NetBSD/sys/netinet/ip_fil_netbsd.c
christos bd67b97d6a PR/25622: IPV6 return RST and through cloned interfaces was broken.
- checksum was computed incorrectly.
- ipv6 packet was not initialized properly.
- fixed code to be more similar to the v4 counterpart.
2004-05-20 13:55:31 +00:00

1603 lines
33 KiB
C

/* $NetBSD: ip_fil_netbsd.c,v 1.10 2004/05/20 13:55:32 christos Exp $ */
/*
* Copyright (C) 1993-2003 by Darren Reed.
*
* See the IPFILTER.LICENCE file for details on licencing.
*/
#if !defined(lint)
static const char sccsid[] = "@(#)ip_fil.c 2.41 6/5/96 (C) 1993-2000 Darren Reed";
static const char rcsid[] = "@(#)Id: ip_fil_netbsd.c,v 2.55.2.2 2004/03/22 12:18:08 darrenr Exp";
#endif
#if defined(KERNEL) || defined(_KERNEL)
# undef KERNEL
# undef _KERNEL
# define KERNEL 1
# define _KERNEL 1
#endif
#include <sys/param.h>
#if (NetBSD >= 199905) && !defined(IPFILTER_LKM) && defined(_KERNEL)
# include "opt_ipfilter_log.h"
# include "opt_pfil_hooks.h"
# include "opt_ipsec.h"
#endif
#include <sys/errno.h>
#include <sys/types.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/systm.h>
#if (NetBSD > 199609)
# include <sys/dirent.h>
#else
# include <sys/dir.h>
#endif
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_var.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 "netinet/ip_compat.h"
#ifdef USE_INET6
# include <netinet/icmp6.h>
# if (__NetBSD_Version__ > 106009999)
# include <netinet6/nd6.h>
# endif
#endif
#include "netinet/ip_fil.h"
#include "netinet/ip_nat.h"
#include "netinet/ip_frag.h"
#include "netinet/ip_state.h"
#include "netinet/ip_proxy.h"
#include "netinet/ip_auth.h"
#ifdef IPFILTER_SYNC
#include "netinet/ip_sync.h"
#endif
#ifdef IPFILTER_SCAN
#include "netinet/ip_scan.h"
#endif
#include "netinet/ip_pool.h"
#include <sys/md5.h>
#include <sys/kernel.h>
extern int ip_optcopy __P((struct ip *, struct ip *));
#ifdef IPFILTER_M_IPFILTER
MALLOC_DEFINE(M_IPFILTER, "IP Filter", "IP Filter packet filter data structures");
#endif
#if __NetBSD_Version__ >= 105009999
# define csuminfo csum_flags
#endif
static int (*fr_savep) __P((ip_t *, int, void *, int, struct mbuf **));
static int fr_send_ip __P((fr_info_t *, mb_t *, mb_t **));
#ifdef KMUTEX_T
extern ipfmutex_t ipf_rw;
extern ipfrwlock_t ipf_mutex;
#endif
#ifdef USE_INET6
static int ipfr_fastroute6 __P((struct mbuf *, struct mbuf **,
fr_info_t *, frdest_t *));
#endif
#if (__NetBSD_Version__ >= 104040000)
# include <sys/callout.h>
struct callout fr_slowtimer_ch;
#endif
#include <sys/conf.h>
#if defined(NETBSD_PF)
# include <net/pfil.h>
/*
* We provide the fr_checkp name just to minimize changes later.
*/
int (*fr_checkp) __P((ip_t *ip, int hlen, void *ifp, int out, mb_t **mp));
#endif /* NETBSD_PF */
#if (__NetBSD_Version__ >= 106080000) && defined(_KERNEL)
const struct cdevsw ipl_cdevsw = {
iplopen, iplclose, iplread, nowrite, iplioctl,
nostop, notty, nopoll, nommap,
};
#endif
#if defined(__NetBSD_Version__) && (__NetBSD_Version__ >= 105110000)
# include <net/pfil.h>
static int fr_check_wrapper(void *, struct mbuf **, struct ifnet *, int );
static int fr_check_wrapper(arg, mp, ifp, dir)
void *arg;
struct mbuf **mp;
struct ifnet *ifp;
int dir;
{
struct ip *ip = mtod(*mp, struct ip *);
int rv, hlen = ip->ip_hl << 2;
#if defined(M_CSUM_TCPv4)
/*
* If the packet is out-bound, we can't delay checksums
* here. For in-bound, the checksum has already been
* validated.
*/
if (dir == PFIL_OUT) {
if ((*mp)->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) {
in_delayed_cksum(*mp);
(*mp)->m_pkthdr.csum_flags &=
~(M_CSUM_TCPv4|M_CSUM_UDPv4);
}
}
#endif /* M_CSUM_TCPv4 */
/*
* We get the packet with all fields in network byte
* order. We expect ip_len and ip_off to be in host
* order. We frob them, call the filter, then frob
* them back.
*
* Note, we don't need to update the checksum, because
* it has already been verified.
