librpc: Avoid talloc in GUID_from_data_blob()

This is often found in inner loops in the dsdb code, because LDB DNs often contain a GUID string

Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Garming Sam <garming@catalyst.net.nz>

diff --git a/librpc/ndr/uuid.c b/librpc/ndr/uuid.c
index 9d955abc3d55f1151d17da0d03cee0f628b09782..fbd305e54019d570447a96ad766f11db01f38ccf 100644 (file)
--- a/librpc/ndr/uuid.c
+++ b/librpc/ndr/uuid.c
@@ -71,13 +71,10 @@ _PUBLIC_ NTSTATUS GUID_from_data_blob(const DATA_BLOB *s, struct GUID *guid)
        switch(s->length) {
        case 36:
        {
-               TALLOC_CTX *mem_ctx;
-               const char *string;
+               char string[37];
+               memcpy(string, s->data, 36);
+               string[36] = 0;
 
-               mem_ctx = talloc_new(NULL);
-               NT_STATUS_HAVE_NO_MEMORY(mem_ctx);
-               string = talloc_strndup(mem_ctx, (const char *)s->data, s->length);
-               NT_STATUS_HAVE_NO_MEMORY(string);
                if (11 == sscanf(string,
                                 "%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
                                 &time_low, &time_mid, &time_hi_and_version, 
@@ -85,26 +82,21 @@ _PUBLIC_ NTSTATUS GUID_from_data_blob(const DATA_BLOB *s, struct GUID *guid)
                                 &node[0], &node[1], &node[2], &node[3], &node[4], &node[5])) {
                        status = NT_STATUS_OK;
                }
-               talloc_free(mem_ctx);
                break;
        }
        case 38:
        {
-               TALLOC_CTX *mem_ctx;
-               const char *string;
-
-               mem_ctx = talloc_new(NULL);
-               NT_STATUS_HAVE_NO_MEMORY(mem_ctx);
-               string = talloc_strndup(mem_ctx, (const char *)s->data, s->length);
-               NT_STATUS_HAVE_NO_MEMORY(string);
-               if (11 == sscanf((const char *)s->data, 
+               char string[39];
+               memcpy(string, s->data, 38);
+               string[38] = 0;
+
+               if (11 == sscanf(string, 
                                 "{%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x}",
                                 &time_low, &time_mid, &time_hi_and_version, 
                                 &clock_seq[0], &clock_seq[1],
                                 &node[0], &node[1], &node[2], &node[3], &node[4], &node[5])) {
                        status = NT_STATUS_OK;
                }
-               talloc_free(mem_ctx);
                break;
        }
        case 32: