This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / net / netfilter / xt_length.c

diff --git a/net/netfilter/xt_length.c b/net/netfilter/xt_length.c
new file mode 100644 (file)
index 0000000..109132c
--- /dev/null
+++ b/net/netfilter/xt_length.c
@@ -0,0 +1,91 @@
+/* Kernel module to match packet length. */
+/* (C) 1999-2001 James Morris <jmorros@intercode.com.au>
+ *
+ * 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/ipv6.h>
+#include <net/ip.h>
+
+#include <linux/netfilter/xt_length.h>
+#include <linux/netfilter/x_tables.h>
+
+MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
+MODULE_DESCRIPTION("IP tables packet length matching module");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ipt_length");
+MODULE_ALIAS("ip6t_length");
+
+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_length_info *info = matchinfo;
+       u_int16_t pktlen = ntohs(skb->nh.iph->tot_len);
+       
+       return (pktlen >= info->min && pktlen <= info->max) ^ 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_length_info *info = matchinfo;
+       u_int16_t pktlen = ntohs(skb->nh.ipv6h->payload_len) + sizeof(struct ipv6hdr);
+       
+       return (pktlen >= info->min && pktlen <= info->max) ^ info->invert;
+}
+
+static struct xt_match length_match = {
+       .name           = "length",
+       .match          = match,
+       .matchsize      = sizeof(struct xt_length_info),
+       .family         = AF_INET,
+       .me             = THIS_MODULE,
+};
+
+static struct xt_match length6_match = {
+       .name           = "length",
+       .match          = match6,
+       .matchsize      = sizeof(struct xt_length_info),
+       .family         = AF_INET6,
+       .me             = THIS_MODULE,
+};
+
+static int __init xt_length_init(void)
+{
+       int ret;
+       ret = xt_register_match(&length_match);
+       if (ret)
+               return ret;
+       ret = xt_register_match(&length6_match);
+       if (ret)
+               xt_unregister_match(&length_match);
+
+       return ret;
+}
+
+static void __exit xt_length_fini(void)
+{
+       xt_unregister_match(&length_match);
+       xt_unregister_match(&length6_match);
+}
+
+module_init(xt_length_init);
+module_exit(xt_length_fini);