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Message-Id: <1412356824-6362-2-git-send-email-pablo@netfilter.org>
Date: Fri, 3 Oct 2014 19:20:16 +0200
From: Pablo Neira Ayuso <pablo@...filter.org>
To: netfilter-devel@...r.kernel.org
Cc: davem@...emloft.net, netdev@...r.kernel.org
Subject: [PATCH 1/9] netfilter: nft_reject: introduce icmp code abstraction for inet and bridge
This patch introduces the NFT_REJECT_ICMPX_UNREACH type which provides
an abstraction to the ICMP and ICMPv6 codes that you can use from the
inet and bridge tables, they are:
* NFT_REJECT_ICMPX_NO_ROUTE: no route to host - network unreachable
* NFT_REJECT_ICMPX_PORT_UNREACH: port unreachable
* NFT_REJECT_ICMPX_HOST_UNREACH: host unreachable
* NFT_REJECT_ICMPX_ADMIN_PROHIBITED: administratevely prohibited
You can still use the specific codes when restricting the rule to match
the corresponding layer 3 protocol.
I decided to not overload the existing NFT_REJECT_ICMP_UNREACH to have
different semantics depending on the table family and to allow the user
to specify ICMP family specific codes if they restrict it to the
corresponding family.
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
---
include/net/netfilter/ipv4/nf_reject.h | 1 +
include/net/netfilter/nft_reject.h | 9 +--
include/uapi/linux/netfilter/nf_tables.h | 21 +++++++
net/bridge/netfilter/nft_reject_bridge.c | 95 ++++++++++++++++++++++++++++--
net/ipv4/netfilter/nft_reject_ipv4.c | 1 -
net/netfilter/nft_reject.c | 37 ++++++++++++
net/netfilter/nft_reject_inet.c | 94 +++++++++++++++++++++++++++--
7 files changed, 241 insertions(+), 17 deletions(-)
diff --git a/include/net/netfilter/ipv4/nf_reject.h b/include/net/netfilter/ipv4/nf_reject.h
index f713b5a..8ce0638 100644
--- a/include/net/netfilter/ipv4/nf_reject.h
+++ b/include/net/netfilter/ipv4/nf_reject.h
@@ -5,6 +5,7 @@
#include <net/tcp.h>
#include <net/route.h>
#include <net/dst.h>
+#include <net/icmp.h>
static inline void nf_send_unreach(struct sk_buff *skb_in, int code)
{
diff --git a/include/net/netfilter/nft_reject.h b/include/net/netfilter/nft_reject.h
index 36b0da2..60fa153 100644
--- a/include/net/netfilter/nft_reject.h
+++ b/include/net/netfilter/nft_reject.h
@@ -14,12 +14,7 @@ int nft_reject_init(const struct nft_ctx *ctx,
int nft_reject_dump(struct sk_buff *skb, const struct nft_expr *expr);
-void nft_reject_ipv4_eval(const struct nft_expr *expr,
- struct nft_data data[NFT_REG_MAX + 1],
- const struct nft_pktinfo *pkt);
-
-void nft_reject_ipv6_eval(const struct nft_expr *expr,
- struct nft_data data[NFT_REG_MAX + 1],
- const struct nft_pktinfo *pkt);
+int nft_reject_icmp_code(u8 code);
+int nft_reject_icmpv6_code(u8 code);
#endif
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index b72ccfe..c26df67 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -749,13 +749,34 @@ enum nft_queue_attributes {
*
* @NFT_REJECT_ICMP_UNREACH: reject using ICMP unreachable
* @NFT_REJECT_TCP_RST: reject using TCP RST
+ * @NFT_REJECT_ICMPX_UNREACH: abstracted ICMP unreachable for bridge and inet
*/
enum nft_reject_types {
NFT_REJECT_ICMP_UNREACH,
NFT_REJECT_TCP_RST,
+ NFT_REJECT_ICMPX_UNREACH,
};
/**
+ * enum nft_reject_code - Generic reject codes for IPv4/IPv6
+ *
+ * @NFT_REJECT_ICMPX_NO_ROUTE: no route to host / network unreachable
+ * @NFT_REJECT_ICMPX_PORT_UNREACH: port unreachable
+ * @NFT_REJECT_ICMPX_HOST_UNREACH: host unreachable
+ * @NFT_REJECT_ICMPX_ADMIN_PROHIBITED: administratively prohibited
+ *
+ * These codes are mapped to real ICMP and ICMPv6 codes.
