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-rw-r--r--usbmuxd/main.c548
1 files changed, 548 insertions, 0 deletions
diff --git a/usbmuxd/main.c b/usbmuxd/main.c
new file mode 100644
index 0000000..dde99c2
--- /dev/null
+++ b/usbmuxd/main.c
@@ -0,0 +1,548 @@
+/*
+ usbmuxd - iPhone/iPod Touch USB multiplex server daemon
+
+Copyright (C) 2009 Hector Martin "marcan" <hector@marcansoft.com>
+
+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 or version 3.
+
+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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+*/
+
+#define _BSD_SOURCE
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <pwd.h>
+#include <grp.h>
+
+#include "log.h"
+#include "usb.h"
+#include "device.h"
+#include "client.h"
+
+static const char *socket_path = "/var/run/usbmuxd";
+static const char *lockfile = "/var/run/usbmuxd.pid";
+
+int should_exit;
+
+static int verbose = 0;
+static int foreground = 0;
+static int drop_privileges = 0;
+static const char *drop_user = "usbmux";
+static int opt_udev = 0;
+static int opt_exit = 0;
+static int exit_signal = 0;
+static int daemon_pipe;
+
+static int report_to_parent = 0;
+
+int create_socket(void) {
+ struct sockaddr_un bind_addr;
+ int listenfd;
+
+ if(unlink(socket_path) == -1 && errno != ENOENT) {
+ usbmuxd_log(LL_FATAL, "unlink(%s) failed: %s", socket_path, strerror(errno));
+ return -1;
+ }
+
+ listenfd = socket(AF_UNIX, SOCK_STREAM, 0);
+ if (listenfd == -1) {
+ usbmuxd_log(LL_FATAL, "socket() failed: %s", strerror(errno));
+ return -1;
+ }
+
+ bzero(&bind_addr, sizeof(bind_addr));
+ bind_addr.sun_family = AF_UNIX;
+ strcpy(bind_addr.sun_path, socket_path);
+ if (bind(listenfd, (struct sockaddr*)&bind_addr, sizeof(bind_addr)) != 0) {
+ usbmuxd_log(LL_FATAL, "bind() failed: %s", strerror(errno));
+ return -1;
+ }
+
+ // Start listening
+ if (listen(listenfd, 5) != 0) {
+ usbmuxd_log(LL_FATAL, "listen() failed: %s", strerror(errno));
+ return -1;
+ }
+
+ chmod(socket_path, 0666);
+
+ return listenfd;
+}
+
+void handle_signal(int sig)
+{
+ if (sig != SIGUSR1) {
+ usbmuxd_log(LL_NOTICE,"Caught signal %d, exiting", sig);
+ should_exit = 1;
+ } else {
+ if(opt_udev) {
+ usbmuxd_log(LL_INFO, "Caught SIGUSR1, checking if we can terminate (no more devices attached)...");
+ if (device_get_count() > 0) {
+ // we can't quit, there are still devices attached.
+ usbmuxd_log(LL_NOTICE, "Refusing to terminate, there are still devices attached. Kill me with signal 15 (TERM) to force quit.");
+ } else {
+ // it's safe to quit
+ should_exit = 1;
+ }
+ } else {
+ usbmuxd_log(LL_INFO, "Caught SIGUSR1 but we weren't started in --udev mode, ignoring");
+ }
+ }
+}
+
+void set_signal_handlers(void)
+{
+ struct sigaction sa;
+ memset(&sa, 0, sizeof(struct sigaction));
+ sa.sa_handler = handle_signal;
+ sigaction(SIGINT, &sa, NULL);
+ sigaction(SIGQUIT, &sa, NULL);
+ sigaction(SIGTERM, &sa, NULL);
+ sigaction(SIGUSR1, &sa, NULL);
+}
+
