Method empty

src/socket.cpp:840–915

Pull up to tcp_readsize data bytes out of the socket into our local buffer. */

/* Pull up to tcp_readsize data bytes out of the socket into our local buffer. */
int SIPpSocket::empty()
{

    int readsize=0;
    if (ss_transport == T_UDP || ss_transport == T_SCTP) {
        readsize = SIPP_MAX_MSG_SIZE;
    } else {
        readsize = tcp_readsize;
    }

    struct socketbuf *socketbuf;
    char *buffer;
    int ret = -1;
    /* Where should we start sending packets to, ideally we should begin to parse
     * the Via, Contact, and Route headers.  But for now SIPp always sends to the
     * host specified on the command line; or for UAS mode to the address that
     * sent the last message. */
    sipp_socklen_t addrlen = sizeof(struct sockaddr_storage);

    buffer = (char *)malloc(readsize);
    if (!buffer) {
        ERROR("Could not allocate memory for read!");
    }
    socketbuf = alloc_socketbuf(buffer, readsize, NO_COPY, nullptr);

    switch(ss_transport) {
    case T_TCP:
    case T_UDP:
        ret = recvfrom(ss_fd, buffer, readsize, 0, (struct sockaddr *)&socketbuf->addr,  &addrlen);
        break;
    case T_TLS:
#if defined(USE_OPENSSL) || defined(USE_WOLFSSL)
        ret = SSL_read(ss_ssl, buffer, readsize);
        /* XXX: Check for clean shutdown. */
#else
        ERROR("TLS support is not enabled!");
#endif
        break;
    case T_SCTP:
#ifdef USE_SCTP
        struct sctp_sndrcvinfo recvinfo;
        memset(&recvinfo, 0, sizeof(recvinfo));
        int msg_flags = 0;

        ret = sctp_recvmsg(ss_fd, (void*)buffer, readsize,
                           (struct sockaddr *) &socketbuf->addr, &addrlen, &recvinfo, &msg_flags);

        if (MSG_NOTIFICATION & msg_flags) {
            errno = 0;
            handleSCTPNotify(buffer);
            ret = -2;
        }
#else
        ERROR("SCTP support is not enabled!");
#endif
        break;
    }
    if (ret <= 0) {