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* Re: [PATCH net-next v4 1/3] ipv4: support sport, dport and ip_proto in RTM_GETROUTE
From: Eric Dumazet @ 2018-05-22 15:04 UTC (permalink / raw)
  To: Roopa Prabhu, davem; +Cc: netdev, nikolay, dsa, idosch
In-Reply-To: <1527000668-25253-2-git-send-email-roopa@cumulusnetworks.com>



On 05/22/2018 07:51 AM, Roopa Prabhu wrote:
> From: Roopa Prabhu <roopa@cumulusnetworks.com>
> 
> 

...

> diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
> index 4d622112..cf5cfc5 100644
> --- a/net/ipv4/fib_frontend.c
> +++ b/net/ipv4/fib_frontend.c
> @@ -649,6 +649,10 @@ const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
>  	[RTA_ENCAP]		= { .type = NLA_NESTED },
>  	[RTA_UID]		= { .type = NLA_U32 },
>  	[RTA_MARK]		= { .type = NLA_U32 },
> +	[RTA_TABLE]		= { .type = NLA_U32 },
> +	[RTA_IP_PROTO]		= { .type = NLA_U8 },
> +	[RTA_SPORT]		= { .type = NLA_U16 },
> +	[RTA_DPORT]		= { .type = NLA_U16 },
>  };

Hi Roopa

RTA_TABLE addition looks like a bug fix for net tree ?

This should be sent as an independent patch IMO.

Thanks.

^ permalink raw reply

* [PATCH net-next v4 3/3] selftests: net: initial fib rule tests
From: Roopa Prabhu @ 2018-05-22 14:51 UTC (permalink / raw)
  To: davem; +Cc: netdev, nikolay, dsa, idosch
In-Reply-To: <1527000668-25253-1-git-send-email-roopa@cumulusnetworks.com>

From: Roopa Prabhu <roopa@cumulusnetworks.com>

This adds a first set of tests for fib rule match/action for
ipv4 and ipv6. Initial tests only cover action lookup table.
can be extended to cover other actions in the future.
Uses ip route get to validate the rule lookup.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
---
 tools/testing/selftests/net/Makefile          |   2 +-
 tools/testing/selftests/net/fib_rule_tests.sh | 248 ++++++++++++++++++++++++++
 2 files changed, 249 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/net/fib_rule_tests.sh

diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
index e60dddb..7cb0f49 100644
--- a/tools/testing/selftests/net/Makefile
+++ b/tools/testing/selftests/net/Makefile
@@ -6,7 +6,7 @@ CFLAGS += -I../../../../usr/include/
 
 TEST_PROGS := run_netsocktests run_afpackettests test_bpf.sh netdevice.sh rtnetlink.sh
 TEST_PROGS += fib_tests.sh fib-onlink-tests.sh pmtu.sh udpgso.sh
-TEST_PROGS += udpgso_bench.sh
+TEST_PROGS += udpgso_bench.sh fib_rule_tests.sh
 TEST_PROGS_EXTENDED := in_netns.sh
 TEST_GEN_FILES =  socket
 TEST_GEN_FILES += psock_fanout psock_tpacket msg_zerocopy
diff --git a/tools/testing/selftests/net/fib_rule_tests.sh b/tools/testing/selftests/net/fib_rule_tests.sh
new file mode 100644
index 0000000..d4cfb6a
--- /dev/null
+++ b/tools/testing/selftests/net/fib_rule_tests.sh
@@ -0,0 +1,248 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# This test is for checking IPv4 and IPv6 FIB rules API
+
+ret=0
+
+PAUSE_ON_FAIL=${PAUSE_ON_FAIL:=no}
+IP="ip -netns testns"
+
+RTABLE=100
+GW_IP4=192.51.100.2
+SRC_IP=192.51.100.3
+GW_IP6=2001:db8:1::2
+SRC_IP6=2001:db8:1::3
+
+DEV_ADDR=192.51.100.1
+DEV=dummy0
+
+log_test()
+{
+	local rc=$1
+	local expected=$2
+	local msg="$3"
+
+	if [ ${rc} -eq ${expected} ]; then
+		nsuccess=$((nsuccess+1))
+		printf "\n    TEST: %-50s  [ OK ]\n" "${msg}"
+	else
+		nfail=$((nfail+1))
+		printf "\n    TEST: %-50s  [FAIL]\n" "${msg}"
+		if [ "${PAUSE_ON_FAIL}" = "yes" ]; then
+			echo
+			echo "hit enter to continue, 'q' to quit"
+			read a
+			[ "$a" = "q" ] && exit 1
+		fi
+	fi
+}
+
+log_section()
+{
+	echo
+	echo "######################################################################"
+	echo "TEST SECTION: $*"
+	echo "######################################################################"
+}
+
+setup()
+{
+	set -e
+	ip netns add testns
+	$IP link set dev lo up
+
+	$IP link add dummy0 type dummy
+	$IP link set dev dummy0 up
+	$IP address add 198.51.100.1/24 dev dummy0
+	$IP -6 address add 2001:db8:1::1/64 dev dummy0
+
+	set +e
+}
+
+cleanup()
+{
+	$IP link del dev dummy0 &> /dev/null
+	ip netns del testns
+}
+
+fib_check_iproute_support()
+{
+	ip rule help 2>&1 | grep -q $1
+	if [ $? -ne 0 ]; then
+		echo "SKIP: iproute2 iprule too old, missing $1 match"
+		return 1
+	fi
+
+	ip route get help 2>&1 | grep -q $2
+	if [ $? -ne 0 ]; then
+		echo "SKIP: iproute2 get route too old, missing $2 match"
+		return 1
+	fi
+
+	return 0
+}
+
+fib_rule6_del()
+{
+	$IP -6 rule del $1
+	log_test $? 0 "rule6 del $1"
+}
+
+fib_rule6_del_by_pref()
+{
+	pref=$($IP -6 rule show | grep "$1 lookup $TABLE" | cut -d ":" -f 1)
+	$IP -6 rule del pref $pref
+}
+
+fib_rule6_test_match_n_redirect()
+{
+	local match="$1"
+	local getmatch="$2"
+
+	$IP -6 rule add $match table $RTABLE
+	$IP -6 route get $GW_IP6 $getmatch | grep -q "table $RTABLE"
+	log_test $? 0 "rule6 check: $1"
+
+	fib_rule6_del_by_pref "$match"
+	log_test $? 0 "rule6 del by pref: $match"
+}
+
+fib_rule6_test()
+{
+	# setup the fib rule redirect route
+	$IP -6 route add table $RTABLE default via $GW_IP6 dev $DEV onlink
+
+	match="oif $DEV"
+	fib_rule6_test_match_n_redirect "$match" "$match" "oif redirect to table"
+
+	match="from $SRC_IP6 iif $DEV"
+	fib_rule6_test_match_n_redirect "$match" "$match" "iif redirect to table"
+
+	match="tos 0x10"
+	fib_rule6_test_match_n_redirect "$match" "$match" "tos redirect to table"
+
+	match="fwmark 0x64"
+	getmatch="mark 0x64"
+	fib_rule6_test_match_n_redirect "$match" "$getmatch" "fwmark redirect to table"
+
+	fib_check_iproute_support "uidrange" "uid"
+	if [ $? -eq 0 ]; then
+		match="uidrange 100-100"
+		getmatch="uid 100"
+		fib_rule6_test_match_n_redirect "$match" "$getmatch" "uid redirect to table"
+	fi
+
+	fib_check_iproute_support "sport" "sport"
+	if [ $? -eq 0 ]; then
+		match="sport 666 dport 777"
+		fib_rule6_test_match_n_redirect "$match" "$match" "sport and dport redirect to table"
+	fi
+
+	fib_check_iproute_support "ipproto" "ipproto"
+	if [ $? -eq 0 ]; then
+		match="ipproto tcp"
+		fib_rule6_test_match_n_redirect "$match" "$match" "ipproto match"
+	fi
+
+	fib_check_iproute_support "ipproto" "ipproto"
+	if [ $? -eq 0 ]; then
+		match="ipproto icmp"
+		fib_rule6_test_match_n_redirect "$match" "$match" "ipproto icmp match"
+	fi
+}
+
+fib_rule4_del()
+{
+	$IP rule del $1
+	log_test $? 0 "del $1"
+}
+
+fib_rule4_del_by_pref()
+{
+	pref=$($IP rule show | grep "$1 lookup $TABLE" | cut -d ":" -f 1)
+	$IP rule del pref $pref
+}
+
+fib_rule4_test_match_n_redirect()
+{
+	local match="$1"
+	local getmatch="$2"
+
+	$IP rule add $match table $RTABLE
+	$IP route get $GW_IP4 $getmatch | grep -q "table $RTABLE"
+	log_test $? 0 "rule4 check: $1"
+
+	fib_rule4_del_by_pref "$match"
+	log_test $? 0 "rule4 del by pref: $match"
+}
+
+fib_rule4_test()
+{
+	# setup the fib rule redirect route
+	$IP route add table $RTABLE default via $GW_IP4 dev $DEV onlink
+
+	match="oif $DEV"
+	fib_rule4_test_match_n_redirect "$match" "$match" "oif redirect to table"
+
+	match="from $SRC_IP iif $DEV"
+	fib_rule4_test_match_n_redirect "$match" "$match" "iif redirect to table"
+
+	match="tos 0x10"
+	fib_rule4_test_match_n_redirect "$match" "$match" "tos redirect to table"
+
+	match="fwmark 0x64"
+	getmatch="mark 0x64"
+	fib_rule4_test_match_n_redirect "$match" "$getmatch" "fwmark redirect to table"
+
+	fib_check_iproute_support "uidrange" "uid"
+	if [ $? -eq 0 ]; then
+		match="uidrange 100-100"
+		getmatch="uid 100"
+		fib_rule4_test_match_n_redirect "$match" "$getmatch" "uid redirect to table"
+	fi
+
+	fib_check_iproute_support "sport" "sport"
+	if [ $? -eq 0 ]; then
+		match="sport 666 dport 777"
+		fib_rule4_test_match_n_redirect "$match" "$match" "sport and dport redirect to table"
+	fi
+
+	fib_check_iproute_support "ipproto" "ipproto"
+	if [ $? -eq 0 ]; then
+		match="ipproto tcp"
+		fib_rule4_test_match_n_redirect "$match" "$match" "ipproto tcp match"
+	fi
+
+	fib_check_iproute_support "ipproto" "ipproto"
+	if [ $? -eq 0 ]; then
+		match="ipproto icmp"
+		fib_rule4_test_match_n_redirect "$match" "$match" "ipproto icmp match"
+	fi
+}
+
+run_fibrule_tests()
+{
+	log_section "IPv4 fib rule"
+	fib_rule4_test
+	log_section "IPv6 fib rule"
+	fib_rule6_test
+}
+
+if [ "$(id -u)" -ne 0 ];then
+	echo "SKIP: Need root privileges"
+	exit 0
+fi
+
+if [ ! -x "$(command -v ip)" ]; then
+	echo "SKIP: Could not run test without ip tool"
+	exit 0
+fi
+
+# start clean
+cleanup &> /dev/null
+setup
+run_fibrule_tests
+cleanup
+
+exit $ret
-- 
2.1.4

^ permalink raw reply related

* [PATCH net-next v4 2/3] ipv6: support sport, dport and ip_proto in RTM_GETROUTE
From: Roopa Prabhu @ 2018-05-22 14:51 UTC (permalink / raw)
  To: davem; +Cc: netdev, nikolay, dsa, idosch
In-Reply-To: <1527000668-25253-1-git-send-email-roopa@cumulusnetworks.com>

From: Roopa Prabhu <roopa@cumulusnetworks.com>

This is a followup to fib6 rules sport, dport and ipproto
match support. Only supports tcp, udp and icmp for ipproto.
Used by fib rule self tests.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
---
 net/ipv6/route.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index cc24ed3..7f1babb 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -63,6 +63,7 @@
 #include <net/lwtunnel.h>
 #include <net/ip_tunnels.h>
 #include <net/l3mdev.h>
+#include <net/ip.h>
 #include <trace/events/fib6.h>
 
 #include <linux/uaccess.h>
@@ -4083,6 +4084,9 @@ static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
 	[RTA_UID]		= { .type = NLA_U32 },
 	[RTA_MARK]		= { .type = NLA_U32 },
 	[RTA_TABLE]		= { .type = NLA_U32 },
+	[RTA_IP_PROTO]		= { .type = NLA_U8 },
+	[RTA_SPORT]		= { .type = NLA_U16 },
+	[RTA_DPORT]		= { .type = NLA_U16 },
 };
 
 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
@@ -4794,6 +4798,19 @@ static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 	else
 		fl6.flowi6_uid = iif ? INVALID_UID : current_uid();
 
+	if (tb[RTA_SPORT])
+		fl6.fl6_sport = nla_get_be16(tb[RTA_SPORT]);
+
+	if (tb[RTA_DPORT])
+		fl6.fl6_dport = nla_get_be16(tb[RTA_DPORT]);
+
+	if (tb[RTA_IP_PROTO]) {
+		err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
+						  &fl6.flowi6_proto, extack);
+		if (err)
+			goto errout;
+	}
+
 	if (iif) {
 		struct net_device *dev;
 		int flags = 0;
-- 
2.1.4

^ permalink raw reply related

* [PATCH net-next v4 1/3] ipv4: support sport, dport and ip_proto in RTM_GETROUTE
From: Roopa Prabhu @ 2018-05-22 14:51 UTC (permalink / raw)
  To: davem; +Cc: netdev, nikolay, dsa, idosch
In-Reply-To: <1527000668-25253-1-git-send-email-roopa@cumulusnetworks.com>

From: Roopa Prabhu <roopa@cumulusnetworks.com>

This is a followup to fib rules sport, dport and ipproto
match support. Only supports tcp, udp and icmp for ipproto.
Used by fib rule self tests.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
---
 include/net/ip.h               |   3 +
 include/uapi/linux/rtnetlink.h |   3 +
 net/ipv4/Makefile              |   2 +-
 net/ipv4/fib_frontend.c        |   4 ++
 net/ipv4/netlink.c             |  23 +++++++
 net/ipv4/route.c               | 146 ++++++++++++++++++++++++++++++-----------
 6 files changed, 141 insertions(+), 40 deletions(-)
 create mode 100644 net/ipv4/netlink.c

diff --git a/include/net/ip.h b/include/net/ip.h
index bada1f1..0d2281b 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -664,4 +664,7 @@ extern int sysctl_icmp_msgs_burst;
 int ip_misc_proc_init(void);
 #endif
 
+int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto,
+				struct netlink_ext_ack *extack);
+
 #endif	/* _IP_H */
diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index 9b15005..cabb210 100644
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -327,6 +327,9 @@ enum rtattr_type_t {
 	RTA_PAD,
 	RTA_UID,
 	RTA_TTL_PROPAGATE,
+	RTA_IP_PROTO,
+	RTA_SPORT,
+	RTA_DPORT,
 	__RTA_MAX
 };
 
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index b379520..13f2ba9 100644
--- a/net/ipv4/Makefile
+++ b/net/ipv4/Makefile
@@ -14,7 +14,7 @@ obj-y     := route.o inetpeer.o protocol.o \
 	     udp_offload.o arp.o icmp.o devinet.o af_inet.o igmp.o \
 	     fib_frontend.o fib_semantics.o fib_trie.o fib_notifier.o \
 	     inet_fragment.o ping.o ip_tunnel_core.o gre_offload.o \
-	     metrics.o
+	     metrics.o netlink.o
 
 obj-$(CONFIG_NET_IP_TUNNEL) += ip_tunnel.o
 obj-$(CONFIG_SYSCTL) += sysctl_net_ipv4.o
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 4d622112..cf5cfc5 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -649,6 +649,10 @@ const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
 	[RTA_ENCAP]		= { .type = NLA_NESTED },
 	[RTA_UID]		= { .type = NLA_U32 },
 	[RTA_MARK]		= { .type = NLA_U32 },
+	[RTA_TABLE]		= { .type = NLA_U32 },
+	[RTA_IP_PROTO]		= { .type = NLA_U8 },
+	[RTA_SPORT]		= { .type = NLA_U16 },
+	[RTA_DPORT]		= { .type = NLA_U16 },
 };
 
 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
diff --git a/net/ipv4/netlink.c b/net/ipv4/netlink.c
new file mode 100644
index 0000000..f86bb4f
--- /dev/null
+++ b/net/ipv4/netlink.c
@@ -0,0 +1,23 @@
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <linux/types.h>
+#include <net/net_namespace.h>
+#include <net/netlink.h>
+#include <net/ip.h>
+
+int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto,
+				struct netlink_ext_ack *extack)
+{
+	*ip_proto = nla_get_u8(attr);
+
+	switch (*ip_proto) {
+	case IPPROTO_TCP:
+	case IPPROTO_UDP:
+	case IPPROTO_ICMP:
+		return 0;
+	default:
+		NL_SET_ERR_MSG(extack, "Unsupported ip proto");
+		return -EOPNOTSUPP;
+	}
+}
+EXPORT_SYMBOL_GPL(rtm_getroute_parse_ip_proto);
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 2cfa1b5..0e401dc 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2574,11 +2574,10 @@ struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
 EXPORT_SYMBOL_GPL(ip_route_output_flow);
 
 /* called with rcu_read_lock held */
-static int rt_fill_info(struct net *net,  __be32 dst, __be32 src, u32 table_id,
-			struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
-			u32 seq)
+static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
+			struct rtable *rt, u32 table_id, struct flowi4 *fl4,
+			struct sk_buff *skb, u32 portid, u32 seq)
 {
-	struct rtable *rt = skb_rtable(skb);
 	struct rtmsg *r;
 	struct nlmsghdr *nlh;
 	unsigned long expires = 0;
@@ -2674,7 +2673,7 @@ static int rt_fill_info(struct net *net,  __be32 dst, __be32 src, u32 table_id,
 			}
 		} else
 #endif
-			if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
+			if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif))
 				goto nla_put_failure;
 	}
 
@@ -2689,43 +2688,93 @@ static int rt_fill_info(struct net *net,  __be32 dst, __be32 src, u32 table_id,
 	return -EMSGSIZE;
 }
 
+static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst,
+						   u8 ip_proto, __be16 sport,
+						   __be16 dport)
+{
+	struct sk_buff *skb;
+	struct iphdr *iph;
+
+	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!skb)
+		return NULL;
+
+	/* Reserve room for dummy headers, this skb can pass
+	 * through good chunk of routing engine.
+	 */
+	skb_reset_mac_header(skb);
+	skb_reset_network_header(skb);
+	skb->protocol = htons(ETH_P_IP);
+	iph = skb_put(skb, sizeof(struct iphdr));
+	iph->protocol = ip_proto;
+	iph->saddr = src;
+	iph->daddr = dst;
+	iph->version = 0x4;
+	iph->frag_off = 0;
+	iph->ihl = 0x5;
+	skb_set_transport_header(skb, skb->len);
+
+	switch (iph->protocol) {
+	case IPPROTO_UDP: {
+		struct udphdr *udph;
+
+		udph = skb_put_zero(skb, sizeof(struct udphdr));
+		udph->source = sport;
+		udph->dest = dport;
+		udph->len = sizeof(struct udphdr);
+		udph->check = 0;
+		break;
+	}
+	case IPPROTO_TCP: {
+		struct tcphdr *tcph;
+
+		tcph = skb_put_zero(skb, sizeof(struct tcphdr));
+		tcph->source	= sport;
+		tcph->dest	= dport;
+		tcph->doff	= sizeof(struct tcphdr) / 4;
+		tcph->rst = 1;
+		tcph->check = ~tcp_v4_check(sizeof(struct tcphdr),
+					    src, dst, 0);
+		break;
+	}
+	case IPPROTO_ICMP: {
+		struct icmphdr *icmph;
+
+		icmph = skb_put_zero(skb, sizeof(struct icmphdr));
+		icmph->type = ICMP_ECHO;
+		icmph->code = 0;
+	}
+	}
+
+	return skb;
+}
+
 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 			     struct netlink_ext_ack *extack)
 {
 	struct net *net = sock_net(in_skb->sk);
-	struct rtmsg *rtm;
 	struct nlattr *tb[RTA_MAX+1];
+	u32 table_id = RT_TABLE_MAIN;
+	__be16 sport = 0, dport = 0;
 	struct fib_result res = {};
+	u8 ip_proto = IPPROTO_UDP;
 	struct rtable *rt = NULL;
+	struct sk_buff *skb;
+	struct rtmsg *rtm;
 	struct flowi4 fl4;
 	__be32 dst = 0;
 	__be32 src = 0;
+	kuid_t uid;
 	u32 iif;
 	int err;
 	int mark;
-	struct sk_buff *skb;
-	u32 table_id = RT_TABLE_MAIN;
-	kuid_t uid;
 
 	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy,
 			  extack);
 	if (err < 0)
-		goto errout;
+		return err;
 
 	rtm = nlmsg_data(nlh);
-
-	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
-	if (!skb) {
-		err = -ENOBUFS;
-		goto errout;
-	}
-
-	/* Reserve room for dummy headers, this skb can pass
-	   through good chunk of routing engine.
-	 */
-	skb_reset_mac_header(skb);
-	skb_reset_network_header(skb);
-
 	src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
 	dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
 	iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
@@ -2735,14 +2784,22 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 	else
 		uid = (iif ? INVALID_UID : current_uid());
 
-	/* Bugfix: need to give ip_route_input enough of an IP header to
-	 * not gag.
-	 */
-	ip_hdr(skb)->protocol = IPPROTO_UDP;
-	ip_hdr(skb)->saddr = src;
-	ip_hdr(skb)->daddr = dst;
+	if (tb[RTA_IP_PROTO]) {
+		err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
+						  &ip_proto, extack);
+		if (err)
+			return err;
+	}
+
+	if (tb[RTA_SPORT])
+		sport = nla_get_be16(tb[RTA_SPORT]);
 
-	skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
+	if (tb[RTA_DPORT])
+		dport = nla_get_be16(tb[RTA_DPORT]);
+
+	skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport);
+	if (!skb)
+		return -ENOBUFS;
 
 	memset(&fl4, 0, sizeof(fl4));
 	fl4.daddr = dst;
@@ -2751,6 +2808,11 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 	fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
 	fl4.flowi4_mark = mark;
 	fl4.flowi4_uid = uid;
+	if (sport)
+		fl4.fl4_sport = sport;
+	if (dport)
+		fl4.fl4_dport = dport;
+	fl4.flowi4_proto = ip_proto;
 
 	rcu_read_lock();
 
@@ -2760,10 +2822,10 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 		dev = dev_get_by_index_rcu(net, iif);
 		if (!dev) {
 			err = -ENODEV;
-			goto errout_free;
+			goto errout_rcu;
 		}
 
-		skb->protocol	= htons(ETH_P_IP);
+		fl4.flowi4_iif = iif; /* for rt_fill_info */
 		skb->dev	= dev;
 		skb->mark	= mark;
 		err = ip_route_input_rcu(skb, dst, src, rtm->rtm_tos,
@@ -2783,7 +2845,7 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 	}
 
 	if (err)
-		goto errout_free;
+		goto errout_rcu;
 
 	if (rtm->rtm_flags & RTM_F_NOTIFY)
 		rt->rt_flags |= RTCF_NOTIFY;
@@ -2791,34 +2853,40 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 	if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
 		table_id = res.table ? res.table->tb_id : 0;
 
+	/* reset skb for netlink reply msg */
+	skb_trim(skb, 0);
+	skb_reset_network_header(skb);
+	skb_reset_transport_header(skb);
+	skb_reset_mac_header(skb);
+
 	if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
 		if (!res.fi) {
 			err = fib_props[res.type].error;
 			if (!err)
 				err = -EHOSTUNREACH;
-			goto errout_free;
+			goto errout_rcu;
 		}
 		err = fib_dump_info(skb, NETLINK_CB(in_skb).portid,
 				    nlh->nlmsg_seq, RTM_NEWROUTE, table_id,
 				    rt->rt_type, res.prefix, res.prefixlen,
 				    fl4.flowi4_tos, res.fi, 0);
 	} else {
-		err = rt_fill_info(net, dst, src, table_id, &fl4, skb,
+		err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb,
 				   NETLINK_CB(in_skb).portid, nlh->nlmsg_seq);
 	}
 	if (err < 0)
-		goto errout_free;
+		goto errout_rcu;
 
 	rcu_read_unlock();
 
 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
-errout:
-	return err;
 
 errout_free:
+	return err;
+errout_rcu:
 	rcu_read_unlock();
 	kfree_skb(skb);
-	goto errout;
+	goto errout_free;
 }
 
 void ip_rt_multicast_event(struct in_device *in_dev)
-- 
2.1.4

^ permalink raw reply related

* [PATCH net-next v4 0/3] fib rule selftest
From: Roopa Prabhu @ 2018-05-22 14:51 UTC (permalink / raw)
  To: davem; +Cc: netdev, nikolay, dsa, idosch

From: Roopa Prabhu <roopa@cumulusnetworks.com>

This series adds a new test to test fib rules.
ip route get is used to test fib rule matches.
This series also extends ip route get to match on
sport and dport to test recent support of sport
and dport fib rule match.

v2 - address ido's commemt to make sport dport
ip route get to work correctly for input route
get. I don't support ip route get on ip-proto match yet.
ip route get creates a udp packet and i have left
it at that. We could extend ip route get to support
a few ip proto matches in followup patches.

v3 - Support ip_proto (only tcp and udp) match in getroute.
dropped printing of new match attrs in ip route get, 
because ipv6 does not print it. And ipv6 currrently shares
the dump api with ipv6 notify and its better to not add them
to the notify api. dropped it to keep the api consistent between
ipv4 and ipv6 (though uid is already printed in the ipv4 case).
If we need it, both ipv4 and ipv6 can be enhanced to provide
a separate get api. Moved skb creation for ipv4 to a separate func.

v4 - drop separate skb for netlink and fix concerns around rcu and netlink
     reply (as pointed out by DaveM). I now try to reset the skb after the route
     lookup and before the netlink send (testing shows this is ok. More eyes and
     any feedback here will be helpful)

Roopa Prabhu (3):
  ipv4: support sport, dport and ip_proto in RTM_GETROUTE
  ipv6: support sport, dport and ip_proto in RTM_GETROUTE
  selftests: net: initial fib rule tests

 include/uapi/linux/rtnetlink.h                |   2 +
 net/ipv4/route.c                              | 152 ++++++++++++-----
 net/ipv6/route.c                              |  25 +++
 tools/testing/selftests/net/Makefile          |   2 +-
 tools/testing/selftests/net/fib_rule_tests.sh | 224 ++++++++++++++++++++++++++
 5 files changed, 366 insertions(+), 39 deletions(-)
 create mode 100644 tools/testing/selftests/net/fib_rule_tests.sh

-- 
2.1.4

^ permalink raw reply

* Re: [PATCH net-next 00/13] nfp: abm: add basic support for advanced buffering NIC
From: Or Gerlitz @ 2018-05-22 14:50 UTC (permalink / raw)
  To: Jakub Kicinski
  Cc: David Miller, Linux Netdev List, oss-drivers, Andy Gospodarek,
	linux-internal
In-Reply-To: <CAJpBn1ywEO2MayK=EvzzLYLXfZ2xuWCfyiaAYLtL-gnrj2gKwQ@mail.gmail.com>

On Tue, May 22, 2018 at 10:56 AM, Jakub Kicinski
<jakub.kicinski@netronome.com> wrote:
> On Mon, May 21, 2018 at 11:32 PM, Or Gerlitz wrote:
>> On Tue, May 22, 2018 at 8:12 AM, Jakub Kicinski wrote:
>>> Hi!
>>>
>>> This series lays groundwork for advanced buffer management NIC feature.
>>> It makes necessary NFP core changes, spawns representors and adds devlink
>>> glue.  Following series will add the actual buffering configuration (patch
>>> series size limit).
>>>
>>> First three patches add support for configuring NFP buffer pools via a
>>> mailbox.  The existing devlink APIs are used for the purpose.
>>>
>>> Third patch allows us to perform small reads from the NFP memory.
>>>
>>> The rest of the patch set adds eswitch mode change support and makes
>>> the driver spawn appropriate representors.
>>
>> Hi Jakub,
>>
>> Could you provide more higher level description on the abm use-case
>> and nature of these representors? I understand that under abm you are
>> modeling the nic as switch with vNIC ports, does vNIC port and vNIC
>> port rep have the same characteristics as VF and VF rep (xmit on one side
>> <--> send on 2nd side),  does traffic is to be offloaded using TC, etc.
>> What one would be doing with vNIC instance, hand it to container ala the Intel
>> VMDQ concept?
>> can this be seen as veth HW offload? etc

> Yes, the reprs can be used like VF reprs but that's not the main use
> case. We are targeting container world with ABM, so no VFs and no
> SR-IOV.  There is only one vNIC per port and no veth offload etc. In

one vNIC for multiple containers? or you have a (v?) port per container?

