/* $NetBSD: ip_nat6.c,v 1.13 2024/09/08 09:36:51 rillig Exp $ */
/*
* Copyright (C) 2012 by Darren Reed.
*
* See the IPFILTER.LICENCE file for details on licencing.
*/
#if defined(KERNEL) || defined(_KERNEL)
# undef KERNEL
# undef ipf_nat6_KERNEL
# define KERNEL 1
# define ipf_nat6_KERNEL 1
#endif
#include <sys/errno.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/file.h>
#if defined(_KERNEL) && defined(__NetBSD_Version__) && \
(__NetBSD_Version__ >= 399002000)
# include <sys/kauth.h>
#endif
#if !defined(_KERNEL)
# include <stdio.h>
# include <string.h>
# include <stdlib.h>
# define ipf_nat6_KERNEL
# ifdef ipf_nat6__OpenBSD__
struct file;
# endif
# include <sys/uio.h>
# undef ipf_nat6_KERNEL
#endif
#if defined(_KERNEL) && (__FreeBSD_version >= 220000)
# include <sys/filio.h>
# include <sys/fcntl.h>
#else
# include <sys/ioctl.h>
#endif
#if !defined(AIX)
# include <sys/fcntl.h>
#endif
#if !defined(linux)
# include <sys/protosw.h>
#endif
#include <sys/socket.h>
#if defined(_KERNEL)
# include <sys/systm.h>
# if !defined(__SVR4) && !defined(__svr4__)
# include <sys/mbuf.h>
# endif
#endif
#if defined(__SVR4) || defined(__svr4__)
# include <sys/filio.h>
# include <sys/byteorder.h>
# ifdef ipf_nat6_KERNEL
# include <sys/dditypes.h>
# endif
# include <sys/stream.h>
# include <sys/kmem.h>
#endif
#if ipf_nat6__FreeBSD_version >= 300000
# include <sys/queue.h>
#endif
#include <net/if.h>
#if ipf_nat6__FreeBSD_version >= 300000
# include <net/if_var.h>
#endif
#ifdef sun
# include <net/af.h>
#endif
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#ifdef RFC1825
# include <vpn/md5.h>
# include <vpn/ipsec.h>
extern struct ifnet vpnif;
#endif
#if !defined(linux)
# include <netinet/ip_var.h>
#endif
#include <netinet/tcp.h>
#include <netinet/udp.h>
#include <netinet/ip_icmp.h>
#include "netinet/ip_compat.h"
#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_lookup.h"
#include "netinet/ip_dstlist.h"
#include "netinet/ip_sync.h"
#if (__FreeBSD_version >= 300000)
# include <sys/malloc.h>
#endif
#ifdef HAS_SYS_MD5_H
# include <sys/md5.h>
#else
# include "md5.h"
#endif
/* END OF INCLUDES */
#undef SOCKADDR_IN
#define SOCKADDR_IN struct sockaddr_in
__KERNEL_RCSID(0, "Id: ip_nat6.c,v 1.1.1.2 2012/07/22 13:45:29 darrenr Exp");
#ifdef USE_INET6
static struct hostmap *ipf_nat6_hostmap(ipf_nat_softc_t *, ipnat_t *,
i6addr_t *, i6addr_t *,
i6addr_t *, u_32_t);
static int ipf_nat6_match(fr_info_t *, ipnat_t *);
static void ipf_nat6_tabmove(ipf_nat_softc_t *, nat_t *);
static int ipf_nat6_decap(fr_info_t *, nat_t *);
static int ipf_nat6_nextaddr(fr_info_t *, nat_addr_t *, i6addr_t *,
i6addr_t *);
static int ipf_nat6_icmpquerytype(int);
static int ipf_nat6_out(fr_info_t *, nat_t *, int, u_32_t);
static int ipf_nat6_in(fr_info_t *, nat_t *, int, u_32_t);
static int ipf_nat6_builddivertmp(ipf_nat_softc_t *, ipnat_t *);
static int ipf_nat6_nextaddrinit(ipf_main_softc_t *, char *,
nat_addr_t *, int, void *);
static int ipf_nat6_insert(ipf_main_softc_t *, ipf_nat_softc_t *,
nat_t *);
#define NINCLSIDE6(y,x) ATOMIC_INCL(softn->ipf_nat_stats.ns_side6[y].x)
#define NBUMPSIDE(y,x) softn->ipf_nat_stats.ns_side[y].x++
#define NBUMPSIDE6(y,x) softn->ipf_nat_stats.ns_side6[y].x++
#define NBUMPSIDE6D(y,x) \
do { \
softn->ipf_nat_stats.ns_side6[y].x++; \
DT(x); \
} while (0)
#define NBUMPSIDE6DX(y,x,z) \
do { \
softn->ipf_nat_stats.ns_side6[y].x++; \
DT(z); \
} while (0)
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_ruleaddrinit */
/* Returns: int - 0 == success, else failure */
/* Parameters: in(I) - NAT rule that requires address fields to be init'd */
/* */
/* For each of the source/destination address fields in a NAT rule, call */
/* ipf_nat6_nextaddrinit() to prepare the structure for active duty. Other */
/* IPv6 specific actions can also be taken care of here. */
/* ------------------------------------------------------------------------ */
int
ipf_nat6_ruleaddrinit(ipf_main_softc_t *softc, ipf_nat_softc_t *softn,
ipnat_t *n)
{
int idx, error;
if (n->in_redir == NAT_BIMAP) {
n->in_ndstip6 = n->in_osrcip6;
n->in_ndstmsk6 = n->in_osrcmsk6;
n->in_odstip6 = n->in_nsrcip6;
n->in_odstmsk6 = n->in_nsrcmsk6;
}
if (n->in_redir & NAT_REDIRECT)
idx = 1;
else
idx = 0;
/*
* Initialise all of the address fields.
*/
error = ipf_nat6_nextaddrinit(softc, n->in_names, &n->in_osrc, 1,
n->in_ifps[idx]);
if (error != 0)
return error;
error = ipf_nat6_nextaddrinit(softc, n->in_names, &n->in_odst, 1,
n->in_ifps[idx]);
if (error != 0)
return error;
error = ipf_nat6_nextaddrinit(softc, n->in_names, &n->in_nsrc, 1,
n->in_ifps[idx]);
if (error != 0)
return error;
error = ipf_nat6_nextaddrinit(softc, n->in_names, &n->in_ndst, 1,
n->in_ifps[idx]);
if (error != 0)
return error;
if (n->in_redir & NAT_DIVERTUDP)
ipf_nat6_builddivertmp(softn, n);
return 0;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_addrdr */
/* Returns: Nil */
/* Parameters: n(I) - pointer to NAT rule to add */
/* */
/* Adds a redirect rule to the hash table of redirect rules and the list of */
/* loaded NAT rules. Updates the bitmask indicating which netmasks are in */
/* use by redirect rules. */
/* ------------------------------------------------------------------------ */
void
ipf_nat6_addrdr(ipf_nat_softc_t *softn, ipnat_t *n)
{
i6addr_t *mask;
ipnat_t **np;
i6addr_t j;
u_int hv;
int k;
if ((n->in_redir & NAT_BIMAP) == NAT_BIMAP) {
k = count6bits(n->in_nsrcmsk6.i6);
mask = &n->in_nsrcmsk6;
IP6_AND(&n->in_odstip6, &n->in_odstmsk6, &j);
hv = NAT_HASH_FN6(&j, 0, softn->ipf_nat_rdrrules_sz);
} else if (n->in_odstatype == FRI_NORMAL) {
k = count6bits(n->in_odstmsk6.i6);
mask = &n->in_odstmsk6;
IP6_AND(&n->in_odstip6, &n->in_odstmsk6, &j);
hv = NAT_HASH_FN6(&j, 0, softn->ipf_nat_rdrrules_sz);
} else {
k = 0;
hv = 0;
mask = NULL;
}
ipf_inet6_mask_add(k, mask, &softn->ipf_nat6_rdr_mask);
np = softn->ipf_nat_rdr_rules + hv;
while (*np != NULL)
np = &(*np)->in_rnext;
n->in_rnext = NULL;
n->in_prnext = np;
n->in_hv[0] = hv;
n->in_use++;
*np = n;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_addmap */
/* Returns: Nil */
/* Parameters: n(I) - pointer to NAT rule to add */
/* */
/* Adds a NAT map rule to the hash table of rules and the list of loaded */
/* NAT rules. Updates the bitmask indicating which netmasks are in use by */
/* redirect rules. */
/* ------------------------------------------------------------------------ */
void
ipf_nat6_addmap(ipf_nat_softc_t *softn, ipnat_t *n)
{
i6addr_t *mask;
ipnat_t **np;
i6addr_t j;
u_int hv;
int k;
if (n->in_osrcatype == FRI_NORMAL) {
k = count6bits(n->in_osrcmsk6.i6);
mask = &n->in_osrcmsk6;
IP6_AND(&n->in_osrcip6, &n->in_osrcmsk6, &j);
hv = NAT_HASH_FN6(&j, 0, softn->ipf_nat_maprules_sz);
} else {
k = 0;
hv = 0;
mask = NULL;
}
ipf_inet6_mask_add(k, mask, &softn->ipf_nat6_map_mask);
np = softn->ipf_nat_map_rules + hv;
while (*np != NULL)
np = &(*np)->in_mnext;
n->in_mnext = NULL;
n->in_pmnext = np;
n->in_hv[1] = hv;
n->in_use++;
*np = n;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_del_rdr */
/* Returns: Nil */
/* Parameters: n(I) - pointer to NAT rule to delete */
/* */
/* Removes a NAT rdr rule from the hash table of NAT rdr rules. */
/* ------------------------------------------------------------------------ */
void
ipf_nat6_delrdr(ipf_nat_softc_t *softn, ipnat_t *n)
{
i6addr_t *mask;
int k;
if ((n->in_redir & NAT_BIMAP) == NAT_BIMAP) {
k = count6bits(n->in_nsrcmsk6.i6);
mask = &n->in_nsrcmsk6;
} else if (n->in_odstatype == FRI_NORMAL) {
k = count6bits(n->in_odstmsk6.i6);
mask = &n->in_odstmsk6;
} else {
k = 0;
mask = NULL;
}
ipf_inet6_mask_del(k, mask, &softn->ipf_nat6_rdr_mask);
if (n->in_rnext != NULL)
n->in_rnext->in_prnext = n->in_prnext;
*n->in_prnext = n->in_rnext;
n->in_use--;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_delmap */
/* Returns: Nil */
/* Parameters: n(I) - pointer to NAT rule to delete */
/* */
/* Removes a NAT map rule from the hash table of NAT map rules. */
/* ------------------------------------------------------------------------ */
void
ipf_nat6_delmap(ipf_nat_softc_t *softn, ipnat_t *n)
{
i6addr_t *mask;
int k;
if (n->in_osrcatype == FRI_NORMAL) {
k = count6bits(n->in_osrcmsk6.i6);
mask = &n->in_osrcmsk6;
} else {
k = 0;
mask = NULL;
}
ipf_inet6_mask_del(k, mask, &softn->ipf_nat6_map_mask);
if (n->in_mnext != NULL)
n->in_mnext->in_pmnext = n->in_pmnext;
*n->in_pmnext = n->in_mnext;
n->in_use--;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_hostmap */
/* Returns: struct hostmap* - NULL if no hostmap could be created, */
/* else a pointer to the hostmapping to use */
/* Parameters: np(I) - pointer to NAT rule */
/* real(I) - real IP address */
/* map(I) - mapped IP address */
/* port(I) - destination port number */
/* Write Locks: ipf_nat */
/* */
/* Check if an ip address has already been allocated for a given mapping */
/* that is not doing port based translation. If is not yet allocated, then */
/* create a new entry if a non-NULL NAT rule pointer has been supplied. */
/* ------------------------------------------------------------------------ */
static struct hostmap *
ipf_nat6_hostmap(ipf_nat_softc_t *softn, ipnat_t *np, i6addr_t *src,
i6addr_t *dst, i6addr_t *map, u_32_t port)
{
hostmap_t *hm;
u_int hv;
hv = (src->i6[3] ^ dst->i6[3]);
hv += (src->i6[2] ^ dst->i6[2]);
hv += (src->i6[1] ^ dst->i6[1]);
hv += (src->i6[0] ^ dst->i6[0]);
hv += src->i6[3];
hv += src->i6[2];
hv += src->i6[1];
hv += src->i6[0];
hv += dst->i6[3];
hv += dst->i6[2];
hv += dst->i6[1];
hv += dst->i6[0];
hv %= softn->ipf_nat_hostmap_sz;
for (hm = softn->ipf_hm_maptable[hv]; hm; hm = hm->hm_next)
if (IP6_EQ(&hm->hm_osrc6, src) &&
IP6_EQ(&hm->hm_odst6, dst) &&
((np == NULL) || (np == hm->hm_ipnat)) &&
((port == 0) || (port == hm->hm_port))) {
softn->ipf_nat_stats.ns_hm_addref++;
hm->hm_ref++;
return hm;
}
if (np == NULL) {
softn->ipf_nat_stats.ns_hm_nullnp++;
return NULL;
}
KMALLOC(hm, hostmap_t *);
if (hm) {
hm->hm_next = softn->ipf_hm_maplist;
hm->hm_pnext = &softn->ipf_hm_maplist;
if (softn->ipf_hm_maplist != NULL)
softn->ipf_hm_maplist->hm_pnext = &hm->hm_next;
softn->ipf_hm_maplist = hm;
hm->hm_hnext = softn->ipf_hm_maptable[hv];
hm->hm_phnext = softn->ipf_hm_maptable + hv;
if (softn->ipf_hm_maptable[hv] != NULL)
softn->ipf_hm_maptable[hv]->hm_phnext = &hm->hm_hnext;
softn->ipf_hm_maptable[hv] = hm;
hm->hm_ipnat = np;
np->in_use++;
hm->hm_osrcip6 = *src;
hm->hm_odstip6 = *dst;
hm->hm_nsrcip6 = *map;
hm->hm_ndstip6.i6[0] = 0;
hm->hm_ndstip6.i6[1] = 0;
hm->hm_ndstip6.i6[2] = 0;
hm->hm_ndstip6.i6[3] = 0;
hm->hm_ref = 1;
hm->hm_port = port;
hm->hm_hv = hv;
hm->hm_v = 6;
softn->ipf_nat_stats.ns_hm_new++;
} else {
softn->ipf_nat_stats.ns_hm_newfail++;
}
return hm;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_newmap */
/* Returns: int - -1 == error, 0 == success */
/* Parameters: fin(I) - pointer to packet information */
/* nat(I) - pointer to NAT entry */
/* ni(I) - pointer to structure with misc. information needed */
/* to create new NAT entry. */
/* */
/* Given an empty NAT structure, populate it with new information about a */
/* new NAT session, as defined by the matching NAT rule. */
/* ni.nai_ip is passed in uninitialised and must be set, in host byte order,*/
/* to the new IP address for the translation. */
/* ------------------------------------------------------------------------ */
int
ipf_nat6_newmap(fr_info_t *fin, nat_t *nat, natinfo_t *ni)
{
ipf_main_softc_t *softc = fin->fin_main_soft;
ipf_nat_softc_t *softn = softc->ipf_nat_soft;
u_short st_port, dport, sport, port, sp, dp;
i6addr_t in, st_ip;
hostmap_t *hm;
u_32_t flags;
ipnat_t *np;
nat_t *natl;
int l;
/*
* If it's an outbound packet which doesn't match any existing
* record, then create a new port
*/
l = 0;
hm = NULL;
np = ni->nai_np;
st_ip = np->in_snip6;
st_port = np->in_spnext;
flags = nat->nat_flags;
if (flags & IPN_ICMPQUERY) {
sport = fin->fin_data[1];
dport = 0;
} else {
sport = htons(fin->fin_data[0]);
dport = htons(fin->fin_data[1]);
}
/*
* Do a loop until we either run out of entries to try or we find
* a NAT mapping that isn't currently being used. This is done
* because the change to the source is not (usually) being fixed.
*/
do {
port = 0;
in = np->in_nsrc.na_nextaddr;
if (l == 0) {
/*
* Check to see if there is an existing NAT
* setup for this IP address pair.
