[NETFILTER] x_tables: Abstraction layer for {ip,ip6,arp}_tables

[cascardo/linux.git] / net / netfilter / xt_comment.c

diff --git a/net/netfilter/xt_comment.c b/net/netfilter/xt_comment.c
new file mode 100644 (file)
index 0000000..4ba6fd6
--- /dev/null
+++ b/net/netfilter/xt_comment.c
@@ -0,0 +1,80 @@
+/*
+ * Implements a dummy match to allow attaching comments to rules
+ *
+ * 2003-05-13 Brad Fisher (brad@info-link.net)
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_comment.h>
+
+MODULE_AUTHOR("Brad Fisher <brad@info-link.net>");
+MODULE_DESCRIPTION("iptables comment match module");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ipt_comment");
+MODULE_ALIAS("ip6t_comment");
+
+static int
+match(const struct sk_buff *skb,
+      const struct net_device *in,
+      const struct net_device *out,
+      const void *matchinfo,
+      int offset,
+      unsigned int protooff,
+      int *hotdrop)
+{
+       /* We always match */
+       return 1;
+}
+
+static int
+checkentry(const char *tablename,
+           const void *ip,
+           void *matchinfo,
+           unsigned int matchsize,
+           unsigned int hook_mask)
+{
+       /* Check the size */
+       if (matchsize != XT_ALIGN(sizeof(struct xt_comment_info)))
+               return 0;
+       return 1;
+}
+
+static struct xt_match comment_match = {
+       .name           = "comment",
+       .match          = match,
+       .checkentry     = checkentry,
+       .me             = THIS_MODULE
+};
+
+static struct xt_match comment6_match = {
+       .name           = "comment",
+       .match          = match,
+       .checkentry     = checkentry,
+       .me             = THIS_MODULE
+};
+
+static int __init init(void)
+{
+       int ret;
+
+       ret = xt_register_match(AF_INET, &comment_match);
+       if (ret)
+               return ret;
+
+       ret = xt_register_match(AF_INET6, &comment6_match);
+       if (ret)
+               xt_unregister_match(AF_INET, &comment_match);
+
+       return ret;
+}
+
+static void __exit fini(void)
+{
+       xt_unregister_match(AF_INET, &comment_match);
+       xt_unregister_match(AF_INET6, &comment6_match);
+}
+
+module_init(init);
+module_exit(fini);