s3-rpc_client: move protos to cli_lsarpc.h

[Samba/ekacnet.git] / source3 / rpc_server / srv_pipe_hnd.c

/* 
 *  Unix SMB/CIFS implementation.
 *  RPC Pipe client / server routines
 *  Copyright (C) Andrew Tridgell              1992-1998,
 *  Largely re-written : 2005
 *  Copyright (C) Jeremy Allison                1998 - 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 "librpc/gen_ndr/ndr_named_pipe_auth.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_RPC_SRV

static int pipes_open;

static pipes_struct *InternalPipes;

/* TODO
 * the following prototypes are declared here to avoid
 * code being moved about too much for a patch to be
 * disrupted / less obvious.
 *
 * these functions, and associated functions that they
 * call, should be moved behind a .so module-loading
 * system _anyway_.  so that's the next step...
 */

static int close_internal_rpc_pipe_hnd(struct pipes_struct *p);

/****************************************************************************
 Internal Pipe iterator functions.
****************************************************************************/

pipes_struct *get_first_internal_pipe(void)
{
        return InternalPipes;
}

pipes_struct *get_next_internal_pipe(pipes_struct *p)
{
        return p->next;
}

/****************************************************************************
 Initialise an outgoing packet.
****************************************************************************/

static bool pipe_init_outgoing_data(pipes_struct *p)
{
        output_data *o_data = &p->out_data;

        /* Reset the offset counters. */
        o_data->data_sent_length = 0;
        o_data->current_pdu_sent = 0;

        prs_mem_free(&o_data->frag);

        /* Free any memory in the current return data buffer. */
        prs_mem_free(&o_data->rdata);

        /*
         * Initialize the outgoing RPC data buffer.
         * we will use this as the raw data area for replying to rpc requests.
         */     
        if(!prs_init(&o_data->rdata, 128, p->mem_ctx, MARSHALL)) {
                DEBUG(0,("pipe_init_outgoing_data: malloc fail.\n"));
                return False;
        }

        return True;
}

/****************************************************************************
 Make an internal namedpipes structure
****************************************************************************/

static struct pipes_struct *make_internal_rpc_pipe_p(TALLOC_CTX *mem_ctx,
                                                     const struct ndr_syntax_id *syntax,
                                                     const char *client_address,
                                                     struct auth_serversupplied_info *server_info)
{
        pipes_struct *p;

        DEBUG(4,("Create pipe requested %s\n",
                 get_pipe_name_from_syntax(talloc_tos(), syntax)));

        p = TALLOC_ZERO_P(mem_ctx, struct pipes_struct);

        if (!p) {
                DEBUG(0,("ERROR! no memory for pipes_struct!\n"));
                return NULL;
        }

        p->mem_ctx = talloc_named(p, 0, "pipe %s %p",
                                 get_pipe_name_from_syntax(talloc_tos(),
                                                           syntax), p);
        if (p->mem_ctx == NULL) {
                DEBUG(0,("open_rpc_pipe_p: talloc_init failed.\n"));
                TALLOC_FREE(p);
                return NULL;
        }

        if (!init_pipe_handle_list(p, syntax)) {
                DEBUG(0,("open_rpc_pipe_p: init_pipe_handles failed.\n"));
                TALLOC_FREE(p);
                return NULL;
        }

        /*
         * Initialize the incoming RPC data buffer with one PDU worth of memory.
         * We cheat here and say we're marshalling, as we intend to add incoming
         * data directly into the prs_struct and we want it to auto grow. We will
         * change the type to UNMARSALLING before processing the stream.
         */

        if(!prs_init(&p->in_data.data, 128, p->mem_ctx, MARSHALL)) {
                DEBUG(0,("open_rpc_pipe_p: malloc fail for in_data struct.\n"));
                close_policy_by_pipe(p);
                TALLOC_FREE(p);
                return NULL;
        }

        p->server_info = copy_serverinfo(p, server_info);
        if (p->server_info == NULL) {
                DEBUG(0, ("open_rpc_pipe_p: copy_serverinfo failed\n"));
                close_policy_by_pipe(p);
                TALLOC_FREE(p);
                return NULL;
        }

        DLIST_ADD(InternalPipes, p);

        memcpy(p->client_address, client_address, sizeof(p->client_address));

        p->endian = RPC_LITTLE_ENDIAN;

        /*
         * Initialize the outgoing RPC data buffer with no memory.
         */     
        prs_init_empty(&p->out_data.rdata, p->mem_ctx, MARSHALL);

        p->syntax = *syntax;

        DEBUG(4,("Created internal pipe %s (pipes_open=%d)\n",
                 get_pipe_name_from_syntax(talloc_tos(), syntax), pipes_open));

        talloc_set_destructor(p, close_internal_rpc_pipe_hnd);

        return p;
}

/****************************************************************************
 Sets the fault state on incoming packets.
****************************************************************************/

static void set_incoming_fault(pipes_struct *p)
{
        prs_mem_free(&p->in_data.data);
        p->in_data.pdu_needed_len = 0;
        p->in_data.pdu_received_len = 0;
        p->fault_state = True;
        DEBUG(10, ("set_incoming_fault: Setting fault state on pipe %s\n",
                   get_pipe_name_from_syntax(talloc_tos(), &p->syntax)));
}

/****************************************************************************
 Ensures we have at least RPC_HEADER_LEN amount of data in the incoming buffer.
****************************************************************************/

static ssize_t fill_rpc_header(pipes_struct *p, char *data, size_t data_to_copy)
{
        size_t len_needed_to_complete_hdr = MIN(data_to_copy, RPC_HEADER_LEN - p->in_data.pdu_received_len);

