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-rw-r--r--net/sched/sch_cake.c41
1 files changed, 30 insertions, 11 deletions
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 60f8ae578819..cae006bef565 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -1553,30 +1553,49 @@ static unsigned int cake_drop(struct Qdisc *sch, struct sk_buff **to_free)
static u8 cake_handle_diffserv(struct sk_buff *skb, u16 wash)
{
- int wlen = skb_network_offset(skb);
+ const int offset = skb_network_offset(skb);
+ u16 *buf, buf_;
u8 dscp;
switch (tc_skb_protocol(skb)) {
case htons(ETH_P_IP):
- wlen += sizeof(struct iphdr);
- if (!pskb_may_pull(skb, wlen) ||
- skb_try_make_writable(skb, wlen))
+ buf = skb_header_pointer(skb, offset, sizeof(buf_), &buf_);
+ if (unlikely(!buf))
return 0;
- dscp = ipv4_get_dsfield(ip_hdr(skb)) >> 2;
- if (wash && dscp)
+ /* ToS is in the second byte of iphdr */
+ dscp = ipv4_get_dsfield((struct iphdr *)buf) >> 2;
+
+ if (wash && dscp) {
+ const int wlen = offset + sizeof(struct iphdr);
+
+ if (!pskb_may_pull(skb, wlen) ||
+ skb_try_make_writable(skb, wlen))
+ return 0;
+
ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, 0);
+ }
+
return dscp;
case htons(ETH_P_IPV6):
- wlen += sizeof(struct ipv6hdr);
- if (!pskb_may_pull(skb, wlen) ||
- skb_try_make_writable(skb, wlen))
+ buf = skb_header_pointer(skb, offset, sizeof(buf_), &buf_);
+ if (unlikely(!buf))
return 0;
- dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2;
- if (wash && dscp)
+ /* Traffic class is in the first and second bytes of ipv6hdr */
+ dscp = ipv6_get_dsfield((struct ipv6hdr *)buf) >> 2;
+
+ if (wash && dscp) {
+ const int wlen = offset + sizeof(struct ipv6hdr);
+
+ if (!pskb_may_pull(skb, wlen) ||
+ skb_try_make_writable(skb, wlen))
+ return 0;
+
ipv6_change_dsfield(ipv6_hdr(skb), INET_ECN_MASK, 0);
+ }
+
return dscp;
case htons(ETH_P_ARP):