source: branches/samba-3.5.x/source3/winbindd/winbindd_dual_ndr.c

/*
   Unix SMB/CIFS implementation.

   Provide parent->child communication based on NDR marshalling

   Copyright (C) Volker Lendecke 2009

   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/>.
*/

/*
 * This file implements an RPC between winbind parent and child processes,
 * leveraging the autogenerated marshalling routines for MSRPC. This is not
 * MSRPC, as it does not go through the whole DCERPC fragmentation, we just
 * leverage much the same infrastructure we already have for it.
 */

#include "includes.h"
#include "winbindd/winbindd.h"
#include "winbindd/winbindd_proto.h"
#include "librpc/gen_ndr/srv_wbint.h"

struct wb_ndr_transport_priv {
        struct winbindd_domain *domain;
        struct winbindd_child *child;
};

struct wb_ndr_dispatch_state {
        struct wb_ndr_transport_priv *transport;
        uint32_t opnum;
        const struct ndr_interface_call *call;
        void *r;
        DATA_BLOB req_blob, resp_blob;
        struct winbindd_request request;
        struct winbindd_response *response;
};

static void wb_ndr_dispatch_done(struct tevent_req *subreq);

static struct tevent_req *wb_ndr_dispatch_send(TALLOC_CTX *mem_ctx,
                                               struct tevent_context *ev,
                                               struct rpc_pipe_client *cli,
                                               const struct ndr_interface_table *table,
                                               uint32_t opnum,
                                               void *r)
{
        struct tevent_req *req, *subreq;
        struct wb_ndr_dispatch_state *state;
        struct wb_ndr_transport_priv *transport = talloc_get_type_abort(
                cli->transport->priv, struct wb_ndr_transport_priv);
        struct ndr_push *push;
        enum ndr_err_code ndr_err;

        req = tevent_req_create(mem_ctx, &state,
                                struct wb_ndr_dispatch_state);
        if (req == NULL) {
                return NULL;
        }

        state->r = r;
        state->call = &table->calls[opnum];
        state->transport = transport;
        state->opnum = opnum;

        push = ndr_push_init_ctx(state, NULL);
        if (tevent_req_nomem(push, req)) {
                return tevent_req_post(req, ev);
        }

        ndr_err = state->call->ndr_push(push, NDR_IN, r);
        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
                tevent_req_nterror(req, ndr_map_error2ntstatus(ndr_err));
                TALLOC_FREE(push);
                return tevent_req_post(req, ev);
        }

        state->req_blob = ndr_push_blob(push);

        if ((transport->domain != NULL)
            && wcache_fetch_ndr(state, transport->domain, opnum,
                                &state->req_blob, &state->resp_blob)) {
                tevent_req_done(req);
                return tevent_req_post(req, ev);
        }

        state->request.cmd = WINBINDD_DUAL_NDRCMD;
        state->request.data.ndrcmd = opnum;
        state->request.extra_data.data = (char *)state->req_blob.data;
        state->request.extra_len = state->req_blob.length;

        subreq = wb_child_request_send(state, ev, transport->child,
                                       &state->request);
        if (tevent_req_nomem(subreq, req)) {
                return tevent_req_post(req, ev);
        }
        tevent_req_set_callback(subreq, wb_ndr_dispatch_done, req);
        return req;
}

static void wb_ndr_dispatch_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct wb_ndr_dispatch_state *state = tevent_req_data(
                req, struct wb_ndr_dispatch_state);
        int ret, err;

        ret = wb_child_request_recv(subreq, state, &state->response, &err);
        TALLOC_FREE(subreq);
        if (ret == -1) {
                tevent_req_nterror(req, map_nt_error_from_unix(err));
                return;
        }

        state->resp_blob = data_blob_const(
                state->response->extra_data.data,
                state->response->length - sizeof(struct winbindd_response));

        if (state->transport->domain != NULL) {
                wcache_store_ndr(state->transport->domain, state->opnum,
                                 &state->req_blob, &state->resp_blob);
        }

        tevent_req_done(req);
}

static NTSTATUS wb_ndr_dispatch_recv(struct tevent_req *req,
                                     TALLOC_CTX *mem_ctx)
{
        struct wb_ndr_dispatch_state *state = tevent_req_data(
                req, struct wb_ndr_dispatch_state);
        NTSTATUS status;
        struct ndr_pull *pull;
        enum ndr_err_code ndr_err;

        if (tevent_req_is_nterror(req, &status)) {
                return status;
        }

        pull = ndr_pull_init_blob(&state->resp_blob, mem_ctx, NULL);
        if (pull == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        /* have the ndr parser alloc memory for us */
        pull->flags |= LIBNDR_FLAG_REF_ALLOC;
        ndr_err = state->call->ndr_pull(pull, NDR_OUT, state->r);
        TALLOC_FREE(pull);