+int main_loop(int listenfd)
+{
+ int to, cnt, i, dto;
+ struct fdlist pollfds;
+
+ while(!should_exit) {
+ usbmuxd_log(LL_FLOOD, "main_loop iteration");
+ to = usb_get_timeout();
+ usbmuxd_log(LL_FLOOD, "USB timeout is %d ms", to);
+ dto = device_get_timeout();
+ usbmuxd_log(LL_FLOOD, "Device timeout is %d ms", to);
+ if(dto < to)
+ to = dto;
+
+ fdlist_create(&pollfds);
+ fdlist_add(&pollfds, FD_LISTEN, listenfd, POLLIN);
+ usb_get_fds(&pollfds);
+ client_get_fds(&pollfds);
+ usbmuxd_log(LL_FLOOD, "fd count is %d", pollfds.count);
+
+ cnt = poll(pollfds.fds, pollfds.count, to);
+ usbmuxd_log(LL_FLOOD, "poll() returned %d", cnt);
+
+ if(cnt == -1) {
+ if(errno == EINTR && should_exit) {
+ usbmuxd_log(LL_INFO, "event processing interrupted");
+ fdlist_free(&pollfds);
+ return 0;
+ }
+ } else if(cnt == 0) {
+ if(usb_process() < 0) {
+ usbmuxd_log(LL_FATAL, "usb_process() failed");
+ fdlist_free(&pollfds);
+ return -1;
+ }
+ device_check_timeouts();
+ } else {
+ int done_usb = 0;
+ for(i=0; i<pollfds.count; i++) {
+ if(pollfds.fds[i].revents) {
+ if(!done_usb && pollfds.owners[i] == FD_USB) {
+ if(usb_process() < 0) {
+ usbmuxd_log(LL_FATAL, "usb_process() failed");
+ fdlist_free(&pollfds);
+ return -1;
+ }
+ done_usb = 1;
+ }
+ if(pollfds.owners[i] == FD_LISTEN) {
+ if(client_accept(listenfd) < 0) {
+ usbmuxd_log(LL_FATAL, "client_accept() failed");
+ fdlist_free(&pollfds);
+ return -1;
+ }
+ }
+ if(pollfds.owners[i] == FD_CLIENT) {
+ client_process(pollfds.fds[i].fd, pollfds.fds[i].revents);
+ }
+ }
+ }
+ }
+ fdlist_free(&pollfds);
+ }
+ return 0;
+}
+
+/**
+ * make this program run detached from the current console
+ */
+static int daemonize(void)
+{
+ pid_t pid;
+ pid_t sid;
+ int pfd[2];
+ int res;
+
+ // already a daemon
+ if (getppid() == 1)
+ return 0;
+
+ if((res = pipe(pfd)) < 0) {
+ usbmuxd_log(LL_FATAL, "pipe() failed.");
+ return res;
+ }
+
+ pid = fork();
+ if (pid < 0) {
+ usbmuxd_log(LL_FATAL, "fork() failed.");
+ return pid;
+ }
+
+ if (pid > 0) {
+ // exit parent process
+ int status;
+ close(pfd[1]);
+
+ if((res = read(pfd[0],&status,sizeof(int))) != sizeof(int)) {
+ fprintf(stderr, "usbmuxd: ERROR: Failed to get init status from child, check syslog for messages.\n");
+ exit(1);
+ }
+ if(status != 0)
+ fprintf(stderr, "usbmuxd: ERROR: Child process exited with error %d, check syslog for messages.\n", status);
+ exit(status);
+ }
+ // At this point we are executing as the child process
+ // but we need to do one more fork
+
+ daemon_pipe = pfd[1];
+ close(pfd[0]);
+ report_to_parent = 1;
+
+ // Change the file mode mask
+ umask(0);
+
+ // Create a new SID for the child process
+ sid = setsid();
+ if (sid < 0) {
+ usbmuxd_log(LL_FATAL, "setsid() failed.");
+ return -1;
+ }
+
+ pid = fork();
+ if (pid < 0) {
+ usbmuxd_log(LL_FATAL, "fork() failed (second).");
+ return pid;
+ }
+
+ if (pid > 0) {
+ // exit parent process
+ close(daemon_pipe);
+ exit(0);
+ }
+
+ // Change the current working directory.
