Commit 4c30719f authored by Stephen Hemminger's avatar Stephen Hemminger Committed by David S. Miller
Browse files

[PKT_SCHED] dsmark: handle cloned and non-linear skb's 



Make dsmark work properly with non-linear and cloned skb's
Before modifying the header, it needs to check that skb header is
writeable.

Note: this makes the assumption, that if it queues a good skb
then a good skb will come out of the embedded qdisc.

Signed-off-by: default avatarStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5b0ac72b

net/sched/sch_dsmark.c

+15 −4
Original line number Diff line number Diff line
@@ -187,13 +187,19 @@ static int dsmark_enqueue(struct sk_buff *skb,struct Qdisc *sch) 
	pr_debug("dsmark_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);



	if (p->set_tc_index) {

		/* FIXME: Safe with non-linear skbs? --RR */

		switch (skb->protocol) {

			case __constant_htons(ETH_P_IP):

				if (skb_cow_head(skb, sizeof(struct iphdr)))

					goto drop;



				skb->tc_index = ipv4_get_dsfield(ip_hdr(skb))

					& ~INET_ECN_MASK;

				break;



			case __constant_htons(ETH_P_IPV6):

				if (skb_cow_head(skb, sizeof(struct ipv6hdr)))

					goto drop;



				skb->tc_index = ipv6_get_dsfield(ipv6_hdr(skb))

					& ~INET_ECN_MASK;

				break;
@@ -217,14 +223,14 @@ static int dsmark_enqueue(struct sk_buff *skb,struct Qdisc *sch) 
		case TC_ACT_STOLEN:

			kfree_skb(skb);

			return NET_XMIT_SUCCESS;



		case TC_ACT_SHOT:

			kfree_skb(skb);

			sch->qstats.drops++;

			return NET_XMIT_BYPASS;

			goto drop;

#endif

		case TC_ACT_OK:

			skb->tc_index = TC_H_MIN(res.classid);

			break;



		default:

			if (p->default_index != NO_DEFAULT_INDEX)

				skb->tc_index = p->default_index;
@@ -243,6 +249,11 @@ static int dsmark_enqueue(struct sk_buff *skb,struct Qdisc *sch) 
	sch->q.qlen++;



	return NET_XMIT_SUCCESS;



drop:

	kfree_skb(skb);

	sch->qstats.drops++;

	return NET_XMIT_BYPASS;

}



static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)

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