openwrt/package/network/utils/iproute2/patches/190-add-cake-to-tc.patch

--- a/include/uapi/linux/pkt_sched.h
+++ b/include/uapi/linux/pkt_sched.h
@@ -934,4 +934,118 @@ 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, // was _ETHERNET
+	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
--- /dev/null
+++ b/man/man8/tc-cake.8
@@ -0,0 +1,710 @@
+.TH CAKE 8 "19 July 2018" "iproute2" "Linux"
+.SH NAME
+CAKE \- Common Applications Kept Enhanced (CAKE)
+.SH SYNOPSIS
+.B tc qdisc ... cake
+.br
+[
+.BR bandwidth
+RATE |
+.BR unlimited*
+|
+.BR autorate-ingress
+]
+.br
+[
+.BR rtt
+TIME |
+.BR datacentre
+|
+.BR lan
+|
+.BR metro
+|
+.BR regional
+|
+.BR internet*
+|
+.BR oceanic
+|
+.BR satellite
+|
+.BR interplanetary
+]
+.br
+[
+.BR besteffort
+|
+.BR diffserv8
+|
+.BR diffserv4
+|
+.BR diffserv3*
+]
+.br
+[
+.BR flowblind
+|
+.BR srchost
+|
+.BR dsthost
+|
+.BR hosts
+|
+.BR flows
+|
+.BR dual-srchost
+|
+.BR dual-dsthost
+|
+.BR triple-isolate*
+]
+.br
+[
+.BR nat
+|
+.BR nonat*
+]
+.br
+[
+.BR wash
+|
+.BR nowash*
+]
+.br
+[
+.BR split-gso*
+|
+.BR no-split-gso
+]
+.br
+[
+.BR ack-filter
+|
+.BR ack-filter-aggressive
+|
+.BR no-ack-filter*
+]
+.br
+[
+.BR memlimit
+LIMIT ]
+.br
+[
+.BR ptm
+|
+.BR atm
+|
+.BR noatm*
+]
+.br
+[
+.BR overhead
+N |
+.BR conservative
+|
+.BR raw*
+]
+.br
+[
+.BR mpu
+N ]
+.br
+[
+.BR ingress
+|
+.BR egress*
+]
+.br
+(* marks defaults)
+
+
+.SH DESCRIPTION
+CAKE (Common Applications Kept Enhanced) is a shaping-capable queue discipline
+which uses both AQM and FQ.  It combines COBALT, which is an AQM algorithm
+combining Codel and BLUE, a shaper which operates in deficit mode, and a variant
+of DRR++ for flow isolation.  8-way set-associative hashing is used to virtually
+eliminate hash collisions.  Priority queuing is available through a simplified
+diffserv implementation.  Overhead compensation for various encapsulation
+schemes is tightly integrated.
+
+All settings are optional; the default settings are chosen to be sensible in
+most common deployments.  Most people will only need to set the
+.B bandwidth
+parameter to get useful results, but reading the
+.B Overhead Compensation
+and
+.B Round Trip Time
+sections is strongly encouraged.
+
+.SH SHAPER PARAMETERS
+CAKE uses a deficit-mode shaper, which does not exhibit the initial burst
+typical of token-bucket shapers.  It will automatically burst precisely as much
+as required to maintain the configured throughput.  As such, it is very
+straightforward to configure.
+.PP
+.B unlimited
+(default)
+.br
+	No limit on the bandwidth.
+.PP
+.B bandwidth
+RATE
+.br
+	Set the shaper bandwidth.  See
+.BR tc(8)
+or examples below for details of the RATE value.
+.PP
+.B autorate-ingress
+.br
+	Automatic capacity estimation based on traffic arriving at this qdisc.
+This is most likely to be useful with cellular links, which tend to change
+quality randomly.  A
+.B bandwidth
+parameter can be used in conjunction to specify an initial estimate.  The shaper
+will periodically be set to a bandwidth slightly below the estimated rate.  This
+estimator cannot estimate the bandwidth of links downstream of itself.
+
+.SH OVERHEAD COMPENSATION PARAMETERS
+The size of each packet on the wire may differ from that seen by Linux.  The
+following parameters allow CAKE to compensate for this difference by internally
+considering each packet to be bigger than Linux informs it.  To assist users who
+are not expert network engineers, keywords have been provided to represent a
+number of common link technologies.
+
+.SS	Manual Overhead Specification
+.B overhead
+BYTES
+.br
+	Adds BYTES to the size of each packet.  BYTES may be negative; values
+between -64 and 256 (inclusive) are accepted.
+.PP
+.B mpu
+BYTES
+.br
+	Rounds each packet (including overhead) up to a minimum length
+BYTES. BYTES may not be negative; values between 0 and 256 (inclusive)
+are accepted.
+.PP
+.B atm
+.br
+	Compensates for ATM cell framing, which is normally found on ADSL links.
+This is performed after the
+.B overhead
+parameter above.  ATM uses fixed 53-byte cells, each of which can carry 48 bytes
+payload.
+.PP
+.B ptm
+.br
+	Compensates for PTM encoding, which is normally found on VDSL2 links and
+uses a 64b/65b encoding scheme. It is even more efficient to simply
+derate the specified shaper bandwidth by a factor of 64/65 or 0.984. See
+ITU G.992.3 Annex N and IEEE 802.3 Section 61.3 for details.
+.PP
+.B noatm
+.br
+	Disables ATM and PTM compensation.
+
+.SS	Failsafe Overhead Keywords
+These two keywords are provided for quick-and-dirty setup.  Use them if you
+can't be bothered to read the rest of this section.
+.PP
+.B raw
+(default)
+.br
+	Turns off all overhead compensation in CAKE.  The packet size reported
+by Linux will be used directly.
+.PP
+	Other overhead keywords may be added after "raw".  The effect of this is
+to make the overhead compensation operate relative to the reported packet size,
+not the underlying IP packet size.
+.PP
+.B conservative
+.br
+	Compensates for more overhead than is likely to occur on any
+widely-deployed link technology.
+.br
+	Equivalent to
+.B overhead 48 atm.
+
+.SS ADSL Overhead Keywords
+Most ADSL modems have a way to check which framing scheme is in use.  Often this
+is also specified in the settings document provided by the ISP.  The keywords in
+this section are intended to correspond with these sources of information.  All
+of them implicitly set the
+.B atm
+flag.
+.PP
+.B pppoa-vcmux
+.br
+	Equivalent to
+.B overhead 10 atm
+.PP
+.B pppoa-llc
+.br
+	Equivalent to
+.B overhead 14 atm
+.PP
+.B pppoe-vcmux
+.br
+	Equivalent to
+.B overhead 32 atm
+.PP
+.B pppoe-llcsnap
+.br
+	Equivalent to
+.B overhead 40 atm
+.PP
+.B bridged-vcmux
+.br
+	Equivalent to
+.B overhead 24 atm
+.PP
+.B bridged-llcsnap
+.br
+	Equivalent to
+.B overhead 32 atm
+.PP
+.B ipoa-vcmux
+.br
+	Equivalent to
+.B overhead 8 atm
+.PP
+.B ipoa-llcsnap
+.br
+	Equivalent to
+.B overhead 16 atm
+.PP
+See also the Ethernet Correction Factors section below.
+
+.SS VDSL2 Overhead Keywords
+ATM was dropped from VDSL2 in favour of PTM, which is a much more
+straightforward framing scheme.  Some ISPs retained PPPoE for compatibility with
+their existing back-end systems.
