ip_fil_freebsd.c revision 341379 
1/*	$FreeBSD: stable/10/sys/contrib/ipfilter/netinet/ip_fil_freebsd.c 341379 2018-12-01 18:17:51Z 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#if !defined(__hpux)
42# include <sys/mbuf.h>
43#endif
44#include <sys/socket.h>
45# include <sys/selinfo.h>
46# include <netinet/tcp_var.h>
47
48#include <net/if.h>
49# include <net/if_var.h>
50#  include <net/netisr.h>
51#include <net/route.h>
52#include <netinet/in.h>
53#include <netinet/in_var.h>
54#include <netinet/in_systm.h>
55#include <netinet/ip.h>
56#include <netinet/ip_var.h>
57#include <netinet/tcp.h>
58#if defined(__FreeBSD_version) && (__FreeBSD_version >= 800000)
59#include <net/vnet.h>
60#else
61#define CURVNET_SET(arg)
62#define CURVNET_RESTORE()
63#endif
64#include <netinet/udp.h>
65#include <netinet/tcpip.h>
66#include <netinet/ip_icmp.h>
67#include "netinet/ip_compat.h"
68#ifdef USE_INET6
69# include <netinet/icmp6.h>
70#endif
71#include "netinet/ip_fil.h"
72#include "netinet/ip_nat.h"
73#include "netinet/ip_frag.h"
74#include "netinet/ip_state.h"
75#include "netinet/ip_proxy.h"
76#include "netinet/ip_auth.h"
77#include "netinet/ip_sync.h"
78#include "netinet/ip_lookup.h"
79#include "netinet/ip_dstlist.h"
80#ifdef	IPFILTER_SCAN
81#include "netinet/ip_scan.h"
82#endif
83#include "netinet/ip_pool.h"
84# include <sys/malloc.h>
85#include <sys/kernel.h>
86#ifdef CSUM_DATA_VALID
87#include <machine/in_cksum.h>
88#endif
89extern	int	ip_optcopy __P((struct ip *, struct ip *));
90
91
92# ifdef IPFILTER_M_IPFILTER
93MALLOC_DEFINE(M_IPFILTER, "ipfilter", "IP Filter packet filter data structures");
94# endif
95
96
97static	u_short	ipid = 0;
98static	int	(*ipf_savep) __P((void *, ip_t *, int, void *, int, struct mbuf **));
99static	int	ipf_send_ip __P((fr_info_t *, mb_t *));
100static void	ipf_timer_func __P((void *arg));
101int		ipf_locks_done = 0;
102
103ipf_main_softc_t ipfmain;
104
105# include <sys/conf.h>
106# if defined(NETBSD_PF)
107#  include <net/pfil.h>
108# endif /* NETBSD_PF */
109/*
110 * We provide the ipf_checkp name just to minimize changes later.
111 */
112int (*ipf_checkp) __P((void *, ip_t *ip, int hlen, void *ifp, int out, mb_t **mp));
113
114
115static eventhandler_tag ipf_arrivetag, ipf_departtag, ipf_clonetag;
116
117static void ipf_ifevent(void *arg);
118
119static void ipf_ifevent(arg)
120	void *arg;
121{
122        ipf_sync(arg, NULL);
123}
124
125
126
127static int
128ipf_check_wrapper(void *arg, struct mbuf **mp, struct ifnet *ifp, int dir)
129{
130	struct ip *ip = mtod(*mp, struct ip *);
131	int rv;
132
133	/*
134	 * IPFilter expects evreything in network byte order
135	 */
136#if (__FreeBSD_version < 1000019)
137	ip->ip_len = htons(ip->ip_len);
138	ip->ip_off = htons(ip->ip_off);
139#endif
140	rv = ipf_check(&ipfmain, ip, ip->ip_hl << 2, ifp, (dir == PFIL_OUT),
141		       mp);
142#if (__FreeBSD_version < 1000019)
143	if ((rv == 0) && (*mp != NULL)) {
144		ip = mtod(*mp, struct ip *);
145		ip->ip_len = ntohs(ip->ip_len);
146		ip->ip_off = ntohs(ip->ip_off);
147	}
148#endif
149	return rv;
150}
151
152# ifdef USE_INET6
153#  include <netinet/ip6.h>
154
155static int
156ipf_check_wrapper6(void *arg, struct mbuf **mp, struct ifnet *ifp, int dir)
157{
158	return (ipf_check(&ipfmain, mtod(*mp, struct ip *),
159			  sizeof(struct ip6_hdr), ifp, (dir == PFIL_OUT), mp));
160}
161# endif
162#if	defined(IPFILTER_LKM)
163int ipf_identify(s)
164	char *s;
165{
166	if (strcmp(s, "ipl") == 0)
167		return 1;
168	return 0;
169}
170#endif /* IPFILTER_LKM */
171
172
173static void
174ipf_timer_func(arg)
175	void *arg;
176{
177	ipf_main_softc_t *softc = arg;
178	SPL_INT(s);
179
180	SPL_NET(s);
181	READ_ENTER(&softc->ipf_global);
182
183        if (softc->ipf_running > 0)
184		ipf_slowtimer(softc);
185
186	if (softc->ipf_running == -1 || softc->ipf_running == 1) {
187#if 0
188		softc->ipf_slow_ch = timeout(ipf_timer_func, softc, hz/2);
189#endif
190		callout_init(&softc->ipf_slow_ch, 1);
191		callout_reset(&softc->ipf_slow_ch,
192			(hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT,
193			ipf_timer_func, softc);
194	}
195	RWLOCK_EXIT(&softc->ipf_global);
196	SPL_X(s);
197}
198
199
200int
201ipfattach(softc)
202	ipf_main_softc_t *softc;
203{
204#ifdef USE_SPL
205	int s;
206#endif
207
208	SPL_NET(s);
209	if (softc->ipf_running > 0) {
210		SPL_X(s);
211		return EBUSY;
212	}
213
214	if (ipf_init_all(softc) < 0) {
215		SPL_X(s);
216		return EIO;
217	}
218
219
220	if (ipf_checkp != ipf_check) {
221		ipf_savep = ipf_checkp;
222		ipf_checkp = ipf_check;
223	}
224
225	bzero((char *)ipfmain.ipf_selwait, sizeof(ipfmain.ipf_selwait));
226	softc->ipf_running = 1;
227
228	if (softc->ipf_control_forwarding & 1)
229		V_ipforwarding = 1;
230
231	ipid = 0;
232
233	SPL_X(s);
234#if 0
235	softc->ipf_slow_ch = timeout(ipf_timer_func, softc,
236				     (hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT);
237#endif
238	callout_init(&softc->ipf_slow_ch, 1);
239	callout_reset(&softc->ipf_slow_ch, (hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT,
240		ipf_timer_func, softc);
241	return 0;
242}
243
244
245/*
246 * Disable the filter by removing the hooks from the IP input/output
247 * stream.
