1/*	$NetBSD: ip_log.c,v 1.14 2010/08/11 11:57:36 pgoyette Exp $	*/
2
3/*
4 * Copyright (C) 1997-2003 by Darren Reed.
5 *
6 * See the IPFILTER.LICENCE file for details on licencing.
7 *
8 * Id: ip_log.c,v 2.75.2.25 2009/07/22 01:46:43 darrenr Exp
9 */
10
11#include <sys/cdefs.h>
12__KERNEL_RCSID(0, "$NetBSD: ip_log.c,v 1.14 2010/08/11 11:57:36 pgoyette Exp $");
13
14#include <sys/param.h>
15#if defined(KERNEL) || defined(_KERNEL)
16# undef KERNEL
17# undef _KERNEL
18# define        KERNEL	1
19# define        _KERNEL	1
20#endif
21#if defined(__NetBSD__) && (NetBSD >= 199905) && !defined(IPFILTER_LKM) && \
22    defined(_KERNEL)
23# if (__NetBSD_Version__ < 399001400)
24#  include "opt_ipfilter_log.h"
25# else
26#  include "opt_ipfilter.h"
27# endif
28#endif
29#if defined(__FreeBSD__) && !defined(IPFILTER_LKM)
30# if defined(_KERNEL)
31#  if defined(__FreeBSD_version) && (__FreeBSD_version >= 300000)
32#   include "opt_ipfilter.h"
33#  endif
34# else
35#  include <osreldate.h>
36# endif
37#endif
38#ifndef SOLARIS
39# define SOLARIS (defined(sun) && (defined(__svr4__) || defined(__SVR4)))
40#endif
41#include <sys/errno.h>
42#include <sys/types.h>
43#include <sys/file.h>
44#ifndef _KERNEL
45# include <stdio.h>
46# include <string.h>
47# include <stdlib.h>
48# include <ctype.h>
49# define _KERNEL
50# define KERNEL
51# ifdef __OpenBSD__
52struct file;
53# endif
54# include <sys/uio.h>
55# undef _KERNEL
56# undef KERNEL
57#endif
58#if (defined(__FreeBSD_version) && (__FreeBSD_version >= 220000)) && \
59    defined(_KERNEL)
60# include <sys/fcntl.h>
61# include <sys/filio.h>
62#else
63# include <sys/ioctl.h>
64#endif
65#include <sys/time.h>
66#if defined(_KERNEL)
67# include <sys/systm.h>
68# if (defined(NetBSD) && (__NetBSD_Version__ >= 104000000))
69#  include <sys/proc.h>
70# endif
71#endif /* _KERNEL */
72#if !SOLARIS && !defined(__hpux) && !defined(linux)
73# if (defined(NetBSD) && (NetBSD > 199609)) || \
74     (defined(OpenBSD) && (OpenBSD > 199603)) || \
75     (defined(__FreeBSD_version) && (__FreeBSD_version >= 300000))
76#  include <sys/dirent.h>
77# else
78#  include <sys/dir.h>
79# endif
80# include <sys/mbuf.h>
81# include <sys/select.h>
82# if __FreeBSD_version >= 500000
83#  include <sys/selinfo.h>
84# endif
85#else
86# if !defined(__hpux) && defined(_KERNEL)
87#  include <sys/filio.h>
88#  include <sys/cred.h>
89#  include <sys/ddi.h>
90#  include <sys/sunddi.h>
91#  include <sys/ksynch.h>
92#  include <sys/kmem.h>
93#  include <sys/mkdev.h>
94#  include <sys/dditypes.h>
95#  include <sys/cmn_err.h>
96# endif /* !__hpux */
97#endif /* !SOLARIS && !__hpux */
98#if !defined(linux)
99# include <sys/protosw.h>
100#endif
101#include <sys/socket.h>
102
103#include <net/if.h>
104#ifdef sun
105# include <net/af.h>
106#endif
107#if __FreeBSD_version >= 300000
108# include <net/if_var.h>
109#endif
110#include <netinet/in.h>
111#ifdef __sgi
112# include <sys/ddi.h>
113# ifdef IFF_DRVRLOCK /* IRIX6 */
114#  include <sys/hashing.h>
115# endif
116#endif
117#if !defined(__hpux) && !defined(linux) && \
118    !(defined(__sgi) && !defined(IFF_DRVRLOCK)) /*IRIX<6*/
119# include <netinet/in_var.h>
120#endif
121#include <netinet/in_systm.h>
122#include <netinet/ip.h>
123#include <netinet/tcp.h>
124#include <netinet/udp.h>
125#include <netinet/ip_icmp.h>
126#ifdef USE_INET6
127# include <netinet/icmp6.h>
128#endif
