Пример #1
0
/*
 *	Store logins in the RADIUS utmp file.
 */
static rlm_rcode_t mod_accounting(void *instance, REQUEST *request)
{
	rlm_rcode_t	rcode = RLM_MODULE_OK;
	struct radutmp	ut, u;
	vp_cursor_t	cursor;
	VALUE_PAIR	*vp;
	int		status = -1;
	int		protocol = -1;
	time_t		t;
	int		fd = -1;
	int		port_seen = 0;
	int		off;
	rlm_radutmp_t	*inst = instance;
	char		ip_name[32]; /* 255.255.255.255 */
	char const	*nas;
	NAS_PORT	*cache;
	int		r;
	
	char		*filename = NULL;
	char		*expanded = NULL;

	if (request->packet->src_ipaddr.af != AF_INET) {
		DEBUG("rlm_radutmp: IPv6 not supported!");
		return RLM_MODULE_NOOP;
	}

	/*
	 *	Which type is this.
	 */
	if ((vp = pairfind(request->packet->vps, PW_ACCT_STATUS_TYPE, 0, TAG_ANY)) == NULL) {
		RDEBUG("No Accounting-Status-Type record.");
		return RLM_MODULE_NOOP;
	}
	status = vp->vp_integer;

	/*
	 *	Look for weird reboot packets.
	 *
	 *	ComOS (up to and including 3.5.1b20) does not send
	 *	standard PW_STATUS_ACCOUNTING_XXX messages.
	 *
	 *	Check for:  o no Acct-Session-Time, or time of 0
	 *		    o Acct-Session-Id of "00000000".
	 *
	 *	We could also check for NAS-Port, that attribute
	 *	should NOT be present (but we don't right now).
	 */
	if ((status != PW_STATUS_ACCOUNTING_ON) &&
	    (status != PW_STATUS_ACCOUNTING_OFF)) do {
		int check1 = 0;
		int check2 = 0;

		if ((vp = pairfind(request->packet->vps, PW_ACCT_SESSION_TIME, 0, TAG_ANY))
		     == NULL || vp->vp_date == 0)
			check1 = 1;
		if ((vp = pairfind(request->packet->vps, PW_ACCT_SESSION_ID, 0, TAG_ANY))
		     != NULL && vp->length == 8 &&
		     memcmp(vp->vp_strvalue, "00000000", 8) == 0)
			check2 = 1;
		if (check1 == 0 || check2 == 0) {
			break;
		}
		INFO("rlm_radutmp: converting reboot records.");
		if (status == PW_STATUS_STOP)
			status = PW_STATUS_ACCOUNTING_OFF;
		if (status == PW_STATUS_START)
			status = PW_STATUS_ACCOUNTING_ON;
	} while(0);

	time(&t);
	memset(&ut, 0, sizeof(ut));
	ut.porttype = 'A';
	ut.nas_address = htonl(INADDR_NONE);

	/*
	 *	First, find the interesting attributes.
	 */
	for (vp = paircursor(&cursor, &request->packet->vps);
	     vp;
	     vp = pairnext(&cursor)) {
		if (!vp->da->vendor) switch (vp->da->attr) {
			case PW_LOGIN_IP_HOST:
			case PW_FRAMED_IP_ADDRESS:
				ut.framed_address = vp->vp_ipaddr;
				break;
			case PW_FRAMED_PROTOCOL:
				protocol = vp->vp_integer;
				break;
			case PW_NAS_IP_ADDRESS:
				ut.nas_address = vp->vp_ipaddr;
				break;
			case PW_NAS_PORT:
				ut.nas_port = vp->vp_integer;
				port_seen = 1;
				break;
			case PW_ACCT_DELAY_TIME:
				ut.delay = vp->vp_integer;
				break;
			case PW_ACCT_SESSION_ID:
				/*
				 *	If length > 8, only store the
				 *	last 8 bytes.
				 */
				off = vp->length - sizeof(ut.session_id);
				/*
				 * 	Ascend is br0ken - it adds a \0
				 * 	to the end of any string.
				 * 	Compensate.
				 */
				if (vp->length > 0 &&
				    vp->vp_strvalue[vp->length - 1] == 0)
					off--;
				if (off < 0) off = 0;
				memcpy(ut.session_id, vp->vp_strvalue + off,
					sizeof(ut.session_id));
				break;
			case PW_NAS_PORT_TYPE:
				if (vp->vp_integer <= 4)
					ut.porttype = porttypes[vp->vp_integer];
				break;
			case PW_CALLING_STATION_ID:
				if(inst->caller_id_ok)
					strlcpy(ut.caller_id,
						vp->vp_strvalue,
						sizeof(ut.caller_id));
				break;
		}
	}