248 */
249int
250ipfdetach(softc)
251	ipf_main_softc_t *softc;
252{
253#ifdef USE_SPL
254	int s;
255#endif
256
257	if (softc->ipf_control_forwarding & 2)
258		V_ipforwarding = 0;
259
260	SPL_NET(s);
261
262#if 0
263	if (softc->ipf_slow_ch.callout != NULL)
264		untimeout(ipf_timer_func, softc, softc->ipf_slow_ch);
265	bzero(&softc->ipf_slow, sizeof(softc->ipf_slow));
266#endif
267	callout_drain(&softc->ipf_slow_ch);
268
269#ifndef NETBSD_PF
270	if (ipf_checkp != NULL)
271		ipf_checkp = ipf_savep;
272	ipf_savep = NULL;
273#endif
274
275	ipf_fini_all(softc);
276
277	softc->ipf_running = -2;
278
279	SPL_X(s);
280
281	return 0;
282}
283
284
285/*
286 * Filter ioctl interface.
287 */
288int
289ipfioctl(dev, cmd, data, mode, p)
290	struct thread *p;
291#    define	p_cred	td_ucred
292#    define	p_uid	td_ucred->cr_ruid
293	struct cdev *dev;
294	ioctlcmd_t cmd;
295	caddr_t data;
296	int mode;
297{
298	int error = 0, unit = 0;
299	SPL_INT(s);
300
301#if (BSD >= 199306)
302        if (securelevel_ge(p->p_cred, 3) && (mode & FWRITE))
303	{
304		ipfmain.ipf_interror = 130001;
305		return EPERM;
306	}
307#endif
308
309	unit = GET_MINOR(dev);
310	if ((IPL_LOGMAX < unit) || (unit < 0)) {
311		ipfmain.ipf_interror = 130002;
312		return ENXIO;
313	}
314
315	if (ipfmain.ipf_running <= 0) {
316		if (unit != IPL_LOGIPF && cmd != SIOCIPFINTERROR) {
317			ipfmain.ipf_interror = 130003;
318			return EIO;
319		}
320		if (cmd != SIOCIPFGETNEXT && cmd != SIOCIPFGET &&
321		    cmd != SIOCIPFSET && cmd != SIOCFRENB &&
322		    cmd != SIOCGETFS && cmd != SIOCGETFF &&
323		    cmd != SIOCIPFINTERROR) {
324			ipfmain.ipf_interror = 130004;
325			return EIO;
326		}
327	}
328
329	SPL_NET(s);
330
331	CURVNET_SET(TD_TO_VNET(p));
332	error = ipf_ioctlswitch(&ipfmain, unit, data, cmd, mode, p->p_uid, p);
333	CURVNET_RESTORE();
334	if (error != -1) {
335		SPL_X(s);
336		return error;
337	}
338
339	SPL_X(s);
340
341	return error;
342}
343
344
345/*
346 * ipf_send_reset - this could conceivably be a call to tcp_respond(), but that
347 * requires a large amount of setting up and isn't any more efficient.
348 */
349int
350ipf_send_reset(fin)
351	fr_info_t *fin;
352{
353	struct tcphdr *tcp, *tcp2;
354	int tlen = 0, hlen;
355	struct mbuf *m;
356#ifdef USE_INET6
357	ip6_t *ip6;
358#endif
359	ip_t *ip;
360
361	tcp = fin->fin_dp;
362	if (tcp->th_flags & TH_RST)
363		return -1;		/* feedback loop */
364
365	if (ipf_checkl4sum(fin) == -1)
366		return -1;
367
368	tlen = fin->fin_dlen - (TCP_OFF(tcp) << 2) +
369			((tcp->th_flags & TH_SYN) ? 1 : 0) +
370			((tcp->th_flags & TH_FIN) ? 1 : 0);
371
372#ifdef USE_INET6
373	hlen = (fin->fin_v == 6) ? sizeof(ip6_t) : sizeof(ip_t);
374#else
375	hlen = sizeof(ip_t);
376#endif
377#ifdef MGETHDR
378	MGETHDR(m, M_DONTWAIT, MT_HEADER);
379#else
380	MGET(m, M_DONTWAIT, MT_HEADER);
381#endif
382	if (m == NULL)
383		return -1;
384	if (sizeof(*tcp2) + hlen > MLEN) {
385		MCLGET(m, M_DONTWAIT);
386		if ((m->m_flags & M_EXT) == 0) {
387			FREE_MB_T(m);
388			return -1;
389		}
390	}
391
392	m->m_len = sizeof(*tcp2) + hlen;
393#if (BSD >= 199103)
394	m->m_data += max_linkhdr;
395	m->m_pkthdr.len = m->m_len;
396	m->m_pkthdr.rcvif = (struct ifnet *)0;
397#endif
398	ip = mtod(m, struct ip *);
399	bzero((char *)ip, hlen);
400#ifdef USE_INET6
401	ip6 = (ip6_t *)ip;
402#endif
403	tcp2 = (struct tcphdr *)((char *)ip + hlen);
404	tcp2->th_sport = tcp->th_dport;
405	tcp2->th_dport = tcp->th_sport;
406
407	if (tcp->th_flags & TH_ACK) {
408		tcp2->th_seq = tcp->th_ack;
409		tcp2->th_flags = TH_RST;
410		tcp2->th_ack = 0;
411	} else {
412		tcp2->th_seq = 0;
413		tcp2->th_ack = ntohl(tcp->th_seq);
414		tcp2->th_ack += tlen;
415		tcp2->th_ack = htonl(tcp2->th_ack);
416		tcp2->th_flags = TH_RST|TH_ACK;
417	}
418	TCP_X2_A(tcp2, 0);
419	TCP_OFF_A(tcp2, sizeof(*tcp2) >> 2);
420	tcp2->th_win = tcp->th_win;
421	tcp2->th_sum = 0;
422	tcp2->th_urp = 0;
423
424#ifdef USE_INET6
425	if (fin->fin_v == 6) {
426		ip6->ip6_flow = ((ip6_t *)fin->fin_ip)->ip6_flow;
427		ip6->ip6_plen = htons(sizeof(struct tcphdr));
428		ip6->ip6_nxt = IPPROTO_TCP;
429		ip6->ip6_hlim = 0;
430		ip6->ip6_src = fin->fin_dst6.in6;
431		ip6->ip6_dst = fin->fin_src6.in6;
432		tcp2->th_sum = in6_cksum(m, IPPROTO_TCP,
433					 sizeof(*ip6), sizeof(*tcp2));
434		return ipf_send_ip(fin, m);
435	}
436#endif
437	ip->ip_p = IPPROTO_TCP;
438	ip->ip_len = htons(sizeof(struct tcphdr));
439	ip->ip_src.s_addr = fin->fin_daddr;
440	ip->ip_dst.s_addr = fin->fin_saddr;
441	tcp2->th_sum = in_cksum(m, hlen + sizeof(*tcp2));
442	ip->ip_len = htons(hlen + sizeof(*tcp2));
443	return ipf_send_ip(fin, m);
444}
445
446
447/*
448 * ip_len must be in network byte order when called.