+.PP
+.B pppoe-ptm
+.br
+	Equivalent to
+.B overhead 30 ptm
+
+.br
+	PPPoE: 2B PPP + 6B PPPoE +
+.br
+	ETHERNET: 6B dest MAC + 6B src MAC + 2B ethertype + 4B Frame Check Sequence +
+.br
+	PTM: 1B Start of Frame (S) + 1B End of Frame (Ck) + 2B TC-CRC (PTM-FCS)
+.br
+.PP
+.B bridged-ptm
+.br
+	Equivalent to
+.B overhead 22 ptm
+.br
+	ETHERNET: 6B dest MAC + 6B src MAC + 2B ethertype + 4B Frame Check Sequence +
+.br
+	PTM: 1B Start of Frame (S) + 1B End of Frame (Ck) + 2B TC-CRC (PTM-FCS)
+.br
+.PP
+See also the Ethernet Correction Factors section below.
+
+.SS DOCSIS Cable Overhead Keyword
+DOCSIS is the universal standard for providing Internet service over cable-TV
+infrastructure.
+
+In this case, the actual on-wire overhead is less important than the packet size
+the head-end equipment uses for shaping and metering.  This is specified to be
+an Ethernet frame including the CRC (aka FCS).
+.PP
+.B docsis
+.br
+	Equivalent to
+.B overhead 18 mpu 64 noatm
+
+.SS Ethernet Overhead Keywords
+.PP
+.B ethernet
+.br
+	Accounts for Ethernet's preamble, inter-frame gap, and Frame Check
+Sequence.  Use this keyword when the bottleneck being shaped for is an
+actual Ethernet cable.
+.br
+	Equivalent to
+.B overhead 38 mpu 84 noatm
+.PP
+.B ether-vlan
+.br
+	Adds 4 bytes to the overhead compensation, accounting for an IEEE 802.1Q
+VLAN header appended to the Ethernet frame header.  NB: Some ISPs use one or
+even two of these within PPPoE; this keyword may be repeated as necessary to
+express this.
+
+.SH ROUND TRIP TIME PARAMETERS
+Active Queue Management (AQM) consists of embedding congestion signals in the
+packet flow, which receivers use to instruct senders to slow down when the queue
+is persistently occupied.  CAKE uses ECN signalling when available, and packet
+drops otherwise, according to a combination of the Codel and BLUE AQM algorithms
+called COBALT.
+
+Very short latencies require a very rapid AQM response to adequately control
+latency.  However, such a rapid response tends to impair throughput when the
+actual RTT is relatively long.  CAKE allows specifying the RTT it assumes for
+tuning various parameters.  Actual RTTs within an order of magnitude of this
+will generally work well for both throughput and latency management.
+
+At the 'lan' setting and below, the time constants are similar in magnitude to
+the jitter in the Linux kernel itself, so congestion might be signalled
+prematurely. The flows will then become sparse and total throughput reduced,
+leaving little or no back-pressure for the fairness logic to work against. Use
+the "metro" setting for local lans unless you have a custom kernel.
+.PP
+.B rtt
+TIME
+.br
+	Manually specify an RTT.
+.PP
+.B datacentre
+.br
+	For extremely high-performance 10GigE+ networks only.  Equivalent to
+.B rtt 100us.
+.PP
+.B lan
+.br
+	For pure Ethernet (not Wi-Fi) networks, at home or in the office.  Don't
+use this when shaping for an Internet access link.  Equivalent to
+.B rtt 1ms.
+.PP
+.B metro
+.br
+	For traffic mostly within a single city.  Equivalent to
+.B rtt 10ms.
+.PP
+.B regional
+.br
+	For traffic mostly within a European-sized country.  Equivalent to
+.B rtt 30ms.
+.PP
+.B internet
+(default)
+.br
+	This is suitable for most Internet traffic.  Equivalent to
+.B rtt 100ms.
+.PP
+.B oceanic
+.br
+	For Internet traffic with generally above-average latency, such as that
+suffered by Australasian residents.  Equivalent to
+.B rtt 300ms.
+.PP
+.B satellite
+.br
+	For traffic via geostationary satellites.  Equivalent to
+.B rtt 1000ms.
+.PP
+.B interplanetary
+.br
+	So named because Jupiter is about 1 light-hour from Earth.  Use this to
+(almost) completely disable AQM actions.  Equivalent to
+.B rtt 3600s.
+
+.SH FLOW ISOLATION PARAMETERS
+With flow isolation enabled, CAKE places packets from different flows into
+different queues, each of which carries its own AQM state.  Packets from each
+queue are then delivered fairly, according to a DRR++ algorithm which minimises
+latency for "sparse" flows.  CAKE uses a set-associative hashing algorithm to
+minimise flow collisions.
+
+These keywords specify whether fairness based on source address, destination
+address, individual flows, or any combination of those is desired.
+.PP
+.B flowblind
+.br
+	Disables flow isolation; all traffic passes through a single queue for
+each tin.
+.PP
+.B srchost
+.br
+	Flows are defined only by source address.  Could be useful on the egress
+path of an ISP backhaul.
+.PP
+.B dsthost
+.br
+	Flows are defined only by destination address.  Could be useful on the
+ingress path of an ISP backhaul.
+.PP
+.B hosts
+.br
+	Flows are defined by source-destination host pairs.  This is host
+isolation, rather than flow isolation.
+.PP
+.B flows
+.br
+	Flows are defined by the entire 5-tuple of source address, destination
+address, transport protocol, source port and destination port.  This is the type
+of flow isolation performed by SFQ and fq_codel.
+.PP
+.B dual-srchost
+.br
+	Flows are defined by the 5-tuple, and fairness is applied first over
+source addresses, then over individual flows.  Good for use on egress traffic
+from a LAN to the internet, where it'll prevent any one LAN host from
+monopolising the uplink, regardless of the number of flows they use.
+.PP
+.B dual-dsthost
+.br
+	Flows are defined by the 5-tuple, and fairness is applied first over
+destination addresses, then over individual flows.  Good for use on ingress
+traffic to a LAN from the internet, where it'll prevent any one LAN host from
+monopolising the downlink, regardless of the number of flows they use.
+.PP
+.B triple-isolate
+(default)
+.br
+	Flows are defined by the 5-tuple, and fairness is applied over source
+*and* destination addresses intelligently (ie. not merely by host-pairs), and
+also over individual flows.  Use this if you're not certain whether to use
+dual-srchost or dual-dsthost; it'll do both jobs at once, preventing any one
+host on *either* side of the link from monopolising it with a large number of
+flows.
+.PP
+.B nat
+.br
+	Instructs Cake to perform a NAT lookup before applying flow-isolation
+rules, to determine the true addresses and port numbers of the packet, to
+improve fairness between hosts "inside" the NAT.  This has no practical effect
+in "flowblind" or "flows" modes, or if NAT is performed on a different host.
+.PP
+.B nonat
+(default)
+.br
+	Cake will not perform a NAT lookup.  Flow isolation will be performed
+using the addresses and port numbers directly visible to the interface Cake is
+attached to.
+
+.SH PRIORITY QUEUE PARAMETERS
+CAKE can divide traffic into "tins" based on the Diffserv field.  Each tin has
+its own independent set of flow-isolation queues, and is serviced based on a WRR
+algorithm.  To avoid perverse Diffserv marking incentives, tin weights have a
+"priority sharing" value when bandwidth used by that tin is below a threshold,
+and a lower "bandwidth sharing" value when above.  Bandwidth is compared against
+the threshold using the same algorithm as the deficit-mode shaper.
+
+Detailed customisation of tin parameters is not provided.  The following presets
+perform all necessary tuning, relative to the current shaper bandwidth and RTT
+settings.
+.PP
+.B besteffort
+.br
+	Disables priority queuing by placing all traffic in one tin.
