newlib-cygwin/winsup/cygwin/shared.cc

364 lines
11 KiB
C++

/* shared.cc: shared data area support.
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 "miscfuncs.h"
#include <unistd.h>
#include "cygerrno.h"
#include "pinfo.h"
#include "path.h"
#include "fhandler.h"
#include "dtable.h"
#include "cygheap.h"
#include "heap.h"
#include "shared_info_magic.h"
#include "registry.h"
#include "cygwin_version.h"
#include "spinlock.h"
#include <alloca.h>
#include <wchar.h>
shared_info NO_COPY *cygwin_shared;
user_info NO_COPY *user_shared;
HANDLE NO_COPY cygwin_shared_h;
HANDLE NO_COPY cygwin_user_h;
/* This function returns a handle to the top-level directory in the global
NT namespace used to implement global objects including shared memory. */
static HANDLE NO_COPY shared_parent_dir;
HANDLE
get_shared_parent_dir ()
{
UNICODE_STRING uname;
OBJECT_ATTRIBUTES attr;
NTSTATUS status;
if (!shared_parent_dir)
{
WCHAR bnoname[MAX_PATH];
__small_swprintf (bnoname, L"\\BaseNamedObjects\\%s%s-%S",
cygwin_version.shared_id,
_cygwin_testing ? cygwin_version.dll_build_date : "",
&cygheap->installation_key);
RtlInitUnicodeString (&uname, bnoname);
InitializeObjectAttributes (&attr, &uname, OBJ_OPENIF, NULL,
everyone_sd (CYG_SHARED_DIR_ACCESS));
status = NtCreateDirectoryObject (&shared_parent_dir,
CYG_SHARED_DIR_ACCESS, &attr);
if (!NT_SUCCESS (status))
api_fatal ("NtCreateDirectoryObject(%S): %y", &uname, status);
}
return shared_parent_dir;
}
static HANDLE NO_COPY session_parent_dir;
HANDLE
get_session_parent_dir ()
{
UNICODE_STRING uname;
OBJECT_ATTRIBUTES attr;
NTSTATUS status;
if (!session_parent_dir)
{
PROCESS_SESSION_INFORMATION psi;
status = NtQueryInformationProcess (NtCurrentProcess (),
ProcessSessionInformation,
&psi, sizeof psi, NULL);
if (!NT_SUCCESS (status) || psi.SessionId == 0)
session_parent_dir = get_shared_parent_dir ();
else
{
WCHAR bnoname[MAX_PATH];
__small_swprintf (bnoname,
L"\\Sessions\\BNOLINKS\\%d\\%s%s-%S",
psi.SessionId, cygwin_version.shared_id,
_cygwin_testing ? cygwin_version.dll_build_date : "",
&cygheap->installation_key);
RtlInitUnicodeString (&uname, bnoname);
InitializeObjectAttributes (&attr, &uname, OBJ_OPENIF, NULL,
everyone_sd(CYG_SHARED_DIR_ACCESS));
status = NtCreateDirectoryObject (&session_parent_dir,
CYG_SHARED_DIR_ACCESS, &attr);
if (!NT_SUCCESS (status))
api_fatal ("NtCreateDirectoryObject(%S): %y", &uname, status);
}
}
return session_parent_dir;
}
char * __stdcall
shared_name (char *ret_buf, const char *str, int num)
{
__small_sprintf (ret_buf, "%s.%d", str, num);
return ret_buf;
}
WCHAR * __stdcall
shared_name (WCHAR *ret_buf, const WCHAR *str, int num)
{
__small_swprintf (ret_buf, L"%W.%d", str, num);
return ret_buf;
}
#define page_const ((ptrdiff_t) 65535)
#define pround(n) ((ptrdiff_t)(((n) + page_const) & ~page_const))
/* The order in offsets is so that the constant blocks shared_info
and user_info are right below the cygwin DLL, then the pinfo block
which changes with each process. Below that is the console_state,
an optional block which only exists when running in a Windows console
window. Therefore, if we are not running in a console, we have 64K
more of contiguous memory below the Cygwin DLL. */
static ptrdiff_t offsets[] =
{
- pround (sizeof (shared_info)), /* SH_CYGWIN_SHARED */
- pround (sizeof (shared_info)) /* SH_USER_SHARED */
- pround (sizeof (user_info)),
- pround (sizeof (shared_info)) /* SH_MYSELF */
- pround (sizeof (user_info))
