Function libcoap_sys::coap_dtls_hello

pub unsafe extern "C" fn coap_dtls_hello(
    coap_session: *mut coap_session_t, 
    data: *const u8, 
    data_len: usize
) -> c_int

Handling client HELLO messages from a new candiate peer. Note that session->tls is empty.

Internal function.

@param coap_session The CoAP session. @param data Encrypted datagram. @param data_len Encrypted datagram size.

@return @c 0 if a cookie verification message has been sent, @c 1 if the HELLO contains a valid cookie and a server session should be created, @c -1 if the message is invalid.