freebsd-dev/sys/netpfil/pf/if_pflog.c
Kristof Provost c3e14afc18 pflog: Correctly initialise subrulenr
subrulenr is considered unset if it's set to -1, not if it's set to 1.
See contrib/tcpdump/print-pflog.c pflog_print() for a user.

This caused incorrect pflog output (tcpdump -n -e -ttt -i pflog0):
  rule 0..16777216(match)
instead of the correct output of
  rule 0/0(match)

PR:		214832
Submitted by:	andywhite@gmail.com
2016-12-05 21:52:10 +00:00

319 lines
7.3 KiB
C

/*-
* 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.
*
* $OpenBSD: if_pflog.c,v 1.26 2007/10/18 21:58:18 mpf Exp $
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_bpf.h"
#include "opt_pf.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <net/bpf.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_clone.h>
#include <net/if_pflog.h>
#include <net/if_types.h>
#include <net/vnet.h>
#include <net/pfvar.h>
#if defined(INET) || defined(INET6)
#include <netinet/in.h>
#endif
#ifdef INET
#include <netinet/in_var.h>
#include <netinet/ip.h>
#endif
#ifdef INET6
#include <netinet6/in6_var.h>
#include <netinet6/nd6.h>
#endif /* INET6 */
#ifdef INET
#include <machine/in_cksum.h>
#endif /* INET */
#define PFLOGMTU (32768 + MHLEN + MLEN)
#ifdef PFLOGDEBUG
#define DPRINTF(x) do { if (pflogdebug) printf x ; } while (0)
#else
#define DPRINTF(x)
#endif
static int pflogoutput(struct ifnet *, struct mbuf *,
const struct sockaddr *, struct route *);
static void pflogattach(int);
static int pflogioctl(struct ifnet *, u_long, caddr_t);
static void pflogstart(struct ifnet *);
static int pflog_clone_create(struct if_clone *, int, caddr_t);
static void pflog_clone_destroy(struct ifnet *);
static const char pflogname[] = "pflog";
static VNET_DEFINE(struct if_clone *, pflog_cloner);
#define V_pflog_cloner VNET(pflog_cloner)
VNET_DEFINE(struct ifnet *, pflogifs[PFLOGIFS_MAX]); /* for fast access */
#define V_pflogifs VNET(pflogifs)
static void
pflogattach(int npflog __unused)
{
int i;
for (i = 0; i < PFLOGIFS_MAX; i++)
V_pflogifs[i] = NULL;
V_pflog_cloner = if_clone_simple(pflogname, pflog_clone_create,
pflog_clone_destroy, 1);
}
static int
pflog_clone_create(struct if_clone *ifc, int unit, caddr_t param)
{
struct ifnet *ifp;
if (unit >= PFLOGIFS_MAX)
return (EINVAL);
ifp = if_alloc(IFT_PFLOG);
if (ifp == NULL) {
return (ENOSPC);
}
if_initname(ifp, pflogname, unit);
ifp->if_mtu = PFLOGMTU;
ifp->if_ioctl = pflogioctl;
ifp->if_output = pflogoutput;
ifp->if_start = pflogstart;
ifp->if_snd.ifq_maxlen = ifqmaxlen;
ifp->if_hdrlen = PFLOG_HDRLEN;
if_attach(ifp);
bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN);
V_pflogifs[unit] = ifp;
return (0);
}
static void
pflog_clone_destroy(struct ifnet *ifp)
{
int i;
for (i = 0; i < PFLOGIFS_MAX; i++)
if (V_pflogifs[i] == ifp)
V_pflogifs[i] = NULL;
bpfdetach(ifp);
if_detach(ifp);
if_free(ifp);
}
/*
* Start output on the pflog interface.
*/
static void
pflogstart(struct ifnet *ifp)
{
struct mbuf *m;
for (;;) {
IF_LOCK(&ifp->if_snd);
_IF_DEQUEUE(&ifp->if_snd, m);
IF_UNLOCK(&ifp->if_snd);
if (m == NULL)
return;
else
m_freem(m);
}
}
static int
pflogoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
struct route *rt)
{
m_freem(m);
return (0);
}
/* ARGSUSED */
static int
pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
switch (cmd) {
case SIOCSIFFLAGS:
if (ifp->if_flags & IFF_UP)
ifp->if_drv_flags |= IFF_DRV_RUNNING;
else
ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
break;
default:
return (ENOTTY);
}
return (0);
}
static 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, int lookupsafe)
{
struct ifnet *ifn;
struct pfloghdr hdr;
if (kif == NULL || m == NULL || rm == NULL || pd == NULL)
return ( 1);
if ((ifn = V_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));
}
/*
* XXXGL: we avoid pf_socket_lookup() when we are holding
* state lock, since this leads to unsafe LOR.
* These conditions are very very rare, however.
*/
if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done && lookupsafe)
pd->lookup.done = pf_socket_lookup(dir, pd, m);
if (pd->lookup.done > 0)
hdr.uid = pd->lookup.uid;
else
hdr.uid = UID_MAX;
hdr.pid = NO_PID;
hdr.rule_uid = rm->cuid;
hdr.rule_pid = rm->cpid;
hdr.dir = dir;
#ifdef INET
if (af == AF_INET && dir == PF_OUT) {
struct ip *ip;
ip = mtod(m, struct ip *);
ip->ip_sum = 0;
ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
}
#endif /* INET */
if_inc_counter(ifn, IFCOUNTER_OPACKETS, 1);
if_inc_counter(ifn, IFCOUNTER_OBYTES, m->m_pkthdr.len);
BPF_MTAP2(ifn, &hdr, PFLOG_HDRLEN, m);
return (0);
}
static void
vnet_pflog_init(const void *unused __unused)
{
pflogattach(1);
}
VNET_SYSINIT(vnet_pflog_init, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY,
vnet_pflog_init, NULL);
static void
vnet_pflog_uninit(const void *unused __unused)
{
if_clone_detach(V_pflog_cloner);
}
/*
* Detach after pf is gone; otherwise we might touch pflog memory
* from within pf after freeing pflog.
*/
VNET_SYSUNINIT(vnet_pflog_uninit, SI_SUB_INIT_IF, SI_ORDER_SECOND,
vnet_pflog_uninit, NULL);
static int
pflog_modevent(module_t mod, int type, void *data)
{
int error = 0;
switch (type) {
case MOD_LOAD:
PF_RULES_WLOCK();
pflog_packet_ptr = pflog_packet;
PF_RULES_WUNLOCK();
break;
case MOD_UNLOAD:
PF_RULES_WLOCK();
pflog_packet_ptr = NULL;
PF_RULES_WUNLOCK();
break;
default:
error = EOPNOTSUPP;
break;
}
return error;
}
static moduledata_t pflog_mod = { pflogname, pflog_modevent, 0 };
#define PFLOG_MODVER 1
/* Do not run before pf is initialized as we depend on its locks. */
DECLARE_MODULE(pflog, pflog_mod, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY);
MODULE_VERSION(pflog, PFLOG_MODVER);
MODULE_DEPEND(pflog, pf, PF_MODVER, PF_MODVER, PF_MODVER);