*/
hm = ipf_nat6_hostmap(softn, np, &fin->fin_src6,
&fin->fin_dst6, &in, 0);
if (hm != NULL)
in = hm->hm_nsrcip6;
} else if ((l == 1) && (hm != NULL)) {
ipf_nat_hostmapdel(softc, &hm);
}
nat->nat_hm = hm;
if (IP6_ISONES(&np->in_nsrcmsk6) && (np->in_spnext == 0)) {
if (l > 0) {
NBUMPSIDE6DX(1, ns_exhausted, ns_exhausted_1);
return -1;
}
}
if ((np->in_redir == NAT_BIMAP) &&
IP6_EQ(&np->in_osrcmsk6, &np->in_nsrcmsk6)) {
i6addr_t temp;
/*
* map the address block in a 1:1 fashion
*/
temp.i6[0] = fin->fin_src6.i6[0] &
~np->in_osrcmsk6.i6[0];
temp.i6[1] = fin->fin_src6.i6[1] &
~np->in_osrcmsk6.i6[1];
temp.i6[2] = fin->fin_src6.i6[2] &
~np->in_osrcmsk6.i6[0];
temp.i6[3] = fin->fin_src6.i6[3] &
~np->in_osrcmsk6.i6[3];
in = np->in_nsrcip6;
IP6_MERGE(&in, &temp, &np->in_osrc);
#ifdef NEED_128BIT_MATH
} else if (np->in_redir & NAT_MAPBLK) {
if ((l >= np->in_ppip) || ((l > 0) &&
!(flags & IPN_TCPUDP))) {
NBUMPSIDE6DX(1, ns_exhausted, ns_exhausted_2);
return -1;
}
/*
* map-block - Calculate destination address.
*/
IP6_MASK(&in, &fin->fin_src6, &np->in_osrcmsk6);
in = ntohl(in);
inb = in;
in.s_addr /= np->in_ippip;
in.s_addr &= ntohl(~np->in_nsrcmsk6);
in.s_addr += ntohl(np->in_nsrcaddr6);
/*
* Calculate destination port.
*/
if ((flags & IPN_TCPUDP) &&
(np->in_ppip != 0)) {
port = ntohs(sport) + l;
port %= np->in_ppip;
port += np->in_ppip *
(inb.s_addr % np->in_ippip);
port += MAPBLK_MINPORT;
port = htons(port);
}
#endif
} else if (IP6_ISZERO(&np->in_nsrcaddr) &&
IP6_ISONES(&np->in_nsrcmsk)) {
/*
* 0/32 - use the interface's IP address.
*/
if ((l > 0) ||
ipf_ifpaddr(softc, 6, FRI_NORMAL, fin->fin_ifp,
&in, NULL) == -1) {
NBUMPSIDE6DX(1, ns_new_ifpaddr,
ns_new_ifpaddr_1);
return -1;
}
} else if (IP6_ISZERO(&np->in_nsrcip6) &&
IP6_ISZERO(&np->in_nsrcmsk6)) {
/*
* 0/0 - use the original source address/port.
*/
if (l > 0) {
NBUMPSIDE6DX(1, ns_exhausted, ns_exhausted_3);
return -1;
}
in = fin->fin_src6;
} else if (!IP6_ISONES(&np->in_nsrcmsk6) &&
(np->in_spnext == 0) && ((l > 0) || (hm == NULL))) {
IP6_INC(&np->in_snip6);
}
natl = NULL;
if ((flags & IPN_TCPUDP) &&
((np->in_redir & NAT_MAPBLK) == 0) &&
(np->in_flags & IPN_AUTOPORTMAP)) {
#ifdef NEED_128BIT_MATH
/*
* "ports auto" (without map-block)
*/
if ((l > 0) && (l % np->in_ppip == 0)) {
if ((l > np->in_ppip) &&
!IP6_ISONES(&np->in_nsrcmsk)) {
IP6_INC(&np->in_snip6)
}
}
if (np->in_ppip != 0) {
port = ntohs(sport);
port += (l % np->in_ppip);
port %= np->in_ppip;
port += np->in_ppip *
(ntohl(fin->fin_src6) %
np->in_ippip);
port += MAPBLK_MINPORT;
port = htons(port);
}
#endif
} else if (((np->in_redir & NAT_MAPBLK) == 0) &&
(flags & IPN_TCPUDPICMP) && (np->in_spnext != 0)) {
/*
* Standard port translation. Select next port.
*/
if (np->in_flags & IPN_SEQUENTIAL) {
port = np->in_spnext;
} else {
port = ipf_random() % (np->in_spmax -
np->in_spmin + 1);
port += np->in_spmin;
}
port = htons(port);
np->in_spnext++;
if (np->in_spnext > np->in_spmax) {
np->in_spnext = np->in_spmin;
if (!IP6_ISONES(&np->in_nsrcmsk6)) {
IP6_INC(&np->in_snip6);
}
}
}
if (np->in_flags & IPN_SIPRANGE) {
if (IP6_GT(&np->in_snip, &np->in_nsrcmsk))
np->in_snip6 = np->in_nsrcip6;
} else {
i6addr_t a1, a2;
a1 = np->in_snip6;
IP6_INC(&a1);
IP6_AND(&a1, &np->in_nsrcmsk6, &a2);
if (!IP6_ISONES(&np->in_nsrcmsk6) &&
IP6_GT(&a2, &np->in_nsrcip6)) {
IP6_ADD(&np->in_nsrcip6, 1, &np->in_snip6);
}
}
if ((port == 0) && (flags & (IPN_TCPUDPICMP|IPN_ICMPQUERY)))
port = sport;
/*
* Here we do a lookup of the connection as seen from
* the outside. If an IP# pair already exists, try
* again. So if you have A->B becomes C->B, you can
* also have D->E become C->E but not D->B causing
* another C->B. Also take protocol and ports into
* account when determining whether a pre-existing
* NAT setup will cause an external conflict where
* this is appropriate.
*/
sp = fin->fin_data[0];
dp = fin->fin_data[1];
fin->fin_data[0] = fin->fin_data[1];
fin->fin_data[1] = ntohs(port);
natl = ipf_nat6_inlookup(fin, flags & ~(SI_WILDP|NAT_SEARCH),
(u_int)fin->fin_p, &fin->fin_dst6.in6,
&in.in6);
fin->fin_data[0] = sp;
fin->fin_data[1] = dp;
/*
* Has the search wrapped around and come back to the
* start ?
*/
if ((natl != NULL) &&
(np->in_spnext != 0) && (st_port == np->in_spnext) &&
(!IP6_ISZERO(&np->in_snip6) &&
IP6_EQ(&st_ip, &np->in_snip6))) {
NBUMPSIDE6D(1, ns_wrap);
return -1;
}
l++;
} while (natl != NULL);
/* Setup the NAT table */
nat->nat_osrc6 = fin->fin_src6;
nat->nat_nsrc6 = in;
nat->nat_odst6 = fin->fin_dst6;
nat->nat_ndst6 = fin->fin_dst6;
if (nat->nat_hm == NULL)
nat->nat_hm = ipf_nat6_hostmap(softn, np, &fin->fin_src6,
&fin->fin_dst6,
&nat->nat_nsrc6, 0);
if (flags & IPN_TCPUDP) {
nat->nat_osport = sport;
nat->nat_nsport = port; /* sport */
nat->nat_odport = dport;
nat->nat_ndport = dport;
((tcphdr_t *)fin->fin_dp)->th_sport = port;
} else if (flags & IPN_ICMPQUERY) {
nat->nat_oicmpid = fin->fin_data[1];
((struct icmp6_hdr *)fin->fin_dp)->icmp6_id = port;
nat->nat_nicmpid = port;
}
return 0;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_newrdr */
/* Returns: int - -1 == error, 0 == success (no move), 1 == success and */
/* allow rule to be moved if IPN_ROUNDR is set. */
/* Parameters: fin(I) - pointer to packet information */
/* nat(I) - pointer to NAT entry */
/* ni(I) - pointer to structure with misc. information needed */
/* to create new NAT entry. */
/* */
/* ni.nai_ip is passed in uninitialised and must be set, in host byte order,*/
/* to the new IP address for the translation. */
/* ------------------------------------------------------------------------ */
int
ipf_nat6_newrdr(fr_info_t *fin, nat_t *nat, natinfo_t *ni)
{
ipf_main_softc_t *softc = fin->fin_main_soft;
ipf_nat_softc_t *softn = softc->ipf_nat_soft;
u_short nport, dport, sport;
u_short sp, dp;
hostmap_t *hm;
u_32_t flags;
i6addr_t in;
ipnat_t *np;
nat_t *natl;
int move;
move = 1;
hm = NULL;
in.i6[0] = 0;
in.i6[1] = 0;
in.i6[2] = 0;
in.i6[3] = 0;
np = ni->nai_np;
flags = nat->nat_flags;
if (flags & IPN_ICMPQUERY) {
dport = fin->fin_data[1];
sport = 0;
} else {
sport = htons(fin->fin_data[0]);
dport = htons(fin->fin_data[1]);
}
/* TRACE sport, dport */
/*
* If the matching rule has IPN_STICKY set, then we want to have the
* same rule kick in as before. Why would this happen? If you have
* a collection of rdr rules with "round-robin sticky", the current
* packet might match a different one to the previous connection but
* we want the same destination to be used.
*/
if (((np->in_flags & (IPN_ROUNDR|IPN_SPLIT)) != 0) &&
((np->in_flags & IPN_STICKY) != 0)) {
hm = ipf_nat6_hostmap(softn, NULL, &fin->fin_src6,
&fin->fin_dst6, &in, (u_32_t)dport);
if (hm != NULL) {
in = hm->hm_ndstip6;
np = hm->hm_ipnat;
ni->nai_np = np;
move = 0;
}
}
/*
* Otherwise, it's an inbound packet. Most likely, we don't
* want to rewrite source ports and source addresses. Instead,
* we want to rewrite to a fixed internal address and fixed
* internal port.
*/
if (np->in_flags & IPN_SPLIT) {
in = np->in_dnip6;
if ((np->in_flags & (IPN_ROUNDR|IPN_STICKY)) == IPN_STICKY) {
hm = ipf_nat6_hostmap(softn, NULL, &fin->fin_src6,
&fin->fin_dst6, &in,
(u_32_t)dport);
if (hm != NULL) {
in = hm->hm_ndstip6;
move = 0;
}
}
if (hm == NULL || hm->hm_ref == 1) {
if (IP6_EQ(&np->in_ndstip6, &in)) {
np->in_dnip6 = np->in_ndstmsk6;
move = 0;
} else {
np->in_dnip6 = np->in_ndstip6;
}
}
} else if (IP6_ISZERO(&np->in_ndstaddr) &&
IP6_ISONES(&np->in_ndstmsk)) {
/*
* 0/32 - use the interface's IP address.
*/
if (ipf_ifpaddr(softc, 6, FRI_NORMAL, fin->fin_ifp,
&in, NULL) == -1) {
NBUMPSIDE6DX(0, ns_new_ifpaddr, ns_new_ifpaddr_2);
return -1;
}
} else if (IP6_ISZERO(&np->in_ndstip6) &&
IP6_ISZERO(&np->in_ndstmsk6)) {
/*
* 0/0 - use the original destination address/port.
*/
in = fin->fin_dst6;
} else if (np->in_redir == NAT_BIMAP &&
IP6_EQ(&np->in_ndstmsk6, &np->in_odstmsk6)) {
i6addr_t temp;
/*
* map the address block in a 1:1 fashion
*/
temp.i6[0] = fin->fin_dst6.i6[0] & ~np->in_osrcmsk6.i6[0];
temp.i6[1] = fin->fin_dst6.i6[1] & ~np->in_osrcmsk6.i6[1];
temp.i6[2] = fin->fin_dst6.i6[2] & ~np->in_osrcmsk6.i6[0];
temp.i6[3] = fin->fin_dst6.i6[3] & ~np->in_osrcmsk6.i6[3];
in = np->in_ndstip6;
IP6_MERGE(&in, &temp, &np->in_ndstmsk6);
} else {
in = np->in_ndstip6;
}
if ((np->in_dpnext == 0) || ((flags & NAT_NOTRULEPORT) != 0))
nport = dport;
else {
/*
* Whilst not optimized for the case where
* pmin == pmax, the gain is not significant.
*/
if (((np->in_flags & IPN_FIXEDDPORT) == 0) &&
(np->in_odport != np->in_dtop)) {
nport = ntohs(dport) - np->in_odport + np->in_dpmax;
nport = htons(nport);
} else {
nport = htons(np->in_dpnext);
np->in_dpnext++;
if (np->in_dpnext > np->in_dpmax)
np->in_dpnext = np->in_dpmin;
}
}
/*
* When the redirect-to address is set to 0.0.0.0, just
* assume a blank `forwarding' of the packet. We don't
* setup any translation for this either.
*/
if (IP6_ISZERO(&in)) {
if (nport == dport) {
NBUMPSIDE6D(0, ns_xlate_null);
return -1;
}
in = fin->fin_dst6;
}
/*
* Check to see if this redirect mapping already exists and if
* it does, return "failure" (allowing it to be created will just
* cause one or both of these "connections" to stop working.)
*/
sp = fin->fin_data[0];
dp = fin->fin_data[1];
fin->fin_data[1] = fin->fin_data[0];
fin->fin_data[0] = ntohs(nport);
natl = ipf_nat6_outlookup(fin, flags & ~(SI_WILDP|NAT_SEARCH),
(u_int)fin->fin_p, &in.in6,
&fin->fin_src6.in6);
fin->fin_data[0] = sp;
fin->fin_data[1] = dp;
if (natl != NULL) {
NBUMPSIDE6D(0, ns_xlate_exists);
return -1;
}
nat->nat_ndst6 = in;
nat->nat_odst6 = fin->fin_dst6;
nat->nat_nsrc6 = fin->fin_src6;
nat->nat_osrc6 = fin->fin_src6;
if ((nat->nat_hm == NULL) && ((np->in_flags & IPN_STICKY) != 0))
nat->nat_hm = ipf_nat6_hostmap(softn, np, &fin->fin_src6,
&fin->fin_dst6, &in,
(u_32_t)dport);
if (flags & IPN_TCPUDP) {
nat->nat_odport = dport;
nat->nat_ndport = nport;
nat->nat_osport = sport;
nat->nat_nsport = sport;
((tcphdr_t *)fin->fin_dp)->th_dport = nport;
} else if (flags & IPN_ICMPQUERY) {
nat->nat_oicmpid = fin->fin_data[1];
((struct icmp6_hdr *)fin->fin_dp)->icmp6_id = nport;
nat->nat_nicmpid = nport;
}
return move;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_add */
/* Returns: nat6_t* - NULL == failure to create new NAT structure, */
/* else pointer to new NAT structure */
/* Parameters: fin(I) - pointer to packet information */
/* np(I) - pointer to NAT rule */
/* natsave(I) - pointer to where to store NAT struct pointer */
/* flags(I) - flags describing the current packet */
/* direction(I) - direction of packet (in/out) */
/* Write Lock: ipf_nat */
/* */
/* Attempts to create a new NAT entry. Does not actually change the packet */
/* in any way. */
/* */
/* This fucntion is in three main parts: (1) deal with creating a new NAT */
/* structure for a "MAP" rule (outgoing NAT translation); (2) deal with */
/* creating a new NAT structure for a "RDR" rule (incoming NAT translation) */
/* and (3) building that structure and putting it into the NAT table(s). */
/* */
/* NOTE: natsave should NOT be used top point back to an ipstate_t struct */
/* as it can result in memory being corrupted. */
/* ------------------------------------------------------------------------ */
nat_t *
ipf_nat6_add(fr_info_t *fin, ipnat_t *np, nat_t **natsave, u_int flags,
int direction)
{
ipf_main_softc_t *softc = fin->fin_main_soft;
ipf_nat_softc_t *softn = softc->ipf_nat_soft;
hostmap_t *hm = NULL;
nat_t *nat, *natl;
natstat_t *nsp;
u_int nflags;
natinfo_t ni;
int move;
#if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6) && defined(ICK_M_CTL_MAGIC)
qpktinfo_t *qpi = fin->fin_qpi;
#endif
nsp = &softn->ipf_nat_stats;
if ((nsp->ns_active * 100 / softn->ipf_nat_table_max) >
softn->ipf_nat_table_wm_high) {
softn->ipf_nat_doflush = 1;
}
if (nsp->ns_active >= softn->ipf_nat_table_max) {
NBUMPSIDE6(fin->fin_out, ns_table_max);
return NULL;
}
move = 1;
nflags = np->in_flags & flags;
nflags &= NAT_FROMRULE;
ni.nai_np = np;
ni.nai_dport = 0;
ni.nai_sport = 0;
/* Give me a new nat */
KMALLOC(nat, nat_t *);
if (nat == NULL) {
NBUMPSIDE6(fin->fin_out, ns_memfail);
/*
* Try to automatically tune the max # of entries in the
* table allowed to be less than what will cause kmem_alloc()
* to fail and try to eliminate panics due to out of memory
* conditions arising.
*/
if ((softn->ipf_nat_table_max > softn->ipf_nat_table_sz) &&
(nsp->ns_active > 100)) {
softn->ipf_nat_table_max = nsp->ns_active - 100;
printf("table_max reduced to %d\n",
softn->ipf_nat_table_max);
}
return NULL;
}
if (flags & IPN_ICMPQUERY) {
/*
* In the ICMP query NAT code, we translate the ICMP id fields
* to make them unique. This is indepedent of the ICMP type
* (e.g. in the unlikely event that a host sends an echo and
* a tstamp request with the same id, both packets will have
* their ip address/id field changed in the same way).
