[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: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Stephen Hemminger 2008-01-21 02:23:49 -08:00 committed by David S. Miller
parent 5b0ac72bc5
commit 4c30719f4f

View File

@ -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)