path: root/sys/net/if_pflog.c

/*	$OpenBSD: if_pflog.c,v 1.30 2010/09/21 10:45:26 henning Exp $	*/
/*
 * The authors of this code are John Ioannidis (ji@tla.org),
 * Angelos D. Keromytis (kermit@csd.uch.gr) and 
 * Niels Provos (provos@physnet.uni-hamburg.de).
 *
 * This code was written by John Ioannidis for BSD/OS in Athens, Greece, 
 * in November 1995.
 *
 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
 * by Angelos D. Keromytis.
 *
 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
 * and Niels Provos.
 *
 * Copyright (C) 1995, 1996, 1997, 1998 by John Ioannidis, Angelos D. Keromytis
 * and Niels Provos.
 * Copyright (c) 2001, Angelos D. Keromytis, Niels Provos.
 *
 * Permission to use, copy, and modify this software with or without fee
 * is hereby granted, provided that this entire notice is included in
 * all copies of any software which is or includes a copy or
 * modification of this software. 
 * You may use this code under the GNU public license if you so wish. Please
 * contribute changes back to the authors under this freer than GPL license
 * so that we may further the use of strong encryption without limitations to
 * all.
 *
 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
 * PURPOSE.
 */

#include "bpfilter.h"
#include "pflog.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/ioctl.h>

#include <net/if.h>
#include <net/if_types.h>
#include <net/route.h>
#include <net/bpf.h>

#ifdef	INET
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <netinet/udp.h>
#include <netinet/ip_icmp.h>
#endif

#ifdef INET6
#ifndef INET
#include <netinet/in.h>
#endif
#include <netinet6/nd6.h>
#include <netinet/icmp6.h>
#endif /* INET6 */

#include <net/pfvar.h>
#include <net/if_pflog.h>

#define PFLOGMTU	(32768 + MHLEN + MLEN)

#ifdef PFLOGDEBUG
#define DPRINTF(x)    do { if (pflogdebug) printf x ; } while (0)
#else
#define DPRINTF(x)
#endif

void	pflogattach(int);
int	pflogoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
	    	       struct rtentry *);
int	pflogioctl(struct ifnet *, u_long, caddr_t);
void	pflogstart(struct ifnet *);
int	pflog_clone_create(struct if_clone *, int);
int	pflog_clone_destroy(struct ifnet *);

LIST_HEAD(, pflog_softc)	pflogif_list;
struct if_clone	pflog_cloner =
    IF_CLONE_INITIALIZER("pflog", pflog_clone_create, pflog_clone_destroy);

struct ifnet	*pflogifs[PFLOGIFS_MAX];	/* for fast access */
struct mbuf	*mfake = NULL;

void
pflogattach(int npflog)
{
	int	i;
	LIST_INIT(&pflogif_list);
	for (i = 0; i < PFLOGIFS_MAX; i++)
		pflogifs[i] = NULL;
	if (mfake == NULL)
		mfake = m_get(M_DONTWAIT, MT_HEADER);
	if_clone_attach(&pflog_cloner);
}

int
pflog_clone_create(struct if_clone *ifc, int unit)
{
	struct ifnet *ifp;
	struct pflog_softc *pflogif;
	int s;

	if (unit >= PFLOGIFS_MAX)
		return (EINVAL);

	if ((pflogif = malloc(sizeof(*pflogif),
	    M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL)
		return (ENOMEM);

	pflogif->sc_unit = unit;
	ifp = &pflogif->sc_if;
	snprintf(ifp->if_xname, sizeof ifp->if_xname, "pflog%d", unit);
	ifp->if_softc = pflogif;
	ifp->if_mtu = PFLOGMTU;
	ifp->if_ioctl = pflogioctl;
	ifp->if_output = pflogoutput;
	ifp->if_start = pflogstart;
	ifp->if_type = IFT_PFLOG;
	ifp->if_snd.ifq_maxlen = ifqmaxlen;
	ifp->if_hdrlen = PFLOG_HDRLEN;
	if_attach(ifp);
	if_alloc_sadl(ifp);

#if NBPFILTER > 0
	bpfattach(&pflogif->sc_if.if_bpf, ifp, DLT_PFLOG, PFLOG_HDRLEN);
#endif

	s = splnet();
	LIST_INSERT_HEAD(&pflogif_list, pflogif, sc_list);
	pflogifs[unit] = ifp;
	splx(s);

	return (0);
}

int
pflog_clone_destroy(struct ifnet *ifp)
{
	struct pflog_softc	*pflogif = ifp->if_softc;
	int			 s;

	s = splnet();
	pflogifs[pflogif->sc_unit] = NULL;
	LIST_REMOVE(pflogif, sc_list);
	splx(s);

	if_detach(ifp);
	free(pflogif, M_DEVBUF);
	return (0);
}

/*
 * Start output on the pflog interface.
 */
void
pflogstart(struct ifnet *ifp)
{
	struct mbuf *m;
	int s;

	for (;;) {
		s = splnet();
		IF_DROP(&ifp->if_snd);
		IF_DEQUEUE(&ifp->if_snd, m);
		splx(s);

		if (m == NULL)
			return;
		else
			m_freem(m);
	}
}

int
pflogoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
	struct rtentry *rt)
{
	m_freem(m);
	return (0);
}