*/
/* The icmp6_id field is used by the sender to identify the
* process making the icmp request. (the receiver justs
* copies it back in its response). So, it closely matches
* the concept of source port. We overlay sport, so we can
* maximally reuse the existing code.
*/
ni.nai_sport = fin->fin_data[1];
ni.nai_dport = 0;
}
bzero((char *)nat, sizeof(*nat));
nat->nat_flags = flags;
nat->nat_redir = np->in_redir;
nat->nat_dir = direction;
nat->nat_pr[0] = fin->fin_p;
nat->nat_pr[1] = fin->fin_p;
/*
* Search the current table for a match and create a new mapping
* if there is none found.
*/
if (np->in_redir & NAT_DIVERTUDP) {
move = ipf_nat6_newdivert(fin, nat, &ni);
} else if (np->in_redir & NAT_REWRITE) {
move = ipf_nat6_newrewrite(fin, nat, &ni);
} else if (direction == NAT_OUTBOUND) {
/*
* We can now arrange to call this for the same connection
* because ipf_nat6_new doesn't protect the code path into
* this function.
*/
natl = ipf_nat6_outlookup(fin, nflags, (u_int)fin->fin_p,
&fin->fin_src6.in6,
&fin->fin_dst6.in6);
if (natl != NULL) {
KFREE(nat);
nat = natl;
goto done;
}
move = ipf_nat6_newmap(fin, nat, &ni);
} else {
/*
* NAT_INBOUND is used for redirects rules
*/
natl = ipf_nat6_inlookup(fin, nflags, (u_int)fin->fin_p,
&fin->fin_src6.in6,
&fin->fin_dst6.in6);
if (natl != NULL) {
KFREE(nat);
nat = natl;
goto done;
}
move = ipf_nat6_newrdr(fin, nat, &ni);
}
if (move == -1)
goto badnat;
np = ni.nai_np;
nat->nat_mssclamp = np->in_mssclamp;
nat->nat_me = natsave;
nat->nat_fr = fin->fin_fr;
nat->nat_rev = fin->fin_rev;
nat->nat_ptr = np;
nat->nat_dlocal = np->in_dlocal;
if ((np->in_apr != NULL) && ((nat->nat_flags & NAT_SLAVE) == 0)) {
if (ipf_proxy_new(fin, nat) == -1) {
NBUMPSIDE6D(fin->fin_out, ns_appr_fail);
goto badnat;
}
}
nat->nat_ifps[0] = np->in_ifps[0];
if (np->in_ifps[0] != NULL) {
COPYIFNAME(np->in_v[0], np->in_ifps[0], nat->nat_ifnames[0]);
}
nat->nat_ifps[1] = np->in_ifps[1];
if (np->in_ifps[1] != NULL) {
COPYIFNAME(np->in_v[1], np->in_ifps[1], nat->nat_ifnames[1]);
}
if (ipf_nat6_finalise(fin, nat) == -1) {
goto badnat;
}
np->in_use++;
if ((move == 1) && (np->in_flags & IPN_ROUNDR)) {
if ((np->in_redir & (NAT_REDIRECT|NAT_MAP)) == NAT_REDIRECT) {
ipf_nat6_delrdr(softn, np);
ipf_nat6_addrdr(softn, np);
} else if ((np->in_redir & (NAT_REDIRECT|NAT_MAP)) == NAT_MAP) {
ipf_nat6_delmap(softn, np);
ipf_nat6_addmap(softn, np);
}
}
if (flags & SI_WILDP)
nsp->ns_wilds++;
softn->ipf_nat_stats.ns_proto[nat->nat_pr[0]]++;
goto done;
badnat:
NBUMPSIDE6(fin->fin_out, ns_badnatnew);
if ((hm = nat->nat_hm) != NULL)
ipf_nat_hostmapdel(softc, &hm);
KFREE(nat);
nat = NULL;
done:
if (nat != NULL && np != NULL)
np->in_hits++;
if (natsave != NULL)
*natsave = nat;
return nat;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_finalise */
/* Returns: int - 0 == sucess, -1 == failure */
/* Parameters: fin(I) - pointer to packet information */
/* nat(I) - pointer to NAT entry */
/* Write Lock: ipf_nat */
/* */
/* This is the tail end of constructing a new NAT entry and is the same */
/* for both IPv4 and IPv6. */
/* ------------------------------------------------------------------------ */
/*ARGSUSED*/
int
ipf_nat6_finalise(fr_info_t *fin, nat_t *nat)
{
ipf_main_softc_t *softc = fin->fin_main_soft;
ipf_nat_softc_t *softn = softc->ipf_nat_soft;
u_32_t sum1, sum2, sumd;
frentry_t *fr;
switch (fin->fin_p)
{
case IPPROTO_ICMPV6 :
sum1 = LONG_SUM6(&nat->nat_osrc6);
sum1 += ntohs(nat->nat_oicmpid);
sum2 = LONG_SUM6(&nat->nat_nsrc6);
sum2 += ntohs(nat->nat_nicmpid);
CALC_SUMD(sum1, sum2, sumd);
nat->nat_sumd[0] = (sumd & 0xffff) + (sumd >> 16);
sum1 = LONG_SUM6(&nat->nat_odst6);
sum2 = LONG_SUM6(&nat->nat_ndst6);
CALC_SUMD(sum1, sum2, sumd);
nat->nat_sumd[0] += (sumd & 0xffff) + (sumd >> 16);
break;
case IPPROTO_TCP :
case IPPROTO_UDP :
sum1 = LONG_SUM6(&nat->nat_osrc6);
sum1 += ntohs(nat->nat_osport);
sum2 = LONG_SUM6(&nat->nat_nsrc6);
sum2 += ntohs(nat->nat_nsport);
CALC_SUMD(sum1, sum2, sumd);
nat->nat_sumd[0] = (sumd & 0xffff) + (sumd >> 16);
sum1 = LONG_SUM6(&nat->nat_odst6);
sum1 += ntohs(nat->nat_odport);
sum2 = LONG_SUM6(&nat->nat_ndst6);
sum2 += ntohs(nat->nat_ndport);
CALC_SUMD(sum1, sum2, sumd);
nat->nat_sumd[0] += (sumd & 0xffff) + (sumd >> 16);
break;
default :
sum1 = LONG_SUM6(&nat->nat_osrc6);
sum2 = LONG_SUM6(&nat->nat_nsrc6);
CALC_SUMD(sum1, sum2, sumd);
nat->nat_sumd[0] = (sumd & 0xffff) + (sumd >> 16);
sum1 = LONG_SUM6(&nat->nat_odst6);
sum2 = LONG_SUM6(&nat->nat_ndst6);
CALC_SUMD(sum1, sum2, sumd);
nat->nat_sumd[0] += (sumd & 0xffff) + (sumd >> 16);
break;
}
/*
* Compute the partial checksum, just in case.
* This is only ever placed into outbound packets so care needs
* to be taken over which pair of addresses are used.
*/
if (nat->nat_dir == NAT_OUTBOUND) {
sum1 = LONG_SUM6(&nat->nat_nsrc6);
sum1 += LONG_SUM6(&nat->nat_ndst6);
} else {
sum1 = LONG_SUM6(&nat->nat_osrc6);
sum1 += LONG_SUM6(&nat->nat_odst6);
}
sum1 += nat->nat_pr[1];
nat->nat_sumd[1] = (sum1 & 0xffff) + (sum1 >> 16);
if ((nat->nat_flags & SI_CLONE) == 0)
nat->nat_sync = ipf_sync_new(softc, SMC_NAT, fin, nat);
if ((nat->nat_ifps[0] != NULL) && (nat->nat_ifps[0] != (void *)-1)) {
nat->nat_mtu[0] = GETIFMTU_6(nat->nat_ifps[0]);
}
if ((nat->nat_ifps[1] != NULL) && (nat->nat_ifps[1] != (void *)-1)) {
nat->nat_mtu[1] = GETIFMTU_6(nat->nat_ifps[1]);
}
nat->nat_v[0] = 6;
nat->nat_v[1] = 6;
if (ipf_nat6_insert(softc, softn, nat) == 0) {
if (softn->ipf_nat_logging)
ipf_nat_log(softc, softn, nat, NL_NEW);
fr = nat->nat_fr;
if (fr != NULL) {
MUTEX_ENTER(&fr->fr_lock);
fr->fr_ref++;
MUTEX_EXIT(&fr->fr_lock);
}
return 0;
}
NBUMPSIDE6D(fin->fin_out, ns_unfinalised);
/*
* nat6_insert failed, so cleanup time...
*/
if (nat->nat_sync != NULL)
ipf_sync_del_nat(softc->ipf_sync_soft, nat->nat_sync);
return -1;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_insert */
/* Returns: int - 0 == sucess, -1 == failure */
/* Parameters: softc(I) - pointer to soft context main structure */
/* softn(I) - pointer to NAT context structure */
/* nat(I) - pointer to NAT structure */
/* Write Lock: ipf_nat */
/* */
/* Insert a NAT entry into the hash tables for searching and add it to the */
/* list of active NAT entries. Adjust global counters when complete. */
/* ------------------------------------------------------------------------ */
static int
ipf_nat6_insert(ipf_main_softc_t *softc, ipf_nat_softc_t *softn, nat_t *nat)
{
u_int hv0, hv1;
u_32_t sp, dp;
ipnat_t *in;
/*
* Try and return an error as early as possible, so calculate the hash
* entry numbers first and then proceed.
*/
if ((nat->nat_flags & (SI_W_SPORT|SI_W_DPORT)) == 0) {
if ((nat->nat_flags & IPN_TCPUDP) != 0) {
sp = nat->nat_osport;
dp = nat->nat_odport;
} else if ((nat->nat_flags & IPN_ICMPQUERY) != 0) {
sp = 0;
dp = nat->nat_oicmpid;
} else {
sp = 0;
dp = 0;
}
hv0 = NAT_HASH_FN6(&nat->nat_osrc6, sp, 0xffffffff);
hv0 = NAT_HASH_FN6(&nat->nat_odst6, hv0 + dp,
softn->ipf_nat_table_sz);
/*
* TRACE nat6_osrc6, nat6_osport, nat6_odst6,
* nat6_odport, hv0
*/
if ((nat->nat_flags & IPN_TCPUDP) != 0) {
sp = nat->nat_nsport;
dp = nat->nat_ndport;
} else if ((nat->nat_flags & IPN_ICMPQUERY) != 0) {
sp = 0;
dp = nat->nat_nicmpid;
} else {
sp = 0;
dp = 0;
}
hv1 = NAT_HASH_FN6(&nat->nat_nsrc6, sp, 0xffffffff);
hv1 = NAT_HASH_FN6(&nat->nat_ndst6, hv1 + dp,
softn->ipf_nat_table_sz);
/*
* TRACE nat6_nsrcaddr, nat6_nsport, nat6_ndstaddr,
* nat6_ndport, hv0
*/
} else {
hv0 = NAT_HASH_FN6(&nat->nat_osrc6, 0, 0xffffffff);
hv0 = NAT_HASH_FN6(&nat->nat_odst6, hv0,
softn->ipf_nat_table_sz);
/* TRACE nat6_osrcip6, nat6_odstip6, hv0 */
hv1 = NAT_HASH_FN6(&nat->nat_nsrc6, 0, 0xffffffff);
hv1 = NAT_HASH_FN6(&nat->nat_ndst6, hv1,
softn->ipf_nat_table_sz);
/* TRACE nat6_nsrcip6, nat6_ndstip6, hv1 */
}
if ((nat->nat_dir & NAT_OUTBOUND) == NAT_OUTBOUND) {
nat->nat_hv[0] = hv0;
nat->nat_hv[1] = hv1;
} else {
nat->nat_hv[0] = hv1;
nat->nat_hv[1] = hv0;
}
MUTEX_INIT(&nat->nat_lock, "nat entry lock");
in = nat->nat_ptr;
nat->nat_ref = nat->nat_me ? 2 : 1;
nat->nat_ifnames[0][LIFNAMSIZ - 1] = '\0';
nat->nat_ifps[0] = ipf_resolvenic(softc, nat->nat_ifnames[0],
nat->nat_v[0]);
if (nat->nat_ifnames[1][0] != '\0') {
nat->nat_ifnames[1][LIFNAMSIZ - 1] = '\0';
nat->nat_ifps[1] = ipf_resolvenic(softc, nat->nat_ifnames[1],
nat->nat_v[1]);
} else if (in->in_ifnames[1] != -1) {
char *name;
name = in->in_names + in->in_ifnames[1];
if (name[1] != '\0' && name[0] != '-' && name[0] != '*') {
(void) strncpy(nat->nat_ifnames[1],
nat->nat_ifnames[0], LIFNAMSIZ);
nat->nat_ifnames[1][LIFNAMSIZ - 1] = '\0';
nat->nat_ifps[1] = nat->nat_ifps[0];
}
}
if ((nat->nat_ifps[0] != NULL) && (nat->nat_ifps[0] != (void *)-1)) {
nat->nat_mtu[0] = GETIFMTU_6(nat->nat_ifps[0]);
}
if ((nat->nat_ifps[1] != NULL) && (nat->nat_ifps[1] != (void *)-1)) {
nat->nat_mtu[1] = GETIFMTU_6(nat->nat_ifps[1]);
}
return ipf_nat_hashtab_add(softc, softn, nat);
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_icmperrorlookup */
/* Returns: nat6_t* - point to matching NAT structure */
/* Parameters: fin(I) - pointer to packet information */
/* dir(I) - direction of packet (in/out) */
/* */
/* Check if the ICMP error message is related to an existing TCP, UDP or */
/* ICMP query nat entry. It is assumed that the packet is already of the */
/* the required length. */
/* ------------------------------------------------------------------------ */
nat_t *
ipf_nat6_icmperrorlookup(fr_info_t *fin, int dir)
{
ipf_main_softc_t *softc = fin->fin_main_soft;
ipf_nat_softc_t *softn = softc->ipf_nat_soft;
struct icmp6_hdr *orgicmp;
int flags = 0, minlen;
nat_stat_side_t *nside;
tcphdr_t *tcp = NULL;
u_short data[2];
ip6_t *oip6;
nat_t *nat;
u_int p;
minlen = 40;
nside = &softn->ipf_nat_stats.ns_side6[fin->fin_out];
/*
* Does it at least have the return (basic) IP header ?
* Only a basic IP header (no options) should be with an ICMP error
* header. Also, if it's not an error type, then return.
*/
if (!(fin->fin_flx & FI_ICMPERR)) {
ATOMIC_INCL(nside->ns_icmp_basic);
return NULL;
}
/*
* Check packet size
*/
if (fin->fin_plen < ICMP6ERR_IPICMPHLEN) {
ATOMIC_INCL(nside->ns_icmp_size);
return NULL;
}
oip6 = (ip6_t *)((char *)fin->fin_dp + 8);
/*
* Is the buffer big enough for all of it ? It's the size of the IP
* header claimed in the encapsulated part which is of concern. It
* may be too big to be in this buffer but not so big that it's
* outside the ICMP packet, leading to TCP deref's causing problems.
* This is possible because we don't know how big oip_hl is when we
* do the pullup early in ipf_check() and thus can't gaurantee it is
* all here now.
*/
#ifdef ipf_nat6_KERNEL
{
mb_t *m;
m = fin->fin_m;
# if defined(MENTAT)
if ((char *)oip6 + fin->fin_dlen - ICMPERR_ICMPHLEN >
(char *)m->b_wptr) {
ATOMIC_INCL(nside->ns_icmp_mbuf);
return NULL;
}
# else
if ((char *)oip6 + fin->fin_dlen - ICMPERR_ICMPHLEN >
(char *)fin->fin_ip + M_LEN(m)) {
ATOMIC_INCL(nside->ns_icmp_mbuf);
return NULL;
}
# endif
}
#endif
if (IP6_NEQ(&fin->fin_dst6, &oip6->ip6_src)) {
ATOMIC_INCL(nside->ns_icmp_address);
return NULL;
}
p = oip6->ip6_nxt;
if (p == IPPROTO_TCP)
flags = IPN_TCP;
else if (p == IPPROTO_UDP)
flags = IPN_UDP;
else if (p == IPPROTO_ICMPV6) {
orgicmp = (struct icmp6_hdr *)(oip6 + 1);
/* see if this is related to an ICMP query */
if (ipf_nat6_icmpquerytype(orgicmp->icmp6_type)) {
data[0] = fin->fin_data[0];
data[1] = fin->fin_data[1];
fin->fin_data[0] = 0;
fin->fin_data[1] = orgicmp->icmp6_id;
flags = IPN_ICMPERR|IPN_ICMPQUERY;
/*
* NOTE : dir refers to the direction of the original
* ip packet. By definition the icmp error
* message flows in the opposite direction.
