ip_fil_freebsd.c revision 342607 
1/*	$FreeBSD: stable/10/sys/contrib/ipfilter/netinet/ip_fil_freebsd.c 342607 2018-12-30 04:37:49Z cy $	*/
2
3/*
4 * Copyright (C) 2012 by Darren Reed.
5 *
6 * See the IPFILTER.LICENCE file for details on licencing.
7 */
8#if !defined(lint)
9static const char sccsid[] = "@(#)ip_fil.c	2.41 6/5/96 (C) 1993-2000 Darren Reed";
10static const char rcsid[] = "@(#)$Id$";
11#endif
12
13#if defined(KERNEL) || defined(_KERNEL)
14# undef KERNEL
15# undef _KERNEL
16# define	KERNEL	1
17# define	_KERNEL	1
18#endif
19#if defined(__FreeBSD_version) && (__FreeBSD_version >= 400000) && \
20    !defined(KLD_MODULE) && !defined(IPFILTER_LKM)
21# include "opt_inet6.h"
22#endif
23#if defined(__FreeBSD_version) && (__FreeBSD_version >= 440000) && \
24    !defined(KLD_MODULE) && !defined(IPFILTER_LKM)
25# include "opt_random_ip_id.h"
26#endif
27#include <sys/param.h>
28#include <sys/errno.h>
29#include <sys/types.h>
30#include <sys/file.h>
31# include <sys/fcntl.h>
32# include <sys/filio.h>
33#include <sys/time.h>
34#include <sys/systm.h>
35# include <sys/dirent.h>
36#if defined(__FreeBSD_version) && (__FreeBSD_version >= 800000)
37#include <sys/jail.h>
38#endif
39# include <sys/mbuf.h>
40# include <sys/sockopt.h>
41# include <sys/mbuf.h>
42#include <sys/socket.h>
43# include <sys/selinfo.h>
44# include <netinet/tcp_var.h>
45
46#include <net/if.h>
47# include <net/if_var.h>
48#  include <net/netisr.h>
49#include <net/route.h>
50#include <netinet/in.h>
51#include <netinet/in_var.h>
52#include <netinet/in_systm.h>
53#include <netinet/ip.h>
54#include <netinet/ip_var.h>
55#include <netinet/tcp.h>
56#if defined(__FreeBSD_version) && (__FreeBSD_version >= 800000)
57#include <net/vnet.h>
58#else
59#define CURVNET_SET(arg)
60#define CURVNET_RESTORE()
61#endif
62#include <netinet/udp.h>
63#include <netinet/tcpip.h>
64#include <netinet/ip_icmp.h>
65#include "netinet/ip_compat.h"
66#ifdef USE_INET6
67# include <netinet/icmp6.h>
68#endif
69#include "netinet/ip_fil.h"
70#include "netinet/ip_nat.h"
71#include "netinet/ip_frag.h"
72#include "netinet/ip_state.h"
73#include "netinet/ip_proxy.h"
74#include "netinet/ip_auth.h"
75#include "netinet/ip_sync.h"
76#include "netinet/ip_lookup.h"
77#include "netinet/ip_dstlist.h"
78#ifdef	IPFILTER_SCAN
79#include "netinet/ip_scan.h"
80#endif
81#include "netinet/ip_pool.h"
82# include <sys/malloc.h>
83#include <sys/kernel.h>
84#ifdef CSUM_DATA_VALID
85#include <machine/in_cksum.h>
86#endif
87extern	int	ip_optcopy __P((struct ip *, struct ip *));
88
89# ifdef IPFILTER_M_IPFILTER
90MALLOC_DEFINE(M_IPFILTER, "ipfilter", "IP Filter packet filter data structures");
91# endif
92
93
94static	u_short	ipid = 0;
95static	int	(*ipf_savep) __P((void *, ip_t *, int, void *, int, struct mbuf **));
96static	int	ipf_send_ip __P((fr_info_t *, mb_t *));
97static void	ipf_timer_func __P((void *arg));
98int		ipf_locks_done = 0;
99
100ipf_main_softc_t ipfmain;
101
102# include <sys/conf.h>
103#  include <net/pfil.h>
104/*
105 * We provide the ipf_checkp name just to minimize changes later.
106 */
107int (*ipf_checkp) __P((void *, ip_t *ip, int hlen, void *ifp, int out, mb_t **mp));
108
109
110static eventhandler_tag ipf_arrivetag, ipf_departtag, ipf_clonetag;
111
112static void ipf_ifevent(void *arg);
113
114static void ipf_ifevent(arg)
115	void *arg;
116{
117        ipf_sync(arg, NULL);
118}
119
120
121
122static int
123ipf_check_wrapper(void *arg, struct mbuf **mp, struct ifnet *ifp, int dir)
124{
125	struct ip *ip = mtod(*mp, struct ip *);
126	int rv;
127
128	/*
129	 * IPFilter expects evreything in network byte order
130	 */
131#if (__FreeBSD_version < 1000019)
132	ip->ip_len = htons(ip->ip_len);
133	ip->ip_off = htons(ip->ip_off);
134#endif
135	rv = ipf_check(&ipfmain, ip, ip->ip_hl << 2, ifp, (dir == PFIL_OUT),
136		       mp);
137#if (__FreeBSD_version < 1000019)
138	if ((rv == 0) && (*mp != NULL)) {
139		ip = mtod(*mp, struct ip *);
140		ip->ip_len = ntohs(ip->ip_len);
141		ip->ip_off = ntohs(ip->ip_off);
142	}
143#endif
144	return rv;
145}
146
147# ifdef USE_INET6
148#  include <netinet/ip6.h>
149
150static int
151ipf_check_wrapper6(void *arg, struct mbuf **mp, struct ifnet *ifp, int dir)
152{
153	return (ipf_check(&ipfmain, mtod(*mp, struct ip *),
154			  sizeof(struct ip6_hdr), ifp, (dir == PFIL_OUT), mp));
155}
156# endif
157#if	defined(IPFILTER_LKM)
158int ipf_identify(s)
159	char *s;
160{
161	if (strcmp(s, "ipl") == 0)
162		return 1;
163	return 0;
164}
165#endif /* IPFILTER_LKM */
166
167
168static void
169ipf_timer_func(arg)
170	void *arg;
171{
172	ipf_main_softc_t *softc = arg;
173	SPL_INT(s);
174
175	SPL_NET(s);
176	READ_ENTER(&softc->ipf_global);
177
178        if (softc->ipf_running > 0)
179		ipf_slowtimer(softc);
180
181	if (softc->ipf_running == -1 || softc->ipf_running == 1) {
182#if 0
183		softc->ipf_slow_ch = timeout(ipf_timer_func, softc, hz/2);
184#endif
185		callout_init(&softc->ipf_slow_ch, 1);
186		callout_reset(&softc->ipf_slow_ch,
187			(hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT,
188			ipf_timer_func, softc);
189	}
190	RWLOCK_EXIT(&softc->ipf_global);
191	SPL_X(s);
192}
193
194
195int
196ipfattach(softc)
197	ipf_main_softc_t *softc;
198{
199#ifdef USE_SPL
200	int s;
201#endif
202
203	SPL_NET(s);
204	if (softc->ipf_running > 0) {
205		SPL_X(s);
206		return EBUSY;
207	}
208
209	if (ipf_init_all(softc) < 0) {
210		SPL_X(s);
211		return EIO;
212	}
213
214
215	if (ipf_checkp != ipf_check) {
216		ipf_savep = ipf_checkp;
217		ipf_checkp = ipf_check;
218	}
219
220	bzero((char *)ipfmain.ipf_selwait, sizeof(ipfmain.ipf_selwait));
221	softc->ipf_running = 1;
222
223	if (softc->ipf_control_forwarding & 1)
224		V_ipforwarding = 1;
225
226	ipid = 0;
227
228	SPL_X(s);
229#if 0
230	softc->ipf_slow_ch = timeout(ipf_timer_func, softc,
231				     (hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT);
232#endif
233	callout_init(&softc->ipf_slow_ch, 1);
234	callout_reset(&softc->ipf_slow_ch, (hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT,
235		ipf_timer_func, softc);
236	return 0;
237}
238
239
240/*
241 * Disable the filter by removing the hooks from the IP input/output
242 * stream.
