net/ipv4/ipip.c

/* */
This source file includes following definitions.
ipip_rcv
init_module
cleanup_module
   1 /*
   2  *      Linux NET3:     IP/IP protocol decoder. 
   3  *
   4  *      Authors:
   5  *              Sam Lantinga (slouken@cs.ucdavis.edu)  02/01/95
   6  *
   7  *      Fixes:
   8  *              Alan Cox        :       Merged and made usable non modular (its so tiny its silly as
   9  *                                      a module taking up 2 pages).
  10  *              Alan Cox        :       Fixed bug with 1.3.18 and IPIP not working (now needs to set skb->h.iph)
  11  *                                      to keep ip_forward happy.
  12  *              Alan Cox        :       More fixes for 1.3.21, and firewall fix. Maybe this will work soon 8).
  13  *              Kai Schulte     :       Fixed #defines for IP_FIREWALL->FIREWALL
  14  *
  15  *      This program is free software; you can redistribute it and/or
  16  *      modify it under the terms of the GNU General Public License
  17  *      as published by the Free Software Foundation; either version
  18  *      2 of the License, or (at your option) any later version.
  19  *
  20  */
  21  
  22 #include <linux/module.h>
  23 
  24 #include <linux/config.h>
  25 #include <linux/types.h>
  26 #include <linux/sched.h>
  27 #include <linux/kernel.h>
  28 #include <linux/skbuff.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/in.h>
  31 #include <linux/tcp.h>
  32 #include <linux/udp.h>
  33 #include <linux/firewall.h>
  34 #include <linux/config.h>       /* For CONFIG_FIREWALL */
  35 
  36 #include <net/datalink.h>
  37 #include <net/sock.h>
  38 #include <net/ip.h>
  39 #include <net/icmp.h>
  40 #include <net/protocol.h>
  41 #include <net/ipip.h>
  42 
  43 /*
  44  *      The IPIP protocol driver.
  45  *
  46  *      On entry here
  47  *              skb->data is the original IP header
  48  *              skb->ip_hdr points to the initial IP header.
  49  *              skb->h.raw points at the new header.
  50  */
  51 
  52 int ipip_rcv(struct sk_buff *skb, struct device *dev, struct options *opt, 
     /*  */
  53                 __u32 daddr, unsigned short len, __u32 saddr,
  54                                    int redo, struct inet_protocol *protocol)
  55 {
  56 #ifdef CONFIG_FIREWALL
  57         int err;
  58 #endif
  59         /* Don't unlink in the middle of a turnaround */
  60         MOD_INC_USE_COUNT;
  61 #ifdef TUNNEL_DEBUG
  62         printk("ipip_rcv: got a packet!\n");
  63 #endif
  64         /*
  65          *      Discard the original IP header
  66          */
  67          
  68         skb_pull(skb, ((struct iphdr *)skb->data)->ihl<<2);
  69         
  70         /*
  71          *      Adjust pointers
  72          */
  73          
  74         skb->h.iph=(struct iphdr *)skb->data;
  75         skb->ip_hdr=(struct iphdr *)skb->data;
  76         memset(skb->proto_priv, 0, sizeof(struct options));
  77         if (skb->ip_hdr->ihl > 5) 
  78         {
  79                 if (ip_options_compile(NULL, skb))
  80                         return 0;
  81         }
  82         
  83 #ifdef CONFIG_FIREWALL
  84         /*
  85          *      Check the firewall [well spotted Olaf]
  86          */
  87          
  88         if((err=call_in_firewall(PF_INET, skb->dev, skb->ip_hdr))<FW_ACCEPT)
  89         {
  90                 if(err==FW_REJECT)
  91                         icmp_send(skb,ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0 , dev);
  92                 kfree_skb(skb, FREE_READ);
  93                 return 0;
  94         }       
  95 #endif
  96 
  97         /*
  98          *      If you want to add LZ compressed IP or things like that here,
  99          *      and in drivers/net/tunnel.c are the places to add.
 100          */
 101         
 102         /* skb=lzw_uncompress(skb); */
 103         
 104         /*
 105          *      Feed to IP forward.
 106          */
 107          
 108         if(ip_forward(skb, dev, 0, daddr))
 109                 kfree_skb(skb, FREE_READ);
 110         MOD_DEC_USE_COUNT;
 111         return(0);
 112 }
 113 
 114 #ifdef MODULE
 115 
 116 static struct inet_protocol ipip_protocol = {
 117   ipip_rcv,             /* IPIP handler          */
 118 #if 0
 119   NULL,                 /* Will be UDP fraglist handler */
 120 #endif
 121   NULL,                 /* TUNNEL error control    */
 122   0,                    /* next                 */
 123   IPPROTO_IPIP,         /* protocol ID          */
 124   0,                    /* copy                 */
 125   NULL,                 /* data                 */
 126   "IPIP"                /* name                 */
 127 };
 128 
 129 
 130 /*
 131  *      And now the modules code and kernel interface.
 132  */
 133 
 134 int init_module( void) 
     /*  */
 135 {
 136         inet_add_protocol(&ipip_protocol);
 137         return 0;
 138 }
 139 
 140 void cleanup_module( void) 
     /*  */
 141 {
 142         if ( inet_del_protocol(&ipip_protocol) < 0 )
 143                 printk("ipip close: can't remove protocol\n");
 144 }
 145 
 146 #endif
/* */
root/net/ipv4/ipip.c

DEFINITIONS