129#if !defined(linux)
130# include <netinet/ip_var.h>
131#endif
132#ifndef _KERNEL
133# include <syslog.h>
134#endif
135#include "netinet/ip_compat.h"
136#include <netinet/tcpip.h>
137#include "netinet/ip_fil.h"
138#include "netinet/ip_nat.h"
139#include "netinet/ip_frag.h"
140#include "netinet/ip_state.h"
141#include "netinet/ip_auth.h"
142#if (__FreeBSD_version >= 300000) || defined(__NetBSD__)
143# include <sys/malloc.h>
144#endif
145/* END OF INCLUDES */
146
147#ifdef	IPFILTER_LOG
148
149# if defined(IPL_SELECT)
150#  include	<machine/sys/user.h>
151#  include	<sys/kthread_iface.h>
152#  define	READ_COLLISION	0x001
153
154iplog_select_t	iplog_ss[IPL_LOGSIZE];
155
156extern int selwait;
157# endif /* IPL_SELECT */
158
159# if defined(linux) && defined(_KERNEL)
160wait_queue_head_t	iplh_linux[IPL_LOGSIZE];
161# endif
162# if SOLARIS && defined(_KERNEL)
163extern	kcondvar_t	iplwait;
164extern	struct pollhead	iplpollhead[IPL_LOGSIZE];
165# endif
166
167iplog_t	**iplh[IPL_LOGSIZE], *iplt[IPL_LOGSIZE], *ipll[IPL_LOGSIZE];
168int	iplused[IPL_LOGSIZE];
169static fr_info_t	iplcrc[IPL_LOGSIZE];
170int	ipl_suppress = 1;
171int	ipl_logmax = IPL_LOGMAX;
172int	ipl_logall = 0;
173int	ipl_log_init = 0;
174int	ipl_logsize = IPFILTER_LOGSIZE;
175int	ipl_magic[IPL_LOGSIZE] = { IPL_MAGIC, IPL_MAGIC_NAT, IPL_MAGIC_STATE,
176				   IPL_MAGIC, IPL_MAGIC, IPL_MAGIC,
177				   IPL_MAGIC, IPL_MAGIC };
178
179
180/* ------------------------------------------------------------------------ */
181/* Function:    fr_loginit                                                  */
182/* Returns:     int - 0 == success (always returned)                        */
183/* Parameters:  Nil                                                         */
184/*                                                                          */
185/* Initialise log buffers & pointers.  Also iniialised the CRC to a local   */
186/* secret for use in calculating the "last log checksum".                   */
187/* ------------------------------------------------------------------------ */
188int
189fr_loginit(void)
190{
191	int	i;
192
193	for (i = IPL_LOGMAX; i >= 0; i--) {
194		iplt[i] = NULL;
195		ipll[i] = NULL;
196		iplh[i] = &iplt[i];
197		iplused[i] = 0;
198		bzero((char *)&iplcrc[i], sizeof(iplcrc[i]));
199# ifdef	IPL_SELECT
200		iplog_ss[i].read_waiter = 0;
201		iplog_ss[i].state = 0;
202# endif
203# if defined(linux) && defined(_KERNEL)
204		init_waitqueue_head(iplh_linux + i);
205# endif
206	}
207
208# if SOLARIS && defined(_KERNEL)
209	cv_init(&iplwait, "ipl condvar", CV_DRIVER, NULL);
210# endif
211	MUTEX_INIT(&ipl_mutex, "ipf log mutex");
212
213	ipl_log_init = 1;
214
215	return 0;
216}
217
218
219/* ------------------------------------------------------------------------ */
220/* Function:    fr_logunload                                                */
221/* Returns:     Nil                                                         */
222/* Parameters:  Nil                                                         */
223/*                                                                          */
224/* Clean up any log data that has accumulated without being read.           */
225/* ------------------------------------------------------------------------ */
226void
227fr_logunload(void)
228{
229	int i;
230
231	if (ipl_log_init == 0)
232		return;
