winbindd_util.c

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/* 
   Unix SMB/CIFS implementation.

   Winbind daemon for ntdom nss module

   Copyright (C) Tim Potter 2000-2001
   Copyright (C) 2001 by Martin Pool <[e-mail]>
   
   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.
*/

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

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_WINBIND

/**
 * @file winbindd_util.c
 *
 * Winbind daemon for NT domain authentication nss module.
 **/


/**
 * Used to clobber name fields that have an undefined value.
 *
 * Correct code should never look at a field that has this value.
 **/

static const fstring name_deadbeef = "<deadbeef>";

/* The list of trusted domains.  Note that the list can be deleted and
   recreated using the init_domain_list() function so pointers to
   individual winbindd_domain structures cannot be made.  Keep a copy of
   the domain name instead. */

static struct winbindd_domain *_domain_list;

/**
   When was the last scan of trusted domains done?
   
   0 == not ever
*/

static time_t last_trustdom_scan;

struct winbindd_domain *domain_list(void)
{
	/* Initialise list */

	if (!_domain_list) 
		init_domain_list();

	return _domain_list;
}

/* Free all entries in the trusted domain list */

void free_domain_list(void)
{
	struct winbindd_domain *domain = _domain_list;

	while(domain) {
		struct winbindd_domain *next = domain->next;
		
		DLIST_REMOVE(_domain_list, domain);
		SAFE_FREE(domain);
		domain = next;
	}
}

static BOOL is_internal_domain(const DOM_SID *sid)
{
	if (sid == NULL)
		return False;

	return (sid_check_is_domain(sid) || sid_check_is_builtin(sid));
}

static BOOL is_in_internal_domain(const DOM_SID *sid)
{
	if (sid == NULL)
		return False;

	return (sid_check_is_in_our_domain(sid) || sid_check_is_in_builtin(sid));
}


/* Add a trusted domain to our list of domains */
static struct winbindd_domain *add_trusted_domain(const char *domain_name, const char *alt_name,
						  struct winbindd_methods *methods,
						  const DOM_SID *sid)
{
	struct winbindd_domain *domain;
	const char *alternative_name = NULL;
	
	/* ignore alt_name if we are not in an AD domain */
	
	if ( (lp_security() == SEC_ADS) && alt_name && *alt_name) {
		alternative_name = alt_name;
	}
        
	/* We can't call domain_list() as this function is called from
	   init_domain_list() and we'll get stuck in a loop. */
	for (domain = _domain_list; domain; domain = domain->next) {
		if (strequal(domain_name, domain->name) ||
		    strequal(domain_name, domain->alt_name)) {
			return domain;
		}
		if (alternative_name && *alternative_name) {
			if (strequal(alternative_name, domain->name) ||
			    strequal(alternative_name, domain->alt_name)) {
				return domain;
			}
		}
		if (sid) {
			if (is_null_sid(sid)) {
				
			} else if (sid_equal(sid, &domain->sid)) {
				return domain;
			}
		}
	}
        
	/* Create new domain entry */

	if ((domain = SMB_MALLOC_P(struct winbindd_domain)) == NULL)
		return NULL;

	/* Fill in fields */
        
	ZERO_STRUCTP(domain);

	/* prioritise the short name */
	if (strchr_m(domain_name, '.') && alternative_name && *alternative_name) {
		fstrcpy(domain->name, alternative_name);
		fstrcpy(domain->alt_name, domain_name);
	} else {
		fstrcpy(domain->name, domain_name);
		if (alternative_name) {
			fstrcpy(domain->alt_name, alternative_name);
		}
	}

	domain->methods = methods;
	domain->backend = NULL;
	domain->internal = is_internal_domain(sid);
	domain->sequence_number = DOM_SEQUENCE_NONE;
	domain->last_seq_check = 0;
	domain->initialized = False;
	if (sid) {
		sid_copy(&domain->sid, sid);
	}
	
	/* Link to domain list */
	DLIST_ADD(_domain_list, domain);
        