+ if ((chdir("/")) < 0) {
+ usbmuxd_log(LL_FATAL, "chdir() failed");
+ return -2;
+ }
+ // Redirect standard files to /dev/null
+ if (!freopen("/dev/null", "r", stdin)) {
+ usbmuxd_log(LL_FATAL, "Redirection of stdin failed.");
+ return -3;
+ }
+ if (!freopen("/dev/null", "w", stdout)) {
+ usbmuxd_log(LL_FATAL, "Redirection of stdout failed.");
+ return -3;
+ }
+
+ return 0;
+}
+
+static int notify_parent(int status)
+{
+ int res;
+
+ report_to_parent = 0;
+ if ((res = write(daemon_pipe, &status, sizeof(int))) != sizeof(int)) {
+ usbmuxd_log(LL_FATAL, "Could not notify parent!");
+ if(res >= 0)
+ return -2;
+ else
+ return res;
+ }
+ close(daemon_pipe);
+ if (!freopen("/dev/null", "w", stderr)) {
+ usbmuxd_log(LL_FATAL, "Redirection of stderr failed.");
+ return -1;
+ }
+ return 0;
+}
+
+static void usage()
+{
+ printf("usage: usbmuxd [options]\n");
+ printf("\t-h|--help Print this message.\n");
+ printf("\t-v|--verbose Be verbose (use twice or more to increase).\n");
+ printf("\t-f|--foreground Do not daemonize (implies one -v).\n");
+ printf("\t-U|--user[=USER] Change to this user after startup (needs usb privileges).\n");
+ printf("\t If USER is not specified, defaults to usbmux.\n");
+ printf("\t-u|--udev Run in udev operation mode.\n");
+ printf("\t-x|--exit Tell a running instance to exit if there are no devices\n");
+ printf("\t connected (must be in udev mode).\n");
+ printf("\t-X|--force-exit Tell a running instance to exit, even if there are still\n");
+ printf("\t devices connected (always works).\n");
+ printf("\n");
+}
+
+static void parse_opts(int argc, char **argv)
+{
+ static struct option longopts[] = {
+ {"help", 0, NULL, 'h'},
+ {"foreground", 0, NULL, 'f'},
+ {"verbose", 0, NULL, 'v'},
+ {"user", 2, NULL, 'U'},
+ {"udev", 0, NULL, 'u'},
+ {"exit", 0, NULL, 'x'},
+ {"force-exit", 0, NULL, 'X'},
+ {NULL, 0, NULL, 0}
+ };
+ int c;
+
+ while (1) {
+ c = getopt_long(argc, argv, "hfvuU::xX", longopts, (int *) 0);
+ if (c == -1) {
+ break;
+ }
+
+ switch (c) {
+ case 'h':
+ usage();
+ exit(0);
+ case 'f':
+ foreground = 1;
+ break;
+ case 'v':
+ ++verbose;
+ break;
+ case 'U':
+ drop_privileges = 1;
+ if(optarg)
+ drop_user = optarg;
+ break;
+ case 'u':
+ opt_udev = 1;
+ break;
+ case 'x':
+ opt_exit = 1;
+ exit_signal = SIGUSR1;
+ break;
+ case 'X':
+ opt_exit = 1;
+ exit_signal = SIGTERM;
+ break;
+ default:
+ usage();
+ exit(2);
+ }
+ }
+}
+
+int main(int argc, char *argv[])
+{
+ int listenfd;
+ int res = 0;
+ int lfd;
+ struct flock lock;
+ char pids[10];
+
+ parse_opts(argc, argv);
+
+ argc -= optind;
+ argv += optind;
+
+ if (!foreground) {
+ verbose += LL_WARNING;
+ log_enable_syslog();
+ } else {
+ verbose += LL_NOTICE;
+ }
+
+ /* set log level to specified verbosity */
+ log_level = verbose;
+
+ usbmuxd_log(LL_NOTICE, "usbmux v0.1 starting up");
+ should_exit = 0;
+
+ set_signal_handlers();
+
+ res = lfd = open(lockfile, O_WRONLY|O_CREAT, 0644);
+ if(res == -1) {
+ usbmuxd_log(LL_FATAL, "Could not open lockfile");
+ goto terminate;
+ }
+ lock.l_type = F_WRLCK;
+ lock.l_whence = SEEK_SET;
+ lock.l_start = 0;
+ lock.l_len = 0;
+ fcntl(lfd, F_GETLK, &lock);
+ close(lfd);
+ if (lock.l_type != F_UNLCK) {
+ if (opt_exit) {
+ if (lock.l_pid && !kill(lock.l_pid, 0)) {
+ usbmuxd_log(LL_NOTICE, "Sending signal %d to instance with pid %d", exit_signal, lock.l_pid);
+ res = 0;
+ if (kill(lock.l_pid, exit_signal) < 0) {
+ usbmuxd_log(LL_FATAL, "Could not deliver signal %d to pid %d", exit_signal, lock.l_pid);