        DEBUG(10,("fill_rpc_header: data_to_copy = %u, len_needed_to_complete_hdr = %u, receive_len = %u\n",
                        (unsigned int)data_to_copy, (unsigned int)len_needed_to_complete_hdr,
                        (unsigned int)p->in_data.pdu_received_len ));

        if (p->in_data.current_in_pdu == NULL) {
                p->in_data.current_in_pdu = talloc_array(p, uint8_t,
                                                         RPC_HEADER_LEN);
        }
        if (p->in_data.current_in_pdu == NULL) {
                DEBUG(0, ("talloc failed\n"));
                return -1;
        }

        memcpy((char *)&p->in_data.current_in_pdu[p->in_data.pdu_received_len], data, len_needed_to_complete_hdr);
        p->in_data.pdu_received_len += len_needed_to_complete_hdr;

        return (ssize_t)len_needed_to_complete_hdr;
}

/****************************************************************************
 Unmarshalls a new PDU header. Assumes the raw header data is in current_in_pdu.
****************************************************************************/

static ssize_t unmarshall_rpc_header(pipes_struct *p)
{
        /*
         * Unmarshall the header to determine the needed length.
         */

        prs_struct rpc_in;

        if(p->in_data.pdu_received_len != RPC_HEADER_LEN) {
                DEBUG(0,("unmarshall_rpc_header: assert on rpc header length failed.\n"));
                set_incoming_fault(p);
                return -1;
        }

        prs_init_empty( &rpc_in, p->mem_ctx, UNMARSHALL);
        prs_set_endian_data( &rpc_in, p->endian);

        prs_give_memory( &rpc_in, (char *)&p->in_data.current_in_pdu[0],
                                        p->in_data.pdu_received_len, False);

        /*
         * Unmarshall the header as this will tell us how much
         * data we need to read to get the complete pdu.
         * This also sets the endian flag in rpc_in.
         */

        if(!smb_io_rpc_hdr("", &p->hdr, &rpc_in, 0)) {
                DEBUG(0,("unmarshall_rpc_header: failed to unmarshall RPC_HDR.\n"));
                set_incoming_fault(p);
                prs_mem_free(&rpc_in);
                return -1;
        }

        /*
         * Validate the RPC header.
         */

        if(p->hdr.major != 5 && p->hdr.minor != 0) {
                DEBUG(0,("unmarshall_rpc_header: invalid major/minor numbers in RPC_HDR.\n"));
                set_incoming_fault(p);
                prs_mem_free(&rpc_in);
                return -1;
        }

        /*
         * If there's not data in the incoming buffer this should be the start of a new RPC.
         */

        if(prs_offset(&p->in_data.data) == 0) {

                /*
                 * AS/U doesn't set FIRST flag in a BIND packet it seems.
                 */

                if ((p->hdr.pkt_type == DCERPC_PKT_REQUEST) && !(p->hdr.flags & DCERPC_PFC_FLAG_FIRST)) {
                        /*
                         * Ensure that the FIRST flag is set. If not then we have
                         * a stream missmatch.
                         */

                        DEBUG(0,("unmarshall_rpc_header: FIRST flag not set in first PDU !\n"));
                        set_incoming_fault(p);
                        prs_mem_free(&rpc_in);
                        return -1;
                }

                /*
                 * If this is the first PDU then set the endianness
                 * flag in the pipe. We will need this when parsing all
                 * data in this RPC.
                 */

                p->endian = rpc_in.bigendian_data;

                DEBUG(5,("unmarshall_rpc_header: using %sendian RPC\n",
                                p->endian == RPC_LITTLE_ENDIAN ? "little-" : "big-" ));

        } else {

                /*
                 * If this is *NOT* the first PDU then check the endianness
                 * flag in the pipe is the same as that in the PDU.
                 */

                if (p->endian != rpc_in.bigendian_data) {
                        DEBUG(0,("unmarshall_rpc_header: FIRST endianness flag (%d) different in next PDU !\n", (int)p->endian));
                        set_incoming_fault(p);
                        prs_mem_free(&rpc_in);
                        return -1;
                }
        }

        /*
         * Ensure that the pdu length is sane.
         */

        if((p->hdr.frag_len < RPC_HEADER_LEN) || (p->hdr.frag_len > RPC_MAX_PDU_FRAG_LEN)) {
                DEBUG(0,("unmarshall_rpc_header: assert on frag length failed.\n"));
                set_incoming_fault(p);
                prs_mem_free(&rpc_in);
                return -1;
        }

        DEBUG(10,("unmarshall_rpc_header: type = %u, flags = %u\n", (unsigned int)p->hdr.pkt_type,
                        (unsigned int)p->hdr.flags ));

        p->in_data.pdu_needed_len = (uint32)p->hdr.frag_len - RPC_HEADER_LEN;

        prs_mem_free(&rpc_in);

        p->in_data.current_in_pdu = TALLOC_REALLOC_ARRAY(
                p, p->in_data.current_in_pdu, uint8_t, p->hdr.frag_len);
        if (p->in_data.current_in_pdu == NULL) {
                DEBUG(0, ("talloc failed\n"));
                set_incoming_fault(p);
                return -1;
        }

        return 0; /* No extra data processed. */
}

/****************************************************************************
 Call this to free any talloc'ed memory. Do this before and after processing
 a complete PDU.
****************************************************************************/

static void free_pipe_context(pipes_struct *p)
{
        if (p->mem_ctx) {
                DEBUG(3,("free_pipe_context: destroying talloc pool of size "
                         "%lu\n", (unsigned long)talloc_total_size(p->mem_ctx) ));
                talloc_free_children(p->mem_ctx);
        } else {
                p->mem_ctx = talloc_named(p, 0, "pipe %s %p",
                                    get_pipe_name_from_syntax(talloc_tos(),
                                                              &p->syntax), p);
                if (p->mem_ctx == NULL) {
                        p->fault_state = True;
                }
        }
}

/****************************************************************************
 Processes a request pdu. This will do auth processing if needed, and
 appends the data into the complete stream if the LAST flag is not set.
****************************************************************************/

static bool process_request_pdu(pipes_struct *p, prs_struct *rpc_in_p)
{
        uint32 ss_padding_len = 0;
        size_t data_len = p->hdr.frag_len - RPC_HEADER_LEN - RPC_HDR_REQ_LEN -
                                (p->hdr.auth_len ? RPC_HDR_AUTH_LEN : 0) - p->hdr.auth_len;

        if(!p->pipe_bound) {
                DEBUG(0,("process_request_pdu: rpc request with no bind.\n"));
                set_incoming_fault(p);
                return False;
        }

        /*
         * Check if we need to do authentication processing.
         * This is only done on requests, not binds.
         */

