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().
  ...

1 files changed, 573 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c
new file mode 100644
index 000000000..9e95b37a7
--- /dev/null
+++ b/tools/testing/selftests/bpf/cgroup_helpers.c
@@ -0,0 +1,573 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <sched.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <linux/limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <linux/sched.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <ftw.h>
+
+#include "cgroup_helpers.h"
+#include "bpf_util.h"
+
+/*
+ * To avoid relying on the system setup, when setup_cgroup_env is called
+ * we create a new mount namespace, and cgroup namespace. The cgroupv2
+ * root is mounted at CGROUP_MOUNT_PATH. Unfortunately, most people don't
+ * have cgroupv2 enabled at this point in time. It's easier to create our
+ * own mount namespace and manage it ourselves. We assume /mnt exists.
+ *
+ * Related cgroupv1 helpers are named *classid*(), since we only use the
+ * net_cls controller for tagging net_cls.classid. We assume the default
+ * mount under /sys/fs/cgroup/net_cls, which should be the case for the
+ * vast majority of users.
+ */
+
+#define WALK_FD_LIMIT			16
+
+#define CGROUP_MOUNT_PATH		"/mnt"
+#define CGROUP_MOUNT_DFLT		"/sys/fs/cgroup"
+#define NETCLS_MOUNT_PATH		CGROUP_MOUNT_DFLT "/net_cls"
+#define CGROUP_WORK_DIR			"/cgroup-test-work-dir"
+
+#define format_cgroup_path_pid(buf, path, pid) \
+	snprintf(buf, sizeof(buf), "%s%s%d%s", CGROUP_MOUNT_PATH, \
+	CGROUP_WORK_DIR, pid, path)
+
+#define format_cgroup_path(buf, path) \
+	format_cgroup_path_pid(buf, path, getpid())
+
+#define format_parent_cgroup_path(buf, path) \
+	format_cgroup_path_pid(buf, path, getppid())
+
+#define format_classid_path(buf)				\
+	snprintf(buf, sizeof(buf), "%s%s", NETCLS_MOUNT_PATH,	\
+		 CGROUP_WORK_DIR)
+
+static int __enable_controllers(const char *cgroup_path, const char *controllers)
+{
+	char path[PATH_MAX + 1];
+	char enable[PATH_MAX + 1];
+	char *c, *c2;
+	int fd, cfd;
+	ssize_t len;
+
+	/* If not controllers are passed, enable all available controllers */
+	if (!controllers) {
+		snprintf(path, sizeof(path), "%s/cgroup.controllers",
+			 cgroup_path);
+		fd = open(path, O_RDONLY);
+		if (fd < 0) {
+			log_err("Opening cgroup.controllers: %s", path);
+			return 1;
+		}
+		len = read(fd, enable, sizeof(enable) - 1);
+		if (len < 0) {
+			close(fd);
+			log_err("Reading cgroup.controllers: %s", path);
+			return 1;
+		} else if (len == 0) { /* No controllers to enable */
+			close(fd);
+			return 0;
+		}
+		enable[len] = 0;
+		close(fd);
+	} else {
+		bpf_strlcpy(enable, controllers, sizeof(enable));
+	}
+
+	snprintf(path, sizeof(path), "%s/cgroup.subtree_control", cgroup_path);
+	cfd = open(path, O_RDWR);
+	if (cfd < 0) {
+		log_err("Opening cgroup.subtree_control: %s", path);
+		return 1;
+	}
+
+	for (c = strtok_r(enable, " ", &c2); c; c = strtok_r(NULL, " ", &c2)) {
+		if (dprintf(cfd, "+%s\n", c) <= 0) {
+			log_err("Enabling controller %s: %s", c, path);
+			close(cfd);
+			return 1;
+		}
+	}
+	close(cfd);
+	return 0;
+}
+
+/**
+ * enable_controllers() - Enable cgroup v2 controllers
+ * @relative_path: The cgroup path, relative to the workdir
+ * @controllers: List of controllers to enable in cgroup.controllers format
+ *
+ *
+ * Enable given cgroup v2 controllers, if @controllers is NULL, enable all
+ * available controllers.
