fcgiapp.c

FastCGI,语言无关的、可伸缩架构的CGI开放扩展

 *----------------------------------------------------------------------
 */
static int AlignInt8(unsigned n) {
    return (n + 7) & (UINT_MAX - 7);
}

/*
 *----------------------------------------------------------------------
 *
 * AlignPtr8 --
 *
 *      Returns the smallest pointer greater than or equal to p
 *      that's a multiple of 8.
 *
 *----------------------------------------------------------------------
 */
static unsigned char *AlignPtr8(unsigned char *p) {
    unsigned long u = (unsigned long) p;
    u = ((u + 7) & (ULONG_MAX - 7)) - u;
    return p + u;
}


/*
 * State associated with a stream
 */
typedef struct FCGX_Stream_Data {
    unsigned char *buff;      /* buffer after alignment */
    int bufflen;              /* number of bytes buff can store */
    unsigned char *mBuff;     /* buffer as returned by Malloc */
    unsigned char *buffStop;  /* reader: last valid byte + 1 of entire buffer.
                               * stop generally differs from buffStop for
                               * readers because of record structure.
                               * writer: buff + bufflen */
    int type;                 /* reader: FCGI_PARAMS or FCGI_STDIN
                               * writer: FCGI_STDOUT or FCGI_STDERR */
    int eorStop;              /* reader: stop stream at end-of-record */
    int skip;                 /* reader: don't deliver content bytes */
    int contentLen;           /* reader: bytes of unread content */
    int paddingLen;           /* reader: bytes of unread padding */
    int isAnythingWritten;    /* writer: data has been written to ipcFd */
    int rawWrite;             /* writer: write data without stream headers */
    FCGX_Request *reqDataPtr; /* request data not specific to one stream */
} FCGX_Stream_Data;

/*
 *----------------------------------------------------------------------
 *
 * WriteCloseRecords --
 *
 *      Writes an EOF record for the stream content if necessary.
 *      If this is the last writer to close, writes an FCGI_END_REQUEST
 *      record.
 *
 *----------------------------------------------------------------------
 */
static void WriteCloseRecords(struct FCGX_Stream *stream)
{
    FCGX_Stream_Data *data = (FCGX_Stream_Data *)stream->data;
    /*
     * Enter rawWrite mode so final records won't be encapsulated as
     * stream data.
     */
    data->rawWrite = TRUE;
    /*
     * Generate EOF for stream content if needed.
     */
    if(!(data->type == FCGI_STDERR
            && stream->wrNext == data->buff
            && !data->isAnythingWritten)) {
        FCGI_Header header;
        header = MakeHeader(data->type, data->reqDataPtr->requestId, 0, 0);
        FCGX_PutStr((char *) &header, sizeof(header), stream);
    };
    /*
     * Generate FCGI_END_REQUEST record if needed.
     */
    if(data->reqDataPtr->nWriters == 1) {
        FCGI_EndRequestRecord endRequestRecord;
        endRequestRecord.header = MakeHeader(FCGI_END_REQUEST,
                data->reqDataPtr->requestId,
                sizeof(endRequestRecord.body), 0);
        endRequestRecord.body = MakeEndRequestBody(
                data->reqDataPtr->appStatus, FCGI_REQUEST_COMPLETE);
        FCGX_PutStr((char *) &endRequestRecord,
                sizeof(endRequestRecord), stream);
    }
    data->reqDataPtr->nWriters--;
}



static int write_it_all(int fd, char *buf, int len)
{
    int wrote;

    while (len) {
        wrote = OS_Write(fd, buf, len);
        if (wrote < 0)
            return wrote;
        len -= wrote;
        buf += wrote;
    }
    return len;
}

/*
 *----------------------------------------------------------------------
 *
 * EmptyBuffProc --
 *
 *      Encapsulates any buffered stream content in a FastCGI
 *      record.  Writes the data, making the buffer empty.
 *
 *----------------------------------------------------------------------
 */
static void EmptyBuffProc(struct FCGX_Stream *stream, int doClose)
{
    FCGX_Stream_Data *data = (FCGX_Stream_Data *)stream->data;
    int cLen, eLen;
    /*
     * If the buffer contains stream data, fill in the header.
     * Pad the record to a multiple of 8 bytes in length.  Padding
     * can't overflow the buffer because the buffer is a multiple
     * of 8 bytes in length.  If the buffer contains no stream
     * data, reclaim the space reserved for the header.
     */
    if(!data->rawWrite) {
        cLen = stream->wrNext - data->buff - sizeof(FCGI_Header);
        if(cLen > 0) {
            eLen = AlignInt8(cLen);
            /*
             * Giving the padding a well-defined value keeps Purify happy.
             */
            memset(stream->wrNext, 0, eLen - cLen);
            stream->wrNext += eLen - cLen;
            *((FCGI_Header *) data->buff)
                    = MakeHeader(data->type,
                            data->reqDataPtr->requestId, cLen, eLen - cLen);
        } else {
            stream->wrNext = data->buff;
	}
    }
    if(doClose) {
        WriteCloseRecords(stream);
    };
    if (stream->wrNext != data->buff) {
        data->isAnythingWritten = TRUE;
        if (write_it_all(data->reqDataPtr->ipcFd, (char *)data->buff, stream->wrNext - data->buff) < 0) {
            SetError(stream, OS_Errno);
            return;
        }
        stream->wrNext = data->buff;
    }
    /*
     * The buffer is empty.
     */
    if(!data->rawWrite) {
        stream->wrNext += sizeof(FCGI_Header);
    }
}