233
234	for (i = IPL_LOGMAX; i >= 0; i--)
235		(void) ipflog_clear(i);
236
237# if SOLARIS && defined(_KERNEL)
238	cv_destroy(&iplwait);
239# endif
240	MUTEX_DESTROY(&ipl_mutex);
241
242	ipl_log_init = 0;
243}
244
245
246/* ------------------------------------------------------------------------ */
247/* Function:    ipflog                                                      */
248/* Returns:     int - 0 == success, -1 == failure                           */
249/* Parameters:  fin(I)   - pointer to packet information                    */
250/*              flags(I) - flags from filter rules                          */
251/*                                                                          */
252/* Create a log record for a packet given that it has been triggered by a   */
253/* rule (or the default setting).  Calculate the transport protocol header  */
254/* size using predetermined size of a couple of popular protocols and thus  */
255/* how much data to copy into the log, including part of the data body if   */
256/* requested.                                                               */
257/* ------------------------------------------------------------------------ */
258int
259ipflog(fr_info_t *fin, u_int flags)
260{
261	register size_t hlen;
262	int types[2], mlen;
263	size_t sizes[2];
264	void *ptrs[2];
265	ipflog_t ipfl;
266	u_char p;
267	mb_t *m;
268# if (SOLARIS || defined(__hpux)) && defined(_KERNEL) && \
269  !defined(_INET_IP_STACK_H)
270	qif_t *ifp;
271# else
272	struct ifnet *ifp;
273# endif /* SOLARIS || __hpux */
274
275	m = fin->fin_m;
276	if (m == NULL)
277		return -1;
278
279	ipfl.fl_nattag.ipt_num[0] = 0;
280	ifp = fin->fin_ifp;
281	if (fin->fin_exthdr != NULL)
282		hlen = (char *)fin->fin_dp - (char *)fin->fin_ip;
283	else
284		hlen = fin->fin_hlen;
285	/*
286	 * calculate header size.
287	 */
288	if (fin->fin_off == 0) {
289		p = fin->fin_fi.fi_p;
290		if (p == IPPROTO_TCP)
291			hlen += MIN(sizeof(tcphdr_t), fin->fin_dlen);
292		else if (p == IPPROTO_UDP)
293			hlen += MIN(sizeof(udphdr_t), fin->fin_dlen);
294		else if (p == IPPROTO_ICMP) {
295			struct icmp *icmp;
296
297			icmp = (struct icmp *)fin->fin_dp;
298
299			/*
300			 * For ICMP, if the packet is an error packet, also
301			 * include the information about the packet which
302			 * caused the error.
303			 */
304			switch (icmp->icmp_type)
305			{
306			case ICMP_UNREACH :
307			case ICMP_SOURCEQUENCH :
308			case ICMP_REDIRECT :
309			case ICMP_TIMXCEED :
310			case ICMP_PARAMPROB :
311				hlen += MIN(sizeof(struct icmp) + 8,
312					    fin->fin_dlen);
313				break;
314			default :
315				hlen += MIN(sizeof(struct icmp),
316					    fin->fin_dlen);
317				break;
318			}
319		}
320# ifdef USE_INET6
321		else if (p == IPPROTO_ICMPV6) {
322			struct icmp6_hdr *icmp;
323
324			icmp = (struct icmp6_hdr *)fin->fin_dp;
325
326			/*
327			 * For ICMPV6, if the packet is an error packet, also
328			 * include the information about the packet which
329			 * caused the error.
330			 */
331			if (icmp->icmp6_type < 128) {
332				hlen += MIN(sizeof(struct icmp6_hdr) + 8,
333					    fin->fin_dlen);
334			} else {
335				hlen += MIN(sizeof(struct icmp6_hdr),
336					    fin->fin_dlen);
337			}
338		}
339# endif
340	}
341	/*
342	 * Get the interface number and name to which this packet is
343	 * currently associated.
