New upstream version 240

[systemd.git] / src / udev / udev-builtin-net_id.c

/* SPDX-License-Identifier: LGPL-2.1+ */

/*
 * Predictable network interface device names based on:
 *  - firmware/bios-provided index numbers for on-board devices
 *  - firmware-provided pci-express hotplug slot index number
 *  - physical/geographical location of the hardware
 *  - the interface's MAC address
 *
 * http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames
 *
 * Two character prefixes based on the type of interface:
 *   en — Ethernet
 *   ib — InfiniBand
 *   sl — serial line IP (slip)
 *   wl — wlan
 *   ww — wwan
 *
 * Type of names:
 *   b<number>                             — BCMA bus core number
 *   c<bus_id>                             — bus id of a grouped CCW or CCW device,
 *                                           with all leading zeros stripped [s390]
 *   o<index>[n<phys_port_name>|d<dev_port>]
 *                                         — on-board device index number
 *   s<slot>[f<function>][n<phys_port_name>|d<dev_port>]
 *                                         — hotplug slot index number
 *   x<MAC>                                — MAC address
 *   [P<domain>]p<bus>s<slot>[f<function>][n<phys_port_name>|d<dev_port>]
 *                                         — PCI geographical location
 *   [P<domain>]p<bus>s<slot>[f<function>][u<port>][..][c<config>][i<interface>]
 *                                         — USB port number chain
 *   v<slot>                               - VIO slot number (IBM PowerVM)
 *   a<vendor><model>i<instance>           — Platform bus ACPI instance id
 *
 * All multi-function PCI devices will carry the [f<function>] number in the
 * device name, including the function 0 device.
 *
 * SR-IOV virtual devices are named based on the name of the parent interface,
 * with a suffix of "v<N>", where <N> is the virtual device number.
 *
 * When using PCI geography, The PCI domain is only prepended when it is not 0.
 *
 * For USB devices the full chain of port numbers of hubs is composed. If the
 * name gets longer than the maximum number of 15 characters, the name is not
 * exported.
 * The usual USB configuration == 1 and interface == 0 values are suppressed.
 *
 * PCI Ethernet card with firmware index "1":
 *   ID_NET_NAME_ONBOARD=eno1
 *   ID_NET_NAME_ONBOARD_LABEL=Ethernet Port 1
 *
 * PCI Ethernet card in hotplug slot with firmware index number:
 *   /sys/devices/pci0000:00/0000:00:1c.3/0000:05:00.0/net/ens1
 *   ID_NET_NAME_MAC=enx000000000466
 *   ID_NET_NAME_PATH=enp5s0
 *   ID_NET_NAME_SLOT=ens1
 *
 * PCI Ethernet multi-function card with 2 ports:
 *   /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.0/net/enp2s0f0
 *   ID_NET_NAME_MAC=enx78e7d1ea46da
 *   ID_NET_NAME_PATH=enp2s0f0
 *   /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.1/net/enp2s0f1
 *   ID_NET_NAME_MAC=enx78e7d1ea46dc
 *   ID_NET_NAME_PATH=enp2s0f1
 *
 * PCI wlan card:
 *   /sys/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/net/wlp3s0
 *   ID_NET_NAME_MAC=wlx0024d7e31130
 *   ID_NET_NAME_PATH=wlp3s0
 *
 * PCI IB host adapter with 2 ports:
 *   /sys/devices/pci0000:00/0000:00:03.0/0000:15:00.0/net/ibp21s0f0
 *   ID_NET_NAME_PATH=ibp21s0f0
 *   /sys/devices/pci0000:00/0000:00:03.0/0000:15:00.1/net/ibp21s0f1
 *   ID_NET_NAME_PATH=ibp21s0f1
 *
 * USB built-in 3G modem:
 *   /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4:1.6/net/wwp0s29u1u4i6
 *   ID_NET_NAME_MAC=wwx028037ec0200
 *   ID_NET_NAME_PATH=wwp0s29u1u4i6
 *
 * USB Android phone:
 *   /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0/net/enp0s29u1u2
 *   ID_NET_NAME_MAC=enxd626b3450fb5
 *   ID_NET_NAME_PATH=enp0s29u1u2
 *
 * s390 grouped CCW interface:
 *  /sys/devices/css0/0.0.0007/0.0.f5f0/group_device/net/encf5f0
 *  ID_NET_NAME_MAC=enx026d3c00000a
 *  ID_NET_NAME_PATH=encf5f0
 */

#include <errno.h>
#include <fcntl.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <linux/pci_regs.h>

#include "alloc-util.h"
#include "dirent-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "fs-util.h"
#include "parse-util.h"
#include "proc-cmdline.h"
#include "stdio-util.h"
#include "string-util.h"
#include "strv.h"
#include "strxcpyx.h"
#include "udev-builtin.h"

#define ONBOARD_INDEX_MAX (16*1024-1)