> In the most basic scenario with 1 PF corresponding to 1 port there is no
> real use for switching.

multiple containers? please clarify it a little better

> The main purpose here is that we want to setup the buffering and QoS
> inside the NIC (both for TX and RX) and then use eBPF to perform
> filtering, queue assignment and per-application RSS. That's pretty
> much it at this point.

> Switching if any will be a basic bridge offload.  QoS configuration
> will all be done using TC qdisc offload, RED etc. exactly like mlxsw :)

I guess I'll understand it better once you clarify the multiple
containers thing,
thanks for the details and openness

^ permalink raw reply

* Re: [PATCH 1/4] arcnet: com20020: Add com20020 io mapped version
From: Andrea Greco @ 2018-05-22 14:44 UTC (permalink / raw)
  To: David Miller; +Cc: tobin, a.greco, m.grzeschik, linux-kernel, netdev
In-Reply-To: <20180518.135152.51730771671749217.davem@davemloft.net>

On 05/18/2018 07:51 PM, David Miller wrote:
> From: Andrea Greco <andrea.greco.gapmilano@gmail.com>
> Date: Fri, 18 May 2018 14:18:41 +0200
> 
>> In com20020.c found this:
>> /* FIXME: do this some other way! */
>> if (!dev->dev_addr[0])
>> dev->dev_addr[0] = arcnet_inb(ioaddr, 8);
>>
>> NODE-ID, must be univoque, for all arcnet network.
>> My previews idea was take random value but, this could create a
>> collision over network.
>>
>> A possible solution is:
>> In case of collision com20020 set a bit in status register.
>> Then peak a new NODE-ID and repeat this while correct NODE-ID is found.
>>
>> Other ideas is pass it via DTS.
>> But suppose have 2 same product in same network, same address same problem.
>> For this reason i prefer left standard driver behavior.
>>
>> Other ideas for solve this ?
> 
> Is there no way to obtain a unique value from the device?
> 
> If having a unique ID to talk on the ARCNET is so critical, there must
> be some way to properly allocation and use a unique ID.

Device can rise interrupt in case of Duplicate ID over the network.

> I guess this must be a general problem with this driver already.
I think arcnet network and relative NODE-ID designed during project 
phase, and address is always fixed.

In fact:
Other version of this dirver: PCI, ISA friends.
Simple work as module, and Node-ID is param of modules.

My opinion is that:
Before run `ifconfig arc0 up`, user has to setup hardware address with 
`ip link set dev arc0 address D2`.

All this is like a IP network with static address. If your IP address is 
duplicated, is not IP problem.

> You still need to address the issue of 'dev' being leaked on probe
> error paths.
For solve this,i think all considered a random address could be a good 
solution.

Regards, Andrea

^ permalink raw reply

* pull-request: wireless-drivers 2018-05-22
From: Kalle Valo @ 2018-05-22 14:28 UTC (permalink / raw)
  To: David Miller; +Cc: linux-wireless, netdev, linux-kernel

Hi Dave,

here's a pull request to net tree for 4.17. Please let me know if you
have any problems.

Kalle

The following changes since commit a8d7aa17bbc970971ccdf71988ea19230ab368b1:

  dccp: fix tasklet usage (2018-05-03 15:14:57 -0400)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers.git tags/wireless-drivers-for-davem-2018-05-22

for you to fetch changes up to 813477aa49aac5deba04eb4956360dde58a0e807:

  MAINTAINERS: change Kalle as wcn36xx maintainer (2018-05-22 15:36:41 +0300)

----------------------------------------------------------------
wireless-drivers fixes for 4.17

Hopefully the last fixes for 4.17. ssb is again causing problems so we
had to revert a commit and fix it better. Also a small fix to bcma and
some MAINTAINERS file updates.

ssb

* fix regression with all module PCI cards, for example using b43 and
  b44 drivers

* try again fixing a MIPS linker error

bcma

* fix truncated info log messages

----------------------------------------------------------------
Kalle Valo (3):
      MAINTAINERS: update Kalle's email address
      MAINTAINERS: change Kalle as ath.ko maintainer
      MAINTAINERS: change Kalle as wcn36xx maintainer

Rafał Miłecki (3):
      bcma: fix buffer size caused crash in bcma_core_mips_print_irq()
      Revert "ssb: Prevent build of PCI host features in module"
      ssb: make SSB_PCICORE_HOSTMODE depend on SSB = y

 MAINTAINERS                | 8 ++++----
 drivers/bcma/driver_mips.c | 2 +-
 drivers/ssb/Kconfig        | 4 ++--
 3 files changed, 7 insertions(+), 7 deletions(-)

^ permalink raw reply

* RE: [PATCH v2] packet: track ring entry use using a shadow ring to prevent RX ring overrun
From: Jon Rosen (jrosen) @ 2018-05-22 14:12 UTC (permalink / raw)
  To: Willem de Bruijn
  Cc: David S. Miller, Willem de Bruijn, Eric Dumazet, Kees Cook,
	David Windsor, Rosen, Rami, Reshetova, Elena, Mike Maloney,
	Benjamin Poirier, Thomas Gleixner, Greg Kroah-Hartman,
	open list:NETWORKING [GENERAL], open list
In-Reply-To: <CAF=yD-Kfto4jJYMFzn=PV8OYdhEmdNfW+aakDhRMzRBWhWY0UQ@mail.gmail.com>

On Monday, May 21, 2018 2:17 PM, Jon Rosen (jrosen) <jrosen@cisco.com> wrote:
> On Monday, May 21, 2018 1:07 PM, Willem de Bruijn
> <willemdebruijn.kernel@gmail.com> wrote:
>> On Mon, May 21, 2018 at 8:57 AM, Jon Rosen (jrosen) <jrosen@cisco.com> wrote:

...snip...

>>
>> A setsockopt for userspace to signal a stricter interpretation of
>> tp_status to elide the shadow hack could then be considered.
>> It's not pretty. Either way, no full new version is required.
>>
>>> As much as I would like to find a solution that doesn't require
>>> the spin lock I have yet to do so. Maybe the answer is that
>>> existing applications will need to suffer the performance impact
>>> but a new version or option for TPACKET_V1/V2 could be added to
>>> indicate strict adherence of the TP_STATUS_USER bit and then the
>>> original diffs could be used.

It looks like adding new socket options is pretty rare so I
wonder if a better option might be to define a new TP_STATUS_XXX
bit which would signal from a userspace application to the kernel
that it strictly interprets the TP_STATUS_USER bit to determine
ownership.

Todays applications set tp_status = TP_STATUS_KERNEL(0) for the
kernel to pick up the entry.  We could define a new value to pass
ownership as well as one to indicate to other kernel threads that
an entry is inuse:

        #define TP_STATUS_USER_TO_KERNEL        (1 << 8)
        #define TP_STATUS_INUSE                 (1 << 9)

If the kernel sees tp_status == TP_STATUS_KERNEL then it should
use the shadow method for tacking ownership. If it sees tp_status
== TP_STATUS_USER_TO_KERNEL then it can use the TP_STATUS_INUSE
method.

>>>
>>> There is another option I was considering but have yet to try
>>> which would avoid needing a shadow ring by using counter(s) to
>>> track maximum sequence number queued to userspace vs. the next
>>> sequence number to be allocated in the ring.  If the difference
>>> is greater than the size of the ring then the ring can be
>>> considered full and the allocation would fail. Of course this may
>>> create an additional hotspot between cores, not sure if that
>>> would be significant or not.
>>
>> Please do have a look, but I don't think that this will work in this
>> case in practice. It requires tracking the producer tail. Updating
>> the slowest writer requires probing each subsequent slot's status
>> byte to find the new tail, which is a lot of (by then cold) cacheline
>> reads.
>
> I've thought about it a little more and am not convinced it's
> workable but I'll spend a little more time on it before giving
> up.

I've given up on this method.  Just don't see how to make it work.


^ permalink raw reply

* Re: [PATCH net-next v15 4/7] sch_cake: Add NAT awareness to packet classifier
From: Toke Høiland-Jørgensen @ 2018-05-22 14:11 UTC (permalink / raw)
  To: Pablo Neira Ayuso; +Cc: netdev, cake, netfilter-devel
In-Reply-To: <20180522140759.2rl25eggaoaecw4m@salvia>

Pablo Neira Ayuso <pablo@netfilter.org> writes:

> Hi Toke,
>
> On Tue, May 22, 2018 at 03:57:38PM +0200, Toke Høiland-Jørgensen wrote:
>> When CAKE is deployed on a gateway that also performs NAT (which is a
>> common deployment mode), the host fairness mechanism cannot distinguish
>> internal hosts from each other, and so fails to work correctly.
>> 
>> To fix this, we add an optional NAT awareness mode, which will query the
>> kernel conntrack mechanism to obtain the pre-NAT addresses for each packet
>> and use that in the flow and host hashing.
>> 
>> When the shaper is enabled and the host is already performing NAT, the cost
>> of this lookup is negligible. However, in unlimited mode with no NAT being
>> performed, there is a significant CPU cost at higher bandwidths. For this
>> reason, the feature is turned off by default.
>> 
>> Cc: netfilter-devel@vger.kernel.org
>> Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
>> ---
>>  net/sched/sch_cake.c |   79 ++++++++++++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 79 insertions(+)
>> 
>> diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
>> index 68ac908470f1..6f7cae705c84 100644
>> --- a/net/sched/sch_cake.c
>> +++ b/net/sched/sch_cake.c
>> @@ -71,6 +71,12 @@
>>  #include <net/tcp.h>
>>  #include <net/flow_dissector.h>
>>  
>> +#if IS_REACHABLE(CONFIG_NF_CONNTRACK)
>> +#include <net/netfilter/nf_conntrack_core.h>
>> +#include <net/netfilter/nf_conntrack_zones.h>
>> +#include <net/netfilter/nf_conntrack.h>
>> +#endif
>> +
>>  #define CAKE_SET_WAYS (8)
>>  #define CAKE_MAX_TINS (8)
>>  #define CAKE_QUEUES (1024)
>> @@ -516,6 +522,60 @@ static bool cobalt_should_drop(struct cobalt_vars *vars,
>>  	return drop;
>>  }
>>  
>> +#if IS_REACHABLE(CONFIG_NF_CONNTRACK)
>> +
>> +static void cake_update_flowkeys(struct flow_keys *keys,
>> +				 const struct sk_buff *skb)
>> +{
>> +	const struct nf_conntrack_tuple *tuple;
>> +	enum ip_conntrack_info ctinfo;
>> +	struct nf_conn *ct;
>> +	bool rev = false;
>> +
>> +	if (tc_skb_protocol(skb) != htons(ETH_P_IP))
>> +		return;
>> +
>> +	ct = nf_ct_get(skb, &ctinfo);
>> +	if (ct) {
>> +		tuple = nf_ct_tuple(ct, CTINFO2DIR(ctinfo));
>> +	} else {
>> +		const struct nf_conntrack_tuple_hash *hash;
>> +		struct nf_conntrack_tuple srctuple;
>> +
>> +		if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
>> +				       NFPROTO_IPV4, dev_net(skb->dev),
>> +				       &srctuple))
>> +			return;
>> +
>> +		hash = nf_conntrack_find_get(dev_net(skb->dev),
>> +					     &nf_ct_zone_dflt,
>> +					     &srctuple);
>> +		if (!hash)
>> +			return;
>> +
>> +		rev = true;
>> +		ct = nf_ct_tuplehash_to_ctrack(hash);
>> +		tuple = nf_ct_tuple(ct, !hash->tuple.dst.dir);
>> +	}
>> +
>> +	keys->addrs.v4addrs.src = rev ? tuple->dst.u3.ip : tuple->src.u3.ip;
>> +	keys->addrs.v4addrs.dst = rev ? tuple->src.u3.ip : tuple->dst.u3.ip;
>> +
>> +	if (keys->ports.ports) {
>> +		keys->ports.src = rev ? tuple->dst.u.all : tuple->src.u.all;
>> +		keys->ports.dst = rev ? tuple->src.u.all : tuple->dst.u.all;
>> +	}
>> +	if (rev)
>> +		nf_ct_put(ct);
>> +}
>
> This is going to pull in the nf_conntrack module, even if you may not
> want it, as soon as cake is in place.

Yeah, we are aware of that; we get a moddep on nf_conntrack. Our main
deployment scenario has been home routers where conntrack is used
anyway, so this has not been much of an issue. However, if there is a
way to avoid this, and instead detect at runtime if conntrack is
available, that would certainly be useful. Is there? :)

-Toke

^ permalink raw reply

* Re: [net-next PATCH v2 2/4] net: Enable Tx queue selection based on Rx queues
From: Tom Herbert @ 2018-05-22 14:09 UTC (permalink / raw)
  To: Willem de Bruijn
  Cc: Amritha Nambiar, Linux Kernel Network Developers, David S. Miller,
	Alexander Duyck, Sridhar Samudrala, Eric Dumazet,
	Hannes Frederic Sowa
In-Reply-To: <CAF=yD-+Um_ZjcPJyL6G8h0isBDG35q1d=mB4X7NB=unu813KOg@mail.gmail.com>

On Mon, May 21, 2018 at 8:12 AM, Willem de Bruijn
<willemdebruijn.kernel@gmail.com> wrote:
> On Mon, May 21, 2018 at 10:51 AM, Tom Herbert <tom@herbertland.com> wrote:
>> On Sat, May 19, 2018 at 1:27 PM, Willem de Bruijn
>> <willemdebruijn.kernel@gmail.com> wrote:
>>> On Sat, May 19, 2018 at 4:13 PM, Willem de Bruijn
>>> <willemdebruijn.kernel@gmail.com> wrote:
>>>> On Fri, May 18, 2018 at 12:03 AM, Tom Herbert <tom@herbertland.com> wrote:
>>>>> On Tue, May 15, 2018 at 6:26 PM, Amritha Nambiar
>>>>> <amritha.nambiar@intel.com> wrote:
>>>>>> This patch adds support to pick Tx queue based on the Rx queue map
>>>>>> configuration set by the admin through the sysfs attribute
>>>>>> for each Tx queue. If the user configuration for receive
>>>>>> queue map does not apply, then the Tx queue selection falls back
>>>>>> to CPU map based selection and finally to hashing.
>>>>>>
>>>>>> Signed-off-by: Amritha Nambiar <amritha.nambiar@intel.com>
>>>>>> Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
>>>>>> ---
>>>
>>>>>> +static int get_xps_queue(struct net_device *dev, struct sk_buff *skb)
>>>>>> +{
>>>>>> +#ifdef CONFIG_XPS
>>>>>> +       enum xps_map_type i = XPS_MAP_RXQS;
>>>>>> +       struct xps_dev_maps *dev_maps;
>>>>>> +       struct sock *sk = skb->sk;
>>>>>> +       int queue_index = -1;
>>>>>> +       unsigned int tci = 0;
>>>>>> +
>>>>>> +       if (sk && sk->sk_rx_queue_mapping <= dev->real_num_rx_queues &&
>>>>>> +           dev->ifindex == sk->sk_rx_ifindex)
>>>>>> +               tci = sk->sk_rx_queue_mapping;
>>>>>> +
>>>>>> +       rcu_read_lock();
>>>>>> +       while (queue_index < 0 && i < __XPS_MAP_MAX) {
>>>>>> +               if (i == XPS_MAP_CPUS)
>>>>>
>>>>> This while loop typifies exactly why I don't think the XPS maps should
>>>>> be an array.
>>>>
>>>> +1
>>>
>>> as a matter of fact, as enabling both cpu and rxqueue map at the same
>>> time makes no sense, only one map is needed at any one time. The
>>> only difference is in how it is indexed. It should probably not be possible
>>> to configure both at the same time. Keeping a single map probably also
>>> significantly simplifies patch 1/4.
>>
>> Willem,
>>
>> I think it might makes sense to have them both. Maybe one application
>> is spin polling that needs this, where others might be happy with
>> normal CPU mappings as default.
>
> Some entries in the rx_queue table have queue_pair affinity
> configured, the others return -1 to fall through to the cpu
> affinity table?
>
Right, that's the intent of the while loop.

> I guess that implies flow steering to those special purpose
> queues. I wonder whether this would be used this in practice.
> I does make the code more complex by having to duplicate
> the map lookup logic (mostly, patch 1/4).

That's a good pont. I think we need more information on how the
feature is going to be used in practice. My assumption is that there
are some number of "special" queues for which spin polling is being
done.

Tom

^ permalink raw reply

* Re: [PATCH net-next v15 4/7] sch_cake: Add NAT awareness to packet classifier
From: Pablo Neira Ayuso @ 2018-05-22 14:07 UTC (permalink / raw)
  To: Toke Høiland-Jørgensen; +Cc: netdev, cake, netfilter-devel
In-Reply-To: <152699745846.21931.4558451708304709296.stgit@alrua-kau>

Hi Toke,

On Tue, May 22, 2018 at 03:57:38PM +0200, Toke Høiland-Jørgensen wrote:
> When CAKE is deployed on a gateway that also performs NAT (which is a
> common deployment mode), the host fairness mechanism cannot distinguish
> internal hosts from each other, and so fails to work correctly.
> 
> To fix this, we add an optional NAT awareness mode, which will query the
> kernel conntrack mechanism to obtain the pre-NAT addresses for each packet
> and use that in the flow and host hashing.
> 
> When the shaper is enabled and the host is already performing NAT, the cost
> of this lookup is negligible. However, in unlimited mode with no NAT being
> performed, there is a significant CPU cost at higher bandwidths. For this
> reason, the feature is turned off by default.
> 
> Cc: netfilter-devel@vger.kernel.org
> Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
> ---
>  net/sched/sch_cake.c |   79 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 79 insertions(+)
> 
> diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
> index 68ac908470f1..6f7cae705c84 100644
> --- a/net/sched/sch_cake.c
> +++ b/net/sched/sch_cake.c
> @@ -71,6 +71,12 @@
>  #include <net/tcp.h>
>  #include <net/flow_dissector.h>
>  
> +#if IS_REACHABLE(CONFIG_NF_CONNTRACK)
> +#include <net/netfilter/nf_conntrack_core.h>
> +#include <net/netfilter/nf_conntrack_zones.h>
> +#include <net/netfilter/nf_conntrack.h>
> +#endif
> +
>  #define CAKE_SET_WAYS (8)
>  #define CAKE_MAX_TINS (8)
>  #define CAKE_QUEUES (1024)
> @@ -516,6 +522,60 @@ static bool cobalt_should_drop(struct cobalt_vars *vars,
>  	return drop;
>  }
>  
> +#if IS_REACHABLE(CONFIG_NF_CONNTRACK)
> +
> +static void cake_update_flowkeys(struct flow_keys *keys,
> +				 const struct sk_buff *skb)
> +{
> +	const struct nf_conntrack_tuple *tuple;
> +	enum ip_conntrack_info ctinfo;
> +	struct nf_conn *ct;
> +	bool rev = false;
> +
> +	if (tc_skb_protocol(skb) != htons(ETH_P_IP))
> +		return;
> +
> +	ct = nf_ct_get(skb, &ctinfo);
> +	if (ct) {
> +		tuple = nf_ct_tuple(ct, CTINFO2DIR(ctinfo));
> +	} else {
> +		const struct nf_conntrack_tuple_hash *hash;
> +		struct nf_conntrack_tuple srctuple;
> +
> +		if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
> +				       NFPROTO_IPV4, dev_net(skb->dev),
> +				       &srctuple))
> +			return;
> +
> +		hash = nf_conntrack_find_get(dev_net(skb->dev),
> +					     &nf_ct_zone_dflt,
> +					     &srctuple);
> +		if (!hash)
> +			return;
> +
> +		rev = true;
> +		ct = nf_ct_tuplehash_to_ctrack(hash);
> +		tuple = nf_ct_tuple(ct, !hash->tuple.dst.dir);
> +	}
> +
> +	keys->addrs.v4addrs.src = rev ? tuple->dst.u3.ip : tuple->src.u3.ip;
> +	keys->addrs.v4addrs.dst = rev ? tuple->src.u3.ip : tuple->dst.u3.ip;
> +
> +	if (keys->ports.ports) {
> +		keys->ports.src = rev ? tuple->dst.u.all : tuple->src.u.all;
> +		keys->ports.dst = rev ? tuple->src.u.all : tuple->dst.u.all;
> +	}
> +	if (rev)
> +		nf_ct_put(ct);
> +}

This is going to pull in the nf_conntrack module, even if you may not
want it, as soon as cake is in place.

^ permalink raw reply

* Re: [PATCH net-next 2/2] tcp: do not aggressively quick ack after ECN events
From: Soheil Hassas Yeganeh @ 2018-05-22 14:04 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: David S . Miller, netdev, Van Jacobson, Neal Cardwell,
	Yuchung Cheng, Eric Dumazet
In-Reply-To: <20180521220857.229273-3-edumazet@google.com>

On Mon, May 21, 2018 at 6:08 PM, Eric Dumazet <edumazet@google.com> wrote:
> ECN signals currently forces TCP to enter quickack mode for
> up to 16 (TCP_MAX_QUICKACKS) following incoming packets.
>
> We believe this is not needed, and only sending one immediate ack
> for the current packet should be enough.
>
> This should reduce the extra load noticed in DCTCP environments,
> after congestion events.
>
> This is part 2 of our effort to reduce pure ACK packets.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Acked-by: Soheil Hassas Yeganeh <soheil@google.com>

Thanks for the patch!

^ permalink raw reply

* Re: [PATCH net-next 1/2] tcp: add max_quickacks param to tcp_incr_quickack and tcp_enter_quickack_mode
From: Soheil Hassas Yeganeh @ 2018-05-22 14:03 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: David S . Miller, netdev, Van Jacobson, Neal Cardwell,
	Yuchung Cheng, Eric Dumazet
In-Reply-To: <20180521220857.229273-2-edumazet@google.com>

On Mon, May 21, 2018 at 6:08 PM, Eric Dumazet <edumazet@google.com> wrote:
> We want to add finer control of the number of ACK packets sent after
> ECN events.
>
> This patch is not changing current behavior, it only enables following
> change.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Acked-by: Soheil Hassas Yeganeh <soheil@google.com>

> ---
>  net/ipv4/tcp_input.c | 24 +++++++++++++-----------
>  1 file changed, 13 insertions(+), 11 deletions(-)
>
> diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
> index aebb29ab2fdf2ceaa182cd11928f145a886149ff..2e970e9f4e09d966b703af2d14d521a4328eba7e 100644
> --- a/net/ipv4/tcp_input.c
> +++ b/net/ipv4/tcp_input.c
> @@ -203,21 +203,23 @@ static void tcp_measure_rcv_mss(struct sock *sk, const struct sk_buff *skb)
>         }
>  }
>
> -static void tcp_incr_quickack(struct sock *sk)
> +static void tcp_incr_quickack(struct sock *sk, unsigned int max_quickacks)
>  {
>         struct inet_connection_sock *icsk = inet_csk(sk);
>         unsigned int quickacks = tcp_sk(sk)->rcv_wnd / (2 * icsk->icsk_ack.rcv_mss);
>
>         if (quickacks == 0)
>                 quickacks = 2;
> +       quickacks = min(quickacks, max_quickacks);
>         if (quickacks > icsk->icsk_ack.quick)
> -               icsk->icsk_ack.quick = min(quickacks, TCP_MAX_QUICKACKS);
> +               icsk->icsk_ack.quick = quickacks;
>  }
>
> -static void tcp_enter_quickack_mode(struct sock *sk)
> +static void tcp_enter_quickack_mode(struct sock *sk, unsigned int max_quickacks)
>  {
>         struct inet_connection_sock *icsk = inet_csk(sk);
> -       tcp_incr_quickack(sk);
> +
> +       tcp_incr_quickack(sk, max_quickacks);
>         icsk->icsk_ack.pingpong = 0;
>         icsk->icsk_ack.ato = TCP_ATO_MIN;
>  }
> @@ -261,7 +263,7 @@ static void __tcp_ecn_check_ce(struct tcp_sock *tp, const struct sk_buff *skb)
>                  * it is probably a retransmit.
>                  */
>                 if (tp->ecn_flags & TCP_ECN_SEEN)
> -                       tcp_enter_quickack_mode((struct sock *)tp);
> +                       tcp_enter_quickack_mode((struct sock *)tp, TCP_MAX_QUICKACKS);
>                 break;
>         case INET_ECN_CE:
>                 if (tcp_ca_needs_ecn((struct sock *)tp))
> @@ -269,7 +271,7 @@ static void __tcp_ecn_check_ce(struct tcp_sock *tp, const struct sk_buff *skb)
>
>                 if (!(tp->ecn_flags & TCP_ECN_DEMAND_CWR)) {
>                         /* Better not delay acks, sender can have a very low cwnd */
> -                       tcp_enter_quickack_mode((struct sock *)tp);
> +                       tcp_enter_quickack_mode((struct sock *)tp, TCP_MAX_QUICKACKS);
>                         tp->ecn_flags |= TCP_ECN_DEMAND_CWR;
>                 }
>                 tp->ecn_flags |= TCP_ECN_SEEN;
> @@ -686,7 +688,7 @@ static void tcp_event_data_recv(struct sock *sk, struct sk_buff *skb)
>                 /* The _first_ data packet received, initialize
>                  * delayed ACK engine.
>                  */
> -               tcp_incr_quickack(sk);
> +               tcp_incr_quickack(sk, TCP_MAX_QUICKACKS);
>                 icsk->icsk_ack.ato = TCP_ATO_MIN;
>         } else {
>                 int m = now - icsk->icsk_ack.lrcvtime;
> @@ -702,7 +704,7 @@ static void tcp_event_data_recv(struct sock *sk, struct sk_buff *skb)
>                         /* Too long gap. Apparently sender failed to
>                          * restart window, so that we send ACKs quickly.
>                          */
> -                       tcp_incr_quickack(sk);
> +                       tcp_incr_quickack(sk, TCP_MAX_QUICKACKS);
>                         sk_mem_reclaim(sk);
>                 }
>         }
> @@ -4179,7 +4181,7 @@ static void tcp_send_dupack(struct sock *sk, const struct sk_buff *skb)
>         if (TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq &&
>             before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt)) {
>                 NET_INC_STATS(sock_net(sk), LINUX_MIB_DELAYEDACKLOST);
> -               tcp_enter_quickack_mode(sk);
> +               tcp_enter_quickack_mode(sk, TCP_MAX_QUICKACKS);
>
>                 if (tcp_is_sack(tp) && sock_net(sk)->ipv4.sysctl_tcp_dsack) {
>                         u32 end_seq = TCP_SKB_CB(skb)->end_seq;
> @@ -4706,7 +4708,7 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
>                 tcp_dsack_set(sk, TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq);
>
>  out_of_window:
> -               tcp_enter_quickack_mode(sk);
> +               tcp_enter_quickack_mode(sk, TCP_MAX_QUICKACKS);
>                 inet_csk_schedule_ack(sk);
>  drop:
>                 tcp_drop(sk, skb);
> @@ -5790,7 +5792,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
>                          * to stand against the temptation 8)     --ANK
>                          */
>                         inet_csk_schedule_ack(sk);
> -                       tcp_enter_quickack_mode(sk);
> +                       tcp_enter_quickack_mode(sk, TCP_MAX_QUICKACKS);
>                         inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
>                                                   TCP_DELACK_MAX, TCP_RTO_MAX);
>
> --
> 2.17.0.441.gb46fe60e1d-goog
>

^ permalink raw reply

* [PATCH net-next v15 5/7] sch_cake: Add DiffServ handling
From: Toke Høiland-Jørgensen @ 2018-05-22 13:57 UTC (permalink / raw)
  To: netdev, cake
In-Reply-To: <152699741881.21931.11656377745581563912.stgit@alrua-kau>

This adds support for DiffServ-based priority queueing to CAKE. If the
shaper is in use, each priority tier gets its own virtual clock, which
limits that tier's rate to a fraction of the overall shaped rate, to
discourage trying to game the priority mechanism.

