at v2.6.16 58 lines 1.4 kB view raw
1/* net/atm/ipcommon.c - Common items for all ways of doing IP over ATM */ 2 3/* Written 1996-2000 by Werner Almesberger, EPFL LRC/ICA */ 4 5 6#include <linux/module.h> 7#include <linux/string.h> 8#include <linux/skbuff.h> 9#include <linux/netdevice.h> 10#include <linux/in.h> 11#include <linux/atmdev.h> 12#include <linux/atmclip.h> 13 14#include "common.h" 15#include "ipcommon.h" 16 17 18#if 0 19#define DPRINTK(format,args...) printk(KERN_DEBUG format,##args) 20#else 21#define DPRINTK(format,args...) 22#endif 23 24 25/* 26 * skb_migrate appends the list at "from" to "to", emptying "from" in the 27 * process. skb_migrate is atomic with respect to all other skb operations on 28 * "from" and "to". Note that it locks both lists at the same time, so beware 29 * of potential deadlocks. 30 * 31 * This function should live in skbuff.c or skbuff.h. 32 */ 33 34 35void skb_migrate(struct sk_buff_head *from,struct sk_buff_head *to) 36{ 37 unsigned long flags; 38 struct sk_buff *skb_from = (struct sk_buff *) from; 39 struct sk_buff *skb_to = (struct sk_buff *) to; 40 struct sk_buff *prev; 41 42 spin_lock_irqsave(&from->lock,flags); 43 spin_lock(&to->lock); 44 prev = from->prev; 45 from->next->prev = to->prev; 46 prev->next = skb_to; 47 to->prev->next = from->next; 48 to->prev = from->prev; 49 to->qlen += from->qlen; 50 spin_unlock(&to->lock); 51 from->prev = skb_from; 52 from->next = skb_from; 53 from->qlen = 0; 54 spin_unlock_irqrestore(&from->lock,flags); 55} 56 57 58EXPORT_SYMBOL(skb_migrate);