* [PATCH net-next v4] Add Common Applications Kept Enhanced (cake) qdisc
@ 2018-04-27 12:17 Toke Høiland-Jørgensen
2018-04-27 12:17 ` [PATCH iproute2-next v5] Add support for cake qdisc Toke Høiland-Jørgensen
2018-04-27 13:17 ` [PATCH net-next v4] Add Common Applications Kept Enhanced (cake) qdisc Eric Dumazet
0 siblings, 2 replies; 7+ messages in thread
From: Toke Høiland-Jørgensen @ 2018-04-27 12:17 UTC (permalink / raw)
To: netdev; +Cc: cake, Toke Høiland-Jørgensen, Dave Taht
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
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>
---
Changelog:
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.
include/uapi/linux/pkt_sched.h | 105 ++
net/sched/Kconfig | 11 +
net/sched/Makefile | 1 +
net/sched/sch_cake.c | 2641 ++++++++++++++++++++++++++++++++
4 files changed, 2758 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..bc581473c0b0 100644
--- a/include/uapi/linux/pkt_sched.h
+++ b/include/uapi/linux/pkt_sched.h
@@ -934,4 +934,109 @@ enum {
#define TCA_CBS_MAX (__TCA_CBS_MAX - 1)
+/* CAKE */
+enum {
+ TCA_CAKE_UNSPEC,
+ TCA_CAKE_BASE_RATE,
+ 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_CAPACITY_ESTIMATE,
+ 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_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_BYTES64,
+ TCA_CAKE_TIN_STATS_THRESHOLD_RATE,
+ 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..52af01a3f5bc
--- /dev/null
+++ b/net/sched/sch_cake.c
@@ -0,0 +1,2641 @@
+// 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 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/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)
+#define CAKE_SPLIT_GSO_THRESHOLD (125000000) /* 1Gbps */
+#define US2TIME(a) (a * (u64)NSEC_PER_USEC)
+
+typedef u64 cobalt_time_t;
+typedef s64 cobalt_tdiff_t;
+
+/**
+ * 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 {
+ cobalt_time_t interval;
+ cobalt_time_t target;
+ cobalt_time_t 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;
+ cobalt_time_t drop_next;
+ cobalt_time_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 sk_buff *ackcheck;
+ struct list_head flowchain;
+ s32 deficit;
+ 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 */
+ u32 perturb;
+ 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) */
+ u64 tin_time_next_packet;
+ u32 tin_rate_ns;
+ u32 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 */
+ cobalt_time_t avge_delay;
+ cobalt_time_t peak_delay;
+ cobalt_time_t 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 cake_tin_data *tins;
+
+ struct cake_heap_entry overflow_heap[CAKE_QUEUES * CAKE_MAX_TINS];
+ u16 overflow_timeout;
+
+ u16 tin_cnt;
+ u8 tin_mode;
+#define CAKE_FLOW_NAT_FLAG 64
+ u8 flow_mode;
+ u8 ack_filter;
+ u8 atm_mode;
+
+ /* time_next = time_this + ((len * rate_ns) >> rate_shft) */
+ u16 rate_shft;
+ u64 time_next_packet;
+ u64 failsafe_next_packet;
+ u32 rate_ns;
+ u32 rate_bps;
+ u16 rate_flags;
+ s16 rate_overhead;
+ u16 rate_mpu;
+ u32 interval;
+ u32 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 */
+ u64 last_packet_time;
+ u64 avg_packet_interval;
+ u64 avg_window_begin;
+ u32 avg_window_bytes;
+ u32 avg_peak_bandwidth;
+ u64 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 {
+ cobalt_time_t enqueue_time;
+ u32 adjusted_len;
+};
+
+static inline cobalt_time_t cobalt_get_time(void)
+{
+ return ktime_get_ns();
+}
+
+static inline u32 cobalt_time_to_us(cobalt_time_t val)
+{
+ do_div(val, NSEC_PER_USEC);
+ return (u32)val;
+}
+
+static inline 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 inline cobalt_time_t cobalt_get_enqueue_time(const struct sk_buff *skb)
+{
+ return get_cobalt_cb(skb)->enqueue_time;
+}
+
+static inline void cobalt_set_enqueue_time(struct sk_buff *skb,
+ cobalt_time_t now)
+{
+ get_cobalt_cb(skb)->enqueue_time = now;
+}
+
+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};
+
+/* 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 = vars->rec_inv_sqrt;
+ u32 invsqrt2 = ((u64)invsqrt * invsqrt) >> 32;
+ u64 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 cobalt_time_t cobalt_control(cobalt_time_t t,
+ cobalt_time_t interval,
+ u32 rec_inv_sqrt)
+{
+ return 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,
+ cobalt_time_t now)
+{
+ bool up = false;
+
+ if ((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,
+ cobalt_time_t now)
+{
+ bool down = false;
+
+ if (vars->p_drop && (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 && (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,
+ cobalt_time_t now,
+ struct sk_buff *skb,
+ u32 bulk_flows)
+{
+ bool drop = false;
+
+ /* Simplified Codel implementation */
+ cobalt_tdiff_t sojourn = now - cobalt_get_enqueue_time(skb);
+
+/* 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.
+ */
+
+ cobalt_tdiff_t schedule = now - vars->drop_next;
+
+ bool over_target = sojourn > p->target &&
+ sojourn > p->mtu_time * bulk_flows * 2 &&
+ sojourn > p->mtu_time * 4;
+ bool next_due = vars->count && 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 = 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 = now - vars->drop_next;
+ next_due = vars->count && 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 = now + p->interval;
+ else if (schedule > 0 && !drop)
+ vars->drop_next = now;
+
+ return drop;
+}
+
+#if IS_REACHABLE(CONFIG_NF_CONNTRACK)
+
+static inline void cake_update_flowkeys(struct flow_keys *keys,
+ const struct sk_buff *skb)
+{
+ enum ip_conntrack_info ctinfo;
+ bool rev = false;
+
+ struct nf_conn *ct;
+ const struct nf_conntrack_tuple *tuple;
+
+ 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 inline 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.
+ */
+
+static inline bool cake_dsrc(int flow_mode)
+{
+ return (flow_mode & CAKE_FLOW_DUAL_SRC) == CAKE_FLOW_DUAL_SRC;
+}
+
+static inline bool cake_ddst(int flow_mode)
+{
+ return (flow_mode & CAKE_FLOW_DUAL_DST) == CAKE_FLOW_DUAL_DST;
+}
+
+static inline u32
+cake_hash(struct cake_tin_data *q, const struct sk_buff *skb, int flow_mode)
+{
+ struct flow_keys keys, host_keys;
+ u32 flow_hash = 0, srchost_hash, dsthost_hash;
+ u16 reduced_hash, srchost_idx, dsthost_idx;
+
+ if (unlikely(flow_mode == CAKE_FLOW_NONE))
+ return 0;
+
+ 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.
