Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Alexei Starovoitov says:

====================
pull-request: bpf-next 2019-05-31

The following pull-request contains BPF updates for your *net-next* tree.

Lots of exciting new features in the first PR of this developement cycle!
The main changes are:

1) misc verifier improvements, from Alexei.

2) bpftool can now convert btf to valid C, from Andrii.

3) verifier can insert explicit ZEXT insn when requested by 32-bit JITs.
   This feature greatly improves BPF speed on 32-bit architectures. From Jiong.

4) cgroups will now auto-detach bpf programs. This fixes issue of thousands
   bpf programs got stuck in dying cgroups. From Roman.

5) new bpf_send_signal() helper, from Yonghong.

6) cgroup inet skb programs can signal CN to the stack, from Lawrence.

7) miscellaneous cleanups, from many developers.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 35 insertions, 13 deletions

diff --git a/samples/bpf/hbm_out_kern.c b/samples/bpf/hbm_out_kern.c
index f806863d0b79..829934bd43cb 100644
--- a/samples/bpf/hbm_out_kern.c
+++ b/samples/bpf/hbm_out_kern.c
@@ -62,11 +62,12 @@ int _hbm_out_cg(struct __sk_buff *skb)
 	unsigned int queue_index = 0;
 	unsigned long long curtime;
 	int credit;
-	signed long long delta = 0, zero = 0;
+	signed long long delta = 0, new_credit;
 	int max_credit = MAX_CREDIT;
 	bool congestion_flag = false;
 	bool drop_flag = false;
 	bool cwr_flag = false;
+	bool ecn_ce_flag = false;
 	struct hbm_vqueue *qdp;
 	struct hbm_queue_stats *qsp = NULL;
 	int rv = ALLOW_PKT;
@@ -99,9 +100,11 @@ int _hbm_out_cg(struct __sk_buff *skb)
 	 */
 	if (delta > 0) {
 		qdp->lasttime = curtime;
-		credit += CREDIT_PER_NS(delta, qdp->rate);
-		if (credit > MAX_CREDIT)
+		new_credit = credit + CREDIT_PER_NS(delta, qdp->rate);
+		if (new_credit > MAX_CREDIT)
 			credit = MAX_CREDIT;
+		else
+			credit = new_credit;
 	}
 	credit -= len;
 	qdp->credit = credit;
@@ -119,13 +122,16 @@ int _hbm_out_cg(struct __sk_buff *skb)
 	// Set flags (drop, congestion, cwr)
 	// Dropping => we are congested, so ignore congestion flag
 	if (credit < -DROP_THRESH ||
-	    (len > LARGE_PKT_THRESH &&
-	     credit < -LARGE_PKT_DROP_THRESH)) {
-		// Very congested, set drop flag
+	    (len > LARGE_PKT_THRESH && credit < -LARGE_PKT_DROP_THRESH)) {
+		// Very congested, set drop packet
 		drop_flag = true;
+		if (pkti.ecn)
+			congestion_flag = true;
+		else if (pkti.is_tcp)
+			cwr_flag = true;
 	} else if (credit < 0) {
 		// Congested, set congestion flag
-		if (pkti.ecn) {
+		if (pkti.ecn || pkti.is_tcp) {
 			if (credit < -MARK_THRESH)
 				congestion_flag = true;
 			else
@@ -136,22 +142,38 @@ int _hbm_out_cg(struct __sk_buff *skb)
 	}
 
 	if (congestion_flag) {
-		if (!bpf_skb_ecn_set_ce(skb)) {
-			if (len > LARGE_PKT_THRESH) {
+		if (bpf_skb_ecn_set_ce(skb)) {
+			ecn_ce_flag = true;
+		} else {
+			if (pkti.is_tcp) {
+				unsigned int rand = bpf_get_prandom_u32();
+
+				if (-credit >= MARK_THRESH +
+				    (rand % MARK_REGION_SIZE)) {
+					// Do congestion control
+					cwr_flag = true;
+				}
+			} else if (len > LARGE_PKT_THRESH) {
 				// Problem if too many small packets?
 				drop_flag = true;
 			}
 		}
 	}
 
-	if (drop_flag)
-		rv = DROP_PKT;
+	if (qsp != NULL)
+		if (qsp->no_cn)
+			cwr_flag = false;
 
-	hbm_update_stats(qsp, len, curtime, congestion_flag, drop_flag);
+	hbm_update_stats(qsp, len, curtime, congestion_flag, drop_flag,
+			 cwr_flag, ecn_ce_flag, &pkti, credit);
 
-	if (rv == DROP_PKT)
+	if (drop_flag) {
 		__sync_add_and_fetch(&(qdp->credit), len);
+		rv = DROP_PKT;
+	}
 
+	if (cwr_flag)
+		rv |= 2;
 	return rv;
 }
 char _license[] SEC("license") = "GPL";