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