Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / net / netfilter / xt_ecn.c

diff --git a/kernel/net/netfilter/xt_ecn.c b/kernel/net/netfilter/xt_ecn.c
new file mode 100644 (file)
index 0000000..3c831a8
--- /dev/null
+++ b/kernel/net/netfilter/xt_ecn.c
@@ -0,0 +1,179 @@
+/*
+ * Xtables module for matching the value of the IPv4/IPv6 and TCP ECN bits
+ *
+ * (C) 2002 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2011 Patrick McHardy <kaber@trash.net>
+ *
+ * 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/xt_ecn.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv6/ip6_tables.h>
+
+MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
+MODULE_DESCRIPTION("Xtables: Explicit Congestion Notification (ECN) flag match");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ipt_ecn");
+MODULE_ALIAS("ip6t_ecn");
+
+static bool match_tcp(const struct sk_buff *skb, struct xt_action_param *par)
+{
+       const struct xt_ecn_info *einfo = par->matchinfo;
+       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, par->thoff, sizeof(_tcph), &_tcph);
+       if (th == NULL)
+               return false;
+
+       if (einfo->operation & XT_ECN_OP_MATCH_ECE) {
+               if (einfo->invert & XT_ECN_OP_MATCH_ECE) {
+                       if (th->ece == 1)
+                               return false;
+               } else {
+                       if (th->ece == 0)
+                               return false;
+               }
+       }
+
+       if (einfo->operation & XT_ECN_OP_MATCH_CWR) {
+               if (einfo->invert & XT_ECN_OP_MATCH_CWR) {
+                       if (th->cwr == 1)
+                               return false;
+               } else {
+                       if (th->cwr == 0)
+                               return false;
+               }
+       }
+
+       return true;
+}
+
+static inline bool match_ip(const struct sk_buff *skb,
+                           const struct xt_ecn_info *einfo)
+{
+       return ((ip_hdr(skb)->tos & XT_ECN_IP_MASK) == einfo->ip_ect) ^
+              !!(einfo->invert & XT_ECN_OP_MATCH_IP);
+}
+
+static bool ecn_mt4(const struct sk_buff *skb, struct xt_action_param *par)
+{
+       const struct xt_ecn_info *info = par->matchinfo;
+
+       if (info->operation & XT_ECN_OP_MATCH_IP && !match_ip(skb, info))
+               return false;
+
+       if (info->operation & (XT_ECN_OP_MATCH_ECE | XT_ECN_OP_MATCH_CWR) &&
+           !match_tcp(skb, par))
+               return false;
+
+       return true;
+}
+
+static int ecn_mt_check4(const struct xt_mtchk_param *par)
+{
+       const struct xt_ecn_info *info = par->matchinfo;
+       const struct ipt_ip *ip = par->entryinfo;
+
+       if (info->operation & XT_ECN_OP_MATCH_MASK)
+               return -EINVAL;
+
+       if (info->invert & XT_ECN_OP_MATCH_MASK)
+               return -EINVAL;
+
+       if (info->operation & (XT_ECN_OP_MATCH_ECE | XT_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 inline bool match_ipv6(const struct sk_buff *skb,
+                             const struct xt_ecn_info *einfo)
+{
+       return (((ipv6_hdr(skb)->flow_lbl[0] >> 4) & XT_ECN_IP_MASK) ==
+               einfo->ip_ect) ^
+              !!(einfo->invert & XT_ECN_OP_MATCH_IP);
+}
+
+static bool ecn_mt6(const struct sk_buff *skb, struct xt_action_param *par)
+{
+       const struct xt_ecn_info *info = par->matchinfo;
+
+       if (info->operation & XT_ECN_OP_MATCH_IP && !match_ipv6(skb, info))
+               return false;
+
+       if (info->operation & (XT_ECN_OP_MATCH_ECE | XT_ECN_OP_MATCH_CWR) &&
+           !match_tcp(skb, par))
+               return false;
+
+       return true;
+}
+
+static int ecn_mt_check6(const struct xt_mtchk_param *par)
+{
+       const struct xt_ecn_info *info = par->matchinfo;
+       const struct ip6t_ip6 *ip = par->entryinfo;
+
+       if (info->operation & XT_ECN_OP_MATCH_MASK)
+               return -EINVAL;
+
+       if (info->invert & XT_ECN_OP_MATCH_MASK)
+               return -EINVAL;
+
+       if (info->operation & (XT_ECN_OP_MATCH_ECE | XT_ECN_OP_MATCH_CWR) &&
+           (ip->proto != IPPROTO_TCP || ip->invflags & IP6T_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_mt4,
+               .matchsize      = sizeof(struct xt_ecn_info),
+               .checkentry     = ecn_mt_check4,
+               .me             = THIS_MODULE,
+       },
+       {
+               .name           = "ecn",
+               .family         = NFPROTO_IPV6,
+               .match          = ecn_mt6,
+               .matchsize      = sizeof(struct xt_ecn_info),
+               .checkentry     = ecn_mt_check6,
+               .me             = THIS_MODULE,
+       },
+};
+
+static int __init ecn_mt_init(void)
+{
+       return xt_register_matches(ecn_mt_reg, ARRAY_SIZE(ecn_mt_reg));
+}
+
+static void __exit ecn_mt_exit(void)
+{
+       xt_unregister_matches(ecn_mt_reg, ARRAY_SIZE(ecn_mt_reg));
+}
+
+module_init(ecn_mt_init);
+module_exit(ecn_mt_exit);