package/busybox/patches/340-lock_util.patch

   1 Index: busybox-1.8.1/include/applets.h
   2 ===================================================================
   3 --- busybox-1.8.1.orig/include/applets.h        2007-11-10 16:54:28.318054115 +0100
   4 +++ busybox-1.8.1/include/applets.h     2007-11-10 17:39:21.487529096 +0100
   5 @@ -218,6 +218,7 @@
   6  USE_LOAD_POLICY(APPLET(load_policy, _BB_DIR_USR_SBIN, _BB_SUID_NEVER))
   7  USE_LOADFONT(APPLET(loadfont, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
   8  USE_LOADKMAP(APPLET(loadkmap, _BB_DIR_SBIN, _BB_SUID_NEVER))
   9 +USE_LOCK(APPLET_NOUSAGE(lock, lock, _BB_DIR_BIN, _BB_SUID_NEVER))
  10  USE_LOGGER(APPLET(logger, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
  11  USE_LOGIN(APPLET(login, _BB_DIR_BIN, _BB_SUID_ALWAYS))
  12  USE_LOGNAME(APPLET_NOFORK(logname, logname, _BB_DIR_USR_BIN, _BB_SUID_NEVER, logname))
  13 Index: busybox-1.8.1/miscutils/Config.in
  14 ===================================================================
  15 --- busybox-1.8.1.orig/miscutils/Config.in      2007-11-10 16:54:16.477379354 +0100
  16 +++ busybox-1.8.1/miscutils/Config.in   2007-11-10 16:54:28.366056851 +0100
  17 @@ -244,6 +244,12 @@
  18           Enables the 'hdparm -d' option to get/set using_dma flag.
  19           This is dangerous stuff, so you should probably say N.
  20
  21 +config LOCK
  22 +       bool "lock"
  23 +       default y
  24 +       help
  25 +         Small utility for using locks in scripts
  26 +
  27  config MAKEDEVS
  28         bool "makedevs"
  29         default n
  30 Index: busybox-1.8.1/miscutils/Kbuild
  31 ===================================================================
  32 --- busybox-1.8.1.orig/miscutils/Kbuild 2007-11-10 16:54:16.481379580 +0100
  33 +++ busybox-1.8.1/miscutils/Kbuild      2007-11-10 16:54:28.370057076 +0100
  34 @@ -16,6 +16,7 @@
  35  lib-$(CONFIG_HDPARM)      += hdparm.o
  36  lib-$(CONFIG_LAST)        += last.o
  37  lib-$(CONFIG_LESS)        += less.o
  38 +lib-$(CONFIG_LOCK)        += lock.o
  39  lib-$(CONFIG_MAKEDEVS)    += makedevs.o
  40  lib-$(CONFIG_MICROCOM)    += microcom.o
  41  lib-$(CONFIG_MOUNTPOINT)  += mountpoint.o
  42 Index: busybox-1.8.1/miscutils/lock.c
  43 ===================================================================
  44 --- /dev/null   1970-01-01 00:00:00.000000000 +0000
  45 +++ busybox-1.8.1/miscutils/lock.c      2007-11-10 17:40:37.203843924 +0100
  46 @@ -0,0 +1,132 @@
  47 +/*
  48 + * Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org>
  49 + *
  50 + * This is free software, licensed under the GNU General Public License v2.
  51 + */
  52 +#include <sys/types.h>
  53 +#include <sys/file.h>
  54 +#include <sys/stat.h>
  55 +#include <signal.h>
  56 +#include <fcntl.h>
  57 +#include <unistd.h>
  58 +#include <stdio.h>
  59 +#include "busybox.h"
  60 +
  61 +static int unlock = 0;
  62 +static int shared = 0;
  63 +static int waitonly = 0;
  64 +static int fd;
  65 +static char *file;
  66 +
  67 +static void usage(char *name)
  68 +{
  69 +       fprintf(stderr, "Usage: %s [-suw] <filename>\n"
  70 +                       "       -s      Use shared locking\n"
  71 +                       "       -u      Unlock\n"
  72 +                       "       -w      Wait for the lock to become free, don't acquire lock\n"
  73 +                                       "\n", name);
  74 +       exit(1);
  75 +}
  76 +
  77 +static void exit_unlock(int sig)
  78 +{
  79 +       flock(fd, LOCK_UN);
  80 +       exit(0);
  81 +}
  82 +
  83 +static int do_unlock(void)
  84 +{
  85 +       FILE *f;
  86 +       int i;
  87 +
  88 +       if ((f = fopen(file, "r")) == NULL)
  89 +               return 0;
  90 +
  91 +       fscanf(f, "%d", &i);
  92 +       if (i > 0)
  93 +               kill(i, SIGTERM);
  94 +
  95 +       fclose(f);
  96 +
  97 +       return 0;
  98 +}
  99 +
 100 +static int do_lock(void)
 101 +{
 102 +       int pid;
 103 +       char pidstr[8];
 104 +
 105 +       if ((fd = open(file, O_RDWR | O_CREAT | O_EXCL, 0700)) < 0) {
 106 +               if ((fd = open(file, O_RDWR)) < 0) {
 107 +                       fprintf(stderr, "Can't open %s\n", file);
 108 +                       return 1;
 109 +               }
 110 +       }
 111 +
 112 +       if (flock(fd, (shared ? LOCK_SH : LOCK_EX)) < 0) {
 113 +               fprintf(stderr, "Can't lock %s\n", file);
 114 +               return 1;
 115 +       }
 116 +
 117 +       pid = fork();
 118 +
 119 +       if (pid < 0)
 120 +               return -1;
 121 +
 122 +       if (pid == 0) {
 123 +               signal(SIGKILL, exit_unlock);
 124 +               signal(SIGTERM, exit_unlock);
 125 +               signal(SIGINT, exit_unlock);
 126 +               if (waitonly)
 127 +                       exit_unlock(0);
 128 +               else
 129 +                       while (1)
 130 +                               sleep(1);
 131 +       } else {
 132 +               if (!waitonly) {
 133 +                       lseek(fd, 0, SEEK_SET);
 134 +                       ftruncate(fd, 0);
 135 +                       sprintf(pidstr, "%d\n", pid);
 136 +                       write(fd, pidstr, strlen(pidstr));
 137 +                       close(fd);
 138 +               }
 139 +
 140 +               return 0;
 141 +       }
 142 +       return 0;
 143 +}
 144 +
 145 +int lock_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 146 +int lock_main(int argc, char **argv)
 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 +}