*/
NTOHS(ip->ip_len);
NTOHS(ip->ip_off);
rv = fr_check(ip, hlen, ifp, (dir == PFIL_OUT), mp);
if (rv == 0 && *mp != NULL) {
ip = mtod(*mp, struct ip *);
HTONS(ip->ip_len);
HTONS(ip->ip_off);
}
return (rv);
}
# ifdef USE_INET6
# include <netinet/ip6.h>
static int fr_check_wrapper6(void *, struct mbuf **, struct ifnet *, int );
static int fr_check_wrapper6(arg, mp, ifp, dir)
void *arg;
struct mbuf **mp;
struct ifnet *ifp;
int dir;
{
return (fr_check(mtod(*mp, struct ip *), sizeof(struct ip6_hdr),
ifp, (dir == PFIL_OUT), mp));
}
# endif
#endif /* __NetBSD_Version >= 105110000 */
#if defined(IPFILTER_LKM)
int iplidentify(s)
char *s;
{
if (strcmp(s, "ipl") == 0)
return 1;
return 0;
}
#endif /* IPFILTER_LKM */
/*
* Try to detect the case when compiling for NetBSD with pseudo-device
*/
#if defined(PFIL_HOOKS)
void
ipfilterattach(count)
int count;
{
# if 0
if (iplattach() != 0)
printf("IP Filter failed to attach\n");
# endif
}
#endif
int iplattach()
{
int s;
#if defined(NETBSD_PF) && (__NetBSD_Version__ >= 104200000)
int error = 0;
# if defined(__NetBSD_Version__) && (__NetBSD_Version__ >= 105110000)
struct pfil_head *ph_inet;
# ifdef USE_INET6
struct pfil_head *ph_inet6;
# endif
# endif
#endif
SPL_NET(s);
if ((fr_running > 0) || (fr_checkp == fr_check)) {
printf("IP Filter: already initialized\n");
SPL_X(s);
return EBUSY;
}
if (fr_initialise() < 0) {
SPL_X(s);
return EIO;
}
#ifdef NETBSD_PF
# if (__NetBSD_Version__ >= 104200000)
# if __NetBSD_Version__ >= 105110000
ph_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET);
# ifdef USE_INET6
ph_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6);
# endif
if (ph_inet == NULL
# ifdef USE_INET6
&& ph_inet6 == NULL
# endif
) {
printf("pfil_head_get failed\n");
return ENODEV;
}
if (ph_inet != NULL)
error = pfil_add_hook((void *)fr_check_wrapper, NULL,
PFIL_IN|PFIL_OUT, ph_inet);
else
error = 0;
# else
error = pfil_add_hook((void *)fr_check, PFIL_IN|PFIL_OUT,
&inetsw[ip_protox[IPPROTO_IP]].pr_pfh);
# endif
if (error) {
# ifdef USE_INET6
goto pfil_error;
# else
fr_deinitialise();
SPL_X(s);
return error;
# endif
}
# else
pfil_add_hook((void *)fr_check, PFIL_IN|PFIL_OUT);
# endif
# ifdef USE_INET6
# if __NetBSD_Version__ >= 105110000
if (ph_inet6 != NULL)
error = pfil_add_hook((void *)fr_check_wrapper6, NULL,
PFIL_IN|PFIL_OUT, ph_inet6);
else
error = 0;
if (error) {
pfil_remove_hook((void *)fr_check_wrapper6, NULL,
PFIL_IN|PFIL_OUT, ph_inet6);
# else
error = pfil_add_hook((void *)fr_check, PFIL_IN|PFIL_OUT,
&inetsw[ip_protox[IPPROTO_IPV6]].pr_pfh);
if (error) {
pfil_remove_hook((void *)fr_check, PFIL_IN|PFIL_OUT,
&inetsw[ip_protox[IPPROTO_IP]].pr_pfh);
# endif
pfil_error:
fr_deinitialise();
SPL_X(s);
return error;
}
# endif
#endif
bzero((char *)frcache, sizeof(frcache));
fr_savep = fr_checkp;
fr_checkp = fr_check;
if (fr_control_forwarding & 1)
ipforwarding = 1;
SPL_X(s);
#if (__NetBSD_Version__ >= 104010000)
callout_init(&fr_slowtimer_ch);
callout_reset(&fr_slowtimer_ch, (hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT,
fr_slowtimer, NULL);
#else
timeout(fr_slowtimer, NULL, (hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT);
#endif
return 0;
}
/*
* Disable the filter by removing the hooks from the IP input/output
* stream.
*/
int ipldetach()
{
int s;
#if defined(NETBSD_PF) && (__NetBSD_Version__ >= 104200000)
int error = 0;
# if __NetBSD_Version__ >= 105150000
struct pfil_head *ph_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET);
# ifdef USE_INET6
struct pfil_head *ph_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6);
# endif
# endif
#endif
SPL_NET(s);
#if (__NetBSD_Version__ >= 104010000)
callout_stop(&fr_slowtimer_ch);
#else
untimeout(fr_slowtimer, NULL);
#endif /* NetBSD */
fr_checkp = fr_savep;
(void) frflush(IPL_LOGIPF, FR_INQUE|FR_OUTQUE|FR_INACTIVE);
(void) frflush(IPL_LOGIPF, FR_INQUE|FR_OUTQUE);
if (fr_control_forwarding & 2)
ipforwarding = 0;
#ifdef NETBSD_PF
# if (__NetBSD_Version__ >= 104200000)
# if __NetBSD_Version__ >= 105110000
if (ph_inet != NULL)
error = pfil_remove_hook((void *)fr_check_wrapper, NULL,
PFIL_IN|PFIL_OUT, ph_inet);
else
error = 0;
# else
error = pfil_remove_hook((void *)fr_check, PFIL_IN|PFIL_OUT,
&inetsw[ip_protox[IPPROTO_IP]].pr_pfh);
# endif
if (error)
return error;
# else
pfil_remove_hook((void *)fr_check, PFIL_IN|PFIL_OUT);
# endif
# ifdef USE_INET6
# if __NetBSD_Version__ >= 105110000
if (ph_inet6 != NULL)
error = pfil_remove_hook((void *)fr_check_wrapper6, NULL,
PFIL_IN|PFIL_OUT, ph_inet6);
else
error = 0;
# else
error = pfil_remove_hook((void *)fr_check, PFIL_IN|PFIL_OUT,
&inetsw[ip_protox[IPPROTO_IPV6]].pr_pfh);
# endif
if (error)
return error;
# endif
#endif
fr_deinitialise();
SPL_X(s);
return 0;
}
/*
* Filter ioctl interface.