/* So here's the deal: net_id is supposed to be an excercise in providing stable names for network devices. However, we
 * also want to keep updating the naming scheme used in future versions of net_id. These two goals of course are
 * contradictory: on one hand we want things to not change and on the other hand we want them to improve. Our way out
 * of this dilemma is to introduce the "naming scheme" concept: each time we improve the naming logic we define a new
 * flag for it. Then, we keep a list of schemes, each identified by a name associated with the flags it implements. Via
 * a kernel command line and environment variable we then allow the user to pick the scheme they want us to follow:
 * installers could "freeze" the used scheme at the moment of installation this way.
 *
 * Developers: each time you tweak the naming logic here, define a new flag below, and condition the tweak with
 * it. Each time we do a release we'll then add a new scheme entry and include all newly defined flags.
 *
 * Note that this is only half a solution to the problem though: not only udev/net_id gets updated all the time, the
 * kernel gets too. And thus a kernel that previously didn't expose some sysfs attribute we look for might eventually
 * do, and thus affect our naming scheme too. Thus, enforcing a naming scheme will make interfacing more stable across
 * OS versions, but not fully stabilize them. */
typedef enum NamingSchemeFlags {
        /* First, the individual features */
        NAMING_SR_IOV_V        = 1 << 0, /* Use "v" suffix for SR-IOV, see 609948c7043a40008b8299529c978ed8e11de8f6*/
        NAMING_NPAR_ARI        = 1 << 1, /* Use NPAR "ARI", see 6bc04997b6eab35d1cb9fa73889892702c27be09 */
        NAMING_INFINIBAND      = 1 << 2, /* Use "ib" prefix for infiniband, see 938d30aa98df887797c9e05074a562ddacdcdf5e */
        NAMING_ZERO_ACPI_INDEX = 1 << 3, /* Allow zero acpi_index field, see d81186ef4f6a888a70f20a1e73a812d6acb9e22f */

        /* And now the masks that combine the features above */
        NAMING_V238 = 0,
        NAMING_V239 = NAMING_V238|NAMING_SR_IOV_V|NAMING_NPAR_ARI,
        NAMING_V240 = NAMING_V239|NAMING_INFINIBAND|NAMING_ZERO_ACPI_INDEX,

        _NAMING_SCHEME_FLAGS_INVALID = -1,
} NamingSchemeFlags;

typedef struct NamingScheme {
        const char *name;
        NamingSchemeFlags flags;
} NamingScheme;

static const NamingScheme naming_schemes[] = {
        { "v238", NAMING_V238 },
        { "v239", NAMING_V239 },
        { "v240", NAMING_V240 },
        /* … add more schemes here, as the logic to name devices is updated … */
};

enum netname_type{
        NET_UNDEF,
        NET_PCI,
        NET_USB,
        NET_BCMA,
        NET_VIRTIO,
        NET_CCW,
        NET_VIO,
        NET_PLATFORM,
};

struct netnames {
        enum netname_type type;

        uint8_t mac[6];
        bool mac_valid;

        sd_device *pcidev;
        char pci_slot[IFNAMSIZ];
        char pci_path[IFNAMSIZ];
        char pci_onboard[IFNAMSIZ];
        const char *pci_onboard_label;

        char usb_ports[IFNAMSIZ];
        char bcma_core[IFNAMSIZ];
        char ccw_busid[IFNAMSIZ];
        char vio_slot[IFNAMSIZ];
        char platform_path[IFNAMSIZ];
};

struct virtfn_info {
        sd_device *physfn_pcidev;
        char suffix[IFNAMSIZ];
};

static const NamingScheme* naming_scheme_from_name(const char *name) {
        size_t i;

        if (streq(name, "latest"))
                return naming_schemes + ELEMENTSOF(naming_schemes) - 1;

        for (i = 0; i < ELEMENTSOF(naming_schemes); i++)
                if (streq(naming_schemes[i].name, name))
                        return naming_schemes + i;

        return NULL;
}

static const NamingScheme* naming_scheme(void) {
        static const NamingScheme *cache = NULL;
        _cleanup_free_ char *buffer = NULL;
        const char *e, *k;

        if (cache)
                return cache;

        /* Acquire setting from the kernel command line */
        (void) proc_cmdline_get_key("net.naming-scheme", 0, &buffer);

        /* Also acquire it from an env var */
        e = getenv("NET_NAMING_SCHEME");
        if (e) {
                if (*e == ':') {
                        /* If prefixed with ':' the kernel cmdline takes precedence */
                        k = buffer ?: e + 1;
                } else
                        k = e; /* Otherwise the env var takes precedence */
        } else
                k = buffer;

        if (k) {
                cache = naming_scheme_from_name(k);
                if (cache) {
                        log_info("Using interface naming scheme '%s'.", cache->name);
                        return cache;
                }

                log_warning("Unknown interface naming scheme '%s' requested, ignoring.", k);
        }

        cache = naming_scheme_from_name(DEFAULT_NET_NAMING_SCHEME);
        assert(cache);
        log_info("Using default interface naming scheme '%s'.", cache->name);

        return cache;
}

static bool naming_scheme_has(NamingSchemeFlags flags) {
        return FLAGS_SET(naming_scheme()->flags, flags);
}

