source: vendor/3.6.0/source4/libnet/libnet_rpc.c

/* 
   Unix SMB/CIFS implementation.
   
   Copyright (C) Stefan Metzmacher  2004
   Copyright (C) Rafal Szczesniak   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 "libnet/libnet.h"
#include "libcli/libcli.h"
#include "libcli/composite/composite.h"
#include "librpc/rpc/dcerpc_proto.h"
#include "librpc/gen_ndr/ndr_lsa_c.h"
#include "librpc/gen_ndr/ndr_samr.h"


struct rpc_connect_srv_state {
        struct libnet_context *ctx;
        struct libnet_RpcConnect r;
        const char *binding;

        /* information about the progress */
        void (*monitor_fn)(struct monitor_msg*);
};


static void continue_pipe_connect(struct composite_context *ctx);


/**
 * Initiates connection to rpc pipe on remote server
 * 
 * @param ctx initialised libnet context
 * @param mem_ctx memory context of this call
 * @param r data structure containing necessary parameters and return values
 * @return composite context of this call
 **/

static struct composite_context* libnet_RpcConnectSrv_send(struct libnet_context *ctx,
                                                           TALLOC_CTX *mem_ctx,
                                                           struct libnet_RpcConnect *r,
                                                           void (*monitor)(struct monitor_msg*))
{
        struct composite_context *c;    
        struct rpc_connect_srv_state *s;
        struct dcerpc_binding *b;
        struct composite_context *pipe_connect_req;

        /* composite context allocation and setup */
        c = composite_create(ctx, ctx->event_ctx);
        if (c == NULL) return c;

        s = talloc_zero(c, struct rpc_connect_srv_state);
        if (composite_nomem(s, c)) return c;

        c->private_data = s;
        s->monitor_fn   = monitor;

        s->ctx = ctx;
        s->r = *r;
        ZERO_STRUCT(s->r.out);

        /* prepare binding string */
        switch (r->level) {
        case LIBNET_RPC_CONNECT_SERVER:
                s->binding = talloc_asprintf(s, "ncacn_np:%s", r->in.name);
                break;
        case LIBNET_RPC_CONNECT_SERVER_ADDRESS:
                s->binding = talloc_asprintf(s, "ncacn_np:%s", r->in.address);
                break;

        case LIBNET_RPC_CONNECT_BINDING:
                s->binding = talloc_strdup(s, r->in.binding);
                break;

        case LIBNET_RPC_CONNECT_DC:
        case LIBNET_RPC_CONNECT_PDC:
                /* this should never happen - DC and PDC level has a separate
                   composite function */
        case LIBNET_RPC_CONNECT_DC_INFO:
                /* this should never happen - DC_INFO level has a separate
                   composite function */
                composite_error(c, NT_STATUS_INVALID_LEVEL);
                return c;
        }

        /* parse binding string to the structure */
        c->status = dcerpc_parse_binding(c, s->binding, &b);
        if (!NT_STATUS_IS_OK(c->status)) {
                DEBUG(0, ("Failed to parse dcerpc binding '%s'\n", s->binding));
                composite_error(c, c->status);
                return c;
        }

        switch (r->level) {
        case LIBNET_RPC_CONNECT_SERVER:
        case LIBNET_RPC_CONNECT_SERVER_ADDRESS:
                b->flags = r->in.dcerpc_flags;
        }

        if (DEBUGLEVEL >= 10) {
                b->flags |= DCERPC_DEBUG_PRINT_BOTH;
        }

        if (r->level == LIBNET_RPC_CONNECT_SERVER_ADDRESS) {
                b->target_hostname = talloc_strdup(b, r->in.name);
                if (composite_nomem(b->target_hostname, c)) {
                        return c;
                }
        }

        /* connect to remote dcerpc pipe */
        pipe_connect_req = dcerpc_pipe_connect_b_send(c, b, r->in.dcerpc_iface,
                                                      ctx->cred, c->event_ctx,
                                                      ctx->lp_ctx);
        if (composite_nomem(pipe_connect_req, c)) return c;

        composite_continue(c, pipe_connect_req, continue_pipe_connect, c);
        return c;
}


/*
  Step 2 of RpcConnectSrv - get rpc connection
*/
static void continue_pipe_connect(struct composite_context *ctx)
{
        struct composite_context *c;
        struct rpc_connect_srv_state *s;

        c = talloc_get_type(ctx->async.private_data, struct composite_context);
        s = talloc_get_type(c->private_data, struct rpc_connect_srv_state);