        /*
         * Read the RPC request header.
         */

        if(!smb_io_rpc_hdr_req("req", &p->hdr_req, rpc_in_p, 0)) {
                DEBUG(0,("process_request_pdu: failed to unmarshall RPC_HDR_REQ.\n"));
                set_incoming_fault(p);
                return False;
        }

        switch(p->auth.auth_type) {
                case PIPE_AUTH_TYPE_NONE:
                        break;

                case PIPE_AUTH_TYPE_SPNEGO_NTLMSSP:
                case PIPE_AUTH_TYPE_NTLMSSP:
                {
                        NTSTATUS status;
                        if(!api_pipe_ntlmssp_auth_process(p, rpc_in_p, &ss_padding_len, &status)) {
                                DEBUG(0,("process_request_pdu: failed to do auth processing.\n"));
                                DEBUG(0,("process_request_pdu: error was %s.\n", nt_errstr(status) ));
                                set_incoming_fault(p);
                                return False;
                        }
                        break;
                }

                case PIPE_AUTH_TYPE_SCHANNEL:
                        if (!api_pipe_schannel_process(p, rpc_in_p, &ss_padding_len)) {
                                DEBUG(3,("process_request_pdu: failed to do schannel processing.\n"));
                                set_incoming_fault(p);
                                return False;
                        }
                        break;

                default:
                        DEBUG(0,("process_request_pdu: unknown auth type %u set.\n", (unsigned int)p->auth.auth_type ));
                        set_incoming_fault(p);
                        return False;
        }

        /* Now we've done the sign/seal we can remove any padding data. */
        if (data_len > ss_padding_len) {
                data_len -= ss_padding_len;
        }

        /*
         * Check the data length doesn't go over the 15Mb limit.
         * increased after observing a bug in the Windows NT 4.0 SP6a
         * spoolsv.exe when the response to a GETPRINTERDRIVER2 RPC
         * will not fit in the initial buffer of size 0x1068   --jerry 22/01/2002
         */
        
        if(prs_offset(&p->in_data.data) + data_len > MAX_RPC_DATA_SIZE) {
                DEBUG(0,("process_request_pdu: rpc data buffer too large (%u) + (%u)\n",
                                (unsigned int)prs_data_size(&p->in_data.data), (unsigned int)data_len ));
                set_incoming_fault(p);
                return False;
        }

        /*
         * Append the data portion into the buffer and return.
         */

        if(!prs_append_some_prs_data(&p->in_data.data, rpc_in_p, prs_offset(rpc_in_p), data_len)) {
                DEBUG(0,("process_request_pdu: Unable to append data size %u to parse buffer of size %u.\n",
                                (unsigned int)data_len, (unsigned int)prs_data_size(&p->in_data.data) ));
                set_incoming_fault(p);
                return False;
        }

        if(p->hdr.flags & DCERPC_PFC_FLAG_LAST) {
                bool ret = False;
                /*
                 * Ok - we finally have a complete RPC stream.
                 * Call the rpc command to process it.
                 */

                /*
                 * Ensure the internal prs buffer size is *exactly* the same
                 * size as the current offset.
                 */

                if(!prs_set_buffer_size(&p->in_data.data, prs_offset(&p->in_data.data))) {
                        DEBUG(0,("process_request_pdu: Call to prs_set_buffer_size failed!\n"));
                        set_incoming_fault(p);
                        return False;
                }

                /*
                 * Set the parse offset to the start of the data and set the
                 * prs_struct to UNMARSHALL.
                 */

                prs_set_offset(&p->in_data.data, 0);
                prs_switch_type(&p->in_data.data, UNMARSHALL);

                /*
                 * Process the complete data stream here.
                 */

                free_pipe_context(p);

                if(pipe_init_outgoing_data(p)) {
                        ret = api_pipe_request(p);
                }

                free_pipe_context(p);

                /*
                 * We have consumed the whole data stream. Set back to
                 * marshalling and set the offset back to the start of
                 * the buffer to re-use it (we could also do a prs_mem_free()
                 * and then re_init on the next start of PDU. Not sure which
                 * is best here.... JRA.
                 */

                prs_switch_type(&p->in_data.data, MARSHALL);
                prs_set_offset(&p->in_data.data, 0);
                return ret;
        }

        return True;
}

/****************************************************************************
 Processes a finished PDU stored in current_in_pdu. The RPC_HEADER has
 already been parsed and stored in p->hdr.
****************************************************************************/

static void process_complete_pdu(pipes_struct *p)
{
        prs_struct rpc_in;
        size_t data_len = p->in_data.pdu_received_len - RPC_HEADER_LEN;
        char *data_p = (char *)&p->in_data.current_in_pdu[RPC_HEADER_LEN];
        bool reply = False;

        if(p->fault_state) {
                DEBUG(10,("process_complete_pdu: pipe %s in fault state.\n",
                          get_pipe_name_from_syntax(talloc_tos(), &p->syntax)));
                set_incoming_fault(p);
                setup_fault_pdu(p, NT_STATUS(DCERPC_FAULT_OP_RNG_ERROR));
                return;
        }

        prs_init_empty( &rpc_in, p->mem_ctx, UNMARSHALL);

        /*
         * Ensure we're using the corrent endianness for both the 
         * RPC header flags and the raw data we will be reading from.
         */

        prs_set_endian_data( &rpc_in, p->endian);
        prs_set_endian_data( &p->in_data.data, p->endian);

        prs_give_memory( &rpc_in, data_p, (uint32)data_len, False);

        DEBUG(10,("process_complete_pdu: processing packet type %u\n",
                        (unsigned int)p->hdr.pkt_type ));

        switch (p->hdr.pkt_type) {
                case DCERPC_PKT_REQUEST:
                        reply = process_request_pdu(p, &rpc_in);
                        break;

                case DCERPC_PKT_PING: /* CL request - ignore... */
                        DEBUG(0,("process_complete_pdu: Error. Connectionless packet type %u received on pipe %s.\n",
                                (unsigned int)p->hdr.pkt_type,
                                 get_pipe_name_from_syntax(talloc_tos(),
                                                           &p->syntax)));
                        break;

                case DCERPC_PKT_RESPONSE: /* No responses here. */
                        DEBUG(0,("process_complete_pdu: Error. DCERPC_PKT_RESPONSE received from client on pipe %s.\n",
                                 get_pipe_name_from_syntax(talloc_tos(),
                                                           &p->syntax)));
                        break;