*/
if (dir == NAT_INBOUND)
nat = ipf_nat6_inlookup(fin, flags, p,
&oip6->ip6_dst,
&oip6->ip6_src);
else
nat = ipf_nat6_outlookup(fin, flags, p,
&oip6->ip6_dst,
&oip6->ip6_src);
fin->fin_data[0] = data[0];
fin->fin_data[1] = data[1];
return nat;
}
}
if (flags & IPN_TCPUDP) {
minlen += 8; /* + 64bits of data to get ports */
/* TRACE (fin,minlen) */
if (fin->fin_plen < ICMPERR_IPICMPHLEN + minlen) {
ATOMIC_INCL(nside->ns_icmp_short);
return NULL;
}
data[0] = fin->fin_data[0];
data[1] = fin->fin_data[1];
tcp = (tcphdr_t *)(oip6 + 1);
fin->fin_data[0] = ntohs(tcp->th_dport);
fin->fin_data[1] = ntohs(tcp->th_sport);
if (dir == NAT_INBOUND) {
nat = ipf_nat6_inlookup(fin, flags, p, &oip6->ip6_dst,
&oip6->ip6_src);
} else {
nat = ipf_nat6_outlookup(fin, flags, p, &oip6->ip6_dst,
&oip6->ip6_src);
}
fin->fin_data[0] = data[0];
fin->fin_data[1] = data[1];
return nat;
}
if (dir == NAT_INBOUND)
nat = ipf_nat6_inlookup(fin, 0, p, &oip6->ip6_dst,
&oip6->ip6_src);
else
nat = ipf_nat6_outlookup(fin, 0, p, &oip6->ip6_dst,
&oip6->ip6_src);
return nat;
}
/* result = ip1 - ip2 */
u_32_t
ipf_nat6_ip6subtract(i6addr_t *ip1, i6addr_t *ip2)
{
i6addr_t l1, l2, d;
u_short *s1, *s2, *ds;
u_32_t r;
int i;
l1 = *ip1;
l2 = *ip2;
s1 = (u_short *)&l1;
s2 = (u_short *)&l2;
ds = (u_short *)&d;
for (i = 7; i > 0; i--) {
if (s1[i] > s2[i]) {
ds[i] = s2[i] + 0x10000 - s1[i];
s2[i - 1] += 0x10000;
} else {
ds[i] = s2[i] - s1[i];
}
}
if (s2[0] > s1[0]) {
ds[0] = s2[0] + 0x10000 - s1[0];
} else {
ds[0] = s2[0] - s1[0];
}
for (i = 0, r = 0; i < 8; i++) {
r += ds[i];
}
return r;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_icmperror */
/* Returns: nat6_t* - point to matching NAT structure */
/* Parameters: fin(I) - pointer to packet information */
/* nflags(I) - NAT flags for this packet */
/* dir(I) - direction of packet (in/out) */
/* */
/* Fix up an ICMP packet which is an error message for an existing NAT */
/* session. This will correct both packet header data and checksums. */
/* */
/* This should *ONLY* be used for incoming ICMP error packets to make sure */
/* a NAT'd ICMP packet gets correctly recognised. */
/* ------------------------------------------------------------------------ */
nat_t *
ipf_nat6_icmperror(fr_info_t *fin, u_int *nflags, int dir)
{
ipf_main_softc_t *softc = fin->fin_main_soft;
ipf_nat_softc_t *softn = softc->ipf_nat_soft;
u_32_t sum1, sum2, sumd, sumd2;
i6addr_t a1, a2, a3, a4;
struct icmp6_hdr *icmp6;
int flags, dlen, odst;
u_short *csump;
tcphdr_t *tcp;
ip6_t *oip6;
nat_t *nat;
void *dp;
if ((fin->fin_flx & (FI_SHORT|FI_FRAGBODY))) {
NBUMPSIDE6D(fin->fin_out, ns_icmp_short);
return NULL;
}
/*
* ipf_nat6_icmperrorlookup() will return NULL for `defective' packets.
*/
if ((fin->fin_v != 6) || !(nat = ipf_nat6_icmperrorlookup(fin, dir))) {
NBUMPSIDE6D(fin->fin_out, ns_icmp_notfound);
return NULL;
}
tcp = NULL;
csump = NULL;
flags = 0;
sumd2 = 0;
*nflags = IPN_ICMPERR;
icmp6 = fin->fin_dp;
oip6 = (ip6_t *)((u_char *)icmp6 + sizeof(*icmp6));
dp = (u_char *)oip6 + sizeof(*oip6);
if (oip6->ip6_nxt == IPPROTO_TCP) {
tcp = (tcphdr_t *)dp;
csump = (u_short *)&tcp->th_sum;
flags = IPN_TCP;
} else if (oip6->ip6_nxt == IPPROTO_UDP) {
udphdr_t *udp;
udp = (udphdr_t *)dp;
tcp = (tcphdr_t *)dp;
csump = (u_short *)&udp->uh_sum;
flags = IPN_UDP;
} else if (oip6->ip6_nxt == IPPROTO_ICMPV6)
flags = IPN_ICMPQUERY;
dlen = fin->fin_plen - ((char *)dp - (char *)fin->fin_ip);
/*
* Need to adjust ICMP header to include the real IP#'s and
* port #'s. Only apply a checksum change relative to the
* IP address change as it will be modified again in ipf_nat6_checkout
* for both address and port. Two checksum changes are
* necessary for the two header address changes. Be careful
* to only modify the checksum once for the port # and twice
* for the IP#.
*/
/*
* Step 1
* Fix the IP addresses in the offending IP packet. You also need
* to adjust the IP header checksum of that offending IP packet.
*
* Normally, you would expect that the ICMP checksum of the
* ICMP error message needs to be adjusted as well for the
* IP address change in oip.
* However, this is a NOP, because the ICMP checksum is
* calculated over the complete ICMP packet, which includes the
* changed oip IP addresses and oip6->ip6_sum. However, these
* two changes cancel each other out (if the delta for
* the IP address is x, then the delta for ip_sum is minus x),
* so no change in the icmp_cksum is necessary.
*
* Inbound ICMP
* ------------
* MAP rule, SRC=a,DST=b -> SRC=c,DST=b
* - response to outgoing packet (a,b)=>(c,b) (OIP_SRC=c,OIP_DST=b)
* - OIP_SRC(c)=nat6_newsrcip, OIP_DST(b)=nat6_newdstip
*=> OIP_SRC(c)=nat6_oldsrcip, OIP_DST(b)=nat6_olddstip
*
* RDR rule, SRC=a,DST=b -> SRC=a,DST=c
* - response to outgoing packet (c,a)=>(b,a) (OIP_SRC=b,OIP_DST=a)
* - OIP_SRC(b)=nat6_olddstip, OIP_DST(a)=nat6_oldsrcip
*=> OIP_SRC(b)=nat6_newdstip, OIP_DST(a)=nat6_newsrcip
*
* REWRITE out rule, SRC=a,DST=b -> SRC=c,DST=d
* - response to outgoing packet (a,b)=>(c,d) (OIP_SRC=c,OIP_DST=d)
* - OIP_SRC(c)=nat6_newsrcip, OIP_DST(d)=nat6_newdstip
*=> OIP_SRC(c)=nat6_oldsrcip, OIP_DST(d)=nat6_olddstip
*
* REWRITE in rule, SRC=a,DST=b -> SRC=c,DST=d
* - response to outgoing packet (d,c)=>(b,a) (OIP_SRC=b,OIP_DST=a)
* - OIP_SRC(b)=nat6_olddstip, OIP_DST(a)=nat6_oldsrcip
*=> OIP_SRC(b)=nat6_newdstip, OIP_DST(a)=nat6_newsrcip
*
* Outbound ICMP
* -------------
* MAP rule, SRC=a,DST=b -> SRC=c,DST=b
* - response to incoming packet (b,c)=>(b,a) (OIP_SRC=b,OIP_DST=a)
* - OIP_SRC(b)=nat6_olddstip, OIP_DST(a)=nat6_oldsrcip
*=> OIP_SRC(b)=nat6_newdstip, OIP_DST(a)=nat6_newsrcip
*
* RDR rule, SRC=a,DST=b -> SRC=a,DST=c
* - response to incoming packet (a,b)=>(a,c) (OIP_SRC=a,OIP_DST=c)
* - OIP_SRC(a)=nat6_newsrcip, OIP_DST(c)=nat6_newdstip
*=> OIP_SRC(a)=nat6_oldsrcip, OIP_DST(c)=nat6_olddstip
*
* REWRITE out rule, SRC=a,DST=b -> SRC=c,DST=d
* - response to incoming packet (d,c)=>(b,a) (OIP_SRC=c,OIP_DST=d)
* - OIP_SRC(c)=nat6_olddstip, OIP_DST(d)=nat6_oldsrcip
*=> OIP_SRC(b)=nat6_newdstip, OIP_DST(a)=nat6_newsrcip
*
* REWRITE in rule, SRC=a,DST=b -> SRC=c,DST=d
* - response to incoming packet (a,b)=>(c,d) (OIP_SRC=b,OIP_DST=a)
* - OIP_SRC(b)=nat6_newsrcip, OIP_DST(a)=nat6_newdstip
*=> OIP_SRC(a)=nat6_oldsrcip, OIP_DST(c)=nat6_olddstip
*/
if (((fin->fin_out == 0) && ((nat->nat_redir & NAT_MAP) != 0)) ||
((fin->fin_out == 1) && ((nat->nat_redir & NAT_REDIRECT) != 0))) {
a1 = nat->nat_osrc6;
a4.in6 = oip6->ip6_src;
a3 = nat->nat_odst6;
a2.in6 = oip6->ip6_dst;
oip6->ip6_src = a1.in6;
oip6->ip6_dst = a3.in6;
odst = 1;
} else {
a1 = nat->nat_ndst6;
a2.in6 = oip6->ip6_dst;
a3 = nat->nat_nsrc6;
a4.in6 = oip6->ip6_src;
oip6->ip6_dst = a3.in6;
oip6->ip6_src = a1.in6;
odst = 0;
}
sumd = 0;
if (IP6_NEQ(&a3, &a2) || IP6_NEQ(&a1, &a4)) {
if (IP6_GT(&a3, &a2)) {
sumd = ipf_nat6_ip6subtract(&a2, &a3);
sumd--;
} else {
sumd = ipf_nat6_ip6subtract(&a2, &a3);
}
if (IP6_GT(&a1, &a4)) {
sumd += ipf_nat6_ip6subtract(&a4, &a1);
sumd--;
} else {
sumd += ipf_nat6_ip6subtract(&a4, &a1);
}
sumd = ~sumd;
}
sumd2 = sumd;
sum1 = 0;
sum2 = 0;
/*
* Fix UDP pseudo header checksum to compensate for the
* IP address change.
*/
if (((flags & IPN_TCPUDP) != 0) && (dlen >= 4)) {
u_32_t sum3, sum4;
/*
* Step 2 :
* For offending TCP/UDP IP packets, translate the ports as
* well, based on the NAT specification. Of course such
* a change may be reflected in the ICMP checksum as well.
*
* Since the port fields are part of the TCP/UDP checksum
* of the offending IP packet, you need to adjust that checksum
* as well... except that the change in the port numbers should
* be offset by the checksum change. However, the TCP/UDP
* checksum will also need to change if there has been an
* IP address change.
*/
if (odst == 1) {
sum1 = ntohs(nat->nat_osport);
sum4 = ntohs(tcp->th_sport);
sum3 = ntohs(nat->nat_odport);
sum2 = ntohs(tcp->th_dport);
tcp->th_sport = htons(sum1);
tcp->th_dport = htons(sum3);
} else {
sum1 = ntohs(nat->nat_ndport);
sum2 = ntohs(tcp->th_dport);
sum3 = ntohs(nat->nat_nsport);
sum4 = ntohs(tcp->th_sport);
tcp->th_dport = htons(sum3);
tcp->th_sport = htons(sum1);
}
sumd += sum1 - sum4;
sumd += sum3 - sum2;
if (sumd != 0 || sumd2 != 0) {
/*
* At this point, sumd is the delta to apply to the
* TCP/UDP header, given the changes in both the IP
* address and the ports and sumd2 is the delta to
* apply to the ICMP header, given the IP address
* change delta that may need to be applied to the
* TCP/UDP checksum instead.
*
* If we will both the IP and TCP/UDP checksums
* then the ICMP checksum changes by the address
* delta applied to the TCP/UDP checksum. If we
* do not change the TCP/UDP checksum them we
* apply the delta in ports to the ICMP checksum.
*/
if (oip6->ip6_nxt == IPPROTO_UDP) {
if ((dlen >= 8) && (*csump != 0)) {
ipf_fix_datacksum(csump, sumd);
} else {
sumd2 = sum4 - sum1;
if (sum1 > sum4)
sumd2--;
sumd2 += sum2 - sum3;
if (sum3 > sum2)
sumd2--;
}
} else if (oip6->ip6_nxt == IPPROTO_TCP) {
if (dlen >= 18) {
ipf_fix_datacksum(csump, sumd);
} else {
sumd2 = sum4 - sum1;
if (sum1 > sum4)
sumd2--;
sumd2 += sum2 - sum3;
if (sum3 > sum2)
sumd2--;
}
}
if (sumd2 != 0) {
sumd2 = (sumd2 & 0xffff) + (sumd2 >> 16);
sumd2 = (sumd2 & 0xffff) + (sumd2 >> 16);
sumd2 = (sumd2 & 0xffff) + (sumd2 >> 16);
ipf_fix_incksum(0, &icmp6->icmp6_cksum,
sumd2, 0);
}
}
} else if (((flags & IPN_ICMPQUERY) != 0) && (dlen >= 8)) {
struct icmp6_hdr *orgicmp;
/*
* XXX - what if this is bogus hl and we go off the end ?
* In this case, ipf_nat6_icmperrorlookup() will have
* returned NULL.
*/
orgicmp = (struct icmp6_hdr *)dp;
if (odst == 1) {
if (orgicmp->icmp6_id != nat->nat_osport) {
/*
* Fix ICMP checksum (of the offening ICMP
* query packet) to compensate the change
* in the ICMP id of the offending ICMP
* packet.
*
* Since you modify orgicmp->icmp6_id with
* a delta (say x) and you compensate that
* in origicmp->icmp6_cksum with a delta
* minus x, you don't have to adjust the
* overall icmp->icmp6_cksum
*/
sum1 = ntohs(orgicmp->icmp6_id);
sum2 = ntohs(nat->nat_osport);
CALC_SUMD(sum1, sum2, sumd);
orgicmp->icmp6_id = nat->nat_oicmpid;
ipf_fix_datacksum(&orgicmp->icmp6_cksum, sumd);
}
} /* nat6_dir == NAT_INBOUND is impossible for icmp queries */
}
return nat;
}
/*
* MAP-IN MAP-OUT RDR-IN RDR-OUT
* osrc X == src == src X
* odst X == dst == dst X
* nsrc == dst X X == dst
* ndst == src X X == src
* MAP = NAT_OUTBOUND, RDR = NAT_INBOUND
*/
/*
* NB: these lookups don't lock access to the list, it assumed that it has
* already been done!
