/* 
   Unix SMB/CIFS implementation.
   
   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/composite/composite.h"
#include "auth/credentials/credentials.h"
#include "librpc/ndr/libndr.h"
#include "librpc/gen_ndr/samr.h"
#include "librpc/gen_ndr/ndr_samr_c.h"
#include "librpc/gen_ndr/lsa.h"
#include "librpc/gen_ndr/ndr_lsa_c.h"
#include "libcli/security/security.h"


struct create_user_state {
	struct libnet_CreateUser r;
	struct libnet_DomainOpen domain_open;
	struct libnet_rpc_useradd user_add;
	struct libnet_context *ctx;

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


static void continue_rpc_useradd(struct composite_context *ctx);
static void continue_domain_open_create(struct composite_context *ctx);


/**
 * Sends request to create user account
 *
 * @param ctx initialised libnet context
 * @param mem_ctx memory context of this call
 * @param r pointer to a structure containing arguments and results of this call
 * @param monitor function pointer for receiving monitor messages
 * @return compostite context of this request
 */
struct composite_context* libnet_CreateUser_send(struct libnet_context *ctx,
						 TALLOC_CTX *mem_ctx,
						 struct libnet_CreateUser *r,
						 void (*monitor)(struct monitor_msg*))
{
	struct composite_context *c;
	struct create_user_state *s;
	struct composite_context *create_req;
	bool prereq_met = false;

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

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

	c->private_data = s;

	/* store arguments in the state structure */
	s->ctx = ctx;
	s->r   = *r;
	ZERO_STRUCT(s->r.out);

	/* prerequisite: make sure the domain is opened */
	prereq_met = samr_domain_opened(ctx, s->r.in.domain_name, &c, &s->domain_open,
					continue_domain_open_create, monitor);
	if (!prereq_met) return c;

	/* prepare arguments for useradd call */
	s->user_add.in.username       = r->in.user_name;
	s->user_add.in.domain_handle  = ctx->samr.handle;

	/* send the request */
	create_req = libnet_rpc_useradd_send(ctx->samr.pipe, &s->user_add, monitor);
	if (composite_nomem(create_req, c)) return c;

	/* set the next stage */
	composite_continue(c, create_req, continue_rpc_useradd, c);
	return c;
}


/*
 * Stage 0.5 (optional): receive result of domain open request
 * and send useradd request
 */
static void continue_domain_open_create(struct composite_context *ctx)
{
	struct composite_context *c;
	struct create_user_state *s;
	struct composite_context *create_req;
	struct monitor_msg msg;

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

	/* receive result of DomainOpen call */
	c->status = libnet_DomainOpen_recv(ctx, s->ctx, c, &s->domain_open);
	if (!composite_is_ok(c)) return;

	/* send monitor message */
	if (s->monitor_fn) s->monitor_fn(&msg);
	
	/* prepare arguments for useradd call */
	s->user_add.in.username       = s->r.in.user_name;
	s->user_add.in.domain_handle  = s->ctx->samr.handle;

	/* send the request */
	create_req = libnet_rpc_useradd_send(s->ctx->samr.pipe, &s->user_add, s->monitor_fn);
	if (composite_nomem(create_req, c)) return;

	/* set the next stage */
	composite_continue(c, create_req, continue_rpc_useradd, c);
}


/*
 * Stage 1: receive result of useradd call
 */
static void continue_rpc_useradd(struct composite_context *ctx)
{
	struct composite_context *c;
	struct create_user_state *s;
	struct monitor_msg msg;

	c = talloc_get_type(ctx->async.private_data, struct composite_context);
	s = talloc_get_type(c->private_data, struct create_user_state);
	
	/* receive result of the call */
	c->status = libnet_rpc_useradd_recv(ctx, c, &s->user_add);
	if (!composite_is_ok(c)) return;

	/* send monitor message */
	if (s->monitor_fn) s->monitor_fn(&msg);

	/* we're done */
	composite_done(c);
}


/**
 * Receive result of CreateUser call
 *
 * @param c composite context returned by send request routine
 * @param mem_ctx memory context of this call
 * @param r pointer to a structure containing arguments and result of this call
 * @return nt status
 */
NTSTATUS libnet_CreateUser_recv(struct composite_context *c, TALLOC_CTX *mem_ctx,
				struct libnet_CreateUser *r)
{
	NTSTATUS status;
	struct create_user_state *s;

	r->out.error_string = NULL;

	/* wait for result of async request and check status code */
	status = composite_wait(c);
	if (!NT_STATUS_IS_OK(status)) {
		s = talloc_get_type(c->private_data, struct create_user_state);
		r->out.error_string = talloc_strdup(mem_ctx, nt_errstr(status));
	}

	return status;
}


/**
 * Synchronous version of CreateUser call
 *
 * @param ctx initialised libnet context
 * @param mem_ctx memory context of this call
 * @param r pointer to a structure containing arguments and result of this call
 * @return nt status
 */
NTSTATUS libnet_CreateUser(struct libnet_context *ctx, TALLOC_CTX *mem_ctx,
			   struct libnet_CreateUser *r)
{
	struct composite_context *c;

	c = libnet_CreateUser_send(ctx, mem_ctx, r, NULL);
	return libnet_CreateUser_recv(c, mem_ctx, r);
}


struct delete_user_state {
	struct libnet_DeleteUser r;
	struct libnet_context *ctx;
	struct libnet_DomainOpen domain_open;
	struct libnet_rpc_userdel user_del;

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


static void continue_rpc_userdel(struct composite_context *ctx);
static void continue_domain_open_delete(struct composite_context *ctx);


/**
 * Sends request to delete user account
 *
 * @param ctx initialised libnet context
 * @param mem_ctx memory context of this call
 * @param r pointer to structure containing arguments and result of this call
 * @param monitor function pointer for receiving monitor messages
 */
struct composite_context *libnet_DeleteUser_send(struct libnet_context *ctx,
						 TALLOC_CTX *mem_ctx,
						 struct libnet_DeleteUser *r,
						 void (*monitor)(struct monitor_msg*))
{
	struct composite_context *c;
	struct delete_user_state *s;
	struct composite_context *delete_req;
	bool prereq_met = false;

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

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

	c->private_data = s;

	/* store arguments in state structure */
	s->ctx = ctx;
	s->r   = *r;
	ZERO_STRUCT(s->r.out);
	
	/* prerequisite: make sure the domain is opened before proceeding */
	prereq_met = samr_domain_opened(ctx, s->r.in.domain_name, &c, &s->domain_open,
					continue_domain_open_delete, monitor);
	if (!prereq_met) return c;

	/* prepare arguments for userdel call */
	s->user_del.in.username       = r->in.user_name;
	s->user_del.in.domain_handle  = ctx->samr.handle;

	/* send request */
	delete_req = libnet_rpc_userdel_send(ctx->samr.pipe, &s->user_del, monitor);
	if (composite_nomem(delete_req, c)) return c;
	
	/* set the next stage */
	composite_continue(c, delete_req, continue_rpc_userdel, c);
	return c;
}


/*
 * Stage 0.5 (optional): receive result of domain open request
 * and send useradd request
 */
static void continue_domain_open_delete(struct composite_context *ctx)
{
	struct composite_context *c;
	struct delete_user_state *s;
	struct composite_context *delete_req;
	struct monitor_msg msg;

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

	/* receive result of DomainOpen call */
	c->status = libnet_DomainOpen_recv(ctx, s->ctx, c, &s->domain_open);
	if (!composite_is_ok(c)) return;
	
	/* send monitor message */
	if (s->monitor_fn) s->monitor_fn(&msg);

	/* prepare arguments for userdel call */
	s->user_del.in.username       = s->r.in.user_name;
	s->user_del.in.domain_handle  = s->ctx->samr.handle;

	/* send request */
	delete_req = libnet_rpc_userdel_send(s->ctx->samr.pipe, &s->user_del, s->monitor_fn);
	if (composite_nomem(delete_req, c)) return;

	/* set the next stage */
	composite_continue(c, delete_req, continue_rpc_userdel, c);
}


/*
 * Stage 1: receive result of userdel call and finish the composite function
 */
static void continue_rpc_userdel(struct composite_context *ctx)
{
	struct composite_context *c;
	struct delete_user_state *s;
	struct monitor_msg msg;

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

	/* receive result of userdel call */
	c->status = libnet_rpc_userdel_recv(ctx, c, &s->user_del);
	if (!composite_is_ok(c)) return;

	/* send monitor message */
	if (s->monitor_fn) s->monitor_fn(&msg);

	/* we're done */
	composite_done(c);
}


/**
 * Receives result of asynchronous DeleteUser call
 *
 * @param c composite context returned by async DeleteUser call
 * @param mem_ctx memory context of this call
 * @param r pointer to structure containing arguments and result
 */
NTSTATUS libnet_DeleteUser_recv(struct composite_context *c, TALLOC_CTX *mem_ctx,
				struct libnet_DeleteUser *r)
{
	NTSTATUS status;
	struct delete_user_state *s;

	r->out.error_string = NULL;

