source: vendor/3.5.5/source4/librpc/rpc/pyrpc.c

/* 
   Unix SMB/CIFS implementation.
   Samba utility functions
   Copyright (C) Jelmer Vernooij <jelmer@samba.org> 2008
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include <Python.h>
#include <structmember.h>
#include "librpc/rpc/pyrpc.h"
#include "librpc/rpc/dcerpc.h"
#include "lib/events/events.h"
#include "param/pyparam.h"
#include "auth/credentials/pycredentials.h"

#ifndef Py_RETURN_NONE
#define Py_RETURN_NONE return Py_INCREF(Py_None), Py_None
#endif

static PyObject *py_dcerpc_run_function(dcerpc_InterfaceObject *iface,
                                        const struct PyNdrRpcMethodDef *md,
                                        PyObject *args, PyObject *kwargs)
{
        TALLOC_CTX *mem_ctx;
        NTSTATUS status;
        void *r;
        PyObject *result = Py_None;

        if (md->pack_in_data == NULL || md->unpack_out_data == NULL) {
                PyErr_SetString(PyExc_NotImplementedError, "No marshalling code available yet");
                return NULL;
        }

        mem_ctx = talloc_new(NULL);
        if (mem_ctx == NULL) {
                PyErr_NoMemory();
                return NULL;
        }

        r = talloc_zero_size(mem_ctx, md->table->calls[md->opnum].struct_size);
        if (r == NULL) {
                PyErr_NoMemory();
                return NULL;
        }

        if (!md->pack_in_data(args, kwargs, r)) {
                talloc_free(mem_ctx);
                return NULL;
        }

        status = md->call(iface->pipe, mem_ctx, r);
        if (NT_STATUS_IS_ERR(status)) {
                PyErr_SetDCERPCStatus(iface->pipe, status);
                talloc_free(mem_ctx);
                return NULL;
        }

        result = md->unpack_out_data(r);

        talloc_free(mem_ctx);
        return result;
}

static PyObject *py_dcerpc_call_wrapper(PyObject *self, PyObject *args, void *wrapped, PyObject *kwargs)
{       
        dcerpc_InterfaceObject *iface = (dcerpc_InterfaceObject *)self;
        const struct PyNdrRpcMethodDef *md = (const struct PyNdrRpcMethodDef *)wrapped;

        return py_dcerpc_run_function(iface, md, args, kwargs);
}


bool PyInterface_AddNdrRpcMethods(PyTypeObject *ifacetype, const struct PyNdrRpcMethodDef *mds)
{
        int i;
        for (i = 0; mds[i].name; i++) {
                PyObject *ret;
                struct wrapperbase *wb = (struct wrapperbase *)calloc(sizeof(struct wrapperbase), 1);

                wb->name = discard_const_p(char, mds[i].name);
                wb->flags = PyWrapperFlag_KEYWORDS;
                wb->wrapper = (wrapperfunc)py_dcerpc_call_wrapper;
                wb->doc = discard_const_p(char, mds[i].doc);
                
                ret = PyDescr_NewWrapper(ifacetype, wb, discard_const_p(void, &mds[i]));

                PyDict_SetItemString(ifacetype->tp_dict, mds[i].name, 
                                     (PyObject *)ret);
        }

        return true;
}

static bool PyString_AsGUID(PyObject *object, struct GUID *uuid)
{
        NTSTATUS status;
        status = GUID_from_string(PyString_AsString(object), uuid);
        if (NT_STATUS_IS_ERR(status)) {
                PyErr_SetNTSTATUS(status);
                return false;
        }
        return true;
}

static bool ndr_syntax_from_py_object(PyObject *object, struct ndr_syntax_id *syntax_id)
{
        ZERO_STRUCTP(syntax_id);

        if (PyString_Check(object)) {
                return PyString_AsGUID(object, &syntax_id->uuid);
        } else if (PyTuple_Check(object)) {
                if (PyTuple_Size(object) < 1 || PyTuple_Size(object) > 2) {
                        PyErr_SetString(PyExc_ValueError, "Syntax ID tuple has invalid size");
                        return false;
                }

                if (!PyString_Check(PyTuple_GetItem(object, 0))) {
                        PyErr_SetString(PyExc_ValueError, "Expected GUID as first element in tuple");
                        return false;
                }

                if (!PyString_AsGUID(PyTuple_GetItem(object, 0), &syntax_id->uuid)) 
                        return false;

                if (!PyInt_Check(PyTuple_GetItem(object, 1))) {
                        PyErr_SetString(PyExc_ValueError, "Expected version as second element in tuple");
                        return false;
                }

                syntax_id->if_version = PyInt_AsLong(PyTuple_GetItem(object, 1));
                return true;
        }