449 */
450static int
451ipf_send_ip(fin, m)
452	fr_info_t *fin;
453	mb_t *m;
454{
455	fr_info_t fnew;
456	ip_t *ip, *oip;
457	int hlen;
458
459	ip = mtod(m, ip_t *);
460	bzero((char *)&fnew, sizeof(fnew));
461	fnew.fin_main_soft = fin->fin_main_soft;
462
463	IP_V_A(ip, fin->fin_v);
464	switch (fin->fin_v)
465	{
466	case 4 :
467		oip = fin->fin_ip;
468		hlen = sizeof(*oip);
469		fnew.fin_v = 4;
470		fnew.fin_p = ip->ip_p;
471		fnew.fin_plen = ntohs(ip->ip_len);
472		IP_HL_A(ip, sizeof(*oip) >> 2);
473		ip->ip_tos = oip->ip_tos;
474		ip->ip_id = fin->fin_ip->ip_id;
475#if defined(FreeBSD) && (__FreeBSD_version > 460000)
476		ip->ip_off = htons(path_mtu_discovery ? IP_DF : 0);
477#else
478		ip->ip_off = 0;
479#endif
480		ip->ip_ttl = V_ip_defttl;
481		ip->ip_sum = 0;
482		break;
483#ifdef USE_INET6
484	case 6 :
485	{
486		ip6_t *ip6 = (ip6_t *)ip;
487
488		ip6->ip6_vfc = 0x60;
489		ip6->ip6_hlim = IPDEFTTL;
490
491		hlen = sizeof(*ip6);
492		fnew.fin_p = ip6->ip6_nxt;
493		fnew.fin_v = 6;
494		fnew.fin_plen = ntohs(ip6->ip6_plen) + hlen;
495		break;
496	}
497#endif
498	default :
499		return EINVAL;
500	}
501#ifdef IPSEC
502	m->m_pkthdr.rcvif = NULL;
503#endif
504
505	fnew.fin_ifp = fin->fin_ifp;
506	fnew.fin_flx = FI_NOCKSUM;
507	fnew.fin_m = m;
508	fnew.fin_ip = ip;
509	fnew.fin_mp = &m;
510	fnew.fin_hlen = hlen;
511	fnew.fin_dp = (char *)ip + hlen;
512	(void) ipf_makefrip(hlen, ip, &fnew);
513
514	return ipf_fastroute(m, &m, &fnew, NULL);
515}
516
517
518int
519ipf_send_icmp_err(type, fin, dst)
520	int type;
521	fr_info_t *fin;
522	int dst;
523{
524	int err, hlen, xtra, iclen, ohlen, avail, code;
525	struct in_addr dst4;
526	struct icmp *icmp;
527	struct mbuf *m;
528	i6addr_t dst6;
529	void *ifp;
530#ifdef USE_INET6
531	ip6_t *ip6;
532#endif
533	ip_t *ip, *ip2;
534
535	if ((type < 0) || (type >= ICMP_MAXTYPE))
536		return -1;
537
538	code = fin->fin_icode;
539#ifdef USE_INET6
540#if 0
541	/* XXX Fix an off by one error: s/>/>=/
542	 was:
543	 if ((code < 0) || (code > sizeof(icmptoicmp6unreach)/sizeof(int)))
544	 Fix obtained from NetBSD ip_fil_netbsd.c r1.4: */
545#endif
546	if ((code < 0) || (code >= sizeof(icmptoicmp6unreach)/sizeof(int)))
547		return -1;
548#endif
549
550	if (ipf_checkl4sum(fin) == -1)
551		return -1;
552#ifdef MGETHDR
553	MGETHDR(m, M_DONTWAIT, MT_HEADER);
554#else
555	MGET(m, M_DONTWAIT, MT_HEADER);
556#endif
557	if (m == NULL)
558		return -1;
559	avail = MHLEN;
560
561	xtra = 0;
562	hlen = 0;
563	ohlen = 0;
564	dst4.s_addr = 0;
565	ifp = fin->fin_ifp;
566	if (fin->fin_v == 4) {
567		if ((fin->fin_p == IPPROTO_ICMP) && !(fin->fin_flx & FI_SHORT))
568			switch (ntohs(fin->fin_data[0]) >> 8)
569			{
570			case ICMP_ECHO :
571			case ICMP_TSTAMP :
572			case ICMP_IREQ :
573			case ICMP_MASKREQ :
574				break;
575			default :
576				FREE_MB_T(m);
577				return 0;
578			}
579
580		if (dst == 0) {
581			if (ipf_ifpaddr(&ipfmain, 4, FRI_NORMAL, ifp,
582					&dst6, NULL) == -1) {
583				FREE_MB_T(m);
584				return -1;
585			}
586			dst4 = dst6.in4;
587		} else
588			dst4.s_addr = fin->fin_daddr;
589
590		hlen = sizeof(ip_t);
591		ohlen = fin->fin_hlen;
592		iclen = hlen + offsetof(struct icmp, icmp_ip) + ohlen;
593		if (fin->fin_hlen < fin->fin_plen)
594			xtra = MIN(fin->fin_dlen, 8);
595		else
596			xtra = 0;
597	}
598
599#ifdef USE_INET6
600	else if (fin->fin_v == 6) {
601		hlen = sizeof(ip6_t);
602		ohlen = sizeof(ip6_t);
603		iclen = hlen + offsetof(struct icmp, icmp_ip) + ohlen;
604		type = icmptoicmp6types[type];
605		if (type == ICMP6_DST_UNREACH)
606			code = icmptoicmp6unreach[code];
607
608		if (iclen + max_linkhdr + fin->fin_plen > avail) {
609			MCLGET(m, M_DONTWAIT);
610			if ((m->m_flags & M_EXT) == 0) {
611				FREE_MB_T(m);
612				return -1;
613			}
614			avail = MCLBYTES;
615		}
