os_win32.c

FastCGI,语言无关的、可伸缩架构的CGI开放扩展

/*
 * os_win32.c --
 *
 *
 *  Copyright (c) 1995 Open Market, Inc.
 *  All rights reserved.
 *
 *  This file contains proprietary and confidential information and
 *  remains the unpublished property of Open Market, Inc. Use,
 *  disclosure, or reproduction is prohibited except as permitted by
 *  express written license agreement with Open Market, Inc.
 *
 *  Bill Snapper
 *  [e-mail]
 *
 * (Special thanks to Karen and Bill.  They made my job much easier and
 *  significantly more enjoyable.)
 */
#ifndef lint
static const char rcsid[] = "$Id: os_win32.c,v 1.33 2002/03/05 18:15:15 robs Exp $";
#endif /* not lint */

#define WIN32_LEAN_AND_MEAN 
#include <windows.h>
#include <winsock2.h>
#include <stdlib.h>
#include <assert.h>
#include <stdio.h>
#include <sys/timeb.h>
#include <process.h>

#define DLLAPI  __declspec(dllexport)

#include "fcgimisc.h"
#include "fcgios.h"

#define WIN32_OPEN_MAX 128 /* XXX: Small hack */

/*
 * millisecs to wait for a client connection before checking the 
 * shutdown flag (then go back to waiting for a connection, etc).
 */
#define ACCEPT_TIMEOUT 1000

#define MUTEX_VARNAME "_FCGI_MUTEX_"
#define SHUTDOWN_EVENT_NAME "_FCGI_SHUTDOWN_EVENT_"
#define LOCALHOST "localhost"

static HANDLE hIoCompPort = INVALID_HANDLE_VALUE;
static HANDLE hStdinCompPort = INVALID_HANDLE_VALUE;
static HANDLE hStdinThread = INVALID_HANDLE_VALUE;

static HANDLE stdioHandles[3] = {INVALID_HANDLE_VALUE, INVALID_HANDLE_VALUE,
				 INVALID_HANDLE_VALUE};

// This is a nail for listening to more than one port..
static HANDLE acceptMutex = INVALID_HANDLE_VALUE;

static BOOLEAN shutdownPending = FALSE;
static BOOLEAN shutdownNow = FALSE;

/*
 * An enumeration of the file types
 * supported by the FD_TABLE structure.
 *
 * XXX: Not all currently supported.  This allows for future
 *      functionality.
 */
typedef enum {
    FD_UNUSED,
    FD_FILE_SYNC,
    FD_FILE_ASYNC,
    FD_SOCKET_SYNC,
    FD_SOCKET_ASYNC,
    FD_PIPE_SYNC,
    FD_PIPE_ASYNC
} FILE_TYPE;

typedef union {
    HANDLE fileHandle;
    SOCKET sock;
    unsigned int value;
} DESCRIPTOR;

/*
 * Structure used to map file handle and socket handle
 * values into values that can be used to create unix-like
 * select bitmaps, read/write for both sockets/files.
 */
struct FD_TABLE {
    DESCRIPTOR fid;
    FILE_TYPE type;
    char *path;
    DWORD Errno;
    unsigned long instance;
    int status;
    int offset;			/* only valid for async file writes */
    LPDWORD offsetHighPtr;	/* pointers to offset high and low words */
    LPDWORD offsetLowPtr;	/* only valid for async file writes (logs) */
    HANDLE  hMapMutex;		/* mutex handle for multi-proc offset update */
    LPVOID  ovList;		/* List of associated OVERLAPPED_REQUESTs */
};

/* 
 * XXX Note there is no dyanmic sizing of this table, so if the
 * number of open file descriptors exceeds WIN32_OPEN_MAX the 
 * app will blow up.
 */
static struct FD_TABLE fdTable[WIN32_OPEN_MAX];

static CRITICAL_SECTION  fdTableCritical;

struct OVERLAPPED_REQUEST {
    OVERLAPPED overlapped;
    unsigned long instance;	/* file instance (won't match after a close) */
    OS_AsyncProc procPtr;	/* callback routine */
    ClientData clientData;	/* callback argument */
    ClientData clientData1;	/* additional clientData */
};
typedef struct OVERLAPPED_REQUEST *POVERLAPPED_REQUEST;

static const char *bindPathPrefix = "\\\\.\\pipe\\FastCGI\\";

static FILE_TYPE listenType = FD_UNUSED;

// XXX This should be a DESCRIPTOR
static HANDLE hListen = INVALID_HANDLE_VALUE;

static BOOLEAN libInitialized = FALSE;

/*
 *--------------------------------------------------------------
 *
 * Win32NewDescriptor --
 *
 *	Set up for I/O descriptor masquerading.
 *
 * Results:
 *	Returns "fake id" which masquerades as a UNIX-style "small
 *	non-negative integer" file/socket descriptor.
 *	Win32_* routine below will "do the right thing" based on the
 *	descriptor's actual type. -1 indicates failure.
 *
 * Side effects:
 *	Entry in fdTable is reserved to represent the socket/file.
 *
 *--------------------------------------------------------------
 */
static int Win32NewDescriptor(FILE_TYPE type, int fd, int desiredFd)
{
    int index = -1;