CAKE defaults to a simple, three-tier mode that interprets most code points
as "best effort", but places CS1 traffic into a low-priority "bulk" tier
which is assigned 1/16 of the total rate, and a few code points indicating
latency-sensitive or control traffic (specifically TOS4, VA, EF, CS6, CS7)
into a "latency sensitive" high-priority tier, which is assigned 1/4 rate.
The other supported DiffServ modes are a 4-tier mode matching the 802.11e
precedence rules, as well as two 8-tier modes, one of which implements
strict precedence of the eight priority levels.

This commit also adds an optional DiffServ 'wash' mode, which will zero out
the DSCP fields of any packet passing through CAKE. While this can
technically be done with other mechanisms in the kernel, having the feature
available in CAKE significantly decreases configuration complexity; and the
implementation cost is low on top of the other DiffServ-handling code.

Filters and applications can set the skb->priority field to override the
DSCP-based classification into tiers. If TC_H_MAJ(skb->priority) matches
CAKE's qdisc handle, the minor number will be interpreted as a priority
tier if it is less than or equal to the number of configured priority
tiers.

Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
---
 net/sched/sch_cake.c |  412 +++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 404 insertions(+), 8 deletions(-)

diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 6f7cae705c84..6384765e97b0 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -298,6 +298,68 @@ static void cobalt_set_enqueue_time(struct sk_buff *skb,
 
 static u16 quantum_div[CAKE_QUEUES + 1] = {0};
 
+/* Diffserv lookup tables */
+
+static const u8 precedence[] = {
+	0, 0, 0, 0, 0, 0, 0, 0,
+	1, 1, 1, 1, 1, 1, 1, 1,
+	2, 2, 2, 2, 2, 2, 2, 2,
+	3, 3, 3, 3, 3, 3, 3, 3,
+	4, 4, 4, 4, 4, 4, 4, 4,
+	5, 5, 5, 5, 5, 5, 5, 5,
+	6, 6, 6, 6, 6, 6, 6, 6,
+	7, 7, 7, 7, 7, 7, 7, 7,
+};
+
+static const u8 diffserv8[] = {
+	2, 5, 1, 2, 4, 2, 2, 2,
+	0, 2, 1, 2, 1, 2, 1, 2,
+	5, 2, 4, 2, 4, 2, 4, 2,
+	3, 2, 3, 2, 3, 2, 3, 2,
+	6, 2, 3, 2, 3, 2, 3, 2,
+	6, 2, 2, 2, 6, 2, 6, 2,
+	7, 2, 2, 2, 2, 2, 2, 2,
+	7, 2, 2, 2, 2, 2, 2, 2,
+};
+
+static const u8 diffserv4[] = {
+	0, 2, 0, 0, 2, 0, 0, 0,
+	1, 0, 0, 0, 0, 0, 0, 0,
+	2, 0, 2, 0, 2, 0, 2, 0,
+	2, 0, 2, 0, 2, 0, 2, 0,
+	3, 0, 2, 0, 2, 0, 2, 0,
+	3, 0, 0, 0, 3, 0, 3, 0,
+	3, 0, 0, 0, 0, 0, 0, 0,
+	3, 0, 0, 0, 0, 0, 0, 0,
+};
+
+static const u8 diffserv3[] = {
+	0, 0, 0, 0, 2, 0, 0, 0,
+	1, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 2, 0, 2, 0,
+	2, 0, 0, 0, 0, 0, 0, 0,
+	2, 0, 0, 0, 0, 0, 0, 0,
+};
+
+static const u8 besteffort[] = {
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+};
+
+/* tin priority order for stats dumping */
+
+static const u8 normal_order[] = {0, 1, 2, 3, 4, 5, 6, 7};
+static const u8 bulk_order[] = {1, 0, 2, 3};
+
 #define REC_INV_SQRT_CACHE (16)
 static u32 cobalt_rec_inv_sqrt_cache[REC_INV_SQRT_CACHE] = {0};
 
@@ -1415,6 +1477,46 @@ static unsigned int cake_drop(struct Qdisc *sch, struct sk_buff **to_free)
 	return idx + (tin << 16);
 }
 
+static void cake_wash_diffserv(struct sk_buff *skb)
+{
+	switch (skb->protocol) {
+	case htons(ETH_P_IP):
+		ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, 0);
+		break;
+	case htons(ETH_P_IPV6):
+		ipv6_change_dsfield(ipv6_hdr(skb), INET_ECN_MASK, 0);
+		break;
+	default:
+		break;
+	}
+}
+
+static u8 cake_handle_diffserv(struct sk_buff *skb, u16 wash)
+{
+	u8 dscp;
+
+	switch (skb->protocol) {
+	case htons(ETH_P_IP):
+		dscp = ipv4_get_dsfield(ip_hdr(skb)) >> 2;
+		if (wash && dscp)
+			ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, 0);
+		return dscp;
+
+	case htons(ETH_P_IPV6):
+		dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2;
+		if (wash && dscp)
+			ipv6_change_dsfield(ipv6_hdr(skb), INET_ECN_MASK, 0);
+		return dscp;
+
+	case htons(ETH_P_ARP):
+		return 0x38;  /* CS7 - Net Control */
+
+	default:
+		/* If there is no Diffserv field, treat as best-effort */
+		return 0;
+	}
+}
+
 static void cake_reconfigure(struct Qdisc *sch);
 
 static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
@@ -1429,7 +1531,26 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 	struct cake_flow *flow;
 	u32 idx, tin;
 
-	tin = 0;
+	if (TC_H_MAJ(skb->priority) == sch->handle &&
+	    TC_H_MIN(skb->priority) > 0 &&
+	    TC_H_MIN(skb->priority) <= q->tin_cnt) {
+		tin = TC_H_MIN(skb->priority) - 1;
+
+		if (q->rate_flags & CAKE_FLAG_WASH)
+			cake_wash_diffserv(skb);
+	} else if (q->tin_mode != CAKE_DIFFSERV_BESTEFFORT) {
+		/* extract the Diffserv Precedence field, if it exists */
+		/* and clear DSCP bits if washing */
+		tin = q->tin_index[cake_handle_diffserv(skb,
+				q->rate_flags & CAKE_FLAG_WASH)];
+		if (unlikely(tin >= q->tin_cnt))
+			tin = 0;
+	} else {
+		tin = 0;
+		if (q->rate_flags & CAKE_FLAG_WASH)
+			cake_wash_diffserv(skb);
+	}
+
 	b = &q->tins[tin];
 
 	/* choose flow to insert into */
@@ -1930,18 +2051,275 @@ static void cake_set_rate(struct cake_tin_data *b, u64 rate, u32 mtu,
 	b->cparams.p_dec = 1 << 20; /* 1/4096 */
 }
 
-static void cake_reconfigure(struct Qdisc *sch)
+static int cake_config_besteffort(struct Qdisc *sch)
 {
 	struct cake_sched_data *q = qdisc_priv(sch);
 	struct cake_tin_data *b = &q->tins[0];
-	int c, ft = 0;
+	u32 mtu = psched_mtu(qdisc_dev(sch));
+	u64 rate = q->rate_bps;
 
 	q->tin_cnt = 1;
-	cake_set_rate(b, q->rate_bps, psched_mtu(qdisc_dev(sch)),
+
+	q->tin_index = besteffort;
+	q->tin_order = normal_order;
+
+	cake_set_rate(b, rate, mtu,
 		      us_to_ns(q->target), us_to_ns(q->interval));
 	b->tin_quantum_band = 65535;
 	b->tin_quantum_prio = 65535;
 
+	return 0;
+}
+
+static int cake_config_precedence(struct Qdisc *sch)
+{
+	/* convert high-level (user visible) parameters into internal format */
+	struct cake_sched_data *q = qdisc_priv(sch);
+	u32 mtu = psched_mtu(qdisc_dev(sch));
+	u64 rate = q->rate_bps;
+	u32 quantum1 = 256;
+	u32 quantum2 = 256;
+	u32 i;
+
+	q->tin_cnt = 8;
+	q->tin_index = precedence;
+	q->tin_order = normal_order;
+
+	for (i = 0; i < q->tin_cnt; i++) {
+		struct cake_tin_data *b = &q->tins[i];
+
+		cake_set_rate(b, rate, mtu, us_to_ns(q->target),
+			      us_to_ns(q->interval));
+
+		b->tin_quantum_prio = max_t(u16, 1U, quantum1);
+		b->tin_quantum_band = max_t(u16, 1U, quantum2);
+
+		/* calculate next class's parameters */
+		rate  *= 7;
+		rate >>= 3;
+
+		quantum1  *= 3;
+		quantum1 >>= 1;
+
+		quantum2  *= 7;
+		quantum2 >>= 3;
+	}
+
+	return 0;
+}
+
+/*	List of known Diffserv codepoints:
+ *
+ *	Least Effort (CS1)
+ *	Best Effort (CS0)
+ *	Max Reliability & LLT "Lo" (TOS1)
+ *	Max Throughput (TOS2)
+ *	Min Delay (TOS4)
+ *	LLT "La" (TOS5)
+ *	Assured Forwarding 1 (AF1x) - x3
+ *	Assured Forwarding 2 (AF2x) - x3
+ *	Assured Forwarding 3 (AF3x) - x3
+ *	Assured Forwarding 4 (AF4x) - x3
+ *	Precedence Class 2 (CS2)
+ *	Precedence Class 3 (CS3)
+ *	Precedence Class 4 (CS4)
+ *	Precedence Class 5 (CS5)
+ *	Precedence Class 6 (CS6)
+ *	Precedence Class 7 (CS7)
+ *	Voice Admit (VA)
+ *	Expedited Forwarding (EF)
+
+ *	Total 25 codepoints.
+ */
+
+/*	List of traffic classes in RFC 4594:
+ *		(roughly descending order of contended priority)
+ *		(roughly ascending order of uncontended throughput)
+ *
+ *	Network Control (CS6,CS7)      - routing traffic
+ *	Telephony (EF,VA)         - aka. VoIP streams
+ *	Signalling (CS5)               - VoIP setup
+ *	Multimedia Conferencing (AF4x) - aka. video calls
+ *	Realtime Interactive (CS4)     - eg. games
+ *	Multimedia Streaming (AF3x)    - eg. YouTube, NetFlix, Twitch
+ *	Broadcast Video (CS3)
+ *	Low Latency Data (AF2x,TOS4)      - eg. database
+ *	Ops, Admin, Management (CS2,TOS1) - eg. ssh
+ *	Standard Service (CS0 & unrecognised codepoints)
+ *	High Throughput Data (AF1x,TOS2)  - eg. web traffic
+ *	Low Priority Data (CS1)           - eg. BitTorrent
+
+ *	Total 12 traffic classes.
+ */
+
+static int cake_config_diffserv8(struct Qdisc *sch)
+{
+/*	Pruned list of traffic classes for typical applications:
+ *
+ *		Network Control          (CS6, CS7)
+ *		Minimum Latency          (EF, VA, CS5, CS4)
+ *		Interactive Shell        (CS2, TOS1)
+ *		Low Latency Transactions (AF2x, TOS4)
+ *		Video Streaming          (AF4x, AF3x, CS3)
+ *		Bog Standard             (CS0 etc.)
+ *		High Throughput          (AF1x, TOS2)
+ *		Background Traffic       (CS1)
+ *
+ *		Total 8 traffic classes.
+ */
+
+	struct cake_sched_data *q = qdisc_priv(sch);
+	u32 mtu = psched_mtu(qdisc_dev(sch));
+	u64 rate = q->rate_bps;
+	u32 quantum1 = 256;
+	u32 quantum2 = 256;
+	u32 i;
+
+	q->tin_cnt = 8;
+
+	/* codepoint to class mapping */
+	q->tin_index = diffserv8;
+	q->tin_order = normal_order;
+
+	/* class characteristics */
+	for (i = 0; i < q->tin_cnt; i++) {
+		struct cake_tin_data *b = &q->tins[i];
+
+		cake_set_rate(b, rate, mtu, us_to_ns(q->target),
+			      us_to_ns(q->interval));
+
+		b->tin_quantum_prio = max_t(u16, 1U, quantum1);
+		b->tin_quantum_band = max_t(u16, 1U, quantum2);
+
+		/* calculate next class's parameters */
+		rate  *= 7;
+		rate >>= 3;
+
+		quantum1  *= 3;
+		quantum1 >>= 1;
+
+		quantum2  *= 7;
+		quantum2 >>= 3;
+	}
+
+	return 0;
+}
+
+static int cake_config_diffserv4(struct Qdisc *sch)
+{
+/*  Further pruned list of traffic classes for four-class system:
+ *
+ *	    Latency Sensitive  (CS7, CS6, EF, VA, CS5, CS4)
+ *	    Streaming Media    (AF4x, AF3x, CS3, AF2x, TOS4, CS2, TOS1)
+ *	    Best Effort        (CS0, AF1x, TOS2, and those not specified)
+ *	    Background Traffic (CS1)
+ *
+ *		Total 4 traffic classes.
+ */
+
+	struct cake_sched_data *q = qdisc_priv(sch);
+	u32 mtu = psched_mtu(qdisc_dev(sch));
+	u64 rate = q->rate_bps;
+	u32 quantum = 1024;
+
+	q->tin_cnt = 4;
+
+	/* codepoint to class mapping */
+	q->tin_index = diffserv4;
+	q->tin_order = bulk_order;
+
+	/* class characteristics */
+	cake_set_rate(&q->tins[0], rate, mtu,
+		      us_to_ns(q->target), us_to_ns(q->interval));
+	cake_set_rate(&q->tins[1], rate >> 4, mtu,
+		      us_to_ns(q->target), us_to_ns(q->interval));
+	cake_set_rate(&q->tins[2], rate >> 1, mtu,
+		      us_to_ns(q->target), us_to_ns(q->interval));
+	cake_set_rate(&q->tins[3], rate >> 2, mtu,
+		      us_to_ns(q->target), us_to_ns(q->interval));
+
+	/* priority weights */
+	q->tins[0].tin_quantum_prio = quantum;
+	q->tins[1].tin_quantum_prio = quantum >> 4;
+	q->tins[2].tin_quantum_prio = quantum << 2;
+	q->tins[3].tin_quantum_prio = quantum << 4;
+
+	/* bandwidth-sharing weights */
+	q->tins[0].tin_quantum_band = quantum;
+	q->tins[1].tin_quantum_band = quantum >> 4;
+	q->tins[2].tin_quantum_band = quantum >> 1;
+	q->tins[3].tin_quantum_band = quantum >> 2;
+
+	return 0;
+}
+
+static int cake_config_diffserv3(struct Qdisc *sch)
+{
+/*  Simplified Diffserv structure with 3 tins.
+ *		Low Priority		(CS1)
+ *		Best Effort
+ *		Latency Sensitive	(TOS4, VA, EF, CS6, CS7)
+ */
+	struct cake_sched_data *q = qdisc_priv(sch);
+	u32 mtu = psched_mtu(qdisc_dev(sch));
+	u64 rate = q->rate_bps;
+	u32 quantum = 1024;
+
+	q->tin_cnt = 3;
+
+	/* codepoint to class mapping */
+	q->tin_index = diffserv3;
+	q->tin_order = bulk_order;
+
+	/* class characteristics */
+	cake_set_rate(&q->tins[0], rate, mtu,
+		      us_to_ns(q->target), us_to_ns(q->interval));
+	cake_set_rate(&q->tins[1], rate >> 4, mtu,
+		      us_to_ns(q->target), us_to_ns(q->interval));
+	cake_set_rate(&q->tins[2], rate >> 2, mtu,
+		      us_to_ns(q->target), us_to_ns(q->interval));
+
+	/* priority weights */
+	q->tins[0].tin_quantum_prio = quantum;
+	q->tins[1].tin_quantum_prio = quantum >> 4;
+	q->tins[2].tin_quantum_prio = quantum << 4;
+
+	/* bandwidth-sharing weights */
+	q->tins[0].tin_quantum_band = quantum;
+	q->tins[1].tin_quantum_band = quantum >> 4;
+	q->tins[2].tin_quantum_band = quantum >> 2;
+
+	return 0;
+}
+
+static void cake_reconfigure(struct Qdisc *sch)
+{
+	struct cake_sched_data *q = qdisc_priv(sch);
+	int c, ft;
+
+	switch (q->tin_mode) {
+	case CAKE_DIFFSERV_BESTEFFORT:
+		ft = cake_config_besteffort(sch);
+		break;
+
+	case CAKE_DIFFSERV_PRECEDENCE:
+		ft = cake_config_precedence(sch);
+		break;
+
+	case CAKE_DIFFSERV_DIFFSERV8:
+		ft = cake_config_diffserv8(sch);
+		break;
+
+	case CAKE_DIFFSERV_DIFFSERV4:
+		ft = cake_config_diffserv4(sch);
+		break;
+
+	case CAKE_DIFFSERV_DIFFSERV3:
+	default:
+		ft = cake_config_diffserv3(sch);
+		break;
+	}
+
 	for (c = q->tin_cnt; c < CAKE_MAX_TINS; c++) {
 		cake_clear_tin(sch, c);
 		q->tins[c].cparams.mtu_time = q->tins[ft].cparams.mtu_time;
@@ -1997,6 +2375,16 @@ static int cake_change(struct Qdisc *sch, struct nlattr *opt,
 	if (tb[TCA_CAKE_BASE_RATE64])
 		q->rate_bps = nla_get_u64(tb[TCA_CAKE_BASE_RATE64]);
 
+	if (tb[TCA_CAKE_DIFFSERV_MODE])
+		q->tin_mode = nla_get_u32(tb[TCA_CAKE_DIFFSERV_MODE]);
+
+	if (tb[TCA_CAKE_WASH]) {
+		if (!!nla_get_u32(tb[TCA_CAKE_WASH]))
+			q->rate_flags |= CAKE_FLAG_WASH;
+		else
+			q->rate_flags &= ~CAKE_FLAG_WASH;
+	}
+
 	if (tb[TCA_CAKE_FLOW_MODE])
 		q->flow_mode = (nla_get_u32(tb[TCA_CAKE_FLOW_MODE]) &
 				CAKE_FLOW_MASK);
@@ -2060,7 +2448,7 @@ static int cake_init(struct Qdisc *sch, struct nlattr *opt,
 	int i, j, err;
 
 	sch->limit = 10240;
-	q->tin_mode = CAKE_DIFFSERV_BESTEFFORT;
+	q->tin_mode = CAKE_DIFFSERV_DIFFSERV3;
 	q->flow_mode  = CAKE_FLOW_TRIPLE;
 
 	q->rate_bps = 0; /* unlimited by default */
@@ -2170,6 +2558,13 @@ static int cake_dump(struct Qdisc *sch, struct sk_buff *skb)
 			!!(q->flow_mode & CAKE_FLOW_NAT_FLAG)))
 		goto nla_put_failure;
 
+	if (nla_put_u32(skb, TCA_CAKE_DIFFSERV_MODE, q->tin_mode))
+		goto nla_put_failure;
+
+	if (nla_put_u32(skb, TCA_CAKE_WASH,
+			!!(q->rate_flags & CAKE_FLAG_WASH)))
+		goto nla_put_failure;
+
 	return nla_nest_end(skb, opts);
 
 nla_put_failure:
@@ -2223,7 +2618,7 @@ static int cake_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
 	} while (0)
 
 	for (i = 0; i < q->tin_cnt; i++) {
-		struct cake_tin_data *b = &q->tins[i];
+		struct cake_tin_data *b = &q->tins[q->tin_order[i]];
 
 		ts = nla_nest_start(d->skb, i + 1);
 		if (!ts)
@@ -2322,7 +2717,8 @@ static int cake_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 	u32 idx = cl - 1;
 
 	if (idx < CAKE_QUEUES * q->tin_cnt) {
-		const struct cake_tin_data *b = &q->tins[idx / CAKE_QUEUES];
+		const struct cake_tin_data *b = \
+			&q->tins[q->tin_order[idx / CAKE_QUEUES]];
 		const struct sk_buff *skb;
 
 		flow = &b->flows[idx % CAKE_QUEUES];
@@ -2394,7 +2790,7 @@ static void cake_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 		return;
 
 	for (i = 0; i < q->tin_cnt; i++) {
-		struct cake_tin_data *b = &q->tins[i];
+		struct cake_tin_data *b = &q->tins[q->tin_order[i]];
 
 		for (j = 0; j < CAKE_QUEUES; j++) {
 			if (list_empty(&b->flows[j].flowchain) ||

^ permalink raw reply related

* [PATCH net-next v15 2/7] sch_cake: Add ingress mode
From: Toke Høiland-Jørgensen @ 2018-05-22 13:57 UTC (permalink / raw)
  To: netdev, cake
In-Reply-To: <152699741881.21931.11656377745581563912.stgit@alrua-kau>

The ingress mode is meant to be enabled when CAKE runs downlink of the
actual bottleneck (such as on an IFB device). The mode changes the shaper
to also account dropped packets to the shaped rate, as these have already
traversed the bottleneck.

Enabling ingress mode will also tune the AQM to always keep at least two
packets queued *for each flow*. This is done by scaling the minimum queue
occupancy level that will disable the AQM by the number of active bulk
flows. The rationale for this is that retransmits are more expensive in
ingress mode, since dropped packets have to traverse the bottleneck again
when they are retransmitted; thus, being more lenient and keeping a minimum
number of packets queued will improve throughput in cases where the number
of active flows are so large that they saturate the bottleneck even at
their minimum window size.

This commit also adds a separate switch to enable ingress mode rate
autoscaling. If enabled, the autoscaling code will observe the actual
traffic rate and adjust the shaper rate to match it. This can help avoid
latency increases in the case where the actual bottleneck rate decreases
below the shaped rate. The scaling filters out spikes by an EWMA filter.

Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
---
 net/sched/sch_cake.c |   85 ++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 81 insertions(+), 4 deletions(-)

diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 7ea4aa261cec..10e208e4255d 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -435,7 +435,8 @@ static bool cobalt_queue_empty(struct cobalt_vars *vars,
 static bool cobalt_should_drop(struct cobalt_vars *vars,
 			       struct cobalt_params *p,
 			       ktime_t now,
-			       struct sk_buff *skb)
+			       struct sk_buff *skb,
+			       u32 bulk_flows)
 {
 	bool next_due, over_target, drop = false;
 	ktime_t schedule;
@@ -459,6 +460,7 @@ static bool cobalt_should_drop(struct cobalt_vars *vars,
 	sojourn = ktime_to_ns(ktime_sub(now, cobalt_get_enqueue_time(skb)));
 	schedule = ktime_sub(now, vars->drop_next);
 	over_target = sojourn > p->target &&
+		      sojourn > p->mtu_time * bulk_flows * 2 &&
 		      sojourn > p->mtu_time * 4;
 	next_due = vars->count && ktime_to_ns(schedule) >= 0;
 
@@ -913,6 +915,9 @@ static unsigned int cake_drop(struct Qdisc *sch, struct sk_buff **to_free)
 	b->tin_dropped++;
 	sch->qstats.drops++;
 
+	if (q->rate_flags & CAKE_FLAG_INGRESS)
+		cake_advance_shaper(q, b, skb, now, true);
+
 	__qdisc_drop(skb, to_free);
 	sch->q.qlen--;
 
@@ -990,8 +995,46 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 		cake_heapify_up(q, b->overflow_idx[idx]);
 
 	/* incoming bandwidth capacity estimate */
-	q->avg_window_bytes = 0;
-	q->last_packet_time = now;
+	if (q->rate_flags & CAKE_FLAG_AUTORATE_INGRESS) {
+		u64 packet_interval = \
+			ktime_to_ns(ktime_sub(now, q->last_packet_time));
+
+		if (packet_interval > NSEC_PER_SEC)
+			packet_interval = NSEC_PER_SEC;
+
+		/* filter out short-term bursts, eg. wifi aggregation */
+		q->avg_packet_interval = \
+			cake_ewma(q->avg_packet_interval,
+				  packet_interval,
+				  (packet_interval > q->avg_packet_interval ?
+					  2 : 8));
+
+		q->last_packet_time = now;
+
+		if (packet_interval > q->avg_packet_interval) {
+			u64 window_interval = \
+				ktime_to_ns(ktime_sub(now,
+						      q->avg_window_begin));
+			u64 b = q->avg_window_bytes * (u64)NSEC_PER_SEC;
+
+			do_div(b, window_interval);
+			q->avg_peak_bandwidth =
+				cake_ewma(q->avg_peak_bandwidth, b,
+					  b > q->avg_peak_bandwidth ? 2 : 8);
+			q->avg_window_bytes = 0;
+			q->avg_window_begin = now;
+
+			if (ktime_after(now,
+					ktime_add_ms(q->last_reconfig_time,
+						     250))) {
+				q->rate_bps = (q->avg_peak_bandwidth * 15) >> 4;
+				cake_reconfigure(sch);
+			}
+		}
+	} else {
+		q->avg_window_bytes = 0;
+		q->last_packet_time = now;
+	}
 
 	/* flowchain */
 	if (!flow->set || flow->set == CAKE_SET_DECAYING) {
@@ -1251,15 +1294,27 @@ static struct sk_buff *cake_dequeue(struct Qdisc *sch)
 		}
 
 		/* Last packet in queue may be marked, shouldn't be dropped */
-		if (!cobalt_should_drop(&flow->cvars, &b->cparams, now, skb) ||
+		if (!cobalt_should_drop(&flow->cvars, &b->cparams, now, skb,
+					(b->bulk_flow_count *
+					 !!(q->rate_flags &
+					    CAKE_FLAG_INGRESS))) ||
 		    !flow->head)
 			break;
 
+		/* drop this packet, get another one */
+		if (q->rate_flags & CAKE_FLAG_INGRESS) {
+			len = cake_advance_shaper(q, b, skb,
+						  now, true);
+			flow->deficit -= len;
+			b->tin_deficit -= len;
+		}
 		flow->dropped++;
 		b->tin_dropped++;
 		qdisc_tree_reduce_backlog(sch, 1, qdisc_pkt_len(skb));
 		qdisc_qstats_drop(sch);
 		kfree_skb(skb);
+		if (q->rate_flags & CAKE_FLAG_INGRESS)
+			goto retry;
 	}
 
 	b->tin_ecn_mark += !!flow->cvars.ecn_marked;
@@ -1442,6 +1497,20 @@ static int cake_change(struct Qdisc *sch, struct nlattr *opt,
 			q->target = 1;
 	}
 
+	if (tb[TCA_CAKE_AUTORATE]) {
+		if (!!nla_get_u32(tb[TCA_CAKE_AUTORATE]))
+			q->rate_flags |= CAKE_FLAG_AUTORATE_INGRESS;
+		else
+			q->rate_flags &= ~CAKE_FLAG_AUTORATE_INGRESS;
+	}
+
+	if (tb[TCA_CAKE_INGRESS]) {
+		if (!!nla_get_u32(tb[TCA_CAKE_INGRESS]))
+			q->rate_flags |= CAKE_FLAG_INGRESS;
+		else
+			q->rate_flags &= ~CAKE_FLAG_INGRESS;
+	}
+
 	if (tb[TCA_CAKE_MEMORY])
 		q->buffer_config_limit = nla_get_u32(tb[TCA_CAKE_MEMORY]);
 
@@ -1565,6 +1634,14 @@ static int cake_dump(struct Qdisc *sch, struct sk_buff *skb)
 	if (nla_put_u32(skb, TCA_CAKE_MEMORY, q->buffer_config_limit))
 		goto nla_put_failure;
 
+	if (nla_put_u32(skb, TCA_CAKE_AUTORATE,
+			!!(q->rate_flags & CAKE_FLAG_AUTORATE_INGRESS)))
+		goto nla_put_failure;
+
+	if (nla_put_u32(skb, TCA_CAKE_INGRESS,
+			!!(q->rate_flags & CAKE_FLAG_INGRESS)))
+		goto nla_put_failure;
+
 	return nla_nest_end(skb, opts);
 
 nla_put_failure:

^ permalink raw reply related

* [PATCH net-next v15 6/7] sch_cake: Add overhead compensation support to the rate shaper
From: Toke Høiland-Jørgensen @ 2018-05-22 13:57 UTC (permalink / raw)
  To: netdev, cake
In-Reply-To: <152699741881.21931.11656377745581563912.stgit@alrua-kau>

This commit adds configurable overhead compensation support to the rate
shaper. With this feature, userspace can configure the actual bottleneck
link overhead and encapsulation mode used, which will be used by the shaper
to calculate the precise duration of each packet on the wire.