243 */
244int
245ipfdetach(softc)
246	ipf_main_softc_t *softc;
247{
248#ifdef USE_SPL
249	int s;
250#endif
251
252	if (softc->ipf_control_forwarding & 2)
253		V_ipforwarding = 0;
254
255	SPL_NET(s);
256
257#if 0
258	if (softc->ipf_slow_ch.callout != NULL)
259		untimeout(ipf_timer_func, softc, softc->ipf_slow_ch);
260	bzero(&softc->ipf_slow, sizeof(softc->ipf_slow));
261#endif
262	callout_drain(&softc->ipf_slow_ch);
263
264#ifndef NETBSD_PF
265	if (ipf_checkp != NULL)
266		ipf_checkp = ipf_savep;
267	ipf_savep = NULL;
268#endif
269
270	ipf_fini_all(softc);
271
272	softc->ipf_running = -2;
273
274	SPL_X(s);
275
276	return 0;
277}
278
279
280/*
281 * Filter ioctl interface.
282 */
283int
284ipfioctl(dev, cmd, data, mode, p)
285	struct thread *p;
286#    define	p_cred	td_ucred
287#    define	p_uid	td_ucred->cr_ruid
288	struct cdev *dev;
289	ioctlcmd_t cmd;
290	caddr_t data;
291	int mode;
292{
293	int error = 0, unit = 0;
294	SPL_INT(s);
295
296#if (BSD >= 199306)
297        if (securelevel_ge(p->p_cred, 3) && (mode & FWRITE))
298	{
299		ipfmain.ipf_interror = 130001;
300		return EPERM;
301	}
302#endif
303
304	unit = GET_MINOR(dev);
305	if ((IPL_LOGMAX < unit) || (unit < 0)) {
306		ipfmain.ipf_interror = 130002;
307		return ENXIO;
308	}
309
310	if (ipfmain.ipf_running <= 0) {
311		if (unit != IPL_LOGIPF && cmd != SIOCIPFINTERROR) {
312			ipfmain.ipf_interror = 130003;
313			return EIO;
314		}
315		if (cmd != SIOCIPFGETNEXT && cmd != SIOCIPFGET &&
316		    cmd != SIOCIPFSET && cmd != SIOCFRENB &&
317		    cmd != SIOCGETFS && cmd != SIOCGETFF &&
318		    cmd != SIOCIPFINTERROR) {
319			ipfmain.ipf_interror = 130004;
320			return EIO;
321		}
322	}
323
324	SPL_NET(s);
325
326	CURVNET_SET(TD_TO_VNET(p));
327	error = ipf_ioctlswitch(&ipfmain, unit, data, cmd, mode, p->p_uid, p);
328	CURVNET_RESTORE();
329	if (error != -1) {
330		SPL_X(s);
331		return error;
332	}
333
334	SPL_X(s);
335
336	return error;
337}
338
339
340/*
341 * ipf_send_reset - this could conceivably be a call to tcp_respond(), but that
342 * requires a large amount of setting up and isn't any more efficient.
