SockaddrIn Class — netty Architecture

Source Code

transport-classes-io_uring/src/main/java/io/netty/channel/uring/SockaddrIn.java lines 30–240

final class SockaddrIn {
    static final byte[] IPV4_MAPPED_IPV6_PREFIX = {
            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, (byte) 0xff, (byte) 0xff };
    static final int IPV4_ADDRESS_LENGTH = 4;
    static final int IPV6_ADDRESS_LENGTH = 16;
    static final byte[] SOCKADDR_IN6_EMPTY_ARRAY = new byte[Native.SIZEOF_SOCKADDR_IN6];
    static final byte[] SOCKADDR_IN_EMPTY_ARRAY = new byte[Native.SIZEOF_SOCKADDR_IN];

    private SockaddrIn() { }

    static int set(boolean ipv6, ByteBuffer memory, InetSocketAddress address) {
        if (ipv6) {
            return setIPv6(memory, address.getAddress(), address.getPort());
        }
        return setIPv4(memory, address.getAddress(), address.getPort());
    }

    /**
     * <pre>{@code
     * struct sockaddr_in {
     *      sa_family_t    sin_family; // address family: AF_INET
     *      in_port_t      sin_port;   // port in network byte order
     *      struct in_addr sin_addr;   // internet address
     * };
     *
     * // Internet address.
     * struct in_addr {
     *     uint32_t       s_addr;     // address in network byte order
     * };
     * }</pre>
     */
    static int setIPv4(ByteBuffer memory, InetAddress address, int port) {
        int position = memory.position();
        memory.mark();
        try {
            // memset
            memory.put(SOCKADDR_IN_EMPTY_ARRAY);

            memory.putShort(position + Native.SOCKADDR_IN_OFFSETOF_SIN_FAMILY, Native.AF_INET);
            memory.putShort(position + Native.SOCKADDR_IN_OFFSETOF_SIN_PORT, handleNetworkOrder(memory.order(),
                    (short) port));

            byte[] bytes = address.getAddress();
            int offset = 0;
            if (bytes.length == IPV6_ADDRESS_LENGTH) {
                // IPV6 mapped IPV4 address, we only need the last 4 bytes.
                offset = IPV4_MAPPED_IPV6_PREFIX.length;
            }
            assert bytes.length == offset + IPV4_ADDRESS_LENGTH;
            memory.position(position + Native.SOCKADDR_IN_OFFSETOF_SIN_ADDR + Native.IN_ADDRESS_OFFSETOF_S_ADDR);
            memory.put(bytes, offset, IPV4_ADDRESS_LENGTH);
            return Native.SIZEOF_SOCKADDR_IN;
        } finally {
            // Restore position as we did change it via memory.put(byte[]...).
            memory.reset();
        }
    }

    /**
     * <pre>{@code
     * struct sockaddr_in6 {
     *     sa_family_t     sin6_family;   // AF_INET6
     *     in_port_t       sin6_port;     // port number
     *     uint32_t        sin6_flowinfo; // IPv6 flow information
     *     struct in6_addr sin6_addr;     // IPv6 address
     *     uint32_t        sin6_scope_id; /* Scope ID (new in 2.4)
     * };
     *
     * struct in6_addr {
     *     unsigned char s6_addr[16];   // IPv6 address
     * };
     * }</pre>
     */
    static int setIPv6(ByteBuffer memory, InetAddress address, int port) {
        int position = memory.position();
        memory.mark();
        try {
            // memset
            memory.put(SOCKADDR_IN6_EMPTY_ARRAY);
            memory.putShort(position + Native.SOCKADDR_IN6_OFFSETOF_SIN6_FAMILY, Native.AF_INET6);
            memory.putShort(position + Native.SOCKADDR_IN6_OFFSETOF_SIN6_PORT,