616		xtra = MIN(fin->fin_plen, avail - iclen - max_linkhdr);
617		xtra = MIN(xtra, IPV6_MMTU - iclen);
618		if (dst == 0) {
619			if (ipf_ifpaddr(&ipfmain, 6, FRI_NORMAL, ifp,
620					&dst6, NULL) == -1) {
621				FREE_MB_T(m);
622				return -1;
623			}
624		} else
625			dst6 = fin->fin_dst6;
626	}
627#endif
628	else {
629		FREE_MB_T(m);
630		return -1;
631	}
632
633	avail -= (max_linkhdr + iclen);
634	if (avail < 0) {
635		FREE_MB_T(m);
636		return -1;
637	}
638	if (xtra > avail)
639		xtra = avail;
640	iclen += xtra;
641	m->m_data += max_linkhdr;
642	m->m_pkthdr.rcvif = (struct ifnet *)0;
643	m->m_pkthdr.len = iclen;
644	m->m_len = iclen;
645	ip = mtod(m, ip_t *);
646	icmp = (struct icmp *)((char *)ip + hlen);
647	ip2 = (ip_t *)&icmp->icmp_ip;
648
649	icmp->icmp_type = type;
650	icmp->icmp_code = fin->fin_icode;
651	icmp->icmp_cksum = 0;
652#ifdef icmp_nextmtu
653	if (type == ICMP_UNREACH && fin->fin_icode == ICMP_UNREACH_NEEDFRAG) {
654		if (fin->fin_mtu != 0) {
655			icmp->icmp_nextmtu = htons(fin->fin_mtu);
656
657		} else if (ifp != NULL) {
658			icmp->icmp_nextmtu = htons(GETIFMTU_4(ifp));
659
660		} else {	/* make up a number... */
661			icmp->icmp_nextmtu = htons(fin->fin_plen - 20);
662		}
663	}
664#endif
665
666	bcopy((char *)fin->fin_ip, (char *)ip2, ohlen);
667
668#ifdef USE_INET6
669	ip6 = (ip6_t *)ip;
670	if (fin->fin_v == 6) {
671		ip6->ip6_flow = ((ip6_t *)fin->fin_ip)->ip6_flow;
672		ip6->ip6_plen = htons(iclen - hlen);
673		ip6->ip6_nxt = IPPROTO_ICMPV6;
674		ip6->ip6_hlim = 0;
675		ip6->ip6_src = dst6.in6;
676		ip6->ip6_dst = fin->fin_src6.in6;
677		if (xtra > 0)
678			bcopy((char *)fin->fin_ip + ohlen,
679			      (char *)&icmp->icmp_ip + ohlen, xtra);
680		icmp->icmp_cksum = in6_cksum(m, IPPROTO_ICMPV6,
681					     sizeof(*ip6), iclen - hlen);
682	} else
683#endif
684	{
685		ip->ip_p = IPPROTO_ICMP;
686		ip->ip_src.s_addr = dst4.s_addr;
687		ip->ip_dst.s_addr = fin->fin_saddr;
688
689		if (xtra > 0)
690			bcopy((char *)fin->fin_ip + ohlen,
691			      (char *)&icmp->icmp_ip + ohlen, xtra);
692		icmp->icmp_cksum = ipf_cksum((u_short *)icmp,
693					     sizeof(*icmp) + 8);
694		ip->ip_len = htons(iclen);
695		ip->ip_p = IPPROTO_ICMP;
696	}
697	err = ipf_send_ip(fin, m);
698	return err;
699}
700
701
702
703
704/*
705 * m0 - pointer to mbuf where the IP packet starts
706 * mpp - pointer to the mbuf pointer that is the start of the mbuf chain
707 */
708int
709ipf_fastroute(m0, mpp, fin, fdp)
710	mb_t *m0, **mpp;
711	fr_info_t *fin;
712	frdest_t *fdp;
713{
714	register struct ip *ip, *mhip;
715	register struct mbuf *m = *mpp;
716	register struct route *ro;
717	int len, off, error = 0, hlen, code;
718	struct ifnet *ifp, *sifp;
719	struct sockaddr_in *dst;
720	struct route iproute;
721	u_short ip_off;
722	frdest_t node;
723	frentry_t *fr;
724
725	ro = NULL;
726
727#ifdef M_WRITABLE
728	/*
729	* HOT FIX/KLUDGE:
730	*
731	* If the mbuf we're about to send is not writable (because of
732	* a cluster reference, for example) we'll need to make a copy
733	* of it since this routine modifies the contents.
734	*
735	* If you have non-crappy network hardware that can transmit data
736	* from the mbuf, rather than making a copy, this is gonna be a
737	* problem.
738	*/
739	if (M_WRITABLE(m) == 0) {
740		m0 = m_dup(m, M_DONTWAIT);
741		if (m0 != NULL) {
742			FREE_MB_T(m);
743			m = m0;
744			*mpp = m;
745		} else {
746			error = ENOBUFS;
747			FREE_MB_T(m);
748			goto done;
749		}
750	}
751#endif
752
753#ifdef USE_INET6
754	if (fin->fin_v == 6) {
755		/*
756		 * currently "to <if>" and "to <if>:ip#" are not supported
757		 * for IPv6
758		 */
759		return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
760	}
761#endif
762
763	hlen = fin->fin_hlen;
764	ip = mtod(m0, struct ip *);
765	ifp = NULL;
766
767	/*
768	 * Route packet.
