source: branches/samba-3.5.x/source4/lib/messaging/pymessaging.c

/* 
   Unix SMB/CIFS implementation.
   Copyright © Jelmer Vernooij <jelmer@samba.org> 2008

   Based on the equivalent for EJS:
   Copyright © Andrew Tridgell <tridge@samba.org> 2005
   
   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 "scripting/python/modules.h"
#include "libcli/util/pyerrors.h"
#include "librpc/rpc/pyrpc.h"
#include "lib/messaging/irpc.h"
#include "lib/messaging/messaging.h"
#include "lib/events/events.h"
#include "cluster/cluster.h"
#include "param/param.h"
#include "param/pyparam.h"

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

PyAPI_DATA(PyTypeObject) messaging_Type;
PyAPI_DATA(PyTypeObject) irpc_ClientConnectionType;

/* FIXME: This prototype should be in py_irpc.h, or shared otherwise */
extern const struct PyNdrRpcMethodDef py_ndr_irpc_methods[];

static bool server_id_from_py(PyObject *object, struct server_id *server_id)
{
        if (!PyTuple_Check(object)) {
                PyErr_SetString(PyExc_ValueError, "Expected tuple");
                return false;
        }

        if (PyTuple_Size(object) == 3) {
                return PyArg_ParseTuple(object, "iii", &server_id->id, &server_id->id2, &server_id->node);
        } else {
                int id, id2;
                if (!PyArg_ParseTuple(object, "ii", &id, &id2))
                        return false;
                *server_id = cluster_id(id, id2);
                return true;
        }
}

typedef struct {
        PyObject_HEAD
        TALLOC_CTX *mem_ctx;
        struct messaging_context *msg_ctx;
} messaging_Object;

PyObject *py_messaging_connect(PyTypeObject *self, PyObject *args, PyObject *kwargs)
{
        struct tevent_context *ev;
        const char *kwnames[] = { "own_id", "messaging_path", NULL };
        PyObject *own_id = Py_None;
        const char *messaging_path = NULL;
        messaging_Object *ret;

        if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|Oz:connect", 
                discard_const_p(char *, kwnames), &own_id, &messaging_path)) {
                return NULL;
        }

        ret = PyObject_New(messaging_Object, &messaging_Type);
        if (ret == NULL)
                return NULL;

        ret->mem_ctx = talloc_new(NULL);

        ev = s4_event_context_init(ret->mem_ctx);

        if (messaging_path == NULL) {
                messaging_path = lp_messaging_path(ret->mem_ctx, 
                                                                   py_default_loadparm_context(ret->mem_ctx));
        } else {
                messaging_path = talloc_strdup(ret->mem_ctx, messaging_path);
        }

        if (own_id != Py_None) {
                struct server_id server_id;

                if (!server_id_from_py(own_id, &server_id)) 
                        return NULL;

                ret->msg_ctx = messaging_init(ret->mem_ctx, 
                                            messaging_path,
                                            server_id,
                                        py_iconv_convenience(ret->mem_ctx),
                                            ev);
        } else {
                ret->msg_ctx = messaging_client_init(ret->mem_ctx, 
                                            messaging_path,
                                        py_iconv_convenience(ret->mem_ctx),
                                            ev);
        }

        if (ret->msg_ctx == NULL) {
                PyErr_SetString(PyExc_RuntimeError, "messaging_connect unable to create a messaging context");
                talloc_free(ret->mem_ctx);
                return NULL;
        }

        return (PyObject *)ret;
}

static void py_messaging_dealloc(PyObject *self)
{
        messaging_Object *iface = (messaging_Object *)self;
        talloc_free(iface->msg_ctx);
        PyObject_Del(self);
}

static PyObject *py_messaging_send(PyObject *self, PyObject *args, PyObject *kwargs)
{
        messaging_Object *iface = (messaging_Object *)self;
        uint32_t msg_type;
        DATA_BLOB data;
        PyObject *target;
        NTSTATUS status;
        struct server_id server;
        const char *kwnames[] = { "target", "msg_type", "data", NULL };
        int length;

        if (!PyArg_ParseTupleAndKeywords(args, kwargs, "Ois#|:send", 
                discard_const_p(char *, kwnames), &target, &msg_type, &data.data, &length)) {
                return NULL;
        }

        data.length = length;

        if (!server_id_from_py(target, &server)) 
                return NULL;

        status = messaging_send(iface->msg_ctx, server, msg_type, &data);
        if (NT_STATUS_IS_ERR(status)) {
                PyErr_SetNTSTATUS(status);
                return NULL;
        }

        Py_RETURN_NONE;
}

static void py_msg_callback_wrapper(struct messaging_context *msg, void *private_data,
                               uint32_t msg_type, 
                               struct server_id server_id, DATA_BLOB *data)
{
        PyObject *callback = (PyObject *)private_data;