        PyErr_SetString(PyExc_TypeError, "Expected UUID or syntax id tuple");
        return false;
}       

static PyObject *py_iface_server_name(PyObject *obj, void *closure)
{
        const char *server_name;
        dcerpc_InterfaceObject *iface = (dcerpc_InterfaceObject *)obj;
        
        server_name = dcerpc_server_name(iface->pipe);
        if (server_name == NULL)
                Py_RETURN_NONE;

        return PyString_FromString(server_name);
}

static PyObject *py_ndr_syntax_id(struct ndr_syntax_id *syntax_id)
{
        PyObject *ret;
        char *uuid_str;

        uuid_str = GUID_string(NULL, &syntax_id->uuid);
        if (uuid_str == NULL)
                return NULL;

        ret = Py_BuildValue("(s,i)", uuid_str, syntax_id->if_version);

        talloc_free(uuid_str);

        return ret;
}

static PyObject *py_iface_abstract_syntax(PyObject *obj, void *closure)
{
        dcerpc_InterfaceObject *iface = (dcerpc_InterfaceObject *)obj;

        return py_ndr_syntax_id(&iface->pipe->syntax);
}

static PyObject *py_iface_transfer_syntax(PyObject *obj, void *closure)
{
        dcerpc_InterfaceObject *iface = (dcerpc_InterfaceObject *)obj;

        return py_ndr_syntax_id(&iface->pipe->transfer_syntax);
}

static PyGetSetDef dcerpc_interface_getsetters[] = {
        { discard_const_p(char, "server_name"), py_iface_server_name, NULL,
          discard_const_p(char, "name of the server, if connected over SMB") },
        { discard_const_p(char, "abstract_syntax"), py_iface_abstract_syntax, NULL, 
          discard_const_p(char, "syntax id of the abstract syntax") },
        { discard_const_p(char, "transfer_syntax"), py_iface_transfer_syntax, NULL, 
          discard_const_p(char, "syntax id of the transfersyntax") },
        { NULL }
};

static PyMemberDef dcerpc_interface_members[] = {
        { discard_const_p(char, "request_timeout"), T_INT, 
          offsetof(struct dcerpc_pipe, request_timeout), 0,
          discard_const_p(char, "request timeout, in seconds") },
        { NULL }
};

void PyErr_SetDCERPCStatus(struct dcerpc_pipe *p, NTSTATUS status)
{
        if (p != NULL && NT_STATUS_EQUAL(status, NT_STATUS_NET_WRITE_FAULT)) {
                const char *errstr = dcerpc_errstr(NULL, p->last_fault_code);
                PyErr_SetObject(PyExc_RuntimeError, 
                        Py_BuildValue("(i,s)", p->last_fault_code,
                                      errstr));
        } else {
                PyErr_SetNTSTATUS(status);
        }
}

static PyObject *py_iface_request(PyObject *self, PyObject *args, PyObject *kwargs)
{
        dcerpc_InterfaceObject *iface = (dcerpc_InterfaceObject *)self;
        int opnum;
        DATA_BLOB data_in, data_out;
        NTSTATUS status;
        char *in_data;
        int in_length;
        PyObject *ret;
        PyObject *object = NULL;
        struct GUID object_guid;
        TALLOC_CTX *mem_ctx = talloc_new(NULL);
        const char *kwnames[] = { "opnum", "data", "object", NULL };

        if (!PyArg_ParseTupleAndKeywords(args, kwargs, "is#|O:request", 
                discard_const_p(char *, kwnames), &opnum, &in_data, &in_length, &object)) {
                return NULL;
        }

        data_in.data = (uint8_t *)talloc_memdup(mem_ctx, in_data, in_length);
        data_in.length = in_length;