769	 */
770	ro = &iproute;
771	bzero(ro, sizeof (*ro));
772	dst = (struct sockaddr_in *)&ro->ro_dst;
773	dst->sin_family = AF_INET;
774	dst->sin_addr = ip->ip_dst;
775
776	fr = fin->fin_fr;
777	if ((fr != NULL) && !(fr->fr_flags & FR_KEEPSTATE) && (fdp != NULL) &&
778	    (fdp->fd_type == FRD_DSTLIST)) {
779		if (ipf_dstlist_select_node(fin, fdp->fd_ptr, NULL, &node) == 0)
780			fdp = &node;
781	}
782
783	if (fdp != NULL)
784		ifp = fdp->fd_ptr;
785	else
786		ifp = fin->fin_ifp;
787
788	if ((ifp == NULL) && ((fr == NULL) || !(fr->fr_flags & FR_FASTROUTE))) {
789		error = -2;
790		goto bad;
791	}
792
793	if ((fdp != NULL) && (fdp->fd_ip.s_addr != 0))
794		dst->sin_addr = fdp->fd_ip;
795
796	dst->sin_len = sizeof(*dst);
797	in_rtalloc(ro, M_GETFIB(m0));
798
799	if ((ifp == NULL) && (ro->ro_rt != NULL))
800		ifp = ro->ro_rt->rt_ifp;
801
802	if ((ro->ro_rt == NULL) || (ifp == NULL)) {
803		if (in_localaddr(ip->ip_dst))
804			error = EHOSTUNREACH;
805		else
806			error = ENETUNREACH;
807		goto bad;
808	}
809	if (ro->ro_rt->rt_flags & RTF_GATEWAY)
810		dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway;
811	if (ro->ro_rt)
812		counter_u64_add(ro->ro_rt->rt_pksent, 1);
813
814	/*
815	 * For input packets which are being "fastrouted", they won't
816	 * go back through output filtering and miss their chance to get
817	 * NAT'd and counted.  Duplicated packets aren't considered to be
818	 * part of the normal packet stream, so do not NAT them or pass
819	 * them through stateful checking, etc.
820	 */
821	if ((fdp != &fr->fr_dif) && (fin->fin_out == 0)) {
822		sifp = fin->fin_ifp;
823		fin->fin_ifp = ifp;
824		fin->fin_out = 1;
825		(void) ipf_acctpkt(fin, NULL);
826		fin->fin_fr = NULL;
827		if (!fr || !(fr->fr_flags & FR_RETMASK)) {
828			u_32_t pass;
829
830			(void) ipf_state_check(fin, &pass);
831		}
832
833		switch (ipf_nat_checkout(fin, NULL))
834		{
835		case 0 :
836			break;
837		case 1 :
838			ip->ip_sum = 0;
839			break;
840		case -1 :
841			error = -1;
842			goto bad;
843			break;
844		}
845
846		fin->fin_ifp = sifp;
847		fin->fin_out = 0;
848	} else
849		ip->ip_sum = 0;
850	/*
851	 * If small enough for interface, can just send directly.
852	 */
853	if (ntohs(ip->ip_len) <= ifp->if_mtu) {
854		if (!ip->ip_sum)
855			ip->ip_sum = in_cksum(m, hlen);
856		error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst,
857			    ro
858			);
859		goto done;
860	}
861	/*
862	 * Too large for interface; fragment if possible.
863	 * Must be able to put at least 8 bytes per fragment.
864	 */
865	ip_off = ntohs(ip->ip_off);
866	if (ip_off & IP_DF) {
867		error = EMSGSIZE;
868		goto bad;
869	}
870	len = (ifp->if_mtu - hlen) &~ 7;
871	if (len < 8) {
872		error = EMSGSIZE;
873		goto bad;
874	}
875
876    {
877	int mhlen, firstlen = len;
878	struct mbuf **mnext = &m->m_act;
879
880	/*
881	 * Loop through length of segment after first fragment,
882	 * make new header and copy data of each part and link onto chain.
883	 */
884	m0 = m;
885	mhlen = sizeof (struct ip);
886	for (off = hlen + len; off < ntohs(ip->ip_len); off += len) {
887#ifdef MGETHDR
888		MGETHDR(m, M_DONTWAIT, MT_HEADER);
889#else
890		MGET(m, M_DONTWAIT, MT_HEADER);
891#endif
892		if (m == NULL) {
893			m = m0;
894			error = ENOBUFS;
895			goto bad;
896		}
897		m->m_data += max_linkhdr;
898		mhip = mtod(m, struct ip *);
899		bcopy((char *)ip, (char *)mhip, sizeof(*ip));
900		if (hlen > sizeof (struct ip)) {
901			mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
902			IP_HL_A(mhip, mhlen >> 2);
903		}
904		m->m_len = mhlen;
905		mhip->ip_off = ((off - hlen) >> 3) + ip_off;
906		if (off + len >= ntohs(ip->ip_len))
907			len = ntohs(ip->ip_len) - off;
908		else
909			mhip->ip_off |= IP_MF;
910		mhip->ip_len = htons((u_short)(len + mhlen));
911		*mnext = m;
912		m->m_next = m_copy(m0, off, len);
913		if (m->m_next == 0) {
914			error = ENOBUFS;	/* ??? */
915			goto sendorfree;
916		}
917		m->m_pkthdr.len = mhlen + len;
918		m->m_pkthdr.rcvif = NULL;
919		mhip->ip_off = htons((u_short)mhip->ip_off);
920		mhip->ip_sum = 0;
921		mhip->ip_sum = in_cksum(m, mhlen);
922		mnext = &m->m_act;
923	}
924	/*
925	 * Update first fragment by trimming what's been copied out
926	 * and updating header, then send each fragment (in order).
