1 /* Copyright (C) 1991-2022 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
_hurd_sig_post(pid_t pid,int sig,mach_port_t arg_refport)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)
93