        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
                return ndr_map_error2ntstatus(ndr_err);
        }

        return NT_STATUS_OK;
}

static NTSTATUS wb_ndr_dispatch(struct rpc_pipe_client *cli,
                                TALLOC_CTX *mem_ctx,
                                const struct ndr_interface_table *table,
                                uint32_t opnum, void *r)
{
        TALLOC_CTX *frame = talloc_stackframe();
        struct event_context *ev;
        struct tevent_req *req;
        NTSTATUS status = NT_STATUS_OK;

        ev = event_context_init(frame);
        if (ev == NULL) {
                status = NT_STATUS_NO_MEMORY;
                goto fail;
        }

        req = wb_ndr_dispatch_send(frame, ev, cli, table, opnum, r);
        if (req == NULL) {
                status = NT_STATUS_NO_MEMORY;
                goto fail;
        }

        if (!tevent_req_poll(req, ev)) {
                status = map_nt_error_from_unix(errno);
                goto fail;
        }

        status = wb_ndr_dispatch_recv(req, mem_ctx);
 fail:
        TALLOC_FREE(frame);
        return status;
}

struct rpc_pipe_client *wbint_rpccli_create(TALLOC_CTX *mem_ctx,
                                            struct winbindd_domain *domain,
                                            struct winbindd_child *child)
{
        struct rpc_pipe_client *result;
        struct wb_ndr_transport_priv *transp;

        result = talloc(mem_ctx, struct rpc_pipe_client);
        if (result == NULL) {
                return NULL;
        }
        result->abstract_syntax = ndr_table_wbint.syntax_id;
        result->transfer_syntax = ndr_transfer_syntax;
        result->dispatch = wb_ndr_dispatch;
        result->dispatch_send = wb_ndr_dispatch_send;
        result->dispatch_recv = wb_ndr_dispatch_recv;
        result->max_xmit_frag = RPC_MAX_PDU_FRAG_LEN;
        result->max_recv_frag = RPC_MAX_PDU_FRAG_LEN;
        result->desthost = NULL;
        result->srv_name_slash = NULL;

        /*
         * Initialize a fake transport. Due to our own wb_ndr_dispatch
         * function we don't use all the fragmentation engine in
         * cli_pipe, which would use all the _read and _write
         * functions in rpc_cli_transport. But we need a place to
         * store the child struct in, and we're re-using
         * result->transport->priv for that.
         */

        result->transport = talloc_zero(result, struct rpc_cli_transport);
        if (result->transport == NULL) {
                TALLOC_FREE(result);
                return NULL;
        }
        transp = talloc(result->transport, struct wb_ndr_transport_priv);
        if (transp == NULL) {
                TALLOC_FREE(result);
                return NULL;
        }
        transp->domain = domain;
        transp->child = child;
        result->transport->priv = transp;
        return result;
}

enum winbindd_result winbindd_dual_ndrcmd(struct winbindd_domain *domain,
                                          struct winbindd_cli_state *state)
{
        pipes_struct p;
        struct api_struct *fns;
        int num_fns;
        bool ret;

        wbint_get_pipe_fns(&fns, &num_fns);

        if (state->request->data.ndrcmd >= num_fns) {
                return WINBINDD_ERROR;
        }

        DEBUG(10, ("winbindd_dual_ndrcmd: Running command %s (%s)\n",
                   fns[state->request->data.ndrcmd].name,
                   domain ? domain->name : "no domain"));

        ZERO_STRUCT(p);
        p.mem_ctx = talloc_stackframe();
        p.in_data.data.buffer_size = state->request->extra_len;
        p.in_data.data.data_p = state->request->extra_data.data;
        prs_init(&p.out_data.rdata, 0, state->mem_ctx, false);

        ret = fns[state->request->data.ndrcmd].fn(&p);
        TALLOC_FREE(p.mem_ctx);
        if (!ret) {
                return WINBINDD_ERROR;
        }

        state->response->extra_data.data =
                talloc_memdup(state->mem_ctx, p.out_data.rdata.data_p,
                              p.out_data.rdata.data_offset);
        state->response->length += p.out_data.rdata.data_offset;
        prs_mem_free(&p.out_data.rdata);
        if (state->response->extra_data.data == NULL) {
                return WINBINDD_ERROR;
        }
        return WINBINDD_OK;
}

/*
 * Just a dummy to make srv_wbint.c happy
 */
NTSTATUS rpc_srv_register(int version, const char *clnt, const char *srv,
                          const struct ndr_interface_table *iface,
                          const struct api_struct *cmds, int size)
{
        return NT_STATUS_OK;
}