Import IP Filter v3.1.7 into FreeBSD tree

1 files changed, 731 insertions, 0 deletions

diff --git a/contrib/ipfilter/ip_sfil.c b/contrib/ipfilter/ip_sfil.c
new file mode 100644
index 0000000..debc512
--- /dev/null
+++ b/contrib/ipfilter/ip_sfil.c
@@ -0,0 +1,731 @@
+/*
+ * (C)opyright 1993,1994,1995 by Darren Reed.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that this notice is preserved and due credit is given
+ * to the original author and the contributors.
+ *
+ * I hate legaleese, don't you ?
+ */
+#if !defined(lint) && defined(LIBC_SCCS)
+static	char	sccsid[] = "%W% %G% (C) 1993-1995 Darren Reed";
+static	char	rcsid[] = "$Id: ip_sfil.c,v 2.0.1.3 1997/02/04 14:49:15 darrenr Exp $";
+#endif
+
+#include <sys/types.h>
+#include <sys/errno.h>
+#include <sys/param.h>
+#include <sys/cpuvar.h>
+#include <sys/open.h>
+#include <sys/ioctl.h>
+#include <sys/systm.h>
+#include <sys/cred.h>
+#include <sys/ddi.h>
+#include <sys/sunddi.h>
+#include <sys/ksynch.h>
+#include <sys/kmem.h>
+#include <sys/mkdev.h>
+#include <sys/protosw.h>
+#include <sys/socket.h>
+#include <sys/dditypes.h>
+#include <sys/cmn_err.h>
+#include <net/if.h>
+#include <net/af.h>
+#include <net/route.h>
+#include <netinet/in.h>
+#include <netinet/in_systm.h>
+#include <netinet/ip.h>
+#include <netinet/ip_var.h>
+#include <netinet/tcp.h>
+#include <netinet/udp.h>
+#include <netinet/tcpip.h>
+#include <netinet/ip_icmp.h>
+#include "ip_fil.h"
+#include "ip_compat.h"
+#include "ip_state.h"
+#include "ip_frag.h"
+#include "ip_nat.h"
+#include <inet/ip_ire.h>
+#ifndef	MIN
+#define	MIN(a,b)	(((a)<(b))?(a):(b))
+#endif
+
+extern	fr_flags, fr_active;
+
+int	ipfr_timer_id = 0;
+int	ipl_unreach = ICMP_UNREACH_HOST;
+int	send_reset();
+
+#ifdef	IPFILTER_LOG
+int	ipllog();
+static	void	frflush();
+char	iplbuf[IPLLOGSIZE];
+caddr_t	iplh = iplbuf, iplt = iplbuf;
+static	int	iplused = 0;
+#endif /* IPFILTER_LOG */
+static	int	frrequest();
+kmutex_t	ipl_mutex, ipf_mutex, ipfs_mutex;
+kmutex_t	ipf_frag, ipf_state, ipf_nat;
+kcondvar_t	iplwait;
+
+extern	void	ipfr_slowtimer();
+
+
+int ipldetach()
+{
+	int	i = FR_INQUE|FR_OUTQUE;
+
+	untimeout(ipfr_timer_id);
+	frflush((caddr_t)&i);
+	ipfr_unload();
+	fr_stateunload();
+	ip_natunload();
+	cv_destroy(&iplwait);
+	mutex_destroy(&ipl_mutex);
+	mutex_destroy(&ipf_mutex);
+	mutex_destroy(&ipfs_mutex);
+	mutex_destroy(&ipf_frag);
+	mutex_destroy(&ipf_state);
+	mutex_destroy(&ipf_nat);
+	return 0;
+}
+
+
+int iplattach()
+{
+	bzero((char *)nat_table, sizeof(nat_t *) * NAT_SIZE * 2);
+	mutex_init(&ipl_mutex, "ipf log mutex", MUTEX_DRIVER, NULL);
+	mutex_init(&ipf_mutex, "ipf filter mutex", MUTEX_DRIVER, NULL);
+	mutex_init(&ipfs_mutex, "ipf solaris mutex", MUTEX_DRIVER, NULL);
+	mutex_init(&ipf_frag, "ipf fragment mutex", MUTEX_DRIVER, NULL);
+	mutex_init(&ipf_state, "ipf IP state mutex", MUTEX_DRIVER, NULL);
+	mutex_init(&ipf_nat, "ipf IP NAT mutex", MUTEX_DRIVER, NULL);
+	cv_init(&iplwait, "ipl condvar", CV_DRIVER, NULL);
+	ipfr_timer_id = timeout(ipfr_slowtimer, NULL, HZ/2);
+	return 0;