	DEBUG(2,("Added domain %s %s %s\n", 
		 domain->name, domain->alt_name,
		 &domain->sid?sid_string_static(&domain->sid):""));
        
	return domain;
}

/********************************************************************
  rescan our domains looking for new trusted domains
********************************************************************/

struct trustdom_state {
	TALLOC_CTX *mem_ctx;
	struct winbindd_response *response;
};

static void trustdom_recv(void *private_data, BOOL success);

static void add_trusted_domains( struct winbindd_domain *domain )
{
	TALLOC_CTX *mem_ctx;
	struct winbindd_request *request;
	struct winbindd_response *response;

	struct trustdom_state *state;

	mem_ctx = talloc_init("add_trusted_domains");
	if (mem_ctx == NULL) {
		DEBUG(0, ("talloc_init failed\n"));
		return;
	}

	request = TALLOC_ZERO_P(mem_ctx, struct winbindd_request);
	response = TALLOC_P(mem_ctx, struct winbindd_response);
	state = TALLOC_P(mem_ctx, struct trustdom_state);

	if ((request == NULL) || (response == NULL) || (state == NULL)) {
		DEBUG(0, ("talloc failed\n"));
		talloc_destroy(mem_ctx);
		return;
	}

	state->mem_ctx = mem_ctx;
	state->response = response;

	request->length = sizeof(*request);
	request->cmd = WINBINDD_LIST_TRUSTDOM;

	async_domain_request(mem_ctx, domain, request, response,
			     trustdom_recv, state);
}

static void trustdom_recv(void *private_data, BOOL success)
{
	extern struct winbindd_methods cache_methods;
	struct trustdom_state *state =
		talloc_get_type_abort(private_data, struct trustdom_state);
	struct winbindd_response *response = state->response;
	char *p;

	if ((!success) || (response->result != WINBINDD_OK)) {
		DEBUG(1, ("Could not receive trustdoms\n"));
		talloc_destroy(state->mem_ctx);
		return;
	}

	p = response->extra_data;

	while ((p != NULL) && (*p != '\0')) {
		char *q, *sidstr, *alt_name;
		DOM_SID sid;

		alt_name = strchr(p, '\\');
		if (alt_name == NULL) {
			DEBUG(0, ("Got invalid trustdom response\n"));
			break;
		}

		*alt_name = '\0';
		alt_name += 1;

		sidstr = strchr(alt_name, '\\');
		if (sidstr == NULL) {
			DEBUG(0, ("Got invalid trustdom response\n"));
			break;
		}

		*sidstr = '\0';
		sidstr += 1;

		q = strchr(sidstr, '\n');
		if (q != NULL)
			*q = '\0';

		if (!string_to_sid(&sid, sidstr)) {
			DEBUG(0, ("Got invalid trustdom response\n"));
			break;
		}

		if (find_domain_from_name_noinit(p) == NULL) {
			struct winbindd_domain *domain;
			char *alternate_name = NULL;
			
			/* use the real alt_name if we have one, else pass in NULL */

			if ( !strequal( alt_name, "(null)" ) )
				alternate_name = alt_name;

			domain = add_trusted_domain(p, alternate_name,
						    &cache_methods,
						    &sid);
			setup_domain_child(domain, &domain->child, NULL);
		}
		p=q;
		if (p != NULL)
			p += 1;
	}

	SAFE_FREE(response->extra_data);
	talloc_destroy(state->mem_ctx);
}

/********************************************************************
 Periodically we need to refresh the trusted domain cache for smbd 
********************************************************************/

void rescan_trusted_domains( void )
{
	time_t now = time(NULL);
	
	/* see if the time has come... */
	
	if ((now >= last_trustdom_scan) &&
	    ((now-last_trustdom_scan) < WINBINDD_RESCAN_FREQ) )
		return;
		
	/* this will only add new domains we didn't already know about */
	
	add_trusted_domains( find_our_domain() );

	last_trustdom_scan = now;
	
	return;	
}

struct init_child_state {
	TALLOC_CTX *mem_ctx;
	struct winbindd_domain *domain;
	struct winbindd_request *request;
	struct winbindd_response *response;
	void (*continuation)(void *private_data, BOOL success);
	void *private_data;
};

static void init_child_recv(void *private_data, BOOL success);
static void init_child_getdc_recv(void *private_data, BOOL success);