/*
 * Return codes for Process* functions
 */
#define STREAM_RECORD 0
#define SKIP          1
#define BEGIN_RECORD  2
#define MGMT_RECORD   3

/*
 *----------------------------------------------------------------------
 *
 * ProcessManagementRecord --
 *
 *      Reads and responds to a management record.  The only type of
 *      management record this library understands is FCGI_GET_VALUES.
 *      The only variables that this library's FCGI_GET_VALUES
 *      understands are FCGI_MAX_CONNS, FCGI_MAX_REQS, and FCGI_MPXS_CONNS.
 *      Ignore other FCGI_GET_VALUES variables; respond to other
 *      management records with a FCGI_UNKNOWN_TYPE record.
 *
 *----------------------------------------------------------------------
 */
static int ProcessManagementRecord(int type, FCGX_Stream *stream)
{
    FCGX_Stream_Data *data = (FCGX_Stream_Data *)stream->data;
    ParamsPtr paramsPtr = NewParams(3);
    char **pPtr;
    char response[64]; /* 64 = 8 + 3*(1+1+14+1)* + padding */
    char *responseP = &response[FCGI_HEADER_LEN];
    char *name, value = '\0';
    int len, paddedLen;
    if(type == FCGI_GET_VALUES) {
        ReadParams(paramsPtr, stream);
        if((FCGX_GetError(stream) != 0) || (data->contentLen != 0)) {
            FreeParams(&paramsPtr);
            return FCGX_PROTOCOL_ERROR;
        }
        for (pPtr = paramsPtr->vec; pPtr < paramsPtr->cur; pPtr++) {
            name = *pPtr;
            *(strchr(name, '=')) = '\0';
            if(strcmp(name, FCGI_MAX_CONNS) == 0) {
                value = '1';
            } else if(strcmp(name, FCGI_MAX_REQS) == 0) {
                value = '1';
            } else if(strcmp(name, FCGI_MPXS_CONNS) == 0) {
                value = '0';
            } else {
                name = NULL;
            }
            if(name != NULL) {
                len = strlen(name);
                sprintf(responseP, "%c%c%s%c", len, 1, name, value);
                responseP += len + 3;
	    }
        }
        len = responseP - &response[FCGI_HEADER_LEN];
        paddedLen = AlignInt8(len);
        *((FCGI_Header *) response)
            = MakeHeader(FCGI_GET_VALUES_RESULT, FCGI_NULL_REQUEST_ID,
                         len, paddedLen - len);
        FreeParams(&paramsPtr);
    } else {
        paddedLen = len = sizeof(FCGI_UnknownTypeBody);
        ((FCGI_UnknownTypeRecord *) response)->header
            = MakeHeader(FCGI_UNKNOWN_TYPE, FCGI_NULL_REQUEST_ID,
                         len, 0);
        ((FCGI_UnknownTypeRecord *) response)->body
            = MakeUnknownTypeBody(type);
    }
    if (write_it_all(data->reqDataPtr->ipcFd, response, FCGI_HEADER_LEN + paddedLen) < 0) {
        SetError(stream, OS_Errno);
        return -1;
    }

    return MGMT_RECORD;
}

/*
 *----------------------------------------------------------------------
 *
 * ProcessBeginRecord --
 *
 *      Reads an FCGI_BEGIN_REQUEST record.
 *
 * Results:
 *      BEGIN_RECORD for normal return.  FCGX_PROTOCOL_ERROR for
 *      protocol error.  SKIP for attempt to multiplex
 *      connection.  -1 for error from write (errno in stream).
 *
 * Side effects:
 *      In case of BEGIN_RECORD return, stores requestId, role,
 *      keepConnection values, and sets isBeginProcessed = TRUE.
 *
 *----------------------------------------------------------------------
 */
static int ProcessBeginRecord(int requestId, FCGX_Stream *stream)
{
    FCGX_Stream_Data *data = (FCGX_Stream_Data *)stream->data;
    FCGI_BeginRequestBody body;
    if(requestId == 0 || data->contentLen != sizeof(body)) {
        return FCGX_PROTOCOL_ERROR;
    }
    if(data->reqDataPtr->isBeginProcessed) {
        /*
         * The Web server is multiplexing the connection.  This library
         * doesn't know how to handle multiplexing, so respond with
         * FCGI_END_REQUEST{protocolStatus = FCGI_CANT_MPX_CONN}
         */
        FCGI_EndRequestRecord endRequestRecord;
        endRequestRecord.header = MakeHeader(FCGI_END_REQUEST,
                requestId, sizeof(endRequestRecord.body), 0);
        endRequestRecord.body
                = MakeEndRequestBody(0, FCGI_CANT_MPX_CONN);
        if (write_it_all(data->reqDataPtr->ipcFd, (char *)&endRequestRecord, sizeof(endRequestRecord)) < 0) {
            SetError(stream, OS_Errno);
            return -1;
        }

