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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/netfilter/xt_limit.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/netfilter/xt_limit.c')
-rw-r--r--net/netfilter/xt_limit.c215
1 files changed, 215 insertions, 0 deletions
diff --git a/net/netfilter/xt_limit.c b/net/netfilter/xt_limit.c
new file mode 100644
index 000000000..8b4fd2785
--- /dev/null
+++ b/net/netfilter/xt_limit.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* (C) 1999 Jérôme de Vivie <devivie@info.enserb.u-bordeaux.fr>
+ * (C) 1999 Hervé Eychenne <eychenne@info.enserb.u-bordeaux.fr>
+ * (C) 2006-2012 Patrick McHardy <kaber@trash.net>
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/interrupt.h>
+
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_limit.h>
+
+struct xt_limit_priv {
+ unsigned long prev;
+ u32 credit;
+};
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Herve Eychenne <rv@wallfire.org>");
+MODULE_DESCRIPTION("Xtables: rate-limit match");
+MODULE_ALIAS("ipt_limit");
+MODULE_ALIAS("ip6t_limit");
+
+/* The algorithm used is the Simple Token Bucket Filter (TBF)
+ * see net/sched/sch_tbf.c in the linux source tree
+ */
+
+/* Rusty: This is my (non-mathematically-inclined) understanding of
+ this algorithm. The `average rate' in jiffies becomes your initial
+ amount of credit `credit' and the most credit you can ever have
+ `credit_cap'. The `peak rate' becomes the cost of passing the
+ test, `cost'.
+
+ `prev' tracks the last packet hit: you gain one credit per jiffy.
+ If you get credit balance more than this, the extra credit is
+ discarded. Every time the match passes, you lose `cost' credits;
+ if you don't have that many, the test fails.
+
+ See Alexey's formal explanation in net/sched/sch_tbf.c.
+
+ To get the maximum range, we multiply by this factor (ie. you get N
+ credits per jiffy). We want to allow a rate as low as 1 per day
+ (slowest userspace tool allows), which means
+ CREDITS_PER_JIFFY*HZ*60*60*24 < 2^32. ie. */
+#define MAX_CPJ (0xFFFFFFFF / (HZ*60*60*24))
+
+/* Repeated shift and or gives us all 1s, final shift and add 1 gives
+ * us the power of 2 below the theoretical max, so GCC simply does a
+ * shift. */
+#define _POW2_BELOW2(x) ((x)|((x)>>1))
+#define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2))
+#define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4))
+#define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8))
+#define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16))
+#define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1)
+
+#define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ)
+
+static bool
+limit_mt(const struct sk_buff *skb, struct xt_action_param *par)
+{
+ const struct xt_rateinfo *r = par->matchinfo;
+ struct xt_limit_priv *priv = r->master;
+ unsigned long now;
+ u32 old_credit, new_credit, credit_increase = 0;
+ bool ret;
+
+ /* fastpath if there is nothing to update */
+ if ((READ_ONCE(priv->credit) < r->cost) && (READ_ONCE(priv->prev) == jiffies))
+ return false;
+
+ do {
+ now = jiffies;
+ credit_increase += (now - xchg(&priv->prev, now)) * CREDITS_PER_JIFFY;
+ old_credit = READ_ONCE(priv->credit);
+ new_credit = old_credit;
+ new_credit += credit_increase;
+ if (new_credit > r->credit_cap)
+ new_credit = r->credit_cap;
+ if (new_credit >= r->cost) {
