From 466ff3c456383456630ce9d67abae991566c158e Mon Sep 17 00:00:00 2001
From: Nikias Bassen
Date: Wed, 8 Apr 2009 01:08:37 +0200
Subject: Implemented lockfile stuff to prevent multiple running instances.
Implemented daemonizing, use -f to run in foreground. Implemented logging to
syslog (or to std{out,err} when running in foreground). Modified the udev
rules file (removed --pidfile etc.).
---
85-usbmuxd.rules | 4 +-
main.c | 213 ++++++++++++++++++++++++++++++++++++++++++++++++-------
2 files changed, 190 insertions(+), 27 deletions(-)
diff --git a/85-usbmuxd.rules b/85-usbmuxd.rules
index 90d49ea..69ddef8 100644
--- a/85-usbmuxd.rules
+++ b/85-usbmuxd.rules
@@ -30,8 +30,8 @@ ACTION=="add", SUBSYSTEM=="usb_endpoint", KERNEL=="usbdev*_ep04", SYMLINK+="usbm
ACTION=="add", SUBSYSTEM=="usb_endpoint", KERNEL=="usbdev*_ep85", SYMLINK+="usbmux/out"
# Start and stop 'usbmuxd' as required.
-ACTION=="add", SUBSYSTEM=="usb_endpoint", KERNEL=="usbdev*_ep85", RUN+="/sbin/start-stop-daemon --start --oknodo --background --make-pidfile --pidfile /var/run/usbmuxd.pid --exec /usr/local/sbin/usbmuxd"
-ACTION=="remove", SUBSYSTEM=="usb_endpoint", KERNEL=="usbdev*_ep85", RUN+="/sbin/start-stop-daemon --stop --signal 2 --pidfile /var/run/usbmuxd.pid --exec /usr/local/sbin/usbmuxd"
+ACTION=="add", SUBSYSTEM=="usb_endpoint", KERNEL=="usbdev*_ep85", RUN+="/sbin/start-stop-daemon --start --oknodo --exec /usr/local/sbin/usbmuxd"
+ACTION=="remove", SUBSYSTEM=="usb_endpoint", KERNEL=="usbdev*_ep85", RUN+="/sbin/start-stop-daemon --stop --signal 2 --exec /usr/local/sbin/usbmuxd"
# skip
LABEL="usbmuxd_rules_end"
diff --git a/main.c b/main.c
index 832ff7f..0af0735 100644
--- a/main.c
+++ b/main.c
@@ -24,6 +24,10 @@
#include <errno.h>
#include <stdlib.h>
#include <string.h>
+#include <getopt.h>
+#include <stdarg.h>
+#include <syslog.h>
+#include <fcntl.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/stat.h>
@@ -43,9 +47,12 @@
#define DEFAULT_CHILDREN_CAPACITY 10
#define DEBUG_LEVEL 0
+#define LOCKFILE "/var/run/usbmuxd.lock"
+
static int quit_flag = 0;
static int fsock = -1;
static int verbose = DEBUG_LEVEL;
+static int foreground = 0;
struct device_use_info {
uint32_t device_id;
@@ -764,7 +771,43 @@ leave:
*/
static int daemonize()
{
- // TODO still to be implemented, also logging is missing!
+ pid_t pid;
+ pid_t sid;
+
+ // already a daemon
+ if (getppid() == 1) return 0;
+
+ pid = fork();
+ if (pid < 0) {
+ exit(EXIT_FAILURE);
+ }
+
+ if (pid > 0) {
+ // exit parent process
+ exit(EXIT_SUCCESS);
+ }
+
+ // At this point we are executing as the child process
+
+ // Change the file mode mask
+ umask(0);
+
+ // Create a new SID for the child process
+ sid = setsid();
+ if (sid < 0) {
+ return -1;
+ }
+
+ // Change the current working directory.
+ if ((chdir("/")) < 0) {
+ return -2;
+ }
+
+ // Redirect standard files to /dev/null
+ freopen("/dev/null", "r", stdin);
+ freopen("/dev/null", "w", stdout);
+ freopen("/dev/null", "w", stderr);
+
return 0;
}
@@ -779,12 +822,85 @@ static void clean_exit(int sig)
quit_flag = 1;
}
+static void logmsg(int prio, char *format, ...)
+{
+ va_list args;
+ va_start(args, format);
+
+ if (!foreground) {
+ // daemon. log using syslog.
+ vsyslog(prio, format, args);
+ } else {
+ // running in foreground. log to stdout/stderr.
