From: Andrew Bartlett <abartlet@samba.org>
Date: Wed, 15 Jun 2016 03:54:06 +0000 (+1200)
Subject: librpc: Avoid talloc in GUID_from_data_blob()
X-Git-Tag: tdb-1.3.10~701
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=4304eac85437d72f4aed36fc7797004cd97fbc9a;p=thirdparty%2Fsamba.git

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 9d955abc3d5..fbd305e5401 100644
--- 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: