source: trunk/server/libcli/cldap/cldap.c@ 751

/* 
   Unix SMB/CIFS implementation.

   cldap client library

   Copyright (C) Andrew Tridgell 2005
   Copyright (C) Stefan Metzmacher 2009
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/*
  see RFC1798 for details of CLDAP

  basic properties
    - carried over UDP on port 389
    - request and response matched by message ID
    - request consists of only a single searchRequest element
    - response can be in one of two forms
       - a single searchResponse, followed by a searchResult
       - a single searchResult
*/

#include "includes.h"
#include <tevent.h>
#include "../lib/util/dlinklist.h"
#include "../libcli/ldap/ldap_message.h"
#include "../libcli/ldap/ldap_ndr.h"
#include "../libcli/cldap/cldap.h"
#include "../lib/tsocket/tsocket.h"
#include "../libcli/security/dom_sid.h"
#include "../librpc/gen_ndr/ndr_nbt.h"
#include "../lib/util/asn1.h"
#include "../lib/util/tevent_ntstatus.h"

#undef strcasecmp

/*
  context structure for operations on cldap packets
*/
struct cldap_socket {
        /* the low level socket */
        struct tdgram_context *sock;

        /*
         * Are we in connected mode, which means
         * we get ICMP errors back instead of timing
         * out requests. And we can only send requests
         * to the connected peer.
         */
        bool connected;

        /*
         * we allow sync requests only, if the caller
         * did not pass an event context to cldap_socket_init()
         */
        struct {
                bool allow_poll;
                struct tevent_context *ctx;
        } event;

        /* the queue for outgoing dgrams */
        struct tevent_queue *send_queue;

        /* do we have an async tsocket_recvfrom request pending */
        struct tevent_req *recv_subreq;

        struct {
                /* a queue of pending search requests */
                struct cldap_search_state *list;

                /* mapping from message_id to pending request */
                struct idr_context *idr;
        } searches;

        /* what to do with incoming request packets */
        struct {
                void (*handler)(struct cldap_socket *,
                                void *private_data,
                                struct cldap_incoming *);
                void *private_data;
        } incoming;
};

struct cldap_search_state {
        struct cldap_search_state *prev, *next;

        struct {
                struct cldap_socket *cldap;
        } caller;

        int message_id;

        struct {
                uint32_t idx;
                uint32_t delay;
                uint32_t count;
                struct tsocket_address *dest;
                DATA_BLOB blob;
        } request;

        struct {
                struct cldap_incoming *in;
                struct asn1_data *asn1;
        } response;

        struct tevent_req *req;
};

static int cldap_socket_destructor(struct cldap_socket *c)
{
        while (c->searches.list) {
                struct cldap_search_state *s = c->searches.list;
                DLIST_REMOVE(c->searches.list, s);
                ZERO_STRUCT(s->caller);
        }

        talloc_free(c->recv_subreq);
        talloc_free(c->send_queue);
        talloc_free(c->sock);
        return 0;
}

static void cldap_recvfrom_done(struct tevent_req *subreq);

static bool cldap_recvfrom_setup(struct cldap_socket *c)
{
        if (c->recv_subreq) {
                return true;
        }

        if (!c->searches.list && !c->incoming.handler) {
                return true;
        }

        c->recv_subreq = tdgram_recvfrom_send(c, c->event.ctx, c->sock);
        if (!c->recv_subreq) {
                return false;
        }
        tevent_req_set_callback(c->recv_subreq, cldap_recvfrom_done, c);

        return true;
}

static void cldap_recvfrom_stop(struct cldap_socket *c)
{
        if (!c->recv_subreq) {
                return;
        }

        if (c->searches.list || c->incoming.handler) {
                return;
        }

        talloc_free(c->recv_subreq);
        c->recv_subreq = NULL;
}

static bool cldap_socket_recv_dgram(struct cldap_socket *c,
                                    struct cldap_incoming *in);

