./tools/notsd-move

1 files changed, 770 insertions, 0 deletions

diff --git a/src/grp-udev/libudev-core/udev-builtin-path_id.c b/src/grp-udev/libudev-core/udev-builtin-path_id.c
new file mode 100644
index 0000000000..df1a999683
--- /dev/null
+++ b/src/grp-udev/libudev-core/udev-builtin-path_id.c
@@ -0,0 +1,770 @@
+/*
+ * compose persistent device path
+ *
+ * Copyright (C) 2009-2011 Kay Sievers <kay@vrfy.org>
+ *
+ * Logic based on Hannes Reinecke's shell script.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <ctype.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "systemd-basic/alloc-util.h"
+#include "systemd-basic/string-util.h"
+#include "udev.h"
+
+_printf_(2,3)
+static int path_prepend(char **path, const char *fmt, ...) {
+        va_list va;
+        char *pre;
+        int err = 0;
+
+        va_start(va, fmt);
+        err = vasprintf(&pre, fmt, va);
+        va_end(va);
+        if (err < 0)
+                goto out;
+
+        if (*path != NULL) {
+                char *new;
+
+                err = asprintf(&new, "%s-%s", pre, *path);
+                free(pre);
+                if (err < 0)
+                        goto out;
+                free(*path);
+                *path = new;
+        } else {
+                *path = pre;
+        }
+out:
+        return err;
+}
+
+/*
+** Linux only supports 32 bit luns.
+** See drivers/scsi/scsi_scan.c::scsilun_to_int() for more details.
+*/
+static int format_lun_number(struct udev_device *dev, char **path) {
+        unsigned long lun = strtoul(udev_device_get_sysnum(dev), NULL, 10);
+
+        /* address method 0, peripheral device addressing with bus id of zero */
+        if (lun < 256)
+                return path_prepend(path, "lun-%lu", lun);
+        /* handle all other lun addressing methods by using a variant of the original lun format */
+        return path_prepend(path, "lun-0x%04lx%04lx00000000", lun & 0xffff, (lun >> 16) & 0xffff);
+}
+
+static struct udev_device *skip_subsystem(struct udev_device *dev, const char *subsys) {
+        struct udev_device *parent = dev;
+
+        assert(dev);
+        assert(subsys);
+
+        while (parent != NULL) {
+                const char *subsystem;
+
+                subsystem = udev_device_get_subsystem(parent);
+                if (subsystem == NULL || !streq(subsystem, subsys))
+                        break;
+                dev = parent;
+                parent = udev_device_get_parent(parent);
+        }
+        return dev;
+}
+
+static struct udev_device *handle_scsi_fibre_channel(struct udev_device *parent, char **path) {
+        struct udev *udev  = udev_device_get_udev(parent);
+        struct udev_device *targetdev;
+        struct udev_device *fcdev = NULL;
+        const char *port;
+        char *lun = NULL;
+
+        assert(parent);
+        assert(path);
+
+        targetdev = udev_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_target");
+        if (targetdev == NULL)
+                return NULL;
+
+        fcdev = udev_device_new_from_subsystem_sysname(udev, "fc_transport", udev_device_get_sysname(targetdev));
+        if (fcdev == NULL)
+                return NULL;
+        port = udev_device_get_sysattr_value(fcdev, "port_name");
+        if (port == NULL) {
+                parent = NULL;
+                goto out;
+        }
+
+        format_lun_number(parent, &lun);
+        path_prepend(path, "fc-%s-%s", port, lun);
+        free(lun);
+out:
+        udev_device_unref(fcdev);
+        return parent;
+}
+
+static struct udev_device *handle_scsi_sas_wide_port(struct udev_device *parent, char **path) {
+        struct udev *udev  = udev_device_get_udev(parent);
+        struct udev_device *targetdev;
+        struct udev_device *target_parent;
+        struct udev_device *sasdev;
+        const char *sas_address;
+        char *lun = NULL;
+
+        assert(parent);
+        assert(path);
+
+        targetdev = udev_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_target");
+        if (targetdev == NULL)
+                return NULL;
+
+        target_parent = udev_device_get_parent(targetdev);
+        if (target_parent == NULL)
+                return NULL;
+
+        sasdev = udev_device_new_from_subsystem_sysname(udev, "sas_device",
+                                udev_device_get_sysname(target_parent));
+        if (sasdev == NULL)
+                return NULL;
+
+        sas_address = udev_device_get_sysattr_value(sasdev, "sas_address");