+}
+
+
+static	void	frzerostats(data)
+caddr_t	data;
+{
+	struct	friostat	fio;
+
+	bcopy((char *)frstats, (char *)fio.f_st,
+		sizeof(struct filterstats) * 2);
+	fio.f_fin[0] = ipfilter[0][0];
+	fio.f_fin[1] = ipfilter[0][1];
+	fio.f_fout[0] = ipfilter[1][0];
+	fio.f_fout[1] = ipfilter[1][1];
+	fio.f_acctin[0] = ipacct[0][0];
+	fio.f_acctin[1] = ipacct[0][1];
+	fio.f_acctout[0] = ipacct[1][0];
+	fio.f_acctout[1] = ipacct[1][1];
+	fio.f_active = fr_active;
+	IWCOPY((caddr_t)&fio, data, sizeof(fio));
+	bzero((char *)frstats, sizeof(*frstats) * 2);
+}
+
+
+#ifdef	IPFILTER_LOG
+static void frflush(data)
+caddr_t data;
+{
+	struct frentry *f, **fp;
+	int flags, flushed = 0, set = fr_active;
+
+	IRCOPY(data, (caddr_t)&flags, sizeof(flags));
+	bzero((char *)frcache, sizeof(frcache[0]) * 2);
+
+	if (flags & FR_INACTIVE)
+		set = 1 - set;
+	if (flags & FR_OUTQUE) {
+		for (fp = &ipfilter[1][set]; (f = *fp); ) {
+			*fp = f->fr_next;
+			KFREE(f);
+			flushed++;
+		}
+		for (fp = &ipacct[1][set]; (f = *fp); ) {
+			*fp = f->fr_next;
+			KFREE(f);
+			flushed++;
+		}
+	}
+	if (flags & FR_INQUE) {
+		for (fp = &ipfilter[0][set]; (f = *fp); ) {
+			*fp = f->fr_next;
+			KFREE(f);
+			flushed++;
+		}
+		for (fp = &ipacct[0][set]; (f = *fp); ) {
+			*fp = f->fr_next;
+			KFREE(f);
+			flushed++;
+		}
+	}
+
+	IWCOPY((caddr_t)&flushed, data, sizeof(flushed));
+}
+#endif /* IPFILTER_LOG */
+
+
+/*
+ * Filter ioctl interface.
+ */
+int iplioctl(dev, cmd, data, mode, cp, rp)
+dev_t dev;
+int cmd;
+caddr_t data;
+int mode;
+cred_t *cp;
+int *rp;
+{
+	int error = 0;
+
+	switch (cmd) {
+	case SIOCFRENB :
+	{
+		u_int	enable;
+
+		if (!(mode & FWRITE))
+			return EPERM;
+		IRCOPY(data, (caddr_t)&enable, sizeof(enable));
+		break;
+	}
+	case SIOCSETFF :
+		if (!(mode & FWRITE))
+			return EPERM;
+		mutex_enter(&ipf_mutex);
+		IRCOPY(data, (caddr_t)&fr_flags, sizeof(fr_flags));
+		mutex_exit(&ipf_mutex);
+		break;
+	case SIOCGETFF :
+		IWCOPY((caddr_t)&fr_flags, data, sizeof(fr_flags));
+		break;
+	case SIOCINAFR :
+	case SIOCRMAFR :
+	case SIOCADAFR :
+	case SIOCZRLST :
+		if (!(mode & FWRITE))
+			return EPERM;
+		mutex_enter(&ipf_mutex);
+		error = frrequest(cmd, data, fr_active);
+		mutex_exit(&ipf_mutex);
+		break;
+	case SIOCINIFR :
+	case SIOCRMIFR :
+	case SIOCADIFR :
+		if (!(mode & FWRITE))
+			return EPERM;
+		mutex_enter(&ipf_mutex);
+		error = frrequest(cmd, data, 1 - fr_active);
+		mutex_exit(&ipf_mutex);
+		break;
+	case SIOCSWAPA :
+		if (!(mode & FWRITE))
+			return EPERM;
+		mutex_enter(&ipf_mutex);
+		bzero((char *)frcache, sizeof(frcache[0]) * 2);
+		IWCOPY((caddr_t)&fr_active, (caddr_t)data, sizeof(fr_active));
+		fr_active = 1 - fr_active;
+		mutex_exit(&ipf_mutex);
+		break;
+	case SIOCGETFS :
+	{
+		struct	friostat	fio;
+
+		mutex_enter(&ipf_mutex);
+		bcopy((char *)frstats, (char *)fio.f_st,
+			sizeof(struct filterstats) * 2);
+		fio.f_fin[0] = ipfilter[0][0];
+		fio.f_fin[1] = ipfilter[0][1];
+		fio.f_fout[0] = ipfilter[1][0];
+		fio.f_fout[1] = ipfilter[1][1];
+		fio.f_acctin[0] = ipacct[0][0];
