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 %s with %d\n",
  33                         name, argv[1], argv[2],
  34                         sync?"sync":"async", ret);
  35         }
  36         vxdprintk(VXD_CBIT(switch, 1),
  37                 "%s: (%s %s) returned %s with %d",
  38                 name, argv[1], argv[2], sync?"sync":"async", ret);
  39         return ret;
  40 }
  41
  42 /*
  43  *      vshelper path is set via /proc/sys
  44  *      invoked by vserver sys_reboot(), with
  45  *      the following arguments
  46  *
  47  *      argv [0] = vshelper_path;
  48  *      argv [1] = action: "restart", "halt", "poweroff", ...
  49  *      argv [2] = context identifier
  50  *
  51  *      envp [*] = type-specific parameters
  52  */
  53
  54 long vs_reboot(unsigned int cmd, void * arg)
  55 {
  56         char id_buf[8], cmd_buf[16];
  57         char uid_buf[16], pid_buf[16];
  58
  59         char *argv[] = {vshelper_path, NULL, id_buf, 0};
  60         char *envp[] = {"HOME=/", "TERM=linux",
  61                         "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
  62                         uid_buf, pid_buf, cmd_buf, 0};
  63
  64         snprintf(id_buf, sizeof(id_buf)-1, "%d", vx_current_xid());
  65
  66         snprintf(cmd_buf, sizeof(cmd_buf)-1, "VS_CMD=%08x", cmd);
  67         snprintf(uid_buf, sizeof(uid_buf)-1, "VS_UID=%d", current->uid);
  68         snprintf(pid_buf, sizeof(pid_buf)-1, "VS_PID=%d", current->pid);
  69
  70         switch (cmd) {
  71         case LINUX_REBOOT_CMD_RESTART:
  72                 argv[1] = "restart";
  73                 break;
  74
  75         case LINUX_REBOOT_CMD_HALT:
  76                 argv[1] = "halt";
  77                 break;
  78
  79         case LINUX_REBOOT_CMD_POWER_OFF:
  80                 argv[1] = "poweroff";
  81                 break;
  82
  83         case LINUX_REBOOT_CMD_SW_SUSPEND:
  84                 argv[1] = "swsusp";
  85                 break;
  86
  87         default:
  88                 return 0;
  89         }
  90
  91         if (do_vshelper(vshelper_path, argv, envp, 1))
  92                 return -EPERM;
  93         return 0;
  94 }
  95
  96
  97 /*
  98  *      argv [0] = vshelper_path;
  99  *      argv [1] = action: "startup", "shutdown"
 100  *      argv [2] = context identifier
 101  *
 102  *      envp [*] = type-specific parameters
 103  */
 104
 105 long vs_state_change(struct vx_info *vxi, unsigned int cmd)
 106 {
 107         char id_buf[8], cmd_buf[16];
 108         char *argv[] = {vshelper_path, NULL, id_buf, 0};
 109         char *envp[] = {"HOME=/", "TERM=linux",
 110                         "PATH=/sbin:/usr/sbin:/bin:/usr/bin", cmd_buf, 0};
 111
 112         snprintf(id_buf, sizeof(id_buf)-1, "%d", vxi->vx_id);
 113         snprintf(cmd_buf, sizeof(cmd_buf)-1, "VS_CMD=%08x", cmd);
 114
 115         switch (cmd) {
 116         case VSC_STARTUP:
 117                 argv[1] = "startup";
 118                 break;
 119         case VSC_SHUTDOWN:
 120                 argv[1] = "shutdown";
 121                 break;
 122         default:
 123                 return 0;
 124         }
 125
 126         do_vshelper(vshelper_path, argv, envp, 1);
 127         return 0;
 128 }
 129