+ *
+ * If successful, 0 is returned.
+ */
+int enable_controllers(const char *relative_path, const char *controllers)
+{
+	char cgroup_path[PATH_MAX + 1];
+
+	format_cgroup_path(cgroup_path, relative_path);
+	return __enable_controllers(cgroup_path, controllers);
+}
+
+static int __write_cgroup_file(const char *cgroup_path, const char *file,
+			       const char *buf)
+{
+	char file_path[PATH_MAX + 1];
+	int fd;
+
+	snprintf(file_path, sizeof(file_path), "%s/%s", cgroup_path, file);
+	fd = open(file_path, O_RDWR);
+	if (fd < 0) {
+		log_err("Opening %s", file_path);
+		return 1;
+	}
+
+	if (dprintf(fd, "%s", buf) <= 0) {
+		log_err("Writing to %s", file_path);
+		close(fd);
+		return 1;
+	}
+	close(fd);
+	return 0;
+}
+
+/**
+ * write_cgroup_file() - Write to a cgroup file
+ * @relative_path: The cgroup path, relative to the workdir
+ * @file: The name of the file in cgroupfs to write to
+ * @buf: Buffer to write to the file
+ *
+ * Write to a file in the given cgroup's directory.
+ *
+ * If successful, 0 is returned.
+ */
+int write_cgroup_file(const char *relative_path, const char *file,
+		      const char *buf)
+{
+	char cgroup_path[PATH_MAX - 24];
+
+	format_cgroup_path(cgroup_path, relative_path);
+	return __write_cgroup_file(cgroup_path, file, buf);
+}
+
+/**
+ * write_cgroup_file_parent() - Write to a cgroup file in the parent process
+ *                              workdir
+ * @relative_path: The cgroup path, relative to the parent process workdir
+ * @file: The name of the file in cgroupfs to write to
+ * @buf: Buffer to write to the file
+ *
+ * Write to a file in the given cgroup's directory under the parent process
+ * workdir.
+ *
+ * If successful, 0 is returned.
+ */
+int write_cgroup_file_parent(const char *relative_path, const char *file,
+			     const char *buf)
+{
+	char cgroup_path[PATH_MAX - 24];
+
+	format_parent_cgroup_path(cgroup_path, relative_path);
+	return __write_cgroup_file(cgroup_path, file, buf);
+}
+
+/**
+ * setup_cgroup_environment() - Setup the cgroup environment
+ *
+ * After calling this function, cleanup_cgroup_environment should be called
+ * once testing is complete.
+ *
+ * This function will print an error to stderr and return 1 if it is unable
+ * to setup the cgroup environment. If setup is successful, 0 is returned.
