/* 
   Unix SMB/CIFS implementation.

   Winbind daemon connection manager

   Copyright (C) Tim Potter                2001
   Copyright (C) Andrew Bartlett           2002
   Copyright (C) Gerald (Jerry) Carter     2003-2005.
   Copyright (C) Volker Lendecke           2004-2005
   
   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 2 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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

/*
   We need to manage connections to domain controllers without having to
   mess up the main winbindd code with other issues.  The aim of the
   connection manager is to:
  
       - make connections to domain controllers and cache them
       - re-establish connections when networks or servers go down
       - centralise the policy on connection timeouts, domain controller
	 selection etc
       - manage re-entrancy for when winbindd becomes able to handle
	 multiple outstanding rpc requests
  
   Why not have connection management as part of the rpc layer like tng?
   Good question.  This code may morph into libsmb/rpc_cache.c or something
   like that but at the moment it's simply staying as part of winbind.	I
   think the TNG architecture of forcing every user of the rpc layer to use
   the connection caching system is a bad idea.	 It should be an optional
   method of using the routines.

   The TNG design is quite good but I disagree with some aspects of the
   implementation. -tpot

 */

/*
   TODO:

     - I'm pretty annoyed by all the make_nmb_name() stuff.  It should be
       moved down into another function.

     - Take care when destroying cli_structs as they can be shared between
       various sam handles.

 */

#include "includes.h"
#include "winbindd.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_WINBIND


/****************************************************************** 
   Disabling schannl on the LSA pipe for now since 
   both Win2K-SP4 SR1 & Win2K3-SP1 fail the open_policy() 
   call (return codes 0xc0020042 and 0xc0020041 respectively).
   We really need to fix this soon.  Had to disable on the 
   SAMR pipe as well for now.   --jerry
******************************************************************/

#define DISABLE_SCHANNEL_WIN2K3_SP1	1


/* Choose between anonymous or authenticated connections.  We need to use
   an authenticated connection if DCs have the RestrictAnonymous registry
   entry set > 0, or the "Additional restrictions for anonymous
   connections" set in the win2k Local Security Policy. 
   
   Caller to free() result in domain, username, password
*/

static void cm_get_ipc_userpass(char **username, char **domain, char **password)
{
	*username = secrets_fetch(SECRETS_AUTH_USER, NULL);
	*domain = secrets_fetch(SECRETS_AUTH_DOMAIN, NULL);
	*password = secrets_fetch(SECRETS_AUTH_PASSWORD, NULL);
	
	if (*username && **username) {

		if (!*domain || !**domain)
			*domain = smb_xstrdup(lp_workgroup());
		
		if (!*password || !**password)
			*password = smb_xstrdup("");

		DEBUG(3, ("cm_get_ipc_userpass: Retrieved auth-user from secrets.tdb [%s\\%s]\n", 
			  *domain, *username));

	} else {
		DEBUG(3, ("cm_get_ipc_userpass: No auth-user defined\n"));
		*username = smb_xstrdup("");
		*domain = smb_xstrdup("");
		*password = smb_xstrdup("");
	}
}

static BOOL get_dc_name_via_netlogon(const struct winbindd_domain *domain,
				     fstring dcname, struct in_addr *dc_ip)
{
	struct winbindd_domain *our_domain;
	NTSTATUS result;
	struct rpc_pipe_client *cli;
	TALLOC_CTX *mem_ctx;

	fstring tmp;
	char *p;

	/* Hmmmm. We can only open one connection to the NETLOGON pipe at the
	 * moment.... */

	if (IS_DC)
		return False;

	if (domain->primary)
		return False;

	our_domain = find_our_domain();

	if ((mem_ctx = talloc_init("get_dc_name_via_netlogon")) == NULL)
		return False;

	{
		/* These var's can be ignored -- we're not requesting
		   anything in the credential chain here */
		unsigned char *session_key;
		DOM_CRED *creds;
		result = cm_connect_netlogon(our_domain, mem_ctx, &cli,
					     &session_key, &creds);
	}

	if (!NT_STATUS_IS_OK(result))
		return False;

	result = rpccli_netlogon_getdcname(cli, mem_ctx, domain->dcname,
					   domain->name, tmp);

	talloc_destroy(mem_ctx);

	if (!NT_STATUS_IS_OK(result))
		return False;

	/* cli_netlogon_getdcname gives us a name with \\ */
	p = tmp;
	if (*p == '\\') p+=1;
	if (*p == '\\') p+=1;

	fstrcpy(dcname, p);

	if (!resolve_name(dcname, dc_ip, 0x20))
		return False;

	return True;
}

/************************************************************************
 Given a fd with a just-connected TCP connection to a DC, open a connection
 to the pipe.
************************************************************************/

static NTSTATUS cm_prepare_connection(const struct winbindd_domain *domain,
				      const int sockfd,
				      const char *controller,
				      struct cli_state **cli,
				      BOOL *retry)
{
	char *machine_password, *machine_krb5_principal;
	char *ipc_username, *ipc_domain, *ipc_password;

