diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 2e308e90ffea..3c38ac9a92a7 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -2359,6 +2359,13 @@ union bpf_attr {
  *	Return
  *		A **struct bpf_tcp_sock** pointer on success, or NULL in
  *		case of failure.
+ *
+ * int bpf_skb_ecn_set_ce(struct sk_buf *skb)
+ *     Description
+ *             Sets ECN of IP header to ce (congestion encountered) if
+ *             current value is ect (ECN capable). Works with IPv6 and IPv4.
+ *     Return
+ *             1 if set, 0 if not set.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -2457,7 +2464,8 @@ union bpf_attr {
 	FN(spin_lock),			\
 	FN(spin_unlock),		\
 	FN(sk_fullsock),		\
-	FN(tcp_sock),
+	FN(tcp_sock),			\
+	FN(skb_ecn_set_ce),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
diff --git a/net/core/filter.c b/net/core/filter.c
index 85749f6ec789..558ca72f2254 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5426,6 +5426,32 @@ static const struct bpf_func_proto bpf_tcp_sock_proto = {
 	.arg1_type	= ARG_PTR_TO_SOCK_COMMON,
 };
 
+BPF_CALL_1(bpf_skb_ecn_set_ce, struct sk_buff *, skb)
+{
+	unsigned int iphdr_len;
+
+	if (skb->protocol == cpu_to_be16(ETH_P_IP))
+		iphdr_len = sizeof(struct iphdr);
+	else if (skb->protocol == cpu_to_be16(ETH_P_IPV6))
+		iphdr_len = sizeof(struct ipv6hdr);
+	else
+		return 0;
+
+	if (skb_headlen(skb) < iphdr_len)
+		return 0;
+
+	if (skb_cloned(skb) && !skb_clone_writable(skb, iphdr_len))
+		return 0;
+
+	return INET_ECN_set_ce(skb);
+}
+
+static const struct bpf_func_proto bpf_skb_ecn_set_ce_proto = {
+	.func           = bpf_skb_ecn_set_ce,
+	.gpl_only       = false,
+	.ret_type       = RET_INTEGER,
+	.arg1_type      = ARG_PTR_TO_CTX,
+};
 #endif /* CONFIG_INET */
 
 bool bpf_helper_changes_pkt_data(void *func)
@@ -5585,6 +5611,8 @@ cg_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 #ifdef CONFIG_INET
 	case BPF_FUNC_tcp_sock:
 		return &bpf_tcp_sock_proto;
+	case BPF_FUNC_skb_ecn_set_ce:
+		return &bpf_skb_ecn_set_ce_proto;
 #endif
 	default:
 		return sk_filter_func_proto(func_id, prog);
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 0c62ac39c697..65e667bdf979 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -52,6 +52,7 @@ hostprogs-y += xdpsock
 hostprogs-y += xdp_fwd
 hostprogs-y += task_fd_query
 hostprogs-y += xdp_sample_pkts
+hostprogs-y += hbm
 
 # Libbpf dependencies
 LIBBPF = $(TOOLS_PATH)/lib/bpf/libbpf.a
@@ -107,6 +108,7 @@ xdpsock-objs := xdpsock_user.o
 xdp_fwd-objs := xdp_fwd_user.o
 task_fd_query-objs := bpf_load.o task_fd_query_user.o $(TRACE_HELPERS)
 xdp_sample_pkts-objs := xdp_sample_pkts_user.o $(TRACE_HELPERS)
+hbm-objs := bpf_load.o hbm.o $(CGROUP_HELPERS)
 
 # Tell kbuild to always build the programs
 always := $(hostprogs-y)
@@ -164,6 +166,7 @@ always += xdp_adjust_tail_kern.o
 always += xdp_fwd_kern.o
 always += task_fd_query_kern.o
 always += xdp_sample_pkts_kern.o
+always += hbm_out_kern.o
 
 KBUILD_HOSTCFLAGS += -I$(objtree)/usr/include
 KBUILD_HOSTCFLAGS += -I$(srctree)/tools/lib/
@@ -263,6 +266,8 @@ $(BPF_SAMPLES_PATH)/*.c: verify_target_bpf $(LIBBPF)
 $(src)/*.c: verify_target_bpf $(LIBBPF)
 
 $(obj)/tracex5_kern.o: $(obj)/syscall_nrs.h
+$(obj)/hbm_out_kern.o: $(src)/hbm.h $(src)/hbm_kern.h
+$(obj)/hbm.o: $(src)/hbm.h
 
 # asm/sysreg.h - inline assembly used by it is incompatible with llvm.
 # But, there is no easy way to fix it, so just exclude it since it is
diff --git a/samples/bpf/do_hbm_test.sh b/samples/bpf/do_hbm_test.sh
new file mode 100755
index 000000000000..56c8b4115c95
--- /dev/null
+++ b/samples/bpf/do_hbm_test.sh
@@ -0,0 +1,436 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (c) 2019 Facebook
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of version 2 of the GNU General Public
+# License as published by the Free Software Foundation.
+
+Usage() {
+  echo "Script for testing HBM (Host Bandwidth Manager) framework."
+  echo "It creates a cgroup to use for testing and load a BPF program to limit"
+  echo "egress or ingress bandwidht. It then uses iperf3 or netperf to create"
+  echo "loads. The output is the goodput in Mbps (unless -D was used)."
+  echo ""
+  echo "USAGE: $name [out] [-b=<prog>|--bpf=<prog>] [-c=<cc>|--cc=<cc>] [-D]"
+  echo "             [-d=<delay>|--delay=<delay>] [--debug] [-E]"
+  echo "             [-f=<#flows>|--flows=<#flows>] [-h] [-i=<id>|--id=<id >]"
+  echo "             [-l] [-N] [-p=<port>|--port=<port>] [-P]"
+  echo "             [-q=<qdisc>] [-R] [-s=<server>|--server=<server]"
+  echo "             [-S|--stats] -t=<time>|--time=<time>] [-w] [cubic|dctcp]"
+  echo "  Where:"
+  echo "    out               egress (default)"
+  echo "    -b or --bpf       BPF program filename to load and attach."
+  echo "                      Default is hbm_out_kern.o for egress,"
+  echo "    -c or -cc         TCP congestion control (cubic or dctcp)"
+  echo "    --debug           print BPF trace buffer"
+  echo "    -d or --delay     add a delay in ms using netem"
+  echo "    -D                In addition to the goodput in Mbps, it also outputs"
+  echo "                      other detailed information. This information is"
+  echo "                      test dependent (i.e. iperf3 or netperf)."
