1  /* Copyright (C) 1991-2023 Free Software Foundation, Inc.
       2     This file is part of the GNU C Library.
       3  
       4     The GNU C Library is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the License, or (at your option) any later version.
       8  
       9     The GNU C Library is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <errno.h>
      19  #include <sys/types.h>
      20  #include <signal.h>
      21  #include <hurd.h>
      22  #include <hurd/port.h>
      23  #include <hurd/signal.h>
      24  #include <hurd/msg.h>
      25  
      26  /* Send a `sig_post' RPC to process number PID.  If PID is zero,
      27     send the message to all processes in the current process's process group.
      28     If PID is < -1, send SIG to all processes in process group - PID.
      29     SIG and REFPORT are passed along in the request message.  */
      30  error_t
      31  _hurd_sig_post (pid_t pid, int sig, mach_port_t arg_refport)
      32  {
      33    int delivered = 0;		/* Set when we deliver any signal.  */
      34    error_t err;
      35    mach_port_t proc;
      36    struct hurd_userlink ulink;
      37  
      38    inline void kill_pid (pid_t pid) /* Kill one PID.  */
      39      {
      40        err = HURD_MSGPORT_RPC (__proc_getmsgport (proc, pid, &msgport),
      41  			      (refport = arg_refport, 0), 0,
      42  			      /* If no message port we cannot send signals.  */
      43  			      msgport == MACH_PORT_NULL ? EPERM
      44  			      : __msg_sig_post (msgport, sig, 0, refport));
      45        if (! err)
      46  	delivered = 1;
      47      }
      48  
      49    proc = _hurd_port_get (&_hurd_ports[INIT_PORT_PROC], &ulink);
      50  
      51    if (pid <= 0)
      52      {
      53        /* Send SIG to each process in pgrp (- PID).  */
      54        mach_msg_type_number_t npids = 10, i;
      55        pid_t pidsbuf[10], *pids = pidsbuf;
      56  
      57        err = __proc_getpgrppids (proc, - pid, &pids, &npids);
      58        if (!err)
      59  	{
      60  	  int self = 0;
      61  	  for (i = 0; i < npids; ++i)
      62  	    if (pids[i] == _hurd_pid)
      63  	      /* We must do ourselves last so we are not suspended
      64  		 and fail to suspend the other processes in the pgrp.  */
      65  	      self = 1;
      66  	    else
      67  	      {
      68  		kill_pid (pids[i]);
      69  		if (err == ESRCH)
      70  		  /* The process died already.  Ignore it.  */
      71  		  err = 0;
      72  	      }
      73  	  if (pids != pidsbuf)
      74  	    __vm_deallocate (__mach_task_self (),
      75  			     (vm_address_t) pids, npids * sizeof (pids[0]));
      76  
      77  	  if (self)
      78  	    kill_pid (_hurd_pid);
      79  	}
      80      }
      81    else
      82      kill_pid (pid);
      83  
      84    _hurd_port_free (&_hurd_ports[INIT_PORT_PROC], &ulink, proc);
      85  
      86    /* If we delivered no signals, but ERR is clear, this must mean that
      87       every kill_pid call failed with ESRCH, meaning all the processes in
      88       the pgrp died between proc_getpgrppids and kill_pid; in that case we
      89       fail with ESRCH.  */
      90    return delivered ? 0 : err ?: ESRCH;
      91  }
      92  weak_alias (_hurd_sig_post, hurd_sig_post)