	/*
	 *	If we didn't find out the NAS address, use the
	 *	originator's IP address.
	 */
	if (ut.nas_address == htonl(INADDR_NONE)) {
		ut.nas_address = request->packet->src_ipaddr.ipaddr.ip4addr.s_addr;
		nas = request->client->shortname;

	} else if (request->packet->src_ipaddr.ipaddr.ip4addr.s_addr == ut.nas_address) {		/* might be a client, might not be. */
		nas = request->client->shortname;

	} else {
		/*
		 *	The NAS isn't a client, it's behind
		 *	a proxy server.  In that case, just
		 *	get the IP address.
		 */
		nas = ip_ntoa(ip_name, ut.nas_address);
	}

	/*
	 *	Set the protocol field.
	 */
	if (protocol == PW_PPP) {
		ut.proto = 'P';
	} else if (protocol == PW_SLIP) {
		ut.proto = 'S';
	} else {
		ut.proto = 'T';
	}
	
	ut.time = t - ut.delay;

	/*
	 *	Get the utmp filename, via xlat.
	 */
	filename = NULL;
	if (radius_axlat(&filename, request, inst->filename, NULL, NULL) < 0) {
		return RLM_MODULE_FAIL;
	}

	/*
	 *	See if this was a reboot.
	 *
	 *	Hmm... we may not want to zap all of the users when the NAS comes up, because of issues with receiving
	 *	UDP packets out of order.
	 */
	if (status == PW_STATUS_ACCOUNTING_ON && (ut.nas_address != htonl(INADDR_NONE))) {
		RIDEBUG("NAS %s restarted (Accounting-On packet seen)", nas);
		rcode = radutmp_zap(request, filename, ut.nas_address, ut.time);
		
		goto finish;
	}

	if (status == PW_STATUS_ACCOUNTING_OFF && (ut.nas_address != htonl(INADDR_NONE))) {
		RIDEBUG("NAS %s rebooted (Accounting-Off packet seen)", nas);	
		rcode = radutmp_zap(request, filename, ut.nas_address, ut.time);
		
		goto finish;
	}

	/*
	 *	If we don't know this type of entry pretend we succeeded.
	 */
	if (status != PW_STATUS_START && status != PW_STATUS_STOP && status != PW_STATUS_ALIVE) {
		REDEBUG("NAS %s port %u unknown packet type %d)", nas, ut.nas_port, status);
		rcode = RLM_MODULE_NOOP;
		
		goto finish;
	}

	/*
	 *	Translate the User-Name attribute, or whatever else they told us to use.
	 */
	if (radius_axlat(&expanded, request, inst->username, NULL, NULL) < 0) {
		rcode = RLM_MODULE_FAIL;
		
		goto finish;
	}
	strlcpy(ut.login, expanded, RUT_NAMESIZE);
	TALLOC_FREE(expanded);

	/*
	 *	Perhaps we don't want to store this record into
	 *	radutmp. We skip records:
	 *
	 *	- without a NAS-Port (telnet / tcp access)
	 *	- with the username "!root" (console admin login)
	 */
	if (!port_seen) {
		RWDEBUG2("No NAS-Port seen.  Cannot do anything. Checkrad will probably not work!");
		rcode = RLM_MODULE_NOOP;
		
		goto finish;
	}

	if (strncmp(ut.login, "!root", RUT_NAMESIZE) == 0) {
		RDEBUG2("Not recording administrative user");
		rcode = RLM_MODULE_NOOP;
		
		goto finish;
	}

	/*
	 *	Enter into the radutmp file.
	 */
	fd = open(filename, O_RDWR|O_CREAT, inst->permission);
	if (fd < 0) {
		REDEBUG("Error accessing file %s: %s", filename, strerror(errno));
		rcode = RLM_MODULE_FAIL;
	
		goto finish;
	}

	/*
	 *	Lock the utmp file, prefer lockf() over flock().
	 */
	rad_lockfd(fd, LOCK_LEN);

