freebsd-dev/sbin/ipfw/nat64stl.c
Andrey V. Elsukov 2403d47744 Fix SIGSEGV in ipfw(8) when NAT64 prefix length is omitted.
Submitted by:	Evgeniy Khramtsov <evgeniy at khramtsov org>
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D25734
2020-08-05 11:26:49 +00:00

557 lines
14 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2015-2019 Yandex LLC
* Copyright (c) 2015-2019 Andrey V. Elsukov <ae@FreeBSD.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/socket.h>
#include "ipfw2.h"
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <inttypes.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/ip_fw.h>
#include <netinet6/ip_fw_nat64.h>
#include <arpa/inet.h>
typedef int (nat64stl_cb_t)(ipfw_nat64stl_cfg *i, const char *name,
uint8_t set);
static int nat64stl_foreach(nat64stl_cb_t *f, const char *name, uint8_t set,
int sort);
static void nat64stl_create(const char *name, uint8_t set, int ac, char **av);
static void nat64stl_config(const char *name, uint8_t set, int ac, char **av);
static void nat64stl_destroy(const char *name, uint8_t set);
static void nat64stl_stats(const char *name, uint8_t set);
static void nat64stl_reset_stats(const char *name, uint8_t set);
static int nat64stl_show_cb(ipfw_nat64stl_cfg *cfg, const char *name,
uint8_t set);
static int nat64stl_destroy_cb(ipfw_nat64stl_cfg *cfg, const char *name,
uint8_t set);
static struct _s_x nat64cmds[] = {
{ "create", TOK_CREATE },
{ "config", TOK_CONFIG },
{ "destroy", TOK_DESTROY },
{ "list", TOK_LIST },
{ "show", TOK_LIST },
{ "stats", TOK_STATS },
{ NULL, 0 }
};
#define IPV6_ADDR_INT32_WKPFX htonl(0x64ff9b)
#define IN6_IS_ADDR_WKPFX(a) \
((a)->__u6_addr.__u6_addr32[0] == IPV6_ADDR_INT32_WKPFX && \
(a)->__u6_addr.__u6_addr32[1] == 0 && \
(a)->__u6_addr.__u6_addr32[2] == 0)
int
ipfw_check_nat64prefix(const struct in6_addr *prefix, int length)
{
switch (length) {
case 32:
case 40:
case 48:
case 56:
case 64:
/* Well-known prefix has 96 prefix length */
if (IN6_IS_ADDR_WKPFX(prefix))
return (EINVAL);
/* FALLTHROUGH */
case 96:
/* Bits 64 to 71 must be set to zero */
if (prefix->__u6_addr.__u6_addr8[8] != 0)
return (EINVAL);
/* XXX: looks incorrect */
if (IN6_IS_ADDR_MULTICAST(prefix) ||
IN6_IS_ADDR_UNSPECIFIED(prefix) ||
IN6_IS_ADDR_LOOPBACK(prefix))
return (EINVAL);
return (0);
}
return (EINVAL);
}
static struct _s_x nat64statscmds[] = {
{ "reset", TOK_RESET },
{ NULL, 0 }
};
/*
* This one handles all nat64stl-related commands
* ipfw [set N] nat64stl NAME {create | config} ...