+        if (sas_address == NULL) {
+                parent = NULL;
+                goto out;
+        }
+
+        format_lun_number(parent, &lun);
+        path_prepend(path, "sas-%s-%s", sas_address, lun);
+        free(lun);
+out:
+        udev_device_unref(sasdev);
+        return parent;
+}
+
+static struct udev_device *handle_scsi_sas(struct udev_device *parent, char **path)
+{
+        struct udev *udev  = udev_device_get_udev(parent);
+        struct udev_device *targetdev;
+        struct udev_device *target_parent;
+        struct udev_device *port;
+        struct udev_device *expander;
+        struct udev_device *target_sasdev = NULL;
+        struct udev_device *expander_sasdev = NULL;
+        struct udev_device *port_sasdev = NULL;
+        const char *sas_address = NULL;
+        const char *phy_id;
+        const char *phy_count;
+        char *lun = NULL;
+
+        assert(parent);
+        assert(path);
+
+        targetdev = udev_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_target");
+        if (targetdev == NULL)
+                return NULL;
+
+        target_parent = udev_device_get_parent(targetdev);
+        if (target_parent == NULL)
+                return NULL;
+
+        /* Get sas device */
+        target_sasdev = udev_device_new_from_subsystem_sysname(udev,
+                          "sas_device", udev_device_get_sysname(target_parent));
+        if (target_sasdev == NULL)
+                return NULL;
+
+        /* The next parent is sas port */
+        port = udev_device_get_parent(target_parent);
+        if (port == NULL) {
+                parent = NULL;
+                goto out;
+        }
+
+        /* Get port device */
+        port_sasdev = udev_device_new_from_subsystem_sysname(udev,
+                          "sas_port", udev_device_get_sysname(port));
+
+        phy_count = udev_device_get_sysattr_value(port_sasdev, "num_phys");
+        if (phy_count == NULL) {
+               parent = NULL;
+               goto out;
+        }
+
+        /* Check if we are simple disk */
+        if (strncmp(phy_count, "1", 2) != 0) {
+                 parent = handle_scsi_sas_wide_port(parent, path);
+                 goto out;
+        }
+
+        /* Get connected phy */
+        phy_id = udev_device_get_sysattr_value(target_sasdev, "phy_identifier");
+        if (phy_id == NULL) {
+                parent = NULL;
+                goto out;
+        }
+
+        /* The port's parent is either hba or expander */
+        expander = udev_device_get_parent(port);
+        if (expander == NULL) {
+                parent = NULL;
+                goto out;
+        }
+
+        /* Get expander device */
+        expander_sasdev = udev_device_new_from_subsystem_sysname(udev,
+                          "sas_device", udev_device_get_sysname(expander));
+        if (expander_sasdev != NULL) {
+                 /* Get expander's address */
+                 sas_address = udev_device_get_sysattr_value(expander_sasdev,
+                                                    "sas_address");
+                 if (sas_address == NULL) {
+                        parent = NULL;
+                        goto out;
+                 }
+        }
+
+        format_lun_number(parent, &lun);
+        if (sas_address)
+                 path_prepend(path, "sas-exp%s-phy%s-%s", sas_address, phy_id, lun);
+        else
+                 path_prepend(path, "sas-phy%s-%s", phy_id, lun);
+
+        free(lun);
+out:
+        udev_device_unref(target_sasdev);
+        udev_device_unref(expander_sasdev);
+        udev_device_unref(port_sasdev);
+        return parent;
+}
+
+static struct udev_device *handle_scsi_iscsi(struct udev_device *parent, char **path) {
+        struct udev *udev  = udev_device_get_udev(parent);
+        struct udev_device *transportdev;
+        struct udev_device *sessiondev = NULL;
+        const char *target;
+        char *connname;
+        struct udev_device *conndev = NULL;
+        const char *addr;
+        const char *port;
+        char *lun = NULL;
+
+        assert(parent);
+        assert(path);
+
+        /* find iscsi session */
+        transportdev = parent;
+        for (;;) {
+                transportdev = udev_device_get_parent(transportdev);
+                if (transportdev == NULL)
+                        return NULL;
+                if (startswith(udev_device_get_sysname(transportdev), "session"))
+                        break;
+        }
