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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_htcp.c
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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 'net/ipv4/tcp_htcp.c')
-rw-r--r--net/ipv4/tcp_htcp.c317
1 files changed, 317 insertions, 0 deletions
diff --git a/net/ipv4/tcp_htcp.c b/net/ipv4/tcp_htcp.c
new file mode 100644
index 000000000..52b1f2665
--- /dev/null
+++ b/net/ipv4/tcp_htcp.c
@@ -0,0 +1,317 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * H-TCP congestion control. The algorithm is detailed in:
+ * R.N.Shorten, D.J.Leith:
+ * "H-TCP: TCP for high-speed and long-distance networks"
+ * Proc. PFLDnet, Argonne, 2004.
+ * https://www.hamilton.ie/net/htcp3.pdf
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <net/tcp.h>
+
+#define ALPHA_BASE (1<<7) /* 1.0 with shift << 7 */
+#define BETA_MIN (1<<6) /* 0.5 with shift << 7 */
+#define BETA_MAX 102 /* 0.8 with shift << 7 */
+
+static int use_rtt_scaling __read_mostly = 1;
+module_param(use_rtt_scaling, int, 0644);
+MODULE_PARM_DESC(use_rtt_scaling, "turn on/off RTT scaling");
+
+static int use_bandwidth_switch __read_mostly = 1;
+module_param(use_bandwidth_switch, int, 0644);
+MODULE_PARM_DESC(use_bandwidth_switch, "turn on/off bandwidth switcher");
+
+struct htcp {
+ u32 alpha; /* Fixed point arith, << 7 */
+ u8 beta; /* Fixed point arith, << 7 */
+ u8 modeswitch; /* Delay modeswitch
+ until we had at least one congestion event */
+ u16 pkts_acked;
+ u32 packetcount;
+ u32 minRTT;
+ u32 maxRTT;
+ u32 last_cong; /* Time since last congestion event end */
+ u32 undo_last_cong;
+
+ u32 undo_maxRTT;
+ u32 undo_old_maxB;
+
+ /* Bandwidth estimation */
+ u32 minB;
+ u32 maxB;
+ u32 old_maxB;
+ u32 Bi;
+ u32 lasttime;
+};
+
+static inline u32 htcp_cong_time(const struct htcp *ca)
+{
+ return jiffies - ca->last_cong;
+}
+
+static inline u32 htcp_ccount(const struct htcp *ca)
+{
+ return htcp_cong_time(ca) / ca->minRTT;
+}
+
+static inline void htcp_reset(struct htcp *ca)
+{
+ ca->undo_last_cong = ca->last_cong;
+ ca->undo_maxRTT = ca->maxRTT;
+ ca->undo_old_maxB = ca->old_maxB;
+
+ ca->last_cong = jiffies;
+}
+
+static u32 htcp_cwnd_undo(struct sock *sk)
+{
+ struct htcp *ca = inet_csk_ca(sk);
+
+ if (ca->undo_last_cong) {
+ ca->last_cong = ca->undo_last_cong;
+ ca->maxRTT = ca->undo_maxRTT;
+ ca->old_maxB = ca->undo_old_maxB;
+ ca->undo_last_cong = 0;
+ }
+
+ return tcp_reno_undo_cwnd(sk);
+}
+
+static inline void measure_rtt(struct sock *sk, u32 srtt)
+{
+ const struct inet_connection_sock *icsk = inet_csk(sk);
+ struct htcp *ca = inet_csk_ca(sk);
+
+ /* keep track of minimum RTT seen so far, minRTT is zero at first */
+ if (ca->minRTT > srtt || !ca->minRTT)
+ ca->minRTT = srtt;