static void cldap_recvfrom_done(struct tevent_req *subreq)
{
        struct cldap_socket *c = tevent_req_callback_data(subreq,
                                 struct cldap_socket);
        struct cldap_incoming *in = NULL;
        ssize_t ret;
        bool setup_done;

        c->recv_subreq = NULL;

        in = talloc_zero(c, struct cldap_incoming);
        if (!in) {
                goto nomem;
        }

        ret = tdgram_recvfrom_recv(subreq,
                                   &in->recv_errno,
                                   in,
                                   &in->buf,
                                   &in->src);
        talloc_free(subreq);
        subreq = NULL;
        if (ret >= 0) {
                in->len = ret;
        }
        if (ret == -1 && in->recv_errno == 0) {
                in->recv_errno = EIO;
        }

        /* this function should free or steal 'in' */
        setup_done = cldap_socket_recv_dgram(c, in);
        in = NULL;

        if (!setup_done && !cldap_recvfrom_setup(c)) {
                goto nomem;
        }

        return;

nomem:
        talloc_free(subreq);
        talloc_free(in);
        /*TODO: call a dead socket handler */
        return;
}

/*
  handle recv events on a cldap socket
*/
static bool cldap_socket_recv_dgram(struct cldap_socket *c,
                                    struct cldap_incoming *in)
{
        DATA_BLOB blob;
        struct asn1_data *asn1;
        void *p;
        struct cldap_search_state *search;
        NTSTATUS status;

        if (in->recv_errno != 0) {
                goto error;
        }

        blob = data_blob_const(in->buf, in->len);

        asn1 = asn1_init(in);
        if (!asn1) {
                goto nomem;
        }

        if (!asn1_load(asn1, blob)) {
                goto nomem;
        }

        in->ldap_msg = talloc(in, struct ldap_message);
        if (in->ldap_msg == NULL) {
                goto nomem;
        }

        /* this initial decode is used to find the message id */
        status = ldap_decode(asn1, NULL, in->ldap_msg);
        if (!NT_STATUS_IS_OK(status)) {
                goto nterror;
        }

        /* find the pending request */
        p = idr_find(c->searches.idr, in->ldap_msg->messageid);
        if (p == NULL) {
                if (!c->incoming.handler) {
                        goto done;
                }

                /* this function should free or steal 'in' */
                c->incoming.handler(c, c->incoming.private_data, in);
                return false;
        }

        search = talloc_get_type(p, struct cldap_search_state);
        search->response.in = talloc_move(search, &in);
        search->response.asn1 = asn1;
        search->response.asn1->ofs = 0;

        DLIST_REMOVE(c->searches.list, search);

        if (!cldap_recvfrom_setup(c)) {
                goto nomem;
        }

        tevent_req_done(search->req);
        talloc_free(in);
        return true;

nomem:
        in->recv_errno = ENOMEM;
error:
        status = map_nt_error_from_unix(in->recv_errno);
nterror:
        /* in connected mode the first pending search gets the error */
        if (!c->connected) {
                /* otherwise we just ignore the error */
                goto done;
        }
        if (!c->searches.list) {
                goto done;
        }
        tevent_req_nterror(c->searches.list->req, status);
done:
        talloc_free(in);
        return false;
}

/*
  initialise a cldap_sock
*/
NTSTATUS cldap_socket_init(TALLOC_CTX *mem_ctx,
                           struct tevent_context *ev,
                           const struct tsocket_address *local_addr,
                           const struct tsocket_address *remote_addr,
                           struct cldap_socket **_cldap)
{
        struct cldap_socket *c = NULL;
        struct tsocket_address *any = NULL;
        NTSTATUS status;
        int ret;

        c = talloc_zero(mem_ctx, struct cldap_socket);
        if (!c) {
                goto nomem;
        }

        if (!ev) {
                ev = tevent_context_init(c);
                if (!ev) {
                        goto nomem;
                }
                c->event.allow_poll = true;
        }
        c->event.ctx = ev;