*/
int iplioctl(dev, cmd, data, mode
#if (NetBSD >= 199511)
, p)
struct proc *p;
#else
)
#endif
dev_t dev;
u_long cmd;
caddr_t data;
int mode;
{
int s;
int error = 0, unit = 0, tmp;
friostat_t fio;
if ((securelevel >= 2) && (mode & FWRITE))
return EPERM;
unit = GET_MINOR(dev);
if ((IPL_LOGMAX < unit) || (unit < 0))
return ENXIO;
if (fr_running <= 0) {
if (unit != IPL_LOGIPF)
return EIO;
if (cmd != SIOCIPFGETNEXT && cmd != SIOCIPFGET &&
cmd != SIOCIPFSET && cmd != SIOCFRENB &&
cmd != SIOCGETFS && cmd != SIOCGETFF)
return EIO;
}
SPL_NET(s);
error = fr_ioctlswitch(unit, data, cmd, mode);
if (error != -1) {
SPL_X(s);
return error;
}
error = 0;
switch (cmd)
{
case FIONREAD :
#ifdef IPFILTER_LOG
BCOPYOUT(&iplused[IPL_LOGIPF], (caddr_t)data,
sizeof(iplused[IPL_LOGIPF]));
#endif
break;
case SIOCFRENB :
if (!(mode & FWRITE))
error = EPERM;
else {
BCOPYIN(data, &tmp, sizeof(tmp));
if (tmp) {
if (fr_running > 0)
error = 0;
else
error = iplattach();
if (error == 0)
fr_running = 1;
else
(void) ipldetach();
} else {
error = ipldetach();
if (error == 0)
fr_running = -1;
}
}
break;
case SIOCIPFSET :
if (!(mode & FWRITE)) {
error = EPERM;
break;
}
case SIOCIPFGETNEXT :
case SIOCIPFGET :
error = fr_ipftune(cmd, data);
break;
case SIOCSETFF :
if (!(mode & FWRITE))
error = EPERM;
else
BCOPYIN(data, &fr_flags, sizeof(fr_flags));
break;
case SIOCGETFF :
BCOPYOUT(&fr_flags, data, sizeof(fr_flags));
break;
case SIOCFUNCL :
error = fr_resolvefunc(data);
break;
case SIOCINAFR :
case SIOCRMAFR :
case SIOCADAFR :
case SIOCZRLST :
if (!(mode & FWRITE))
error = EPERM;
else
error = frrequest(unit, cmd, data, fr_active, 1);
break;
case SIOCINIFR :
case SIOCRMIFR :
case SIOCADIFR :
if (!(mode & FWRITE))
error = EPERM;
else
error = frrequest(unit, cmd, data, 1 - fr_active, 1);
break;
case SIOCSWAPA :
if (!(mode & FWRITE))
error = EPERM;
else {
bzero((char *)frcache, sizeof(frcache[0]) * 2);
*(u_int *)data = fr_active;
fr_active = 1 - fr_active;
}
break;
case SIOCGETFS :
fr_getstat(&fio);
error = fr_outobj(data, &fio, IPFOBJ_IPFSTAT);
break;
case SIOCFRZST :
if (!(mode & FWRITE))
error = EPERM;
else
error = fr_zerostats(data);
break;
case SIOCIPFFL :
if (!(mode & FWRITE))
error = EPERM;
else {
BCOPYIN(data, &tmp, sizeof(tmp));
tmp = frflush(unit, tmp);
BCOPYOUT(&tmp, data, sizeof(tmp));
}
break;
case SIOCSTLCK :
BCOPYIN(data, &tmp, sizeof(tmp));
fr_state_lock = tmp;
fr_nat_lock = tmp;
fr_frag_lock = tmp;
fr_auth_lock = tmp;
break;
#ifdef IPFILTER_LOG
case SIOCIPFFB :
if (!(mode & FWRITE))
error = EPERM;
else
*(int *)data = ipflog_clear(unit);
break;
#endif /* IPFILTER_LOG */
case SIOCGFRST :
error = fr_outobj(data, fr_fragstats(), IPFOBJ_FRAGSTAT);
break;
case SIOCFRSYN :
if (!(mode & FWRITE))
error = EPERM;
else {
frsync();
}
break;
default :
error = EINVAL;
break;
}
SPL_X(s);
return error;
}
void fr_forgetifp(ifp)
void *ifp;
{
register frentry_t *f;
WRITE_ENTER(&ipf_mutex);
for (f = ipacct[0][fr_active]; (f != NULL); f = f->fr_next)
if (f->fr_ifa == ifp)
f->fr_ifa = (void *)-1;
for (f = ipacct[1][fr_active]; (f != NULL); f = f->fr_next)
if (f->fr_ifa == ifp)
f->fr_ifa = (void *)-1;
for (f = ipfilter[0][fr_active]; (f != NULL); f = f->fr_next)
if (f->fr_ifa == ifp)
f->fr_ifa = (void *)-1;
for (f = ipfilter[1][fr_active]; (f != NULL); f = f->fr_next)
if (f->fr_ifa == ifp)
f->fr_ifa = (void *)-1;
#ifdef USE_INET6
for (f = ipacct6[0][fr_active]; (f != NULL); f = f->fr_next)
if (f->fr_ifa == ifp)
f->fr_ifa = (void *)-1;
for (f = ipacct6[1][fr_active]; (f != NULL); f = f->fr_next)
if (f->fr_ifa == ifp)
f->fr_ifa = (void *)-1;
for (f = ipfilter6[0][fr_active]; (f != NULL); f = f->fr_next)
if (f->fr_ifa == ifp)
f->fr_ifa = (void *)-1;
for (f = ipfilter6[1][fr_active]; (f != NULL); f = f->fr_next)
if (f->fr_ifa == ifp)
f->fr_ifa = (void *)-1;
#endif
RWLOCK_EXIT(&ipf_mutex);
fr_natsync(ifp);
}
/*
* routines below for saving IP headers to buffer
*/
int iplopen(dev, flags
#if (NetBSD >= 199511)
, devtype, p)
int devtype;
struct proc *p;
#else
)
#endif
dev_t dev;
int flags;
{
u_int min = GET_MINOR(dev);
if (IPL_LOGMAX < min)
min = ENXIO;
else
min = 0;
return min;
}
int iplclose(dev, flags
#if (NetBSD >= 199511)
, devtype, p)
int devtype;
struct proc *p;
#else
)
#endif
dev_t dev;
int flags;
{
u_int min = GET_MINOR(dev);
if (IPL_LOGMAX < min)
min = ENXIO;
else
min = 0;
return min;
}
/*
* 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.
