* The non-resolvable private address shall not be + * equal to the public address. + */ + if (bacmp(&hdev->bdaddr, &nrpa)) + break; + } + + *own_addr_type = ADDR_LE_DEV_RANDOM; + set_random_addr(req, &nrpa); + return 0; + } + + /* If forcing static address is in use or there is no public + * address use the static address as random address (but skip + * the HCI command if the current random address is already the + * static one. + * + * In case BR/EDR has been disabled on a dual-mode controller + * and a static address has been configured, then use that + * address instead of the public BR/EDR address. + */ + if (hci_dev_test_flag(hdev, HCI_FORCE_STATIC_ADDR) || + !bacmp(&hdev->bdaddr, BDADDR_ANY) || + (!hci_dev_test_flag(hdev, HCI_BREDR_ENABLED) && + bacmp(&hdev->static_addr, BDADDR_ANY))) { + *own_addr_type = ADDR_LE_DEV_RANDOM; + if (bacmp(&hdev->static_addr, &hdev->random_addr)) + hci_req_add(req, HCI_OP_LE_SET_RANDOM_ADDR, 6, + &hdev->static_addr); + return 0; + } + + /* Neither privacy nor static address is being used so use a + * public address. + */ + *own_addr_type = ADDR_LE_DEV_PUBLIC; + + return 0; +} + +static bool disconnected_whitelist_entries(struct hci_dev *hdev) +{ + struct bdaddr_list *b; + + list_for_each_entry(b, &hdev->whitelist, list) { + struct hci_conn *conn; + + conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK, &b->bdaddr); + if (!conn) + return true; + + if (conn->state != BT_CONNECTED && conn->state != BT_CONFIG) + return true; + } + + return false; +} + +void __hci_update_page_scan(struct hci_request *req) +{ + struct hci_dev *hdev = req->hdev; + u8 scan; + + if (!hci_dev_test_flag(hdev, HCI_BREDR_ENABLED)) + return; + + if (!hdev_is_powered(hdev)) + return; + + if (mgmt_powering_down(hdev)) + return; + + if (hci_dev_test_flag(hdev, HCI_CONNECTABLE) || + disconnected_whitelist_entries(hdev)) + scan = SCAN_PAGE; + else + scan = SCAN_DISABLED; + + if (test_bit(HCI_PSCAN, &hdev->flags) == !!(scan & SCAN_PAGE)) + return; + + if (hci_dev_test_flag(hdev, HCI_DISCOVERABLE)) + scan |= SCAN_INQUIRY; + + hci_req_add(req, HCI_OP_WRITE_SCAN_ENABLE, 1, &scan); +} + +void hci_update_page_scan(struct hci_dev *hdev) +{ + struct hci_request req; + + hci_req_init(&req, hdev); + __hci_update_page_scan(&req); + hci_req_run(&req, NULL); +} + +/* This function controls the background scanning based on hdev->pend_le_conns + * list. If there are pending LE connection we start the background scanning, + * otherwise we stop it. + * + * This function requires the caller holds hdev->lock. + */ +void __hci_update_background_scan(struct hci_request *req) +{ + struct hci_dev *hdev = req->hdev; + struct hci_conn *conn; + + if (!test_bit(HCI_UP, &hdev->flags) || + test_bit(HCI_INIT, &hdev->flags) || + hci_dev_test_flag(hdev, HCI_SETUP) || + hci_dev_test_flag(hdev, HCI_CONFIG) || + hci_dev_test_flag(hdev, HCI_AUTO_OFF) || + hci_dev_test_flag(hdev, HCI_UNREGISTER)) + return; + + /* No point in doing scanning if LE support hasn't been enabled */ + if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) + return; + + /* If discovery is active don't interfere with it */ + if (hdev->discovery.state != DISCOVERY_STOPPED) + return; + + /* Reset RSSI and UUID filters when starting background scanning + * since these filters are meant for service discovery only. + * + * The Start Discovery and Start Service Discovery operations + * ensure to set proper values for RSSI threshold and UUID + * filter list. So it is safe to just reset them here. + */ + hci_discovery_filter_clear(hdev); + + if (list_empty(&hdev->pend_le_conns) && + list_empty(&hdev->pend_le_reports)) { + /* If there is no pending LE connections or devices + * to be scanned for, we should stop the background + * scanning. + */ + + /* If controller is not scanning we are done. */ + if (!hci_dev_test_flag(hdev, HCI_LE_SCAN)) + return; + + hci_req_add_le_scan_disable(req); + + BT_DBG("%s stopping background scanning", hdev->name); + } else { + /* If there is at least one pending LE connection, we should + * keep the background scan running. + */ + + /* If controller is connecting, we should not start scanning + * since some controllers are not able to scan and connect at + * the same time. + */ + conn = hci_conn_hash_lookup_state(hdev, LE_LINK, BT_CONNECT); + if (conn) + return; + + /* If controller is currently scanning, we stop it to ensure we + * don't miss any advertising (due to duplicates filter). + */ + if (hci_dev_test_flag(hdev, HCI_LE_SCAN)) + hci_req_add_le_scan_disable(req); + + hci_req_add_le_passive_scan(req); + + BT_DBG("%s starting background scanning", hdev->name); + } +} + +static void update_background_scan_complete(struct hci_dev *hdev, u8 status, + u16 opcode) +{ + if (status) + BT_DBG("HCI request failed to update background scanning: " + "status 0x%2.2x", status); +} + +void hci_update_background_scan(struct hci_dev *hdev) +{ + int err; + struct hci_request req; + + hci_req_init(&req, hdev); + + __hci_update_background_scan(&req); + + err = hci_req_run(&req, update_background_scan_complete); + if (err && err != -ENODATA) + BT_ERR("Failed to run HCI request: err %d", err); +} |