        if (!local_addr) {
                /* we use ipv4 here instead of ip, as otherwise we end
                   up with a PF_INET6 socket, and sendto() for ipv4
                   addresses will fail. That breaks cldap name
                   resolution for winbind to IPv4 hosts. */
                ret = tsocket_address_inet_from_strings(c, "ipv4",
                                                        NULL, 0,
                                                        &any);
                if (ret != 0) {
                        status = map_nt_error_from_unix(errno);
                        goto nterror;
                }
                local_addr = any;
        }

        c->searches.idr = idr_init(c);
        if (!c->searches.idr) {
                goto nomem;
        }

        ret = tdgram_inet_udp_socket(local_addr, remote_addr,
                                     c, &c->sock);
        if (ret != 0) {
                status = map_nt_error_from_unix(errno);
                goto nterror;
        }
        talloc_free(any);

        if (remote_addr) {
                c->connected = true;
        }

        c->send_queue = tevent_queue_create(c, "cldap_send_queue");
        if (!c->send_queue) {
                goto nomem;
        }

        talloc_set_destructor(c, cldap_socket_destructor);

        *_cldap = c;
        return NT_STATUS_OK;

nomem:
        status = NT_STATUS_NO_MEMORY;
nterror:
        talloc_free(c);
        return status;
}

/*
  setup a handler for incoming requests
*/
NTSTATUS cldap_set_incoming_handler(struct cldap_socket *c,
                                    void (*handler)(struct cldap_socket *,
                                                    void *private_data,
                                                    struct cldap_incoming *),
                                    void *private_data)
{
        if (c->connected) {
                return NT_STATUS_PIPE_CONNECTED;
        }

        /* if sync requests are allowed, we don't allow an incoming handler */
        if (c->event.allow_poll) {
                return NT_STATUS_INVALID_PIPE_STATE;
        }

        c->incoming.handler = handler;
        c->incoming.private_data = private_data;

        if (!cldap_recvfrom_setup(c)) {
                ZERO_STRUCT(c->incoming);
                return NT_STATUS_NO_MEMORY;
        }

        return NT_STATUS_OK;
}

struct cldap_reply_state {
        struct tsocket_address *dest;
        DATA_BLOB blob;
};

static void cldap_reply_state_destroy(struct tevent_req *subreq);

/*
  queue a cldap reply for send
*/
NTSTATUS cldap_reply_send(struct cldap_socket *cldap, struct cldap_reply *io)
{
        struct cldap_reply_state *state = NULL;
        struct ldap_message *msg;
        DATA_BLOB blob1, blob2;
        NTSTATUS status;
        struct tevent_req *subreq;

        if (cldap->connected) {
                return NT_STATUS_PIPE_CONNECTED;
        }

        if (!io->dest) {
                return NT_STATUS_INVALID_ADDRESS;
        }

        state = talloc(cldap, struct cldap_reply_state);
        NT_STATUS_HAVE_NO_MEMORY(state);

        state->dest = tsocket_address_copy(io->dest, state);
        if (!state->dest) {
                goto nomem;
        }

        msg = talloc(state, struct ldap_message);
        if (!msg) {
                goto nomem;
        }

        msg->messageid       = io->messageid;
        msg->controls        = NULL;

        if (io->response) {
                msg->type = LDAP_TAG_SearchResultEntry;
                msg->r.SearchResultEntry = *io->response;

                if (!ldap_encode(msg, NULL, &blob1, state)) {
                        status = NT_STATUS_INVALID_PARAMETER;
                        goto failed;
                }
        } else {
                blob1 = data_blob(NULL, 0);
        }

        msg->type = LDAP_TAG_SearchResultDone;
        msg->r.SearchResultDone = *io->result;

        if (!ldap_encode(msg, NULL, &blob2, state)) {
                status = NT_STATUS_INVALID_PARAMETER;
                goto failed;
        }
        talloc_free(msg);

