From 8dcdbfb4779be708faa7712ce7d77aca2e45711f Mon Sep 17 00:00:00 2001
From: Jon Shallow <supjps-libcoap@jpshallow.com>
Date: Tue, 11 Dec 2018 13:17:21 +0000
Subject: [PATCH] endpoint->hello information memory leak when
 coap_free_endpoint() called

Information set up in the pseudo session held in endpoint->hello is not freed
off when coap_free_endpoint() is called.

A solution is to split coap_session_free() into two parts with
coap_session_free() calling a new function coap_session_mfree().

Then coap_mfree_endpoint() can call coap_session_mfree() to free off the
endpoint specific hello information.

Makefile.am

Add coap_mfree_endpoint and coap_session_mfree to the CTAGS_IGNORE list.

libcoap-2.{map|sym}

Remove coap_mfree_endpoint as it is not a public function

include/coap2/coap_session.h

Add in new coap_session_mfree() function definition

src/coap_io.c

Call coap_session_mfree() from within coap_mfree_endpoint()

src/coap_session.c

Move some of the functionality out of coap_session_free() into a new
function coap_session_mfree() and  call coap_session_mfree().
---
 Makefile.am                  |  2 ++
 include/coap2/coap_session.h |  1 +
 libcoap-2.map                |  1 -
 libcoap-2.sym                |  1 -
 src/coap_io.c                |  2 ++
 src/coap_session.c           | 29 ++++++++++++++++-------------
 6 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/Makefile.am b/Makefile.am
index 7142f7d8..5b4d2fb1 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -157,8 +157,10 @@ coap_dtls_send \
 coap_dtls_session_update_mtu \
 coap_dtls_startup \
 coap_endpoint_new_dtls_session \
+coap_mfree_endpoint \
 coap_packet_extract_pbuf \
 coap_pdu_from_pbuf \
+coap_session_mfree \
 coap_socket_accept_tcp \
 coap_socket_bind_tcp \
 coap_socket_bind_udp \
diff --git a/include/coap2/coap_session.h b/include/coap2/coap_session.h
index a02e1916..ef152315 100644
--- a/include/coap2/coap_session.h
+++ b/include/coap2/coap_session.h
@@ -368,6 +368,7 @@ coap_session_t *coap_session_get_by_peer(struct coap_context_t *ctx,
   const struct coap_address_t *remote_addr, int ifindex);
 
 void coap_session_free(coap_session_t *session);
+void coap_session_mfree(coap_session_t *session);
 
  /**
   * @defgroup cc Rate Control
diff --git a/libcoap-2.map b/libcoap-2.map
index a7baaf0c..584d9149 100644
--- a/libcoap-2.map
+++ b/libcoap-2.map
@@ -78,7 +78,6 @@ global:
   coap_malloc_endpoint;
   coap_malloc_type;
   coap_memory_init;
-  coap_mfree_endpoint;
   coap_network_read;
   coap_network_send;
   coap_new_client_session;
diff --git a/libcoap-2.sym b/libcoap-2.sym
index 05bf66a1..b52ce217 100644
--- a/libcoap-2.sym
+++ b/libcoap-2.sym
@@ -76,7 +76,6 @@ coap_log_impl
 coap_malloc_endpoint
 coap_malloc_type
 coap_memory_init
-coap_mfree_endpoint
 coap_network_read
 coap_network_send
 coap_new_client_session
diff --git a/src/coap_io.c b/src/coap_io.c
index 9a6b7896..37ecbf0a 100644
--- a/src/coap_io.c
+++ b/src/coap_io.c
@@ -94,6 +94,7 @@ struct coap_endpoint_t *
 void
 coap_mfree_endpoint(struct coap_endpoint_t *ep) {
   ep_initialized = 0;
+  coap_session_mfree(&ep->hello);
 }
 
 int
@@ -183,6 +184,7 @@ struct coap_endpoint_t *
 
 void
 coap_mfree_endpoint(struct coap_endpoint_t *ep) {
+  coap_session_mfree(&ep->hello);
   coap_free_type(COAP_ENDPOINT, ep);
 }
 
diff --git a/src/coap_session.c b/src/coap_session.c
index 89244196..ce5a762c 100644
--- a/src/coap_session.c
+++ b/src/coap_session.c
@@ -144,14 +144,9 @@ coap_make_session(coap_proto_t proto, coap_session_type_t type,
   return session;
 }
 
-void coap_session_free(coap_session_t *session) {
+void coap_session_mfree(coap_session_t *session) {
   coap_queue_t *q, *tmp;
 
-  if (!session)
-    return;
-  assert(session->ref == 0);
-  if (session->ref)
-    return;
   if (session->partial_pdu)
     coap_delete_pdu(session->partial_pdu);
   if (session->proto == COAP_PROTO_DTLS)
@@ -160,13 +155,6 @@ void coap_session_free(coap_session_t *session) {
     coap_tls_free_session(session);
   if (session->sock.flags != COAP_SOCKET_EMPTY)
     coap_socket_close(&session->sock);
-  if (session->endpoint) {
-    if (session->endpoint->sessions)
-      LL_DELETE(session->endpoint->sessions, session);
-  } else if (session->context) {
-    if (session->context->sessions)
-      LL_DELETE(session->context->sessions, session);
-  }
   if (session->psk_identity)
     coap_free(session->psk_identity);
   if (session->psk_key)
@@ -177,7 +165,22 @@ void coap_session_free(coap_session_t *session) {
       session->context->nack_handler(session->context, session, q->pdu, session->proto == COAP_PROTO_DTLS ? COAP_NACK_TLS_FAILED : COAP_NACK_NOT_DELIVERABLE, q->id);
     coap_delete_node(q);
   }
+}
 
+void coap_session_free(coap_session_t *session) {
+  if (!session)
+    return;
+  assert(session->ref == 0);
+  if (session->ref)
+    return;
+  if (session->endpoint) {
+    if (session->endpoint->sessions)
+      LL_DELETE(session->endpoint->sessions, session);
+  } else if (session->context) {
+    if (session->context->sessions)
+      LL_DELETE(session->context->sessions, session);
+  }
+  coap_session_mfree(session);
   coap_log(LOG_DEBUG, "***%s: session closed\n", coap_session_str(session));
 
   coap_free_type(COAP_SESSION, session);