net: sched: sch_red: Add qevents "early_drop" and "mark"

In order to allow acting on dropped and/or ECN-marked packets, add two new
qevents to the RED qdisc: "early_drop" and "mark". Filters attached at
"early_drop" block are executed as packets are early-dropped, those
attached at the "mark" block are executed as packets are ECN-marked.

Two new attributes are introduced: TCA_RED_EARLY_DROP_BLOCK with the block
index for the "early_drop" qevent, and TCA_RED_MARK_BLOCK for the "mark"
qevent. Absence of these attributes signifies "don't care": no block is
allocated in that case, or the existing blocks are left intact in case of
the change callback.

For purposes of offloading, blocks attached to these qevents appear with
newly-introduced binder types, FLOW_BLOCK_BINDER_TYPE_RED_EARLY_DROP and
FLOW_BLOCK_BINDER_TYPE_RED_MARK.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/flow_offload.h b/include/net/flow_offload.h
index 3bafb51..3e793ac 100644 (file)
--- a/include/net/flow_offload.h
+++ b/include/net/flow_offload.h
@@ -424,6 +424,8 @@ enum flow_block_binder_type {
        FLOW_BLOCK_BINDER_TYPE_UNSPEC,
        FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS,
        FLOW_BLOCK_BINDER_TYPE_CLSACT_EGRESS,
+       FLOW_BLOCK_BINDER_TYPE_RED_EARLY_DROP,
+       FLOW_BLOCK_BINDER_TYPE_RED_MARK,
 };
 
 struct flow_block {

diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h
index a95f3ae..9e7c2c6 100644 (file)
--- a/include/uapi/linux/pkt_sched.h
+++ b/include/uapi/linux/pkt_sched.h
@@ -257,6 +257,8 @@ enum {
        TCA_RED_STAB,
        TCA_RED_MAX_P,
        TCA_RED_FLAGS,          /* bitfield32 */
+       TCA_RED_EARLY_DROP_BLOCK, /* u32 */
+       TCA_RED_MARK_BLOCK,     /* u32 */
        __TCA_RED_MAX,
 };
 

diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c
index 225ce37..de2be4d 100644 (file)
--- a/net/sched/sch_red.c
+++ b/net/sched/sch_red.c
@@ -46,6 +46,8 @@ struct red_sched_data {
        struct red_vars         vars;
        struct red_stats        stats;
        struct Qdisc            *qdisc;
+       struct tcf_qevent       qe_early_drop;
+       struct tcf_qevent       qe_mark;
 };
 
 #define TC_RED_SUPPORTED_FLAGS (TC_RED_HISTORIC_FLAGS | TC_RED_NODROP)
@@ -92,6 +94,9 @@ static int red_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_
 
                if (INET_ECN_set_ce(skb)) {
                        q->stats.prob_mark++;
+                       skb = tcf_qevent_handle(&q->qe_mark, sch, skb, root_lock, to_free, &ret);
+                       if (!skb)
+                               return NET_XMIT_CN | ret;
                } else if (!red_use_nodrop(q)) {
                        q->stats.prob_drop++;
                        goto congestion_drop;
@@ -109,6 +114,9 @@ static int red_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_
 
                if (INET_ECN_set_ce(skb)) {
                        q->stats.forced_mark++;
+                       skb = tcf_qevent_handle(&q->qe_mark, sch, skb, root_lock, to_free, &ret);
+                       if (!skb)
+                               return NET_XMIT_CN | ret;
                } else if (!red_use_nodrop(q)) {
                        q->stats.forced_drop++;
                        goto congestion_drop;
@@ -129,6 +137,10 @@ static int red_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_
        return ret;
 
 congestion_drop:
+       skb = tcf_qevent_handle(&q->qe_early_drop, sch, skb, root_lock, to_free, &ret);
+       if (!skb)
+               return NET_XMIT_CN | ret;
+
        qdisc_drop(skb, sch, to_free);
        return NET_XMIT_CN;
 }
@@ -202,6 +214,8 @@ static void red_destroy(struct Qdisc *sch)
 {
        struct red_sched_data *q = qdisc_priv(sch);
 
