ajp_msg.c

Apache官方在今天放出产品系列2.2的最新版本2.2.11的源码包 最流行的HTTP服务器软件之一

 * @param msg       AJP Message to get value from
 * @param value     Pointer to Byte array
 * @param valuelen  Byte array len
 * @return          APR_SUCCESS or error
 */
apr_status_t ajp_msg_append_bytes(ajp_msg_t *msg, const apr_byte_t *value,
                                  apr_size_t valuelen)
{
    if (! valuelen) {
        return APR_SUCCESS; /* Shouldn't we indicate an error ? */
    }

    if ((msg->len + valuelen) > msg->max_size) {
        return ajp_log_overflow(msg, "ajp_msg_append_bytes");
    }

    /* We checked for space !!  */
    memcpy(msg->buf + msg->len, value, valuelen);
    msg->len += valuelen;

    return APR_SUCCESS;
}

/**
 * Get a 32bits unsigned value from AJP Message
 *
 * @param msg       AJP Message to get value from
 * @param rvalue    Pointer where value will be returned
 * @return          APR_SUCCESS or error
 */
apr_status_t ajp_msg_get_uint32(ajp_msg_t *msg, apr_uint32_t *rvalue)
{
    apr_uint32_t value;

    if ((msg->pos + 3) > msg->len) {
        return ajp_log_overflow(msg, "ajp_msg_get_uint32");
    }

    value  = ((msg->buf[(msg->pos++)] & 0xFF) << 24);
    value |= ((msg->buf[(msg->pos++)] & 0xFF) << 16);
    value |= ((msg->buf[(msg->pos++)] & 0xFF) << 8);
    value |= ((msg->buf[(msg->pos++)] & 0xFF));

    *rvalue = value;
    return APR_SUCCESS;
}


/**
 * Get a 16bits unsigned value from AJP Message
 *
 * @param msg       AJP Message to get value from
 * @param rvalue    Pointer where value will be returned
 * @return          APR_SUCCESS or error
 */
apr_status_t ajp_msg_get_uint16(ajp_msg_t *msg, apr_uint16_t *rvalue)
{
    apr_uint16_t value;

    if ((msg->pos + 1) > msg->len) {
        return ajp_log_overflow(msg, "ajp_msg_get_uint16");
    }

    value  = ((msg->buf[(msg->pos++)] & 0xFF) << 8);
    value += ((msg->buf[(msg->pos++)] & 0xFF));

    *rvalue = value;
    return APR_SUCCESS;
}

/**
 * Peek a 16bits unsigned value from AJP Message, position in message
 * is not updated
 *
 * @param msg       AJP Message to get value from
 * @param rvalue    Pointer where value will be returned
 * @return          APR_SUCCESS or error
 */
apr_status_t ajp_msg_peek_uint16(ajp_msg_t *msg, apr_uint16_t *rvalue)
{
    apr_uint16_t value;

    if ((msg->pos + 1) > msg->len) {
        return ajp_log_overflow(msg, "ajp_msg_peek_uint16");
    }

    value = ((msg->buf[(msg->pos)] & 0xFF) << 8);
    value += ((msg->buf[(msg->pos + 1)] & 0xFF));

    *rvalue = value;
    return APR_SUCCESS;
}

/**
 * Peek a 8bits unsigned value from AJP Message, position in message
 * is not updated
 *
 * @param msg       AJP Message to get value from
 * @param rvalue    Pointer where value will be returned
 * @return          APR_SUCCESS or error
 */
apr_status_t ajp_msg_peek_uint8(ajp_msg_t *msg, apr_byte_t *rvalue)
{
    if (msg->pos > msg->len) {
        return ajp_log_overflow(msg, "ajp_msg_peek_uint8");
    }

    *rvalue = msg->buf[msg->pos];
    return APR_SUCCESS;
}

/**
 * Get a 8bits unsigned value from AJP Message
 *
 * @param msg       AJP Message to get value from
 * @param rvalue    Pointer where value will be returned
 * @return          APR_SUCCESS or error
 */
apr_status_t ajp_msg_get_uint8(ajp_msg_t *msg, apr_byte_t *rvalue)
{

    if (msg->pos > msg->len) {
        return ajp_log_overflow(msg, "ajp_msg_get_uint8");
    }

    *rvalue = msg->buf[msg->pos++];
    return APR_SUCCESS;
}


/**
 * Get a String value from AJP Message
 *
 * @param msg       AJP Message to get value from
 * @param rvalue    Pointer where value will be returned
 * @return          APR_SUCCESS or error
 */
apr_status_t ajp_msg_get_string(ajp_msg_t *msg, const char **rvalue)
{
    apr_uint16_t size;
    apr_size_t   start;
    apr_status_t status;

    status = ajp_msg_get_uint16(msg, &size);
    start = msg->pos;

    if ((status != APR_SUCCESS) || (size + start > msg->max_size)) {
        return ajp_log_overflow(msg, "ajp_msg_get_string");
    }

    msg->pos += (apr_size_t)size;
    msg->pos++;                   /* a String in AJP is NULL terminated */

