func()

in netlink.go [162:200]

• 28 lines of code
• 9 McCabe index (conditional complexity)

func (c *NetlinkClient) Receive(nonBlocking bool, p NetlinkParser) ([]syscall.NetlinkMessage, error) {
	var flags int
	if nonBlocking {
		flags |= syscall.MSG_DONTWAIT
	}

	// XXX (akroh): A possible enhancement is to use the MSG_PEEK flag to
	// check the message size and increase the buffer size to handle it all.
	nr, from, err := syscall.Recvfrom(c.fd, c.readBuf, flags)
	if err != nil {
		// EAGAIN or EWOULDBLOCK will be returned for non-blocking reads where
		// the read would normally have blocked.
		return nil, err
	}
	if nr < syscall.NLMSG_HDRLEN {
		return nil, fmt.Errorf("not enough bytes (%v) received to form a netlink header", nr)
	}
	fromNetlink, ok := from.(*syscall.SockaddrNetlink)
	if !ok || fromNetlink.Pid != 0 {
		// Spoofed packet received on audit netlink socket.
		return nil, errors.New("message received was not from the kernel")
	}

	buf := c.readBuf[:nr]

	// Dump raw data for inspection purposes.
	if c.respWriter != nil {
		if _, err = c.respWriter.Write(buf); err != nil {
			return nil, err
		}
	}

	msgs, err := p(buf)
	if err != nil {
		return nil, fmt.Errorf("failed to parse netlink messages (bytes_received=%v): %w", nr, err)
	}

	return msgs, nil
}