Merge pull request #15690 from janosbrodbeck/pr/dtls/session_get_set_udp_ep

sock/dtls: add getter/setter for the remote UDP endpoint of sock_dtls_session_t

pkg/tinydtls/contrib/sock_dtls.c

@@ -345,6 +345,24 @@ void sock_dtls_session_destroy(sock_dtls_t *sock, sock_dtls_session_t *remote)
     dtls_close(sock->dtls_ctx, &remote->dtls_session);
 }
 
+void sock_dtls_session_get_udp_ep(const sock_dtls_session_t *session,
+                                  sock_udp_ep_t *ep)
+{
+    assert(session);
+    assert(ep);
+
+    _session_to_ep(&session->dtls_session, ep);
+}
+
+void sock_dtls_session_set_udp_ep(sock_dtls_session_t *session,
+                                  const sock_udp_ep_t *ep)
+{
+    assert(session);
+    assert(ep);
+
+    _ep_to_session(ep, &session->dtls_session);
+}
+
 ssize_t sock_dtls_send_aux(sock_dtls_t *sock, sock_dtls_session_t *remote,
                            const void *data, size_t len, uint32_t timeout,
                            sock_dtls_aux_tx_t *aux)

sys/include/net/sock/dtls.h

@@ -664,6 +664,31 @@ int sock_dtls_session_init(sock_dtls_t *sock, const sock_udp_ep_t *ep,
  */
 void sock_dtls_session_destroy(sock_dtls_t *sock, sock_dtls_session_t *remote);
 
+/**
+ * @brief Get the remote UDP endpoint from a session.
+ *
+ * @pre `(session != NULL) && (ep != NULL)`
+ *
+ * @param[in]  session   DTLS session
+ * @param[out] ep        UDP endpoint
+ */
+void sock_dtls_session_get_udp_ep(const sock_dtls_session_t *session,
+                                  sock_udp_ep_t *ep);
+
+/**
+ * @brief Set the remote UDP endpoint from a session.
+ *
+ * @pre `(session != NULL) && (ep != NULL)`
+ *
+ * @param[in]   session   DTLS session
+ * @param[in]   ep        UDP endpoint
+ *
+ * @note Function should only be needed when doing a blocking handshake with
+ *       @ref sock_dtls_send() to set the remote UDP endpoint.
+ */
+void sock_dtls_session_set_udp_ep(sock_dtls_session_t *session,
+                                  const sock_udp_ep_t *ep);
+
 /**
  * @brief Receive handshake messages and application data from remote peer.
  *
@@ -882,6 +907,14 @@ ssize_t sock_dtls_send_aux(sock_dtls_t *sock, sock_dtls_session_t *remote,
  * @note    When blocking, we will need an extra thread to call
  *          @ref sock_dtls_recv() function to handle the incoming handshake
  *          messages.
+ *          An example for a blocking handshake is:
+ *              1. Create an empty @ref sock_dtls_session_t object.
+ *              2. Set the UDP endpoint of the peer you want to connect to in the
+ *                 session object with @ref sock_dtls_session_set_udp_ep().
+ *              3. Call @ref sock_dtls_send() with a timeout greater than 0.
+ *                 The send function blocks until the handshake completes or the
+ *                 timeout expires. If the handshake was successful the data has
+ *                 been sent.
  *
  * @return The number of bytes sent on success
  * @return  -ENOTCONN, if `timeout == 0` and no existing session exists with