        state->blob = data_blob_talloc(state, NULL, blob1.length + blob2.length);
        if (!state->blob.data) {
                goto nomem;
        }

        memcpy(state->blob.data, blob1.data, blob1.length);
        memcpy(state->blob.data+blob1.length, blob2.data, blob2.length);
        data_blob_free(&blob1);
        data_blob_free(&blob2);

        subreq = tdgram_sendto_queue_send(state,
                                          cldap->event.ctx,
                                          cldap->sock,
                                          cldap->send_queue,
                                          state->blob.data,
                                          state->blob.length,
                                          state->dest);
        if (!subreq) {
                goto nomem;
        }
        /* the callback will just free the state, as we don't need a result */
        tevent_req_set_callback(subreq, cldap_reply_state_destroy, state);

        return NT_STATUS_OK;

nomem:
        status = NT_STATUS_NO_MEMORY;
failed:
        talloc_free(state);
        return status;
}

static void cldap_reply_state_destroy(struct tevent_req *subreq)
{
        struct cldap_reply_state *state = tevent_req_callback_data(subreq,
                                          struct cldap_reply_state);

        /* we don't want to know the result here, we just free the state */
        talloc_free(subreq);
        talloc_free(state);
}

static int cldap_search_state_destructor(struct cldap_search_state *s)
{
        if (s->caller.cldap) {
                if (s->message_id != -1) {
                        idr_remove(s->caller.cldap->searches.idr, s->message_id);
                        s->message_id = -1;
                }
                DLIST_REMOVE(s->caller.cldap->searches.list, s);
                cldap_recvfrom_stop(s->caller.cldap);
                ZERO_STRUCT(s->caller);
        }

        return 0;
}

static void cldap_search_state_queue_done(struct tevent_req *subreq);
static void cldap_search_state_wakeup_done(struct tevent_req *subreq);

/*
  queue a cldap reply for send
*/
struct tevent_req *cldap_search_send(TALLOC_CTX *mem_ctx,
                                    struct cldap_socket *cldap,
                                    const struct cldap_search *io)
{
        struct tevent_req *req, *subreq;
        struct cldap_search_state *state = NULL;
        struct ldap_message *msg;
        struct ldap_SearchRequest *search;
        struct timeval now;
        struct timeval end;
        uint32_t i;
        int ret;

        req = tevent_req_create(mem_ctx, &state,
                                struct cldap_search_state);
        if (!req) {
                return NULL;
        }
        ZERO_STRUCTP(state);
        state->req = req;
        state->caller.cldap = cldap;
        state->message_id = -1;

        talloc_set_destructor(state, cldap_search_state_destructor);

        if (io->in.dest_address) {
                if (cldap->connected) {
                        tevent_req_nterror(req, NT_STATUS_PIPE_CONNECTED);
                        goto post;
                }
                ret = tsocket_address_inet_from_strings(state,
                                                        "ip",
                                                        io->in.dest_address,
                                                        io->in.dest_port,
                                                        &state->request.dest);
                if (ret != 0) {
                        tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER);
                        goto post;
                }
        } else {
                if (!cldap->connected) {
                        tevent_req_nterror(req, NT_STATUS_INVALID_ADDRESS);
                        goto post;
                }
                state->request.dest = NULL;
        }

        state->message_id = idr_get_new_random(cldap->searches.idr,
                                               state, UINT16_MAX);
        if (state->message_id == -1) {
                tevent_req_nterror(req, NT_STATUS_INSUFFICIENT_RESOURCES);
                goto post;
        }

        msg = talloc(state, struct ldap_message);
        if (tevent_req_nomem(msg, req)) {
                goto post;
        }

        msg->messageid  = state->message_id;
        msg->type       = LDAP_TAG_SearchRequest;
        msg->controls   = NULL;
        search = &msg->r.SearchRequest;