+ */
+ 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;
+ u32 i, k;
+ bool allocate_src = false;
+ bool allocate_dst = false;
+
+ /* 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;
+}
+
+/* helper functions : might be changed when/if skb use a standard list_head */
+/* remove one skb from head of slot queue */
+
+static inline struct sk_buff *dequeue_head(struct cake_flow *flow)
+{
+ struct sk_buff *skb = flow->head;
+
+ if (skb) {
+ flow->head = skb->next;
+ skb->next = NULL;
+
+ if (skb == flow->ackcheck)
+ flow->ackcheck = NULL;
+ }
+
+ return skb;
+}
+
+/* add skb to flow queue (tail add) */
+
+static inline 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 struct sk_buff *cake_ack_filter(struct cake_sched_data *q,
+ struct cake_flow *flow)
+{
+ int seglen;
+ struct sk_buff *skb = flow->tail, *skb_check, *skb_check_prev;
+ struct iphdr *iph, *iph_check;
+ struct ipv6hdr *ipv6h, *ipv6h_check;
+ struct tcphdr *tcph, *tcph_check;
+ bool otherconn_ack_seen = false;
+ struct sk_buff *otherconn_checked_to = NULL;
+ bool thisconn_redundant_seen = false, thisconn_seen_last = false;
+ struct sk_buff *thisconn_checked_to = NULL, *thisconn_ack = NULL;
+ bool aggressive = q->ack_filter == CAKE_ACK_AGGRESSIVE;
+
+ /* no other possible ACKs to filter */
+ if (flow->head == skb)
+ return NULL;
+
+ iph = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb);
+ ipv6h = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(skb);
+
+ /* check that the innermost network header is v4/v6, and contains TCP */
+ if (pskb_may_pull(skb, ((unsigned char *)iph - skb->head) + sizeof(struct iphdr)) &&
+ iph->version == 4) {
+ if (iph->protocol != IPPROTO_TCP)
+ return NULL;
+ seglen = ntohs(iph->tot_len) - (4 * iph->ihl);
+ tcph = (struct tcphdr *)((void *)iph + (4 * iph->ihl));
+ if (!pskb_may_pull(skb, ((unsigned char *)tcph - skb->head) + sizeof(struct tcphdr)))
+ return NULL;
+ } else if (pskb_may_pull(skb, ((unsigned char *)ipv6h - skb->head) + sizeof(struct ipv6hdr) + sizeof(struct tcphdr)) &&
+ ipv6h->version == 6) {
+ if (ipv6h->nexthdr != IPPROTO_TCP)
+ return NULL;
+ seglen = ntohs(ipv6h->payload_len);
+ tcph = (struct tcphdr *)((void *)ipv6h +
+ sizeof(struct ipv6hdr));
+ } else {
+ return NULL;
+ }
+
+ /* 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 end of the queue,
+ * we have already returned if it is the only packet in the flow.
+ * stop before last packet in queue, don't compare trigger ACK to itself
+ * start where we finished last time if recorded in ->ackcheck
+ * otherwise start from the the head of the flow queue.
+ */
+ skb_check_prev = flow->ackcheck;
+ skb_check = flow->ackcheck ?: flow->head;
+
+ while (skb_check->next) {
+ bool pure_ack, thisconn;
+
+ /* don't increment if at head of flow queue (_prev == NULL) */
+ if (skb_check_prev) {
+ skb_check_prev = skb_check;
+ skb_check = skb_check->next;
+ if (!skb_check->next)
+ break;
+ } else {
+ skb_check_prev = ERR_PTR(-1);
+ }
+
+ iph_check = skb_check->encapsulation ?
+ inner_ip_hdr(skb_check) : ip_hdr(skb_check);
+ ipv6h_check = skb_check->encapsulation ?
+ inner_ipv6_hdr(skb_check) : ipv6_hdr(skb_check);
+
+ if (pskb_may_pull(skb_check, ((unsigned char *)iph_check - skb_check->head) + sizeof(struct iphdr)) &&
+ iph_check->version == 4) {
+ if (iph_check->protocol != IPPROTO_TCP)
+ continue;
+ seglen = (ntohs(iph_check->tot_len) -
+ (4 * iph_check->ihl));
+ tcph_check = (struct tcphdr *)((void *)iph_check
+ + (4 * iph_check->ihl));
+ if (iph->version == 4 &&
+ iph_check->saddr == iph->saddr &&
+ iph_check->daddr == iph->daddr) {
+ thisconn = true;
+ } else {
+ thisconn = false;
+ }
+ } else if (pskb_may_pull(skb_check, ((unsigned char *)ipv6h_check - skb_check->head) + sizeof(struct ipv6hdr)) &&
+ ipv6h_check->version == 6) {
+ if (ipv6h_check->nexthdr != IPPROTO_TCP)
+ continue;
+ seglen = ntohs(ipv6h_check->payload_len);
+ tcph_check = (struct tcphdr *)((void *)ipv6h_check +
+ sizeof(struct ipv6hdr));
+ if (ipv6h->version == 6 &&
+ ipv6_addr_cmp(&ipv6h_check->saddr, &ipv6h->saddr) &&
+ ipv6_addr_cmp(&ipv6h_check->daddr,
+ &ipv6h->daddr)) {
+ thisconn = true;
+ } else {
+ thisconn = false;
+ }
+ } else {
+ continue;
+ }
+
+ if (!pskb_may_pull(skb_check, ((unsigned char *)tcph_check - skb_check->head) + sizeof(struct tcphdr)))
+ continue;
+
+ /* stricter criteria apply to ACKs that we may filter
+ * 3 reserved flags must be unset to avoid future breakage
+ * ECE/CWR/NS can be safely ignored
+ * ACK must be set
+ * All other flags URG/PSH/RST/SYN/FIN must be unset
+ * 0x0FFF0000 = all TCP flags (confirm ACK=1, others zero)
+ * 0x01C00000 = NS/CWR/ECE (safe to ignore)
+ * 0x0E3F0000 = 0x0FFF0000 & ~0x01C00000
+ * must be 'pure' ACK, contain zero bytes of segment data
+ * options are ignored
+ */
+ if ((tcp_flag_word(tcph_check) &
+ (TCP_FLAG_ACK | TCP_FLAG_SYN)) != TCP_FLAG_ACK) {
+ continue;
+ } else if (((tcp_flag_word(tcph_check) &
+ cpu_to_be32(0x0E3F0000)) != TCP_FLAG_ACK) ||
+ ((seglen - 4 * tcph_check->doff) != 0)) {
+ pure_ack = false;
+ } else {
+ pure_ack = true;
+ }
+
+ /* if we find an ACK belonging to a different connection
+ * continue checking for other ACKs this round however
+ * restart checking from the other connection next time.