+  echo "    -E                enable ECN (not required for dctcp)"
+  echo "    -f or --flows     number of concurrent flows (default=1)"
+  echo "    -i or --id        cgroup id (an integer, default is 1)"
+  echo "    -N                use netperf instead of iperf3"
+  echo "    -l                do not limit flows using loopback"
+  echo "    -h                Help"
+  echo "    -p or --port      iperf3 port (default is 5201)"
+  echo "    -P                use an iperf3 instance for each flow"
+  echo "    -q                use the specified qdisc"
+  echo "    -r or --rate      rate in Mbps (default 1s 1Gbps)"
+  echo "    -R                Use TCP_RR for netperf. 1st flow has req"
+  echo "                      size of 10KB, rest of 1MB. Reply in all"
+  echo "                      cases is 1 byte."
+  echo "                      More detailed output for each flow can be found"
+  echo "                      in the files netperf.<cg>.<flow>, where <cg> is the"
+  echo "                      cgroup id as specified with the -i flag, and <flow>"
+  echo "                      is the flow id starting at 1 and increasing by 1 for"
+  echo "                      flow (as specified by -f)."
+  echo "    -s or --server    hostname of netperf server. Used to create netperf"
+  echo "                      test traffic between to hosts (default is within host)"
+  echo "                      netserver must be running on the host."
+  echo "    -S or --stats     whether to update hbm stats (default is yes)."
+  echo "    -t or --time      duration of iperf3 in seconds (default=5)"
+  echo "    -w                Work conserving flag. cgroup can increase its"
+  echo "                      bandwidth beyond the rate limit specified"
+  echo "                      while there is available bandwidth. Current"
+  echo "                      implementation assumes there is only one NIC"
+  echo "                      (eth0), but can be extended to support multiple"
+  echo "                       NICs."
+  echo "    cubic or dctcp    specify which TCP CC to use"
+  echo " "
+  exit
+}
+
+#set -x
+
+debug_flag=0
+args="$@"
+name="$0"
+netem=0
+cc=x
+dir="-o"
+dir_name="out"
+dur=5
+flows=1
+id=1
+prog=""
+port=5201
+rate=1000
+multi_iperf=0
+flow_cnt=1
+use_netperf=0
+rr=0
+ecn=0
+details=0
+server=""
+qdisc=""
+flags=""
+do_stats=0
+
+function start_hbm () {
+  rm -f hbm.out
+  echo "./hbm $dir -n $id -r $rate -t $dur $flags $dbg $prog" > hbm.out
+  echo " " >> hbm.out
+  ./hbm $dir -n $id -r $rate -t $dur $flags $dbg $prog >> hbm.out 2>&1  &
+  echo $!
+}
+
+processArgs () {
+  for i in $args ; do
+    case $i in
+    # Support for upcomming ingress rate limiting
+    #in)         # support for upcoming ingress rate limiting
+    #  dir="-i"
+    #  dir_name="in"
+    #  ;;
+    out)
+      dir="-o"
+      dir_name="out"
+      ;;
+    -b=*|--bpf=*)
+      prog="${i#*=}"
+      ;;
+    -c=*|--cc=*)
+      cc="${i#*=}"
+      ;;
+    --debug)
+      flags="$flags -d"
+      debug_flag=1
+      ;;
+    -d=*|--delay=*)
+      netem="${i#*=}"
+      ;;
+    -D)
+      details=1
+      ;;
+    -E)
+     ecn=1
+     ;;
+    # Support for upcomming fq Early Departure Time egress rate limiting
+    #--edt)
+    # prog="hbm_out_edt_kern.o"
+    # qdisc="fq"
+    # ;;
+    -f=*|--flows=*)
+      flows="${i#*=}"
+      ;;
+    -i=*|--id=*)
+      id="${i#*=}"
+      ;;
+    -l)
+      flags="$flags -l"
+      ;;
+    -N)
+      use_netperf=1
+      ;;
+    -p=*|--port=*)
+      port="${i#*=}"
+      ;;
+    -P)
+      multi_iperf=1
+      ;;
+    -q=*)
+      qdisc="${i#*=}"
+      ;;
+    -r=*|--rate=*)
+      rate="${i#*=}"
+      ;;
+    -R)
+      rr=1
+      ;;
+    -s=*|--server=*)
+      server="${i#*=}"
+      ;;
+    -S|--stats)
+      flags="$flags -s"
+      do_stats=1
+      ;;
+    -t=*|--time=*)
+      dur="${i#*=}"
+      ;;
+    -w)
+      flags="$flags -w"
+      ;;
+    cubic)
+      cc=cubic
+      ;;
+    dctcp)
+      cc=dctcp
+      ;;
+    *)
+      echo "Unknown arg:$i"
+      Usage
+      ;;
+    esac
+  done
+}
+
+processArgs
+
+if [ $debug_flag -eq 1 ] ; then
+  rm -f hbm_out.log
+fi
+
+hbm_pid=$(start_hbm)
+usleep 100000
+
+host=`hostname`
+cg_base_dir=/sys/fs/cgroup
+cg_dir="$cg_base_dir/cgroup-test-work-dir/hbm$id"
+
+echo $$ >> $cg_dir/cgroup.procs
+
+ulimit -l unlimited
+
+rm -f ss.out
+rm -f hbm.[0-9]*.$dir_name
+if [ $ecn -ne 0 ] ; then
+  sysctl -w -q -n net.ipv4.tcp_ecn=1
+fi
+
+if [ $use_netperf -eq 0 ] ; then
+  cur_cc=`sysctl -n net.ipv4.tcp_congestion_control`
+  if [ "$cc" != "x" ] ; then
+    sysctl -w -q -n net.ipv4.tcp_congestion_control=$cc
+  fi
+fi
+
+if [ "$netem" -ne "0" ] ; then
