Introduce os_memdup()

This can be used to clean the code and reduce size by converting
os_malloc() followed by os_memcpy() cases to use a single function call.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

src/utils/os.h

@@ -614,6 +614,18 @@ size_t os_strlcpy(char *dest, const char *src, size_t siz);
  */
 int os_memcmp_const(const void *a, const void *b, size_t len);
 
+
+/**
+ * os_memdup - Allocate duplicate of passed memory chunk
+ * @src: Source buffer to duplicate
+ * @len: Length of source buffer
+ * Returns: %NULL if allocation failed, copy of src buffer otherwise
+ *
+ * This function allocates a memory block like os_malloc() would, and
+ * copies the given source buffer into it.
+ */
+void * os_memdup(const void *src, size_t len);
+
 /**
  * os_exec - Execute an external program
  * @program: Path to the program

src/utils/os_none.c

@@ -114,6 +114,12 @@ void * os_zalloc(size_t size)
 }
 
 
+void * os_memdup(const void *src, size_t n)
+{
+	return NULL;
+}
+
+
 #ifdef OS_NO_C_LIB_DEFINES
 void * os_malloc(size_t size)
 {

src/utils/os_unix.c

@@ -508,6 +508,16 @@ int os_memcmp_const(const void *a, const void *b, size_t len)
 }
 
 
+void * os_memdup(const void *src, size_t len)
+{
+	void *r = os_malloc(len);
+
+	if (r)
+		os_memcpy(r, src, len);
+	return r;
+}
+
+
 #ifdef WPA_TRACE
 
 #if defined(WPA_TRACE_BFD) && defined(CONFIG_TESTING_OPTIONS)
@@ -540,6 +550,8 @@ static int testing_fail_alloc(void)
 		i++;
 	if (i < res && os_strcmp(func[i], "os_strdup") == 0)
 		i++;
+	if (i < res && os_strcmp(func[i], "os_memdup") == 0)
+		i++;
 
 	pos = wpa_trace_fail_func;
 

src/utils/os_win32.c

@@ -283,3 +283,13 @@ int os_exec(const char *program, const char *arg, int wait_completion)
 {
 	return -1;
 }
+
+
+void * os_memdup(const void *src, size_t len)
+{
+	void *r = os_malloc(len);
+
+	if (r)
+		os_memcpy(r, src, len);
+	return r;
+}