winsup/cygserver/msg.cc

   1 /* msg.cc: Single unix specification IPC interface for Cygwin.
   2
   3    Copyright 2003, 2004 Red Hat, Inc.
   4
   5 This file is part of Cygwin.
   6
   7 This software is a copyrighted work licensed under the terms of the
   8 Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
   9 details. */
  10
  11 #ifdef __OUTSIDE_CYGWIN__
  12 #include "woutsup.h"
  13
  14 #include <errno.h>
  15 #include <pthread.h>
  16 #include <stdio.h>
  17 #include <stdlib.h>
  18 #include <string.h>
  19 #include <time.h>
  20
  21 #include "cygserver.h"
  22 #include "process.h"
  23 #include "transport.h"
  24
  25 #include "cygserver_ipc.h"
  26 #include "cygserver_msg.h"
  27
  28 client_request_msg::client_request_msg ()
  29   : client_request (CYGSERVER_REQUEST_MSG,
  30                     &_parameters, sizeof (_parameters))
  31 {
  32 }
  33
  34 void
  35 client_request_msg::serve (transport_layer_base *const conn,
  36                            process_cache *const cache)
  37 {
  38   if (msglen () != sizeof (_parameters.in))
  39     {
  40       syscall_printf ("bad request body length: expecting %lu bytes, got %lu",
  41                       sizeof (_parameters), msglen ());
  42       error_code (EINVAL);
  43       msglen (0);
  44       return;
  45     }
  46   if (support_msgqueues == TUN_FALSE)
  47     {
  48       syscall_printf ("Message queue support not started");
  49       error_code (ENOSYS);
  50       if (_parameters.in.msgop == MSGOP_msgrcv)
  51         _parameters.out.rcv = -1;
  52       else
  53         _parameters.out.ret = -1;
  54       msglen (sizeof (_parameters.out));
  55       return;
  56     }
  57   process *const client = cache->process (_parameters.in.ipcblk.cygpid,
  58                                           _parameters.in.ipcblk.winpid,
  59                                           _parameters.in.ipcblk.signal_arrived);
  60   if (!client)
  61     {
  62       error_code (EAGAIN);
  63       msglen (0);
  64       return;
  65     }
  66   if (!conn->impersonate_client ())
  67     {
  68       client->release ();
  69       error_code (EACCES);
  70       msglen (0);
  71       return;
  72     }
  73   if (!adjust_identity_info (&_parameters.in.ipcblk))
  74     {
  75       client->release ();
  76       conn->revert_to_self ();
  77       error_code (EACCES);
  78       msglen (0);
  79       return;
  80     }
  81   /* Early revert_to_self since IPC code runs in kernel mode. */
  82   conn->revert_to_self ();
  83   /* sysv_msg.cc takes care of itself. */
  84   client->release ();
  85   thread td = { client, &_parameters.in.ipcblk, {-1, -1} };
  86   int res;
  87   msgop_t msgop = _parameters.in.msgop; /* Get's overwritten otherwise. */
  88   switch (msgop)
  89     {
  90       case MSGOP_msgctl:
  91         res = msgctl (&td, &_parameters.in.ctlargs);
  92         break;
  93       case MSGOP_msgget:
  94         res = msgget (&td, &_parameters.in.getargs);
  95         break;
  96       case MSGOP_msgrcv:
  97         res = msgrcv (&td, &_parameters.in.rcvargs);
  98         break;
  99       case MSGOP_msgsnd:
 100         res = msgsnd (&td, &_parameters.in.sndargs);
 101         break;
 102       default:
 103         res = ENOSYS;
 104         td.td_retval[0] = -1;
 105         break;
 106     }
 107   /* Allocated by the call to adjust_identity_info(). */
 108   if (_parameters.in.ipcblk.gidlist)
 109     free (_parameters.in.ipcblk.gidlist);
 110   error_code (res);
 111   if (msgop == MSGOP_msgrcv)
 112     _parameters.out.rcv = td.td_retval[0];
 113   else
 114     _parameters.out.ret = td.td_retval[0];
 115   msglen (sizeof (_parameters.out));
 116 }
 117 #endif /* __OUTSIDE_CYGWIN__ */