From linux-bluetooth Tue Mar 04 22:02:03 2014 From: Benjamin Adler Date: Tue, 04 Mar 2014 22:02:03 +0000 To: linux-bluetooth Subject: Re: Receiving data in BLE non-connectable undirected advertisements Message-Id: <53164D5B.3030903 () gmx ! net> X-MARC-Message: https://marc.info/?l=linux-bluetooth&m=139397053126709 MIME-Version: 1 Content-Type: multipart/mixed; boundary="--------------000409050901010807010503" This is a multi-part message in MIME format. --------------000409050901010807010503 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Marcel, On 03.03.2014 15:28, Marcel Holtmann wrote: > maybe you need to just read the HCI part of the Bluetooth Core specification. The tools/ibeacon.c is a perfect example on how to get started with HCI commands. You just need to figure out on how to do scanning instead of advertising. during the last days, I fought through those 2600 pages, and I think I now have a rough idea how things might work. The source of my lescanner.c is attached, and it doesn't work yet. My questions are: - why do you open urandom, but never use it? - searching for the reason of "Failed to open HCI user channel", I found a commit log from you, saying that the HCI user channel means exclusive access to the device, so I'll have to disable e.g. bluetoothd. Is that a limitation inherent to bluetooth, or just to bluez? Is there a way to process those advertisements and still use bluetoothd, e.g. for skype? - in bt_hci_register(), what is the "bt_hci_destroy_func_t destroy" parameter used for? It seems it's always null when used in the examples? - I was hoping that line 134 would cause advertising_report_callback() to be called when advertisements are received. Unfortunately, that's not the case, nothing happens. What am I missing? - I'm also confused by how those btle advertisements are handled, they seem to be a subevent/subtype of a generic btle event. How can I process this correctly in advertising_report_callback()? I'd be grateful if you could give me some hints to some of these questions. Cheers, ben output from lescanner: # ./tools/lescanner Low Energy Passive Non-Connectable Undirected Advertisement Scanner 5.15 Registering for command-complete-events... Registering for advertising-events... Lets see whether we can provoke an error... Setting bt event-mask... Setting bt le event-mask... Setting bt le scan parameters... Enabling le scan... check_error_callback: succeeded check_error_callback: succeeded check_error_callback: succeeded check_error_callback: succeeded --------------000409050901010807010503 Content-Type: text/x-csrc; name="lescanner.c" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="lescanner.c" /* * * BlueZ - Bluetooth protocol stack for Linux * * Copyright (C) 2011-2012 Intel Corporation * Copyright (C) 2004-2010 Marcel Holtmann * * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * 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. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * */ #ifdef HAVE_CONFIG_H #include #endif #include #include #include #include #include #include #include #include #include #include "monitor/mainloop.h" #include "monitor/bt.h" #include "src/shared/util.h" #include "src/shared/hci.h" static int urandom_fd; static struct bt_hci *hci_dev; static void shutdown_timeout(int id, void *user_data) { fprintf(stdout, "shutdown_timeout()\n"); mainloop_remove_timeout(id); mainloop_quit(); } static void shutdown_complete(const void *data, uint8_t size, void *user_data) { fprintf(stdout, "shutdown_complete()\n"); unsigned int id = PTR_TO_UINT(user_data); shutdown_timeout(id, NULL); } static void shutdown_device(void) { fprintf(stdout, "shutdown_device()\n"); uint8_t enable = 0x00; unsigned int id; bt_hci_flush(hci_dev); id = mainloop_add_timeout(5, shutdown_timeout, NULL, NULL); bt_hci_send(hci_dev, BT_HCI_CMD_LE_SET_ADV_ENABLE, &enable, 1, NULL, NULL, NULL); bt_hci_send(hci_dev, BT_HCI_CMD_RESET, NULL, 0, shutdown_complete, UINT_TO_PTR(id), NULL); } static void check_error_callback(const void *data, uint8_t size, void *user_data) { uint8_t status = *((uint8_t *) data); if (status) { fprintf(stderr, "check_error_callback: error occurred, status is %d\n", status); shutdown_device(); return; } else { fprintf(stdout, "check_error_callback: succeeded\n"); } } static void advertising_report_callback(const void *data, uint8_t size, void *user_data) { const struct bt_hci_evt_le_adv_report *report_adv = data; fprintf(stdout, "Received %d reports, event-type %d.