    EnterCriticalSection(&fdTableCritical);

    /*
     * If desiredFd is set, try to get this entry (this is used for
     * mapping stdio handles).  Otherwise try to get the fd entry.
     * If this is not available, find a the first empty slot.  .
     */
    if (desiredFd >= 0 && desiredFd < WIN32_OPEN_MAX)
    {
        if (fdTable[desiredFd].type == FD_UNUSED) 
        {
            index = desiredFd;
        }
	}
    else if (fd > 0)
    {
        if (fd < WIN32_OPEN_MAX && fdTable[fd].type == FD_UNUSED)
        {
	        index = fd;
        }
        else 
        {
            int i;

            for (i = 1; i < WIN32_OPEN_MAX; ++i)
            {
	            if (fdTable[i].type == FD_UNUSED)
                {
                    index = i;
                    break;
                }
            }
        }
    }
    
    if (index != -1) 
    {
        fdTable[index].fid.value = fd;
        fdTable[index].type = type;
        fdTable[index].path = NULL;
        fdTable[index].Errno = NO_ERROR;
        fdTable[index].status = 0;
        fdTable[index].offset = -1;
        fdTable[index].offsetHighPtr = fdTable[index].offsetLowPtr = NULL;
        fdTable[index].hMapMutex = NULL;
        fdTable[index].ovList = NULL;
    }

    LeaveCriticalSection(&fdTableCritical);
    return index;
}

/*
 *--------------------------------------------------------------
 *
 * StdinThread--
 *
 *	This thread performs I/O on stadard input.  It is needed
 *      because you can't guarantee that all applications will
 *      create standard input with sufficient access to perform
 *      asynchronous I/O.  Since we don't want to block the app
 *      reading from stdin we make it look like it's using I/O
 *      completion ports to perform async I/O.
 *
 * Results:
 *	Data is read from stdin and posted to the io completion
 *      port.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */
static void StdinThread(void * startup) 
{
    int doIo = TRUE;
    unsigned long fd;
    unsigned long bytesRead;
    POVERLAPPED_REQUEST pOv;

    // Touch the arg to prevent warning
    startup = NULL;

    while(doIo) {
        /*
         * Block until a request to read from stdin comes in or a
         * request to terminate the thread arrives (fd = -1).
         */
        if (!GetQueuedCompletionStatus(hStdinCompPort, &bytesRead, &fd,
	    (LPOVERLAPPED *)&pOv, (DWORD)-1) && !pOv) {
            doIo = 0;
            break;
        }

	ASSERT((fd == STDIN_FILENO) || (fd == -1));
        if(fd == -1) {
            doIo = 0;
            break;
        }
        ASSERT(pOv->clientData1 != NULL);

        if(ReadFile(stdioHandles[STDIN_FILENO], pOv->clientData1, bytesRead,
                    &bytesRead, NULL)) {
            PostQueuedCompletionStatus(hIoCompPort, bytesRead,
                                       STDIN_FILENO, (LPOVERLAPPED)pOv);
        } else {
            doIo = 0;
            break;
        }
    }

    ExitThread(0);
}

void OS_ShutdownPending(void)
{
    shutdownPending = TRUE;
}

static void ShutdownRequestThread(void * arg)
{
    HANDLE shutdownEvent = (HANDLE) arg;
    
    WaitForSingleObject(shutdownEvent, INFINITE);

    shutdownPending = TRUE;

    if (listenType == FD_PIPE_SYNC)
    {
        // Its a hassle to get ConnectNamedPipe to return early,
        // so just wack the whole process - yes, this will toast
        // any requests in progress, but at least its a clean 
        // shutdown (its better than TerminateProcess())
        exit(0);
    }
       
    // FD_SOCKET_SYNC: When in Accept(), select() is used to poll
    // the shutdownPending flag - yeah this isn't pretty either
    // but its only one process doing it if an Accept mutex is used.
    // This at least buys no toasted requests.
}

/*
 *--------------------------------------------------------------
 *
 * OS_LibInit --
 *
 *	Set up the OS library for use.
 *
 * Results:
 *	Returns 0 if success, -1 if not.
 *
 * Side effects:
 *	Sockets initialized, pseudo file descriptors setup, etc.
 *
 *--------------------------------------------------------------
 */
int OS_LibInit(int stdioFds[3])
{
    WORD  wVersion;
    WSADATA wsaData;
    int err;
    int fakeFd;
    char *cLenPtr = NULL;
    char *val = NULL;
        
    if(libInitialized)
        return 0;

    InitializeCriticalSection(&fdTableCritical);   
        
    /*
     * Initialize windows sockets library.
     */
    wVersion = MAKEWORD(2,0);
    err = WSAStartup( wVersion, &wsaData );
    if (err) {
        fprintf(stderr, "Error starting Windows Sockets.  Error: %d",
		WSAGetLastError());
	exit(111);
    }