enum winbindd_result init_child_connection(struct winbindd_domain *domain,
					   void (*continuation)(void *private_data,
								BOOL success),
					   void *private_data)
{
	TALLOC_CTX *mem_ctx;
	struct winbindd_request *request;
	struct winbindd_response *response;
	struct init_child_state *state;

	mem_ctx = talloc_init("init_child_connection");
	if (mem_ctx == NULL) {
		DEBUG(0, ("talloc_init failed\n"));
		return WINBINDD_ERROR;
	}

	request = TALLOC_ZERO_P(mem_ctx, struct winbindd_request);
	response = TALLOC_P(mem_ctx, struct winbindd_response);
	state = TALLOC_P(mem_ctx, struct init_child_state);

	if ((request == NULL) || (response == NULL) || (state == NULL)) {
		DEBUG(0, ("talloc failed\n"));
		continuation(private_data, False);
		return WINBINDD_ERROR;
	}

	request->length = sizeof(*request);

	state->mem_ctx = mem_ctx;
	state->domain = domain;
	state->request = request;
	state->response = response;
	state->continuation = continuation;
	state->private_data = private_data;

	if (domain->primary) {
		/* The primary domain has to find the DC name itself */
		request->cmd = WINBINDD_INIT_CONNECTION;
		fstrcpy(request->domain_name, domain->name);
		request->data.init_conn.is_primary = True;
		fstrcpy(request->data.init_conn.dcname, "");

		async_request(mem_ctx, &domain->child, request, response,
			      init_child_recv, state);
		return WINBINDD_PENDING;
	}

	/* This is *not* the primary domain, let's ask our DC about a DC
	 * name */

	request->cmd = WINBINDD_GETDCNAME;
	fstrcpy(request->domain_name, domain->name);

	async_domain_request(mem_ctx, find_our_domain(), request, response,
			     init_child_getdc_recv, state);
	return WINBINDD_PENDING;
}

static void init_child_getdc_recv(void *private_data, BOOL success)
{
	struct init_child_state *state =
		talloc_get_type_abort(private_data, struct init_child_state);
	const char *dcname = "";

	DEBUG(10, ("Received getdcname response\n"));

	if (success && (state->response->result == WINBINDD_OK)) {
		dcname = state->response->data.dc_name;
	}

	state->request->cmd = WINBINDD_INIT_CONNECTION;
	fstrcpy(state->request->domain_name, state->domain->name);
	state->request->data.init_conn.is_primary = False;
	fstrcpy(state->request->data.init_conn.dcname, dcname);

	async_request(state->mem_ctx, &state->domain->child,
		      state->request, state->response,
		      init_child_recv, state);
}

static void init_child_recv(void *private_data, BOOL success)
{
	struct init_child_state *state =
		talloc_get_type_abort(private_data, struct init_child_state);

	DEBUG(5, ("Received child initialization response for domain %s\n",
		  state->domain->name));

	if ((!success) || (state->response->result != WINBINDD_OK)) {
		DEBUG(3, ("Could not init child\n"));
		state->continuation(state->private_data, False);
		talloc_destroy(state->mem_ctx);
		return;
	}

	fstrcpy(state->domain->name,
		state->response->data.domain_info.name);
	fstrcpy(state->domain->alt_name,
		state->response->data.domain_info.alt_name);
	string_to_sid(&state->domain->sid,
		      state->response->data.domain_info.sid);
	state->domain->native_mode =
		state->response->data.domain_info.native_mode;
	state->domain->active_directory =
		state->response->data.domain_info.active_directory;
	state->domain->sequence_number =
		state->response->data.domain_info.sequence_number;

	state->domain->initialized = 1;

	if (state->continuation != NULL)
		state->continuation(state->private_data, True);
	talloc_destroy(state->mem_ctx);
}

enum winbindd_result winbindd_dual_init_connection(struct winbindd_domain *domain,
						   struct winbindd_cli_state *state)
{
	struct in_addr ipaddr;

