88 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			88 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* The system call implemented in this file:
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 *   m_type:	SYS_PRIVCTL
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 *
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 * The parameters for this system call are:
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 *    m1_i1:	PR_PROC_NR 	(process number of caller)	
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 *
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 * Changes:
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 *   Jul 13, 2005   created to dynamically start services  (Jorrit N. Herder) 
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 */
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#include "../system.h"
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#include "../ipc.h"
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#include <signal.h>
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#if USE_PRIVCTL
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#define FILLED_MASK	(~0)
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/*===========================================================================*
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 *				do_privctl				     *
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 *===========================================================================*/
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PUBLIC int do_privctl(m_ptr)
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message *m_ptr;			/* pointer to request message */
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{
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/* Handle sys_privctl(). Update a process' privileges. If the process is not
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 * yet a system process, make sure it gets its own privilege structure.
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 */
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  register struct proc *caller_ptr;
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  register struct proc *rp;
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  register struct priv *sp;
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  int proc_nr;
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  int priv_id;
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  int old_flags;
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  int i;
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  /* Check whether caller is allowed to make this call. Privileged proceses 
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   * can only update the privileges of processes that are inhibited from 
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   * running by the NO_PRIV flag. This flag is set when a privileged process
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   * forks. 
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   */
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  caller_ptr = proc_addr(m_ptr->m_source);
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  if (! (priv(caller_ptr)->s_flags & SYS_PROC)) return(EPERM); 
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  proc_nr = m_ptr->PR_PROC_NR;
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  if (! isokprocn(proc_nr)) return(EINVAL);
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  rp = proc_addr(proc_nr);
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  if (! (rp->p_rts_flags & NO_PRIV)) return(EPERM);
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  /* Make sure this process has its own privileges structure. This may fail, 
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   * since there are only a limited number of system processes. Then copy the
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   * privileges from the caller and restore some defaults.
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   */
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  if ((i=get_priv(rp, SYS_PROC)) != OK) return(i);
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  priv_id = priv(rp)->s_id;			/* backup privilege id */
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  *priv(rp) = *priv(caller_ptr);		/* copy from caller */
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  priv(rp)->s_id = priv_id;			/* restore privilege id */
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  priv(rp)->s_proc_nr = proc_nr;		/* reassociate process nr */
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  for (i=0; i< BITMAP_CHUNKS(NR_SYS_PROCS); i++)	/* remove pending: */
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      priv(rp)->s_notify_pending.chunk[i] = 0;		/* - notifications */
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  priv(rp)->s_int_pending = 0;				/* - interrupts */
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  sigemptyset(&priv(rp)->s_sig_pending);		/* - signals */
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  /* Now update the process' privileges as requested. */
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  rp->p_priv->s_trap_mask = FILLED_MASK;
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  for (i=0; i<BITMAP_CHUNKS(NR_SYS_PROCS); i++) {
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	rp->p_priv->s_ipc_to.chunk[i] = FILLED_MASK;
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  }
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  unset_sys_bit(rp->p_priv->s_ipc_to, USER_PRIV_ID);
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  /* All process that this process can send to must be able to reply. 
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   * Therefore, their send masks should be updated as well. 
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   */
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  for (i=0; i<NR_SYS_PROCS; i++) {
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      if (get_sys_bit(rp->p_priv->s_ipc_to, i)) {
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          set_sys_bit(priv_addr(i)->s_ipc_to, priv_id(rp));
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      }
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  }
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  /* Done. Privileges have been set. Allow process to run again. */
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  old_flags = rp->p_rts_flags;		/* save value of the flags */
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  rp->p_rts_flags &= ~NO_PRIV; 		
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  if (old_flags != 0 && rp->p_rts_flags == 0) lock_ready(rp);
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  return(OK);
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}
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#endif /* USE_PRIVCTL */
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