__pskb_pull_tail(9) [centos man page]

__PSKB_PULL_TAIL(9)						 Linux Networking					       __PSKB_PULL_TAIL(9)

NAME

       __pskb_pull_tail - advance tail of skb header

SYNOPSIS

       unsigned char * __pskb_pull_tail(struct sk_buff * skb, int delta);

ARGUMENTS

       skb
	   buffer to reallocate

       delta
	   number of bytes to advance tail

DESCRIPTION

       The function makes a sense only on a fragmented sk_buff, it expands header moving its tail forward and copying necessary data from
       fragmented part.

       sk_buff MUST have reference count of 1.

       Returns NULL (and sk_buff does not change) if pull failed or value of new tail of skb in the case of success.

       All the pointers pointing into skb header may change and must be reloaded after call to this function.

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014						       __PSKB_PULL_TAIL(9)

STRUCT 
SK_BUFF(9)						 Linux Networking						 STRUCT SK_BUFF(9)

NAME

       struct_sk_buff - socket buffer

SYNOPSIS

       struct sk_buff {
	 struct sk_buff * next;
	 struct sk_buff * prev;
	 ktime_t tstamp;
	 struct sock * sk;
	 struct net_device * dev;
	 char cb[48];
	 unsigned long _skb_dst;
       #ifdef CONFIG_XFRM
	 struct sec_path * sp;
       #endif
	 unsigned int len;
	 unsigned int data_len;
	 __u16 mac_len;
	 __u16 hdr_len;
	 union {unnamed_union};
	 __u16 vlan_tci;
	 sk_buff_data_t transport_header;
	 sk_buff_data_t network_header;
	 sk_buff_data_t mac_header;
	 sk_buff_data_t tail;
	 sk_buff_data_t end;
	 unsigned char * head;
	 unsigned char * data;
	 unsigned int truesize;
	 atomic_t users;
       };

MEMBERS

       next
	   Next buffer in list

       prev
	   Previous buffer in list

       tstamp
	   Time we arrived

       sk
	   Socket we are owned by

       dev
	   Device we arrived on/are leaving by

       cb[48]
	   Control buffer. Free for use by every layer. Put private vars here

       _skb_dst
	   destination entry

       sp
	   the security path, used for xfrm

       len
	   Length of actual data

       data_len
	   Data length

       mac_len
	   Length of link layer header

       hdr_len
	   writable header length of cloned skb

       {unnamed_union}
	   anonymous

       vlan_tci
	   vlan tag control information

       transport_header
	   Transport layer header

       network_header
	   Network layer header

       mac_header
	   Link layer header

       tail
	   Tail pointer

       end
	   End pointer

       head
	   Head of buffer

       data
	   Data head pointer

       truesize
	   Buffer size

       users
	   User count - see {datagram,tcp}.c

COPYRIGHT

Kernel Hackers Manual 2.6.					     July 2010							 STRUCT SK_BUFF(9)