kernel/vserver/helper.c

   1 /*
   2  *  linux/kernel/vserver/helper.c
   3  *
   4  *  Virtual Context Support
   5  *
   6  *  Copyright (C) 2004-2007  Herbert Pötzl
   7  *
   8  *  V0.01  basic helper
   9  *
  10  */
  11
  12 #include <linux/errno.h>
  13 #include <linux/kmod.h>
  14 #include <linux/sched.h>
  15 #include <linux/reboot.h>
  16 #include <linux/vs_context.h>
  17 #include <linux/vs_network.h>
  18 #include <linux/vserver/signal.h>
  19
  20 #include <asm/uaccess.h>
  21 #include <asm/unistd.h>
  22
  23
  24 char vshelper_path[255] = "/sbin/vshelper";
  25
  26
  27 static int do_vshelper(char *name, char *argv[], char *envp[], int sync)
  28 {
  29         int ret;
  30
  31         if ((ret = call_usermodehelper(name, argv, envp, sync))) {
  32                 printk( KERN_WARNING
  33                         "%s: (%s %s) returned %s with %d\n",
  34                         name, argv[1], argv[2],
  35                         sync?"sync":"async", ret);
  36         }
  37         vxdprintk(VXD_CBIT(switch, 4),
  38                 "%s: (%s %s) returned %s with %d",
  39                 name, argv[1], argv[2], sync?"sync":"async", ret);
  40         return ret;
  41 }
  42
  43 /*
  44  *      vshelper path is set via /proc/sys
  45  *      invoked by vserver sys_reboot(), with
  46  *      the following arguments
  47  *
  48  *      argv [0] = vshelper_path;
  49  *      argv [1] = action: "restart", "halt", "poweroff", ...
  50  *      argv [2] = context identifier
  51  *
  52  *      envp [*] = type-specific parameters
  53  */
  54
  55 long vs_reboot_helper(struct vx_info *vxi, int cmd, void __user *arg)
  56 {
  57         char id_buf[8], cmd_buf[16];
  58         char uid_buf[16], pid_buf[16];
  59         int ret;
  60
  61         char *argv[] = {vshelper_path, NULL, id_buf, 0};
  62         char *envp[] = {"HOME=/", "TERM=linux",
  63                         "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
  64                         uid_buf, pid_buf, cmd_buf, 0};
  65
  66         if (vx_info_state(vxi, VXS_HELPER))
  67                 return -EAGAIN;
  68         vxi->vx_state |= VXS_HELPER;
  69
  70         snprintf(id_buf, sizeof(id_buf)-1, "%d", vxi->vx_id);
  71
  72         snprintf(cmd_buf, sizeof(cmd_buf)-1, "VS_CMD=%08x", cmd);
  73         snprintf(uid_buf, sizeof(uid_buf)-1, "VS_UID=%d", current->uid);
  74         snprintf(pid_buf, sizeof(pid_buf)-1, "VS_PID=%d", current->pid);
  75
  76         switch (cmd) {
  77         case LINUX_REBOOT_CMD_RESTART:
  78                 argv[1] = "restart";
  79                 break;
  80
  81         case LINUX_REBOOT_CMD_HALT:
  82                 argv[1] = "halt";
  83                 break;
  84
  85         case LINUX_REBOOT_CMD_POWER_OFF:
  86                 argv[1] = "poweroff";
  87                 break;
  88
  89         case LINUX_REBOOT_CMD_SW_SUSPEND:
  90                 argv[1] = "swsusp";
  91                 break;
  92
  93         default:
  94                 vxi->vx_state &= ~VXS_HELPER;
  95                 return 0;
  96         }
  97
  98 #ifndef CONFIG_VSERVER_LEGACY
  99         ret = do_vshelper(vshelper_path, argv, envp, 1);
 100 #else
 101         ret = do_vshelper(vshelper_path, argv, envp, 0);
 102 #endif
 103         vxi->vx_state &= ~VXS_HELPER;