	BOOL got_mutex;
	BOOL add_failed_connection = True;

	NTSTATUS result = NT_STATUS_UNSUCCESSFUL;

	struct sockaddr peeraddr;
	socklen_t peeraddr_len;

	struct sockaddr_in *peeraddr_in = (struct sockaddr_in *)&peeraddr;

	machine_password = secrets_fetch_machine_password(lp_workgroup(), NULL,
							  NULL);
	
	if (asprintf(&machine_krb5_principal, "%s$@%s", global_myname(),
		     lp_realm()) == -1) {
		SAFE_FREE(machine_password);
		return NT_STATUS_NO_MEMORY;
	}

	cm_get_ipc_userpass(&ipc_username, &ipc_domain, &ipc_password);

	*retry = True;

	got_mutex = secrets_named_mutex(controller,
					WINBIND_SERVER_MUTEX_WAIT_TIME);

	if (!got_mutex) {
		DEBUG(0,("cm_open_connection: mutex grab failed for %s\n",
			 controller));
		result = NT_STATUS_POSSIBLE_DEADLOCK;
		goto done;
	}

	if ((*cli = cli_initialise(NULL)) == NULL) {
		DEBUG(1, ("Could not cli_initialize\n"));
		result = NT_STATUS_NO_MEMORY;
		goto done;
	}

	(*cli)->timeout = 10000; 	/* 10 seconds */
	(*cli)->fd = sockfd;
	fstrcpy((*cli)->desthost, controller);
	(*cli)->use_kerberos = True;

	peeraddr_len = sizeof(peeraddr);

	if ((getpeername((*cli)->fd, &peeraddr, &peeraddr_len) != 0) ||
	    (peeraddr_len != sizeof(struct sockaddr_in)) ||
	    (peeraddr_in->sin_family != PF_INET))
	{
		DEBUG(0,("cm_prepare_connection: %s\n", strerror(errno)));
		goto done;
	}

	if (ntohs(peeraddr_in->sin_port) == 139) {
		struct nmb_name calling;
		struct nmb_name called;

		make_nmb_name(&calling, global_myname(), 0x0);
		make_nmb_name(&called, "*SMBSERVER", 0x20);

		if (!cli_session_request(*cli, &calling, &called)) {
			DEBUG(8, ("cli_session_request failed for %s\n",
				  controller));
			goto done;
		}
	}

	cli_setup_signing_state(*cli, Undefined);

	if (!cli_negprot(*cli)) {
		DEBUG(1, ("cli_negprot failed\n"));
		cli_shutdown(*cli);
		goto done;
	}

	/* Krb5 session */
			
	if ((lp_security() == SEC_ADS) 
	    && ((*cli)->protocol >= PROTOCOL_NT1 &&
		(*cli)->capabilities & CAP_EXTENDED_SECURITY)) {

		ADS_STATUS ads_status;
		(*cli)->use_kerberos = True;
		DEBUG(5, ("connecting to %s from %s with kerberos principal "
			  "[%s]\n", controller, global_myname(),
			  machine_krb5_principal));

		ads_status = cli_session_setup_spnego(*cli,
						      machine_krb5_principal, 
						      machine_password, 
						      lp_workgroup());

		if (!ADS_ERR_OK(ads_status))
			DEBUG(4,("failed kerberos session setup with %s\n",
				 ads_errstr(ads_status)));

		result = ads_ntstatus(ads_status);
	}

	if (NT_STATUS_IS_OK(result))
		goto session_setup_done;

	/* Fall back to non-kerberos session setup */

	(*cli)->use_kerberos = False;

	if ((((*cli)->sec_mode & NEGOTIATE_SECURITY_CHALLENGE_RESPONSE) != 0) &&
	    (strlen(ipc_username) > 0)) {

		/* Only try authenticated if we have a username */

		DEBUG(5, ("connecting to %s from %s with username "
			  "[%s]\\[%s]\n",  controller, global_myname(),
			  ipc_domain, ipc_username));

		if (cli_session_setup(*cli, ipc_username,
				      ipc_password, strlen(ipc_password)+1,
				      ipc_password, strlen(ipc_password)+1,
				      ipc_domain)) {
			DEBUG(5, ("authenticated session setup failed\n"));
			goto session_setup_done;
		}
	}

	/* Fall back to anonymous connection, this might fail later */

	if (cli_session_setup(*cli, "", NULL, 0, NULL, 0, "")) {
		DEBUG(5, ("Connected anonymously\n"));
		goto session_setup_done;
	}

	result = cli_nt_error(*cli);

	if (NT_STATUS_IS_OK(result))
		result = NT_STATUS_UNSUCCESSFUL;

	/* We can't session setup */

	goto done;

 session_setup_done:

	if (!cli_send_tconX(*cli, "IPC$", "IPC", "", 0)) {

		result = cli_nt_error(*cli);

