aboutsummaryrefslogtreecommitdiff
path: root/net/ipv4/tcp_illinois.c
diff options
context:
space:
mode:
authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /net/ipv4/tcp_illinois.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to '')
-rw-r--r--net/ipv4/tcp_illinois.c360
1 files changed, 360 insertions, 0 deletions
diff --git a/net/ipv4/tcp_illinois.c b/net/ipv4/tcp_illinois.c
new file mode 100644
index 000000000..c0c81a2c7
--- /dev/null
+++ b/net/ipv4/tcp_illinois.c
@@ -0,0 +1,360 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * TCP Illinois congestion control.
+ * Home page:
+ * http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html
+ *
+ * The algorithm is described in:
+ * "TCP-Illinois: A Loss and Delay-Based Congestion Control Algorithm
+ * for High-Speed Networks"
+ * http://tamerbasar.csl.illinois.edu/LiuBasarSrikantPerfEvalArtJun2008.pdf
+ *
+ * Implemented from description in paper and ns-2 simulation.
+ * Copyright (C) 2007 Stephen Hemminger <shemminger@linux-foundation.org>
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/inet_diag.h>
+#include <asm/div64.h>
+#include <net/tcp.h>
+
+#define ALPHA_SHIFT 7
+#define ALPHA_SCALE (1u<<ALPHA_SHIFT)
+#define ALPHA_MIN ((3*ALPHA_SCALE)/10) /* ~0.3 */
+#define ALPHA_MAX (10*ALPHA_SCALE) /* 10.0 */
+#define ALPHA_BASE ALPHA_SCALE /* 1.0 */
+#define RTT_MAX (U32_MAX / ALPHA_MAX) /* 3.3 secs */
+
+#define BETA_SHIFT 6
+#define BETA_SCALE (1u<<BETA_SHIFT)
+#define BETA_MIN (BETA_SCALE/8) /* 0.125 */
+#define BETA_MAX (BETA_SCALE/2) /* 0.5 */
+#define BETA_BASE BETA_MAX
+
+static int win_thresh __read_mostly = 15;
+module_param(win_thresh, int, 0);
+MODULE_PARM_DESC(win_thresh, "Window threshold for starting adaptive sizing");
+
+static int theta __read_mostly = 5;
+module_param(theta, int, 0);
+MODULE_PARM_DESC(theta, "# of fast RTT's before full growth");
+
+/* TCP Illinois Parameters */
+struct illinois {
+ u64 sum_rtt; /* sum of rtt's measured within last rtt */
+ u16 cnt_rtt; /* # of rtts measured within last rtt */
+ u32 base_rtt; /* min of all rtt in usec */
+ u32 max_rtt; /* max of all rtt in usec */
+ u32 end_seq; /* right edge of current RTT */
+ u32 alpha; /* Additive increase */
+ u32 beta; /* Muliplicative decrease */
+ u16 acked; /* # packets acked by current ACK */
+ u8 rtt_above; /* average rtt has gone above threshold */
+ u8 rtt_low; /* # of rtts measurements below threshold */
+};
+
+static void rtt_reset(struct sock *sk)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct illinois *ca = inet_csk_ca(sk);
+
+ ca->end_seq = tp->snd_nxt;
+ ca->cnt_rtt = 0;
+ ca->sum_rtt = 0;
+
+ /* TODO: age max_rtt? */
+}
+
+static void tcp_illinois_init(struct sock *sk)
+{
+ struct illinois *ca = inet_csk_ca(sk);
+
+ ca->alpha = ALPHA_MAX;
+ ca->beta = BETA_BASE;
+ ca->base_rtt = 0x7fffffff;
+ ca->max_rtt = 0;
+
+ ca->acked = 0;
+ ca->rtt_low = 0;
+ ca->rtt_above = 0;
+
+ rtt_reset(sk);
+}
+
+/* Measure RTT for each ack. */
+static void tcp_illinois_acked(struct sock *sk, const struct ack_sample *sample)
+{
+ struct illinois *ca = inet_csk_ca(sk);
+ s32 rtt_us = sample->rtt_us;
+
+ ca->acked = sample->pkts_acked;
+
+ /* dup ack, no rtt sample */
+ if (rtt_us < 0)
+ return;
+
+ /* ignore bogus values, this prevents wraparound in alpha math */
+ if (rtt_us > RTT_MAX)
+ rtt_us = RTT_MAX;
+
+ /* keep track of minimum RTT seen so far */
+ if (ca->base_rtt > rtt_us)
+ ca->base_rtt = rtt_us;
+
+ /* and max */
+ if (ca->max_rtt < rtt_us)
+ ca->max_rtt = rtt_us;
+
+ ++ca->cnt_rtt;
+ ca->sum_rtt += rtt_us;
+}
+
+/* Maximum queuing delay */
+static inline u32 max_delay(const struct illinois *ca)
+{
+ return ca->max_rtt - ca->base_rtt;
+}
+
+/* Average queuing delay */
+static inline u32 avg_delay(const struct illinois *ca)
+{
+ u64 t = ca->sum_rtt;
+
+ do_div(t, ca->cnt_rtt);
+ return t - ca->base_rtt;
+}
+
+/*
+ * Compute value of alpha used for additive increase.