*/
#if (BSD >= 199306)
int iplread(dev, uio, ioflag)
int ioflag;
#else
int iplread(dev, uio)
#endif
dev_t dev;
register struct uio *uio;
{
#ifdef IPFILTER_LOG
return ipflog_read(GET_MINOR(dev), uio);
#else
return ENXIO;
#endif
}
/*
* fr_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 fr_send_reset(fin)
fr_info_t *fin;
{
struct tcphdr *tcp, *tcp2;
int tlen = 0, hlen;
struct mbuf *m;
#ifdef USE_INET6
ip6_t *ip6;
#endif
ip_t *ip;
tcp = fin->fin_dp;
if (tcp->th_flags & TH_RST)
return -1; /* feedback loop */
#ifndef IPFILTER_CKSUM
if (fr_checkl4sum(fin) == -1)
return -1;
#endif
m = m_gethdr(M_DONTWAIT, MT_HEADER);
if (m == NULL)
return -1;
tlen = fin->fin_dlen - (TCP_OFF(tcp) << 2) +
((tcp->th_flags & TH_SYN) ? 1 : 0) +
((tcp->th_flags & TH_FIN) ? 1 : 0);
#ifdef USE_INET6
hlen = (fin->fin_v == 6) ? sizeof(ip6_t) : sizeof(ip_t);
#else
hlen = sizeof(ip_t);
#endif
m->m_len = sizeof(*tcp2) + hlen;
m->m_data += max_linkhdr;
m->m_pkthdr.len = m->m_len;
m->m_pkthdr.rcvif = (struct ifnet *)0;
ip = mtod(m, struct ip *);
#ifdef USE_INET6
ip6 = (ip6_t *)ip;
#endif
bzero((char *)ip, sizeof(*tcp2) + hlen);
tcp2 = (struct tcphdr *)((char *)ip + hlen);
tcp2->th_sport = tcp->th_dport;
tcp2->th_dport = tcp->th_sport;
if (tcp->th_flags & TH_ACK) {
tcp2->th_seq = tcp->th_ack;
tcp2->th_flags = TH_RST;
tcp2->th_ack = 0;
} else {
tcp2->th_seq = 0;
tcp2->th_ack = ntohl(tcp->th_seq);
tcp2->th_ack += tlen;
tcp2->th_ack = htonl(tcp2->th_ack);
tcp2->th_flags = TH_RST|TH_ACK;
}
tcp2->th_x2 = 0;
TCP_OFF_A(tcp2, sizeof(*tcp2) >> 2);
tcp2->th_win = tcp->th_win;
tcp2->th_sum = 0;
tcp2->th_urp = 0;
#ifdef USE_INET6
if (fin->fin_v == 6) {
ip6->ip6_flow = 0;
ip6->ip6_plen = htons(sizeof(struct tcphdr));
ip6->ip6_nxt = IPPROTO_TCP;
ip6->ip6_hlim = 0;
ip6->ip6_src = fin->fin_dst6;
ip6->ip6_dst = fin->fin_src6;
tcp2->th_sum = in6_cksum(m, IPPROTO_TCP,
sizeof(*ip6), sizeof(*tcp2));
return fr_send_ip(fin, m, &m);
}
#endif
ip->ip_p = IPPROTO_TCP;
ip->ip_len = htons(sizeof(struct tcphdr));
ip->ip_src.s_addr = fin->fin_daddr;
ip->ip_dst.s_addr = fin->fin_saddr;
tcp2->th_sum = in_cksum(m, hlen + sizeof(*tcp2));
ip->ip_len = hlen + sizeof(*tcp2);
return fr_send_ip(fin, m, &m);
}
/* ------------------------------------------------------------------------ */
/* Function: fr_nextipid */
/* Returns: int - 0 == success, -1 == error (packet should be droppped) */
/* Parameters: fin(I) - pointer to packet information */
/* */
/* Returns the next IPv4 ID to use for this packet. */
/* ------------------------------------------------------------------------ */
INLINE u_short fr_nextipid(fin)
fr_info_t *fin;
{
static u_short ipid = 0;
u_short id;
MUTEX_ENTER(&ipf_rw);
id = ipid++;
MUTEX_EXIT(&ipf_rw);
return id;
}
static int fr_send_ip(fin, m, mpp)
fr_info_t *fin;
mb_t *m, **mpp;
{
ip_t *ip, *oip;
ip = mtod(m, ip_t *);
IP_V_A(ip, fin->fin_v);
switch (fin->fin_v)
{
case 4 :
oip = fin->fin_ip;
IP_HL_A(ip, sizeof(*oip) >> 2);
ip->ip_tos = oip->ip_tos;
ip->ip_id = fr_nextipid(fin);
ip->ip_off = ip_mtudisc ? IP_DF : 0;
ip->ip_ttl = ip_defttl;
ip->ip_sum = 0;
break;
#ifdef USE_INET6
case 6 :
{
ip6_t *ip6 = (ip6_t *)ip;
ip6->ip6_vfc = 0x60;
ip6->ip6_hlim = IPDEFTTL;
break;
}
#endif
default :
return EINVAL;
}
#ifdef IPSEC
m->m_pkthdr.rcvif = NULL;
#endif
return fr_fastroute(m, mpp, fin, NULL);
}
int fr_send_icmp_err(type, fin, dst)
int type;
fr_info_t *fin;
int dst;
{
int err, hlen, xtra, iclen, ohlen, avail, code;
struct in_addr dst4;
struct icmp *icmp;
struct mbuf *m;
void *ifp;
#ifdef USE_INET6
ip6_t *ip6, *ip62;
struct in6_addr dst6;
#endif
ip_t *ip, *ip2;