	/* wait for result of async request and check status code */
	status = composite_wait(c);
	if (!NT_STATUS_IS_OK(status)) {
		s = talloc_get_type(c->private_data, struct delete_user_state);
		r->out.error_string = talloc_steal(mem_ctx, s->r.out.error_string);
	}
	
	return status;
}


/**
 * Synchronous version of DeleteUser call
 *
 * @param ctx initialised libnet context
 * @param mem_ctx memory context of this call
 * @param r pointer to structure containing arguments and result
 */
NTSTATUS libnet_DeleteUser(struct libnet_context *ctx, TALLOC_CTX *mem_ctx,
			   struct libnet_DeleteUser *r)
{
	struct composite_context *c;
	
	c = libnet_DeleteUser_send(ctx, mem_ctx, r, NULL);
	return libnet_DeleteUser_recv(c, mem_ctx, r);
}


struct modify_user_state {
	struct libnet_ModifyUser r;
	struct libnet_context *ctx;
	struct libnet_DomainOpen domain_open;
	struct libnet_rpc_userinfo user_info;
	struct libnet_rpc_usermod user_mod;

	void (*monitor_fn)(struct monitor_msg *);
};


static void continue_rpc_usermod(struct composite_context *ctx);
static void continue_domain_open_modify(struct composite_context *ctx);
static NTSTATUS set_user_changes(TALLOC_CTX *mem_ctx, struct usermod_change *mod,
				 struct libnet_rpc_userinfo *info, struct libnet_ModifyUser *r);
static void continue_rpc_userinfo(struct composite_context *ctx);


/**
 * Sends request to modify user account
 *
 * @param ctx initialised libnet context
 * @param mem_ctx memory context of this call
 * @param r pointer to structure containing arguments and result of this call
 * @param monitor function pointer for receiving monitor messages
 */
struct composite_context *libnet_ModifyUser_send(struct libnet_context *ctx,
						 TALLOC_CTX *mem_ctx,
						 struct libnet_ModifyUser *r,
						 void (*monitor)(struct monitor_msg*))
{
	const uint16_t level = 21;
	struct composite_context *c;
	struct modify_user_state *s;
	struct composite_context *userinfo_req;
	bool prereq_met = false;

	c = composite_create(mem_ctx, ctx->event_ctx);
	if (c == NULL) return NULL;

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

	c->private_data = s;

	s->ctx = ctx;
	s->r = *r;

	prereq_met = samr_domain_opened(ctx, s->r.in.domain_name, &c, &s->domain_open,
					continue_domain_open_modify, monitor);
	if (!prereq_met) return c;

	s->user_info.in.username      = r->in.user_name;
	s->user_info.in.domain_handle = ctx->samr.handle;
	s->user_info.in.level         = level;

	userinfo_req = libnet_rpc_userinfo_send(ctx->samr.pipe, &s->user_info, monitor);
	if (composite_nomem(userinfo_req, c)) return c;

	composite_continue(c, userinfo_req, continue_rpc_userinfo, c);
	return c;
}


/*
 * Stage 0.5 (optional): receive result of domain open request
 * and send userinfo request
 */
static void continue_domain_open_modify(struct composite_context *ctx)
{
	const uint16_t level = 21;
	struct composite_context *c;
	struct modify_user_state *s;
	struct composite_context *userinfo_req;
	struct monitor_msg msg;

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

	c->status = libnet_DomainOpen_recv(ctx, s->ctx, c, &s->domain_open);
	if (!composite_is_ok(c)) return;

	if (s->monitor_fn) s->monitor_fn(&msg);
	
	s->user_info.in.domain_handle  = s->ctx->samr.handle;
	s->user_info.in.username       = s->r.in.user_name;
	s->user_info.in.level          = level;

	userinfo_req = libnet_rpc_userinfo_send(s->ctx->samr.pipe, &s->user_info, s->monitor_fn);
	if (composite_nomem(userinfo_req, c)) return;
	
	composite_continue(c, userinfo_req, continue_rpc_userinfo, c);
}


/*
 * Stage 1: receive result of userinfo call, prepare user changes
 * (set the fields a caller required to change) and send usermod request
 */
static void continue_rpc_userinfo(struct composite_context *ctx)
{
	struct composite_context *c;
	struct modify_user_state *s;
	struct composite_context *usermod_req;

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

	c->status = libnet_rpc_userinfo_recv(ctx, c, &s->user_info);
	if (!composite_is_ok(c)) return;

	s->user_mod.in.domain_handle = s->ctx->samr.handle;
	s->user_mod.in.username      = s->r.in.user_name;

	c->status = set_user_changes(c, &s->user_mod.in.change, &s->user_info, &s->r);

	usermod_req = libnet_rpc_usermod_send(s->ctx->samr.pipe, &s->user_mod, s->monitor_fn);
	if (composite_nomem(usermod_req, c)) return;

	composite_continue(c, usermod_req, continue_rpc_usermod, c);
}


/*
 * Prepare user changes: compare userinfo result to requested changes and
 * set the field values and flags accordingly for user modify call
 */
static NTSTATUS set_user_changes(TALLOC_CTX *mem_ctx, struct usermod_change *mod,
				 struct libnet_rpc_userinfo *info, struct libnet_ModifyUser *r)
{
	struct samr_UserInfo21 *user;

	if (mod == NULL || info == NULL || r == NULL || info->in.level != 21) {
		return NT_STATUS_INVALID_PARAMETER;
	}

	user = &info->out.info.info21;
	mod->fields = 0;        /* reset flag field before setting individual flags */