+ char msgbuf[256];
+ FILE *lfp = stdout;
+ switch(prio) {
+ case LOG_EMERG:
+ case LOG_ALERT:
+ case LOG_CRIT:
+ case LOG_ERR:
+ case LOG_WARNING:
+ lfp = stderr;
+ break;
+ default:
+ lfp = stdout;
+ }
+ strcpy(msgbuf, "usbmuxd: ");
+ vsnprintf(msgbuf+9, 244, format, args);
+ strcat(msgbuf, "\n");
+ fputs(msgbuf, lfp);
+ }
+
+ va_end(args);
+}
+
+static void usage()
+{
+ printf("usage: usbmuxd [options]\n");
+ printf("\t-h|--help print this message.\n");
+ printf("\t-v|--verbose be verbose\n");
+ printf("\t-f|--foreground do not daemonize\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' },
+ { NULL, 0, NULL, 0}
+ };
+ int c;
+
+ while (1) {
+ c = getopt_long(argc, argv, "hfv", longopts, (int *) 0);
+ if (c == -1) {
+ break;
+ }
+
+ switch (c) {
+ case 'h':
+ usage();
+ exit(0);
+ case 'f':
+ foreground = 1;
+ break;
+ case 'v':
+ sock_stuff_set_verbose(++verbose);
+ break;
+ default:
+ usage();
+ exit(2);
+ }
+ }
+}
+
/**
* main function. Initializes all stuff and then loops waiting in accept.
*/
int main(int argc, char **argv)
{
- int foreground = 1;
struct sockaddr_un c_addr;
socklen_t len = sizeof(struct sockaddr_un);
struct client_data *cdata = NULL;
@@ -793,20 +909,47 @@ int main(int argc, char **argv)
int i;
int result = 0;
int cnt = 0;
+ FILE *lfd = NULL;
+ struct flock lock;
- for (i = 1; i < argc; i++) {
- if (argv[i] != NULL && (!strncmp("-v", argv[i], 2) || !strncmp("--verbose", argv[i], 10))) {
- sock_stuff_set_verbose(++verbose);
- }
+ parse_opts(argc, argv);
+
+ argc -= optind;
+ argv += optind;
+
+ if (!foreground) {
+ openlog("usbmuxd", LOG_PID, 0);
}
- if (verbose >= 2) fprintf(stderr, "usbmuxd: starting\n");
+ if (verbose >= 2) logmsg(LOG_NOTICE, "starting");
- // TODO: Parameter checking.
+ // signal(SIGHUP, reload_conf); // none yet
+ signal(SIGINT, clean_exit);
+ signal(SIGQUIT, clean_exit);
+ signal(SIGTERM, clean_exit);
+ signal(SIGPIPE, SIG_IGN);
+
+ // check for other running instance
+ lfd = fopen(LOCKFILE, "r");
+ if (lfd) {
+ lock.l_type = 0;
+ lock.l_whence = SEEK_SET;
+ lock.l_start = 0;
+ lock.l_len = 0;
+ fcntl(fileno(lfd), F_GETLK, &lock);
+ fclose(lfd);
+ if (lock.l_type != F_UNLCK) {
+ logmsg(LOG_NOTICE, "another instance is already running. exiting.");
+ return -1;
+ }
+ }
fsock = create_unix_socket(USBMUXD_SOCKET_FILE);
if (fsock < 0) {
- if (verbose >= 1) fprintf(stderr, "Could not create socket, exiting\n");
+ logmsg(LOG_ERR, "Could not create socket, exiting");
+ if (!foreground) {
+ closelog();
+ }
return -1;
}
@@ -814,26 +957,36 @@ int main(int argc, char **argv)
if (!foreground) {
if (daemonize() < 0) {
+ fprintf(stderr, "usbmuxd: FATAL: Could not daemonize!\n");
+ syslog(LOG_ERR, "FATAL: Could not daemonize!");
+ closelog();
exit(EXIT_FAILURE);
}
}
- // signal(SIGHUP, reload_conf); // none yet
- signal(SIGINT, clean_exit);
- signal(SIGQUIT, clean_exit);
- signal(SIGTERM, clean_exit);
- signal(SIGPIPE, SIG_IGN);
+ // now open the lockfile and place the lock
+ lfd = fopen(LOCKFILE, "w");
+ if (lfd) {
+ lock.l_type = F_WRLCK;
+ lock.l_whence = SEEK_SET;
+ lock.l_start = 0;
+ lock.l_len = 0;
+ fcntl(fileno(lfd), F_SETLK, &lock);
+ }
// Reserve space for 10 clients which should be enough. If not, the
// buffer gets enlarged later.