        ZERO_STRUCT(data_out);

        if (object != NULL && !PyString_AsGUID(object, &object_guid)) {
                return NULL;
        }

        status = dcerpc_request(iface->pipe, object?&object_guid:NULL,
                                opnum, mem_ctx, &data_in, &data_out);

        if (NT_STATUS_IS_ERR(status)) {
                PyErr_SetDCERPCStatus(iface->pipe, status);
                talloc_free(mem_ctx);
                return NULL;
        }

        ret = PyString_FromStringAndSize((char *)data_out.data, data_out.length);

        talloc_free(mem_ctx);
        return ret;
}

static PyObject *py_iface_alter_context(PyObject *self, PyObject *args, PyObject *kwargs)
{
        dcerpc_InterfaceObject *iface = (dcerpc_InterfaceObject *)self;
        NTSTATUS status;
        const char *kwnames[] = { "abstract_syntax", "transfer_syntax", NULL };
        PyObject *py_abstract_syntax = Py_None, *py_transfer_syntax = Py_None;
        struct ndr_syntax_id abstract_syntax, transfer_syntax;

        if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O|O:alter_context", 
                discard_const_p(char *, kwnames), &py_abstract_syntax,
                &py_transfer_syntax)) {
                return NULL;
        }

        if (!ndr_syntax_from_py_object(py_abstract_syntax, &abstract_syntax))
                return NULL;

        if (py_transfer_syntax == Py_None) {
                transfer_syntax = ndr_transfer_syntax;
        } else {
                if (!ndr_syntax_from_py_object(py_transfer_syntax, 
                                               &transfer_syntax))
                        return NULL;
        }

        status = dcerpc_alter_context(iface->pipe, iface->pipe, &abstract_syntax, 
                                      &transfer_syntax);

        if (NT_STATUS_IS_ERR(status)) {
                PyErr_SetDCERPCStatus(iface->pipe, status);
                return NULL;
        }

        Py_RETURN_NONE;
}

PyObject *py_dcerpc_interface_init_helper(PyTypeObject *type, PyObject *args, PyObject *kwargs, const struct ndr_interface_table *table)
{
        dcerpc_InterfaceObject *ret;
        const char *binding_string;
        struct cli_credentials *credentials;
        struct loadparm_context *lp_ctx = NULL;
        PyObject *py_lp_ctx = Py_None, *py_credentials = Py_None, *py_basis = Py_None;
        TALLOC_CTX *mem_ctx = NULL;
        struct tevent_context *event_ctx;
        NTSTATUS status;

        const char *kwnames[] = {
                "binding", "lp_ctx", "credentials", "basis_connection", NULL
        };

        if (!PyArg_ParseTupleAndKeywords(args, kwargs, "s|OOO:samr", discard_const_p(char *, kwnames), &binding_string, &py_lp_ctx, &py_credentials, &py_basis)) {
                return NULL;
        }

        lp_ctx = lp_from_py_object(py_lp_ctx);
        if (lp_ctx == NULL) {
                PyErr_SetString(PyExc_TypeError, "Expected loadparm context");
                return NULL;
        }

        status = dcerpc_init(lp_ctx);
        if (!NT_STATUS_IS_OK(status)) {
                PyErr_SetNTSTATUS(status);
                return NULL;
        }
        credentials = cli_credentials_from_py_object(py_credentials);
        if (credentials == NULL) {
                PyErr_SetString(PyExc_TypeError, "Expected credentials");
                return NULL;
        }
        ret = PyObject_New(dcerpc_InterfaceObject, type);

        event_ctx = event_context_init(mem_ctx);

        if (py_basis != Py_None) {
                struct dcerpc_pipe *base_pipe;

                if (!PyObject_TypeCheck(py_basis, &dcerpc_InterfaceType)) {
                        PyErr_SetString(PyExc_ValueError, "basis_connection must be a DCE/RPC connection");
                        talloc_free(mem_ctx);
                        return NULL;
                }

                base_pipe = ((dcerpc_InterfaceObject *)py_basis)->pipe;

                status = dcerpc_secondary_context(base_pipe, &ret->pipe, table);
        } else {
                status = dcerpc_pipe_connect(NULL, &ret->pipe, binding_string, 
                             table, credentials, event_ctx, lp_ctx);
        }
        if (NT_STATUS_IS_ERR(status)) {
                PyErr_SetNTSTATUS(status);
                talloc_free(mem_ctx);
                return NULL;
        }

        ret->pipe->conn->flags |= DCERPC_NDR_REF_ALLOC;
        return (PyObject *)ret;
}

static PyMethodDef dcerpc_interface_methods[] = {
        { "request", (PyCFunction)py_iface_request, METH_VARARGS|METH_KEYWORDS, "S.request(opnum, data, object=None) -> data\nMake a raw request" },
        { "alter_context", (PyCFunction)py_iface_alter_context, METH_VARARGS|METH_KEYWORDS, "S.alter_context(syntax)\nChange to a different interface" },
        { NULL, NULL, 0, NULL },
};


static void dcerpc_interface_dealloc(PyObject* self)
{
        dcerpc_InterfaceObject *interface = (dcerpc_InterfaceObject *)self;
        talloc_free(interface->pipe);
        PyObject_Del(self);
}

static PyObject *dcerpc_interface_new(PyTypeObject *self, PyObject *args, PyObject *kwargs)
{
        dcerpc_InterfaceObject *ret;
        const char *binding_string;
        struct cli_credentials *credentials;
        struct loadparm_context *lp_ctx = NULL;
        PyObject *py_lp_ctx = Py_None, *py_credentials = Py_None;
        TALLOC_CTX *mem_ctx = NULL;
        struct tevent_context *event_ctx;
        NTSTATUS status;