	/* account name change */
	SET_FIELD_LSA_STRING(r->in, user, mod, account_name, USERMOD_FIELD_ACCOUNT_NAME);

	/* full name change */
	SET_FIELD_LSA_STRING(r->in, user, mod, full_name, USERMOD_FIELD_FULL_NAME);

	/* description change */
	SET_FIELD_LSA_STRING(r->in, user, mod, description, USERMOD_FIELD_DESCRIPTION);

	/* comment change */
	SET_FIELD_LSA_STRING(r->in, user, mod, comment, USERMOD_FIELD_COMMENT);

	/* home directory change */
	SET_FIELD_LSA_STRING(r->in, user, mod, home_directory, USERMOD_FIELD_HOME_DIRECTORY);

	/* home drive change */
	SET_FIELD_LSA_STRING(r->in, user, mod, home_drive, USERMOD_FIELD_HOME_DRIVE);

	/* logon script change */
	SET_FIELD_LSA_STRING(r->in, user, mod, logon_script, USERMOD_FIELD_LOGON_SCRIPT);

	/* profile path change */
	SET_FIELD_LSA_STRING(r->in, user, mod, profile_path, USERMOD_FIELD_PROFILE_PATH);

	/* account expiry change */
	SET_FIELD_NTTIME(r->in, user, mod, acct_expiry, USERMOD_FIELD_ACCT_EXPIRY);

	/* account flags change */
	SET_FIELD_ACCT_FLAGS(r->in, user, mod, acct_flags, USERMOD_FIELD_ACCT_FLAGS);

	return NT_STATUS_OK;
}


/*
 * Stage 2: receive result of usermod request and finish the composite function
 */
static void continue_rpc_usermod(struct composite_context *ctx)
{
	struct composite_context *c;
	struct modify_user_state *s;
	struct monitor_msg msg;

	c = talloc_get_type(ctx->async.private_data, struct composite_context);
	s = talloc_get_type(c->private_data, struct modify_user_state);
	
	c->status = libnet_rpc_usermod_recv(ctx, c, &s->user_mod);
	if (!composite_is_ok(c)) return;
	
	if (s->monitor_fn) s->monitor_fn(&msg);
	composite_done(c);
}


/**
 * Receive result of ModifyUser call
 *
 * @param c composite context returned by send request routine
 * @param mem_ctx memory context of this call
 * @param r pointer to a structure containing arguments and result of this call
 * @return nt status
 */
NTSTATUS libnet_ModifyUser_recv(struct composite_context *c, TALLOC_CTX *mem_ctx,
				struct libnet_ModifyUser *r)
{
	NTSTATUS status = composite_wait(c);
	return status;
}


/**
 * Synchronous version of ModifyUser call
 *
 * @param ctx initialised libnet context
 * @param mem_ctx memory context of this call
 * @param r pointer to a structure containing arguments and result of this call
 * @return nt status
 */
NTSTATUS libnet_ModifyUser(struct libnet_context *ctx, TALLOC_CTX *mem_ctx,
			   struct libnet_ModifyUser *r)
{
	struct composite_context *c;

	c = libnet_ModifyUser_send(ctx, mem_ctx, r, NULL);
	return libnet_ModifyUser_recv(c, mem_ctx, r);
}


struct user_info_state {
	struct libnet_context *ctx;
	const char *domain_name;
	enum libnet_UserInfo_level level;
	const char *user_name;
	const char *sid_string;
	struct libnet_LookupName lookup;
	struct libnet_DomainOpen domopen;
	struct libnet_rpc_userinfo userinfo;

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


static void continue_name_found(struct composite_context *ctx);
static void continue_domain_open_info(struct composite_context *ctx);
static void continue_info_received(struct composite_context *ctx);


/**
 * Sends request to get user account information
 *
 * @param ctx initialised libnet context
 * @param mem_ctx memory context of this call
 * @param r pointer to a structure containing arguments and results of this call
 * @param monitor function pointer for receiving monitor messages
 * @return compostite context of this request
 */
struct composite_context* libnet_UserInfo_send(struct libnet_context *ctx,
					       TALLOC_CTX *mem_ctx,
					       struct libnet_UserInfo *r,
					       void (*monitor)(struct monitor_msg*))
{
	struct composite_context *c;
	struct user_info_state *s;
	struct composite_context *lookup_req, *info_req;
	bool prereq_met = false;

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

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

	c->private_data = s;