                case DCERPC_PKT_FAULT:
                case DCERPC_PKT_WORKING: /* CL request - reply to a ping when a call in process. */
                case DCERPC_PKT_NOCALL: /* CL - server reply to a ping call. */
                case DCERPC_PKT_REJECT:
                case DCERPC_PKT_ACK:
                case DCERPC_PKT_CL_CANCEL:
                case DCERPC_PKT_FACK:
                case DCERPC_PKT_CANCEL_ACK:
                        DEBUG(0,("process_complete_pdu: Error. Connectionless packet type %u received on pipe %s.\n",
                                (unsigned int)p->hdr.pkt_type,
                                 get_pipe_name_from_syntax(talloc_tos(),
                                                           &p->syntax)));
                        break;

                case DCERPC_PKT_BIND:
                        /*
                         * We assume that a pipe bind is only in one pdu.
                         */
                        if(pipe_init_outgoing_data(p)) {
                                reply = api_pipe_bind_req(p, &rpc_in);
                        }
                        break;

                case DCERPC_PKT_BIND_ACK:
                case DCERPC_PKT_BIND_NAK:
                        DEBUG(0,("process_complete_pdu: Error. DCERPC_PKT_BINDACK/DCERPC_PKT_BINDNACK packet type %u received on pipe %s.\n",
                                (unsigned int)p->hdr.pkt_type,
                                 get_pipe_name_from_syntax(talloc_tos(),
                                                           &p->syntax)));
                        break;


                case DCERPC_PKT_ALTER:
                        /*
                         * We assume that a pipe bind is only in one pdu.
                         */
                        if(pipe_init_outgoing_data(p)) {
                                reply = api_pipe_alter_context(p, &rpc_in);
                        }
                        break;

                case DCERPC_PKT_ALTER_RESP:
                        DEBUG(0,("process_complete_pdu: Error. DCERPC_PKT_ALTER_RESP on pipe %s: Should only be server -> client.\n",
                                 get_pipe_name_from_syntax(talloc_tos(),
                                                           &p->syntax)));
                        break;

                case DCERPC_PKT_AUTH3:
                        /*
                         * The third packet in an NTLMSSP auth exchange.
                         */
                        if(pipe_init_outgoing_data(p)) {
                                reply = api_pipe_bind_auth3(p, &rpc_in);
                        }
                        break;

                case DCERPC_PKT_SHUTDOWN:
                        DEBUG(0,("process_complete_pdu: Error. DCERPC_PKT_SHUTDOWN on pipe %s: Should only be server -> client.\n",
                                 get_pipe_name_from_syntax(talloc_tos(),
                                                           &p->syntax)));
                        break;

                case DCERPC_PKT_CO_CANCEL:
                        /* For now just free all client data and continue processing. */
                        DEBUG(3,("process_complete_pdu: DCERPC_PKT_CO_CANCEL. Abandoning rpc call.\n"));
                        /* As we never do asynchronous RPC serving, we can never cancel a
                           call (as far as I know). If we ever did we'd have to send a cancel_ack
                           reply. For now, just free all client data and continue processing. */
                        reply = True;
                        break;
#if 0
                        /* Enable this if we're doing async rpc. */
                        /* We must check the call-id matches the outstanding callid. */
                        if(pipe_init_outgoing_data(p)) {
                                /* Send a cancel_ack PDU reply. */
                                /* We should probably check the auth-verifier here. */
                                reply = setup_cancel_ack_reply(p, &rpc_in);
                        }
                        break;
#endif

                case DCERPC_PKT_ORPHANED:
                        /* We should probably check the auth-verifier here.
                           For now just free all client data and continue processing. */
                        DEBUG(3,("process_complete_pdu: DCERPC_PKT_ORPHANED. Abandoning rpc call.\n"));
                        reply = True;
                        break;

                default:
                        DEBUG(0,("process_complete_pdu: Unknown rpc type = %u received.\n", (unsigned int)p->hdr.pkt_type ));
                        break;
        }

        /* Reset to little endian. Probably don't need this but it won't hurt. */
        prs_set_endian_data( &p->in_data.data, RPC_LITTLE_ENDIAN);

        if (!reply) {
                DEBUG(3,("process_complete_pdu: DCE/RPC fault sent on "
                         "pipe %s\n", get_pipe_name_from_syntax(talloc_tos(),
                                                                &p->syntax)));
                set_incoming_fault(p);
                setup_fault_pdu(p, NT_STATUS(DCERPC_FAULT_OP_RNG_ERROR));
                prs_mem_free(&rpc_in);
        } else {
                /*
                 * Reset the lengths. We're ready for a new pdu.
                 */
                TALLOC_FREE(p->in_data.current_in_pdu);
                p->in_data.pdu_needed_len = 0;
                p->in_data.pdu_received_len = 0;
        }

        prs_mem_free(&rpc_in);
}

/****************************************************************************
 Accepts incoming data on an rpc pipe. Processes the data in pdu sized units.
****************************************************************************/

static ssize_t process_incoming_data(pipes_struct *p, char *data, size_t n)
{
        size_t data_to_copy = MIN(n, RPC_MAX_PDU_FRAG_LEN - p->in_data.pdu_received_len);

        DEBUG(10,("process_incoming_data: Start: pdu_received_len = %u, pdu_needed_len = %u, incoming data = %u\n",
                (unsigned int)p->in_data.pdu_received_len, (unsigned int)p->in_data.pdu_needed_len,
                (unsigned int)n ));

        if(data_to_copy == 0) {
                /*
                 * This is an error - data is being received and there is no
                 * space in the PDU. Free the received data and go into the fault state.
                 */
                DEBUG(0,("process_incoming_data: No space in incoming pdu buffer. Current size = %u \
incoming data size = %u\n", (unsigned int)p->in_data.pdu_received_len, (unsigned int)n ));
                set_incoming_fault(p);
                return -1;
        }

        /*
         * If we have no data already, wait until we get at least a RPC_HEADER_LEN
         * number of bytes before we can do anything.
         */

        if((p->in_data.pdu_needed_len == 0) && (p->in_data.pdu_received_len < RPC_HEADER_LEN)) {
                /*
                 * Always return here. If we have more data then the RPC_HEADER
                 * will be processed the next time around the loop.
                 */
                return fill_rpc_header(p, data, data_to_copy);
        }

        /*
         * At this point we know we have at least an RPC_HEADER_LEN amount of data
         * stored in current_in_pdu.
         */

