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_base.h>
  17 #include <linux/vs_context.h>
  18 #include <linux/vs_network.h>
  19 #include <linux/vserver/signal.h>
  20
  21 #include <asm/uaccess.h>
  22 #include <asm/unistd.h>
  23
  24
  25 char vshelper_path[255] = "/sbin/vshelper";
  26
  27
  28 static int do_vshelper(char *name, char *argv[], char *envp[], int sync)
  29 {
  30         int ret;
  31
  32         if ((ret = call_usermodehelper(name, argv, envp, sync))) {
  33                 printk( KERN_WARNING
  34                         "%s: (%s %s) returned %s with %d\n",
  35                         name, argv[1], argv[2],
  36                         sync?"sync":"async", ret);
  37         }
  38         vxdprintk(VXD_CBIT(switch, 4),
  39                 "%s: (%s %s) returned %s with %d",
  40                 name, argv[1], argv[2], sync?"sync":"async", ret);
  41         return ret;
  42 }
  43
  44 /*
  45  *      vshelper path is set via /proc/sys
  46  *      invoked by vserver sys_reboot(), with
  47  *      the following arguments
  48  *
  49  *      argv [0] = vshelper_path;
  50  *      argv [1] = action: "restart", "halt", "poweroff", ...
  51  *      argv [2] = context identifier
  52  *
  53  *      envp [*] = type-specific parameters
  54  */
  55
  56 long vs_reboot_helper(struct vx_info *vxi, int cmd, void __user *arg)
  57 {
  58         char id_buf[8], cmd_buf[16];
  59         char uid_buf[16], pid_buf[16];
  60         int ret;
  61
  62         char *argv[] = {vshelper_path, NULL, id_buf, 0};
  63         char *envp[] = {"HOME=/", "TERM=linux",
  64                         "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
  65                         uid_buf, pid_buf, cmd_buf, 0};
  66
  67         if (vx_info_state(vxi, VXS_HELPER))
  68                 return -EAGAIN;
  69         vxi->vx_state |= VXS_HELPER;
  70
  71         snprintf(id_buf, sizeof(id_buf)-1, "%d", vxi->vx_id);
  72
  73         snprintf(cmd_buf, sizeof(cmd_buf)-1, "VS_CMD=%08x", cmd);
  74         snprintf(uid_buf, sizeof(uid_buf)-1, "VS_UID=%d", current->uid);
  75         snprintf(pid_buf, sizeof(pid_buf)-1, "VS_PID=%d", current->pid);
  76
  77         switch (cmd) {
  78         case LINUX_REBOOT_CMD_RESTART:
  79                 argv[1] = "restart";
  80                 break;
  81
  82         case LINUX_REBOOT_CMD_HALT:
  83                 argv[1] = "halt";
  84                 break;
  85
  86         case LINUX_REBOOT_CMD_POWER_OFF:
  87                 argv[1] = "poweroff";
  88                 break;
  89
  90         case LINUX_REBOOT_CMD_SW_SUSPEND:
  91                 argv[1] = "swsusp";
  92                 break;
  93
  94         default:
  95                 vxi->vx_state &= ~VXS_HELPER;
  96                 return 0;
  97         }
  98
  99 #ifndef CONFIG_VSERVER_LEGACY
 100         ret = do_vshelper(vshelper_path, argv, envp, 1);
 101 #else
 102         ret = do_vshelper(vshelper_path, argv, envp, 0);
 103 #endif
 104         vxi->vx_state &= ~VXS_HELPER;
 105         __wakeup_vx_info(vxi);
 106         return (ret) ? -EPERM : 0;
 107 }
 108
 109
 110 long vs_reboot(unsigned int cmd, void __user * arg)
 111 {
 112         struct vx_info *vxi = current->vx_info;
 113         long ret = 0;
 114
 115         vxdprintk(VXD_CBIT(misc, 5),
 116                 "vs_reboot(%p[#%d],%d)",
 117                 vxi, vxi?vxi->vx_id:0, cmd);
 118
 119         ret = vs_reboot_helper(vxi, cmd, arg);
 120         if (ret)
 121                 return ret;
 122
 123         vxi->reboot_cmd = cmd;
 124         if (vx_info_flags(vxi, VXF_REBOOT_KILL, 0)) {
 125                 switch (cmd) {
 126                 case LINUX_REBOOT_CMD_RESTART:
 127                 case LINUX_REBOOT_CMD_HALT:
 128                 case LINUX_REBOOT_CMD_POWER_OFF:
 129                         vx_info_kill(vxi, 0, SIGKILL);
 130                         vx_info_kill(vxi, 1, SIGKILL);
 131                 default:
 132                         break;
 133                 }
 134         }
 135         return 0;
 136 }
 137
 138
 139 /*
 140  *      argv [0] = vshelper_path;
 141  *      argv [1] = action: "startup", "shutdown"
 142  *      argv [2] = context identifier
 143  *
 144  *      envp [*] = type-specific parameters
 145  */
 146
 147 long vs_state_change(struct vx_info *vxi, unsigned int cmd)
 148 {
 149         char id_buf[8], cmd_buf[16];
 150         char *argv[] = {vshelper_path, NULL, id_buf, 0};
 151         char *envp[] = {"HOME=/", "TERM=linux",
 152                         "PATH=/sbin:/usr/sbin:/bin:/usr/bin", cmd_buf, 0};
 153
 154         if (!vx_info_flags(vxi, VXF_SC_HELPER, 0))
 155                 return 0;
 156
 157         snprintf(id_buf, sizeof(id_buf)-1, "%d", vxi->vx_id);
 158         snprintf(cmd_buf, sizeof(cmd_buf)-1, "VS_CMD=%08x", cmd);
 159
 160         switch (cmd) {
 161         case VSC_STARTUP:
 162                 argv[1] = "startup";
 163                 break;
 164         case VSC_SHUTDOWN:
 165                 argv[1] = "shutdown";
 166                 break;
 167         default:
 168                 return 0;
 169         }
 170
 171         return do_vshelper(vshelper_path, argv, envp, 1);
 172 }
 173
 174
 175 /*
 176  *      argv [0] = vshelper_path;
 177  *      argv [1] = action: "netup", "netdown"
 178  *      argv [2] = context identifier
 179  *
 180  *      envp [*] = type-specific parameters
 181  */
 182
 183 long vs_net_change(struct nx_info *nxi, unsigned int cmd)
 184 {
 185         char id_buf[8], cmd_buf[16];
 186         char *argv[] = {vshelper_path, NULL, id_buf, 0};
 187         char *envp[] = {"HOME=/", "TERM=linux",
 188                         "PATH=/sbin:/usr/sbin:/bin:/usr/bin", cmd_buf, 0};
 189
 190         if (!nx_info_flags(nxi, NXF_SC_HELPER, 0))
 191                 return 0;
 192
 193         snprintf(id_buf, sizeof(id_buf)-1, "%d", nxi->nx_id);
 194         snprintf(cmd_buf, sizeof(cmd_buf)-1, "VS_CMD=%08x", cmd);
 195
 196         switch (cmd) {
 197         case VSC_NETUP:
 198                 argv[1] = "netup";
 199                 break;
 200         case VSC_NETDOWN:
 201                 argv[1] = "netdown";
 202                 break;
 203         default:
 204                 return 0;
 205         }
 206
 207         return do_vshelper(vshelper_path, argv, envp, 1);
 208 }
 209