newlib-cygwin/winsup/cygwin/shared.cc

291 lines
7.7 KiB
C++

/* shared.cc: shared data area support.
Copyright 1996, 1997, 1998, 1999, 2000 Cygnus Solutions.
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 <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <grp.h>
#include <pwd.h>
#include "winsup.h"
#define SHAREDVER (unsigned)(cygwin_version.api_major << 16 | \
cygwin_version.api_minor)
shared_info NO_COPY *cygwin_shared = NULL;
/* The handle of the shared data area. */
HANDLE cygwin_shared_h = NULL;
/* 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};
char envbuf[6];
__small_sprintf (buf, "%s.%s.%d", cygwin_version.shared_id, str, num);
if (GetEnvironmentVariable("CYGWIN_TESTING", envbuf, 5))
strcat(buf, cygwin_version.dll_build_date);
return buf;
}
/* Open the shared memory map. */
static void __stdcall
open_shared_file_map ()
{
cygwin_shared = (shared_info *) open_shared ("shared",
cygwin_shared_h,
sizeof (*cygwin_shared),
(void *)0xa000000);
ProtectHandle (cygwin_shared);
}
void * __stdcall
open_shared (const char *name, HANDLE &shared_h, DWORD size, void *addr)
{
void *shared;
if (!shared_h)
{
char *mapname;
if (!name)
mapname = NULL;
else
{
mapname = shared_name (name, 0);
shared_h = OpenFileMappingA (FILE_MAP_READ | FILE_MAP_WRITE,
TRUE, mapname);
}
if (!shared_h &&
!(shared_h = CreateFileMappingA ((HANDLE) 0xffffffff,
&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, %E. Terminating.");
debug_printf ("name %s, shared %p, h %p", name, shared, 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 ()
{
/* Ya, Win32 provides a way for a dll to watch when it's first loaded.
We may eventually want to use it but for now we have this. */
if (inited)
{
if (inited != SHAREDVER)
api_fatal ("Shared region version mismatch. Version %x != %x.\n"
"Are you using multiple versions of cygwin1.dll?\n"
"Run 'cygcheck -r -s -v' to find out.",
inited, SHAREDVER);
return;
}
/* Initialize the mount table. */
mount.init ();
/* Initialize the process table. */
p.init ();
/* Initialize the queue of deleted files. */
delqueue.init ();
/* Initialize tty table. */
tty.init ();
/* Fetch misc. registry entries. */
reg_key reg (KEY_READ, NULL);
/* Note that reserving a huge amount of heap space does not result in
swapping 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", 128);
if (heap_chunk_in_mb < 4)
{
heap_chunk_in_mb = 4;
reg.set_int ("heap_chunk_in_mb", heap_chunk_in_mb);
}
inited = SHAREDVER;
}
void __stdcall
shared_init ()
{
open_shared_file_map ();
cygwin_shared->initialize ();
}
void __stdcall
shared_terminate ()
{
if (cygwin_shared_h)
ForceCloseHandle (cygwin_shared_h);
}
unsigned
shared_info::heap_chunk_size ()
{
return heap_chunk_in_mb << 20;
}
/* For apps that wish to access the shared data. */
shared_info *
cygwin_getshared ()
{
return cygwin_shared;
}
/*
* 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;
}
extern PSID get_admin_sid ();
extern PSID get_system_sid ();
extern PSID get_creator_owner_sid ();
PSECURITY_ATTRIBUTES __stdcall
sec_user (PVOID sa_buf, PSID sid2, BOOL inherit)
{
if (! sa_buf)
return inherit ? &sec_none_nih : &sec_none;
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));
char sid_buf[MAX_SID_LEN];
PSID sid = (PSID) sid_buf;
if (myself->psid)
CopySid (MAX_SID_LEN, sid, myself->psid);
else if (! lookup_name (getlogin (), myself->logsrv, sid))
return inherit ? &sec_none_nih : &sec_none;
size_t acl_len = sizeof (ACL)
+ 4 * (sizeof (ACCESS_ALLOWED_ACE) - sizeof (DWORD))
+ GetLengthSid (sid)
+ GetLengthSid (get_admin_sid ())
+ GetLengthSid (get_system_sid ())
+ GetLengthSid (get_creator_owner_sid ());
if (sid2)
acl_len += sizeof (ACCESS_ALLOWED_ACE) - sizeof (DWORD)
+ GetLengthSid (sid2);
if (! InitializeAcl (acl, acl_len, ACL_REVISION))
debug_printf("InitializeAcl %E");
if (! AddAccessAllowedAce (acl, ACL_REVISION,
SPECIFIC_RIGHTS_ALL | STANDARD_RIGHTS_ALL,
sid))
debug_printf("AddAccessAllowedAce(%s) %E", getlogin());
if (! AddAccessAllowedAce (acl, ACL_REVISION,
SPECIFIC_RIGHTS_ALL | STANDARD_RIGHTS_ALL,
get_admin_sid ()))
debug_printf("AddAccessAllowedAce(admin) %E");
if (! AddAccessAllowedAce (acl, ACL_REVISION,
SPECIFIC_RIGHTS_ALL | STANDARD_RIGHTS_ALL,
get_system_sid ()))
debug_printf("AddAccessAllowedAce(system) %E");
if (! AddAccessAllowedAce (acl, ACL_REVISION,
SPECIFIC_RIGHTS_ALL | STANDARD_RIGHTS_ALL,
get_creator_owner_sid ()))
debug_printf("AddAccessAllowedAce(creator_owner) %E");
if (sid2)
if (! AddAccessAllowedAce (acl, ACL_REVISION,
SPECIFIC_RIGHTS_ALL | STANDARD_RIGHTS_ALL,
sid2))
debug_printf("AddAccessAllowedAce(sid2) %E");
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;
}
SECURITY_ATTRIBUTES *__stdcall
sec_user_nih (PVOID sa_buf, PSID sid2)
{
return sec_user (sa_buf, sid2, FALSE);
}