kernel/vserver/helper.c

   1 /*
   2  *  linux/kernel/vserver/helper.c
   3  *
   4  *  Virtual Context Support
   5  *
   6  *  Copyright (C) 2004-2005  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 int do_vshelper(char *name, char *argv[], char *envp[], int sync)
  27 {
  28         int ret;
  29
  30         if ((ret = call_usermodehelper(name, argv, envp, sync))) {
  31                 printk( KERN_WARNING
  32                         "%s: (%s %s) returned with %d\n",
  33                         name, argv[1], argv[2], ret);
  34         }
  35         vxdprintk(VXD_CBIT(switch, 1),
  36                 "%s: (%s %s) returned with %d",
  37                 name, argv[1], argv[2], ret);
  38         return ret;
  39 }
  40
  41 /*
  42  *      vshelper path is set via /proc/sys
  43  *      invoked by vserver sys_reboot(), with
  44  *      the following arguments
  45  *
  46  *      argv [0] = vshelper_path;
  47  *      argv [1] = action: "restart", "halt", "poweroff", ...
  48  *      argv [2] = context identifier
  49  *
  50  *      envp [*] = type-specific parameters
  51  */
  52
  53 long vs_reboot(unsigned int cmd, void * arg)
  54 {
  55         char id_buf[8], cmd_buf[16];
  56         char uid_buf[16], pid_buf[16];
  57
  58         char *argv[] = {vshelper_path, NULL, id_buf, 0};
  59         char *envp[] = {"HOME=/", "TERM=linux",
  60                         "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
  61                         uid_buf, pid_buf, cmd_buf, 0};
  62
  63         snprintf(id_buf, sizeof(id_buf)-1, "%d", vx_current_xid());
  64
  65         snprintf(cmd_buf, sizeof(cmd_buf)-1, "VS_CMD=%08x", cmd);
  66         snprintf(uid_buf, sizeof(uid_buf)-1, "VS_UID=%d", current->uid);
  67         snprintf(pid_buf, sizeof(pid_buf)-1, "VS_PID=%d", current->pid);
  68
  69         switch (cmd) {
  70         case LINUX_REBOOT_CMD_RESTART:
  71                 argv[1] = "restart";
  72                 break;
  73
  74         case LINUX_REBOOT_CMD_HALT:
  75                 argv[1] = "halt";
  76                 break;
  77
  78         case LINUX_REBOOT_CMD_POWER_OFF:
  79                 argv[1] = "poweroff";
  80                 break;
  81
  82         case LINUX_REBOOT_CMD_SW_SUSPEND:
  83                 argv[1] = "swsusp";
  84                 break;
  85         }
  86
  87         if (do_vshelper(vshelper_path, argv, envp, 1))
  88                 return -EPERM;
  89         return 0;
  90 }
  91
  92
  93 /*
  94  *      invoked by vserver sys_reboot(), with
  95  *      the following arguments
  96  *
  97  *      argv [0] = vshelper_path;
  98  *      argv [1] = action: "startup", "shutdown"
  99  *      argv [2] = context identifier
 100  *
 101  *      envp [*] = type-specific parameters
 102  */
 103
 104 long vs_context_state(struct vx_info *vxi, unsigned int cmd)
 105 {
 106         char id_buf[8], cmd_buf[16];
 107         char *argv[] = {vshelper_path, NULL, id_buf, 0};
 108         char *envp[] = {"HOME=/", "TERM=linux",
 109                         "PATH=/sbin:/usr/sbin:/bin:/usr/bin", cmd_buf, 0};
 110
 111         snprintf(id_buf, sizeof(id_buf)-1, "%d", vxi->vx_id);
 112         snprintf(cmd_buf, sizeof(cmd_buf)-1, "VS_CMD=%08x", cmd);
 113
 114         switch (cmd) {
 115         case VS_CONTEXT_CREATED:
 116                 argv[1] = "startup";
 117                 break;
 118         case VS_CONTEXT_DESTROY:
 119                 argv[1] = "shutdown";
 120                 break;
 121         default:
 122                 return 0;
 123         }
 124
 125         do_vshelper(vshelper_path, argv, envp, 1);
 126         return 0;
 127 }
 128