+
+ /* max RTT */
+ if (icsk->icsk_ca_state == TCP_CA_Open) {
+ if (ca->maxRTT < ca->minRTT)
+ ca->maxRTT = ca->minRTT;
+ if (ca->maxRTT < srtt &&
+ srtt <= ca->maxRTT + msecs_to_jiffies(20))
+ ca->maxRTT = srtt;
+ }
+}
+
+static void measure_achieved_throughput(struct sock *sk,
+ const struct ack_sample *sample)
+{
+ const struct inet_connection_sock *icsk = inet_csk(sk);
+ const struct tcp_sock *tp = tcp_sk(sk);
+ struct htcp *ca = inet_csk_ca(sk);
+ u32 now = tcp_jiffies32;
+
+ if (icsk->icsk_ca_state == TCP_CA_Open)
+ ca->pkts_acked = sample->pkts_acked;
+
+ if (sample->rtt_us > 0)
+ measure_rtt(sk, usecs_to_jiffies(sample->rtt_us));
+
+ if (!use_bandwidth_switch)
+ return;
+
+ /* achieved throughput calculations */
+ if (!((1 << icsk->icsk_ca_state) & (TCPF_CA_Open | TCPF_CA_Disorder))) {
+ ca->packetcount = 0;
+ ca->lasttime = now;
+ return;
+ }
+
+ ca->packetcount += sample->pkts_acked;
+
+ if (ca->packetcount >= tcp_snd_cwnd(tp) - (ca->alpha >> 7 ? : 1) &&
+ now - ca->lasttime >= ca->minRTT &&
+ ca->minRTT > 0) {
+ __u32 cur_Bi = ca->packetcount * HZ / (now - ca->lasttime);
+
+ if (htcp_ccount(ca) <= 3) {
+ /* just after backoff */
+ ca->minB = ca->maxB = ca->Bi = cur_Bi;
+ } else {
+ ca->Bi = (3 * ca->Bi + cur_Bi) / 4;
+ if (ca->Bi > ca->maxB)
+ ca->maxB = ca->Bi;
+ if (ca->minB > ca->maxB)
+ ca->minB = ca->maxB;
+ }
+ ca->packetcount = 0;
+ ca->lasttime = now;
+ }
+}
+
+static inline void htcp_beta_update(struct htcp *ca, u32 minRTT, u32 maxRTT)
+{
+ if (use_bandwidth_switch) {
+ u32 maxB = ca->maxB;
+ u32 old_maxB = ca->old_maxB;
+
+ ca->old_maxB = ca->maxB;
+ if (!between(5 * maxB, 4 * old_maxB, 6 * old_maxB)) {
+ ca->beta = BETA_MIN;
+ ca->modeswitch = 0;
+ return;
+ }
+ }
+
+ if (ca->modeswitch && minRTT > msecs_to_jiffies(10) && maxRTT) {
+ ca->beta = (minRTT << 7) / maxRTT;
+ if (ca->beta < BETA_MIN)
+ ca->beta = BETA_MIN;
+ else if (ca->beta > BETA_MAX)
+ ca->beta = BETA_MAX;
+ } else {
+ ca->beta = BETA_MIN;
+ ca->modeswitch = 1;
+ }
+}
+
+static inline void htcp_alpha_update(struct htcp *ca)
+{
+ u32 minRTT = ca->minRTT;
+ u32 factor = 1;
+ u32 diff = htcp_cong_time(ca);
+
+ if (diff > HZ) {
+ diff -= HZ;
+ factor = 1 + (10 * diff + ((diff / 2) * (diff / 2) / HZ)) / HZ;
+ }
+
+ if (use_rtt_scaling && minRTT) {
+ u32 scale = (HZ << 3) / (10 * minRTT);
+
+ /* clamping ratio to interval [0.5,10]<<3 */
+ scale = min(max(scale, 1U << 2), 10U << 3);
+ factor = (factor << 3) / scale;
+ if (!factor)
+ factor = 1;
+ }
+
+ ca->alpha = 2 * factor * ((1 << 7) - ca->beta);
+ if (!ca->alpha)
+ ca->alpha = ALPHA_BASE;
+}
+
+/*
+ * After we have the rtt data to calculate beta, we'd still prefer to wait one
+ * rtt before we adjust our beta to ensure we are working from a consistent
+ * data.