+ */
+int setup_cgroup_environment(void)
+{
+	char cgroup_workdir[PATH_MAX - 24];
+
+	format_cgroup_path(cgroup_workdir, "");
+
+	if (unshare(CLONE_NEWNS)) {
+		log_err("unshare");
+		return 1;
+	}
+
+	if (mount("none", "/", NULL, MS_REC | MS_PRIVATE, NULL)) {
+		log_err("mount fakeroot");
+		return 1;
+	}
+
+	if (mount("none", CGROUP_MOUNT_PATH, "cgroup2", 0, NULL) && errno != EBUSY) {
+		log_err("mount cgroup2");
+		return 1;
+	}
+
+	/* Cleanup existing failed runs, now that the environment is setup */
+	cleanup_cgroup_environment();
+
+	if (mkdir(cgroup_workdir, 0777) && errno != EEXIST) {
+		log_err("mkdir cgroup work dir");
+		return 1;
+	}
+
+	/* Enable all available controllers to increase test coverage */
+	if (__enable_controllers(CGROUP_MOUNT_PATH, NULL) ||
+	    __enable_controllers(cgroup_workdir, NULL))
+		return 1;
+
+	return 0;
+}
+
+static int nftwfunc(const char *filename, const struct stat *statptr,
+		    int fileflags, struct FTW *pfwt)
+{
+	if ((fileflags & FTW_D) && rmdir(filename))
+		log_err("Removing cgroup: %s", filename);
+	return 0;
+}
+
+static int join_cgroup_from_top(const char *cgroup_path)
+{
+	char cgroup_procs_path[PATH_MAX + 1];
+	pid_t pid = getpid();
+	int fd, rc = 0;
+
+	snprintf(cgroup_procs_path, sizeof(cgroup_procs_path),
+		 "%s/cgroup.procs", cgroup_path);
+
+	fd = open(cgroup_procs_path, O_WRONLY);
+	if (fd < 0) {
+		log_err("Opening Cgroup Procs: %s", cgroup_procs_path);
+		return 1;
+	}
+
+	if (dprintf(fd, "%d\n", pid) < 0) {
+		log_err("Joining Cgroup");
+		rc = 1;
+	}
+
+	close(fd);
+	return rc;
+}
+
+/**
+ * join_cgroup() - Join a cgroup
+ * @relative_path: The cgroup path, relative to the workdir, to join
+ *
+ * This function expects a cgroup to already be created, relative to the cgroup
+ * work dir, and it joins it. For example, passing "/my-cgroup" as the path
+ * would actually put the calling process into the cgroup
+ * "/cgroup-test-work-dir/my-cgroup"
+ *
+ * On success, it returns 0, otherwise on failure it returns 1.
+ */
+int join_cgroup(const char *relative_path)
+{
+	char cgroup_path[PATH_MAX + 1];
+
+	format_cgroup_path(cgroup_path, relative_path);
+	return join_cgroup_from_top(cgroup_path);
+}
+
+/**
+ * join_parent_cgroup() - Join a cgroup in the parent process workdir
+ * @relative_path: The cgroup path, relative to parent process workdir, to join
+ *
+ * See join_cgroup().
+ *
+ * On success, it returns 0, otherwise on failure it returns 1.
+ */
+int join_parent_cgroup(const char *relative_path)
+{
+	char cgroup_path[PATH_MAX + 1];
+
+	format_parent_cgroup_path(cgroup_path, relative_path);
+	return join_cgroup_from_top(cgroup_path);
+}
+
+/**
+ * cleanup_cgroup_environment() - Cleanup Cgroup Testing Environment
+ *
+ * This is an idempotent function to delete all temporary cgroups that
+ * have been created during the test, including the cgroup testing work
+ * directory.
+ *
+ * At call time, it moves the calling process to the root cgroup, and then
+ * runs the deletion process. It is idempotent, and should not fail, unless
+ * a process is lingering.
+ *
+ * On failure, it will print an error to stderr, and try to continue.
+ */
+void cleanup_cgroup_environment(void)
+{
+	char cgroup_workdir[PATH_MAX + 1];
+
+	format_cgroup_path(cgroup_workdir, "");
+	join_cgroup_from_top(CGROUP_MOUNT_PATH);
+	nftw(cgroup_workdir, nftwfunc, WALK_FD_LIMIT, FTW_DEPTH | FTW_MOUNT);
+}
+
+/**
+ * get_root_cgroup() - Get the FD of the root cgroup
+ *
+ * On success, it returns the file descriptor. On failure, it returns -1.
+ * If there is a failure, it prints the error to stderr.
+ */
+int get_root_cgroup(void)
+{
+	int fd;
+
+	fd = open(CGROUP_MOUNT_PATH, O_RDONLY);
+	if (fd < 0) {
+		log_err("Opening root cgroup");
+		return -1;
+	}
+	return fd;
+}
+
+/*
+ * remove_cgroup() - Remove a cgroup
+ * @relative_path: The cgroup path, relative to the workdir, to remove
+ *
+ * This function expects a cgroup to already be created, relative to the cgroup
+ * work dir. It also expects the cgroup doesn't have any children or live
+ * processes and it removes the cgroup.
