mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-22 23:12:32 +00:00
5d2a9d2a3a
The "new style" busybox applet approach moves all config and build definitions related to an applet to its .c file. This makes the patches easier to maintain, as they only add new files to the busybox build directory, without modifying BusyBox files. Signed-off-by: Magnus Kroken <mkroken@gmail.com> Tested-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
159 lines
2.9 KiB
Diff
159 lines
2.9 KiB
Diff
--- /dev/null
|
|
+++ b/miscutils/lock.c
|
|
@@ -0,0 +1,155 @@
|
|
+/*
|
|
+ * Copyright (C) 2006 Felix Fietkau <nbd@nbd.name>
|
|
+ *
|
|
+ * This is free software, licensed under the GNU General Public License v2.
|
|
+ */
|
|
+
|
|
+//config:config LOCK
|
|
+//config: bool "lock"
|
|
+//config: default n
|
|
+//config: help
|
|
+//config: Small utility for using locks in scripts
|
|
+
|
|
+//applet:IF_LOCK(APPLET(lock, BB_DIR_BIN, BB_SUID_DROP))
|
|
+
|
|
+//kbuild:lib-$(CONFIG_LOCK) += lock.o
|
|
+
|
|
+//usage:#define lock_trivial_usage NOUSAGE_STR
|
|
+//usage:#define lock_full_usage ""
|
|
+
|
|
+#include <sys/types.h>
|
|
+#include <sys/file.h>
|
|
+#include <sys/stat.h>
|
|
+#include <signal.h>
|
|
+#include <fcntl.h>
|
|
+#include <unistd.h>
|
|
+#include <stdio.h>
|
|
+#include "busybox.h"
|
|
+
|
|
+static int unlock = 0;
|
|
+static int shared = 0;
|
|
+static int waitonly = 0;
|
|
+static int try_lock = 0;
|
|
+static int fd;
|
|
+static char *file;
|
|
+
|
|
+static void usage(char *name)
|
|
+{
|
|
+ fprintf(stderr, "Usage: %s [-suw] <filename>\n"
|
|
+ " -s Use shared locking\n"
|
|
+ " -u Unlock\n"
|
|
+ " -w Wait for the lock to become free, don't acquire lock\n"
|
|
+ " -n Don't wait for the lock to become free. Fail with exit code\n"
|
|
+ "\n", name);
|
|
+ exit(1);
|
|
+}
|
|
+
|
|
+static void exit_unlock(int sig)
|
|
+{
|
|
+ flock(fd, LOCK_UN);
|
|
+ exit(0);
|
|
+}
|
|
+
|
|
+static int do_unlock(void)
|
|
+{
|
|
+ FILE *f;
|
|
+ int i;
|
|
+
|
|
+ if ((f = fopen(file, "r")) == NULL)
|
|
+ return 0;
|
|
+
|
|
+ fscanf(f, "%d", &i);
|
|
+ if (i > 0)
|
|
+ kill(i, SIGTERM);
|
|
+
|
|
+ fclose(f);
|
|
+
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+static int do_lock(void)
|
|
+{
|
|
+ int pid;
|
|
+ int flags;
|
|
+ char pidstr[8];
|
|
+
|
|
+ if ((fd = open(file, O_RDWR | O_CREAT | O_EXCL, 0700)) < 0) {
|
|
+ if ((fd = open(file, O_RDWR)) < 0) {
|
|
+ fprintf(stderr, "Can't open %s\n", file);
|
|
+ return 1;
|
|
+ }
|
|
+ }
|
|
+
|
|
+ flags = shared ? LOCK_SH : LOCK_EX;
|
|
+ flags |= try_lock ? LOCK_NB : 0;
|
|
+
|
|
+ if (flock(fd, flags) < 0) {
|
|
+ fprintf(stderr, "Can't lock %s\n", file);
|
|
+ return 1;
|
|
+ }
|
|
+
|
|
+ pid = fork();
|
|
+
|
|
+ if (pid < 0)
|
|
+ return -1;
|
|
+
|
|
+ if (pid == 0) {
|
|
+ signal(SIGKILL, exit_unlock);
|
|
+ signal(SIGTERM, exit_unlock);
|
|
+ signal(SIGINT, exit_unlock);
|
|
+ if (waitonly)
|
|
+ exit_unlock(0);
|
|
+ else
|
|
+ while (1)
|
|
+ sleep(1);
|
|
+ } else {
|
|
+ if (!waitonly) {
|
|
+ lseek(fd, 0, SEEK_SET);
|
|
+ ftruncate(fd, 0);
|
|
+ sprintf(pidstr, "%d\n", pid);
|
|
+ write(fd, pidstr, strlen(pidstr));
|
|
+ close(fd);
|
|
+ }
|
|
+
|
|
+ return 0;
|
|
+ }
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+int lock_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
|
+int lock_main(int argc, char **argv)
|
|
+{
|
|
+ char **args = &argv[1];
|
|
+ int c = argc - 1;
|
|
+
|
|
+ while ((*args != NULL) && (*args)[0] == '-') {
|
|
+ char *ch = *args;
|
|
+ while (*(++ch) > 0) {
|
|
+ switch(*ch) {
|
|
+ case 'w':
|
|
+ waitonly = 1;
|
|
+ break;
|
|
+ case 's':
|
|
+ shared = 1;
|
|
+ break;
|
|
+ case 'u':
|
|
+ unlock = 1;
|
|
+ break;
|
|
+ case 'n':
|
|
+ try_lock = 1;
|
|
+ break;
|
|
+ }
|
|
+ }
|
|
+ c--;
|
|
+ args++;
|
|
+ }
|
|
+
|
|
+ if (c != 1)
|
|
+ usage(argv[0]);
|
|
+
|
|
+ file = *args;
|
|
+ if (unlock)
|
|
+ return do_unlock();
|
|
+ else
|
|
+ return do_lock();
|
|
+}
|