+  if [ "$qdisc" != "" ] ; then
+    echo "WARNING: Ignoring -q options because -d option used"
+  fi
+  tc qdisc del dev lo root > /dev/null 2>&1
+  tc qdisc add dev lo root netem delay $netem\ms > /dev/null 2>&1
+elif [ "$qdisc" != "" ] ; then
+  tc qdisc del dev lo root > /dev/null 2>&1
+  tc qdisc add dev lo root $qdisc > /dev/null 2>&1
+fi
+
+n=0
+m=$[$dur * 5]
+hn="::1"
+if [ $use_netperf -ne 0 ] ; then
+  if [ "$server" != "" ] ; then
+    hn=$server
+  fi
+fi
+
+( ping6 -i 0.2 -c $m $hn > ping.out 2>&1 ) &
+
+if [ $use_netperf -ne 0 ] ; then
+  begNetserverPid=`ps ax | grep netserver | grep --invert-match "grep" | \
+                   awk '{ print $1 }'`
+  if [ "$begNetserverPid" == "" ] ; then
+    if [ "$server" == "" ] ; then
+      ( ./netserver > /dev/null 2>&1) &
+      usleep 100000
+    fi
+  fi
+  flow_cnt=1
+  if [ "$server" == "" ] ; then
+    np_server=$host
+  else
+    np_server=$server
+  fi
+  if [ "$cc" == "x" ] ; then
+    np_cc=""
+  else
+    np_cc="-K $cc,$cc"
+  fi
+  replySize=1
+  while [ $flow_cnt -le $flows ] ; do
+    if [ $rr -ne 0 ] ; then
+      reqSize=1M
+      if [ $flow_cnt -eq 1 ] ; then
+        reqSize=10K
+      fi
+      if [ "$dir" == "-i" ] ; then
+        replySize=$reqSize
+        reqSize=1
+      fi
+      ( ./netperf -H $np_server -l $dur -f m -j -t TCP_RR  -- -r $reqSize,$replySize $np_cc -k P50_lATENCY,P90_LATENCY,LOCAL_TRANSPORT_RETRANS,REMOTE_TRANSPORT_RETRANS,LOCAL_SEND_THROUGHPUT,LOCAL_RECV_THROUGHPUT,REQUEST_SIZE,RESPONSE_SIZE > netperf.$id.$flow_cnt ) &
+    else
+      if [ "$dir" == "-i" ] ; then
+        ( ./netperf -H $np_server -l $dur -f m -j -t TCP_RR -- -r 1,10M $np_cc -k P50_LATENCY,P90_LATENCY,LOCAL_TRANSPORT_RETRANS,LOCAL_SEND_THROUGHPUT,REMOTE_TRANSPORT_RETRANS,REMOTE_SEND_THROUGHPUT,REQUEST_SIZE,RESPONSE_SIZE > netperf.$id.$flow_cnt ) &
+      else
+        ( ./netperf -H $np_server -l $dur -f m -j -t TCP_STREAM -- $np_cc -k P50_lATENCY,P90_LATENCY,LOCAL_TRANSPORT_RETRANS,LOCAL_SEND_THROUGHPUT,REQUEST_SIZE,RESPONSE_SIZE > netperf.$id.$flow_cnt ) &
+      fi
+    fi
+    flow_cnt=$[flow_cnt+1]
+  done
+
+# sleep for duration of test (plus some buffer)
+  n=$[dur+2]
+  sleep $n
+
+# force graceful termination of netperf
+  pids=`pgrep netperf`
+  for p in $pids ; do
+    kill -SIGALRM $p
+  done
+
+  flow_cnt=1
+  rate=0
+  if [ $details -ne 0 ] ; then
+    echo ""
+    echo "Details for HBM in cgroup $id"
+    if [ $do_stats -eq 1 ] ; then
+      if [ -e hbm.$id.$dir_name ] ; then
+        cat hbm.$id.$dir_name
+      fi
+    fi
+  fi
+  while [ $flow_cnt -le $flows ] ; do
+    if [ "$dir" == "-i" ] ; then
+      r=`cat netperf.$id.$flow_cnt | grep -o "REMOTE_SEND_THROUGHPUT=[0-9]*" | grep -o "[0-9]*"`
+    else
+      r=`cat netperf.$id.$flow_cnt | grep -o "LOCAL_SEND_THROUGHPUT=[0-9]*" | grep -o "[0-9]*"`
+    fi
+    echo "rate for flow $flow_cnt: $r"
+    rate=$[rate+r]
+    if [ $details -ne 0 ] ; then
+      echo "-----"
+      echo "Details for cgroup $id, flow $flow_cnt"
+      cat netperf.$id.$flow_cnt
+    fi
+    flow_cnt=$[flow_cnt+1]
+  done
+  if [ $details -ne 0 ] ; then
+    echo ""
+    delay=`grep "avg" ping.out | grep -o "= [0-9.]*/[0-9.]*" | grep -o "[0-9.]*$"`
+    echo "PING AVG DELAY:$delay"
+    echo "AGGREGATE_GOODPUT:$rate"
+  else
+    echo $rate
+  fi
+elif [ $multi_iperf -eq 0 ] ; then
+  (iperf3 -s -p $port -1 > /dev/null 2>&1) &
+  usleep 100000
+  iperf3 -c $host -p $port -i 0 -P $flows -f m -t $dur > iperf.$id
+  rates=`grep receiver iperf.$id | grep -o "[0-9.]* Mbits" | grep -o "^[0-9]*"`
+  rate=`echo $rates | grep -o "[0-9]*$"`
+
+  if [ $details -ne 0 ] ; then
+    echo ""
+    echo "Details for HBM in cgroup $id"
+    if [ $do_stats -eq 1 ] ; then
+      if [ -e hbm.$id.$dir_name ] ; then
+        cat hbm.$id.$dir_name
+      fi
+    fi
+    delay=`grep "avg" ping.out | grep -o "= [0-9.]*/[0-9.]*" | grep -o "[0-9.]*$"`
+    echo "PING AVG DELAY:$delay"
+    echo "AGGREGATE_GOODPUT:$rate"
+  else
+    echo $rate
+  fi
+else
+  flow_cnt=1
+  while [ $flow_cnt -le $flows ] ; do
+    (iperf3 -s -p $port -1 > /dev/null 2>&1) &
+    ( iperf3 -c $host -p $port -i 0 -P 1 -f m -t $dur | grep receiver | grep -o "[0-9.]* Mbits" | grep -o "^[0-9]*" | grep -o "[0-9]*$" > iperf3.$id.$flow_cnt ) &
+    port=$[port+1]
+    flow_cnt=$[flow_cnt+1]
+  done
+  n=$[dur+1]
+  sleep $n
+  flow_cnt=1
+  rate=0
+  if [ $details -ne 0 ] ; then
+    echo ""
+    echo "Details for HBM in cgroup $id"
+    if [ $do_stats -eq 1 ] ; then
+      if [ -e hbm.$id.$dir_name ] ; then
+        cat hbm.$id.$dir_name
+      fi
+    fi
+  fi
+
+  while [ $flow_cnt -le $flows ] ; do
+    r=`cat iperf3.$id.$flow_cnt`