if ((type < 0) || (type > ICMP_MAXTYPE))
return -1;
code = fin->fin_icode;
#ifdef USE_INET6
if ((code < 0) || (code > sizeof(icmptoicmp6unreach)/sizeof(int)))
return -1;
#endif
#ifndef IPFILTER_CKSUM
if (fr_checkl4sum(fin) == -1)
return -1;
#endif
xtra = 0;
hlen = 0;
ohlen = 0;
avail = 0;
m = NULL;
ifp = fin->fin_ifp;
if (fin->fin_v == 4) {
if ((fin->fin_p == IPPROTO_ICMP) &&
!(fin->fin_flx & FI_SHORT))
switch (ntohs(fin->fin_data[0]) >> 8)
{
case ICMP_ECHO :
case ICMP_TSTAMP :
case ICMP_IREQ :
case ICMP_MASKREQ :
break;
default :
return 0;
}
avail = MHLEN;
m = m_gethdr(M_DONTWAIT, MT_HEADER);
if (m == NULL)
return -1;
if (dst == 0) {
if (fr_ifpaddr(4, FRI_NORMAL, ifp,
&dst4, NULL) == -1) {
FREE_MB_T(m);
return -1;
}
} else
dst4.s_addr = fin->fin_daddr;
hlen = sizeof(ip_t);
ohlen = fin->fin_hlen;
if (fin->fin_hlen < fin->fin_plen)
xtra = MIN(fin->fin_dlen, 8);
else
xtra = 0;
}
#ifdef USE_INET6
else if (fin->fin_v == 6) {
hlen = sizeof(ip6_t);
ohlen = sizeof(ip6_t);
type = icmptoicmp6types[type];
if (type == ICMP6_DST_UNREACH)
code = icmptoicmp6unreach[code];
MGETHDR(m, M_DONTWAIT, MT_HEADER);
if (m == NULL)
return -1;
MCLGET(m, M_DONTWAIT);
if (m == NULL)
return -1;
avail = (m->m_flags & M_EXT) ? MCLBYTES : MHLEN;
xtra = MIN(fin->fin_plen,
avail - hlen - sizeof(*icmp) - max_linkhdr);
if (dst == 0) {
if (fr_ifpaddr(6, FRI_NORMAL, ifp,
(struct in_addr *)&dst6, NULL) == -1) {
FREE_MB_T(m);
return -1;
}
} else
dst6 = fin->fin_dst6;
}
#endif
else
return -1;
iclen = hlen + sizeof(*icmp) + xtra;
avail -= (max_linkhdr + iclen);
m->m_data += max_linkhdr;
m->m_pkthdr.rcvif = (struct ifnet *)0;
if (xtra > avail)
xtra = avail;
iclen += xtra;
m->m_pkthdr.len = iclen;
if (avail < 0) {
m_freem(m);
return -1;
}
m->m_len = iclen;
ip = mtod(m, ip_t *);
icmp = (struct icmp *)((char *)ip + hlen);
ip2 = (ip_t *)&icmp->icmp_ip;
icmp->icmp_type = type;
icmp->icmp_code = fin->fin_icode;
icmp->icmp_cksum = 0;
#ifdef icmp_nextmtu
if (type == ICMP_UNREACH &&
fin->fin_icode == ICMP_UNREACH_NEEDFRAG && ifp)
icmp->icmp_nextmtu = htons(((struct ifnet *)ifp)->if_mtu);
#endif
bcopy((char *)fin->fin_ip, (char *)ip2, ohlen);
#if defined(M_CSUM_IPv4)
/*
* Clear any in-bound checksum flags for this packet.
*/
m->m_pkthdr.csuminfo = 0;
#endif /* __NetBSD__ && M_CSUM_IPv4 */
#ifdef USE_INET6
ip6 = (ip6_t *)ip;
if (fin->fin_v == 6) {
ip62 = (ip6_t *)ip2;
ip6->ip6_flow = 0;
ip6->ip6_plen = htons(iclen - hlen);
ip6->ip6_nxt = IPPROTO_ICMPV6;
ip6->ip6_hlim = 0;
ip6->ip6_src = dst6;
ip6->ip6_dst = fin->fin_src6;
if (xtra > 0)
bcopy((char *)fin->fin_ip + ohlen,
(char *)&icmp->icmp_ip + ohlen, xtra);
icmp->icmp_cksum = in6_cksum(m, IPPROTO_ICMPV6,
sizeof(*ip6), iclen - hlen);
} else
#endif
{
ip->ip_p = IPPROTO_ICMP;
ip->ip_src.s_addr = dst4.s_addr;
ip->ip_dst.s_addr = fin->fin_saddr;
if (xtra > 0)
bcopy((char *)fin->fin_ip + ohlen,
(char *)&icmp->icmp_ip + ohlen, xtra);
icmp->icmp_cksum = ipf_cksum((u_short *)icmp,
sizeof(*icmp) + 8);
ip->ip_len = iclen;
ip->ip_p = IPPROTO_ICMP;
}
err = fr_send_ip(fin, m, &m);
return err;
}
int fr_fastroute(m0, mpp, fin, fdp)
mb_t *m0, **mpp;
fr_info_t *fin;
frdest_t *fdp;
{
register struct ip *ip, *mhip;
register struct mbuf *m = m0;
register struct route *ro;
int len, off, error = 0, hlen, code;
struct ifnet *ifp, *sifp;
struct sockaddr_in *dst;
struct route iproute;
u_short ip_off;
frentry_t *fr;
#ifdef M_WRITABLE
/*
* HOT FIX/KLUDGE:
*
* If the mbuf we're about to send is not writable (because of
* a cluster reference, for example) we'll need to make a copy
* of it since this routine modifies the contents.