	/* store arguments in the state structure */
	s->monitor_fn = monitor;
	s->ctx = ctx;
	s->domain_name = talloc_strdup(c, r->in.domain_name);
	s->level = r->in.level;
	switch (s->level) {
	case USER_INFO_BY_NAME:
		s->user_name = talloc_strdup(c, r->in.data.user_name);
		s->sid_string = NULL;
		break;
	case USER_INFO_BY_SID:
		s->user_name = NULL;
		s->sid_string = dom_sid_string(c, r->in.data.user_sid);
		break;
	}

	/* prerequisite: make sure the domain is opened */
	prereq_met = samr_domain_opened(ctx, s->domain_name, &c, &s->domopen,
					continue_domain_open_info, monitor);
	if (!prereq_met) return c;

	switch (s->level) {
	case USER_INFO_BY_NAME:
		/* prepare arguments for LookupName call */
		s->lookup.in.domain_name = s->domain_name;
		s->lookup.in.name        = s->user_name;

		/* send the request */
		lookup_req = libnet_LookupName_send(ctx, c, &s->lookup,
						    s->monitor_fn);
		if (composite_nomem(lookup_req, c)) return c;

		/* set the next stage */
		composite_continue(c, lookup_req, continue_name_found, c);
		break;
	case USER_INFO_BY_SID:
		/* prepare arguments for UserInfo call */
		s->userinfo.in.domain_handle = s->ctx->samr.handle;
		s->userinfo.in.sid = s->sid_string;
		s->userinfo.in.level = 21;

		/* send the request */
		info_req = libnet_rpc_userinfo_send(s->ctx->samr.pipe,
						    &s->userinfo,
						    s->monitor_fn);
		if (composite_nomem(info_req, c)) return c;

		/* set the next stage */
		composite_continue(c, info_req, continue_info_received, c);
		break;
	}

	return c;
}


/*
 * Stage 0.5 (optional): receive result of domain open request
 * and send LookupName request
 */
static void continue_domain_open_info(struct composite_context *ctx)
{
	struct composite_context *c;
	struct user_info_state *s;
	struct composite_context *lookup_req, *info_req;
	struct monitor_msg msg;

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

	/* receive result of DomainOpen call */
	c->status = libnet_DomainOpen_recv(ctx, s->ctx, c, &s->domopen);
	if (!composite_is_ok(c)) return;

	/* send monitor message */
	if (s->monitor_fn) s->monitor_fn(&msg);

	switch (s->level) {
	case USER_INFO_BY_NAME:
		/* prepare arguments for LookupName call */
		s->lookup.in.domain_name = s->domain_name;
		s->lookup.in.name        = s->user_name;

		/* send the request */
		lookup_req = libnet_LookupName_send(s->ctx, c, &s->lookup, s->monitor_fn);
		if (composite_nomem(lookup_req, c)) return;

		/* set the next stage */
		composite_continue(c, lookup_req, continue_name_found, c);
		break;

	case USER_INFO_BY_SID:
		/* prepare arguments for UserInfo call */
		s->userinfo.in.domain_handle = s->ctx->samr.handle;
		s->userinfo.in.sid = s->sid_string;
		s->userinfo.in.level = 21;

		/* send the request */
		info_req = libnet_rpc_userinfo_send(s->ctx->samr.pipe,
						    &s->userinfo,
						    s->monitor_fn);
		if (composite_nomem(info_req, c)) return;

		/* set the next stage */
		composite_continue(c, info_req, continue_info_received, c);
		break;
	}
}


/*
 * Stage 1: receive the name (if found) and send userinfo request
 */
static void continue_name_found(struct composite_context *ctx)
{
	struct composite_context *c;
	struct user_info_state *s;
	struct composite_context *info_req;

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

	/* receive result of LookupName call */
	c->status = libnet_LookupName_recv(ctx, c, &s->lookup);
	if (!composite_is_ok(c)) return;

	/* we're only interested in user accounts this time */
	if (s->lookup.out.sid_type != SID_NAME_USER) {
		composite_error(c, NT_STATUS_NO_SUCH_USER);
		return;
	}

	/* prepare arguments for UserInfo call */
	s->userinfo.in.domain_handle = s->ctx->samr.handle;
	s->userinfo.in.sid = s->lookup.out.sidstr;
	s->userinfo.in.level = 21;

	/* send the request */
	info_req = libnet_rpc_userinfo_send(s->ctx->samr.pipe, &s->userinfo, s->monitor_fn);
	if (composite_nomem(info_req, c)) return;

	/* set the next stage */
	composite_continue(c, info_req, continue_info_received, c);
}


/*
 * Stage 2: receive user account information and finish the composite function
 */
static void continue_info_received(struct composite_context *ctx)
{
	struct composite_context *c;
	struct user_info_state *s;

	c = talloc_get_type(ctx->async.private_data, struct composite_context);
	s = talloc_get_type(c->private_data, struct user_info_state);
	