+#    echo "rate for flow $flow_cnt: $r"
+  if [ $details -ne 0 ] ; then
+    echo "Rate for cgroup $id, flow $flow_cnt LOCAL_SEND_THROUGHPUT=$r"
+  fi
+    rate=$[rate+r]
+    flow_cnt=$[flow_cnt+1]
+  done
+  if [ $details -ne 0 ] ; then
+    delay=`grep "avg" ping.out | grep -o "= [0-9.]*/[0-9.]*" | grep -o "[0-9.]*$"`
+    echo "PING AVG DELAY:$delay"
+    echo "AGGREGATE_GOODPUT:$rate"
+  else
+    echo $rate
+  fi
+fi
+
+if [ $use_netperf -eq 0 ] ; then
+  sysctl -w -q -n net.ipv4.tcp_congestion_control=$cur_cc
+fi
+if [ $ecn -ne 0 ] ; then
+  sysctl -w -q -n net.ipv4.tcp_ecn=0
+fi
+if [ "$netem" -ne "0" ] ; then
+  tc qdisc del dev lo root > /dev/null 2>&1
+fi
+
+sleep 2
+
+hbmPid=`ps ax | grep "hbm " | grep --invert-match "grep" | awk '{ print $1 }'`
+if [ "$hbmPid" == "$hbm_pid" ] ; then
+  kill $hbm_pid
+fi
+
+sleep 1
+
+# Detach any BPF programs that may have lingered
+ttx=`bpftool cgroup tree | grep hbm`
+v=2
+for x in $ttx ; do
+    if [ "${x:0:36}" == "/sys/fs/cgroup/cgroup-test-work-dir/" ] ; then
+	cg=$x ; v=0
+    else
+	if [ $v -eq 0 ] ; then
+	    id=$x ; v=1
+	else
+	    if [ $v -eq 1 ] ; then
+		type=$x ; bpftool cgroup detach $cg $type id $id
+		v=0
+	    fi
+	fi
+    fi
+done
+
+if [ $use_netperf -ne 0 ] ; then
+  if [ "$server" == "" ] ; then
+    if [ "$begNetserverPid" == "" ] ; then
+      netserverPid=`ps ax | grep netserver | grep --invert-match "grep" | awk '{ print $1 }'`
+      if [ "$netserverPid" != "" ] ; then
+        kill $netserverPid
+      fi
+    fi
+  fi
+fi
+exit
diff --git a/samples/bpf/hbm.c b/samples/bpf/hbm.c
new file mode 100644
index 000000000000..8408ccb7409f
--- /dev/null
+++ b/samples/bpf/hbm.c
@@ -0,0 +1,441 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Example program for Host Bandwidth Managment
+ *
+ * This program loads a cgroup skb BPF program to enforce cgroup output
+ * (egress) or input (ingress) bandwidth limits.
+ *
+ * USAGE: hbm [-d] [-l] [-n <id>] [-r <rate>] [-s] [-t <secs>] [-w] [-h] [prog]
+ *   Where:
+ *    -d	Print BPF trace debug buffer
+ *    -l	Also limit flows doing loopback
+ *    -n <#>	To create cgroup \"/hbm#\" and attach prog
+ *		Default is /hbm1
+ *    -r <rate>	Rate limit in Mbps
+ *    -s	Get HBM stats (marked, dropped, etc.)
+ *    -t <time>	Exit after specified seconds (deault is 0)
+ *    -w	Work conserving flag. cgroup can increase its bandwidth
+ *		beyond the rate limit specified while there is available
+ *		bandwidth. Current implementation assumes there is only
+ *		NIC (eth0), but can be extended to support multiple NICs.
+ *		Currrently only supported for egress.
+ *    -h	Print this info
+ *    prog	BPF program file name. Name defaults to hbm_out_kern.o
+ */
+
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <sys/resource.h>
+#include <sys/time.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/unistd.h>
+
+#include <linux/bpf.h>
+#include <bpf/bpf.h>
+
+#include "bpf_load.h"
+#include "bpf_rlimit.h"
+#include "cgroup_helpers.h"
+#include "hbm.h"
+#include "bpf_util.h"
+#include "bpf/bpf.h"
+#include "bpf/libbpf.h"
+
+bool outFlag = true;
+int minRate = 1000;		/* cgroup rate limit in Mbps */
+int rate = 1000;		/* can grow if rate conserving is enabled */
+int dur = 1;
+bool stats_flag;
+bool loopback_flag;
+bool debugFlag;
+bool work_conserving_flag;
+
+static void Usage(void);
+static void read_trace_pipe2(void);
+static void do_error(char *msg, bool errno_flag);
+
+#define DEBUGFS "/sys/kernel/debug/tracing/"
+
+struct bpf_object *obj;
+int bpfprog_fd;
+int cgroup_storage_fd;
+
+static void read_trace_pipe2(void)
+{
+	int trace_fd;
+	FILE *outf;
+	char *outFname = "hbm_out.log";
+
+	trace_fd = open(DEBUGFS "trace_pipe", O_RDONLY, 0);
+	if (trace_fd < 0) {
+		printf("Error opening trace_pipe\n");
+		return;
+	}
+
+//	Future support of ingress
+//	if (!outFlag)
+//		outFname = "hbm_in.log";
+	outf = fopen(outFname, "w");
+
+	if (outf == NULL)
+		printf("Error creating %s\n", outFname);
+
+	while (1) {
+		static char buf[4097];
+		ssize_t sz;
+
+		sz = read(trace_fd, buf, sizeof(buf) - 1);
+		if (sz > 0) {
+			buf[sz] = 0;
+			puts(buf);
+			if (outf != NULL) {
+				fprintf(outf, "%s\n", buf);
+				fflush(outf);
+			}
+		}
+	}
+}
+
+static void do_error(char *msg, bool errno_flag)
+{
+	if (errno_flag)
+		printf("ERROR: %s, errno: %d\n", msg, errno);
+	else
+		printf("ERROR: %s\n", msg);
+	exit(1);
+}
+
+static int prog_load(char *prog)
+{
+	struct bpf_prog_load_attr prog_load_attr = {
+		.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+		.file = prog,
+		.expected_attach_type = BPF_CGROUP_INET_EGRESS,
+	};
+	int map_fd;
+	struct bpf_map *map;
+
+	int ret = 0;
+
+	if (access(prog, O_RDONLY) < 0) {
