newlib/winsup/cygwin/shared.cc

305 lines
8.3 KiB
C++

/* shared.cc: shared data area support.
Copyright 1996, 1997, 1998, 1999, 2000, 2001 Red Hat, Inc.
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#include "winsup.h"
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <grp.h>
#include <pwd.h>
#include <errno.h>
#include "pinfo.h"
#include "security.h"
#include "fhandler.h"
#include "path.h"
#include "dtable.h"
#include "cygerrno.h"
#include "cygheap.h"
#include "heap.h"
#include "shared_info_magic.h"
#include "registry.h"
#include "cygwin_version.h"
shared_info NO_COPY *cygwin_shared = NULL;
mount_info NO_COPY *mount_table = NULL;
HANDLE cygwin_mount_h;
/* General purpose security attribute objects for global use. */
SECURITY_ATTRIBUTES NO_COPY sec_none;
SECURITY_ATTRIBUTES NO_COPY sec_none_nih;
SECURITY_ATTRIBUTES NO_COPY sec_all;
SECURITY_ATTRIBUTES NO_COPY sec_all_nih;
char * __stdcall
shared_name (const char *str, int num)
{
static NO_COPY char buf[MAX_PATH] = {0};
extern bool _cygwin_testing;
__small_sprintf (buf, "%s.%s.%d", cygwin_version.shared_id, str, num);
if (!_cygwin_testing)
strcat (buf, cygwin_version.dll_build_date);
return buf;
}
void * __stdcall
open_shared (const char *name, int n, HANDLE &shared_h, DWORD size, void *addr)
{
void *shared;
if (!shared_h)
{
char *mapname;
if (!name)
mapname = NULL;
else
{
mapname = shared_name (name, n);
shared_h = OpenFileMappingA (FILE_MAP_READ | FILE_MAP_WRITE,
TRUE, mapname);
}
if (!shared_h &&
!(shared_h = CreateFileMappingA (INVALID_HANDLE_VALUE,
&sec_all,
PAGE_READWRITE,
0,
size,
mapname)))
api_fatal ("CreateFileMappingA, %E. Terminating.");
}
shared = (shared_info *) MapViewOfFileEx (shared_h,
FILE_MAP_READ | FILE_MAP_WRITE,
0, 0, 0, addr);
if (!shared)
{
/* Probably win95, so try without specifying the address. */
shared = (shared_info *) MapViewOfFileEx (shared_h,
FILE_MAP_READ|FILE_MAP_WRITE,
0, 0, 0, 0);
}
if (!shared)
api_fatal ("MapViewOfFileEx '%s'(%p), %E. Terminating.", name, shared_h);
debug_printf ("name %s, shared %p (wanted %p), h %p", name, shared, addr, shared_h);
/* FIXME: I couldn't find anywhere in the documentation a note about
whether the memory is initialized to zero. The code assumes it does
and since this part seems to be working, we'll leave it as is. */
return shared;
}
void
shared_info::initialize ()
{
if (version)
{
if (version != SHARED_VERSION_MAGIC)
multiple_cygwin_problem ("shared", version, SHARED_VERSION);
else if (cb != SHARED_INFO_CB)
multiple_cygwin_problem ("shared size", cb, SHARED_INFO_CB);
return;
}
/* Initialize the queue of deleted files. */
delqueue.init ();
/* Initialize tty table. */
tty.init ();
version = SHARED_VERSION_MAGIC;
cb = sizeof (*this);
if (cb != SHARED_INFO_CB)
system_printf ("size of shared memory region changed from %u to %u",
SHARED_INFO_CB, cb);
}
void __stdcall
memory_init ()
{
/* Initialize general shared memory */
HANDLE shared_h = cygheap ? cygheap->shared_h : NULL;
cygwin_shared = (shared_info *) open_shared ("shared",
CYGWIN_VERSION_SHARED_DATA,
shared_h,
sizeof (*cygwin_shared),
cygwin_shared_address);
cygwin_shared->initialize ();
/* Allocate memory for the per-user mount table */
char user_name[UNLEN + 1];
DWORD user_name_len = UNLEN + 1;
if (!GetUserName (user_name, &user_name_len))
strcpy (user_name, "unknown");
/* Initialize the Cygwin heap, if necessary */
if (!cygheap)
{
cygheap_init ();
cygheap->user.set_name (user_name);
}
cygheap->shared_h = shared_h;
ProtectHandle (cygheap->shared_h);
heap_init ();
mount_table = (mount_info *) open_shared (user_name, MOUNT_VERSION,
cygwin_mount_h,
sizeof (mount_info), 0);
debug_printf ("opening mount table for '%s' at %p", cygheap->user.name (),
mount_table_address);
ProtectHandle (cygwin_mount_h);
debug_printf ("mount table version %x at %p", mount_table->version, mount_table);