        /*
         * If pdu_needed_len is zero this is a new pdu. 
         * Unmarshall the header so we know how much more
         * data we need, then loop again.
         */

        if(p->in_data.pdu_needed_len == 0) {
                ssize_t rret = unmarshall_rpc_header(p);
                if (rret == -1 || p->in_data.pdu_needed_len > 0) {
                        return rret;
                }
                /* If rret == 0 and pdu_needed_len == 0 here we have a PDU that consists
                   of an RPC_HEADER only. This is a DCERPC_PKT_SHUTDOWN, DCERPC_PKT_CO_CANCEL or DCERPC_PKT_ORPHANED
                   pdu type. Deal with this in process_complete_pdu(). */
        }

        /*
         * Ok - at this point we have a valid RPC_HEADER in p->hdr.
         * Keep reading until we have a full pdu.
         */

        data_to_copy = MIN(data_to_copy, p->in_data.pdu_needed_len);

        /*
         * Copy as much of the data as we need into the current_in_pdu buffer.
         * pdu_needed_len becomes zero when we have a complete pdu.
         */

        memcpy( (char *)&p->in_data.current_in_pdu[p->in_data.pdu_received_len], data, data_to_copy);
        p->in_data.pdu_received_len += data_to_copy;
        p->in_data.pdu_needed_len -= data_to_copy;

        /*
         * Do we have a complete PDU ?
         * (return the number of bytes handled in the call)
         */

        if(p->in_data.pdu_needed_len == 0) {
                process_complete_pdu(p);
                return data_to_copy;
        }

        DEBUG(10,("process_incoming_data: not a complete PDU yet. pdu_received_len = %u, pdu_needed_len = %u\n",
                (unsigned int)p->in_data.pdu_received_len, (unsigned int)p->in_data.pdu_needed_len ));

        return (ssize_t)data_to_copy;
}

/****************************************************************************
 Accepts incoming data on an internal rpc pipe.
****************************************************************************/

static ssize_t write_to_internal_pipe(struct pipes_struct *p, char *data, size_t n)
{
        size_t data_left = n;

        while(data_left) {
                ssize_t data_used;

                DEBUG(10,("write_to_pipe: data_left = %u\n", (unsigned int)data_left ));

                data_used = process_incoming_data(p, data, data_left);

                DEBUG(10,("write_to_pipe: data_used = %d\n", (int)data_used ));

                if(data_used < 0) {
                        return -1;
                }

                data_left -= data_used;
                data += data_used;
        }       

        return n;
}

/****************************************************************************
 Replies to a request to read data from a pipe.

 Headers are interspersed with the data at PDU intervals. By the time
 this function is called, the start of the data could possibly have been
 read by an SMBtrans (file_offset != 0).

 Calling create_rpc_reply() here is a hack. The data should already
 have been prepared into arrays of headers + data stream sections.
****************************************************************************/

static ssize_t read_from_internal_pipe(struct pipes_struct *p, char *data, size_t n,
                                       bool *is_data_outstanding)
{
        uint32 pdu_remaining = 0;
        ssize_t data_returned = 0;

        if (!p) {
                DEBUG(0,("read_from_pipe: pipe not open\n"));
                return -1;              
        }

        DEBUG(6,(" name: %s len: %u\n",
                 get_pipe_name_from_syntax(talloc_tos(), &p->syntax),
                 (unsigned int)n));

        /*
         * We cannot return more than one PDU length per
         * read request.
         */

        /*
         * This condition should result in the connection being closed.  
         * Netapp filers seem to set it to 0xffff which results in domain
         * authentications failing.  Just ignore it so things work.
         */

        if(n > RPC_MAX_PDU_FRAG_LEN) {
                DEBUG(5,("read_from_pipe: too large read (%u) requested on "
                         "pipe %s. We can only service %d sized reads.\n",
                         (unsigned int)n,
                         get_pipe_name_from_syntax(talloc_tos(), &p->syntax),
                         RPC_MAX_PDU_FRAG_LEN ));
                n = RPC_MAX_PDU_FRAG_LEN;
        }

        /*
         * Determine if there is still data to send in the
         * pipe PDU buffer. Always send this first. Never
         * send more than is left in the current PDU. The
         * client should send a new read request for a new
         * PDU.
         */

        pdu_remaining = prs_offset(&p->out_data.frag)
                - p->out_data.current_pdu_sent;

        if (pdu_remaining > 0) {
                data_returned = (ssize_t)MIN(n, pdu_remaining);

                DEBUG(10,("read_from_pipe: %s: current_pdu_len = %u, "
                          "current_pdu_sent = %u returning %d bytes.\n",
                          get_pipe_name_from_syntax(talloc_tos(), &p->syntax),
                          (unsigned int)prs_offset(&p->out_data.frag),
                          (unsigned int)p->out_data.current_pdu_sent,
                          (int)data_returned));

                memcpy(data,
                       prs_data_p(&p->out_data.frag)
                       + p->out_data.current_pdu_sent,
                       data_returned);

                p->out_data.current_pdu_sent += (uint32)data_returned;
                goto out;
        }

        /*
         * At this point p->current_pdu_len == p->current_pdu_sent (which
         * may of course be zero if this is the first return fragment.
         */

        DEBUG(10,("read_from_pipe: %s: fault_state = %d : data_sent_length "
                  "= %u, prs_offset(&p->out_data.rdata) = %u.\n",
                  get_pipe_name_from_syntax(talloc_tos(), &p->syntax),
                  (int)p->fault_state,
                  (unsigned int)p->out_data.data_sent_length,
                  (unsigned int)prs_offset(&p->out_data.rdata) ));

        if(p->out_data.data_sent_length >= prs_offset(&p->out_data.rdata)) {
                /*
                 * We have sent all possible data, return 0.
                 */
                data_returned = 0;
                goto out;
        }