	/*
	 *	Find the entry for this NAS / portno combination.
	 */
	if ((cache = nas_port_find(inst->nas_port_list, ut.nas_address, ut.nas_port)) != NULL) {
		lseek(fd, (off_t)cache->offset, SEEK_SET);
	}

	r = 0;
	off = 0;
	while (read(fd, &u, sizeof(u)) == sizeof(u)) {
		off += sizeof(u);
		if ((u.nas_address != ut.nas_address) || (u.nas_port != ut.nas_port)) {
			continue;
		}

		/*
		 *	Don't compare stop records to unused entries.
		 */
		if (status == PW_STATUS_STOP && u.type == P_IDLE) {
			continue;
		}

		if ((status == PW_STATUS_STOP) && strncmp(ut.session_id, u.session_id, sizeof(u.session_id)) != 0) {
			/*
			 *	Don't complain if this is not a
			 *	login record (some clients can
			 *	send _only_ logout records).
			 */
			if (u.type == P_LOGIN) {
				RWDEBUG("Logout entry for NAS %s port %u has wrong ID", nas, u.nas_port);
			}
			
			r = -1;
			break;
		}

		if ((status == PW_STATUS_START) && strncmp(ut.session_id, u.session_id, sizeof(u.session_id)) == 0  &&
		    u.time >= ut.time) {
			if (u.type == P_LOGIN) {
				INFO("rlm_radutmp: Login entry for NAS %s port %u duplicate",
				       nas, u.nas_port);
				r = -1;
				break;
			}
			
			RWDEBUG("Login entry for NAS %s port %u wrong order", nas, u.nas_port);
			r = -1;
			break;
		}

		/*
		 *	FIXME: the ALIVE record could need some more checking, but anyway I'd
		 *	rather rewrite this mess -- miquels.
		 */
		if ((status == PW_STATUS_ALIVE) && strncmp(ut.session_id, u.session_id, sizeof(u.session_id)) == 0  &&
		    u.type == P_LOGIN) {
			/*
			 *	Keep the original login time.
			 */
			ut.time = u.time;
		}

		if (lseek(fd, -(off_t)sizeof(u), SEEK_CUR) < 0) {
			RWDEBUG("negative lseek!");
			lseek(fd, (off_t)0, SEEK_SET);
			off = 0;
		} else {
			off -= sizeof(u);
		}
		
		r = 1;
		break;
	} /* read the file until we find a match */

	/*
	 *	Found the entry, do start/update it with
	 *	the information from the packet.
	 */
	if ((r >= 0) && (status == PW_STATUS_START || status == PW_STATUS_ALIVE)) {
		/*
		 *	Remember where the entry was, because it's
		 *	easier than searching through the entire file.
		 */
		if (!cache) {
			cache = talloc_zero(inst, NAS_PORT);
			if (cache) {
				cache->nasaddr = ut.nas_address;
				cache->port = ut.nas_port;
				cache->offset = off;
				cache->next = inst->nas_port_list;
				inst->nas_port_list = cache;
			}
		}

		ut.type = P_LOGIN;
		if (write(fd, &ut, sizeof(u)) < 0) {
			REDEBUG("Failed writing: %s", strerror(errno));
			
			rcode = RLM_MODULE_FAIL;
			goto finish;
		}
	}

	/*
	 *	The user has logged off, delete the entry by
	 *	re-writing it in place.
	 */
	if (status == PW_STATUS_STOP) {
		if (r > 0) {
			u.type = P_IDLE;
			u.time = ut.time;
			u.delay = ut.delay;
			if (write(fd, &u, sizeof(u)) < 0) {
				REDEBUG("Failed writing: %s", strerror(errno));
			
				rcode = RLM_MODULE_FAIL;
				goto finish;
			}
		} else if (r == 0) {
			RWDEBUG("Logout for NAS %s port %u, but no Login record", nas, ut.nas_port);
		}
	}

	finish:
	
	talloc_free(filename);
	
	if (fd > -1) {
		close(fd);	/* and implicitely release the locks */
	}
	
	return rcode;
}
Пример #2
0
/*
 *	Store logins in the RADIUS utmp file.
 */
static rlm_rcode_t radutmp_accounting(void *instance, REQUEST *request)
{
	rlm_radutmp_t	*inst = instance;
	struct radutmp	utmp, u;
	VALUE_PAIR	*vp;
	int		status = -1;
	uint32_t	nas_address = 0;
	uint32_t	framed_address = 0;
	int		protocol = -1;
	int		fd;
	int		port_seen = 0;
	char		buffer[256];
	char		filename[1024];
	char		ip_name[32]; /* 255.255.255.255 */
	const char	*nas;
	NAS_PORT	*nas_port, myPort;
	radutmp_cache_t *cache;
	int		read_size;
	rbnode_t	*node;