* ipfw [set N] nat64stl NAME stats [reset]
* ipfw [set N] nat64stl {NAME | all} destroy
* ipfw [set N] nat64stl {NAME | all} {list | show}
*/
#define nat64stl_check_name table_check_name
void
ipfw_nat64stl_handler(int ac, char *av[])
{
const char *name;
int tcmd;
uint8_t set;
if (g_co.use_set != 0)
set = g_co.use_set - 1;
else
set = 0;
ac--; av++;
NEED1("nat64stl needs instance name");
name = *av;
if (nat64stl_check_name(name) != 0) {
if (strcmp(name, "all") == 0)
name = NULL;
else
errx(EX_USAGE, "nat64stl instance name %s is invalid",
name);
}
ac--; av++;
NEED1("nat64stl needs command");
tcmd = get_token(nat64cmds, *av, "nat64stl command");
if (name == NULL && tcmd != TOK_DESTROY && tcmd != TOK_LIST)
errx(EX_USAGE, "nat64stl instance name required");
switch (tcmd) {
case TOK_CREATE:
ac--; av++;
nat64stl_create(name, set, ac, av);
break;
case TOK_CONFIG:
ac--; av++;
nat64stl_config(name, set, ac, av);
break;
case TOK_LIST:
nat64stl_foreach(nat64stl_show_cb, name, set, 1);
break;
case TOK_DESTROY:
if (name == NULL)
nat64stl_foreach(nat64stl_destroy_cb, NULL, set, 0);
else
nat64stl_destroy(name, set);
break;
case TOK_STATS:
ac--; av++;
if (ac == 0) {
nat64stl_stats(name, set);
break;
}
tcmd = get_token(nat64statscmds, *av, "stats command");
if (tcmd == TOK_RESET)
nat64stl_reset_stats(name, set);
}
}
static void
nat64stl_fill_ntlv(ipfw_obj_ntlv *ntlv, const char *name, uint8_t set)
{
ntlv->head.type = IPFW_TLV_EACTION_NAME(1); /* it doesn't matter */
ntlv->head.length = sizeof(ipfw_obj_ntlv);
ntlv->idx = 1;
ntlv->set = set;
strlcpy(ntlv->name, name, sizeof(ntlv->name));
}
static struct _s_x nat64newcmds[] = {
{ "table4", TOK_TABLE4 },
{ "table6", TOK_TABLE6 },
{ "prefix6", TOK_PREFIX6 },
{ "log", TOK_LOG },
{ "-log", TOK_LOGOFF },
{ "allow_private", TOK_PRIVATE },
{ "-allow_private", TOK_PRIVATEOFF },
{ NULL, 0 }
};
/*
* Creates new nat64stl instance
* ipfw nat64stl <NAME> create table4 <name> table6 <name> [ prefix6 <prefix>]
* Request: [ ipfw_obj_lheader ipfw_nat64stl_cfg ]
*/
#define NAT64STL_HAS_TABLE4 0x01
#define NAT64STL_HAS_TABLE6 0x02
#define NAT64STL_HAS_PREFIX6 0x04
static void
nat64stl_create(const char *name, uint8_t set, int ac, char *av[])
{
char buf[sizeof(ipfw_obj_lheader) + sizeof(ipfw_nat64stl_cfg)];
ipfw_nat64stl_cfg *cfg;
ipfw_obj_lheader *olh;
int tcmd, flags;
char *p;
memset(buf, 0, sizeof(buf));
olh = (ipfw_obj_lheader *)buf;
cfg = (ipfw_nat64stl_cfg *)(olh + 1);
/* Some reasonable defaults */
inet_pton(AF_INET6, "64:ff9b::", &cfg->prefix6);
cfg->plen6 = 96;
cfg->set = set;
flags = NAT64STL_HAS_PREFIX6;
while (ac > 0) {
tcmd = get_token(nat64newcmds, *av, "option");
ac--; av++;
switch (tcmd) {
case TOK_TABLE4:
NEED1("table name required");
table_fill_ntlv(&cfg->ntlv4, *av, set, 4);
flags |= NAT64STL_HAS_TABLE4;
ac--; av++;
break;
case TOK_TABLE6:
NEED1("table name required");
table_fill_ntlv(&cfg->ntlv6, *av, set, 6);
flags |= NAT64STL_HAS_TABLE6;
ac--; av++;
break;
case TOK_PREFIX6:
NEED1("IPv6 prefix6 required");
if ((p = strchr(*av, '/')) != NULL)
*p++ = '\0';
else
errx(EX_USAGE,
"Prefix length required: %s", *av);
if (inet_pton(AF_INET6, *av, &cfg->prefix6) != 1)
errx(EX_USAGE,
"Bad prefix: %s", *av);
cfg->plen6 = strtol(p, NULL, 10);
if (ipfw_check_nat64prefix(&cfg->prefix6,
cfg->plen6) != 0)
errx(EX_USAGE,
"Bad prefix length: %s", p);
flags |= NAT64STL_HAS_PREFIX6;
ac--; av++;
break;
case TOK_LOG:
cfg->flags |= NAT64_LOG;
break;
case TOK_LOGOFF:
cfg->flags &= ~NAT64_LOG;
break;
case TOK_PRIVATE:
cfg->flags |= NAT64_ALLOW_PRIVATE;
break;
case TOK_PRIVATEOFF:
cfg->flags &= ~NAT64_ALLOW_PRIVATE;
break;
}
}
/* Check validness */
if ((flags & NAT64STL_HAS_TABLE4) != NAT64STL_HAS_TABLE4)
errx(EX_USAGE, "table4 required");
if ((flags & NAT64STL_HAS_TABLE6) != NAT64STL_HAS_TABLE6)
errx(EX_USAGE, "table6 required");
if ((flags & NAT64STL_HAS_PREFIX6) != NAT64STL_HAS_PREFIX6)