/* Initialize the Cygwin per-user mount table, if necessary */
if (!mount_table->version)
{
mount_table->version = MOUNT_VERSION_MAGIC;
debug_printf ("initializing mount table");
mount_table->cb = sizeof (*mount_table);
if (mount_table->cb != MOUNT_INFO_CB)
system_printf ("size of mount table region changed from %u to %u",
MOUNT_INFO_CB, mount_table->cb);
mount_table->init (); /* Initialize the mount table. */
}
else if (mount_table->version != MOUNT_VERSION_MAGIC)
multiple_cygwin_problem ("mount", mount_table->version, MOUNT_VERSION);
else if (mount_table->cb != MOUNT_INFO_CB)
multiple_cygwin_problem ("mount table size", mount_table->cb, MOUNT_INFO_CB);
}
void __stdcall
shared_terminate ()
{
if (cygheap->shared_h)
ForceCloseHandle (cygheap->shared_h);
if (cygwin_mount_h)
ForceCloseHandle (cygwin_mount_h);
}
unsigned
shared_info::heap_chunk_size ()
{
if (!heap_chunk_in_mb)
{
/* Fetch misc. registry entries. */
reg_key reg (KEY_READ, NULL);
/* Note that reserving a huge amount of heap space does not result in
the use of swap since we are not committing it. */
/* FIXME: We should not be restricted to a fixed size heap no matter
what the fixed size is. */
heap_chunk_in_mb = reg.get_int ("heap_chunk_in_mb", 256);
if (heap_chunk_in_mb < 4)
{
heap_chunk_in_mb = 4;
reg.set_int ("heap_chunk_in_mb", heap_chunk_in_mb);
}
}
return heap_chunk_in_mb << 20;
}
/*
* Function to return a common SECURITY_DESCRIPTOR * that
* allows all access.
*/
static NO_COPY SECURITY_DESCRIPTOR *null_sdp = 0;
SECURITY_DESCRIPTOR *__stdcall
get_null_sd ()
{
static NO_COPY SECURITY_DESCRIPTOR sd;
if (null_sdp == 0)
{
InitializeSecurityDescriptor (&sd, SECURITY_DESCRIPTOR_REVISION);
SetSecurityDescriptorDacl (&sd, TRUE, 0, FALSE);
null_sdp = &sd;
}
return null_sdp;
}
BOOL
sec_acl (PACL acl, BOOL admins, PSID sid1, PSID sid2)
{
size_t acl_len = MAX_DACL_LEN(5);
if (!InitializeAcl (acl, acl_len, ACL_REVISION))
{
debug_printf ("InitializeAcl %E");
return FALSE;
}
if (sid2)
if (!AddAccessAllowedAce (acl, ACL_REVISION,
GENERIC_ALL, sid2))
debug_printf ("AddAccessAllowedAce(sid2) %E");
if (sid1)
if (!AddAccessAllowedAce (acl, ACL_REVISION,
GENERIC_ALL, sid1))
debug_printf ("AddAccessAllowedAce(sid1) %E", sid1);
if (admins)
if (!AddAccessAllowedAce (acl, ACL_REVISION,
GENERIC_ALL, well_known_admins_sid))
debug_printf ("AddAccessAllowedAce(admin) %E");
if (!AddAccessAllowedAce (acl, ACL_REVISION,
GENERIC_ALL, well_known_system_sid))
debug_printf ("AddAccessAllowedAce(system) %E");
#if 0 /* Does not seem to help */
if (!AddAccessAllowedAce (acl, ACL_REVISION,
GENERIC_ALL, well_known_creator_owner_sid))
debug_printf ("AddAccessAllowedAce(creator_owner) %E");
#endif
return TRUE;
}
PSECURITY_ATTRIBUTES __stdcall
__sec_user (PVOID sa_buf, PSID sid2, BOOL inherit)
{
PSECURITY_ATTRIBUTES psa = (PSECURITY_ATTRIBUTES) sa_buf;
PSECURITY_DESCRIPTOR psd = (PSECURITY_DESCRIPTOR)
((char *) sa_buf + sizeof (*psa));
PACL acl = (PACL) ((char *) sa_buf + sizeof (*psa) + sizeof (*psd));
cygsid sid;
if (!(sid = cygheap->user.orig_sid ()) ||
(!sec_acl (acl, TRUE, sid, sid2)))
return inherit ? &sec_none : &sec_none_nih;
if (!InitializeSecurityDescriptor (psd, SECURITY_DESCRIPTOR_REVISION))
debug_printf ("InitializeSecurityDescriptor %E");
/*
* Setting the owner lets the created security attribute not work
* on NT4 SP3 Server. Don't know why, but the function still does
* what it should do also if the owner isn't set.
*/
#if 0
if (!SetSecurityDescriptorOwner (psd, sid, FALSE))
debug_printf ("SetSecurityDescriptorOwner %E");
#endif
if (!SetSecurityDescriptorDacl (psd, TRUE, acl, FALSE))
debug_printf ("SetSecurityDescriptorDacl %E");
psa->nLength = sizeof (SECURITY_ATTRIBUTES);
psa->lpSecurityDescriptor = psd;
psa->bInheritHandle = inherit;
return psa;
}