This feature is needed because CAKE is often deployed one or two hops
upstream of the actual bottleneck (which can be, e.g., inside a DSL or
cable modem). In this case, the link layer characteristics and overhead
reported by the kernel does not match the actual bottleneck. Being able to
set the actual values in use makes it possible to configure the shaper rate
much closer to the actual bottleneck rate (our experience shows it is
possible to get with 0.1% of the actual physical bottleneck rate), thus
keeping latency low without sacrificing bandwidth.

The overhead compensation has three tunables: A fixed per-packet overhead
size (which, if set, will be accounted from the IP packet header), a
minimum packet size (MPU) and a framing mode supporting either ATM or PTM
framing. We include a set of common keywords in TC to help users configure
the right parameters. If no overhead value is set, the value reported by
the kernel is used.

Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
---
 net/sched/sch_cake.c |  124 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 123 insertions(+), 1 deletion(-)

diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 6384765e97b0..87c3b01b773e 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -272,6 +272,7 @@ enum {
 
 struct cobalt_skb_cb {
 	ktime_t enqueue_time;
+	u32     adjusted_len;
 };
 
 static u64 us_to_ns(u64 us)
@@ -1315,6 +1316,88 @@ static u64 cake_ewma(u64 avg, u64 sample, u32 shift)
 	return avg;
 }
 
+static u32 cake_calc_overhead(struct cake_sched_data *q, u32 len, u32 off)
+{
+	if (q->rate_flags & CAKE_FLAG_OVERHEAD)
+		len -= off;
+
+	if (q->max_netlen < len)
+		q->max_netlen = len;
+	if (q->min_netlen > len)
+		q->min_netlen = len;
+
+	len += q->rate_overhead;
+
+	if (len < q->rate_mpu)
+		len = q->rate_mpu;
+
+	if (q->atm_mode == CAKE_ATM_ATM) {
+		len += 47;
+		len /= 48;
+		len *= 53;
+	} else if (q->atm_mode == CAKE_ATM_PTM) {
+		/* Add one byte per 64 bytes or part thereof.
+		 * This is conservative and easier to calculate than the
+		 * precise value.
+		 */
+		len += (len + 63) / 64;
+	}
+
+	if (q->max_adjlen < len)
+		q->max_adjlen = len;
+	if (q->min_adjlen > len)
+		q->min_adjlen = len;
+
+	return len;
+}
+
+static u32 cake_overhead(struct cake_sched_data *q, const struct sk_buff *skb)
+{
+	const struct skb_shared_info *shinfo = skb_shinfo(skb);
+	unsigned int hdr_len, last_len = 0;
+	u32 off = skb_network_offset(skb);
+	u32 len = qdisc_pkt_len(skb);
+	u16 segs = 1;
+
+	q->avg_netoff = cake_ewma(q->avg_netoff, off << 16, 8);
+
+	if (!shinfo->gso_size)
+		return cake_calc_overhead(q, len, off);
+
+	/* borrowed from qdisc_pkt_len_init() */
+	hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
+
+	/* + transport layer */
+	if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 |
+						SKB_GSO_TCPV6))) {
+		const struct tcphdr *th;
+		struct tcphdr _tcphdr;
+
+		th = skb_header_pointer(skb, skb_transport_offset(skb),
+					sizeof(_tcphdr), &_tcphdr);
+		if (likely(th))
+			hdr_len += __tcp_hdrlen(th);
+	} else {
+		struct udphdr _udphdr;
+
+		if (skb_header_pointer(skb, skb_transport_offset(skb),
+				       sizeof(_udphdr), &_udphdr))
+			hdr_len += sizeof(struct udphdr);
+	}
+
+	if (unlikely(shinfo->gso_type & SKB_GSO_DODGY))
+		segs = DIV_ROUND_UP(skb->len - hdr_len,
+				    shinfo->gso_size);
+	else
+		segs = shinfo->gso_segs;
+
+	len = shinfo->gso_size + hdr_len;
+	last_len = skb->len - shinfo->gso_size * (segs - 1);
+
+	return (cake_calc_overhead(q, len, off) * (segs - 1) +
+		cake_calc_overhead(q, last_len, off));
+}
+
 static void cake_heap_swap(struct cake_sched_data *q, u16 i, u16 j)
 {
 	struct cake_heap_entry ii = q->overflow_heap[i];
@@ -1392,7 +1475,7 @@ static int cake_advance_shaper(struct cake_sched_data *q,
 			       struct sk_buff *skb,
 			       ktime_t now, bool drop)
 {
-	u32 len = qdisc_pkt_len(skb);
+	u32 len = get_cobalt_cb(skb)->adjusted_len;
 
 	/* charge packet bandwidth to this tin
 	 * and to the global shaper.
@@ -1589,6 +1672,7 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 		b->max_skblen = len;
 
 	cobalt_set_enqueue_time(skb, now);
+	get_cobalt_cb(skb)->adjusted_len = cake_overhead(q, skb);
 	flow_queue_add(flow, skb);
 
 	if (q->ack_filter)
@@ -2389,6 +2473,31 @@ static int cake_change(struct Qdisc *sch, struct nlattr *opt,
 		q->flow_mode = (nla_get_u32(tb[TCA_CAKE_FLOW_MODE]) &
 				CAKE_FLOW_MASK);
 
+	if (tb[TCA_CAKE_ATM])
+		q->atm_mode = nla_get_u32(tb[TCA_CAKE_ATM]);
+
+	if (tb[TCA_CAKE_OVERHEAD]) {
+		q->rate_overhead = nla_get_s32(tb[TCA_CAKE_OVERHEAD]);
+		q->rate_flags |= CAKE_FLAG_OVERHEAD;
+
+		q->max_netlen = 0;
+		q->max_adjlen = 0;
+		q->min_netlen = ~0;
+		q->min_adjlen = ~0;
+	}
+
+	if (tb[TCA_CAKE_RAW]) {
+		q->rate_flags &= ~CAKE_FLAG_OVERHEAD;
+
+		q->max_netlen = 0;
+		q->max_adjlen = 0;
+		q->min_netlen = ~0;
+		q->min_adjlen = ~0;
+	}
+
+	if (tb[TCA_CAKE_MPU])
+		q->rate_mpu = nla_get_u32(tb[TCA_CAKE_MPU]);
+
 	if (tb[TCA_CAKE_RTT]) {
 		q->interval = nla_get_u32(tb[TCA_CAKE_RTT]);
 
@@ -2565,6 +2674,19 @@ static int cake_dump(struct Qdisc *sch, struct sk_buff *skb)
 			!!(q->rate_flags & CAKE_FLAG_WASH)))
 		goto nla_put_failure;
 
+	if (nla_put_u32(skb, TCA_CAKE_OVERHEAD, q->rate_overhead))
+		goto nla_put_failure;
+
+	if (!(q->rate_flags & CAKE_FLAG_OVERHEAD))
+		if (nla_put_u32(skb, TCA_CAKE_RAW, 0))
+			goto nla_put_failure;
+
+	if (nla_put_u32(skb, TCA_CAKE_ATM, q->atm_mode))
+		goto nla_put_failure;
+
+	if (nla_put_u32(skb, TCA_CAKE_MPU, q->rate_mpu))
+		goto nla_put_failure;
+
 	return nla_nest_end(skb, opts);
 
 nla_put_failure:

^ permalink raw reply related

* [PATCH net-next v15 4/7] sch_cake: Add NAT awareness to packet classifier
From: Toke Høiland-Jørgensen @ 2018-05-22 13:57 UTC (permalink / raw)
  To: netdev, cake; +Cc: netfilter-devel
In-Reply-To: <152699741881.21931.11656377745581563912.stgit@alrua-kau>

When CAKE is deployed on a gateway that also performs NAT (which is a
common deployment mode), the host fairness mechanism cannot distinguish
internal hosts from each other, and so fails to work correctly.

To fix this, we add an optional NAT awareness mode, which will query the
kernel conntrack mechanism to obtain the pre-NAT addresses for each packet
and use that in the flow and host hashing.

When the shaper is enabled and the host is already performing NAT, the cost
of this lookup is negligible. However, in unlimited mode with no NAT being
performed, there is a significant CPU cost at higher bandwidths. For this
reason, the feature is turned off by default.

Cc: netfilter-devel@vger.kernel.org
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
---
 net/sched/sch_cake.c |   79 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)

diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 68ac908470f1..6f7cae705c84 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -71,6 +71,12 @@
 #include <net/tcp.h>
 #include <net/flow_dissector.h>
 
+#if IS_REACHABLE(CONFIG_NF_CONNTRACK)
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_conntrack_zones.h>
+#include <net/netfilter/nf_conntrack.h>
+#endif
+
 #define CAKE_SET_WAYS (8)
 #define CAKE_MAX_TINS (8)
 #define CAKE_QUEUES (1024)
@@ -516,6 +522,60 @@ static bool cobalt_should_drop(struct cobalt_vars *vars,
 	return drop;
 }
 
+#if IS_REACHABLE(CONFIG_NF_CONNTRACK)
+
+static void cake_update_flowkeys(struct flow_keys *keys,
+				 const struct sk_buff *skb)
+{
+	const struct nf_conntrack_tuple *tuple;
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct;
+	bool rev = false;
+
+	if (tc_skb_protocol(skb) != htons(ETH_P_IP))
+		return;
+
+	ct = nf_ct_get(skb, &ctinfo);
+	if (ct) {
+		tuple = nf_ct_tuple(ct, CTINFO2DIR(ctinfo));
+	} else {
+		const struct nf_conntrack_tuple_hash *hash;
+		struct nf_conntrack_tuple srctuple;
+
+		if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
+				       NFPROTO_IPV4, dev_net(skb->dev),
+				       &srctuple))
+			return;
+
+		hash = nf_conntrack_find_get(dev_net(skb->dev),
+					     &nf_ct_zone_dflt,
+					     &srctuple);
+		if (!hash)
+			return;
+
+		rev = true;
+		ct = nf_ct_tuplehash_to_ctrack(hash);
+		tuple = nf_ct_tuple(ct, !hash->tuple.dst.dir);
+	}
+
+	keys->addrs.v4addrs.src = rev ? tuple->dst.u3.ip : tuple->src.u3.ip;
+	keys->addrs.v4addrs.dst = rev ? tuple->src.u3.ip : tuple->dst.u3.ip;
+
+	if (keys->ports.ports) {
+		keys->ports.src = rev ? tuple->dst.u.all : tuple->src.u.all;
+		keys->ports.dst = rev ? tuple->src.u.all : tuple->dst.u.all;
+	}
+	if (rev)
+		nf_ct_put(ct);
+}
+#else
+static void cake_update_flowkeys(struct flow_keys *keys,
+				 const struct sk_buff *skb)
+{
+	/* There is nothing we can do here without CONNTRACK */
+}
+#endif
+
 /* Cake has several subtle multiple bit settings. In these cases you
  *  would be matching triple isolate mode as well.
  */
@@ -543,6 +603,9 @@ static u32 cake_hash(struct cake_tin_data *q, const struct sk_buff *skb,
 	skb_flow_dissect_flow_keys(skb, &keys,
 				   FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
 
+	if (flow_mode & CAKE_FLOW_NAT_FLAG)
+		cake_update_flowkeys(&keys, skb);
+
 	/* flow_hash_from_keys() sorts the addresses by value, so we have
 	 * to preserve their order in a separate data structure to treat
 	 * src and dst host addresses as independently selectable.
@@ -1919,6 +1982,18 @@ static int cake_change(struct Qdisc *sch, struct nlattr *opt,
 	if (err < 0)
 		return err;
 
+	if (tb[TCA_CAKE_NAT]) {
+#if IS_REACHABLE(CONFIG_NF_CONNTRACK)
+		q->flow_mode &= ~CAKE_FLOW_NAT_FLAG;
+		q->flow_mode |= CAKE_FLOW_NAT_FLAG *
+			!!nla_get_u32(tb[TCA_CAKE_NAT]);
+#else
+		NL_SET_ERR_MSG_ATTR(extack, "No conntrack support in kernel",
+				    tb[TCA_CAKE_NAT]);
+		return -EOPNOTSUPP;
+#endif
+	}
+
 	if (tb[TCA_CAKE_BASE_RATE64])
 		q->rate_bps = nla_get_u64(tb[TCA_CAKE_BASE_RATE64]);
 
@@ -2091,6 +2166,10 @@ static int cake_dump(struct Qdisc *sch, struct sk_buff *skb)
 	if (nla_put_u32(skb, TCA_CAKE_ACK_FILTER, q->ack_filter))
 		goto nla_put_failure;
 
+	if (nla_put_u32(skb, TCA_CAKE_NAT,
+			!!(q->flow_mode & CAKE_FLOW_NAT_FLAG)))
+		goto nla_put_failure;
+
 	return nla_nest_end(skb, opts);
 
 nla_put_failure:

^ permalink raw reply related

* [PATCH net-next v15 1/7] sched: Add Common Applications Kept Enhanced (cake) qdisc
From: Toke Høiland-Jørgensen @ 2018-05-22 13:57 UTC (permalink / raw)
  To: netdev, cake; +Cc: Pete Heist, Georgios Amanakis, Dave Taht
In-Reply-To: <152699741881.21931.11656377745581563912.stgit@alrua-kau>

sch_cake targets the home router use case and is intended to squeeze the
most bandwidth and latency out of even the slowest ISP links and routers,
while presenting an API simple enough that even an ISP can configure it.

Example of use on a cable ISP uplink:

tc qdisc add dev eth0 cake bandwidth 20Mbit nat docsis ack-filter

To shape a cable download link (ifb and tc-mirred setup elided)

tc qdisc add dev ifb0 cake bandwidth 200mbit nat docsis ingress wash

CAKE is filled with:

* A hybrid Codel/Blue AQM algorithm, "Cobalt", tied to an FQ_Codel
  derived Flow Queuing system, which autoconfigures based on the bandwidth.
* A novel "triple-isolate" mode (the default) which balances per-host
  and per-flow FQ even through NAT.
* An deficit based shaper, that can also be used in an unlimited mode.
* 8 way set associative hashing to reduce flow collisions to a minimum.
* A reasonable interpretation of various diffserv latency/loss tradeoffs.
* Support for zeroing diffserv markings for entering and exiting traffic.
* Support for interacting well with Docsis 3.0 shaper framing.
* Extensive support for DSL framing types.
* Support for ack filtering.
* Extensive statistics for measuring, loss, ecn markings, latency
  variation.

A paper describing the design of CAKE is available at
https://arxiv.org/abs/1804.07617, and will be published at the 2018 IEEE
International Symposium on Local and Metropolitan Area Networks (LANMAN).

This patch adds the base shaper and packet scheduler, while subsequent
commits add the optional (configurable) features. The full userspace API
and most data structures are included in this commit, but options not
understood in the base version will be ignored.

Various versions baking have been available as an out of tree build for
kernel versions going back to 3.10, as the embedded router world has been
running a few years behind mainline Linux. A stable version has been
generally available on lede-17.01 and later.

sch_cake replaces a combination of iptables, tc filter, htb and fq_codel
in the sqm-scripts, with sane defaults and vastly simpler configuration.

CAKE's principal author is Jonathan Morton, with contributions from
Kevin Darbyshire-Bryant, Toke Høiland-Jørgensen, Sebastian Moeller,
Ryan Mounce, Guido Sarducci, Dean Scarff, Nils Andreas Svee, Dave Täht,
and Loganaden Velvindron.

Testing from Pete Heist, Georgios Amanakis, and the many other members of
the cake@lists.bufferbloat.net mailing list.

tc -s qdisc show dev eth2
qdisc cake 1: root refcnt 2 bandwidth 100Mbit diffserv3 triple-isolate rtt 100.0ms raw overhead 0
 Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0
 memory used: 0b of 5000000b
 capacity estimate: 100Mbit
 min/max network layer size:        65535 /       0
 min/max overhead-adjusted size:    65535 /       0
 average network hdr offset:            0

                   Bulk  Best Effort        Voice
  thresh       6250Kbit      100Mbit       25Mbit
  target          5.0ms        5.0ms        5.0ms
  interval      100.0ms      100.0ms      100.0ms
  pk_delay          0us          0us          0us
  av_delay          0us          0us          0us
  sp_delay          0us          0us          0us
  pkts                0            0            0
  bytes               0            0            0
  way_inds            0            0            0
  way_miss            0            0            0
  way_cols            0            0            0
  drops               0            0            0
  marks               0            0            0
  ack_drop            0            0            0
  sp_flows            0            0            0
  bk_flows            0            0            0
  un_flows            0            0            0
  max_len             0            0            0
  quantum           300         1514          762

Tested-by: Pete Heist <peteheist@gmail.com>
Tested-by: Georgios Amanakis <gamanakis@gmail.com>
Signed-off-by: Dave Taht <dave.taht@gmail.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
---
 include/uapi/linux/pkt_sched.h |  113 ++
 net/sched/Kconfig              |   11 
 net/sched/Makefile             |    1 
 net/sched/sch_cake.c           | 1850 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 1975 insertions(+)
 create mode 100644 net/sched/sch_cake.c

diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h
index 37b5096ae97b..07648e6ea569 100644
--- a/include/uapi/linux/pkt_sched.h
+++ b/include/uapi/linux/pkt_sched.h
@@ -934,4 +934,117 @@ enum {
 
 #define TCA_CBS_MAX (__TCA_CBS_MAX - 1)
 
+/* CAKE */
+enum {
+	TCA_CAKE_UNSPEC,
+	TCA_CAKE_PAD,
+	TCA_CAKE_BASE_RATE64,
+	TCA_CAKE_DIFFSERV_MODE,
+	TCA_CAKE_ATM,
+	TCA_CAKE_FLOW_MODE,
+	TCA_CAKE_OVERHEAD,
+	TCA_CAKE_RTT,
+	TCA_CAKE_TARGET,
+	TCA_CAKE_AUTORATE,
+	TCA_CAKE_MEMORY,
+	TCA_CAKE_NAT,
+	TCA_CAKE_RAW,
+	TCA_CAKE_WASH,
+	TCA_CAKE_MPU,
+	TCA_CAKE_INGRESS,
+	TCA_CAKE_ACK_FILTER,
+	TCA_CAKE_SPLIT_GSO,
+	__TCA_CAKE_MAX
+};
+#define TCA_CAKE_MAX	(__TCA_CAKE_MAX - 1)
+
+enum {
+	__TCA_CAKE_STATS_INVALID,
+	TCA_CAKE_STATS_PAD,
+	TCA_CAKE_STATS_CAPACITY_ESTIMATE64,
+	TCA_CAKE_STATS_MEMORY_LIMIT,
+	TCA_CAKE_STATS_MEMORY_USED,
+	TCA_CAKE_STATS_AVG_NETOFF,
+	TCA_CAKE_STATS_MIN_NETLEN,
+	TCA_CAKE_STATS_MAX_NETLEN,
+	TCA_CAKE_STATS_MIN_ADJLEN,
+	TCA_CAKE_STATS_MAX_ADJLEN,
+	TCA_CAKE_STATS_TIN_STATS,
+	TCA_CAKE_STATS_DEFICIT,
+	TCA_CAKE_STATS_COBALT_COUNT,
+	TCA_CAKE_STATS_DROPPING,
+	TCA_CAKE_STATS_DROP_NEXT_US,
+	TCA_CAKE_STATS_P_DROP,
+	TCA_CAKE_STATS_BLUE_TIMER_US,
+	__TCA_CAKE_STATS_MAX
+};
+#define TCA_CAKE_STATS_MAX (__TCA_CAKE_STATS_MAX - 1)
+
+enum {
+	__TCA_CAKE_TIN_STATS_INVALID,
+	TCA_CAKE_TIN_STATS_PAD,
+	TCA_CAKE_TIN_STATS_SENT_PACKETS,
+	TCA_CAKE_TIN_STATS_SENT_BYTES64,
+	TCA_CAKE_TIN_STATS_DROPPED_PACKETS,
+	TCA_CAKE_TIN_STATS_DROPPED_BYTES64,
+	TCA_CAKE_TIN_STATS_ACKS_DROPPED_PACKETS,
+	TCA_CAKE_TIN_STATS_ACKS_DROPPED_BYTES64,
+	TCA_CAKE_TIN_STATS_ECN_MARKED_PACKETS,
+	TCA_CAKE_TIN_STATS_ECN_MARKED_BYTES64,
+	TCA_CAKE_TIN_STATS_BACKLOG_PACKETS,
+	TCA_CAKE_TIN_STATS_BACKLOG_BYTES,
+	TCA_CAKE_TIN_STATS_THRESHOLD_RATE64,
+	TCA_CAKE_TIN_STATS_TARGET_US,
+	TCA_CAKE_TIN_STATS_INTERVAL_US,
+	TCA_CAKE_TIN_STATS_WAY_INDIRECT_HITS,
+	TCA_CAKE_TIN_STATS_WAY_MISSES,
+	TCA_CAKE_TIN_STATS_WAY_COLLISIONS,
+	TCA_CAKE_TIN_STATS_PEAK_DELAY_US,
+	TCA_CAKE_TIN_STATS_AVG_DELAY_US,
+	TCA_CAKE_TIN_STATS_BASE_DELAY_US,
+	TCA_CAKE_TIN_STATS_SPARSE_FLOWS,
+	TCA_CAKE_TIN_STATS_BULK_FLOWS,
+	TCA_CAKE_TIN_STATS_UNRESPONSIVE_FLOWS,
+	TCA_CAKE_TIN_STATS_MAX_SKBLEN,
+	TCA_CAKE_TIN_STATS_FLOW_QUANTUM,
+	__TCA_CAKE_TIN_STATS_MAX
+};
+#define TCA_CAKE_TIN_STATS_MAX (__TCA_CAKE_TIN_STATS_MAX - 1)
+#define TC_CAKE_MAX_TINS (8)
+
+enum {
+	CAKE_FLOW_NONE = 0,
+	CAKE_FLOW_SRC_IP,
+	CAKE_FLOW_DST_IP,
+	CAKE_FLOW_HOSTS,    /* = CAKE_FLOW_SRC_IP | CAKE_FLOW_DST_IP */
+	CAKE_FLOW_FLOWS,
+	CAKE_FLOW_DUAL_SRC, /* = CAKE_FLOW_SRC_IP | CAKE_FLOW_FLOWS */
+	CAKE_FLOW_DUAL_DST, /* = CAKE_FLOW_DST_IP | CAKE_FLOW_FLOWS */
+	CAKE_FLOW_TRIPLE,   /* = CAKE_FLOW_HOSTS  | CAKE_FLOW_FLOWS */
+	CAKE_FLOW_MAX,
+};
+
+enum {
+	CAKE_DIFFSERV_DIFFSERV3 = 0,
+	CAKE_DIFFSERV_DIFFSERV4,
+	CAKE_DIFFSERV_DIFFSERV8,
+	CAKE_DIFFSERV_BESTEFFORT,
+	CAKE_DIFFSERV_PRECEDENCE,
+	CAKE_DIFFSERV_MAX
+};
+
+enum {
+	CAKE_ACK_NONE = 0,
+	CAKE_ACK_FILTER,
+	CAKE_ACK_AGGRESSIVE,
+	CAKE_ACK_MAX
+};
+
+enum {
+	CAKE_ATM_NONE = 0,
+	CAKE_ATM_ATM,
+	CAKE_ATM_PTM,
+	CAKE_ATM_MAX
+};
+
 #endif
diff --git a/net/sched/Kconfig b/net/sched/Kconfig
index a01169fb5325..6e7d614b5757 100644
--- a/net/sched/Kconfig
+++ b/net/sched/Kconfig
@@ -284,6 +284,17 @@ config NET_SCH_FQ_CODEL
 
 	  If unsure, say N.
 
