__pskb_pull_tail(9) [suse 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 2.6.					     July 2010						       __PSKB_PULL_TAIL(9)

__SKB_RECV_DATAGRAM(9)						 Linux Networking					    __SKB_RECV_DATAGRAM(9)

NAME

       __skb_recv_datagram - Receive a datagram skbuff

SYNOPSIS

       struct sk_buff * __skb_recv_datagram(struct sock * sk, unsigned int flags, int * peeked, int * off, int * err);

ARGUMENTS

       sk
	   socket

       flags
	   MSG_ flags

       peeked
	   returns non-zero if this packet has been seen before

       off
	   an offset in bytes to peek skb from. Returns an offset within an skb where data actually starts

       err
	   error code returned

DESCRIPTION

       Get a datagram skbuff, understands the peeking, nonblocking wakeups and possible races. This replaces identical code in packet, raw and
       udp, as well as the IPX AX.25 and Appletalk. It also finally fixes the long standing peek and read race for datagram sockets. If you alter
       this routine remember it must be re-entrant.

       This function will lock the socket if a skb is returned, so the caller needs to unlock the socket in that case (usually by calling
       skb_free_datagram)

       * It does not lock socket since today. This function is * free of race conditions. This measure should/can improve * significantly datagram
       socket latencies at high loads, * when data copying to user space takes lots of time. * (BTW I've just killed the last cli in
       IP/IPv6/core/netlink/packet * 8) Great win.) * --ANK (980729)

       The order of the tests when we find no data waiting are specified quite explicitly by POSIX 1003.1g, don't change them without having the
       standard around please.

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014						    __SKB_RECV_DATAGRAM(9)