344	 */
345# if (SOLARIS || defined(__hpux)) && defined(_KERNEL) && \
346     !defined(_INET_IP_STACK_H)
347	ipfl.fl_unit = (u_int)ifp->qf_ppa;
348	COPYIFNAME(fin->fin_v, ifp, ipfl.fl_ifname);
349# else
350#  if (defined(NetBSD) && (NetBSD <= 1991011) && (NetBSD >= 199603)) || \
351      (defined(OpenBSD) && (OpenBSD >= 199603)) || defined(linux) || \
352      (defined(__FreeBSD__) && (__FreeBSD_version >= 501113)) || \
353      (SOLARIS && defined(_INET_IP_STACK_H))
354	COPYIFNAME(fin->fin_v, ifp, ipfl.fl_ifname);
355#  else
356	ipfl.fl_unit = (u_int)ifp->if_unit;
357#   if defined(_KERNEL)
358	if ((ipfl.fl_ifname[0] = ifp->if_name[0]))
359		if ((ipfl.fl_ifname[1] = ifp->if_name[1]))
360			if ((ipfl.fl_ifname[2] = ifp->if_name[2]))
361				ipfl.fl_ifname[3] = ifp->if_name[3];
362#   else
363	COPYIFNAME(fin->fin_v, ifp, ipfl.fl_ifname);
364	ipfl.fl_ifname[sizeof(ipfl.fl_ifname) - 1] = '\0';
365#   endif
366#  endif
367# endif /* __hpux || SOLARIS */
368	mlen = fin->fin_plen - hlen;
369	if (!ipl_logall) {
370		mlen = (flags & FR_LOGBODY) ? MIN(mlen, 128) : 0;
371	} else if ((flags & FR_LOGBODY) == 0) {
372		mlen = 0;
373	}
374	if (mlen < 0)
375		mlen = 0;
376	ipfl.fl_plen = (u_char)mlen;
377	ipfl.fl_hlen = (u_char)hlen;
378	ipfl.fl_rule = fin->fin_rule;
379	(void) strncpy(ipfl.fl_group, fin->fin_group, FR_GROUPLEN);
380	if (fin->fin_fr != NULL) {
381		ipfl.fl_loglevel = fin->fin_fr->fr_loglevel;
382		ipfl.fl_logtag = fin->fin_fr->fr_logtag;
383	} else {
384		ipfl.fl_loglevel = 0xffff;
385		ipfl.fl_logtag = FR_NOLOGTAG;
386	}
387	if (fin->fin_nattag != NULL)
388		bcopy(fin->fin_nattag, (void *)&ipfl.fl_nattag,
389		      sizeof(ipfl.fl_nattag));
390	ipfl.fl_flags = flags;
391	ipfl.fl_dir = fin->fin_out;
392	ipfl.fl_lflags = fin->fin_flx;
393	ptrs[0] = (void *)&ipfl;
394	sizes[0] = sizeof(ipfl);
395	types[0] = 0;
396# if defined(MENTAT) && defined(_KERNEL)
397	/*
398	 * Are we copied from the mblk or an aligned array ?
399	 */
400	if (fin->fin_ip == (ip_t *)m->b_rptr) {
401		ptrs[1] = m;
402		sizes[1] = hlen + mlen;
403		types[1] = 1;
404	} else {
405		ptrs[1] = fin->fin_ip;
406		sizes[1] = hlen + mlen;
407		types[1] = 0;
408	}
409# else
410	ptrs[1] = m;
411	sizes[1] = hlen + mlen;
412	types[1] = 1;
413# endif /* MENTAT */
414	return ipllog(IPL_LOGIPF, fin, ptrs, sizes, types, 2);
415}
416
417
418/* ------------------------------------------------------------------------ */
419/* Function:    ipllog                                                      */
420/* Returns:     int - 0 == success, -1 == failure                           */
421/* Parameters:  dev(I)    - device that owns this log record                */
422/*              fin(I)    - pointer to packet information                   */
423/*              items(I)  - array of pointers to log data                   */
424/*              itemsz(I) - array of size of valid memory pointed to        */
425/*              types(I)  - type of data pointed to by items pointers       */
426/*              cnt(I)    - number of elements in arrays items/itemsz/types */
427/*                                                                          */
428/* Takes an array of parameters and constructs one record to include the    */
429/* miscellaneous packet information, as well as packet data, for reading    */
430/* from the log device.                                                     */
431/* ------------------------------------------------------------------------ */
432int
433ipllog(int dev, fr_info_t *fin, void **items, size_t *itemsz, int *types, int cnt)
434{
435	char *buf, *ptr;
436	iplog_t *ipl;
437	size_t len;
438	int i;
439	SPL_INT(s);
440
441	/*
442	 * Get the total amount of data to be logged.
443	 */
444	for (i = 0, len = sizeof(iplog_t); i < cnt; i++)
445		len += itemsz[i];
446
447	/*
448	 * check that we have space to record this information and can
449	 * allocate that much.