\n", report_adv->num_reports, report_adv->event_type); } static void command_complete_callback(const void *data, uint8_t size, void *user_data) { const struct bt_hci_evt_cmd_complete *report_cmd_complete = data; fprintf(stdout, "command_complete, ncmd %d, opcode %d.\n", report_cmd_complete->ncmd, report_cmd_complete->opcode); } static void local_features_callback(const void *data, uint8_t size, void *user_data) { const struct bt_hci_rsp_read_local_features *rsp = data; if (rsp->status) { fprintf(stderr, "Failed to read local features\n"); shutdown_device(); return; } if (!(rsp->features[4] & 0x40)) { fprintf(stderr, "Controller without Low Energy support\n"); shutdown_device(); return; } //bt_hci_send(hci_dev, BT_HCI_CMD_LE_READ_ADV_TX_POWER, NULL, 0, adv_tx_power_callback, NULL, NULL); // Register for command_complete events fprintf(stdout, "Registering for command-complete-events...\n"); bt_hci_register(hci_dev, BT_HCI_EVT_CMD_COMPLETE, command_complete_callback, //bt_hci_callback_func_t callback, NULL, //void *user_data, NULL //bt_hci_destroy_func_t destroy TODO: ask what this does? ); // Register for advertising events fprintf(stdout, "Registering for advertising-events...\n"); bt_hci_register(hci_dev, BT_HCI_EVT_LE_META_EVENT, // 0x3e is LE META Event, subevent code is 0x02 BT_HCI_EVT_LE_ADV_REPORT ?? advertising_report_callback, //bt_hci_callback_func_t callback, NULL, //void *user_data, NULL //bt_hci_destroy_func_t destroy TODO: ask what this does? ); fprintf(stdout, "Lets see whether we can provoke an error...\n"); bt_hci_register(hci_dev, 0xff, // 0xff seems to be undefined advertising_report_callback, //bt_hci_callback_func_t callback, NULL, //void *user_data, NULL //bt_hci_destroy_func_t destroy TODO: ask what this does? ); // #define BT_HCI_CMD_SET_EVENT_MASK 0x0c01 // struct bt_hci_cmd_set_event_mask { // uint8_t mask[8]; // } __attribute__ ((packed)); struct bt_hci_cmd_set_event_mask event_mask; memset(&event_mask, 0, sizeof(event_mask)); event_mask.mask[0] = 0x20; // receive LE meta events // There is no BT_HCI_RSP_SET_EVENT_MASK, so we only check for errors in the callback fprintf(stdout, "Setting bt event-mask...\n"); bt_hci_send(hci_dev, BT_HCI_CMD_SET_EVENT_MASK, &event_mask, sizeof(event_mask), check_error_callback, NULL, NULL); // #define BT_HCI_CMD_LE_SET_EVENT_MASK 0x2001 // struct bt_hci_cmd_le_set_event_mask { // uint8_t mask[8]; // } __attribute__ ((packed)); struct bt_hci_cmd_le_set_event_mask event_mask_le; memset(&event_mask_le, 0, sizeof(event_mask_le)); event_mask_le.mask[7] = 0x2; // receive only le_advertising_reports // There is no BT_HCI_RSP_LE_SET_EVENT_MASK, so we only check for errors in the callback fprintf(stdout, "Setting bt le event-mask...\n"); bt_hci_send(hci_dev, BT_HCI_CMD_LE_SET_EVENT_MASK, &event_mask_le, sizeof(event_mask_le), check_error_callback, NULL, NULL); // #define BT_HCI_CMD_LE_SET_SCAN_PARAMETERS 0x200b // struct bt_hci_cmd_le_set_scan_parameters { // uint8_t type; // uint16_t interval; // uint16_t window; // uint8_t own_addr_type; // uint8_t filter_policy; // } __attribute__ ((packed)); struct bt_hci_cmd_le_set_scan_parameters scan_parameters; memset(&scan_parameters, 0, sizeof(scan_parameters)); scan_parameters.type = 0; // bt-core-spec 4.1, pdf-page 1255: passive scanning scan_parameters.interval = 0x0100; // Interval of minimum 0x10 is 16 * 0.625msec => 10 msec. Interval of maximum 0x4000 is 16384 * 0.625msec => 10240msec scan_parameters.window = 0x0100; // window, must be less than or equal to interval scan_parameters.own_addr_type = 0x0; // // bt-core-spec 4.1, pdf-page 1256: public address scan_parameters.filter_policy = 0x0; // // bt-core-spec 4.1, pdf-page 1256: accept all advertisements, not just from whitelist // There is no BT_HCI_RSP_LE_SET_SCAN_PARAMETERS, so we only check for errors in the callback fprintf(stdout, "Setting bt le scan parameters...