Hi All
I've upgraded my kernel from 2.6.17 to 2.6.39,one of the kernel module can't be compiled.
the original code is :

struct iphdr *iph = skb->nh.iph;
struct icmphdr *icmp = (void *)iph + iph->ihl * 4 ;

if(!(iph->protocol == IPPROTO_ICMP))
return ((0) ^ info->invert);

after I searched from google,I modified the code become:

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
struct iphdr *iph = ip_hdr(skb);
#else
struct iphdr *iph = skb->nh.iph;
#endif
struct icmphdr *icmp = (void *)iph + iph->ihl * 4 ;

if(!(iph->protocol == IPPROTO_ICMP))
return ((0) ^ info->invert);

But still can't work.
Error message:
icmpid/xt_icmpid.c: In function 'match':
icmpid/xt_icmpid.c:48:16: error: implicit declaration of function 'ip_hdr'
icmpid/xt_icmpid.c:48:29: warning: initialization makes pointer from integer without a cast
icmpid/xt_icmpid.c:53:43: error: dereferencing pointer to incomplete type
icmpid/xt_icmpid.c:55:13: error: dereferencing pointer to incomplete type

Does anyone know how to modify it? thanks for any help~

Hi,

in order to help you we need some basic information:
- what are your distribution and version?
- why so huge a jump (from 2.6.17 to 2.6.39)? wouldn't it be simpler to upgrade your distribution's version, or to install a newer one?
- do you try to compile a vanilla kernel (coming directly from kernel.org) or an already patched one?
- how did you configure your kernel? Did you re-use an old ".config" and issued a "make oldconfig" or not?
- which kernel module is involved?
- what are the exact error messages you got before modifying the code?

- what are your distribution and version?
Fedora 5 to Fedora 14
- why so huge a jump (from 2.6.17 to 2.6.39)? wouldn't it be simpler to upgrade your distribution's version, or to install a newer one?
Install a newer one
- do you try to compile a vanilla kernel (coming directly from kernel.org) or an already patched one?
Coming directly from kernel.org
- how did you configure your kernel? Did you re-use an old ".config" and issued a "make oldconfig" or not?
The problem is caused by kernel 2.6.22 redefined new skbuff.h,all structure were changed.
2.4.x~2.6.22 has an old structure. >2.6.22 has a new structure.
- which kernel module is involved?
No other kernel module is involved.
- what are the exact error messages you got before modifying the code?
46 //#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
47 //struct iphdr *iph = ip_hdr(skb);
48 //#else
49 struct iphdr *iph = skb->nh.iph;
50 //#endif
51 struct icmphdr *icmp = (void *)iph + iph->ihl * 4 ;
52
53 if(!(iph->protocol == IPPROTO_ICMP))
54 return ((0) ^ info->invert);

icmpid/xt_icmpid.c: In function 'match':
icmpid/xt_icmpid.c:49:32: error: 'struct sk_buff' has no member named 'nh'
icmpid/xt_icmpid.c:51:43: error: dereferencing pointer to incomplete type
icmpid/xt_icmpid.c:53:13: error: dereferencing pointer to incomplete type

I know what caused my problem.
After I included ip.h , all errors were disappear.