From: Jan Engelhardt <jengelh@xxxxxxxxxx>
Prepare the ECN match for augmentation by an IPv6 counterpart. Since
no symbol dependencies to ipv6.ko are added, having a single ecn match
module is the more so welcome.
Signed-off-by: Jan Engelhardt <jengelh@xxxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/linux/netfilter/Kbuild | 1 +
include/linux/netfilter/xt_ecn.h | 35 +++++++++
include/linux/netfilter_ipv4/ipt_ecn.h | 31 +--------
net/ipv4/netfilter/Kconfig | 10 +-
net/ipv4/netfilter/Makefile | 1 -
net/ipv4/netfilter/ipt_ecn.c | 127 -------------------------------
net/netfilter/Kconfig | 9 ++
net/netfilter/Makefile | 1 +
net/netfilter/xt_ecn.c | 128 ++++++++++++++++++++++++++++++++
9 files changed, 180 insertions(+), 163 deletions(-)
create mode 100644 include/linux/netfilter/xt_ecn.h
delete mode 100644 net/ipv4/netfilter/ipt_ecn.c
create mode 100644 net/netfilter/xt_ecn.c
diff --git a/include/linux/netfilter/Kbuild b/include/linux/netfilter/Kbuild
index e630a2e..e144f54 100644
--- a/include/linux/netfilter/Kbuild
+++ b/include/linux/netfilter/Kbuild
@@ -43,6 +43,7 @@ header-y += xt_cpu.h
header-y += xt_dccp.h
header-y += xt_devgroup.h
header-y += xt_dscp.h
+header-y += xt_ecn.h
header-y += xt_esp.h
header-y += xt_hashlimit.h
header-y += xt_helper.h
diff --git a/include/linux/netfilter/xt_ecn.h b/include/linux/netfilter/xt_ecn.h
new file mode 100644
index 0000000..065c1a5
--- /dev/null
+++ b/include/linux/netfilter/xt_ecn.h
@@ -0,0 +1,35 @@
+/* iptables module for matching the ECN header in IPv4 and TCP header
+ *
+ * (C) 2002 Harald Welte <laforge@xxxxxxxxxxxx>
+ *
+ * This software is distributed under GNU GPL v2, 1991
+ *
+ * ipt_ecn.h,v 1.4 2002/08/05 19:39:00 laforge Exp
+*/
+#ifndef _XT_ECN_H
+#define _XT_ECN_H
+
+#include <linux/types.h>
+#include <linux/netfilter/xt_dscp.h>
+
+#define IPT_ECN_IP_MASK (~XT_DSCP_MASK)
+
+#define IPT_ECN_OP_MATCH_IP 0x01
+#define IPT_ECN_OP_MATCH_ECE 0x10
+#define IPT_ECN_OP_MATCH_CWR 0x20
+
+#define IPT_ECN_OP_MATCH_MASK 0xce
+
+/* match info */
+struct ipt_ecn_info {
+ __u8 operation;
+ __u8 invert;
+ __u8 ip_ect;
+ union {
+ struct {
+ __u8 ect;
+ } tcp;
+ } proto;
+};
+
+#endif /* _XT_ECN_H */
diff --git a/include/linux/netfilter_ipv4/ipt_ecn.h b/include/linux/netfilter_ipv4/ipt_ecn.h
index eabf95f..b1124ec 100644
--- a/include/linux/netfilter_ipv4/ipt_ecn.h
+++ b/include/linux/netfilter_ipv4/ipt_ecn.h
@@ -1,35 +1,6 @@
-/* iptables module for matching the ECN header in IPv4 and TCP header
- *
- * (C) 2002 Harald Welte <laforge@xxxxxxxxxxxx>
- *
- * This software is distributed under GNU GPL v2, 1991
- *
- * ipt_ecn.h,v 1.4 2002/08/05 19:39:00 laforge Exp
-*/
#ifndef _IPT_ECN_H
#define _IPT_ECN_H
-#include <linux/types.h>
-#include <linux/netfilter/xt_dscp.h>
-
-#define IPT_ECN_IP_MASK (~XT_DSCP_MASK)
-
-#define IPT_ECN_OP_MATCH_IP 0x01
-#define IPT_ECN_OP_MATCH_ECE 0x10
-#define IPT_ECN_OP_MATCH_CWR 0x20
-
-#define IPT_ECN_OP_MATCH_MASK 0xce
-
-/* match info */
-struct ipt_ecn_info {
- __u8 operation;
- __u8 invert;
- __u8 ip_ect;
- union {
- struct {
- __u8 ect;
- } tcp;
- } proto;
-};
+#include <linux/netfilter/xt_ecn.h>
#endif /* _IPT_ECN_H */
diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index 7e1f5cd..53b9c79 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -76,11 +76,11 @@ config IP_NF_MATCH_AH
config IP_NF_MATCH_ECN
tristate '"ecn" match support'
depends on NETFILTER_ADVANCED
- help
- This option adds a `ECN' match, which allows you to match against
- the IPv4 and TCP header ECN fields.