+ */
+enum nft_reject_inet_code {
+ NFT_REJECT_ICMPX_NO_ROUTE = 0,
+ NFT_REJECT_ICMPX_PORT_UNREACH,
+ NFT_REJECT_ICMPX_HOST_UNREACH,
+ NFT_REJECT_ICMPX_ADMIN_PROHIBITED,
+ __NFT_REJECT_ICMPX_MAX
+};
+#define NFT_REJECT_ICMPX_MAX (__NFT_REJECT_ICMPX_MAX + 1)
+
+/**
* enum nft_reject_attributes - nf_tables reject expression netlink attributes
*
* @NFTA_REJECT_TYPE: packet type to use (NLA_U32: nft_reject_types)
diff --git a/net/bridge/netfilter/nft_reject_bridge.c b/net/bridge/netfilter/nft_reject_bridge.c
index ee3ffe9..a764795 100644
--- a/net/bridge/netfilter/nft_reject_bridge.c
+++ b/net/bridge/netfilter/nft_reject_bridge.c
@@ -14,21 +14,106 @@
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nft_reject.h>
+#include <net/netfilter/ipv4/nf_reject.h>
+#include <net/netfilter/ipv6/nf_reject.h>
static void nft_reject_bridge_eval(const struct nft_expr *expr,
struct nft_data data[NFT_REG_MAX + 1],
const struct nft_pktinfo *pkt)
{
+ struct nft_reject *priv = nft_expr_priv(expr);
+ struct net *net = dev_net((pkt->in != NULL) ? pkt->in : pkt->out);
+
switch (eth_hdr(pkt->skb)->h_proto) {
case htons(ETH_P_IP):
- return nft_reject_ipv4_eval(expr, data, pkt);
+ switch (priv->type) {
+ case NFT_REJECT_ICMP_UNREACH:
+ nf_send_unreach(pkt->skb, priv->icmp_code);
+ break;
+ case NFT_REJECT_TCP_RST:
+ nf_send_reset(pkt->skb, pkt->ops->hooknum);
+ break;
+ case NFT_REJECT_ICMPX_UNREACH:
+ nf_send_unreach(pkt->skb,
+ nft_reject_icmp_code(priv->icmp_code));
+ break;
+ }
+ break;
case htons(ETH_P_IPV6):
- return nft_reject_ipv6_eval(expr, data, pkt);
+ switch (priv->type) {
+ case NFT_REJECT_ICMP_UNREACH:
+ nf_send_unreach6(net, pkt->skb, priv->icmp_code,
+ pkt->ops->hooknum);
+ break;
+ case NFT_REJECT_TCP_RST:
+ nf_send_reset6(net, pkt->skb, pkt->ops->hooknum);
+ break;
+ case NFT_REJECT_ICMPX_UNREACH:
+ nf_send_unreach6(net, pkt->skb,
+ nft_reject_icmpv6_code(priv->icmp_code),
+ pkt->ops->hooknum);
+ break;
+ }
+ break;
default:
/* No explicit way to reject this protocol, drop it. */
- data[NFT_REG_VERDICT].verdict = NF_DROP;
break;
}
+ data[NFT_REG_VERDICT].verdict = NF_DROP;
+}
+
+static int nft_reject_bridge_init(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ struct nft_reject *priv = nft_expr_priv(expr);
+ int icmp_code;
+
+ if (tb[NFTA_REJECT_TYPE] == NULL)
+ return -EINVAL;
+
+ priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
+ switch (priv->type) {
+ case NFT_REJECT_ICMP_UNREACH:
+ case NFT_REJECT_ICMPX_UNREACH:
+ if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
+ return -EINVAL;
+
+ icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
+ if (priv->type == NFT_REJECT_ICMPX_UNREACH &&
+ icmp_code > NFT_REJECT_ICMPX_MAX)
+ return -EINVAL;
+
+ priv->icmp_code = icmp_code;
+ break;
+ case NFT_REJECT_TCP_RST:
+ break;
+ default:
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static int nft_reject_bridge_dump(struct sk_buff *skb,
+ const struct nft_expr *expr)
+{
