old version maemo18

[kernel-power] / kernel-maemo-2.6.28 / debian / JoikuSpot_Bouncer.c

diff --git a/kernel-maemo-2.6.28/debian/JoikuSpot_Bouncer.c b/kernel-maemo-2.6.28/debian/JoikuSpot_Bouncer.c
new file mode 100644 (file)
index 0000000..8ff74a8
--- /dev/null
+++ b/kernel-maemo-2.6.28/debian/JoikuSpot_Bouncer.c
@@ -0,0 +1,196 @@
+/* 
+ * Implementation of JoikuSpotBouncer module
+ * JoikuSpot_Bouncer.c
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the license, or ( at your option ) any later version
+ */
+
+#include <linux/module.h>         /* needed by all kernel modules          */
+#include <linux/init.h>           /* needed for custom init/exit functions */
+#include <linux/kernel.h>         /* needed for KERN_ALERT macro           */
+#include <linux/netfilter.h>      /* Hook register/unregister              */
+#include <linux/netfilter_ipv4.h> /* nf_hook_priorities                    */
+#include <linux/ip.h>             /* Ip header                             */
+#include <linux/tcp.h>            /* Tcp Header                            */
+#include <linux/udp.h>            /* Udp Header                            */
+#include <net/inet_hashtables.h>  /* __inet_lookup()                       */
+#include <net/inet_sock.h>        /* struct inet_sock                      */
+
+
+/* Special macro to indicate license (to avoid tainting the kernel) */
+
+MODULE_LICENSE( "Dual MIT/GPL" );
+MODULE_AUTHOR ( "JoikuSoft Oy Ltd <info@joikusoft.com>" );
+
+extern struct inet_hashinfo tcp_hashinfo;
+extern struct proto udp_prot;
+extern struct rwlock_t udp_hash_lock;
+
+static struct sock *__udp4_lib_lookup( struct net *net ,
+    unsigned long int saddr ,
+    unsigned short int sport ,
+    unsigned long int daddr ,
+    unsigned short int dport ,
+    int dif ,
+    struct hlist_head udptable[] )
+    {
+    struct sock *sk , *result = NULL;
+    struct hlist_node *node;
+    unsigned short int hnum = ntohs( dport );
+    int badness = -1;
+
+    read_lock( &udp_hash_lock );
+
+    sk_for_each ( sk , node , &udptable[ udp_hashfn ( net , hnum ) ] )
+        {
+        struct inet_sock *inet = inet_sk( sk );
+
+        if ( net_eq ( sock_net( sk ) , net ) && sk->sk_hash == hnum &&
+            !ipv6_only_sock( sk ) )
+            {
+
+            int score = ( sk->sk_family == PF_INET ? 1 : 0 );
+
+            if ( inet->rcv_saddr )
+                {
+                if ( inet->rcv_saddr != daddr )
+                    {
+                    continue;
+                    }
+                score += 2;
+                }
+            if ( inet->daddr )
+                {
+                if ( inet->daddr != saddr )
+                    {
+                    continue;
+                    }
+                score += 2;
+                }
+            if ( inet->dport )
+                {
+                if ( inet->dport != sport )
+                    {
+                    continue;
+                    }
+                score += 2;
+                }
+            if ( sk->sk_bound_dev_if )
+                {
+                if ( sk->sk_bound_dev_if != dif )
+                    {
+                    continue;
+                    }
+                score += 2;
+                }
+            if ( score == 9 )
+                {
+                result = sk;
+                break;
+                }
+                else if ( score > badness )
+                {
+                result  = sk;
+                badness = score;
+                }
+            }
+        }
+    if ( result )
+        {
+        sock_hold ( result );
+        }
+    read_unlock ( &udp_hash_lock );
+    return result;
+    }
+
+
+static unsigned int joikuspot_nf_hook ( unsigned int hook ,
+    struct sk_buff *pskb ,
+    const struct net_device *in ,
+    const struct net_device *out ,
+    int ( *okfn ) ( struct sk_buff * ) )
+    {
+    struct sock *sk;
+    struct iphdr *iph = ipip_hdr ( pskb );
+
+    if ( iph->protocol == 6 )
+        {
+        struct tcphdr *th, tcph;
+
+        th = skb_header_pointer (
+            pskb , iph->ihl << 2 , sizeof( tcph ) , &tcph );
+
+        sk = __inet_lookup( dev_net ( pskb->dst->dev ) , &tcp_hashinfo , 
+            iph->saddr , th->source , iph->daddr , th->dest , inet_iif ( pskb ) );
+
+        if( !sk )
+            {
+            return NF_DROP;
+            }
+        else
+            {
+            return NF_ACCEPT;
+            }
+        }
+
+    if ( iph->protocol == 17 )
+        {
+        struct udphdr *uh, udph;
+
+        uh = skb_header_pointer (
+            pskb , iph->ihl << 2 , sizeof( udph ) , &udph );
+
+        sk = __udp4_lib_lookup( dev_net ( pskb->dst->dev ) , iph->saddr , uh->source ,
+            iph->daddr , uh->dest , inet_iif ( pskb ) , udp_prot.h.udp_hash );
+
+        if ( sk != NULL )
+            {
+            return NF_ACCEPT;
+            }
+        else
+            {
+            return NF_DROP;
+            }
+        }
+
+    return NF_ACCEPT;
+    }
+
+
+static struct nf_hook_ops joikuspot_ops =
+    {
+    .hook     = joikuspot_nf_hook,
+    .owner    = THIS_MODULE,
+    .pf       = PF_INET,
+    .hooknum  = NF_INET_LOCAL_IN,
+    .priority = NF_IP_PRI_FIRST
+    };
+
+static int joikuspot_init( void )
+    {
+    int retval = 0;
+
+    printk( KERN_DEBUG "JoikuSpot Bouncer Kernel Module init\n" );
+
+    retval = nf_register_hook( &joikuspot_ops );
+
+    if ( retval < 0 )
+        {
+        return retval;
+        }
+
+    return retval;
+    }
+
+static void joikuspot_exit( void ) 
+    {
+    nf_unregister_hook ( &joikuspot_ops );
+    printk( KERN_DEBUG "JoikuSpot Bouncer Kernel Module exit\n" );
+    }
+
+module_init( joikuspot_init ); 
+module_exit( joikuspot_exit );
+