winsup/cygserver/shm.cc

   1 /* shm.cc: Single unix specification IPC interface for Cygwin.
   2
   3    Copyright 2003, 2004, 2012 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_shm.h"
  27
  28 client_request_shm::client_request_shm ()
  29   : client_request (CYGSERVER_REQUEST_SHM,
  30                     &_parameters, sizeof (_parameters))
  31 {
  32 }
  33
  34 void
  35 client_request_shm::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_sharedmem == TUN_FALSE)
  47     {
  48       syscall_printf ("Shared memory support not started");
  49       error_code (ENOSYS);
  50       if (_parameters.in.shmop == SHMOP_shmat)
  51         _parameters.out.ptr = (vm_offset_t)0;
  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_shm.cc takes care of itself. */
  84   client->release ();
  85   thread td = { client, &_parameters.in.ipcblk, {0, 0} };
  86   int res;
  87   shmop_t shmop = _parameters.in.shmop; /* Get's overwritten otherwise. */
  88   switch (shmop)
  89     {
  90       case SHMOP_shmat:
  91         ipc_p_vmspace (td.ipcblk);
  92         res = shmat (&td, &_parameters.in.atargs);
  93         break;
  94       case SHMOP_shmctl:
  95         res = shmctl (&td, &_parameters.in.ctlargs);
  96         break;
  97       case SHMOP_shmdt:
  98         ipc_p_vmspace (td.ipcblk);
  99         res = shmdt (&td, &_parameters.in.dtargs);
 100         break;
 101       case SHMOP_shmget:
 102         res = shmget (&td, &_parameters.in.getargs);
 103         break;
 104       case SHMOP_shmfork:
 105         res = cygwin_shmfork_myhook (&td, &_parameters.in.forkargs);
 106         break;
 107       default:
 108         res = ENOSYS;
 109         td.td_retval[0] = -1;
 110         break;
 111     }
 112   /* Allocated by the call to adjust_identity_info(). */
 113   if (_parameters.in.ipcblk.gidlist)
 114     free (_parameters.in.ipcblk.gidlist);
 115   error_code (res);
 116   if (shmop == SHMOP_shmat)
 117     _parameters.out.ptr = td.td_retval[0];
 118   else
 119     _parameters.out.ret = td.td_retval[0];
 120   if (shmop == SHMOP_shmget)
 121     _parameters.out.obj = td.td_retval[1];
 122   msglen (sizeof (_parameters.out));
 123 }
 124 #endif /* __OUTSIDE_CYGWIN__ */