343 */
344int
345ipf_send_reset(fin)
346	fr_info_t *fin;
347{
348	struct tcphdr *tcp, *tcp2;
349	int tlen = 0, hlen;
350	struct mbuf *m;
351#ifdef USE_INET6
352	ip6_t *ip6;
353#endif
354	ip_t *ip;
355
356	tcp = fin->fin_dp;
357	if (tcp->th_flags & TH_RST)
358		return -1;		/* feedback loop */
359
360	if (ipf_checkl4sum(fin) == -1)
361		return -1;
362
363	tlen = fin->fin_dlen - (TCP_OFF(tcp) << 2) +
364			((tcp->th_flags & TH_SYN) ? 1 : 0) +
365			((tcp->th_flags & TH_FIN) ? 1 : 0);
366
367#ifdef USE_INET6
368	hlen = (fin->fin_v == 6) ? sizeof(ip6_t) : sizeof(ip_t);
369#else
370	hlen = sizeof(ip_t);
371#endif
372#ifdef MGETHDR
373	MGETHDR(m, M_DONTWAIT, MT_HEADER);
374#else
375	MGET(m, M_DONTWAIT, MT_HEADER);
376#endif
377	if (m == NULL)
378		return -1;
379	if (sizeof(*tcp2) + hlen > MLEN) {
380		MCLGET(m, M_DONTWAIT);
381		if ((m->m_flags & M_EXT) == 0) {
382			FREE_MB_T(m);
383			return -1;
384		}
385	}
386
387	m->m_len = sizeof(*tcp2) + hlen;
388#if (BSD >= 199103)
389	m->m_data += max_linkhdr;
390	m->m_pkthdr.len = m->m_len;
391	m->m_pkthdr.rcvif = (struct ifnet *)0;
392#endif
393	ip = mtod(m, struct ip *);
394	bzero((char *)ip, hlen);
395#ifdef USE_INET6
396	ip6 = (ip6_t *)ip;
397#endif
398	tcp2 = (struct tcphdr *)((char *)ip + hlen);
399	tcp2->th_sport = tcp->th_dport;
400	tcp2->th_dport = tcp->th_sport;
401
402	if (tcp->th_flags & TH_ACK) {
403		tcp2->th_seq = tcp->th_ack;
404		tcp2->th_flags = TH_RST;
405		tcp2->th_ack = 0;
406	} else {
407		tcp2->th_seq = 0;
408		tcp2->th_ack = ntohl(tcp->th_seq);
409		tcp2->th_ack += tlen;
410		tcp2->th_ack = htonl(tcp2->th_ack);
411		tcp2->th_flags = TH_RST|TH_ACK;
412	}
413	TCP_X2_A(tcp2, 0);
414	TCP_OFF_A(tcp2, sizeof(*tcp2) >> 2);
415	tcp2->th_win = tcp->th_win;
416	tcp2->th_sum = 0;
417	tcp2->th_urp = 0;
418
419#ifdef USE_INET6
420	if (fin->fin_v == 6) {
421		ip6->ip6_flow = ((ip6_t *)fin->fin_ip)->ip6_flow;
422		ip6->ip6_plen = htons(sizeof(struct tcphdr));
423		ip6->ip6_nxt = IPPROTO_TCP;
424		ip6->ip6_hlim = 0;
425		ip6->ip6_src = fin->fin_dst6.in6;
426		ip6->ip6_dst = fin->fin_src6.in6;
427		tcp2->th_sum = in6_cksum(m, IPPROTO_TCP,
428					 sizeof(*ip6), sizeof(*tcp2));
429		return ipf_send_ip(fin, m);
430	}
431#endif
432	ip->ip_p = IPPROTO_TCP;
433	ip->ip_len = htons(sizeof(struct tcphdr));
434	ip->ip_src.s_addr = fin->fin_daddr;
435	ip->ip_dst.s_addr = fin->fin_saddr;
436	tcp2->th_sum = in_cksum(m, hlen + sizeof(*tcp2));
437	ip->ip_len = htons(hlen + sizeof(*tcp2));
438	return ipf_send_ip(fin, m);
439}
440
441
442/*
443 * ip_len must be in network byte order when called.
444 */
445static int
446ipf_send_ip(fin, m)
447	fr_info_t *fin;
448	mb_t *m;
449{
450	fr_info_t fnew;
451	ip_t *ip, *oip;
452	int hlen;
453
454	ip = mtod(m, ip_t *);
455	bzero((char *)&fnew, sizeof(fnew));
456	fnew.fin_main_soft = fin->fin_main_soft;
457
458	IP_V_A(ip, fin->fin_v);
459	switch (fin->fin_v)
460	{
461	case 4 :
462		oip = fin->fin_ip;
463		hlen = sizeof(*oip);
464		fnew.fin_v = 4;
465		fnew.fin_p = ip->ip_p;
466		fnew.fin_plen = ntohs(ip->ip_len);
467		IP_HL_A(ip, sizeof(*oip) >> 2);
468		ip->ip_tos = oip->ip_tos;
469		ip->ip_id = fin->fin_ip->ip_id;
470		ip->ip_off = htons(V_path_mtu_discovery ? IP_DF : 0);
471		ip->ip_ttl = V_ip_defttl;
472		ip->ip_sum = 0;
473		break;
474#ifdef USE_INET6
475	case 6 :
476	{
477		ip6_t *ip6 = (ip6_t *)ip;
478
479		ip6->ip6_vfc = 0x60;
480		ip6->ip6_hlim = IPDEFTTL;
481
482		hlen = sizeof(*ip6);
483		fnew.fin_p = ip6->ip6_nxt;
484		fnew.fin_v = 6;
485		fnew.fin_plen = ntohs(ip6->ip6_plen) + hlen;
486		break;
487	}
488#endif
489	default :
490		return EINVAL;
491	}
492#ifdef IPSEC
493	m->m_pkthdr.rcvif = NULL;
494#endif
495
496	fnew.fin_ifp = fin->fin_ifp;
497	fnew.fin_flx = FI_NOCKSUM;
498	fnew.fin_m = m;
499	fnew.fin_ip = ip;
500	fnew.fin_mp = &m;
501	fnew.fin_hlen = hlen;
502	fnew.fin_dp = (char *)ip + hlen;
503	(void) ipf_makefrip(hlen, ip, &fnew);
504
505	return ipf_fastroute(m, &m, &fnew, NULL);
506}
507
508
509int
510ipf_send_icmp_err(type, fin, dst)
511	int type;
512	fr_info_t *fin;
513	int dst;
514{
515	int err, hlen, xtra, iclen, ohlen, avail, code;
516	struct in_addr dst4;
517	struct icmp *icmp;
518	struct mbuf *m;
519	i6addr_t dst6;
520	void *ifp;
521#ifdef USE_INET6
522	ip6_t *ip6;
523#endif
524	ip_t *ip, *ip2;
525
526	if ((type < 0) || (type >= ICMP_MAXTYPE))
527		return -1;
528
529	code = fin->fin_icode;
530#ifdef USE_INET6
531	/* See NetBSD ip_fil_netbsd.c r1.4: */
532	if ((code < 0) || (code >= sizeof(icmptoicmp6unreach)/sizeof(int)))
533		return -1;
534#endif
535
536	if (ipf_checkl4sum(fin) == -1)
537		return -1;
538#ifdef MGETHDR
539	MGETHDR(m, M_DONTWAIT, MT_HEADER);
540#else