+ */
+ if (thisconn && (tcph_check->source != tcph->source ||
+ tcph_check->dest != tcph->dest)) {
+ thisconn = false;
+ }
+
+ /* new ack sequence must be greater
+ */
+ if (thisconn &&
+ ((int32_t)(ntohl(tcph_check->ack_seq) - ntohl(tcph->ack_seq)) > 0))
+ continue;
+
+ /* DupACKs with an equal sequence number shouldn't be filtered,
+ * but we can filter if the triggering packet is a SACK
+ */
+ if (thisconn &&
+ (ntohl(tcph_check->ack_seq) == ntohl(tcph->ack_seq)) &&
+ pskb_may_pull(skb, ((unsigned char *)tcph - skb->head) + (tcph->doff * 4))) {
+ /* inspired by tcp_parse_options in tcp_input.c */
+ bool sack = false;
+ int length = (tcph->doff * 4) - 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 == TCPOPT_SACK) {
+ sack = true;
+ break;
+ }
+ ptr += opsize - 2;
+ length -= opsize;
+ }
+ if (!sack)
+ continue;
+ }
+
+ /* somewhat complicated control flow for 'conservative'
+ * ACK filtering that aims to be more polite to slow-start and
+ * in the presence of packet loss.
+ * does not filter if there is one 'redundant' ACK in the queue.
+ * 'data' ACKs won't be filtered but do count as redundant ACKs.
+ */
+ if (thisconn) {
+ thisconn_seen_last = true;
+ /* if aggressive and this is a data ack we can skip
+ * checking it next time.
+ */
+ thisconn_checked_to = (aggressive && !pure_ack) ?
+ skb_check : skb_check_prev;
+ /* the first pure ack for this connection.
+ * record where it is, but only break if aggressive
+ * or already seen data ack from the same connection
+ */
+ if (pure_ack && !thisconn_ack) {
+ thisconn_ack = skb_check_prev;
+ if (aggressive || thisconn_redundant_seen)
+ break;
+ /* data ack or subsequent pure ack */
+ } else {
+ thisconn_redundant_seen = true;
+ /* this is the second ack for this connection
+ * break to filter the first pure ack
+ */
+ if (thisconn_ack)
+ break;
+ }
+ /* track packets from non-matching tcp connections that will
+ * need evaluation on the next run.
+ * if there are packets from both the matching connection and
+ * others that requre checking next run, track which was updated
+ * last and return the older of the two to ensure full coverage.
+ * if a non-matching pure ack has been seen, cannot skip any
+ * further on the next run so don't update.
+ */
+ } else if (!otherconn_ack_seen) {
+ thisconn_seen_last = false;
+ if (pure_ack) {
+ otherconn_ack_seen = true;
+ /* if aggressive we don't care about old data,
+ * start from the pure ack.
+ * otherwise if there is a previous data ack,
+ * start checking from it next time.
+ */
+ if (aggressive || !otherconn_checked_to)
+ otherconn_checked_to = skb_check_prev;
+ } else {
+ otherconn_checked_to = aggressive ?
+ skb_check : skb_check_prev;
+ }
+ }
+ }
+
+ /* skb_check is reused at this point
+ * it is the pure ACK to be filtered (if any)
+ */
+ skb_check = NULL;
+
+ /* next time start checking from the older/nearest to head of unfiltered
+ * but important tcp packets from this connection and other connections.
+ * if none seen, start after the last packet evaluated in the loop.
+ */
+ if (thisconn_checked_to && otherconn_checked_to)
+ flow->ackcheck = thisconn_seen_last ?
+ otherconn_checked_to : thisconn_checked_to;
+ else if (thisconn_checked_to)
+ flow->ackcheck = thisconn_checked_to;
+ else if (otherconn_checked_to)
+ flow->ackcheck = otherconn_checked_to;
+ else
+ flow->ackcheck = skb_check_prev;
+
+ /* if filtering, the pure ACK from the flow queue */
+ if (thisconn_ack && (aggressive || thisconn_redundant_seen)) {
+ if (PTR_ERR(thisconn_ack) == -1) {
+ skb_check = flow->head;
+ flow->head = flow->head->next;
+ } else {
+ skb_check = thisconn_ack->next;
+ thisconn_ack->next = thisconn_ack->next->next;
+ }
+ }
+
+ /* we just filtered that ack, fix up the list */
+ if (flow->ackcheck == skb_check)
+ flow->ackcheck = thisconn_ack;
+ /* check the entire flow queue next time */
+ if (PTR_ERR(flow->ackcheck) == -1)
+ flow->ackcheck = NULL;
+
+ return skb_check;
+}
+
+static inline cobalt_time_t cake_ewma(cobalt_time_t avg, cobalt_time_t sample,
+ u32 shift)
+{
+ avg -= avg >> shift;
+ avg += sample >> shift;
+ return avg;
+}
+
+static inline u32 cake_overhead(struct cake_sched_data *q, struct sk_buff *skb)
+{
+ const struct skb_shared_info *shinfo = skb_shinfo(skb);
+ u32 off = skb_network_offset(skb);
+ u32 len = qdisc_pkt_len(skb);
+ u16 segs = 1;
+
+ if (unlikely(shinfo->gso_size)) {
+ /* borrowed from qdisc_pkt_len_init() */
+ unsigned int hdr_len;
+
+ 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;
+
+ /* The last segment may be shorter; we ignore this, which means
+ * that we will over-estimate the size of the whole GSO segment
+ * by the difference in size. This is conservative, so we live
+ * with that to avoid the complexity of dealing with it.
+ */
+ len = shinfo->gso_size + hdr_len;
+ }
+
+ q->avg_netoff = cake_ewma(q->avg_netoff, off << 16, 8);
+
+ 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;
+
+ get_cobalt_cb(skb)->adjusted_len = len * segs;
+ return len;
+}
+
+static inline 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 inline 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 m = i;
+ u32 mb = cake_heap_get_backlog(q, m);
+
+ 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,
+ u64 now, bool drop)
+{
+ u32 len = get_cobalt_cb(skb)->adjusted_len;
+
+ /* charge packet bandwidth to this tin
+ * and to the global shaper.