-
- To compile it as a module, choose M here. If unsure, say N.
+ select NETFILTER_XT_MATCH_ECN
+ ---help---
+ This is a backwards-compat option for the user's convenience
+ (e.g. when running oldconfig). It selects
+ CONFIG_NETFILTER_XT_MATCH_ECN.
config IP_NF_MATCH_RPFILTER
tristate '"rpfilter" reverse path filter match support'
diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile
index 123dd88..213a462 100644
--- a/net/ipv4/netfilter/Makefile
+++ b/net/ipv4/netfilter/Makefile
@@ -49,7 +49,6 @@ obj-$(CONFIG_IP_NF_SECURITY) += iptable_security.o
# matches
obj-$(CONFIG_IP_NF_MATCH_AH) += ipt_ah.o
-obj-$(CONFIG_IP_NF_MATCH_ECN) += ipt_ecn.o
obj-$(CONFIG_IP_NF_MATCH_RPFILTER) += ipt_rpfilter.o
# targets
diff --git a/net/ipv4/netfilter/ipt_ecn.c b/net/ipv4/netfilter/ipt_ecn.c
deleted file mode 100644
index 2b57e52..0000000
--- a/net/ipv4/netfilter/ipt_ecn.c
+++ /dev/null
@@ -1,127 +0,0 @@
-/* IP tables module for matching the value of the IPv4 and TCP ECN bits
- *
- * (C) 2002 by Harald Welte <laforge@xxxxxxxxxxxx>
- *
- * 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/in.h>
-#include <linux/ip.h>
-#include <net/ip.h>
-#include <linux/module.h>
-#include <linux/skbuff.h>
-#include <linux/tcp.h>
-
-#include <linux/netfilter/x_tables.h>
-#include <linux/netfilter_ipv4/ip_tables.h>
-#include <linux/netfilter_ipv4/ipt_ecn.h>
-
-MODULE_AUTHOR("Harald Welte <laforge@xxxxxxxxxxxxx>");
-MODULE_DESCRIPTION("Xtables: Explicit Congestion Notification (ECN) flag match for IPv4");
-MODULE_LICENSE("GPL");
-
-static inline bool match_ip(const struct sk_buff *skb,
- const struct ipt_ecn_info *einfo)
-{
- return ((ip_hdr(skb)->tos & IPT_ECN_IP_MASK) == einfo->ip_ect) ^
- !!(einfo->invert & IPT_ECN_OP_MATCH_IP);
-}
-
-static inline bool match_tcp(const struct sk_buff *skb,
- const struct ipt_ecn_info *einfo,
- bool *hotdrop)
-{
- struct tcphdr _tcph;
- const struct tcphdr *th;
-
- /* In practice, TCP match does this, so can't fail. But let's
- * be good citizens.