541	MGET(m, M_DONTWAIT, MT_HEADER);
542#endif
543	if (m == NULL)
544		return -1;
545	avail = MHLEN;
546
547	xtra = 0;
548	hlen = 0;
549	ohlen = 0;
550	dst4.s_addr = 0;
551	ifp = fin->fin_ifp;
552	if (fin->fin_v == 4) {
553		if ((fin->fin_p == IPPROTO_ICMP) && !(fin->fin_flx & FI_SHORT))
554			switch (ntohs(fin->fin_data[0]) >> 8)
555			{
556			case ICMP_ECHO :
557			case ICMP_TSTAMP :
558			case ICMP_IREQ :
559			case ICMP_MASKREQ :
560				break;
561			default :
562				FREE_MB_T(m);
563				return 0;
564			}
565
566		if (dst == 0) {
567			if (ipf_ifpaddr(&ipfmain, 4, FRI_NORMAL, ifp,
568					&dst6, NULL) == -1) {
569				FREE_MB_T(m);
570				return -1;
571			}
572			dst4 = dst6.in4;
573		} else
574			dst4.s_addr = fin->fin_daddr;
575
576		hlen = sizeof(ip_t);
577		ohlen = fin->fin_hlen;
578		iclen = hlen + offsetof(struct icmp, icmp_ip) + ohlen;
579		if (fin->fin_hlen < fin->fin_plen)
580			xtra = MIN(fin->fin_dlen, 8);
581		else
582			xtra = 0;
583	}
584
585#ifdef USE_INET6
586	else if (fin->fin_v == 6) {
587		hlen = sizeof(ip6_t);
588		ohlen = sizeof(ip6_t);
589		iclen = hlen + offsetof(struct icmp, icmp_ip) + ohlen;
590		type = icmptoicmp6types[type];
591		if (type == ICMP6_DST_UNREACH)
592			code = icmptoicmp6unreach[code];
593
594		if (iclen + max_linkhdr + fin->fin_plen > avail) {
595			MCLGET(m, M_DONTWAIT);
596			if ((m->m_flags & M_EXT) == 0) {
597				FREE_MB_T(m);
598				return -1;
599			}
600			avail = MCLBYTES;
601		}
602		xtra = MIN(fin->fin_plen, avail - iclen - max_linkhdr);
603		xtra = MIN(xtra, IPV6_MMTU - iclen);
604		if (dst == 0) {
605			if (ipf_ifpaddr(&ipfmain, 6, FRI_NORMAL, ifp,
606					&dst6, NULL) == -1) {
607				FREE_MB_T(m);
608				return -1;
609			}
610		} else
611			dst6 = fin->fin_dst6;
612	}
613#endif
614	else {
615		FREE_MB_T(m);
616		return -1;
617	}
618
619	avail -= (max_linkhdr + iclen);
620	if (avail < 0) {
621		FREE_MB_T(m);
622		return -1;
623	}
624	if (xtra > avail)
625		xtra = avail;
626	iclen += xtra;
627	m->m_data += max_linkhdr;
628	m->m_pkthdr.rcvif = (struct ifnet *)0;
629	m->m_pkthdr.len = iclen;
630	m->m_len = iclen;
631	ip = mtod(m, ip_t *);
632	icmp = (struct icmp *)((char *)ip + hlen);
633	ip2 = (ip_t *)&icmp->icmp_ip;
634
635	icmp->icmp_type = type;
636	icmp->icmp_code = fin->fin_icode;
637	icmp->icmp_cksum = 0;
638#ifdef icmp_nextmtu
639	if (type == ICMP_UNREACH && fin->fin_icode == ICMP_UNREACH_NEEDFRAG) {
640		if (fin->fin_mtu != 0) {
641			icmp->icmp_nextmtu = htons(fin->fin_mtu);
642
643		} else if (ifp != NULL) {
644			icmp->icmp_nextmtu = htons(GETIFMTU_4(ifp));
645
646		} else {	/* make up a number... */
647			icmp->icmp_nextmtu = htons(fin->fin_plen - 20);
648		}
649	}
650#endif
651
652	bcopy((char *)fin->fin_ip, (char *)ip2, ohlen);
653
654#ifdef USE_INET6
655	ip6 = (ip6_t *)ip;
656	if (fin->fin_v == 6) {
657		ip6->ip6_flow = ((ip6_t *)fin->fin_ip)->ip6_flow;
658		ip6->ip6_plen = htons(iclen - hlen);
659		ip6->ip6_nxt = IPPROTO_ICMPV6;
660		ip6->ip6_hlim = 0;
661		ip6->ip6_src = dst6.in6;
662		ip6->ip6_dst = fin->fin_src6.in6;
663		if (xtra > 0)
664			bcopy((char *)fin->fin_ip + ohlen,
665			      (char *)&icmp->icmp_ip + ohlen, xtra);
666		icmp->icmp_cksum = in6_cksum(m, IPPROTO_ICMPV6,
667					     sizeof(*ip6), iclen - hlen);
668	} else
669#endif
670	{
671		ip->ip_p = IPPROTO_ICMP;
672		ip->ip_src.s_addr = dst4.s_addr;
673		ip->ip_dst.s_addr = fin->fin_saddr;
674
675		if (xtra > 0)
676			bcopy((char *)fin->fin_ip + ohlen,
677			      (char *)&icmp->icmp_ip + ohlen, xtra);
678		icmp->icmp_cksum = ipf_cksum((u_short *)icmp,
679					     sizeof(*icmp) + 8);
680		ip->ip_len = htons(iclen);
681		ip->ip_p = IPPROTO_ICMP;
682	}
683	err = ipf_send_ip(fin, m);
684	return err;
685}
686
687
688
689
690/*
691 * m0 - pointer to mbuf where the IP packet starts
692 * mpp - pointer to the mbuf pointer that is the start of the mbuf chain
693 */
694int
695ipf_fastroute(m0, mpp, fin, fdp)
696	mb_t *m0, **mpp;
697	fr_info_t *fin;
698	frdest_t *fdp;
699{
700	register struct ip *ip, *mhip;
701	register struct mbuf *m = *mpp;
702	register struct route *ro;
703	int len, off, error = 0, hlen, code;
704	struct ifnet *ifp, *sifp;
705	struct sockaddr_in *dst;
706	struct route iproute;
707	u_short ip_off;
708	frdest_t node;
709	frentry_t *fr;
710
711	ro = NULL;
712
713#ifdef M_WRITABLE
714	/*
715	* HOT FIX/KLUDGE:
716	*
717	* If the mbuf we're about to send is not writable (because of
718	* a cluster reference, for example) we'll need to make a copy
719	* of it since this routine modifies the contents.
720	*
721	* If you have non-crappy network hardware that can transmit data
722	* from the mbuf, rather than making a copy, this is gonna be a
723	* problem.
