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|
/* SPDX-License-Identifier: GPL-2.0+ */
/*
* compose persistent device path
*
* Logic based on Hannes Reinecke's shell script.
*/
#include <ctype.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 "alloc-util.h"
#include "dirent-util.h"
#include "fd-util.h"
#include "libudev-private.h"
#include "string-util.h"
#include "strv.h"
#include "sysexits.h"
#include "udev-builtin.h"
_printf_(2,3)
static void path_prepend(char **path, const char *fmt, ...) {
va_list va;
_cleanup_free_ char *pre = NULL;
int r;
va_start(va, fmt);
r = vasprintf(&pre, fmt, va);
va_end(va);
if (r < 0) {
log_oom();
exit(EX_OSERR);
}
if (*path) {
char *new;
new = strjoin(pre, "-", *path);
if (!new) {
log_oom();
exit(EX_OSERR);
}
free_and_replace(*path, new);
} else
*path = TAKE_PTR(pre);
}
/*
** Linux only supports 32 bit luns.
** See drivers/scsi/scsi_scan.c::scsilun_to_int() for more details.
*/
static void format_lun_number(struct udev_device *dev, char **path) {
unsigned long lun = strtoul(udev_device_get_sysnum(dev), NULL, 10);
if (lun < 256)
/* address method 0, peripheral device addressing with bus id of zero */
path_prepend(path, "lun-%lu", lun);
else
/* handle all other lun addressing methods by using a variant of the original lun format */
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) {
const char *subsystem;
subsystem = udev_device_get_subsystem(parent);
if (!streq_ptr(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_device *targetdev;
_cleanup_(udev_device_unrefp) struct udev_device *fcdev = NULL;
const char *port;
_cleanup_free_ char *lun = NULL;
assert(parent);
assert(path);
targetdev = udev_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_target");
if (!targetdev)
return NULL;
fcdev = udev_device_new_from_subsystem_sysname(NULL, "fc_transport", udev_device_get_sysname(targetdev));
if (!fcdev)
return NULL;
port = udev_device_get_sysattr_value(fcdev, "port_name");
if (!port)
return NULL;
format_lun_number(parent, &lun);
path_prepend(path, "fc-%s-%s", port, lun);
return parent;
}
static struct udev_device *handle_scsi_sas_wide_port(struct udev_device *parent, char **path) {
struct udev_device *targetdev, *target_parent;
_cleanup_(udev_device_unrefp) struct udev_device *sasdev = NULL;
const char *sas_address;
_cleanup_free_ char *lun = NULL;
assert(parent);
assert(path);
targetdev = udev_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_target");
if (!targetdev)
return NULL;
target_parent = udev_device_get_parent(targetdev);
if (!target_parent)
return NULL;
sasdev = udev_device_new_from_subsystem_sysname(NULL, "sas_device",
udev_device_get_sysname(target_parent));
if (!sasdev)
return NULL;
sas_address = udev_device_get_sysattr_value(sasdev, "sas_address");
if (!sas_address)
return NULL;
format_lun_number(parent, &lun);
path_prepend(path, "sas-%s-%s", sas_address, lun);
return parent;
}
static struct udev_device *handle_scsi_sas(struct udev_device *parent, char **path)
{
struct udev_device *targetdev, *target_parent, *port, *expander;
_cleanup_(udev_device_unrefp) struct udev_device
*target_sasdev = NULL, *expander_sasdev = NULL, *port_sasdev = NULL;
const char *sas_address = NULL;
const char *phy_id;
const char *phy_count;
_cleanup_free_ char *lun = NULL;
assert(parent);
assert(path);
targetdev = udev_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_target");
if (!targetdev)
return NULL;
target_parent = udev_device_get_parent(targetdev);
if (!target_parent)
return NULL;
/* Get sas device */
target_sasdev = udev_device_new_from_subsystem_sysname(NULL, "sas_device", udev_device_get_sysname(target_parent));
if (!target_sasdev)
return NULL;
/* The next parent is sas port */
port = udev_device_get_parent(target_parent);
if (!port)
return NULL;
/* Get port device */
port_sasdev = udev_device_new_from_subsystem_sysname(NULL, "sas_port", udev_device_get_sysname(port));
phy_count = udev_device_get_sysattr_value(port_sasdev, "num_phys");
if (!phy_count)
return NULL;
/* Check if we are simple disk */
if (strncmp(phy_count, "1", 2) != 0)
return handle_scsi_sas_wide_port(parent, path);
/* Get connected phy */
phy_id = udev_device_get_sysattr_value(target_sasdev, "phy_identifier");
if (!phy_id)
return NULL;
/* The port's parent is either hba or expander */
expander = udev_device_get_parent(port);
if (!expander)
return NULL;
/* Get expander device */
expander_sasdev = udev_device_new_from_subsystem_sysname(NULL, "sas_device", udev_device_get_sysname(expander));
if (expander_sasdev) {
/* Get expander's address */
sas_address = udev_device_get_sysattr_value(expander_sasdev, "sas_address");
if (!sas_address)
return NULL;
}
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);
return parent;
}
static struct udev_device *handle_scsi_iscsi(struct udev_device *parent, char **path) {
struct udev_device *transportdev;
_cleanup_(udev_device_unrefp) struct udev_device
