From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@ppc970.osdl.org>
Date: Sat, 16 Apr 2005 15:20:36 -0700
Subject: Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
---
 net/ipv4/netfilter/ipt_REDIRECT.c | 129 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 129 insertions(+)
 create mode 100644 net/ipv4/netfilter/ipt_REDIRECT.c

(limited to 'net/ipv4/netfilter/ipt_REDIRECT.c')

diff --git a/net/ipv4/netfilter/ipt_REDIRECT.c b/net/ipv4/netfilter/ipt_REDIRECT.c
new file mode 100644
index 00000000000..d2e13447678
--- /dev/null
+++ b/net/ipv4/netfilter/ipt_REDIRECT.c
@@ -0,0 +1,129 @@
+/* Redirect.  Simple mapping which alters dst to a local IP address. */
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2004 Netfilter Core Team <coreteam@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/types.h>
+#include <linux/ip.h>
+#include <linux/timer.h>
+#include <linux/module.h>
+#include <linux/netfilter.h>
+#include <linux/netdevice.h>
+#include <linux/if.h>
+#include <linux/inetdevice.h>
+#include <net/protocol.h>
+#include <net/checksum.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/netfilter_ipv4/ip_nat_rule.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
+MODULE_DESCRIPTION("iptables REDIRECT target module");
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+/* FIXME: Take multiple ranges --RR */
+static int
+redirect_check(const char *tablename,
+	       const struct ipt_entry *e,
+	       void *targinfo,
+	       unsigned int targinfosize,
+	       unsigned int hook_mask)
+{
+	const struct ip_nat_multi_range_compat *mr = targinfo;
+
+	if (strcmp(tablename, "nat") != 0) {
+		DEBUGP("redirect_check: bad table `%s'.\n", table);
+		return 0;
+	}
+	if (targinfosize != IPT_ALIGN(sizeof(*mr))) {
+		DEBUGP("redirect_check: size %u.\n", targinfosize);
+		return 0;
+	}
+	if (hook_mask & ~((1 << NF_IP_PRE_ROUTING) | (1 << NF_IP_LOCAL_OUT))) {
+		DEBUGP("redirect_check: bad hooks %x.\n", hook_mask);
+		return 0;
+	}
+	if (mr->range[0].flags & IP_NAT_RANGE_MAP_IPS) {
+		DEBUGP("redirect_check: bad MAP_IPS.\n");
+		return 0;
+	}
+	if (mr->rangesize != 1) {
+		DEBUGP("redirect_check: bad rangesize %u.\n", mr->rangesize);
+		return 0;
+	}
+	return 1;
+}
+
+static unsigned int
+redirect_target(struct sk_buff **pskb,
+		const struct net_device *in,
+		const struct net_device *out,
+		unsigned int hooknum,
+		const void *targinfo,
+		void *userinfo)
+{
+	struct ip_conntrack *ct;
+	enum ip_conntrack_info ctinfo;
+	u_int32_t newdst;
+	const struct ip_nat_multi_range_compat *mr = targinfo;
+	struct ip_nat_range newrange;
+
+	IP_NF_ASSERT(hooknum == NF_IP_PRE_ROUTING
+		     || hooknum == NF_IP_LOCAL_OUT);
+
+	ct = ip_conntrack_get(*pskb, &ctinfo);
+	IP_NF_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED));
+
+	/* Local packets: make them go to loopback */
+	if (hooknum == NF_IP_LOCAL_OUT)
+		newdst = htonl(0x7F000001);
+	else {
+		struct in_device *indev;
+
+		/* Device might not have an associated in_device. */
+		indev = (struct in_device *)(*pskb)->dev->ip_ptr;
+		if (indev == NULL || indev->ifa_list == NULL)
+			return NF_DROP;
+
+		/* Grab first address on interface. */
+		newdst = indev->ifa_list->ifa_local;
+	}
+
+	/* Transfer from original range. */
+	newrange = ((struct ip_nat_range)
+		{ mr->range[0].flags | IP_NAT_RANGE_MAP_IPS,
+		  newdst, newdst,
+		  mr->range[0].min, mr->range[0].max });
+
+	/* Hand modified range to generic setup. */
+	return ip_nat_setup_info(ct, &newrange, hooknum);
+}
+
+static struct ipt_target redirect_reg = {
+	.name		= "REDIRECT",
+	.target		= redirect_target,
+	.checkentry	= redirect_check,
+	.me		= THIS_MODULE,
+};
+
+static int __init init(void)
+{
+	return ipt_register_target(&redirect_reg);
+}
+
+static void __exit fini(void)
+{
+	ipt_unregister_target(&redirect_reg);
+}
+
+module_init(init);
+module_exit(fini);
-- 
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