patch-2.4.14 linux/net/ipv4/netfilter/ipt_ttl.c
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- Lines: 76
- Date:
Tue Oct 30 15:08:12 2001
- Orig file:
v2.4.13/linux/net/ipv4/netfilter/ipt_ttl.c
- Orig date:
Wed Dec 31 16:00:00 1969
diff -u --recursive --new-file v2.4.13/linux/net/ipv4/netfilter/ipt_ttl.c linux/net/ipv4/netfilter/ipt_ttl.c
@@ -0,0 +1,75 @@
+/* IP tables module for matching the value of the TTL
+ *
+ * ipt_ttl.c,v 1.5 2000/11/13 11:16:08 laforge Exp
+ *
+ * (C) 2000,2001 by Harald Welte <laforge@gnumonks.org>
+ *
+ * This software is distributed under the terms GNU GPL
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+
+#include <linux/netfilter_ipv4/ipt_ttl.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+
+MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
+MODULE_DESCRIPTION("IP tables TTL matching module");
+MODULE_LICENSE("GPL");
+
+static int match(const struct sk_buff *skb, const struct net_device *in,
+ const struct net_device *out, const void *matchinfo,
+ int offset, const void *hdr, u_int16_t datalen,
+ int *hotdrop)
+{
+ const struct ipt_ttl_info *info = matchinfo;
+ const struct iphdr *iph = skb->nh.iph;
+
+ switch (info->mode) {
+ case IPT_TTL_EQ:
+ return (iph->ttl == info->ttl);
+ break;
+ case IPT_TTL_NE:
+ return (!(iph->ttl == info->ttl));
+ break;
+ case IPT_TTL_LT:
+ return (iph->ttl < info->ttl);
+ break;
+ case IPT_TTL_GT:
+ return (iph->ttl > info->ttl);
+ break;
+ default:
+ printk(KERN_WARNING "ipt_ttl: unknown mode %d\n",
+ info->mode);
+ return 0;
+ }
+
+ return 0;
+}
+
+static int checkentry(const char *tablename, const struct ipt_ip *ip,
+ void *matchinfo, unsigned int matchsize,
+ unsigned int hook_mask)
+{
+ if (matchsize != IPT_ALIGN(sizeof(struct ipt_ttl_info)))
+ return 0;
+
+ return 1;
+}
+
+static struct ipt_match ttl_match = { { NULL, NULL }, "ttl", &match,
+ &checkentry, NULL, THIS_MODULE };
+
+static int __init init(void)
+{
+ return ipt_register_match(&ttl_match);
+}
+
+static void __exit fini(void)
+{
+ ipt_unregister_match(&ttl_match);
+
+}
+
+module_init(init);
+module_exit(fini);
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