	/*
	 *	Which type is this.
	 */
	if ((vp = pairfind(request->packet->vps, PW_ACCT_STATUS_TYPE, 0, TAG_ANY)) == NULL) {
		radlog(L_ERR, "rlm_radutmp: No Accounting-Status-Type record.");
		return RLM_MODULE_NOOP;
	}
	status = vp->vp_integer;

	/*
	 *	Look for weird reboot packets.
	 *
	 *	ComOS (up to and including 3.5.1b20) does not send
	 *	standard PW_STATUS_ACCOUNTING_* messages.
	 *
	 *	Check for:  o no Acct-Session-Time, or time of 0
	 *		    o Acct-Session-Id of "00000000".
	 *
	 *	We could also check for NAS-Port, that attribute
	 *	should NOT be present (but we don't right now).
	 */
	if ((status != PW_STATUS_ACCOUNTING_ON) &&
	    (status != PW_STATUS_ACCOUNTING_OFF)) do {
		int check1 = 0;
		int check2 = 0;

		if ((vp = pairfind(request->packet->vps, PW_ACCT_SESSION_TIME, 0, TAG_ANY))
		     == NULL || vp->vp_date == 0)
			check1 = 1;
		if ((vp = pairfind(request->packet->vps, PW_ACCT_SESSION_ID, 0, TAG_ANY))
		     != NULL && vp->length == 8 &&
		     memcmp(vp->vp_strvalue, "00000000", 8) == 0)
			check2 = 1;
		if (check1 == 0 || check2 == 0) {
#if 0 /* Cisco sometimes sends START records without username. */
			radlog(L_ERR, "rlm_radutmp: no username in record");
			return RLM_MODULE_FAIL;
#else
			break;
#endif
		}
		radlog(L_INFO, "rlm_radutmp: converting reboot records.");
		if (status == PW_STATUS_STOP)
			status = PW_STATUS_ACCOUNTING_OFF;
		if (status == PW_STATUS_START)
			status = PW_STATUS_ACCOUNTING_ON;
	} while(0);

	memset(&utmp, 0, sizeof(utmp));
	utmp.porttype = 'A';

	/*
	 *	First, find the interesting attributes.
	 */
	for (vp = request->packet->vps; vp; vp = vp->next) {
		switch (vp->da->attribute) {
			case PW_LOGIN_IP_HOST:
			case PW_FRAMED_IP_ADDRESS:
				framed_address = vp->vp_ipaddr;
				utmp.framed_address = vp->vp_ipaddr;
				break;
			case PW_FRAMED_PROTOCOL:
				protocol = vp->vp_integer;
				break;
			case PW_NAS_IP_ADDRESS:
				nas_address = vp->vp_ipaddr;
				utmp.nas_address = vp->vp_ipaddr;
				break;
			case PW_NAS_PORT:
				utmp.nas_port = vp->vp_integer;
				port_seen = 1;
				break;
			case PW_ACCT_DELAY_TIME:
				utmp.delay = vp->vp_integer;
				break;
			case PW_ACCT_SESSION_ID:
				/*
				 *	If it's too big, only use the
				 *	last bit.
				 */
				if (vp->length > sizeof(utmp.session_id)) {
					int length = vp->length - sizeof(utmp.session_id);

					/*
					 * 	Ascend is br0ken - it
					 * 	adds a \0 to the end
					 * 	of any string.
					 * 	Compensate.
					 */
					if (vp->vp_strvalue[vp->length - 1] == 0) {
						length--;
					}

					memcpy(utmp.session_id,
					      vp->vp_strvalue + length,
					      sizeof(utmp.session_id));
				} else {
					memset(utmp.session_id, 0,
					       sizeof(utmp.session_id));
					memcpy(utmp.session_id,
					       vp->vp_strvalue,
					       vp->length);
				}
				break;
			case PW_NAS_PORT_TYPE:
				if (vp->vp_integer <= 4)
					utmp.porttype = porttypes[vp->vp_integer];
				break;
			case PW_CALLING_STATION_ID:
				if(inst->callerid_ok)
					strlcpy(utmp.caller_id,
						(char *)vp->vp_strvalue,
						sizeof(utmp.caller_id));
				break;
		}
	}

