Linux Device Drivers Development

The socket buffer structure

This structure wraps any packet that transits through an NIC:

struct sk_buff { 
  struct sk_buff * next; 
  struct sk_buff * prev; 
  ktime_t tstamp; 
  struct rb_node     rbnode; /* used in netem & tcp stack */ 
  struct sock * sk; 
  struct net_device * dev; 
  unsigned int       len; 
  unsigned int       data_len; 
  __u16              mac_len; 
  __u16              hdr_len; 
  unsigned int len; 
  unsigned int data_len; 
  __u16 mac_len; 
  __u16 hdr_len; 
  __u32 priority; 
  dma_cookie_t dma_cookie; 
  sk_buff_data_t tail; 
  sk_buff_data_t end; 
  unsigned char * head; 
  unsigned char * data; 
  unsigned int truesize; 
  atomic_t users; 
}; 

The following explain the elements in the structure:

• next and prev : These represent the next and previous buffers in the list.
• sk: This is the socket associated with this ...