+.PP
+.B precedence
+.br
+	Enables legacy interpretation of TOS "Precedence" field.  Use of this
+preset on the modern Internet is firmly discouraged.
+.PP
+.B diffserv4
+.br
+	Provides a general-purpose Diffserv implementation with four tins:
+.br
+		Bulk (CS1), 6.25% threshold, generally low priority.
+.br
+		Best Effort (general), 100% threshold.
+.br
+		Video (AF4x, AF3x, CS3, AF2x, CS2, TOS4, TOS1), 50% threshold.
+.br
+		Voice (CS7, CS6, EF, VA, CS5, CS4), 25% threshold.
+.PP
+.B diffserv3
+(default)
+.br
+	Provides a simple, general-purpose Diffserv implementation with three tins:
+.br
+		Bulk (CS1), 6.25% threshold, generally low priority.
+.br
+		Best Effort (general), 100% threshold.
+.br
+		Voice (CS7, CS6, EF, VA, TOS4), 25% threshold, reduced Codel interval.
+
+.SH OTHER PARAMETERS
+.B memlimit
+LIMIT
+.br
+	Limit the memory consumed by Cake to LIMIT bytes. Note that this does
+not translate directly to queue size (so do not size this based on bandwidth
+delay product considerations, but rather on worst case acceptable memory
+consumption), as there is some overhead in the data structures containing the
+packets, especially for small packets.
+
+	By default, the limit is calculated based on the bandwidth and RTT
+settings.
+
+.PP
+.B wash
+
+.br
+	Traffic entering your diffserv domain is frequently mis-marked in
+transit from the perspective of your network, and traffic exiting yours may be
+mis-marked from the perspective of the transiting provider.
+
+Apply the wash option to clear all extra diffserv (but not ECN bits), after
+priority queuing has taken place.
+
+If you are shaping inbound, and cannot trust the diffserv markings (as is the
+case for Comcast Cable, among others), it is best to use a single queue
+"besteffort" mode with wash.
+
+.PP
+.B split-gso
+
+.br
+	This option controls whether CAKE will split General Segmentation
+Offload (GSO) super-packets into their on-the-wire components and
+dequeue them individually.
+
+.br
+Super-packets are created by the networking stack to improve efficiency.
+However, because they are larger they take longer to dequeue, which
+translates to higher latency for competing flows, especially at lower
+bandwidths. CAKE defaults to splitting GSO packets to achieve the lowest
+possible latency. At link speeds higher than 10 Gbps, setting the
+no-split-gso parameter can increase the maximum achievable throughput by
+retaining the full GSO packets.
+
+.SH OVERRIDING CLASSIFICATION WITH TC FILTERS
+
+CAKE supports overriding of its internal classification of packets through the
+tc filter mechanism. Packets can be assigned to different priority tins by
+setting the
+.B priority
+field on the skb, and the flow hashing can be overridden by setting the
+.B classid
+parameter.
+
+.PP
+.B Tin override
+
+.br
+        To assign a priority tin, the major number of the priority field needs
+to match the qdisc handle of the cake instance; if it does, the minor number
+will be interpreted as the tin index. For example, to classify all ICMP packets
+as 'bulk', the following filter can be used:
+
+.br
+        # tc qdisc replace dev eth0 handle 1: root cake diffserv3
+        # tc filter add dev eth0 parent 1: protocol ip prio 1 \\
+          u32 match icmp type 0 0 action skbedit priority 1:1
+
+.PP
+.B Flow hash override
+
+.br
+        To override flow hashing, the classid can be set. CAKE will interpret
+the major number of the classid as the host hash used in host isolation mode,
+and the minor number as the flow hash used for flow-based queueing. One or both
+of those can be set, and will be used if the relevant flow isolation parameter
+is set (i.e., the major number will be ignored if CAKE is not configured in
+hosts mode, and the minor number will be ignored if CAKE is not configured in
+flows mode).
+
+.br
+This example will assign all ICMP packets to the first queue:
+
+.br
+        # tc qdisc replace dev eth0 handle 1: root cake
+        # tc filter add dev eth0 parent 1: protocol ip prio 1 \\
+          u32 match icmp type 0 0 classid 0:1
+
+.br
+If only one of the host and flow overrides is set, CAKE will compute the other
+hash from the packet as normal. Note, however, that the host isolation mode
+works by assigning a host ID to the flow queue; so if overriding both host and
+flow, the same flow cannot have more than one host assigned. In addition, it is
+not possible to assign different source and destination host IDs through the
+override mechanism; if a host ID is assigned, it will be used as both source and
+destination host.
+
+
+
+.SH EXAMPLES
+# tc qdisc delete root dev eth0
+.br
+# tc qdisc add root dev eth0 cake bandwidth 100Mbit ethernet
+.br
+# tc -s qdisc show dev eth0
+.br
+qdisc cake 1: root refcnt 2 bandwidth 100Mbit diffserv3 triple-isolate rtt 100.0ms noatm overhead 38 mpu 84
+ 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
+
+After some use:
+.br
+# tc -s qdisc show dev eth0
+
+qdisc cake 1: root refcnt 2 bandwidth 100Mbit diffserv3 triple-isolate rtt 100.0ms noatm overhead 38 mpu 84
+ Sent 44709231 bytes 31931 pkt (dropped 45, overlimits 93782 requeues 0)
+ backlog 33308b 22p requeues 0
+ memory used: 292352b of 5000000b
+ capacity estimate: 100Mbit
+ min/max network layer size:           28 /    1500
+ min/max overhead-adjusted size:       84 /    1538
+ average network hdr offset:           14
+
+                   Bulk  Best Effort        Voice
+  thresh       6250Kbit      100Mbit       25Mbit
+  target          5.0ms        5.0ms        5.0ms
+  interval      100.0ms      100.0ms      100.0ms
+  pk_delay        8.7ms        6.9ms        5.0ms
+  av_delay        4.9ms        5.3ms        3.8ms
+  sp_delay        727us        1.4ms        511us
+  pkts             2590        21271         8137
+  bytes         3081804     30302659     11426206
+  way_inds            0           46            0
+  way_miss            3           17            4
+  way_cols            0            0            0
+  drops              20           15           10
+  marks               0            0            0
+  ack_drop            0            0            0
+  sp_flows            2            4            1
+  bk_flows            1            2            1
+  un_flows            0            0            0
+  max_len          1514         1514         1514
+  quantum           300         1514          762
+
+.SH SEE ALSO
+.BR tc (8),
+.BR tc-codel (8),
+.BR tc-fq_codel (8),
+.BR tc-htb (8)
+
+.SH AUTHORS
+Cake's principal author is Jonathan Morton, with contributions from
+Tony Ambardar, Kevin Darbyshire-Bryant, Toke Høiland-Jørgensen,
+Sebastian Moeller, Ryan Mounce, Dean Scarff, Nils Andreas Svee, and Dave Täht.
+
+This manual page was written by Loganaden Velvindron. Please report corrections
+to the Linux Networking mailing list <[email protected]>.
