RTP: Revise the workaround of private addresses and fix bugs.

    void decode(int tick);

private:

    bool isNatAddress(struct sockaddr_storage *addr);

    enum {

        NORMAL = 0,

        SEND_ONLY = 1,

    AudioCodec *mCodec;

    uint32_t mCodecMagic;

    uint32_t mDtmfMagic;

    bool mFixRemote;

    int mTick;

    int mSampleRate;

    if (codec) {

        mRemote = *remote;

        mCodec = codec;

        // Here we should never get an private address, but some buggy proxy

        // servers do give us one. To solve this, we replace the address when

        // the first time we successfully decode an incoming packet.

        mFixRemote = false;

        if (remote->ss_family == AF_INET) {

            unsigned char *address =

                (unsigned char *)&((sockaddr_in *)remote)->sin_addr;

            if (address[0] == 10 ||

                (address[0] == 172 && (address[1] >> 4) == 1) ||

                (address[0] == 192 && address[1] == 168)) {

                mFixRemote = true;

            }

        }

    }

    LOGD("stream[%d] is configured as %s %dkHz %dms", mSocket,

        sizeof(mRemote));

}

bool AudioStream::isNatAddress(struct sockaddr_storage *addr) {

    if (addr->ss_family != AF_INET) return false;

    struct sockaddr_in *s4 = (struct sockaddr_in *)addr;

    unsigned char *d = (unsigned char *) &s4->sin_addr;

    if ((d[0] == 10)

        || ((d[0] == 172) && (d[1] & 0x10))

        || ((d[0] == 192) && (d[1] == 168))) return true;

    return false;

}

void AudioStream::decode(int tick)

{

    char c;

            MSG_TRUNC | MSG_DONTWAIT) >> 1;

    } else {

        __attribute__((aligned(4))) uint8_t buffer[2048];

        struct sockaddr_storage src_addr;

        socklen_t addrlen;

        length = recvfrom(mSocket, buffer, sizeof(buffer),

            MSG_TRUNC|MSG_DONTWAIT, (sockaddr*)&src_addr, &addrlen);

        sockaddr_storage remote;

        socklen_t len = sizeof(remote);

        // The following if clause is for fixing the target address if

        // proxy server did not replace the NAT address with its media

        // port in SDP. Although it is proxy server's responsibility for

        // replacing the connection address with correct one, we will change

        // the target address as we detect the difference for now until we

        // know the best way to get rid of this issue.

        if ((memcmp((void*)&src_addr, (void*)&mRemote, addrlen) != 0) &&

            isNatAddress(&mRemote)) {

            memcpy((void*)&mRemote, (void*)&src_addr, addrlen);

        }

        length = recvfrom(mSocket, buffer, sizeof(buffer),

            MSG_TRUNC | MSG_DONTWAIT, (sockaddr *)&remote, &len);

        // Do we need to check SSRC, sequence, and timestamp? They are not

        // reliable but at least they can be used to identify duplicates?

        if (length >= 0) {

            length = mCodec->decode(samples, &buffer[offset], length);

        }

        if (length > 0 && mFixRemote) {

            mRemote = remote;

            mFixRemote = false;

        }

    }

    if (length != mSampleCount) {

    if (length <= 0) {

        LOGD("stream[%d] decoder error", mSocket);

        return;

    }