		DEBUG(1,("failed tcon_X with %s\n", nt_errstr(result)));

		if (NT_STATUS_IS_OK(result))
			result = NT_STATUS_UNSUCCESSFUL;

		cli_shutdown(*cli);
		goto done;
	}

	secrets_named_mutex_release(controller);
	got_mutex = False;
	*retry = False;

	/* set the domain if empty; needed for schannel connections */
	if ( !*(*cli)->domain )
		fstrcpy( (*cli)->domain, domain->name );

	(*cli)->pipe_auth_flags = 0;

	result = NT_STATUS_OK;
	add_failed_connection = False;

 done:
	if (got_mutex)
		secrets_named_mutex_release(controller);

	SAFE_FREE(machine_password);
	SAFE_FREE(machine_krb5_principal);
	SAFE_FREE(ipc_username);
	SAFE_FREE(ipc_domain);
	SAFE_FREE(ipc_password);

	if (add_failed_connection)
		add_failed_connection_entry(domain->name, controller, result);

	return result;
}

struct dc_name_ip {
	fstring name;
	struct in_addr ip;
};

static BOOL add_one_dc_unique(TALLOC_CTX *mem_ctx, const char *domain_name,
			      const char *dcname, struct in_addr ip,
			      struct dc_name_ip **dcs, int *num)
{
	if (!NT_STATUS_IS_OK(check_negative_conn_cache(domain_name, dcname)))
		return False;

	*dcs = TALLOC_REALLOC_ARRAY(mem_ctx, *dcs, struct dc_name_ip, (*num)+1);

	if (*dcs == NULL)
		return False;

	fstrcpy((*dcs)[*num].name, dcname);
	(*dcs)[*num].ip = ip;
	*num += 1;
	return True;
}

static BOOL add_sockaddr_to_array(TALLOC_CTX *mem_ctx,
				  struct in_addr ip, uint16 port,
				  struct sockaddr_in **addrs, int *num)
{
	*addrs = TALLOC_REALLOC_ARRAY(mem_ctx, *addrs, struct sockaddr_in, (*num)+1);

	if (*addrs == NULL)
		return False;

	(*addrs)[*num].sin_family = PF_INET;
	putip((char *)&((*addrs)[*num].sin_addr), (char *)&ip);
	(*addrs)[*num].sin_port = htons(port);

	*num += 1;
	return True;
}

static void mailslot_name(struct in_addr dc_ip, fstring name)
{
	fstr_sprintf(name, "\\MAILSLOT\\NET\\GETDC%X", dc_ip.s_addr);
}

static BOOL send_getdc_request(struct in_addr dc_ip,
			       const char *domain_name,
			       const DOM_SID *sid)
{
	pstring outbuf;
	char *p;
	fstring my_acct_name;
	fstring my_mailslot;

	mailslot_name(dc_ip, my_mailslot);

	memset(outbuf, '\0', sizeof(outbuf));

	p = outbuf;

	SCVAL(p, 0, SAMLOGON);
	p++;

	SCVAL(p, 0, 0); /* Count pointer ... */
	p++;

	SIVAL(p, 0, 0); /* The sender's token ... */
	p += 2;

	p += dos_PutUniCode(p, global_myname(), sizeof(pstring), True);
	fstr_sprintf(my_acct_name, "%s$", global_myname());
	p += dos_PutUniCode(p, my_acct_name, sizeof(pstring), True);

	memcpy(p, my_mailslot, strlen(my_mailslot)+1);
	p += strlen(my_mailslot)+1;

	SIVAL(p, 0, 0x80);
	p+=4;

	SIVAL(p, 0, sid_size(sid));
	p+=4;

	p = ALIGN4(p, outbuf);

	sid_linearize(p, sid_size(sid), sid);
	p += sid_size(sid);

	SIVAL(p, 0, 1);
	SSVAL(p, 4, 0xffff);
	SSVAL(p, 6, 0xffff);
	p+=8;

	return cli_send_mailslot(False, "\\MAILSLOT\\NET\\NTLOGON", 0,
				 outbuf, PTR_DIFF(p, outbuf),
				 global_myname(), 0, domain_name, 0x1c,
				 dc_ip);
}

static BOOL receive_getdc_response(struct in_addr dc_ip,
				   const char *domain_name,
				   fstring dc_name)
{
	struct packet_struct *packet;
	fstring my_mailslot;
	char *buf, *p;
	fstring dcname, user, domain;
	int len;

	mailslot_name(dc_ip, my_mailslot);

	packet = receive_unexpected(DGRAM_PACKET, 0, my_mailslot);

	if (packet == NULL) {
		DEBUG(5, ("Did not receive packet for %s\n", my_mailslot));
		return False;
	}

