[Aodvimpl] How to modify kaodv-ipenc.c to port aodv-uu 0.9.5 to Linux kernel 2.6.26? (re-post for unsuccesful mail delivery)

[Wang R. <wan...@gm...>]

(I recieved a fail to deliver message from my university's mail
server, so I try to post it again using gmail. If my last post
delivered successfully, just ignore it. sorry for the inconvenience)

Hi,
         I am trying to port aodv-uu 0.9.5 to Linux kernel 2.6.26. The
netfilter implementation has changed since 2.6.24 :

    [NETFILTER]: Replace sk_buff ** with sk_buff *

    With all the users of the double pointers removed, this patch mops up by
    finally replacing all occurances of sk_buff ** in the netfilter API by
sk_buff *.

So the original 0.9.5 implementation of struct sk_buff
*ip_pkt_encapsulate(struct sk_buff *skb, __u32 dest) no longer works.
I tried to modify ip_pkt_encapsulate by using pskb_expand_head instead
of skb_copy_expand:
struct sk_buff *ip_pkt_encapsulate(struct sk_buff *skb, __u32 dest)
{
    int oldlen;

    struct min_ipenc_hdr *ipe;
    struct iphdr *iph;

    /* Allocate new data space at head */
    if( pskb_expand_head(skb,0,
                   sizeof(struct min_ipenc_hdr),GFP_ATOMIC) < 0) {
                   printk("Could not expand skb header\n");
                   kfree_skb(skb);
                   return NULL;
    }

#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22))
    iph = skb->nh.iph;
#else
    iph = (struct iphdr *)skb->network_header;
#endif
    oldlen = skb->len;
         skb_put(skb, sizeof(struct min_ipenc_hdr));

    /* Move the data */
    memmove(skb->data + (iph->ihl << 2) + sizeof(struct min_ipenc_hdr),
            skb->data + (iph->ihl << 2), oldlen - (iph->ihl << 2));

    /* Update pointers */
#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22))
    iph = skb->nh.iph = (struct iphdr *)skb->data;
#else
    iph = (struct iphdr *)skb->data;
    skb->network_header = skb->data;
#endif

    ipe = (struct min_ipenc_hdr *)(skb->data + (iph->ihl << 2));
…
}

But the kaodv module crashes when sending paged packages, saying that
the skb is not linear, so I added:
If(!skb_make_writable(skb,skb->len)) {
         printk("Could not make skb writable\n");
         return NULL;
}
just before calling pskb_expand_head. The module stops crashing this
time, but the package still cannot deliver correctly.
Can anybody tell me how to modify ip_pkt_encapsulate to correctly add
the additional header to the paged skb?

Wang Rui
wan...@ue..., wan...@gm...