- pround (sizeof (_pinfo)),
- pround (sizeof (shared_info)) /* SH_SHARED_CONSOLE */
- pround (sizeof (user_info))
- pround (sizeof (_pinfo))
- pround (sizeof (fhandler_console::console_state)),
0
};
#define off_addr(x) ((void *)((caddr_t) cygwin_hmodule + offsets[x]))
void * __stdcall
open_shared (const WCHAR *name, int n, HANDLE& shared_h, DWORD size,
shared_locations m, PSECURITY_ATTRIBUTES psa, DWORD access)
{
return open_shared (name, n, shared_h, size, &m, psa, access);
}
void * __stdcall
open_shared (const WCHAR *name, int n, HANDLE& shared_h, DWORD size,
shared_locations *m, PSECURITY_ATTRIBUTES psa, DWORD access)
{
void *shared;
void *addr;
if (*m == SH_JUSTCREATE || *m == SH_JUSTOPEN)
addr = NULL;
else
{
addr = off_addr (*m);
VirtualFree (addr, 0, MEM_RELEASE);
}
WCHAR map_buf[MAX_PATH];
WCHAR *mapname = NULL;
if (shared_h)
*m = SH_JUSTOPEN;
else
{
if (name)
mapname = shared_name (map_buf, name, n);
if (*m == SH_JUSTOPEN)
shared_h = OpenFileMappingW (access, FALSE, mapname);
else
{
shared_h = CreateFileMappingW (INVALID_HANDLE_VALUE, psa,
PAGE_READWRITE, 0, size, mapname);
if (GetLastError () == ERROR_ALREADY_EXISTS)
*m = SH_JUSTOPEN;
}
if (shared_h)
/* ok! */;
else if (*m != SH_JUSTOPEN)
api_fatal ("CreateFileMapping %W, %E. Terminating.", mapname);
else
return NULL;
}
shared = (shared_info *) MapViewOfFileEx (shared_h, access, 0, 0, 0, addr);
if (!shared && addr)
{
shared = (shared_info *) MapViewOfFileEx (shared_h,
FILE_MAP_READ|FILE_MAP_WRITE,
0, 0, 0, NULL);
#ifdef DEBUGGING
system_printf ("relocating shared object %W(%d) from %p to %p", name, n, addr, shared);
#endif
offsets[0] = 0;
}
if (!shared)
api_fatal ("MapViewOfFileEx '%W'(%p), %E. Terminating.", mapname, shared_h);
if (*m == SH_CYGWIN_SHARED && offsets[0])
{
/* Reserve subsequent shared memory areas in non-relocated case only.
There's no good reason to reserve the console shmem, because it's
not yet known if we will allocate it at all. */
for (int i = SH_USER_SHARED; i < SH_SHARED_CONSOLE; i++)
{
DWORD size = offsets[i - 1] - offsets[i];
if (!VirtualAlloc (off_addr (i), size, MEM_RESERVE, PAGE_NOACCESS))
continue; /* oh well */
}
}
debug_printf ("name %W, n %d, shared %p (wanted %p), h %p, *m %d",
mapname, n, shared, addr, shared_h, *m);
return shared;
}
/* Second half of user shared initialization: Initialize content. */
void
user_info::initialize ()
{
/* Wait for initialization of the Cygwin per-user shared, if necessary */
spinlock sversion (version, CURR_USER_MAGIC);
if (!sversion)
{
cb = sizeof (*user_shared);
/* Initialize mount table from system fstab prior to calling
internal_getpwsid. This allows to convert pw_dir and pw_shell
paths given in DOS notation to valid POSIX paths. */
mountinfo.init (false);
cygpsid sid (cygheap->user.sid ());
struct passwd *pw = internal_getpwsid (sid);
/* Correct the user name with what's defined in /etc/passwd before
loading the user fstab file. */
if (pw)
cygheap->user.set_name (pw->pw_name);
/* After fetching the user infos, add mount entries from user's fstab. */
mountinfo.init (true);
}
else if (sversion != CURR_USER_MAGIC)
sversion.multiple_cygwin_problem ("user shared memory version", version,
sversion);
else if (user_shared->cb != sizeof (*user_shared))
sversion.multiple_cygwin_problem ("user shared memory size", cb,
sizeof (*user_shared));
}
/* First half of user shared initialization: Create shared mem region. */
void