\n"); bt_hci_send(hci_dev, BT_HCI_CMD_LE_SET_SCAN_PARAMETERS, &scan_parameters, sizeof(scan_parameters), check_error_callback, NULL, NULL); /* This is non-le scanning, so we try without first // #define BT_HCI_CMD_WRITE_SCAN_ENABLE 0x0c1a // struct bt_hci_cmd_write_scan_enable { // uint8_t enable; // } __attribute__ ((packed)); struct bt_hci_cmd_write_scan_enable scan_enable; memset(&scan_enable, 0, sizeof(bt_hci_cmd_write_scan_enable)); scan_enable.enable = 1; // enable! // There is no BT_HCI_RSP_WRITE_SCAN_ENABLE, so we only check for errors in the callback bt_hci_send(hci_dev, BT_HCI_CMD_WRITE_SCAN_ENABLE, &scan_enable, sizeof(bt_hci_cmd_write_scan_enable), check_error_callback, NULL, NULL); */ // #define BT_HCI_CMD_LE_SET_SCAN_ENABLE 0x200c // struct bt_hci_cmd_le_set_scan_enable { // uint8_t enable; // uint8_t filter_dup; // } __attribute__ ((packed)); struct bt_hci_cmd_le_set_scan_enable scan_enable_le; memset(&scan_enable_le, 0, sizeof(scan_enable_le)); scan_enable_le.enable = 1; // enable! scan_enable_le.filter_dup = 0; // do not filter out duplicates // There is no BT_HCI_RSP_LE_SET_SCAN_ENABLE, so we only check for errors in the callback fprintf(stdout, "Enabling le scan...\n"); bt_hci_send(hci_dev, BT_HCI_CMD_LE_SET_SCAN_ENABLE, &scan_enable_le, sizeof(scan_enable_le), check_error_callback, NULL, NULL); } static void start_scanning(void) { bt_hci_send(hci_dev, BT_HCI_CMD_RESET, NULL, 0, NULL, NULL, NULL); #warning: bt-core-spec says not to issue commands while reset-in-progress? bt_hci_send(hci_dev, BT_HCI_CMD_READ_LOCAL_FEATURES, NULL, 0, local_features_callback, NULL, NULL); } static void signal_callback(int signum, void *user_data) { static bool terminated = false; switch (signum) { case SIGINT: case SIGTERM: if (!terminated) { shutdown_device(); terminated = true; } break; } } static void usage(void) { printf("lescanner - Low Energy Passive Non-Connectable Undirected Advertisement Scanner\n" "Usage:\n"); printf("\tlescanner [options]\n"); printf("Options:\n" "\t-i, --index Use specified controller\n" "\t-h, --help Show help options\n"); } static const struct option main_options[] = { { "index", required_argument, NULL, 'i' }, { "version", no_argument, NULL, 'v' }, { "help", no_argument, NULL, 'h' }, { } }; int main(int argc, char *argv[]) { uint16_t index = 0; const char *str; sigset_t mask; int exit_status; for (;;) { int opt; opt = getopt_long(argc, argv, "i:vh", main_options, NULL); if (opt < 0) break; switch (opt) { case 'i': if (strlen(optarg) > 3 && !strncmp(optarg, "hci", 3)) str = optarg + 3; else str = optarg; if (!isdigit(*str)) { usage(); return EXIT_FAILURE; } index = atoi(str); break; case 'v': printf("%s\n", VERSION); return EXIT_SUCCESS; case 'h': usage(); return EXIT_SUCCESS; default: return EXIT_FAILURE; } } if (argc - optind > 0) { fprintf(stderr, "Invalid command line parameters\n"); return EXIT_FAILURE; } urandom_fd = open("/dev/urandom", O_RDONLY); if (urandom_fd < 0) { fprintf(stderr, "Failed to open /dev/urandom device\n"); return EXIT_FAILURE; } mainloop_init(); sigemptyset(&mask); sigaddset(&mask, SIGINT); sigaddset(&mask, SIGTERM); mainloop_set_signal(&mask, signal_callback, NULL, NULL); printf("Low Energy Passive Non-Connectable Undirected Advertisement Scanner %s\n", VERSION); hci_dev = bt_hci_new_user_channel(index); if (!hci_dev) { fprintf(stderr, "Failed to open HCI user channel\n"); exit_status = EXIT_FAILURE; goto done; } start_scanning(); exit_status = mainloop_run(); bt_hci_unref(hci_dev); done: close(urandom_fd); return exit_status; } --------------000409050901010807010503-- -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html