diff options
Diffstat (limited to 'src/modules/bluetooth/proximity-helper.c')
| -rw-r--r-- | src/modules/bluetooth/proximity-helper.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/src/modules/bluetooth/proximity-helper.c b/src/modules/bluetooth/proximity-helper.c new file mode 100644 index 00000000..3767f01c --- /dev/null +++ b/src/modules/bluetooth/proximity-helper.c @@ -0,0 +1,202 @@ +/* + * Small SUID helper that allows us to ping a BT device. Borrows + * heavily from bluez-utils' l2ping, which is licensed as GPL2+ + * and comes with a copyright like this: + * + * Copyright (C) 2000-2001 Qualcomm Incorporated + * Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com> + * Copyright (C) 2002-2007 Marcel Holtmann <marcel@holtmann.org> + * + * + * 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 <config.h> +#endif + +#undef NDEBUG + +#include <assert.h> +#include <stdio.h> +#include <errno.h> +#include <unistd.h> +#include <stdlib.h> +#include <sys/time.h> +#include <sys/select.h> + +#include <bluetooth/bluetooth.h> +#include <bluetooth/hci.h> +#include <bluetooth/hci_lib.h> +#include <bluetooth/l2cap.h> + +#define PING_STRING "PulseAudio" +#define IDENT 200 +#define TIMEOUT 4 +#define INTERVAL 2 + +static void update_status(int found) { + static int status = -1; + + if (!found && status != 0) + printf("-"); + if (found && status <= 0) + printf("+"); + + fflush(stdout); + status = !!found; +} + +int main(int argc, char *argv[]) { + struct sockaddr_l2 addr; + union { + l2cap_cmd_hdr hdr; + uint8_t buf[L2CAP_CMD_HDR_SIZE + sizeof(PING_STRING)]; + } packet; + int fd = -1; + uint8_t id = IDENT; + int connected = 0; + + assert(argc == 2); + + for (;;) { + fd_set fds; + struct timeval end; + ssize_t r; + + if (!connected) { + + if (fd >= 0) + close(fd); + + if ((fd = socket(PF_BLUETOOTH, SOCK_RAW, BTPROTO_L2CAP)) < 0) { + fprintf(stderr, "socket(PF_BLUETOOTH, SOCK_RAW, BTPROTO_L2CAP) failed: %s", strerror(errno)); + goto finish; + } + + memset(&addr, 0, sizeof(addr)); + addr.l2_family = AF_BLUETOOTH; + bacpy(&addr.l2_bdaddr, BDADDR_ANY); + + if (bind(fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { + fprintf(stderr, "bind() failed: %s", strerror(errno)); + goto finish; + } + + memset(&addr, 0, sizeof(addr)); + addr.l2_family = AF_BLUETOOTH; + str2ba(argv[1], &addr.l2_bdaddr); + + if (connect(fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { + + if (errno == EHOSTDOWN || errno == ECONNRESET || errno == ETIMEDOUT) { + update_status(0); + sleep(INTERVAL); + continue; + } + + fprintf(stderr, "connect() failed: %s", strerror(errno)); + goto finish; + } + + connected = 1; + } + + assert(connected); + + memset(&packet, 0, sizeof(packet)); + strcpy((char*) packet.buf + L2CAP_CMD_HDR_SIZE, PING_STRING); + packet.hdr.ident = id; + packet.hdr.len = htobs(sizeof(PING_STRING)); + packet.hdr.code = L2CAP_ECHO_REQ; + + if ((r = send(fd, &packet, sizeof(packet), 0)) < 0) { + + if (errno == EHOSTDOWN || errno == ECONNRESET || errno == ETIMEDOUT) { + update_status(0); + connected = 0; + sleep(INTERVAL); + continue; + } + + fprintf(stderr, "send() failed: %s", strerror(errno)); + goto finish; + } + + assert(r == sizeof(packet)); + + gettimeofday(&end, NULL); + end.tv_sec += TIMEOUT; + + for (;;) { + struct timeval now, delta; + + gettimeofday(&now, NULL); + + if (timercmp(&end, &now, <=)) { + update_status(0); + connected = 0; + sleep(INTERVAL); + break; + } + + timersub(&end, &now, &delta); + + FD_ZERO(&fds); + FD_SET(fd, &fds); + + if (select(fd+1, &fds, NULL, NULL, &delta) < 0) { + fprintf(stderr, "select() failed: %s", strerror(errno)); + goto finish; + } + + if ((r = recv(fd, &packet, sizeof(packet), 0)) <= 0) { + + if (errno == EHOSTDOWN || errno == ECONNRESET || errno == ETIMEDOUT) { + update_status(0); + connected = 0; + sleep(INTERVAL); + break; + } + + fprintf(stderr, "send() failed: %s", r == 0 ? "EOF" : strerror(errno)); + goto finish; + } + + assert(r >= L2CAP_CMD_HDR_SIZE); + + if (packet.hdr.ident != id) + continue; + + if (packet.hdr.code == L2CAP_ECHO_RSP || packet.hdr.code == L2CAP_COMMAND_REJ) { + + if (++id >= 0xFF) + id = IDENT; + + update_status(1); + sleep(INTERVAL); + break; + } + } + } + +finish: + + if (fd >= 0) + close(fd); + + return 1; +} |