	DEBUG(5, ("Received packet for %s\n", my_mailslot));

	buf = packet->packet.dgram.data;
	len = packet->packet.dgram.datasize;

	if (len < 70) {
		/* 70 is a completely arbitrary value to make sure
		   the SVAL below does not read uninitialized memory */
		DEBUG(3, ("GetDC got short response\n"));
		return False;
	}

	/* This should be (buf-4)+SVAL(buf-4, smb_vwv12)... */
	p = buf+SVAL(buf, smb_vwv10);

	if (CVAL(p,0) != SAMLOGON_R) {
		DEBUG(8, ("GetDC got invalid response type %d\n", CVAL(p, 0)));
		return False;
	}

	p+=2;
	pull_ucs2(buf, dcname, p, sizeof(dcname), PTR_DIFF(buf+len, p),
		  STR_TERMINATE|STR_NOALIGN);
	p = skip_unibuf(p, PTR_DIFF(buf+len, p));
	pull_ucs2(buf, user, p, sizeof(dcname), PTR_DIFF(buf+len, p),
		  STR_TERMINATE|STR_NOALIGN);
	p = skip_unibuf(p, PTR_DIFF(buf+len, p));
	pull_ucs2(buf, domain, p, sizeof(dcname), PTR_DIFF(buf+len, p),
		  STR_TERMINATE|STR_NOALIGN);
	p = skip_unibuf(p, PTR_DIFF(buf+len, p));

	if (!strequal(domain, domain_name)) {
		DEBUG(3, ("GetDC: Expected domain %s, got %s\n",
			  domain_name, domain));
		return False;
	}

	p = dcname;
	if (*p == '\\')	p += 1;
	if (*p == '\\')	p += 1;

	fstrcpy(dc_name, p);

	DEBUG(10, ("GetDC gave name %s for domain %s\n",
		   dc_name, domain));

	return True;
}

/*******************************************************************
 convert an ip to a name
*******************************************************************/

static void dcip_to_name( const char *domainname, const char *realm, 
                          const DOM_SID *sid, struct in_addr ip, fstring name )
{
	int i;

	/* try GETDC requests first */
	
	send_getdc_request(ip, domainname, sid);
	smb_msleep(100);

	for (i=0; i<5; i++) {
		if (receive_getdc_response(ip, domainname, name))
			return;
		smb_msleep(500);
	}

	/* try node status request */

	if ( name_status_find(domainname, 0x1c, 0x20, ip, name) )
		return;

	/* backup in case the netbios stuff fails */

	fstrcpy( name, inet_ntoa(ip) );

#ifdef WITH_ADS
	/* for active directory servers, try to get the ldap server name.
	   None of these failure should be considered critical for now */

	if ( lp_security() == SEC_ADS ) 
	{
		ADS_STRUCT *ads;
		ADS_STATUS status;

		ads = ads_init( realm, domainname, NULL );
		ads->auth.flags |= ADS_AUTH_NO_BIND;

		if ( !ads_try_connect( ads, inet_ntoa(ip), LDAP_PORT ) )  {
			ads_destroy( &ads );
			return;
		}

		status = ads_server_info(ads);
		if ( !ADS_ERR_OK(status) ) {
			ads_destroy( &ads );
			return;
		}

		fstrcpy(name, ads->config.ldap_server_name);

		ads_destroy( &ads );
	}
#endif

	return;
}

/*******************************************************************
 Retreive a list of IP address for domain controllers.  Fill in 
 the dcs[]  with results.
*******************************************************************/

static BOOL get_dcs(TALLOC_CTX *mem_ctx, const struct winbindd_domain *domain,
		    struct dc_name_ip **dcs, int *num_dcs)
{
	fstring dcname;
	struct  in_addr ip;
	struct  ip_service *ip_list = NULL;
	int     iplist_size = 0;
	int     i;
	BOOL    is_our_domain;


	is_our_domain = strequal(domain->name, lp_workgroup());

	if ( !is_our_domain 
		&& get_dc_name_via_netlogon(domain, dcname, &ip) 
		&& add_one_dc_unique(mem_ctx, domain->name, dcname, ip, dcs, num_dcs) )
	{
		return True;
	}

	if ( is_our_domain 
		&& must_use_pdc(domain->name) 
		&& get_pdc_ip(domain->name, &ip)) 
	{
		if (add_one_dc_unique(mem_ctx, domain->name, inet_ntoa(ip), ip, dcs, num_dcs)) 
			return True;
	}

	/* try standard netbios queries first */

	get_sorted_dc_list(domain->name, &ip_list, &iplist_size, False);

	/* check for security = ads and use DNS if we can */

	if ( iplist_size==0 && lp_security() == SEC_ADS ) 
		get_sorted_dc_list(domain->alt_name, &ip_list, &iplist_size, True);

	/* FIXME!! this is where we should re-insert the GETDC requests --jerry */

	/* now add to the dc array.  We'll wait until the last minute 
	   to look up the name of the DC.  But we fill in the char* for 
	   the ip now in to make the failed connection cache work */

	for ( i=0; i<iplist_size; i++ ) {
		add_one_dc_unique(mem_ctx, domain->name, inet_ntoa(ip_list[i].ip), 
			ip_list[i].ip, dcs, num_dcs);
	}