--- a/man/man8/tc.8
+++ b/man/man8/tc.8
@@ -795,6 +795,7 @@ was written by Alexey N. Kuznetsov and a
 .BR tc-basic (8),
 .BR tc-bfifo (8),
 .BR tc-bpf (8),
+.BR tc-cake (8),
 .BR tc-cbq (8),
 .BR tc-cgroup (8),
 .BR tc-choke (8),
--- a/tc/Makefile
+++ b/tc/Makefile
@@ -66,6 +66,7 @@ TCMODULES += q_codel.o
 TCMODULES += q_fq_codel.o
 TCMODULES += q_fq.o
 TCMODULES += q_pie.o
+TCMODULES += q_cake.o
 TCMODULES += q_hhf.o
 TCMODULES += q_clsact.o
 TCMODULES += e_bpf.o
--- /dev/null
+++ b/tc/q_cake.c
@@ -0,0 +1,805 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+
+/*
+ * Common Applications Kept Enhanced  --  CAKE
+ *
+ *  Copyright (C) 2014-2018 Jonathan Morton <[email protected]>
+ *  Copyright (C) 2017-2018 Toke Høiland-Jørgensen <[email protected]>
+ */
+
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <string.h>
+#include <inttypes.h>
+
+#include "utils.h"
+#include "tc_util.h"
+
+struct cake_preset {
+	char *name;
+	unsigned int target;
+	unsigned int interval;
+};
+
+static struct cake_preset presets[] = {
+	{"datacentre",		5,		100},
+	{"lan",			50,		1000},
+	{"metro",		500,		10000},
+	{"regional",		1500,		30000},
+	{"internet",		5000,		100000},
+	{"oceanic",		15000,		300000},
+	{"satellite",		50000,		1000000},
+	{"interplanetary",	50000000,	1000000000},
+};
+
+static const char * diffserv_names[CAKE_DIFFSERV_MAX] = {
+	[CAKE_DIFFSERV_DIFFSERV3] = "diffserv3",
+	[CAKE_DIFFSERV_DIFFSERV4] = "diffserv4",
+	[CAKE_DIFFSERV_DIFFSERV8] = "diffserv8",
+	[CAKE_DIFFSERV_BESTEFFORT] = "besteffort",
+	[CAKE_DIFFSERV_PRECEDENCE] = "precedence",
+};
+
+static const char * flowmode_names[CAKE_FLOW_MAX] = {
+	[CAKE_FLOW_NONE] = "flowblind",
+	[CAKE_FLOW_SRC_IP] = "srchost",
+	[CAKE_FLOW_DST_IP] = "dsthost",
+	[CAKE_FLOW_HOSTS] = "hosts",
+	[CAKE_FLOW_FLOWS] = "flows",
+	[CAKE_FLOW_DUAL_SRC] = "dual-srchost",
+	[CAKE_FLOW_DUAL_DST] = "dual-dsthost",
+	[CAKE_FLOW_TRIPLE] = "triple-isolate",
+};
+
+static struct cake_preset *find_preset(char *argv)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(presets); i++)
+		if (!strcmp(argv, presets[i].name))
+			return &presets[i];
+	return NULL;
+}
+
+static void explain(void)
+{
+	fprintf(stderr,
+"Usage: ... cake [ bandwidth RATE | unlimited* | autorate-ingress ]\n"
+"                [ rtt TIME | datacentre | lan | metro | regional |\n"
+"                  internet* | oceanic | satellite | interplanetary ]\n"
+"                [ besteffort | diffserv8 | diffserv4 | diffserv3* ]\n"
+"                [ flowblind | srchost | dsthost | hosts | flows |\n"
+"                  dual-srchost | dual-dsthost | triple-isolate* ]\n"
+"                [ nat | nonat* ]\n"
+"                [ wash | nowash* ]\n"
+"                [ split-gso* | no-split-gso ]\n"
+"                [ ack-filter | ack-filter-aggressive | no-ack-filter* ]\n"
+"                [ memlimit LIMIT ]\n"
+"                [ ptm | atm | noatm* ] [ overhead N | conservative | raw* ]\n"
+"                [ mpu N ] [ ingress | egress* ]\n"
+"                (* marks defaults)\n");
+}
+
+static int cake_parse_opt(struct qdisc_util *qu, int argc, char **argv,
+			  struct nlmsghdr *n, const char *dev)
+{
+	struct cake_preset *preset, *preset_set = NULL;
+	bool overhead_override = false;
+	bool overhead_set = false;
+	unsigned int interval = 0;
+	unsigned int diffserv = 0;
+	unsigned int memlimit = 0;
+	unsigned int target = 0;
+	__u64 bandwidth = 0;
+	int ack_filter = -1;
+	struct rtattr *tail;
+	int split_gso = -1;
+	int unlimited = 0;
+	int flowmode = -1;
+	int autorate = -1;
+	int ingress = -1;
+	int overhead = 0;
+	int wash = -1;
+	int nat = -1;
+	int atm = -1;
+	int mpu = 0;
+
+	while (argc > 0) {
+		if (strcmp(*argv, "bandwidth") == 0) {
+			NEXT_ARG();
+			if (get_rate64(&bandwidth, *argv)) {
+				fprintf(stderr, "Illegal \"bandwidth\"\n");
+				return -1;
+			}
+			unlimited = 0;
+			autorate = 0;
+		} else if (strcmp(*argv, "unlimited") == 0) {
+			bandwidth = 0;
+			unlimited = 1;
+			autorate = 0;
+		} else if (strcmp(*argv, "autorate-ingress") == 0) {
+			autorate = 1;
+		} else if (strcmp(*argv, "rtt") == 0) {
+			NEXT_ARG();
+			if (get_time(&interval, *argv)) {
+				fprintf(stderr, "Illegal \"rtt\"\n");
+				return -1;
+			}
+			target = interval / 20;
+			if (!target)
+				target = 1;
+		} else if ((preset = find_preset(*argv))) {
+			if (preset_set)
+				duparg(*argv, preset_set->name);
+			preset_set = preset;
+			target = preset->target;
+			interval = preset->interval;
+		} else if (strcmp(*argv, "besteffort") == 0) {
+			diffserv = CAKE_DIFFSERV_BESTEFFORT;
+		} else if (strcmp(*argv, "precedence") == 0) {
+			diffserv = CAKE_DIFFSERV_PRECEDENCE;
+		} else if (strcmp(*argv, "diffserv8") == 0) {
+			diffserv = CAKE_DIFFSERV_DIFFSERV8;
+		} else if (strcmp(*argv, "diffserv4") == 0) {
+			diffserv = CAKE_DIFFSERV_DIFFSERV4;
+		} else if (strcmp(*argv, "diffserv") == 0) {
+			diffserv = CAKE_DIFFSERV_DIFFSERV4;
+		} else if (strcmp(*argv, "diffserv3") == 0) {
+			diffserv = CAKE_DIFFSERV_DIFFSERV3;
+		} else if (strcmp(*argv, "nowash") == 0) {
+			wash = 0;
+		} else if (strcmp(*argv, "wash") == 0) {
+			wash = 1;
+		} else if (strcmp(*argv, "split-gso") == 0) {
+			split_gso = 1;
+		} else if (strcmp(*argv, "no-split-gso") == 0) {
+			split_gso = 0;
+		} else if (strcmp(*argv, "flowblind") == 0) {
+			flowmode = CAKE_FLOW_NONE;
+		} else if (strcmp(*argv, "srchost") == 0) {
+			flowmode = CAKE_FLOW_SRC_IP;
+		} else if (strcmp(*argv, "dsthost") == 0) {
+			flowmode = CAKE_FLOW_DST_IP;
+		} else if (strcmp(*argv, "hosts") == 0) {
+			flowmode = CAKE_FLOW_HOSTS;
+		} else if (strcmp(*argv, "flows") == 0) {
+			flowmode = CAKE_FLOW_FLOWS;
+		} else if (strcmp(*argv, "dual-srchost") == 0) {
+			flowmode = CAKE_FLOW_DUAL_SRC;
+		} else if (strcmp(*argv, "dual-dsthost") == 0) {
+			flowmode = CAKE_FLOW_DUAL_DST;
+		} else if (strcmp(*argv, "triple-isolate") == 0) {
+			flowmode = CAKE_FLOW_TRIPLE;
+		} else if (strcmp(*argv, "nat") == 0) {
+			nat = 1;
+		} else if (strcmp(*argv, "nonat") == 0) {
+			nat = 0;
+		} else if (strcmp(*argv, "ptm") == 0) {
+			atm = CAKE_ATM_PTM;
+		} else if (strcmp(*argv, "atm") == 0) {
+			atm = CAKE_ATM_ATM;
+		} else if (strcmp(*argv, "noatm") == 0) {
+			atm = CAKE_ATM_NONE;
+		} else if (strcmp(*argv, "raw") == 0) {
+			atm = CAKE_ATM_NONE;
+			overhead = 0;
+			overhead_set = true;
+			overhead_override = true;
+		} else if (strcmp(*argv, "conservative") == 0) {
+			/*
+			 * Deliberately over-estimate overhead:
+			 * one whole ATM cell plus ATM framing.