+ * If small window then use 1.0, equivalent to Reno.
+ *
+ * For larger windows, adjust based on average delay.
+ * A. If average delay is at minimum (we are uncongested),
+ * then use large alpha (10.0) to increase faster.
+ * B. If average delay is at maximum (getting congested)
+ * then use small alpha (0.3)
+ *
+ * The result is a convex window growth curve.
+ */
+static u32 alpha(struct illinois *ca, u32 da, u32 dm)
+{
+ u32 d1 = dm / 100; /* Low threshold */
+
+ if (da <= d1) {
+ /* If never got out of low delay zone, then use max */
+ if (!ca->rtt_above)
+ return ALPHA_MAX;
+
+ /* Wait for 5 good RTT's before allowing alpha to go alpha max.
+ * This prevents one good RTT from causing sudden window increase.
+ */
+ if (++ca->rtt_low < theta)
+ return ca->alpha;
+
+ ca->rtt_low = 0;
+ ca->rtt_above = 0;
+ return ALPHA_MAX;
+ }
+
+ ca->rtt_above = 1;
+
+ /*
+ * Based on:
+ *
+ * (dm - d1) amin amax
+ * k1 = -------------------
+ * amax - amin
+ *
+ * (dm - d1) amin
+ * k2 = ---------------- - d1
+ * amax - amin
+ *
+ * k1
+ * alpha = ----------
+ * k2 + da
+ */
+
+ dm -= d1;
+ da -= d1;
+ return (dm * ALPHA_MAX) /
+ (dm + (da * (ALPHA_MAX - ALPHA_MIN)) / ALPHA_MIN);
+}
+
+/*
+ * Beta used for multiplicative decrease.
+ * For small window sizes returns same value as Reno (0.5)
+ *
+ * If delay is small (10% of max) then beta = 1/8
+ * If delay is up to 80% of max then beta = 1/2
+ * In between is a linear function
+ */
+static u32 beta(u32 da, u32 dm)
+{
+ u32 d2, d3;
+
+ d2 = dm / 10;
+ if (da <= d2)
+ return BETA_MIN;
+
+ d3 = (8 * dm) / 10;
+ if (da >= d3 || d3 <= d2)
+ return BETA_MAX;
+
+ /*
+ * Based on:
+ *
+ * bmin d3 - bmax d2
+ * k3 = -------------------
+ * d3 - d2
+ *
+ * bmax - bmin
+ * k4 = -------------
+ * d3 - d2
+ *
+ * b = k3 + k4 da
+ */
+ return (BETA_MIN * d3 - BETA_MAX * d2 + (BETA_MAX - BETA_MIN) * da)
+ / (d3 - d2);
+}
+
+/* Update alpha and beta values once per RTT */
+static void update_params(struct sock *sk)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct illinois *ca = inet_csk_ca(sk);
+
+ if (tcp_snd_cwnd(tp) < win_thresh) {
+ ca->alpha = ALPHA_BASE;
+ ca->beta = BETA_BASE;
+ } else if (ca->cnt_rtt > 0) {
+ u32 dm = max_delay(ca);
+ u32 da = avg_delay(ca);
+
+ ca->alpha = alpha(ca, da, dm);
+ ca->beta = beta(da, dm);
+ }
+
+ rtt_reset(sk);
+}
+
+/*
+ * In case of loss, reset to default values
+ */
+static void tcp_illinois_state(struct sock *sk, u8 new_state)
+{
+ struct illinois *ca = inet_csk_ca(sk);
+
+ if (new_state == TCP_CA_Loss) {
+ ca->alpha = ALPHA_BASE;
+ ca->beta = BETA_BASE;
+ ca->rtt_low = 0;
+ ca->rtt_above = 0;
+ rtt_reset(sk);
+ }
+}
+
+/*
+ * Increase window in response to successful acknowledgment.