+
+        /* find iscsi session device */
+        sessiondev = udev_device_new_from_subsystem_sysname(udev, "iscsi_session", udev_device_get_sysname(transportdev));
+        if (sessiondev == NULL)
+                return NULL;
+        target = udev_device_get_sysattr_value(sessiondev, "targetname");
+        if (target == NULL) {
+                parent = NULL;
+                goto out;
+        }
+
+        if (asprintf(&connname, "connection%s:0", udev_device_get_sysnum(transportdev)) < 0) {
+                parent = NULL;
+                goto out;
+        }
+        conndev = udev_device_new_from_subsystem_sysname(udev, "iscsi_connection", connname);
+        free(connname);
+        if (conndev == NULL) {
+                parent = NULL;
+                goto out;
+        }
+        addr = udev_device_get_sysattr_value(conndev, "persistent_address");
+        port = udev_device_get_sysattr_value(conndev, "persistent_port");
+        if (addr == NULL || port == NULL) {
+                parent = NULL;
+                goto out;
+        }
+
+        format_lun_number(parent, &lun);
+        path_prepend(path, "ip-%s:%s-iscsi-%s-%s", addr, port, target, lun);
+        free(lun);
+out:
+        udev_device_unref(sessiondev);
+        udev_device_unref(conndev);
+        return parent;
+}
+
+static struct udev_device *handle_scsi_ata(struct udev_device *parent, char **path) {
+        struct udev *udev  = udev_device_get_udev(parent);
+        struct udev_device *targetdev;
+        struct udev_device *target_parent;
+        struct udev_device *atadev;
+        const char *port_no;
+
+        assert(parent);
+        assert(path);
+
+        targetdev = udev_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_host");
+        if (!targetdev)
+                return NULL;
+
+        target_parent = udev_device_get_parent(targetdev);
+        if (!target_parent)
+                return NULL;
+
+        atadev = udev_device_new_from_subsystem_sysname(udev, "ata_port", udev_device_get_sysname(target_parent));
+        if (!atadev)
+                return NULL;
+
+        port_no = udev_device_get_sysattr_value(atadev, "port_no");
+        if (!port_no) {
+               parent = NULL;
+               goto out;
+        }
+        path_prepend(path, "ata-%s", port_no);
+out:
+        udev_device_unref(atadev);
+        return parent;
+}
+
+static struct udev_device *handle_scsi_default(struct udev_device *parent, char **path) {
+        struct udev_device *hostdev;
+        int host, bus, target, lun;
+        const char *name;
+        char *base;
+        char *pos;
+        DIR *dir;
+        struct dirent *dent;
+        int basenum;
+
+        assert(parent);
+        assert(path);
+
+        hostdev = udev_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_host");
+        if (hostdev == NULL)
+                return NULL;
+
+        name = udev_device_get_sysname(parent);
+        if (sscanf(name, "%d:%d:%d:%d", &host, &bus, &target, &lun) != 4)
+                return NULL;
+
+        /*
+         * Rebase host offset to get the local relative number
+         *
+         * Note: This is by definition racy, unreliable and too simple.
+         * Please do not copy this model anywhere. It's just a left-over
+         * from the time we had no idea how things should look like in
+         * the end.
+         *
+         * Making assumptions about a global in-kernel counter and use
+         * that to calculate a local offset is a very broken concept. It
+         * can only work as long as things are in strict order.
+         *
+         * The kernel needs to export the instance/port number of a
+         * controller directly, without the need for rebase magic like
+         * this. Manual driver unbind/bind, parallel hotplug/unplug will
+         * get into the way of this "I hope it works" logic.
+         */
+        basenum = -1;
+        base = strdup(udev_device_get_syspath(hostdev));
+        if (base == NULL)
+                return NULL;
+        pos = strrchr(base, '/');
+        if (pos == NULL) {
+                parent = NULL;
+                goto out;
+        }
+        pos[0] = '\0';
+        dir = opendir(base);
+        if (dir == NULL) {
+                parent = NULL;
+                goto out;
+        }
+        for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
+                char *rest;
+                int i;
+
+                if (dent->d_name[0] == '.')
