patch-1.3.22 linux/net/ipv4/ipip.c

• Lines: 96
• Date: Fri Sep 1 14:35:17 1995
• Orig file: v1.3.21/linux/net/ipv4/ipip.c
• Orig date: Fri Aug 18 08:44:59 1995

diff -u --recursive --new-file v1.3.21/linux/net/ipv4/ipip.c linux/net/ipv4/ipip.c
@@ -9,6 +9,7 @@
  *					a module taking up 2 pages).
  *		Alan Cox	: 	Fixed bug with 1.3.18 and IPIP not working (now needs to set skb->h.iph)
  *					to keep ip_forward happy.
+ *		Alan Cox	:	More fixes for 1.3.21, and firewall fix. Maybe this will work soon 8).
  *
  *	This program is free software; you can redistribute it and/or
  *	modify it under the terms of the GNU General Public License
@@ -18,6 +19,7 @@
  */
  
 #include <linux/types.h>
+#include <linux/sched.h>
 #include <linux/kernel.h>
 #include <linux/skbuff.h>
 #include <linux/netdevice.h>
@@ -25,8 +27,12 @@
 #include <net/datalink.h>
 #include <net/sock.h>
 #include <net/ip.h>
+#include <net/icmp.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
 #include <net/protocol.h>
 #include <net/ipip.h>
+#include <linux/ip_fw.h>
 
 /*
  * NB. we must include the kernel idenfication string in to install the module.
@@ -46,19 +52,64 @@
 
 
 /*
- *	The driver.
+ *	The IPIP protocol driver.
+ *
+ *	On entry here
+ *		skb->data is the original IP header
+ *		skb->ip_hdr points to the initial IP header.
+ *		skb->h.raw points at the new header.
  */
 
 int ipip_rcv(struct sk_buff *skb, struct device *dev, struct options *opt, 
 		unsigned long daddr, unsigned short len, unsigned long saddr,
                                    int redo, struct inet_protocol *protocol)
 {
+#ifdef CONFIG_IP_FIREWALL
+	int err;
+#endif
 	/* Don't unlink in the middle of a turnaround */
 	MOD_INC_USE_COUNT;
 #ifdef TUNNEL_DEBUG
 	printk("ipip_rcv: got a packet!\n");
 #endif
-	skb->h.iph=skb->data;	/* Correct IP header pointer on to new header */
+	/*
+	 *	Discard the original IP header
+	 */
+	 
+	skb_pull(skb, ((struct iphdr *)skb->data)->ihl<<2);
+	
+	/*
+	 *	Adjust pointers
+	 */
+	 
+	skb->h.iph=(struct iphdr *)skb->data;
+	skb->ip_hdr=(struct iphdr *)skb->data;
+	
+#ifdef CONFIG_IP_FIREWALL
+	/*
+	 *	Check the firewall [well spotted Olaf]
+	 */
+	 
+	if((err=ip_fw_chk(skb->ip_hdr,dev,ip_fw_blk_chain, ip_fw_blk_policy,0))<1)
+	{
+		if(err==-1)
+			icmp_send(skb,ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0 , dev);
+		kfree_skb(skb, FREE_READ);
+		return 0;
+	}	
+#endif
+
+	/*
+	 *	If you want to add LZ compressed IP or things like that here,
+	 *	and in drivers/net/tunnel.c are the places to add.
+	 */
+	
+	/* skb=lzw_uncompress(skb); */
+	
+	/*
+	 *	Feed to IP forward.
+	 */
+	 
 	if(ip_forward(skb, dev, 0, daddr, 0))
 		kfree_skb(skb, FREE_READ);
 	MOD_DEC_USE_COUNT;