+			 * A safe choice if the actual overhead is unknown.
+			 */
+			atm = CAKE_ATM_ATM;
+			overhead = 48;
+			overhead_set = true;
+
+		/* Various ADSL framing schemes, all over ATM cells */
+		} else if (strcmp(*argv, "ipoa-vcmux") == 0) {
+			atm = CAKE_ATM_ATM;
+			overhead += 8;
+			overhead_set = true;
+		} else if (strcmp(*argv, "ipoa-llcsnap") == 0) {
+			atm = CAKE_ATM_ATM;
+			overhead += 16;
+			overhead_set = true;
+		} else if (strcmp(*argv, "bridged-vcmux") == 0) {
+			atm = CAKE_ATM_ATM;
+			overhead += 24;
+			overhead_set = true;
+		} else if (strcmp(*argv, "bridged-llcsnap") == 0) {
+			atm = CAKE_ATM_ATM;
+			overhead += 32;
+			overhead_set = true;
+		} else if (strcmp(*argv, "pppoa-vcmux") == 0) {
+			atm = CAKE_ATM_ATM;
+			overhead += 10;
+			overhead_set = true;
+		} else if (strcmp(*argv, "pppoa-llc") == 0) {
+			atm = CAKE_ATM_ATM;
+			overhead += 14;
+			overhead_set = true;
+		} else if (strcmp(*argv, "pppoe-vcmux") == 0) {
+			atm = CAKE_ATM_ATM;
+			overhead += 32;
+			overhead_set = true;
+		} else if (strcmp(*argv, "pppoe-llcsnap") == 0) {
+			atm = CAKE_ATM_ATM;
+			overhead += 40;
+			overhead_set = true;
+
+		/* Typical VDSL2 framing schemes, both over PTM */
+		/* PTM has 64b/65b coding which absorbs some bandwidth */
+		} else if (strcmp(*argv, "pppoe-ptm") == 0) {
+			/* 2B PPP + 6B PPPoE + 6B dest MAC + 6B src MAC
+			 * + 2B ethertype + 4B Frame Check Sequence
+			 * + 1B Start of Frame (S) + 1B End of Frame (Ck)
+			 * + 2B TC-CRC (PTM-FCS) = 30B
+			 */
+			atm = CAKE_ATM_PTM;
+			overhead += 30;
+			overhead_set = true;
+		} else if (strcmp(*argv, "bridged-ptm") == 0) {
+			/* 6B dest MAC + 6B src MAC + 2B ethertype
+			 * + 4B Frame Check Sequence
+			 * + 1B Start of Frame (S) + 1B End of Frame (Ck)
+			 * + 2B TC-CRC (PTM-FCS) = 22B
+			 */
+			atm = CAKE_ATM_PTM;
+			overhead += 22;
+			overhead_set = true;
+		} else if (strcmp(*argv, "via-ethernet") == 0) {
+			/*
+			 * We used to use this flag to manually compensate for
+			 * Linux including the Ethernet header on Ethernet-type
+			 * interfaces, but not on IP-type interfaces.
+			 *
+			 * It is no longer needed, because Cake now adjusts for
+			 * that automatically, and is thus ignored.
+			 *
+			 * It would be deleted entirely, but it appears in the
+			 * stats output when the automatic compensation is
+			 * active.
+			 */
+		} else if (strcmp(*argv, "ethernet") == 0) {
+			/* ethernet pre-amble & interframe gap & FCS
+			 * you may need to add vlan tag
+			 */
+			overhead += 38;
+			overhead_set = true;
+			mpu = 84;
+
+		/* Additional Ethernet-related overhead used by some ISPs */
+		} else if (strcmp(*argv, "ether-vlan") == 0) {
+			/* 802.1q VLAN tag - may be repeated */
+			overhead += 4;
+			overhead_set = true;
+
+		/*
+		 * DOCSIS cable shapers account for Ethernet frame with FCS,
+		 * but not interframe gap or preamble.
+		 */
+		} else if (strcmp(*argv, "docsis") == 0) {
+			atm = CAKE_ATM_NONE;
+			overhead += 18;
+			overhead_set = true;
+			mpu = 64;
+		} else if (strcmp(*argv, "overhead") == 0) {
+			char *p = NULL;
+
+			NEXT_ARG();
+			overhead = strtol(*argv, &p, 10);
+			if (!p || *p || !*argv ||
+			    overhead < -64 || overhead > 256) {
+				fprintf(stderr,
+					"Illegal \"overhead\", valid range is -64 to 256\\n");
+				return -1;
+			}
+			overhead_set = true;
+
+		} else if (strcmp(*argv, "mpu") == 0) {
+			char *p = NULL;
+
+			NEXT_ARG();
+			mpu = strtol(*argv, &p, 10);
+			if (!p || *p || !*argv || mpu < 0 || mpu > 256) {
+				fprintf(stderr,
+					"Illegal \"mpu\", valid range is 0 to 256\\n");
+				return -1;
+			}
+		} else if (strcmp(*argv, "ingress") == 0) {
+			ingress = 1;
+		} else if (strcmp(*argv, "egress") == 0) {
+			ingress = 0;
+		} else if (strcmp(*argv, "no-ack-filter") == 0) {
+			ack_filter = CAKE_ACK_NONE;
+		} else if (strcmp(*argv, "ack-filter") == 0) {
+			ack_filter = CAKE_ACK_FILTER;
+		} else if (strcmp(*argv, "ack-filter-aggressive") == 0) {
+			ack_filter = CAKE_ACK_AGGRESSIVE;
+		} else if (strcmp(*argv, "memlimit") == 0) {
+			NEXT_ARG();
+			if (get_size(&memlimit, *argv)) {
+				fprintf(stderr,
+					"Illegal value for \"memlimit\": \"%s\"\n", *argv);
+				return -1;
+			}
+		} else if (strcmp(*argv, "help") == 0) {
+			explain();
+			return -1;
+		} else {
+			fprintf(stderr, "What is \"%s\"?\n", *argv);
+			explain();
+			return -1;
+		}
+		argc--; argv++;
+	}
+
+	tail = NLMSG_TAIL(n);
+	addattr_l(n, 1024, TCA_OPTIONS, NULL, 0);
+	if (bandwidth || unlimited)
+		addattr_l(n, 1024, TCA_CAKE_BASE_RATE64, &bandwidth,
+			  sizeof(bandwidth));
+	if (diffserv)
+		addattr_l(n, 1024, TCA_CAKE_DIFFSERV_MODE, &diffserv,
+			  sizeof(diffserv));
+	if (atm != -1)
+		addattr_l(n, 1024, TCA_CAKE_ATM, &atm, sizeof(atm));