*
* If you have non-crappy network hardware that can transmit data
* from the mbuf, rather than making a copy, this is gonna be a
* problem.
*/
if (M_WRITABLE(m) == 0) {
if ((m0 = m_dup(m, M_DONTWAIT)) != 0) {
m_freem(m);
m = m0;
} else {
error = ENOBUFS;
m_freem(m);
fr_frouteok[1]++;
}
}
#endif
#ifdef USE_INET6
if (fin->fin_v == 6)
return ipfr_fastroute6(m0, mpp, fin, fdp);
#endif
hlen = fin->fin_hlen;
ip = mtod(m0, struct ip *);
#if defined(M_CSUM_IPv4)
/*
* Clear any in-bound checksum flags for this packet.
*/
m0->m_pkthdr.csuminfo = 0;
#endif /* __NetBSD__ && M_CSUM_IPv4 */
/*
* Route packet.
*/
ro = &iproute;
bzero((caddr_t)ro, sizeof (*ro));
dst = (struct sockaddr_in *)&ro->ro_dst;
dst->sin_family = AF_INET;
dst->sin_addr = ip->ip_dst;
fr = fin->fin_fr;
if (fdp != NULL)
ifp = fdp->fd_ifp;
else
ifp = fin->fin_ifp;
if ((ifp == NULL) && (!fr || !(fr->fr_flags & FR_FASTROUTE))) {
error = -2;
goto bad;
}
/*
* In case we're here due to "to <if>" being used with "keep state",
* check that we're going in the correct direction.
*/
if ((fr != NULL) && (fin->fin_rev != 0)) {
if ((ifp != NULL) && (fdp == &fr->fr_tif))
return -1;
} else if (fdp != NULL) {
if (fdp->fd_ip.s_addr != 0)
dst->sin_addr = fdp->fd_ip;
}
dst->sin_len = sizeof(*dst);
rtalloc(ro);
if ((ifp == NULL) && (ro->ro_rt != NULL))
ifp = ro->ro_rt->rt_ifp;
if ((ro->ro_rt == NULL) || (ifp == NULL)) {
if (in_localaddr(ip->ip_dst))
error = EHOSTUNREACH;
else
error = ENETUNREACH;
goto bad;
}
if (ro->ro_rt->rt_flags & RTF_GATEWAY)
dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway;
if (ro->ro_rt)
ro->ro_rt->rt_use++;
/*
* For input packets which are being "fastrouted", they won't
* go back through output filtering and miss their chance to get
* NAT'd and counted.
*/
if (fin->fin_out == 0) {
sifp = fin->fin_ifp;
fin->fin_ifp = ifp;
fin->fin_out = 1;
(void) fr_acctpkt(fin, NULL);
fin->fin_fr = NULL;
if (!fr || !(fr->fr_flags & FR_RETMASK)) {
u_32_t pass;
(void) fr_checkstate(fin, &pass);
}
switch (fr_checknatout(fin, NULL))
{
case 0 :
break;
case 1 :
ip->ip_sum = 0;
break;
case -1 :
error = -1;
goto done;
break;
}
fin->fin_ifp = sifp;
fin->fin_out = 0;
} else
ip->ip_sum = 0;
/*
* If small enough for interface, can just send directly.
*/
if (ip->ip_len <= ifp->if_mtu) {
ip->ip_len = htons(ip->ip_len);
ip->ip_off = htons(ip->ip_off);
#if defined(M_CSUM_IPv4)
if (ifp->if_capabilities & IFCAP_CSUM_IPv4)
m->m_pkthdr.csuminfo |= M_CSUM_IPv4;
else if (ip->ip_sum == 0)
ip->ip_sum = in_cksum(m, hlen);
#else
if (!ip->ip_sum)
ip->ip_sum = in_cksum(m, hlen);
#endif /* M_CSUM_IPv4 */
error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst,
ro->ro_rt);
goto done;
}
/*
* Too large for interface; fragment if possible.
* Must be able to put at least 8 bytes per fragment.
*/
ip_off = ip->ip_off;
if (ip_off & IP_DF) {
error = EMSGSIZE;
goto bad;
}
len = (ifp->if_mtu - hlen) &~ 7;
if (len < 8) {
error = EMSGSIZE;
goto bad;
}
{
int mhlen, firstlen = len;
struct mbuf **mnext = &m->m_act;
/*
* Loop through length of segment after first fragment,
* make new header and copy data of each part and link onto chain.
*/
m0 = m;
mhlen = sizeof (struct ip);
for (off = hlen + len; off < ip->ip_len; off += len) {
#ifdef MGETHDR
MGETHDR(m, M_DONTWAIT, MT_HEADER);
#else
MGET(m, M_DONTWAIT, MT_HEADER);
#endif
if (m == 0) {
error = ENOBUFS;
goto bad;
}
m->m_data += max_linkhdr;
mhip = mtod(m, struct ip *);
bcopy((char *)ip, (char *)mhip, sizeof(*ip));
if (hlen > sizeof (struct ip)) {
mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
IP_HL_A(mhip, mhlen >> 2);
}
m->m_len = mhlen;
mhip->ip_off = ((off - hlen) >> 3) + ip_off;
if (off + len >= ip->ip_len)
len = ip->ip_len - off;
else
mhip->ip_off |= IP_MF;
mhip->ip_len = htons((u_short)(len + mhlen));
m->m_next = m_copy(m0, off, len);
if (m->m_next == 0) {
error = ENOBUFS; /* ??? */
goto sendorfree;
}
m->m_pkthdr.len = mhlen + len;
m->m_pkthdr.rcvif = NULL;
mhip->ip_off = htons((u_short)mhip->ip_off);
mhip->ip_sum = 0;
mhip->ip_sum = in_cksum(m, mhlen);
*mnext = m;
mnext = &m->m_act;
}
/*
* Update first fragment by trimming what's been copied out
* and updating header, then send each fragment (in order).