927	 */
928	m_adj(m0, hlen + firstlen - ip->ip_len);
929	ip->ip_len = htons((u_short)(hlen + firstlen));
930	ip->ip_off = htons((u_short)IP_MF);
931	ip->ip_sum = 0;
932	ip->ip_sum = in_cksum(m0, hlen);
933sendorfree:
934	for (m = m0; m; m = m0) {
935		m0 = m->m_act;
936		m->m_act = 0;
937		if (error == 0)
938			error = (*ifp->if_output)(ifp, m,
939			    (struct sockaddr *)dst,
940			    ro
941			    );
942		else
943			FREE_MB_T(m);
944	}
945    }
946done:
947	if (!error)
948		ipfmain.ipf_frouteok[0]++;
949	else
950		ipfmain.ipf_frouteok[1]++;
951
952	if ((ro != NULL) && (ro->ro_rt != NULL)) {
953		RTFREE(ro->ro_rt);
954	}
955	return 0;
956bad:
957	if (error == EMSGSIZE) {
958		sifp = fin->fin_ifp;
959		code = fin->fin_icode;
960		fin->fin_icode = ICMP_UNREACH_NEEDFRAG;
961		fin->fin_ifp = ifp;
962		(void) ipf_send_icmp_err(ICMP_UNREACH, fin, 1);
963		fin->fin_ifp = sifp;
964		fin->fin_icode = code;
965	}
966	FREE_MB_T(m);
967	goto done;
968}
969
970
971int
972ipf_verifysrc(fin)
973	fr_info_t *fin;
974{
975	struct sockaddr_in *dst;
976	struct route iproute;
977
978	bzero((char *)&iproute, sizeof(iproute));
979	dst = (struct sockaddr_in *)&iproute.ro_dst;
980	dst->sin_len = sizeof(*dst);
981	dst->sin_family = AF_INET;
982	dst->sin_addr = fin->fin_src;
983	in_rtalloc(&iproute, 0);
984	if (iproute.ro_rt == NULL)
985		return 0;
986	return (fin->fin_ifp == iproute.ro_rt->rt_ifp);
987}
988
989
990/*
991 * return the first IP Address associated with an interface
992 */
993int
994ipf_ifpaddr(softc, v, atype, ifptr, inp, inpmask)
995	ipf_main_softc_t *softc;
996	int v, atype;
997	void *ifptr;
998	i6addr_t *inp, *inpmask;
999{
1000#ifdef USE_INET6
1001	struct in6_addr *inp6 = NULL;
1002#endif
1003	struct sockaddr *sock, *mask;
1004	struct sockaddr_in *sin;
1005	struct ifaddr *ifa;
1006	struct ifnet *ifp;
1007
1008	if ((ifptr == NULL) || (ifptr == (void *)-1))
1009		return -1;
1010
1011	sin = NULL;
1012	ifp = ifptr;
1013
1014	if (v == 4)
1015		inp->in4.s_addr = 0;
1016#ifdef USE_INET6
1017	else if (v == 6)
1018		bzero((char *)inp, sizeof(*inp));
1019#endif
1020	ifa = TAILQ_FIRST(&ifp->if_addrhead);
1021
1022	sock = ifa->ifa_addr;
1023	while (sock != NULL && ifa != NULL) {
1024		sin = (struct sockaddr_in *)sock;
1025		if ((v == 4) && (sin->sin_family == AF_INET))
1026			break;
1027#ifdef USE_INET6
1028		if ((v == 6) && (sin->sin_family == AF_INET6)) {
1029			inp6 = &((struct sockaddr_in6 *)sin)->sin6_addr;
1030			if (!IN6_IS_ADDR_LINKLOCAL(inp6) &&
1031			    !IN6_IS_ADDR_LOOPBACK(inp6))
1032				break;
1033		}
1034#endif
1035		ifa = TAILQ_NEXT(ifa, ifa_link);
1036		if (ifa != NULL)
1037			sock = ifa->ifa_addr;
1038	}
1039
1040	if (ifa == NULL || sin == NULL)
1041		return -1;
1042
1043	mask = ifa->ifa_netmask;
1044	if (atype == FRI_BROADCAST)
1045		sock = ifa->ifa_broadaddr;
1046	else if (atype == FRI_PEERADDR)
1047		sock = ifa->ifa_dstaddr;
1048
1049	if (sock == NULL)
1050		return -1;
1051
1052#ifdef USE_INET6
1053	if (v == 6) {
1054		return ipf_ifpfillv6addr(atype, (struct sockaddr_in6 *)sock,
1055					 (struct sockaddr_in6 *)mask,
1056					 inp, inpmask);
1057	}
1058#endif
1059	return ipf_ifpfillv4addr(atype, (struct sockaddr_in *)sock,
1060				 (struct sockaddr_in *)mask,
1061				 &inp->in4, &inpmask->in4);
1062}
1063
1064
1065u_32_t
1066ipf_newisn(fin)
1067	fr_info_t *fin;
1068{
1069	u_32_t newiss;
1070	newiss = arc4random();
1071	return newiss;
1072}
1073
1074
1075/* ------------------------------------------------------------------------ */
1076/* Function:    ipf_nextipid                                                */
1077/* Returns:     int - 0 == success, -1 == error (packet should be droppped) */
1078/* Parameters:  fin(I) - pointer to packet information                      */
1079/*                                                                          */
1080/* Returns the next IPv4 ID to use for this packet.                         */
1081/* ------------------------------------------------------------------------ */
1082u_short
1083ipf_nextipid(fin)
1084	fr_info_t *fin;
1085{
1086	u_short id;
1087
1088#ifndef	RANDOM_IP_ID
1089	MUTEX_ENTER(&ipfmain.ipf_rw);
1090	id = ipid++;
1091	MUTEX_EXIT(&ipfmain.ipf_rw);
1092#else
1093	id = ip_randomid();
1094#endif
1095
1096	return id;
1097}
1098
1099
1100INLINE int
1101ipf_checkv4sum(fin)
1102	fr_info_t *fin;
1103{
1104#ifdef CSUM_DATA_VALID
1105	int manual = 0;
1106	u_short sum;
1107	ip_t *ip;
1108	mb_t *m;
1109
1110	if ((fin->fin_flx & FI_NOCKSUM) != 0)
1111		return 0;
1112
1113	if ((fin->fin_flx & FI_SHORT) != 0)
1114		return 1;
1115
1116	if (fin->fin_cksum != FI_CK_NEEDED)
1117		return (fin->fin_cksum > FI_CK_NEEDED) ? 0 : -1;
1118
1119	m = fin->fin_m;
1120	if (m == NULL) {
1121		manual = 1;
1122		goto skipauto;
1123	}
1124	ip = fin->fin_ip;
1125
1126	if ((m->m_pkthdr.csum_flags & (CSUM_IP_CHECKED|CSUM_IP_VALID)) ==
1127	    CSUM_IP_CHECKED) {
1128		fin->fin_cksum = FI_CK_BAD;
1129		fin->fin_flx |= FI_BAD;
1130		return -1;
1131	}
1132	if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
1133		/* Depending on the driver, UDP may have zero checksum */
1134		if (fin->fin_p == IPPROTO_UDP && (fin->fin_flx &
1135		    (FI_FRAG|FI_SHORT|FI_BAD)) == 0) {
1136			udphdr_t *udp = fin->fin_dp;
