winsup/cygwin/fhandler_mqueue.cc

   1 /* fhandler_mqueue.cc: fhandler for POSIX message queue
   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 #include "winsup.h"
  10 #include "shared_info.h"
  11 #include "path.h"
  12 #include "fhandler.h"
  13 #include "dtable.h"
  14
  15 fhandler_mqueue::fhandler_mqueue () :
  16   fhandler_base ()
  17 {
  18   nohandle (true);
  19   close_on_exec (true);
  20 }
  21
  22 struct mq_info *
  23 fhandler_mqueue::mqinfo (const char *name, int8_t *mptr, HANDLE sect,
  24                          size_t size, mode_t mode, int flags)
  25 {
  26   WCHAR buf[MAX_PATH];
  27   UNICODE_STRING uname;
  28   OBJECT_ATTRIBUTES attr;
  29   NTSTATUS status;
  30
  31   set_name (name);
  32   mqinfo ()->mqi_hdr = (struct mq_hdr *) mptr;
  33   mqinfo ()->mqi_sect = sect;
  34   mqinfo ()->mqi_sectsize = size;
  35   mqinfo ()->mqi_mode = mode;
  36   mqinfo ()->mqi_flags = flags;
  37
  38   __small_swprintf (buf, L"mqueue/mtx%s", name);
  39   RtlInitUnicodeString (&uname, buf);
  40   InitializeObjectAttributes (&attr, &uname, OBJ_OPENIF | OBJ_CASE_INSENSITIVE,
  41                               get_shared_parent_dir (),
  42                               everyone_sd (CYG_MUTANT_ACCESS));
  43   status = NtCreateMutant (&mqinfo ()->mqi_lock, CYG_MUTANT_ACCESS, &attr,
  44                            FALSE);
  45   if (!NT_SUCCESS (status))
  46     goto err;
  47
  48   wcsncpy (buf + 7, L"snd", 3);
  49   /* same length, no RtlInitUnicodeString required */
  50   InitializeObjectAttributes (&attr, &uname, OBJ_OPENIF | OBJ_CASE_INSENSITIVE,
  51                               get_shared_parent_dir (),
  52                               everyone_sd (CYG_EVENT_ACCESS));
  53   status = NtCreateEvent (&mqinfo ()->mqi_waitsend, CYG_EVENT_ACCESS, &attr,
  54                           NotificationEvent, FALSE);
  55   if (!NT_SUCCESS (status))
  56     goto err;
  57   wcsncpy (buf + 7, L"rcv", 3);
  58   /* same length, same attributes, no more init required */
  59   status = NtCreateEvent (&mqinfo ()->mqi_waitrecv, CYG_EVENT_ACCESS, &attr,
  60                           NotificationEvent, FALSE);
  61   if (!NT_SUCCESS (status))
  62     goto err;
  63
  64   mqinfo ()->mqi_magic = MQI_MAGIC;
  65   return mqinfo ();
  66
  67 err:
  68   if (mqinfo ()->mqi_waitsend)
  69     NtClose (mqinfo ()->mqi_waitsend);
  70   if (mqinfo ()->mqi_lock)
  71     NtClose (mqinfo ()->mqi_lock);
  72   __seterrno_from_nt_status (status);
  73   return NULL;
  74 }
  75
  76 char *
  77 fhandler_mqueue::get_proc_fd_name (char *buf)
  78 {
  79   return strcpy (buf, get_name ());
  80 }
  81
  82 int __reg2
  83 fhandler_mqueue::fstat (struct stat *buf)
  84 {
  85   int ret = fhandler_base::fstat (buf);
  86   if (!ret)
  87     {
  88       buf->st_mode = S_IFREG | mqinfo ()->mqi_mode;
  89       buf->st_dev = FH_MQUEUE;
  90       buf->st_ino = hash_path_name (0, get_name ());
  91     }
  92   return ret;
  93 }
  94
  95 int
  96 fhandler_mqueue::dup (fhandler_base *child, int flags)
  97 {
  98   /* FIXME */
  99   set_errno (EBADF);
 100   return -1;
 101 }
 102
 103 void
 104 fhandler_mqueue::fixup_after_fork (HANDLE parent)
 105 {
 106   __try
 107     {
 108       PVOID mptr = NULL;
 109       SIZE_T filesize = mqinfo ()->mqi_sectsize;
 110       NTSTATUS status;
 111
 112       DuplicateHandle (parent, mqinfo ()->mqi_sect,
 113                        GetCurrentProcess (), &mqinfo ()->mqi_sect,
 114                        0, FALSE, DUPLICATE_SAME_ACCESS);
 115       status = NtMapViewOfSection (mqinfo ()->mqi_sect, NtCurrentProcess (),
 116                                    &mptr, 0, filesize, NULL, &filesize,
 117                                    ViewShare, 0, PAGE_READWRITE);
 118       if (!NT_SUCCESS (status))
 119         api_fatal ("Mapping message queue failed in fork\n");
 120       else
 121         mqinfo ()->mqi_hdr = (struct mq_hdr *) mptr;
 122       DuplicateHandle (parent, mqinfo ()->mqi_waitsend,
 123                        GetCurrentProcess (), &mqinfo ()->mqi_waitsend,
 124                        0, FALSE, DUPLICATE_SAME_ACCESS);
 125       DuplicateHandle (parent, mqinfo ()->mqi_waitrecv,
 126                        GetCurrentProcess (), &mqinfo ()->mqi_waitrecv,
 127                        0, FALSE, DUPLICATE_SAME_ACCESS);
 128       DuplicateHandle (parent, mqinfo ()->mqi_lock,
 129                        GetCurrentProcess (), &mqinfo ()->mqi_lock,
 130                        0, FALSE, DUPLICATE_SAME_ACCESS);
 131     }
 132   __except (EFAULT) {}
 133   __endtry
 134 }
 135
 136 int
 137 fhandler_mqueue::close ()
 138 {
 139   int ret = -1;
 140
 141   __try
 142     {
 143       mqinfo ()->mqi_magic = 0;          /* just in case */
 144       NtUnmapViewOfSection (NtCurrentProcess (), mqinfo ()->mqi_hdr);
 145       NtClose (mqinfo ()->mqi_sect);
 146       NtClose (mqinfo ()->mqi_waitsend);
 147       NtClose (mqinfo ()->mqi_waitrecv);
 148       NtClose (mqinfo ()->mqi_lock);
 149       ret = 0;
 150     }
 151   __except (EFAULT) {}
 152   __endtry
 153   return ret;
 154 }