+       tcf_qevent_destroy(&q->qe_mark, sch);
+       tcf_qevent_destroy(&q->qe_early_drop, sch);
        del_timer_sync(&q->adapt_timer);
        red_offload(sch, false);
        qdisc_put(q->qdisc);
@@ -213,6 +227,8 @@ static const struct nla_policy red_policy[TCA_RED_MAX + 1] = {
        [TCA_RED_STAB]  = { .len = RED_STAB_SIZE },
        [TCA_RED_MAX_P] = { .type = NLA_U32 },
        [TCA_RED_FLAGS] = NLA_POLICY_BITFIELD32(TC_RED_SUPPORTED_FLAGS),
+       [TCA_RED_EARLY_DROP_BLOCK] = { .type = NLA_U32 },
+       [TCA_RED_MARK_BLOCK] = { .type = NLA_U32 },
 };
 
 static int __red_change(struct Qdisc *sch, struct nlattr **tb,
@@ -328,12 +344,38 @@ static int red_init(struct Qdisc *sch, struct nlattr *opt,
        q->qdisc = &noop_qdisc;
        q->sch = sch;
        timer_setup(&q->adapt_timer, red_adaptative_timer, 0);
-       return __red_change(sch, tb, extack);
+
+       err = __red_change(sch, tb, extack);
+       if (err)
+               return err;
+
+       err = tcf_qevent_init(&q->qe_early_drop, sch,
+                             FLOW_BLOCK_BINDER_TYPE_RED_EARLY_DROP,
+                             tb[TCA_RED_EARLY_DROP_BLOCK], extack);
+       if (err)
+               goto err_early_drop_init;
+
+       err = tcf_qevent_init(&q->qe_mark, sch,
+                             FLOW_BLOCK_BINDER_TYPE_RED_MARK,
+                             tb[TCA_RED_MARK_BLOCK], extack);
+       if (err)
+               goto err_mark_init;
+
+       return 0;
+
+err_mark_init:
+       tcf_qevent_destroy(&q->qe_early_drop, sch);
+err_early_drop_init:
+       del_timer_sync(&q->adapt_timer);
+       red_offload(sch, false);
+       qdisc_put(q->qdisc);
+       return err;
 }
 
 static int red_change(struct Qdisc *sch, struct nlattr *opt,
                      struct netlink_ext_ack *extack)
 {
+       struct red_sched_data *q = qdisc_priv(sch);
        struct nlattr *tb[TCA_RED_MAX + 1];
        int err;
 
@@ -345,6 +387,16 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt,
        if (err < 0)
                return err;
 
+       err = tcf_qevent_validate_change(&q->qe_early_drop,
+                                        tb[TCA_RED_EARLY_DROP_BLOCK], extack);
+       if (err)
+               return err;
+
+       err = tcf_qevent_validate_change(&q->qe_mark,
+                                        tb[TCA_RED_MARK_BLOCK], extack);
+       if (err)
+               return err;
+
        return __red_change(sch, tb, extack);
 }
 
@@ -389,7 +441,9 @@ static int red_dump(struct Qdisc *sch, struct sk_buff *skb)
        if (nla_put(skb, TCA_RED_PARMS, sizeof(opt), &opt) ||
            nla_put_u32(skb, TCA_RED_MAX_P, q->parms.max_P) ||
            nla_put_bitfield32(skb, TCA_RED_FLAGS,
-                              q->flags, TC_RED_SUPPORTED_FLAGS))
+                              q->flags, TC_RED_SUPPORTED_FLAGS) ||
+           tcf_qevent_dump(skb, TCA_RED_MARK_BLOCK, &q->qe_mark) ||
+           tcf_qevent_dump(skb, TCA_RED_EARLY_DROP_BLOCK, &q->qe_early_drop))
                goto nla_put_failure;
        return nla_nest_end(skb, opts);