Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
| 35 | void 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 | |
| 61 | EXPORT_SYMBOL(skb_migrate); |