	/*
	 *	If we didn't find out the NAS address, use the
	 *	originator's IP address.
	 */
	if (nas_address == 0) {
		nas_address = request->packet->src_ipaddr;
		utmp.nas_address = nas_address;
		nas = request->client->shortname;

	} else if (request->packet->src_ipaddr.ipaddr.ip4addr.s_addr == nas_address) {		/* might be a client, might not be. */
		nas = request->client->shortname;

	} else {
		/*
		 *	The NAS isn't a client, it's behind
		 *	a proxy server.  In that case, just
		 *	get the IP address.
		 */
		nas = ip_ntoa(ip_name, nas_address);
	}


	/*
	 *	Set the protocol field.
	 */
	if (protocol == PW_PPP)
		utmp.proto = 'P';
	else if (protocol == PW_SLIP)
		utmp.proto = 'S';
	else
		utmp.proto = 'T';

	utmp.time = request->timestamp - utmp.delay;

	/*
	 *	Get the utmp filename, via xlat.
	 */
	radius_xlat(filename, sizeof(filename), inst->filename, request, NULL);

	/*
	 *	Future: look up filename in filename tree, to get
	 *	radutmp_cache_t pointer
	 */
	cache = &inst->cache;

	/*
	 *	For now, double-check the filename, to be sure it isn't
	 *	changing.
	 */
	if (!cache->filename) {
		cache->filename = strdup(filename);
		rad_assert(cache->filename != NULL);

	} else if (strcmp(cache->filename, filename) != 0) {
		radlog(L_ERR, "rlm_radutmp: We do not support dynamically named files.");
		return RLM_MODULE_FAIL;
	}

	/*
	 *	If the lookup failed, create a new one, and add it
	 *	to the filename tree, and cache the file, as below.
	 */

	/*
	 *	For aging, in the future.
	 */
	cache->last_used = request->timestamp;

	/*
	 *	If we haven't already read the file, then read the
	 *	entire file, in order to cache its entries.
	 */
	if (!cache->cached_file) {
		cache_file(inst, cache);
	}

	/*
	 *	See if this was a reboot.
	 *
	 *	Hmm... we may not want to zap all of the users when
	 *	the NAS comes up, because of issues with receiving
	 *	UDP packets out of order.
	 */
	if (status == PW_STATUS_ACCOUNTING_ON && nas_address) {
		radlog(L_INFO, "rlm_radutmp: NAS %s restarted (Accounting-On packet seen)",
		       nas);
		if (!radutmp_zap(inst, cache, nas_address, utmp.time)) {
			rad_assert(0 == 1);
		}
		return RLM_MODULE_OK;
	}

	if (status == PW_STATUS_ACCOUNTING_OFF && nas_address) {
		radlog(L_INFO, "rlm_radutmp: NAS %s rebooted (Accounting-Off packet seen)",
		       nas);
		if (!radutmp_zap(inst, cache, nas_address, utmp.time)) {
			rad_assert(0 == 1);
		}
		return RLM_MODULE_OK;
	}

	/*
	 *	If we don't know this type of entry, then pretend we
	 *	succeeded.
	 */
	if (status != PW_STATUS_START &&
	    status != PW_STATUS_STOP &&
	    status != PW_STATUS_ALIVE) {
		radlog(L_ERR, "rlm_radutmp: NAS %s port %u unknown packet type %d, ignoring it.",
		       nas, utmp.nas_port, status);
		return RLM_MODULE_NOOP;
	}

	/*
	 *	Perhaps we don't want to store this record into
	 *	radutmp. We skip records:
	 *
	 *	- without a NAS-Port (telnet / tcp access)
	 *	- with the username "!root" (console admin login)
	 */
	if (!port_seen) {
		DEBUG2("  rlm_radutmp: No NAS-Port in the packet.  Cannot do anything.");
		DEBUG2("  rlm_radumtp: WARNING: checkrad will probably not work!");
		return RLM_MODULE_NOOP;
	}

	/*
	 *	Translate the User-Name attribute, or whatever else
	 *	they told us to use.
	 */
	*buffer = '\0';
	radius_xlat(buffer, sizeof(buffer), inst->username, request, NULL);

	/*
	 *	Don't log certain things...
	 */
	if (strcmp(buffer, "!root") == 0) {
		DEBUG2("  rlm_radutmp: Not recording administrative user");

		return RLM_MODULE_NOOP;
	}
	strlcpy(utmp.login, buffer, RUT_NAMESIZE);