- */
- th = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph);
- if (th == NULL) {
- *hotdrop = false;
- return false;
- }
-
- if (einfo->operation & IPT_ECN_OP_MATCH_ECE) {
- if (einfo->invert & IPT_ECN_OP_MATCH_ECE) {
- if (th->ece == 1)
- return false;
- } else {
- if (th->ece == 0)
- return false;
- }
- }
-
- if (einfo->operation & IPT_ECN_OP_MATCH_CWR) {
- if (einfo->invert & IPT_ECN_OP_MATCH_CWR) {
- if (th->cwr == 1)
- return false;
- } else {
- if (th->cwr == 0)
- return false;
- }
- }
-
- return true;
-}
-
-static bool ecn_mt(const struct sk_buff *skb, struct xt_action_param *par)
-{
- const struct ipt_ecn_info *info = par->matchinfo;
-
- if (info->operation & IPT_ECN_OP_MATCH_IP)
- if (!match_ip(skb, info))
- return false;
-
- if (info->operation & (IPT_ECN_OP_MATCH_ECE|IPT_ECN_OP_MATCH_CWR)) {
- if (!match_tcp(skb, info, &par->hotdrop))
- return false;
- }
-
- return true;
-}
-
-static int ecn_mt_check(const struct xt_mtchk_param *par)
-{
- const struct ipt_ecn_info *info = par->matchinfo;
- const struct ipt_ip *ip = par->entryinfo;
-
- if (info->operation & IPT_ECN_OP_MATCH_MASK)
- return -EINVAL;
-
- if (info->invert & IPT_ECN_OP_MATCH_MASK)
- return -EINVAL;
-
- if (info->operation & (IPT_ECN_OP_MATCH_ECE|IPT_ECN_OP_MATCH_CWR) &&
- (ip->proto != IPPROTO_TCP || ip->invflags & IPT_INV_PROTO)) {
- pr_info("cannot match TCP bits in rule for non-tcp packets\n");
- return -EINVAL;
- }
-
- return 0;
-}
-
-static struct xt_match ecn_mt_reg __read_mostly = {
- .name = "ecn",
- .family = NFPROTO_IPV4,
- .match = ecn_mt,
- .matchsize = sizeof(struct ipt_ecn_info),
- .checkentry = ecn_mt_check,
- .me = THIS_MODULE,
-};
-
-static int __init ecn_mt_init(void)
-{
- return xt_register_match(&ecn_mt_reg);
-}
-
-static void __exit ecn_mt_exit(void)
-{
- xt_unregister_match(&ecn_mt_reg);
-}
-
-module_init(ecn_mt_init);
-module_exit(ecn_mt_exit);
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index bac93ba..20388a9 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -778,6 +778,15 @@ config NETFILTER_XT_MATCH_DSCP
To compile it as a module, choose M here. If unsure, say N.
+config NETFILTER_XT_MATCH_ECN
+ tristate '"ecn" match support'
+ depends on NETFILTER_ADVANCED
+ ---help---
+ This option adds an "ECN" match, which allows you to match against
+ the IPv4 and TCP header ECN fields.
+
+ To compile it as a module, choose M here. If unsure, say N.