+	if (flowmode != -1)
+		addattr_l(n, 1024, TCA_CAKE_FLOW_MODE, &flowmode,
+			  sizeof(flowmode));
+	if (overhead_set)
+		addattr_l(n, 1024, TCA_CAKE_OVERHEAD, &overhead,
+			  sizeof(overhead));
+	if (overhead_override) {
+		unsigned int zero = 0;
+
+		addattr_l(n, 1024, TCA_CAKE_RAW, &zero, sizeof(zero));
+	}
+	if (mpu > 0)
+		addattr_l(n, 1024, TCA_CAKE_MPU, &mpu, sizeof(mpu));
+	if (interval)
+		addattr_l(n, 1024, TCA_CAKE_RTT, &interval, sizeof(interval));
+	if (target)
+		addattr_l(n, 1024, TCA_CAKE_TARGET, &target, sizeof(target));
+	if (autorate != -1)
+		addattr_l(n, 1024, TCA_CAKE_AUTORATE, &autorate,
+			  sizeof(autorate));
+	if (memlimit)
+		addattr_l(n, 1024, TCA_CAKE_MEMORY, &memlimit,
+			  sizeof(memlimit));
+	if (nat != -1)
+		addattr_l(n, 1024, TCA_CAKE_NAT, &nat, sizeof(nat));
+	if (wash != -1)
+		addattr_l(n, 1024, TCA_CAKE_WASH, &wash, sizeof(wash));
+	if (split_gso != -1)
+		addattr_l(n, 1024, TCA_CAKE_SPLIT_GSO, &split_gso,
+			  sizeof(split_gso));
+	if (ingress != -1)
+		addattr_l(n, 1024, TCA_CAKE_INGRESS, &ingress, sizeof(ingress));
+	if (ack_filter != -1)
+		addattr_l(n, 1024, TCA_CAKE_ACK_FILTER, &ack_filter,
+			  sizeof(ack_filter));
+
+	tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
+	return 0;
+}
+
+static void cake_print_mode(unsigned int value, unsigned int max,
+			    const char *key, const char **table)
+{
+	if (value < max && table[value]) {
+		print_string(PRINT_ANY, key, "%s ", table[value]);
+	} else {
+		print_string(PRINT_JSON, key, NULL, "unknown");
+		print_string(PRINT_FP, NULL, "(?%s?)", key);
+	}
+}
+
+static int cake_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
+{
+	struct rtattr *tb[TCA_CAKE_MAX + 1];
+	unsigned int interval = 0;
+	unsigned int memlimit = 0;
+	__u64 bandwidth = 0;
+	int ack_filter = 0;
+	int split_gso = 0;
+	int overhead = 0;
+	int autorate = 0;
+	int ingress = 0;
+	int wash = 0;
+	int raw = 0;
+	int mpu = 0;
+	int atm = 0;
+	int nat = 0;
+
+	SPRINT_BUF(b1);
+	SPRINT_BUF(b2);
+
+	if (opt == NULL)
+		return 0;
+
+	parse_rtattr_nested(tb, TCA_CAKE_MAX, opt);
+
+	if (tb[TCA_CAKE_BASE_RATE64] &&
+	    RTA_PAYLOAD(tb[TCA_CAKE_BASE_RATE64]) >= sizeof(bandwidth)) {
+		bandwidth = rta_getattr_u64(tb[TCA_CAKE_BASE_RATE64]);
+		if (bandwidth) {
+			print_uint(PRINT_JSON, "bandwidth", NULL, bandwidth);
+			print_string(PRINT_FP, NULL, "bandwidth %s ",
+				     sprint_rate(bandwidth, b1));
+		} else
+			print_string(PRINT_ANY, "bandwidth", "bandwidth %s ",
+				     "unlimited");
+	}
+	if (tb[TCA_CAKE_AUTORATE] &&
+		RTA_PAYLOAD(tb[TCA_CAKE_AUTORATE]) >= sizeof(__u32)) {
+		autorate = rta_getattr_u32(tb[TCA_CAKE_AUTORATE]);
+		if (autorate == 1)
+			print_string(PRINT_ANY, "autorate", "%s ",
+				     "autorate-ingress");
+		else if (autorate)
+			print_string(PRINT_ANY, "autorate", "(?autorate?) ",
+				     "unknown");
+	}
+	if (tb[TCA_CAKE_DIFFSERV_MODE] &&
+	    RTA_PAYLOAD(tb[TCA_CAKE_DIFFSERV_MODE]) >= sizeof(__u32)) {
+		cake_print_mode(rta_getattr_u32(tb[TCA_CAKE_DIFFSERV_MODE]),
+				CAKE_DIFFSERV_MAX, "diffserv", diffserv_names);
+	}
+	if (tb[TCA_CAKE_FLOW_MODE] &&
+	    RTA_PAYLOAD(tb[TCA_CAKE_FLOW_MODE]) >= sizeof(__u32)) {
+		cake_print_mode(rta_getattr_u32(tb[TCA_CAKE_FLOW_MODE]),
+				CAKE_FLOW_MAX, "flowmode", flowmode_names);
+	}
+
+	if (tb[TCA_CAKE_NAT] &&
+	    RTA_PAYLOAD(tb[TCA_CAKE_NAT]) >= sizeof(__u32)) {
+		nat = rta_getattr_u32(tb[TCA_CAKE_NAT]);
+	}
+
+	if (nat)
+		print_string(PRINT_FP, NULL, "nat ", NULL);
+	else
+		print_string(PRINT_FP, NULL, "nonat ", NULL);
+	print_bool(PRINT_JSON, "nat", NULL, nat);
+
+	if (tb[TCA_CAKE_WASH] &&
+	    RTA_PAYLOAD(tb[TCA_CAKE_WASH]) >= sizeof(__u32)) {
+		wash = rta_getattr_u32(tb[TCA_CAKE_WASH]);
+	}
+	if (tb[TCA_CAKE_ATM] &&
+	    RTA_PAYLOAD(tb[TCA_CAKE_ATM]) >= sizeof(__u32)) {
+		atm = rta_getattr_u32(tb[TCA_CAKE_ATM]);
+	}
+	if (tb[TCA_CAKE_OVERHEAD] &&
+	    RTA_PAYLOAD(tb[TCA_CAKE_OVERHEAD]) >= sizeof(__s32)) {
+		overhead = *(__s32 *) RTA_DATA(tb[TCA_CAKE_OVERHEAD]);
+	}
+	if (tb[TCA_CAKE_MPU] &&
+	    RTA_PAYLOAD(tb[TCA_CAKE_MPU]) >= sizeof(__u32)) {
+		mpu = rta_getattr_u32(tb[TCA_CAKE_MPU]);
+	}
+	if (tb[TCA_CAKE_INGRESS] &&
+	    RTA_PAYLOAD(tb[TCA_CAKE_INGRESS]) >= sizeof(__u32)) {
+		ingress = rta_getattr_u32(tb[TCA_CAKE_INGRESS]);
+	}
+	if (tb[TCA_CAKE_ACK_FILTER] &&
+	    RTA_PAYLOAD(tb[TCA_CAKE_ACK_FILTER]) >= sizeof(__u32)) {
+		ack_filter = rta_getattr_u32(tb[TCA_CAKE_ACK_FILTER]);
+	}
+	if (tb[TCA_CAKE_SPLIT_GSO] &&
+	    RTA_PAYLOAD(tb[TCA_CAKE_SPLIT_GSO]) >= sizeof(__u32)) {
+		split_gso = rta_getattr_u32(tb[TCA_CAKE_SPLIT_GSO]);
+	}
+	if (tb[TCA_CAKE_RAW]) {
+		raw = 1;
+	}
+	if (tb[TCA_CAKE_RTT] &&
+	    RTA_PAYLOAD(tb[TCA_CAKE_RTT]) >= sizeof(__u32)) {