+		fio.f_acctin[1] = ipacct[0][1];
+		fio.f_acctout[0] = ipacct[1][0];
+		fio.f_acctout[1] = ipacct[1][1];
+		fio.f_active = fr_active;
+		mutex_exit(&ipf_mutex);
+		IWCOPY((caddr_t)&fio, data, sizeof(fio));
+		break;
+	}
+	case SIOCFRZST :
+		if (!(mode & FWRITE))
+			return EPERM;
+		frzerostats(data);
+		break;
+#ifdef	IPFILTER_LOG
+	case	SIOCIPFFL :
+		if (!(mode & FWRITE))
+			return EPERM;
+		mutex_enter(&ipf_mutex);
+		frflush(data);
+		mutex_exit(&ipf_mutex);
+		break;
+	case	SIOCIPFFB :
+		if (!(mode & FWRITE))
+			return EPERM;
+		mutex_enter(&ipl_mutex);
+		IWCOPY((caddr_t)&iplused, data, sizeof(iplused));
+		iplh = iplt = iplbuf;
+		iplused = 0;
+		mutex_exit(&ipl_mutex);
+		break;
+#endif /* IPFILTER_LOG */
+	case SIOCFRSYN :
+		if (!(mode & FWRITE))
+			return EPERM;
+		error = ipfsync();
+		break;
+	case SIOCADNAT :
+	case SIOCRMNAT :
+	case SIOCGNATS :
+	case SIOCGNATL :
+	case SIOCFLNAT :
+	case SIOCCNATL :
+		error = nat_ioctl(data, cmd, mode);
+		break;
+	case SIOCGFRST :
+		IWCOPY((caddr_t)ipfr_fragstats(), data, sizeof(ipfrstat_t));
+		break;
+	case SIOCGIPST :   
+		IWCOPY((caddr_t)fr_statetstats(), data, sizeof(ips_stat_t));
+		break;
+	default :
+		error = EINVAL;
+		break;
+	}
+	return error;
+}
+
+
+ill_t	*get_unit(name)
+char	*name;
+{
+	ill_t	*il;
+	int	len = strlen(name) + 1;	/* includes \0 */
+
+	for (il = ill_g_head; il; il = il->ill_next)
+		if ((len == il->ill_name_length) &&
+		    !strncmp(il->ill_name, name, len))
+			return il;
+	return NULL;
+}
+
+
+static int frrequest(req, data, set)
+int req, set;
+caddr_t data;
+{
+	register frentry_t *fp, *f, **fprev;
+	register frentry_t **ftail;
+	frentry_t fr;
+	frdest_t *fdp;
+	int error = 0, in;
+	ill_t *ill;
+	ipif_t *ipif;
+	ire_t *ire;
+
+	fp = &fr;
+	IRCOPY(data, (caddr_t)fp, sizeof(*fp));
+
+	bzero((char *)frcache, sizeof(frcache[0]) * 2);
+
+	in = (fp->fr_flags & FR_INQUE) ? 0 : 1;
+	if (fp->fr_flags & FR_ACCOUNT)
+		ftail = fprev = &ipacct[in][set];
+	else if (fp->fr_flags & (FR_OUTQUE|FR_INQUE))
+		ftail = fprev = &ipfilter[in][set];
+	else
+		return ESRCH;
+
+	if (*fp->fr_ifname) {
+		fp->fr_ifa = (struct ifnet *)get_unit((char *)fp->fr_ifname);
+		if (!fp->fr_ifa)
+			fp->fr_ifa = (struct ifnet *)-1;
+	}
+
+	fdp = &fp->fr_dif;
+	fp->fr_flags &= ~FR_DUP;
+	if (*fdp->fd_ifname) {
+		ill = get_unit(fdp->fd_ifname);
+		if (!ill)
+			ire = (ire_t *)-1;
+		else if ((ipif = ill->ill_ipif)) {
+			ire = ire_lookup_myaddr(ipif->ipif_local_addr);
+			if (!ire)
+				ire = (ire_t *)-1;
+			else
+				fp->fr_flags |= FR_DUP;
+		}
+		fdp->fd_ifp = (struct ifnet *)ire;
+	}
+
+	fdp = &fp->fr_tif;
+	if (*fdp->fd_ifname) {
+		ill = get_unit(fdp->fd_ifname);
+		if (!ill)
+			ire = (ire_t *)-1;
+		else if ((ipif = ill->ill_ipif)) {
+			ire = ire_lookup_myaddr(ipif->ipif_local_addr);
+			if (!ire)
+				ire = (ire_t *)-1;
+		}
+		fdp->fd_ifp = (struct ifnet *)ire;
+	}
+
+	/*
+	 * Look for a matching filter rule, but don't include the next or
+	 * interface pointer in the comparison (fr_next, fr_ifa).
