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Date: Tue, 15 Mar 2011 20:44:17 +0100
From: kaber@...sh.net
To: davem@...emloft.net
Cc: netfilter-devel@...r.kernel.org, netdev@...r.kernel.org
Subject: [PATCH 37/37] netfilter: xt_addrtype: ipv6 support
From: Florian Westphal <fwestphal@...aro.com>
The kernel will refuse certain types that do not work in ipv6 mode.
We can then add these features incrementally without risk of userspace
breakage.
Signed-off-by: Florian Westphal <fwestphal@...aro.com>
Signed-off-by: Patrick McHardy <kaber@...sh.net>
---
include/linux/netfilter/xt_addrtype.h | 17 ++++++
net/netfilter/Kconfig | 1 +
net/netfilter/xt_addrtype.c | 98 ++++++++++++++++++++++++++++++++-
3 files changed, 114 insertions(+), 2 deletions(-)
diff --git a/include/linux/netfilter/xt_addrtype.h b/include/linux/netfilter/xt_addrtype.h
index b492fc8..b156baa 100644
--- a/include/linux/netfilter/xt_addrtype.h
+++ b/include/linux/netfilter/xt_addrtype.h
@@ -10,6 +10,23 @@ enum {
XT_ADDRTYPE_LIMIT_IFACE_OUT = 0x0008,
};
+
+/* rtn_type enum values from rtnetlink.h, but shifted */
+enum {
+ XT_ADDRTYPE_UNSPEC = 1 << 0,
+ XT_ADDRTYPE_UNICAST = 1 << 1, /* 1 << RTN_UNICAST */
+ XT_ADDRTYPE_LOCAL = 1 << 2, /* 1 << RTN_LOCAL, etc */
+ XT_ADDRTYPE_BROADCAST = 1 << 3,
+ XT_ADDRTYPE_ANYCAST = 1 << 4,
+ XT_ADDRTYPE_MULTICAST = 1 << 5,
+ XT_ADDRTYPE_BLACKHOLE = 1 << 6,
+ XT_ADDRTYPE_UNREACHABLE = 1 << 7,
+ XT_ADDRTYPE_PROHIBIT = 1 << 8,
+ XT_ADDRTYPE_THROW = 1 << 9,
+ XT_ADDRTYPE_NAT = 1 << 10,
+ XT_ADDRTYPE_XRESOLVE = 1 << 11,
+};
+
struct xt_addrtype_info_v1 {
__u16 source; /* source-type mask */
__u16 dest; /* dest-type mask */
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 32bff6d..c3f988a 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -652,6 +652,7 @@ comment "Xtables matches"
config NETFILTER_XT_MATCH_ADDRTYPE
tristate '"addrtype" address type match support'
depends on NETFILTER_ADVANCED
+ depends on (IPV6 || IPV6=n)
---help---
This option allows you to match what routing thinks of an address,
eg. UNICAST, LOCAL, BROADCAST, ...
diff --git a/net/netfilter/xt_addrtype.c b/net/netfilter/xt_addrtype.c
index e89c0b8..2220b85 100644
--- a/net/netfilter/xt_addrtype.c
+++ b/net/netfilter/xt_addrtype.c
@@ -16,6 +16,12 @@
#include <linux/ip.h>
#include <net/route.h>
+#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
+#include <net/ipv6.h>
+#include <net/ip6_route.h>
+#include <net/ip6_fib.h>
+#endif
+
#include <linux/netfilter/xt_addrtype.h>
#include <linux/netfilter/x_tables.h>
@@ -23,6 +29,73 @@ MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@...sh.net>");
MODULE_DESCRIPTION("Xtables: address type match");
MODULE_ALIAS("ipt_addrtype");
+MODULE_ALIAS("ip6t_addrtype");
+
+#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
+static u32 xt_addrtype_rt6_to_type(const struct rt6_info *rt)
+{
+ u32 ret;
+
+ if (!rt)
+ return XT_ADDRTYPE_UNREACHABLE;
+
+ if (rt->rt6i_flags & RTF_REJECT)
+ ret = XT_ADDRTYPE_UNREACHABLE;
+ else
+ ret = 0;
+
+ if (rt->rt6i_flags & RTF_LOCAL)
+ ret |= XT_ADDRTYPE_LOCAL;
+ if (rt->rt6i_flags & RTF_ANYCAST)
+ ret |= XT_ADDRTYPE_ANYCAST;
+ 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) {
+ struct rt6_info *rt;
+ u32 type;
+ int ifindex = dev ? dev->ifindex : 0;
+
+ rt = rt6_lookup(net, addr, NULL, ifindex, !!dev);
+
+ type = xt_addrtype_rt6_to_type(rt);
+
+ dst_release(&rt->dst);
+ return !!(mask & type);
+ }
+ 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)
@@ -53,7 +126,7 @@ addrtype_mt_v1(const struct sk_buff *skb, struct xt_action_param *par)
{
struct net *net = dev_net(par->in ? par->in : par->out);
const struct xt_addrtype_info_v1 *info = par->matchinfo;
- const struct iphdr *iph = ip_hdr(skb);
+ const struct iphdr *iph;
const struct net_device *dev = NULL;
bool ret = true;
@@ -62,6 +135,11 @@ addrtype_mt_v1(const struct sk_buff *skb, struct xt_action_param *par)
else if (info->flags & XT_ADDRTYPE_LIMIT_IFACE_OUT)
dev = par->out;
+#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
+ 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);
@@ -98,6 +176,22 @@ static int addrtype_mt_checkentry_v1(const struct xt_mtchk_param *par)
return -EINVAL;
}
+#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
+ 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 PROHIBT (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;
}
@@ -111,7 +205,7 @@ static struct xt_match addrtype_mt_reg[] __read_mostly = {
},
{
.name = "addrtype",
- .family = NFPROTO_IPV4,
+ .family = NFPROTO_UNSPEC,
.revision = 1,
.match = addrtype_mt_v1,
.checkentry = addrtype_mt_checkentry_v1,
--
1.7.2.3
--
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