        search->basedn          = "";
        search->scope           = LDAP_SEARCH_SCOPE_BASE;
        search->deref           = LDAP_DEREFERENCE_NEVER;
        search->timelimit       = 0;
        search->sizelimit       = 0;
        search->attributesonly  = false;
        search->num_attributes  = str_list_length(io->in.attributes);
        search->attributes      = io->in.attributes;
        search->tree            = ldb_parse_tree(msg, io->in.filter);
        if (tevent_req_nomem(search->tree, req)) {
                goto post;
        }

        if (!ldap_encode(msg, NULL, &state->request.blob, state)) {
                tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER);
                goto post;
        }
        talloc_free(msg);

        state->request.idx = 0;
        state->request.delay = 10*1000*1000;
        state->request.count = 3;
        if (io->in.timeout > 0) {
                state->request.delay = io->in.timeout * 1000 * 1000;
                state->request.count = io->in.retries + 1;
        }

        now = tevent_timeval_current();
        end = now;
        for (i = 0; i < state->request.count; i++) {
                end = tevent_timeval_add(&end, 0, state->request.delay);
        }

        if (!tevent_req_set_endtime(req, state->caller.cldap->event.ctx, end)) {
                tevent_req_nomem(NULL, req);
                goto post;
        }

        subreq = tdgram_sendto_queue_send(state,
                                          state->caller.cldap->event.ctx,
                                          state->caller.cldap->sock,
                                          state->caller.cldap->send_queue,
                                          state->request.blob.data,
                                          state->request.blob.length,
                                          state->request.dest);
        if (tevent_req_nomem(subreq, req)) {
                goto post;
        }
        tevent_req_set_callback(subreq, cldap_search_state_queue_done, req);

        DLIST_ADD_END(cldap->searches.list, state, struct cldap_search_state *);

        return req;

 post:
        return tevent_req_post(req, cldap->event.ctx);
}

static void cldap_search_state_queue_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(subreq,
                                 struct tevent_req);
        struct cldap_search_state *state = tevent_req_data(req,
                                           struct cldap_search_state);
        ssize_t ret;
        int sys_errno = 0;
        struct timeval next;

        ret = tdgram_sendto_queue_recv(subreq, &sys_errno);
        talloc_free(subreq);
        if (ret == -1) {
                NTSTATUS status;
                status = map_nt_error_from_unix(sys_errno);
                DLIST_REMOVE(state->caller.cldap->searches.list, state);
                ZERO_STRUCT(state->caller.cldap);
                tevent_req_nterror(req, status);
                return;
        }

        state->request.idx++;

        /* wait for incoming traffic */
        if (!cldap_recvfrom_setup(state->caller.cldap)) {
                tevent_req_nomem(NULL, req);
                return;
        }

        if (state->request.idx > state->request.count) {
                /* we just wait for the response or a timeout */
                return;
        }

        next = tevent_timeval_current_ofs(0, state->request.delay);
        subreq = tevent_wakeup_send(state,
                                    state->caller.cldap->event.ctx,
                                    next);
        if (tevent_req_nomem(subreq, req)) {
                return;
        }
        tevent_req_set_callback(subreq, cldap_search_state_wakeup_done, req);
}

static void cldap_search_state_wakeup_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(subreq,
                                 struct tevent_req);
        struct cldap_search_state *state = tevent_req_data(req,
                                           struct cldap_search_state);
        bool ok;

        ok = tevent_wakeup_recv(subreq);
        talloc_free(subreq);
        if (!ok) {
                tevent_req_nterror(req, NT_STATUS_INTERNAL_ERROR);
                return;
        }

        subreq = tdgram_sendto_queue_send(state,
                                          state->caller.cldap->event.ctx,
                                          state->caller.cldap->sock,
                                          state->caller.cldap->send_queue,
                                          state->request.blob.data,
                                          state->request.blob.length,
                                          state->request.dest);
        if (tevent_req_nomem(subreq, req)) {
                return;
        }
        tevent_req_set_callback(subreq, cldap_search_state_queue_done, req);
}

