ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/package/utils/busybox/patches/220-add_lock_util.patch b/package/utils/busybox/patches/220-add_lock_util.patch
new file mode 100644
index 0000000..579b705
--- /dev/null
+++ b/package/utils/busybox/patches/220-add_lock_util.patch
@@ -0,0 +1,158 @@
+--- /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)
++{
++ pid_t pid;
++ int flags;
++ char pidstr[12];
++
++ 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);
++ snprintf(pidstr, sizeof(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();
++}