+ const struct nft_reject *priv = nft_expr_priv(expr);
+
+ if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type)))
+ goto nla_put_failure;
+
+ switch (priv->type) {
+ case NFT_REJECT_ICMP_UNREACH:
+ case NFT_REJECT_ICMPX_UNREACH:
+ if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
+ goto nla_put_failure;
+ break;
+ }
+
+ return 0;
+
+nla_put_failure:
+ return -1;
}
static struct nft_expr_type nft_reject_bridge_type;
@@ -36,8 +121,8 @@ static const struct nft_expr_ops nft_reject_bridge_ops = {
.type = &nft_reject_bridge_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_reject)),
.eval = nft_reject_bridge_eval,
- .init = nft_reject_init,
- .dump = nft_reject_dump,
+ .init = nft_reject_bridge_init,
+ .dump = nft_reject_bridge_dump,
};
static struct nft_expr_type nft_reject_bridge_type __read_mostly = {
diff --git a/net/ipv4/netfilter/nft_reject_ipv4.c b/net/ipv4/netfilter/nft_reject_ipv4.c
index e79718a..ed33299 100644
--- a/net/ipv4/netfilter/nft_reject_ipv4.c
+++ b/net/ipv4/netfilter/nft_reject_ipv4.c
@@ -16,7 +16,6 @@
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables.h>
-#include <net/icmp.h>
#include <net/netfilter/ipv4/nf_reject.h>
#include <net/netfilter/nft_reject.h>
diff --git a/net/netfilter/nft_reject.c b/net/netfilter/nft_reject.c
index f3448c2..ec8a456 100644
--- a/net/netfilter/nft_reject.c
+++ b/net/netfilter/nft_reject.c
@@ -17,6 +17,8 @@
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nft_reject.h>
+#include <linux/icmp.h>
+#include <linux/icmpv6.h>
const struct nla_policy nft_reject_policy[NFTA_REJECT_MAX + 1] = {
[NFTA_REJECT_TYPE] = { .type = NLA_U32 },
@@ -70,5 +72,40 @@ nla_put_failure:
}
EXPORT_SYMBOL_GPL(nft_reject_dump);
+static u8 icmp_code_v4[NFT_REJECT_ICMPX_MAX] = {
+ [NFT_REJECT_ICMPX_NO_ROUTE] = ICMP_NET_UNREACH,
+ [NFT_REJECT_ICMPX_PORT_UNREACH] = ICMP_PORT_UNREACH,
+ [NFT_REJECT_ICMPX_HOST_UNREACH] = ICMP_HOST_UNREACH,
+ [NFT_REJECT_ICMPX_ADMIN_PROHIBITED] = ICMP_PKT_FILTERED,
+};
+
+int nft_reject_icmp_code(u8 code)
+{
+ if (code > NFT_REJECT_ICMPX_MAX)
+ return -EINVAL;
+
+ return icmp_code_v4[code];
+}
+
+EXPORT_SYMBOL_GPL(nft_reject_icmp_code);
+
+
+static u8 icmp_code_v6[NFT_REJECT_ICMPX_MAX] = {
+ [NFT_REJECT_ICMPX_NO_ROUTE] = ICMPV6_NOROUTE,
+ [NFT_REJECT_ICMPX_PORT_UNREACH] = ICMPV6_PORT_UNREACH,
+ [NFT_REJECT_ICMPX_HOST_UNREACH] = ICMPV6_ADDR_UNREACH,
+ [NFT_REJECT_ICMPX_ADMIN_PROHIBITED] = ICMPV6_ADM_PROHIBITED,
+};
+
+int nft_reject_icmpv6_code(u8 code)
+{
+ if (code > NFT_REJECT_ICMPX_MAX)
+ return -EINVAL;
+
+ return icmp_code_v6[code];
+}
+
+EXPORT_SYMBOL_GPL(nft_reject_icmpv6_code);
+
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@...sh.net>");
diff --git a/net/netfilter/nft_reject_inet.c b/net/netfilter/nft_reject_inet.c
index b718a52..7b5f9d5 100644
--- a/net/netfilter/nft_reject_inet.c
+++ b/net/netfilter/nft_reject_inet.c
@@ -14,17 +14,103 @@
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nft_reject.h>