+                        continue;
+                if (dent->d_type != DT_DIR && dent->d_type != DT_LNK)
+                        continue;
+                if (!startswith(dent->d_name, "host"))
+                        continue;
+                i = strtoul(&dent->d_name[4], &rest, 10);
+                if (rest[0] != '\0')
+                        continue;
+                /*
+                 * find the smallest number; the host really needs to export its
+                 * own instance number per parent device; relying on the global host
+                 * enumeration and plainly rebasing the numbers sounds unreliable
+                 */
+                if (basenum == -1 || i < basenum)
+                        basenum = i;
+        }
+        closedir(dir);
+        if (basenum == -1) {
+                parent = NULL;
+                goto out;
+        }
+        host -= basenum;
+
+        path_prepend(path, "scsi-%u:%u:%u:%u", host, bus, target, lun);
+out:
+        free(base);
+        return hostdev;
+}
+
+static struct udev_device *handle_scsi_hyperv(struct udev_device *parent, char **path) {
+        struct udev_device *hostdev;
+        struct udev_device *vmbusdev;
+        const char *guid_str;
+        char *lun = NULL;
+        char guid[38];
+        size_t i, k;
+
+        assert(parent);
+        assert(path);
+
+        hostdev = udev_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_host");
+        if (!hostdev)
+                return NULL;
+
+        vmbusdev = udev_device_get_parent(hostdev);
+        if (!vmbusdev)
+                return NULL;
+
+        guid_str = udev_device_get_sysattr_value(vmbusdev, "device_id");
+        if (!guid_str)
+                return NULL;
+
+        if (strlen(guid_str) < 37 || guid_str[0] != '{' || guid_str[36] != '}')
+                return NULL;
+
+        for (i = 1, k = 0; i < 36; i++) {
+                if (guid_str[i] == '-')
+                        continue;
+                guid[k++] = guid_str[i];
+        }
+        guid[k] = '\0';
+
+        format_lun_number(parent, &lun);
+        path_prepend(path, "vmbus-%s-%s", guid, lun);
+        free(lun);
+        return parent;
+}
+
+static struct udev_device *handle_scsi(struct udev_device *parent, char **path, bool *supported_parent) {
+        const char *devtype;
+        const char *name;
+        const char *id;
+
+        devtype = udev_device_get_devtype(parent);
+        if (devtype == NULL || !streq(devtype, "scsi_device"))
+                return parent;
+
+        /* firewire */
+        id = udev_device_get_sysattr_value(parent, "ieee1394_id");
+        if (id != NULL) {
+                parent = skip_subsystem(parent, "scsi");
+                path_prepend(path, "ieee1394-0x%s", id);
+                *supported_parent = true;
+                goto out;
+        }
+
+        /* scsi sysfs does not have a "subsystem" for the transport */
+        name = udev_device_get_syspath(parent);
+
+        if (strstr(name, "/rport-") != NULL) {
+                parent = handle_scsi_fibre_channel(parent, path);
+                *supported_parent = true;
+                goto out;
+        }
+
+        if (strstr(name, "/end_device-") != NULL) {
+                parent = handle_scsi_sas(parent, path);
+                *supported_parent = true;
+                goto out;
+        }
+
+        if (strstr(name, "/session") != NULL) {
+                parent = handle_scsi_iscsi(parent, path);
+                *supported_parent = true;
+                goto out;
+        }
+
+        if (strstr(name, "/ata") != NULL) {
+                parent = handle_scsi_ata(parent, path);
+                goto out;
+        }
+
+        if (strstr(name, "/vmbus_") != NULL) {
+                parent = handle_scsi_hyperv(parent, path);
+                goto out;
+        }
+
+        parent = handle_scsi_default(parent, path);
+out:
+        return parent;
+}
+
+static struct udev_device *handle_cciss(struct udev_device *parent, char **path) {
+        const char *str;
+        unsigned int controller, disk;
+
+        str = udev_device_get_sysname(parent);
+        if (sscanf(str, "c%ud%u%*s", &controller, &disk) != 2)
+                return NULL;
+
+        path_prepend(path, "cciss-disk%u", disk);
+        parent = skip_subsystem(parent, "cciss");
+        return parent;
+}
+
+static void handle_scsi_tape(struct udev_device *dev, char **path) {
+        const char *name;
+
+        /* must be the last device in the syspath */
+        if (*path != NULL)
+                return;
+
+        name = udev_device_get_sysname(dev);