+ */
+ if (q->rate_ns) {
+ s64 tdiff1 = b->tin_time_next_packet - now;
+ s64 tdiff2 = (len * (u64)b->tin_rate_ns) >> b->tin_rate_shft;
+ s64 tdiff3 = (len * (u64)q->rate_ns) >> q->rate_shft;
+ s64 tdiff4 = tdiff3 + (tdiff3 >> 1);
+
+ if (tdiff1 < 0)
+ b->tin_time_next_packet += tdiff2;
+ else if (tdiff1 < tdiff2)
+ b->tin_time_next_packet = now + tdiff2;
+
+ q->time_next_packet += tdiff3;
+ if (!drop)
+ q->failsafe_next_packet += tdiff4;
+ }
+ return len;
+}
+
+static unsigned int cake_drop(struct Qdisc *sch, struct sk_buff **to_free)
+{
+ struct cake_sched_data *q = qdisc_priv(sch);
+ struct sk_buff *skb;
+ u32 idx = 0, tin = 0, len;
+ struct cake_tin_data *b;
+ struct cake_flow *flow;
+ struct cake_heap_entry qq;
+ u64 now = cobalt_get_time();
+
+ 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);
+
+ 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--;
+
+ cake_heapify(q, 0);
+
+ return idx + (tin << 16);
+}
+
+static inline 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 inline 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,
+ struct sk_buff **to_free)
+{
+ struct cake_sched_data *q = qdisc_priv(sch);
+ u32 idx, tin;
+ struct cake_tin_data *b;
+ struct cake_flow *flow;
+ /* signed len to handle corner case filtered ACK larger than trigger */
+ int len = qdisc_pkt_len(skb);
+ u64 now = cobalt_get_time();
+ struct sk_buff *ack = NULL;
+
+ /* extract the Diffserv Precedence field, if it exists */
+ /* and clear DSCP bits if washing */
+ if (q->tin_mode != CAKE_DIFFSERV_BESTEFFORT) {
+ 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 */
+ idx = cake_hash(b, skb, q->flow_mode);
+ flow = &b->flows[idx];
+
+ /* ensure shaper state isn't stale */
+ if (!b->tin_backlog) {
+ if (b->tin_time_next_packet < now)
+ b->tin_time_next_packet = now;
+
+ if (!sch->q.qlen) {
+ if (q->time_next_packet < now) {
+ q->failsafe_next_packet = now;
+ q->time_next_packet = now;
+ } else if (q->time_next_packet > now &&
+ q->failsafe_next_packet > now) {
+ u64 next = min(q->time_next_packet,
+ q->failsafe_next_packet);
+ sch->qstats.overlimits++;
+ qdisc_watchdog_schedule_ns(&q->watchdog, next);
+ }
+ }
+ }
+
+ if (unlikely(len > b->max_skblen))
+ b->max_skblen = len;
+
+ /* Split GSO aggregates if they're likely to impair flow isolation */
+
+ 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;
+ }
+ /* 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, len);
+ consume_skb(skb);
+ } else {
+ /* 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;
+ }
+
+ if (q->overflow_timeout)
+ cake_heapify_up(q, b->overflow_idx[idx]);
+
+ /* incoming bandwidth capacity estimate */
+ if (q->rate_flags & CAKE_FLAG_AUTORATE_INGRESS) {
+ u64 packet_interval = 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 = 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 (q->rate_flags & CAKE_FLAG_AUTORATE_INGRESS &&
+ now - q->last_reconfig_time >
+ (NSEC_PER_SEC / 4)) {
+ 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) {
+ 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 sk_buff *skb;
+ struct cake_tin_data *b = &q->tins[q->cur_tin];
+ struct cake_flow *flow;
+ struct cake_host *srchost, *dsthost;
+ struct list_head *head;
+ u32 len;
+ u16 host_load;
+ cobalt_time_t now = ktime_get_ns();
+ cobalt_time_t delay;
+ bool first_flow = true;
+
+begin:
+ if (!sch->q.qlen)
+ return NULL;
+
+ /* global hard shaper */
+ if (q->time_next_packet > now && q->failsafe_next_packet > now) {
+ u64 next = min(q->time_next_packet, 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.
+ */
+ int tin, best_tin = 0;
+ s64 best_time = 0xFFFFFFFFFFFFUL;
+
+ for (tin = 0; tin < q->tin_cnt; tin++) {
+ b = q->tins + tin;
+ if ((b->sparse_flow_count + b->bulk_flow_count) > 0) {
+ s64 tdiff = b->tin_time_next_packet - now;
+
+ if (tdiff <= 0 || tdiff <= best_time) {
+ best_time = tdiff;
+ 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 ||
+ 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,
+ (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;
+ }
+ 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;
+ qdisc_bstats_update(sch, skb);
+
+ /* collect delay stats */
+ delay = 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 (q->time_next_packet > now && sch->q.qlen) {
+ u64 next = min(q->time_next_packet, 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) {
+ u64 next = now + q->tins[i].cparams.target;
+
+ qdisc_watchdog_schedule_ns(&q->watchdog, 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_RATE] = { .type = NLA_U32 },
+ [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,
+ cobalt_time_t ns_target, cobalt_time_t rtt_est_ns)
+{
+ /* convert byte-rate into time-per-byte
+ * so it will always unwedge in reasonable time.