+		printf("Error accessing file %s: %s\n", prog, strerror(errno));
+		return 1;
+	}
+	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &bpfprog_fd))
+		ret = 1;
+	if (!ret) {
+		map = bpf_object__find_map_by_name(obj, "queue_stats");
+		map_fd = bpf_map__fd(map);
+		if (map_fd < 0) {
+			printf("Map not found: %s\n", strerror(map_fd));
+			ret = 1;
+		}
+	}
+
+	if (ret) {
+		printf("ERROR: load_bpf_file failed for: %s\n", prog);
+		printf("  Output from verifier:\n%s\n------\n", bpf_log_buf);
+		ret = -1;
+	} else {
+		ret = map_fd;
+	}
+
+	return ret;
+}
+
+static int run_bpf_prog(char *prog, int cg_id)
+{
+	int map_fd;
+	int rc = 0;
+	int key = 0;
+	int cg1 = 0;
+	int type = BPF_CGROUP_INET_EGRESS;
+	char cg_dir[100];
+	struct hbm_queue_stats qstats = {0};
+
+	sprintf(cg_dir, "/hbm%d", cg_id);
+	map_fd = prog_load(prog);
+	if (map_fd  == -1)
+		return 1;
+
+	if (setup_cgroup_environment()) {
+		printf("ERROR: setting cgroup environment\n");
+		goto err;
+	}
+	cg1 = create_and_get_cgroup(cg_dir);
+	if (!cg1) {
+		printf("ERROR: create_and_get_cgroup\n");
+		goto err;
+	}
+	if (join_cgroup(cg_dir)) {
+		printf("ERROR: join_cgroup\n");
+		goto err;
+	}
+
+	qstats.rate = rate;
+	qstats.stats = stats_flag ? 1 : 0;
+	qstats.loopback = loopback_flag ? 1 : 0;
+	if (bpf_map_update_elem(map_fd, &key, &qstats, BPF_ANY)) {
+		printf("ERROR: Could not update map element\n");
+		goto err;
+	}
+
+	if (!outFlag)
+		type = BPF_CGROUP_INET_INGRESS;
+	if (bpf_prog_attach(bpfprog_fd, cg1, type, 0)) {
+		printf("ERROR: bpf_prog_attach fails!\n");
+		log_err("Attaching prog");
+		goto err;
+	}
+
+	if (work_conserving_flag) {
+		struct timeval t0, t_last, t_new;
+		FILE *fin;
+		unsigned long long last_eth_tx_bytes, new_eth_tx_bytes;
+		signed long long last_cg_tx_bytes, new_cg_tx_bytes;
+		signed long long delta_time, delta_bytes, delta_rate;
+		int delta_ms;
+#define DELTA_RATE_CHECK 10000		/* in us */
+#define RATE_THRESHOLD 9500000000	/* 9.5 Gbps */
+
+		bpf_map_lookup_elem(map_fd, &key, &qstats);
+		if (gettimeofday(&t0, NULL) < 0)
+			do_error("gettimeofday failed", true);
+		t_last = t0;
+		fin = fopen("/sys/class/net/eth0/statistics/tx_bytes", "r");
+		if (fscanf(fin, "%llu", &last_eth_tx_bytes) != 1)
+			do_error("fscanf fails", false);
+		fclose(fin);
+		last_cg_tx_bytes = qstats.bytes_total;
+		while (true) {
+			usleep(DELTA_RATE_CHECK);
+			if (gettimeofday(&t_new, NULL) < 0)
+				do_error("gettimeofday failed", true);
+			delta_ms = (t_new.tv_sec - t0.tv_sec) * 1000 +
+				(t_new.tv_usec - t0.tv_usec)/1000;
+			if (delta_ms > dur * 1000)
+				break;
+			delta_time = (t_new.tv_sec - t_last.tv_sec) * 1000000 +
+				(t_new.tv_usec - t_last.tv_usec);
+			if (delta_time == 0)
+				continue;
+			t_last = t_new;
+			fin = fopen("/sys/class/net/eth0/statistics/tx_bytes",
+				    "r");
+			if (fscanf(fin, "%llu", &new_eth_tx_bytes) != 1)
+				do_error("fscanf fails", false);
+			fclose(fin);
+			printf("  new_eth_tx_bytes:%llu\n",
+			       new_eth_tx_bytes);
+			bpf_map_lookup_elem(map_fd, &key, &qstats);
+			new_cg_tx_bytes = qstats.bytes_total;
+			delta_bytes = new_eth_tx_bytes - last_eth_tx_bytes;
+			last_eth_tx_bytes = new_eth_tx_bytes;
+			delta_rate = (delta_bytes * 8000000) / delta_time;
+			printf("%5d - eth_rate:%.1fGbps cg_rate:%.3fGbps",
+			       delta_ms, delta_rate/1000000000.0,
+			       rate/1000.0);
+			if (delta_rate < RATE_THRESHOLD) {
+				/* can increase cgroup rate limit, but first
+				 * check if we are using the current limit.
+				 * Currently increasing by 6.25%, unknown
+				 * if that is the optimal rate.
+				 */
+				int rate_diff100;
+
+				delta_bytes = new_cg_tx_bytes -
+					last_cg_tx_bytes;
+				last_cg_tx_bytes = new_cg_tx_bytes;
+				delta_rate = (delta_bytes * 8000000) /
+					delta_time;
+				printf(" rate:%.3fGbps",
+				       delta_rate/1000000000.0);
+				rate_diff100 = (((long long)rate)*1000000 -
+						     delta_rate) * 100 /
+					(((long long) rate) * 1000000);
+				printf("  rdiff:%d", rate_diff100);
+				if (rate_diff100  <= 3) {
+					rate += (rate >> 4);
+					if (rate > RATE_THRESHOLD / 1000000)
+						rate = RATE_THRESHOLD / 1000000;
+					qstats.rate = rate;
+					printf(" INC\n");
+				} else {
+					printf("\n");
+				}
+			} else {
+				/* Need to decrease cgroup rate limit.
+				 * Currently decreasing by 12.5%, unknown
+				 * if that is optimal
+				 */
+				printf(" DEC\n");
+				rate -= (rate >> 3);
+				if (rate < minRate)
+					rate = minRate;
+				qstats.rate = rate;
+			}
+			if (bpf_map_update_elem(map_fd, &key, &qstats, BPF_ANY))
+				do_error("update map element fails", false);
+		}
+	} else {
+		sleep(dur);
+	}
+	// Get stats!
