winsup/cygserver/sem.cc

   1 /* sem.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_sem.h"
  25
  26 client_request_sem::client_request_sem ()
  27   : client_request (CYGSERVER_REQUEST_SEM,
  28                     &_parameters, sizeof (_parameters))
  29 {
  30 }
  31
  32 void
  33 client_request_sem::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_semaphores == TUN_FALSE)
  45     {
  46       syscall_printf ("Semaphore support not started");
  47       error_code (ENOSYS);
  48       _parameters.out.ret = -1;
  49       msglen (sizeof (_parameters.out));
  50       return;
  51     }
  52   process *const client = cache->process (_parameters.in.ipcblk.cygpid,
  53                                           _parameters.in.ipcblk.winpid);
  54   if (!client)
  55     {
  56       error_code (EAGAIN);
  57       msglen (0);
  58       return;
  59     }
  60   if (!conn->impersonate_client ())
  61     {
  62       client->release ();
  63       error_code (EACCES);
  64       msglen (0);
  65       return;
  66     }
  67   if (!adjust_identity_info (&_parameters.in.ipcblk))
  68     {
  69       client->release ();
  70       conn->revert_to_self ();
  71       error_code (EACCES);
  72       msglen (0);
  73       return;
  74     }
  75   /* Early revert_to_self since IPC code runs in kernel mode. */
  76   conn->revert_to_self ();
  77   /* sysv_sem.cc takes care of itself. */
  78   client->release ();
  79   thread td (client, &_parameters.in.ipcblk, true);
  80   int res;
  81   switch (_parameters.in.semop)
  82     {
  83       case SEMOP_semctl:
  84         res = semctl (&td, &_parameters.in.ctlargs);
  85         break;
  86       case SEMOP_semget:
  87         res = semget (&td, &_parameters.in.getargs);
  88         break;
  89       case SEMOP_semop:
  90         res = semop (&td, &_parameters.in.opargs);
  91         break;
  92       default:
  93         res = ENOSYS;
  94         td.td_retval[0] = -1;
  95         break;
  96     }
  97   /* Allocated by the call to adjust_identity_info(). */
  98   if (_parameters.in.ipcblk.gidlist)
  99     free (_parameters.in.ipcblk.gidlist);
 100   error_code (res);
 101   _parameters.out.ret = td.td_retval[0];
 102   msglen (sizeof (_parameters.out));
 103 }
 104 #endif /* __OUTSIDE_CYGWIN__ */