+config NET_SCH_CAKE
+	tristate "Common Applications Kept Enhanced (CAKE)"
+	help
+	  Say Y here if you want to use the Common Applications Kept Enhanced
+          (CAKE) queue management algorithm.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called sch_cake.
+
+	  If unsure, say N.
+
 config NET_SCH_FQ
 	tristate "Fair Queue"
 	help
diff --git a/net/sched/Makefile b/net/sched/Makefile
index 8811d3804878..435054cee32c 100644
--- a/net/sched/Makefile
+++ b/net/sched/Makefile
@@ -50,6 +50,7 @@ obj-$(CONFIG_NET_SCH_CHOKE)	+= sch_choke.o
 obj-$(CONFIG_NET_SCH_QFQ)	+= sch_qfq.o
 obj-$(CONFIG_NET_SCH_CODEL)	+= sch_codel.o
 obj-$(CONFIG_NET_SCH_FQ_CODEL)	+= sch_fq_codel.o
+obj-$(CONFIG_NET_SCH_CAKE)	+= sch_cake.o
 obj-$(CONFIG_NET_SCH_FQ)	+= sch_fq.o
 obj-$(CONFIG_NET_SCH_HHF)	+= sch_hhf.o
 obj-$(CONFIG_NET_SCH_PIE)	+= sch_pie.o
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
new file mode 100644
index 000000000000..7ea4aa261cec
--- /dev/null
+++ b/net/sched/sch_cake.c
@@ -0,0 +1,1850 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+
+/* COMMON Applications Kept Enhanced (CAKE) discipline
+ *
+ * Copyright (C) 2014-2018 Jonathan Morton <chromatix99@gmail.com>
+ * Copyright (C) 2015-2018 Toke Høiland-Jørgensen <toke@toke.dk>
+ * Copyright (C) 2014-2018 Dave Täht <dave.taht@gmail.com>
+ * Copyright (C) 2015-2018 Sebastian Moeller <moeller0@gmx.de>
+ * (C) 2015-2018 Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk>
+ * Copyright (C) 2017-2018 Ryan Mounce <ryan@mounce.com.au>
+ *
+ * The CAKE Principles:
+ *		   (or, how to have your cake and eat it too)
+ *
+ * This is a combination of several shaping, AQM and FQ techniques into one
+ * easy-to-use package:
+ *
+ * - An overall bandwidth shaper, to move the bottleneck away from dumb CPE
+ *   equipment and bloated MACs.  This operates in deficit mode (as in sch_fq),
+ *   eliminating the need for any sort of burst parameter (eg. token bucket
+ *   depth).  Burst support is limited to that necessary to overcome scheduling
+ *   latency.
+ *
+ * - A Diffserv-aware priority queue, giving more priority to certain classes,
+ *   up to a specified fraction of bandwidth.  Above that bandwidth threshold,
+ *   the priority is reduced to avoid starving other tins.
+ *
+ * - Each priority tin has a separate Flow Queue system, to isolate traffic
+ *   flows from each other.  This prevents a burst on one flow from increasing
+ *   the delay to another.  Flows are distributed to queues using a
+ *   set-associative hash function.
+ *
+ * - Each queue is actively managed by Cobalt, which is a combination of the
+ *   Codel and Blue AQM algorithms.  This serves flows fairly, and signals
+ *   congestion early via ECN (if available) and/or packet drops, to keep
+ *   latency low.  The codel parameters are auto-tuned based on the bandwidth
+ *   setting, as is necessary at low bandwidths.
+ *
+ * The configuration parameters are kept deliberately simple for ease of use.
+ * Everything has sane defaults.  Complete generality of configuration is *not*
+ * a goal.
+ *
+ * The priority queue operates according to a weighted DRR scheme, combined with
+ * a bandwidth tracker which reuses the shaper logic to detect which side of the
+ * bandwidth sharing threshold the tin is operating.  This determines whether a
+ * priority-based weight (high) or a bandwidth-based weight (low) is used for
+ * that tin in the current pass.
+ *
+ * This qdisc was inspired by Eric Dumazet's fq_codel code, which he kindly
+ * granted us permission to leverage.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/jiffies.h>
+#include <linux/string.h>
+#include <linux/in.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/skbuff.h>
+#include <linux/jhash.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/reciprocal_div.h>
+#include <net/netlink.h>
+#include <linux/version.h>
+#include <linux/if_vlan.h>
+#include <net/pkt_sched.h>
+#include <net/pkt_cls.h>
+#include <net/tcp.h>
+#include <net/flow_dissector.h>
+
+#define CAKE_SET_WAYS (8)
+#define CAKE_MAX_TINS (8)
+#define CAKE_QUEUES (1024)
+#define CAKE_FLOW_MASK 63
+#define CAKE_FLOW_NAT_FLAG 64
+
+/* struct cobalt_params - contains codel and blue parameters
+ * @interval:	codel initial drop rate
+ * @target:     maximum persistent sojourn time & blue update rate
+ * @mtu_time:   serialisation delay of maximum-size packet
+ * @p_inc:      increment of blue drop probability (0.32 fxp)
+ * @p_dec:      decrement of blue drop probability (0.32 fxp)
+ */
+struct cobalt_params {
+	u64	interval;
+	u64	target;
+	u64	mtu_time;
+	u32	p_inc;
+	u32	p_dec;
+};
+
+/* struct cobalt_vars - contains codel and blue variables
+ * @count:		codel dropping frequency
+ * @rec_inv_sqrt:	reciprocal value of sqrt(count) >> 1
+ * @drop_next:		time to drop next packet, or when we dropped last
+ * @blue_timer:		Blue time to next drop
+ * @p_drop:		BLUE drop probability (0.32 fxp)
+ * @dropping:		set if in dropping state
+ * @ecn_marked:		set if marked
+ */
+struct cobalt_vars {
+	u32	count;
+	u32	rec_inv_sqrt;
+	ktime_t	drop_next;
+	ktime_t	blue_timer;
+	u32     p_drop;
+	bool	dropping;
+	bool    ecn_marked;
+};
+
+enum {
+	CAKE_SET_NONE = 0,
+	CAKE_SET_SPARSE,
+	CAKE_SET_SPARSE_WAIT, /* counted in SPARSE, actually in BULK */
+	CAKE_SET_BULK,
+	CAKE_SET_DECAYING
+};
+
+struct cake_flow {
+	/* this stuff is all needed per-flow at dequeue time */
+	struct sk_buff	  *head;
+	struct sk_buff	  *tail;
+	struct list_head  flowchain;
+	s32		  deficit;
+	u32		  dropped;
+	struct cobalt_vars cvars;
+	u16		  srchost; /* index into cake_host table */
+	u16		  dsthost;
+	u8		  set;
+}; /* please try to keep this structure <= 64 bytes */
+
+struct cake_host {
+	u32 srchost_tag;
+	u32 dsthost_tag;
+	u16 srchost_refcnt;
+	u16 dsthost_refcnt;
+};
+
+struct cake_heap_entry {
+	u16 t:3, b:10;
+};
+
+struct cake_tin_data {
+	struct cake_flow flows[CAKE_QUEUES];
+	u32	backlogs[CAKE_QUEUES];
+	u32	tags[CAKE_QUEUES]; /* for set association */
+	u16	overflow_idx[CAKE_QUEUES];
+	struct cake_host hosts[CAKE_QUEUES]; /* for triple isolation */
+	u16	flow_quantum;
+
+	struct cobalt_params cparams;
+	u32	drop_overlimit;
+	u16	bulk_flow_count;
+	u16	sparse_flow_count;
+	u16	decaying_flow_count;
+	u16	unresponsive_flow_count;
+
+	u32	max_skblen;
+
+	struct list_head new_flows;
+	struct list_head old_flows;
+	struct list_head decaying_flows;
+
+	/* time_next = time_this + ((len * rate_ns) >> rate_shft) */
+	ktime_t	time_next_packet;
+	u64	tin_rate_ns;
+	u64	tin_rate_bps;
+	u16	tin_rate_shft;
+
+	u16	tin_quantum_prio;
+	u16	tin_quantum_band;
+	s32	tin_deficit;
+	u32	tin_backlog;
+	u32	tin_dropped;
+	u32	tin_ecn_mark;
+
+	u32	packets;
+	u64	bytes;
+
+	u32	ack_drops;
+
+	/* moving averages */
+	u64 avge_delay;
+	u64 peak_delay;
+	u64 base_delay;
+
+	/* hash function stats */
+	u32	way_directs;
+	u32	way_hits;
+	u32	way_misses;
+	u32	way_collisions;
+}; /* number of tins is small, so size of this struct doesn't matter much */
+
+struct cake_sched_data {
+	struct tcf_proto __rcu *filter_list; /* optional external classifier */
+	struct tcf_block *block;
+	struct cake_tin_data *tins;
+
+	struct cake_heap_entry overflow_heap[CAKE_QUEUES * CAKE_MAX_TINS];
+	u16		overflow_timeout;
+
+	u16		tin_cnt;
+	u8		tin_mode;
+	u8		flow_mode;
+	u8		ack_filter;
+	u8		atm_mode;
+
+	/* time_next = time_this + ((len * rate_ns) >> rate_shft) */
+	u16		rate_shft;
+	ktime_t		time_next_packet;
+	ktime_t		failsafe_next_packet;
+	u64		rate_ns;
+	u64		rate_bps;
+	u16		rate_flags;
+	s16		rate_overhead;
+	u16		rate_mpu;
+	u64		interval;
+	u64		target;
+
+	/* resource tracking */
+	u32		buffer_used;
+	u32		buffer_max_used;
+	u32		buffer_limit;
+	u32		buffer_config_limit;
+
+	/* indices for dequeue */
+	u16		cur_tin;
+	u16		cur_flow;
+
+	struct qdisc_watchdog watchdog;
+	const u8	*tin_index;
+	const u8	*tin_order;
+
+	/* bandwidth capacity estimate */
+	ktime_t		last_packet_time;
+	ktime_t		avg_window_begin;
+	u64		avg_packet_interval;
+	u64		avg_window_bytes;
+	u64		avg_peak_bandwidth;
+	ktime_t		last_reconfig_time;
+
+	/* packet length stats */
+	u32		avg_netoff;
+	u16		max_netlen;
+	u16		max_adjlen;
+	u16		min_netlen;
+	u16		min_adjlen;
+};
+
+enum {
+	CAKE_FLAG_OVERHEAD	   = BIT(0),
+	CAKE_FLAG_AUTORATE_INGRESS = BIT(1),
+	CAKE_FLAG_INGRESS	   = BIT(2),
+	CAKE_FLAG_WASH		   = BIT(3),
+	CAKE_FLAG_SPLIT_GSO	   = BIT(4)
+};
+
+/* COBALT operates the Codel and BLUE algorithms in parallel, in order to
+ * obtain the best features of each.  Codel is excellent on flows which
+ * respond to congestion signals in a TCP-like way.  BLUE is more effective on
+ * unresponsive flows.
+ */
+
+struct cobalt_skb_cb {
+	ktime_t enqueue_time;
+};
+
+static u64 us_to_ns(u64 us)
+{
+	return us * NSEC_PER_USEC;
+}
+
+static struct cobalt_skb_cb *get_cobalt_cb(const struct sk_buff *skb)
+{
+	qdisc_cb_private_validate(skb, sizeof(struct cobalt_skb_cb));
+	return (struct cobalt_skb_cb *)qdisc_skb_cb(skb)->data;
+}
+
+static ktime_t cobalt_get_enqueue_time(const struct sk_buff *skb)
+{
+	return get_cobalt_cb(skb)->enqueue_time;
+}
+
+static void cobalt_set_enqueue_time(struct sk_buff *skb,
+				    ktime_t now)
+{
+	get_cobalt_cb(skb)->enqueue_time = now;
+}
+
+static u16 quantum_div[CAKE_QUEUES + 1] = {0};
+
+#define REC_INV_SQRT_CACHE (16)
+static u32 cobalt_rec_inv_sqrt_cache[REC_INV_SQRT_CACHE] = {0};
+
+/* http://en.wikipedia.org/wiki/Methods_of_computing_square_roots
+ * new_invsqrt = (invsqrt / 2) * (3 - count * invsqrt^2)
+ *
+ * Here, invsqrt is a fixed point number (< 1.0), 32bit mantissa, aka Q0.32
+ */
+
+static void cobalt_newton_step(struct cobalt_vars *vars)
+{
+	u32 invsqrt, invsqrt2;
+	u64 val;
+
+	invsqrt = vars->rec_inv_sqrt;
+	invsqrt2 = ((u64)invsqrt * invsqrt) >> 32;
+	val = (3LL << 32) - ((u64)vars->count * invsqrt2);
+
+	val >>= 2; /* avoid overflow in following multiply */
+	val = (val * invsqrt) >> (32 - 2 + 1);
+
+	vars->rec_inv_sqrt = val;
+}
+
+static void cobalt_invsqrt(struct cobalt_vars *vars)
+{
+	if (vars->count < REC_INV_SQRT_CACHE)
+		vars->rec_inv_sqrt = cobalt_rec_inv_sqrt_cache[vars->count];
+	else
+		cobalt_newton_step(vars);
+}
+
+/* There is a big difference in timing between the accurate values placed in
+ * the cache and the approximations given by a single Newton step for small
+ * count values, particularly when stepping from count 1 to 2 or vice versa.
+ * Above 16, a single Newton step gives sufficient accuracy in either
+ * direction, given the precision stored.
+ *
+ * The magnitude of the error when stepping up to count 2 is such as to give
+ * the value that *should* have been produced at count 4.
+ */
+
+static void cobalt_cache_init(void)
+{
+	struct cobalt_vars v;
+
+	memset(&v, 0, sizeof(v));
+	v.rec_inv_sqrt = ~0U;
+	cobalt_rec_inv_sqrt_cache[0] = v.rec_inv_sqrt;
+
+	for (v.count = 1; v.count < REC_INV_SQRT_CACHE; v.count++) {
+		cobalt_newton_step(&v);
+		cobalt_newton_step(&v);
+		cobalt_newton_step(&v);
+		cobalt_newton_step(&v);
+
+		cobalt_rec_inv_sqrt_cache[v.count] = v.rec_inv_sqrt;
+	}
+}
+
+static void cobalt_vars_init(struct cobalt_vars *vars)
+{
+	memset(vars, 0, sizeof(*vars));
+
+	if (!cobalt_rec_inv_sqrt_cache[0]) {
+		cobalt_cache_init();
+		cobalt_rec_inv_sqrt_cache[0] = ~0;
+	}
+}
+
+/* CoDel control_law is t + interval/sqrt(count)
+ * We maintain in rec_inv_sqrt the reciprocal value of sqrt(count) to avoid
+ * both sqrt() and divide operation.
+ */
+static ktime_t cobalt_control(ktime_t t,
+			      u64 interval,
+			      u32 rec_inv_sqrt)
+{
+	return ktime_add_ns(t, reciprocal_scale(interval,
+						rec_inv_sqrt));
+}
+
+/* Call this when a packet had to be dropped due to queue overflow.  Returns
+ * true if the BLUE state was quiescent before but active after this call.
+ */
+static bool cobalt_queue_full(struct cobalt_vars *vars,
+			      struct cobalt_params *p,
+			      ktime_t now)
+{
+	bool up = false;
+
+	if (ktime_to_ns(ktime_sub(now, vars->blue_timer)) > p->target) {
+		up = !vars->p_drop;
+		vars->p_drop += p->p_inc;
+		if (vars->p_drop < p->p_inc)
+			vars->p_drop = ~0;
+		vars->blue_timer = now;
+	}
+	vars->dropping = true;
+	vars->drop_next = now;
+	if (!vars->count)
+		vars->count = 1;
+
+	return up;
+}
+
+/* Call this when the queue was serviced but turned out to be empty.  Returns
+ * true if the BLUE state was active before but quiescent after this call.
+ */
+static bool cobalt_queue_empty(struct cobalt_vars *vars,
+			       struct cobalt_params *p,
+			       ktime_t now)
+{
+	bool down = false;
+
+	if (vars->p_drop &&
+	    ktime_to_ns(ktime_sub(now, vars->blue_timer)) > p->target) {
+		if (vars->p_drop < p->p_dec)
+			vars->p_drop = 0;
+		else
+			vars->p_drop -= p->p_dec;
+		vars->blue_timer = now;
+		down = !vars->p_drop;
+	}
+	vars->dropping = false;
+
+	if (vars->count && ktime_to_ns(ktime_sub(now, vars->drop_next)) >= 0) {
+		vars->count--;
+		cobalt_invsqrt(vars);
+		vars->drop_next = cobalt_control(vars->drop_next,
+						 p->interval,
+						 vars->rec_inv_sqrt);
+	}
+
+	return down;
+}
+
+/* Call this with a freshly dequeued packet for possible congestion marking.
+ * Returns true as an instruction to drop the packet, false for delivery.
+ */
+static bool cobalt_should_drop(struct cobalt_vars *vars,
+			       struct cobalt_params *p,
+			       ktime_t now,
+			       struct sk_buff *skb)
+{
+	bool next_due, over_target, drop = false;
+	ktime_t schedule;
+	u64 sojourn;
+
+/* The 'schedule' variable records, in its sign, whether 'now' is before or
+ * after 'drop_next'.  This allows 'drop_next' to be updated before the next
+ * scheduling decision is actually branched, without destroying that
+ * information.  Similarly, the first 'schedule' value calculated is preserved
+ * in the boolean 'next_due'.
+ *
+ * As for 'drop_next', we take advantage of the fact that 'interval' is both
+ * the delay between first exceeding 'target' and the first signalling event,
+ * *and* the scaling factor for the signalling frequency.  It's therefore very
+ * natural to use a single mechanism for both purposes, and eliminates a
+ * significant amount of reference Codel's spaghetti code.  To help with this,
+ * both the '0' and '1' entries in the invsqrt cache are 0xFFFFFFFF, as close
+ * as possible to 1.0 in fixed-point.
+ */
+
+	sojourn = ktime_to_ns(ktime_sub(now, cobalt_get_enqueue_time(skb)));
+	schedule = ktime_sub(now, vars->drop_next);
+	over_target = sojourn > p->target &&
+		      sojourn > p->mtu_time * 4;
+	next_due = vars->count && ktime_to_ns(schedule) >= 0;
+
+	vars->ecn_marked = false;
+
+	if (over_target) {
+		if (!vars->dropping) {
+			vars->dropping = true;
+			vars->drop_next = cobalt_control(now,
+							 p->interval,
+							 vars->rec_inv_sqrt);
+		}
+		if (!vars->count)
+			vars->count = 1;
+	} else if (vars->dropping) {
+		vars->dropping = false;
+	}
+
+	if (next_due && vars->dropping) {
+		/* Use ECN mark if possible, otherwise drop */
+		drop = !(vars->ecn_marked = INET_ECN_set_ce(skb));
+
+		vars->count++;
+		if (!vars->count)
+			vars->count--;
+		cobalt_invsqrt(vars);
+		vars->drop_next = cobalt_control(vars->drop_next,
+						 p->interval,
+						 vars->rec_inv_sqrt);
+		schedule = ktime_sub(now, vars->drop_next);
+	} else {
+		while (next_due) {
+			vars->count--;
+			cobalt_invsqrt(vars);
+			vars->drop_next = cobalt_control(vars->drop_next,
+							 p->interval,
+							 vars->rec_inv_sqrt);
+			schedule = ktime_sub(now, vars->drop_next);
+			next_due = vars->count && ktime_to_ns(schedule) >= 0;
+		}
+	}
+
+	/* Simple BLUE implementation.  Lack of ECN is deliberate. */
+	if (vars->p_drop)
+		drop |= (prandom_u32() < vars->p_drop);
+
+	/* Overload the drop_next field as an activity timeout */
+	if (!vars->count)
+		vars->drop_next = ktime_add_ns(now, p->interval);
+	else if (ktime_to_ns(schedule) > 0 && !drop)
+		vars->drop_next = now;
+
+	return drop;
+}
+
+/* Cake has several subtle multiple bit settings. In these cases you
+ *  would be matching triple isolate mode as well.
+ */
+
+static bool cake_dsrc(int flow_mode)
+{
+	return (flow_mode & CAKE_FLOW_DUAL_SRC) == CAKE_FLOW_DUAL_SRC;
+}
+
+static bool cake_ddst(int flow_mode)
+{
+	return (flow_mode & CAKE_FLOW_DUAL_DST) == CAKE_FLOW_DUAL_DST;
+}
+
+static u32 cake_hash(struct cake_tin_data *q, const struct sk_buff *skb,
+		     int flow_mode)
+{
+	u32 flow_hash = 0, srchost_hash, dsthost_hash;
+	u16 reduced_hash, srchost_idx, dsthost_idx;
+	struct flow_keys keys, host_keys;
+
+	if (unlikely(flow_mode == CAKE_FLOW_NONE))
+		return 0;
+
+	skb_flow_dissect_flow_keys(skb, &keys,
+				   FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
+
+	/* flow_hash_from_keys() sorts the addresses by value, so we have
+	 * to preserve their order in a separate data structure to treat
+	 * src and dst host addresses as independently selectable.
+	 */
+	host_keys = keys;
+	host_keys.ports.ports     = 0;
+	host_keys.basic.ip_proto  = 0;
+	host_keys.keyid.keyid     = 0;
+	host_keys.tags.flow_label = 0;
+
+	switch (host_keys.control.addr_type) {
+	case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
+		host_keys.addrs.v4addrs.src = 0;
+		dsthost_hash = flow_hash_from_keys(&host_keys);
+		host_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
+		host_keys.addrs.v4addrs.dst = 0;
+		srchost_hash = flow_hash_from_keys(&host_keys);
+		break;
+
+	case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
+		memset(&host_keys.addrs.v6addrs.src, 0,
+		       sizeof(host_keys.addrs.v6addrs.src));
+		dsthost_hash = flow_hash_from_keys(&host_keys);
+		host_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
+		memset(&host_keys.addrs.v6addrs.dst, 0,
+		       sizeof(host_keys.addrs.v6addrs.dst));
+		srchost_hash = flow_hash_from_keys(&host_keys);
+		break;
+
+	default:
+		dsthost_hash = 0;
+		srchost_hash = 0;
+	}
+
+	/* This *must* be after the above switch, since as a
+	 * side-effect it sorts the src and dst addresses.
+	 */
+	if (flow_mode & CAKE_FLOW_FLOWS)
+		flow_hash = flow_hash_from_keys(&keys);
+
+	if (!(flow_mode & CAKE_FLOW_FLOWS)) {
+		if (flow_mode & CAKE_FLOW_SRC_IP)
+			flow_hash ^= srchost_hash;
+
+		if (flow_mode & CAKE_FLOW_DST_IP)
+			flow_hash ^= dsthost_hash;
+	}
+
+	reduced_hash = flow_hash % CAKE_QUEUES;
+
+	/* set-associative hashing */
+	/* fast path if no hash collision (direct lookup succeeds) */
+	if (likely(q->tags[reduced_hash] == flow_hash &&
+		   q->flows[reduced_hash].set)) {
+		q->way_directs++;
+	} else {
+		u32 inner_hash = reduced_hash % CAKE_SET_WAYS;
+		u32 outer_hash = reduced_hash - inner_hash;
+		bool allocate_src = false;
+		bool allocate_dst = false;
+		u32 i, k;
+
+		/* check if any active queue in the set is reserved for
+		 * this flow.
+		 */
+		for (i = 0, k = inner_hash; i < CAKE_SET_WAYS;
+		     i++, k = (k + 1) % CAKE_SET_WAYS) {
+			if (q->tags[outer_hash + k] == flow_hash) {
+				if (i)
+					q->way_hits++;
+
+				if (!q->flows[outer_hash + k].set) {
+					/* need to increment host refcnts */
+					allocate_src = cake_dsrc(flow_mode);
+					allocate_dst = cake_ddst(flow_mode);
+				}
+
+				goto found;
+			}
+		}
+
+		/* no queue is reserved for this flow, look for an
+		 * empty one.
+		 */
+		for (i = 0; i < CAKE_SET_WAYS;
+			 i++, k = (k + 1) % CAKE_SET_WAYS) {
+			if (!q->flows[outer_hash + k].set) {
+				q->way_misses++;
+				allocate_src = cake_dsrc(flow_mode);
+				allocate_dst = cake_ddst(flow_mode);
+				goto found;
+			}
+		}
+
+		/* With no empty queues, default to the original
+		 * queue, accept the collision, update the host tags.
+		 */
+		q->way_collisions++;
+		q->hosts[q->flows[reduced_hash].srchost].srchost_refcnt--;
+		q->hosts[q->flows[reduced_hash].dsthost].dsthost_refcnt--;
+		allocate_src = cake_dsrc(flow_mode);
+		allocate_dst = cake_ddst(flow_mode);
+found:
+		/* reserve queue for future packets in same flow */
+		reduced_hash = outer_hash + k;
+		q->tags[reduced_hash] = flow_hash;
+
+		if (allocate_src) {
+			srchost_idx = srchost_hash % CAKE_QUEUES;
+			inner_hash = srchost_idx % CAKE_SET_WAYS;
+			outer_hash = srchost_idx - inner_hash;
+			for (i = 0, k = inner_hash; i < CAKE_SET_WAYS;
+				i++, k = (k + 1) % CAKE_SET_WAYS) {
+				if (q->hosts[outer_hash + k].srchost_tag ==
+				    srchost_hash)
+					goto found_src;
+			}
+			for (i = 0; i < CAKE_SET_WAYS;
+				i++, k = (k + 1) % CAKE_SET_WAYS) {
+				if (!q->hosts[outer_hash + k].srchost_refcnt)
+					break;
+			}
+			q->hosts[outer_hash + k].srchost_tag = srchost_hash;
+found_src:
+			srchost_idx = outer_hash + k;
+			q->hosts[srchost_idx].srchost_refcnt++;
+			q->flows[reduced_hash].srchost = srchost_idx;
+		}
+
+		if (allocate_dst) {
+			dsthost_idx = dsthost_hash % CAKE_QUEUES;
+			inner_hash = dsthost_idx % CAKE_SET_WAYS;
+			outer_hash = dsthost_idx - inner_hash;
+			for (i = 0, k = inner_hash; i < CAKE_SET_WAYS;
+			     i++, k = (k + 1) % CAKE_SET_WAYS) {
+				if (q->hosts[outer_hash + k].dsthost_tag ==
+				    dsthost_hash)
+					goto found_dst;
+			}
+			for (i = 0; i < CAKE_SET_WAYS;
+			     i++, k = (k + 1) % CAKE_SET_WAYS) {
+				if (!q->hosts[outer_hash + k].dsthost_refcnt)
+					break;
+			}
+			q->hosts[outer_hash + k].dsthost_tag = dsthost_hash;
+found_dst:
+			dsthost_idx = outer_hash + k;
+			q->hosts[dsthost_idx].dsthost_refcnt++;
+			q->flows[reduced_hash].dsthost = dsthost_idx;
+		}
+	}
+
+	return reduced_hash;
+}
+
+static u32 cake_classify(struct Qdisc *sch, struct cake_tin_data *t,
+			 struct sk_buff *skb, int flow_mode, int *qerr)
+{
+	struct cake_sched_data *q = qdisc_priv(sch);
+	struct tcf_proto *filter;
+	struct tcf_result res;
+	int result;
+
+	filter = rcu_dereference_bh(q->filter_list);
+	if (!filter)
+		return cake_hash(t, skb, flow_mode) + 1;
+
+	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
+	result = tcf_classify(skb, filter, &res, false);
+	if (result >= 0) {
+#ifdef CONFIG_NET_CLS_ACT
+		switch (result) {
+		case TC_ACT_STOLEN:
+		case TC_ACT_QUEUED:
+		case TC_ACT_TRAP:
+			*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
+			/* fall through */
+		case TC_ACT_SHOT:
+			return 0;
+		}
+#endif
+		if (TC_H_MIN(res.classid) <= CAKE_QUEUES)
+			return TC_H_MIN(res.classid);
+	}
+	return 0;
+}
+
+/* helper functions : might be changed when/if skb use a standard list_head */
+/* remove one skb from head of slot queue */
+
+static struct sk_buff *dequeue_head(struct cake_flow *flow)
+{
+	struct sk_buff *skb = flow->head;
+
+	if (skb) {
+		flow->head = skb->next;
+		skb->next = NULL;
+	}
+
+	return skb;
+}
+
+/* add skb to flow queue (tail add) */
+
+static void flow_queue_add(struct cake_flow *flow, struct sk_buff *skb)
+{
+	if (!flow->head)
+		flow->head = skb;
+	else
+		flow->tail->next = skb;
+	flow->tail = skb;
+	skb->next = NULL;
+}
+
+static u64 cake_ewma(u64 avg, u64 sample, u32 shift)
+{
+	avg -= avg >> shift;
+	avg += sample >> shift;
+	return avg;
+}
+
+static void cake_heap_swap(struct cake_sched_data *q, u16 i, u16 j)
+{
+	struct cake_heap_entry ii = q->overflow_heap[i];
+	struct cake_heap_entry jj = q->overflow_heap[j];
+
+	q->overflow_heap[i] = jj;
+	q->overflow_heap[j] = ii;
+
+	q->tins[ii.t].overflow_idx[ii.b] = j;
+	q->tins[jj.t].overflow_idx[jj.b] = i;
+}
+
+static u32 cake_heap_get_backlog(const struct cake_sched_data *q, u16 i)
+{
+	struct cake_heap_entry ii = q->overflow_heap[i];
+
+	return q->tins[ii.t].backlogs[ii.b];
+}
+
+static void cake_heapify(struct cake_sched_data *q, u16 i)
+{
+	static const u32 a = CAKE_MAX_TINS * CAKE_QUEUES;
+	u32 mb = cake_heap_get_backlog(q, i);
+	u32 m = i;
+
+	while (m < a) {
+		u32 l = m + m + 1;
+		u32 r = l + 1;
+
+		if (l < a) {
+			u32 lb = cake_heap_get_backlog(q, l);
+
+			if (lb > mb) {
+				m  = l;
+				mb = lb;
+			}
+		}
+
+		if (r < a) {
+			u32 rb = cake_heap_get_backlog(q, r);
+
+			if (rb > mb) {
+				m  = r;
+				mb = rb;
+			}
+		}
+
+		if (m != i) {
+			cake_heap_swap(q, i, m);
+			i = m;
+		} else {
+			break;
+		}
+	}
+}
+
+static void cake_heapify_up(struct cake_sched_data *q, u16 i)
+{
+	while (i > 0 && i < CAKE_MAX_TINS * CAKE_QUEUES) {
+		u16 p = (i - 1) >> 1;
+		u32 ib = cake_heap_get_backlog(q, i);
+		u32 pb = cake_heap_get_backlog(q, p);
+
+		if (ib > pb) {
+			cake_heap_swap(q, i, p);
+			i = p;
+		} else {
+			break;
+		}
+	}
+}
+
+static int cake_advance_shaper(struct cake_sched_data *q,
+			       struct cake_tin_data *b,
+			       struct sk_buff *skb,
+			       ktime_t now, bool drop)
+{
+	u32 len = qdisc_pkt_len(skb);
+
+	/* charge packet bandwidth to this tin
+	 * and to the global shaper.
+	 */
+	if (q->rate_ns) {
+		u64 tin_dur = (len * b->tin_rate_ns) >> b->tin_rate_shft;
+		u64 global_dur = (len * q->rate_ns) >> q->rate_shft;
+		u64 failsafe_dur = global_dur + (global_dur >> 1);
+
+		if (ktime_before(b->time_next_packet, now))
+			b->time_next_packet = ktime_add_ns(b->time_next_packet,
+							   tin_dur);
+
+		else if (ktime_before(b->time_next_packet,
+				      ktime_add_ns(now, tin_dur)))
+			b->time_next_packet = ktime_add_ns(now, tin_dur);
+
+		q->time_next_packet = ktime_add_ns(q->time_next_packet,
+						   global_dur);
+		if (!drop)
+			q->failsafe_next_packet = \
+				ktime_add_ns(q->failsafe_next_packet,
+					     failsafe_dur);
+	}
+	return len;
+}
+
+static unsigned int cake_drop(struct Qdisc *sch, struct sk_buff **to_free)
+{
+	struct cake_sched_data *q = qdisc_priv(sch);
+	ktime_t now = ktime_get();