/* skip intermediate virtio devices */
static sd_device *skip_virtio(sd_device *dev) {
        sd_device *parent;

        /* there can only ever be one virtio bus per parent device, so we can
         * safely ignore any virtio buses. see
         * http://lists.linuxfoundation.org/pipermail/virtualization/2015-August/030331.html */
        for (parent = dev; parent; ) {
                const char *subsystem;

                if (sd_device_get_subsystem(parent, &subsystem) < 0)
                        break;

                if (!streq(subsystem, "virtio"))
                        break;

                if (sd_device_get_parent(parent, &parent) < 0)
                        return NULL;
        }

        return parent;
}

static int get_virtfn_info(sd_device *dev, struct netnames *names, struct virtfn_info *ret) {
        _cleanup_(sd_device_unrefp) sd_device *physfn_pcidev = NULL;
        const char *physfn_link_file, *syspath;
        _cleanup_free_ char *physfn_pci_syspath = NULL;
        _cleanup_free_ char *virtfn_pci_syspath = NULL;
        struct dirent *dent;
        _cleanup_closedir_ DIR *dir = NULL;
        char suffix[IFNAMSIZ];
        int r;

        assert(dev);
        assert(names);
        assert(ret);

        r = sd_device_get_syspath(names->pcidev, &syspath);
        if (r < 0)
                return r;

        /* Check if this is a virtual function. */
        physfn_link_file = strjoina(syspath, "/physfn");
        r = chase_symlinks(physfn_link_file, NULL, 0, &physfn_pci_syspath);
        if (r < 0)
                return r;

        /* Get physical function's pci device. */
        r = sd_device_new_from_syspath(&physfn_pcidev, physfn_pci_syspath);
        if (r < 0)
                return r;

        /* Find the virtual function number by finding the right virtfn link. */
        dir = opendir(physfn_pci_syspath);
        if (!dir)
                return -errno;

        FOREACH_DIRENT_ALL(dent, dir, break) {
                _cleanup_free_ char *virtfn_link_file = NULL;

                if (!startswith(dent->d_name, "virtfn"))
                        continue;

                virtfn_link_file = strjoin(physfn_pci_syspath, "/", dent->d_name);
                if (!virtfn_link_file)
                        return -ENOMEM;

                if (chase_symlinks(virtfn_link_file, NULL, 0, &virtfn_pci_syspath) < 0)
                        continue;

                if (streq(syspath, virtfn_pci_syspath)) {
                        if (!snprintf_ok(suffix, sizeof(suffix), "v%s", &dent->d_name[6]))
                                return -ENOENT;

                        break;
                }
        }
        if (isempty(suffix))
                return -ENOENT;

        ret->physfn_pcidev = TAKE_PTR(physfn_pcidev);
        strncpy(ret->suffix, suffix, sizeof(ret->suffix));

        return 0;
}

/* retrieve on-board index number and label from firmware */
static int dev_pci_onboard(sd_device *dev, struct netnames *names) {
        unsigned long idx, dev_port = 0;
        const char *attr, *port_name = NULL;
        size_t l;
        char *s;
        int r;

        /* ACPI _DSM  — device specific method for naming a PCI or PCI Express device */
        if (sd_device_get_sysattr_value(names->pcidev, "acpi_index", &attr) < 0) {
                /* SMBIOS type 41 — Onboard Devices Extended Information */
                r = sd_device_get_sysattr_value(names->pcidev, "index", &attr);
                if (r < 0)
                        return r;
        }

        r = safe_atolu(attr, &idx);
        if (r < 0)
                return r;
        if (idx == 0 && !naming_scheme_has(NAMING_ZERO_ACPI_INDEX))
                return -EINVAL;

        /* Some BIOSes report rubbish indexes that are excessively high (2^24-1 is an index VMware likes to report for
         * example). Let's define a cut-off where we don't consider the index reliable anymore. We pick some arbitrary
         * cut-off, which is somewhere beyond the realistic number of physical network interface a system might
         * have. Ideally the kernel would already filter his crap for us, but it doesn't currently. */
        if (idx > ONBOARD_INDEX_MAX)
                return -ENOENT;

        /* kernel provided port index for multiple ports on a single PCI function */
        if (sd_device_get_sysattr_value(dev, "dev_port", &attr) >= 0)
                dev_port = strtoul(attr, NULL, 10);