	/*
	 *	First, try to open the file.  If it doesn't exist,
	 *	nuke the existing caches, and try to create it.
	 *
	 *	FIXME: Create any intermediate directories, as
	 *	appropriate.  See rlm_detail.
	 */
	fd = open(cache->filename, O_RDWR, inst->permission);
	if (fd < 0) {
		if (errno == ENOENT) {
			DEBUG2("  rlm_radutmp: File %s doesn't exist, creating it.", cache->filename);
			if (!cache_reset(inst, cache)) return RLM_MODULE_FAIL;

			/*
			 *	Try to create the file.
			 */
			fd = open(cache->filename, O_RDWR | O_CREAT,
				  inst->permission);
		}
	} else {		/* exists, but may be empty */
		struct stat buf;

		/*
		 *	If the file is empty, reset the cache.
		 */
		if ((stat(cache->filename, &buf) == 0) &&
		    (buf.st_size == 0) &&
		    (!cache_reset(inst, cache))) {
			return RLM_MODULE_FAIL;
		}
		DEBUG2("  rlm_radutmp: File %s was truncated.  Resetting cache.",
		       cache->filename);
	}

	/*
	 *	Error from creation, or error other than ENOENT: die.
	 */
	if (fd < 0) {
		radlog(L_ERR, "rlm_radutmp: Error accessing file %s: %s",
		       cache->filename, strerror(errno));
		return RLM_MODULE_FAIL;
	}

	/*
	 *	OK.  Now that we've prepared everything we want to do,
	 *	let's see if we've cached the entry.
	 */
	myPort.nas_address = utmp.nas_address;
	myPort.nas_port = utmp.nas_port;

	pthread_mutex_lock(&cache->mutex);
	node = rbtree_find(cache->nas_ports, &myPort);
	pthread_mutex_unlock(&cache->mutex);

	if (node) {
		nas_port = rbtree_node2data(cache->nas_ports, node);
#if 0

		/*
		 *	stat the file, and get excited if it's been
		 *	truncated.
		 *
		 *	i.e wipe out the cache, and re-read the file.
		 */

		/*
		 *	Now find the new entry.
		 */
		pthread_mutex_lock(&cache->mutex);
		node = rbtree_find(cache->nas_ports, &myPort);
		pthread_mutex_unlock(&cache->mutex);
#endif
	}

	if (!node) {
		radutmp_simul_t *user;

		/*
		 *	Not found in the cache, and we're trying to
		 *	delete an existing record: ignore it.
		 */
		if (status == PW_STATUS_STOP) {
			DEBUG2("  rlm_radumtp: Logout entry for NAS %s port %u with no Login: ignoring it.",
			       nas, utmp.nas_port);
			return RLM_MODULE_NOOP;
		}

		pthread_mutex_lock(&cache->mutex);

		/*
		 *	It's a START or ALIVE.  Try to find a free
		 *	offset where we can store the new entry, or
		 *	create one, if one doesn't already exist.
		 */
		if (!cache->free_offsets) {
			cache->free_offsets = rad_malloc(sizeof(NAS_PORT));
			memset(cache->free_offsets, 0,
			       sizeof(*(cache->free_offsets)));
			cache->free_offsets->offset = cache->max_offset;
			cache->max_offset += sizeof(u);
		}

		/*
		 *	Grab the offset, and put it into the various
		 *	caches.
		 */
		nas_port = cache->free_offsets;
		cache->free_offsets = nas_port->next;

		nas_port->nas_address = nas_address;
		nas_port->nas_port = utmp.nas_port;

		if (!rbtree_insert(cache->nas_ports, nas_port)) {
			rad_assert(0 == 1);
		}

		/*
		 *	Allocate new entry, and add it
		 *	to the tree.
		 */
		user = rad_malloc(sizeof(user));
		strlcpy(user->login, utmp.login,
			sizeof(user->login));
		user->simul_count = 1;

		if (!rbtree_insert(inst->user_tree, user)) {
			rad_assert(0 == 1);
		}

		pthread_mutex_unlock(&cache->mutex);

	}

	/*
	 *	Entry was found, or newly created in the cache.
	 *	Seek to the place in the file.
	 */
	lseek(fd, nas_port->offset, SEEK_SET);

	/*
	 *	Lock the utmp file, prefer lockf() over flock().
	 */
	rad_lockfd(fd, LOCK_LEN);

