revert of mass delete of the posix subsystem. perhaps there is hope for it yet.

[reactos.git] / posix / lib / psxdll / unistd / fork.c

diff --git a/posix/lib/psxdll/unistd/fork.c b/posix/lib/psxdll/unistd/fork.c
new file mode 100644 (file)
index 0000000..53674ac
--- /dev/null
+++ b/posix/lib/psxdll/unistd/fork.c
@@ -0,0 +1,250 @@
+/* $Id: fork.c,v 1.3 2002/10/29 04:45:46 rex Exp $
+ */
+/*
+ * COPYRIGHT:   See COPYING in the top level directory
+ * PROJECT:     ReactOS POSIX+ Subsystem
+ * FILE:        subsys/psx/lib/psxdll/unistd/fork.c
+ * PURPOSE:     create a new process
+ * PROGRAMMER:  KJK::Hyperion <noog@libero.it>
+ * UPDATE HISTORY:
+ *              14/05/2002: Created
+ */
+
+#include <ddk/ntddk.h>
+#include <napi/teb.h>
+#include <sys/types.h>
+#include <stddef.h>
+#include <unistd.h>
+#include <errno.h>
+#include <psx/debug.h>
+#include <psx/errno.h>
+
+#include <windows.h>
+
+typedef struct _PORT_MESSAGE {
+ USHORT DataSize;
+ USHORT MessageSize;
+ USHORT MessageType;
+ USHORT VirtualRangesOffset;
+ CLIENT_ID ClientId;
+ ULONG MessageId;
+ ULONG SectionSize;
+ /* UCHAR Data[]; */
+} PORT_MESSAGE, *PPORT_MESSAGE;
+
+struct CSRSS_MESSAGE {
+ ULONG Unknown1;
+ ULONG Opcode;
+ ULONG Status;
+ ULONG Unknown2;
+};
+
+NTSTATUS STDCALL CsrClientCallServer(
+ IN PVOID Message,
+ IN PVOID Unknown,
+ IN ULONG Opcode,
+ IN ULONG Size
+);
+
+pid_t fork(void)
+{
+ NTSTATUS nErrCode;
+ CONTEXT ctxThreadContext;
+ HANDLE hProcess;
+ HANDLE hThread;
+ INITIAL_TEB itInitialTeb;
+ CLIENT_ID ciClientId;
+ MEMORY_BASIC_INFORMATION mbiStackInfo;
+ THREAD_BASIC_INFORMATION tbiThreadInfo;
+
+ struct __tagcsrmsg{
+  PORT_MESSAGE PortMessage;
+  struct CSRSS_MESSAGE CsrssMessage;
+  PROCESS_INFORMATION ProcessInformation;
+  CLIENT_ID Debugger;
+  ULONG CreationFlags;
+  ULONG VdmInfo[2];
+ } csrmsg;
+
+ /* STEP 1: Duplicate current process */ 
+ nErrCode = NtCreateProcess
+ (
+  &hProcess,
+  PROCESS_ALL_ACCESS,
+  NULL,
+  NtCurrentProcess(),
+  TRUE,
+  0,
+  0,
+  0
+ );
+
+ /* failure */
+ if(!NT_SUCCESS(nErrCode))
+ {
+  ERR("NtCreateProcess() failed with status 0x%08X\n", nErrCode);
+  goto fail;
+ }
+
+ /* STEP 2: Duplicate current thread */
+ /* 2.1: duplicate registers */
+ ctxThreadContext.ContextFlags =
+  CONTEXT_FULL | CONTEXT_DEBUG_REGISTERS | CONTEXT_FLOATING_POINT;
+ 
+ /* get the current thread's registers */
+ nErrCode = NtGetContextThread(NtCurrentThread(), &ctxThreadContext);
+ 
+ /* failure */
+ if(!NT_SUCCESS(nErrCode))
+ {
+  ERR("NtGetContextThread() failed with status 0x%08X\n", nErrCode);
+  goto cleanup_and_fail;
+ }
+
+ /* redirect the child process to the child_branch label (see 4.3 below) */
+ ctxThreadContext.Eip = (ULONG)&&child_branch;
+ 
+ /* 2.2: duplicate stack */
+ /* get stack base and size */
+ nErrCode = NtQueryVirtualMemory
+ (
+  NtCurrentProcess(),
+  (PVOID)ctxThreadContext.Esp,
+  MemoryBasicInformation,
+  &mbiStackInfo,
+  sizeof(mbiStackInfo),
+  0
+ );
+ 
+ /* failure */