+ */
+static void tcp_illinois_cong_avoid(struct sock *sk, u32 ack, u32 acked)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct illinois *ca = inet_csk_ca(sk);
+
+ if (after(ack, ca->end_seq))
+ update_params(sk);
+
+ /* RFC2861 only increase cwnd if fully utilized */
+ if (!tcp_is_cwnd_limited(sk))
+ return;
+
+ /* In slow start */
+ if (tcp_in_slow_start(tp))
+ tcp_slow_start(tp, acked);
+
+ else {
+ u32 delta;
+
+ /* snd_cwnd_cnt is # of packets since last cwnd increment */
+ tp->snd_cwnd_cnt += ca->acked;
+ ca->acked = 1;
+
+ /* This is close approximation of:
+ * tp->snd_cwnd += alpha/tp->snd_cwnd
+ */
+ delta = (tp->snd_cwnd_cnt * ca->alpha) >> ALPHA_SHIFT;
+ if (delta >= tcp_snd_cwnd(tp)) {
+ tcp_snd_cwnd_set(tp, min(tcp_snd_cwnd(tp) + delta / tcp_snd_cwnd(tp),
+ (u32)tp->snd_cwnd_clamp));
+ tp->snd_cwnd_cnt = 0;
+ }
+ }
+}
+
+static u32 tcp_illinois_ssthresh(struct sock *sk)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct illinois *ca = inet_csk_ca(sk);
+ u32 decr;
+
+ /* Multiplicative decrease */
+ decr = (tcp_snd_cwnd(tp) * ca->beta) >> BETA_SHIFT;
+ return max(tcp_snd_cwnd(tp) - decr, 2U);
+}
+
+/* Extract info for Tcp socket info provided via netlink. */
+static size_t tcp_illinois_info(struct sock *sk, u32 ext, int *attr,
+ union tcp_cc_info *info)
+{
+ const struct illinois *ca = inet_csk_ca(sk);
+
+ if (ext & (1 << (INET_DIAG_VEGASINFO - 1))) {
+ info->vegas.tcpv_enabled = 1;
+ info->vegas.tcpv_rttcnt = ca->cnt_rtt;
+ info->vegas.tcpv_minrtt = ca->base_rtt;
+ info->vegas.tcpv_rtt = 0;
+
+ if (info->vegas.tcpv_rttcnt > 0) {
+ u64 t = ca->sum_rtt;
+
+ do_div(t, info->vegas.tcpv_rttcnt);
+ info->vegas.tcpv_rtt = t;
+ }
+ *attr = INET_DIAG_VEGASINFO;
+ return sizeof(struct tcpvegas_info);
+ }
+ return 0;
+}
+
+static struct tcp_congestion_ops tcp_illinois __read_mostly = {
+ .init = tcp_illinois_init,
+ .ssthresh = tcp_illinois_ssthresh,
+ .undo_cwnd = tcp_reno_undo_cwnd,
+ .cong_avoid = tcp_illinois_cong_avoid,
+ .set_state = tcp_illinois_state,
+ .get_info = tcp_illinois_info,
+ .pkts_acked = tcp_illinois_acked,
+
+ .owner = THIS_MODULE,
+ .name = "illinois",
+};
+
+static int __init tcp_illinois_register(void)
+{
+ BUILD_BUG_ON(sizeof(struct illinois) > ICSK_CA_PRIV_SIZE);
+ return tcp_register_congestion_control(&tcp_illinois);
+}
+
+static void __exit tcp_illinois_unregister(void)
+{
+ tcp_unregister_congestion_control(&tcp_illinois);
+}
+
+module_init(tcp_illinois_register);
+module_exit(tcp_illinois_unregister);
+
+MODULE_AUTHOR("Stephen Hemminger, Shao Liu");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TCP Illinois");
+MODULE_VERSION("1.0");