        PyObject_CallFunction(callback, discard_const_p(char, "i(iii)s#"), msg_type, 
                              server_id.id, server_id.id2, server_id.node, 
                              data->data, data->length);
}

static PyObject *py_messaging_register(PyObject *self, PyObject *args, PyObject *kwargs)
{
        messaging_Object *iface = (messaging_Object *)self;
        int msg_type = -1;
        PyObject *callback;
        NTSTATUS status;
        const char *kwnames[] = { "callback", "msg_type", NULL };
        
        if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O|i:send", 
                discard_const_p(char *, kwnames), &callback, &msg_type)) {
                return NULL;
        }

        Py_INCREF(callback);

        if (msg_type == -1) {
                uint32_t msg_type32 = msg_type;
                status = messaging_register_tmp(iface->msg_ctx, callback,
                                                py_msg_callback_wrapper, &msg_type32);
                msg_type = msg_type32;
        } else {
                status = messaging_register(iface->msg_ctx, callback,
                                    msg_type, py_msg_callback_wrapper);
        }
        if (NT_STATUS_IS_ERR(status)) {
                PyErr_SetNTSTATUS(status);
                return NULL;
        }

        return PyLong_FromLong(msg_type);
}

static PyObject *py_messaging_deregister(PyObject *self, PyObject *args, PyObject *kwargs)
{
        messaging_Object *iface = (messaging_Object *)self;
        int msg_type = -1;
        PyObject *callback;
        const char *kwnames[] = { "callback", "msg_type", NULL };

        if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O|i:send", 
                discard_const_p(char *, kwnames), &callback, &msg_type)) {
                return NULL;
        }

        messaging_deregister(iface->msg_ctx, msg_type, callback);

        Py_DECREF(callback);

        Py_RETURN_NONE;
}

static PyObject *py_messaging_add_name(PyObject *self, PyObject *args, PyObject *kwargs)
{
        messaging_Object *iface = (messaging_Object *)self;
        NTSTATUS status;
        char *name;
        const char *kwnames[] = { "name", NULL };

        if (!PyArg_ParseTupleAndKeywords(args, kwargs, "s|:send", 
                discard_const_p(char *, kwnames), &name)) {
                return NULL;
        }

        status = irpc_add_name(iface->msg_ctx, name);
        if (NT_STATUS_IS_ERR(status)) {
                PyErr_SetNTSTATUS(status);
                return NULL;
        }

        Py_RETURN_NONE;
}


static PyObject *py_messaging_remove_name(PyObject *self, PyObject *args, PyObject *kwargs)
{
        messaging_Object *iface = (messaging_Object *)self;
        char *name;
        const char *kwnames[] = { "name", NULL };

        if (!PyArg_ParseTupleAndKeywords(args, kwargs, "s|:send", 
                discard_const_p(char *, kwnames), &name)) {
                return NULL;
        }

        irpc_remove_name(iface->msg_ctx, name);

        Py_RETURN_NONE;
}

static PyMethodDef py_messaging_methods[] = {
        { "send", (PyCFunction)py_messaging_send, METH_VARARGS|METH_KEYWORDS, 
                "S.send(target, msg_type, data) -> None\nSend a message" },
        { "register", (PyCFunction)py_messaging_register, METH_VARARGS|METH_KEYWORDS,
                "S.register(callback, msg_type=None) -> msg_type\nRegister a message handler" },
        { "deregister", (PyCFunction)py_messaging_deregister, METH_VARARGS|METH_KEYWORDS,
                "S.deregister(callback, msg_type) -> None\nDeregister a message handler" },
        { "add_name", (PyCFunction)py_messaging_add_name, METH_VARARGS|METH_KEYWORDS, "S.add_name(name) -> None\nListen on another name" },
        { "remove_name", (PyCFunction)py_messaging_remove_name, METH_VARARGS|METH_KEYWORDS, "S.remove_name(name) -> None\nStop listening on a name" },
        { NULL, NULL, 0, NULL }
};

static PyObject *py_messaging_server_id(PyObject *obj, void *closure)
{
        messaging_Object *iface = (messaging_Object *)obj;
        struct server_id server_id = messaging_get_server_id(iface->msg_ctx);

        return Py_BuildValue("(iii)", server_id.id, server_id.id2, 
                             server_id.node);
}

static PyGetSetDef py_messaging_getset[] = {
        { discard_const_p(char, "server_id"), py_messaging_server_id, NULL, 
          discard_const_p(char, "local server id") },
        { NULL },
};


