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-rw-r--r--include/net/red.h33
-rw-r--r--include/uapi/linux/pkt_sched.h16
-rw-r--r--net/sched/sch_red.c43
3 files changed, 89 insertions, 3 deletions
diff --git a/include/net/red.h b/include/net/red.h
index 9665582c4687..6a2aaa6c7c41 100644
--- a/include/net/red.h
+++ b/include/net/red.h
@@ -179,6 +179,39 @@ static inline bool red_check_params(u32 qth_min, u32 qth_max, u8 Wlog)
return true;
}
+static inline int red_get_flags(unsigned char qopt_flags,
+ unsigned char historic_mask,
+ struct nlattr *flags_attr,
+ unsigned char supported_mask,
+ struct nla_bitfield32 *p_flags,
+ unsigned char *p_userbits,
+ struct netlink_ext_ack *extack)
+{
+ struct nla_bitfield32 flags;
+
+ if (qopt_flags && flags_attr) {
+ NL_SET_ERR_MSG_MOD(extack, "flags should be passed either through qopt, or through a dedicated attribute");
+ return -EINVAL;
+ }
+
+ if (flags_attr) {
+ flags = nla_get_bitfield32(flags_attr);
+ } else {
+ flags.selector = historic_mask;
+ flags.value = qopt_flags & historic_mask;
+ }
+
+ *p_flags = flags;
+ *p_userbits = qopt_flags & ~historic_mask;
+ return 0;
+}
+
+static inline int red_validate_flags(unsigned char flags,
+ struct netlink_ext_ack *extack)
+{
+ return 0;
+}
+
static inline void red_set_parms(struct red_parms *p,
u32 qth_min, u32 qth_max, u8 Wlog, u8 Plog,
u8 Scell_log, u8 *stab, u32 max_P)
diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h
index bbe791b24168..6325507935ea 100644
--- a/include/uapi/linux/pkt_sched.h
+++ b/include/uapi/linux/pkt_sched.h
@@ -256,6 +256,7 @@ enum {
TCA_RED_PARMS,
TCA_RED_STAB,
TCA_RED_MAX_P,
+ TCA_RED_FLAGS, /* bitfield32 */
__TCA_RED_MAX,
};
@@ -268,12 +269,27 @@ struct tc_red_qopt {
unsigned char Wlog; /* log(W) */
unsigned char Plog; /* log(P_max/(qth_max-qth_min)) */
unsigned char Scell_log; /* cell size for idle damping */
+
+ /* This field can be used for flags that a RED-like qdisc has
+ * historically supported. E.g. when configuring RED, it can be used for
+ * ECN, HARDDROP and ADAPTATIVE. For SFQ it can be used for ECN,
+ * HARDDROP. Etc. Because this field has not been validated, and is
+ * copied back on dump, any bits besides those to which a given qdisc
+ * has assigned a historical meaning need to be considered for free use
+ * by userspace tools.
+ *
+ * Any further flags need to be passed differently, e.g. through an
+ * attribute (such as TCA_RED_FLAGS above). Such attribute should allow
+ * passing both recent and historic flags in one value.