*/
m_adj(m0, hlen + firstlen - ip->ip_len);
ip->ip_len = htons((u_short)(hlen + firstlen));
ip->ip_off = htons((u_short)IP_MF);
ip->ip_sum = 0;
ip->ip_sum = in_cksum(m0, hlen);
sendorfree:
for (m = m0; m; m = m0) {
m0 = m->m_act;
m->m_act = 0;
if (error == 0)
error = (*ifp->if_output)(ifp, m,
(struct sockaddr *)dst, ro->ro_rt);
else
m_freem(m);
}
}
done:
if (!error)
fr_frouteok[0]++;
else
fr_frouteok[1]++;
if (ro->ro_rt) {
RTFREE(ro->ro_rt);
}
*mpp = NULL;
return 0;
bad:
if (error == EMSGSIZE) {
sifp = fin->fin_ifp;
code = fin->fin_icode;
fin->fin_icode = ICMP_UNREACH_NEEDFRAG;
fin->fin_ifp = ifp;
(void) fr_send_icmp_err(ICMP_UNREACH, fin, 1);
fin->fin_ifp = sifp;
fin->fin_icode = code;
}
m_freem(m);
goto done;
}
#if defined(USE_INET6)
/*
* This is the IPv6 specific fastroute code. It doesn't clean up the mbuf's
* or ensure that it is an IPv6 packet that is being forwarded, those are
* expected to be done by the called (ipfr_fastroute).
*/
static int ipfr_fastroute6(m0, mpp, fin, fdp)
struct mbuf *m0, **mpp;
fr_info_t *fin;
frdest_t *fdp;
{
struct route_in6 ip6route;
struct sockaddr_in6 *dst6;
struct route_in6 *ro;
struct ifnet *ifp;
frentry_t *fr;
u_long mtu;
int error;
ro = &ip6route;
fr = fin->fin_fr;
bzero((caddr_t)ro, sizeof(*ro));
dst6 = (struct sockaddr_in6 *)&ro->ro_dst;
dst6->sin6_family = AF_INET6;
dst6->sin6_len = sizeof(struct sockaddr_in6);
dst6->sin6_addr = fin->fin_fi.fi_src.in6;
if (fdp != NULL)
ifp = fdp->fd_ifp;
else
ifp = fin->fin_ifp;
if ((fr != NULL) && (fin->fin_rev != 0)) {
if ((ifp != NULL) && (fdp == &fr->fr_tif))
return 0;
} else if (fdp != NULL) {
if (IP6_NOTZERO(&fdp->fd_ip6))
dst6->sin6_addr = fdp->fd_ip6.in6;
}
rtalloc((struct route *)ro);
if ((ifp == NULL) && (ro->ro_rt != NULL))
ifp = ro->ro_rt->rt_ifp;
if ((ro->ro_rt == NULL) || (ifp == NULL)) {
error = EHOSTUNREACH;
goto bad;
}
/* KAME */
if (IN6_IS_ADDR_LINKLOCAL(&dst6->sin6_addr))
dst6->sin6_addr.s6_addr16[1] = htons(ifp->if_index);
{
#if (__NetBSD_Version__ >= 106010000)
struct in6_addr finaldst = fin->fin_src6;
int frag;
/* Determine path MTU. */
error = ip6_getpmtu(ro, ro, ifp, &finaldst, &mtu, &frag);
if (error)
goto bad;
#else
mtu = nd_ifinfo[ifp->if_index].linkmtu;
#endif
if (ro->ro_rt->rt_flags & RTF_GATEWAY)
dst6 = (struct sockaddr_in6 *)ro->ro_rt->rt_gateway;
ro->ro_rt->rt_use++;
if (m0->m_pkthdr.len <= mtu)
error = nd6_output(ifp, fin->fin_ifp, m0,
dst6, ro->ro_rt);
else
error = EMSGSIZE;
}
bad:
if (ro->ro_rt != NULL) {
RTFREE(ro->ro_rt);
}
return error;
}
#endif
int fr_verifysrc(fin)
fr_info_t *fin;
{
struct sockaddr_in *dst;
struct route iproute;
bzero((char *)&iproute, sizeof(iproute));
dst = (struct sockaddr_in *)&iproute.ro_dst;
dst->sin_len = sizeof(*dst);
dst->sin_family = AF_INET;
dst->sin_addr = fin->fin_src;
rtalloc(&iproute);
if (iproute.ro_rt == NULL)
return 0;
return (fin->fin_ifp == iproute.ro_rt->rt_ifp);
}
/*
* return the first IP Address associated with an interface
*/
int fr_ifpaddr(v, atype, ifptr, inp, inpmask)
int v, atype;
void *ifptr;
struct in_addr *inp, *inpmask;
{
#ifdef USE_INET6
struct in6_addr *inp6 = NULL;
#endif
struct sockaddr *sock, *mask;
struct sockaddr_in *sin;
struct ifaddr *ifa;
struct ifnet *ifp;
if ((ifptr == NULL) || (ifptr == (void *)-1))
return -1;
ifp = ifptr;
mask = NULL;
if (v == 4)
inp->s_addr = 0;
#ifdef USE_INET6
else if (v == 6)
bzero((char *)inp, sizeof(struct in6_addr));
#endif
ifa = ifp->if_addrlist.tqh_first;
sock = ifa->ifa_addr;
while (sock != NULL && ifa != NULL) {
sin = (struct sockaddr_in *)sock;
if ((v == 4) && (sin->sin_family == AF_INET))
break;
#ifdef USE_INET6
if ((v == 6) && (sin->sin_family == AF_INET6)) {
inp6 = &((struct sockaddr_in6 *)sin)->sin6_addr;
if (!IN6_IS_ADDR_LINKLOCAL(inp6) &&
!IN6_IS_ADDR_LOOPBACK(inp6))
break;
}
#endif
ifa = ifa->ifa_list.tqe_next;
if (ifa != NULL)
sock = ifa->ifa_addr;
}
if (ifa == NULL || sock == NULL)
return -1;
mask = ifa->ifa_netmask;
if (atype == FRI_BROADCAST)
sock = ifa->ifa_broadaddr;
else if (atype == FRI_PEERADDR)
sock = ifa->ifa_dstaddr;
#ifdef USE_INET6
if (v == 6)
return fr_ifpfillv6addr(atype, (struct sockaddr_in6 *)sock,
(struct sockaddr_in6 *)mask,
inp, inpmask);
#endif
return fr_ifpfillv4addr(atype, (struct sockaddr_in *)sock,
(struct sockaddr_in *)mask, inp, inpmask);
}
u_32_t fr_newisn(fin)
fr_info_t *fin;
{
u_32_t newiss;
#if __NetBSD_Version >= 105190000 /* 1.5T */
size_t asz;
if (fin->fin_v == 4)
asz = sizeof(struct in_addr);
else if (fin->fin_v == 6)
asz = sizeof(fin->fin_src);
newiss = tcp_new_iss1((void *)&fin->fin_src, (void *)&fin->fin_dst,
fin->fin_sport, fin->fin_dport, asz);
#else
static int iss_seq_off = 0;
u_char hash[16];
MD5_CTX ctx;
/*
* Compute the base value of the ISS. It is a hash
* of (saddr, sport, daddr, dport, secret).
