SKB_INSERT

Section: Networking Functions (9)
Updated: November 24, 1997
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NAME

__skb_insert, skb_insert, skb_append - insert an sk_buff into a list

SYNOPSIS

#include <linux/skbuff.h>

void __skb_insert(struct sk_buff *newsk, struct sk_buff *prev, struct sk_buff *next, struct sk_buff_head *list)
void skb_insert(struct sk_buff *old, struct sk_buff *newsk)
void skb_append(struct sk_buff *old, struct sk_buff *newsk)

DESCRIPTION

skb_insert and skb_append are essentially wrapper functions for __skb_insert (see NOTES, below.) __skb_insert inserts newsk into list, and resets the appropriate next and prev

pointers. prev and next are used to frame newsk in list. After setting the next and prev pointers in newsk, __skb_insert sets the prev pointer in next and the next pointer in prev, sets the list pointer in newsk, and increments the qlen counter in list.

skb_insert and skb_append should be used to add sk_buffs to a list rather than performing this task manually; in addition to performing this task in a standardized way, these functions also provide for interrupt diasabling and prevent list mangling. Both of these functions use the list pointer in old to determine to which list newsk should be attached.

The skb_insert function adds newsk to the list before old.

The skb_append function adds newsk to the list after old.

RETURN VALUE

None.

NOTES

It is important to note the difference between not only skb_insert, skb_append and __skb_insert, but all the __skb_ functions and their skb_ counterparts. Essentially, the __skb_ functions are non-atomic, and should only be used with interrupts disabled. As a convenience, the skb_ functions are provided, which perform interrupt disable / enable wrapper functionality in addition to performing their specific tasks.

AVAILABILITY

Linux 1.0+

AUTHOR

Cyrus Durgin <cider@speakeasy.org>