	/* Ensure null termination */
	state->request.domain_name
		[sizeof(state->request.domain_name)-1]='\0';
	state->request.data.init_conn.dcname
		[sizeof(state->request.data.init_conn.dcname)-1]='\0';

	if (strlen(state->request.data.init_conn.dcname) > 0) {
		fstrcpy(domain->dcname, state->request.data.init_conn.dcname);
	}

	if (strlen(domain->dcname) > 0) {
		if (!resolve_name(domain->dcname, &ipaddr, 0x20)) {
			DEBUG(2, ("Could not resolve DC name %s for domain %s\n",
				  domain->dcname, domain->name));
			return WINBINDD_ERROR;
		}

		domain->dcaddr.sin_family = PF_INET;
		putip((char *)&(domain->dcaddr.sin_addr), (char *)&ipaddr);
		domain->dcaddr.sin_port = 0;
	}

	set_dc_type_and_flags(domain);

	if (!domain->initialized) {
		DEBUG(1, ("Could not initialize domain %s\n",
			  state->request.domain_name));
		return WINBINDD_ERROR;
	}

	fstrcpy(state->response.data.domain_info.name, domain->name);
	fstrcpy(state->response.data.domain_info.alt_name, domain->alt_name);
	fstrcpy(state->response.data.domain_info.sid,
		sid_string_static(&domain->sid));
	
	state->response.data.domain_info.native_mode
		= domain->native_mode;
	state->response.data.domain_info.active_directory
		= domain->active_directory;
	state->response.data.domain_info.primary
		= domain->primary;
	state->response.data.domain_info.sequence_number =
		domain->sequence_number;

	return WINBINDD_OK;
}

/* Look up global info for the winbind daemon */
void init_domain_list(void)
{
	extern struct winbindd_methods cache_methods;
	extern struct winbindd_methods passdb_methods;
	struct winbindd_domain *domain;

	/* Free existing list */
	free_domain_list();

	/* Add ourselves as the first entry. */

	if (IS_DC) {
		domain = add_trusted_domain(get_global_sam_name(), NULL,
					    &passdb_methods,
					    get_global_sam_sid());
	} else {

		DOM_SID our_sid;

		if (!secrets_fetch_domain_sid(lp_workgroup(), &our_sid)) {
			smb_panic("Could not fetch our SID - did we join?\n");
		}
	
		domain = add_trusted_domain( lp_workgroup(), lp_realm(),
					     &cache_methods, &our_sid);
	}

	domain->primary = True;
	setup_domain_child(domain, &domain->child, NULL);

	/* Add our local SAM domains */

	domain = add_trusted_domain("BUILTIN", NULL, &passdb_methods,
				    &global_sid_Builtin);
	setup_domain_child(domain, &domain->child, NULL);

	if (!IS_DC) {
		domain = add_trusted_domain(get_global_sam_name(), NULL,
					    &passdb_methods,
					    get_global_sam_sid());
		setup_domain_child(domain, &domain->child, NULL);
	}
}

/** 
 * Given a domain name, return the struct winbindd domain info for it 
 *
 * @note Do *not* pass lp_workgroup() to this function.  domain_list
 *       may modify it's value, and free that pointer.  Instead, our local
 *       domain may be found by calling find_our_domain().
 *       directly.
 *
 *
 * @return The domain structure for the named domain, if it is working.
 */

struct winbindd_domain *find_domain_from_name_noinit(const char *domain_name)
{
	struct winbindd_domain *domain;

	/* Search through list */

	for (domain = domain_list(); domain != NULL; domain = domain->next) {
		if (strequal(domain_name, domain->name) ||
		    (domain->alt_name[0] &&
		     strequal(domain_name, domain->alt_name))) {
			return domain;
		}
	}

	/* Not found */

	return NULL;
}

struct winbindd_domain *find_domain_from_name(const char *domain_name)
{
	struct winbindd_domain *domain;

	domain = find_domain_from_name_noinit(domain_name);

	if (domain == NULL)
		return NULL;

	if (!domain->initialized)
		set_dc_type_and_flags(domain);

	return domain;
}

/* Given a domain sid, return the struct winbindd domain info for it */

struct winbindd_domain *find_domain_from_sid_noinit(const DOM_SID *sid)
{
	struct winbindd_domain *domain;

	/* Search through list */

	for (domain = domain_list(); domain != NULL; domain = domain->next) {
		if (sid_compare_domain(sid, &domain->sid) == 0)
			return domain;
	}

	/* Not found */

	return NULL;
}

/* Given a domain sid, return the struct winbindd domain info for it */