freebsd-nq/sys/netpfil/pf/if_pflog.c
Bjoern A. Zeeb 7d7751a071 Make sure pflog is attached after pf is initializaed so we can
borrow pf's lock, and also make sure pflog goes after pf is gone
in order to avoid callouts in VNETs to an already freed instance.

Reported by:    Ivan Klymenko, Johan Hendriks  on current@ today
Obtained from:  projects/vnet
Sponsored by:   The FreeBSD Foundation
MFC after:      13 days
Approved by:	re (gjb)
2016-06-23 22:31:10 +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);