winsup/cygserver/sem.cc

   1 /* sem.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_sem.h"
  27
  28 client_request_sem::client_request_sem ()
  29   : client_request (CYGSERVER_REQUEST_SEM,
  30                     &_parameters, sizeof (_parameters))
  31 {
  32 }
  33
  34 void
  35 client_request_sem::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_semaphores == TUN_FALSE)
  47     {
  48       syscall_printf ("Semaphore support not started");
  49       error_code (ENOSYS);
  50       _parameters.out.ret = -1;
  51       msglen (sizeof (_parameters.out));
  52       return;
  53     }
  54   process *const client = cache->process (_parameters.in.ipcblk.cygpid,
  55                                           _parameters.in.ipcblk.winpid,
  56                                           _parameters.in.ipcblk.signal_arrived);
  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_sem.cc takes care of itself. */
  81   client->release ();
  82   thread td = { client, &_parameters.in.ipcblk, {-1, -1} };
  83   int res;
  84   switch (_parameters.in.semop)
  85     {
  86       case SEMOP_semctl:
  87         res = semctl (&td, &_parameters.in.ctlargs);
  88         break;
  89       case SEMOP_semget:
  90         res = semget (&td, &_parameters.in.getargs);
  91         break;
  92       case SEMOP_semop:
  93         res = semop (&td, &_parameters.in.opargs);
  94         break;
  95       default:
  96         res = ENOSYS;
  97         td.td_retval[0] = -1;
  98         break;
  99     }
 100   /* Allocated by the call to adjust_identity_info(). */
 101   if (_parameters.in.ipcblk.gidlist)
 102     free (_parameters.in.ipcblk.gidlist);
 103   error_code (res);
 104   _parameters.out.ret = td.td_retval[0];
 105   msglen (sizeof (_parameters.out));
 106 }
 107 #endif /* __OUTSIDE_CYGWIN__ */