        /* receive result of rpc pipe connection */
        c->status = dcerpc_pipe_connect_b_recv(ctx, c, &s->r.out.dcerpc_pipe);
        
        /* post monitor message */
        if (s->monitor_fn) {
                struct monitor_msg msg;
                struct msg_net_rpc_connect data;
                struct dcerpc_binding *binding = s->r.out.dcerpc_pipe->binding;
                
                /* prepare monitor message and post it */
                data.host        = binding->host;
                data.endpoint    = binding->endpoint;
                data.transport   = binding->transport;
                data.domain_name = binding->target_hostname;
                
                msg.type      = mon_NetRpcConnect;
                msg.data      = (void*)&data;
                msg.data_size = sizeof(data);
                s->monitor_fn(&msg);
        }

        composite_done(c);      
}


/**
 * Receives result of connection to rpc pipe on remote server
 *
 * @param c composite context
 * @param ctx initialised libnet context
 * @param mem_ctx memory context of this call
 * @param r data structure containing necessary parameters and return values
 * @return nt status of rpc connection
 **/

static NTSTATUS libnet_RpcConnectSrv_recv(struct composite_context *c,
                                          struct libnet_context *ctx,
                                          TALLOC_CTX *mem_ctx,
                                          struct libnet_RpcConnect *r)
{
        NTSTATUS status;
        struct rpc_connect_srv_state *s = talloc_get_type(c->private_data,
                                          struct rpc_connect_srv_state);

        status = composite_wait(c);
        if (NT_STATUS_IS_OK(status)) {
                /* move the returned rpc pipe between memory contexts */
                s = talloc_get_type(c->private_data, struct rpc_connect_srv_state);
                r->out.dcerpc_pipe = talloc_steal(mem_ctx, s->r.out.dcerpc_pipe);

                /* reference created pipe structure to long-term libnet_context
                   so that it can be used by other api functions even after short-term
                   mem_ctx is freed */
                if (r->in.dcerpc_iface == &ndr_table_samr) {
                        ctx->samr.pipe = talloc_reference(ctx, r->out.dcerpc_pipe);

                } else if (r->in.dcerpc_iface == &ndr_table_lsarpc) {
                        ctx->lsa.pipe = talloc_reference(ctx, r->out.dcerpc_pipe);
                }

                r->out.error_string = talloc_strdup(mem_ctx, "Success");

        } else {
                r->out.error_string = talloc_asprintf(mem_ctx, "Error: %s", nt_errstr(status));
        }

        talloc_free(c);
        return status;
}


struct rpc_connect_dc_state {
        struct libnet_context *ctx;
        struct libnet_RpcConnect r;
        struct libnet_RpcConnect r2;
        struct libnet_LookupDCs f;
        const char *connect_name;

        /* information about the progress */
        void (*monitor_fn)(struct monitor_msg *);
};


static void continue_lookup_dc(struct tevent_req *req);
static void continue_rpc_connect(struct composite_context *ctx);


/**
 * Initiates connection to rpc pipe on domain pdc
 * 
 * @param ctx initialised libnet context
 * @param mem_ctx memory context of this call
 * @param r data structure containing necessary parameters and return values
 * @return composite context of this call
 **/

static struct composite_context* libnet_RpcConnectDC_send(struct libnet_context *ctx,
                                                          TALLOC_CTX *mem_ctx,
                                                          struct libnet_RpcConnect *r,
                                                          void (*monitor)(struct monitor_msg *msg))
{
        struct composite_context *c;
        struct rpc_connect_dc_state *s;
        struct tevent_req *lookup_dc_req;

        /* composite context allocation and setup */
        c = composite_create(ctx, ctx->event_ctx);
        if (c == NULL) return c;

        s = talloc_zero(c, struct rpc_connect_dc_state);
        if (composite_nomem(s, c)) return c;

        c->private_data = s;
        s->monitor_fn   = monitor;

        s->ctx = ctx;
        s->r   = *r;
        ZERO_STRUCT(s->r.out);

        switch (r->level) {
        case LIBNET_RPC_CONNECT_PDC:
                s->f.in.name_type = NBT_NAME_PDC;
                break;

        case LIBNET_RPC_CONNECT_DC:
                s->f.in.name_type = NBT_NAME_LOGON;
                break;

        default:
                break;
        }

        s->f.in.domain_name = r->in.name;
        s->f.out.num_dcs    = 0;
        s->f.out.dcs        = NULL;

        /* find the domain pdc first */
        lookup_dc_req = libnet_LookupDCs_send(ctx, c, &s->f);
        if (composite_nomem(lookup_dc_req, c)) return c;

        tevent_req_set_callback(lookup_dc_req, continue_lookup_dc, c);
        return c;
}