+ */
+ static const u64 MIN_RATE = 64;
+ u64 rate_ns = 0;
+ u8 rate_shft = 0;
+ cobalt_time_t byte_target_ns;
+ u32 byte_target = mtu;
+
+ b->flow_quantum = 1514;
+ if (rate) {
+ b->flow_quantum = max(min(rate >> 12, 1514ULL), 300ULL);
+ rate_shft = 32;
+ rate_ns = ((u64)NSEC_PER_SEC) << rate_shft;
+ do_div(rate_ns, max(MIN_RATE, rate));
+ while (!!(rate_ns >> 32)) {
+ 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, ns_target);
+ b->cparams.interval = max(rtt_est_ns +
+ b->cparams.target - ns_target,
+ 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 int cake_config_besteffort(struct Qdisc *sch)
+{
+ struct cake_sched_data *q = qdisc_priv(sch);
+ struct cake_tin_data *b = &q->tins[0];
+ u32 rate = q->rate_bps;
+ u32 mtu = psched_mtu(qdisc_dev(sch));
+
+ q->tin_cnt = 1;
+
+ q->tin_index = besteffort;
+ q->tin_order = normal_order;
+
+ cake_set_rate(b, rate, mtu, US2TIME(q->target), US2TIME(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 rate = q->rate_bps;
+ u32 mtu = psched_mtu(qdisc_dev(sch));
+ 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, US2TIME(q->target),
+ US2TIME(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 rate = q->rate_bps;
+ u32 mtu = psched_mtu(qdisc_dev(sch));
+ 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, US2TIME(q->target),
+ US2TIME(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 rate = q->rate_bps;
+ u32 mtu = psched_mtu(qdisc_dev(sch));
+ 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,
+ US2TIME(q->target), US2TIME(q->interval));
+ cake_set_rate(&q->tins[1], rate >> 4, mtu,
+ US2TIME(q->target), US2TIME(q->interval));
+ cake_set_rate(&q->tins[2], rate >> 1, mtu,
+ US2TIME(q->target), US2TIME(q->interval));
+ cake_set_rate(&q->tins[3], rate >> 2, mtu,
+ US2TIME(q->target), US2TIME(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 rate = q->rate_bps;
+ u32 mtu = psched_mtu(qdisc_dev(sch));
+ 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,
+ US2TIME(q->target), US2TIME(q->interval));
+ cake_set_rate(&q->tins[1], rate >> 4, mtu,
+ US2TIME(q->target), US2TIME(q->interval));
+ cake_set_rate(&q->tins[2], rate >> 2, mtu,
+ US2TIME(q->target), US2TIME(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;
+ }
+
+ 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 = (u64)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_RATE])
+ q->rate_bps = nla_get_u32(tb[TCA_CAKE_BASE_RATE]);
+
+ if (tb[TCA_CAKE_DIFFSERV_MODE])
+ q->tin_mode = nla_get_u32(tb[TCA_CAKE_DIFFSERV_MODE]);
+
+ if (tb[TCA_CAKE_ATM])
+ q->atm_mode = nla_get_u32(tb[TCA_CAKE_ATM]);
+
+ 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]);
+
+ if (tb[TCA_CAKE_NAT]) {
+ q->flow_mode &= ~CAKE_FLOW_NAT_FLAG;
+ q->flow_mode |= CAKE_FLOW_NAT_FLAG *
+ !!nla_get_u32(tb[TCA_CAKE_NAT]);
+ }
+
+ if (tb[TCA_CAKE_OVERHEAD]) {
+ q->rate_overhead = nla_get_s32(tb[TCA_CAKE_OVERHEAD]);
+ q->rate_flags |= CAKE_FLAG_OVERHEAD;
+
+ q->max_netlen = q->max_adjlen = 0;
+ q->min_netlen = q->min_adjlen = ~0;
+ }
+
+ if (tb[TCA_CAKE_RAW]) {
+ q->rate_flags &= ~CAKE_FLAG_OVERHEAD;
+
+ q->max_netlen = q->max_adjlen = 0;
+ q->min_netlen = 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]);
+
+ 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_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_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]);
+
+ 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);
+ sch_tree_unlock(sch);
+ }
+
+ return 0;
+}
+
+
+static void cake_free(void *addr)
+{
+ if (addr)
+ kvfree(addr);
+}
+
+static void cake_destroy(struct Qdisc *sch)
+{
+ struct cake_sched_data *q = qdisc_priv(sch);
+
+ qdisc_watchdog_cancel(&q->watchdog);
+
+ if (q->tins)
+ cake_free(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;
+
+ sch->limit = 10240;
+ q->tin_mode = CAKE_DIFFSERV_DIFFSERV3;
+ 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;
+ }
+
+ 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 | __GFP_NOWARN);
+ if (!q->tins)
+ goto nomem;
+
+ for (i = 0; i < CAKE_MAX_TINS; i++) {
+ struct cake_tin_data *b = q->tins + i;
+
+ b->perturb = prandom_u32();
+ 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 = 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_u32(skb, TCA_CAKE_BASE_RATE, q->rate_bps))
+ 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_ATM, q->atm_mode))
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, TCA_CAKE_FLOW_MODE,
+ q->flow_mode & ~CAKE_FLOW_NAT_FLAG))
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, TCA_CAKE_NAT,
+ !!(q->flow_mode & CAKE_FLOW_NAT_FLAG)))
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, TCA_CAKE_SPLIT_GSO, !!(q->rate_flags & CAKE_FLAG_SPLIT_GSO)))
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, TCA_CAKE_WASH,
+ !!(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 (nla_put_u32(skb, TCA_CAKE_MPU, q->rate_mpu))
+ 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_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_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;
+
+ if (nla_put_u32(skb, TCA_CAKE_ACK_FILTER, q->ack_filter))
+ 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 cake_sched_data *q = qdisc_priv(sch);
+ struct nlattr *stats = nla_nest_start(d->skb, TCA_STATS_APP);
+ 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);
+
+ PUT_STAT_U32(CAPACITY_ESTIMATE, 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
+
+ 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[q->tin_order[i]];
+
+ ts = nla_nest_start(d->skb, i + 1);
+ if (!ts)
+ goto nla_put_failure;
+
+ PUT_TSTAT_U32(THRESHOLD_RATE, b->tin_rate_bps);
+ PUT_TSTAT_U32(TARGET_US, cobalt_time_to_us(b->cparams.target));
+ PUT_TSTAT_U32(INTERVAL_US, cobalt_time_to_us(b->cparams.interval));
+
+ PUT_TSTAT_U32(SENT_PACKETS, b->packets);
+ PUT_TSTAT_U64(SENT_BYTES64, b->bytes);
+ PUT_TSTAT_U32(DROPPED_PACKETS, b->tin_dropped);
+ PUT_TSTAT_U32(ECN_MARKED_PACKETS, b->tin_ecn_mark);
+ PUT_TSTAT_U64(BACKLOG_BYTES64, b->tin_backlog);
+ PUT_TSTAT_U32(ACKS_DROPPED_PACKETS, b->ack_drops);
+
+ PUT_TSTAT_U32(PEAK_DELAY_US, cobalt_time_to_us(b->peak_delay));
+ PUT_TSTAT_U32(AVG_DELAY_US, cobalt_time_to_us(b->avge_delay));
+ PUT_TSTAT_U32(BASE_DELAY_US, cobalt_time_to_us(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_ops cake_qdisc_ops __read_mostly = {
+ .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.");
--
2.17.0
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH iproute2-next v5] Add support for cake qdisc
2018-04-27 12:17 [PATCH net-next v4] Add Common Applications Kept Enhanced (cake) qdisc Toke Høiland-Jørgensen
@ 2018-04-27 12:17 ` Toke Høiland-Jørgensen
2018-04-27 16:17 ` [Cake] " Stephen Hemminger
2018-04-27 13:17 ` [PATCH net-next v4] Add Common Applications Kept Enhanced (cake) qdisc Eric Dumazet
1 sibling, 1 reply; 7+ messages in thread
From: Toke Høiland-Jørgensen @ 2018-04-27 12:17 UTC (permalink / raw)
To: netdev; +Cc: cake, Toke Høiland-Jørgensen, Dave Taht
sch_cake 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 besteffort
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.