*/
MD5Init(&ctx);
MD5Update(&ctx, (u_char *) &fin->fin_fi.fi_src,
sizeof(fin->fin_fi.fi_src));
MD5Update(&ctx, (u_char *) &fin->fin_fi.fi_dst,
sizeof(fin->fin_fi.fi_dst));
MD5Update(&ctx, (u_char *) &fin->fin_dat, sizeof(fin->fin_dat));
MD5Update(&ctx, ipf_iss_secret, sizeof(ipf_iss_secret));
MD5Final(hash, &ctx);
memcpy(&newiss, hash, sizeof(newiss));
/*
* Now increment our "timer", and add it in to
* the computed value.
*
* XXX Use `addin'?
* XXX TCP_ISSINCR too large to use?
*/
iss_seq_off += 0x00010000;
newiss += iss_seq_off;
#endif
return newiss;
}
INLINE void fr_checkv4sum(fin)
fr_info_t *fin;
{
#ifdef M_CSUM_TCP_UDP_BAD
int manual, pflag, cflags, active;
mb_t *m;
if ((fin->fin_flx & FI_NOCKSUM) != 0)
return;
manual = 0;
m = fin->fin_m;
if (m == NULL) {
manual = 1;
goto skipauto;
}
switch (fin->fin_p)
{
case IPPROTO_UDP :
pflag = M_CSUM_UDPv4;
break;
case IPPROTO_TCP :
pflag = M_CSUM_TCPv4;
break;
default :
pflag = 0;
manual = 1;
break;
}
active = ((struct ifnet *)fin->fin_ifp)->if_csum_flags_rx & pflag;
active |= M_CSUM_TCP_UDP_BAD | M_CSUM_DATA;
cflags = m->m_pkthdr.csum_flags & active;
if (pflag != 0) {
if (cflags == (pflag | M_CSUM_TCP_UDP_BAD)) {
fin->fin_flx |= FI_BAD;
} else if (cflags == (pflag | M_CSUM_DATA)) {
if ((m->m_pkthdr.csum_data ^ 0xffff) != 0)
fin->fin_flx |= FI_BAD;
} else if (cflags == pflag) {
;
} else {
manual = 1;
}
}
skipauto:
# ifdef IPFILTER_CKSUM
if (manual != 0)
if (fr_checkl4sum(fin) == -1)
fin->fin_flx |= FI_BAD;
# else
;
# endif
#else
# ifdef IPFILTER_CKSUM
if (fr_checkl4sum(fin) == -1)
fin->fin_flx |= FI_BAD;
# endif
#endif
}
#ifdef USE_INET6
INLINE void fr_checkv6sum(fin)
fr_info_t *fin;
{
# ifdef M_CSUM_TCP_UDP_BAD
int manual, pflag, cflags, active;
mb_t *m;
if ((fin->fin_flx & FI_NOCKSUM) != 0)
return;
manual = 0;
m = fin->fin_m;
switch (fin->fin_p)
{
case IPPROTO_UDP :
pflag = M_CSUM_UDPv6;
break;
case IPPROTO_TCP :
pflag = M_CSUM_TCPv6;
break;
default :
pflag = 0;
manual = 1;
break;
}
active = ((struct ifnet *)fin->fin_ifp)->if_csum_flags_rx & pflag;
active |= M_CSUM_TCP_UDP_BAD | M_CSUM_DATA;
cflags = m->m_pkthdr.csum_flags & active;
if (pflag != 0) {
if (cflags == (pflag | M_CSUM_TCP_UDP_BAD)) {
fin->fin_flx |= FI_BAD;
} else if (cflags == (pflag | M_CSUM_DATA)) {
if ((m->m_pkthdr.csum_data ^ 0xffff) != 0)
fin->fin_flx |= FI_BAD;
} else if (cflags == pflag) {
;
} else {
manual = 1;
}
}
# ifdef IPFILTER_CKSUM
if (manual != 0)
if (fr_checkl4sum(fin) == -1)
fin->fin_flx |= FI_BAD;
# endif
# else
# ifdef IPFILTER_CKSUM
if (fr_checkl4sum(fin) == -1)
fin->fin_flx |= FI_BAD;
# endif
# endif
}
#endif /* USE_INET6 */