+	u32 idx = 0, tin = 0, len;
+	struct cake_heap_entry qq;
+	struct cake_tin_data *b;
+	struct cake_flow *flow;
+	struct sk_buff *skb;
+
+	if (!q->overflow_timeout) {
+		int i;
+		/* Build fresh max-heap */
+		for (i = CAKE_MAX_TINS * CAKE_QUEUES / 2; i >= 0; i--)
+			cake_heapify(q, i);
+	}
+	q->overflow_timeout = 65535;
+
+	/* select longest queue for pruning */
+	qq  = q->overflow_heap[0];
+	tin = qq.t;
+	idx = qq.b;
+
+	b = &q->tins[tin];
+	flow = &b->flows[idx];
+	skb = dequeue_head(flow);
+	if (unlikely(!skb)) {
+		/* heap has gone wrong, rebuild it next time */
+		q->overflow_timeout = 0;
+		return idx + (tin << 16);
+	}
+
+	if (cobalt_queue_full(&flow->cvars, &b->cparams, now))
+		b->unresponsive_flow_count++;
+
+	len = qdisc_pkt_len(skb);
+	q->buffer_used      -= skb->truesize;
+	b->backlogs[idx]    -= len;
+	b->tin_backlog      -= len;
+	sch->qstats.backlog -= len;
+	qdisc_tree_reduce_backlog(sch, 1, len);
+
+	flow->dropped++;
+	b->tin_dropped++;
+	sch->qstats.drops++;
+
+	__qdisc_drop(skb, to_free);
+	sch->q.qlen--;
+
+	cake_heapify(q, 0);
+
+	return idx + (tin << 16);
+}
+
+static void cake_reconfigure(struct Qdisc *sch);
+
+static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
+			struct sk_buff **to_free)
+{
+	struct cake_sched_data *q = qdisc_priv(sch);
+	int len = qdisc_pkt_len(skb);
+	int uninitialized_var(ret);
+	ktime_t now = ktime_get();
+	struct cake_tin_data *b;
+	struct cake_flow *flow;
+	u32 idx, tin;
+
+	tin = 0;
+	b = &q->tins[tin];
+
+	/* choose flow to insert into */
+	idx = cake_classify(sch, b, skb, q->flow_mode, &ret);
+	if (idx == 0) {
+		if (ret & __NET_XMIT_BYPASS)
+			qdisc_qstats_drop(sch);
+		__qdisc_drop(skb, to_free);
+		return ret;
+	}
+	idx--;
+	flow = &b->flows[idx];
+
+	/* ensure shaper state isn't stale */
+	if (!b->tin_backlog) {
+		if (ktime_before(b->time_next_packet, now))
+			b->time_next_packet = now;
+
+		if (!sch->q.qlen) {
+			if (ktime_before(q->time_next_packet, now)) {
+				q->failsafe_next_packet = now;
+				q->time_next_packet = now;
+			} else if (ktime_after(q->time_next_packet, now) &&
+				   ktime_after(q->failsafe_next_packet, now)) {
+				u64 next = \
+					min(ktime_to_ns(q->time_next_packet),
+					    ktime_to_ns(
+						   q->failsafe_next_packet));
+				sch->qstats.overlimits++;
+				qdisc_watchdog_schedule_ns(&q->watchdog, next);
+			}
+		}
+	}
+
+	if (unlikely(len > b->max_skblen))
+		b->max_skblen = len;
+
+	cobalt_set_enqueue_time(skb, now);
+	flow_queue_add(flow, skb);
+
+	sch->q.qlen++;
+	q->buffer_used      += skb->truesize;
+
+	/* stats */
+	b->packets++;
+	b->bytes	    += len;
+	b->backlogs[idx]    += len;
+	b->tin_backlog      += len;
+	sch->qstats.backlog += len;
+	q->avg_window_bytes += len;
+
+	if (q->overflow_timeout)
+		cake_heapify_up(q, b->overflow_idx[idx]);
+
+	/* incoming bandwidth capacity estimate */
+	q->avg_window_bytes = 0;
+	q->last_packet_time = now;
+
+	/* flowchain */
+	if (!flow->set || flow->set == CAKE_SET_DECAYING) {
+		struct cake_host *srchost = &b->hosts[flow->srchost];
+		struct cake_host *dsthost = &b->hosts[flow->dsthost];
+		u16 host_load = 1;
+
+		if (!flow->set) {
+			list_add_tail(&flow->flowchain, &b->new_flows);
+		} else {
+			b->decaying_flow_count--;
+			list_move_tail(&flow->flowchain, &b->new_flows);
+		}
+		flow->set = CAKE_SET_SPARSE;
+		b->sparse_flow_count++;
+
+		if (cake_dsrc(q->flow_mode))
+			host_load = max(host_load, srchost->srchost_refcnt);
+
+		if (cake_ddst(q->flow_mode))
+			host_load = max(host_load, dsthost->dsthost_refcnt);
+
+		flow->deficit = (b->flow_quantum *
+				 quantum_div[host_load]) >> 16;
+	} else if (flow->set == CAKE_SET_SPARSE_WAIT) {
+		/* this flow was empty, accounted as a sparse flow, but actually
+		 * in the bulk rotation.
+		 */
+		flow->set = CAKE_SET_BULK;
+		b->sparse_flow_count--;
+		b->bulk_flow_count++;
+	}
+
+	if (q->buffer_used > q->buffer_max_used)
+		q->buffer_max_used = q->buffer_used;
+
+	if (q->buffer_used > q->buffer_limit) {
+		u32 dropped = 0;
+
+		while (q->buffer_used > q->buffer_limit) {
+			dropped++;
+			cake_drop(sch, to_free);
+		}
+		b->drop_overlimit += dropped;
+	}
+	return NET_XMIT_SUCCESS;
+}
+
+static struct sk_buff *cake_dequeue_one(struct Qdisc *sch)
+{
+	struct cake_sched_data *q = qdisc_priv(sch);
+	struct cake_tin_data *b = &q->tins[q->cur_tin];
+	struct cake_flow *flow = &b->flows[q->cur_flow];
+	struct sk_buff *skb = NULL;
+	u32 len;
+
+	if (flow->head) {
+		skb = dequeue_head(flow);
+		len = qdisc_pkt_len(skb);
+		b->backlogs[q->cur_flow] -= len;
+		b->tin_backlog		 -= len;
+		sch->qstats.backlog      -= len;
+		q->buffer_used		 -= skb->truesize;
+		sch->q.qlen--;
+
+		if (q->overflow_timeout)
+			cake_heapify(q, b->overflow_idx[q->cur_flow]);
+	}
+	return skb;
+}
+
+/* Discard leftover packets from a tin no longer in use. */
+static void cake_clear_tin(struct Qdisc *sch, u16 tin)
+{
+	struct cake_sched_data *q = qdisc_priv(sch);
+	struct sk_buff *skb;
+
+	q->cur_tin = tin;
+	for (q->cur_flow = 0; q->cur_flow < CAKE_QUEUES; q->cur_flow++)
+		while (!!(skb = cake_dequeue_one(sch)))
+			kfree_skb(skb);
+}
+
+static struct sk_buff *cake_dequeue(struct Qdisc *sch)
+{
+	struct cake_sched_data *q = qdisc_priv(sch);
+	struct cake_tin_data *b = &q->tins[q->cur_tin];
+	struct cake_host *srchost, *dsthost;
+	ktime_t now = ktime_get();
+	struct cake_flow *flow;
+	struct list_head *head;
+	bool first_flow = true;
+	struct sk_buff *skb;
+	u16 host_load;
+	u64 delay;
+	u32 len;
+
+begin:
+	if (!sch->q.qlen)
+		return NULL;
+
+	/* global hard shaper */
+	if (ktime_after(q->time_next_packet, now) &&
+	    ktime_after(q->failsafe_next_packet, now)) {
+		u64 next = min(ktime_to_ns(q->time_next_packet),
+			       ktime_to_ns(q->failsafe_next_packet));
+
+		sch->qstats.overlimits++;
+		qdisc_watchdog_schedule_ns(&q->watchdog, next);
+		return NULL;
+	}
+
+	/* Choose a class to work on. */
+	if (!q->rate_ns) {
+		/* In unlimited mode, can't rely on shaper timings, just balance
+		 * with DRR
+		 */
+		while (b->tin_deficit < 0 ||
+		       !(b->sparse_flow_count + b->bulk_flow_count)) {
+			if (b->tin_deficit <= 0)
+				b->tin_deficit += b->tin_quantum_band;
+
+			q->cur_tin++;
+			b++;
+			if (q->cur_tin >= q->tin_cnt) {
+				q->cur_tin = 0;
+				b = q->tins;
+			}
+		}
+	} else {
+		/* In shaped mode, choose:
+		 * - Highest-priority tin with queue and meeting schedule, or
+		 * - The earliest-scheduled tin with queue.
+		 */
+		ktime_t best_time = KTIME_MAX;
+		int tin, best_tin = 0;
+
+		for (tin = 0; tin < q->tin_cnt; tin++) {
+			b = q->tins + tin;
+			if ((b->sparse_flow_count + b->bulk_flow_count) > 0) {
+				ktime_t time_to_pkt = \
+					ktime_sub(b->time_next_packet, now);
+
+				if (ktime_to_ns(time_to_pkt) <= 0 ||
+				    ktime_compare(time_to_pkt,
+						  best_time) <= 0) {
+					best_time = time_to_pkt;
+					best_tin = tin;
+				}
+			}
+		}
+
+		q->cur_tin = best_tin;
+		b = q->tins + best_tin;
+	}
+
+retry:
+	/* service this class */
+	head = &b->decaying_flows;
+	if (!first_flow || list_empty(head)) {
+		head = &b->new_flows;
+		if (list_empty(head)) {
+			head = &b->old_flows;
+			if (unlikely(list_empty(head))) {
+				head = &b->decaying_flows;
+				if (unlikely(list_empty(head)))
+					goto begin;
+			}
+		}
+	}
+	flow = list_first_entry(head, struct cake_flow, flowchain);
+	q->cur_flow = flow - b->flows;
+	first_flow = false;
+
+	/* triple isolation (modified DRR++) */
+	srchost = &b->hosts[flow->srchost];
+	dsthost = &b->hosts[flow->dsthost];
+	host_load = 1;
+
+	if (cake_dsrc(q->flow_mode))
+		host_load = max(host_load, srchost->srchost_refcnt);
+
+	if (cake_ddst(q->flow_mode))
+		host_load = max(host_load, dsthost->dsthost_refcnt);
+
+	WARN_ON(host_load > CAKE_QUEUES);
+
+	/* flow isolation (DRR++) */
+	if (flow->deficit <= 0) {
+		/* The shifted prandom_u32() is a way to apply dithering to
+		 * avoid accumulating roundoff errors
+		 */
+		flow->deficit += (b->flow_quantum * quantum_div[host_load] +
+				  (prandom_u32() >> 16)) >> 16;
+		list_move_tail(&flow->flowchain, &b->old_flows);
+
+		/* Keep all flows with deficits out of the sparse and decaying
+		 * rotations.  No non-empty flow can go into the decaying
+		 * rotation, so they can't get deficits
+		 */
+		if (flow->set == CAKE_SET_SPARSE) {
+			if (flow->head) {
+				b->sparse_flow_count--;
+				b->bulk_flow_count++;
+				flow->set = CAKE_SET_BULK;
+			} else {
+				/* we've moved it to the bulk rotation for
+				 * correct deficit accounting but we still want
+				 * to count it as a sparse flow, not a bulk one.
+				 */
+				flow->set = CAKE_SET_SPARSE_WAIT;
+			}
+		}
+		goto retry;
+	}
+
+	/* Retrieve a packet via the AQM */
+	while (1) {
+		skb = cake_dequeue_one(sch);
+		if (!skb) {
+			/* this queue was actually empty */
+			if (cobalt_queue_empty(&flow->cvars, &b->cparams, now))
+				b->unresponsive_flow_count--;
+
+			if (flow->cvars.p_drop || flow->cvars.count ||
+			    ktime_before(now, flow->cvars.drop_next)) {
+				/* keep in the flowchain until the state has
+				 * decayed to rest
+				 */
+				list_move_tail(&flow->flowchain,
+					       &b->decaying_flows);
+				if (flow->set == CAKE_SET_BULK) {
+					b->bulk_flow_count--;
+					b->decaying_flow_count++;
+				} else if (flow->set == CAKE_SET_SPARSE ||
+					   flow->set == CAKE_SET_SPARSE_WAIT) {
+					b->sparse_flow_count--;
+					b->decaying_flow_count++;
+				}
+				flow->set = CAKE_SET_DECAYING;
+			} else {
+				/* remove empty queue from the flowchain */
+				list_del_init(&flow->flowchain);
+				if (flow->set == CAKE_SET_SPARSE ||
+				    flow->set == CAKE_SET_SPARSE_WAIT)
+					b->sparse_flow_count--;
+				else if (flow->set == CAKE_SET_BULK)
+					b->bulk_flow_count--;
+				else
+					b->decaying_flow_count--;
+
+				flow->set = CAKE_SET_NONE;
+				srchost->srchost_refcnt--;
+				dsthost->dsthost_refcnt--;
+			}
+			goto begin;
+		}
+
+		/* Last packet in queue may be marked, shouldn't be dropped */
+		if (!cobalt_should_drop(&flow->cvars, &b->cparams, now, skb) ||
+		    !flow->head)
+			break;
+
+		flow->dropped++;
+		b->tin_dropped++;
+		qdisc_tree_reduce_backlog(sch, 1, qdisc_pkt_len(skb));
+		qdisc_qstats_drop(sch);
+		kfree_skb(skb);
+	}
+
+	b->tin_ecn_mark += !!flow->cvars.ecn_marked;
+	qdisc_bstats_update(sch, skb);
+
+	/* collect delay stats */
+	delay = ktime_to_ns(ktime_sub(now, cobalt_get_enqueue_time(skb)));
+	b->avge_delay = cake_ewma(b->avge_delay, delay, 8);
+	b->peak_delay = cake_ewma(b->peak_delay, delay,
+				  delay > b->peak_delay ? 2 : 8);
+	b->base_delay = cake_ewma(b->base_delay, delay,
+				  delay < b->base_delay ? 2 : 8);
+
+	len = cake_advance_shaper(q, b, skb, now, false);
+	flow->deficit -= len;
+	b->tin_deficit -= len;
+
+	if (ktime_after(q->time_next_packet, now) && sch->q.qlen) {
+		u64 next = min(ktime_to_ns(q->time_next_packet),
+			       ktime_to_ns(q->failsafe_next_packet));
+
+		qdisc_watchdog_schedule_ns(&q->watchdog, next);
+	} else if (!sch->q.qlen) {
+		int i;
+
+		for (i = 0; i < q->tin_cnt; i++) {
+			if (q->tins[i].decaying_flow_count) {
+				ktime_t next = \
+					ktime_add_ns(now,
+						     q->tins[i].cparams.target);
+
+				qdisc_watchdog_schedule_ns(&q->watchdog,
+							   ktime_to_ns(next));
+				break;
+			}
+		}
+	}
+
+	if (q->overflow_timeout)
+		q->overflow_timeout--;
+
+	return skb;
+}
+
+static void cake_reset(struct Qdisc *sch)
+{
+	u32 c;
+
+	for (c = 0; c < CAKE_MAX_TINS; c++)
+		cake_clear_tin(sch, c);
+}
+
+static const struct nla_policy cake_policy[TCA_CAKE_MAX + 1] = {
+	[TCA_CAKE_BASE_RATE64]   = { .type = NLA_U64 },
+	[TCA_CAKE_DIFFSERV_MODE] = { .type = NLA_U32 },
+	[TCA_CAKE_ATM]		 = { .type = NLA_U32 },
+	[TCA_CAKE_FLOW_MODE]     = { .type = NLA_U32 },
+	[TCA_CAKE_OVERHEAD]      = { .type = NLA_S32 },
+	[TCA_CAKE_RTT]		 = { .type = NLA_U32 },
+	[TCA_CAKE_TARGET]	 = { .type = NLA_U32 },
+	[TCA_CAKE_AUTORATE]      = { .type = NLA_U32 },
+	[TCA_CAKE_MEMORY]	 = { .type = NLA_U32 },
+	[TCA_CAKE_NAT]		 = { .type = NLA_U32 },
+	[TCA_CAKE_RAW]		 = { .type = NLA_U32 },
+	[TCA_CAKE_WASH]		 = { .type = NLA_U32 },
+	[TCA_CAKE_MPU]		 = { .type = NLA_U32 },
+	[TCA_CAKE_INGRESS]	 = { .type = NLA_U32 },
+	[TCA_CAKE_ACK_FILTER]	 = { .type = NLA_U32 },
+};
+
+static void cake_set_rate(struct cake_tin_data *b, u64 rate, u32 mtu,
+			  u64 target_ns, u64 rtt_est_ns)
+{
+	/* convert byte-rate into time-per-byte
+	 * so it will always unwedge in reasonable time.
+	 */
+	static const u64 MIN_RATE = 64;
+	u32 byte_target = mtu;
+	u64 byte_target_ns;
+	u8  rate_shft = 0;
+	u64 rate_ns = 0;
+
+	b->flow_quantum = 1514;
+	if (rate) {
+		b->flow_quantum = max(min(rate >> 12, 1514ULL), 300ULL);
+		rate_shft = 34;
+		rate_ns = ((u64)NSEC_PER_SEC) << rate_shft;
+		rate_ns = div64_u64(rate_ns, max(MIN_RATE, rate));
+		while (!!(rate_ns >> 34)) {
+			rate_ns >>= 1;
+			rate_shft--;
+		}
+	} /* else unlimited, ie. zero delay */
+
+	b->tin_rate_bps  = rate;
+	b->tin_rate_ns   = rate_ns;
+	b->tin_rate_shft = rate_shft;
+
+	byte_target_ns = (byte_target * rate_ns) >> rate_shft;
+
+	b->cparams.target = max((byte_target_ns * 3) / 2, target_ns);
+	b->cparams.interval = max(rtt_est_ns +
+				     b->cparams.target - target_ns,
+				     b->cparams.target * 2);
+	b->cparams.mtu_time = byte_target_ns;
+	b->cparams.p_inc = 1 << 24; /* 1/256 */
+	b->cparams.p_dec = 1 << 20; /* 1/4096 */
+}
+
+static void cake_reconfigure(struct Qdisc *sch)
+{
+	struct cake_sched_data *q = qdisc_priv(sch);
+	struct cake_tin_data *b = &q->tins[0];
+	int c, ft = 0;
+
+	q->tin_cnt = 1;
+	cake_set_rate(b, q->rate_bps, psched_mtu(qdisc_dev(sch)),
+		      us_to_ns(q->target), us_to_ns(q->interval));
+	b->tin_quantum_band = 65535;
+	b->tin_quantum_prio = 65535;
+
+	for (c = q->tin_cnt; c < CAKE_MAX_TINS; c++) {
+		cake_clear_tin(sch, c);
+		q->tins[c].cparams.mtu_time = q->tins[ft].cparams.mtu_time;
+	}
+
+	q->rate_ns   = q->tins[ft].tin_rate_ns;
+	q->rate_shft = q->tins[ft].tin_rate_shft;
+
+	if (q->buffer_config_limit) {
+		q->buffer_limit = q->buffer_config_limit;
+	} else if (q->rate_bps) {
+		u64 t = q->rate_bps * q->interval;
+
+		do_div(t, USEC_PER_SEC / 4);
+		q->buffer_limit = max_t(u32, t, 4U << 20);
+	} else {
+		q->buffer_limit = ~0;
+	}
+
+	sch->flags &= ~TCQ_F_CAN_BYPASS;
+
+	q->buffer_limit = min(q->buffer_limit,
+			      max(sch->limit * psched_mtu(qdisc_dev(sch)),
+				  q->buffer_config_limit));
+}
+
+static int cake_change(struct Qdisc *sch, struct nlattr *opt,
+		       struct netlink_ext_ack *extack)
+{
+	struct cake_sched_data *q = qdisc_priv(sch);
+	struct nlattr *tb[TCA_CAKE_MAX + 1];
+	int err;
+
+	if (!opt)
+		return -EINVAL;
+
+	err = nla_parse_nested(tb, TCA_CAKE_MAX, opt, cake_policy, extack);
+	if (err < 0)
+		return err;
+
+	if (tb[TCA_CAKE_BASE_RATE64])
+		q->rate_bps = nla_get_u64(tb[TCA_CAKE_BASE_RATE64]);
+
+	if (tb[TCA_CAKE_FLOW_MODE])
+		q->flow_mode = (nla_get_u32(tb[TCA_CAKE_FLOW_MODE]) &
+				CAKE_FLOW_MASK);
+
+	if (tb[TCA_CAKE_RTT]) {
+		q->interval = nla_get_u32(tb[TCA_CAKE_RTT]);
+
+		if (!q->interval)
+			q->interval = 1;
+	}
+
+	if (tb[TCA_CAKE_TARGET]) {
+		q->target = nla_get_u32(tb[TCA_CAKE_TARGET]);
+
+		if (!q->target)
+			q->target = 1;
+	}
+
+	if (tb[TCA_CAKE_MEMORY])
+		q->buffer_config_limit = nla_get_u32(tb[TCA_CAKE_MEMORY]);
+
+	if (q->tins) {
+		sch_tree_lock(sch);
+		cake_reconfigure(sch);
+		sch_tree_unlock(sch);
+	}
+
+	return 0;
+}
+
+static void cake_destroy(struct Qdisc *sch)
+{
+	struct cake_sched_data *q = qdisc_priv(sch);
+
+	qdisc_watchdog_cancel(&q->watchdog);
+	tcf_block_put(q->block);
+	kvfree(q->tins);
+}
+
+static int cake_init(struct Qdisc *sch, struct nlattr *opt,
+		     struct netlink_ext_ack *extack)
+{
+	struct cake_sched_data *q = qdisc_priv(sch);
+	int i, j, err;
+
+	sch->limit = 10240;
+	q->tin_mode = CAKE_DIFFSERV_BESTEFFORT;
+	q->flow_mode  = CAKE_FLOW_TRIPLE;
+
+	q->rate_bps = 0; /* unlimited by default */
+
+	q->interval = 100000; /* 100ms default */
+	q->target   =   5000; /* 5ms: codel RFC argues
+			       * for 5 to 10% of interval
+			       */
+
+	q->cur_tin = 0;
+	q->cur_flow  = 0;
+
+	if (opt) {
+		int err = cake_change(sch, opt, extack);
+
+		if (err)
+			return err;
+	}
+
+	err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
+	if (err)
+		return err;
+
+	qdisc_watchdog_init(&q->watchdog, sch);
+
+	quantum_div[0] = ~0;
+	for (i = 1; i <= CAKE_QUEUES; i++)
+		quantum_div[i] = 65535 / i;
+
+	q->tins = kvzalloc(CAKE_MAX_TINS * sizeof(struct cake_tin_data),
+			   GFP_KERNEL);
+	if (!q->tins)
+		goto nomem;
+
+	for (i = 0; i < CAKE_MAX_TINS; i++) {
+		struct cake_tin_data *b = q->tins + i;
+
+		INIT_LIST_HEAD(&b->new_flows);
+		INIT_LIST_HEAD(&b->old_flows);
+		INIT_LIST_HEAD(&b->decaying_flows);
+		b->sparse_flow_count = 0;
+		b->bulk_flow_count = 0;
+		b->decaying_flow_count = 0;
+
+		for (j = 0; j < CAKE_QUEUES; j++) {
+			struct cake_flow *flow = b->flows + j;
+			u32 k = j * CAKE_MAX_TINS + i;
+
+			INIT_LIST_HEAD(&flow->flowchain);
+			cobalt_vars_init(&flow->cvars);
+
+			q->overflow_heap[k].t = i;
+			q->overflow_heap[k].b = j;
+			b->overflow_idx[j] = k;
+		}
+	}
+
+	cake_reconfigure(sch);
+	q->avg_peak_bandwidth = q->rate_bps;
+	q->min_netlen = ~0;
+	q->min_adjlen = ~0;
+	return 0;
+
+nomem:
+	cake_destroy(sch);
+	return -ENOMEM;
+}
+
+static int cake_dump(struct Qdisc *sch, struct sk_buff *skb)
+{
+	struct cake_sched_data *q = qdisc_priv(sch);
+	struct nlattr *opts;
+
+	opts = nla_nest_start(skb, TCA_OPTIONS);
+	if (!opts)
+		goto nla_put_failure;
+
+	if (nla_put_u64_64bit(skb, TCA_CAKE_BASE_RATE64, q->rate_bps,
+			      TCA_CAKE_PAD))
+		goto nla_put_failure;
+
+	if (nla_put_u32(skb, TCA_CAKE_FLOW_MODE,
+			q->flow_mode & CAKE_FLOW_MASK))
+		goto nla_put_failure;
+
+	if (nla_put_u32(skb, TCA_CAKE_RTT, q->interval))
+		goto nla_put_failure;
+
+	if (nla_put_u32(skb, TCA_CAKE_TARGET, q->target))
+		goto nla_put_failure;
+
+	if (nla_put_u32(skb, TCA_CAKE_MEMORY, q->buffer_config_limit))
+		goto nla_put_failure;
+
+	return nla_nest_end(skb, opts);
+
+nla_put_failure:
+	return -1;
+}
+
+static int cake_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
+{
+	struct nlattr *stats = nla_nest_start(d->skb, TCA_STATS_APP);
+	struct cake_sched_data *q = qdisc_priv(sch);
+	struct nlattr *tstats, *ts;
+	int i;
+
+	if (!stats)
+		return -1;
+
+#define PUT_STAT_U32(attr, data) do {				       \
+		if (nla_put_u32(d->skb, TCA_CAKE_STATS_ ## attr, data)) \
+			goto nla_put_failure;			       \
+	} while (0)
+#define PUT_STAT_U64(attr, data) do {				       \
+		if (nla_put_u64_64bit(d->skb, TCA_CAKE_STATS_ ## attr, \
+					data, TCA_CAKE_STATS_PAD)) \
+			goto nla_put_failure;			       \
+	} while (0)
+
+	PUT_STAT_U64(CAPACITY_ESTIMATE64, q->avg_peak_bandwidth);
+	PUT_STAT_U32(MEMORY_LIMIT, q->buffer_limit);
+	PUT_STAT_U32(MEMORY_USED, q->buffer_max_used);
+	PUT_STAT_U32(AVG_NETOFF, ((q->avg_netoff + 0x8000) >> 16));
+	PUT_STAT_U32(MAX_NETLEN, q->max_netlen);
+	PUT_STAT_U32(MAX_ADJLEN, q->max_adjlen);
+	PUT_STAT_U32(MIN_NETLEN, q->min_netlen);
+	PUT_STAT_U32(MIN_ADJLEN, q->min_adjlen);
+
+#undef PUT_STAT_U32
+#undef PUT_STAT_U64
+
+	tstats = nla_nest_start(d->skb, TCA_CAKE_STATS_TIN_STATS);
+	if (!tstats)
+		goto nla_put_failure;
+
+#define PUT_TSTAT_U32(attr, data) do {					\
+		if (nla_put_u32(d->skb, TCA_CAKE_TIN_STATS_ ## attr, data)) \
+			goto nla_put_failure;				\
+	} while (0)
+#define PUT_TSTAT_U64(attr, data) do {					\
+		if (nla_put_u64_64bit(d->skb, TCA_CAKE_TIN_STATS_ ## attr, \
+					data, TCA_CAKE_TIN_STATS_PAD))	\
+			goto nla_put_failure;				\
+	} while (0)
+
+	for (i = 0; i < q->tin_cnt; i++) {
+		struct cake_tin_data *b = &q->tins[i];
+
+		ts = nla_nest_start(d->skb, i + 1);
+		if (!ts)
+			goto nla_put_failure;
+
+		PUT_TSTAT_U64(THRESHOLD_RATE64, b->tin_rate_bps);
+		PUT_TSTAT_U64(SENT_BYTES64, b->bytes);
+		PUT_TSTAT_U32(BACKLOG_BYTES, b->tin_backlog);
+
+		PUT_TSTAT_U32(TARGET_US,
+			      ktime_to_us(ns_to_ktime(b->cparams.target)));
+		PUT_TSTAT_U32(INTERVAL_US,
+			      ktime_to_us(ns_to_ktime(b->cparams.interval)));
+
+		PUT_TSTAT_U32(SENT_PACKETS, b->packets);
+		PUT_TSTAT_U32(DROPPED_PACKETS, b->tin_dropped);
+		PUT_TSTAT_U32(ECN_MARKED_PACKETS, b->tin_ecn_mark);
+		PUT_TSTAT_U32(ACKS_DROPPED_PACKETS, b->ack_drops);
+
+		PUT_TSTAT_U32(PEAK_DELAY_US,
+			      ktime_to_us(ns_to_ktime(b->peak_delay)));
+		PUT_TSTAT_U32(AVG_DELAY_US,
+			      ktime_to_us(ns_to_ktime(b->avge_delay)));
+		PUT_TSTAT_U32(BASE_DELAY_US,
+			      ktime_to_us(ns_to_ktime(b->base_delay)));
+
+		PUT_TSTAT_U32(WAY_INDIRECT_HITS, b->way_hits);
+		PUT_TSTAT_U32(WAY_MISSES, b->way_misses);
+		PUT_TSTAT_U32(WAY_COLLISIONS, b->way_collisions);
+
+		PUT_TSTAT_U32(SPARSE_FLOWS, b->sparse_flow_count +
+					    b->decaying_flow_count);
+		PUT_TSTAT_U32(BULK_FLOWS, b->bulk_flow_count);
+		PUT_TSTAT_U32(UNRESPONSIVE_FLOWS, b->unresponsive_flow_count);
+		PUT_TSTAT_U32(MAX_SKBLEN, b->max_skblen);
+
+		PUT_TSTAT_U32(FLOW_QUANTUM, b->flow_quantum);
+		nla_nest_end(d->skb, ts);
+	}
+
+#undef PUT_TSTAT_U32
+#undef PUT_TSTAT_U64
+
+	nla_nest_end(d->skb, tstats);
+	return nla_nest_end(d->skb, stats);
+
+nla_put_failure:
+	nla_nest_cancel(d->skb, stats);
+	return -1;
+}
+
+static struct Qdisc *cake_leaf(struct Qdisc *sch, unsigned long arg)
+{
+	return NULL;
+}
+
+static unsigned long cake_find(struct Qdisc *sch, u32 classid)
+{
+	return 0;
+}
+
+static unsigned long cake_bind(struct Qdisc *sch, unsigned long parent,
+			       u32 classid)
+{
+	return 0;
+}
+
+static void cake_unbind(struct Qdisc *q, unsigned long cl)
+{
+}
+
+static struct tcf_block *cake_tcf_block(struct Qdisc *sch, unsigned long cl,
+					struct netlink_ext_ack *extack)
+{
+	struct cake_sched_data *q = qdisc_priv(sch);
+
+	if (cl)
+		return NULL;
+	return q->block;
+}
+
+static int cake_dump_class(struct Qdisc *sch, unsigned long cl,
+			   struct sk_buff *skb, struct tcmsg *tcm)
+{
+	tcm->tcm_handle |= TC_H_MIN(cl);
+	return 0;
+}
+
+static int cake_dump_class_stats(struct Qdisc *sch, unsigned long cl,
+				 struct gnet_dump *d)
+{
+	struct cake_sched_data *q = qdisc_priv(sch);
+	const struct cake_flow *flow = NULL;
+	struct gnet_stats_queue qs = { 0 };
+	struct nlattr *stats;
+	u32 idx = cl - 1;
+
+	if (idx < CAKE_QUEUES * q->tin_cnt) {
+		const struct cake_tin_data *b = &q->tins[idx / CAKE_QUEUES];
+		const struct sk_buff *skb;
+
+		flow = &b->flows[idx % CAKE_QUEUES];
+
+		if (flow->head) {
+			sch_tree_lock(sch);
+			skb = flow->head;
+			while (skb) {
+				qs.qlen++;
+				skb = skb->next;
+			}
+			sch_tree_unlock(sch);
+		}
+		qs.backlog = b->backlogs[idx % CAKE_QUEUES];
+		qs.drops = flow->dropped;
+	}
+	if (gnet_stats_copy_queue(d, NULL, &qs, qs.qlen) < 0)
+		return -1;
+	if (flow) {
+		ktime_t now = ktime_get();
+
+		stats = nla_nest_start(d->skb, TCA_STATS_APP);
+		if (!stats)
+			return -1;
+
+#define PUT_STAT_U32(attr, data) do {				       \
+		if (nla_put_u32(d->skb, TCA_CAKE_STATS_ ## attr, data)) \
+			goto nla_put_failure;			       \
+	} while (0)
+#define PUT_STAT_S32(attr, data) do {				       \
+		if (nla_put_s32(d->skb, TCA_CAKE_STATS_ ## attr, data)) \
+			goto nla_put_failure;			       \
+	} while (0)
+
+		PUT_STAT_S32(DEFICIT, flow->deficit);
+		PUT_STAT_U32(DROPPING, flow->cvars.dropping);
+		PUT_STAT_U32(COBALT_COUNT, flow->cvars.count);
+		PUT_STAT_U32(P_DROP, flow->cvars.p_drop);
+		if (flow->cvars.p_drop) {
+			PUT_STAT_S32(BLUE_TIMER_US,
+				     ktime_to_us(
+					     ktime_sub(now,
+						     flow->cvars.blue_timer)));
+		}
+		if (flow->cvars.dropping) {
+			PUT_STAT_S32(DROP_NEXT_US,
+				     ktime_to_us(
+					     ktime_sub(now,
+						       flow->cvars.drop_next)));
+		}
+
+		if (nla_nest_end(d->skb, stats) < 0)
+			return -1;
+	}
+
+	return 0;
+
+nla_put_failure:
+	nla_nest_cancel(d->skb, stats);
+	return -1;
+}
+
+static void cake_walk(struct Qdisc *sch, struct qdisc_walker *arg)
+{
+	struct cake_sched_data *q = qdisc_priv(sch);
+	unsigned int i, j;
+
+	if (arg->stop)
+		return;
+
+	for (i = 0; i < q->tin_cnt; i++) {
+		struct cake_tin_data *b = &q->tins[i];
+
+		for (j = 0; j < CAKE_QUEUES; j++) {
+			if (list_empty(&b->flows[j].flowchain) ||
+			    arg->count < arg->skip) {
+				arg->count++;
+				continue;
+			}
+			if (arg->fn(sch, i * CAKE_QUEUES + j + 1, arg) < 0) {
+				arg->stop = 1;
+				break;
+			}
+			arg->count++;
+		}
+	}
+}
+
+static const struct Qdisc_class_ops cake_class_ops = {
+	.leaf		=	cake_leaf,
+	.find		=	cake_find,
+	.tcf_block	=	cake_tcf_block,
+	.bind_tcf	=	cake_bind,
+	.unbind_tcf	=	cake_unbind,
+	.dump		=	cake_dump_class,
+	.dump_stats	=	cake_dump_class_stats,
+	.walk		=	cake_walk,
+};
+
+static struct Qdisc_ops cake_qdisc_ops __read_mostly = {
+	.cl_ops		=	&cake_class_ops,
+	.id		=	"cake",
+	.priv_size	=	sizeof(struct cake_sched_data),
+	.enqueue	=	cake_enqueue,
+	.dequeue	=	cake_dequeue,
+	.peek		=	qdisc_peek_dequeued,
+	.init		=	cake_init,
+	.reset		=	cake_reset,
+	.destroy	=	cake_destroy,
+	.change		=	cake_change,
+	.dump		=	cake_dump,
+	.dump_stats	=	cake_dump_stats,
+	.owner		=	THIS_MODULE,
+};
+
+static int __init cake_module_init(void)
+{
+	return register_qdisc(&cake_qdisc_ops);
+}
+
+static void __exit cake_module_exit(void)
+{
+	unregister_qdisc(&cake_qdisc_ops);
+}
+
+module_init(cake_module_init)
+module_exit(cake_module_exit)
+MODULE_AUTHOR("Jonathan Morton");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("The CAKE shaper.");

