Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 | /*
* iptables module to match inet_addr_type() of an ip.
*
* Copyright (c) 2004 Patrick McHardy <kaber@trash.net>
* (C) 2007 Laszlo Attila Toth <panther@balabit.hu>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/ip.h>
#include <net/route.h>
#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
#include <net/ipv6.h>
#include <net/ip6_route.h>
#include <net/ip6_fib.h>
#endif
#include <linux/netfilter_ipv6.h>
#include <linux/netfilter/xt_addrtype.h>
#include <linux/netfilter/x_tables.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_DESCRIPTION("Xtables: address type match");
MODULE_ALIAS("ipt_addrtype");
MODULE_ALIAS("ip6t_addrtype");
#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
static u32 match_lookup_rt6(struct net *net, const struct net_device *dev,
const struct in6_addr *addr, u16 mask)
{
const struct nf_afinfo *afinfo;
struct flowi6 flow;
struct rt6_info *rt;
u32 ret = 0;
int route_err;
memset(&flow, 0, sizeof(flow));
flow.daddr = *addr;
if (dev)
flow.flowi6_oif = dev->ifindex;
rcu_read_lock();
afinfo = nf_get_afinfo(NFPROTO_IPV6);
if (afinfo != NULL) {
const struct nf_ipv6_ops *v6ops;
if (dev && (mask & XT_ADDRTYPE_LOCAL)) {
v6ops = nf_get_ipv6_ops();
if (v6ops && v6ops->chk_addr(net, addr, dev, true))
ret = XT_ADDRTYPE_LOCAL;
}
route_err = afinfo->route(net, (struct dst_entry **)&rt,
flowi6_to_flowi(&flow), false);
} else {
route_err = 1;
}
rcu_read_unlock();
if (route_err)
return XT_ADDRTYPE_UNREACHABLE;
if (rt->rt6i_flags & RTF_REJECT)
ret = XT_ADDRTYPE_UNREACHABLE;
if (dev == NULL && rt->rt6i_flags & RTF_LOCAL)
ret |= XT_ADDRTYPE_LOCAL;
if (ipv6_anycast_destination((struct dst_entry *)rt, addr))
ret |= XT_ADDRTYPE_ANYCAST;
dst_release(&rt->dst);
return ret;
}
static bool match_type6(struct net *net, const struct net_device *dev,
const struct in6_addr *addr, u16 mask)
{
int addr_type = ipv6_addr_type(addr);
if ((mask & XT_ADDRTYPE_MULTICAST) &&
!(addr_type & IPV6_ADDR_MULTICAST))
return false;
if ((mask & XT_ADDRTYPE_UNICAST) && !(addr_type & IPV6_ADDR_UNICAST))
return false;
if ((mask & XT_ADDRTYPE_UNSPEC) && addr_type != IPV6_ADDR_ANY)
return false;
if ((XT_ADDRTYPE_LOCAL | XT_ADDRTYPE_ANYCAST |
XT_ADDRTYPE_UNREACHABLE) & mask)
return !!(mask & match_lookup_rt6(net, dev, addr, mask));
return true;
}
static bool
addrtype_mt6(struct net *net, const struct net_device *dev,
const struct sk_buff *skb, const struct xt_addrtype_info_v1 *info)
{
const struct ipv6hdr *iph = ipv6_hdr(skb);
bool ret = true;
if (info->source)
ret &= match_type6(net, dev, &iph->saddr, info->source) ^
(info->flags & XT_ADDRTYPE_INVERT_SOURCE);
if (ret && info->dest)
ret &= match_type6(net, dev, &iph->daddr, info->dest) ^
!!(info->flags & XT_ADDRTYPE_INVERT_DEST);
return ret;
}
#endif
static inline bool match_type(struct net *net, const struct net_device *dev,
__be32 addr, u_int16_t mask)
{
return !!(mask & (1 << inet_dev_addr_type(net, dev, addr)));
}
static bool
addrtype_mt_v0(const struct sk_buff *skb, struct xt_action_param *par)
{
struct net *net = par->net;