	/*
	 *	If it WAS found in the cache, double-check it against
	 *	what is in the file.
	 */
	if (node) {
		/*
		 *	If we didn't read anything, then this entry
		 *	doesn't exist.
		 *
		 *	Similarly, if the entry in the file doesn't
		 *	match what we recall, then nuke the cache
		 *	entry.
		 */
		read_size = read(fd, &u, sizeof(u));
		if ((read_size < 0) ||
		    ((read_size > 0) && (read_size  != sizeof(u)))) {
			/*
			 *	Bad read, or bad record.
			 */
			radlog(L_ERR, "rlm_radutmp: Badly formed file %s",
			       cache->filename);
			close(fd);
			return RLM_MODULE_FAIL;
		}

		rad_assert(read_size != 0);

		/*
		 *	We've read a record, go poke at it.
		 */
		if (read_size > 0) {
			/*
			 *	If these aren't true, then
			 *
			 *	a) we have cached a "logout" entry,
			 *	   which we don't do.
			 *
			 *	b) we have cached the wrong NAS address
			 *
			 *	c) we have cached the wrong NAS port.
			 */
			rad_assert(u.type == P_LOGIN);
			rad_assert(u.nas_address == utmp.nas_address);
			rad_assert(u.nas_port == utmp.nas_port);

			/*
			 *	An update for the same session.
			 */
			if (strncmp(utmp.session_id, u.session_id,
				    sizeof(u.session_id)) == 0) {

				/*
				 *	It's a duplicate start, so we
				 *	don't bother writing it.
				 */
				if (status == PW_STATUS_START) {
					DEBUG2("  rlm_radutmp: Login entry for NAS %s port %u duplicate, ignoring it.",
					       nas, u.nas_port);
					close(fd);
					return RLM_MODULE_OK;


				/*
				 *	ALIVE for this session, keep the
				 *	original login time.
				 */
				} else if (status == PW_STATUS_ALIVE) {
					utmp.time = u.time;

				/*
				 *	Stop: delete it from our cache.
				 */
				} else if (status == PW_STATUS_STOP) {
					radutmp_simul_t *user, myUser;

					pthread_mutex_lock(&cache->mutex);
					rbtree_deletebydata(cache->nas_ports,
							    nas_port);

					strlcpy(myUser.login,
						u.login, sizeof(myUser.login));
					user = rbtree_finddata(inst->user_tree,
							       &myUser);
					rad_assert(user != NULL);
					rad_assert(user->simul_count > 0);

					user->simul_count--;
					if (user->simul_count == 0) {
						rbtree_deletebydata(inst->user_tree, user);
					}

					pthread_mutex_unlock(&cache->mutex);

 				} else {
					/*
					 *	We don't know how to
					 *	handle this.
					 */
					rad_assert(0 == 1);
				}

			} else { /* session ID doesn't match */
				/*
				 *	STOP for the right NAS & port,
				 *	but the Acct-Session-Id is
				 *	different.  This means that
				 *	we missed the original "stop",
				 *	and a new "start".
				 */
				if (status == PW_STATUS_STOP) {
					radlog(L_ERR, "rlm_radutmp: Logout entry for NAS %s port %u has old Acct-Session-ID, ignoring it.",
					       nas, u.nas_port);
					close(fd);
					return RLM_MODULE_OK;
				}
			} /* checked session ID's */
		}  /* else we haven't read anything from the file. */
	} /* else the entry wasn't cached, but could have been inserted */

	/*
	 *	Hmm... we may have received a start or alive packet
	 *	AFTER a stop or nas-down, in that case, we want to
	 *	discard the new packet.  However, the original code
	 *	could over-write an idle record with a new login
	 *	record for another NAS && port, so we won't worry
	 *	about this case too much.
	 */

	/*
	 *	Seek to where the entry is, and write it blindly.
	 */
	lseek(fd, nas_port->offset, SEEK_SET); /* FIXME: err */

	if (status != PW_STATUS_STOP) {
		utmp.type = P_LOGIN;
		rad_assert(nas_port != NULL); /* it WAS cached */
	} else {
		/* FIXME: maybe assert that the entry was deleted... */
		memcpy(&utmp, &u, sizeof(utmp));
		utmp.type = P_IDLE;
	}

	write(fd, &utmp, sizeof(utmp)); /* FIXME: err */

	close(fd);	/* and implicitly release the locks */

	return RLM_MODULE_OK;
}