at v2.6.12 61 lines 1.5 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 struct sk_buff *skb; 38 unsigned long flags; 39 struct sk_buff *skb_from = (struct sk_buff *) from; 40 struct sk_buff *skb_to = (struct sk_buff *) to; 41 struct sk_buff *prev; 42 43 spin_lock_irqsave(&from->lock,flags); 44 spin_lock(&to->lock); 45 prev = from->prev; 46 from->next->prev = to->prev; 47 prev->next = skb_to; 48 to->prev->next = from->next; 49 to->prev = from->prev; 50 for (skb = from->next; skb != skb_to; skb = skb->next) 51 skb->list = to; 52 to->qlen += from->qlen; 53 spin_unlock(&to->lock); 54 from->prev = skb_from; 55 from->next = skb_from; 56 from->qlen = 0; 57 spin_unlock_irqrestore(&from->lock,flags); 58} 59 60 61EXPORT_SYMBOL(skb_migrate);