/*
  Step 2 of RpcConnectDC: get domain controller name and
  initiate RpcConnect to it
*/
static void continue_lookup_dc(struct tevent_req *req)
{
        struct composite_context *c;
        struct rpc_connect_dc_state *s;
        struct composite_context *rpc_connect_req;
        struct monitor_msg msg;
        struct msg_net_lookup_dc data;

        c = tevent_req_callback_data(req, struct composite_context);
        s = talloc_get_type_abort(c->private_data, struct rpc_connect_dc_state);
        
        /* receive result of domain controller lookup */
        c->status = libnet_LookupDCs_recv(req, c, &s->f);
        if (!composite_is_ok(c)) return;

        /* decide on preferred address type depending on DC type */
        s->connect_name = s->f.out.dcs[0].name;

        /* post monitor message */
        if (s->monitor_fn) {
                /* prepare a monitor message and post it */
                data.domain_name = s->f.in.domain_name;
                data.hostname    = s->f.out.dcs[0].name;
                data.address     = s->f.out.dcs[0].address;
                
                msg.type         = mon_NetLookupDc;
                msg.data         = &data;
                msg.data_size    = sizeof(data);
                s->monitor_fn(&msg);
        }

        /* ok, pdc has been found so do attempt to rpc connect */
        s->r2.level            = LIBNET_RPC_CONNECT_SERVER_ADDRESS;

        /* this will cause yet another name resolution, but at least
         * we pass the right name down the stack now */
        s->r2.in.name          = talloc_strdup(s, s->connect_name);
        s->r2.in.address       = talloc_steal(s, s->f.out.dcs[0].address);
        s->r2.in.dcerpc_iface  = s->r.in.dcerpc_iface;  
        s->r2.in.dcerpc_flags  = s->r.in.dcerpc_flags;

        /* send rpc connect request to the server */
        rpc_connect_req = libnet_RpcConnectSrv_send(s->ctx, c, &s->r2, s->monitor_fn);
        if (composite_nomem(rpc_connect_req, c)) return;

        composite_continue(c, rpc_connect_req, continue_rpc_connect, c);
}


/*
  Step 3 of RpcConnectDC: get rpc connection to the server
*/
static void continue_rpc_connect(struct composite_context *ctx)
{
        struct composite_context *c;
        struct rpc_connect_dc_state *s;

        c = talloc_get_type(ctx->async.private_data, struct composite_context);
        s = talloc_get_type(c->private_data, struct rpc_connect_dc_state);

        c->status = libnet_RpcConnectSrv_recv(ctx, s->ctx, c, &s->r2);

        /* error string is to be passed anyway */
        s->r.out.error_string  = s->r2.out.error_string;
        if (!composite_is_ok(c)) return;

        s->r.out.dcerpc_pipe = s->r2.out.dcerpc_pipe;
        
        /* post monitor message */
        if (s->monitor_fn) {
                struct monitor_msg msg;
                struct msg_net_rpc_connect data;
                struct dcerpc_binding *binding = s->r.out.dcerpc_pipe->binding;

                data.host        = binding->host;
                data.endpoint    = binding->endpoint;
                data.transport   = binding->transport;
                data.domain_name = binding->target_hostname;
                
                msg.type      = mon_NetRpcConnect;
                msg.data      = (void*)&data;
                msg.data_size = sizeof(data);
                s->monitor_fn(&msg);
        }

        composite_done(c);
}


/**
 * Receives result of connection to rpc pipe on domain pdc
 *
 * @param c composite context
 * @param ctx initialised libnet context
 * @param mem_ctx memory context of this call
 * @param r data structure containing necessary parameters and return values
 * @return nt status of rpc connection
 **/

static NTSTATUS libnet_RpcConnectDC_recv(struct composite_context *c,
                                         struct libnet_context *ctx,
                                         TALLOC_CTX *mem_ctx,
                                         struct libnet_RpcConnect *r)
{
        NTSTATUS status;
        struct rpc_connect_dc_state *s = talloc_get_type(c->private_data,
                                         struct rpc_connect_dc_state);

        status = composite_wait(c);
        if (NT_STATUS_IS_OK(status)) {
                /* move connected rpc pipe between memory contexts 
                   
                   The use of talloc_reparent(talloc_parent(), ...) is
                   bizarre, but it is needed because of the absolutely
                   atrocious use of talloc in this code. We need to
                   force the original parent to change, but finding
                   the original parent is well nigh impossible at this
                   point in the code (yes, I tried).
                 */
                r->out.dcerpc_pipe = talloc_reparent(talloc_parent(s->r.out.dcerpc_pipe), 
                                                     mem_ctx, s->r.out.dcerpc_pipe);

