Merge pull request #17 from adamblack1/bufferOverflowBranch

Fix "Potential buffer overflow #14" (SlimList_ToString), Performance improvements

Makefile

@@ -22,8 +22,8 @@ CPP_PLATFORM = Gcc
 # set OS_PLATFROM to win to build with winsock
 # OS_PLATFORM = win
 
-#CFLAGS are set to override malloc and free to get memory leak detection in C programs
-CPPUTEST_CFLAGS = -Dmalloc=cpputest_malloc -Dfree=cpputest_free
+#CFLAGS are set to override malloc, free, etc to get memory leak detection in C programs
+CPPUTEST_CFLAGS = -Dmalloc=cpputest_malloc -Dfree=cpputest_free -Drealloc=cpputest_realloc
 CPPFLAGS = -Wall
 #GCOVFLAGS = -fprofile-arcs -ftest-coverage
 

include/CSlim/SlimList.h

@@ -6,11 +6,23 @@ extern "C" {
 #endif
 
 typedef struct SlimList SlimList;
+typedef struct Node SlimListIterator;
 
 SlimList* SlimList_Create(void);
 void SlimList_Destroy(SlimList*);
+
+SlimListIterator* SlimList_CreateIterator(SlimList*);
+int SlimList_Iterator_HasItem(SlimListIterator*);
+void SlimList_Iterator_Advance(SlimListIterator**);
+void SlimList_Iterator_AdvanceBy(SlimListIterator**, int);
+
+char* SlimList_Iterator_GetString(SlimListIterator*);
+SlimList* SlimList_Iterator_GetList(SlimListIterator*);
+void SlimList_Iterator_Replace(SlimListIterator*, const char*);
+
 extern void SlimList_AddString(SlimList*, char const *);
 void SlimList_AddList(SlimList* self, SlimList* element);
+void SlimList_PopHead(SlimList* self);
 int SlimList_GetLength(SlimList*);
 int SlimList_Equals(SlimList* self, SlimList* other);
 SlimList * SlimList_GetListAt(SlimList* self, int index);
@@ -20,7 +32,8 @@ SlimList* SlimList_GetHashAt(SlimList* self, int index);
 void SlimList_ReplaceAt(SlimList* self, int index, char const * replacementString);
 void SlimList_AddBuffer(SlimList* self, char const* buffer, int length);
 SlimList* SlimList_GetTailAt(SlimList*, int index);
-char* SlimList_ToString(SlimList*);
+char* SlimList_ToString(SlimList*); /// Use CSlim_DestroyString to deallocate the string
+
 #ifdef __cplusplus
 }
 #endif

include/CSlim/SlimUtil.h

@@ -1,8 +1,17 @@
 #ifndef SLIMUTILS_H
 #define SLIMUTILS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 char * CSlim_BuyBuf(char const*, int);
 char * CSlim_BuyString(char const*);
 
+char* CSlim_CreateEmptyString(void);
+void CSlim_ConcatenateString(char**, const char*);
+void CSlim_DestroyString(char*);
+
 typedef struct MapStringInt
 {
 	const char* string;
@@ -12,4 +21,9 @@ typedef struct MapStringInt
 int CSlim_MapToIntFrom(MapStringInt*, const char*);
 const char* CSlim_MapToStringFrom(MapStringInt*, int);
 int CSlim_IsCharacter(unsigned char const* byte);
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif

src/CSlim/ListExecutor.c

@@ -43,7 +43,11 @@ char* InvalidCommand(SlimList* instruction) {
 
 char* MalformedInstruction(SlimList* instruction) {
 	static char msg[128];
-	snprintf(msg, (size_t)128, "__EXCEPTION__:message:<<MALFORMED_INSTRUCTION %s.>>", SlimList_ToString(instruction));
+
+	char* listAsAString = SlimList_ToString(instruction);
+	snprintf(msg, (size_t)128, "__EXCEPTION__:message:<<MALFORMED_INSTRUCTION %s.>>", listAsAString);
+	CSlim_DestroyString(listAsAString);
+
 	return CSlim_BuyString(msg);
 }
 
@@ -105,15 +109,16 @@ char* Dispatch(ListExecutor* self, SlimList* instruction) {
 SlimList* ListExecutor_Execute(ListExecutor* self, SlimList* instructions)
 {
 	SlimList* results = SlimList_Create();
-	int numberOfInstructions = SlimList_GetLength(instructions);
-	int n;
-	for (n=0; n<numberOfInstructions; n++) {
-		SlimList* instruction = SlimList_GetListAt(instructions, n);
+
+	SlimListIterator* iterator = SlimList_CreateIterator(instructions);
+	while (SlimList_Iterator_HasItem(iterator)) {
+		SlimList* instruction = SlimList_Iterator_GetList(iterator);
 		char* id = SlimList_GetStringAt(instruction, 0);
 		char* result = Dispatch(self, instruction);
 		AddResult(results, id, result);
-		if (result)
-			free(result);
+
+		free(result);
+		SlimList_Iterator_Advance(&iterator);
 	}
 
 	return results;

src/CSlim/SlimConnectionHandler.c

@@ -39,41 +39,43 @@ void SlimConnectionHandler_RegisterSlimMessageHandler(SlimConnectionHandler* sel
 int read_size(SlimConnectionHandler* self)
 {
 	char size[7];
-	size_t size_i = 0;
+	int size_i = 0;
 	char colon;
 	memset(size, (size_t)0, (size_t)7);
 
-	if (self->recvFunc(self->comLink, size, 6) == 6)
+	int receiveResult = self->recvFunc(self->comLink, size, 6);
+	if (receiveResult == 6)
 	{
 		if ((self->recvFunc(self->comLink, &colon, 1)) == 1 && colon == ':')
 		{
 			size_i = atoi(size);
 		}
+	} else if (receiveResult == -1) {
+		size_i = -1;;
 	}
-	return (int)size_i;
+	return size_i;
 }
 
 
 int SlimConnectionHandler_Run(SlimConnectionHandler* self)
 {
-	char * message = (char*)malloc((size_t)3);
-	message[0] = 0;
-	int numbytes;
 
 	if (self->sendFunc(self->comLink, "Slim -- V0.0\n", 13) == -1)
 	{
 		return -1;
 	}
 
+	char* message = NULL;
 	while(1)
 	{
 		int size_i = read_size(self);
+
 		if (size_i > 0)
 		{
 			free(message);
 			message = (char*)malloc(size_i + (size_t)1);
 			memset(message, 0, (size_t)size_i + (size_t)1);
-			numbytes = self->recvFunc(self->comLink, message, size_i);
+			int numbytes = self->recvFunc(self->comLink, message, size_i);
 			if (numbytes != size_i)
 			{
 				printf("did not receive right number of bytes.  %d expected but received %d\n", size_i, numbytes);
@@ -92,6 +94,9 @@ int SlimConnectionHandler_Run(SlimConnectionHandler* self)
 			free(length_buffer);
 			send_result = self->sendFunc(self->comLink, response_message, response_length);
 			SlimList_Release(response_message);
+		} else if (size_i == -1)
+		{
+			break;
 		}
 	}
 	free(message);