Hi Will,
The EmbedReceiveFrom and EmbedGenerateCookie functions are for DTLS (with WOLFSSL_DTLS defined). The "struct sockaddr_storage" is a POSIX compliant data type for UDP.
If you are using DTLS and called wolfSSL_CTX_new with a wolfDTLSv1_2_client_method or wolfDTLSv1_client_method then you'll want to implement your own IO callbacks for the read/writes.
To do this define WOLFSSL_USER_IO and set the callbacks using wolfSSL_SetIORecv, wolfSSL_SetIOSend and wolfSSL_set_fd. A good example for this is here:
https://github.com/wolfSSL/wolfssl-exam … ack.c#L182
Let me know if you have any other questions or issues.
Thanks,
David Garske, wolfSSL