hello Michael,
So i can access source ip address of packet in
kernel stack code after eth header is removed and
processed in function eth_type_trans in eth.c as
u32 someaddr = ((struct iphdr *) (skb->data +
sizeof(struct ethhdr))->saddr;
Is that right?
regards,
linux_lover.
--- "Michael R. Hines" <mhines@xxxxxxxxxx> wrote:
>
> Indeed they are readable.
>
> They are located within the region pointed to by
> skb->data
>
> more specifically:
>
> u32 someaddr = ((struct iphdr *) (skb->data +
> sizeof(struct
> ethhdr))->saddr; //if I remember correctly
>
> ......Assuming you're reading the packet directly
> from the network card.
>
> Otherwise, skb->data may be moved up by a header or
> two.
> For example, if you're inside the IP receive
> functions, the pointer will be
> moved up by sizeof(struct ethhdr) bytes.
>
> At 07:50 AM 4/10/2005, linux lover wrote:
> >hello,
> > Does skbuffs provide facility to access other
> >layers headers at any layer? What i want, if packet
> is
> >processed at LINK layer then can IP addresses(SRC &
> >DST) of packets is readable at Link layer?
> >
> >regards,
> >linux_lover.
> >
> >
> >
> >__________________________________
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> /*********************************/
> Michael R. Hines
> Grad Student, Florida State
> Dept. Computer Science
> http://www.cs.fsu.edu/~mhines/
> Jusqu'à ce que le futur vienne...
> /*********************************/
>
>
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