/*
  receive a cldap reply
*/
NTSTATUS cldap_search_recv(struct tevent_req *req,
                           TALLOC_CTX *mem_ctx,
                           struct cldap_search *io)
{
        struct cldap_search_state *state = tevent_req_data(req,
                                           struct cldap_search_state);
        struct ldap_message *ldap_msg;
        NTSTATUS status;

        if (tevent_req_is_nterror(req, &status)) {
                goto failed;
        }

        ldap_msg = talloc(mem_ctx, struct ldap_message);
        if (!ldap_msg) {
                goto nomem;
        }

        status = ldap_decode(state->response.asn1, NULL, ldap_msg);
        if (!NT_STATUS_IS_OK(status)) {
                goto failed;
        }

        ZERO_STRUCT(io->out);

        /* the first possible form has a search result in first place */
        if (ldap_msg->type == LDAP_TAG_SearchResultEntry) {
                io->out.response = talloc(mem_ctx, struct ldap_SearchResEntry);
                if (!io->out.response) {
                        goto nomem;
                }
                *io->out.response = ldap_msg->r.SearchResultEntry;

                /* decode the 2nd part */
                status = ldap_decode(state->response.asn1, NULL, ldap_msg);
                if (!NT_STATUS_IS_OK(status)) {
                        goto failed;
                }
        }

        if (ldap_msg->type != LDAP_TAG_SearchResultDone) {
                status = NT_STATUS_LDAP(LDAP_PROTOCOL_ERROR);
                goto failed;
        }

        io->out.result = talloc(mem_ctx, struct ldap_Result);
        if (!io->out.result) {
                goto nomem;
        }
        *io->out.result = ldap_msg->r.SearchResultDone;

        if (io->out.result->resultcode != LDAP_SUCCESS) {
                status = NT_STATUS_LDAP(io->out.result->resultcode);
                goto failed;
        }

        tevent_req_received(req);
        return NT_STATUS_OK;

nomem:
        status = NT_STATUS_NO_MEMORY;
failed:
        tevent_req_received(req);
        return status;
}


/*
  synchronous cldap search
*/
NTSTATUS cldap_search(struct cldap_socket *cldap,
                      TALLOC_CTX *mem_ctx,
                      struct cldap_search *io)
{
        struct tevent_req *req;
        NTSTATUS status;

        if (!cldap->event.allow_poll) {
                return NT_STATUS_INVALID_PIPE_STATE;
        }

        if (cldap->searches.list) {
                return NT_STATUS_PIPE_BUSY;
        }

        req = cldap_search_send(mem_ctx, cldap, io);
        NT_STATUS_HAVE_NO_MEMORY(req);

        if (!tevent_req_poll(req, cldap->event.ctx)) {
                talloc_free(req);
                return NT_STATUS_INTERNAL_ERROR;
        }

        status = cldap_search_recv(req, mem_ctx, io);
        talloc_free(req);

        return status;
}

struct cldap_netlogon_state {
        struct cldap_search search;
};

static void cldap_netlogon_state_done(struct tevent_req *subreq);
/*
  queue a cldap netlogon for send
*/
struct tevent_req *cldap_netlogon_send(TALLOC_CTX *mem_ctx,
                                      struct cldap_socket *cldap,
                                      const struct cldap_netlogon *io)
{
        struct tevent_req *req, *subreq;
        struct cldap_netlogon_state *state;
        char *filter;
        static const char * const attr[] = { "NetLogon", NULL };

