skb_push(9) [suse man page]

SKB_PUSH(9)							 Linux Networking						       SKB_PUSH(9)

NAME

       skb_push - add data to the start of a buffer

SYNOPSIS

       unsigned char * skb_push(struct sk_buff * skb, unsigned int len);

ARGUMENTS

       skb
	   buffer to use

       len
	   amount of data to add

DESCRIPTION

       This function extends the used data area of the buffer at the buffer start. If this would exceed the total buffer headroom the kernel will
       panic. A pointer to the first byte of the extra data is returned.

COPYRIGHT

Kernel Hackers Manual 2.6.					     July 2010							       SKB_PUSH(9)

CFG80211_TESTMODE_AL(9) 					     Test mode						   CFG80211_TESTMODE_AL(9)

NAME

       cfg80211_testmode_alloc_reply_skb - allocate testmode reply

SYNOPSIS

       struct sk_buff * cfg80211_testmode_alloc_reply_skb(struct wiphy * wiphy, int approxlen);

ARGUMENTS

       wiphy
	   the wiphy

       approxlen
	   an upper bound of the length of the data that will be put into the skb

DESCRIPTION

       This function allocates and pre-fills an skb for a reply to the testmode command. Since it is intended for a reply, calling it outside of
       the testmode_cmd operation is invalid.

       The returned skb is pre-filled with the wiphy index and set up in a way that any data that is put into the skb (with skb_put, nla_put or
       similar) will end up being within the NL80211_ATTR_TESTDATA attribute, so all that needs to be done with the skb is adding data for the
       corresponding userspace tool which can then read that data out of the testdata attribute. You must not modify the skb in any other way.

       When done, call cfg80211_testmode_reply with the skb and return its error code as the result of the testmode_cmd operation.

RETURN

       An allocated and pre-filled skb.  NULL if any errors happen.

AUTHOR

       Johannes Berg <johannes@sipsolutions.net>
	   Author.

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014						   CFG80211_TESTMODE_AL(9)