* Support for DSL framing types and shapers.
* Support for ack filtering.
* Extensive statistics for measuring, loss, ecn markings, latency variation.
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.
Signed-off-by: Dave Taht <dave.taht@gmail.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
---
Changelog:
v5:
- Print the SPLIT_GSO flag
- Switch to print_u64() for JSON output
- Fix a format string for mpu option output
v4:
- Switch stats parsing to use nested netlink attributes
- Tweaks to JSON stats output keys
v3:
- Remove accidentally included test flag
v2:
- Updated netlink config ABI
- Remove diffserv-llt mode
- Various tweaks and clean-ups of stats output
man/man8/tc-cake.8 | 632 ++++++++++++++++++++++++++++++++++++++
man/man8/tc.8 | 1 +
tc/Makefile | 1 +
tc/q_cake.c | 739 +++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 1373 insertions(+)
create mode 100644 man/man8/tc-cake.8
create mode 100644 tc/q_cake.c
diff --git a/man/man8/tc-cake.8 b/man/man8/tc-cake.8
new file mode 100644
index 00000000..dff2e360
--- /dev/null
+++ b/man/man8/tc-cake.8
@@ -0,0 +1,632 @@
+.TH CAKE 8 "27 April 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 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.
+
+.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-red (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 <netdev@vger.kernel.org>.
diff --git a/man/man8/tc.8 b/man/man8/tc.8
index 840880fb..716dfec5 100644
--- a/man/man8/tc.8
+++ b/man/man8/tc.8
@@ -795,6 +795,7 @@ was written by Alexey N. Kuznetsov and added in Linux 2.2.
.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),
diff --git a/tc/Makefile b/tc/Makefile
index dfd00267..d9a43568 100644
--- 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
diff --git a/tc/q_cake.c b/tc/q_cake.c
new file mode 100644
index 00000000..a1e66f4e
--- /dev/null
+++ b/tc/q_cake.c
@@ -0,0 +1,739 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
+/*
+ * Common Applications Kept Enhanced -- CAKE
+ *
+ * Copyright (C) 2014-2018 Jonathan Morton <chromatix99@gmail.com>
+ * Copyright (C) 2017-2018 Toke Høiland-Jørgensen <toke@toke.dk>
+ */
+
+#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"
+
+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"
+" [ 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)
+{
+ int unlimited = 0;
+ unsigned bandwidth = 0;
+ unsigned interval = 0;
+ unsigned target = 0;
+ unsigned diffserv = 0;
+ unsigned memlimit = 0;
+ int overhead = 0;
+ bool overhead_set = false;
+ bool overhead_override = false;
+ int mpu = 0;
+ int flowmode = -1;
+ int nat = -1;
+ int atm = -1;
+ int autorate = -1;
+ int wash = -1;
+ int ingress = -1;
+ int ack_filter = -1;
+ struct rtattr *tail;
+
+ while (argc > 0) {
+ if (strcmp(*argv, "bandwidth") == 0) {
+ NEXT_ARG();
+ if (get_rate(&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 (strcmp(*argv, "datacentre") == 0) {
+ interval = 100;
+ target = 5;
+ } else if (strcmp(*argv, "lan") == 0) {
+ interval = 1000;
+ target = 50;
+ } else if (strcmp(*argv, "metro") == 0) {
+ interval = 10000;
+ target = 500;
+ } else if (strcmp(*argv, "regional") == 0) {
+ interval = 30000;
+ target = 1500;
+ } else if (strcmp(*argv, "internet") == 0) {
+ interval = 100000;
+ target = 5000;
+ } else if (strcmp(*argv, "oceanic") == 0) {
+ interval = 300000;
+ target = 15000;
+ } else if (strcmp(*argv, "satellite") == 0) {
+ interval = 1000000;
+ target = 50000;
+ } else if (strcmp(*argv, "interplanetary") == 0) {
+ interval = 1000000000;
+ target = 50000000;
+
+ } 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, "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_RATE, &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 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 (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 int cake_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
+{
+ struct rtattr *tb[TCA_CAKE_MAX + 1];
+ unsigned bandwidth = 0;
+ unsigned diffserv = 0;
+ unsigned flowmode = 0;
+ unsigned interval = 0;
+ unsigned memlimit = 0;
+ int overhead = 0;
+ int raw = 0;
+ int mpu = 0;
+ int atm = 0;
+ int nat = 0;
+ int autorate = 0;
+ int wash = 0;
+ int ingress = 0;
+ int ack_filter = 0;
+ int split_gso = 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_RATE] &&
+ RTA_PAYLOAD(tb[TCA_CAKE_BASE_RATE]) >= sizeof(__u32)) {
+ bandwidth = rta_getattr_u32(tb[TCA_CAKE_BASE_RATE]);
+ 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", "autorate_%s ", "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)) {
+ diffserv = rta_getattr_u32(tb[TCA_CAKE_DIFFSERV_MODE]);
+ switch(diffserv) {
+ case CAKE_DIFFSERV_DIFFSERV3:
+ print_string(PRINT_ANY, "diffserv", "%s ", "diffserv3");
+ break;
+ case CAKE_DIFFSERV_DIFFSERV4:
+ print_string(PRINT_ANY, "diffserv", "%s ", "diffserv4");
+ break;
+ case CAKE_DIFFSERV_DIFFSERV8:
+ print_string(PRINT_ANY, "diffserv", "%s ", "diffserv8");
+ break;
+ case CAKE_DIFFSERV_BESTEFFORT:
+ print_string(PRINT_ANY, "diffserv", "%s ", "besteffort");
+ break;
+ case CAKE_DIFFSERV_PRECEDENCE:
+ print_string(PRINT_ANY, "diffserv", "%s ", "precedence");
+ break;
+ default:
+ print_string(PRINT_ANY, "diffserv", "(?diffserv?) ", "unknown");
+ break;
+ };
+ }
+ if (tb[TCA_CAKE_FLOW_MODE] &&
+ RTA_PAYLOAD(tb[TCA_CAKE_FLOW_MODE]) >= sizeof(__u32)) {
+ flowmode = rta_getattr_u32(tb[TCA_CAKE_FLOW_MODE]);
+ switch(flowmode) {
+ case CAKE_FLOW_NONE:
+ print_string(PRINT_ANY, "flowmode", "%s ", "flowblind");
+ break;
+ case CAKE_FLOW_SRC_IP:
+ print_string(PRINT_ANY, "flowmode", "%s ", "srchost");