                /* reference created pipe structure to long-term libnet_context
                   so that it can be used by other api functions even after short-term
                   mem_ctx is freed */
                if (r->in.dcerpc_iface == &ndr_table_samr) {
                        ctx->samr.pipe = talloc_reference(ctx, r->out.dcerpc_pipe);

                } else if (r->in.dcerpc_iface == &ndr_table_lsarpc) {
                        ctx->lsa.pipe = talloc_reference(ctx, r->out.dcerpc_pipe);
                }

        } else {
                r->out.error_string = talloc_asprintf(mem_ctx,
                                                      "Failed to rpc connect: %s",
                                                      nt_errstr(status));
        }

        talloc_free(c);
        return status;
}



struct rpc_connect_dci_state {
        struct libnet_context *ctx;
        struct libnet_RpcConnect r;
        struct libnet_RpcConnect rpc_conn;
        struct policy_handle lsa_handle;
        struct lsa_QosInfo qos;
        struct lsa_ObjectAttribute attr;
        struct lsa_OpenPolicy2 lsa_open_policy;
        struct dcerpc_pipe *lsa_pipe;
        struct lsa_QueryInfoPolicy2 lsa_query_info2;
        struct lsa_QueryInfoPolicy lsa_query_info;
        struct dcerpc_binding *final_binding;
        struct dcerpc_pipe *final_pipe;

        /* information about the progress */
        void (*monitor_fn)(struct monitor_msg*);
};


static void continue_dci_rpc_connect(struct composite_context *ctx);
static void continue_lsa_policy(struct tevent_req *subreq);
static void continue_lsa_query_info(struct tevent_req *subreq);
static void continue_lsa_query_info2(struct tevent_req *subreq);
static void continue_epm_map_binding(struct composite_context *ctx);
static void continue_secondary_conn(struct composite_context *ctx);
static void continue_epm_map_binding_send(struct composite_context *c);


/**
 * Initiates connection to rpc pipe on remote server or pdc. Received result
 * contains info on the domain name, domain sid and realm.
 * 
 * @param ctx initialised libnet context
 * @param mem_ctx memory context of this call
 * @param r data structure containing necessary parameters and return values. Must be a talloc context
 * @return composite context of this call
 **/

static struct composite_context* libnet_RpcConnectDCInfo_send(struct libnet_context *ctx,
                                                              TALLOC_CTX *mem_ctx,
                                                              struct libnet_RpcConnect *r,
                                                              void (*monitor)(struct monitor_msg*))
{
        struct composite_context *c, *conn_req;
        struct rpc_connect_dci_state *s;

        /* composite context allocation and setup */
        c = composite_create(ctx, ctx->event_ctx);
        if (c == NULL) return c;

        s = talloc_zero(c, struct rpc_connect_dci_state);
        if (composite_nomem(s, c)) return c;

        c->private_data = s;
        s->monitor_fn   = monitor;

        s->ctx = ctx;
        s->r   = *r;
        ZERO_STRUCT(s->r.out);


        /* proceed to pure rpc connection if the binding string is provided,
           otherwise try to connect domain controller */
        if (r->in.binding == NULL) {
                /* Pass on any binding flags (such as anonymous fallback) that have been set */
                s->rpc_conn.in.dcerpc_flags = r->in.dcerpc_flags;

                s->rpc_conn.in.name         = r->in.name;
                s->rpc_conn.level           = LIBNET_RPC_CONNECT_DC;
        } else {
                s->rpc_conn.in.binding      = r->in.binding;
                s->rpc_conn.level           = LIBNET_RPC_CONNECT_BINDING;
        }

        /* we need to query information on lsarpc interface first */
        s->rpc_conn.in.dcerpc_iface    = &ndr_table_lsarpc;
        
        /* request connection to the lsa pipe on the pdc */
        conn_req = libnet_RpcConnect_send(ctx, c, &s->rpc_conn, s->monitor_fn);
        if (composite_nomem(c, conn_req)) return c;

        composite_continue(c, conn_req, continue_dci_rpc_connect, c);
        return c;
}