+		interval = rta_getattr_u32(tb[TCA_CAKE_RTT]);
+	}
+
+	if (wash)
+		print_string(PRINT_FP, NULL, "wash ", NULL);
+	else
+		print_string(PRINT_FP, NULL, "nowash ", NULL);
+	print_bool(PRINT_JSON, "wash", NULL, wash);
+
+	if (ingress)
+		print_string(PRINT_FP, NULL, "ingress ", NULL);
+	print_bool(PRINT_JSON, "ingress", NULL, ingress);
+
+	if (ack_filter == CAKE_ACK_AGGRESSIVE)
+		print_string(PRINT_ANY, "ack-filter", "ack-filter-%s ",
+			     "aggressive");
+	else if (ack_filter == CAKE_ACK_FILTER)
+		print_string(PRINT_ANY, "ack-filter", "ack-filter ", "enabled");
+	else
+		print_string(PRINT_ANY, "ack-filter", "no-ack-filter ", "disabled");
+
+	if (split_gso)
+		print_string(PRINT_FP, NULL, "split-gso ", NULL);
+	else
+		print_string(PRINT_FP, NULL, "no-split-gso ", NULL);
+	print_bool(PRINT_JSON, "split_gso", NULL, split_gso);
+
+	if (interval)
+		print_string(PRINT_FP, NULL, "rtt %s ",
+			     sprint_time(interval, b2));
+	print_uint(PRINT_JSON, "rtt", NULL, interval);
+
+	if (raw)
+		print_string(PRINT_FP, NULL, "raw ", NULL);
+	print_bool(PRINT_JSON, "raw", NULL, raw);
+
+	if (atm == CAKE_ATM_ATM)
+		print_string(PRINT_ANY, "atm", "%s ", "atm");
+	else if (atm == CAKE_ATM_PTM)
+		print_string(PRINT_ANY, "atm", "%s ", "ptm");
+	else if (!raw)
+		print_string(PRINT_ANY, "atm", "%s ", "noatm");
+
+	print_int(PRINT_ANY, "overhead", "overhead %d ", overhead);
+
+	if (mpu)
+		print_uint(PRINT_ANY, "mpu", "mpu %u ", mpu);
+
+	if (memlimit) {
+		print_uint(PRINT_JSON, "memlimit", NULL, memlimit);
+		print_string(PRINT_FP, NULL, "memlimit %s",
+			     sprint_size(memlimit, b1));
+	}
+
+	return 0;
+}
+
+static void cake_print_json_tin(struct rtattr **tstat)
+{
+#define PRINT_TSTAT_JSON(type, name, attr) if (tstat[TCA_CAKE_TIN_STATS_ ## attr]) \
+		print_u64(PRINT_JSON, name, NULL,			\
+			rta_getattr_ ## type((struct rtattr *)		\
+					     tstat[TCA_CAKE_TIN_STATS_ ## attr]))
+
+	open_json_object(NULL);
+	PRINT_TSTAT_JSON(u64, "threshold_rate", THRESHOLD_RATE64);
+	PRINT_TSTAT_JSON(u64, "sent_bytes", SENT_BYTES64);
+	PRINT_TSTAT_JSON(u32, "backlog_bytes", BACKLOG_BYTES);
+	PRINT_TSTAT_JSON(u32, "target_us", TARGET_US);
+	PRINT_TSTAT_JSON(u32, "interval_us", INTERVAL_US);
+	PRINT_TSTAT_JSON(u32, "peak_delay_us", PEAK_DELAY_US);
+	PRINT_TSTAT_JSON(u32, "avg_delay_us", AVG_DELAY_US);
+	PRINT_TSTAT_JSON(u32, "base_delay_us", BASE_DELAY_US);
+	PRINT_TSTAT_JSON(u32, "sent_packets", SENT_PACKETS);
+	PRINT_TSTAT_JSON(u32, "way_indirect_hits", WAY_INDIRECT_HITS);
+	PRINT_TSTAT_JSON(u32, "way_misses", WAY_MISSES);
+	PRINT_TSTAT_JSON(u32, "way_collisions", WAY_COLLISIONS);
+	PRINT_TSTAT_JSON(u32, "drops", DROPPED_PACKETS);
+	PRINT_TSTAT_JSON(u32, "ecn_mark", ECN_MARKED_PACKETS);
+	PRINT_TSTAT_JSON(u32, "ack_drops", ACKS_DROPPED_PACKETS);
+	PRINT_TSTAT_JSON(u32, "sparse_flows", SPARSE_FLOWS);
+	PRINT_TSTAT_JSON(u32, "bulk_flows", BULK_FLOWS);
+	PRINT_TSTAT_JSON(u32, "unresponsive_flows", UNRESPONSIVE_FLOWS);
+	PRINT_TSTAT_JSON(u32, "max_pkt_len", MAX_SKBLEN);
+	PRINT_TSTAT_JSON(u32, "flow_quantum", FLOW_QUANTUM);
+	close_json_object();
+
+#undef PRINT_TSTAT_JSON
+}
+
+static int cake_print_xstats(struct qdisc_util *qu, FILE *f,
+			     struct rtattr *xstats)
+{
+	struct rtattr *st[TCA_CAKE_STATS_MAX + 1];
+	SPRINT_BUF(b1);
+	int i;
+
+	if (xstats == NULL)
+		return 0;
+
+#define GET_STAT_U32(attr) rta_getattr_u32(st[TCA_CAKE_STATS_ ## attr])
+#define GET_STAT_S32(attr) (*(__s32 *)RTA_DATA(st[TCA_CAKE_STATS_ ## attr]))
+#define GET_STAT_U64(attr) rta_getattr_u64(st[TCA_CAKE_STATS_ ## attr])
+
+	parse_rtattr_nested(st, TCA_CAKE_STATS_MAX, xstats);
+
+	if (st[TCA_CAKE_STATS_MEMORY_USED] &&
+	    st[TCA_CAKE_STATS_MEMORY_LIMIT]) {
+		print_string(PRINT_FP, NULL, " memory used: %s",
+			sprint_size(GET_STAT_U32(MEMORY_USED), b1));
+
+		print_string(PRINT_FP, NULL, " of %s\n",
+			sprint_size(GET_STAT_U32(MEMORY_LIMIT), b1));
+
+		print_uint(PRINT_JSON, "memory_used", NULL,
+			GET_STAT_U32(MEMORY_USED));
+		print_uint(PRINT_JSON, "memory_limit", NULL,
+			GET_STAT_U32(MEMORY_LIMIT));
+	}
+
+	if (st[TCA_CAKE_STATS_CAPACITY_ESTIMATE64]) {
+		print_string(PRINT_FP, NULL, " capacity estimate: %s\n",
+			sprint_rate(GET_STAT_U64(CAPACITY_ESTIMATE64), b1));
+		print_uint(PRINT_JSON, "capacity_estimate", NULL,
+			GET_STAT_U64(CAPACITY_ESTIMATE64));
+	}
+
+	if (st[TCA_CAKE_STATS_MIN_NETLEN] &&
+	    st[TCA_CAKE_STATS_MAX_NETLEN]) {
+		print_uint(PRINT_ANY, "min_network_size",
+			   " min/max network layer size: %12u",
+			   GET_STAT_U32(MIN_NETLEN));
+		print_uint(PRINT_ANY, "max_network_size",
+			   " /%8u\n", GET_STAT_U32(MAX_NETLEN));
+	}
+
+	if (st[TCA_CAKE_STATS_MIN_ADJLEN] &&
+	    st[TCA_CAKE_STATS_MAX_ADJLEN]) {
+		print_uint(PRINT_ANY, "min_adj_size",