	SAFE_FREE( ip_list );

	return True;
}

static BOOL find_new_dc(TALLOC_CTX *mem_ctx,
			const struct winbindd_domain *domain,
			fstring dcname, struct sockaddr_in *addr, int *fd)
{
	struct dc_name_ip *dcs = NULL;
	int num_dcs = 0;

	const char **dcnames = NULL;
	int num_dcnames = 0;

	struct sockaddr_in *addrs = NULL;
	int num_addrs = 0;

	int i, fd_index;

	if (!get_dcs(mem_ctx, domain, &dcs, &num_dcs) || (num_dcs == 0))
		return False;

	for (i=0; i<num_dcs; i++) {

		add_string_to_array(mem_ctx, dcs[i].name,
				    &dcnames, &num_dcnames);
		add_sockaddr_to_array(mem_ctx, dcs[i].ip, 445,
				      &addrs, &num_addrs);

		add_string_to_array(mem_ctx, dcs[i].name,
				    &dcnames, &num_dcnames);
		add_sockaddr_to_array(mem_ctx, dcs[i].ip, 139,
				      &addrs, &num_addrs);
	}

	if ((num_dcnames == 0) || (num_dcnames != num_addrs))
		return False;

	if ( !open_any_socket_out(addrs, num_addrs, 10000, &fd_index, fd) ) 
	{
		for (i=0; i<num_dcs; i++) {
			add_failed_connection_entry(domain->name,
				dcs[i].name, NT_STATUS_UNSUCCESSFUL);
		}
		return False;
	}

	*addr = addrs[fd_index];

	/* if we have no name on the server or just an IP address for 
	   the name, now try to get the name */

	if ( is_ipaddress(dcnames[fd_index]) || *dcnames[fd_index] == '\0' )
		dcip_to_name( domain->name, domain->alt_name, &domain->sid, addr->sin_addr, dcname );
	else
		fstrcpy(dcname, dcnames[fd_index]);

	return True;
}

static NTSTATUS cm_open_connection(struct winbindd_domain *domain,
				   struct winbindd_cm_conn *new_conn)
{
	TALLOC_CTX *mem_ctx;
	NTSTATUS result;

	int retries;

	if ((mem_ctx = talloc_init("cm_open_connection")) == NULL)
		return NT_STATUS_NO_MEMORY;

	for (retries = 0; retries < 3; retries++) {

		int fd = -1;
		BOOL retry;

		result = NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND;

		if ((strlen(domain->dcname) > 0) &&
		    NT_STATUS_IS_OK(check_negative_conn_cache(domain->name,
							      domain->dcname))) {
			int dummy;
			if (!open_any_socket_out(&domain->dcaddr, 1, 10000,
						 &dummy, &fd)) {
				fd = -1;
			}
		}

		if ((fd == -1) &&
		    !find_new_dc(mem_ctx, domain, domain->dcname,
				 &domain->dcaddr, &fd))
			break;

		new_conn->cli = NULL;

		result = cm_prepare_connection(domain, fd, domain->dcname,
			&new_conn->cli, &retry);

		if (!retry)
			break;
	}

	talloc_destroy(mem_ctx);
	return result;
}

/* Return true if a connection is still alive */

void invalidate_cm_connection(struct winbindd_cm_conn *conn)
{
	if (conn->samr_pipe != NULL) {
		cli_rpc_close(conn->samr_pipe);
		conn->samr_pipe = NULL;
	}

	if (conn->lsa_pipe != NULL) {
		cli_rpc_close(conn->lsa_pipe);
		conn->lsa_pipe = NULL;
	}

	if (conn->netlogon_auth2_pipe != NULL) {
		cli_rpc_close(conn->netlogon_auth2_pipe);
		conn->netlogon_auth2_pipe = NULL;
	}

	if (conn->netlogon_pipe != NULL) {
		cli_rpc_close(conn->netlogon_pipe);
		conn->netlogon_pipe = NULL;
	}

	if (conn->cli)
		cli_shutdown(conn->cli);

	conn->cli = NULL;
}

void close_conns_after_fork(void)
{
	struct winbindd_domain *domain;

	for (domain = domain_list(); domain; domain = domain->next) {
		if (domain->conn.cli == NULL)
			continue;

		if (domain->conn.cli->fd == -1)
			continue;

		close(domain->conn.cli->fd);
		domain->conn.cli->fd = -1;
	}
}

static BOOL connection_ok(struct winbindd_domain *domain)
{
	if (domain->conn.cli == NULL) {
		DEBUG(8, ("Connection to %s for domain %s has NULL "
			  "cli!\n", domain->dcname, domain->name));
		return False;
	}

	if (!domain->conn.cli->initialised) {
		DEBUG(3, ("Connection to %s for domain %s was never "
			  "initialised!\n", domain->dcname, domain->name));
		return False;
	}

	if (domain->conn.cli->fd == -1) {
		DEBUG(3, ("Connection to %s for domain %s has died or was "
			  "never started (fd == -1)\n", 
			  domain->dcname, domain->name));
		return False;
	}

	return True;
}
	
/* Initialize a new connection up to the RPC BIND. */

static NTSTATUS init_dc_connection(struct winbindd_domain *domain)
{
	if (connection_ok(domain))
		return NT_STATUS_OK;

	invalidate_cm_connection(&domain->conn);

	return cm_open_connection(domain, &domain->conn);
}

/**********************************************************************************
 We can 'sense' certain things about the DC by it's replies to certain questions.