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

        filter = talloc_asprintf(state, "(&(NtVer=%s)", 
                                 ldap_encode_ndr_uint32(state, io->in.version));
        if (tevent_req_nomem(filter, req)) {
                goto post;
        }
        if (io->in.user) {
                filter = talloc_asprintf_append_buffer(filter, "(User=%s)", io->in.user);
                if (tevent_req_nomem(filter, req)) {
                        goto post;
                }
        }
        if (io->in.host) {
                filter = talloc_asprintf_append_buffer(filter, "(Host=%s)", io->in.host);
                if (tevent_req_nomem(filter, req)) {
                        goto post;
                }
        }
        if (io->in.realm) {
                filter = talloc_asprintf_append_buffer(filter, "(DnsDomain=%s)", io->in.realm);
                if (tevent_req_nomem(filter, req)) {
                        goto post;
                }
        }
        if (io->in.acct_control != -1) {
                filter = talloc_asprintf_append_buffer(filter, "(AAC=%s)", 
                                                ldap_encode_ndr_uint32(state, io->in.acct_control));
                if (tevent_req_nomem(filter, req)) {
                        goto post;
                }
        }
        if (io->in.domain_sid) {
                struct dom_sid *sid = dom_sid_parse_talloc(state, io->in.domain_sid);
                if (tevent_req_nomem(sid, req)) {
                        goto post;
                }
                filter = talloc_asprintf_append_buffer(filter, "(domainSid=%s)",
                                                ldap_encode_ndr_dom_sid(state, sid));
                if (tevent_req_nomem(filter, req)) {
                        goto post;
                }
        }
        if (io->in.domain_guid) {
                struct GUID guid;
                NTSTATUS status;
                status = GUID_from_string(io->in.domain_guid, &guid);
                if (tevent_req_nterror(req, status)) {
                        goto post;
                }
                filter = talloc_asprintf_append_buffer(filter, "(DomainGuid=%s)",
                                                ldap_encode_ndr_GUID(state, &guid));
                if (tevent_req_nomem(filter, req)) {
                        goto post;
                }
        }
        filter = talloc_asprintf_append_buffer(filter, ")");
        if (tevent_req_nomem(filter, req)) {
                goto post;
        }

        if (io->in.dest_address) {
                state->search.in.dest_address = talloc_strdup(state,
                                                io->in.dest_address);
                if (tevent_req_nomem(state->search.in.dest_address, req)) {
                        goto post;
                }
                state->search.in.dest_port = io->in.dest_port;
        } else {
                state->search.in.dest_address   = NULL;
                state->search.in.dest_port      = 0;
        }
        state->search.in.filter         = filter;
        state->search.in.attributes     = attr;
        state->search.in.timeout        = 2;
        state->search.in.retries        = 2;

        subreq = cldap_search_send(state, cldap, &state->search);
        if (tevent_req_nomem(subreq, req)) {
                goto post;
        }
        tevent_req_set_callback(subreq, cldap_netlogon_state_done, req);

        return req;
post:
        return tevent_req_post(req, cldap->event.ctx);
}

static void cldap_netlogon_state_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(subreq,
                                 struct tevent_req);
        struct cldap_netlogon_state *state = tevent_req_data(req,
                                             struct cldap_netlogon_state);
        NTSTATUS status;

        status = cldap_search_recv(subreq, state, &state->search);
        talloc_free(subreq);

        if (tevent_req_nterror(req, status)) {
                return;
        }

        tevent_req_done(req);
}

/*
  receive a cldap netlogon reply
*/
NTSTATUS cldap_netlogon_recv(struct tevent_req *req,
                             TALLOC_CTX *mem_ctx,
                             struct cldap_netlogon *io)
{
        struct cldap_netlogon_state *state = tevent_req_data(req,
                                             struct cldap_netlogon_state);
        NTSTATUS status;
        DATA_BLOB *data;

        if (tevent_req_is_nterror(req, &status)) {
                goto failed;
        }

        if (state->search.out.response == NULL) {
                status = NT_STATUS_NOT_FOUND;
                goto failed;
        }

        if (state->search.out.response->num_attributes != 1 ||
            strcasecmp(state->search.out.response->attributes[0].name, "netlogon") != 0 ||
            state->search.out.response->attributes[0].num_values != 1 ||
            state->search.out.response->attributes[0].values->length < 2) {
                status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
                goto failed;
        }
        data = state->search.out.response->attributes[0].values;

        status = pull_netlogon_samlogon_response(data, mem_ctx,
                                                 &io->out.netlogon);
        if (!NT_STATUS_IS_OK(status)) {
                goto failed;
        }

        if (io->in.map_response) {
                map_netlogon_samlogon_response(&io->out.netlogon);
        }

        status =  NT_STATUS_OK;
failed:
        tevent_req_received(req);
        return status;
}