*/
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_inlookup */
/* Returns: nat6_t* - NULL == no match, */
/* else pointer to matching NAT entry */
/* Parameters: fin(I) - pointer to packet information */
/* flags(I) - NAT flags for this packet */
/* p(I) - protocol for this packet */
/* src(I) - source IP address */
/* mapdst(I) - destination IP address */
/* */
/* Lookup a nat entry based on the mapped destination ip address/port and */
/* real source address/port. We use this lookup when receiving a packet, */
/* we're looking for a table entry, based on the destination address. */
/* */
/* NOTE: THE PACKET BEING CHECKED (IF FOUND) HAS A MAPPING ALREADY. */
/* */
/* NOTE: IT IS ASSUMED THAT IS ONLY HELD WITH A READ LOCK WHEN */
/* THIS FUNCTION IS CALLED WITH NAT_SEARCH SET IN nflags. */
/* */
/* flags -> relevant are IPN_UDP/IPN_TCP/IPN_ICMPQUERY that indicate if */
/* the packet is of said protocol */
/* ------------------------------------------------------------------------ */
nat_t *
ipf_nat6_inlookup(fr_info_t *fin, u_int flags, u_int p, struct in6_addr *src,
struct in6_addr *mapdst)
{
ipf_main_softc_t *softc = fin->fin_main_soft;
ipf_nat_softc_t *softn = softc->ipf_nat_soft;
u_short sport, dport;
nat_t *nat;
int nflags;
i6addr_t dst;
void *ifp;
u_int hv;
ifp = fin->fin_ifp;
sport = 0;
dport = 0;
dst.in6 = *mapdst;
switch (p)
{
case IPPROTO_TCP :
case IPPROTO_UDP :
sport = htons(fin->fin_data[0]);
dport = htons(fin->fin_data[1]);
break;
case IPPROTO_ICMPV6 :
if (flags & IPN_ICMPERR)
sport = fin->fin_data[1];
else
dport = fin->fin_data[1];
break;
default :
break;
}
if ((flags & SI_WILDP) != 0)
goto find_in_wild_ports;
hv = NAT_HASH_FN6(&dst, dport, 0xffffffff);
hv = NAT_HASH_FN6(src, hv + sport, softn->ipf_nat_table_sz);
nat = softn->ipf_nat_table[1][hv];
/* TRACE dst, dport, src, sport, hv, nat */
for (; nat; nat = nat->nat_hnext[1]) {
if (nat->nat_ifps[0] != NULL) {
if ((ifp != NULL) && (ifp != nat->nat_ifps[0]))
continue;
}
if (nat->nat_pr[0] != p)
continue;
switch (nat->nat_dir)
{
case NAT_INBOUND :
if (nat->nat_v[0] != 6)
continue;
if (IP6_NEQ(&nat->nat_osrc6, src) ||
IP6_NEQ(&nat->nat_odst6, &dst))
continue;
if ((nat->nat_flags & IPN_TCPUDP) != 0) {
if (nat->nat_osport != sport)
continue;
if (nat->nat_odport != dport)
continue;
} else if (p == IPPROTO_ICMPV6) {
if (nat->nat_osport != dport) {
continue;
}
}
break;
case NAT_OUTBOUND :
if (nat->nat_v[1] != 6)
continue;
if (IP6_NEQ(&nat->nat_ndst6, src) ||
IP6_NEQ(&nat->nat_nsrc6, &dst))
continue;
if ((nat->nat_flags & IPN_TCPUDP) != 0) {
if (nat->nat_ndport != sport)
continue;
if (nat->nat_nsport != dport)
continue;
} else if (p == IPPROTO_ICMPV6) {
if (nat->nat_osport != dport) {
continue;
}
}
break;
}
if ((nat->nat_flags & IPN_TCPUDP) != 0) {
#ifdef IPF_V6_PROXIES
if ((nat->nat_ptr != NULL) && (nat->nat_aps != NULL))
if (appr_match(fin, nat) != 0)
continue;
#endif
}
if ((nat->nat_ifps[0] == NULL) && (ifp != NULL)) {
nat->nat_ifps[0] = ifp;
nat->nat_mtu[0] = GETIFMTU_6(ifp);
}
return nat;
}
/*
* So if we didn't find it but there are wildcard members in the hash
* table, go back and look for them. We do this search and update here
* because it is modifying the NAT table and we want to do this only
* for the first packet that matches. The exception, of course, is
* for "dummy" (FI_IGNORE) lookups.
*/
find_in_wild_ports:
if (!(flags & NAT_TCPUDP) || !(flags & NAT_SEARCH)) {
NBUMPSIDE6DX(0, ns_lookup_miss, ns_lookup_miss_1);
return NULL;
}
if (softn->ipf_nat_stats.ns_wilds == 0 || (fin->fin_flx & FI_NOWILD)) {
NBUMPSIDE6D(0, ns_lookup_nowild);
return NULL;
}
RWLOCK_EXIT(&softc->ipf_nat);
hv = NAT_HASH_FN6(&dst, 0, 0xffffffff);
hv = NAT_HASH_FN6(src, hv, softn->ipf_nat_table_sz);
WRITE_ENTER(&softc->ipf_nat);
nat = softn->ipf_nat_table[1][hv];
/* TRACE dst, src, hv, nat */
for (; nat; nat = nat->nat_hnext[1]) {
if (nat->nat_ifps[0] != NULL) {
if ((ifp != NULL) && (ifp != nat->nat_ifps[0]))
continue;
}
if (nat->nat_pr[0] != fin->fin_p)
continue;
switch (nat->nat_dir)
{
case NAT_INBOUND :
if (nat->nat_v[0] != 6)
continue;
if (IP6_NEQ(&nat->nat_osrc6, src) ||
IP6_NEQ(&nat->nat_odst6, &dst))
continue;
break;
case NAT_OUTBOUND :
if (nat->nat_v[1] != 6)
continue;
if (IP6_NEQ(&nat->nat_ndst6, src) ||
IP6_NEQ(&nat->nat_nsrc6, &dst))
continue;
break;
}
nflags = nat->nat_flags;
if (!(nflags & (NAT_TCPUDP|SI_WILDP)))
continue;
if (ipf_nat_wildok(nat, (int)sport, (int)dport, nflags,
NAT_INBOUND) == 1) {
if ((fin->fin_flx & FI_IGNORE) != 0)
break;
if ((nflags & SI_CLONE) != 0) {
nat = ipf_nat_clone(fin, nat);
if (nat == NULL)
break;
} else {
MUTEX_ENTER(&softn->ipf_nat_new);
softn->ipf_nat_stats.ns_wilds--;
MUTEX_EXIT(&softn->ipf_nat_new);
}
if (nat->nat_dir == NAT_INBOUND) {
if (nat->nat_osport == 0) {
nat->nat_osport = sport;
nat->nat_nsport = sport;
}
if (nat->nat_odport == 0) {
nat->nat_odport = dport;
nat->nat_ndport = dport;
}
} else {
if (nat->nat_osport == 0) {
nat->nat_osport = dport;
nat->nat_nsport = dport;
}
if (nat->nat_odport == 0) {
nat->nat_odport = sport;
nat->nat_ndport = sport;
}
}
if ((nat->nat_ifps[0] == NULL) && (ifp != NULL)) {
nat->nat_ifps[0] = ifp;
nat->nat_mtu[0] = GETIFMTU_6(ifp);
}
nat->nat_flags &= ~(SI_W_DPORT|SI_W_SPORT);
ipf_nat6_tabmove(softn, nat);
break;
}
}
MUTEX_DOWNGRADE(&softc->ipf_nat);
if (nat == NULL) {
NBUMPSIDE6DX(0, ns_lookup_miss, ns_lookup_miss_2);
}
return nat;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_tabmove */
/* Returns: Nil */
/* Parameters: nat(I) - pointer to NAT structure */
/* Write Lock: ipf_nat */
/* */
/* This function is only called for TCP/UDP NAT table entries where the */
/* original was placed in the table without hashing on the ports and we now */
/* want to include hashing on port numbers. */
/* ------------------------------------------------------------------------ */
static void
ipf_nat6_tabmove(ipf_nat_softc_t *softn, nat_t *nat)
{
u_int rhv0, rhv1, hv0, hv1;
nat_t **natp;
if (nat->nat_flags & SI_CLONE)
return;
/*
* Remove the NAT entry from the old location
*/
if (nat->nat_hnext[0])
nat->nat_hnext[0]->nat_phnext[0] = nat->nat_phnext[0];
*nat->nat_phnext[0] = nat->nat_hnext[0];
softn->ipf_nat_stats.ns_side[0].ns_bucketlen[nat->nat_hv[0]]--;
if (nat->nat_hnext[1])
nat->nat_hnext[1]->nat_phnext[1] = nat->nat_phnext[1];
*nat->nat_phnext[1] = nat->nat_hnext[1];
softn->ipf_nat_stats.ns_side[1].ns_bucketlen[nat->nat_hv[1]]--;
/*
* Add into the NAT table in the new position
*/
rhv0 = NAT_HASH_FN6(&nat->nat_osrc6, nat->nat_osport, 0xffffffff);
rhv0 = NAT_HASH_FN6(&nat->nat_odst6, rhv0 + nat->nat_odport,
softn->ipf_nat_table_sz);
rhv1 = NAT_HASH_FN6(&nat->nat_nsrc6, nat->nat_nsport, 0xffffffff);
rhv1 = NAT_HASH_FN6(&nat->nat_ndst6, rhv1 + nat->nat_ndport,
softn->ipf_nat_table_sz);
if ((nat->nat_dir & NAT_OUTBOUND) == NAT_OUTBOUND) {
nat->nat_hv[0] = rhv0;
nat->nat_hv[1] = rhv1;
} else {
nat->nat_hv[0] = rhv1;
nat->nat_hv[1] = rhv0;
}
hv0 = nat->nat_hv[0] % softn->ipf_nat_table_sz;
hv1 = nat->nat_hv[1] % softn->ipf_nat_table_sz;
/* TRACE nat_osrc6, nat_osport, nat_odst6, nat_odport, hv0 */
/* TRACE nat_nsrc6, nat_nsport, nat_ndst6, nat_ndport, hv1 */
natp = &softn->ipf_nat_table[0][hv0];
if (*natp)
(*natp)->nat_phnext[0] = &nat->nat_hnext[0];
nat->nat_phnext[0] = natp;
nat->nat_hnext[0] = *natp;
*natp = nat;
softn->ipf_nat_stats.ns_side[0].ns_bucketlen[hv0]++;
natp = &softn->ipf_nat_table[1][hv1];
if (*natp)
(*natp)->nat_phnext[1] = &nat->nat_hnext[1];
nat->nat_phnext[1] = natp;
nat->nat_hnext[1] = *natp;
*natp = nat;
softn->ipf_nat_stats.ns_side[1].ns_bucketlen[hv1]++;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_outlookup */
/* Returns: nat6_t* - NULL == no match, */
/* else pointer to matching NAT entry */
/* Parameters: fin(I) - pointer to packet information */
/* flags(I) - NAT flags for this packet */
/* p(I) - protocol for this packet */
/* src(I) - source IP address */
/* dst(I) - destination IP address */
/* rw(I) - 1 == write lock on held, 0 == read lock. */
/* */
/* Lookup a nat entry based on the source 'real' ip address/port and */
/* destination address/port. We use this lookup when sending a packet out, */
/* we're looking for a table entry, based on the source address. */
/* */
/* NOTE: THE PACKET BEING CHECKED (IF FOUND) HAS A MAPPING ALREADY. */
/* */
/* NOTE: IT IS ASSUMED THAT IS ONLY HELD WITH A READ LOCK WHEN */
/* THIS FUNCTION IS CALLED WITH NAT_SEARCH SET IN nflags. */
/* */
/* flags -> relevant are IPN_UDP/IPN_TCP/IPN_ICMPQUERY that indicate if */
/* the packet is of said protocol */
/* ------------------------------------------------------------------------ */
nat_t *
ipf_nat6_outlookup(fr_info_t *fin, u_int flags, u_int p, struct in6_addr *src,
struct in6_addr *dst)
{
ipf_main_softc_t *softc = fin->fin_main_soft;
ipf_nat_softc_t *softn = softc->ipf_nat_soft;
u_short sport, dport;
nat_t *nat;
void *ifp;
u_int hv;
ifp = fin->fin_ifp;
sport = 0;
dport = 0;
switch (p)
{
case IPPROTO_TCP :
case IPPROTO_UDP :
sport = htons(fin->fin_data[0]);
dport = htons(fin->fin_data[1]);
break;
case IPPROTO_ICMPV6 :
if (flags & IPN_ICMPERR)
sport = fin->fin_data[1];
else
dport = fin->fin_data[1];
break;
default :
break;
}
if ((flags & SI_WILDP) != 0)
goto find_out_wild_ports;
hv = NAT_HASH_FN6(src, sport, 0xffffffff);
hv = NAT_HASH_FN6(dst, hv + dport, softn->ipf_nat_table_sz);
nat = softn->ipf_nat_table[0][hv];
/* TRACE src, sport, dst, dport, hv, nat */
for (; nat; nat = nat->nat_hnext[0]) {
if (nat->nat_ifps[1] != NULL) {
if ((ifp != NULL) && (ifp != nat->nat_ifps[1]))
continue;
}
if (nat->nat_pr[1] != p)
continue;
switch (nat->nat_dir)
{
case NAT_INBOUND :
if (nat->nat_v[1] != 6)
continue;
if (IP6_NEQ(&nat->nat_ndst6, src) ||
IP6_NEQ(&nat->nat_nsrc6, dst))
continue;
if ((nat->nat_flags & IPN_TCPUDP) != 0) {
if (nat->nat_ndport != sport)
continue;
if (nat->nat_nsport != dport)
continue;
} else if (p == IPPROTO_ICMPV6) {
if (nat->nat_osport != dport) {
continue;
}
}
break;
case NAT_OUTBOUND :
if (nat->nat_v[0] != 6)
continue;
if (IP6_NEQ(&nat->nat_osrc6, src) ||
IP6_NEQ(&nat->nat_odst6, dst))
continue;
if ((nat->nat_flags & IPN_TCPUDP) != 0) {
if (nat->nat_odport != dport)
continue;
if (nat->nat_osport != sport)
continue;
} else if (p == IPPROTO_ICMPV6) {
if (nat->nat_osport != dport) {
continue;
}
}
break;
}
#ifdef IPF_V6_PROXIES
if ((nat->nat_ptr != NULL) && (nat->nat_aps != NULL))
if (appr_match(fin, nat) != 0)
continue;
#endif
if ((nat->nat_ifps[1] == NULL) && (ifp != NULL)) {
nat->nat_ifps[1] = ifp;
nat->nat_mtu[1] = GETIFMTU_6(ifp);
}
return nat;
}
/*
* So if we didn't find it but there are wildcard members in the hash
* table, go back and look for them. We do this search and update here
* because it is modifying the NAT table and we want to do this only
* for the first packet that matches. The exception, of course, is
* for "dummy" (FI_IGNORE) lookups.
*/
find_out_wild_ports:
if (!(flags & NAT_TCPUDP) || !(flags & NAT_SEARCH)) {
NBUMPSIDE6DX(1, ns_lookup_miss, ns_lookup_miss_3);
return NULL;
}
if (softn->ipf_nat_stats.ns_wilds == 0 || (fin->fin_flx & FI_NOWILD)) {
NBUMPSIDE6D(1, ns_lookup_nowild);
return NULL;
}
RWLOCK_EXIT(&softc->ipf_nat);
hv = NAT_HASH_FN6(src, 0, 0xffffffff);
hv = NAT_HASH_FN6(dst, hv, softn->ipf_nat_table_sz);
WRITE_ENTER(&softc->ipf_nat);
nat = softn->ipf_nat_table[0][hv];
for (; nat; nat = nat->nat_hnext[0]) {
if (nat->nat_ifps[1] != NULL) {
if ((ifp != NULL) && (ifp != nat->nat_ifps[1]))
continue;
}
if (nat->nat_pr[1] != fin->fin_p)
continue;
switch (nat->nat_dir)
{
case NAT_INBOUND :
if (nat->nat_v[1] != 6)
continue;
if (IP6_NEQ(&nat->nat_ndst6, src) ||
IP6_NEQ(&nat->nat_nsrc6, dst))
continue;
break;
case NAT_OUTBOUND :
if (nat->nat_v[0] != 6)
continue;
if (IP6_NEQ(&nat->nat_osrc6, src) ||
IP6_NEQ(&nat->nat_odst6, dst))
continue;
break;
}
if (!(nat->nat_flags & (NAT_TCPUDP|SI_WILDP)))
continue;
if (ipf_nat_wildok(nat, (int)sport, (int)dport, nat->nat_flags,
NAT_OUTBOUND) == 1) {
if ((fin->fin_flx & FI_IGNORE) != 0)
break;
if ((nat->nat_flags & SI_CLONE) != 0) {
nat = ipf_nat_clone(fin, nat);
if (nat == NULL)
break;
} else {
MUTEX_ENTER(&softn->ipf_nat_new);
softn->ipf_nat_stats.ns_wilds--;
MUTEX_EXIT(&softn->ipf_nat_new);
}
if (nat->nat_dir == NAT_OUTBOUND) {
if (nat->nat_osport == 0) {
nat->nat_osport = sport;
nat->nat_nsport = sport;
}
if (nat->nat_odport == 0) {
nat->nat_odport = dport;
nat->nat_ndport = dport;
}
} else {
if (nat->nat_osport == 0) {
nat->nat_osport = dport;
nat->nat_nsport = dport;
}
if (nat->nat_odport == 0) {
nat->nat_odport = sport;
nat->nat_ndport = sport;
}
}
if ((nat->nat_ifps[1] == NULL) && (ifp != NULL)) {
nat->nat_ifps[1] = ifp;
nat->nat_mtu[1] = GETIFMTU_6(ifp);
}
nat->nat_flags &= ~(SI_W_DPORT|SI_W_SPORT);
ipf_nat6_tabmove(softn, nat);
break;
}
}
MUTEX_DOWNGRADE(&softc->ipf_nat);
if (nat == NULL) {
NBUMPSIDE6DX(1, ns_lookup_miss, ns_lookup_miss_4);
}
return nat;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_lookupredir */
/* Returns: nat6_t* - NULL == no match, */
/* else pointer to matching NAT entry */
/* Parameters: softc(I) - pointer to soft context main structure */
/* np(I) - pointer to description of packet to find NAT */
/* table entry for. */
/* */
/* Lookup the NAT tables to search for a matching redirect */
/* The contents of natlookup_t should imitate those found in a packet that */
/* would be translated - ie a packet coming in for RDR or going out for MAP.*/
/* We can do the lookup in one of two ways, imitating an inbound or */
/* outbound packet. By default we assume outbound, unless IPN_IN is set. */
/* For IN, the fields are set as follows: */
/* nl_real* = source information */
/* nl_out* = destination information (translated) */
/* For an out packet, the fields are set like this: */
/* nl_in* = source information (untranslated) */
/* nl_out* = destination information (translated) */
/* ------------------------------------------------------------------------ */
nat_t *
ipf_nat6_lookupredir(ipf_main_softc_t *softc, natlookup_t *np)
{
fr_info_t fi;
nat_t *nat;
bzero((char *)&fi, sizeof(fi));
fi.fin_main_soft = softc;
if (np->nl_flags & IPN_IN) {
fi.fin_data[0] = ntohs(np->nl_realport);
fi.fin_data[1] = ntohs(np->nl_outport);
} else {
fi.fin_data[0] = ntohs(np->nl_inport);
fi.fin_data[1] = ntohs(np->nl_outport);
}
if (np->nl_flags & IPN_TCP)
fi.fin_p = IPPROTO_TCP;
else if (np->nl_flags & IPN_UDP)
fi.fin_p = IPPROTO_UDP;
else if (np->nl_flags & (IPN_ICMPERR|IPN_ICMPQUERY))
fi.fin_p = IPPROTO_ICMPV6;
/*
* We can do two sorts of lookups:
* - IPN_IN: we have the `real' and `out' address, look for `in'.