errx(EX_USAGE, "prefix6 required");
olh->count = 1;
olh->objsize = sizeof(*cfg);
olh->size = sizeof(buf);
strlcpy(cfg->name, name, sizeof(cfg->name));
if (do_set3(IP_FW_NAT64STL_CREATE, &olh->opheader, sizeof(buf)) != 0)
err(EX_OSERR, "nat64stl instance creation failed");
}
/*
* Configures existing nat64stl instance
* ipfw nat64stl <NAME> config <options>
* Request: [ ipfw_obj_header ipfw_nat64stl_cfg ]
*/
static void
nat64stl_config(const char *name, uint8_t set, int ac, char **av)
{
char buf[sizeof(ipfw_obj_header) + sizeof(ipfw_nat64stl_cfg)];
ipfw_nat64stl_cfg *cfg;
ipfw_obj_header *oh;
char *opt;
size_t sz;
int tcmd;
if (ac == 0)
errx(EX_USAGE, "config options required");
memset(&buf, 0, sizeof(buf));
oh = (ipfw_obj_header *)buf;
cfg = (ipfw_nat64stl_cfg *)(oh + 1);
sz = sizeof(buf);
nat64stl_fill_ntlv(&oh->ntlv, name, set);
if (do_get3(IP_FW_NAT64STL_CONFIG, &oh->opheader, &sz) != 0)
err(EX_OSERR, "failed to get config for instance %s", name);
while (ac > 0) {
tcmd = get_token(nat64newcmds, *av, "option");
opt = *av;
ac--; av++;
switch (tcmd) {
#if 0
case TOK_TABLE4:
NEED1("table name required");
table_fill_ntlv(&cfg->ntlv4, *av, set, 4);
ac--; av++;
break;
case TOK_TABLE6:
NEED1("table name required");
table_fill_ntlv(&cfg->ntlv6, *av, set, 6);
ac--; av++;
break;
#endif
case TOK_LOG:
cfg->flags |= NAT64_LOG;
break;
case TOK_LOGOFF:
cfg->flags &= ~NAT64_LOG;
break;
case TOK_PRIVATE:
cfg->flags |= NAT64_ALLOW_PRIVATE;
break;
case TOK_PRIVATEOFF:
cfg->flags &= ~NAT64_ALLOW_PRIVATE;
break;
default:
errx(EX_USAGE, "Can't change %s option", opt);
}
}
if (do_set3(IP_FW_NAT64STL_CONFIG, &oh->opheader, sizeof(buf)) != 0)
err(EX_OSERR, "nat64stl instance configuration failed");
}
/*
* Destroys nat64stl instance.
* Request: [ ipfw_obj_header ]
*/
static void
nat64stl_destroy(const char *name, uint8_t set)
{
ipfw_obj_header oh;
memset(&oh, 0, sizeof(oh));
nat64stl_fill_ntlv(&oh.ntlv, name, set);
if (do_set3(IP_FW_NAT64STL_DESTROY, &oh.opheader, sizeof(oh)) != 0)
err(EX_OSERR, "failed to destroy nat instance %s", name);
}
/*
* Get nat64stl instance statistics.
* Request: [ ipfw_obj_header ]
* Reply: [ ipfw_obj_header ipfw_obj_ctlv [ uint64_t x N ] ]
*/
static int
nat64stl_get_stats(const char *name, uint8_t set,
struct ipfw_nat64stl_stats *stats)
{
ipfw_obj_header *oh;
ipfw_obj_ctlv *oc;
size_t sz;
sz = sizeof(*oh) + sizeof(*oc) + sizeof(*stats);
oh = calloc(1, sz);
nat64stl_fill_ntlv(&oh->ntlv, name, set);
if (do_get3(IP_FW_NAT64STL_STATS, &oh->opheader, &sz) == 0) {
oc = (ipfw_obj_ctlv *)(oh + 1);
memcpy(stats, oc + 1, sizeof(*stats));
free(oh);
return (0);
}
free(oh);
return (-1);
}
static void
nat64stl_stats(const char *name, uint8_t set)
{
struct ipfw_nat64stl_stats stats;
if (nat64stl_get_stats(name, set, &stats) != 0)
err(EX_OSERR, "Error retrieving stats");
if (g_co.use_set != 0 || set != 0)
printf("set %u ", set);
printf("nat64stl %s\n", name);
printf("\t%ju packets translated from IPv6 to IPv4\n",
(uintmax_t)stats.opcnt64);
printf("\t%ju packets translated from IPv4 to IPv6\n",
(uintmax_t)stats.opcnt46);
printf("\t%ju IPv6 fragments created\n",
(uintmax_t)stats.ofrags);
printf("\t%ju IPv4 fragments received\n",
(uintmax_t)stats.ifrags);
printf("\t%ju output packets dropped due to no bufs, etc.\n",
(uintmax_t)stats.oerrors);
printf("\t%ju output packets discarded due to no IPv4 route\n",
(uintmax_t)stats.noroute4);
printf("\t%ju output packets discarded due to no IPv6 route\n",
(uintmax_t)stats.noroute6);
printf("\t%ju packets discarded due to unsupported protocol\n",
(uintmax_t)stats.noproto);
printf("\t%ju packets discarded due to memory allocation problems\n",
(uintmax_t)stats.nomem);
printf("\t%ju packets discarded due to some errors\n",
(uintmax_t)stats.dropped);
}
/*
* Reset nat64stl instance statistics specified by @oh->ntlv.