/*
  sync cldap netlogon search
*/
NTSTATUS cldap_netlogon(struct cldap_socket *cldap,
                        TALLOC_CTX *mem_ctx,
                        struct cldap_netlogon *io)
{
        struct tevent_req *req;
        NTSTATUS status;

        if (!cldap->event.allow_poll) {
                return NT_STATUS_INVALID_PIPE_STATE;
        }

        if (cldap->searches.list) {
                return NT_STATUS_PIPE_BUSY;
        }

        req = cldap_netlogon_send(mem_ctx, cldap, io);
        NT_STATUS_HAVE_NO_MEMORY(req);

        if (!tevent_req_poll(req, cldap->event.ctx)) {
                talloc_free(req);
                return NT_STATUS_INTERNAL_ERROR;
        }

        status = cldap_netlogon_recv(req, mem_ctx, io);
        talloc_free(req);

        return status;
}


/*
  send an empty reply (used on any error, so the client doesn't keep waiting
  or send the bad request again)
*/
NTSTATUS cldap_empty_reply(struct cldap_socket *cldap,
                           uint32_t message_id,
                           struct tsocket_address *dest)
{
        NTSTATUS status;
        struct cldap_reply reply;
        struct ldap_Result result;

        reply.messageid    = message_id;
        reply.dest         = dest;
        reply.response     = NULL;
        reply.result       = &result;

        ZERO_STRUCT(result);

        status = cldap_reply_send(cldap, &reply);

        return status;
}

/*
  send an error reply (used on any error, so the client doesn't keep waiting
  or send the bad request again)
*/
NTSTATUS cldap_error_reply(struct cldap_socket *cldap,
                           uint32_t message_id,
                           struct tsocket_address *dest,
                           int resultcode,
                           const char *errormessage)
{
        NTSTATUS status;
        struct cldap_reply reply;
        struct ldap_Result result;

        reply.messageid    = message_id;
        reply.dest         = dest;
        reply.response     = NULL;
        reply.result       = &result;

        ZERO_STRUCT(result);
        result.resultcode       = resultcode;
        result.errormessage     = errormessage;

        status = cldap_reply_send(cldap, &reply);

        return status;
}


/*
  send a netlogon reply 
*/
NTSTATUS cldap_netlogon_reply(struct cldap_socket *cldap,
                              uint32_t message_id,
                              struct tsocket_address *dest,
                              uint32_t version,
                              struct netlogon_samlogon_response *netlogon)
{
        NTSTATUS status;
        struct cldap_reply reply;
        struct ldap_SearchResEntry response;
        struct ldap_Result result;
        TALLOC_CTX *tmp_ctx = talloc_new(cldap);
        DATA_BLOB blob;

        status = push_netlogon_samlogon_response(&blob, tmp_ctx,
                                                 netlogon);
        if (!NT_STATUS_IS_OK(status)) {
                talloc_free(tmp_ctx);
                return status;
        }
        reply.messageid    = message_id;
        reply.dest         = dest;
        reply.response     = &response;
        reply.result       = &result;

        ZERO_STRUCT(result);

        response.dn = "";
        response.num_attributes = 1;
        response.attributes = talloc(tmp_ctx, struct ldb_message_element);
        NT_STATUS_HAVE_NO_MEMORY(response.attributes);
        response.attributes->name = "netlogon";
        response.attributes->num_values = 1;
        response.attributes->values = &blob;

        status = cldap_reply_send(cldap, &reply);

        talloc_free(tmp_ctx);

        return status;
}