package/busybox/patches/340-lock_util.patch

   1 diff -ruN busybox-1.3.1-old/include/applets.h busybox-1.3.1/include/applets.h
   2 --- busybox-1.3.1-old/include/applets.h 2006-12-28 07:43:24.000000000 +0100
   3 +++ busybox-1.3.1/include/applets.h     2006-12-28 03:11:36.000000000 +0100
   4 @@ -180,6 +180,7 @@
   5  USE_LN(APPLET(ln, _BB_DIR_BIN, _BB_SUID_NEVER))
   6  USE_LOADFONT(APPLET(loadfont, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
   7  USE_LOADKMAP(APPLET(loadkmap, _BB_DIR_SBIN, _BB_SUID_NEVER))
   8 +USE_LOCK(APPLET_NOUSAGE(lock, lock, _BB_DIR_BIN, _BB_SUID_NEVER))
   9  USE_LOGGER(APPLET(logger, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
  10  USE_LOGIN(APPLET(login, _BB_DIR_BIN, _BB_SUID_ALWAYS))
  11  USE_LOGNAME(APPLET(logname, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
  12 diff -ruN busybox-1.3.1-old/miscutils/Config.in busybox-1.3.1/miscutils/Config.in
  13 --- busybox-1.3.1-old/miscutils/Config.in       2006-12-27 05:56:09.000000000 +0100
  14 +++ busybox-1.3.1/miscutils/Config.in   2006-12-28 03:14:16.000000000 +0100
  15 @@ -232,6 +232,12 @@
  16           Enables the 'hdparm -d' option to get/set using_dma flag.
  17           This is dangerous stuff, so you should probably say N.
  18
  19 +config LOCK
  20 +       bool "lock"
  21 +       default y
  22 +       help
  23 +         Small utility for using locks in scripts
  24 +
  25  config MAKEDEVS
  26         bool "makedevs"
  27         default n
  28 diff -ruN busybox-1.3.1-old/miscutils/Kbuild busybox-1.3.1/miscutils/Kbuild
  29 --- busybox-1.3.1-old/miscutils/Kbuild  2006-12-27 05:56:09.000000000 +0100
  30 +++ busybox-1.3.1/miscutils/Kbuild      2006-12-28 03:15:47.000000000 +0100
  31 @@ -15,6 +15,7 @@
  32  lib-$(CONFIG_HDPARM)      += hdparm.o
  33  lib-$(CONFIG_LAST)        += last.o
  34  lib-$(CONFIG_LESS)        += less.o
  35 +lib-$(CONFIG_LOCK)        += lock.o
  36  lib-$(CONFIG_MAKEDEVS)    += makedevs.o
  37  lib-$(CONFIG_MOUNTPOINT)  += mountpoint.o
  38  lib-$(CONFIG_MT)          += mt.o
  39 diff -ruN busybox-1.3.1-old/miscutils/lock.c busybox-1.3.1/miscutils/lock.c
  40 --- busybox-1.3.1-old/miscutils/lock.c  1970-01-01 01:00:00.000000000 +0100
  41 +++ busybox-1.3.1/miscutils/lock.c      2006-12-28 03:11:36.000000000 +0100
  42 @@ -0,0 +1,136 @@
  43 +/*
  44 + * Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org>
  45 + *
  46 + * This is free software, licensed under the GNU General Public License v2.
  47 + */
  48 +#include <sys/types.h>
  49 +#include <sys/file.h>
  50 +#include <sys/stat.h>
  51 +#include <signal.h>
  52 +#include <fcntl.h>
  53 +#include <unistd.h>
  54 +#include <stdio.h>
  55 +#include "busybox.h"
  56 +
  57 +static int unlock = 0;
  58 +static int shared = 0;
  59 +static int waitonly = 0;
  60 +static int fd;
  61 +static char *file;
  62 +
  63 +static void usage(char *name)
  64 +{
  65 +       fprintf(stderr, "Usage: %s [-suw] <filename>\n"
  66 +                       "       -s      Use shared locking\n"
  67 +                       "       -u      Unlock\n"
  68 +                       "       -w      Wait for the lock to become free, don't acquire lock\n"
  69 +                                       "\n", name);
  70 +       exit(1);
  71 +}
  72 +
  73 +static void exit_unlock(int sig)
  74 +{
  75 +       flock(fd, LOCK_UN);
  76 +       unlink(file);
  77 +       exit(0);
  78 +}
  79 +
  80 +static int do_unlock(void)
  81 +{
  82 +       FILE *f;
  83 +       int i;
  84 +
  85 +       if ((f = fopen(file, "r")) == NULL)
  86 +               return 0;
  87 +
  88 +       fscanf(f, "%d", &i);
  89 +       if (i > 0)
  90 +               kill(i, SIGTERM);
  91 +
  92 +       fclose(f);
  93 +
  94 +       return 0;
  95 +}
  96 +
  97 +static int do_lock(void)
  98 +{
  99 +       int pid;
 100 +       char pidstr[8];
 101 +
 102 +       if ((fd = open(file, O_RDWR | O_CREAT | O_EXCL, 0700)) < 0) {
 103 +               if ((fd = open(file, O_RDWR)) < 0) {
 104 +                       fprintf(stderr, "Can't open %s\n", file);
 105 +                       return 1;
 106 +               }
 107 +       }
 108 +
 109 +       if (flock(fd, (shared ? LOCK_SH : LOCK_EX)) < 0) {
 110 +               fprintf(stderr, "Can't lock %s\n", file);
 111 +               return 1;
 112 +       }
 113 +
 114 +       pid = fork();
 115 +
 116 +       if (pid < 0)
 117 +               return -1;
 118 +
 119 +       if (pid == 0) {
 120 +               signal(SIGKILL, exit_unlock);
 121 +               signal(SIGTERM, exit_unlock);
 122 +               signal(SIGINT, exit_unlock);
 123 +               if (waitonly)
 124 +                       exit_unlock(0);
 125 +               else
 126 +                       while (1)
 127 +                               sleep(1);
 128 +       } else {
 129 +               if (!waitonly) {
 130 +                       lseek(fd, 0, SEEK_SET);
 131 +                       ftruncate(fd, 0);
 132 +                       sprintf(pidstr, "%d\n", pid);
 133 +                       write(fd, pidstr, strlen(pidstr));
 134 +                       close(fd);
 135 +               }
 136 +
 137 +               return 0;
 138 +       }
 139 +       return 0;
 140 +}
 141 +
 142 +#ifndef CONFIG_LOCK
 143 +int main(int argc, char **argv)
 144 +#else
 145 +int lock_main(int argc, char **argv)
 146 +#endif
 147 +{
 148 +       char **args = &argv[1];
 149 +       int c = argc - 1;
 150 +
 151 +       while ((*args != NULL) && (*args)[0] == '-') {
 152 +               char *ch = *args;
 153 +               while (*(++ch) > 0) {
 154 +                       switch(*ch) {
 155 +                               case 'w':
 156 +                                       waitonly = 1;
 157 +                                       break;
 158 +                               case 's':
 159 +                                       shared = 1;
 160 +                                       break;
 161 +                               case 'u':
 162 +                                       unlock = 1;
 163 +                                       break;
 164 +                       }
 165 +               }
 166 +               c--;
 167 +               args++;
 168 +       }
 169 +
 170 +       if (c != 1)
 171 +               usage(argv[0]);
 172 +
 173 +       file = *args;
 174 +       if (unlock)
 175 +               return do_unlock();
 176 +       else
 177 +               return do_lock();
 178 +}