* - default: we have the `in' and `out' address, look for `real'.
*/
if (np->nl_flags & IPN_IN) {
if ((nat = ipf_nat6_inlookup(&fi, np->nl_flags, fi.fin_p,
&np->nl_realip6,
&np->nl_outip6))) {
np->nl_inip6 = nat->nat_odst6.in6;
np->nl_inport = nat->nat_odport;
}
} else {
/*
* If nl_inip is non null, this is a lookup based on the real
* ip address. Else, we use the fake.
*/
if ((nat = ipf_nat6_outlookup(&fi, np->nl_flags, fi.fin_p,
&np->nl_inip6, &np->nl_outip6))) {
if ((np->nl_flags & IPN_FINDFORWARD) != 0) {
fr_info_t fin;
bzero((char *)&fin, sizeof(fin));
fin.fin_p = nat->nat_pr[0];
fin.fin_data[0] = ntohs(nat->nat_ndport);
fin.fin_data[1] = ntohs(nat->nat_nsport);
if (ipf_nat6_inlookup(&fin, np->nl_flags,
fin.fin_p,
&nat->nat_ndst6.in6,
&nat->nat_nsrc6.in6) !=
NULL) {
np->nl_flags &= ~IPN_FINDFORWARD;
}
}
np->nl_realip6 = nat->nat_odst6.in6;
np->nl_realport = nat->nat_odport;
}
}
return nat;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_match */
/* Returns: int - 0 == no match, 1 == match */
/* Parameters: fin(I) - pointer to packet information */
/* np(I) - pointer to NAT rule */
/* */
/* Pull the matching of a packet against a NAT rule out of that complex */
/* loop inside ipf_nat6_checkin() and lay it out properly in its own */
/* function. */
/* ------------------------------------------------------------------------ */
static int
ipf_nat6_match(fr_info_t *fin, ipnat_t *np)
{
frtuc_t *ft;
int match;
match = 0;
switch (np->in_osrcatype)
{
case FRI_NORMAL :
match = IP6_MASKNEQ(&fin->fin_src6, &np->in_osrcmsk6,
&np->in_osrcip6);
break;
case FRI_LOOKUP :
match = (*np->in_osrcfunc)(fin->fin_main_soft, np->in_osrcptr,
6, &fin->fin_src6, fin->fin_plen);
break;
}
match ^= ((np->in_flags & IPN_NOTSRC) != 0);
if (match)
return 0;
match = 0;
switch (np->in_odstatype)
{
case FRI_NORMAL :
match = IP6_MASKNEQ(&fin->fin_dst6, &np->in_odstmsk6,
&np->in_odstip6);
break;
case FRI_LOOKUP :
match = (*np->in_odstfunc)(fin->fin_main_soft, np->in_odstptr,
6, &fin->fin_dst6, fin->fin_plen);
break;
}
match ^= ((np->in_flags & IPN_NOTDST) != 0);
if (match)
return 0;
ft = &np->in_tuc;
if (!(fin->fin_flx & FI_TCPUDP) ||
(fin->fin_flx & (FI_SHORT|FI_FRAGBODY))) {
if (ft->ftu_scmp || ft->ftu_dcmp)
return 0;
return 1;
}
return ipf_tcpudpchk(&fin->fin_fi, ft);
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_checkout */
/* Returns: int - -1 == packet failed NAT checks so block it, */
/* 0 == no packet translation occurred, */
/* 1 == packet was successfully translated. */
/* Parameters: fin(I) - pointer to packet information */
/* passp(I) - pointer to filtering result flags */
/* */
/* Check to see if an outcoming packet should be changed. ICMP packets are */
/* first checked to see if they match an existing entry (if an error), */
/* otherwise a search of the current NAT table is made. If neither results */
/* in a match then a search for a matching NAT rule is made. Create a new */
/* NAT entry if a we matched a NAT rule. Lastly, actually change the */
/* packet header(s) as required. */
/* ------------------------------------------------------------------------ */
int
ipf_nat6_checkout(fr_info_t *fin, u_32_t *passp)
{
ipf_main_softc_t *softc = fin->fin_main_soft;
ipf_nat_softc_t *softn = softc->ipf_nat_soft;
struct icmp6_hdr *icmp6 = NULL;
struct ifnet *ifp, *sifp;
#ifdef IPF_V6_PROXIES
tcphdr_t *tcp = NULL;
#endif
int rval, natfailed;
ipnat_t *np = NULL;
u_int nflags = 0;
i6addr_t ipa, iph;
int natadd = 1;
frentry_t *fr;
nat_t *nat;
if (softn->ipf_nat_stats.ns_rules == 0 || softn->ipf_nat_lock != 0)
return 0;
icmp6 = NULL;
natfailed = 0;
fr = fin->fin_fr;
sifp = fin->fin_ifp;
if (fr != NULL) {
ifp = fr->fr_tifs[fin->fin_rev].fd_ptr;
if ((ifp != NULL) && (ifp != (void *)-1))
fin->fin_ifp = ifp;
}
ifp = fin->fin_ifp;
if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) {
switch (fin->fin_p)
{
case IPPROTO_TCP :
nflags = IPN_TCP;
break;
case IPPROTO_UDP :
nflags = IPN_UDP;
break;
case IPPROTO_ICMPV6 :
icmp6 = fin->fin_dp;
/*
* Apart from ECHO request and reply, all other
* informational messages should not be translated
* so as to keep IPv6 working.
*/
if (icmp6->icmp6_type > ICMP6_ECHO_REPLY)
return 0;
/*
* This is an incoming packet, so the destination is
* the icmp6_id and the source port equals 0
*/
if ((fin->fin_flx & FI_ICMPQUERY) != 0)
nflags = IPN_ICMPQUERY;
break;
default :
break;
}
#ifdef IPF_V6_PROXIES
if ((nflags & IPN_TCPUDP))
tcp = fin->fin_dp;
#endif
}
ipa = fin->fin_src6;
READ_ENTER(&softc->ipf_nat);
if ((fin->fin_p == IPPROTO_ICMPV6) && !(nflags & IPN_ICMPQUERY) &&
(nat = ipf_nat6_icmperror(fin, &nflags, NAT_OUTBOUND)))
/*EMPTY*/;
else if ((fin->fin_flx & FI_FRAG) && (nat = ipf_frag_natknown(fin)))
natadd = 0;
else if ((nat = ipf_nat6_outlookup(fin, nflags|NAT_SEARCH,
(u_int)fin->fin_p,
&fin->fin_src6.in6,
&fin->fin_dst6.in6))) {
nflags = nat->nat_flags;
} else if (fin->fin_off == 0) {
u_32_t hv, nmsk = 0;
i6addr_t *msk;
/*
* If there is no current entry in the nat table for this IP#,
* create one for it (if there is a matching rule).
*/
maskloop:
msk = &softn->ipf_nat6_map_active_masks[nmsk];
IP6_AND(&ipa, msk, &iph);
hv = NAT_HASH_FN6(&iph, 0, softn->ipf_nat_maprules_sz);
for (np = softn->ipf_nat_map_rules[hv]; np; np = np->in_mnext) {
if ((np->in_ifps[1] && (np->in_ifps[1] != ifp)))
continue;
if (np->in_v[0] != 6)
continue;
if (np->in_pr[1] && (np->in_pr[1] != fin->fin_p))
continue;
if ((np->in_flags & IPN_RF) &&
!(np->in_flags & nflags))
continue;
if (np->in_flags & IPN_FILTER) {
switch (ipf_nat6_match(fin, np))
{
case 0 :
continue;
case -1 :
rval = -1;
goto outmatchfail;
case 1 :
default :
break;
}
} else if (!IP6_MASKEQ(&ipa, &np->in_osrcmsk,
&np->in_osrcip6))
continue;
if ((fr != NULL) &&
!ipf_matchtag(&np->in_tag, &fr->fr_nattag))
continue;
#ifdef IPF_V6_PROXIES
if (np->in_plabel != -1) {
if (((np->in_flags & IPN_FILTER) == 0) &&
(np->in_odport != fin->fin_data[1]))
continue;
if (appr_ok(fin, tcp, np) == 0)
continue;
}
#endif
if (np->in_flags & IPN_NO) {
np->in_hits++;
break;
}
MUTEX_ENTER(&softn->ipf_nat_new);
nat = ipf_nat6_add(fin, np, NULL, nflags, NAT_OUTBOUND);
MUTEX_EXIT(&softn->ipf_nat_new);
if (nat != NULL) {
np->in_hits++;
break;
}
natfailed = -1;
}
if ((np == NULL) && (nmsk < softn->ipf_nat6_map_max)) {
nmsk++;
goto maskloop;
}
}
if (nat != NULL) {
rval = ipf_nat6_out(fin, nat, natadd, nflags);
if (rval == 1) {
MUTEX_ENTER(&nat->nat_lock);
ipf_nat_update(fin, nat);
nat->nat_bytes[1] += fin->fin_plen;
nat->nat_pkts[1]++;
MUTEX_EXIT(&nat->nat_lock);
}
} else
rval = natfailed;
outmatchfail:
RWLOCK_EXIT(&softc->ipf_nat);
switch (rval)
{
case -1 :
if (passp != NULL) {
NBUMPSIDE6D(1, ns_drop);
*passp = FR_BLOCK;
fin->fin_reason = FRB_NATV6;
}
fin->fin_flx |= FI_BADNAT;
NBUMPSIDE6D(1, ns_badnat);
break;
case 0 :
NBUMPSIDE6D(1, ns_ignored);
break;
case 1 :
NBUMPSIDE6D(1, ns_translated);
break;
}
fin->fin_ifp = sifp;
return rval;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_out */
/* Returns: int - -1 == packet failed NAT checks so block it, */
/* 1 == packet was successfully translated. */
/* Parameters: fin(I) - pointer to packet information */
/* nat(I) - pointer to NAT structure */
/* natadd(I) - flag indicating if it is safe to add frag cache */
/* nflags(I) - NAT flags set for this packet */
/* */
/* Translate a packet coming "out" on an interface. */
/* ------------------------------------------------------------------------ */
static int
ipf_nat6_out(fr_info_t *fin, nat_t *nat, int natadd, u_32_t nflags)
{
ipf_main_softc_t *softc = fin->fin_main_soft;
ipf_nat_softc_t *softn = softc->ipf_nat_soft;
struct icmp6_hdr *icmp6;
tcphdr_t *tcp;
ipnat_t *np;
int skip;
int i;
tcp = NULL;
icmp6 = NULL;
np = nat->nat_ptr;
if ((natadd != 0) && (fin->fin_flx & FI_FRAG) && (np != NULL))
(void) ipf_frag_natnew(softc, fin, 0, nat);
/*
* Address assignment is after the checksum modification because
* we are using the address in the packet for determining the
* correct checksum offset (the ICMP error could be coming from
* anyone...)
*/
switch (nat->nat_dir)
{
case NAT_OUTBOUND :
fin->fin_ip6->ip6_src = nat->nat_nsrc6.in6;
fin->fin_src6 = nat->nat_nsrc6;
fin->fin_ip6->ip6_dst = nat->nat_ndst6.in6;
fin->fin_dst6 = nat->nat_ndst6;
break;
case NAT_INBOUND :
fin->fin_ip6->ip6_src = nat->nat_odst6.in6;
fin->fin_src6 = nat->nat_ndst6;
fin->fin_ip6->ip6_dst = nat->nat_osrc6.in6;
fin->fin_dst6 = nat->nat_nsrc6;
break;
case NAT_DIVERTIN :
{
mb_t *m;
skip = ipf_nat6_decap(fin, nat);
if (skip <= 0) {
NBUMPSIDE6D(1, ns_decap_fail);
return -1;
}
m = fin->fin_m;
#if defined(MENTAT) && defined(_KERNEL)
m->b_rptr += skip;
#else
m->m_data += skip;
m->m_len -= skip;
# ifdef M_PKTHDR
if (m->m_flags & M_PKTHDR)
m->m_pkthdr.len -= skip;
# endif
#endif
MUTEX_ENTER(&nat->nat_lock);
ipf_nat_update(fin, nat);
MUTEX_EXIT(&nat->nat_lock);
fin->fin_flx |= FI_NATED;
if (np != NULL && np->in_tag.ipt_num[0] != 0)
fin->fin_nattag = &np->in_tag;
return 1;
/* NOTREACHED */
}
case NAT_DIVERTOUT :
{
udphdr_t *uh;
ip6_t *ip6;
mb_t *m;
m = M_DUP(np->in_divmp);
if (m == NULL) {
NBUMPSIDE6D(1, ns_divert_dup);
return -1;
}
ip6 = MTOD(m, ip6_t *);
ip6->ip6_plen = htons(fin->fin_plen + 8);
uh = (udphdr_t *)(ip6 + 1);
uh->uh_ulen = htons(fin->fin_plen);
PREP_MB_T(fin, m);
fin->fin_ip6 = ip6;
fin->fin_plen += sizeof(ip6_t) + 8; /* UDP + new IPv4 hdr */
fin->fin_dlen += sizeof(ip6_t) + 8; /* UDP + old IPv4 hdr */
nflags &= ~IPN_TCPUDPICMP;
break;
}
default :
break;
}
if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) {
u_short *csump;
if ((nat->nat_nsport != 0) && (nflags & IPN_TCPUDP)) {
tcp = fin->fin_dp;
switch (nat->nat_dir)
{
case NAT_OUTBOUND :
tcp->th_sport = nat->nat_nsport;
fin->fin_data[0] = ntohs(nat->nat_nsport);
tcp->th_dport = nat->nat_ndport;
fin->fin_data[1] = ntohs(nat->nat_ndport);
break;
case NAT_INBOUND :
tcp->th_sport = nat->nat_odport;
fin->fin_data[0] = ntohs(nat->nat_odport);
tcp->th_dport = nat->nat_osport;
fin->fin_data[1] = ntohs(nat->nat_osport);
break;
}
}
if ((nat->nat_nsport != 0) && (nflags & IPN_ICMPQUERY)) {
icmp6 = fin->fin_dp;
icmp6->icmp6_id = nat->nat_nicmpid;
}
csump = ipf_nat_proto(fin, nat, nflags);
/*
* The above comments do not hold for layer 4 (or higher)
* checksums...
