winsup/cygserver/shm.cc

   1 /* shm.cc: Single unix specification IPC interface for Cygwin.
   2
   3 This file is part of Cygwin.
   4
   5 This software is a copyrighted work licensed under the terms of the
   6 Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
   7 details. */
   8
   9 #ifdef __OUTSIDE_CYGWIN__
  10 #include "woutsup.h"
  11
  12 #include <errno.h>
  13 #include <pthread.h>
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <string.h>
  17 #include <time.h>
  18
  19 #include "cygserver.h"
  20 #include "process.h"
  21 #include "transport.h"
  22
  23 #include "cygserver_ipc.h"
  24 #include "cygserver_shm.h"
  25
  26 client_request_shm::client_request_shm ()
  27   : client_request (CYGSERVER_REQUEST_SHM,
  28                     &_parameters, sizeof (_parameters))
  29 {
  30 }
  31
  32 void
  33 client_request_shm::serve (transport_layer_base *const conn,
  34                            process_cache *const cache)
  35 {
  36   if (msglen () != sizeof (_parameters.in))
  37     {
  38       syscall_printf ("bad request body length: expecting %lu bytes, got %lu",
  39                       sizeof (_parameters), msglen ());
  40       error_code (EINVAL);
  41       msglen (0);
  42       return;
  43     }
  44   if (support_sharedmem == TUN_FALSE)
  45     {
  46       syscall_printf ("Shared memory support not started");
  47       error_code (ENOSYS);
  48       if (_parameters.in.shmop == SHMOP_shmat)
  49         _parameters.out.ptr = (vm_offset_t)0;
  50       else
  51         _parameters.out.ret = -1;
  52       msglen (sizeof (_parameters.out));
  53       return;
  54     }
  55   process *const client = cache->process (_parameters.in.ipcblk.cygpid,
  56                                           _parameters.in.ipcblk.winpid);
  57   if (!client)
  58     {
  59       error_code (EAGAIN);
  60       msglen (0);
  61       return;
  62     }
  63   if (!conn->impersonate_client ())
  64     {
  65       client->release ();
  66       error_code (EACCES);
  67       msglen (0);
  68       return;
  69     }
  70   if (!adjust_identity_info (&_parameters.in.ipcblk))
  71     {
  72       client->release ();
  73       conn->revert_to_self ();
  74       error_code (EACCES);
  75       msglen (0);
  76       return;
  77     }
  78   /* Early revert_to_self since IPC code runs in kernel mode. */
  79   conn->revert_to_self ();
  80   /* sysv_shm.cc takes care of itself. */
  81   client->release ();
  82   thread td (client, &_parameters.in.ipcblk, false);
  83   int res;
  84   shmop_t shmop = _parameters.in.shmop; /* Get's overwritten otherwise. */
  85   switch (shmop)
  86     {
  87       case SHMOP_shmat:
  88         ipc_p_vmspace (td.ipcblk);
  89         res = shmat (&td, &_parameters.in.atargs);
  90         break;
  91       case SHMOP_shmctl:
  92         res = shmctl (&td, &_parameters.in.ctlargs);
  93         break;
  94       case SHMOP_shmdt:
  95         ipc_p_vmspace (td.ipcblk);
  96         res = shmdt (&td, &_parameters.in.dtargs);
  97         break;
  98       case SHMOP_shmget:
  99         res = shmget (&td, &_parameters.in.getargs);
 100         break;
 101       case SHMOP_shmfork:
 102         res = cygwin_shmfork_myhook (&td, &_parameters.in.forkargs);
 103         break;
 104       default:
 105         res = ENOSYS;
 106         td.td_retval[0] = -1;
 107         break;
 108     }
 109   /* Allocated by the call to adjust_identity_info(). */
 110   if (_parameters.in.ipcblk.gidlist)
 111     free (_parameters.in.ipcblk.gidlist);
 112   error_code (res);
 113   if (shmop == SHMOP_shmat)
 114     _parameters.out.ptr = td.td_retval[0];
 115   else
 116     _parameters.out.ret = td.td_retval[0];
 117   if (shmop == SHMOP_shmget)
 118     _parameters.out.obj = td.td_retval[1];
 119   msglen (sizeof (_parameters.out));
 120 }
 121 #endif /* __OUTSIDE_CYGWIN__ */