diff -urN vpnclient.orig/Makefile vpnclient/Makefile
--- vpnclient.orig/Makefile	2008-06-23 17:59:12.000000000 +0100
+++ vpnclient/Makefile	2009-03-01 23:12:18.000000000 +0000
@@ -12,7 +12,9 @@
 SOURCE_OBJS := linuxcniapi.o frag.o IPSecDrvOS_linux.o interceptor.o linuxkernelapi.o
 
 ifeq ($(SUBARCH),x86_64)
-CFLAGS += -mcmodel=kernel -mno-red-zone
+# Must NOT fiddle with CFLAGS
+# CFLAGS += -mcmodel=kernel -mno-red-zone
+EXTRA_CFLAGS += -mcmodel=kernel -mno-red-zone
 NO_SOURCE_OBJS := libdriver64.so
 else
 NO_SOURCE_OBJS := libdriver.so
diff -urN vpnclient.orig/frag.c vpnclient/frag.c
--- vpnclient.orig/frag.c	2008-06-23 17:59:12.000000000 +0100
+++ vpnclient/frag.c	2009-03-01 23:12:18.000000000 +0000
@@ -22,7 +22,9 @@
 #include "frag.h"
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
-#define SKB_IPHDR(skb) ((struct iphdr*)skb->network_header)
+/* 2.6.22 added an inline function for 32-/64-bit usage here, so use it.
+ */
+#define SKB_IPHDR(skb) ((struct iphdr*)skb_network_header)
 #else
 #define SKB_IPHDR(skb) skb->nh.iph
 #endif
diff -urN vpnclient.orig/interceptor.c vpnclient/interceptor.c
--- vpnclient.orig/interceptor.c	2008-06-23 17:59:12.000000000 +0100
+++ vpnclient/interceptor.c	2009-03-01 23:12:59.000000000 +0000
@@ -637,19 +637,28 @@
 
     reset_inject_status(&pBinding->recv_stat);
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
-    if (skb->mac_header)
+/* 2.6.22 added an inline function for 32-/64-bit usage here, so use it.
+ */
+    if (skb_mac_header_was_set(skb))
 #else
     if (skb->mac.raw)
 #endif
     {
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
-        hard_header_len = skb->data - skb->mac_header;
+/* 2.6.22 added an inline function for 32-/64-bit usage here, so use it.
+ */
+        hard_header_len = skb->data - skb_mac_header(skb);
 #else
         hard_header_len = skb->data - skb->mac.raw;
 #endif
         if ((hard_header_len < 0) || (hard_header_len > skb_headroom(skb)))
         {
-            printk(KERN_DEBUG "bad hh len %d\n", hard_header_len);
+            printk(KERN_DEBUG "bad hh len %d, mac: %d, data: %p, head: %p\n",
+                hard_header_len,
+                skb->mac_header,    /* actually ptr in 32-bit */
+                skb->data,
+                skb->head);
+
             hard_header_len = 0;
         }
     }
@@ -664,7 +673,9 @@
     {
     case ETH_HLEN:
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
-        CniNewFragment(ETH_HLEN, skb->mac_header, &MacHdr, CNI_USE_BUFFER);
+/* 2.6.22 added an inline function for 32-/64-bit usage here, so use it.
+ */
+        CniNewFragment(ETH_HLEN, skb_mac_header(skb), &MacHdr, CNI_USE_BUFFER);
 #else
         CniNewFragment(ETH_HLEN, skb->mac.raw, &MacHdr, CNI_USE_BUFFER);
 #endif
@@ -782,7 +793,9 @@
 #endif //LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
     reset_inject_status(&pBinding->send_stat);
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
-    hard_header_len = skb->network_header - skb->data;
+/* 2.6.22 added an inline function for 32-/64-bit usage here, so use it.
+ */
+    hard_header_len = skb_network_header(skb) - skb->data;
 #else
     hard_header_len = skb->nh.raw - skb->data;
 #endif
diff -urN vpnclient.orig/linuxcniapi.c vpnclient/linuxcniapi.c
--- vpnclient.orig/linuxcniapi.c	2008-06-23 17:59:12.000000000 +0100
+++ vpnclient/linuxcniapi.c	2009-03-01 23:12:18.000000000 +0000
@@ -338,8 +338,12 @@
     skb->ip_summed = CHECKSUM_UNNECESSARY;
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
-    skb->network_header = (sk_buff_data_t) skb->data;
-    skb->mac_header = (sk_buff_data_t)pMac;
+/* 2.6.22 added an inline function for 32-/64-bit usage here, so use it.
+ * We have to use (pMac - skb->data) to get an offset.
+ * We need to cast ptrs to byte ptrs and take the difference.
+ */
+    skb_reset_network_header(skb);
+    skb_set_mac_header(skb, (int)((void *)pMac - (void *)skb->data));
 #else
     skb->nh.iph = (struct iphdr *) skb->data;
     skb->mac.raw = pMac;
@@ -478,8 +482,12 @@
     skb->dev = pBinding->pDevice;
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
-    skb->mac_header = (sk_buff_data_t)pMac;
-    skb->network_header = (sk_buff_data_t)pIP;
+/* 2.6.22 added an inline function for 32-/64-bit usage here, so use it.
+ * We have to use (pIP/pMac - skb->data) to get an offset.
+ * We need to cast ptrs to byte ptrs and take the difference.
+ */
+    skb_set_mac_header(skb, (int)((void *)pMac - (void *)skb->data));
+    skb_set_network_header(skb, (int)((void *)pIP - (void *)skb->data));
 #else
     skb->mac.raw = pMac;
     skb->nh.raw = pIP;
@@ -487,8 +495,13 @@
 
     /*ip header length is in 32bit words */
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
-    skb->transport_header = (sk_buff_data_t)
-      (pIP + (((struct iphdr*)(skb->network_header))->ihl * 4));
+/* 2.6.22 added an inline function for 32-/64-bit usage here, so use it.
+ * We have to use (pIP - skb->data) to get an offset.
+ * We need to cast ptrs to byte ptrs and take the difference.
+ */
+    skb_set_transport_header(skb,
+        ((int)((void *)pIP - (void *)skb->data) +
+           (((struct iphdr*)(skb_network_header(skb)))->ihl * 4)));
 #else
     skb->h.raw = pIP + (skb->nh.iph->ihl * 4);
 #endif
diff -urN vpnclient.orig/linuxkernelapi.c vpnclient/linuxkernelapi.c
--- vpnclient.orig/linuxkernelapi.c	2008-06-23 17:59:12.000000000 +0100
+++ vpnclient/linuxkernelapi.c	2009-03-01 23:12:18.000000000 +0000
@@ -9,7 +9,10 @@
     void*rc = kmalloc(size, GFP_ATOMIC);
     if(NULL == rc)
     {
-        printk("<1> os_malloc size %d failed\n",size);
+/* Allow for 32- or 64-bit size        
+ *        printk("<1> os_malloc size %d failed\n",size);
+ */
+        printk("<1> os_malloc size %ld failed\n", (long)size);
     }
 
     return rc;