 This tells us if this particular remote server is Active Directory, and if it is
 native mode.
**********************************************************************************/

void set_dc_type_and_flags( struct winbindd_domain *domain )
{
	NTSTATUS 		result;
	DS_DOMINFO_CTR		ctr;
	TALLOC_CTX              *mem_ctx = NULL;
	struct rpc_pipe_client  *cli;
	POLICY_HND pol;
	
	char *domain_name = NULL;
	char *dns_name = NULL;
	DOM_SID *dom_sid = NULL;

	ZERO_STRUCT( ctr );
	
	domain->native_mode = False;
	domain->active_directory = False;

	if (domain->internal) {
		domain->initialized = True;
		return;
	}

	result = init_dc_connection(domain);
	if (!NT_STATUS_IS_OK(result)) {
		DEBUG(5, ("set_dc_type_and_flags: Could not open a connection "
			  "to %s: (%s)\n", domain->name, nt_errstr(result)));
		domain->initialized = True;
		return;
	}

	cli = cli_rpc_open_noauth(domain->conn.cli, PI_LSARPC_DS);

	if (cli == NULL) {
		DEBUG(5, ("set_dc_type_and_flags: Could not bind to "
			  "PI_LSARPC_DS on domain %s: (%s)\n",
			  domain->name, nt_errstr(result)));
		domain->initialized = True;
		return;
	}

	result = rpccli_ds_getprimarydominfo(cli, cli->cli->mem_ctx,
					     DsRolePrimaryDomainInfoBasic,
					     &ctr);
	cli_rpc_close(cli);

	if (!NT_STATUS_IS_OK(result)) {
		domain->initialized = True;
		return;
	}
	
	if ((ctr.basic->flags & DSROLE_PRIMARY_DS_RUNNING) &&
	    !(ctr.basic->flags & DSROLE_PRIMARY_DS_MIXED_MODE) )
		domain->native_mode = True;

	cli = cli_rpc_open_noauth(domain->conn.cli, PI_LSARPC);

	if (cli == NULL) {
		domain->initialized = True;
		return;
	}

	mem_ctx = talloc_init("set_dc_type_and_flags on domain %s\n",
			      domain->name);
	if (!mem_ctx) {
		DEBUG(1, ("set_dc_type_and_flags: talloc_init() failed\n"));
		return;
	}

	result = rpccli_lsa_open_policy2(cli, mem_ctx, True, 
					 SEC_RIGHTS_MAXIMUM_ALLOWED, &pol);
		
	if (NT_STATUS_IS_OK(result)) {
		/* This particular query is exactly what Win2k clients use 
		   to determine that the DC is active directory */
		result = rpccli_lsa_query_info_policy2(cli, mem_ctx, &pol,
						       12, &domain_name,
						       &dns_name, NULL,
						       NULL, &dom_sid);
	}

	if (NT_STATUS_IS_OK(result)) {
		if (domain_name)
			fstrcpy(domain->name, domain_name);

		if (dns_name)
			fstrcpy(domain->alt_name, dns_name);

		if (dom_sid) 
			sid_copy(&domain->sid, dom_sid);

		domain->active_directory = True;
	} else {
		
		result = rpccli_lsa_open_policy(cli, mem_ctx, True, 
						SEC_RIGHTS_MAXIMUM_ALLOWED,
						&pol);
			
		if (!NT_STATUS_IS_OK(result))
			goto done;
			
		result = rpccli_lsa_query_info_policy(cli, mem_ctx, 
						      &pol, 5, &domain_name, 
						      &dom_sid);
			
		if (NT_STATUS_IS_OK(result)) {
			if (domain_name)
				fstrcpy(domain->name, domain_name);

			if (dom_sid) 
				sid_copy(&domain->sid, dom_sid);
		}
	}
done:

	cli_rpc_close(cli);
	
	talloc_destroy(mem_ctx);

	domain->initialized = True;
	
	return;
}

static BOOL cm_get_schannel_key(struct winbindd_domain *domain,
				TALLOC_CTX *mem_ctx,
				unsigned char **session_key)
{
	struct rpc_pipe_client *cli;
	DOM_CRED *credentials;

	if (lp_client_schannel() == False)
		return False;

	return NT_STATUS_IS_OK(cm_connect_netlogon(domain, mem_ctx,
						   &cli, session_key,
						   &credentials));
}