        PyObject *syntax, *py_basis = Py_None;
        const char *kwnames[] = {
                "binding", "syntax", "lp_ctx", "credentials", "basis_connection", NULL
        };
        struct ndr_interface_table *table;

        if (!PyArg_ParseTupleAndKeywords(args, kwargs, "sO|OOO:connect", discard_const_p(char *, kwnames), &binding_string, &syntax, &py_lp_ctx, &py_credentials, &py_basis)) {
                return NULL;
        }

        lp_ctx = lp_from_py_object(py_lp_ctx);
        if (lp_ctx == NULL) {
                PyErr_SetString(PyExc_TypeError, "Expected loadparm context");
                return NULL;
        }

        credentials = cli_credentials_from_py_object(py_credentials);
        if (credentials == NULL) {
                PyErr_SetString(PyExc_TypeError, "Expected credentials");
                return NULL;
        }
        ret = PyObject_New(dcerpc_InterfaceObject, &dcerpc_InterfaceType);

        event_ctx = s4_event_context_init(mem_ctx);

        /* Create a dummy interface table struct. TODO: In the future, we should rather just allow 
         * connecting without requiring an interface table.
         */

        table = talloc_zero(mem_ctx, struct ndr_interface_table);

        if (table == NULL) {
                PyErr_SetString(PyExc_MemoryError, "Allocating interface table");
                return NULL;
        }

        if (!ndr_syntax_from_py_object(syntax, &table->syntax_id)) {
                return NULL;
        }

        ret->pipe = NULL;

        if (py_basis != Py_None) {
                struct dcerpc_pipe *base_pipe;

                if (!PyObject_TypeCheck(py_basis, &dcerpc_InterfaceType)) {
                        PyErr_SetString(PyExc_ValueError, "basis_connection must be a DCE/RPC connection");
                        talloc_free(mem_ctx);
                        return NULL;
                }

                base_pipe = ((dcerpc_InterfaceObject *)py_basis)->pipe;

                status = dcerpc_secondary_context(base_pipe, &ret->pipe, 
                                     table);
                ret->pipe = talloc_steal(NULL, ret->pipe);
        } else {
                status = dcerpc_pipe_connect(NULL, &ret->pipe, binding_string, 
                             table, credentials, event_ctx, lp_ctx);
        }

        if (NT_STATUS_IS_ERR(status)) {
                PyErr_SetDCERPCStatus(ret->pipe, status);
                talloc_free(mem_ctx);
                return NULL;
        }
        ret->pipe->conn->flags |= DCERPC_NDR_REF_ALLOC;
        return (PyObject *)ret;
}

PyTypeObject dcerpc_InterfaceType = {
        PyObject_HEAD_INIT(NULL) 0,
        .tp_name = "dcerpc.ClientConnection",
        .tp_basicsize = sizeof(dcerpc_InterfaceObject),
        .tp_dealloc = dcerpc_interface_dealloc,
        .tp_getset = dcerpc_interface_getsetters,
        .tp_members = dcerpc_interface_members,
        .tp_methods = dcerpc_interface_methods,
        .tp_doc = "ClientConnection(binding, syntax, lp_ctx=None, credentials=None) -> connection\n"
"\n"
"binding should be a DCE/RPC binding string (for example: ncacn_ip_tcp:127.0.0.1)\n"
"syntax should be a tuple with a GUID and version number of an interface\n"
"lp_ctx should be a path to a smb.conf file or a param.LoadParm object\n"
"credentials should be a credentials.Credentials object.\n\n",
        .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
        .tp_new = dcerpc_interface_new,
};

void initbase(void)
{
        PyObject *m;

        if (PyType_Ready(&dcerpc_InterfaceType) < 0)
                return;

        m = Py_InitModule3("base", NULL, "DCE/RPC protocol implementation");
        if (m == NULL)
                return;

        Py_INCREF((PyObject *)&dcerpc_InterfaceType);
        PyModule_AddObject(m, "ClientConnection", (PyObject *)&dcerpc_InterfaceType);
}