+ break;
+ case CAKE_FLOW_DST_IP:
+ print_string(PRINT_ANY, "flowmode", "%s ", "dsthost");
+ break;
+ case CAKE_FLOW_HOSTS:
+ print_string(PRINT_ANY, "flowmode", "%s ", "hosts");
+ break;
+ case CAKE_FLOW_FLOWS:
+ print_string(PRINT_ANY, "flowmode", "%s ", "flows");
+ break;
+ case CAKE_FLOW_DUAL_SRC:
+ print_string(PRINT_ANY, "flowmode", "%s ", "dual-srchost");
+ break;
+ case CAKE_FLOW_DUAL_DST:
+ print_string(PRINT_ANY, "flowmode", "%s ", "dual-dsthost");
+ break;
+ case CAKE_FLOW_TRIPLE:
+ print_string(PRINT_ANY, "flowmode", "%s ", "triple-isolate");
+ break;
+ default:
+ print_string(PRINT_ANY, "flowmode", "(?flowmode?) ", "unknown");
+ break;
+ };
+
+ }
+
+ 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);
+ 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);
+ 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_JSON, "ack-filter", NULL, "disabled");
+
+ if (split_gso)
+ print_string(PRINT_FP, NULL, "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(u32, "threshold_rate", THRESHOLD_RATE);
+ 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(u64, "sent_bytes", SENT_BYTES64);
+ 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)
+{
+ SPRINT_BUF(b1);
+ struct rtattr *st[TCA_CAKE_STATS_MAX + 1];
+ int i;
+
+ if (xstats == NULL)
+ return 0;
+
+#define GET_STAT_U32(attr) rta_getattr_u32(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_ESTIMATE]) {
+ print_string(PRINT_FP, NULL, " capacity estimate: %s\n",
+ sprint_rate(GET_STAT_U32(CAPACITY_ESTIMATE), b1));
+ print_uint(PRINT_JSON, "capacity_estimate", NULL,
+ GET_STAT_U32(CAPACITY_ESTIMATE));
+ }
+
+ 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));
+
+#undef GET_STAT_U32
+
+ if (st[TCA_CAKE_STATS_TIN_STATS]) {
+ struct rtattr *tins[TC_CAKE_MAX_TINS + 1];
+ struct rtattr *tstat[TC_CAKE_MAX_TINS][TCA_CAKE_TIN_STATS_MAX + 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, name, attr) PRINT_TSTAT( \
+ name, attr, "s", sprint_ ## pfunc( \
+ rta_getattr_u32(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, " thresh ", THRESHOLD_RATE);
+ SPRINT_TSTAT(time, " target ", TARGET_US);
+ SPRINT_TSTAT(time, " interval", INTERVAL_US);
+ SPRINT_TSTAT(time, " pk_delay", PEAK_DELAY_US);
+ SPRINT_TSTAT(time, " av_delay", AVG_DELAY_US);
+ SPRINT_TSTAT(time, " sp_delay", BASE_DELAY_US);
+
+ 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,
+};
--
2.17.0
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH net-next v4] Add Common Applications Kept Enhanced (cake) qdisc
2018-04-27 12:17 [PATCH net-next v4] Add Common Applications Kept Enhanced (cake) qdisc Toke Høiland-Jørgensen
2018-04-27 12:17 ` [PATCH iproute2-next v5] Add support for cake qdisc Toke Høiland-Jørgensen
@ 2018-04-27 13:17 ` Eric Dumazet
2018-04-27 13:38 ` Toke Høiland-Jørgensen
1 sibling, 1 reply; 7+ messages in thread
From: Eric Dumazet @ 2018-04-27 13:17 UTC (permalink / raw)
To: Toke Høiland-Jørgensen, netdev; +Cc: cake, Dave Taht
On 04/27/2018 05:17 AM, Toke Høiland-Jørgensen wrote:
...
> +
> +static struct sk_buff *cake_ack_filter(struct cake_sched_data *q,
> + struct cake_flow *flow)
> +{
> + int seglen;
> + struct sk_buff *skb = flow->tail, *skb_check, *skb_check_prev;
> + struct iphdr *iph, *iph_check;
> + struct ipv6hdr *ipv6h, *ipv6h_check;
> + struct tcphdr *tcph, *tcph_check;
> + bool otherconn_ack_seen = false;
> + struct sk_buff *otherconn_checked_to = NULL;
> + bool thisconn_redundant_seen = false, thisconn_seen_last = false;
> + struct sk_buff *thisconn_checked_to = NULL, *thisconn_ack = NULL;
> + bool aggressive = q->ack_filter == CAKE_ACK_AGGRESSIVE;
> +
> + /* no other possible ACKs to filter */
> + if (flow->head == skb)
> + return NULL;
> +
> + iph = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb);
> + ipv6h = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(skb);
> +
> + /* check that the innermost network header is v4/v6, and contains TCP */
> + if (pskb_may_pull(skb, ((unsigned char *)iph - skb->head) + sizeof(struct iphdr)) &&
> + iph->version == 4) {
> + if (iph->protocol != IPPROTO_TCP)
> + return NULL;
> + seglen = ntohs(iph->tot_len) - (4 * iph->ihl);
> + tcph = (struct tcphdr *)((void *)iph + (4 * iph->ihl));
> + if (!pskb_may_pull(skb, ((unsigned char *)tcph - skb->head) + sizeof(struct tcphdr)))
> + return NULL;
> + } else if (pskb_may_pull(skb, ((unsigned char *)ipv6h - skb->head) + sizeof(struct ipv6hdr) + sizeof(struct tcphdr)) &&
> + ipv6h->version == 6) {
> + if (ipv6h->nexthdr != IPPROTO_TCP)
> + return NULL;
> + seglen = ntohs(ipv6h->payload_len);
> + tcph = (struct tcphdr *)((void *)ipv6h +
> + sizeof(struct ipv6hdr));
> + } else {
> + return NULL;
> + }
> +
This is still broken.
After pskb_may_pull(), skb->head might have been reallocated.
You need to recompute iph , ipv6h, tcph, otherwise you are reading freed memory and crash kernels
with sufficient debugging (KASAN and other CONFIG_DEBUG_PAGEALLOC / CONFIG_DEBUG_SLAB like options)
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH net-next v4] Add Common Applications Kept Enhanced (cake) qdisc
2018-04-27 13:17 ` [PATCH net-next v4] Add Common Applications Kept Enhanced (cake) qdisc Eric Dumazet
@ 2018-04-27 13:38 ` Toke Høiland-Jørgensen
2018-04-27 13:44 ` Eric Dumazet
0 siblings, 1 reply; 7+ messages in thread
From: Toke Høiland-Jørgensen @ 2018-04-27 13:38 UTC (permalink / raw)
To: Eric Dumazet, netdev; +Cc: cake, Dave Taht
Eric Dumazet <eric.dumazet@gmail.com> writes:
> On 04/27/2018 05:17 AM, Toke Høiland-Jørgensen wrote:
>
> ...
