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
  34         vxi->vx_flags &= ~VXF_STATE_INIT;
  35         return vx_set_init(vxi, init);
  36 }
  37
  38 int vc_new_s_context(uint32_t ctx, void __user *data)
  39 {
  40         int ret = -ENOMEM;
  41         struct vcmd_new_s_context_v1 vc_data;
  42         struct vx_info *new_vxi;
  43
  44         if (copy_from_user(&vc_data, data, sizeof(vc_data)))
  45                 return -EFAULT;
  46
  47         /* legacy hack, will be removed soon */
  48         if (ctx == -2) {
  49                 /* assign flags and initpid */
  50                 if (!current->vx_info)
  51                         return -EINVAL;
  52                 ret = 0;
  53                 if (vc_data.flags & VX_INFO_INIT)
  54                         ret = vx_set_initpid(current->vx_info, current->tgid);
  55                 if (ret == 0) {
  56                         /* We keep the same vx_id, but lower the capabilities */
  57                         current->vx_info->vx_bcaps &= (~vc_data.remove_cap);
  58                         ret = vx_current_xid();
  59                         current->vx_info->vx_flags |= vc_data.flags;
  60                 }
  61                 return ret;
  62         }
  63
  64         if (!vx_check(0, VX_ADMIN) || !capable(CAP_SYS_ADMIN)
  65                 /* might make sense in the future, or not ... */
  66                 || vx_flags(VX_INFO_LOCK, 0))
  67                 return -EPERM;
  68
  69         /* ugly hack for Spectator */
  70         if (ctx == 1) {
  71                 current->xid = 1;
  72                 return 0;
  73         }
  74
  75         if (((ctx > MAX_S_CONTEXT) && (ctx != VX_DYNAMIC_ID)) ||
  76                 (ctx == 0))
  77                 return -EINVAL;
  78
  79         if ((ctx == VX_DYNAMIC_ID) || (ctx < MIN_D_CONTEXT))
  80                 new_vxi = lookup_or_create_vx_info(ctx);
  81         else
  82                 new_vxi = lookup_vx_info(ctx);
  83
  84         if (!new_vxi)
  85                 return -EINVAL;
  86
  87         ret = -EPERM;
  88         if (!vx_info_flags(new_vxi, VXF_STATE_SETUP, 0) &&
  89                 vx_info_flags(new_vxi, VX_INFO_PRIVATE, 0))
  90                 goto out_put;
  91
  92         new_vxi->vx_flags &= ~VXF_STATE_SETUP;
  93
  94         ret = vx_migrate_task(current, new_vxi);
  95         if (ret == 0) {
  96                 current->vx_info->vx_bcaps &= (~vc_data.remove_cap);
  97                 new_vxi->vx_flags |= vc_data.flags;
  98                 if (vc_data.flags & VX_INFO_INIT)
  99                         vx_set_initpid(new_vxi, current->tgid);
 100                 if (vc_data.flags & VX_INFO_NAMESPACE)
 101                         vx_set_namespace(new_vxi,
 102                                 current->namespace, current->fs);
 103                 if (vc_data.flags & VX_INFO_NPROC)
 104                         new_vxi->limit.rlim[RLIMIT_NPROC] =
 105                                 current->signal->rlim[RLIMIT_NPROC].rlim_max;
 106
 107                 /* tweak some defaults for legacy */
 108                 new_vxi->vx_flags |= (VXF_HIDE_NETIF|VXF_INFO_INIT);
 109                 ret = new_vxi->vx_id;
 110         }
 111 out_put:
 112         put_vx_info(new_vxi);
 113         return ret;
 114 }
 115