450	 */
451	if ((iplused[dev] + len) > ipl_logsize)
452		return -1;
453
454	KMALLOCS(buf, char *, len);
455	if (buf == NULL)
456		return -1;
457	ipl = (iplog_t *)buf;
458	ipl->ipl_magic = ipl_magic[dev];
459	ipl->ipl_count = 1;
460	ipl->ipl_next = NULL;
461	ipl->ipl_dsize = len;
462#ifdef _KERNEL
463	GETKTIME(&ipl->ipl_sec);
464#else
465	ipl->ipl_sec = 0;
466	ipl->ipl_usec = 0;
467#endif
468
469	/*
470	 * Loop through all the items to be logged, copying each one to the
471	 * buffer.  Use bcopy for normal data or the mb_t copyout routine.
472	 */
473	for (i = 0, ptr = buf + sizeof(*ipl); i < cnt; i++) {
474		if (types[i] == 0) {
475			memcpy(ptr, items[i], itemsz[i]);
476		} else if (types[i] == 1) {
477			COPYDATA(items[i], 0, itemsz[i], (char *)ptr);
478		}
479		ptr += itemsz[i];
480	}
481
482	SPL_NET(s);
483	MUTEX_ENTER(&ipl_mutex);
484	/*
485	 * Check to see if this log record has a CRC which matches the last
486	 * record logged.  If it does, just up the count on the previous one
487	 * rather than create a new one.
488	 */
489	if (ipl_suppress) {
490		if ((fin != NULL) && (fin->fin_off == 0)) {
491			if ((ipll[dev] != NULL) &&
492			    bcmp((char *)fin, (char *)&iplcrc[dev],
493				 FI_LCSIZE) == 0) {
494				ipll[dev]->ipl_count++;
495				MUTEX_EXIT(&ipl_mutex);
496				SPL_X(s);
497				KFREES(buf, len);
498				return 0;
499			}
500			bcopy((char *)fin, (char *)&iplcrc[dev], FI_LCSIZE);
501		} else
502			bzero((char *)&iplcrc[dev], FI_CSIZE);
503	}
504
505	/*
506	 * advance the log pointer to the next empty record and deduct the
507	 * amount of space we're going to use.
508	 */
509	ipll[dev] = ipl;
510	*iplh[dev] = ipl;
511	iplh[dev] = &ipl->ipl_next;
512	iplused[dev] += len;
513
514	/*
515	 * Now that the log record has been completed and added to the queue,
516	 * wake up any listeners who may want to read it.
517	 */
518# if SOLARIS && defined(_KERNEL)
519	cv_signal(&iplwait);
520	MUTEX_EXIT(&ipl_mutex);
521	pollwakeup(&iplpollhead[dev], POLLRDNORM);
522# else
523	MUTEX_EXIT(&ipl_mutex);
524	WAKEUP(iplh, dev);
525	POLLWAKEUP(dev);
526# endif
527	SPL_X(s);
528# ifdef	IPL_SELECT
529	iplog_input_ready(dev);
530# endif
531	return 0;
532}
533
534
535/* ------------------------------------------------------------------------ */
536/* Function:    ipflog_read                                                 */
537/* Returns:     int    - 0 == success, else error value.                    */
538/* Parameters:  unit(I) - device we are reading from                        */
539/*              uio(O)  - pointer to information about where to store data  */
540/*                                                                          */
541/* Called to handle a read on an IPFilter device.  Returns only complete    */
542/* log messages - will not partially copy a log record out to userland.     */
543/*                                                                          */
544/* NOTE: This function will block and wait for a signal to return data if   */
545/* there is none present.  Asynchronous I/O is not implemented.             */
546/* ------------------------------------------------------------------------ */
547int
548ipflog_read(minor_t unit, struct uio *uio)
549{
550	size_t dlen, copied;
551	int error = 0;
552	iplog_t *ipl;
553	SPL_INT(s);
554
555	/*
556	 * Sanity checks.  Make sure the minor # is valid and we're copying
557	 * a valid chunk of data.
558	 */
559	if (IPL_LOGMAX < unit)
560		return ENXIO;
561	if (uio->uio_resid == 0)
562		return 0;
563	if ((uio->uio_resid < sizeof(iplog_t)) ||
564	    (uio->uio_resid > ipl_logsize))
565		return EINVAL;
566
567	/*
568	 * Lock the log so we can snapshot the variables.  Wait for a signal
569	 * if the log is empty.