        /*
         * We need to create a new PDU from the data left in p->rdata.
         * Create the header/data/footers. This also sets up the fields
         * p->current_pdu_len, p->current_pdu_sent, p->data_sent_length
         * and stores the outgoing PDU in p->current_pdu.
         */

        if(!create_next_pdu(p)) {
                DEBUG(0,("read_from_pipe: %s: create_next_pdu failed.\n",
                         get_pipe_name_from_syntax(talloc_tos(), &p->syntax)));
                return -1;
        }

        data_returned = MIN(n, prs_offset(&p->out_data.frag));

        memcpy( data, prs_data_p(&p->out_data.frag), (size_t)data_returned);
        p->out_data.current_pdu_sent += (uint32)data_returned;

  out:
        (*is_data_outstanding) = prs_offset(&p->out_data.frag) > n;

        if (p->out_data.current_pdu_sent == prs_offset(&p->out_data.frag)) {
                /* We've returned everything in the out_data.frag
                 * so we're done with this pdu. Free it and reset
                 * current_pdu_sent. */
                p->out_data.current_pdu_sent = 0;
                prs_mem_free(&p->out_data.frag);
        }
        return data_returned;
}

/****************************************************************************
 Close an rpc pipe.
****************************************************************************/

static int close_internal_rpc_pipe_hnd(struct pipes_struct *p)
{
        if (!p) {
                DEBUG(0,("Invalid pipe in close_internal_rpc_pipe_hnd\n"));
                return False;
        }

        prs_mem_free(&p->out_data.frag);
        prs_mem_free(&p->out_data.rdata);
        prs_mem_free(&p->in_data.data);

        if (p->auth.auth_data_free_func) {
                (*p->auth.auth_data_free_func)(&p->auth);
        }

        free_pipe_rpc_context( p->contexts );

        /* Free the handles database. */
        close_policy_by_pipe(p);

        DLIST_REMOVE(InternalPipes, p);

        ZERO_STRUCTP(p);

        return 0;
}

bool fsp_is_np(struct files_struct *fsp)
{
        enum FAKE_FILE_TYPE type;

        if ((fsp == NULL) || (fsp->fake_file_handle == NULL)) {
                return false;
        }

        type = fsp->fake_file_handle->type;

        return ((type == FAKE_FILE_TYPE_NAMED_PIPE)
                || (type == FAKE_FILE_TYPE_NAMED_PIPE_PROXY));
}

struct np_proxy_state {
        struct tevent_queue *read_queue;
        struct tevent_queue *write_queue;
        int fd;

        uint8_t *msg;
        size_t sent;
};

static int np_proxy_state_destructor(struct np_proxy_state *state)
{
        if (state->fd != -1) {
                close(state->fd);
        }
        return 0;
}

static struct np_proxy_state *make_external_rpc_pipe_p(TALLOC_CTX *mem_ctx,
                                                       const char *pipe_name,
                                                       struct auth_serversupplied_info *server_info)
{
        struct np_proxy_state *result;
        struct sockaddr_un addr;
        char *socket_path;
        const char *socket_dir;

        DATA_BLOB req_blob;
        struct netr_SamInfo3 *info3;
        struct named_pipe_auth_req req;
        DATA_BLOB rep_blob;
        uint8 rep_buf[20];
        struct named_pipe_auth_rep rep;
        enum ndr_err_code ndr_err;
        NTSTATUS status;
        ssize_t written;

        result = talloc(mem_ctx, struct np_proxy_state);
        if (result == NULL) {
                DEBUG(0, ("talloc failed\n"));
                return NULL;
        }

        result->fd = socket(AF_UNIX, SOCK_STREAM, 0);
        if (result->fd == -1) {
                DEBUG(10, ("socket(2) failed: %s\n", strerror(errno)));
                goto fail;
        }
        talloc_set_destructor(result, np_proxy_state_destructor);

        ZERO_STRUCT(addr);
        addr.sun_family = AF_UNIX;

        socket_dir = lp_parm_const_string(
                GLOBAL_SECTION_SNUM, "external_rpc_pipe", "socket_dir",
                get_dyn_NCALRPCDIR());
        if (socket_dir == NULL) {
                DEBUG(0, ("externan_rpc_pipe:socket_dir not set\n"));
                goto fail;
        }

        socket_path = talloc_asprintf(talloc_tos(), "%s/np/%s",
                                      socket_dir, pipe_name);
        if (socket_path == NULL) {
                DEBUG(0, ("talloc_asprintf failed\n"));
                goto fail;
        }
        strncpy(addr.sun_path, socket_path, sizeof(addr.sun_path));
        TALLOC_FREE(socket_path);

        become_root();
        if (sys_connect(result->fd, (struct sockaddr *)&addr) == -1) {
                unbecome_root();
                DEBUG(0, ("connect(%s) failed: %s\n", addr.sun_path,
                          strerror(errno)));
                goto fail;
        }
        unbecome_root();

        info3 = talloc(talloc_tos(), struct netr_SamInfo3);
        if (info3 == NULL) {
                DEBUG(0, ("talloc failed\n"));
                goto fail;
        }

        status = serverinfo_to_SamInfo3(server_info, NULL, 0, info3);
        if (!NT_STATUS_IS_OK(status)) {
                TALLOC_FREE(info3);
                DEBUG(0, ("serverinfo_to_SamInfo3 failed: %s\n",
                          nt_errstr(status)));
                goto fail;
        }

        req.level = 1;
        req.info.info1 = *info3;

        ndr_err = ndr_push_struct_blob(&req_blob, talloc_tos(), &req,
                (ndr_push_flags_fn_t)ndr_push_named_pipe_auth_req);

        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
                DEBUG(10, ("ndr_push_named_pipe_auth_req failed: %s\n",
                           ndr_errstr(ndr_err)));
                goto fail;
        }

        DEBUG(10, ("named_pipe_auth_req(client)[%u]\n", (uint32_t)req_blob.length));
        dump_data(10, req_blob.data, req_blob.length);

        written = write_data(result->fd, (char *)req_blob.data,
                             req_blob.length);
        if (written == -1) {
                DEBUG(3, ("Could not write auth req data to RPC server\n"));
                goto fail;
        }

        status = read_data(result->fd, (char *)rep_buf, sizeof(rep_buf));
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(3, ("Could not read auth result\n"));
                goto fail;
        }

        rep_blob = data_blob_const(rep_buf, sizeof(rep_buf));

        DEBUG(10,("name_pipe_auth_rep(client)[%u]\n", (uint32_t)rep_blob.length));
        dump_data(10, rep_blob.data, rep_blob.length);

        ndr_err = ndr_pull_struct_blob(&rep_blob, talloc_tos(), &rep,
                (ndr_pull_flags_fn_t)ndr_pull_named_pipe_auth_rep);