+ if(!NT_SUCCESS(nErrCode))
+ {
+  ERR("NtQueryVirtualMemory() failed with status 0x%08X\n", nErrCode);
+  goto cleanup_and_fail;
+ }
+ 
+ itInitialTeb.StackCommit = 0;
+ itInitialTeb.StackReserve = 0;
+ itInitialTeb.StackBase = (PVOID)((ULONG)(mbiStackInfo.BaseAddress) + mbiStackInfo.RegionSize);
+ itInitialTeb.StackLimit = mbiStackInfo.BaseAddress;
+ itInitialTeb.StackAllocate = mbiStackInfo.AllocationBase;
+ 
+ /* 2.3: create duplicate thread */
+ nErrCode = NtCreateThread
+ (
+  &hThread,
+  THREAD_ALL_ACCESS,
+  NULL,
+  hProcess,
+  (CLIENT_ID *)&ciClientId,
+  &ctxThreadContext,
+  &itInitialTeb,
+  TRUE
+ );
+ 
+ /* failure */
+ if(!NT_SUCCESS(nErrCode))
+ {
+  ERR("NtCreateThread() failed with status 0x%08X\n", nErrCode);
+  goto cleanup_and_fail;
+ }
+
+ /* 2.4: duplicate the TEB */
+ /* store the client id in the child thread's stack (see 4.3b) */
+ nErrCode = NtWriteVirtualMemory
+ (
+  hProcess,
+  &ciClientId,
+  &ciClientId,
+  sizeof(ciClientId),
+  0
+ );
+ 
+ /* failure */
+ if(!NT_SUCCESS(nErrCode))
+ {
+  ERR("NtWriteVirtualMemory() failed with status 0x%08X\n", nErrCode);
+  goto cleanup_and_fail;
+ }
+ 
+ /* get the child thread's TEB base */
+ nErrCode = NtQueryInformationThread
+ (
+  hThread,
+  ThreadBasicInformation,
+  &tbiThreadInfo,
+  sizeof(tbiThreadInfo),
+  0
+ );
+ 
+ /* failure */
+ if(!NT_SUCCESS(nErrCode))
+ {
+  ERR("NtQueryInformationThread() failed with status 0x%08X\n", nErrCode);
+  goto cleanup_and_fail;
+ }
+ 
+ /* copy the TEB */ 
+ nErrCode = NtWriteVirtualMemory
+ (
+  hProcess,
+  tbiThreadInfo.TebBaseAddress,
+  NtCurrentTeb(),
+  sizeof(TEB),
+  0
+ );
+ 
+ /* failure */
+ if(!NT_SUCCESS(nErrCode))
+ {
+  ERR("NtWriteVirtualMemory() failed with status 0x%08X\n", nErrCode);
+  goto cleanup_and_fail;
+ }
+ 
+ /* STEP 3: Call Win32 subsystem */
+ memset(&csrmsg, 0, sizeof(csrmsg));
+
+ csrmsg.ProcessInformation.hProcess = hProcess;
+ csrmsg.ProcessInformation.hThread = hThread;
+ csrmsg.ProcessInformation.dwProcessId = (DWORD)ciClientId.UniqueProcess;
+ csrmsg.ProcessInformation.dwThreadId = (DWORD)ciClientId.UniqueThread;
+
+ nErrCode = CsrClientCallServer(&csrmsg, 0, 0x10000, 0x24);
+
+ /* failure */
+ if(!NT_SUCCESS(nErrCode))
+ {
+  ERR("CsrClientCallServer() failed with status 0x%08X\n", nErrCode);
+  goto cleanup_and_fail;
+ }
+ 
+ /* STEP 4: Finalization */
+ /* 4.1: resume thread */
+ nErrCode = NtResumeThread(hThread, 0);
+ 
+ /* 4.2: close superfluous handles */
+ NtClose(hProcess);
+ NtClose(hThread);
+ 
+ /* 4.3: (parent) return the child process id */
+ return ((pid_t)(ciClientId.UniqueProcess));
+
+ /* 4.3b: (child) cleanup and return 0 */
+child_branch:
+ /* restore the thread and process id in the TEB */ 
+ memcpy(&NtCurrentTeb()->Cid, &ciClientId, sizeof(ciClientId));
+ 
+ /* return 0 */
+ return (0);
+
+cleanup_and_fail:
+ NtTerminateProcess(hProcess, nErrCode);
+
+fail:
+ errno = __status_to_errno(nErrCode);
+ return (-1);
+ 
+}
+
+/* EOF */
+