    /*
     * Create the I/O completion port to be used for our I/O queue.
     */
    if (hIoCompPort == INVALID_HANDLE_VALUE) {
	hIoCompPort = CreateIoCompletionPort (INVALID_HANDLE_VALUE, NULL,
					      0, 1);
	if(hIoCompPort == INVALID_HANDLE_VALUE) {
	    printf("<H2>OS_LibInit Failed CreateIoCompletionPort!  ERROR: %d</H2>\r\n\r\n",
	       GetLastError());
	    return -1;
	}
    }

    /*
     * If a shutdown event is in the env, save it (I don't see any to 
     * remove it from the environment out from under the application).
     * Spawn a thread to wait on the shutdown request.
     */
    val = getenv(SHUTDOWN_EVENT_NAME);
    if (val != NULL) 
    {
        HANDLE shutdownEvent = (HANDLE) atoi(val);

        if (_beginthread(ShutdownRequestThread, 0, shutdownEvent) == -1)
        {
            return -1;
        }
    }

    if (acceptMutex == INVALID_HANDLE_VALUE)
    {
        /* If an accept mutex is in the env, use it */
        val = getenv(MUTEX_VARNAME);
        if (val != NULL) 
        {
            acceptMutex = (HANDLE) atoi(val);
        }
    }

    /*
     * Determine if this library is being used to listen for FastCGI
     * connections.  This is communicated by STDIN containing a
     * valid handle to a listener object.  In this case, both the
     * "stdout" and "stderr" handles will be INVALID (ie. closed) by
     * the starting process.
     *
     * The trick is determining if this is a pipe or a socket...
     *
     * XXX: Add the async accept test to determine socket or handle to a
     *      pipe!!!
     */
    if((GetStdHandle(STD_OUTPUT_HANDLE) == INVALID_HANDLE_VALUE) &&
       (GetStdHandle(STD_ERROR_HANDLE)  == INVALID_HANDLE_VALUE) &&
       (GetStdHandle(STD_INPUT_HANDLE)  != INVALID_HANDLE_VALUE) ) 
    {
        DWORD pipeMode = PIPE_READMODE_BYTE | PIPE_WAIT;
        HANDLE oldStdIn = GetStdHandle(STD_INPUT_HANDLE);

        // Move the handle to a "low" number
        if (! DuplicateHandle(GetCurrentProcess(), oldStdIn,
                              GetCurrentProcess(), &hListen,
                              0, TRUE, DUPLICATE_SAME_ACCESS))
        {
            return -1;
        }

        if (! SetStdHandle(STD_INPUT_HANDLE, hListen))
        {
            return -1;
        }

        CloseHandle(oldStdIn);

	/*
	 * Set the pipe handle state so that it operates in wait mode.
	 *
	 * NOTE: The listenFd is not mapped to a pseudo file descriptor
	 *       as all work done on it is contained to the OS library.
	 *
	 * XXX: Initial assumption is that SetNamedPipeHandleState will
	 *      fail if this is an IP socket...
	 */
        if (SetNamedPipeHandleState(hListen, &pipeMode, NULL, NULL)) 
        {
            listenType = FD_PIPE_SYNC;
        } 
        else 
        {
            listenType = FD_SOCKET_SYNC;
        }
    }

    /*
     * If there are no stdioFds passed in, we're done.
     */
    if(stdioFds == NULL) {
        libInitialized = 1;
        return 0;
    }

    /*
     * Setup standard input asynchronous I/O.  There is actually a separate
     * thread spawned for this purpose.  The reason for this is that some
     * web servers use anonymous pipes for the connection between itself
     * and a CGI application.  Anonymous pipes can't perform asynchronous
     * I/O or use I/O completion ports.  Therefore in order to present a
     * consistent I/O dispatch model to an application we emulate I/O
     * completion port behavior by having the standard input thread posting
     * messages to the hIoCompPort which look like a complete overlapped
     * I/O structure.  This keeps the event dispatching simple from the
     * application perspective.
     */
    stdioHandles[STDIN_FILENO] = GetStdHandle(STD_INPUT_HANDLE);

    if(!SetHandleInformation(stdioHandles[STDIN_FILENO],
			     HANDLE_FLAG_INHERIT, 0)) {
/*
 * XXX: Causes error when run from command line.  Check KB
        err = GetLastError();
        DebugBreak();
	exit(99);
 */
    }

    if ((fakeFd = Win32NewDescriptor(FD_PIPE_SYNC,
				     (int)stdioHandles[STDIN_FILENO],
				     STDIN_FILENO)) == -1) {
        return -1;
    } else {
        /*
	 * Set stdin equal to our pseudo FD and create the I/O completion
	 * port to be used for async I/O.
	 */
	stdioFds[STDIN_FILENO] = fakeFd;
    }

    /*
     * Create the I/O completion port to be used for communicating with