/* ARGSUSED */
int
pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
	switch (cmd) {
	case SIOCSIFFLAGS:
		if (ifp->if_flags & IFF_UP)
			ifp->if_flags |= IFF_RUNNING;
		else
			ifp->if_flags &= ~IFF_RUNNING;
		break;
	default:
		return (ENOTTY);
	}

	return (0);
}

int
pflog_packet(struct pfi_kif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir,
    u_int8_t reason, struct pf_rule *rm, struct pf_rule *am,
    struct pf_ruleset *ruleset, struct pf_pdesc *pd)
{
#if NBPFILTER > 0
	struct ifnet *ifn;
	struct pfloghdr hdr;

	if (kif == NULL || m == NULL || rm == NULL || pd == NULL)
		return (-1);

	if ((ifn = pflogifs[rm->logif]) == NULL || !ifn->if_bpf)
		return (0);

	bzero(&hdr, sizeof(hdr));
	hdr.length = PFLOG_REAL_HDRLEN;
	hdr.af = af;
	hdr.action = rm->action;
	hdr.reason = reason;
	memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname));

	if (am == NULL) {
		hdr.rulenr = htonl(rm->nr);
		hdr.subrulenr = -1;
	} else {
		hdr.rulenr = htonl(am->nr);
		hdr.subrulenr = htonl(rm->nr);
		if (ruleset != NULL && ruleset->anchor != NULL)
			strlcpy(hdr.ruleset, ruleset->anchor->name,
			    sizeof(hdr.ruleset));
	}
	if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done)
		pd->lookup.done = pf_socket_lookup(dir, pd);
	if (pd->lookup.done > 0) {
		hdr.uid = pd->lookup.uid;
		hdr.pid = pd->lookup.pid;
	} else {
		hdr.uid = UID_MAX;
		hdr.pid = NO_PID;
	}
	hdr.rule_uid = rm->cuid;
	hdr.rule_pid = rm->cpid;
	hdr.dir = dir;

	PF_ACPY(&hdr.saddr, &pd->nsaddr, pd->af);
	PF_ACPY(&hdr.daddr, &pd->ndaddr, pd->af);
	hdr.sport = pd->nsport;
	hdr.dport = pd->ndport;

	ifn->if_opackets++;
	ifn->if_obytes += m->m_pkthdr.len;

	bpf_mtap_pflog(ifn->if_bpf, (caddr_t)&hdr, m);
#endif

	return (0);
}

void
pflog_bpfcopy(const void *src_arg, void *dst_arg, size_t len)
{
	const struct mbuf	*m;
	struct pfloghdr		*pfloghdr;
	u_int			 count;
	u_char			*dst;
	u_short			 action, reason;
	int			 off = 0, hdrlen = 0;
	union {
		struct tcphdr		tcp;
		struct udphdr		udp;
		struct icmp		icmp;
#ifdef INET6
		struct icmp6_hdr	icmp6;
#endif /* INET6 */
	} pf_hdrs;

	struct pf_pdesc		 pd;
	struct pf_addr		 osaddr, odaddr;
	u_int16_t		 osport, odport;

	m = src_arg;
	dst = dst_arg;

	if (m == NULL)
		panic("pflog_bpfcopy got no mbuf");

	/* first mbuf holds struct pfloghdr */
	pfloghdr = mtod(m, struct pfloghdr *);
	count = min(m->m_len, len);
	bcopy(pfloghdr, dst, count);
	pfloghdr = (struct pfloghdr *)dst;
	dst += count;
	len -= count;
	m = m->m_next;

	/* second mbuf is pkthdr */
	if (len > 0) {
		if (m == NULL)
			panic("no second mbuf");
		bcopy(m, mfake, sizeof(*mfake));
		mfake->m_flags &= ~(M_EXT|M_CLUSTER);
		mfake->m_next = NULL;
		mfake->m_nextpkt = NULL;
		mfake->m_data = dst;
		mfake->m_len = len;
	} else
		return;

	while (len > 0) {
		if (m == 0)
			panic("bpf_mcopy");
		count = min(m->m_len, len);
		bcopy(mtod(m, caddr_t), (caddr_t)dst, count);
		m = m->m_next;
		dst += count;
		len -= count;
	}

	if (mfake->m_flags & M_PKTHDR)
		mfake->m_pkthdr.len = min(mfake->m_pkthdr.len, mfake->m_len);

	/* rewrite addresses if needed */
	memset(&pd, 0, sizeof(pd));
	pd.hdr.any = &pf_hdrs;
	if (pf_setup_pdesc(pfloghdr->af, pfloghdr->dir, &pd, mfake, &action,
	    &reason, NULL, NULL, NULL, NULL, &off, &hdrlen) == -1)
		return;

	PF_ACPY(&osaddr, pd.src, pd.af);
	PF_ACPY(&odaddr, pd.dst, pd.af);
	osport = *pd.sport;
	odport = *pd.dport;

	if ((pfloghdr->rewritten = pf_translate(&pd, &pfloghdr->saddr,
	    pfloghdr->sport, &pfloghdr->daddr, pfloghdr->dport, 0,
	    pfloghdr->dir, mfake))) {
		m_copyback(mfake, off, min(mfake->m_len - off, hdrlen),
		    pd.hdr.any, M_NOWAIT);
		PF_ACPY(&pfloghdr->saddr, &osaddr, pd.af);
		PF_ACPY(&pfloghdr->daddr, &odaddr, pd.af);
		pfloghdr->sport = osport;
		pfloghdr->dport = odport;
	}
}