kernel/vserver/helper.c

   1 /*
   2  *  linux/kernel/vserver/helper.c
   3  *
   4  *  Virtual Context Support
   5  *
   6  *  Copyright (C) 2004  Herbert Pötzl
   7  *
   8  *  V0.01  basic helper
   9  *
  10  */
  11
  12 #include <linux/config.h>
  13 #include <linux/errno.h>
  14 #include <linux/reboot.h>
  15 #include <linux/kmod.h>
  16 #include <linux/vserver.h>
  17 #include <linux/vs_base.h>
  18 #include <linux/vs_context.h>
  19
  20 #include <asm/uaccess.h>
  21 #include <asm/unistd.h>
  22
  23
  24 char vshelper_path[255] = "/sbin/vshelper";
  25
  26
  27 /*
  28  *      vshelper path is set via /proc/sys
  29  *      invoked by vserver sys_reboot(), with
  30  *      the following arguments
  31  *
  32  *      argv [0] = vshelper_path;
  33  *      argv [1] = action: "restart", "halt", "poweroff", ...
  34  *      argv [2] = context identifier
  35  *      argv [3] = additional argument (restart2)
  36  *
  37  *      envp [*] = type-specific parameters
  38  */
  39
  40 long vs_reboot(unsigned int cmd, void * arg)
  41 {
  42         char id_buf[8], cmd_buf[32];
  43         char uid_buf[32], pid_buf[32];
  44         char buffer[256];
  45
  46         char *argv[] = {vshelper_path, NULL, id_buf, NULL, 0};
  47         char *envp[] = {"HOME=/", "TERM=linux",
  48                         "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
  49                         uid_buf, pid_buf, cmd_buf, 0};
  50
  51         snprintf(id_buf, sizeof(id_buf)-1, "%d", vx_current_xid());
  52
  53         snprintf(cmd_buf, sizeof(cmd_buf)-1, "VS_CMD=%08x", cmd);
  54         snprintf(uid_buf, sizeof(uid_buf)-1, "VS_UID=%d", current->uid);
  55         snprintf(pid_buf, sizeof(pid_buf)-1, "VS_PID=%d", current->pid);
  56
  57         switch (cmd) {
  58         case LINUX_REBOOT_CMD_RESTART:
  59                 argv[1] = "restart";
  60                 break;
  61
  62         case LINUX_REBOOT_CMD_HALT:
  63                 argv[1] = "halt";
  64                 break;
  65
  66         case LINUX_REBOOT_CMD_POWER_OFF:
  67                 argv[1] = "poweroff";
  68                 break;
  69
  70         case LINUX_REBOOT_CMD_SW_SUSPEND:
  71                 argv[1] = "swsusp";
  72                 break;
  73
  74         case LINUX_REBOOT_CMD_RESTART2:
  75                 if (strncpy_from_user(&buffer[0], (char *)arg, sizeof(buffer) - 1) < 0)
  76                         return -EFAULT;
  77                 argv[3] = buffer;
  78         default:
  79                 argv[1] = "restart2";
  80                 break;
  81         }
  82
  83         /* maybe we should wait ? */
  84         if (call_usermodehelper(*argv, argv, envp, 0)) {
  85                 printk( KERN_WARNING
  86                         "vs_reboot(): failed to exec (%s %s %s %s)\n",
  87                         vshelper_path, argv[1], argv[2], argv[3]);
  88                 return -EPERM;
  89         }
  90         return 0;
  91 }
  92