        /* kernel provided front panel port name for multiple port PCI device */
        (void) sd_device_get_sysattr_value(dev, "phys_port_name", &port_name);

        s = names->pci_onboard;
        l = sizeof(names->pci_onboard);
        l = strpcpyf(&s, l, "o%lu", idx);
        if (port_name)
                l = strpcpyf(&s, l, "n%s", port_name);
        else if (dev_port > 0)
                l = strpcpyf(&s, l, "d%lu", dev_port);
        if (l == 0)
                names->pci_onboard[0] = '\0';

        if (sd_device_get_sysattr_value(names->pcidev, "label", &names->pci_onboard_label) < 0)
                names->pci_onboard_label = NULL;

        return 0;
}

/* read the 256 bytes PCI configuration space to check the multi-function bit */
static bool is_pci_multifunction(sd_device *dev) {
        _cleanup_close_ int fd = -1;
        const char *filename, *syspath;
        uint8_t config[64];

        if (sd_device_get_syspath(dev, &syspath) < 0)
                return false;

        filename = strjoina(syspath, "/config");
        fd = open(filename, O_RDONLY | O_CLOEXEC);
        if (fd < 0)
                return false;
        if (read(fd, &config, sizeof(config)) != sizeof(config))
                return false;

        /* bit 0-6 header type, bit 7 multi/single function device */
        return config[PCI_HEADER_TYPE] & 0x80;
}

static bool is_pci_ari_enabled(sd_device *dev) {
        const char *a;

        if (sd_device_get_sysattr_value(dev, "ari_enabled", &a) < 0)
                return false;

        return streq(a, "1");
}

static int dev_pci_slot(sd_device *dev, struct netnames *names) {
        unsigned long dev_port = 0;
        unsigned domain, bus, slot, func, hotplug_slot = 0;
        size_t l;
        char *s;
        const char *sysname, *attr, *port_name = NULL, *syspath;
        _cleanup_(sd_device_unrefp) sd_device *pci = NULL;
        sd_device *hotplug_slot_dev;
        char slots[PATH_MAX];
        _cleanup_closedir_ DIR *dir = NULL;
        struct dirent *dent;
        int r;

        r = sd_device_get_sysname(names->pcidev, &sysname);
        if (r < 0)
                return r;

        if (sscanf(sysname, "%x:%x:%x.%u", &domain, &bus, &slot, &func) != 4)
                return -ENOENT;

        if (naming_scheme_has(NAMING_NPAR_ARI) &&
            is_pci_ari_enabled(names->pcidev))
                /* ARI devices support up to 256 functions on a single device ("slot"), and interpret the
                 * traditional 5-bit slot and 3-bit function number as a single 8-bit function number,
                 * where the slot makes up the upper 5 bits. */
                func += slot * 8;

        /* kernel provided port index for multiple ports on a single PCI function */
        if (sd_device_get_sysattr_value(dev, "dev_port", &attr) >= 0) {
                dev_port = strtoul(attr, NULL, 10);
                /* With older kernels IP-over-InfiniBand network interfaces sometimes erroneously
                 * provide the port number in the 'dev_id' sysfs attribute instead of 'dev_port',
                 * which thus stays initialized as 0. */
                if (dev_port == 0 &&
                    sd_device_get_sysattr_value(dev, "type", &attr) >= 0) {
                        unsigned long type;

                        type = strtoul(attr, NULL, 10);
                        if (type == ARPHRD_INFINIBAND &&
                            sd_device_get_sysattr_value(dev, "dev_id", &attr) >= 0)
                                dev_port = strtoul(attr, NULL, 16);
                }
        }

        /* kernel provided front panel port name for multiple port PCI device */
        (void) sd_device_get_sysattr_value(dev, "phys_port_name", &port_name);

        /* compose a name based on the raw kernel's PCI bus, slot numbers */
        s = names->pci_path;
        l = sizeof(names->pci_path);
        if (domain > 0)
                l = strpcpyf(&s, l, "P%u", domain);
        l = strpcpyf(&s, l, "p%us%u", bus, slot);
        if (func > 0 || is_pci_multifunction(names->pcidev))
                l = strpcpyf(&s, l, "f%u", func);
        if (port_name)
                l = strpcpyf(&s, l, "n%s", port_name);
        else if (dev_port > 0)
                l = strpcpyf(&s, l, "d%lu", dev_port);
        if (l == 0)
                names->pci_path[0] = '\0';

        /* ACPI _SUN  — slot user number */
        r = sd_device_new_from_subsystem_sysname(&pci, "subsystem", "pci");
        if (r < 0)
                return r;

        r = sd_device_get_syspath(pci, &syspath);
        if (r < 0)
                return r;
        if (!snprintf_ok(slots, sizeof slots, "%s/slots", syspath))
                return -ENAMETOOLONG;

        dir = opendir(slots);
        if (!dir)
                return -errno;

        hotplug_slot_dev = names->pcidev;
        while (hotplug_slot_dev) {
                if (sd_device_get_sysname(hotplug_slot_dev, &sysname) < 0)
                        continue;