+
config NETFILTER_XT_MATCH_ESP
tristate '"esp" match support'
depends on NETFILTER_ADVANCED
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index b2eee4d..40f4c3d 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -81,6 +81,7 @@ obj-$(CONFIG_NETFILTER_XT_MATCH_CPU) += xt_cpu.o
obj-$(CONFIG_NETFILTER_XT_MATCH_DCCP) += xt_dccp.o
obj-$(CONFIG_NETFILTER_XT_MATCH_DEVGROUP) += xt_devgroup.o
obj-$(CONFIG_NETFILTER_XT_MATCH_DSCP) += xt_dscp.o
+obj-$(CONFIG_NETFILTER_XT_MATCH_ECN) += xt_ecn.o
obj-$(CONFIG_NETFILTER_XT_MATCH_ESP) += xt_esp.o
obj-$(CONFIG_NETFILTER_XT_MATCH_HASHLIMIT) += xt_hashlimit.o
obj-$(CONFIG_NETFILTER_XT_MATCH_HELPER) += xt_helper.o
diff --git a/net/netfilter/xt_ecn.c b/net/netfilter/xt_ecn.c
new file mode 100644
index 0000000..2c198f5
--- /dev/null
+++ b/net/netfilter/xt_ecn.c
@@ -0,0 +1,128 @@
+/* IP tables module for matching the value of the IPv4 and TCP ECN bits
+ *
+ * (C) 2002 by Harald Welte <laforge@xxxxxxxxxxxx>
+ *
+ * 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/in.h>
+#include <linux/ip.h>
+#include <net/ip.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/tcp.h>
+
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ipt_ecn.h>
+
+MODULE_AUTHOR("Harald Welte <laforge@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Xtables: Explicit Congestion Notification (ECN) flag match for IPv4");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ipt_ecn");
+
+static inline bool match_ip(const struct sk_buff *skb,
+ const struct ipt_ecn_info *einfo)
+{
+ return ((ip_hdr(skb)->tos & IPT_ECN_IP_MASK) == einfo->ip_ect) ^
+ !!(einfo->invert & IPT_ECN_OP_MATCH_IP);
+}
+
+static inline bool match_tcp(const struct sk_buff *skb,
+ const struct ipt_ecn_info *einfo,
+ bool *hotdrop)
+{
+ struct tcphdr _tcph;
+ const struct tcphdr *th;
+
+ /* In practice, TCP match does this, so can't fail. But let's
+ * be good citizens.
+ */
+ th = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph);
+ if (th == NULL) {
+ *hotdrop = false;
+ return false;
+ }
+
+ if (einfo->operation & IPT_ECN_OP_MATCH_ECE) {
+ if (einfo->invert & IPT_ECN_OP_MATCH_ECE) {
+ if (th->ece == 1)
+ return false;
+ } else {
+ if (th->ece == 0)
+ return false;
+ }
+ }
+
+ if (einfo->operation & IPT_ECN_OP_MATCH_CWR) {
+ if (einfo->invert & IPT_ECN_OP_MATCH_CWR) {
+ if (th->cwr == 1)
+ return false;
+ } else {
+ if (th->cwr == 0)
+ return false;
+ }
+ }
+
+ return true;
+}
+
+static bool ecn_mt(const struct sk_buff *skb, struct xt_action_param *par)
+{
+ const struct ipt_ecn_info *info = par->matchinfo;
+
+ if (info->operation & IPT_ECN_OP_MATCH_IP)
+ if (!match_ip(skb, info))
+ return false;
+
+ if (info->operation & (IPT_ECN_OP_MATCH_ECE|IPT_ECN_OP_MATCH_CWR)) {
+ if (!match_tcp(skb, info, &par->hotdrop))
+ return false;
+ }
+
+ return true;
+}
+
+static int ecn_mt_check(const struct xt_mtchk_param *par)
+{
+ const struct ipt_ecn_info *info = par->matchinfo;
+ const struct ipt_ip *ip = par->entryinfo;
+
+ if (info->operation & IPT_ECN_OP_MATCH_MASK)
+ return -EINVAL;
+
+ if (info->invert & IPT_ECN_OP_MATCH_MASK)
+ return -EINVAL;
+
+ if (info->operation & (IPT_ECN_OP_MATCH_ECE|IPT_ECN_OP_MATCH_CWR) &&
+ (ip->proto != IPPROTO_TCP || ip->invflags & IPT_INV_PROTO)) {
+ pr_info("cannot match TCP bits in rule for non-tcp packets\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static struct xt_match ecn_mt_reg __read_mostly = {
+ .name = "ecn",
+ .family = NFPROTO_IPV4,
+ .match = ecn_mt,
+ .matchsize = sizeof(struct ipt_ecn_info),
+ .checkentry = ecn_mt_check,
+ .me = THIS_MODULE,
+};
+
+static int __init ecn_mt_init(void)
+{
+ return xt_register_match(&ecn_mt_reg);
+}
+
+static void __exit ecn_mt_exit(void)
+{
+ xt_unregister_match(&ecn_mt_reg);
+}
+
+module_init(ecn_mt_init);
+module_exit(ecn_mt_exit);
--
1.7.7.3
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