const struct xt_addrtype_info *info = par->matchinfo;
const struct iphdr *iph = ip_hdr(skb);
bool ret = true;
if (info->source)
ret &= match_type(net, NULL, iph->saddr, info->source) ^
info->invert_source;
if (info->dest)
ret &= match_type(net, NULL, iph->daddr, info->dest) ^
info->invert_dest;
return ret;
}
static bool
addrtype_mt_v1(const struct sk_buff *skb, struct xt_action_param *par)
{
struct net *net = par->net;
const struct xt_addrtype_info_v1 *info = par->matchinfo;
const struct iphdr *iph;
const struct net_device *dev = NULL;
bool ret = true;
if (info->flags & XT_ADDRTYPE_LIMIT_IFACE_IN)
dev = par->in;
else if (info->flags & XT_ADDRTYPE_LIMIT_IFACE_OUT)
dev = par->out;
#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
if (par->family == NFPROTO_IPV6)
return addrtype_mt6(net, dev, skb, info);
#endif
iph = ip_hdr(skb);
if (info->source)
ret &= match_type(net, dev, iph->saddr, info->source) ^
(info->flags & XT_ADDRTYPE_INVERT_SOURCE);
if (ret && info->dest)
ret &= match_type(net, dev, iph->daddr, info->dest) ^
!!(info->flags & XT_ADDRTYPE_INVERT_DEST);
return ret;
}
static int addrtype_mt_checkentry_v1(const struct xt_mtchk_param *par)
{
struct xt_addrtype_info_v1 *info = par->matchinfo;
if (info->flags & XT_ADDRTYPE_LIMIT_IFACE_IN &&
info->flags & XT_ADDRTYPE_LIMIT_IFACE_OUT) {
pr_info("both incoming and outgoing "
"interface limitation cannot be selected\n");
return -EINVAL;
}
if (par->hook_mask & ((1 << NF_INET_PRE_ROUTING) |
(1 << NF_INET_LOCAL_IN)) &&
info->flags & XT_ADDRTYPE_LIMIT_IFACE_OUT) {
pr_info("output interface limitation "
"not valid in PREROUTING and INPUT\n");
return -EINVAL;
}
if (par->hook_mask & ((1 << NF_INET_POST_ROUTING) |
(1 << NF_INET_LOCAL_OUT)) &&
info->flags & XT_ADDRTYPE_LIMIT_IFACE_IN) {
pr_info("input interface limitation "
"not valid in POSTROUTING and OUTPUT\n");
return -EINVAL;
}
#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
if (par->family == NFPROTO_IPV6) {
if ((info->source | info->dest) & XT_ADDRTYPE_BLACKHOLE) {
pr_err("ipv6 BLACKHOLE matching not supported\n");
return -EINVAL;
}
if ((info->source | info->dest) >= XT_ADDRTYPE_PROHIBIT) {
pr_err("ipv6 PROHIBIT (THROW, NAT ..) matching not supported\n");
return -EINVAL;
}
if ((info->source | info->dest) & XT_ADDRTYPE_BROADCAST) {
pr_err("ipv6 does not support BROADCAST matching\n");
return -EINVAL;
}
}
#endif
return 0;
}
static struct xt_match addrtype_mt_reg[] __read_mostly = {
{
.name = "addrtype",
.family = NFPROTO_IPV4,
.match = addrtype_mt_v0,
.matchsize = sizeof(struct xt_addrtype_info),
.me = THIS_MODULE
},
{
.name = "addrtype",
.family = NFPROTO_UNSPEC,
.revision = 1,
.match = addrtype_mt_v1,
.checkentry = addrtype_mt_checkentry_v1,
.matchsize = sizeof(struct xt_addrtype_info_v1),
.me = THIS_MODULE
}
};
static int __init addrtype_mt_init(void)
{
return xt_register_matches(addrtype_mt_reg,
ARRAY_SIZE(addrtype_mt_reg));
}
static void __exit addrtype_mt_exit(void)
{
xt_unregister_matches(addrtype_mt_reg, ARRAY_SIZE(addrtype_mt_reg));
}
module_init(addrtype_mt_init);
module_exit(addrtype_mt_exit);
|