^ permalink raw reply related

* [PATCH net-next v15 7/7] sch_cake: Conditionally split GSO segments
From: Toke Høiland-Jørgensen @ 2018-05-22 13:57 UTC (permalink / raw)
  To: netdev, cake
In-Reply-To: <152699741881.21931.11656377745581563912.stgit@alrua-kau>

At lower bandwidths, the transmission time of a single GSO segment can add
an unacceptable amount of latency due to HOL blocking. Furthermore, with a
software shaper, any tuning mechanism employed by the kernel to control the
maximum size of GSO segments is thrown off by the artificial limit on
bandwidth. For this reason, we split GSO segments into their individual
packets iff the shaper is active and configured to a bandwidth <= 1 Gbps.

Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
---
 net/sched/sch_cake.c |   99 +++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 73 insertions(+), 26 deletions(-)

diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 87c3b01b773e..c80a7c51b792 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -82,6 +82,7 @@
 #define CAKE_QUEUES (1024)
 #define CAKE_FLOW_MASK 63
 #define CAKE_FLOW_NAT_FLAG 64
+#define CAKE_SPLIT_GSO_THRESHOLD (125000000) /* 1Gbps */
 
 /* struct cobalt_params - contains codel and blue parameters
  * @interval:	codel initial drop rate
@@ -1671,36 +1672,73 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 	if (unlikely(len > b->max_skblen))
 		b->max_skblen = len;
 
-	cobalt_set_enqueue_time(skb, now);
-	get_cobalt_cb(skb)->adjusted_len = cake_overhead(q, skb);
-	flow_queue_add(flow, skb);
-
-	if (q->ack_filter)
-		ack = cake_ack_filter(q, flow);
+	if (skb_is_gso(skb) && q->rate_flags & CAKE_FLAG_SPLIT_GSO) {
+		struct sk_buff *segs, *nskb;
+		netdev_features_t features = netif_skb_features(skb);
+		unsigned int slen = 0;
+
+		segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
+		if (IS_ERR_OR_NULL(segs))
+			return qdisc_drop(skb, sch, to_free);
+
+		while (segs) {
+			nskb = segs->next;
+			segs->next = NULL;
+			qdisc_skb_cb(segs)->pkt_len = segs->len;
+			cobalt_set_enqueue_time(segs, now);
+			get_cobalt_cb(segs)->adjusted_len = cake_overhead(q,
+									  segs);
+			flow_queue_add(flow, segs);
+
+			sch->q.qlen++;
+			slen += segs->len;
+			q->buffer_used += segs->truesize;
+			b->packets++;
+			segs = nskb;
+		}
 
-	if (ack) {
-		b->ack_drops++;
-		sch->qstats.drops++;
-		b->bytes += qdisc_pkt_len(ack);
-		len -= qdisc_pkt_len(ack);
-		q->buffer_used += skb->truesize - ack->truesize;
-		if (q->rate_flags & CAKE_FLAG_INGRESS)
-			cake_advance_shaper(q, b, ack, now, true);
+		/* stats */
+		b->bytes	    += slen;
+		b->backlogs[idx]    += slen;
+		b->tin_backlog      += slen;
+		sch->qstats.backlog += slen;
+		q->avg_window_bytes += slen;
 
-		qdisc_tree_reduce_backlog(sch, 1, qdisc_pkt_len(ack));
-		consume_skb(ack);
+		qdisc_tree_reduce_backlog(sch, 1, len);
+		consume_skb(skb);
 	} else {
-		sch->q.qlen++;
-		q->buffer_used      += skb->truesize;
-	}
+		/* not splitting */
+		cobalt_set_enqueue_time(skb, now);
+		get_cobalt_cb(skb)->adjusted_len = cake_overhead(q, skb);
+		flow_queue_add(flow, skb);
+
+		if (q->ack_filter)
+			ack = cake_ack_filter(q, flow);
+
+		if (ack) {
+			b->ack_drops++;
+			sch->qstats.drops++;
+			b->bytes += qdisc_pkt_len(ack);
+			len -= qdisc_pkt_len(ack);
+			q->buffer_used += skb->truesize - ack->truesize;
+			if (q->rate_flags & CAKE_FLAG_INGRESS)
+				cake_advance_shaper(q, b, ack, now, true);
+
+			qdisc_tree_reduce_backlog(sch, 1, qdisc_pkt_len(ack));
+			consume_skb(ack);
+		} else {
+			sch->q.qlen++;
+			q->buffer_used      += skb->truesize;
+		}
 
-	/* stats */
-	b->packets++;
-	b->bytes	    += len;
-	b->backlogs[idx]    += len;
-	b->tin_backlog      += len;
-	sch->qstats.backlog += len;
-	q->avg_window_bytes += len;
+		/* stats */
+		b->packets++;
+		b->bytes	    += len;
+		b->backlogs[idx]    += len;
+		b->tin_backlog      += len;
+		sch->qstats.backlog += len;
+		q->avg_window_bytes += len;
+	}
 
 	if (q->overflow_timeout)
 		cake_heapify_up(q, b->overflow_idx[idx]);
@@ -2532,6 +2570,11 @@ static int cake_change(struct Qdisc *sch, struct nlattr *opt,
 	if (tb[TCA_CAKE_MEMORY])
 		q->buffer_config_limit = nla_get_u32(tb[TCA_CAKE_MEMORY]);
 
+	if (q->rate_bps && q->rate_bps <= CAKE_SPLIT_GSO_THRESHOLD)
+		q->rate_flags |= CAKE_FLAG_SPLIT_GSO;
+	else
+		q->rate_flags &= ~CAKE_FLAG_SPLIT_GSO;
+
 	if (q->tins) {
 		sch_tree_lock(sch);
 		cake_reconfigure(sch);
@@ -2687,6 +2730,10 @@ static int cake_dump(struct Qdisc *sch, struct sk_buff *skb)
 	if (nla_put_u32(skb, TCA_CAKE_MPU, q->rate_mpu))
 		goto nla_put_failure;
 
+	if (nla_put_u32(skb, TCA_CAKE_SPLIT_GSO,
+			!!(q->rate_flags & CAKE_FLAG_SPLIT_GSO)))
+		goto nla_put_failure;
+
 	return nla_nest_end(skb, opts);
 
 nla_put_failure:

^ permalink raw reply related

* [PATCH net-next v15 0/7] sched: Add Common Applications Kept Enhanced (cake) qdisc
From: Toke Høiland-Jørgensen @ 2018-05-22 13:57 UTC (permalink / raw)
  To: netdev, cake
  Cc: Georgios Amanakis, Pete Heist, Yuchung Cheng, Neal Cardwell,
	Dave Taht, netfilter-devel

This patch series adds the CAKE qdisc, and has been split up to ease
review.

I have attempted to split out each configurable feature into its own patch.
The first commit adds the base shaper and packet scheduler, while
subsequent commits add the optional features. The full userspace API and
most data structures are included in this commit, but options not
understood in the base version will be ignored.

The result of applying the entire series is identical to the out of tree
version that have seen extensive testing in previous deployments, most
notably as an out of tree patch to OpenWrt. However, note that I have only
compile tested the individual patches; so the whole series should be
considered as a unit.

---
Changelog

v15:
  - Handle ECN flags in ACK filter

v14:
  - Handle seqno wraps and DSACKs in ACK filter

v13:
  - Avoid ktime_t to scalar compares
  - Add class dumping and basic stats
  - Fail with ENOTSUPP when requesting NAT mode and conntrack is not
    available.
  - Parse all TCP options in ACK filter and make sure to only drop safe
    ones. Also handle SACK ranges properly.

v12:
  - Get rid of custom time typedefs. Use ktime_t for time and u64 for
    duration instead.

v11:
  - Fix overhead compensation calculation for GSO packets
  - Change configured rate to be u64 (I ran out of bits before I ran out
    of CPU when testing the effects of the above)

v10:
  - Christmas tree gardening (fix variable declarations to be in reverse
    line length order)

v9:
  - Remove duplicated checks around kvfree() and just call it
    unconditionally.
  - Don't pass __GFP_NOWARN when allocating memory
  - Move options in cake_dump() that are related to optional features to
    later patches implementing the features.
  - Support attaching filters to the qdisc and use the classification
    result to select flow queue.
  - Support overriding diffserv priority tin from skb->priority

v8:
  - Remove inline keyword from function definitions
  - Simplify ACK filter; remove the complex state handling to make the
    logic easier to follow. This will potentially be a bit less efficient,
    but I have not been able to measure a difference.

v7:
  - Split up patch into a series to ease review.
  - Constify the ACK filter.

v6:
  - Fix 6in4 encapsulation checks in ACK filter code
  - Checkpatch fixes

v5:
  - Refactor ACK filter code and hopefully fix the safety issues
    properly this time.

v4:
  - Only split GSO packets if shaping at speeds <= 1Gbps
  - Fix overhead calculation code to also work for GSO packets
  - Don't re-implement kvzalloc()
  - Remove local header include from out-of-tree build (fixes kbuild-bot
    complaint).
  - Several fixes to the ACK filter:
    - Check pskb_may_pull() before deref of transport headers.
    - Don't run ACK filter logic on split GSO packets
    - Fix TCP sequence number compare to deal with wraparounds

v3:
  - Use IS_REACHABLE() macro to fix compilation when sch_cake is
    built-in and conntrack is a module.
  - Switch the stats output to use nested netlink attributes instead
    of a versioned struct.
  - Remove GPL boilerplate.
  - Fix array initialisation style.

v2:
  - Fix kbuild test bot complaint
  - Clean up the netlink ABI
  - Fix checkpatch complaints
  - A few tweaks to the behaviour of cake based on testing carried out
    while writing the paper.

---

Toke Høiland-Jørgensen (7):
      sched: Add Common Applications Kept Enhanced (cake) qdisc
      sch_cake: Add ingress mode
      sch_cake: Add optional ACK filter
      sch_cake: Add NAT awareness to packet classifier
      sch_cake: Add DiffServ handling
      sch_cake: Add overhead compensation support to the rate shaper
      sch_cake: Conditionally split GSO segments


 include/uapi/linux/pkt_sched.h |  113 +
 net/sched/Kconfig              |   11 
 net/sched/Makefile             |    1 
 net/sched/sch_cake.c           | 3020 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 3145 insertions(+)
 create mode 100644 net/sched/sch_cake.c

^ permalink raw reply

* [PATCH net-next v15 3/7] sch_cake: Add optional ACK filter
From: Toke Høiland-Jørgensen @ 2018-05-22 13:57 UTC (permalink / raw)
  To: netdev, cake; +Cc: Yuchung Cheng, Neal Cardwell
In-Reply-To: <152699741881.21931.11656377745581563912.stgit@alrua-kau>

The ACK filter is an optional feature of CAKE which is designed to improve
performance on links with very asymmetrical rate limits. On such links
(which are unfortunately quite prevalent, especially for DSL and cable
subscribers), the downstream throughput can be limited by the number of
ACKs capable of being transmitted in the *upstream* direction.

Filtering ACKs can, in general, have adverse effects on TCP performance
because it interferes with ACK clocking (especially in slow start), and it
reduces the flow's resiliency to ACKs being dropped further along the path.
To alleviate these drawbacks, the ACK filter in CAKE tries its best to
always keep enough ACKs queued to ensure forward progress in the TCP flow
being filtered. It does this by only filtering redundant ACKs. In its
default 'conservative' mode, the filter will always keep at least two
redundant ACKs in the queue, while in 'aggressive' mode, it will filter
down to a single ACK.

The ACK filter works by inspecting the per-flow queue on every packet
enqueue. Starting at the head of the queue, the filter looks for another
eligible packet to drop (so the ACK being dropped is always closer to the
head of the queue than the packet being enqueued). An ACK is eligible only
if it ACKs *fewer* bytes than the new packet being enqueued, including any
SACK options. This prevents duplicate ACKs from being filtered, to avoid
interfering with retransmission logic. In addition, we check TCP header
options and only drop those that are known to not interfere with sender
state. In particular, packets with unknown option codes are never dropped.

In aggressive mode, an eligible packet is always dropped, while in
conservative mode, at least two ACKs are kept in the queue. Only pure ACKs
(with no data segments) are considered eligible for dropping, but when an
ACK with data segments is enqueued, this can cause another pure ACK to
become eligible for dropping.

The approach described above ensures that this ACK filter avoids most of
the drawbacks of a naive filtering mechanism that only keeps flow state but
does not inspect the queue. This is the rationale for including the ACK
filter in CAKE itself rather than as separate module (as the TC filter, for
instance).

Our performance evaluation has shown that on a 30/1 Mbps link with a
bidirectional traffic test (RRUL), turning on the ACK filter on the
upstream link improves downstream throughput by ~20% (both modes) and
upstream throughput by ~12% in conservative mode and ~40% in aggressive
mode, at the cost of ~5ms of inter-flow latency due to the increased
congestion.

In *really* pathological cases, the effect can be a lot more; for instance,
the ACK filter increases the achievable downstream throughput on a link
with 100 Kbps in the upstream direction by an order of magnitude (from ~2.5
Mbps to ~25 Mbps).

Finally, even though we consider the ACK filter to be safer than most, we
do not recommend turning it on everywhere: on more symmetrical link
bandwidths the effect is negligible at best.

Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
---
 net/sched/sch_cake.c |  453 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 451 insertions(+), 2 deletions(-)

diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 10e208e4255d..68ac908470f1 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -757,6 +757,432 @@ static void flow_queue_add(struct cake_flow *flow, struct sk_buff *skb)
 	skb->next = NULL;
 }
 
+static struct iphdr *cake_get_iphdr(const struct sk_buff *skb,
+				    struct ipv6hdr *buf)
+{
+	unsigned int offset = skb_network_offset(skb);
+	struct iphdr *iph;
+
+	iph = skb_header_pointer(skb, offset, sizeof(struct iphdr), buf);
+
+	if (!iph)
+		return NULL;
+
+	if (iph->version == 4 && iph->protocol == IPPROTO_IPV6)
+		return skb_header_pointer(skb, offset + iph->ihl * 4,
+					  sizeof(struct ipv6hdr), buf);
+
+	else if (iph->version == 4)
+		return iph;
+
+	else if (iph->version == 6)
+		return skb_header_pointer(skb, offset, sizeof(struct ipv6hdr),
+					  buf);
+
+	return NULL;
+}
+
+static struct tcphdr *cake_get_tcphdr(const struct sk_buff *skb,
+				      void *buf, unsigned int bufsize)
+{
+	unsigned int offset = skb_network_offset(skb);
+	const struct ipv6hdr *ipv6h;
+	const struct tcphdr *tcph;
+	const struct iphdr *iph;
+	struct ipv6hdr _ipv6h;
+	struct tcphdr _tcph;
+
+	ipv6h = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
+
+	if (!ipv6h)
+		return NULL;
+
+	if (ipv6h->version == 4) {
+		iph = (struct iphdr *)ipv6h;
+		offset += iph->ihl * 4;
+
+		/* special-case 6in4 tunnelling, as that is a common way to get
+		 * v6 connectivity in the home
+		 */
+		if (iph->protocol == IPPROTO_IPV6) {
+			ipv6h = skb_header_pointer(skb, offset,
+						   sizeof(_ipv6h), &_ipv6h);
+
+			if (!ipv6h || ipv6h->nexthdr != IPPROTO_TCP)
+				return NULL;
+
+			offset += sizeof(struct ipv6hdr);
+
+		} else if (iph->protocol != IPPROTO_TCP) {
+			return NULL;
+		}
+
+	} else if (ipv6h->version == 6) {
+		if (ipv6h->nexthdr != IPPROTO_TCP)
+			return NULL;
+
+		offset += sizeof(struct ipv6hdr);
+	} else {
+		return NULL;
+	}
+
+	tcph = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
+	if (!tcph)
+		return NULL;
+
+	return skb_header_pointer(skb, offset,
+				  min(__tcp_hdrlen(tcph), bufsize), buf);
+}
+
+static const void *cake_get_tcpopt(const struct tcphdr *tcph,
+				   int code, int *oplen)
+{
+	/* inspired by tcp_parse_options in tcp_input.c */
+	int length = __tcp_hdrlen(tcph) - sizeof(struct tcphdr);
+	const u8 *ptr = (const u8 *)(tcph + 1);
+
+	while (length > 0) {
+		int opcode = *ptr++;
+		int opsize;
+
+		if (opcode == TCPOPT_EOL)
+			break;
+		if (opcode == TCPOPT_NOP) {
+			length--;
+			continue;
+		}
+		opsize = *ptr++;
+		if (opsize < 2 || opsize > length)
+			break;
+
+		if (opcode == code) {
+			*oplen = opsize;
+			return ptr;
+		}
+
+		ptr += opsize - 2;
+		length -= opsize;
+	}
+
+	return NULL;
+}
+
+/* Compare two SACK sequences. A sequence is considered greater if it SACKs more
+ * bytes than the other. In the case where both sequences ACKs bytes that the
+ * other doesn't, A is considered greater. DSACKs in A also makes A be
+ * considered greater.
+ *
+ * @return -1, 0 or 1 as normal compare functions
+ */
+static int cake_tcph_sack_compare(const struct tcphdr *tcph_a,
+				  const struct tcphdr *tcph_b)
+{
+	const struct tcp_sack_block_wire *sack_a, *sack_b;
+	u32 ack_seq_a = ntohl(tcph_a->ack_seq);
+	u32 bytes_a = 0, bytes_b = 0;
+	int oplen_a, oplen_b;
+	bool first = true;
+
+	sack_a = cake_get_tcpopt(tcph_a, TCPOPT_SACK, &oplen_a);
+	sack_b = cake_get_tcpopt(tcph_b, TCPOPT_SACK, &oplen_b);
+
+	/* pointers point to option contents */
+	oplen_a -= TCPOLEN_SACK_BASE;
+	oplen_b -= TCPOLEN_SACK_BASE;
+
+	if (sack_a && oplen_a >= sizeof(*sack_a) &&
+	    (!sack_b || oplen_b < sizeof(*sack_b)))
+		return -1;
+	else if (sack_b && oplen_b >= sizeof(*sack_b) &&
+		 (!sack_a || oplen_a < sizeof(*sack_a)))
+		return 1;
+	else if ((!sack_a || oplen_a < sizeof(*sack_a)) &&
+		 (!sack_b || oplen_b < sizeof(*sack_b)))
+		return 0;
+
+	while (oplen_a >= sizeof(*sack_a)) {
+		const struct tcp_sack_block_wire *sack_tmp = sack_b;
+		u32 start_a = get_unaligned_be32(&sack_a->start_seq);
+		u32 end_a = get_unaligned_be32(&sack_a->end_seq);
+		int oplen_tmp = oplen_b;
+		bool found = false;
+
+		/* DSACK; always considered greater to prevent dropping */
+		if (before(start_a, ack_seq_a))
+			return -1;
+
+		bytes_a += end_a - start_a;
+
+		while (oplen_tmp >= sizeof(*sack_tmp)) {
+			u32 start_b = get_unaligned_be32(&sack_tmp->start_seq);
+			u32 end_b = get_unaligned_be32(&sack_tmp->end_seq);
+
+			/* first time through we count the total size */
+			if (first)
+				bytes_b += end_b - start_b;
+
+			if (!after(start_b, start_a) && !before(end_b, end_a)) {
+				found = true;
+				if (!first)
+					break;
+			}
+			oplen_tmp -= sizeof(*sack_tmp);
+			sack_tmp++;
+		}
+
+		if (!found)
+			return -1;
+
+		oplen_a -= sizeof(*sack_a);
+		sack_a++;
+		first = false;
+	}
+
+	/* If we made it this far, all ranges SACKed by A are covered by B, so
+	 * either the SACKs are equal, or B SACKs more bytes.
+	 */
+	return bytes_b > bytes_a ? 1 : 0;
+}
+
+static void cake_tcph_get_tstamp(const struct tcphdr *tcph,
+				 u32 *tsval, u32 *tsecr)
+{
+	const u8 *ptr;
+	int opsize;
+
+	ptr = cake_get_tcpopt(tcph, TCPOPT_TIMESTAMP, &opsize);
+
+	if (ptr && opsize == TCPOLEN_TIMESTAMP) {
+		*tsval = get_unaligned_be32(ptr);
+		*tsecr = get_unaligned_be32(ptr + 4);
+	}
+}
+
+static bool cake_tcph_may_drop(const struct tcphdr *tcph,
+			       u32 tstamp_new, u32 tsecr_new)
+{
+	/* inspired by tcp_parse_options in tcp_input.c */
+	int length = __tcp_hdrlen(tcph) - sizeof(struct tcphdr);
+	const u8 *ptr = (const u8 *)(tcph + 1);
+	u32 tstamp, tsecr;
+
+	/* 3 reserved flags must be unset to avoid future breakage
+	 * ACK must be set
+	 * ECE/CWR are handled separately
+	 * All other flags URG/PSH/RST/SYN/FIN must be unset
+	 * 0x0FFF0000 = all TCP flags (confirm ACK=1, others zero)
+	 * 0x00C00000 = CWR/ECE (handled separately)
+	 * 0x0F3F0000 = 0x0FFF0000 & ~0x00C00000
+	 */
+	if (((tcp_flag_word(tcph) &
+	      cpu_to_be32(0x0F3F0000)) != TCP_FLAG_ACK))
+		return false;
+
+	while (length > 0) {
+		int opcode = *ptr++;
+		int opsize;
+
+		if (opcode == TCPOPT_EOL)
+			break;
+		if (opcode == TCPOPT_NOP) {
+			length--;
+			continue;
+		}
+		opsize = *ptr++;
+		if (opsize < 2 || opsize > length)
+			break;
+
+		switch (opcode) {
+		case TCPOPT_MD5SIG: /* doesn't influence state */
+			break;
+
+		case TCPOPT_SACK: /* stricter checking performed later */
+			if (opsize % 8 != 2)
+				return false;
+			break;
+
+		case TCPOPT_TIMESTAMP:
+			/* only drop timestamps lower than new */
+			if (opsize != TCPOLEN_TIMESTAMP)
+				return false;
+			tstamp = get_unaligned_be32(ptr);
+			tsecr = get_unaligned_be32(ptr + 4);
+			if (after(tstamp, tstamp_new) ||
+			    after(tsecr, tsecr_new))
+				return false;
+			break;
+
+		case TCPOPT_MSS:  /* these should only be set on SYN */
+		case TCPOPT_WINDOW:
+		case TCPOPT_SACK_PERM:
+		case TCPOPT_FASTOPEN:
+		case TCPOPT_EXP:
+		default: /* don't drop if any unknown options are present */
+			return false;
+		}
+
+		ptr += opsize - 2;
+		length -= opsize;
+	}
+
+	return true;
+}
+
+static struct sk_buff *cake_ack_filter(struct cake_sched_data *q,
+				       struct cake_flow *flow)
+{
+	bool aggressive = q->ack_filter == CAKE_ACK_AGGRESSIVE;
+	struct sk_buff *elig_ack = NULL, *elig_ack_prev = NULL;
+	struct sk_buff *skb_check, *skb_prev = NULL;
+	const struct ipv6hdr *ipv6h, *ipv6h_check;
+	unsigned char _tcph[64], _tcph_check[64];
+	const struct tcphdr *tcph, *tcph_check;
+	const struct iphdr *iph, *iph_check;
+	struct ipv6hdr _iph, _iph_check;
+	const struct sk_buff *skb;
+	int seglen, num_found = 0;
+	u32 tstamp = 0, tsecr = 0;
+	__be32 elig_flags = 0;
+	int sack_comp;
+
+	/* no other possible ACKs to filter */
+	if (flow->head == flow->tail)
+		return NULL;
+
+	skb = flow->tail;
+	tcph = cake_get_tcphdr(skb, _tcph, sizeof(_tcph));
+	iph = cake_get_iphdr(skb, &_iph);
+	if (!tcph)
+		return NULL;
+
+	cake_tcph_get_tstamp(tcph, &tstamp, &tsecr);
+
+	/* the 'triggering' packet need only have the ACK flag set.
+	 * also check that SYN is not set, as there won't be any previous ACKs.
+	 */
+	if ((tcp_flag_word(tcph) &
+	     (TCP_FLAG_ACK | TCP_FLAG_SYN)) != TCP_FLAG_ACK)
+		return NULL;
+
+	/* the 'triggering' ACK is at the tail of the queue, we have already
+	 * returned if it is the only packet in the flow. loop through the rest
+	 * of the queue looking for pure ACKs with the same 5-tuple as the
+	 * triggering one.
+	 */
+	for (skb_check = flow->head;
+	     skb_check && skb_check != skb;
+	     skb_prev = skb_check, skb_check = skb_check->next) {
+		iph_check = cake_get_iphdr(skb_check, &_iph_check);
+		tcph_check = cake_get_tcphdr(skb_check, &_tcph_check,
+					     sizeof(_tcph_check));
+
+		/* only TCP packets with matching 5-tuple are eligible, and only
+		 * drop safe headers
+		 */
+		if (!tcph_check || iph->version != iph_check->version ||
+		    tcph_check->source != tcph->source ||
+		    tcph_check->dest != tcph->dest)
+			continue;
+
+		if (iph_check->version == 4) {
+			if (iph_check->saddr != iph->saddr ||
+			    iph_check->daddr != iph->daddr)
+				continue;
+
+			seglen = ntohs(iph_check->tot_len) -
+				       (4 * iph_check->ihl);
+		} else if (iph_check->version == 6) {
+			ipv6h = (struct ipv6hdr *)iph;
+			ipv6h_check = (struct ipv6hdr *)iph_check;
+
+			if (ipv6_addr_cmp(&ipv6h_check->saddr, &ipv6h->saddr) ||
+			    ipv6_addr_cmp(&ipv6h_check->daddr, &ipv6h->daddr))
+				continue;
+
+			seglen = ntohs(ipv6h_check->payload_len);
+		} else {
+			WARN_ON(1);  /* shouldn't happen */
+			continue;
+		}
+
+		/* If the ECE/CWR flags changed from the previous eligible
+		 * packet in the same flow, we should no longer be dropping that
+		 * previous packet as this would lose information.
+		 */
+		if (elig_ack && (tcp_flag_word(tcph_check) &
+				 (TCP_FLAG_ECE | TCP_FLAG_CWR)) != elig_flags) {
+			elig_ack = NULL;
+			elig_ack_prev = NULL;
+			num_found--;
+		}
+
+		/* Check TCP options and flags, don't drop ACKs with segment
+		 * data, and don't drop ACKs with a higher cumulative ACK
+		 * counter than the triggering packet. Check ACK seqno here to
+		 * avoid parsing SACK options of packets we are going to exclude
+		 * anyway.
+		 */
+		if (!cake_tcph_may_drop(tcph_check, tstamp, tsecr) ||
+		    (seglen - __tcp_hdrlen(tcph_check)) != 0 ||
+		    after(ntohl(tcph_check->ack_seq), ntohl(tcph->ack_seq)))
+			continue;
+
+		/* Check SACK options. The triggering packet must SACK more data
+		 * than the ACK under consideration, or SACK the same range but
+		 * have a larger cumulative ACK counter. The latter is a
+		 * pathological case, but is contained in the following check
+		 * anyway, just to be safe.
+		 */
+		sack_comp = cake_tcph_sack_compare(tcph_check, tcph);
+
+		if (sack_comp < 0 ||
+		    (ntohl(tcph_check->ack_seq) == ntohl(tcph->ack_seq) &&
+		     sack_comp == 0))
+			continue;
+
+		/* At this point we have found an eligible pure ACK to drop; if
+		 * we are in aggressive mode, we are done. Otherwise, keep
+		 * searching unless this is the second eligible ACK we
+		 * found.
+		 *
+		 * Since we want to drop ACK closest to the head of the queue,
+		 * save the first eligible ACK we find, even if we need to loop
+		 * again.
+		 */
+		if (!elig_ack) {
+			elig_ack = skb_check;
+			elig_ack_prev = skb_prev;
+			elig_flags = (tcp_flag_word(tcph_check)
+				      & (TCP_FLAG_ECE | TCP_FLAG_CWR));
+		}
+
+		if (num_found++ > 0)
+			goto found;
+	}
+
+	/* We made it through the queue without finding two eligible ACKs . If
+	 * we found a single eligible ACK we can drop it in aggressive mode if
+	 * we can guarantee that this does not interfere with ECN flag
+	 * information. We ensure this by dropping it only if the enqueued
+	 * packet is consecutive with the eligible ACK, and their flags match.
+	 */
+	if (elig_ack && aggressive && elig_ack->next == skb &&
+	    (elig_flags == (tcp_flag_word(tcph) & (TCP_FLAG_ECE | TCP_FLAG_CWR))))
+		goto found;
+
+	return NULL;
+
+found:
+	if (elig_ack_prev)
+		elig_ack_prev->next = elig_ack->next;
+	else
+		flow->head = elig_ack->next;
+
+	elig_ack->next = NULL;
+
+	return elig_ack;
+}
+
 static u64 cake_ewma(u64 avg, u64 sample, u32 shift)
 {
 	avg -= avg >> shift;
@@ -934,6 +1360,7 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 	struct cake_sched_data *q = qdisc_priv(sch);
 	int len = qdisc_pkt_len(skb);
 	int uninitialized_var(ret);
+	struct sk_buff *ack = NULL;
 	ktime_t now = ktime_get();
 	struct cake_tin_data *b;
 	struct cake_flow *flow;
@@ -980,8 +1407,24 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 	cobalt_set_enqueue_time(skb, now);
 	flow_queue_add(flow, skb);
 
-	sch->q.qlen++;
-	q->buffer_used      += skb->truesize;
+	if (q->ack_filter)
+		ack = cake_ack_filter(q, flow);
+
+	if (ack) {
+		b->ack_drops++;
+		sch->qstats.drops++;
+		b->bytes += qdisc_pkt_len(ack);
+		len -= qdisc_pkt_len(ack);
+		q->buffer_used += skb->truesize - ack->truesize;
+		if (q->rate_flags & CAKE_FLAG_INGRESS)
+			cake_advance_shaper(q, b, ack, now, true);
+
+		qdisc_tree_reduce_backlog(sch, 1, qdisc_pkt_len(ack));
+		consume_skb(ack);
+	} else {
+		sch->q.qlen++;
+		q->buffer_used      += skb->truesize;
+	}
 
 	/* stats */
 	b->packets++;
@@ -1511,6 +1954,9 @@ static int cake_change(struct Qdisc *sch, struct nlattr *opt,
 			q->rate_flags &= ~CAKE_FLAG_INGRESS;
 	}
 
+	if (tb[TCA_CAKE_ACK_FILTER])
+		q->ack_filter = nla_get_u32(tb[TCA_CAKE_ACK_FILTER]);
+
 	if (tb[TCA_CAKE_MEMORY])
 		q->buffer_config_limit = nla_get_u32(tb[TCA_CAKE_MEMORY]);
 
@@ -1642,6 +2088,9 @@ static int cake_dump(struct Qdisc *sch, struct sk_buff *skb)
 			!!(q->rate_flags & CAKE_FLAG_INGRESS)))
 		goto nla_put_failure;
 
+	if (nla_put_u32(skb, TCA_CAKE_ACK_FILTER, q->ack_filter))
+		goto nla_put_failure;
+
 	return nla_nest_end(skb, opts);
 
 nla_put_failure:

^ permalink raw reply related

* Re: [PATCH v2] wcn36xx: Add support for Factory Test Mode (FTM)
From: Kalle Valo @ 2018-05-22 13:57 UTC (permalink / raw)
  To: Ramon Fried
  Cc: jjohnson, linux-kernel, wcn36xx, linux-wireless, netdev,
	Eyal Ilsar, Ramon Fried
In-Reply-To: <20180518103122.28439-1-ramon.fried@gmail.com>

Ramon Fried <ramon.fried@gmail.com> writes:

> From: Eyal Ilsar <eilsar@codeaurora.org>
>
> Introduce infrastructure for supporting Factory Test Mode (FTM) of the
> wireless LAN subsystem. In order for the user space to access the
> firmware in test mode the relevant netlink channel needs to be exposed
> from the kernel driver.
>
> The above is achieved as follows:
> 1) Register wcn36xx driver to testmode callback from netlink
> 2) Add testmode callback implementation to handle incoming FTM commands
> 3) Add FTM command packet structure
> 4) Add handling for GET_BUILD_RELEASE_NUMBER (msgid=0x32A2)
> 5) Add generic handling for all PTT_MSG packets
>
> Signed-off-by: Eyal Ilsar <eilsar@codeaurora.org>
> Signed-off-by: Ramon Fried <ramon.fried@linaro.org>

kbuild bot reported a warning:

drivers/net/wireless/ath/wcn36xx/testmode.c:122:5: warning: 'msg' may be used uninitialized in this function [-Wmaybe-uninitialized]

-- 
Kalle Valo

^ permalink raw reply

* Re: [PATCH v4 0/3] IR decoding using BPF
From: Matthias Reichl @ 2018-05-22 13:50 UTC (permalink / raw)
  To: Sean Young
  Cc: linux-media, linux-kernel, Alexei Starovoitov,
	Mauro Carvalho Chehab, Daniel Borkmann, netdev, Devin Heitmueller,
	Y Song, Quentin Monnet
In-Reply-To: <cover.1526651592.git.sean@mess.org>

Hi Sean,

On Fri, May 18, 2018 at 03:07:27PM +0100, Sean Young wrote:
> The kernel IR decoders (drivers/media/rc/ir-*-decoder.c) support the most
> widely used IR protocols, but there are many protocols which are not
> supported[1]. For example, the lirc-remotes[2] repo has over 2700 remotes,
> many of which are not supported by rc-core. There is a "long tail" of
> unsupported IR protocols, for which lircd is need to decode the IR .
> 
> IR encoding is done in such a way that some simple circuit can decode it;
> therefore, bpf is ideal.
> 
> In order to support all these protocols, here we have bpf based IR decoding.
> The idea is that user-space can define a decoder in bpf, attach it to
> the rc device through the lirc chardev.
> 
> Separate work is underway to extend ir-keytable to have an extensive library
> of bpf-based decoders, and a much expanded library of rc keymaps.
> 
> Another future application would be to compile IRP[3] to a IR BPF program, and
> so support virtually every remote without having to write a decoder for each.
> It might also be possible to support non-button devices such as analog
> directional pads or air conditioning remote controls and decode the target
> temperature in bpf, and pass that to an input device.

Thanks a lot, this looks like a very interesting feature to me!

Unfortunately I don't have time to test it ATM, but please keep
me posted - also on ir-keytable progress - I'm rather excited
to give it a try.

so long & thanks,

Hias

> 
> Thanks,
> 
> Sean Young
> 
> [1] http://www.hifi-remote.com/wiki/index.php?title=DecodeIR
> [2] https://sourceforge.net/p/lirc-remotes/code/ci/master/tree/remotes/
> [3] http://www.hifi-remote.com/wiki/index.php?title=IRP_Notation
> 
> Changes since v3:
>  - Implemented review comments from Quentin Monnet and Y Song (thanks!)
>  - More helpful and better formatted bpf helper documentation
>  - Changed back to bpf_prog_array rather than open-coded implementation
>  - scancodes can be 64 bit
>  - bpf gets passed values in microseconds, not nanoseconds.
>    microseconds is more than than enough (IR receivers support carriers upto
>    70kHz, at which point a single period is already 14 microseconds). Also,
>    this makes it much more consistent with lirc mode2.
>  - Since it looks much more like lirc mode2, rename the program type to
>    BPF_PROG_TYPE_LIRC_MODE2.
>  - Rebased on bpf-next
> 
> Changes since v2:
>  - Fixed locking issues
>  - Improved self-test to cover more cases
>  - Rebased on bpf-next again
> 
> Changes since v1:
>  - Code review comments from Y Song <ys114321@gmail.com> and
>    Randy Dunlap <rdunlap@infradead.org>
>  - Re-wrote sample bpf to be selftest
>  - Renamed RAWIR_DECODER -> RAWIR_EVENT (Kconfig, context, bpf prog type)
>  - Rebase on bpf-next
>  - Introduced bpf_rawir_event context structure with simpler access checking
> 
> Sean Young (3):
>   bpf: bpf_prog_array_copy() should return -ENOENT if exclude_prog not
>     found
>   media: rc: introduce BPF_PROG_LIRC_MODE2
>   bpf: add selftest for lirc_mode2 type program
> 
>  drivers/media/rc/Kconfig                      |  13 +
>  drivers/media/rc/Makefile                     |   1 +
>  drivers/media/rc/bpf-lirc.c                   | 308 ++++++++++++++++++
>  drivers/media/rc/lirc_dev.c                   |  30 ++
>  drivers/media/rc/rc-core-priv.h               |  22 ++
>  drivers/media/rc/rc-ir-raw.c                  |  12 +-
>  include/linux/bpf_rcdev.h                     |  30 ++
>  include/linux/bpf_types.h                     |   3 +
>  include/uapi/linux/bpf.h                      |  53 ++-
>  kernel/bpf/core.c                             |  11 +-
>  kernel/bpf/syscall.c                          |   7 +
>  kernel/trace/bpf_trace.c                      |   2 +
>  tools/bpf/bpftool/prog.c                      |   1 +
>  tools/include/uapi/linux/bpf.h                |  53 ++-
>  tools/include/uapi/linux/lirc.h               | 217 ++++++++++++
>  tools/lib/bpf/libbpf.c                        |   1 +
>  tools/testing/selftests/bpf/Makefile          |   8 +-
>  tools/testing/selftests/bpf/bpf_helpers.h     |   6 +
>  .../testing/selftests/bpf/test_lirc_mode2.sh  |  28 ++
>  .../selftests/bpf/test_lirc_mode2_kern.c      |  23 ++
>  .../selftests/bpf/test_lirc_mode2_user.c      | 154 +++++++++
>  21 files changed, 974 insertions(+), 9 deletions(-)
>  create mode 100644 drivers/media/rc/bpf-lirc.c
>  create mode 100644 include/linux/bpf_rcdev.h
>  create mode 100644 tools/include/uapi/linux/lirc.h
>  create mode 100755 tools/testing/selftests/bpf/test_lirc_mode2.sh
>  create mode 100644 tools/testing/selftests/bpf/test_lirc_mode2_kern.c
>  create mode 100644 tools/testing/selftests/bpf/test_lirc_mode2_user.c
> 
> -- 
> 2.17.0
> 

^ permalink raw reply

* Re: [PATCH net-next v11 2/5] netvsc: refactor notifier/event handling code to use the failover framework
From: Michael S. Tsirkin @ 2018-05-22 13:39 UTC (permalink / raw)
  To: Jiri Pirko
  Cc: Sridhar Samudrala, stephen, davem, netdev, virtualization,
	virtio-dev, jesse.brandeburg, alexander.h.duyck, kubakici,
	jasowang, loseweigh, aaron.f.brown, anjali.singhai
In-Reply-To: <20180522132626.GH2149@nanopsycho>

On Tue, May 22, 2018 at 03:26:26PM +0200, Jiri Pirko wrote:
> Tue, May 22, 2018 at 03:17:37PM CEST, mst@redhat.com wrote:
> >On Tue, May 22, 2018 at 03:14:22PM +0200, Jiri Pirko wrote:
> >> Tue, May 22, 2018 at 03:12:40PM CEST, mst@redhat.com wrote:
> >> >On Tue, May 22, 2018 at 11:08:53AM +0200, Jiri Pirko wrote:
> >> >> Tue, May 22, 2018 at 11:06:37AM CEST, jiri@resnulli.us wrote:
> >> >> >Tue, May 22, 2018 at 04:06:18AM CEST, sridhar.samudrala@intel.com wrote:
> >> >> >>Use the registration/notification framework supported by the generic
> >> >> >>failover infrastructure.
> >> >> >>
> >> >> >>Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
> >> >> >
> >> >> >In previous patchset versions, the common code did
> >> >> >netdev_rx_handler_register() and netdev_upper_dev_link() etc
> >> >> >(netvsc_vf_join()). Now, this is still done in netvsc. Why?
> >> >> >
> >> >> >This should be part of the common "failover" code.
> >> >> >
> >> >> 
> >> >> Also note that in the current patchset you use IFF_FAILOVER flag for
> >> >> master, yet for the slave you use IFF_SLAVE. That is wrong.
> >> >> IFF_FAILOVER_SLAVE should be used.
> >> >
> >> >Or drop IFF_FAILOVER_SLAVE and set both IFF_FAILOVER and IFF_SLAVE?
> >> 
> >> No. IFF_SLAVE is for bonding.
> >
> >What breaks if we reuse it for failover?
> 
> This is exposed to userspace. IFF_SLAVE is expected for bonding slaves.
> And failover slave is not a bonding slave.

That does not really answer the question.  I'd claim it's sufficiently
like a bond slave for IFF_SLAVE to make sense.

In fact you will find that netvsc already sets IFF_SLAVE, and so
does e.g. the eql driver.

The advantage of using IFF_SLAVE is that userspace knows to skip it.  If
we don't set IFF_SLAVE existing userspace tries to use the lowerdev.

-- 
MST

^ permalink raw reply


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