PyTypeObject messaging_Type = {
        PyObject_HEAD_INIT(NULL) 0,
        .tp_name = "irpc.Messaging",
        .tp_basicsize = sizeof(messaging_Object),
        .tp_flags = Py_TPFLAGS_DEFAULT|Py_TPFLAGS_BASETYPE,
        .tp_new = py_messaging_connect,
        .tp_dealloc = py_messaging_dealloc,
        .tp_methods = py_messaging_methods,
        .tp_getset = py_messaging_getset,
        .tp_doc = "Messaging(own_id=None, messaging_path=None)\n" \
                  "Create a new object that can be used to communicate with the peers in the specified messaging path.\n" \
                  "If no path is specified, the default path from smb.conf will be used."
};


/*
  state of a irpc 'connection'
*/
typedef struct {
        PyObject_HEAD
        const char *server_name;
        struct server_id *dest_ids;
        struct messaging_context *msg_ctx;
        TALLOC_CTX *mem_ctx;
} irpc_ClientConnectionObject;

/*
  setup a context for talking to a irpc server
     example: 
        status = irpc.connect("smb_server");
*/

PyObject *py_irpc_connect(PyTypeObject *self, PyObject *args, PyObject *kwargs)
{
        struct tevent_context *ev;
        const char *kwnames[] = { "server", "own_id", "messaging_path", NULL };
        char *server;
        const char *messaging_path = NULL;
        PyObject *own_id = Py_None;
        irpc_ClientConnectionObject *ret;

        if (!PyArg_ParseTupleAndKeywords(args, kwargs, "s|Oz:connect", 
                discard_const_p(char *, kwnames), &server, &own_id, &messaging_path)) {
                return NULL;
        }

        ret = PyObject_New(irpc_ClientConnectionObject, &irpc_ClientConnectionType);
        if (ret == NULL)
                return NULL;

        ret->mem_ctx = talloc_new(NULL);

        ret->server_name = server;

        ev = s4_event_context_init(ret->mem_ctx);

        if (messaging_path == NULL) {
                messaging_path = lp_messaging_path(ret->mem_ctx, 
                                                                   py_default_loadparm_context(ret->mem_ctx));
        } else {
                messaging_path = talloc_strdup(ret->mem_ctx, messaging_path);
        }

        if (own_id != Py_None) {
                struct server_id server_id;

                if (!server_id_from_py(own_id, &server_id)) 
                        return NULL;

                ret->msg_ctx = messaging_init(ret->mem_ctx, 
                                            messaging_path,
                                            server_id,
                                        py_iconv_convenience(ret->mem_ctx),
                                            ev);
        } else {
                ret->msg_ctx = messaging_client_init(ret->mem_ctx, 
                                            messaging_path,
                                        py_iconv_convenience(ret->mem_ctx),
                                            ev);
        }

        if (ret->msg_ctx == NULL) {
                PyErr_SetString(PyExc_RuntimeError, "irpc_connect unable to create a messaging context");
                talloc_free(ret->mem_ctx);
                return NULL;
        }

        ret->dest_ids = irpc_servers_byname(ret->msg_ctx, ret->mem_ctx, ret->server_name);
        if (ret->dest_ids == NULL || ret->dest_ids[0].id == 0) {
                talloc_free(ret->mem_ctx);
                PyErr_SetNTSTATUS(NT_STATUS_OBJECT_NAME_NOT_FOUND);
                return NULL;
        } else {
                return (PyObject *)ret;
        }
}

typedef struct {
        PyObject_HEAD
        struct irpc_request **reqs;
        int count;
        int current;
        TALLOC_CTX *mem_ctx;
        py_data_unpack_fn unpack_fn;
} irpc_ResultObject;

        
static PyObject *irpc_result_next(irpc_ResultObject *iterator)
{
        NTSTATUS status;

        if (iterator->current >= iterator->count) {
                PyErr_SetString(PyExc_StopIteration, "No more results");
                return NULL;
        }

        status = irpc_call_recv(iterator->reqs[iterator->current]);
        iterator->current++;
        if (!NT_STATUS_IS_OK(status)) {
                PyErr_SetNTSTATUS(status);
                return NULL;
        }

        return iterator->unpack_fn(iterator->reqs[iterator->current-1]->r);
}

static PyObject *irpc_result_len(irpc_ResultObject *self)
{
        return PyLong_FromLong(self->count);
}

static PyMethodDef irpc_result_methods[] = {
        { "__len__", (PyCFunction)irpc_result_len, METH_NOARGS, 
                "Number of elements returned"},
        { NULL }
};

static void irpc_result_dealloc(PyObject *self)
{
        talloc_free(((irpc_ResultObject *)self)->mem_ctx);
        PyObject_Del(self);
}