                FOREACH_DIRENT_ALL(dent, dir, break) {
                        unsigned i;
                        char str[PATH_MAX];
                        _cleanup_free_ char *address = NULL;

                        if (dent->d_name[0] == '.')
                                continue;
                        r = safe_atou_full(dent->d_name, 10, &i);
                        if (r < 0 || i <= 0)
                                continue;

                        /* match slot address with device by stripping the function */
                        if (snprintf_ok(str, sizeof str, "%s/%s/address", slots, dent->d_name) &&
                            read_one_line_file(str, &address) >= 0 &&
                            startswith(sysname, address)) {
                                hotplug_slot = i;
                                break;
                        }
                }
                if (hotplug_slot > 0)
                        break;
                if (sd_device_get_parent_with_subsystem_devtype(hotplug_slot_dev, "pci", NULL, &hotplug_slot_dev) < 0)
                        break;
                rewinddir(dir);
        }

        if (hotplug_slot > 0) {
                s = names->pci_slot;
                l = sizeof(names->pci_slot);
                if (domain > 0)
                        l = strpcpyf(&s, l, "P%d", domain);
                l = strpcpyf(&s, l, "s%d", hotplug_slot);
                if (func > 0 || is_pci_multifunction(names->pcidev))
                        l = strpcpyf(&s, l, "f%d", func);
                if (port_name)
                        l = strpcpyf(&s, l, "n%s", port_name);
                else if (dev_port > 0)
                        l = strpcpyf(&s, l, "d%lu", dev_port);
                if (l == 0)
                        names->pci_slot[0] = '\0';
        }

        return 0;
}

static int names_vio(sd_device *dev, struct netnames *names) {
        sd_device *parent;
        unsigned busid, slotid, ethid;
        const char *syspath, *subsystem;
        int r;

        /* check if our direct parent is a VIO device with no other bus in-between */
        r = sd_device_get_parent(dev, &parent);
        if (r < 0)
                return r;

        r = sd_device_get_subsystem(parent, &subsystem);
        if (r < 0)
                return r;
        if (!streq("vio", subsystem))
                return -ENOENT;

        /* The devices' $DEVPATH number is tied to (virtual) hardware (slot id
         * selected in the HMC), thus this provides a reliable naming (e.g.
         * "/devices/vio/30000002/net/eth1"); we ignore the bus number, as
         * there should only ever be one bus, and then remove leading zeros. */
        r = sd_device_get_syspath(dev, &syspath);
        if (r < 0)
                return r;

        if (sscanf(syspath, "/sys/devices/vio/%4x%4x/net/eth%u", &busid, &slotid, &ethid) != 3)
                return -EINVAL;

        xsprintf(names->vio_slot, "v%u", slotid);
        names->type = NET_VIO;
        return 0;
}

#define _PLATFORM_TEST "/sys/devices/platform/vvvvPPPP"
#define _PLATFORM_PATTERN4 "/sys/devices/platform/%4s%4x:%2x/net/eth%u"
#define _PLATFORM_PATTERN3 "/sys/devices/platform/%3s%4x:%2x/net/eth%u"

static int names_platform(sd_device *dev, struct netnames *names, bool test) {
        sd_device *parent;
        char vendor[5];
        unsigned model, instance, ethid;
        const char *syspath, *pattern, *validchars, *subsystem;
        int r;

        /* check if our direct parent is a platform device with no other bus in-between */
        r = sd_device_get_parent(dev, &parent);
        if (r < 0)
                return r;

        r = sd_device_get_subsystem(parent, &subsystem);
        if (r < 0)
                return r;

        if (!streq("platform", subsystem))
                 return -ENOENT;

        r = sd_device_get_syspath(dev, &syspath);
        if (r < 0)
                return r;

        /* syspath is too short, to have a valid ACPI instance */
        if (strlen(syspath) < sizeof _PLATFORM_TEST)
                return -EINVAL;

        /* Vendor ID can be either PNP ID (3 chars A-Z) or ACPI ID (4 chars A-Z and numerals) */
        if (syspath[sizeof _PLATFORM_TEST - 1] == ':') {
                pattern = _PLATFORM_PATTERN4;
                validchars = UPPERCASE_LETTERS DIGITS;
        } else {
                pattern = _PLATFORM_PATTERN3;
                validchars = UPPERCASE_LETTERS;
        }

        /* Platform devices are named after ACPI table match, and instance id
         * eg. "/sys/devices/platform/HISI00C2:00");
         * The Vendor (3 or 4 char), followed by hexdecimal model number : instance id.
         */