+        if (startswith(name, "nst") && strchr("lma", name[3]) != NULL)
+                path_prepend(path, "nst%c", name[3]);
+        else if (startswith(name, "st") && strchr("lma", name[2]) != NULL)
+                path_prepend(path, "st%c", name[2]);
+}
+
+static struct udev_device *handle_usb(struct udev_device *parent, char **path) {
+        const char *devtype;
+        const char *str;
+        const char *port;
+
+        devtype = udev_device_get_devtype(parent);
+        if (devtype == NULL)
+                return parent;
+        if (!streq(devtype, "usb_interface") && !streq(devtype, "usb_device"))
+                return parent;
+
+        str = udev_device_get_sysname(parent);
+        port = strchr(str, '-');
+        if (port == NULL)
+                return parent;
+        port++;
+
+        parent = skip_subsystem(parent, "usb");
+        path_prepend(path, "usb-0:%s", port);
+        return parent;
+}
+
+static struct udev_device *handle_bcma(struct udev_device *parent, char **path) {
+        const char *sysname;
+        unsigned int core;
+
+        sysname = udev_device_get_sysname(parent);
+        if (sscanf(sysname, "bcma%*u:%u", &core) != 1)
+                return NULL;
+
+        path_prepend(path, "bcma-%u", core);
+        return parent;
+}
+
+/* Handle devices of AP bus in System z platform. */
+static struct udev_device *handle_ap(struct udev_device *parent, char **path) {
+        const char *type, *func;
+
+        assert(parent);
+        assert(path);
+
+        type = udev_device_get_sysattr_value(parent, "type");
+        func = udev_device_get_sysattr_value(parent, "ap_functions");
+
+        if (type != NULL && func != NULL) {
+                path_prepend(path, "ap-%s-%s", type, func);
+                goto out;
+        }
+        path_prepend(path, "ap-%s", udev_device_get_sysname(parent));
+out:
+        parent = skip_subsystem(parent, "ap");
+        return parent;
+}
+
+static int builtin_path_id(struct udev_device *dev, int argc, char *argv[], bool test) {
+        struct udev_device *parent;
+        char *path = NULL;
+        bool supported_transport = false;
+        bool supported_parent = false;
+
+        assert(dev);
+
+        /* walk up the chain of devices and compose path */
+        parent = dev;
+        while (parent != NULL) {
+                const char *subsys;
+
+                subsys = udev_device_get_subsystem(parent);
+                if (subsys == NULL) {
+                        ;
+                } else if (streq(subsys, "scsi_tape")) {
+                        handle_scsi_tape(parent, &path);
+                } else if (streq(subsys, "scsi")) {
+                        parent = handle_scsi(parent, &path, &supported_parent);
+                        supported_transport = true;
+                } else if (streq(subsys, "cciss")) {
+                        parent = handle_cciss(parent, &path);
+                        supported_transport = true;
+                } else if (streq(subsys, "usb")) {
+                        parent = handle_usb(parent, &path);
+                        supported_transport = true;
+                } else if (streq(subsys, "bcma")) {
+                        parent = handle_bcma(parent, &path);
+                        supported_transport = true;
+                } else if (streq(subsys, "serio")) {
+                        path_prepend(&path, "serio-%s", udev_device_get_sysnum(parent));
+                        parent = skip_subsystem(parent, "serio");
+                } else if (streq(subsys, "pci")) {
+                        path_prepend(&path, "pci-%s", udev_device_get_sysname(parent));
+                        parent = skip_subsystem(parent, "pci");
+                        supported_parent = true;
+                } else if (streq(subsys, "platform")) {
+                        path_prepend(&path, "platform-%s", udev_device_get_sysname(parent));
+                        parent = skip_subsystem(parent, "platform");
+                        supported_transport = true;
+                        supported_parent = true;
+                } else if (streq(subsys, "acpi")) {
+                        path_prepend(&path, "acpi-%s", udev_device_get_sysname(parent));
+                        parent = skip_subsystem(parent, "acpi");
+                        supported_parent = true;
+                } else if (streq(subsys, "xen")) {
+                        path_prepend(&path, "xen-%s", udev_device_get_sysname(parent));
+                        parent = skip_subsystem(parent, "xen");
+                        supported_parent = true;
