Re: strcut casts unsigned long
Javier Martinez Canillas <[email protected]>
| Newsgroups | org.kernel.vger.linux-c-programming |
|---|---|
| Message-ID | <[email protected]> |
>>
>> I have C question on skbuff.h.
>> skb->_skb_dst is defined as unsigned long and dst_entry is struct.
>>
>> Why strct dst_entry casts unsigned long skb->_skb_dst?
>>
>> See below
>>
>> static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
>> {
>> return (struct dst_entry *)skb->_skb_dst;
>> }
In the kernel, logical addresses are stored in variables of type
unsigned long or void *. Thats why _skb_dst is of type unsigned long.
>>
>> Appreciate any answer!
>>
>> --henry
>
> skb->_skb_dst can be a pointer to both destination cache or routing
> table . We could type cast to any of those .
>
> -Ratheesh
>
>
As Ratheesh said _skb_dst could be a pointer to two diferent data
structures, that is why _skb_dst is not defined as a struct type.
Best regards,
-----------------------------------------
Javier Martínez Canillas
+595 981 88 66 58
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