+ */
unsigned char flags;
#define TC_RED_ECN 1
#define TC_RED_HARDDROP 2
#define TC_RED_ADAPTATIVE 4
};
+#define TC_RED_HISTORIC_FLAGS (TC_RED_ECN | TC_RED_HARDDROP | TC_RED_ADAPTATIVE)
+
struct tc_red_xstats {
__u32 early; /* Early drops */
__u32 pdrop; /* Drops due to queue limits */
diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c
index 1695421333e3..d4ce111704dc 100644
--- a/net/sched/sch_red.c
+++ b/net/sched/sch_red.c
@@ -35,7 +35,11 @@
struct red_sched_data {
u32 limit; /* HARD maximal queue length */
+
unsigned char flags;
+ /* Non-flags in tc_red_qopt.flags. */
+ unsigned char userbits;
+
struct timer_list adapt_timer;
struct Qdisc *sch;
struct red_parms parms;
@@ -44,6 +48,8 @@ struct red_sched_data {
struct Qdisc *qdisc;
};
+static const u32 red_supported_flags = TC_RED_HISTORIC_FLAGS;
+
static inline int red_use_ecn(struct red_sched_data *q)
{
return q->flags & TC_RED_ECN;
@@ -183,9 +189,12 @@ static void red_destroy(struct Qdisc *sch)
}
static const struct nla_policy red_policy[TCA_RED_MAX + 1] = {
+ [TCA_RED_UNSPEC] = { .strict_start_type = TCA_RED_FLAGS },
[TCA_RED_PARMS] = { .len = sizeof(struct tc_red_qopt) },
[TCA_RED_STAB] = { .len = RED_STAB_SIZE },
[TCA_RED_MAX_P] = { .type = NLA_U32 },
+ [TCA_RED_FLAGS] = { .type = NLA_BITFIELD32,
+ .validation_data = &red_supported_flags },
};
static int red_change(struct Qdisc *sch, struct nlattr *opt,
@@ -194,7 +203,10 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt,
struct Qdisc *old_child = NULL, *child = NULL;
struct red_sched_data *q = qdisc_priv(sch);
struct nlattr *tb[TCA_RED_MAX + 1];
+ struct nla_bitfield32 flags_bf;
struct tc_red_qopt *ctl;
+ unsigned char userbits;
+ unsigned char flags;
int err;
u32 max_P;
@@ -216,6 +228,12 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt,
if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog))
return -EINVAL;
+ err = red_get_flags(ctl->flags, TC_RED_HISTORIC_FLAGS,
+ tb[TCA_RED_FLAGS], red_supported_flags,
+ &flags_bf, &userbits, extack);
+ if (err)
+ return err;
+
if (ctl->limit > 0) {
child = fifo_create_dflt(sch, &bfifo_qdisc_ops, ctl->limit,
extack);
@@ -227,7 +245,14 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt,
}
sch_tree_lock(sch);
- q->flags = ctl->flags;
+
+ flags = (q->flags & ~flags_bf.selector) | flags_bf.value;
+ err = red_validate_flags(flags, extack);
+ if (err)
+ goto unlock_out;
+
+ q->flags = flags;
+ q->userbits = userbits;
q->limit = ctl->limit;
if (child) {
qdisc_tree_flush_backlog(q->qdisc);
@@ -256,6 +281,12 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt,
if (old_child)
qdisc_put(old_child);
return 0;
+
+unlock_out:
+ sch_tree_unlock(sch);
+ if (child)
+ qdisc_put(child);
+ return err;
}
static inline void red_adaptative_timer(struct timer_list *t)
@@ -299,10 +330,15 @@ static int red_dump_offload_stats(struct Qdisc *sch)
static int red_dump(struct Qdisc *sch, struct sk_buff *skb)
{
struct red_sched_data *q = qdisc_priv(sch);
+ struct nla_bitfield32 flags_bf = {
+ .selector = red_supported_flags,
+ .value = q->flags,
+ };
struct nlattr *opts = NULL;
struct tc_red_qopt opt = {
.limit = q->limit,
- .flags = q->flags,
+ .flags = (q->flags & TC_RED_HISTORIC_FLAGS) |
+ q->userbits,
.qth_min = q->parms.qth_min >> q->parms.Wlog,
.qth_max = q->parms.qth_max >> q->parms.Wlog,
.Wlog = q->parms.Wlog,
@@ -319,7 +355,8 @@ static int red_dump(struct Qdisc *sch, struct sk_buff *skb)
if (opts == NULL)
goto nla_put_failure;
if (nla_put(skb, TCA_RED_PARMS, sizeof(opt), &opt) ||
- nla_put_u32(skb, TCA_RED_MAX_P, q->parms.max_P))
+ nla_put_u32(skb, TCA_RED_MAX_P, q->parms.max_P) ||
+ nla_put(skb, TCA_RED_FLAGS, sizeof(flags_bf), &flags_bf))
goto nla_put_failure;
return nla_nest_end(skb, opts);