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authorToke Høiland-Jørgensen <toke@toke.dk>2019-03-01 18:04:05 +0300
committerDavid S. Miller <davem@davemloft.net>2019-03-04 07:14:28 +0300
commit4976e3c683f328bc6f2edef555a4ffee6524486f (patch)
treef6954a02688cc21ba365b45a9a0dfbded540f0c0 /net/sched/sch_cake.c
parent0b5c7efdfc6e389ec6840579fe90bdb6f42b08dc (diff)
downloadlinux-4976e3c683f328bc6f2edef555a4ffee6524486f.tar.xz
sch_cake: Simplify logic in cake_select_tin()
With more modes added the logic in cake_select_tin() was getting a bit hairy, and it turns out we can actually simplify it quite a bit. This also allows us to get rid of one of the two diffserv parsing functions, which has the added benefit that already-zeroed DSCP fields won't get re-written. Suggested-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/sch_cake.c')
-rw-r--r--net/sched/sch_cake.c61
1 files changed, 23 insertions, 38 deletions
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index f1cc4779699b..1d2a12132abc 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -1513,20 +1513,6 @@ static unsigned int cake_drop(struct Qdisc *sch, struct sk_buff **to_free)
return idx + (tin << 16);
}
-static void cake_wash_diffserv(struct sk_buff *skb)
-{
- switch (skb->protocol) {
- case htons(ETH_P_IP):
- ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, 0);
- break;
- case htons(ETH_P_IPV6):
- ipv6_change_dsfield(ipv6_hdr(skb), INET_ECN_MASK, 0);
- break;
- default:
- break;
- }
-}
-
static u8 cake_handle_diffserv(struct sk_buff *skb, u16 wash)
{
u8 dscp;
@@ -1558,33 +1544,32 @@ static struct cake_tin_data *cake_select_tin(struct Qdisc *sch,
{
struct cake_sched_data *q = qdisc_priv(sch);
u32 tin;
+ u8 dscp;
- if (TC_H_MAJ(skb->priority) == sch->handle &&
- TC_H_MIN(skb->priority) > 0 &&
- TC_H_MIN(skb->priority) <= q->tin_cnt) {
- tin = q->tin_order[TC_H_MIN(skb->priority) - 1];
+ /* Tin selection: Default to diffserv-based selection, allow overriding
+ * using firewall marks or skb->priority.
+ */
+ dscp = cake_handle_diffserv(skb,
+ q->rate_flags & CAKE_FLAG_WASH);
- if (q->rate_flags & CAKE_FLAG_WASH)
- cake_wash_diffserv(skb);
- } else if (q->tin_mode != CAKE_DIFFSERV_BESTEFFORT) {
- if (q->rate_flags & CAKE_FLAG_FWMARK && /* use fw mark */
- skb->mark &&
- skb->mark <= q->tin_cnt) {
- tin = q->tin_order[skb->mark - 1];
- if (q->rate_flags & CAKE_FLAG_WASH)
- cake_wash_diffserv(skb);
- } else {
- /* extract the Diffserv Precedence field, if it exists */
- /* and clear DSCP bits if washing */
- tin = q->tin_index[cake_handle_diffserv(skb,
- q->rate_flags & CAKE_FLAG_WASH)];
- if (unlikely(tin >= q->tin_cnt))
- tin = 0;
- }
- } else {
+ if (q->tin_mode == CAKE_DIFFSERV_BESTEFFORT)
tin = 0;
- if (q->rate_flags & CAKE_FLAG_WASH)
- cake_wash_diffserv(skb);
+
+ else if (q->rate_flags & CAKE_FLAG_FWMARK && /* use fw mark */
+ skb->mark &&
+ skb->mark <= q->tin_cnt)
+ tin = q->tin_order[skb->mark - 1];
+
+ else if (TC_H_MAJ(skb->priority) == sch->handle &&
+ TC_H_MIN(skb->priority) > 0 &&
+ TC_H_MIN(skb->priority) <= q->tin_cnt)
+ tin = q->tin_order[TC_H_MIN(skb->priority) - 1];
+
+ else {
+ tin = q->tin_index[dscp];
+
+ if (unlikely(tin >= q->tin_cnt))
+ tin = 0;
}
return &q->tins[tin];