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/sched.h>
  17 #include <linux/vs_context.h>
  18
  19 #include <asm/uaccess.h>
  20 #include <asm/unistd.h>
  21
  22
  23 char vshelper_path[255] = "/sbin/vshelper";
  24
  25
  26 /*
  27  *      vshelper path is set via /proc/sys
  28  *      invoked by vserver sys_reboot(), with
  29  *      the following arguments
  30  *
  31  *      argv [0] = vshelper_path;
  32  *      argv [1] = action: "restart", "halt", "poweroff", ...
  33  *      argv [2] = context identifier
  34  *      argv [3] = additional argument (restart2)
  35  *
  36  *      envp [*] = type-specific parameters
  37  */
  38
  39 long vs_reboot(unsigned int cmd, void * arg)
  40 {
  41         char id_buf[8], cmd_buf[32];
  42         char uid_buf[32], pid_buf[32];
  43         char buffer[256];
  44
  45         char *argv[] = {vshelper_path, NULL, id_buf, NULL, 0};
  46         char *envp[] = {"HOME=/", "TERM=linux",
  47                         "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
  48                         uid_buf, pid_buf, cmd_buf, 0};
  49
  50         snprintf(id_buf, sizeof(id_buf)-1, "%d", vx_current_xid());
  51
  52         snprintf(cmd_buf, sizeof(cmd_buf)-1, "VS_CMD=%08x", cmd);
  53         snprintf(uid_buf, sizeof(uid_buf)-1, "VS_UID=%d", current->uid);
  54         snprintf(pid_buf, sizeof(pid_buf)-1, "VS_PID=%d", current->pid);
  55
  56         switch (cmd) {
  57         case LINUX_REBOOT_CMD_RESTART:
  58                 argv[1] = "restart";
  59                 break;
  60
  61         case LINUX_REBOOT_CMD_HALT:
  62                 argv[1] = "halt";
  63                 break;
  64
  65         case LINUX_REBOOT_CMD_POWER_OFF:
  66                 argv[1] = "poweroff";
  67                 break;
  68
  69         case LINUX_REBOOT_CMD_SW_SUSPEND:
  70                 argv[1] = "swsusp";
  71                 break;
  72
  73         case LINUX_REBOOT_CMD_RESTART2:
  74                 if (strncpy_from_user(&buffer[0], (char *)arg, sizeof(buffer) - 1) < 0)
  75                         return -EFAULT;
  76                 argv[3] = buffer;
  77         default:
  78                 argv[1] = "restart2";
  79                 break;
  80         }
  81
  82         /* maybe we should wait ? */
  83         if (call_usermodehelper(*argv, argv, envp, 0)) {
  84                 printk( KERN_WARNING
  85                         "vs_reboot(): failed to exec (%s %s %s %s)\n",
  86                         vshelper_path, argv[1], argv[2], argv[3]);
  87                 return -EPERM;
  88         }
  89         return 0;
  90 }
  91
  92 long vs_context_state(unsigned int cmd)
  93 {
  94         char id_buf[8], cmd_buf[32];
  95
  96         char *argv[] = {vshelper_path, NULL, id_buf, NULL, 0};
  97         char *envp[] = {"HOME=/", "TERM=linux",
  98                         "PATH=/sbin:/usr/sbin:/bin:/usr/bin", cmd_buf, 0};
  99
 100         snprintf(id_buf, sizeof(id_buf)-1, "%d", vx_current_xid());
 101         snprintf(cmd_buf, sizeof(cmd_buf)-1, "VS_CMD=%08x", cmd);
 102
 103         switch (cmd) {
 104         case VS_CONTEXT_CREATED:
 105                 argv[1] = "startup";
 106                 break;
 107         case VS_CONTEXT_DESTROY:
 108                 argv[1] = "shutdown";
 109                 break;
 110         default:
 111                 return 0;
 112         }
 113
 114         if (call_usermodehelper(*argv, argv, envp, 1)) {
 115                 printk( KERN_WARNING
 116                         "vs_context_state(): failed to exec (%s %s %s %s)\n",
 117                         vshelper_path, argv[1], argv[2], argv[3]);
 118                 return 0;
 119         }
 120         return 0;
 121 }
 122