PyTypeObject irpc_ResultIteratorType = {
        PyObject_HEAD_INIT(NULL) 0,
        .tp_name = "irpc.ResultIterator",
        .tp_basicsize = sizeof(irpc_ResultObject),
        .tp_flags = Py_TPFLAGS_DEFAULT|Py_TPFLAGS_BASETYPE,
        .tp_iternext = (iternextfunc)irpc_result_next,
        .tp_iter = PyObject_SelfIter,
        .tp_methods = irpc_result_methods,
        .tp_dealloc = irpc_result_dealloc,
};

static PyObject *py_irpc_call(irpc_ClientConnectionObject *p, struct PyNdrRpcMethodDef *method_def, PyObject *args, PyObject *kwargs)
{
        void *ptr;
        struct irpc_request **reqs;
        int i, count;
        NTSTATUS status;
        TALLOC_CTX *mem_ctx = talloc_new(NULL);
        irpc_ResultObject *ret;

        /* allocate the C structure */
        ptr = talloc_zero_size(mem_ctx, method_def->table->calls[method_def->opnum].struct_size);
        if (ptr == NULL) {
                status = NT_STATUS_NO_MEMORY;
                goto done;
        }

        /* convert the mpr object into a C structure */
        if (!method_def->pack_in_data(args, kwargs, ptr)) {
                talloc_free(mem_ctx);
                return NULL;
        }

        for (count=0;p->dest_ids[count].id;count++) /* noop */ ;

        /* we need to make a call per server */
        reqs = talloc_array(mem_ctx, struct irpc_request *, count);
        if (reqs == NULL) {
                status = NT_STATUS_NO_MEMORY;
                goto done;
        }

        /* make the actual calls */
        for (i=0;i<count;i++) {
                reqs[i] = irpc_call_send(p->msg_ctx, p->dest_ids[i], 
                                         method_def->table, method_def->opnum, ptr, ptr);
                if (reqs[i] == NULL) {
                        status = NT_STATUS_NO_MEMORY;
                        goto done;
                }
                talloc_steal(reqs, reqs[i]);
        }

        ret = PyObject_New(irpc_ResultObject, &irpc_ResultIteratorType);
        ret->mem_ctx = mem_ctx;
        ret->reqs = reqs;
        ret->count = count;
        ret->current = 0;
        ret->unpack_fn = method_def->unpack_out_data;

        return (PyObject *)ret;
done:
        talloc_free(mem_ctx);
        PyErr_SetNTSTATUS(status);
        return NULL;
}

static PyObject *py_irpc_call_wrapper(PyObject *self, PyObject *args, void *wrapped, PyObject *kwargs)
{       
        irpc_ClientConnectionObject *iface = (irpc_ClientConnectionObject *)self;
        struct PyNdrRpcMethodDef *md = wrapped;

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

static void py_irpc_dealloc(PyObject *self)
{
        irpc_ClientConnectionObject *iface = (irpc_ClientConnectionObject *)self;
        talloc_free(iface->mem_ctx);
        PyObject_Del(self);
}

PyTypeObject irpc_ClientConnectionType = {
        PyObject_HEAD_INIT(NULL) 0,
        .tp_name = "irpc.ClientConnection",
        .tp_basicsize = sizeof(irpc_ClientConnectionObject),
        .tp_flags = Py_TPFLAGS_DEFAULT|Py_TPFLAGS_BASETYPE,
        .tp_new = py_irpc_connect,
        .tp_dealloc = py_irpc_dealloc,
        .tp_doc = "ClientConnection(server, own_id=None, messaging_path=None)\n" \
                  "Create a new IRPC client connection to communicate with the servers in the specified path.\n" \
                  "If no path is specified, the default path from smb.conf will be used."
};

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

                wb->name = discard_const_p(char, mds[i].name);
                wb->flags = PyWrapperFlag_KEYWORDS;
                wb->wrapper = (wrapperfunc)py_irpc_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;
}

void initmessaging(void)
{
        PyObject *mod;
        PyObject *dep_irpc;

        dep_irpc = PyImport_ImportModule("samba.dcerpc.irpc");
        if (dep_irpc == NULL)
                return;

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

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

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

        if (!irpc_AddNdrRpcMethods(&irpc_ClientConnectionType, py_ndr_irpc_methods))
                return;

        mod = Py_InitModule3("messaging", NULL, "Internal RPC");
        if (mod == NULL)
                return;

        Py_INCREF((PyObject *)&irpc_ClientConnectionType);
        PyModule_AddObject(mod, "ClientConnection", (PyObject *)&irpc_ClientConnectionType);

        Py_INCREF((PyObject *)&messaging_Type);
        PyModule_AddObject(mod, "Messaging", (PyObject *)&messaging_Type);
}