Bugfix: Remove all memory leaks detected by a valgrind run

src/mqtt.c

@@ -13,6 +13,7 @@
 
 void mqtt_free(MQTTHandle *handle) {
     platform_release(handle);
+    remove_all_subscriptions(handle);
     free(handle);
 }
 
@@ -109,7 +110,7 @@ static inline void parse_packet(MQTTHandle *handle, MQTTPacket *packet) {
                     if (send_puback_packet(handle, payload->packet_id)) {
                         dispatch_subscription(handle, payload);
                     }
-                    break;                    
+                    break;
                 case MQTT_QOS_2:
                     send_pubrec_packet(handle, payload->packet_id, dispatch_subscription_direct, payload);
                     break;
@@ -155,6 +156,7 @@ PlatformTaskFunc(_reader) {
         PlatformStatusCode ret = platform_read(handle, buffer);
         if (ret == PlatformStatusError) {
             handle->reader_alive = false;
+            buffer_release(buffer);
             return 0;
         }
 

src/packet.c

@@ -47,6 +47,37 @@ MQTTPacket *allocate_MQTTPacket(MQTTControlPacketType type) {
 }
 
 void free_MQTTPacket(MQTTPacket *packet) {
+    switch (packet->packet_type) {
+        case PacketTypePublish: {
+            PublishPayload *content = (PublishPayload *)packet->payload;
+            if (content->topic) free(content->topic);
+            if (content->message) free(content->message);
+            break;
+        }
+#if MQTT_SERVER
+        case PacketTypeConnect: {
+            ConnectPayload *content = (ConnectPayload *)packet->payload;
+            if (content->client_id) free(content->client_id);
+            if (content->will_topic) free(content->will_topic);
+            if (content->will_message) free(content->will_message);
+            if (content->username) free(content->username);
+            if (content->password) free(content->password);
+            break;
+        }
+        case PacketTypeSubscribe: {
+            SubscribePayload *content = (SubscribePayload *)packet->payload;
+            if (content->topic) free(content->topic);
+            break;
+        }
+        case PacketTypeUnsubscribe: {
+            UnsubscribePayload *content = (UnsubscribePayload *)packet->payload;
+            if (content->topic) free(content->topic);
+            break;
+        }
+#endif
+        default:
+            break;
+    }
     free(packet->payload);
     packet->payload = NULL;
     free(packet);
@@ -211,7 +242,7 @@ bool decode_publish(Buffer *buffer, PublishPayload *payload, size_t sz) {
             + buffer->data[buffer->position + 1];
         buffer->position += 2;
     }
-    
+
     size_t len = sz - (buffer->position - start_pos) + 1;
     if (len > 1) {
         payload->message = (char *)calloc(1, len);

src/protocol.c

@@ -70,6 +70,7 @@ void handle_pubrel(MQTTHandle *handle, void *context) {
     free(ctx->payload->topic);
     free(ctx->payload->message);
     free(ctx->payload);
+    free(ctx);
 }
 
 /*
@@ -213,11 +214,11 @@ bool send_disconnect_packet(MQTTHandle *handle) {
 
 #if MQTT_CLIENT
 bool send_puback_packet(MQTTHandle *handle, uint16_t packet_id) {
-    PacketIDPayload *payload = (PacketIDPayload *)calloc(1, sizeof(PacketIDPayload));
+    PacketIDPayload payload = { 0 };
-    payload->packet_id = packet_id;
+    payload.packet_id = packet_id;
 
     DEBUG_LOG("Sending PUBACK");
-    Buffer *encoded = mqtt_packet_encode(&(MQTTPacket){ PacketTypePubAck, payload });
+    Buffer *encoded = mqtt_packet_encode(&(MQTTPacket){ PacketTypePubAck, &payload });
     encoded->position = 0;
     return send_buffer(handle, encoded);
 }
@@ -225,8 +226,8 @@ bool send_puback_packet(MQTTHandle *handle, uint16_t packet_id) {
 
 #if MQTT_CLIENT
 bool send_pubrec_packet(MQTTHandle *handle, uint16_t packet_id, MQTTPublishEventHandler callback, PublishPayload *publish) {
-    PacketIDPayload *payload = (PacketIDPayload *)calloc(1, sizeof(PacketIDPayload));
+    PacketIDPayload payload = { 0 };
-    payload->packet_id = packet_id;
+    payload.packet_id = packet_id;
 
     PublishCallback *ctx = (PublishCallback *)malloc(sizeof(PublishCallback));
     ctx->payload = malloc(sizeof(PublishPayload));
@@ -238,7 +239,7 @@ bool send_pubrec_packet(MQTTHandle *handle, uint16_t packet_id, MQTTPublishEvent
 
     expect_packet(handle, PacketTypePubRel, packet_id, handle_pubrel, ctx);
 