	/* receive result of userinfo call */
	c->status = libnet_rpc_userinfo_recv(ctx, c, &s->userinfo);
	if (!composite_is_ok(c)) return;

	composite_done(c);
}


/**
 * Receive result of UserInfo call
 *
 * @param c composite context returned by send request routine
 * @param mem_ctx memory context of this call
 * @param r pointer to a structure containing arguments and result of this call
 * @return nt status
 */
NTSTATUS libnet_UserInfo_recv(struct composite_context *c, TALLOC_CTX *mem_ctx,
			      struct libnet_UserInfo *r)
{
	NTSTATUS status;
	struct user_info_state *s;

	status = composite_wait(c);

	if (NT_STATUS_IS_OK(status) && r != NULL) {
		struct samr_UserInfo21 *info;

		s = talloc_get_type(c->private_data, struct user_info_state);
		info = &s->userinfo.out.info.info21;

		r->out.user_sid = dom_sid_add_rid(mem_ctx, s->ctx->samr.sid, info->rid);
		r->out.primary_group_sid = dom_sid_add_rid(mem_ctx, s->ctx->samr.sid, info->primary_gid);

		/* string fields */
		r->out.account_name   = talloc_steal(mem_ctx, info->account_name.string);
		r->out.full_name      = talloc_steal(mem_ctx, info->full_name.string);
		r->out.description    = talloc_steal(mem_ctx, info->description.string);
		r->out.home_directory = talloc_steal(mem_ctx, info->home_directory.string);
		r->out.home_drive     = talloc_steal(mem_ctx, info->home_drive.string);
		r->out.comment        = talloc_steal(mem_ctx, info->comment.string);
		r->out.logon_script   = talloc_steal(mem_ctx, info->logon_script.string);
		r->out.profile_path   = talloc_steal(mem_ctx, info->profile_path.string);

		/* time fields (allocation) */
		r->out.acct_expiry           = talloc(mem_ctx, struct timeval);
		r->out.allow_password_change = talloc(mem_ctx, struct timeval);
		r->out.force_password_change = talloc(mem_ctx, struct timeval);
		r->out.last_logon            = talloc(mem_ctx, struct timeval);
		r->out.last_logoff           = talloc(mem_ctx, struct timeval);
		r->out.last_password_change  = talloc(mem_ctx, struct timeval);
		
		/* time fields (converting) */
		nttime_to_timeval(r->out.acct_expiry, info->acct_expiry);
		nttime_to_timeval(r->out.allow_password_change, info->allow_password_change);
		nttime_to_timeval(r->out.force_password_change, info->force_password_change);
		nttime_to_timeval(r->out.last_logon, info->last_logon);
		nttime_to_timeval(r->out.last_logoff, info->last_logoff);
		nttime_to_timeval(r->out.last_password_change, info->last_password_change);

		/* flag and number fields */
		r->out.acct_flags = info->acct_flags;

		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;
}


/**
 * Synchronous version of UserInfo call
 *
 * @param ctx initialised libnet context
 * @param mem_ctx memory context of this call
 * @param r pointer to a structure containing arguments and result of this call
 * @return nt status
 */
NTSTATUS libnet_UserInfo(struct libnet_context *ctx, TALLOC_CTX *mem_ctx,
			 struct libnet_UserInfo *r)
{
	struct composite_context *c;
	
	c = libnet_UserInfo_send(ctx, mem_ctx, r, NULL);
	return libnet_UserInfo_recv(c, mem_ctx, r);
}


struct userlist_state {
	struct libnet_context *ctx;
	const char *domain_name;
	struct lsa_DomainInfo dominfo;
	int page_size;
	uint32_t resume_index;
	struct userlist *users;
	uint32_t count;

	struct libnet_DomainOpen domain_open;
	struct lsa_QueryInfoPolicy query_domain;
	struct samr_EnumDomainUsers user_list;

	void (*monitor_fn)(struct monitor_msg*);
};


static void continue_lsa_domain_opened(struct composite_context *ctx);
static void continue_domain_queried(struct rpc_request *req);
static void continue_samr_domain_opened(struct composite_context *ctx);
static void continue_users_enumerated(struct rpc_request *req);


/**
 * Sends request to list (enumerate) user accounts
 *
 * @param ctx initialised libnet context
 * @param mem_ctx memory context of this call
 * @param r pointer to structure containing arguments and results of this call
 * @param monitor function pointer for receiving monitor messages
 * @return compostite context of this request
 */
struct composite_context* libnet_UserList_send(struct libnet_context *ctx,
					       TALLOC_CTX *mem_ctx,
					       struct libnet_UserList *r,
					       void (*monitor)(struct monitor_msg*))
{
	struct composite_context *c;
	struct userlist_state *s;
	struct rpc_request *query_req;
	bool prereq_met = false;

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

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

	c->private_data = s;

	/* store the arguments in the state structure */
	s->ctx          = ctx;
	s->page_size    = r->in.page_size;
	s->resume_index = r->in.resume_index;
	s->domain_name  = talloc_strdup(c, r->in.domain_name);
	s->monitor_fn   = monitor;