724	*/
725	if (M_WRITABLE(m) == 0) {
726		m0 = m_dup(m, M_DONTWAIT);
727		if (m0 != NULL) {
728			FREE_MB_T(m);
729			m = m0;
730			*mpp = m;
731		} else {
732			error = ENOBUFS;
733			FREE_MB_T(m);
734			goto done;
735		}
736	}
737#endif
738
739#ifdef USE_INET6
740	if (fin->fin_v == 6) {
741		/*
742		 * currently "to <if>" and "to <if>:ip#" are not supported
743		 * for IPv6
744		 */
745		return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
746	}
747#endif
748
749	hlen = fin->fin_hlen;
750	ip = mtod(m0, struct ip *);
751	ifp = NULL;
752
753	/*
754	 * Route packet.
755	 */
756	ro = &iproute;
757	bzero(ro, sizeof (*ro));
758	dst = (struct sockaddr_in *)&ro->ro_dst;
759	dst->sin_family = AF_INET;
760	dst->sin_addr = ip->ip_dst;
761
762	fr = fin->fin_fr;
763	if ((fr != NULL) && !(fr->fr_flags & FR_KEEPSTATE) && (fdp != NULL) &&
764	    (fdp->fd_type == FRD_DSTLIST)) {
765		if (ipf_dstlist_select_node(fin, fdp->fd_ptr, NULL, &node) == 0)
766			fdp = &node;
767	}
768
769	if (fdp != NULL)
770		ifp = fdp->fd_ptr;
771	else
772		ifp = fin->fin_ifp;
773
774	if ((ifp == NULL) && ((fr == NULL) || !(fr->fr_flags & FR_FASTROUTE))) {
775		error = -2;
776		goto bad;
777	}
778
779	if ((fdp != NULL) && (fdp->fd_ip.s_addr != 0))
780		dst->sin_addr = fdp->fd_ip;
781
782	dst->sin_len = sizeof(*dst);
783	in_rtalloc(ro, M_GETFIB(m0));
784
785	if ((ifp == NULL) && (ro->ro_rt != NULL))
786		ifp = ro->ro_rt->rt_ifp;
787
788	if ((ro->ro_rt == NULL) || (ifp == NULL)) {
789		if (in_localaddr(ip->ip_dst))
790			error = EHOSTUNREACH;
791		else
792			error = ENETUNREACH;
793		goto bad;
794	}
795	if (ro->ro_rt->rt_flags & RTF_GATEWAY)
796		dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway;
797	if (ro->ro_rt)
798		counter_u64_add(ro->ro_rt->rt_pksent, 1);
799
800	/*
801	 * For input packets which are being "fastrouted", they won't
802	 * go back through output filtering and miss their chance to get
803	 * NAT'd and counted.  Duplicated packets aren't considered to be
804	 * part of the normal packet stream, so do not NAT them or pass
805	 * them through stateful checking, etc.
806	 */
807	if ((fdp != &fr->fr_dif) && (fin->fin_out == 0)) {
808		sifp = fin->fin_ifp;
809		fin->fin_ifp = ifp;
810		fin->fin_out = 1;
811		(void) ipf_acctpkt(fin, NULL);
812		fin->fin_fr = NULL;
813		if (!fr || !(fr->fr_flags & FR_RETMASK)) {
814			u_32_t pass;
815
816			(void) ipf_state_check(fin, &pass);
817		}
818
819		switch (ipf_nat_checkout(fin, NULL))
820		{
821		case 0 :
822			break;
823		case 1 :
824			ip->ip_sum = 0;
825			break;
826		case -1 :
827			error = -1;
828			goto bad;
829			break;
830		}
831
832		fin->fin_ifp = sifp;
833		fin->fin_out = 0;
834	} else
835		ip->ip_sum = 0;
836	/*
837	 * If small enough for interface, can just send directly.
838	 */
839	if (ntohs(ip->ip_len) <= ifp->if_mtu) {
840		if (!ip->ip_sum)
841			ip->ip_sum = in_cksum(m, hlen);
842		error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst,
843			    ro
844			);
845		goto done;
846	}
847	/*
848	 * Too large for interface; fragment if possible.
849	 * Must be able to put at least 8 bytes per fragment.
850	 */
851	ip_off = ntohs(ip->ip_off);
852	if (ip_off & IP_DF) {
853		error = EMSGSIZE;
854		goto bad;
855	}
856	len = (ifp->if_mtu - hlen) &~ 7;
857	if (len < 8) {
858		error = EMSGSIZE;
859		goto bad;
860	}
861
862    {
863	int mhlen, firstlen = len;
864	struct mbuf **mnext = &m->m_act;
865
866	/*
867	 * Loop through length of segment after first fragment,
868	 * make new header and copy data of each part and link onto chain.
869	 */
870	m0 = m;
871	mhlen = sizeof (struct ip);
872	for (off = hlen + len; off < ntohs(ip->ip_len); off += len) {
873#ifdef MGETHDR
874		MGETHDR(m, M_DONTWAIT, MT_HEADER);
875#else
876		MGET(m, M_DONTWAIT, MT_HEADER);
877#endif
878		if (m == NULL) {
879			m = m0;
880			error = ENOBUFS;
881			goto bad;
882		}
883		m->m_data += max_linkhdr;
884		mhip = mtod(m, struct ip *);
885		bcopy((char *)ip, (char *)mhip, sizeof(*ip));
886		if (hlen > sizeof (struct ip)) {
887			mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
888			IP_HL_A(mhip, mhlen >> 2);
889		}
890		m->m_len = mhlen;
891		mhip->ip_off = ((off - hlen) >> 3) + ip_off;
892		if (off + len >= ntohs(ip->ip_len))
893			len = ntohs(ip->ip_len) - off;
894		else
895			mhip->ip_off |= IP_MF;
896		mhip->ip_len = htons((u_short)(len + mhlen));
897		*mnext = m;
898		m->m_next = m_copy(m0, off, len);
899		if (m->m_next == 0) {
900			error = ENOBUFS;	/* ??? */
901			goto sendorfree;
902		}
903		m->m_pkthdr.len = mhlen + len;
904		m->m_pkthdr.rcvif = NULL;
905		mhip->ip_off = htons((u_short)mhip->ip_off);
906		mhip->ip_sum = 0;
907		mhip->ip_sum = in_cksum(m, mhlen);
908		mnext = &m->m_act;
909	}
910	/*
911	 * Update first fragment by trimming what's been copied out
912	 * and updating header, then send each fragment (in order).
