librpc/rpc: add dcerpc_binding_[g|s]et_abstract_syntax()

For now this is just an alternate wrapper to
access binding->object.

Currently callers are reusing binding->object to store the
abstract syntax id instead of just the object uuid.

Some services on Windows use the same GUID for the
'object' and the 'abstract syntax', but they are completely
different things!

Most services use a null object guid, some reuse the
guid of the abstract syntax and use it like a 'class' object.

But the object guid is only really used by DCOM,
in order to call functions relative to an object instance,
which a dynamically allocated object guid.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Guenther Deschner <gd@samba.org>

2 files changed, 60 insertions, 5 deletions

diff --git a/librpc/rpc/binding.c b/librpc/rpc/binding.c
index 65cdb36a0e6..2b584b57326 100644
--- a/librpc/rpc/binding.c
+++ b/librpc/rpc/binding.c
@@ -542,6 +542,49 @@ _PUBLIC_ NTSTATUS dcerpc_binding_set_assoc_group_id(struct dcerpc_binding *b,
 	return NT_STATUS_OK;
 }
 
+_PUBLIC_ struct ndr_syntax_id dcerpc_binding_get_abstract_syntax(const struct dcerpc_binding *b)
+{
+	/*
+	 * For now we just use object, until all callers are fixed.
+	 */
+	return b->object;
+}
+
+_PUBLIC_ NTSTATUS dcerpc_binding_set_abstract_syntax(struct dcerpc_binding *b,
+						     const struct ndr_syntax_id *syntax)
+{
+	NTSTATUS status;
+	struct GUID object;
+
+	/*
+	 * For now we just use object, until all callers are fixed.
+	 */
+
+	if (syntax != NULL) {
+		object = syntax->uuid;
+	} else {
+		object = GUID_zero();
+	}
+
+	/*
+	 * This sets also the string
+	 */
+	status = dcerpc_binding_set_object(b, object);
+	if (!NT_STATUS_IS_OK(status)) {
+		return status;
+	}
+
+	if (syntax != NULL) {
+		/*
+		 * Here we need to reset the whole ndr_syntax_id
+		 * structure including the .if_version
+		 */
+		b->object = *syntax;
+	}
+
+	return NT_STATUS_OK;
+}
+
 _PUBLIC_ const char *dcerpc_binding_get_string_option(const struct dcerpc_binding *b,
 						      const char *name)
 {
@@ -1145,6 +1188,7 @@ _PUBLIC_ NTSTATUS dcerpc_binding_from_tower(TALLOC_CTX *mem_ctx,
 {
 	NTSTATUS status;
 	struct dcerpc_binding *binding;
+	struct ndr_syntax_id abstract_syntax;
 
 	/*
 	 * A tower needs to have at least 4 floors to carry useful
@@ -1172,12 +1216,17 @@ _PUBLIC_ NTSTATUS dcerpc_binding_from_tower(TALLOC_CTX *mem_ctx,
 		return NT_STATUS_NOT_SUPPORTED;
 	}
 
-	/* Set object uuid */
-	status = dcerpc_floor_get_lhs_data(&tower->floors[0], &binding->object);
+	/* Set abstract syntax */
+	status = dcerpc_floor_get_lhs_data(&tower->floors[0], &abstract_syntax);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(1, ("Error pulling abstract syntax: %s", nt_errstr(status)));
+		return status;
+	}
 
+	status = dcerpc_binding_set_abstract_syntax(binding, &abstract_syntax);
 	if (!NT_STATUS_IS_OK(status)) {
-		DEBUG(1, ("Error pulling object uuid and version: %s", nt_errstr(status)));
 		talloc_free(binding);
+		DEBUG(1, ("Error set object uuid and version: %s", nt_errstr(status)));
 		return status;
 	}
 
@@ -1297,6 +1346,7 @@ _PUBLIC_ NTSTATUS dcerpc_binding_build_tower(TALLOC_CTX *mem_ctx,
 {
 	const enum epm_protocol *protseq = NULL;
 	int num_protocols = -1, i;
+	struct ndr_syntax_id abstract_syntax;
 	NTSTATUS status;
 
 	/* Find transport */
@@ -1319,10 +1369,12 @@ _PUBLIC_ NTSTATUS dcerpc_binding_build_tower(TALLOC_CTX *mem_ctx,
 	/* Floor 0 */
 	tower->floors[0].lhs.protocol = EPM_PROTOCOL_UUID;
 
-	tower->floors[0].lhs.lhs_data = dcerpc_floor_pack_lhs_data(tower->floors, &binding->object);
+	abstract_syntax = dcerpc_binding_get_abstract_syntax(binding);
+	tower->floors[0].lhs.lhs_data = dcerpc_floor_pack_lhs_data(tower->floors,
+								   &abstract_syntax);
 
 	if (!dcerpc_floor_pack_rhs_if_version_data(
-		    tower->floors, &binding->object,
+		    tower->floors, &abstract_syntax,
 		    &tower->floors[0].rhs.uuid.unknown)) {
 		return NT_STATUS_NO_MEMORY;
 	}
diff --git a/librpc/rpc/rpc_common.h b/librpc/rpc/rpc_common.h
index 428acfeea3f..fa75b520c32 100644
--- a/librpc/rpc/rpc_common.h
+++ b/librpc/rpc/rpc_common.h
@@ -146,6 +146,9 @@ void dcerpc_binding_get_auth_info(const struct dcerpc_binding *b,
 uint32_t dcerpc_binding_get_assoc_group_id(const struct dcerpc_binding *b);
 NTSTATUS dcerpc_binding_set_assoc_group_id(struct dcerpc_binding *b,
 					   uint32_t assoc_group_id);
+struct ndr_syntax_id dcerpc_binding_get_abstract_syntax(const struct dcerpc_binding *b);
+NTSTATUS dcerpc_binding_set_abstract_syntax(struct dcerpc_binding *b,
+					    const struct ndr_syntax_id *syntax);
 const char *dcerpc_binding_get_string_option(const struct dcerpc_binding *b,
 					     const char *name);
 char *dcerpc_binding_copy_string_option(TALLOC_CTX *mem_ctx,