+ *
+ * On failure, it will print an error to stderr.
+ */
+void remove_cgroup(const char *relative_path)
+{
+	char cgroup_path[PATH_MAX + 1];
+
+	format_cgroup_path(cgroup_path, relative_path);
+	if (rmdir(cgroup_path))
+		log_err("rmdiring cgroup %s .. %s", relative_path, cgroup_path);
+}
+
+/**
+ * create_and_get_cgroup() - Create a cgroup, relative to workdir, and get the FD
+ * @relative_path: The cgroup path, relative to the workdir, to join
+ *
+ * This function creates a cgroup under the top level workdir and returns the
+ * file descriptor. It is idempotent.
+ *
+ * On success, it returns the file descriptor. On failure it returns -1.
+ * If there is a failure, it prints the error to stderr.
+ */
+int create_and_get_cgroup(const char *relative_path)
+{
+	char cgroup_path[PATH_MAX + 1];
+	int fd;
+
+	format_cgroup_path(cgroup_path, relative_path);
+	if (mkdir(cgroup_path, 0777) && errno != EEXIST) {
+		log_err("mkdiring cgroup %s .. %s", relative_path, cgroup_path);
+		return -1;
+	}
+
+	fd = open(cgroup_path, O_RDONLY);
+	if (fd < 0) {
+		log_err("Opening Cgroup");
+		return -1;
+	}
+
+	return fd;
+}
+
+/**
+ * get_cgroup_id() - Get cgroup id for a particular cgroup path
+ * @relative_path: The cgroup path, relative to the workdir, to join
+ *
+ * On success, it returns the cgroup id. On failure it returns 0,
+ * which is an invalid cgroup id.
+ * If there is a failure, it prints the error to stderr.
+ */
+unsigned long long get_cgroup_id(const char *relative_path)
+{
+	int dirfd, err, flags, mount_id, fhsize;
+	union {
+		unsigned long long cgid;
+		unsigned char raw_bytes[8];
+	} id;
+	char cgroup_workdir[PATH_MAX + 1];
+	struct file_handle *fhp, *fhp2;
+	unsigned long long ret = 0;
+
+	format_cgroup_path(cgroup_workdir, relative_path);
+
+	dirfd = AT_FDCWD;
+	flags = 0;
+	fhsize = sizeof(*fhp);
+	fhp = calloc(1, fhsize);
+	if (!fhp) {
+		log_err("calloc");
+		return 0;
+	}
+	err = name_to_handle_at(dirfd, cgroup_workdir, fhp, &mount_id, flags);
+	if (err >= 0 || fhp->handle_bytes != 8) {
+		log_err("name_to_handle_at");
+		goto free_mem;
+	}
+
+	fhsize = sizeof(struct file_handle) + fhp->handle_bytes;
+	fhp2 = realloc(fhp, fhsize);
+	if (!fhp2) {
+		log_err("realloc");
+		goto free_mem;
+	}
+	err = name_to_handle_at(dirfd, cgroup_workdir, fhp2, &mount_id, flags);
+	fhp = fhp2;
+	if (err < 0) {
+		log_err("name_to_handle_at");
+		goto free_mem;
+	}
+
+	memcpy(id.raw_bytes, fhp->f_handle, 8);
+	ret = id.cgid;
+
+free_mem:
+	free(fhp);
+	return ret;
+}
+
+int cgroup_setup_and_join(const char *path) {
+	int cg_fd;
+
+	if (setup_cgroup_environment()) {
+		fprintf(stderr, "Failed to setup cgroup environment\n");
+		return -EINVAL;
+	}
+
+	cg_fd = create_and_get_cgroup(path);
+	if (cg_fd < 0) {
+		fprintf(stderr, "Failed to create test cgroup\n");
+		cleanup_cgroup_environment();
+		return cg_fd;
+	}
+
+	if (join_cgroup(path)) {
+		fprintf(stderr, "Failed to join cgroup\n");
+		cleanup_cgroup_environment();
+		return -EINVAL;
+	}
+	return cg_fd;
+}
+
+/**
+ * setup_classid_environment() - Setup the cgroupv1 net_cls environment
+ *
+ * After calling this function, cleanup_classid_environment should be called
+ * once testing is complete.
