From 4976e3c683f328bc6f2edef555a4ffee6524486f Mon Sep 17 00:00:00 2001 From: =?utf8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Date: Fri, 1 Mar 2019 16:04:05 +0100 Subject: [PATCH] sch_cake: Simplify logic in cake_select_tin() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: David S. Miller --- net/sched/sch_cake.c | 61 ++++++++++++++++++++-------------------------------- 1 file 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]; -- 2.11.0