>
>> +
>> +static struct sk_buff *cake_ack_filter(struct cake_sched_data *q,
>> + struct cake_flow *flow)
>> +{
>> + int seglen;
>> + struct sk_buff *skb = flow->tail, *skb_check, *skb_check_prev;
>> + struct iphdr *iph, *iph_check;
>> + struct ipv6hdr *ipv6h, *ipv6h_check;
>> + struct tcphdr *tcph, *tcph_check;
>> + bool otherconn_ack_seen = false;
>> + struct sk_buff *otherconn_checked_to = NULL;
>> + bool thisconn_redundant_seen = false, thisconn_seen_last = false;
>> + struct sk_buff *thisconn_checked_to = NULL, *thisconn_ack = NULL;
>> + bool aggressive = q->ack_filter == CAKE_ACK_AGGRESSIVE;
>> +
>> + /* no other possible ACKs to filter */
>> + if (flow->head == skb)
>> + return NULL;
>> +
>> + iph = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb);
>> + ipv6h = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(skb);
>> +
>> + /* check that the innermost network header is v4/v6, and contains TCP */
>> + if (pskb_may_pull(skb, ((unsigned char *)iph - skb->head) + sizeof(struct iphdr)) &&
>> + iph->version == 4) {
>> + if (iph->protocol != IPPROTO_TCP)
>> + return NULL;
>> + seglen = ntohs(iph->tot_len) - (4 * iph->ihl);
>> + tcph = (struct tcphdr *)((void *)iph + (4 * iph->ihl));
>> + if (!pskb_may_pull(skb, ((unsigned char *)tcph - skb->head) + sizeof(struct tcphdr)))
>> + return NULL;
>> + } else if (pskb_may_pull(skb, ((unsigned char *)ipv6h - skb->head) + sizeof(struct ipv6hdr) + sizeof(struct tcphdr)) &&
>> + ipv6h->version == 6) {
>> + if (ipv6h->nexthdr != IPPROTO_TCP)
>> + return NULL;
>> + seglen = ntohs(ipv6h->payload_len);
>> + tcph = (struct tcphdr *)((void *)ipv6h +
>> + sizeof(struct ipv6hdr));
>> + } else {
>> + return NULL;
>> + }
>> +
>
>
> This is still broken.
>
> After pskb_may_pull(), skb->head might have been reallocated.
>
> You need to recompute iph , ipv6h, tcph, otherwise you are reading
> freed memory and crash kernels with sufficient debugging (KASAN and
> other CONFIG_DEBUG_PAGEALLOC / CONFIG_DEBUG_SLAB like options)
Ah, right. Will fix.
Is it safe to dereference the iph pointer before calling
pskb_may_pull()?
-Toke
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH net-next v4] Add Common Applications Kept Enhanced (cake) qdisc
2018-04-27 13:38 ` Toke Høiland-Jørgensen
@ 2018-04-27 13:44 ` Eric Dumazet
2018-04-27 13:45 ` Toke Høiland-Jørgensen
0 siblings, 1 reply; 7+ messages in thread
From: Eric Dumazet @ 2018-04-27 13:44 UTC (permalink / raw)
To: Toke Høiland-Jørgensen, Eric Dumazet, netdev; +Cc: cake, Dave Taht
On 04/27/2018 06:38 AM, Toke Høiland-Jørgensen wrote:
>
> Ah, right. Will fix.
>
> Is it safe to dereference the iph pointer before calling
> pskb_may_pull()?
No, please take a look at ip_rcv() for a typical use case.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH net-next v4] Add Common Applications Kept Enhanced (cake) qdisc
2018-04-27 13:44 ` Eric Dumazet
@ 2018-04-27 13:45 ` Toke Høiland-Jørgensen
0 siblings, 0 replies; 7+ messages in thread
From: Toke Høiland-Jørgensen @ 2018-04-27 13:45 UTC (permalink / raw)
To: Eric Dumazet, netdev; +Cc: cake, Dave Taht
Eric Dumazet <eric.dumazet@gmail.com> writes:
> On 04/27/2018 06:38 AM, Toke Høiland-Jørgensen wrote:
>>
>> Ah, right. Will fix.
>>
>> Is it safe to dereference the iph pointer before calling
>> pskb_may_pull()?
>
> No, please take a look at ip_rcv() for a typical use case.
Will do, thanks.
-Toke
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [Cake] [PATCH iproute2-next v5] Add support for cake qdisc
2018-04-27 12:17 ` [PATCH iproute2-next v5] Add support for cake qdisc Toke Høiland-Jørgensen
@ 2018-04-27 16:17 ` Stephen Hemminger
0 siblings, 0 replies; 7+ messages in thread
From: Stephen Hemminger @ 2018-04-27 16:17 UTC (permalink / raw)
To: Toke Høiland-Jørgensen; +Cc: netdev, cake
On Fri, 27 Apr 2018 14:17:06 +0200
Toke Høiland-Jørgensen <toke@toke.dk> wrote:
> + } else if (strcmp(*argv, "datacentre") == 0) {
> + interval = 100;
> + target = 5;
> + } else if (strcmp(*argv, "lan") == 0) {
> + interval = 1000;
> + target = 50;
> + } else if (strcmp(*argv, "metro") == 0) {
> + interval = 10000;
> + target = 500;
> + } else if (strcmp(*argv, "regional") == 0) {
> + interval = 30000;
> + target = 1500;
> + } else if (strcmp(*argv, "internet") == 0) {
> + interval = 100000;
> + target = 5000;
> + } else if (strcmp(*argv, "oceanic") == 0) {
> + interval = 300000;
> + target = 15000;
> + } else if (strcmp(*argv, "satellite") == 0) {
> + interval = 1000000;
> + target = 50000;
> + } else if (strcmp(*argv, "interplanetary") == 0) {
> + interval = 1000000000;
> + target = 50000000;
> +
There enough tuning entries of this type, that it would be better
to make a table that can be expanded.
The code should also only allow one of these options. Use duparg()?
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2018-04-27 16:17 UTC | newest]
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2018-04-27 12:17 [PATCH net-next v4] Add Common Applications Kept Enhanced (cake) qdisc Toke Høiland-Jørgensen
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