913	 */
914	m_adj(m0, hlen + firstlen - ip->ip_len);
915	ip->ip_len = htons((u_short)(hlen + firstlen));
916	ip->ip_off = htons((u_short)IP_MF);
917	ip->ip_sum = 0;
918	ip->ip_sum = in_cksum(m0, hlen);
919sendorfree:
920	for (m = m0; m; m = m0) {
921		m0 = m->m_act;
922		m->m_act = 0;
923		if (error == 0)
924			error = (*ifp->if_output)(ifp, m,
925			    (struct sockaddr *)dst,
926			    ro
927			    );
928		else
929			FREE_MB_T(m);
930	}
931    }
932done:
933	if (!error)
934		ipfmain.ipf_frouteok[0]++;
935	else
936		ipfmain.ipf_frouteok[1]++;
937
938	if ((ro != NULL) && (ro->ro_rt != NULL)) {
939		RTFREE(ro->ro_rt);
940	}
941	return 0;
942bad:
943	if (error == EMSGSIZE) {
944		sifp = fin->fin_ifp;
945		code = fin->fin_icode;
946		fin->fin_icode = ICMP_UNREACH_NEEDFRAG;
947		fin->fin_ifp = ifp;
948		(void) ipf_send_icmp_err(ICMP_UNREACH, fin, 1);
949		fin->fin_ifp = sifp;
950		fin->fin_icode = code;
951	}
952	FREE_MB_T(m);
953	goto done;
954}
955
956
957int
958ipf_verifysrc(fin)
959	fr_info_t *fin;
960{
961	struct sockaddr_in *dst;
962	struct route iproute;
963
964	bzero((char *)&iproute, sizeof(iproute));
965	dst = (struct sockaddr_in *)&iproute.ro_dst;
966	dst->sin_len = sizeof(*dst);
967	dst->sin_family = AF_INET;
968	dst->sin_addr = fin->fin_src;
969	in_rtalloc(&iproute, 0);
970	if (iproute.ro_rt == NULL)
971		return 0;
972	return (fin->fin_ifp == iproute.ro_rt->rt_ifp);
973}
974
975
976/*
977 * return the first IP Address associated with an interface
978 */
979int
980ipf_ifpaddr(softc, v, atype, ifptr, inp, inpmask)
981	ipf_main_softc_t *softc;
982	int v, atype;
983	void *ifptr;
984	i6addr_t *inp, *inpmask;
985{
986#ifdef USE_INET6
987	struct in6_addr *inp6 = NULL;
988#endif
989	struct sockaddr *sock, *mask;
990	struct sockaddr_in *sin;
991	struct ifaddr *ifa;
992	struct ifnet *ifp;
993
994	if ((ifptr == NULL) || (ifptr == (void *)-1))
995		return -1;
996
997	sin = NULL;
998	ifp = ifptr;
999
1000	if (v == 4)
1001		inp->in4.s_addr = 0;
1002#ifdef USE_INET6
1003	else if (v == 6)
1004		bzero((char *)inp, sizeof(*inp));
1005#endif
1006	ifa = TAILQ_FIRST(&ifp->if_addrhead);
1007
1008	sock = ifa->ifa_addr;
1009	while (sock != NULL && ifa != NULL) {
1010		sin = (struct sockaddr_in *)sock;
1011		if ((v == 4) && (sin->sin_family == AF_INET))
1012			break;
1013#ifdef USE_INET6
1014		if ((v == 6) && (sin->sin_family == AF_INET6)) {
1015			inp6 = &((struct sockaddr_in6 *)sin)->sin6_addr;
1016			if (!IN6_IS_ADDR_LINKLOCAL(inp6) &&
1017			    !IN6_IS_ADDR_LOOPBACK(inp6))
1018				break;
1019		}
1020#endif
1021		ifa = TAILQ_NEXT(ifa, ifa_link);
1022		if (ifa != NULL)
1023			sock = ifa->ifa_addr;
1024	}
1025
1026	if (ifa == NULL || sin == NULL)
1027		return -1;
1028
1029	mask = ifa->ifa_netmask;
1030	if (atype == FRI_BROADCAST)
1031		sock = ifa->ifa_broadaddr;
1032	else if (atype == FRI_PEERADDR)
1033		sock = ifa->ifa_dstaddr;
1034
1035	if (sock == NULL)
1036		return -1;
1037
1038#ifdef USE_INET6
1039	if (v == 6) {
1040		return ipf_ifpfillv6addr(atype, (struct sockaddr_in6 *)sock,
1041					 (struct sockaddr_in6 *)mask,
1042					 inp, inpmask);
1043	}
1044#endif
1045	return ipf_ifpfillv4addr(atype, (struct sockaddr_in *)sock,
1046				 (struct sockaddr_in *)mask,
1047				 &inp->in4, &inpmask->in4);
1048}
1049
1050
1051u_32_t
1052ipf_newisn(fin)
1053	fr_info_t *fin;
1054{
1055	u_32_t newiss;
1056	newiss = arc4random();
1057	return newiss;
1058}
1059
1060
1061/* ------------------------------------------------------------------------ */
1062/* Function:    ipf_nextipid                                                */
1063/* Returns:     int - 0 == success, -1 == error (packet should be droppped) */
1064/* Parameters:  fin(I) - pointer to packet information                      */
1065/*                                                                          */
1066/* Returns the next IPv4 ID to use for this packet.                         */
1067/* ------------------------------------------------------------------------ */
1068u_short
1069ipf_nextipid(fin)
1070	fr_info_t *fin;
1071{
1072	u_short id;
1073
1074#ifndef	RANDOM_IP_ID
1075	MUTEX_ENTER(&ipfmain.ipf_rw);
1076	id = ipid++;
1077	MUTEX_EXIT(&ipfmain.ipf_rw);
1078#else
1079	id = ip_randomid();
1080#endif
1081
1082	return id;
1083}
1084
1085
1086INLINE int
1087ipf_checkv4sum(fin)
1088	fr_info_t *fin;
1089{
1090#ifdef CSUM_DATA_VALID
1091	int manual = 0;
1092	u_short sum;
1093	ip_t *ip;
1094	mb_t *m;
1095
1096	if ((fin->fin_flx & FI_NOCKSUM) != 0)
1097		return 0;
1098
1099	if ((fin->fin_flx & FI_SHORT) != 0)
1100		return 1;
1101
1102	if (fin->fin_cksum != FI_CK_NEEDED)
1103		return (fin->fin_cksum > FI_CK_NEEDED) ? 0 : -1;
1104
1105	m = fin->fin_m;
1106	if (m == NULL) {
1107		manual = 1;
1108		goto skipauto;
1109	}
1110	ip = fin->fin_ip;
1111
1112	if ((m->m_pkthdr.csum_flags & (CSUM_IP_CHECKED|CSUM_IP_VALID)) ==
1113	    CSUM_IP_CHECKED) {
