1 files changed, 32 insertions, 30 deletions

diff --git a/kernel/ipt_CRYPT.c b/kernel/ipt_CRYPT.c
index 5fdbc87..0b70319 100644
--- a/kernel/ipt_CRYPT.c
+++ b/kernel/ipt_CRYPT.c
@@ -19,17 +19,6 @@
   USA
 ***/
 
-#include <linux/config.h>
-
-#if defined(CONFIG_MODVERSIONS) && !defined(MODVERSIONS)
- #define MODVERSIONS
-#endif
-
-#if defined(MODVERSIONS) && !defined(__GENKSYMS__)
- #include <linux/modversions.h>
- #include "seppl.ver"
-#endif
-
 #include <linux/module.h>
 #include <linux/skbuff.h>
 #include <linux/ip.h>
@@ -53,16 +42,31 @@ MODULE_DESCRIPTION("SEPPL iptables Encryption Target");
 MODULE_AUTHOR("Lennart Poettering <"PACKAGE_BUGREPORT">");
 #endif
 
-static unsigned int ipt_CRYPT_target(struct sk_buff **pskb, unsigned int hooknum, const struct net_device *in, const struct net_device *out, const void *_ti, void *userinfo) {
+static unsigned int ipt_CRYPT_target(struct sk_buff **pskb,
+                                     const struct net_device *in,
+                                     const struct net_device *out,
+                                     unsigned int hooknum,
+                                     const void *_ti,
+                                     void *userinfo) {
+    
     const struct ipt_crypt_info *ti = _ti;
-    struct iphdr *ih = (*pskb)->nh.iph;
-    unsigned d, new_l, crypt_l, ihl = ih->ihl<<2;
+    struct iphdr *ih;
+    unsigned d, new_l, crypt_l, ihl;
     struct seppl_uncrypt_hdr *uh;
     struct seppl_crypt_hdr *ch;
     u8 *iv, *pl;
     int ivs = ti->key->ivsize;
     int bs = ti->key->blocksize;
     struct scatterlist sg[1];
+
+    if (!skb_ip_make_writable(pskb, (*pskb)->len)) {
+        if (net_ratelimit())
+            printk(KERN_ERR "ipt_DECRYPT: Failed to make skb writable.\n");
+        return NF_DROP;
+    }
+
+    ih = (*pskb)->nh.iph;
+    ihl = ih->ihl<<2;
     
     // Calculate new packet size
     new_l = ihl + sizeof(struct seppl_uncrypt_hdr) + ivs + ((sizeof(struct seppl_crypt_hdr) + ntohs(ih->tot_len) - ihl + bs - 1) / bs) * bs;
@@ -152,20 +156,20 @@ static unsigned int ipt_CRYPT_target(struct sk_buff **pskb, unsigned int hooknum
 static int ipt_CRYPT_check(const char *table, const struct ipt_entry *e, void *_ti, unsigned int ti_size, unsigned int hook_mask) {
     struct ipt_crypt_info *ti = _ti;
     
- 	if (ti_size != IPT_ALIGN(sizeof(struct ipt_crypt_info))) {
+    if (ti_size != IPT_ALIGN(sizeof(struct ipt_crypt_info))) {
         printk(KERN_ERR "ipt_CRYPT: Structure too small\n");
-  		return 0;
-  	}
+        return 0;
+    }
     
-	if (strcmp(table, "mangle") != 0) {
-		printk(KERN_ERR "ipt_CRYPT: Not in mangle table\n");
-		return 0;
-	}
+    if (strcmp(table, "mangle") != 0) {
+        printk(KERN_ERR "ipt_CRYPT: Not in mangle table\n");
+        return 0;
+    }
     
- 	if ((hook_mask & ~(1 << NF_IP_POST_ROUTING)) != 0) { 
- 		printk(KERN_ERR "ipt_CRYPT: Not in POSTROUTING chain\n"); 
- 		return 0; 
- 	} 
+    if ((hook_mask & ~(1 << NF_IP_POST_ROUTING)) != 0) { 
+        printk(KERN_ERR "ipt_CRYPT: Not in POSTROUTING chain\n"); 
+        return 0; 
+    } 
     
     if (!(ti->key = seppl_claim_key(ti->algorithm, ti->name))) {
         printk(KERN_ERR "ipt_CRYPT: Cannot find key\n");
@@ -184,21 +188,19 @@ static void ipt_CRYPT_destroy(void *_ti, unsigned int ti_size) {
 static struct ipt_target ipt_CRYPT_reg = {
     { NULL, NULL },
     "CRYPT",
-    ipt_CRYPT_target,
     ipt_CRYPT_check,
     ipt_CRYPT_destroy,
+    ipt_CRYPT_target,
     THIS_MODULE
 };
 
 static int __init init(void) {
-	return ipt_register_target(&ipt_CRYPT_reg);
+    return ipt_register_target(&ipt_CRYPT_reg);
 }
 
 static void __exit fini(void) {
-	ipt_unregister_target(&ipt_CRYPT_reg);
+    ipt_unregister_target(&ipt_CRYPT_reg);
 }
 
 module_init(init);
 module_exit(fini);
-
-EXPORT_NO_SYMBOLS;