-    Buffer *encoded = mqtt_packet_encode(&(MQTTPacket){ PacketTypePubRec, payload });
+    Buffer *encoded = mqtt_packet_encode(&(MQTTPacket){ PacketTypePubRec, &payload });
     encoded->position = 0;
     return send_buffer(handle, encoded);
 }

src/subscriptions.c

@@ -38,6 +38,18 @@ void remove_subscription(MQTTHandle *handle, char *topic) {
     }
 }
 
+void remove_all_subscriptions(MQTTHandle *handle) {
+    SubscriptionItem *item = handle->subscriptions.items;
+    SubscriptionItem *prev = NULL;
+
+    while (item != NULL) {
+        prev = item;
+        item = item->next;
+        free(prev);
+    }
+    handle->subscriptions.items = NULL;
+}
+
 void subscription_set_pending(MQTTHandle *handle, char *topic, bool pending) {
     SubscriptionItem *item = handle->subscriptions.items;
 

src/subscriptions.h

@@ -18,6 +18,7 @@ typedef struct {
 
 void add_subscription(MQTTHandle *handle, char *topic, MQTTQosLevel qos, MQTTPublishEventHandler callback);
 void remove_subscription(MQTTHandle *handle, char *topic);
+void remove_all_subscriptions(MQTTHandle *handle);
 void subscription_set_pending(MQTTHandle *handle, char *topic, bool pending);
 
 void dispatch_subscription(MQTTHandle *handle, PublishPayload *payload);

tests/decode_packet.c

@@ -11,6 +11,7 @@ TestResult test_vl_int_data_0(void) {
     Buffer *buffer = buffer_from_data_copy(data, sizeof(data));
     uint16_t result = variable_length_int_decode(buffer);
     TESTASSERT(result == 0, "Should decode to 0");
+    buffer_release(buffer);
     TEST_OK();
 }
 
@@ -19,6 +20,7 @@ TestResult test_vl_int_data_127(void) {
     Buffer *buffer = buffer_from_data_copy(data, sizeof(data));
     uint16_t result = variable_length_int_decode(buffer);
     TESTASSERT(result == 127, "Should decode to 127");
+    buffer_release(buffer);
     TEST_OK();
 }
 
@@ -27,6 +29,7 @@ TestResult test_vl_int_data_128(void) {
     Buffer *buffer = buffer_from_data_copy(data, sizeof(data));
     uint16_t result = variable_length_int_decode(buffer);
     TESTASSERT(result == 128, "Should decode to 128");
+    buffer_release(buffer);
     TEST_OK();
 }
 
@@ -35,6 +38,7 @@ TestResult test_vl_int_data_16383(void) {
     Buffer *buffer = buffer_from_data_copy(data, sizeof(data));
     uint16_t result = variable_length_int_decode(buffer);
     TESTASSERT(result == 16383, "Should decode to 16383");
+    buffer_release(buffer);
     TEST_OK();
 }
 
@@ -43,6 +47,7 @@ TestResult test_vl_int_data_16384(void) {
     Buffer *buffer = buffer_from_data_copy(data, sizeof(data));
     uint16_t result = variable_length_int_decode(buffer);
     TESTASSERT(result == 16384, "Should decode to 16384");
+    buffer_release(buffer);
     TEST_OK();
 }
 
@@ -51,6 +56,7 @@ TestResult test_vl_int_data_32767(void) {
     Buffer *buffer = buffer_from_data_copy(data, sizeof(data));
     uint16_t result = variable_length_int_decode(buffer);
     TESTASSERT(result == 32767, "Should decode to 32767");
+    buffer_release(buffer);
     TEST_OK();
 }
 
@@ -62,6 +68,8 @@ TestResult test_utf8_string_empty(void) {
     char *string = utf8_string_decode(buffer);
 
     TESTASSERT(strlen(string) == 0, "Should decode empty string");
+    free(string);
+    buffer_release(buffer);
     TEST_OK();
 }
 
@@ -72,6 +80,8 @@ TestResult test_utf8_string_hello(void) {
     char *string = utf8_string_decode(buffer);
 
     TESTASSERT(strncmp("hello", string, 5) == 0, "Should decode to 'hello' string");
+    free(string);
+    buffer_release(buffer);
     TEST_OK();
 }
 
@@ -114,7 +124,6 @@ TestResult test_decode_connect_invalid(void) {
 
     TESTASSERT(packet == NULL, "Packet should not be valid");
     buffer_release(buffer);
-
     TEST_OK();
 }
 

tests/test.h

@@ -51,6 +51,8 @@ static inline TestResult TESTMEMCMP(Buffer *valid, Buffer *check) {
         TESTRESULT_BUFFER(TestStatusFailureHexdump, "Buffer size differs from valid", check, valid);
     }
     if (memcmp(valid->data, check->data, valid->len) == 0) {
+        buffer_release(check);
+        buffer_release(valid);
         TESTRESULT(TestStatusOk, "Buffer matches valid");
     } else {
         TESTRESULT_BUFFER(TestStatusFailureHexdump, "Buffer and valid differ", check, valid);