1114		fin->fin_cksum = FI_CK_BAD;
1115		fin->fin_flx |= FI_BAD;
1116		return -1;
1117	}
1118	if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
1119		/* Depending on the driver, UDP may have zero checksum */
1120		if (fin->fin_p == IPPROTO_UDP && (fin->fin_flx &
1121		    (FI_FRAG|FI_SHORT|FI_BAD)) == 0) {
1122			udphdr_t *udp = fin->fin_dp;
1123			if (udp->uh_sum == 0) {
1124				/*
1125				 * we're good no matter what the hardware
1126				 * checksum flags and csum_data say (handling
1127				 * of csum_data for zero UDP checksum is not
1128				 * consistent across all drivers)
1129				 */
1130				fin->fin_cksum = 1;
1131				return 0;
1132			}
1133		}
1134
1135		if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
1136			sum = m->m_pkthdr.csum_data;
1137		else
1138			sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
1139					htonl(m->m_pkthdr.csum_data +
1140					fin->fin_dlen + fin->fin_p));
1141		sum ^= 0xffff;
1142		if (sum != 0) {
1143			fin->fin_cksum = FI_CK_BAD;
1144			fin->fin_flx |= FI_BAD;
1145		} else {
1146			fin->fin_cksum = FI_CK_SUMOK;
1147			return 0;
1148		}
1149	} else {
1150		if (m->m_pkthdr.csum_flags == CSUM_DELAY_DATA) {
1151			fin->fin_cksum = FI_CK_L4FULL;
1152			return 0;
1153		} else if (m->m_pkthdr.csum_flags == CSUM_TCP ||
1154			   m->m_pkthdr.csum_flags == CSUM_UDP) {
1155			fin->fin_cksum = FI_CK_L4PART;
1156			return 0;
1157		} else if (m->m_pkthdr.csum_flags == CSUM_IP) {
1158			fin->fin_cksum = FI_CK_L4PART;
1159			return 0;
1160		} else {
1161			manual = 1;
1162		}
1163	}
1164skipauto:
1165	if (manual != 0) {
1166		if (ipf_checkl4sum(fin) == -1) {
1167			fin->fin_flx |= FI_BAD;
1168			return -1;
1169		}
1170	}
1171#else
1172	if (ipf_checkl4sum(fin) == -1) {
1173		fin->fin_flx |= FI_BAD;
1174		return -1;
1175	}
1176#endif
1177	return 0;
1178}
1179
1180
1181#ifdef USE_INET6
1182INLINE int
1183ipf_checkv6sum(fin)
1184	fr_info_t *fin;
1185{
1186	if ((fin->fin_flx & FI_NOCKSUM) != 0)
1187		return 0;
1188
1189	if ((fin->fin_flx & FI_SHORT) != 0)
1190		return 1;
1191
1192	if (fin->fin_cksum != FI_CK_NEEDED)
1193		return (fin->fin_cksum > FI_CK_NEEDED) ? 0 : -1;
1194
1195	if (ipf_checkl4sum(fin) == -1) {
1196		fin->fin_flx |= FI_BAD;
1197		return -1;
1198	}
1199	return 0;
1200}
1201#endif /* USE_INET6 */
1202
1203
1204size_t
1205mbufchainlen(m0)
1206	struct mbuf *m0;
1207	{
1208	size_t len;
1209
1210	if ((m0->m_flags & M_PKTHDR) != 0) {
1211		len = m0->m_pkthdr.len;
1212	} else {
1213		struct mbuf *m;
1214
1215		for (m = m0, len = 0; m != NULL; m = m->m_next)
1216			len += m->m_len;
1217	}
1218	return len;
1219}
1220
1221
1222/* ------------------------------------------------------------------------ */
1223/* Function:    ipf_pullup                                                  */
1224/* Returns:     NULL == pullup failed, else pointer to protocol header      */
1225/* Parameters:  xmin(I)- pointer to buffer where data packet starts         */
1226/*              fin(I) - pointer to packet information                      */
1227/*              len(I) - number of bytes to pullup                          */
1228/*                                                                          */
1229/* Attempt to move at least len bytes (from the start of the buffer) into a */
1230/* single buffer for ease of access.  Operating system native functions are */
1231/* used to manage buffers - if necessary.  If the entire packet ends up in  */
1232/* a single buffer, set the FI_COALESCE flag even though ipf_coalesce() has */
1233/* not been called.  Both fin_ip and fin_dp are updated before exiting _IF_ */
1234/* and ONLY if the pullup succeeds.                                         */
1235/*                                                                          */
1236/* We assume that 'xmin' is a pointer to a buffer that is part of the chain */
1237/* of buffers that starts at *fin->fin_mp.                                  */
1238/* ------------------------------------------------------------------------ */
1239void *
1240ipf_pullup(xmin, fin, len)
1241	mb_t *xmin;
1242	fr_info_t *fin;
1243	int len;
1244{
1245	int dpoff, ipoff;
1246	mb_t *m = xmin;
1247	char *ip;
1248
1249	if (m == NULL)
1250		return NULL;
1251
1252	ip = (char *)fin->fin_ip;
1253	if ((fin->fin_flx & FI_COALESCE) != 0)
1254		return ip;
1255
1256	ipoff = fin->fin_ipoff;
1257	if (fin->fin_dp != NULL)
1258		dpoff = (char *)fin->fin_dp - (char *)ip;
1259	else
1260		dpoff = 0;
1261
1262	if (M_LEN(m) < len) {
1263		mb_t *n = *fin->fin_mp;
1264		/*
1265		 * Assume that M_PKTHDR is set and just work with what is left
1266		 * rather than check..
1267		 * Should not make any real difference, anyway.
1268		 */
1269		if (m != n) {
1270			/*
1271			 * Record the mbuf that points to the mbuf that we're
1272			 * about to go to work on so that we can update the
1273			 * m_next appropriately later.