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wformat-nonliteral"
        if (sscanf(syspath, pattern, vendor, &model, &instance, &ethid) != 4)
                return -EINVAL;
#pragma GCC diagnostic pop

        if (!in_charset(vendor, validchars))
                return -ENOENT;

        ascii_strlower(vendor);

        xsprintf(names->platform_path, "a%s%xi%u", vendor, model, instance);
        names->type = NET_PLATFORM;
        return 0;
}

static int names_pci(sd_device *dev, struct netnames *names) {
        sd_device *parent;
        struct netnames vf_names = {};
        struct virtfn_info vf_info = {};
        const char *subsystem;
        int r;

        assert(dev);
        assert(names);

        r = sd_device_get_parent(dev, &parent);
        if (r < 0)
                return r;
        /* skip virtio subsystem if present */
        parent = skip_virtio(parent);

        if (!parent)
                return -ENOENT;

        /* check if our direct parent is a PCI device with no other bus in-between */
        if (sd_device_get_subsystem(parent, &subsystem) >= 0 &&
            streq("pci", subsystem)) {
                names->type = NET_PCI;
                names->pcidev = parent;
        } else {
                r = sd_device_get_parent_with_subsystem_devtype(dev, "pci", NULL, &names->pcidev);
                if (r < 0)
                        return r;
        }

        if (naming_scheme_has(NAMING_SR_IOV_V) &&
            get_virtfn_info(dev, names, &vf_info) >= 0) {
                /* If this is an SR-IOV virtual device, get base name using physical device and add virtfn suffix. */
                vf_names.pcidev = vf_info.physfn_pcidev;
                dev_pci_onboard(dev, &vf_names);
                dev_pci_slot(dev, &vf_names);
                if (vf_names.pci_onboard[0])
                        if (strlen(vf_names.pci_onboard) + strlen(vf_info.suffix) < sizeof(names->pci_onboard))
                                strscpyl(names->pci_onboard, sizeof(names->pci_onboard),
                                         vf_names.pci_onboard, vf_info.suffix, NULL);
                if (vf_names.pci_slot[0])
                        if (strlen(vf_names.pci_slot) + strlen(vf_info.suffix) < sizeof(names->pci_slot))
                                strscpyl(names->pci_slot, sizeof(names->pci_slot),
                                         vf_names.pci_slot, vf_info.suffix, NULL);
                if (vf_names.pci_path[0])
                        if (strlen(vf_names.pci_path) + strlen(vf_info.suffix) < sizeof(names->pci_path))
                                strscpyl(names->pci_path, sizeof(names->pci_path),
                                         vf_names.pci_path, vf_info.suffix, NULL);
                sd_device_unref(vf_info.physfn_pcidev);
        } else {
                dev_pci_onboard(dev, names);
                dev_pci_slot(dev, names);
        }

        return 0;
}

static int names_usb(sd_device *dev, struct netnames *names) {
        sd_device *usbdev;
        char name[256], *ports, *config, *interf, *s;
        const char *sysname;
        size_t l;
        int r;

        assert(dev);
        assert(names);

        r = sd_device_get_parent_with_subsystem_devtype(dev, "usb", "usb_interface", &usbdev);
        if (r < 0)
                return r;

        r = sd_device_get_sysname(usbdev, &sysname);
        if (r < 0)
                return r;

        /* get USB port number chain, configuration, interface */
        strscpy(name, sizeof(name), sysname);
        s = strchr(name, '-');
        if (!s)
                return -EINVAL;
        ports = s+1;

        s = strchr(ports, ':');
        if (!s)
                return -EINVAL;
        s[0] = '\0';
        config = s+1;

        s = strchr(config, '.');
        if (!s)
                return -EINVAL;
        s[0] = '\0';
        interf = s+1;

        /* prefix every port number in the chain with "u" */
        s = ports;
        while ((s = strchr(s, '.')))
                s[0] = 'u';
        s = names->usb_ports;
        l = strpcpyl(&s, sizeof(names->usb_ports), "u", ports, NULL);

        /* append USB config number, suppress the common config == 1 */
        if (!streq(config, "1"))
                l = strpcpyl(&s, sizeof(names->usb_ports), "c", config, NULL);

        /* append USB interface number, suppress the interface == 0 */
        if (!streq(interf, "0"))
                l = strpcpyl(&s, sizeof(names->usb_ports), "i", interf, NULL);
        if (l == 0)
                return -ENAMETOOLONG;

        names->type = NET_USB;
        return 0;
}

static int names_bcma(sd_device *dev, struct netnames *names) {
        sd_device *bcmadev;
        unsigned core;
        const char *sysname;
        int r;

        assert(dev);
        assert(names);

        r = sd_device_get_parent_with_subsystem_devtype(dev, "bcma", NULL, &bcmadev);
        if (r < 0)
                return r;

        r = sd_device_get_sysname(bcmadev, &sysname);
        if (r < 0)
                return r;