+	 */
+	for (; (f = *ftail); ftail = &f->fr_next)
+		if (bcmp((char *)&f->fr_ip, (char *)&fp->fr_ip,
+			 FR_CMPSIZ) == 0)
+			break;
+
+	/*
+	 * If zero'ing statistics, copy current to caller and zero.
+	 */
+	if (req == SIOCZRLST) {
+		if (!f)
+			return ESRCH;
+		IWCOPY((caddr_t)f, data, sizeof(*f));
+		f->fr_hits = 0;
+		f->fr_bytes = 0;
+		return 0;
+	}
+
+	if (!f) {
+		ftail = fprev;
+		if (req != SIOCINAFR && req != SIOCINIFR)
+			while ((f = *ftail))
+				ftail = &f->fr_next;
+		else if (fp->fr_hits)
+			while (--fp->fr_hits && (f = *ftail))
+				ftail = &f->fr_next;
+		f = NULL;
+	}
+
+	if (req == SIOCDELFR || req == SIOCRMIFR) {
+		if (!f)
+			error = ESRCH;
+		else {
+			*ftail = f->fr_next;
+			KFREE(f);
+		}
+	} else {
+		if (f)
+			error = EEXIST;
+		else {
+			if ((f = (struct frentry *)KMALLOC(sizeof(*f)))) {
+				bcopy((char *)fp, (char *)f, sizeof(*f));
+				f->fr_hits = 0;
+				f->fr_next = *ftail;
+				*ftail = f;
+			} else
+				error = ENOMEM;
+		}
+	}
+	return (error);
+}
+
+
+/*
+ * routines below for saving IP headers to buffer
+ */
+int iplopen(devp, flags, otype, cred)
+dev_t *devp;
+int flags, otype;
+cred_t *cred;
+{
+	u_int min = getminor(*devp);
+
+	if (!(otype & OTYP_CHR))
+		return ENXIO;
+	if (min)
+		min = ENXIO;
+	return min;
+}
+
+
+int iplclose(dev, flags, otype, cred)
+dev_t dev;
+int flags, otype;
+cred_t *cred;
+{
+	u_int	min = getminor(dev);
+
+	if (min)
+		min = ENXIO;
+	return min;
+}
+
+#ifdef	IPFILTER_LOG
+/*
+ * iplread/ipllog
+ * both of these must operate with at least splnet() lest they be
+ * called during packet processing and cause an inconsistancy to appear in
+ * the filter lists.
+ */
+int iplread(dev, uio, cp)
+dev_t dev;
+register struct uio *uio;
+cred_t *cp;
+{
+	register int ret;
+	register size_t sz, sx;
+	char *h, *t;
+	int error, used, usedo, copied;
+
+	if (!uio->uio_resid)
+		return 0;
+	if ((uio->uio_resid < 0) || (uio->uio_resid > IPLLOGSIZE))
+		return EINVAL;
+
+	/*
+	 * Lock the log so we can snapshot the variables.  Wait for a signal
+	 * if the log is empty.
+	 */
+	mutex_enter(&ipl_mutex);
+	while (!iplused) {
+		error = cv_wait_sig(&iplwait, &ipl_mutex);
+		if (!error) {
+			mutex_exit(&ipl_mutex);
+			return EINTR;
+		}
+	}
+	h = iplh;
+	t = iplt;
+	used = iplused;
+	mutex_exit(&ipl_mutex);
+	usedo = used;
+
+	/*
+	 * Given up the mutex, the log can grow more, but we can't hold the
+	 * mutex across the uiomove's.