570	 */
571	SPL_NET(s);
572	MUTEX_ENTER(&ipl_mutex);
573
574	while (iplt[unit] == NULL) {
575# if SOLARIS && defined(_KERNEL)
576		if (!cv_wait_sig(&iplwait, &ipl_mutex.ipf_lk)) {
577			MUTEX_EXIT(&ipl_mutex);
578			return EINTR;
579		}
580# else
581#  if defined(__hpux) && defined(_KERNEL)
582		lock_t *l;
583
584#   ifdef IPL_SELECT
585		if (uio->uio_fpflags & (FNBLOCK|FNDELAY)) {
586			/* this is no blocking system call */
587			MUTEX_EXIT(&ipl_mutex);
588			return 0;
589		}
590#   endif
591
592		MUTEX_EXIT(&ipl_mutex);
593		l = get_sleep_lock(&iplh[unit]);
594		error = sleep(&iplh[unit], PZERO+1);
595		spinunlock(l);
596#  else
597#   if defined(__osf__) && defined(_KERNEL)
598		error = mpsleep(&iplh[unit], PSUSP|PCATCH,  "iplread", 0,
599				&ipl_mutex, MS_LOCK_SIMPLE);
600#   else
601		MUTEX_EXIT(&ipl_mutex);
602		SPL_X(s);
603		error = SLEEP(unit + iplh, "ipl sleep");
604#   endif /* __osf__ */
605#  endif /* __hpux */
606		if (error)
607			return error;
608		SPL_NET(s);
609		MUTEX_ENTER(&ipl_mutex);
610# endif /* SOLARIS */
611	}
612
613# if (defined(BSD) && (BSD >= 199101)) || defined(__FreeBSD__) || \
614     defined(__osf__)
615	uio->uio_rw = UIO_READ;
616# endif
617
618	for (copied = 0; (ipl = iplt[unit]) != NULL; copied += dlen) {
619		dlen = ipl->ipl_dsize;
620		if (dlen > uio->uio_resid)
621			break;
622		/*
623		 * Don't hold the mutex over the uiomove call.
624		 */
625		iplt[unit] = ipl->ipl_next;
626		iplused[unit] -= dlen;
627		MUTEX_EXIT(&ipl_mutex);
628		SPL_X(s);
629		error = UIOMOVE((void *)ipl, dlen, UIO_READ, uio);
630		if (error) {
631			SPL_NET(s);
632			MUTEX_ENTER(&ipl_mutex);
633			ipl->ipl_next = iplt[unit];
634			iplt[unit] = ipl;
635			iplused[unit] += dlen;
636			break;
637		}
638		MUTEX_ENTER(&ipl_mutex);
639		KFREES((void *)ipl, dlen);
640		SPL_NET(s);
641	}
642	if (!iplt[unit]) {
643		iplused[unit] = 0;
644		iplh[unit] = &iplt[unit];
645		ipll[unit] = NULL;
646	}
647
648	MUTEX_EXIT(&ipl_mutex);
649	SPL_X(s);
650	return error;
651}
652
653
654/* ------------------------------------------------------------------------ */
655/* Function:    ipflog_clear                                                */
656/* Returns:     int    - number of log bytes cleared.                       */
657/* Parameters:  unit(I) - device we are reading from                        */
658/*                                                                          */
659/* Deletes all queued up log records for a given output device.             */
660/* ------------------------------------------------------------------------ */
661int
662ipflog_clear(minor_t unit)
663{
664	iplog_t *ipl;
665	int used;
666	SPL_INT(s);
667
668	SPL_NET(s);
669	MUTEX_ENTER(&ipl_mutex);
670	while ((ipl = iplt[unit]) != NULL) {
671		iplt[unit] = ipl->ipl_next;
672		KFREES((void *)ipl, ipl->ipl_dsize);
673	}
674	iplh[unit] = &iplt[unit];
675	ipll[unit] = NULL;
676	used = iplused[unit];
677	iplused[unit] = 0;
678	bzero((char *)&iplcrc[unit], FI_CSIZE);
679	MUTEX_EXIT(&ipl_mutex);
680	SPL_X(s);
681	return used;
682}
683
684
685/* ------------------------------------------------------------------------ */
686/* Function:    ipflog_canread                                              */
687/* Returns:     int    - 0 == no data to read, 1 = data present             */
688/* Parameters:  unit(I) - device we are reading from                        */
689/*                                                                          */
690/* Returns an indication of whether or not there is data present in the     */
691/* current buffer for the selected ipf device.                              */
692/* ------------------------------------------------------------------------ */
693int
694ipflog_canread(int unit)
695{
696	return iplt[unit] != NULL;
697}
698#endif /* IPFILTER_LOG */
699