/*
  Step 2 of RpcConnectDCInfo: receive opened rpc pipe and open
  lsa policy handle
*/
static void continue_dci_rpc_connect(struct composite_context *ctx)
{
        struct composite_context *c;
        struct rpc_connect_dci_state *s;
        struct tevent_req *subreq;

        c = talloc_get_type(ctx->async.private_data, struct composite_context);
        s = talloc_get_type(c->private_data, struct rpc_connect_dci_state);

        c->status = libnet_RpcConnect_recv(ctx, s->ctx, c, &s->rpc_conn);
        if (!NT_STATUS_IS_OK(c->status)) {
                composite_error(c, c->status);
                return;
        }

        /* post monitor message */
        if (s->monitor_fn) {
                struct monitor_msg msg;
                struct msg_net_rpc_connect data;
                struct dcerpc_binding *binding = s->r.out.dcerpc_pipe->binding;

                data.host        = binding->host;
                data.endpoint    = binding->endpoint;
                data.transport   = binding->transport;
                data.domain_name = binding->target_hostname;

                msg.type      = mon_NetRpcConnect;
                msg.data      = (void*)&data;
                msg.data_size = sizeof(data);
                s->monitor_fn(&msg);
        }

        /* prepare to open a policy handle on lsa pipe */
        s->lsa_pipe = s->ctx->lsa.pipe;
        
        s->qos.len                 = 0;
        s->qos.impersonation_level = 2;
        s->qos.context_mode        = 1;
        s->qos.effective_only      = 0;

        s->attr.sec_qos = &s->qos;

        s->lsa_open_policy.in.attr        = &s->attr;
        s->lsa_open_policy.in.system_name = talloc_asprintf(c, "\\");
        if (composite_nomem(s->lsa_open_policy.in.system_name, c)) return;

        s->lsa_open_policy.in.access_mask = SEC_FLAG_MAXIMUM_ALLOWED;
        s->lsa_open_policy.out.handle     = &s->lsa_handle;

        subreq = dcerpc_lsa_OpenPolicy2_r_send(s, c->event_ctx,
                                               s->lsa_pipe->binding_handle,
                                               &s->lsa_open_policy);
        if (composite_nomem(subreq, c)) return;

        tevent_req_set_callback(subreq, continue_lsa_policy, c);
}


/*
  Step 3 of RpcConnectDCInfo: Get policy handle and query lsa info
  for kerberos realm (dns name) and guid. The query may fail.
*/
static void continue_lsa_policy(struct tevent_req *subreq)
{
        struct composite_context *c;
        struct rpc_connect_dci_state *s;

        c = tevent_req_callback_data(subreq, struct composite_context);
        s = talloc_get_type(c->private_data, struct rpc_connect_dci_state);

        c->status = dcerpc_lsa_OpenPolicy2_r_recv(subreq, s);
        TALLOC_FREE(subreq);
        if (!NT_STATUS_IS_OK(c->status)) {
                composite_error(c, c->status);
                return;
        }

        if (NT_STATUS_EQUAL(s->lsa_open_policy.out.result, NT_STATUS_RPC_PROTSEQ_NOT_SUPPORTED)) {
                s->r.out.realm = NULL;
                s->r.out.guid  = NULL;
                s->r.out.domain_name = NULL;
                s->r.out.domain_sid  = NULL;

                /* Skip to the creating the actual connection, no info available on this transport */
                continue_epm_map_binding_send(c);
                return;

        } else if (!NT_STATUS_IS_OK(s->lsa_open_policy.out.result)) {
                composite_error(c, s->lsa_open_policy.out.result);
                return;
        }

        /* post monitor message */
        if (s->monitor_fn) {
                struct monitor_msg msg;

                msg.type      = mon_LsaOpenPolicy;
                msg.data      = NULL;
                msg.data_size = 0;
                s->monitor_fn(&msg);
        }

        /* query lsa info for dns domain name and guid */
        s->lsa_query_info2.in.handle = &s->lsa_handle;
        s->lsa_query_info2.in.level  = LSA_POLICY_INFO_DNS;
        s->lsa_query_info2.out.info  = talloc_zero(c, union lsa_PolicyInformation *);
        if (composite_nomem(s->lsa_query_info2.out.info, c)) return;

        subreq = dcerpc_lsa_QueryInfoPolicy2_r_send(s, c->event_ctx,
                                                    s->lsa_pipe->binding_handle,
                                                    &s->lsa_query_info2);
        if (composite_nomem(subreq, c)) return;

        tevent_req_set_callback(subreq, continue_lsa_query_info2, c);
}


/*
  Step 4 of RpcConnectDCInfo: Get realm and guid if provided (rpc call
  may result in failure) and query lsa info for domain name and sid.
*/
static void continue_lsa_query_info2(struct tevent_req *subreq)
{       
        struct composite_context *c;
        struct rpc_connect_dci_state *s;

        c = tevent_req_callback_data(subreq, struct composite_context);
        s = talloc_get_type(c->private_data, struct rpc_connect_dci_state);

        c->status = dcerpc_lsa_QueryInfoPolicy2_r_recv(subreq, s);
        TALLOC_FREE(subreq);
        