	/* make sure we have lsa domain handle before doing anything */
	prereq_met = lsa_domain_opened(ctx, s->domain_name, &c, &s->domain_open,
				       continue_lsa_domain_opened, monitor);
	if (!prereq_met) return c;

	/* prepare arguments of QueryDomainInfo call */
	s->query_domain.in.handle = &ctx->lsa.handle;
	s->query_domain.in.level  = LSA_POLICY_INFO_DOMAIN;
	s->query_domain.out.info  = talloc_zero(c, union lsa_PolicyInformation *);
	if (composite_nomem(s->query_domain.out.info, c)) return c;

	/* send the request */
	query_req = dcerpc_lsa_QueryInfoPolicy_send(ctx->lsa.pipe, c, &s->query_domain);
	if (composite_nomem(query_req, c)) return c;

	composite_continue_rpc(c, query_req, continue_domain_queried, c);
	return c;
}


/*
 * Stage 0.5 (optional): receive lsa domain handle and send
 * request to query domain info
 */
static void continue_lsa_domain_opened(struct composite_context *ctx)
{
	struct composite_context *c;
	struct userlist_state *s;
	struct rpc_request *query_req;
	
	c = talloc_get_type(ctx->async.private_data, struct composite_context);
	s = talloc_get_type(c->private_data, struct userlist_state);
	
	/* receive lsa domain handle */
	c->status = libnet_DomainOpen_recv(ctx, s->ctx, c, &s->domain_open);
	if (!composite_is_ok(c)) return;

	/* prepare arguments of QueryDomainInfo call */
	s->query_domain.in.handle = &s->ctx->lsa.handle;
	s->query_domain.in.level  = LSA_POLICY_INFO_DOMAIN;
	s->query_domain.out.info  = talloc_zero(c, union lsa_PolicyInformation *);
	if (composite_nomem(s->query_domain.out.info, c)) return;

	/* send the request */
	query_req = dcerpc_lsa_QueryInfoPolicy_send(s->ctx->lsa.pipe, c, &s->query_domain);
	if (composite_nomem(query_req, c)) return;

	composite_continue_rpc(c, query_req, continue_domain_queried, c);
}


/*
 * Stage 1: receive domain info and request to enum users,
 * provided a valid samr handle is opened
 */
static void continue_domain_queried(struct rpc_request *req)
{
	struct composite_context *c;
	struct userlist_state *s;
	struct rpc_request *enum_req;
	bool prereq_met = false;
	
	c = talloc_get_type(req->async.private_data, struct composite_context);
	s = talloc_get_type(c->private_data, struct userlist_state);

	/* receive result of rpc request */
	c->status = dcerpc_ndr_request_recv(req);
	if (!composite_is_ok(c)) return;

	/* get the returned domain info */
	s->dominfo = (*s->query_domain.out.info)->domain;

	/* make sure we have samr domain handle before continuing */
	prereq_met = samr_domain_opened(s->ctx, s->domain_name, &c, &s->domain_open,
					continue_samr_domain_opened, s->monitor_fn);
	if (!prereq_met) return;

	/* prepare arguments of EnumDomainUsers call */
	s->user_list.in.domain_handle = &s->ctx->samr.handle;
	s->user_list.in.max_size = s->page_size;
	s->user_list.in.resume_handle = &s->resume_index;
	s->user_list.in.acct_flags = ACB_NORMAL;
	s->user_list.out.resume_handle = &s->resume_index;
	s->user_list.out.num_entries = talloc(s, uint32_t);
	if (composite_nomem(s->user_list.out.num_entries, c)) return;
	s->user_list.out.sam = talloc(s, struct samr_SamArray *);
	if (composite_nomem(s->user_list.out.sam, c)) return;

	/* send the request */
	enum_req = dcerpc_samr_EnumDomainUsers_send(s->ctx->samr.pipe, c, &s->user_list);
	if (composite_nomem(enum_req, c)) return;

	composite_continue_rpc(c, enum_req, continue_users_enumerated, c);
}


/*
 * Stage 1.5 (optional): receive samr domain handle
 * and request to enumerate accounts
 */
static void continue_samr_domain_opened(struct composite_context *ctx)
{
	struct composite_context *c;
	struct userlist_state *s;
	struct rpc_request *enum_req;

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

	/* receive samr domain handle */
	c->status = libnet_DomainOpen_recv(ctx, s->ctx, c, &s->domain_open);
	if (!composite_is_ok(c)) return;

