skb_cow_data (9) - Linux Man Pages
skb_cow_data: Check that a socket buffer's data buffers are writable
skb_cow_data - Check that a socket buffer's data buffers are writable
int skb_cow_data(struct sk_buff
*skb, int tailbits, struct sk_buff **trailer);
- The socket buffer to check.
- Amount of trailing space to be added
- Returned pointer to the skb where the tailbits space begins
Make sure that the data buffers attached to a socket buffer are writable. If they are not, private copies are made of the data buffers and the socket buffer is set to use these instead.
If tailbits is given, make sure that there is space to write tailbits bytes of data beyond current end of socket buffer. trailer will be set to point to the skb in which this space begins.