        /* In case of error just null the realm and guid and proceed
           to the next step. After all, it doesn't have to be AD domain
           controller we talking to - NT-style PDC also counts */

        if (NT_STATUS_EQUAL(c->status, NT_STATUS_RPC_PROCNUM_OUT_OF_RANGE)) {
                s->r.out.realm = NULL;
                s->r.out.guid  = NULL;

        } else {
                if (!NT_STATUS_IS_OK(c->status)) {
                        s->r.out.error_string = talloc_asprintf(c,
                                                                "lsa_QueryInfoPolicy2 failed: %s",
                                                                nt_errstr(c->status));
                        composite_error(c, c->status);
                        return;
                }

                if (!NT_STATUS_IS_OK(s->lsa_query_info2.out.result)) {
                        s->r.out.error_string = talloc_asprintf(c,
                                                                "lsa_QueryInfoPolicy2 failed: %s",
                                                                nt_errstr(s->lsa_query_info2.out.result));
                        composite_error(c, s->lsa_query_info2.out.result);
                        return;
                }

                /* Copy the dns domain name and guid from the query result */

                /* this should actually be a conversion from lsa_StringLarge */
                s->r.out.realm = (*s->lsa_query_info2.out.info)->dns.dns_domain.string;
                s->r.out.guid  = talloc(c, struct GUID);
                if (composite_nomem(s->r.out.guid, c)) {
                        s->r.out.error_string = NULL;
                        return;
                }
                *s->r.out.guid = (*s->lsa_query_info2.out.info)->dns.domain_guid;
        }

        /* post monitor message */
        if (s->monitor_fn) {
                struct monitor_msg msg;
                
                msg.type      = mon_LsaQueryPolicy;
                msg.data      = NULL;
                msg.data_size = 0;
                s->monitor_fn(&msg);
        }

        /* query lsa info for domain name and sid */
        s->lsa_query_info.in.handle = &s->lsa_handle;
        s->lsa_query_info.in.level  = LSA_POLICY_INFO_DOMAIN;
        s->lsa_query_info.out.info  = talloc_zero(c, union lsa_PolicyInformation *);
        if (composite_nomem(s->lsa_query_info.out.info, c)) return;

        subreq = dcerpc_lsa_QueryInfoPolicy_r_send(s, c->event_ctx,
                                                   s->lsa_pipe->binding_handle,
                                                   &s->lsa_query_info);
        if (composite_nomem(subreq, c)) return;

        tevent_req_set_callback(subreq, continue_lsa_query_info, c);
}


/*
  Step 5 of RpcConnectDCInfo: Get domain name and sid
*/
static void continue_lsa_query_info(struct tevent_req *subreq)
{
        struct composite_context *c;
        struct rpc_connect_dci_state *s;

        c = tevent_req_callback_data(subreq, struct composite_context);
        s = talloc_get_type(c->private_data, struct rpc_connect_dci_state);

        c->status = dcerpc_lsa_QueryInfoPolicy_r_recv(subreq, s);
        TALLOC_FREE(subreq);
        if (!NT_STATUS_IS_OK(c->status)) {
                s->r.out.error_string = talloc_asprintf(c,
                                                        "lsa_QueryInfoPolicy failed: %s",
                                                        nt_errstr(c->status));
                composite_error(c, c->status);
                return;
        }

        /* post monitor message */
        if (s->monitor_fn) {
                struct monitor_msg msg;
                
                msg.type      = mon_LsaQueryPolicy;
                msg.data      = NULL;
                msg.data_size = 0;
                s->monitor_fn(&msg);
        }

        /* Copy the domain name and sid from the query result */
        s->r.out.domain_sid  = (*s->lsa_query_info.out.info)->domain.sid;
        s->r.out.domain_name = (*s->lsa_query_info.out.info)->domain.name.string;

        continue_epm_map_binding_send(c);
}

/* 
   Step 5 (continued) of RpcConnectDCInfo: request endpoint
   map binding.