*/
if (csump != NULL) {
if (nat->nat_dir == NAT_OUTBOUND)
ipf_fix_outcksum(fin->fin_cksum, csump,
nat->nat_sumd[0],
nat->nat_sumd[1] +
fin->fin_dlen);
else
ipf_fix_incksum(fin->fin_cksum, csump,
nat->nat_sumd[0],
nat->nat_sumd[1] +
fin->fin_dlen);
}
}
ipf_sync_update(softc, SMC_NAT, fin, nat->nat_sync);
/* ------------------------------------------------------------- */
/* A few quick notes: */
/* Following are test conditions prior to calling the */
/* ipf_proxy_check routine. */
/* */
/* A NULL tcp indicates a non TCP/UDP packet. When dealing */
/* with a redirect rule, we attempt to match the packet's */
/* source port against in_dport, otherwise we'd compare the */
/* packet's destination. */
/* ------------------------------------------------------------- */
if ((np != NULL) && (np->in_apr != NULL)) {
i = ipf_proxy_check(fin, nat);
if (i == 0) {
i = 1;
} else if (i == -1) {
NBUMPSIDE6D(1, ns_ipf_proxy_fail);
}
} else {
i = 1;
}
fin->fin_flx |= FI_NATED;
return i;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_checkin */
/* Returns: int - -1 == packet failed NAT checks so block it, */
/* 0 == no packet translation occurred, */
/* 1 == packet was successfully translated. */
/* Parameters: fin(I) - pointer to packet information */
/* passp(I) - pointer to filtering result flags */
/* */
/* Check to see if an incoming packet should be changed. ICMP packets are */
/* first checked to see if they match an existing entry (if an error), */
/* otherwise a search of the current NAT table is made. If neither results */
/* in a match then a search for a matching NAT rule is made. Create a new */
/* NAT entry if a we matched a NAT rule. Lastly, actually change the */
/* packet header(s) as required. */
/* ------------------------------------------------------------------------ */
int
ipf_nat6_checkin(fr_info_t *fin, u_32_t *passp)
{
ipf_main_softc_t *softc = fin->fin_main_soft;
ipf_nat_softc_t *softn = softc->ipf_nat_soft;
struct icmp6_hdr *icmp6;
u_int nflags, natadd;
int rval, natfailed;
struct ifnet *ifp;
i6addr_t ipa, iph;
#ifdef IPF_V6_PROXIES
tcphdr_t *tcp;
#endif
u_short dport;
ipnat_t *np;
nat_t *nat;
if (softn->ipf_nat_stats.ns_rules == 0 || softn->ipf_nat_lock != 0)
return 0;
#ifdef IPF_V6_PROXIES
tcp = NULL;
#endif
icmp6 = NULL;
dport = 0;
natadd = 1;
nflags = 0;
natfailed = 0;
ifp = fin->fin_ifp;
if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) {
switch (fin->fin_p)
{
case IPPROTO_TCP :
nflags = IPN_TCP;
break;
case IPPROTO_UDP :
nflags = IPN_UDP;
break;
case IPPROTO_ICMPV6 :
icmp6 = fin->fin_dp;
/*
* Apart from ECHO request and reply, all other
* informational messages should not be translated
* so as to keep IPv6 working.
*/
if (icmp6->icmp6_type > ICMP6_ECHO_REPLY)
return 0;
/*
* This is an incoming packet, so the destination is
* the icmp6_id and the source port equals 0
*/
if ((fin->fin_flx & FI_ICMPQUERY) != 0) {
nflags = IPN_ICMPQUERY;
dport = icmp6->icmp6_id;
} break;
default :
break;
}
if ((nflags & IPN_TCPUDP)) {
#ifdef IPF_V6_PROXIES
tcp = fin->fin_dp;
#endif
dport = fin->fin_data[1];
}
}
ipa = fin->fin_dst6;
READ_ENTER(&softc->ipf_nat);
if ((fin->fin_p == IPPROTO_ICMPV6) && !(nflags & IPN_ICMPQUERY) &&
(nat = ipf_nat6_icmperror(fin, &nflags, NAT_INBOUND)))
/*EMPTY*/;
else if ((fin->fin_flx & FI_FRAG) && (nat = ipf_frag_natknown(fin)))
natadd = 0;
else if ((nat = ipf_nat6_inlookup(fin, nflags|NAT_SEARCH,
(u_int)fin->fin_p,
&fin->fin_src6.in6, &ipa.in6))) {
nflags = nat->nat_flags;
} else if (fin->fin_off == 0) {
u_32_t hv, rmsk = 0;
i6addr_t *msk;
/*
* If there is no current entry in the nat table for this IP#,
* create one for it (if there is a matching rule).
*/
maskloop:
msk = &softn->ipf_nat6_rdr_active_masks[rmsk];
IP6_AND(&ipa, msk, &iph);
hv = NAT_HASH_FN6(&iph, 0, softn->ipf_nat_rdrrules_sz);
for (np = softn->ipf_nat_rdr_rules[hv]; np; np = np->in_rnext) {
if (np->in_ifps[0] && (np->in_ifps[0] != ifp))
continue;
if (np->in_v[0] != 6)
continue;
if (np->in_pr[0] && (np->in_pr[0] != fin->fin_p))
continue;
if ((np->in_flags & IPN_RF) && !(np->in_flags & nflags))
continue;
if (np->in_flags & IPN_FILTER) {
switch (ipf_nat6_match(fin, np))
{
case 0 :
continue;
case -1 :
rval = -1;
goto inmatchfail;
case 1 :
default :
break;
}
} else {
if (!IP6_MASKEQ(&ipa, &np->in_odstmsk6,
&np->in_odstip6)) {
continue;
}
if (np->in_odport &&
((np->in_dtop < dport) ||
(dport < np->in_odport)))
continue;
}
#ifdef IPF_V6_PROXIES
if (np->in_plabel != -1) {
if (!appr_ok(fin, tcp, np)) {
continue;
}
}
#endif
if (np->in_flags & IPN_NO) {
np->in_hits++;
break;
}
MUTEX_ENTER(&softn->ipf_nat_new);
nat = ipf_nat6_add(fin, np, NULL, nflags, NAT_INBOUND);
MUTEX_EXIT(&softn->ipf_nat_new);
if (nat != NULL) {
np->in_hits++;
break;
}
natfailed = -1;
}
if ((np == NULL) && (rmsk < softn->ipf_nat6_rdr_max)) {
rmsk++;
goto maskloop;
}
}
if (nat != NULL) {
rval = ipf_nat6_in(fin, nat, natadd, nflags);
if (rval == 1) {
MUTEX_ENTER(&nat->nat_lock);
ipf_nat_update(fin, nat);
nat->nat_bytes[0] += fin->fin_plen;
nat->nat_pkts[0]++;
MUTEX_EXIT(&nat->nat_lock);
}
} else
rval = natfailed;
inmatchfail:
RWLOCK_EXIT(&softc->ipf_nat);
switch (rval)
{
case -1 :
if (passp != NULL) {
NBUMPSIDE6D(0, ns_drop);
*passp = FR_BLOCK;
fin->fin_reason = FRB_NATV6;
}
fin->fin_flx |= FI_BADNAT;
NBUMPSIDE6D(0, ns_badnat);
break;
case 0 :
NBUMPSIDE6D(0, ns_ignored);
break;
case 1 :
NBUMPSIDE6D(0, ns_translated);
break;
}
return rval;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_in */
/* Returns: int - -1 == packet failed NAT checks so block it, */
/* 1 == packet was successfully translated. */
/* Parameters: fin(I) - pointer to packet information */
/* nat(I) - pointer to NAT structure */
/* natadd(I) - flag indicating if it is safe to add frag cache */
/* nflags(I) - NAT flags set for this packet */
/* Locks Held: (READ) */
/* */
/* Translate a packet coming "in" on an interface. */
/* ------------------------------------------------------------------------ */
static int
ipf_nat6_in(fr_info_t *fin, nat_t *nat, int natadd, u_32_t nflags)
{
ipf_main_softc_t *softc = fin->fin_main_soft;
ipf_nat_softc_t *softn = softc->ipf_nat_soft;
struct icmp6_hdr *icmp6;
u_short *csump;
tcphdr_t *tcp;
ipnat_t *np;
int skip;
int i;
tcp = NULL;
csump = NULL;
np = nat->nat_ptr;
fin->fin_fr = nat->nat_fr;
if (np != NULL) {
if ((natadd != 0) && (fin->fin_flx & FI_FRAG))
(void) ipf_frag_natnew(softc, fin, 0, nat);
/* ------------------------------------------------------------- */
/* A few quick notes: */
/* Following are test conditions prior to calling the */
/* ipf_proxy_check routine. */
/* */
/* A NULL tcp indicates a non TCP/UDP packet. When dealing */
/* with a map rule, we attempt to match the packet's */
/* source port against in_dport, otherwise we'd compare the */
/* packet's destination. */
/* ------------------------------------------------------------- */
if (np->in_apr != NULL) {
i = ipf_proxy_check(fin, nat);
if (i == -1) {
NBUMPSIDE6D(0, ns_ipf_proxy_fail);
return -1;
}
}
}
ipf_sync_update(softc, SMC_NAT, fin, nat->nat_sync);
/*
* Fix up checksums, not by recalculating them, but
* simply computing adjustments.
* Why only do this for some platforms on inbound packets ?
* Because for those that it is done, IP processing is yet to happen
* and so the IPv4 header checksum has not yet been evaluated.
* Perhaps it should always be done for the benefit of things like
* fast forwarding (so that it doesn't need to be recomputed) but with
* header checksum offloading, perhaps it is a moot point.
*/
switch (nat->nat_dir)
{
case NAT_INBOUND :
if ((fin->fin_flx & FI_ICMPERR) == 0) {
fin->fin_ip6->ip6_src = nat->nat_nsrc6.in6;
fin->fin_src6 = nat->nat_nsrc6;
}
fin->fin_ip6->ip6_dst = nat->nat_ndst6.in6;
fin->fin_dst6 = nat->nat_ndst6;
break;
case NAT_OUTBOUND :
if ((fin->fin_flx & FI_ICMPERR) == 0) {
fin->fin_ip6->ip6_src = nat->nat_odst6.in6;
fin->fin_src6 = nat->nat_odst6;
}
fin->fin_ip6->ip6_dst = nat->nat_osrc6.in6;
fin->fin_dst6 = nat->nat_osrc6;
break;
case NAT_DIVERTIN :
{
udphdr_t *uh;
ip6_t *ip6;
mb_t *m;
m = M_DUP(np->in_divmp);
if (m == NULL) {
NBUMPSIDE6D(0, ns_divert_dup);
return -1;
}
ip6 = MTOD(m, ip6_t *);
ip6->ip6_plen = htons(fin->fin_plen + sizeof(udphdr_t));
uh = (udphdr_t *)(ip6 + 1);
uh->uh_ulen = ntohs(fin->fin_plen);
PREP_MB_T(fin, m);
fin->fin_ip6 = ip6;
fin->fin_plen += sizeof(ip6_t) + 8; /* UDP + new IPv6 hdr */
fin->fin_dlen += sizeof(ip6_t) + 8; /* UDP + old IPv6 hdr */
nflags &= ~IPN_TCPUDPICMP;
break;
}
case NAT_DIVERTOUT :
{
mb_t *m;
skip = ipf_nat6_decap(fin, nat);
if (skip <= 0) {
NBUMPSIDE6D(0, ns_decap_fail);
return -1;
}
m = fin->fin_m;
#if defined(MENTAT) && defined(_KERNEL)
m->b_rptr += skip;
#else
m->m_data += skip;
m->m_len -= skip;
# ifdef M_PKTHDR
if (m->m_flags & M_PKTHDR)
m->m_pkthdr.len -= skip;
# endif
#endif
ipf_nat_update(fin, nat);
fin->fin_flx |= FI_NATED;
if (np != NULL && np->in_tag.ipt_num[0] != 0)
fin->fin_nattag = &np->in_tag;
return 1;
/* NOTREACHED */
}
}
if (nflags & IPN_TCPUDP)
tcp = fin->fin_dp;
if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) {
if ((nat->nat_odport != 0) && (nflags & IPN_TCPUDP)) {
switch (nat->nat_dir)
{
case NAT_INBOUND :
tcp->th_sport = nat->nat_nsport;
fin->fin_data[0] = ntohs(nat->nat_nsport);
tcp->th_dport = nat->nat_ndport;
fin->fin_data[1] = ntohs(nat->nat_ndport);
break;
case NAT_OUTBOUND :
tcp->th_sport = nat->nat_odport;
fin->fin_data[0] = ntohs(nat->nat_odport);
tcp->th_dport = nat->nat_osport;
fin->fin_data[1] = ntohs(nat->nat_osport);
break;
}
}
if ((nat->nat_odport != 0) && (nflags & IPN_ICMPQUERY)) {
icmp6 = fin->fin_dp;
icmp6->icmp6_id = nat->nat_nicmpid;
}
csump = ipf_nat_proto(fin, nat, nflags);
}
/*
* The above comments do not hold for layer 4 (or higher) checksums...
*/
if (csump != NULL) {
if (nat->nat_dir == NAT_OUTBOUND)
ipf_fix_incksum(0, csump, nat->nat_sumd[0], 0);
else
ipf_fix_outcksum(0, csump, nat->nat_sumd[0], 0);
}
fin->fin_flx |= FI_NATED;
if (np != NULL && np->in_tag.ipt_num[0] != 0)
fin->fin_nattag = &np->in_tag;
return 1;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_newrewrite */
/* Returns: int - -1 == error, 0 == success (no move), 1 == success and */
/* allow rule to be moved if IPN_ROUNDR is set. */
/* Parameters: fin(I) - pointer to packet information */
/* nat(I) - pointer to NAT entry */
/* ni(I) - pointer to structure with misc. information needed */
/* to create new NAT entry. */
/* Write Lock: ipf_nat */
/* */
/* This function is responsible for setting up an active NAT session where */
/* we are changing both the source and destination parameters at the same */
/* time. The loop in here works differently to elsewhere - each iteration */
/* is responsible for changing a single parameter that can be incremented. */
/* So one pass may increase the source IP#, next source port, next dest. IP#*/
/* and the last destination port for a total of 4 iterations to try each. */
/* This is done to try and exhaustively use the translation space available.*/
/* ------------------------------------------------------------------------ */
int
ipf_nat6_newrewrite(fr_info_t *fin, nat_t *nat, natinfo_t *nai)
{
int src_search = 1;
int dst_search = 1;
fr_info_t frnat;
u_32_t flags;
u_short swap;
ipnat_t *np;
nat_t *natl;
int l = 0;
int changed;
natl = NULL;
changed = -1;
np = nai->nai_np;
flags = nat->nat_flags;
bcopy((char *)fin, (char *)&frnat, sizeof(*fin));
nat->nat_hm = NULL;
do {
changed = -1;
/* TRACE (l, src_search, dst_search, np) */
if ((src_search == 0) && (np->in_spnext == 0) &&
(dst_search == 0) && (np->in_dpnext == 0)) {
if (l > 0)
return -1;
}
/*
* Find a new source address
*/
if (ipf_nat6_nextaddr(fin, &np->in_nsrc, &frnat.fin_src6,
&frnat.fin_src6) == -1) {
return -1;
}
if (IP6_ISZERO(&np->in_nsrcip6) &&
IP6_ISONES(&np->in_nsrcmsk6)) {
src_search = 0;
if (np->in_stepnext == 0)
np->in_stepnext = 1;
} else if (IP6_ISZERO(&np->in_nsrcip6) &&
IP6_ISZERO(&np->in_nsrcmsk6)) {
src_search = 0;
if (np->in_stepnext == 0)
np->in_stepnext = 1;
} else if (IP6_ISONES(&np->in_nsrcmsk)) {
src_search = 0;
if (np->in_stepnext == 0)
np->in_stepnext = 1;
} else if (!IP6_ISONES(&np->in_nsrcmsk6)) {
if (np->in_stepnext == 0 && changed == -1) {
IP6_INC(&np->in_snip);
np->in_stepnext++;
changed = 0;
}
}
if ((flags & IPN_TCPUDPICMP) != 0) {
if (np->in_spnext != 0)
frnat.fin_data[0] = np->in_spnext;
/*
* Standard port translation. Select next port.
*/
if ((flags & IPN_FIXEDSPORT) != 0) {
np->in_stepnext = 2;
} else if ((np->in_stepnext == 1) &&
(changed == -1) && (natl != NULL)) {
np->in_spnext++;
np->in_stepnext++;
changed = 1;
if (np->in_spnext > np->in_spmax)
np->in_spnext = np->in_spmin;
}
} else {
np->in_stepnext = 2;
}
np->in_stepnext &= 0x3;
/*
* Find a new destination address
*/
/* TRACE (fin, np, l, frnat) */
if (ipf_nat6_nextaddr(fin, &np->in_ndst, &frnat.fin_dst6,
&frnat.fin_dst6) == -1)
return -1;
if (IP6_ISZERO(&np->in_ndstip6) &&
IP6_ISONES(&np->in_ndstmsk6)) {
dst_search = 0;
if (np->in_stepnext == 2)
np->in_stepnext = 3;
} else if (IP6_ISZERO(&np->in_ndstip6) &&
IP6_ISZERO(&np->in_ndstmsk6)) {
dst_search = 0;
if (np->in_stepnext == 2)
np->in_stepnext = 3;
} else if (IP6_ISONES(&np->in_ndstmsk6)) {
dst_search = 0;
if (np->in_stepnext == 2)
np->in_stepnext = 3;
} else if (!IP6_ISONES(&np->in_ndstmsk6)) {
if ((np->in_stepnext == 2) && (changed == -1) &&
(natl != NULL)) {
changed = 2;
np->in_stepnext++;
IP6_INC(&np->in_dnip6);
}
}
if ((flags & IPN_TCPUDPICMP) != 0) {
if (np->in_dpnext != 0)
frnat.fin_data[1] = np->in_dpnext;
/*
* Standard port translation. Select next port.