1137			if (udp->uh_sum == 0) {
1138				/*
1139				 * we're good no matter what the hardware
1140				 * checksum flags and csum_data say (handling
1141				 * of csum_data for zero UDP checksum is not
1142				 * consistent across all drivers)
1143				 */
1144				fin->fin_cksum = 1;
1145				return 0;
1146			}
1147		}
1148
1149		if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
1150			sum = m->m_pkthdr.csum_data;
1151		else
1152			sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
1153					htonl(m->m_pkthdr.csum_data +
1154					fin->fin_dlen + fin->fin_p));
1155		sum ^= 0xffff;
1156		if (sum != 0) {
1157			fin->fin_cksum = FI_CK_BAD;
1158			fin->fin_flx |= FI_BAD;
1159		} else {
1160			fin->fin_cksum = FI_CK_SUMOK;
1161			return 0;
1162		}
1163	} else {
1164		if (m->m_pkthdr.csum_flags == CSUM_DELAY_DATA) {
1165			fin->fin_cksum = FI_CK_L4FULL;
1166			return 0;
1167		} else if (m->m_pkthdr.csum_flags == CSUM_TCP ||
1168			   m->m_pkthdr.csum_flags == CSUM_UDP) {
1169			fin->fin_cksum = FI_CK_L4PART;
1170			return 0;
1171		} else if (m->m_pkthdr.csum_flags == CSUM_IP) {
1172			fin->fin_cksum = FI_CK_L4PART;
1173			return 0;
1174		} else {
1175			manual = 1;
1176		}
1177	}
1178skipauto:
1179	if (manual != 0) {
1180		if (ipf_checkl4sum(fin) == -1) {
1181			fin->fin_flx |= FI_BAD;
1182			return -1;
1183		}
1184	}
1185#else
1186	if (ipf_checkl4sum(fin) == -1) {
1187		fin->fin_flx |= FI_BAD;
1188		return -1;
1189	}
1190#endif
1191	return 0;
1192}
1193
1194
1195#ifdef USE_INET6
1196INLINE int
1197ipf_checkv6sum(fin)
1198	fr_info_t *fin;
1199{
1200	if ((fin->fin_flx & FI_NOCKSUM) != 0)
1201		return 0;
1202
1203	if ((fin->fin_flx & FI_SHORT) != 0)
1204		return 1;
1205
1206	if (fin->fin_cksum != FI_CK_NEEDED)
1207		return (fin->fin_cksum > FI_CK_NEEDED) ? 0 : -1;
1208
1209	if (ipf_checkl4sum(fin) == -1) {
1210		fin->fin_flx |= FI_BAD;
1211		return -1;
1212	}
1213	return 0;
1214}
1215#endif /* USE_INET6 */
1216
1217
1218size_t
1219mbufchainlen(m0)
1220	struct mbuf *m0;
1221	{
1222	size_t len;
1223
1224	if ((m0->m_flags & M_PKTHDR) != 0) {
1225		len = m0->m_pkthdr.len;
1226	} else {
1227		struct mbuf *m;
1228
1229		for (m = m0, len = 0; m != NULL; m = m->m_next)
1230			len += m->m_len;
1231	}
1232	return len;
1233}
1234
1235
1236/* ------------------------------------------------------------------------ */
1237/* Function:    ipf_pullup                                                  */
1238/* Returns:     NULL == pullup failed, else pointer to protocol header      */
1239/* Parameters:  xmin(I)- pointer to buffer where data packet starts         */
1240/*              fin(I) - pointer to packet information                      */
1241/*              len(I) - number of bytes to pullup                          */
1242/*                                                                          */
1243/* Attempt to move at least len bytes (from the start of the buffer) into a */
1244/* single buffer for ease of access.  Operating system native functions are */
1245/* used to manage buffers - if necessary.  If the entire packet ends up in  */
1246/* a single buffer, set the FI_COALESCE flag even though ipf_coalesce() has */
1247/* not been called.  Both fin_ip and fin_dp are updated before exiting _IF_ */
1248/* and ONLY if the pullup succeeds.                                         */
1249/*                                                                          */
1250/* We assume that 'xmin' is a pointer to a buffer that is part of the chain */
1251/* of buffers that starts at *fin->fin_mp.                                  */
1252/* ------------------------------------------------------------------------ */
1253void *
1254ipf_pullup(xmin, fin, len)
1255	mb_t *xmin;
1256	fr_info_t *fin;
1257	int len;
1258{
1259	int dpoff, ipoff;
1260	mb_t *m = xmin;
1261	char *ip;
1262
1263	if (m == NULL)
1264		return NULL;
1265
1266	ip = (char *)fin->fin_ip;
1267	if ((fin->fin_flx & FI_COALESCE) != 0)
1268		return ip;
1269
1270	ipoff = fin->fin_ipoff;
1271	if (fin->fin_dp != NULL)
1272		dpoff = (char *)fin->fin_dp - (char *)ip;
1273	else
1274		dpoff = 0;
1275
1276	if (M_LEN(m) < len) {
1277		mb_t *n = *fin->fin_mp;
1278		/*
1279		 * Assume that M_PKTHDR is set and just work with what is left
1280		 * rather than check..
1281		 * Should not make any real difference, anyway.
1282		 */
1283		if (m != n) {
1284			/*
1285			 * Record the mbuf that points to the mbuf that we're
1286			 * about to go to work on so that we can update the
1287			 * m_next appropriately later.
1288			 */
1289			for (; n->m_next != m; n = n->m_next)
1290				;
1291		} else {
1292			n = NULL;
1293		}
1294
1295#ifdef MHLEN
1296		if (len > MHLEN)
1297#else
1298		if (len > MLEN)
1299#endif
1300		{
1301#ifdef HAVE_M_PULLDOWN
1302			if (m_pulldown(m, 0, len, NULL) == NULL)
1303				m = NULL;
1304#else
1305			FREE_MB_T(*fin->fin_mp);
1306			m = NULL;
1307			n = NULL;
1308#endif
1309		} else
1310		{
1311			m = m_pullup(m, len);
1312		}
1313		if (n != NULL)
1314			n->m_next = m;
1315		if (m == NULL) {
1316			/*
1317			 * When n is non-NULL, it indicates that m pointed to
1318			 * a sub-chain (tail) of the mbuf and that the head
1319			 * of this chain has not yet been free'd.