        /* bus num:core num */
        if (sscanf(sysname, "bcma%*u:%u", &core) != 1)
                return -EINVAL;
        /* suppress the common core == 0 */
        if (core > 0)
                xsprintf(names->bcma_core, "b%u", core);

        names->type = NET_BCMA;
        return 0;
}

static int names_ccw(sd_device *dev, struct netnames *names) {
        sd_device *cdev;
        const char *bus_id, *subsys;
        size_t bus_id_len;
        size_t bus_id_start;
        int r;

        assert(dev);
        assert(names);

        /* Retrieve the associated CCW device */
        r = sd_device_get_parent(dev, &cdev);
        if (r < 0)
                return r;

        /* skip virtio subsystem if present */
        cdev = skip_virtio(cdev);
        if (!cdev)
                return -ENOENT;

        r = sd_device_get_subsystem(cdev, &subsys);
        if (r < 0)
                return r;

        /* Network devices are either single or grouped CCW devices */
        if (!STR_IN_SET(subsys, "ccwgroup", "ccw"))
                return -ENOENT;

        /* Retrieve bus-ID of the CCW device.  The bus-ID uniquely
         * identifies the network device on the Linux on System z channel
         * subsystem.  Note that the bus-ID contains lowercase characters.
         */
        r = sd_device_get_sysname(cdev, &bus_id);
        if (r < 0)
                return r;

        /* Check the length of the bus-ID.  Rely on that the kernel provides
         * a correct bus-ID; alternatively, improve this check and parse and
         * verify each bus-ID part...
         */
        bus_id_len = strlen(bus_id);
        if (!IN_SET(bus_id_len, 8, 9))
                return -EINVAL;

        /* Strip leading zeros from the bus id for aesthetic purposes. This
         * keeps the ccw names stable, yet much shorter in general case of
         * bus_id 0.0.0600 -> 600. This is similar to e.g. how PCI domain is
         * not prepended when it is zero. Preserve the last 0 for 0.0.0000.
         */
        bus_id_start = strspn(bus_id, ".0");
        bus_id += bus_id_start < bus_id_len ? bus_id_start : bus_id_len - 1;

        /* Store the CCW bus-ID for use as network device name */
        if (snprintf_ok(names->ccw_busid, sizeof(names->ccw_busid), "c%s", bus_id))
                names->type = NET_CCW;

        return 0;
}

static int names_mac(sd_device *dev, struct netnames *names) {
        const char *s;
        unsigned long i;
        unsigned a1, a2, a3, a4, a5, a6;
        int r;

        /* Some kinds of devices tend to have hardware addresses
         * that are impossible to use in an iface name.
         */
        r = sd_device_get_sysattr_value(dev, "type", &s);
        if (r < 0)
                return r;

        i = strtoul(s, NULL, 0);
        switch (i) {
        /* The persistent part of a hardware address of an InfiniBand NIC
         * is 8 bytes long. We cannot fit this much in an iface name.
         */
        case ARPHRD_INFINIBAND:
                return -EINVAL;
        default:
                break;
        }

        /* check for NET_ADDR_PERM, skip random MAC addresses */
        r = sd_device_get_sysattr_value(dev, "addr_assign_type", &s);
        if (r < 0)
                return r;
        i = strtoul(s, NULL, 0);
        if (i != 0)
                return 0;

        r = sd_device_get_sysattr_value(dev, "address", &s);
        if (r < 0)
                return r;
        if (sscanf(s, "%x:%x:%x:%x:%x:%x", &a1, &a2, &a3, &a4, &a5, &a6) != 6)
                return -EINVAL;

        /* skip empty MAC addresses */
        if (a1 + a2 + a3 + a4 + a5 + a6 == 0)
                return -EINVAL;

        names->mac[0] = a1;
        names->mac[1] = a2;
        names->mac[2] = a3;
        names->mac[3] = a4;
        names->mac[4] = a5;
        names->mac[5] = a6;
        names->mac_valid = true;
        return 0;
}

/* IEEE Organizationally Unique Identifier vendor string */
static int ieee_oui(sd_device *dev, struct netnames *names, bool test) {
        char str[32];

        if (!names->mac_valid)
                return -ENOENT;
        /* skip commonly misused 00:00:00 (Xerox) prefix */
        if (memcmp(names->mac, "\0\0\0", 3) == 0)
                return -EINVAL;
        xsprintf(str, "OUI:%02X%02X%02X%02X%02X%02X", names->mac[0],
                 names->mac[1], names->mac[2], names->mac[3], names->mac[4],
                 names->mac[5]);
        udev_builtin_hwdb_lookup(dev, NULL, str, NULL, test);
        return 0;
}

static int builtin_net_id(sd_device *dev, int argc, char *argv[], bool test) {
        const char *s, *p, *devtype, *prefix = "en";
        struct netnames names = {};
        unsigned long i;
        int r;

