[NETFILTER]: x_tables: replace IPv4 dscp match by address family independent version
This replaces IPv4 dscp match by address family independent version.
This also
- utilizes dsfield.h to get the DS field in IPv4/IPv6 header, and
- checks for the DSCP value from user space.
- fixes Kconfig help text.
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/xt_dscp.c b/net/netfilter/xt_dscp.c
new file mode 100644
index 0000000..82e250d
--- /dev/null
+++ b/net/netfilter/xt_dscp.c
@@ -0,0 +1,113 @@
+/* IP tables module for matching the value of the IPv4/IPv6 DSCP field
+ *
+ * xt_dscp.c,v 1.3 2002/08/05 19:00:21 laforge Exp
+ *
+ * (C) 2002 by Harald Welte <laforge@netfilter.org>
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <net/dsfield.h>
+
+#include <linux/netfilter/xt_dscp.h>
+#include <linux/netfilter/x_tables.h>
+
+MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
+MODULE_DESCRIPTION("x_tables DSCP matching module");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ipt_dscp");
+MODULE_ALIAS("ip6t_dscp");
+
+static int match(const struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ const struct xt_match *match,
+ const void *matchinfo,
+ int offset,
+ unsigned int protoff,
+ int *hotdrop)
+{
+ const struct xt_dscp_info *info = matchinfo;
+ u_int8_t dscp = ipv4_get_dsfield(skb->nh.iph) >> XT_DSCP_SHIFT;
+
+ return (dscp == info->dscp) ^ !!info->invert;
+}
+
+static int match6(const struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ const struct xt_match *match,
+ const void *matchinfo,
+ int offset,
+ unsigned int protoff,
+ int *hotdrop)
+{
+ const struct xt_dscp_info *info = matchinfo;
+ u_int8_t dscp = ipv6_get_dsfield(skb->nh.ipv6h) >> XT_DSCP_SHIFT;
+
+ return (dscp == info->dscp) ^ !!info->invert;
+}
+
+static int checkentry(const char *tablename,
+ const void *info,
+ const struct xt_match *match,
+ void *matchinfo,
+ unsigned int matchsize,
+ unsigned int hook_mask)
+{
+ const u_int8_t dscp = ((struct xt_dscp_info *)matchinfo)->dscp;
+
+ if (dscp > XT_DSCP_MAX) {
+ printk(KERN_ERR "xt_dscp: dscp %x out of range\n", dscp);
+ return 0;
+ }
+
+ return 1;
+}
+
+static struct xt_match dscp_match = {
+ .name = "dscp",
+ .match = match,
+ .checkentry = checkentry,
+ .matchsize = sizeof(struct xt_dscp_info),
+ .family = AF_INET,
+ .me = THIS_MODULE,
+};
+
+static struct xt_match dscp6_match = {
+ .name = "dscp",
+ .match = match6,
+ .checkentry = checkentry,
+ .matchsize = sizeof(struct xt_dscp_info),
+ .family = AF_INET6,
+ .me = THIS_MODULE,
+};
+
+static int __init xt_dscp_match_init(void)
+{
+ int ret;
+ ret = xt_register_match(&dscp_match);
+ if (ret)
+ return ret;
+
+ ret = xt_register_match(&dscp6_match);
+ if (ret)
+ xt_unregister_match(&dscp_match);
+
+ return ret;
+}
+
+static void __exit xt_dscp_match_fini(void)
+{
+ xt_unregister_match(&dscp_match);
+ xt_unregister_match(&dscp6_match);
+}
+
+module_init(xt_dscp_match_init);
+module_exit(xt_dscp_match_fini);