android/system-emulator.c

/*
 *
 *  BlueZ - Bluetooth protocol stack for Linux
 *
 *  Copyright (C) 2013-2014  Intel Corporation. All rights reserved.
 *
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; 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

#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <libgen.h>
#include <poll.h>
#include <sys/wait.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/types.h>
#include <sys/stat.h>

#ifndef WAIT_ANY
#define WAIT_ANY (-1)
#endif

#include "src/shared/mainloop.h"

static char exec_dir[PATH_MAX];

static pid_t daemon_pid = -1;
static pid_t snoop_pid = -1;

static void run_valgrind(char *prg_name)
{
	char *prg_argv[6];
	char *prg_envp[3];

	prg_argv[0] = "/usr/bin/valgrind";
	prg_argv[1] = "--leak-check=full";
	prg_argv[2] = "--track-origins=yes";
	prg_argv[3] = prg_name;
	prg_argv[4] = "-d";
	prg_argv[5] = NULL;

	prg_envp[0] = "G_SLICE=always-malloc";
	prg_envp[1] = "G_DEBUG=gc-friendly";
	prg_envp[2] = NULL;

	execve(prg_argv[0], prg_argv, prg_envp);
}

static void run_bluetoothd(char *prg_name)
{
	char *prg_argv[3];
	char *prg_envp[1];

	prg_argv[0] = prg_name;
	prg_argv[1] = "-d";
	prg_argv[2] = NULL;

	prg_envp[0] = NULL;

	execve(prg_argv[0], prg_argv, prg_envp);
}

static void ctl_start(void)
{
	char prg_name[PATH_MAX];
	pid_t pid;

	snprintf(prg_name, sizeof(prg_name), "%s/%s", exec_dir, "bluetoothd");

	printf("Starting %s\n", prg_name);

	pid = fork();
	if (pid < 0) {
		perror("Failed to fork new process");
		return;
	}

	if (pid == 0) {
		run_valgrind(prg_name);

		/* Fallback to no valgrind if running with valgind failed */
		run_bluetoothd(prg_name);
		exit(0);
	}

	printf("New process %d created\n", pid);

	daemon_pid = pid;
}

static void snoop_start(void)
{
	char prg_name[PATH_MAX];
	char *prg_argv[3];
	char *prg_envp[1];
	pid_t pid;

	snprintf(prg_name, sizeof(prg_name), "%s/%s", exec_dir,
							"bluetoothd-snoop");

	prg_argv[0] = prg_name;
	prg_argv[1] = "/tmp/btsnoop_hci.log";
	prg_argv[2] = NULL;

	prg_envp[0] = NULL;

	printf("Starting %s\n", prg_name);

	pid = fork();
	if (pid < 0) {
		perror("Failed to fork new process");
		return;
	}

	if (pid == 0) {
		execve(prg_argv[0], prg_argv, prg_envp);
		exit(0);
	}

	printf("New process %d created\n", pid);

	snoop_pid = pid;
}

static void snoop_stop(void)
{
	printf("Stoping %s/%s\n", exec_dir, "bluetoothd-snoop");

	kill(snoop_pid, SIGTERM);
}

static void system_socket_callback(int fd, uint32_t events, void *user_data)
{
	char buf[4096];
	ssize_t len;

	if (events & (EPOLLERR | EPOLLHUP)) {
		mainloop_remove_fd(fd);
		return;
	}

	len = read(fd, buf, sizeof(buf));
	if (len < 0)
		return;

	printf("Received %s\n", buf);

	if (!strcmp(buf, "bluetooth.start=daemon")) {
		if (daemon_pid > 0)
			return;

		ctl_start();
	} else if (!strcmp(buf, "bluetooth.start=snoop")) {
		if (snoop_pid > 0)
			return;

		snoop_start();
	} else if (!strcmp(buf, "bluetooth.stop=snoop")) {
		if (snoop_pid > 0)
			snoop_stop();
	}
}

static void signal_callback(int signum, void *user_data)
{
	switch (signum) {
	case SIGINT:
	case SIGTERM:
		mainloop_quit();
		break;
	case SIGCHLD:
		while (1) {
			pid_t pid;
			int status;

			pid = waitpid(WAIT_ANY, &status, WNOHANG);
			if (pid < 0 || pid == 0)
				break;

			printf("Process %d terminated with status=%d\n",
								pid, status);

			if (pid == daemon_pid)
				daemon_pid = -1;
			else if (pid == snoop_pid)
				snoop_pid = -1;
		}
		break;
	}
}

int main(int argc, char *argv[])
{
	const char SYSTEM_SOCKET_PATH[] = "\0android_system";
	sigset_t mask;
	struct sockaddr_un addr;
	int fd;

	mainloop_init();

	sigemptyset(&mask);
	sigaddset(&mask, SIGINT);
	sigaddset(&mask, SIGTERM);
	sigaddset(&mask, SIGCHLD);

	mainloop_set_signal(&mask, signal_callback, NULL, NULL);

	printf("Android system emulator ver %s\n", VERSION);

	snprintf(exec_dir, sizeof(exec_dir), "%s", dirname(argv[0]));

	fd = socket(PF_LOCAL, SOCK_DGRAM | SOCK_CLOEXEC, 0);
	if (fd < 0) {
		perror("Failed to create system socket");
		return EXIT_FAILURE;
	}

	memset(&addr, 0, sizeof(addr));
	addr.sun_family = AF_UNIX;
	memcpy(addr.sun_path, SYSTEM_SOCKET_PATH, sizeof(SYSTEM_SOCKET_PATH));

	if (bind(fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
		perror("Failed to bind system socket");
		close(fd);
		return EXIT_FAILURE;
	}

	mainloop_add_fd(fd, EPOLLIN, system_socket_callback, NULL, NULL);

	/* Make sure bluetoothd creates files with proper permissions */
	umask(0177);

	return mainloop_run();
}