NTSTATUS cm_connect_sam(struct winbindd_domain *domain, TALLOC_CTX *mem_ctx,
			struct rpc_pipe_client **cli, POLICY_HND *sam_handle)
{
	struct winbindd_cm_conn *conn;
	NTSTATUS result;

	result = init_dc_connection(domain);
	if (!NT_STATUS_IS_OK(result))
		return result;

	conn = &domain->conn;

	if (conn->samr_pipe == NULL) {
#ifndef DISABLE_SCHANNEL_WIN2K3_SP1
		unsigned char *session_key;

		if (cm_get_schannel_key(domain, mem_ctx, &session_key))
			conn->samr_pipe = cli_rpc_open_schannel(conn->cli,
								PI_SAMR,
								session_key,
								domain->name);
		else
#endif	/* DISABLE_SCHANNEL_WIN2K3_SP1 */
			conn->samr_pipe = cli_rpc_open_noauth(conn->cli,
							      PI_SAMR);

		if (conn->samr_pipe == NULL) {
			result = NT_STATUS_PIPE_NOT_AVAILABLE;
			goto done;
		}

		result = rpccli_samr_connect(conn->samr_pipe, mem_ctx,
					     SEC_RIGHTS_MAXIMUM_ALLOWED,
					     &conn->sam_connect_handle);
		if (!NT_STATUS_IS_OK(result))
			goto done;

		result = rpccli_samr_open_domain(conn->samr_pipe,
						 mem_ctx,
						 &conn->sam_connect_handle,
						 SEC_RIGHTS_MAXIMUM_ALLOWED,
						 &domain->sid,
						 &conn->sam_domain_handle);
	}

 done:
	if (!NT_STATUS_IS_OK(result)) {
		invalidate_cm_connection(conn);
		return NT_STATUS_UNSUCCESSFUL;
	}

	*cli = conn->samr_pipe;
	*sam_handle = conn->sam_domain_handle;
	return result;
}

NTSTATUS cm_connect_lsa(struct winbindd_domain *domain, TALLOC_CTX *mem_ctx,
			struct rpc_pipe_client **cli, POLICY_HND *lsa_policy)
{
	struct winbindd_cm_conn *conn;
	NTSTATUS result;

	result = init_dc_connection(domain);
	if (!NT_STATUS_IS_OK(result))
		return result;

	conn = &domain->conn;

	if (conn->lsa_pipe == NULL) {
#ifndef DISABLE_SCHANNEL_WIN2K3_SP1
		unsigned char *session_key;

		if (cm_get_schannel_key(domain, mem_ctx, &session_key))
			conn->lsa_pipe = cli_rpc_open_schannel(conn->cli,
							       PI_LSARPC,
							       session_key,
							       domain->name);
		else
#endif	/* DISABLE_SCHANNEL_WIN2K3_SP1 */
			conn->lsa_pipe = cli_rpc_open_noauth(conn->cli,
							     PI_LSARPC);

		if (conn->lsa_pipe == NULL) {
			result = NT_STATUS_PIPE_NOT_AVAILABLE;
			goto done;
		}

		result = rpccli_lsa_open_policy(conn->lsa_pipe, mem_ctx, True,
						SEC_RIGHTS_MAXIMUM_ALLOWED,
						&conn->lsa_policy);
	}

 done:
	if (!NT_STATUS_IS_OK(result)) {
		invalidate_cm_connection(conn);
		return NT_STATUS_UNSUCCESSFUL;
	}

	*cli = conn->lsa_pipe;
	*lsa_policy = conn->lsa_policy;
	return result;
}

/*******************************************************************
 wrapper around retrieving the trust account password
*******************************************************************/

static BOOL get_trust_pw(const char *domain, uint8 ret_pwd[16],
			 uint32 *channel)
{
	DOM_SID sid;
	char *pwd;
	time_t last_set_time;

	/* if we are a DC and this is not our domain, then lookup an account
	   for the domain trust */

	if ( IS_DC && !strequal(domain, lp_workgroup()) &&
	     lp_allow_trusted_domains() ) {

		if (!secrets_fetch_trusted_domain_password(domain, &pwd, &sid,
							   &last_set_time)) {
			DEBUG(0, ("get_trust_pw: could not fetch trust "
				  "account password for trusted domain %s\n",
				  domain));
			return False;
		}

		*channel = SEC_CHAN_DOMAIN;
		E_md4hash(pwd, ret_pwd);
		SAFE_FREE(pwd);

		return True;
	}

	/* Just get the account for the requested domain. In the future this
	 * might also cover to be member of more than one domain. */

	if (secrets_fetch_trust_account_password(domain, ret_pwd,
						 &last_set_time, channel))
		return True;

	DEBUG(5, ("get_trust_pw: could not fetch trust account "
		  "password for domain %s\n", domain));
	return False;
}