+	if (stats_flag && bpf_map_lookup_elem(map_fd, &key, &qstats)) {
+		char fname[100];
+		FILE *fout;
+
+		if (!outFlag)
+			sprintf(fname, "hbm.%d.in", cg_id);
+		else
+			sprintf(fname, "hbm.%d.out", cg_id);
+		fout = fopen(fname, "w");
+		fprintf(fout, "id:%d\n", cg_id);
+		fprintf(fout, "ERROR: Could not lookup queue_stats\n");
+	} else if (stats_flag && qstats.lastPacketTime >
+		   qstats.firstPacketTime) {
+		long long delta_us = (qstats.lastPacketTime -
+				      qstats.firstPacketTime)/1000;
+		unsigned int rate_mbps = ((qstats.bytes_total -
+					   qstats.bytes_dropped) * 8 /
+					  delta_us);
+		double percent_pkts, percent_bytes;
+		char fname[100];
+		FILE *fout;
+
+// Future support of ingress
+//		if (!outFlag)
+//			sprintf(fname, "hbm.%d.in", cg_id);
+//		else
+		sprintf(fname, "hbm.%d.out", cg_id);
+		fout = fopen(fname, "w");
+		fprintf(fout, "id:%d\n", cg_id);
+		fprintf(fout, "rate_mbps:%d\n", rate_mbps);
+		fprintf(fout, "duration:%.1f secs\n",
+			(qstats.lastPacketTime - qstats.firstPacketTime) /
+			1000000000.0);
+		fprintf(fout, "packets:%d\n", (int)qstats.pkts_total);
+		fprintf(fout, "bytes_MB:%d\n", (int)(qstats.bytes_total /
+						     1000000));
+		fprintf(fout, "pkts_dropped:%d\n", (int)qstats.pkts_dropped);
+		fprintf(fout, "bytes_dropped_MB:%d\n",
+			(int)(qstats.bytes_dropped /
+						       1000000));
+		// Marked Pkts and Bytes
+		percent_pkts = (qstats.pkts_marked * 100.0) /
+			(qstats.pkts_total + 1);
+		percent_bytes = (qstats.bytes_marked * 100.0) /
+			(qstats.bytes_total + 1);
+		fprintf(fout, "pkts_marked_percent:%6.2f\n", percent_pkts);
+		fprintf(fout, "bytes_marked_percent:%6.2f\n", percent_bytes);
+
+		// Dropped Pkts and Bytes
+		percent_pkts = (qstats.pkts_dropped * 100.0) /
+			(qstats.pkts_total + 1);
+		percent_bytes = (qstats.bytes_dropped * 100.0) /
+			(qstats.bytes_total + 1);
+		fprintf(fout, "pkts_dropped_percent:%6.2f\n", percent_pkts);
+		fprintf(fout, "bytes_dropped_percent:%6.2f\n", percent_bytes);
+		fclose(fout);
+	}
+
+	if (debugFlag)
+		read_trace_pipe2();
+	return rc;
+err:
+	rc = 1;
+
+	if (cg1)
+		close(cg1);
+	cleanup_cgroup_environment();
+
+	return rc;
+}
+
+static void Usage(void)
+{
+	printf("This program loads a cgroup skb BPF program to enforce\n"
+	       "cgroup output (egress) bandwidth limits.\n\n"
+	       "USAGE: hbm [-o] [-d]  [-l] [-n <id>] [-r <rate>] [-s]\n"
+	       "           [-t <secs>] [-w] [-h] [prog]\n"
+	       "  Where:\n"
+	       "    -o         indicates egress direction (default)\n"
+	       "    -d         print BPF trace debug buffer\n"
+	       "    -l         also limit flows using loopback\n"
+	       "    -n <#>     to create cgroup \"/hbm#\" and attach prog\n"
+	       "               Default is /hbm1\n"
+	       "    -r <rate>  Rate in Mbps\n"
+	       "    -s         Update HBM stats\n"
+	       "    -t <time>  Exit after specified seconds (deault is 0)\n"
+	       "    -w	       Work conserving flag. cgroup can increase\n"
+	       "               bandwidth beyond the rate limit specified\n"
+	       "               while there is available bandwidth. Current\n"
+	       "               implementation assumes there is only eth0\n"
+	       "               but can be extended to support multiple NICs\n"
+	       "    -h         print this info\n"
+	       "    prog       BPF program file name. Name defaults to\n"
+	       "                 hbm_out_kern.o\n");
+}
+
+int main(int argc, char **argv)
+{
+	char *prog = "hbm_out_kern.o";
+	int  k;
+	int cg_id = 1;
+	char *optstring = "iodln:r:st:wh";
+
+	while ((k = getopt(argc, argv, optstring)) != -1) {
+		switch (k) {
+		case'o':
+			break;
+		case 'd':
+			debugFlag = true;
+			break;
+		case 'l':
+			loopback_flag = true;
+			break;
+		case 'n':
+			cg_id = atoi(optarg);
+			break;
+		case 'r':
+			minRate = atoi(optarg) * 1.024;
+			rate = minRate;
+			break;
+		case 's':
+			stats_flag = true;
+			break;
+		case 't':
+			dur = atoi(optarg);
+			break;
+		case 'w':
+			work_conserving_flag = true;
+			break;
+		case '?':
+			if (optopt == 'n' || optopt == 'r' || optopt == 't')
+				fprintf(stderr,
+					"Option -%c requires an argument.\n\n",
+					optopt);
+		case 'h':
+			// fallthrough
+		default:
+			Usage();
+			return 0;
+		}
+	}
+
+	if (optind < argc)
+		prog = argv[optind];
+	printf("HBM prog: %s\n", prog != NULL ? prog : "NULL");
+
+	return run_bpf_prog(prog, cg_id);
+}
diff --git a/samples/bpf/hbm.h b/samples/bpf/hbm.h
new file mode 100644
index 000000000000..518e8147d084
--- /dev/null
+++ b/samples/bpf/hbm.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (c) 2019 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Include file for Host Bandwidth Management (HBM) programs
+ */
+struct hbm_vqueue {
+	struct bpf_spin_lock lock;
+	/* 4 byte hole */
+	unsigned long long lasttime;	/* In ns */
+	int credit;			/* In bytes */
+	unsigned int rate;		/* In bytes per NS << 20 */
+};
+
+struct hbm_queue_stats {
+	unsigned long rate;		/* in Mbps*/
+	unsigned long stats:1,		/* get HBM stats (marked, dropped,..) */
+		loopback:1;		/* also limit flows using loopback */
+	unsigned long long pkts_marked;
+	unsigned long long bytes_marked;
+	unsigned long long pkts_dropped;
+	unsigned long long bytes_dropped;
+	unsigned long long pkts_total;
+	unsigned long long bytes_total;
+	unsigned long long firstPacketTime;
+	unsigned long long lastPacketTime;
+};
diff --git a/samples/bpf/hbm_kern.h b/samples/bpf/hbm_kern.h
new file mode 100644
index 000000000000..c5635d924193
--- /dev/null
+++ b/samples/bpf/hbm_kern.h
@@ -0,0 +1,137 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (c) 2019 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Include file for sample Host Bandwidth Manager (HBM) BPF programs
+ */
+#define KBUILD_MODNAME "foo"
+#include <stddef.h>
+#include <stdbool.h>
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <uapi/linux/ipv6.h>
+#include <uapi/linux/in.h>
+#include <uapi/linux/tcp.h>
+#include <uapi/linux/filter.h>
+#include <uapi/linux/pkt_cls.h>
+#include <net/ipv6.h>
+#include <net/inet_ecn.h>
+#include "bpf_endian.h"
+#include "bpf_helpers.h"
+#include "hbm.h"
+
+#define DROP_PKT	0
+#define ALLOW_PKT	1
+#define TCP_ECN_OK	1
+
+#define HBM_DEBUG 0  // Set to 1 to enable debugging
+#if HBM_DEBUG
+#define bpf_printk(fmt, ...)					\
+({								\
+	char ____fmt[] = fmt;					\
+	bpf_trace_printk(____fmt, sizeof(____fmt),		\
+			 ##__VA_ARGS__);			\
+})
+#else
+#define bpf_printk(fmt, ...)
