kernel/vserver/legacy.c

   1 /*
   2  *  linux/kernel/vserver/legacy.c
   3  *
   4  *  Virtual Server: Legacy Funtions
   5  *
   6  *  Copyright (C) 2001-2003  Jacques Gelinas
   7  *  Copyright (C) 2003-2005  Herbert Pötzl
   8  *
   9  *  V0.01  broken out from vcontext.c V0.05
  10  *
  11  */
  12
  13 #include <linux/sched.h>
  14 #include <linux/vs_base.h>
  15 #include <linux/vs_context.h>
  16 #include <linux/vs_network.h>
  17 #include <linux/vserver/legacy.h>
  18 #include <linux/vserver/namespace.h>
  19 #include <linux/namespace.h>
  20
  21 #include <asm/errno.h>
  22 #include <asm/uaccess.h>
  23
  24
  25 extern int vx_set_init(struct vx_info *, struct task_struct *);
  26
  27 static int vx_set_initpid(struct vx_info *vxi, int pid)
  28 {
  29         struct task_struct *init;
  30
  31         init = find_task_by_real_pid(pid);
  32         if (!init)
  33                 return -ESRCH;
  34         return vx_set_init(vxi, init);
  35 }
  36
  37 int vc_new_s_context(uint32_t ctx, void __user *data)
  38 {
  39         int ret = -ENOMEM;
  40         struct vcmd_new_s_context_v1 vc_data;
  41         struct vx_info *new_vxi;
  42
  43         if (copy_from_user(&vc_data, data, sizeof(vc_data)))
  44                 return -EFAULT;
  45
  46         /* legacy hack, will be removed soon */
  47         if (ctx == -2) {
  48                 /* assign flags and initpid */
  49                 if (!current->vx_info)
  50                         return -EINVAL;
  51                 ret = 0;
  52                 if (vc_data.flags & VX_INFO_INIT)
  53                         ret = vx_set_initpid(current->vx_info, current->tgid);
  54                 if (ret == 0) {
  55                         /* We keep the same vx_id, but lower the capabilities */
  56                         current->vx_info->vx_bcaps &= (~vc_data.remove_cap);
  57                         ret = vx_current_xid();
  58                         current->vx_info->vx_flags |= vc_data.flags;
  59                 }
  60                 return ret;
  61         }
  62
  63         if (!vx_check(0, VX_ADMIN) || !capable(CAP_SYS_ADMIN))
  64                 return -EPERM;
  65
  66         /* ugly hack for Spectator */
  67         if (ctx == 1) {
  68                 current->xid = 1;
  69                 return 0;
  70         }
  71
  72         if (((ctx > MAX_S_CONTEXT) && (ctx != VX_DYNAMIC_ID)) ||
  73                 (ctx == 0))
  74                 return -EINVAL;
  75
  76         if ((ctx == VX_DYNAMIC_ID) || (ctx < MIN_D_CONTEXT))
  77                 new_vxi = lookup_or_create_vx_info(ctx);
  78         else
  79                 new_vxi = lookup_vx_info(ctx);
  80
  81         if (!new_vxi)
  82                 return -EINVAL;
  83
  84         ret = -EPERM;
  85         if (!vx_info_flags(new_vxi, VXF_STATE_SETUP, 0) &&
  86                 vx_info_flags(new_vxi, VX_INFO_PRIVATE, 0))
  87                 goto out_put;
  88
  89         new_vxi->vx_flags &= ~VXF_STATE_SETUP;
  90
  91         ret = vx_migrate_task(current, new_vxi);
  92         if (ret == 0) {
  93                 current->vx_info->vx_bcaps &= (~vc_data.remove_cap);
  94                 new_vxi->vx_flags |= vc_data.flags;
  95                 if (vc_data.flags & VX_INFO_INIT)
  96                         vx_set_initpid(new_vxi, current->tgid);
  97                 if (vc_data.flags & VX_INFO_NAMESPACE)
  98                         vx_set_namespace(new_vxi,
  99                                 current->namespace, current->fs);
 100                 if (vc_data.flags & VX_INFO_NPROC)
 101                         new_vxi->limit.rlim[RLIMIT_NPROC] =
 102                                 current->signal->rlim[RLIMIT_NPROC].rlim_max;
 103
 104                 /* tweak some defaults for legacy */
 105                 new_vxi->vx_flags |= (VXF_HIDE_NETIF|VXF_INFO_INIT);
 106                 ret = new_vxi->vx_id;
 107         }
 108 out_put:
 109         put_vx_info(new_vxi);
 110         return ret;
 111 }
 112