1274			 */
1275			for (; n->m_next != m; n = n->m_next)
1276				;
1277		} else {
1278			n = NULL;
1279		}
1280
1281#ifdef MHLEN
1282		if (len > MHLEN)
1283#else
1284		if (len > MLEN)
1285#endif
1286		{
1287#ifdef HAVE_M_PULLDOWN
1288			if (m_pulldown(m, 0, len, NULL) == NULL)
1289				m = NULL;
1290#else
1291			FREE_MB_T(*fin->fin_mp);
1292			m = NULL;
1293			n = NULL;
1294#endif
1295		} else
1296		{
1297			m = m_pullup(m, len);
1298		}
1299		if (n != NULL)
1300			n->m_next = m;
1301		if (m == NULL) {
1302			/*
1303			 * When n is non-NULL, it indicates that m pointed to
1304			 * a sub-chain (tail) of the mbuf and that the head
1305			 * of this chain has not yet been free'd.
1306			 */
1307			if (n != NULL) {
1308				FREE_MB_T(*fin->fin_mp);
1309			}
1310
1311			*fin->fin_mp = NULL;
1312			fin->fin_m = NULL;
1313			return NULL;
1314		}
1315
1316		if (n == NULL)
1317			*fin->fin_mp = m;
1318
1319		while (M_LEN(m) == 0) {
1320			m = m->m_next;
1321		}
1322		fin->fin_m = m;
1323		ip = MTOD(m, char *) + ipoff;
1324
1325		fin->fin_ip = (ip_t *)ip;
1326		if (fin->fin_dp != NULL)
1327			fin->fin_dp = (char *)fin->fin_ip + dpoff;
1328		if (fin->fin_fraghdr != NULL)
1329			fin->fin_fraghdr = (char *)ip +
1330					   ((char *)fin->fin_fraghdr -
1331					    (char *)fin->fin_ip);
1332	}
1333
1334	if (len == fin->fin_plen)
1335		fin->fin_flx |= FI_COALESCE;
1336	return ip;
1337}
1338
1339
1340int
1341ipf_inject(fin, m)
1342	fr_info_t *fin;
1343	mb_t *m;
1344{
1345	int error = 0;
1346
1347	if (fin->fin_out == 0) {
1348		netisr_dispatch(NETISR_IP, m);
1349	} else {
1350		fin->fin_ip->ip_len = ntohs(fin->fin_ip->ip_len);
1351		fin->fin_ip->ip_off = ntohs(fin->fin_ip->ip_off);
1352		error = ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL);
1353	}
1354
1355	return error;
1356}
1357
1358int ipf_pfil_unhook(void) {
1359	struct pfil_head *ph_inet;
1360#ifdef USE_INET6
1361	struct pfil_head *ph_inet6;
1362#endif
1363
1364	ph_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET);
1365	if (ph_inet != NULL)
1366		pfil_remove_hook((void *)ipf_check_wrapper, NULL,
1367		    PFIL_IN|PFIL_OUT|PFIL_WAITOK, ph_inet);
1368# ifdef USE_INET6
1369	ph_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6);
1370	if (ph_inet6 != NULL)
1371		pfil_remove_hook((void *)ipf_check_wrapper6, NULL,
1372		    PFIL_IN|PFIL_OUT|PFIL_WAITOK, ph_inet6);
1373# endif
1374
1375	return (0);
1376}
1377
1378int ipf_pfil_hook(void) {
1379	struct pfil_head *ph_inet;
1380#ifdef USE_INET6
1381	struct pfil_head *ph_inet6;
1382#endif
1383
1384	ph_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET);
1385#    ifdef USE_INET6
1386	ph_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6);
1387#    endif
1388	if (ph_inet == NULL
1389#    ifdef USE_INET6
1390	    && ph_inet6 == NULL
1391#    endif
1392	   ) {
1393		return ENODEV;
1394	}
1395
1396	if (ph_inet != NULL)
1397		pfil_add_hook((void *)ipf_check_wrapper, NULL,
1398		    PFIL_IN|PFIL_OUT|PFIL_WAITOK, ph_inet);
1399#  ifdef USE_INET6
1400	if (ph_inet6 != NULL)
1401		pfil_add_hook((void *)ipf_check_wrapper6, NULL,
1402				      PFIL_IN|PFIL_OUT|PFIL_WAITOK, ph_inet6);
1403#  endif
1404	return (0);
1405}
1406
1407void
1408ipf_event_reg(void)
1409{
1410	ipf_arrivetag = EVENTHANDLER_REGISTER(ifnet_arrival_event, \
1411					       ipf_ifevent, &ipfmain, \
1412					       EVENTHANDLER_PRI_ANY);
1413	ipf_departtag = EVENTHANDLER_REGISTER(ifnet_departure_event, \
1414					       ipf_ifevent, &ipfmain, \
1415					       EVENTHANDLER_PRI_ANY);
1416	ipf_clonetag  = EVENTHANDLER_REGISTER(if_clone_event, ipf_ifevent, \
1417					       &ipfmain, EVENTHANDLER_PRI_ANY);
1418}
1419
1420void
1421ipf_event_dereg(void)
1422{
1423	if (ipf_arrivetag != NULL) {
1424		EVENTHANDLER_DEREGISTER(ifnet_arrival_event, ipf_arrivetag);
1425	}
1426	if (ipf_departtag != NULL) {
1427		EVENTHANDLER_DEREGISTER(ifnet_departure_event, ipf_departtag);
1428	}
1429	if (ipf_clonetag != NULL) {
1430		EVENTHANDLER_DEREGISTER(if_clone_event, ipf_clonetag);
1431	}
1432}
1433
1434
1435u_32_t
1436ipf_random()
1437{
1438	return arc4random();
1439}
1440
1441
1442u_int
1443ipf_pcksum(fin, hlen, sum)
1444	fr_info_t *fin;
1445	int hlen;
1446	u_int sum;
1447{
1448	struct mbuf *m;
1449	u_int sum2;
1450	int off;
1451
1452	m = fin->fin_m;
1453	off = (char *)fin->fin_dp - (char *)fin->fin_ip;
1454	m->m_data += hlen;
1455	m->m_len -= hlen;
1456	sum2 = in_cksum(fin->fin_m, fin->fin_plen - off);
1457	m->m_len += hlen;
1458	m->m_data -= hlen;
1459
1460	/*
1461	 * Both sum and sum2 are partial sums, so combine them together.
1462	 */
1463	sum += ~sum2 & 0xffff;
1464	while (sum > 0xffff)
1465		sum = (sum & 0xffff) + (sum >> 16);
1466	sum2 = ~sum & 0xffff;
1467	return sum2;
1468}
1469