        /* handle only ARPHRD_ETHER, ARPHRD_SLIP and ARPHRD_INFINIBAND devices */
        r = sd_device_get_sysattr_value(dev, "type", &s);
        if (r < 0)
                return r;

        i = strtoul(s, NULL, 0);
        switch (i) {
        case ARPHRD_ETHER:
                prefix = "en";
                break;
        case ARPHRD_INFINIBAND:
                if (naming_scheme_has(NAMING_INFINIBAND))
                        prefix = "ib";
                else
                        return 0;
                break;
        case ARPHRD_SLIP:
                prefix = "sl";
                break;
        default:
                return 0;
        }

        /* skip stacked devices, like VLANs, ... */
        r = sd_device_get_sysattr_value(dev, "ifindex", &s);
        if (r < 0)
                return r;
        r = sd_device_get_sysattr_value(dev, "iflink", &p);
        if (r < 0)
                return r;
        if (!streq(s, p))
                return 0;

        if (sd_device_get_devtype(dev, &devtype) >= 0) {
                if (streq("wlan", devtype))
                        prefix = "wl";
                else if (streq("wwan", devtype))
                        prefix = "ww";
        }

        udev_builtin_add_property(dev, test, "ID_NET_NAMING_SCHEME", naming_scheme()->name);

        r = names_mac(dev, &names);
        if (r >= 0 && names.mac_valid) {
                char str[IFNAMSIZ];

                xsprintf(str, "%sx%02x%02x%02x%02x%02x%02x", prefix,
                         names.mac[0], names.mac[1], names.mac[2],
                         names.mac[3], names.mac[4], names.mac[5]);
                udev_builtin_add_property(dev, test, "ID_NET_NAME_MAC", str);

                ieee_oui(dev, &names, test);
        }

        /* get path names for Linux on System z network devices */
        if (names_ccw(dev, &names) >= 0 && names.type == NET_CCW) {
                char str[IFNAMSIZ];

                if (snprintf_ok(str, sizeof str, "%s%s", prefix, names.ccw_busid))
                        udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
                return 0;
        }

        /* get ibmveth/ibmvnic slot-based names. */
        if (names_vio(dev, &names) >= 0 && names.type == NET_VIO) {
                char str[IFNAMSIZ];

                if (snprintf_ok(str, sizeof str, "%s%s", prefix, names.vio_slot))
                        udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
                return 0;
        }

        /* get ACPI path names for ARM64 platform devices */
        if (names_platform(dev, &names, test) >= 0 && names.type == NET_PLATFORM) {
                char str[IFNAMSIZ];

                if (snprintf_ok(str, sizeof str, "%s%s", prefix, names.platform_path))
                        udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
                return 0;
        }

        /* get PCI based path names, we compose only PCI based paths */
        if (names_pci(dev, &names) < 0)
                return 0;

        /* plain PCI device */
        if (names.type == NET_PCI) {
                char str[IFNAMSIZ];

                if (names.pci_onboard[0] &&
                    snprintf_ok(str, sizeof str, "%s%s", prefix, names.pci_onboard))
                        udev_builtin_add_property(dev, test, "ID_NET_NAME_ONBOARD", str);

                if (names.pci_onboard_label &&
                    snprintf_ok(str, sizeof str, "%s%s", prefix, names.pci_onboard_label))
                        udev_builtin_add_property(dev, test, "ID_NET_LABEL_ONBOARD", str);

                if (names.pci_path[0] &&
                    snprintf_ok(str, sizeof str, "%s%s", prefix, names.pci_path))
                        udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);

                if (names.pci_slot[0] &&
                    snprintf_ok(str, sizeof str, "%s%s", prefix, names.pci_slot))
                        udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
                return 0;
        }

        /* USB device */
        if (names_usb(dev, &names) >= 0 && names.type == NET_USB) {
                char str[IFNAMSIZ];

                if (names.pci_path[0] &&
                    snprintf_ok(str, sizeof str, "%s%s%s", prefix, names.pci_path, names.usb_ports))
                        udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);

                if (names.pci_slot[0] &&
                    snprintf_ok(str, sizeof str, "%s%s%s", prefix, names.pci_slot, names.usb_ports))
                        udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
                return 0;
        }

        /* Broadcom bus */
        if (names_bcma(dev, &names) >= 0 && names.type == NET_BCMA) {
                char str[IFNAMSIZ];

                if (names.pci_path[0] &&
                    snprintf_ok(str, sizeof str, "%s%s%s", prefix, names.pci_path, names.bcma_core))
                        udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);

                if (names.pci_slot[0] &&
                    snprintf(str, sizeof str, "%s%s%s", prefix, names.pci_slot, names.bcma_core))
                        udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
                return 0;
        }

        return 0;
}

const struct udev_builtin udev_builtin_net_id = {
        .name = "net_id",
        .cmd = builtin_net_id,
        .help = "Network device properties",
};