1320			 */
1321			if (n != NULL) {
1322				FREE_MB_T(*fin->fin_mp);
1323			}
1324
1325			*fin->fin_mp = NULL;
1326			fin->fin_m = NULL;
1327			return NULL;
1328		}
1329
1330		if (n == NULL)
1331			*fin->fin_mp = m;
1332
1333		while (M_LEN(m) == 0) {
1334			m = m->m_next;
1335		}
1336		fin->fin_m = m;
1337		ip = MTOD(m, char *) + ipoff;
1338
1339		fin->fin_ip = (ip_t *)ip;
1340		if (fin->fin_dp != NULL)
1341			fin->fin_dp = (char *)fin->fin_ip + dpoff;
1342		if (fin->fin_fraghdr != NULL)
1343			fin->fin_fraghdr = (char *)ip +
1344					   ((char *)fin->fin_fraghdr -
1345					    (char *)fin->fin_ip);
1346	}
1347
1348	if (len == fin->fin_plen)
1349		fin->fin_flx |= FI_COALESCE;
1350	return ip;
1351}
1352
1353
1354int
1355ipf_inject(fin, m)
1356	fr_info_t *fin;
1357	mb_t *m;
1358{
1359	int error = 0;
1360
1361	if (fin->fin_out == 0) {
1362		netisr_dispatch(NETISR_IP, m);
1363	} else {
1364		fin->fin_ip->ip_len = ntohs(fin->fin_ip->ip_len);
1365		fin->fin_ip->ip_off = ntohs(fin->fin_ip->ip_off);
1366		error = ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL);
1367	}
1368
1369	return error;
1370}
1371
1372int ipf_pfil_unhook(void) {
1373#if defined(NETBSD_PF) && (__FreeBSD_version >= 500011)
1374	struct pfil_head *ph_inet;
1375#  ifdef USE_INET6
1376	struct pfil_head *ph_inet6;
1377#  endif
1378#endif
1379
1380#ifdef NETBSD_PF
1381	ph_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET);
1382	if (ph_inet != NULL)
1383		pfil_remove_hook((void *)ipf_check_wrapper, NULL,
1384		    PFIL_IN|PFIL_OUT|PFIL_WAITOK, ph_inet);
1385# ifdef USE_INET6
1386	ph_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6);
1387	if (ph_inet6 != NULL)
1388		pfil_remove_hook((void *)ipf_check_wrapper6, NULL,
1389		    PFIL_IN|PFIL_OUT|PFIL_WAITOK, ph_inet6);
1390# endif
1391#endif
1392
1393	return (0);
1394}
1395
1396int ipf_pfil_hook(void) {
1397#if defined(NETBSD_PF) && (__FreeBSD_version >= 500011)
1398	struct pfil_head *ph_inet;
1399#  ifdef USE_INET6
1400	struct pfil_head *ph_inet6;
1401#  endif
1402#endif
1403
1404# ifdef NETBSD_PF
1405	ph_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET);
1406#    ifdef USE_INET6
1407	ph_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6);
1408#    endif
1409	if (ph_inet == NULL
1410#    ifdef USE_INET6
1411	    && ph_inet6 == NULL
1412#    endif
1413	   ) {
1414		return ENODEV;
1415	}
1416
1417	if (ph_inet != NULL)
1418		pfil_add_hook((void *)ipf_check_wrapper, NULL,
1419		    PFIL_IN|PFIL_OUT|PFIL_WAITOK, ph_inet);
1420#  ifdef USE_INET6
1421	if (ph_inet6 != NULL)
1422		pfil_add_hook((void *)ipf_check_wrapper6, NULL,
1423				      PFIL_IN|PFIL_OUT|PFIL_WAITOK, ph_inet6);
1424#  endif
1425# endif
1426	return (0);
1427}
1428
1429void
1430ipf_event_reg(void)
1431{
1432	ipf_arrivetag = EVENTHANDLER_REGISTER(ifnet_arrival_event, \
1433					       ipf_ifevent, &ipfmain, \
1434					       EVENTHANDLER_PRI_ANY);
1435	ipf_departtag = EVENTHANDLER_REGISTER(ifnet_departure_event, \
1436					       ipf_ifevent, &ipfmain, \
1437					       EVENTHANDLER_PRI_ANY);
1438	ipf_clonetag  = EVENTHANDLER_REGISTER(if_clone_event, ipf_ifevent, \
1439					       &ipfmain, EVENTHANDLER_PRI_ANY);
1440}
1441
1442void
1443ipf_event_dereg(void)
1444{
1445	if (ipf_arrivetag != NULL) {
1446		EVENTHANDLER_DEREGISTER(ifnet_arrival_event, ipf_arrivetag);
1447	}
1448	if (ipf_departtag != NULL) {
1449		EVENTHANDLER_DEREGISTER(ifnet_departure_event, ipf_departtag);
1450	}
1451	if (ipf_clonetag != NULL) {
1452		EVENTHANDLER_DEREGISTER(if_clone_event, ipf_clonetag);
1453	}
1454}
1455
1456
1457u_32_t
1458ipf_random()
1459{
1460	return arc4random();
1461}
1462
1463
1464u_int
1465ipf_pcksum(fin, hlen, sum)
1466	fr_info_t *fin;
1467	int hlen;
1468	u_int sum;
1469{
1470	struct mbuf *m;
1471	u_int sum2;
1472	int off;
1473
1474	m = fin->fin_m;
1475	off = (char *)fin->fin_dp - (char *)fin->fin_ip;
1476	m->m_data += hlen;
1477	m->m_len -= hlen;
1478	sum2 = in_cksum(fin->fin_m, fin->fin_plen - off);
1479	m->m_len += hlen;
1480	m->m_data -= hlen;
1481
1482	/*
1483	 * Both sum and sum2 are partial sums, so combine them together.
1484	 */
1485	sum += ~sum2 & 0xffff;
1486	while (sum > 0xffff)
1487		sum = (sum & 0xffff) + (sum >> 16);
1488	sum2 = ~sum & 0xffff;
1489	return sum2;
1490}
1491