+                } else if (streq(subsys, "virtio")) {
+                        while (parent && streq_ptr("virtio", udev_device_get_subsystem(parent)))
+                                parent = udev_device_get_parent(parent);
+                        path_prepend(&path, "virtio-pci-%s", udev_device_get_sysname(parent));
+                        supported_transport = true;
+                        supported_parent = true;
+                } else if (streq(subsys, "scm")) {
+                        path_prepend(&path, "scm-%s", udev_device_get_sysname(parent));
+                        parent = skip_subsystem(parent, "scm");
+                        supported_transport = true;
+                        supported_parent = true;
+                } else if (streq(subsys, "ccw")) {
+                        path_prepend(&path, "ccw-%s", udev_device_get_sysname(parent));
+                        parent = skip_subsystem(parent, "ccw");
+                        supported_transport = true;
+                        supported_parent = true;
+                } else if (streq(subsys, "ccwgroup")) {
+                        path_prepend(&path, "ccwgroup-%s", udev_device_get_sysname(parent));
+                        parent = skip_subsystem(parent, "ccwgroup");
+                        supported_transport = true;
+                        supported_parent = true;
+                } else if (streq(subsys, "ap")) {
+                        parent = handle_ap(parent, &path);
+                        supported_transport = true;
+                        supported_parent = true;
+                } else if (streq(subsys, "iucv")) {
+                        path_prepend(&path, "iucv-%s", udev_device_get_sysname(parent));
+                        parent = skip_subsystem(parent, "iucv");
+                        supported_transport = true;
+                        supported_parent = true;
+                } else if (streq(subsys, "nvme")) {
+                        const char *nsid = udev_device_get_sysattr_value(dev, "nsid");
+
+                        if (nsid) {
+                                path_prepend(&path, "nvme-%s", nsid);
+                                parent = skip_subsystem(parent, "nvme");
+                                supported_parent = true;
+                                supported_transport = true;
+                        }
+                }
+
+                if (parent)
+                        parent = udev_device_get_parent(parent);
+        }
+
+        /*
+         * Do not return devices with an unknown parent device type. They
+         * might produce conflicting IDs if the parent does not provide a
+         * unique and predictable name.
+         */
+        if (!supported_parent)
+                path = mfree(path);
+
+        /*
+         * Do not return block devices without a well-known transport. Some
+         * devices do not expose their buses and do not provide a unique
+         * and predictable name that way.
+         */
+        if (streq_ptr(udev_device_get_subsystem(dev), "block") && !supported_transport)
+                path = mfree(path);
+
+        if (path != NULL) {
+                char tag[UTIL_NAME_SIZE];
+                size_t i;
+                const char *p;
+
+                /* compose valid udev tag name */
+                for (p = path, i = 0; *p; p++) {
+                        if ((*p >= '0' && *p <= '9') ||
+                            (*p >= 'A' && *p <= 'Z') ||
+                            (*p >= 'a' && *p <= 'z') ||
+                            *p == '-') {
+                                tag[i++] = *p;
+                                continue;
+                        }
+
+                        /* skip all leading '_' */
+                        if (i == 0)
+                                continue;
+
+                        /* avoid second '_' */
+                        if (tag[i-1] == '_')
+                                continue;
+
+                        tag[i++] = '_';
+                }
+                /* strip trailing '_' */
+                while (i > 0 && tag[i-1] == '_')
+                        i--;
+                tag[i] = '\0';
+
+                udev_builtin_add_property(dev, test, "ID_PATH", path);
+                udev_builtin_add_property(dev, test, "ID_PATH_TAG", tag);
+                free(path);
+                return EXIT_SUCCESS;
+        }
+        return EXIT_FAILURE;
+}
+
+const struct udev_builtin udev_builtin_path_id = {
+        .name = "path_id",
+        .cmd = builtin_path_id,
+        .help = "Compose persistent device path",
+        .run_once = true,
+};