r5405: try to use NBT name pointers when a netbios name is repeated in a NBT

packet. This allows much longer names to fit within the limits of NBT
name packets (rfc1002.txt also says this should be done, although
Samba3 never generates them).

The main reason for doing this is it means that our NBT name pointer
decoding code is tested with the smbtorture tests
(This used to be commit 6e2feef125daceb143c44c0c4ab73b010b311792)

1 files changed, 25 insertions, 7 deletions

diff --git a/source4/libcli/nbt/nbtname.c b/source4/libcli/nbt/nbtname.c
index bf545a6374..12b8884e2d 100644
--- a/source4/libcli/nbt/nbtname.c
+++ b/source4/libcli/nbt/nbtname.c
@@ -214,8 +214,9 @@ NTSTATUS ndr_push_nbt_name(struct ndr_push *ndr, int ndr_flags, struct nbt_name
 	uint_t num_components;
 	uint8_t *components[MAX_COMPONENTS];
 	char *dscope=NULL, *p;
-	uint8_t *cname;
+	uint8_t *cname, *fullname;
 	int i;
+	int fulllen;
 
 	if (!(ndr_flags & NDR_SCALARS)) {
 		return NT_STATUS_OK;
@@ -246,14 +247,31 @@ NTSTATUS ndr_push_nbt_name(struct ndr_push *ndr, int ndr_flags, struct nbt_name
 	if (num_components == MAX_COMPONENTS) {
 		return NT_STATUS_BAD_NETWORK_NAME;
 	}
+
+	fullname = talloc_asprintf(ndr, "%c%s", (unsigned char)strlen(cname), cname);
+	NT_STATUS_HAVE_NO_MEMORY(fullname);
 		
-	/* push the components */
-	for (i=0;i<num_components;i++) {
-		uint8_t len = strlen(components[i]);
-		NDR_CHECK(ndr_push_uint8(ndr, NDR_SCALARS, len));
-		NDR_CHECK(ndr_push_bytes(ndr, components[i], len));
+	for (i=1;i<num_components;i++) {
+		fullname = talloc_asprintf_append(fullname, "%c%s", 
+						  (unsigned char)strlen(components[i]), components[i]);
+		NT_STATUS_HAVE_NO_MEMORY(fullname);
 	}
-	NDR_CHECK(ndr_push_uint8(ndr, NDR_SCALARS, 0));
+
+	/* see if we can find the fullname in the existing packet - if
+	   so, we can use a NBT name pointer. This allows us to fit
+	   longer names into the packet */
+	fulllen = strlen(fullname)+1;
+	for (i=0;i + fulllen < ndr->offset;i++) {
+		if (ndr->data[i] == fullname[0] &&
+		    memcmp(fullname, &ndr->data[i], fulllen) == 0) {
+			talloc_free(fullname);
+			return ndr_push_uint16(ndr, NDR_SCALARS, 0xC000 | i);
+		}
+	}
+
+	NDR_CHECK(ndr_push_bytes(ndr, fullname, fulllen));
+
+	talloc_free(fullname);
 
 	return NT_STATUS_OK;
 }