From 58766a137e2bcdfd3cfb80026207186aa6929c29 Mon Sep 17 00:00:00 2001
From: jcmichelou <jean-claude.michelou@spinetix.com>
Date: Mon, 18 Sep 2017 16:47:06 +0200
Subject: [PATCH] coap_dtls.h, openssl: Add function prototypes for TLS
 support.

---
 include/coap/coap_dtls.h | 33 +++++++++++++++++++++++----------
 src/coap_notls.c         | 16 +++++++++++-----
 src/coap_openssl.c       | 16 +++++++++++-----
 src/net.c                |  9 ++++-----
 4 files changed, 49 insertions(+), 25 deletions(-)

diff --git a/include/coap/coap_dtls.h b/include/coap/coap_dtls.h
index db658141..232ef50e 100644
--- a/include/coap/coap_dtls.h
+++ b/include/coap/coap_dtls.h
@@ -1,7 +1,8 @@
 /*
- * coap_dtls.h -- Datagram Transport Layer Support for libcoap
+ * coap_dtls.h -- (Datagram) Transport Layer Support for libcoap
  *
  * Copyright (C) 2016 Olaf Bergmann <bergmann@tzi.org>
+ * Copyright (C) 2017 Jean-Claude Michelou <jcm@spinetix.com>
  *
  * This file is part of the CoAP library libcoap. Please see README for terms
  * of use.
@@ -155,20 +156,32 @@ int coap_dtls_hello(coap_session_t *session,
 unsigned int coap_dtls_get_overhead(coap_session_t *session);
 
 /**
- * Send data to a TLS peer.
+ * Send data to a TLS peer, with implicit flush.
  *
  * @param session   The CoAP session
  * @param data      pointer to data
  * @param size      number of bytes to send
- * @param flush     set to non-zero if the message should be sent now
- * @return 0 if this would be blocking, -1 if there is an error or the number of cleartext bytes sent
+ * @return          0 if this should be retried, -1 if there is an error or
+ *                  the number of cleartext bytes sent.
  */
-int coap_tls_send(coap_session_t *session,
-                   const uint8_t *data,
-                   size_t data_len,
-                   int flush);
-
-
+ssize_t coap_tls_write(coap_session_t *session,
+                       const uint8_t *data,
+                       size_t data_len
+                       );
+  
+/**
+ * Read some data from a TLS peer.
+ *
+ * @param session   The CoAP session
+ * @param data      pointer to data
+ * @param size      maximum number of bytes to read
+ * @return          0 if this should be retried, -1 if there is an error or
+ *                  the number of cleartext bytes read.
+ */
+ssize_t coap_tls_read(coap_session_t *session,
+                      uint8_t *data,
+                      size_t data_len
+                      );
 
 /** @} */
 
diff --git a/src/coap_notls.c b/src/coap_notls.c
index cf32d05f..73862d96 100644
--- a/src/coap_notls.c
+++ b/src/coap_notls.c
@@ -110,11 +110,17 @@ unsigned int coap_dtls_get_overhead(coap_session_t *session UNUSED) {
   return 0;
 }
 
-int coap_tls_send(coap_session_t *session,
-                  const uint8_t *data,
-                  size_t data_len,
-                  int flush )
-{
+ssize_t coap_tls_write(coap_session_t *session UNUSED,
+                       const uint8_t *data UNUSED,
+                       size_t data_len UNUSED
+) {
+  return -1;
+}
+
+ssize_t coap_tls_read(coap_session_t *session UNUSED,
+                      uint8_t *data UNUSED,
+                      size_t data_len UNUSED
+) {
   return -1;
 }
 
diff --git a/src/coap_openssl.c b/src/coap_openssl.c
index fbd4fc12..558fc137 100644
--- a/src/coap_openssl.c
+++ b/src/coap_openssl.c
@@ -675,11 +675,17 @@ unsigned int coap_dtls_get_overhead(coap_session_t *session) {
   return overhead;
 }
 
-int coap_tls_send(coap_session_t *session,
-                  const uint8_t *data,
-                  size_t data_len,
-                  int flush )
-{
+ssize_t coap_tls_write(coap_session_t *session,
+                       const uint8_t *data,
+                       size_t data_len
+) {
+  return -1;
+}
+
+ssize_t coap_tls_read(coap_session_t *session,
+                      uint8_t *data,
+                      size_t data_len
+) {
   return -1;
 }
 
diff --git a/src/net.c b/src/net.c
index 12b72d51..9d8b1930 100644
--- a/src/net.c
+++ b/src/net.c
@@ -647,8 +647,8 @@ coap_session_send_pdu(coap_session_t *session, coap_pdu_t *pdu) {
 	pdu->token - pdu->hdr_size, pdu->used_size + pdu->hdr_size);
       break;
     case COAP_PROTO_TLS:
-      bytes_written = coap_tls_send(session, pdu->token - pdu->hdr_size,
-	                            pdu->used_size + pdu->hdr_size, 1);
+      bytes_written = coap_tls_write(session, pdu->token - pdu->hdr_size,
+	                             pdu->used_size + pdu->hdr_size);
       break;
     default:
       break;
@@ -1025,11 +1025,10 @@ coap_write_session(coap_context_t *ctx, coap_session_t *session, coap_tick_t now
 	);
 	break;
       case COAP_PROTO_TLS:
-	bytes_written = coap_tls_send(
+	bytes_written = coap_tls_write(
 	  session,
 	  q->pdu->token - q->pdu->hdr_size - session->partial_write,
-	  q->pdu->used_size + q->pdu->hdr_size - session->partial_write,
-	  0
+	  q->pdu->used_size + q->pdu->hdr_size - session->partial_write
 	);
 	break;
     }