+#endif
+
+#define INITIAL_CREDIT_PACKETS	100
+#define MAX_BYTES_PER_PACKET	1500
+#define MARK_THRESH		(40 * MAX_BYTES_PER_PACKET)
+#define DROP_THRESH		(80 * 5 * MAX_BYTES_PER_PACKET)
+#define LARGE_PKT_DROP_THRESH	(DROP_THRESH - (15 * MAX_BYTES_PER_PACKET))
+#define MARK_REGION_SIZE	(LARGE_PKT_DROP_THRESH - MARK_THRESH)
+#define LARGE_PKT_THRESH	120
+#define MAX_CREDIT		(100 * MAX_BYTES_PER_PACKET)
+#define INIT_CREDIT		(INITIAL_CREDIT_PACKETS * MAX_BYTES_PER_PACKET)
+
+// rate in bytes per ns << 20
+#define CREDIT_PER_NS(delta, rate) ((((u64)(delta)) * (rate)) >> 20)
+
+struct bpf_map_def SEC("maps") queue_state = {
+	.type = BPF_MAP_TYPE_CGROUP_STORAGE,
+	.key_size = sizeof(struct bpf_cgroup_storage_key),
+	.value_size = sizeof(struct hbm_vqueue),
+};
+BPF_ANNOTATE_KV_PAIR(queue_state, struct bpf_cgroup_storage_key,
+		     struct hbm_vqueue);
+
+struct bpf_map_def SEC("maps") queue_stats = {
+	.type = BPF_MAP_TYPE_ARRAY,
+	.key_size = sizeof(u32),
+	.value_size = sizeof(struct hbm_queue_stats),
+	.max_entries = 1,
+};
+BPF_ANNOTATE_KV_PAIR(queue_stats, int, struct hbm_queue_stats);
+
+struct hbm_pkt_info {
+	bool	is_ip;
+	bool	is_tcp;
+	short	ecn;
+};
+
+static __always_inline void hbm_get_pkt_info(struct __sk_buff *skb,
+					     struct hbm_pkt_info *pkti)
+{
+	struct iphdr iph;
+	struct ipv6hdr *ip6h;
+
+	bpf_skb_load_bytes(skb, 0, &iph, 12);
+	if (iph.version == 6) {
+		ip6h = (struct ipv6hdr *)&iph;
+		pkti->is_ip = true;
+		pkti->is_tcp = (ip6h->nexthdr == 6);
+		pkti->ecn = (ip6h->flow_lbl[0] >> 4) & INET_ECN_MASK;
+	} else if (iph.version == 4) {
+		pkti->is_ip = true;
+		pkti->is_tcp = (iph.protocol == 6);
+		pkti->ecn = iph.tos & INET_ECN_MASK;
+	} else {
+		pkti->is_ip = false;
+		pkti->is_tcp = false;
+		pkti->ecn = 0;
+	}
+}
+
+static __always_inline void hbm_init_vqueue(struct hbm_vqueue *qdp, int rate)
+{
+		bpf_printk("Initializing queue_state, rate:%d\n", rate * 128);
+		qdp->lasttime = bpf_ktime_get_ns();
+		qdp->credit = INIT_CREDIT;
+		qdp->rate = rate * 128;
+}
+
+static __always_inline void hbm_update_stats(struct hbm_queue_stats *qsp,
+					     int len,
+					     unsigned long long curtime,
+					     bool congestion_flag,
+					     bool drop_flag)
+{
+	if (qsp != NULL) {
+		// Following is needed for work conserving
+		__sync_add_and_fetch(&(qsp->bytes_total), len);
+		if (qsp->stats) {
+			// Optionally update statistics
+			if (qsp->firstPacketTime == 0)
+				qsp->firstPacketTime = curtime;
+			qsp->lastPacketTime = curtime;
+			__sync_add_and_fetch(&(qsp->pkts_total), 1);
+			if (congestion_flag || drop_flag) {
+				__sync_add_and_fetch(&(qsp->pkts_marked), 1);
+				__sync_add_and_fetch(&(qsp->bytes_marked), len);
+			}
+			if (drop_flag) {
+				__sync_add_and_fetch(&(qsp->pkts_dropped), 1);
+				__sync_add_and_fetch(&(qsp->bytes_dropped),
+						     len);
+			}
+		}
+	}
+}
diff --git a/samples/bpf/hbm_out_kern.c b/samples/bpf/hbm_out_kern.c
new file mode 100644
index 000000000000..f806863d0b79
--- /dev/null
+++ b/samples/bpf/hbm_out_kern.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Sample Host Bandwidth Manager (HBM) BPF program.
+ *
+ * A cgroup skb BPF egress program to limit cgroup output bandwidth.
+ * It uses a modified virtual token bucket queue to limit average
+ * egress bandwidth. The implementation uses credits instead of tokens.
+ * Negative credits imply that queueing would have happened (this is
+ * a virtual queue, so no queueing is done by it. However, queueing may
+ * occur at the actual qdisc (which is not used for rate limiting).