 104         __wakeup_vx_info(vxi);
 105         return (ret) ? -EPERM : 0;
 106 }
 107
 108
 109 long vs_reboot(unsigned int cmd, void __user * arg)
 110 {
 111         struct vx_info *vxi = current->vx_info;
 112         long ret = 0;
 113
 114         vxdprintk(VXD_CBIT(misc, 5),
 115                 "vs_reboot(%p[#%d],%d)",
 116                 vxi, vxi?vxi->vx_id:0, cmd);
 117
 118         ret = vs_reboot_helper(vxi, cmd, arg);
 119         if (ret)
 120                 return ret;
 121
 122         vxi->reboot_cmd = cmd;
 123         if (vx_info_flags(vxi, VXF_REBOOT_KILL, 0)) {
 124                 switch (cmd) {
 125                 case LINUX_REBOOT_CMD_RESTART:
 126                 case LINUX_REBOOT_CMD_HALT:
 127                 case LINUX_REBOOT_CMD_POWER_OFF:
 128                         vx_info_kill(vxi, 0, SIGKILL);
 129                         vx_info_kill(vxi, 1, SIGKILL);
 130                 default:
 131                         break;
 132                 }
 133         }
 134         return 0;
 135 }
 136
 137
 138 /*
 139  *      argv [0] = vshelper_path;
 140  *      argv [1] = action: "startup", "shutdown"
 141  *      argv [2] = context identifier
 142  *
 143  *      envp [*] = type-specific parameters
 144  */
 145
 146 long vs_state_change(struct vx_info *vxi, unsigned int cmd)
 147 {
 148         char id_buf[8], cmd_buf[16];
 149         char *argv[] = {vshelper_path, NULL, id_buf, 0};
 150         char *envp[] = {"HOME=/", "TERM=linux",
 151                         "PATH=/sbin:/usr/sbin:/bin:/usr/bin", cmd_buf, 0};
 152
 153         if (!vx_info_flags(vxi, VXF_SC_HELPER, 0))
 154                 return 0;
 155
 156         snprintf(id_buf, sizeof(id_buf)-1, "%d", vxi->vx_id);
 157         snprintf(cmd_buf, sizeof(cmd_buf)-1, "VS_CMD=%08x", cmd);
 158
 159         switch (cmd) {
 160         case VSC_STARTUP:
 161                 argv[1] = "startup";
 162                 break;
 163         case VSC_SHUTDOWN:
 164                 argv[1] = "shutdown";
 165                 break;
 166         default:
 167                 return 0;
 168         }
 169
 170         return do_vshelper(vshelper_path, argv, envp, 1);
 171 }
 172
 173
 174 /*
 175  *      argv [0] = vshelper_path;
 176  *      argv [1] = action: "netup", "netdown"
 177  *      argv [2] = context identifier
 178  *
 179  *      envp [*] = type-specific parameters
 180  */
 181
 182 long vs_net_change(struct nx_info *nxi, unsigned int cmd)
 183 {
 184         char id_buf[8], cmd_buf[16];
 185         char *argv[] = {vshelper_path, NULL, id_buf, 0};
 186         char *envp[] = {"HOME=/", "TERM=linux",
 187                         "PATH=/sbin:/usr/sbin:/bin:/usr/bin", cmd_buf, 0};
 188
 189         if (!nx_info_flags(nxi, NXF_SC_HELPER, 0))
 190                 return 0;
 191
 192         snprintf(id_buf, sizeof(id_buf)-1, "%d", nxi->nx_id);
 193         snprintf(cmd_buf, sizeof(cmd_buf)-1, "VS_CMD=%08x", cmd);
 194
 195         switch (cmd) {
 196         case VSC_NETUP:
 197                 argv[1] = "netup";
 198                 break;
 199         case VSC_NETDOWN:
 200                 argv[1] = "netdown";
 201                 break;
 202         default:
 203                 return 0;
 204         }
 205
 206         return do_vshelper(vshelper_path, argv, envp, 1);
 207 }
 208