	/* prepare arguments of EnumDomainUsers call */
	s->user_list.in.domain_handle = &s->ctx->samr.handle;
	s->user_list.in.max_size = s->page_size;
	s->user_list.in.resume_handle = &s->resume_index;
	s->user_list.in.acct_flags = ACB_NORMAL;
	s->user_list.out.resume_handle = &s->resume_index;
	s->user_list.out.sam = talloc(s, struct samr_SamArray *);
	if (composite_nomem(s->user_list.out.sam, c)) return;
	s->user_list.out.num_entries = talloc(s, uint32_t);
	if (composite_nomem(s->user_list.out.num_entries, c)) return;
	
	/* send the request */
	enum_req = dcerpc_samr_EnumDomainUsers_send(s->ctx->samr.pipe, c, &s->user_list);
	if (composite_nomem(enum_req, c)) return;

	composite_continue_rpc(c, enum_req, continue_users_enumerated, c);
}


/*
 * Stage 2: receive enumerated users and their rids
 */
static void continue_users_enumerated(struct rpc_request *req)
{
	struct composite_context *c;
	struct userlist_state *s;
	int i;

	c = talloc_get_type(req->async.private_data, struct composite_context);
	s = talloc_get_type(c->private_data, struct userlist_state);

	/* receive result of rpc request */
	c->status = dcerpc_ndr_request_recv(req);
	if (!composite_is_ok(c)) return;

	/* get the actual status of the rpc call result
	   (instead of rpc layer status) */
	c->status = s->user_list.out.result;

	/* we're interested in status "ok" as well as two
	   enum-specific status codes */
	if (NT_STATUS_IS_OK(c->status) ||
	    NT_STATUS_EQUAL(c->status, STATUS_MORE_ENTRIES) ||
	    NT_STATUS_EQUAL(c->status, NT_STATUS_NO_MORE_ENTRIES)) {

		/* get enumerated accounts counter and resume handle (the latter allows
		   making subsequent call to continue enumeration) */
		s->resume_index = *s->user_list.out.resume_handle;
		s->count        = *s->user_list.out.num_entries;
		
		/* prepare returned user accounts array */
		s->users        = talloc_array(c, struct userlist, (*s->user_list.out.sam)->count);
		if (composite_nomem(s->users, c)) return;

		for (i = 0; i < (*s->user_list.out.sam)->count; i++) {
			struct dom_sid *user_sid;
			struct samr_SamEntry *entry = &(*s->user_list.out.sam)->entries[i];
			struct dom_sid *domain_sid = (*s->query_domain.out.info)->domain.sid;
			
			/* construct user sid from returned rid and queried domain sid */
			user_sid = dom_sid_add_rid(c, domain_sid, entry->idx);
			if (composite_nomem(user_sid, c)) return;
			
			/* username */
			s->users[i].username = talloc_strdup(c, entry->name.string);
			if (composite_nomem(s->users[i].username, c)) return;

			/* sid string */
			s->users[i].sid = dom_sid_string(c, user_sid);
			if (composite_nomem(s->users[i].sid, c)) return;
		}
		
		/* that's it */
		composite_done(c);

	} else {
		/* something went wrong */
		composite_error(c, c->status);
	}
}


/**
 * Receive result of UserList call
 *
 * @param c composite context returned by send request routine
 * @param mem_ctx memory context of this call
 * @param r pointer to structure containing arguments and result of this call
 * @return nt status
 */
NTSTATUS libnet_UserList_recv(struct composite_context* c, TALLOC_CTX *mem_ctx,
			      struct libnet_UserList *r)
{
	NTSTATUS status;
	struct userlist_state *s;

	if (c == NULL || mem_ctx == NULL || r == NULL) {
		return NT_STATUS_INVALID_PARAMETER;
	}
	
	status = composite_wait(c);
	if (NT_STATUS_IS_OK(status) ||
	    NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES) ||
	    NT_STATUS_EQUAL(status, NT_STATUS_NO_MORE_ENTRIES)) {
		
		s = talloc_get_type(c->private_data, struct userlist_state);
		
		/* get results from composite context */
		r->out.count = s->count;
		r->out.resume_index = s->resume_index;
		r->out.users = talloc_steal(mem_ctx, s->users);
		
		if (NT_STATUS_IS_OK(status)) {
			r->out.error_string = talloc_strdup(mem_ctx, "Success");
		} else {
			/* success, but we're not done yet */
			r->out.error_string = talloc_asprintf(mem_ctx, "Success (status: %s)",
							      nt_errstr(status));
		}

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

	return status;
}


/**
 * Synchronous version of UserList call
 *
 * @param ctx initialised libnet context
 * @param mem_ctx memory context of this call
 * @param r pointer to structure containing arguments and result of this call
 * @return nt status
 */
NTSTATUS libnet_UserList(struct libnet_context *ctx,
			 TALLOC_CTX *mem_ctx,
			 struct libnet_UserList *r)
{
	struct composite_context *c;

	c = libnet_UserList_send(ctx, mem_ctx, r, NULL);
	return libnet_UserList_recv(c, mem_ctx, r);
}