NTSTATUS cm_connect_netlogon(struct winbindd_domain *domain,
			     TALLOC_CTX *mem_ctx,
			     struct rpc_pipe_client **cli,
			     unsigned char **session_key,
			     DOM_CRED **credentials)
{
	struct winbindd_cm_conn *conn;
	NTSTATUS result;

	uint32 neg_flags = NETLOGON_NEG_AUTH2_FLAGS;
	uint8  mach_pwd[16];
	uint32  sec_chan_type;
	DOM_CHAL clnt_chal, srv_chal, rcv_chal;
	const char *server_name;
	const char *account_name;
	UTIME zerotime;

	result = init_dc_connection(domain);
	if (!NT_STATUS_IS_OK(result))
		return result;

	conn = &domain->conn;

	if (conn->netlogon_pipe != NULL) {
		*cli = conn->netlogon_pipe;
		*session_key = (unsigned char *)&conn->sess_key;
		*credentials = &conn->clnt_cred;
		return NT_STATUS_OK;
	}

	if (!get_trust_pw(domain->name, mach_pwd, &sec_chan_type))
		return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;

	conn->netlogon_auth2_pipe = cli_rpc_open_noauth(conn->cli,
							PI_NETLOGON);
	if (conn->netlogon_auth2_pipe == NULL)
		return NT_STATUS_UNSUCCESSFUL;

	if (lp_client_schannel() != False)
		neg_flags |= NETLOGON_NEG_SCHANNEL;

	generate_random_buffer(clnt_chal.data, 8);

	server_name = talloc_asprintf(mem_ctx, "\\\\%s", domain->dcname);

	/* if we are a DC and this is a trusted domain, then we need to use our
	   domain name in the net_req_auth2() request */

	if ( IS_DC ) {
		account_name = talloc_asprintf( mem_ctx, "%s$", lp_workgroup() );
	}
	else {
		account_name = talloc_asprintf(mem_ctx, "%s$", 
			domain->primary ?  global_myname() : domain->name);
	}

	if ((server_name == NULL) || (account_name == NULL))
		return NT_STATUS_NO_MEMORY;

	result = rpccli_net_req_chal(conn->netlogon_auth2_pipe, server_name,
				     global_myname(), &clnt_chal, &srv_chal);
	if (!NT_STATUS_IS_OK(result))
		return result;

	/**************** Long-term Session key **************/

	/* calculate the session key */
	cred_session_key(&clnt_chal, &srv_chal, mach_pwd, conn->sess_key);
	memset((char *)conn->sess_key+8, '\0', 8);

	/* calculate auth2 credentials */
	zerotime.time = 0;
	cred_create(conn->sess_key, &clnt_chal, zerotime,
		    &conn->clnt_cred.challenge);

	result = rpccli_net_auth2(conn->netlogon_auth2_pipe, server_name,
				  account_name, sec_chan_type, global_myname(),
				  &conn->clnt_cred.challenge, &neg_flags,
				  &rcv_chal);

	if (!NT_STATUS_IS_OK(result))
		return result;

	zerotime.time = 0;
	if (!cred_assert(&rcv_chal, conn->sess_key, &srv_chal, zerotime)) {
		DEBUG(0, ("Server replied with bad credential\n"));
		return NT_STATUS_ACCESS_DENIED;
	}

	if ((lp_client_schannel() == True) &&
	    ((neg_flags & NETLOGON_NEG_SCHANNEL) == 0)) {
		DEBUG(3, ("Server did not offer schannel\n"));
		cli_rpc_close(conn->netlogon_auth2_pipe);
		conn->netlogon_auth2_pipe = NULL;
		return NT_STATUS_ACCESS_DENIED;
	}

	if ((lp_client_schannel() == False) ||
	    ((neg_flags & NETLOGON_NEG_SCHANNEL) == 0)) {
		/* keep the existing connection to NETLOGON open */
		conn->netlogon_pipe = conn->netlogon_auth2_pipe;
		conn->netlogon_auth2_pipe = NULL;
		*cli = conn->netlogon_pipe;
		*session_key = (unsigned char *)&conn->sess_key;
		*credentials = &conn->clnt_cred;
		return NT_STATUS_OK;
	}

	conn->netlogon_pipe = cli_rpc_open_schannel(conn->cli, PI_NETLOGON,
						    conn->sess_key,
						    domain->name);

	if (conn->netlogon_pipe == NULL) {
		DEBUG(3, ("Could not open schannel'ed NETLOGON pipe\n"));
		cli_rpc_close(conn->netlogon_auth2_pipe);
		conn->netlogon_auth2_pipe = NULL;
		return NT_STATUS_ACCESS_DENIED;
	}

	*cli = conn->netlogon_pipe;
	*session_key = (unsigned char *)&conn->sess_key;
	*credentials = &conn->clnt_cred;
		
	return NT_STATUS_OK;
}