        return SKIP;
    }
    /*
     * Accept this new request.  Read the record body.
     */
    data->reqDataPtr->requestId = requestId;
    if(FCGX_GetStr((char *) &body, sizeof(body), stream)
            != sizeof(body)) {
        return FCGX_PROTOCOL_ERROR;
    }
    data->reqDataPtr->keepConnection = (body.flags & FCGI_KEEP_CONN);
    data->reqDataPtr->role = (body.roleB1 << 8) + body.roleB0;
    data->reqDataPtr->isBeginProcessed = TRUE;
    return BEGIN_RECORD;
}

/*
 *----------------------------------------------------------------------
 *
 * ProcessHeader --
 *
 *      Interprets FCGI_Header.  Processes FCGI_BEGIN_REQUEST and
 *      management records here; extracts information from stream
 *      records (FCGI_PARAMS, FCGI_STDIN) into stream.
 *
 * Results:
 *      >= 0 for a normal return, < 0 for error
 *
 * Side effects:
 *      XXX: Many (more than there used to be).
 *      If !stream->isRequestIdSet, ProcessHeader initializes
 *      stream->requestId from header and sets stream->isRequestIdSet
 *      to TRUE.  ProcessHeader also sets stream->contentLen to header's
 *      contentLength, and sets stream->paddingLen to the header's
 *      paddingLength.
 *
 *----------------------------------------------------------------------
 */
static int ProcessHeader(FCGI_Header header, FCGX_Stream *stream)
{
    FCGX_Stream_Data *data = (FCGX_Stream_Data *)stream->data;
    int requestId;
    if(header.version != FCGI_VERSION_1) {
        return FCGX_UNSUPPORTED_VERSION;
    }
    requestId =        (header.requestIdB1 << 8)
                         + header.requestIdB0;
    data->contentLen = (header.contentLengthB1 << 8)
                         + header.contentLengthB0;
    data->paddingLen = header.paddingLength;
    if(header.type == FCGI_BEGIN_REQUEST) {
        return ProcessBeginRecord(requestId, stream);
    }
    if(requestId  == FCGI_NULL_REQUEST_ID) {
        return ProcessManagementRecord(header.type, stream);
    }
    if(requestId != data->reqDataPtr->requestId) {
        return SKIP;
    }
    if(header.type != data->type) {
        return FCGX_PROTOCOL_ERROR;
    }
    return STREAM_RECORD;
}

/*
 *----------------------------------------------------------------------
 *
 * FillBuffProc --
 *
 *      Reads bytes from the ipcFd, supplies bytes to a stream client.
 *
 *----------------------------------------------------------------------
 */
static void FillBuffProc(FCGX_Stream *stream)
{
    FCGX_Stream_Data *data = (FCGX_Stream_Data *)stream->data;
    FCGI_Header header;
    int headerLen = 0;
    int status, count;

    for (;;) {
        /*
         * If data->buff is empty, do a read.
         */
        if(stream->rdNext == data->buffStop) {
            count = OS_Read(data->reqDataPtr->ipcFd, (char *)data->buff,
                            data->bufflen);
            if(count <= 0) {
                SetError(stream, (count == 0 ? FCGX_PROTOCOL_ERROR : OS_Errno));
                return;
            }
            stream->rdNext = data->buff;
            data->buffStop = data->buff + count;
	}
        /*
         * Now data->buff is not empty.  If the current record contains
         * more content bytes, deliver all that are present in data->buff.
         */
        if(data->contentLen > 0) {
            count = min(data->contentLen, data->buffStop - stream->rdNext);
            data->contentLen -= count;
            if(!data->skip) {
                stream->wrNext = stream->stop = stream->rdNext + count;
                return;
	    } else {
                stream->rdNext += count;
                if(data->contentLen > 0) {
                    continue;
	        } else {
                    data->skip = FALSE;
	        }
	    }
	}
        /*
         * If the current record (whose content has been fully consumed by
         * the client) was padded, skip over the padding bytes.
         */
        if(data->paddingLen > 0) {
            count = min(data->paddingLen, data->buffStop - stream->rdNext);
            data->paddingLen -= count;
            stream->rdNext += count;
            if(data->paddingLen > 0) {
                continue;
	    }
	}
        /*
         * All done with the current record, including the padding.
         * If we're in a recursive call from ProcessHeader, deliver EOF.
         */
        if(data->eorStop) {
            stream->stop = stream->rdNext;
            stream->isClosed = TRUE;
            return;
        }
        /*
         * Fill header with bytes from the input buffer.
         */
        count = min((int)sizeof(header) - headerLen,
                        data->buffStop - stream->rdNext);
        memcpy(((char *)(&header)) + headerLen, stream->rdNext, count);
        headerLen += count;
        stream->rdNext += count;