+ res = -1;
+ }
+ goto terminate;
+ } else {
+ usbmuxd_log(LL_ERROR, "Could not determine pid of the other running instance!");
+ res = -1;
+ goto terminate;
+ }
+ } else {
+ if (!opt_udev) {
+ usbmuxd_log(LL_ERROR, "Another instance is already running (pid %d). exiting.", lock.l_pid);
+ res = -1;
+ } else {
+ usbmuxd_log(LL_NOTICE, "Another instance is already running (pid %d). exiting.", lock.l_pid);
+ res = 0;
+ }
+ goto terminate;
+ }
+ }
+ unlink(lockfile);
+
+ if (opt_exit) {
+ usbmuxd_log(LL_NOTICE, "No running instance found, none killed. exiting.");
+ goto terminate;
+ }
+
+ if (!foreground) {
+ if ((res = daemonize()) < 0) {
+ fprintf(stderr, "usbmuxd: FATAL: Could not daemonize!\n");
+ usbmuxd_log(LL_FATAL, "Could not daemonize!");
+ goto terminate;
+ }
+ }
+
+ // now open the lockfile and place the lock
+ res = lfd = open(lockfile, O_WRONLY|O_CREAT|O_TRUNC|O_EXCL, 0644);
+ if(res < 0) {
+ usbmuxd_log(LL_FATAL, "Could not open lockfile");
+ goto terminate;
+ }
+ lock.l_type = F_WRLCK;
+ lock.l_whence = SEEK_SET;
+ lock.l_start = 0;
+ lock.l_len = 0;
+ if ((res = fcntl(lfd, F_SETLK, &lock)) < 0) {
+ usbmuxd_log(LL_FATAL, "Lockfile locking failed!");
+ goto terminate;
+ }
+ sprintf(pids, "%d", getpid());
+ if ((res = write(lfd, pids, strlen(pids))) != strlen(pids)) {
+ usbmuxd_log(LL_FATAL, "Could not write pidfile!");
+ if(res >= 0)
+ res = -2;
+ goto terminate;
+ }
+
+ usbmuxd_log(LL_INFO, "Creating socket");
+ res = listenfd = create_socket();
+ if(listenfd < 0)
+ goto terminate;
+
+ // drop elevated privileges
+ if (drop_privileges && (getuid() == 0 || geteuid() == 0)) {
+ struct passwd *pw = getpwnam(drop_user);
+ if (!pw) {
+ usbmuxd_log(LL_FATAL, "Dropping privileges failed, check if user '%s' exists!", drop_user);
+ res = -1;
+ goto terminate;
+ }
+
+ if ((res = initgroups(drop_user, pw->pw_gid)) < 0) {
+ usbmuxd_log(LL_FATAL, "Failed to drop privileges (cannot set supplementary groups)");
+ goto terminate;
+ }
+ if ((res = setgid(pw->pw_gid)) < 0) {
+ usbmuxd_log(LL_FATAL, "Failed to drop privileges (cannot set group ID to %d)", pw->pw_gid);
+ goto terminate;
+ }
+ if ((res = setuid(pw->pw_uid)) < 0) {
+ usbmuxd_log(LL_FATAL, "Failed to drop privileges (cannot set user ID to %d)", pw->pw_uid);
+ goto terminate;
+ }
+
+ // security check
+ if (setuid(0) != -1) {
+ usbmuxd_log(LL_FATAL, "Failed to drop privileges properly!");
+ res = -1;
+ goto terminate;
+ }
+ if (getuid() != pw->pw_uid || getgid() != pw->pw_gid) {
+ usbmuxd_log(LL_FATAL, "Failed to drop privileges properly!");
+ res = -1;
+ goto terminate;
+ }
+ usbmuxd_log(LL_NOTICE, "Successfully dropped privileges to '%s'", drop_user);
+ }
+
+ client_init();
+ device_init();
+ usbmuxd_log(LL_INFO, "Initializing USB");
+ if((res = usb_init()) < 0)
+ goto terminate;
+
+ usbmuxd_log(LL_INFO, "%d device%s detected", res, (res==1)?"":"s");
+
+ usbmuxd_log(LL_NOTICE, "Initialization complete");
+
+ if (report_to_parent)
+ if((res = notify_parent(0)) < 0)
+ goto terminate;
+
+ res = main_loop(listenfd);
+ if(res < 0)
+ usbmuxd_log(LL_FATAL, "main_loop failed");
+
+ usbmuxd_log(LL_NOTICE, "usbmux shutting down");
+ device_kill_connections();
+ usb_shutdown();
+ device_shutdown();
+ client_shutdown();
+ usbmuxd_log(LL_NOTICE, "Shutdown complete");
+
+terminate:
+ log_disable_syslog();
+
+ if (res < 0)
+ res = -res;
+ else
+ res = 0;
+ if (report_to_parent)
+ notify_parent(res);
+
+ return res;
+}
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