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>skb_cow</SPAN
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><H2
>Name</H2
>skb_cow -- copy header of skb when it is required
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><CODE
><CODE
CLASS="FUNCDEF"
>int <TT
CLASS="FUNCTION"
>skb_cow </TT
></CODE
>(struct sk_buff * <TT
CLASS="PARAMETER"
><I
>skb</I
></TT
>, unsigned int <TT
CLASS="PARAMETER"
><I
>headroom</I
></TT
>);</CODE
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>Arguments</H2
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><TT
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><I
>skb</I
></TT
></DT
><DD
><P
> buffer to cow
</P
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><DT
><TT
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><I
>headroom</I
></TT
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><DD
><P
> needed headroom
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><H2
>Description</H2
><P
> If the skb passed lacks sufficient headroom or its data part
is shared, data is reallocated. If reallocation fails, an error
is returned and original skb is not changed.
</P
><P
> The result is skb with writable area skb->head...skb->tail
and at least <TT
CLASS="PARAMETER"
><I
>headroom</I
></TT
> of space at head.
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