+ *
+ * This implementation uses 3 thresholds, one to start marking packets and
+ * the other two to drop packets:
+ *                                  CREDIT
+ *        - <--------------------------|------------------------> +
+ *              |    |          |      0
+ *              |  Large pkt    |
+ *              |  drop thresh  |
+ *   Small pkt drop             Mark threshold
+ *       thresh
+ *
+ * The effect of marking depends on the type of packet:
+ * a) If the packet is ECN enabled and it is a TCP packet, then the packet
+ *    is ECN marked.
+ * b) If the packet is a TCP packet, then we probabilistically call tcp_cwr
+ *    to reduce the congestion window. The current implementation uses a linear
+ *    distribution (0% probability at marking threshold, 100% probability
+ *    at drop threshold).
+ * c) If the packet is not a TCP packet, then it is dropped.
+ *
+ * If the credit is below the drop threshold, the packet is dropped. If it
+ * is a TCP packet, then it also calls tcp_cwr since packets dropped by
+ * by a cgroup skb BPF program do not automatically trigger a call to
+ * tcp_cwr in the current kernel code.
+ *
+ * This BPF program actually uses 2 drop thresholds, one threshold
+ * for larger packets (>= 120 bytes) and another for smaller packets. This
+ * protects smaller packets such as SYNs, ACKs, etc.
+ *
+ * The default bandwidth limit is set at 1Gbps but this can be changed by
+ * a user program through a shared BPF map. In addition, by default this BPF
+ * program does not limit connections using loopback. This behavior can be
+ * overwritten by the user program. There is also an option to calculate
+ * some statistics, such as percent of packets marked or dropped, which
+ * the user program can access.
+ *
+ * A latter patch provides such a program (hbm.c)
+ */
+
+#include "hbm_kern.h"
+
+SEC("cgroup_skb/egress")
+int _hbm_out_cg(struct __sk_buff *skb)
+{
+	struct hbm_pkt_info pkti;
+	int len = skb->len;
+	unsigned int queue_index = 0;
+	unsigned long long curtime;
+	int credit;
+	signed long long delta = 0, zero = 0;
+	int max_credit = MAX_CREDIT;
+	bool congestion_flag = false;
+	bool drop_flag = false;
+	bool cwr_flag = false;
+	struct hbm_vqueue *qdp;
+	struct hbm_queue_stats *qsp = NULL;
+	int rv = ALLOW_PKT;
+
+	qsp = bpf_map_lookup_elem(&queue_stats, &queue_index);
+	if (qsp != NULL && !qsp->loopback && (skb->ifindex == 1))
+		return ALLOW_PKT;
+
+	hbm_get_pkt_info(skb, &pkti);
+
+	// We may want to account for the length of headers in len
+	// calculation, like ETH header + overhead, specially if it
+	// is a gso packet. But I am not doing it right now.
+
+	qdp = bpf_get_local_storage(&queue_state, 0);
+	if (!qdp)
+		return ALLOW_PKT;
+	else if (qdp->lasttime == 0)
+		hbm_init_vqueue(qdp, 1024);
+
+	curtime = bpf_ktime_get_ns();
+
+	// Begin critical section
+	bpf_spin_lock(&qdp->lock);
+	credit = qdp->credit;
+	delta = curtime - qdp->lasttime;
+	/* delta < 0 implies that another process with a curtime greater
+	 * than ours beat us to the critical section and already added
+	 * the new credit, so we should not add it ourselves
+	 */
+	if (delta > 0) {
+		qdp->lasttime = curtime;
+		credit += CREDIT_PER_NS(delta, qdp->rate);
+		if (credit > MAX_CREDIT)
+			credit = MAX_CREDIT;
+	}
+	credit -= len;
+	qdp->credit = credit;
+	bpf_spin_unlock(&qdp->lock);
+	// End critical section
+
+	// Check if we should update rate
+	if (qsp != NULL && (qsp->rate * 128) != qdp->rate) {
+		qdp->rate = qsp->rate * 128;
+		bpf_printk("Updating rate: %d (1sec:%llu bits)\n",
+			   (int)qdp->rate,
+			   CREDIT_PER_NS(1000000000, qdp->rate) * 8);
+	}
+
+	// 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
+		drop_flag = true;
+	} else if (credit < 0) {
+		// Congested, set congestion flag
+		if (pkti.ecn) {
+			if (credit < -MARK_THRESH)
+				congestion_flag = true;
+			else
+				congestion_flag = false;
+		} else {
+			congestion_flag = true;
+		}
+	}
+
+	if (congestion_flag) {
+		if (!bpf_skb_ecn_set_ce(skb)) {
+			if (len > LARGE_PKT_THRESH) {
+				// Problem if too many small packets?
+				drop_flag = true;
+			}
+		}
+	}
+
+	if (drop_flag)
+		rv = DROP_PKT;
+
+	hbm_update_stats(qsp, len, curtime, congestion_flag, drop_flag);
+
+	if (rv == DROP_PKT)
+		__sync_add_and_fetch(&(qdp->credit), len);
+
+	return rv;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 2e308e90ffea..3c38ac9a92a7 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -2359,6 +2359,13 @@ union bpf_attr {
  *	Return
  *		A **struct bpf_tcp_sock** pointer on success, or NULL in
  *		case of failure.
+ *
+ * int bpf_skb_ecn_set_ce(struct sk_buf *skb)
+ *     Description
+ *             Sets ECN of IP header to ce (congestion encountered) if
+ *             current value is ect (ECN capable). Works with IPv6 and IPv4.
+ *     Return
+ *             1 if set, 0 if not set.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -2457,7 +2464,8 @@ union bpf_attr {
 	FN(spin_lock),			\
 	FN(spin_unlock),		\
 	FN(sk_fullsock),		\
-	FN(tcp_sock),
+	FN(tcp_sock),			\
+	FN(skb_ecn_set_ce),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h
index 026bea831e03..c9433a496d54 100644
--- a/tools/testing/selftests/bpf/bpf_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_helpers.h
@@ -180,6 +180,8 @@ static struct bpf_sock *(*bpf_sk_fullsock)(struct bpf_sock *sk) =
 	(void *) BPF_FUNC_sk_fullsock;
 static struct bpf_tcp_sock *(*bpf_tcp_sock)(struct bpf_sock *sk) =
 	(void *) BPF_FUNC_tcp_sock;
+static int (*bpf_skb_ecn_set_ce)(void *ctx) =
+	(void *) BPF_FUNC_skb_ecn_set_ce;
 
 /* llvm builtin functions that eBPF C program may use to
  * emit BPF_LD_ABS and BPF_LD_IND instructions