        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
                DEBUG(0, ("ndr_pull_named_pipe_auth_rep failed: %s\n",
                          ndr_errstr(ndr_err)));
                goto fail;
        }

        if (rep.length != 16) {
                DEBUG(0, ("req invalid length: %u != 16\n",
                          rep.length));
                goto fail;
        }

        if (strcmp(NAMED_PIPE_AUTH_MAGIC, rep.magic) != 0) {
                DEBUG(0, ("req invalid magic: %s != %s\n",
                          rep.magic, NAMED_PIPE_AUTH_MAGIC));
                goto fail;
        }

        if (!NT_STATUS_IS_OK(rep.status)) {
                DEBUG(0, ("req failed: %s\n",
                          nt_errstr(rep.status)));
                goto fail;
        }

        if (rep.level != 1) {
                DEBUG(0, ("req invalid level: %u != 1\n",
                          rep.level));
                goto fail;
        }

        result->msg = NULL;

        result->read_queue = tevent_queue_create(result, "np_read");
        if (result->read_queue == NULL) {
                goto fail;
        }
        result->write_queue = tevent_queue_create(result, "np_write");
        if (result->write_queue == NULL) {
                goto fail;
        }

        return result;

 fail:
        TALLOC_FREE(result);
        return NULL;
}

NTSTATUS np_open(TALLOC_CTX *mem_ctx, const char *name,
                 const char *client_address,
                 struct auth_serversupplied_info *server_info,
                 struct fake_file_handle **phandle)
{
        const char **proxy_list;
        struct fake_file_handle *handle;

        proxy_list = lp_parm_string_list(-1, "np", "proxy", NULL);

        handle = talloc(mem_ctx, struct fake_file_handle);
        if (handle == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        if ((proxy_list != NULL) && str_list_check_ci(proxy_list, name)) {
                struct np_proxy_state *p;

                p = make_external_rpc_pipe_p(handle, name, server_info);

                handle->type = FAKE_FILE_TYPE_NAMED_PIPE_PROXY;
                handle->private_data = p;
        } else {
                struct pipes_struct *p;
                struct ndr_syntax_id syntax;

                if (!is_known_pipename(name, &syntax)) {
                        TALLOC_FREE(handle);
                        return NT_STATUS_OBJECT_NAME_NOT_FOUND;
                }

                p = make_internal_rpc_pipe_p(handle, &syntax, client_address,
                                             server_info);

                handle->type = FAKE_FILE_TYPE_NAMED_PIPE;
                handle->private_data = p;
        }

        if (handle->private_data == NULL) {
                TALLOC_FREE(handle);
                return NT_STATUS_PIPE_NOT_AVAILABLE;
        }

        *phandle = handle;

        return NT_STATUS_OK;
}

struct np_write_state {
        struct event_context *ev;
        struct np_proxy_state *p;
        struct iovec iov;
        ssize_t nwritten;
};

static void np_write_done(struct tevent_req *subreq);

struct tevent_req *np_write_send(TALLOC_CTX *mem_ctx, struct event_context *ev,
                                 struct fake_file_handle *handle,
                                 const uint8_t *data, size_t len)
{
        struct tevent_req *req;
        struct np_write_state *state;
        NTSTATUS status;

        DEBUG(6, ("np_write_send: len: %d\n", (int)len));
        dump_data(50, data, len);

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

        if (len == 0) {
                state->nwritten = 0;
                status = NT_STATUS_OK;
                goto post_status;
        }

        if (handle->type == FAKE_FILE_TYPE_NAMED_PIPE) {
                struct pipes_struct *p = talloc_get_type_abort(
                        handle->private_data, struct pipes_struct);

                state->nwritten = write_to_internal_pipe(p, (char *)data, len);

                status = (state->nwritten >= 0)
                        ? NT_STATUS_OK : NT_STATUS_UNEXPECTED_IO_ERROR;
                goto post_status;
        }

        if (handle->type == FAKE_FILE_TYPE_NAMED_PIPE_PROXY) {
                struct np_proxy_state *p = talloc_get_type_abort(
                        handle->private_data, struct np_proxy_state);
                struct tevent_req *subreq;

                state->ev = ev;
                state->p = p;
                state->iov.iov_base = CONST_DISCARD(void *, data);
                state->iov.iov_len = len;

                subreq = writev_send(state, ev, p->write_queue, p->fd,
                                     false, &state->iov, 1);
                if (subreq == NULL) {
                        goto fail;
                }
                tevent_req_set_callback(subreq, np_write_done, req);
                return req;
        }

        status = NT_STATUS_INVALID_HANDLE;
 post_status:
        if (NT_STATUS_IS_OK(status)) {
                tevent_req_done(req);
        } else {
                tevent_req_nterror(req, status);
        }
        return tevent_req_post(req, ev);
 fail:
        TALLOC_FREE(req);
        return NULL;
}

static void np_write_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct np_write_state *state = tevent_req_data(
                req, struct np_write_state);
        ssize_t received;
        int err;

        received = writev_recv(subreq, &err);
        if (received < 0) {
                tevent_req_nterror(req, map_nt_error_from_unix(err));
                return;
        }
        state->nwritten = received;
        tevent_req_done(req);
}

NTSTATUS np_write_recv(struct tevent_req *req, ssize_t *pnwritten)
{
        struct np_write_state *state = tevent_req_data(
                req, struct np_write_state);
        NTSTATUS status;

        if (tevent_req_is_nterror(req, &status)) {
                return status;
        }
        *pnwritten = state->nwritten;
        return NT_STATUS_OK;
}

static ssize_t rpc_frag_more_fn(uint8_t *buf, size_t buflen, void *priv)
{
        prs_struct hdr_prs;
        struct rpc_hdr_info hdr;
        bool ret;

        if (buflen > RPC_HEADER_LEN) {
                return 0;
        }
        prs_init_empty(&hdr_prs, talloc_tos(), UNMARSHALL);
        prs_give_memory(&hdr_prs, (char *)buf, RPC_HEADER_LEN, false);
        ret = smb_io_rpc_hdr("", &hdr, &hdr_prs, 0);
        prs_mem_free(&hdr_prs);

        if (!ret) {
                return -1;
        }

        return (hdr.frag_len - RPC_HEADER_LEN);
}

struct np_read_state {
        struct event_context *ev;
        struct np_proxy_state *p;
        uint8_t *data;
        size_t len;

        size_t nread;
        bool is_data_outstanding;
};

static void np_read_trigger(struct tevent_req *req, void *private_data);
static void np_read_done(struct tevent_req *subreq);

struct tevent_req *np_read_send(TALLOC_CTX *mem_ctx, struct event_context *ev,
                                struct fake_file_handle *handle,
                                uint8_t *data, size_t len)
{
        struct tevent_req *req;
        struct np_read_state *state;
        NTSTATUS status;

