func NetlinkInetDiagWithBuf()

in sys/linux/inetdiag.go [139:198]
50 lines of code
14 McCabe index (conditional complexity)

func NetlinkInetDiagWithBuf(request syscall.NetlinkMessage, readBuf []byte, resp io.Writer) ([]*InetDiagMsg, error) {
	s, err := syscall.Socket(syscall.AF_NETLINK, syscall.SOCK_RAW, syscall.NETLINK_INET_DIAG)
	if err != nil {
		return nil, err
	}
	defer syscall.Close(s)

	lsa := &syscall.SockaddrNetlink{Family: syscall.AF_NETLINK}
	if err := syscall.Sendto(s, serialize(request), 0, lsa); err != nil {
		return nil, err
	}

	if len(readBuf) == 0 {
		// Default size used in libnl.
		readBuf = make([]byte, os.Getpagesize())
	}

	var inetDiagMsgs []*InetDiagMsg
done:
	for {
		buf := readBuf
		nr, _, err := syscall.Recvfrom(s, buf, 0)
		if err != nil {
			return nil, err
		}
		if nr < syscall.NLMSG_HDRLEN {
			return nil, syscall.EINVAL
		}

		buf = buf[:nr]

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

		msgs, err := syscall.ParseNetlinkMessage(buf)
		if err != nil {
			return nil, err
		}

		for _, m := range msgs {
			if m.Header.Type == syscall.NLMSG_DONE {
				break done
			}
			if m.Header.Type == syscall.NLMSG_ERROR {
				return nil, ParseNetlinkError(m.Data)
			}

			inetDiagMsg, err := ParseInetDiagMsg(m.Data)
			if err != nil {
				return nil, err
			}
			inetDiagMsgs = append(inetDiagMsgs, inetDiagMsg)
		}
	}
	return inetDiagMsgs, nil
}