   We may short-cut to this step if we don't support LSA OpenPolicy on this transport
*/
static void continue_epm_map_binding_send(struct composite_context *c)
{
        struct rpc_connect_dci_state *s;
        struct composite_context *epm_map_req;
        s = talloc_get_type(c->private_data, struct rpc_connect_dci_state);

        /* prepare to get endpoint mapping for the requested interface */
        s->final_binding = talloc_zero(s, struct dcerpc_binding);
        if (composite_nomem(s->final_binding, c)) return;
        
        *s->final_binding = *s->lsa_pipe->binding;
        /* Ensure we keep hold of the member elements */
        if (composite_nomem(talloc_reference(s->final_binding, s->lsa_pipe->binding), c)) return;

        epm_map_req = dcerpc_epm_map_binding_send(c, s->final_binding, s->r.in.dcerpc_iface,
                                                  s->lsa_pipe->conn->event_ctx, s->ctx->lp_ctx);
        if (composite_nomem(epm_map_req, c)) return;

        composite_continue(c, epm_map_req, continue_epm_map_binding, c);
}

/*
  Step 6 of RpcConnectDCInfo: Receive endpoint mapping and create secondary
  rpc connection derived from already used pipe but connected to the requested
  one (as specified in libnet_RpcConnect structure)
*/
static void continue_epm_map_binding(struct composite_context *ctx)
{
        struct composite_context *c, *sec_conn_req;
        struct rpc_connect_dci_state *s;

        c = talloc_get_type(ctx->async.private_data, struct composite_context);
        s = talloc_get_type(c->private_data, struct rpc_connect_dci_state);

        c->status = dcerpc_epm_map_binding_recv(ctx);
        if (!NT_STATUS_IS_OK(c->status)) {
                s->r.out.error_string = talloc_asprintf(c,
                                                        "failed to map pipe with endpoint mapper - %s",
                                                        nt_errstr(c->status));
                composite_error(c, c->status);
                return;
        }

        /* create secondary connection derived from lsa pipe */
        sec_conn_req = dcerpc_secondary_connection_send(s->lsa_pipe, s->final_binding);
        if (composite_nomem(sec_conn_req, c)) return;

        composite_continue(c, sec_conn_req, continue_secondary_conn, c);
}


/*
  Step 7 of RpcConnectDCInfo: Get actual pipe to be returned
  and complete this composite call
*/
static void continue_secondary_conn(struct composite_context *ctx)
{
        struct composite_context *c;
        struct rpc_connect_dci_state *s;

        c = talloc_get_type(ctx->async.private_data, struct composite_context);
        s = talloc_get_type(c->private_data, struct rpc_connect_dci_state);

        c->status = dcerpc_secondary_connection_recv(ctx, &s->final_pipe);
        if (!NT_STATUS_IS_OK(c->status)) {
                s->r.out.error_string = talloc_asprintf(c,
                                                        "secondary connection failed: %s",
                                                        nt_errstr(c->status));
                
                composite_error(c, c->status);
                return;
        }

        s->r.out.dcerpc_pipe = s->final_pipe;

        /* post monitor message */
        if (s->monitor_fn) {
                struct monitor_msg msg;
                struct msg_net_rpc_connect data;
                struct dcerpc_binding *binding = s->r.out.dcerpc_pipe->binding;
                
                /* prepare monitor message and post it */
                data.host        = binding->host;
                data.endpoint    = binding->endpoint;
                data.transport   = binding->transport;
                data.domain_name = binding->target_hostname;
                
                msg.type      = mon_NetRpcConnect;
                msg.data      = (void*)&data;
                msg.data_size = sizeof(data);
                s->monitor_fn(&msg);
        }

        composite_done(c);
}


/**
 * Receives result of connection to rpc pipe and gets basic
 * domain info (name, sid, realm, guid)
 *
 * @param c composite context
 * @param ctx initialised libnet context
 * @param mem_ctx memory context of this call
 * @param r data structure containing return values
 * @return nt status of rpc connection
 **/

static NTSTATUS libnet_RpcConnectDCInfo_recv(struct composite_context *c, struct libnet_context *ctx,
                                             TALLOC_CTX *mem_ctx, struct libnet_RpcConnect *r)
{
        NTSTATUS status;
        struct rpc_connect_dci_state *s = talloc_get_type(c->private_data,
                                          struct rpc_connect_dci_state);

        status = composite_wait(c);
        if (NT_STATUS_IS_OK(status)) {
                r->out.realm        = talloc_steal(mem_ctx, s->r.out.realm);
                r->out.guid         = talloc_steal(mem_ctx, s->r.out.guid);
                r->out.domain_name  = talloc_steal(mem_ctx, s->r.out.domain_name);
                r->out.domain_sid   = talloc_steal(mem_ctx, s->r.out.domain_sid);

                r->out.dcerpc_pipe  = talloc_steal(mem_ctx, s->r.out.dcerpc_pipe);