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

        if (handle->type == FAKE_FILE_TYPE_NAMED_PIPE) {
                struct pipes_struct *p = talloc_get_type_abort(
                        handle->private_data, struct pipes_struct);

                state->nread = read_from_internal_pipe(
                        p, (char *)data, len, &state->is_data_outstanding);

                status = (state->nread >= 0)
                        ? NT_STATUS_OK : NT_STATUS_UNEXPECTED_IO_ERROR;
                goto post_status;
        }

        if (handle->type == FAKE_FILE_TYPE_NAMED_PIPE_PROXY) {
                struct np_proxy_state *p = talloc_get_type_abort(
                        handle->private_data, struct np_proxy_state);

                if (p->msg != NULL) {
                        size_t thistime;

                        thistime = MIN(talloc_get_size(p->msg) - p->sent,
                                       len);

                        memcpy(data, p->msg+p->sent, thistime);
                        state->nread = thistime;
                        p->sent += thistime;

                        if (p->sent < talloc_get_size(p->msg)) {
                                state->is_data_outstanding = true;
                        } else {
                                state->is_data_outstanding = false;
                                TALLOC_FREE(p->msg);
                        }
                        status = NT_STATUS_OK;
                        goto post_status;
                }

                state->ev = ev;
                state->p = p;
                state->data = data;
                state->len = len;

                if (!tevent_queue_add(p->read_queue, ev, req, np_read_trigger,
                                      NULL)) {
                        goto fail;
                }
                return req;
        }

        status = NT_STATUS_INVALID_HANDLE;
 post_status:
        if (NT_STATUS_IS_OK(status)) {
                tevent_req_done(req);
        } else {
                tevent_req_nterror(req, status);
        }
        return tevent_req_post(req, ev);
 fail:
        TALLOC_FREE(req);
        return NULL;
}

static void np_read_trigger(struct tevent_req *req, void *private_data)
{
        struct np_read_state *state = tevent_req_data(
                req, struct np_read_state);
        struct tevent_req *subreq;

        subreq = read_packet_send(state, state->ev, state->p->fd,
                                  RPC_HEADER_LEN, rpc_frag_more_fn, NULL);
        if (tevent_req_nomem(subreq, req)) {
                return;
        }
        tevent_req_set_callback(subreq, np_read_done, req);
}

static void np_read_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct np_read_state *state = tevent_req_data(
                req, struct np_read_state);
        ssize_t received;
        size_t thistime;
        int err;

        received = read_packet_recv(subreq, state->p, &state->p->msg, &err);
        TALLOC_FREE(subreq);
        if (received == -1) {
                tevent_req_nterror(req, map_nt_error_from_unix(err));
                return;
        }

        thistime = MIN(received, state->len);

        memcpy(state->data, state->p->msg, thistime);
        state->p->sent = thistime;
        state->nread = thistime;

        if (state->p->sent < received) {
                state->is_data_outstanding = true;
        } else {
                TALLOC_FREE(state->p->msg);
                state->is_data_outstanding = false;
        }

        tevent_req_done(req);
        return;
}

NTSTATUS np_read_recv(struct tevent_req *req, ssize_t *nread,
                      bool *is_data_outstanding)
{
        struct np_read_state *state = tevent_req_data(
                req, struct np_read_state);
        NTSTATUS status;

        if (tevent_req_is_nterror(req, &status)) {
                return status;
        }
        *nread = state->nread;
        *is_data_outstanding = state->is_data_outstanding;
        return NT_STATUS_OK;
}

/**
 * @brief Create a new RPC client context which uses a local dispatch function.
 *
 * @param[in]  mem_ctx  The memory context to use.
 *
 * @param[in]  abstract_syntax Normally the syntax_id of the autogenerated
 *                             ndr_table_<name>.
 *
 * @param[in]  dispatch The corresponding autogenerated dispatch function
 *                      rpc_<name>_dispatch.
 *
 * @param[in]  serversupplied_info The server supplied authentication function.
 *
 * @param[out] presult  A pointer to store the connected rpc client pipe.
 *
 * @return              NT_STATUS_OK on success, a corresponding NT status if an
 *                      error occured.
 *
 * @code
 *   struct rpc_pipe_client *winreg_pipe;
 *   NTSTATUS status;
 *
 *   status = rpc_pipe_open_internal(tmp_ctx,
 *                                   &ndr_table_winreg.syntax_id,
 *                                   rpc_winreg_dispatch,
 *                                   p->server_info,
 *                                   &winreg_pipe);
 * @endcode
 */
NTSTATUS rpc_pipe_open_internal(TALLOC_CTX *mem_ctx,
                                const struct ndr_syntax_id *abstract_syntax,
                                NTSTATUS (*dispatch) (struct rpc_pipe_client *cli,
                                                      TALLOC_CTX *mem_ctx,
                                                      const struct ndr_interface_table *table,
                                                      uint32_t opnum, void *r),
                                struct auth_serversupplied_info *serversupplied_info,
                                struct rpc_pipe_client **presult)
{
        struct rpc_pipe_client *result;

        result = TALLOC_ZERO_P(mem_ctx, struct rpc_pipe_client);
        if (result == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        result->abstract_syntax = *abstract_syntax;
        result->transfer_syntax = ndr_transfer_syntax;
        result->dispatch = dispatch;

        result->pipes_struct = make_internal_rpc_pipe_p(
                result, abstract_syntax, "", serversupplied_info);
        if (result->pipes_struct == NULL) {
                TALLOC_FREE(result);
                return NT_STATUS_NO_MEMORY;
        }

        result->max_xmit_frag = -1;
        result->max_recv_frag = -1;

        *presult = result;
        return NT_STATUS_OK;
}