+ *
+ * This function will print an error to stderr and return 1 if it is unable
+ * to setup the cgroup environment. If setup is successful, 0 is returned.
+ */
+int setup_classid_environment(void)
+{
+	char cgroup_workdir[PATH_MAX + 1];
+
+	format_classid_path(cgroup_workdir);
+
+	if (mount("tmpfs", CGROUP_MOUNT_DFLT, "tmpfs", 0, NULL) &&
+	    errno != EBUSY) {
+		log_err("mount cgroup base");
+		return 1;
+	}
+
+	if (mkdir(NETCLS_MOUNT_PATH, 0777) && errno != EEXIST) {
+		log_err("mkdir cgroup net_cls");
+		return 1;
+	}
+
+	if (mount("net_cls", NETCLS_MOUNT_PATH, "cgroup", 0, "net_cls") &&
+	    errno != EBUSY) {
+		log_err("mount cgroup net_cls");
+		return 1;
+	}
+
+	cleanup_classid_environment();
+
+	if (mkdir(cgroup_workdir, 0777) && errno != EEXIST) {
+		log_err("mkdir cgroup work dir");
+		return 1;
+	}
+
+	return 0;
+}
+
+/**
+ * set_classid() - Set a cgroupv1 net_cls classid
+ * @id: the numeric classid
+ *
+ * Writes the passed classid into the cgroup work dir's net_cls.classid
+ * file in order to later on trigger socket tagging.
+ *
+ * On success, it returns 0, otherwise on failure it returns 1. If there
+ * is a failure, it prints the error to stderr.
+ */
+int set_classid(unsigned int id)
+{
+	char cgroup_workdir[PATH_MAX - 42];
+	char cgroup_classid_path[PATH_MAX + 1];
+	int fd, rc = 0;
+
+	format_classid_path(cgroup_workdir);
+	snprintf(cgroup_classid_path, sizeof(cgroup_classid_path),
+		 "%s/net_cls.classid", cgroup_workdir);
+
+	fd = open(cgroup_classid_path, O_WRONLY);
+	if (fd < 0) {
+		log_err("Opening cgroup classid: %s", cgroup_classid_path);
+		return 1;
+	}
+
+	if (dprintf(fd, "%u\n", id) < 0) {
+		log_err("Setting cgroup classid");
+		rc = 1;
+	}
+
+	close(fd);
+	return rc;
+}
+
+/**
+ * join_classid() - Join a cgroupv1 net_cls classid
+ *
+ * This function expects the cgroup work dir to be already created, as we
+ * join it here. This causes the process sockets to be tagged with the given
+ * net_cls classid.
+ *
+ * On success, it returns 0, otherwise on failure it returns 1.
+ */
+int join_classid(void)
+{
+	char cgroup_workdir[PATH_MAX + 1];
+
+	format_classid_path(cgroup_workdir);
+	return join_cgroup_from_top(cgroup_workdir);
+}
+
+/**
+ * cleanup_classid_environment() - Cleanup the cgroupv1 net_cls environment
+ *
+ * At call time, it moves the calling process to the root cgroup, and then
+ * runs the deletion process.
+ *
+ * On failure, it will print an error to stderr, and try to continue.
+ */
+void cleanup_classid_environment(void)
+{
+	char cgroup_workdir[PATH_MAX + 1];
+
+	format_classid_path(cgroup_workdir);
+	join_cgroup_from_top(NETCLS_MOUNT_PATH);
+	nftw(cgroup_workdir, nftwfunc, WALK_FD_LIMIT, FTW_DEPTH | FTW_MOUNT);
+}