+	 */
+	sx = sz = MIN(uio->uio_resid, used);
+	if (h <= t)
+		sz = MIN(sz, IPLLOGSIZE + iplbuf - t);
+
+	if (!(ret = uiomove(t, sz, UIO_READ, uio))) {
+		t += sz;
+		sx -= sz;
+		used -= sz;
+		if ((h < t) && (t >= iplbuf + IPLLOGSIZE))
+			t = iplbuf;
+
+		if (sx && !(ret = uiomove(t, sx, UIO_READ, uio)))
+			used -= sx;
+	}
+
+	/*
+	 * copied all the data, now adjust variables to match this.
+	 */
+	mutex_enter(&ipl_mutex);
+	copied = usedo - used;
+	iplused -= copied;
+
+	if (!iplused)	/* minimise wrapping around the end */
+		iplh = iplt = iplbuf;
+	else {
+		iplt += copied;
+		if (iplt >= iplbuf + IPLLOGSIZE)
+			iplt -= IPLLOGSIZE;
+		if (iplt == iplbuf + IPLLOGSIZE)
+			iplt = iplbuf;
+	}
+	mutex_exit(&ipl_mutex);
+	return ret;
+}
+
+
+int ipllog(flags, ip, fin, m)
+u_int flags;
+ip_t *ip;
+fr_info_t *fin;
+mblk_t *m;
+{
+	struct ipl_ci iplci;
+	register int len, mlen, hlen;
+	register u_char *s = (u_char *)ip;
+	ill_t *il = fin->fin_ifp;
+
+	hlen = fin->fin_hlen;
+	if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP)
+		hlen += MIN(sizeof(tcphdr_t), fin->fin_dlen);
+	else if (ip->ip_p == IPPROTO_ICMP) {
+		struct	icmp	*icmp = (struct icmp *)(s + hlen);
+
+		switch (icmp->icmp_type) {
+		case ICMP_UNREACH :
+		case ICMP_SOURCEQUENCH :
+		case ICMP_REDIRECT :
+		case ICMP_TIMXCEED :
+		case ICMP_PARAMPROB :
+			hlen += MIN(sizeof(struct icmp) + 8, fin->fin_dlen);
+			break;
+		default :
+			hlen += MIN(sizeof(struct icmp), fin->fin_dlen);
+			break;
+		}
+	}
+
+	mlen = (flags & FR_LOGBODY) ? MIN(msgdsize(m) - hlen, 128) : 0;
+	len = hlen + sizeof(iplci) + mlen;
+	mutex_enter(&ipl_mutex);
+	if ((iplused + len) > IPLLOGSIZE) {
+		mutex_exit(&ipl_mutex);
+		return 0;
+	}
+	iplused += len;
+
+	uniqtime((struct timeval *)&iplci);
+	iplci.flags = flags;
+	iplci.hlen = (u_char)hlen;
+	iplci.plen = (u_char)mlen;
+	iplci.rule = fin->fin_rule;
+	iplci.unit = (u_char)il->ill_ppa;
+	bcopy(il->ill_name, (char *)iplci.ifname, MIN(il->ill_name_length, 4));
+
+	/*
+	 * Gauranteed to succeed from above
+	 */
+	(void) fr_copytolog(&iplci, sizeof(iplci));
+	len -= sizeof(iplci);
+
+	if (len && m) {
+		s = m->b_rptr;
+		do {
+			if ((hlen = MIN(m->b_wptr - s, len))) {
+				if (fr_copytolog(s, hlen))
+					break;
+				len -= hlen;
+			}
+			if ((m = m->b_cont))
+				s = m->b_rptr;
+		} while (m && len);
+	}
+
+	cv_signal(&iplwait);
+	mutex_exit(&ipl_mutex);
+	return 1;
+}
+#endif /* IPFILTER_LOG */
+
+
+u_short	ipf_cksum(addr, len)
+register u_short *addr;
+register int len;
+{
+	register u_long sum = 0;
+
+	for (sum = 0; len > 1; len -= 2)
+		sum += *addr++;
+
+	/* mop up an odd byte, if necessary */
+	if (len == 1)
+		sum += *(u_char *)addr;
+
+	/*
+	 * add back carry outs from top 16 bits to low 16 bits
+	 */
+	sum = (sum >> 16) + (sum & 0xffff);	/* add hi 16 to low 16 */
+	sum += (sum >> 16);			/* add carry */
+	return (u_short)(~sum);
+}
+
+/*
+ * send_reset - this could conceivably be a call to tcp_respond(), but that
+ * requires a large amount of setting up and isn't any more efficient.
