iproute2: linklayer interface between kernel and tc/userspace

index dbd71b0..09d62b9 100644
@@ -73,9 +73,17 @@ struct tc_estimator {
 #define TC_H_ROOT	(0xFFFFFFFFU)
 #define TC_H_INGRESS    (0xFFFFFFF1U)
 
+/* Need to corrospond to iproute2 tc/tc_core.h "enum link_layer" */
+enum tc_link_layer {
+	TC_LINKLAYER_UNAWARE, /* Indicate unaware old iproute2 util */
+	TC_LINKLAYER_ETHERNET,
+	TC_LINKLAYER_ATM,
+};
+#define TC_LINKLAYER_MASK 0x0F /* limit use to lower 4 bits */
+
 struct tc_ratespec {
 	unsigned char	cell_log;
-	unsigned char	__reserved;
+	__u8		linklayer; /* lower 4 bits */
 	unsigned short	overhead;
 	short		cell_align;
 	unsigned short	mpu;

index 53cbefc..300287e 100644
@@ -322,9 +322,11 @@ int
 print_police(struct action_util *a, FILE *f, struct rtattr *arg)
 {
 	SPRINT_BUF(b1);
+	SPRINT_BUF(b2);
 	struct tc_police *p;
 	struct rtattr *tb[TCA_POLICE_MAX+1];
 	unsigned buffer;
+	unsigned int linklayer;
 
 	if (arg == NULL)
 		return 0;

@@ -360,6 +362,9 @@ print_police(struct action_util *a, FILE *f, struct rtattr *arg)
 	} else
 		fprintf(f, " ");
 	fprintf(f, "overhead %ub ", p->rate.overhead);
+	linklayer = (p->rate.linklayer & TC_LINKLAYER_MASK);
+	if (linklayer > TC_LINKLAYER_ETHERNET || show_details)
+		fprintf(f, "linklayer %s ", sprint_linklayer(linklayer, b2));
 	fprintf(f, "\nref %d bind %d\n",p->refcnt, p->bindcnt);
 
 	return 0;

index 3c5e72c..d76600c 100644
@@ -442,7 +442,9 @@ static int cbq_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 	struct tc_cbq_wrropt *wrr = NULL;
 	struct tc_cbq_fopt *fopt = NULL;
 	struct tc_cbq_ovl *ovl = NULL;
+	unsigned int linklayer;
 	SPRINT_BUF(b1);
+	SPRINT_BUF(b2);
 
 	if (opt == NULL)
 		return 0;

@@ -486,6 +488,9 @@ static int cbq_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 		char buf[64];
 		print_rate(buf, sizeof(buf), r->rate);
 		fprintf(f, "rate %s ", buf);
+		linklayer = (r->linklayer & TC_LINKLAYER_MASK);
+		if (linklayer > TC_LINKLAYER_ETHERNET || show_details)
+			fprintf(f, "linklayer %s ", sprint_linklayer(linklayer, b2));
 		if (show_details) {
 			fprintf(f, "cell %ub ", 1<<r->cell_log);
 			if (r->mpu)

index 9321c0a..7b6f908 100644
@@ -244,9 +244,11 @@ static int htb_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 	struct tc_htb_opt *hopt;
 	struct tc_htb_glob *gopt;
 	double buffer,cbuffer;
+	unsigned int linklayer;
 	SPRINT_BUF(b1);
 	SPRINT_BUF(b2);
 	SPRINT_BUF(b3);
+	SPRINT_BUF(b4);
 
 	if (opt == NULL)
 		return 0;

@@ -268,6 +270,9 @@ static int htb_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 		buffer = tc_calc_xmitsize(hopt->rate.rate, hopt->buffer);
 		fprintf(f, "ceil %s ", sprint_rate(hopt->ceil.rate, b1));
 		cbuffer = tc_calc_xmitsize(hopt->ceil.rate, hopt->cbuffer);
+		linklayer = (hopt->rate.linklayer & TC_LINKLAYER_MASK);
+		if (linklayer > TC_LINKLAYER_ETHERNET || show_details)
+			fprintf(f, "linklayer %s ", sprint_linklayer(linklayer, b4));
 		if (show_details) {
 			fprintf(f, "burst %s/%u mpu %s overhead %s ",
 				sprint_size(buffer, b1),

index 72cfff6..34784a4 100644
@@ -239,10 +239,12 @@ static int tbf_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 {
 	struct rtattr *tb[TCA_TBF_PTAB+1];
 	struct tc_tbf_qopt *qopt;
+	unsigned int linklayer;
 	double buffer, mtu;
 	double latency;
 	SPRINT_BUF(b1);
 	SPRINT_BUF(b2);
+	SPRINT_BUF(b3);
 
 	if (opt == NULL)
 		return 0;

@@ -294,6 +296,9 @@ static int tbf_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 	if (qopt->rate.overhead) {
 		fprintf(f, "overhead %d", qopt->rate.overhead);
 	}
+	linklayer = (qopt->rate.linklayer & TC_LINKLAYER_MASK);
+	if (linklayer > TC_LINKLAYER_ETHERNET || show_details)
+		fprintf(f, "linklayer %s ", sprint_linklayer(linklayer, b3));
 
 	return 0;
 }

index 85b072e..a524337 100644
@@ -102,6 +102,21 @@ static unsigned tc_adjust_size(unsigned sz, unsigned mpu, enum link_layer linkla
 	}
 }
 
+/* Notice, the rate table calculated here, have gotten replaced in the
+ * kernel and is no-longer used for lookups.
+ *
+ * This happened in kernel release v3.8 caused by kernel
+ *  - commit 56b765b79 ("htb: improved accuracy at high rates").
+ * This change unfortunately caused breakage of tc overhead and
+ * linklayer parameters.
+ *
+ * Kernel overhead handling got fixed in kernel v3.10 by
+ * - commit 01cb71d2d47 (net_sched: restore "overhead xxx" handling)
+ *
+ * Kernel linklayer handling got fixed in kernel v3.11 by
+ * - commit 8a8e3d84b17 (net_sched: restore "linklayer atm" handling)
+ */
+
 /*
    rtab[pkt_len>>cell_log] = pkt_xmit_time
  */

@@ -131,6 +146,7 @@ int tc_calc_rtable(struct tc_ratespec *r, __u32 *rtab,
 
 	r->cell_align=-1; // Due to the sz calc
 	r->cell_log=cell_log;
+	r->linklayer = (linklayer & TC_LINKLAYER_MASK);
 	return cell_log;
 }