    *rvalue = (const char *)(msg->buf + start);
    return APR_SUCCESS;
}


/**
 * Get a Byte array from AJP Message
 *
 * @param msg       AJP Message to get value from
 * @param rvalue    Pointer where value will be returned
 * @param rvalueLen Pointer where Byte array len will be returned
 * @return          APR_SUCCESS or error
 */
apr_status_t ajp_msg_get_bytes(ajp_msg_t *msg, apr_byte_t **rvalue,
                               apr_size_t *rvalue_len)
{
    apr_uint16_t size;
    apr_size_t   start;
    apr_status_t status;

    status = ajp_msg_get_uint16(msg, &size);
    /* save the current position */
    start = msg->pos;

    if ((status != APR_SUCCESS) || (size + start > msg->max_size)) {
        return ajp_log_overflow(msg, "ajp_msg_get_bytes");
    }
    msg->pos += (apr_size_t)size;   /* only bytes, no trailer */

    *rvalue     = msg->buf + start;
    *rvalue_len = size;

    return APR_SUCCESS;
}


/**
 * Create an AJP Message from pool
 *
 * @param pool      memory pool to allocate AJP message from
 * @param size      size of the buffer to create
 * @param rmsg      Pointer to newly created AJP message
 * @return          APR_SUCCESS or error
 */
apr_status_t ajp_msg_create(apr_pool_t *pool, apr_size_t size, ajp_msg_t **rmsg)
{
    ajp_msg_t *msg = (ajp_msg_t *)apr_pcalloc(pool, sizeof(ajp_msg_t));

    if (!msg) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, NULL,
                      "ajp_msg_create(): can't allocate AJP message memory");
        return APR_ENOPOOL;
    }

    msg->server_side = 0;

    msg->buf = (apr_byte_t *)apr_palloc(pool, size);

    /* XXX: This should never happen
     * In case if the OS cannont allocate 8K of data
     * we are in serious trouble
     * No need to check the alloc return value, cause the
     * core dump is probably the best solution anyhow.
     */
    if (msg->buf == NULL) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, NULL,
                      "ajp_msg_create(): can't allocate AJP message memory");
        return APR_ENOPOOL;
    }

    msg->len = 0;
    msg->header_len = AJP_HEADER_LEN;
    msg->max_size = size;
    *rmsg = msg;

    return APR_SUCCESS;
}

/**
 * Recopy an AJP Message to another
 *
 * @param smsg      source AJP message
 * @param dmsg      destination AJP message
 * @return          APR_SUCCESS or error
 */
apr_status_t ajp_msg_copy(ajp_msg_t *smsg, ajp_msg_t *dmsg)
{
    if (dmsg == NULL) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, NULL,
                     "ajp_msg_copy(): destination msg is null");
        return AJP_EINVAL;
    }

    if (smsg->len > smsg->max_size) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, NULL,
                     "ajp_msg_copy(): destination buffer too "
                     "small %" APR_SIZE_T_FMT ", max size is %" APR_SIZE_T_FMT,
                     smsg->len, smsg->max_size);
        return  AJP_ETOSMALL;
    }

    memcpy(dmsg->buf, smsg->buf, smsg->len);
    dmsg->len = smsg->len;
    dmsg->pos = smsg->pos;

    return APR_SUCCESS;
}


/**
 * Serialize in an AJP Message a PING command
 *
 * +-----------------------+
 * | PING CMD (1 byte)     |
 * +-----------------------+
 *
 * @param smsg      AJP message to put serialized message
 * @return          APR_SUCCESS or error
 */
apr_status_t ajp_msg_serialize_ping(ajp_msg_t *msg)
{
    apr_status_t rc;
    ajp_msg_reset(msg);

    if ((rc = ajp_msg_append_uint8(msg, CMD_AJP13_PING)) != APR_SUCCESS)
        return rc;

    return APR_SUCCESS;
}

/**
 * Serialize in an AJP Message a CPING command
 *
 * +-----------------------+
 * | CPING CMD (1 byte)    |
 * +-----------------------+
 *
 * @param smsg      AJP message to put serialized message
 * @return          APR_SUCCESS or error
 */
apr_status_t ajp_msg_serialize_cping(ajp_msg_t *msg)
{
    apr_status_t rc;
    ajp_msg_reset(msg);

    if ((rc = ajp_msg_append_uint8(msg, CMD_AJP13_CPING)) != APR_SUCCESS)
        return rc;

    return APR_SUCCESS;
}