+#include <net/netfilter/ipv4/nf_reject.h>
+#include <net/netfilter/ipv6/nf_reject.h>
static void nft_reject_inet_eval(const struct nft_expr *expr,
struct nft_data data[NFT_REG_MAX + 1],
const struct nft_pktinfo *pkt)
{
+ struct nft_reject *priv = nft_expr_priv(expr);
+ struct net *net = dev_net((pkt->in != NULL) ? pkt->in : pkt->out);
+
switch (pkt->ops->pf) {
case NFPROTO_IPV4:
- return nft_reject_ipv4_eval(expr, data, pkt);
+ switch (priv->type) {
+ case NFT_REJECT_ICMP_UNREACH:
+ nf_send_unreach(pkt->skb, priv->icmp_code);
+ break;
+ case NFT_REJECT_TCP_RST:
+ nf_send_reset(pkt->skb, pkt->ops->hooknum);
+ break;
+ case NFT_REJECT_ICMPX_UNREACH:
+ nf_send_unreach(pkt->skb,
+ nft_reject_icmp_code(priv->icmp_code));
+ break;
+ }
+ break;
case NFPROTO_IPV6:
- return nft_reject_ipv6_eval(expr, data, pkt);
+ switch (priv->type) {
+ case NFT_REJECT_ICMP_UNREACH:
+ nf_send_unreach6(net, pkt->skb, priv->icmp_code,
+ pkt->ops->hooknum);
+ break;
+ case NFT_REJECT_TCP_RST:
+ nf_send_reset6(net, pkt->skb, pkt->ops->hooknum);
+ break;
+ case NFT_REJECT_ICMPX_UNREACH:
+ nf_send_unreach6(net, pkt->skb,
+ nft_reject_icmpv6_code(priv->icmp_code),
+ pkt->ops->hooknum);
+ break;
+ }
+ break;
+ }
+ data[NFT_REG_VERDICT].verdict = NF_DROP;
+}
+
+static int nft_reject_inet_init(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ struct nft_reject *priv = nft_expr_priv(expr);
+ int icmp_code;
+
+ if (tb[NFTA_REJECT_TYPE] == NULL)
+ return -EINVAL;
+
+ priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
+ switch (priv->type) {
+ case NFT_REJECT_ICMP_UNREACH:
+ case NFT_REJECT_ICMPX_UNREACH:
+ if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
+ return -EINVAL;
+
+ icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
+ if (priv->type == NFT_REJECT_ICMPX_UNREACH &&
+ icmp_code > NFT_REJECT_ICMPX_MAX)
+ return -EINVAL;
+
+ priv->icmp_code = icmp_code;
+ break;
+ case NFT_REJECT_TCP_RST:
+ break;
+ default:
+ return -EINVAL;
}
+ return 0;
+}
+
+static int nft_reject_inet_dump(struct sk_buff *skb,
+ const struct nft_expr *expr)
+{
+ const struct nft_reject *priv = nft_expr_priv(expr);
+
+ if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type)))
+ goto nla_put_failure;
+
+ switch (priv->type) {
+ case NFT_REJECT_ICMP_UNREACH:
+ case NFT_REJECT_ICMPX_UNREACH:
+ if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
+ goto nla_put_failure;
+ break;
+ }
+
+ return 0;
+
+nla_put_failure:
+ return -1;
}
static struct nft_expr_type nft_reject_inet_type;
@@ -32,8 +118,8 @@ static const struct nft_expr_ops nft_reject_inet_ops = {
.type = &nft_reject_inet_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_reject)),
.eval = nft_reject_inet_eval,
- .init = nft_reject_init,
- .dump = nft_reject_dump,
+ .init = nft_reject_inet_init,
+ .dump = nft_reject_inet_dump,
};
static struct nft_expr_type nft_reject_inet_type __read_mostly = {
--
1.7.10.4
--
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