                /* reference created pipe structure to long-term libnet_context
                   so that it can be used by other api functions even after short-term
                   mem_ctx is freed */
                if (r->in.dcerpc_iface == &ndr_table_samr) {
                        ctx->samr.pipe = talloc_reference(ctx, r->out.dcerpc_pipe);
                        ctx->samr.samr_handle = ctx->samr.pipe->binding_handle;

                } else if (r->in.dcerpc_iface == &ndr_table_lsarpc) {
                        ctx->lsa.pipe = talloc_reference(ctx, r->out.dcerpc_pipe);
                        ctx->lsa.lsa_handle = ctx->lsa.pipe->binding_handle;
                }

        } else {
                if (s->r.out.error_string) {
                        r->out.error_string = talloc_steal(mem_ctx, s->r.out.error_string);
                } else if (r->in.binding == NULL) {
                        r->out.error_string = talloc_asprintf(mem_ctx, "Connection to DC failed: %s", nt_errstr(status));
                } else {
                        r->out.error_string = talloc_asprintf(mem_ctx, "Connection to DC %s failed: %s", 
                                                              r->in.binding, nt_errstr(status));
                }
        }

        talloc_free(c);
        return status;
}


/**
 * Initiates connection to rpc pipe on remote server or pdc, optionally
 * providing domain info
 * 
 * @param ctx initialised libnet context
 * @param mem_ctx memory context of this call
 * @param r data structure containing necessary parameters and return values
 * @return composite context of this call
 **/

struct composite_context* libnet_RpcConnect_send(struct libnet_context *ctx,
                                                 TALLOC_CTX *mem_ctx,
                                                 struct libnet_RpcConnect *r,
                                                 void (*monitor)(struct monitor_msg*))
{
        struct composite_context *c;

        switch (r->level) {
        case LIBNET_RPC_CONNECT_SERVER:
        case LIBNET_RPC_CONNECT_SERVER_ADDRESS:
        case LIBNET_RPC_CONNECT_BINDING:
                c = libnet_RpcConnectSrv_send(ctx, mem_ctx, r, monitor);
                break;

        case LIBNET_RPC_CONNECT_PDC:
        case LIBNET_RPC_CONNECT_DC:
                c = libnet_RpcConnectDC_send(ctx, mem_ctx, r, monitor);
                break;

        case LIBNET_RPC_CONNECT_DC_INFO:
                c = libnet_RpcConnectDCInfo_send(ctx, mem_ctx, r, monitor);
                break;

        default:
                c = talloc_zero(mem_ctx, struct composite_context);
                composite_error(c, NT_STATUS_INVALID_LEVEL);
        }

        return c;
}


/**
 * Receives result of connection to rpc pipe on remote server or pdc
 *
 * @param c composite context
 * @param ctx initialised libnet context
 * @param mem_ctx memory context of this call
 * @param r data structure containing necessary parameters and return values
 * @return nt status of rpc connection
 **/

NTSTATUS libnet_RpcConnect_recv(struct composite_context *c, struct libnet_context *ctx,
                                TALLOC_CTX *mem_ctx, struct libnet_RpcConnect *r)
{
        switch (r->level) {
        case LIBNET_RPC_CONNECT_SERVER:
        case LIBNET_RPC_CONNECT_BINDING:
                return libnet_RpcConnectSrv_recv(c, ctx, mem_ctx, r);

        case LIBNET_RPC_CONNECT_PDC:
        case LIBNET_RPC_CONNECT_DC:
                return libnet_RpcConnectDC_recv(c, ctx, mem_ctx, r);

        case LIBNET_RPC_CONNECT_DC_INFO:
                return libnet_RpcConnectDCInfo_recv(c, ctx, mem_ctx, r);

        default:
                ZERO_STRUCT(r->out);
                return NT_STATUS_INVALID_LEVEL;
        }
}


/**
 * Connect to a rpc pipe on a remote server - sync version
 *
 * @param ctx initialised libnet context
 * @param mem_ctx memory context of this call
 * @param r data structure containing necessary parameters and return values
 * @return nt status of rpc connection
 **/

NTSTATUS libnet_RpcConnect(struct libnet_context *ctx, TALLOC_CTX *mem_ctx,
                           struct libnet_RpcConnect *r)
{
        struct composite_context *c;
        
        c = libnet_RpcConnect_send(ctx, mem_ctx, r, NULL);
        return libnet_RpcConnect_recv(c, ctx, mem_ctx, r);
}