+ */
+int send_reset(ti, qif, q)
+struct tcpiphdr *ti;
+qif_t *qif;
+queue_t *q;
+{
+	struct ip *ip;
+	struct tcphdr *tcp;
+	mblk_t *m;
+	int tlen = 0;
+
+	if (ti->ti_flags & TH_RST)
+		return -1;
+	if (ti->ti_flags & TH_SYN)
+		tlen = 1;
+	if ((m = (mblk_t *)allocb(sizeof(struct tcpiphdr), BPRI_HI)) == NULL)
+		return -1;
+
+	MTYPE(m) = M_DATA;
+	m->b_wptr += sizeof(struct tcpiphdr);
+	bzero((char *)m->b_rptr, sizeof(struct tcpiphdr));
+	ip = (ip_t *)m->b_rptr;
+	tcp = (struct tcphdr *)(m->b_rptr + sizeof(*ip));
+
+	ip->ip_src.s_addr = ti->ti_dst.s_addr;
+	ip->ip_dst.s_addr = ti->ti_src.s_addr;
+	tcp->th_dport = ti->ti_sport;
+	tcp->th_sport = ti->ti_dport;
+	tcp->th_ack = htonl(ntohl(ti->ti_seq) + tlen);
+	tcp->th_off = sizeof(struct tcphdr) >> 2;
+	tcp->th_flags = TH_RST|TH_ACK;
+	/*
+	 * This is to get around a bug in the Solaris 2.4/2.5 TCP checksum
+	 * computation that is done by their put routine.
+	 */
+	tcp->th_sum = htons(0x14);
+	ip->ip_hl = sizeof(*ip) >> 2;
+	ip->ip_v = IPVERSION;
+	ip->ip_p = IPPROTO_TCP;
+	ip->ip_len = htons(sizeof(struct tcpiphdr));
+	ip->ip_tos = ((struct ip *)ti)->ip_tos;
+	ip->ip_off = 0;
+	ip->ip_ttl = 60;
+	ip->ip_sum = 0;
+	ip_wput(qif->qf_ill->ill_wq, m);
+	return 0;
+}
+
+
+int	icmp_error(q, ip, type, code, qif, src)
+queue_t	*q;
+ip_t	*ip;
+int	type, code;
+qif_t	*qif;
+struct	in_addr	src;
+{
+	mblk_t	*mb;
+	struct	icmp	*icmp;
+	ip_t	*nip;
+	int	sz = sizeof(*nip) + sizeof(*icmp) + 8;
+
+	if ((mb = (mblk_t *)allocb(sz, BPRI_HI)) == NULL)
+		return -1;
+	MTYPE(mb) = M_DATA;
+	mb->b_wptr += sz;
+	bzero((char *)mb->b_rptr, sz);
+	nip = (ip_t *)mb->b_rptr;
+	icmp = (struct icmp *)(nip + 1);
+
+	nip->ip_v = IPVERSION;
+	nip->ip_hl = (sizeof(*nip) >> 2);
+	nip->ip_p = IPPROTO_ICMP;
+	nip->ip_id = ip->ip_id;
+	nip->ip_sum = 0;
+	nip->ip_ttl = 60;
+	nip->ip_tos = ip->ip_tos;
+	nip->ip_len = htons(sz);
+	nip->ip_src.s_addr = ip->ip_dst.s_addr;
+	nip->ip_dst.s_addr = ip->ip_src.s_addr;
+
+	icmp->icmp_type = type;
+	icmp->icmp_code = code;
+	icmp->icmp_cksum = 0;
+	bcopy((char *)ip, (char *)&icmp->icmp_ip, sizeof(*ip));
+	bcopy((char *)ip + (ip->ip_hl << 2),
+	      (char *)&icmp->icmp_ip + sizeof(*ip), 8);	/* 64 bits */
+	icmp->icmp_cksum = ipf_cksum(icmp, sizeof(*icmp) + 8);
+	ip_wput(qif->qf_ill->ill_wq, mb);
+	return 0;
+}