+ *
+ * This function should be called when we hit a congestion event since only at
+ * that point do we really have a real sense of maxRTT (the queues en route
+ * were getting just too full now).
+ */
+static void htcp_param_update(struct sock *sk)
+{
+ struct htcp *ca = inet_csk_ca(sk);
+ u32 minRTT = ca->minRTT;
+ u32 maxRTT = ca->maxRTT;
+
+ htcp_beta_update(ca, minRTT, maxRTT);
+ htcp_alpha_update(ca);
+
+ /* add slowly fading memory for maxRTT to accommodate routing changes */
+ if (minRTT > 0 && maxRTT > minRTT)
+ ca->maxRTT = minRTT + ((maxRTT - minRTT) * 95) / 100;
+}
+
+static u32 htcp_recalc_ssthresh(struct sock *sk)
+{
+ const struct tcp_sock *tp = tcp_sk(sk);
+ const struct htcp *ca = inet_csk_ca(sk);
+
+ htcp_param_update(sk);
+ return max((tcp_snd_cwnd(tp) * ca->beta) >> 7, 2U);
+}
+
+static void htcp_cong_avoid(struct sock *sk, u32 ack, u32 acked)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct htcp *ca = inet_csk_ca(sk);
+
+ if (!tcp_is_cwnd_limited(sk))
+ return;
+
+ if (tcp_in_slow_start(tp))
+ tcp_slow_start(tp, acked);
+ else {
+ /* In dangerous area, increase slowly.
+ * In theory this is tp->snd_cwnd += alpha / tp->snd_cwnd
+ */
+ if ((tp->snd_cwnd_cnt * ca->alpha)>>7 >= tcp_snd_cwnd(tp)) {
+ if (tcp_snd_cwnd(tp) < tp->snd_cwnd_clamp)
+ tcp_snd_cwnd_set(tp, tcp_snd_cwnd(tp) + 1);
+ tp->snd_cwnd_cnt = 0;
+ htcp_alpha_update(ca);
+ } else
+ tp->snd_cwnd_cnt += ca->pkts_acked;
+
+ ca->pkts_acked = 1;
+ }
+}
+
+static void htcp_init(struct sock *sk)
+{
+ struct htcp *ca = inet_csk_ca(sk);
+
+ memset(ca, 0, sizeof(struct htcp));
+ ca->alpha = ALPHA_BASE;
+ ca->beta = BETA_MIN;
+ ca->pkts_acked = 1;
+ ca->last_cong = jiffies;
+}
+
+static void htcp_state(struct sock *sk, u8 new_state)
+{
+ switch (new_state) {
+ case TCP_CA_Open:
+ {
+ struct htcp *ca = inet_csk_ca(sk);
+
+ if (ca->undo_last_cong) {
+ ca->last_cong = jiffies;
+ ca->undo_last_cong = 0;
+ }
+ }
+ break;
+ case TCP_CA_CWR:
+ case TCP_CA_Recovery:
+ case TCP_CA_Loss:
+ htcp_reset(inet_csk_ca(sk));
+ break;
+ }
+}
+
+static struct tcp_congestion_ops htcp __read_mostly = {
+ .init = htcp_init,
+ .ssthresh = htcp_recalc_ssthresh,
+ .cong_avoid = htcp_cong_avoid,
+ .set_state = htcp_state,
+ .undo_cwnd = htcp_cwnd_undo,
+ .pkts_acked = measure_achieved_throughput,
+ .owner = THIS_MODULE,
+ .name = "htcp",
+};
+
+static int __init htcp_register(void)
+{
+ BUILD_BUG_ON(sizeof(struct htcp) > ICSK_CA_PRIV_SIZE);
+ BUILD_BUG_ON(BETA_MIN >= BETA_MAX);
+ return tcp_register_congestion_control(&htcp);
+}
+
+static void __exit htcp_unregister(void)
+{
+ tcp_unregister_congestion_control(&htcp);
+}
+
+module_init(htcp_register);
+module_exit(htcp_unregister);
+
+MODULE_AUTHOR("Baruch Even");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("H-TCP");