+			   " min/max overhead-adjusted size: %8u",
+			   GET_STAT_U32(MIN_ADJLEN));
+		print_uint(PRINT_ANY, "max_adj_size",
+			   " /%8u\n", GET_STAT_U32(MAX_ADJLEN));
+	}
+
+	if (st[TCA_CAKE_STATS_AVG_NETOFF])
+		print_uint(PRINT_ANY, "avg_hdr_offset",
+			   " average network hdr offset: %12u\n\n",
+			   GET_STAT_U32(AVG_NETOFF));
+
+	/* class stats */
+	if (st[TCA_CAKE_STATS_DEFICIT])
+		print_int(PRINT_ANY, "deficit", "  deficit %u",
+			  GET_STAT_S32(DEFICIT));
+	if (st[TCA_CAKE_STATS_COBALT_COUNT])
+		print_uint(PRINT_ANY, "count", " count %u",
+			   GET_STAT_U32(COBALT_COUNT));
+
+	if (st[TCA_CAKE_STATS_DROPPING] && GET_STAT_U32(DROPPING)) {
+		print_bool(PRINT_ANY, "dropping", " dropping", true);
+		if (st[TCA_CAKE_STATS_DROP_NEXT_US]) {
+			int drop_next = GET_STAT_S32(DROP_NEXT_US);
+
+			if (drop_next < 0) {
+				print_string(PRINT_FP, NULL, " drop_next -%s",
+					sprint_time(drop_next, b1));
+			} else {
+				print_uint(PRINT_JSON, "drop_next", NULL,
+					drop_next);
+				print_string(PRINT_FP, NULL, " drop_next %s",
+					sprint_time(drop_next, b1));
+			}
+		}
+	}
+
+	if (st[TCA_CAKE_STATS_P_DROP]) {
+		print_uint(PRINT_ANY, "blue_prob", " blue_prob %u",
+			   GET_STAT_U32(P_DROP));
+		if (st[TCA_CAKE_STATS_BLUE_TIMER_US]) {
+			int blue_timer = GET_STAT_S32(BLUE_TIMER_US);
+
+			if (blue_timer < 0) {
+				print_string(PRINT_FP, NULL, " blue_timer -%s",
+					sprint_time(blue_timer, b1));
+			} else {
+				print_uint(PRINT_JSON, "blue_timer", NULL,
+					blue_timer);
+				print_string(PRINT_FP, NULL, " blue_timer %s",
+					sprint_time(blue_timer, b1));
+			}
+		}
+	}
+
+#undef GET_STAT_U32
+#undef GET_STAT_S32
+#undef GET_STAT_U64
+
+	if (st[TCA_CAKE_STATS_TIN_STATS]) {
+		struct rtattr *tstat[TC_CAKE_MAX_TINS][TCA_CAKE_TIN_STATS_MAX + 1];
+		struct rtattr *tins[TC_CAKE_MAX_TINS + 1];
+		int num_tins = 0;
+
+		parse_rtattr_nested(tins, TC_CAKE_MAX_TINS,
+				    st[TCA_CAKE_STATS_TIN_STATS]);
+
+		for (i = 1; i <= TC_CAKE_MAX_TINS && tins[i]; i++) {
+			parse_rtattr_nested(tstat[i-1], TCA_CAKE_TIN_STATS_MAX,
+					    tins[i]);
+			num_tins++;
+		}
+
+		if (!num_tins)
+			return 0;
+
+		if (is_json_context()) {
+			open_json_array(PRINT_JSON, "tins");
+			for (i = 0; i < num_tins; i++)
+				cake_print_json_tin(tstat[i]);
+			close_json_array(PRINT_JSON, NULL);
+
+			return 0;
+		}
+
+
+		switch (num_tins) {
+		case 3:
+			fprintf(f, "                   Bulk  Best Effort        Voice\n");
+			break;
+
+		case 4:
+			fprintf(f, "                   Bulk  Best Effort        Video        Voice\n");
+			break;
+
+		default:
+			fprintf(f, "          ");
+			for (i = 0; i < num_tins; i++)
+				fprintf(f, "        Tin %u", i);
+			fprintf(f, "\n");
+		};
+
+#define GET_TSTAT(i, attr) (tstat[i][TCA_CAKE_TIN_STATS_ ## attr])
+#define PRINT_TSTAT(name, attr, fmts, val)	do {		\
+			if (GET_TSTAT(0, attr)) {		\
+				fprintf(f, name);		\
+				for (i = 0; i < num_tins; i++)	\
+					fprintf(f, " %12" fmts,	val);	\
+				fprintf(f, "\n");			\
+			}						\
+		} while (0)
+
+#define SPRINT_TSTAT(pfunc, type, name, attr) PRINT_TSTAT(		\
+			name, attr, "s", sprint_ ## pfunc(		\
+				rta_getattr_ ## type(GET_TSTAT(i, attr)), b1))
+
+#define PRINT_TSTAT_U32(name, attr)	PRINT_TSTAT(			\
+			name, attr, "u", rta_getattr_u32(GET_TSTAT(i, attr)))
+
+#define PRINT_TSTAT_U64(name, attr)	PRINT_TSTAT(			\
+			name, attr, "llu", rta_getattr_u64(GET_TSTAT(i, attr)))
+
+		SPRINT_TSTAT(rate, u64, "  thresh  ", THRESHOLD_RATE64);
+		SPRINT_TSTAT(time, u32, "  target  ", TARGET_US);
+		SPRINT_TSTAT(time, u32, "  interval", INTERVAL_US);
+		SPRINT_TSTAT(time, u32, "  pk_delay", PEAK_DELAY_US);
+		SPRINT_TSTAT(time, u32, "  av_delay", AVG_DELAY_US);
+		SPRINT_TSTAT(time, u32, "  sp_delay", BASE_DELAY_US);
+		SPRINT_TSTAT(size, u32, "  backlog ", BACKLOG_BYTES);
+
+		PRINT_TSTAT_U32("  pkts    ", SENT_PACKETS);
+		PRINT_TSTAT_U64("  bytes   ", SENT_BYTES64);
+
+		PRINT_TSTAT_U32("  way_inds", WAY_INDIRECT_HITS);
+		PRINT_TSTAT_U32("  way_miss", WAY_MISSES);
+		PRINT_TSTAT_U32("  way_cols", WAY_COLLISIONS);
+		PRINT_TSTAT_U32("  drops   ", DROPPED_PACKETS);
+		PRINT_TSTAT_U32("  marks   ", ECN_MARKED_PACKETS);
+		PRINT_TSTAT_U32("  ack_drop", ACKS_DROPPED_PACKETS);
+		PRINT_TSTAT_U32("  sp_flows", SPARSE_FLOWS);
+		PRINT_TSTAT_U32("  bk_flows", BULK_FLOWS);
+		PRINT_TSTAT_U32("  un_flows", UNRESPONSIVE_FLOWS);
+		PRINT_TSTAT_U32("  max_len ", MAX_SKBLEN);
+		PRINT_TSTAT_U32("  quantum ", FLOW_QUANTUM);
+
+#undef GET_STAT
+#undef PRINT_TSTAT
+#undef SPRINT_TSTAT
+#undef PRINT_TSTAT_U32
+#undef PRINT_TSTAT_U64
+	}
+	return 0;
+}
+
+struct qdisc_util cake_qdisc_util = {
+	.id		= "cake",
+	.parse_qopt	= cake_parse_opt,
+	.print_qopt	= cake_print_opt,
+	.print_xstats	= cake_print_xstats,
+};