* Request: [ ipfw_obj_header ]
*/
static void
nat64stl_reset_stats(const char *name, uint8_t set)
{
ipfw_obj_header oh;
memset(&oh, 0, sizeof(oh));
nat64stl_fill_ntlv(&oh.ntlv, name, set);
if (do_set3(IP_FW_NAT64STL_RESET_STATS, &oh.opheader, sizeof(oh)) != 0)
err(EX_OSERR, "failed to reset stats for instance %s", name);
}
static int
nat64stl_show_cb(ipfw_nat64stl_cfg *cfg, const char *name, uint8_t set)
{
char abuf[INET6_ADDRSTRLEN];
if (name != NULL && strcmp(cfg->name, name) != 0)
return (ESRCH);
if (g_co.use_set != 0 && cfg->set != set)
return (ESRCH);
if (g_co.use_set != 0 || cfg->set != 0)
printf("set %u ", cfg->set);
printf("nat64stl %s table4 %s table6 %s",
cfg->name, cfg->ntlv4.name, cfg->ntlv6.name);
inet_ntop(AF_INET6, &cfg->prefix6, abuf, sizeof(abuf));
printf(" prefix6 %s/%u", abuf, cfg->plen6);
if (cfg->flags & NAT64_LOG)
printf(" log");
if (cfg->flags & NAT64_ALLOW_PRIVATE)
printf(" allow_private");
printf("\n");
return (0);
}
static int
nat64stl_destroy_cb(ipfw_nat64stl_cfg *cfg, const char *name __unused,
uint8_t set)
{
if (g_co.use_set != 0 && cfg->set != set)
return (ESRCH);
nat64stl_destroy(cfg->name, cfg->set);
return (0);
}
/*
* Compare nat64stl instances names.
* Honor number comparison.
*/
static int
nat64name_cmp(const void *a, const void *b)
{
const ipfw_nat64stl_cfg *ca, *cb;
ca = (const ipfw_nat64stl_cfg *)a;
cb = (const ipfw_nat64stl_cfg *)b;
if (ca->set > cb->set)
return (1);
else if (ca->set < cb->set)
return (-1);
return (stringnum_cmp(ca->name, cb->name));
}
/*
* Retrieves nat64stl instance list from kernel,
* optionally sorts it and calls requested function for each instance.
*
* Request: [ ipfw_obj_lheader ]
* Reply: [ ipfw_obj_lheader ipfw_nat64stl_cfg x N ]
*/
static int
nat64stl_foreach(nat64stl_cb_t *f, const char *name, uint8_t set, int sort)
{
ipfw_obj_lheader *olh;
ipfw_nat64stl_cfg *cfg;
size_t sz;
uint32_t i;
int error;
/* Start with reasonable default */
sz = sizeof(*olh) + 16 * sizeof(*cfg);
for (;;) {
if ((olh = calloc(1, sz)) == NULL)
return (ENOMEM);
olh->size = sz;
if (do_get3(IP_FW_NAT64STL_LIST, &olh->opheader, &sz) != 0) {
sz = olh->size;
free(olh);
if (errno != ENOMEM)
return (errno);
continue;
}
if (sort != 0)
qsort(olh + 1, olh->count, olh->objsize,
nat64name_cmp);
cfg = (ipfw_nat64stl_cfg *)(olh + 1);
for (i = 0; i < olh->count; i++) {
error = f(cfg, name, set); /* Ignore errors for now */
cfg = (ipfw_nat64stl_cfg *)((caddr_t)cfg +
olh->objsize);
}
free(olh);
break;
}
return (0);
}