user_info::create (bool reinit)
{
WCHAR name[UNLEN + 1] = L""; /* Large enough for SID */
if (reinit)
{
if (!UnmapViewOfFile (user_shared))
debug_printf("UnmapViewOfFile %E");
if (!ForceCloseHandle (cygwin_user_h))
debug_printf("CloseHandle %E");
cygwin_user_h = NULL;
}
if (!cygwin_user_h)
cygheap->user.get_windows_id (name);
user_shared = (user_info *) open_shared (name, USER_VERSION,
cygwin_user_h, sizeof (user_info),
SH_USER_SHARED, &sec_none);
debug_printf ("opening user shared for '%W' at %p", name, user_shared);
ProtectHandleINH (cygwin_user_h);
debug_printf ("user shared version %x", user_shared->version);
if (reinit)
user_shared->initialize ();
}
void __stdcall
shared_destroy ()
{
ForceCloseHandle (cygwin_shared_h);
UnmapViewOfFile (cygwin_shared);
ForceCloseHandle (cygwin_user_h);
UnmapViewOfFile (user_shared);
}
/* Initialize obcaseinsensitive.*/
void
shared_info::init_obcaseinsensitive ()
{
/* Instead of reading the obcaseinsensitive registry value, test the
actual state of case sensitivity handling in the kernel. */
UNICODE_STRING sysroot;
OBJECT_ATTRIBUTES attr;
HANDLE h;
RtlInitUnicodeString (&sysroot, L"\\SYSTEMROOT");
InitializeObjectAttributes (&attr, &sysroot, 0, NULL, NULL);
/* NtOpenSymbolicLinkObject returns STATUS_ACCESS_DENIED when called
with a 0 access mask. However, if the kernel is case sensitive,
it returns STATUS_OBJECT_NAME_NOT_FOUND because we used the incorrect
case for the filename (It's actually "\\SystemRoot"). */
obcaseinsensitive = NtOpenSymbolicLinkObject (&h, 0, &attr)
!= STATUS_OBJECT_NAME_NOT_FOUND;
}
void inline
shared_info::create ()
{
cygwin_shared = (shared_info *) open_shared (L"shared",
CYGWIN_VERSION_SHARED_DATA,
cygwin_shared_h,
sizeof (*cygwin_shared),
SH_CYGWIN_SHARED,
&sec_all_nih);
cygwin_shared->initialize ();
}
void
shared_info::initialize ()
{
spinlock sversion (version, CURR_SHARED_MAGIC);
if (!sversion)
{
LUID luid;
cb = sizeof (*this);
get_session_parent_dir (); /* Create session dir if first process. */
init_obcaseinsensitive (); /* Initialize obcaseinsensitive */
tty.init (); /* Initialize tty table */
mt.initialize (); /* Initialize shared tape information */
loadavg.initialize (); /* Initialize loadavg information */
NtAllocateLocallyUniqueId (&luid);/* Initialize pid_src to a low */
InterlockedExchange (&pid_src, /* random value to make start pid */
luid.LowPart % 2048);/* less predictably */
forkable_hardlink_support = 0; /* 0: Unknown, 1: Yes, -1: No */
/* Defer debug output printing the installation root and installation key
up to this point. Debug output except for system_printf requires
the global shared memory to exist. */
debug_printf ("Installation root: <%W> key: <%S>",
cygheap->installation_root, &cygheap->installation_key);
}
else if (sversion != CURR_SHARED_MAGIC)
sversion.multiple_cygwin_problem ("system shared memory version",
sversion, CURR_SHARED_MAGIC);
else if (cb != sizeof (*this))
system_printf ("size of shared memory region changed from %lu to %u",
sizeof (*this), cb);
/* FIXME? Shouldn't this be in memory_init? */
cygheap->user_heap.init ();
}
void
memory_init ()
{
shared_info::create (); /* Initialize global shared memory */
user_info::create (false); /* Initialize per-user shared memory */
/* Initialize tty list session stuff. Doesn't really belong here but
this needs to be initialized before any tty or console manipulation
happens and it is a common location. */
tty_list::init_session ();
}