ajp_msg.c

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 * 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) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, NULL,
                      "ajp_msg_get_long(): BufferOverflowException %d %d",
                      msg->pos, msg->len);

        return AJP_EOVERFLOW;
    }

    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) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, NULL,
                      "ajp_msg_get_int(): BufferOverflowException %d %d",
                      msg->pos, msg->len);

        return AJP_EOVERFLOW;
    }

    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) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, NULL,
                      "ajp_msg_peek_int(): BufferOverflowException %d %d",
                      msg->pos, msg->len);

        return AJP_EOVERFLOW;
    }
    
    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) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, NULL,
                      "ajp_msg_peek_uint8(): BufferOverflowException %d %d",
                      msg->pos, msg->len);

        return AJP_EOVERFLOW;
    }
    
    *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) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, NULL,
                      "ajp_msg_get_uint8(): BufferOverflowException %d %d",
                      msg->pos, msg->len);

        return AJP_EOVERFLOW;
    }
    
    *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, 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 > AJP_MSG_BUFFER_SZ)) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, NULL,
                      "ajp_msg_get_string(): BufferOverflowException %d %d",
                      msg->pos, msg->len);

        return AJP_EOVERFLOW;
    }

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

    *rvalue = (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 > AJP_MSG_BUFFER_SZ)) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, NULL,
                      "ajp_msg_get_bytes(): BufferOverflowException %d %d",
                      msg->pos, msg->len);
        return AJP_EOVERFLOW;
    }
    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 rmsg      Pointer to newly created AJP message
 * @return          APR_SUCCESS or error
 */
apr_status_t ajp_msg_create(apr_pool_t *pool, 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, AJP_MSG_BUFFER_SZ);
    
    /* 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;
    *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 > AJP_MSG_BUFFER_SZ) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, NULL,
            "ajp_msg_copy(): destination buffer too small %d, max size is %d",
            smsg->len, AJP_MSG_BUFFER_SZ);
        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;
}