+ ret = true;
+ new_credit -= r->cost;
+ } else {
+ ret = false;
+ }
+ } while (cmpxchg(&priv->credit, old_credit, new_credit) != old_credit);
+
+ return ret;
+}
+
+/* Precision saver. */
+static u32 user2credits(u32 user)
+{
+ /* If multiplying would overflow... */
+ if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY))
+ /* Divide first. */
+ return (user / XT_LIMIT_SCALE) * HZ * CREDITS_PER_JIFFY;
+
+ return (user * HZ * CREDITS_PER_JIFFY) / XT_LIMIT_SCALE;
+}
+
+static int limit_mt_check(const struct xt_mtchk_param *par)
+{
+ struct xt_rateinfo *r = par->matchinfo;
+ struct xt_limit_priv *priv;
+
+ /* Check for overflow. */
+ if (r->burst == 0
+ || user2credits(r->avg * r->burst) < user2credits(r->avg)) {
+ pr_info_ratelimited("Overflow, try lower: %u/%u\n",
+ r->avg, r->burst);
+ return -ERANGE;
+ }
+
+ priv = kmalloc(sizeof(*priv), GFP_KERNEL);
+ if (priv == NULL)
+ return -ENOMEM;
+
+ /* For SMP, we only want to use one set of state. */
+ r->master = priv;
+ /* User avg in seconds * XT_LIMIT_SCALE: convert to jiffies *
+ 128. */
+ priv->prev = jiffies;
+ priv->credit = user2credits(r->avg * r->burst); /* Credits full. */
+ if (r->cost == 0) {
+ r->credit_cap = priv->credit; /* Credits full. */
+ r->cost = user2credits(r->avg);
+ }
+
+ return 0;
+}
+
+static void limit_mt_destroy(const struct xt_mtdtor_param *par)
+{
+ const struct xt_rateinfo *info = par->matchinfo;
+
+ kfree(info->master);
+}
+
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
+struct compat_xt_rateinfo {
+ u_int32_t avg;
+ u_int32_t burst;
+
+ compat_ulong_t prev;
+ u_int32_t credit;
+ u_int32_t credit_cap, cost;
+
+ u_int32_t master;
+};
+
+/* To keep the full "prev" timestamp, the upper 32 bits are stored in the
+ * master pointer, which does not need to be preserved. */
+static void limit_mt_compat_from_user(void *dst, const void *src)
+{
+ const struct compat_xt_rateinfo *cm = src;
+ struct xt_rateinfo m = {
+ .avg = cm->avg,
+ .burst = cm->burst,
+ .prev = cm->prev | (unsigned long)cm->master << 32,
+ .credit = cm->credit,
+ .credit_cap = cm->credit_cap,
+ .cost = cm->cost,
+ };
+ memcpy(dst, &m, sizeof(m));
+}
+
+static int limit_mt_compat_to_user(void __user *dst, const void *src)
+{
+ const struct xt_rateinfo *m = src;
+ struct compat_xt_rateinfo cm = {
+ .avg = m->avg,
+ .burst = m->burst,
+ .prev = m->prev,
+ .credit = m->credit,
+ .credit_cap = m->credit_cap,
+ .cost = m->cost,
+ .master = m->prev >> 32,
+ };
+ return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0;
+}
+#endif /* CONFIG_NETFILTER_XTABLES_COMPAT */
+
+static struct xt_match limit_mt_reg __read_mostly = {
+ .name = "limit",
+ .revision = 0,
+ .family = NFPROTO_UNSPEC,
+ .match = limit_mt,
+ .checkentry = limit_mt_check,
+ .destroy = limit_mt_destroy,
+ .matchsize = sizeof(struct xt_rateinfo),
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
+ .compatsize = sizeof(struct compat_xt_rateinfo),
+ .compat_from_user = limit_mt_compat_from_user,
+ .compat_to_user = limit_mt_compat_to_user,
+#endif
+ .usersize = offsetof(struct xt_rateinfo, prev),
+ .me = THIS_MODULE,
+};
+
+static int __init limit_mt_init(void)
+{
+ return xt_register_match(&limit_mt_reg);
+}
+
+static void __exit limit_mt_exit(void)
+{
+ xt_unregister_match(&limit_mt_reg);
+}
+
+module_init(limit_mt_init);
+module_exit(limit_mt_exit);