children = (struct client_data**)malloc(sizeof(struct client_data*) * children_capacity);
if (!children) {
- if (verbose >= 2) fprintf(stderr, "usbmuxd: Out of memory when allocating memory for child threads. Terminating.\n");
+ logmsg(LOG_ERR, "Out of memory when allocating memory for child threads. Terminating.");
+ if (!foreground) {
+ closelog();
+ }
exit(EXIT_FAILURE);
}
memset(children, 0, sizeof(struct client_data*) * children_capacity);
- if (verbose >= 2) fprintf(stderr, "usbmuxd: waiting for connection\n");
+ if (verbose >= 2) logmsg(LOG_NOTICE, "waiting for connection");
while (!quit_flag) {
// Check the file descriptor before accepting a connection.
// If no connection attempt is made, just repeat...
@@ -845,7 +998,7 @@ int main(int argc, char **argv)
if (children[i]) {
if (children[i]->dead != 0) {
pthread_join(children[i]->thread, NULL);
- if (verbose >= 3) fprintf(stderr, "usbmuxd: reclaimed client thread (fd=%d)\n", children[i]->socket);
+ if (verbose >= 3) logmsg(LOG_NOTICE, "reclaimed client thread (fd=%d)", children[i]->socket);
free(children[i]);
children[i] = NULL;
cnt++;
@@ -864,7 +1017,7 @@ int main(int argc, char **argv)
}
continue;
} else {
- if (verbose >= 3) fprintf(stderr, "usbmuxd: select error: %s\n", strerror(errno));
+ if (verbose >= 3) logmsg(LOG_ERR, "usbmuxd: select error: %s", strerror(errno));
continue;
}
}
@@ -873,7 +1026,7 @@ int main(int argc, char **argv)
memset(cdata, 0, sizeof(struct client_data));
if (!cdata) {
quit_flag = 1;
- if (verbose >= 1) fprintf(stderr, "usbmuxd: Error: Out of memory! Terminating.\n");
+ logmsg(LOG_ERR, "Error: Out of memory! Terminating.");
break;
}
@@ -883,12 +1036,12 @@ int main(int argc, char **argv)
if (errno == EINTR) {
continue;
} else {
- if (verbose >= 3) fprintf(stderr, "usbmuxd: Error in accept: %s\n", strerror(errno));
+ if (verbose >= 3) logmsg(LOG_ERR, "Error in accept: %s", strerror(errno));
continue;
}
}
- if (verbose >= 1) fprintf(stderr, "usbmuxd: new client connected (fd=%d)\n", cdata->socket);
+ if (verbose >= 1) logmsg(LOG_NOTICE, "new client connected (fd=%d)", cdata->socket);
// create client thread:
if (pthread_create(&cdata->thread, NULL, usbmuxd_client_init_thread, cdata) == 0) {
@@ -900,19 +1053,19 @@ int main(int argc, char **argv)
children_capacity++;
children = realloc(children, sizeof(struct client_data*) * children_capacity);
if (!children) {
- if (verbose >= 1) fprintf(stderr, "usbmuxd: Out of memory when enlarging child thread buffer\n");
+ logmsg(LOG_ERR, "Out of memory when enlarging child thread buffer");
}
}
children[i] = cdata;
} else {
- if (verbose >= 3) fprintf(stderr, "usbmuxd: Failed to create client_init_thread.\n");
+ logmsg(LOG_ERR, "Failed to create client_init_thread.");
close(cdata->socket);
free(cdata);
cdata = NULL;
}
}
- if (verbose >= 3) fprintf(stderr, "usbmuxd: terminating\n");
+ if (verbose >= 3) logmsg(LOG_NOTICE, "terminating");
// preparing for shutdown: wait for child threads to terminate (if any)
if (verbose >= 2) fprintf(stderr, "usbmuxd: waiting for child threads to terminate...\n");
@@ -934,7 +1087,17 @@ int main(int argc, char **argv)
unlink(USBMUXD_SOCKET_FILE);
- if (verbose >= 1) fprintf(stderr, "usbmuxd: terminated\n");
+ // unlock lock file and close it.
+ if (lfd) {
+ lock.l_type = F_UNLCK;
+ fcntl(fileno(lfd), F_SETLK, lock);
+ fclose(lfd);
+ }
+
+ if (verbose >= 1) logmsg(LOG_NOTICE, "usbmuxd: terminated");
+ if (!foreground) {
+ closelog();
+ }
return 0;
}
--
cgit v1.1-32-gdbae