[AXIS2C-783] Client seg faults if AXIS2C_HOME variable not set

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.1.0
• Fix Version/s: 1.2.0
• Component/s: code generation, core/clientapi, core/deployment
• Environment: Window XP, Visual Studio 2005
• Assignee: Dinesh Weerapurage
• Reporter: Bill Mitchell
• Created: 22/Nov/07 00:52
• Updated: 30/Nov/07 20:33
• Resolved: 30/Nov/07 13:31

Description

If the AXIS2C_HOME variable is not set, or if the client application code sets the ClientHome argument to a directory that does not containt axis2.xml and related files, the client application fails with a segmentation fault. Investigating this uncovered several issues, best described by highlighting the relevant actions in the code in chronological order:
(1) axis2_dep_engine_check_client_home() in depengine.c detects the problem and stores an error code, AXIS2_ERROR_CONFIG_NOT_FOUND (18). But processing at this point is allowed to continue.
(2) axis2_conf_builder_create_with_file_and_dep_engine_and_conf(), in particular axis2_desc_builder_create_with_file_and_dep_engine(), then changes the status_code in the environment error structure back to success. This is a side-effect of invoking the AXIS2_PARM_CHECK macro.
(3) In axis2_desc_builder_build_om(), the call to axiom_xml_reader_create_for_file() returns an error, but the error number has now been replaced
with AXIS2_ERROR_CREATING_XML_STREAM_READER(141). Axis2_desc_builder_build_om() then replaces this error number with the same value, just to
make sure it is well and truly changed.
(4) In stub.c, axis2_stub_create_with_endpoint_ref_and_client_home() replaces the error 141 with a truly misleading AXIS2_ERROR_NO_MEMORY(2).
(5) In the generated stub code to create the service, axis2_stub_servicename_create() ignores the fact that the returned stub pointer is zero and goes ahead and calls axis2_stub_servicename_populate_services() anyway, where the code dies dereferencing the zero pointer.

Recommendations:
(5) In the generated stub code for axis2_stub_servicename_create(), the fragment
stub = axis2_stub_create_with_endpoint_ref_and_client_home ( env, endpoint_ref, client_home );
axis2_stub_servicename_populate_services( stub, env );
return stub;
should read:
stub = axis2_stub_create_with_endpoint_ref_and_client_home ( env, endpoint_ref, client_home );
if (stub)

{ axis2_stub_servicename_populate_services( stub, env ); }

return stub;

(4) In stub.c, the procedure axis2_stub_create_with_endpoint_ref_and_client_home() really needs to let the underlying error number be returned. In the fragment:
/* create service_client*/
stub->svc_client = axis2_svc_client_create(env , client_home);
if (!stub->svc_client)

{ axis2_stub_free(stub, env); AXIS2_ERROR_SET(env->error, AXIS2_ERROR_NO_MEMORY, AXIS2_FAILURE); return NULL; }

the AXIS2_ERROR_SET invocation should be removed.

(1) Where the client has passed a clienthome parameter, but it does not point to a valid Axis2C home directory structure, I prefer the first error code AXIS2_ERROR_CONFIG_NOT_FOUND to the second AXIS2_ERROR_CREATING_XML_STREAM_READER. So I suggest that axis2_dep_engine_load_client() in depengine.c be changed to treat this as an immediate error instead of letting processing continue. The fragment:
if (client_home && 0 != axutil_strcmp("", client_home))
{
status = axis2_dep_engine_check_client_home(dep_engine, env, client_home);
if (AXIS2_SUCCESS == status)

{ is_repos_exist = AXIS2_TRUE; }

}
else
could be changed to:
if (client_home && 0 != axutil_strcmp("", client_home))
{
status = axis2_dep_engine_check_client_home(dep_engine, env, client_home);
if (AXIS2_SUCCESS != status)

{ return NULL; }

is_repos_exist = AXIS2_TRUE;
}
else
Of course, there may be a good reason to want to continue processing that I have not uncovered. In this case, you could instead do something to resolve item(2), such that the original error code could be returned instead of overlaying it as happens at point (3).