From 300ce174ebc2fcf2b5111a50fa42f79d891927dd Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Sun, 30 Oct 2005 13:47:34 -0800 Subject: [NETEM]: Support time based reordering Change netem to support packets getting reordered because of variations in delay. Introduce a special case version of FIFO that queues packets in order based on the netem delay. Since netem is classful, those users that don't want jitter based reordering can just insert a pfifo instead of the default. This required changes to generic skbuff code to allow finer grain manipulation of sk_buff_head. Insertion into the middle and reverse walk. Signed-off-by: Stephen Hemminger Signed-off-by: Arnaldo Carvalho de Melo --- include/linux/skbuff.h | 38 ++++++++++++++++++++++++++++++-------- 1 file changed, 30 insertions(+), 8 deletions(-) (limited to 'include/linux/skbuff.h') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 4286d832166f..fdfb8fe8c38c 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -603,29 +603,46 @@ static inline void skb_queue_head_init(struct sk_buff_head *list) */ /** - * __skb_queue_head - queue a buffer at the list head + * __skb_queue_after - queue a buffer at the list head * @list: list to use + * @prev: place after this buffer * @newsk: buffer to queue * - * Queue a buffer at the start of a list. This function takes no locks + * Queue a buffer int the middle of a list. This function takes no locks * and you must therefore hold required locks before calling it. * * A buffer cannot be placed on two lists at the same time. */ -extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk); -static inline void __skb_queue_head(struct sk_buff_head *list, - struct sk_buff *newsk) +static inline void __skb_queue_after(struct sk_buff_head *list, + struct sk_buff *prev, + struct sk_buff *newsk) { - struct sk_buff *prev, *next; - + struct sk_buff *next; list->qlen++; - prev = (struct sk_buff *)list; + next = prev->next; newsk->next = next; newsk->prev = prev; next->prev = prev->next = newsk; } +/** + * __skb_queue_head - queue a buffer at the list head + * @list: list to use + * @newsk: buffer to queue + * + * Queue a buffer at the start of a list. This function takes no locks + * and you must therefore hold required locks before calling it. + * + * A buffer cannot be placed on two lists at the same time. + */ +extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk); +static inline void __skb_queue_head(struct sk_buff_head *list, + struct sk_buff *newsk) +{ + __skb_queue_after(list, (struct sk_buff *)list, newsk); +} + /** * __skb_queue_tail - queue a buffer at the list tail * @list: list to use @@ -1203,6 +1220,11 @@ static inline void kunmap_skb_frag(void *vaddr) prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \ skb = skb->next) +#define skb_queue_reverse_walk(queue, skb) \ + for (skb = (queue)->prev; \ + prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \ + skb = skb->prev) + extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, int noblock, int *err); -- cgit v1.2.2