*/
if ((flags & IPN_FIXEDDPORT) != 0) {
np->in_stepnext = 0;
} else if (np->in_stepnext == 3 && changed == -1) {
np->in_dpnext++;
np->in_stepnext++;
changed = 3;
if (np->in_dpnext > np->in_dpmax)
np->in_dpnext = np->in_dpmin;
}
} else {
if (np->in_stepnext == 3)
np->in_stepnext = 0;
}
/* TRACE (frnat) */
/*
* Here we do a lookup of the connection as seen from
* the outside. If an IP# pair already exists, try
* again. So if you have A->B becomes C->B, you can
* also have D->E become C->E but not D->B causing
* another C->B. Also take protocol and ports into
* account when determining whether a pre-existing
* NAT setup will cause an external conflict where
* this is appropriate.
*
* fin_data[] is swapped around because we are doing a
* lookup of the packet is if it were moving in the opposite
* direction of the one we are working with now.
*/
if (flags & IPN_TCPUDP) {
swap = frnat.fin_data[0];
frnat.fin_data[0] = frnat.fin_data[1];
frnat.fin_data[1] = swap;
}
if (fin->fin_out == 1) {
natl = ipf_nat6_inlookup(&frnat,
flags & ~(SI_WILDP|NAT_SEARCH),
(u_int)frnat.fin_p,
&frnat.fin_dst6.in6,
&frnat.fin_src6.in6);
} else {
natl = ipf_nat6_outlookup(&frnat,
flags & ~(SI_WILDP|NAT_SEARCH),
(u_int)frnat.fin_p,
&frnat.fin_dst6.in6,
&frnat.fin_src6.in6);
}
if (flags & IPN_TCPUDP) {
swap = frnat.fin_data[0];
frnat.fin_data[0] = frnat.fin_data[1];
frnat.fin_data[1] = swap;
}
/* TRACE natl, in_stepnext, l */
if ((natl != NULL) && (l > 8)) /* XXX 8 is arbitrary */
return -1;
np->in_stepnext &= 0x3;
l++;
changed = -1;
} while (natl != NULL);
nat->nat_osrc6 = fin->fin_src6;
nat->nat_odst6 = fin->fin_dst6;
nat->nat_nsrc6 = frnat.fin_src6;
nat->nat_ndst6 = frnat.fin_dst6;
if ((flags & IPN_TCPUDP) != 0) {
nat->nat_osport = htons(fin->fin_data[0]);
nat->nat_odport = htons(fin->fin_data[1]);
nat->nat_nsport = htons(frnat.fin_data[0]);
nat->nat_ndport = htons(frnat.fin_data[1]);
} else if ((flags & IPN_ICMPQUERY) != 0) {
nat->nat_oicmpid = fin->fin_data[1];
nat->nat_nicmpid = frnat.fin_data[1];
}
return 0;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_newdivert */
/* Returns: int - -1 == error, 0 == success */
/* Parameters: fin(I) - pointer to packet information */
/* nat(I) - pointer to NAT entry */
/* ni(I) - pointer to structure with misc. information needed */
/* to create new NAT entry. */
/* Write Lock: ipf_nat */
/* */
/* Create a new NAT divert session as defined by the NAT rule. This is */
/* somewhat different to other NAT session creation routines because we */
/* do not iterate through either port numbers or IP addresses, searching */
/* for a unique mapping, however, a complimentary duplicate check is made. */
/* ------------------------------------------------------------------------ */
int
ipf_nat6_newdivert(fr_info_t *fin, nat_t *nat, natinfo_t *nai)
{
ipf_main_softc_t *softc = fin->fin_main_soft;
ipf_nat_softc_t *softn = softc->ipf_nat_soft;
fr_info_t frnat;
ipnat_t *np;
nat_t *natl;
int p;
np = nai->nai_np;
bcopy((char *)fin, (char *)&frnat, sizeof(*fin));
nat->nat_pr[0] = 0;
nat->nat_osrc6 = fin->fin_src6;
nat->nat_odst6 = fin->fin_dst6;
nat->nat_osport = htons(fin->fin_data[0]);
nat->nat_odport = htons(fin->fin_data[1]);
frnat.fin_src6 = np->in_snip6;
frnat.fin_dst6 = np->in_dnip6;
if (np->in_redir & NAT_DIVERTUDP) {
frnat.fin_data[0] = np->in_spnext;
frnat.fin_data[1] = np->in_dpnext;
frnat.fin_flx |= FI_TCPUDP;
p = IPPROTO_UDP;
} else {
frnat.fin_flx &= ~FI_TCPUDP;
p = IPPROTO_IPIP;
}
if (fin->fin_out == 1) {
natl = ipf_nat6_inlookup(&frnat, 0, p, &frnat.fin_dst6.in6,
&frnat.fin_src6.in6);
} else {
natl = ipf_nat6_outlookup(&frnat, 0, p, &frnat.fin_dst6.in6,
&frnat.fin_src6.in6);
}
if (natl != NULL) {
NBUMPSIDE6D(fin->fin_out, ns_divert_exist);
return -1;
}
nat->nat_nsrc6 = frnat.fin_src6;
nat->nat_ndst6 = frnat.fin_dst6;
if (np->in_redir & NAT_DIVERTUDP) {
nat->nat_nsport = htons(frnat.fin_data[0]);
nat->nat_ndport = htons(frnat.fin_data[1]);
}
nat->nat_pr[fin->fin_out] = fin->fin_p;
nat->nat_pr[1 - fin->fin_out] = p;
if (np->in_redir & NAT_REDIRECT)
nat->nat_dir = NAT_DIVERTIN;
else
nat->nat_dir = NAT_DIVERTOUT;
return 0;
}
/* ------------------------------------------------------------------------ */
/* Function: nat6_builddivertmp */
/* Returns: int - -1 == error, 0 == success */
/* Parameters: np(I) - pointer to a NAT rule */
/* */
/* For divert rules, a skeleton packet representing what will be prepended */
/* to the real packet is created. Even though we don't have the full */
/* packet here, a checksum is calculated that we update later when we */
/* fill in the final details. At present a 0 checksum for UDP is being set */
/* here because it is expected that divert will be used for localhost. */
/* ------------------------------------------------------------------------ */
static int
ipf_nat6_builddivertmp(ipf_nat_softc_t *softn, ipnat_t *np)
{
udphdr_t *uh;
size_t len;
ip6_t *ip6;
if ((np->in_redir & NAT_DIVERTUDP) != 0)
len = sizeof(ip6_t) + sizeof(udphdr_t);
else
len = sizeof(ip6_t);
ALLOC_MB_T(np->in_divmp, len);
if (np->in_divmp == NULL) {
ATOMIC_INCL(softn->ipf_nat_stats.ns_divert_build);
return -1;
}
/*
* First, the header to get the packet diverted to the new destination
*/
ip6 = MTOD(np->in_divmp, ip6_t *);
ip6->ip6_vfc = 0x60;
if ((np->in_redir & NAT_DIVERTUDP) != 0)
ip6->ip6_nxt = IPPROTO_UDP;
else
ip6->ip6_nxt = IPPROTO_IPIP;
ip6->ip6_hlim = 255;
ip6->ip6_plen = 0;
ip6->ip6_src = np->in_snip6.in6;
ip6->ip6_dst = np->in_dnip6.in6;
if (np->in_redir & NAT_DIVERTUDP) {
uh = (udphdr_t *)((u_char *)ip6 + sizeof(*ip6));
uh->uh_sum = 0;
uh->uh_ulen = 8;
uh->uh_sport = htons(np->in_spnext);
uh->uh_dport = htons(np->in_dpnext);
}
return 0;
}
#define MINDECAP (sizeof(ip6_t) + sizeof(udphdr_t) + sizeof(ip6_t))
/* ------------------------------------------------------------------------ */
/* Function: nat6_decap */
/* Returns: int - -1 == error, 0 == success */
/* Parameters: fin(I) - pointer to packet information */
/* nat(I) - pointer to current NAT session */
/* */
/* This function is responsible for undoing a packet's encapsulation in the */
/* reverse of an encap/divert rule. After removing the outer encapsulation */
/* it is necessary to call ipf_makefrip() again so that the contents of 'fin'*/
/* match the "new" packet as it may still be used by IPFilter elsewhere. */
/* We use "dir" here as the basis for some of the expectations about the */
/* outer header. If we return an error, the goal is to leave the original */
/* packet information undisturbed - this falls short at the end where we'd */
/* need to back a backup copy of "fin" - expensive. */
/* ------------------------------------------------------------------------ */
static int
ipf_nat6_decap(fr_info_t *fin, nat_t *nat)
{
ipf_main_softc_t *softc = fin->fin_main_soft;
ipf_nat_softc_t *softn = softc->ipf_nat_soft;
char *hdr;
int skip;
mb_t *m;
if ((fin->fin_flx & FI_ICMPERR) != 0) {
return 0;
}
m = fin->fin_m;
skip = fin->fin_hlen;
switch (nat->nat_dir)
{
case NAT_DIVERTIN :
case NAT_DIVERTOUT :
if (fin->fin_plen < MINDECAP)
return -1;
skip += sizeof(udphdr_t);
break;
case NAT_ENCAPIN :
case NAT_ENCAPOUT :
if (fin->fin_plen < (skip + sizeof(ip6_t)))
return -1;
break;
default :
return -1;
/* NOTREACHED */
}
/*
* The aim here is to keep the original packet details in "fin" for
* as long as possible so that returning with an error is for the
* original packet and there is little undoing work to do.
*/
if (M_LEN(m) < skip + sizeof(ip6_t)) {
if (ipf_pr_pullup(fin, skip + sizeof(ip6_t)) == -1)
return -1;
}
hdr = MTOD(fin->fin_m, char *);
fin->fin_ip6 = (ip6_t *)(hdr + skip);
if (ipf_pr_pullup(fin, skip + sizeof(ip6_t)) == -1) {
NBUMPSIDE6D(fin->fin_out, ns_decap_pullup);
return -1;
}
fin->fin_hlen = sizeof(ip6_t);
fin->fin_dlen -= skip;
fin->fin_plen -= skip;
fin->fin_ipoff += skip;
if (ipf_makefrip(sizeof(ip6_t), (ip_t *)hdr, fin) == -1) {
NBUMPSIDE6D(fin->fin_out, ns_decap_bad);
return -1;
}
return skip;
}
/* ------------------------------------------------------------------------ */
/* Function: nat6_nextaddr */
/* Returns: int - -1 == bad input (no new address), */
/* 0 == success and dst has new address */
/* Parameters: fin(I) - pointer to packet information */
/* na(I) - how to generate new address */
/* old(I) - original address being replaced */
/* dst(O) - where to put the new address */
/* Write Lock: ipf_nat */
/* */
/* This function uses the contents of the "na" structure, in combination */
/* with "old" to produce a new address to store in "dst". Not all of the */
/* possible uses of "na" will result in a new address. */
/* ------------------------------------------------------------------------ */
static int
ipf_nat6_nextaddr(fr_info_t *fin, nat_addr_t *na, i6addr_t *old, i6addr_t *dst)
{
ipf_main_softc_t *softc = fin->fin_main_soft;
ipf_nat_softc_t *softn = softc->ipf_nat_soft;
i6addr_t newip, new;
u_32_t amin, amax;
int error;
new.i6[0] = 0;
new.i6[1] = 0;
new.i6[2] = 0;
new.i6[3] = 0;
amin = na->na_addr[0].in4.s_addr;
switch (na->na_atype)
{
case FRI_RANGE :
amax = na->na_addr[1].in4.s_addr;
break;
case FRI_NETMASKED :
case FRI_DYNAMIC :
case FRI_NORMAL :
/*
* Compute the maximum address by adding the inverse of the
* netmask to the minimum address.
*/
amax = ~na->na_addr[1].in4.s_addr;
amax |= amin;
break;
case FRI_LOOKUP :
break;
case FRI_BROADCAST :
case FRI_PEERADDR :
case FRI_NETWORK :
default :
return -1;
}
error = -1;
switch (na->na_function)
{
case IPLT_DSTLIST :
error = ipf_dstlist_select_node(fin, na->na_ptr, dst->i6,
NULL);
break;
case IPLT_NONE :
/*
* 0/0 as the new address means leave it alone.
*/
if (na->na_addr[0].in4.s_addr == 0 &&
na->na_addr[1].in4.s_addr == 0) {
new = *old;
/*
* 0/32 means get the interface's address
*/
} else if (IP6_ISZERO(&na->na_addr[0].in6) &&
IP6_ISONES(&na->na_addr[1].in6)) {
if (ipf_ifpaddr(softc, 6, na->na_atype,
fin->fin_ifp, &newip, NULL) == -1) {
NBUMPSIDE6(fin->fin_out, ns_ifpaddrfail);
return -1;
}
new = newip;
} else {
new.in6 = na->na_nextip6;
}
*dst = new;
error = 0;
break;
default :
NBUMPSIDE6(fin->fin_out, ns_badnextaddr);
break;
}
return error;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_nextaddrinit */
/* Returns: int - 0 == success, else error number */
/* Parameters: na(I) - NAT address information for generating new addr*/
/* base(I) - start of where to find strings */
/* initial(I) - flag indicating if it is the first call for */
/* this "na" structure. */
/* ifp(I) - network interface to derive address */
/* information from. */
/* */
/* This function is expected to be called in two scenarious: when a new NAT */
/* rule is loaded into the kernel and when the list of NAT rules is sync'd */
/* up with the valid network interfaces (possibly due to them changing.) */
/* To distinguish between these, the "initial" parameter is used. If it is */
/* 1 then this indicates the rule has just been reloaded and 0 for when we */
/* are updating information. This difference is important because in */
/* instances where we are not updating address information associated with */
/* a network interface, we don't want to disturb what the "next" address to */
/* come out of ipf_nat6_nextaddr() will be. */
/* ------------------------------------------------------------------------ */
static int
ipf_nat6_nextaddrinit(ipf_main_softc_t *softc, char *base, nat_addr_t *na,
int initial, void *ifp)
{
switch (na->na_atype)
{
case FRI_LOOKUP :
if (na->na_subtype == 0) {
na->na_ptr = ipf_lookup_res_num(softc, IPL_LOGNAT,
na->na_type,
na->na_num,
&na->na_func);
} else if (na->na_subtype == 1) {
na->na_ptr = ipf_lookup_res_name(softc, IPL_LOGNAT,
na->na_type,
base + na->na_num,
&na->na_func);
}
if (na->na_func == NULL) {
IPFERROR(60072);
return ESRCH;
}
if (na->na_ptr == NULL) {
IPFERROR(60073);
return ESRCH;
}
break;
case FRI_DYNAMIC :
case FRI_BROADCAST :
case FRI_NETWORK :
case FRI_NETMASKED :
case FRI_PEERADDR :
if (ifp != NULL)
(void )ipf_ifpaddr(softc, 6, na->na_atype, ifp,
&na->na_addr[0],
&na->na_addr[1]);
break;
case FRI_SPLIT :
case FRI_RANGE :
if (initial)
na->na_nextip6 = na->na_addr[0].in6;
break;
case FRI_NONE :
IP6_ANDASSIGN(&na->na_addr[0].in6, &na->na_addr[1].in6);
return 0;
case FRI_NORMAL :
IP6_ANDASSIGN(&na->na_addr[0].in6, &na->na_addr[1].in6);
break;
default :
IPFERROR(60074);
return EINVAL;
}
if (initial && (na->na_atype == FRI_NORMAL)) {
if (IP6_ISZERO(&na->na_addr[0].in6)) {
if (IP6_ISONES(&na->na_addr[1].in6) ||
IP6_ISZERO(&na->na_addr[1].in6)) {
return 0;
}
}
na->na_nextip6 = na->na_addr[0].in6;
if (!IP6_ISONES(&na->na_addr[1].in6)) {
IP6_INC(&na->na_nextip6);
}
}
return 0;
}
/* ------------------------------------------------------------------------ */
/* Function: ipf_nat6_icmpquerytype */
/* Returns: int - 1 == success, 0 == failure */
/* Parameters: icmptype(I) - ICMP type number */
/* */
/* Tests to see if the ICMP type number passed is a query/response type or */
/* not. */
/* ------------------------------------------------------------------------ */
static int
ipf_nat6_icmpquerytype(int icmptype)
{
/*
* For the ICMP query NAT code, it is essential that both the query
* and the reply match on the NAT rule. Because the NAT structure
* does not keep track of the icmptype, and a single NAT structure
* is used for all icmp types with the same src, dest and id, we
* simply define the replies as queries as well. The funny thing is,
* altough it seems silly to call a reply a query, this is exactly
* as it is defined in the IPv4 specification
*/
switch (icmptype)
{
case ICMP6_ECHO_REPLY:
case ICMP6_ECHO_REQUEST:
/* route aedvertisement/solliciation is currently unsupported: */
/* it would require rewriting the ICMP data section */
case ICMP6_MEMBERSHIP_QUERY:
case ICMP6_MEMBERSHIP_REPORT:
case ICMP6_MEMBERSHIP_REDUCTION:
case ICMP6_WRUREQUEST:
case ICMP6_WRUREPLY:
case MLD6_MTRACE_RESP:
case MLD6_MTRACE:
return 1;
default:
return 0;
}
}
#endif /* USE_INET6 */