*sessiondev = NULL, *conndev = NULL;
const char *target, *connname, *addr, *port;
_cleanup_free_ char *lun = NULL;
assert(parent);
assert(path);
/* find iscsi session */
transportdev = parent;
for (;;) {
transportdev = udev_device_get_parent(transportdev);
if (!transportdev)
return NULL;
if (startswith(udev_device_get_sysname(transportdev), "session"))
break;
}
/* find iscsi session device */
sessiondev = udev_device_new_from_subsystem_sysname(NULL, "iscsi_session", udev_device_get_sysname(transportdev));
if (!sessiondev)
return NULL;
target = udev_device_get_sysattr_value(sessiondev, "targetname");
if (!target)
return NULL;
connname = strjoina("connection", udev_device_get_sysnum(transportdev), ":0");
conndev = udev_device_new_from_subsystem_sysname(NULL, "iscsi_connection", connname);
if (!conndev)
return NULL;
addr = udev_device_get_sysattr_value(conndev, "persistent_address");
port = udev_device_get_sysattr_value(conndev, "persistent_port");
if (!addr || !port)
return NULL;
format_lun_number(parent, &lun);
path_prepend(path, "ip-%s:%s-iscsi-%s-%s", addr, port, target, lun);
return parent;
}
static struct udev_device *handle_scsi_ata(struct udev_device *parent, char **path) {
struct udev_device *targetdev, *target_parent;
_cleanup_(udev_device_unrefp) struct udev_device *atadev = NULL;
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(NULL, "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)
return NULL;
path_prepend(path, "ata-%s", port_no);
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, *base, *pos;
_cleanup_closedir_ DIR *dir = NULL;
struct dirent *dent;
int basenum = -1;
assert(parent);
assert(path);
hostdev = udev_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_host");
if (!hostdev)
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.
*/
base = udev_device_get_syspath(hostdev);
pos = strrchr(base, '/');
if (!pos)
return NULL;
base = strndupa(base, pos - base);
dir = opendir(base);
if (!dir)
return NULL;
FOREACH_DIRENT_ALL(dent, dir, break) {
char *rest;
int i;
if (dent->d_name[0] == '.')
continue;
if (!IN_SET(dent->d_type, DT_DIR, 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;
}
if (basenum == -1)
return hostdev;
host -= basenum;
path_prepend(path, "scsi-%u:%u:%u:%u", host, bus, target, lun);
return hostdev;
}
static struct udev_device *handle_scsi_hyperv(struct udev_device *parent, char **path, size_t guid_str_len) {
struct udev_device *hostdev;
struct udev_device *vmbusdev;
const char *guid_str;
_cleanup_free_ char *lun = NULL;
char guid[39];
size_t i, k;
assert(parent);
assert(path);
assert(guid_str_len < sizeof(guid));
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) < guid_str_len || guid_str[0] != '{' || guid_str[guid_str_len-1] != '}')
return NULL;
for (i = 1, k = 0; i < guid_str_len-1; 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);
return parent;
}
static struct udev_device *handle_scsi(struct udev_device *parent, char **path, bool *supported_parent) {
const char *devtype, *id, *name;
devtype = udev_device_get_devtype(parent);
if (!streq_ptr(devtype, "scsi_device"))
return parent;
/* firewire */
id = udev_device_get_sysattr_value(parent, "ieee1394_id");
if (id) {
path_prepend(path, "ieee1394-0x%s", id);
*supported_parent = true;
return skip_subsystem(parent, "scsi");
}
/* scsi sysfs does not have a "subsystem" for the transport */
name = udev_device_get_syspath(parent);
if (strstr(name, "/rport-")) {
*supported_parent = true;
return handle_scsi_fibre_channel(parent, path);
}
if (strstr(name, "/end_device-")) {
*supported_parent = true;
return handle_scsi_sas(parent, path);
}
if (strstr(name, "/session")) {
*supported_parent = true;
return handle_scsi_iscsi(parent, path);
}
if (strstr(name, "/ata"))
return handle_scsi_ata(parent, path);
if (strstr(name, "/vmbus_"))
return handle_scsi_hyperv(parent, path, 37);
else if (strstr(name, "/VMBUS"))
return handle_scsi_hyperv(parent, path, 38);
return handle_scsi_default(parent, path);
}
static struct udev_device *handle_cciss(struct udev_device *parent, char **path) {
const char *str;
unsigned 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);
return skip_subsystem(parent, "cciss");
}
static void handle_scsi_tape(struct udev_device *dev, char **path) {
const char *name;
/* must be the last device in the syspath */
if (*path)
return;
name = udev_device_get_sysname(dev);
if (startswith(name, "nst") && strchr("lma", name[3]))
path_prepend(path, "nst%c", name[3]);
else if (startswith(name, "st") && strchr("lma", name[2]))
path_prepend(path, "st%c", name[2]);
}
static struct udev_device *handle_usb(struct udev_device *parent, char **path) {
const char *devtype, *str, *port;
devtype = udev_device_get_devtype(parent);
if (!devtype)
return parent;
if (!STR_IN_SET(devtype, "usb_interface", "usb_device"))
return parent;
str = udev_device_get_sysname(parent);
port = strchr(str, '-');
if (!port)
return parent;
port++;
path_prepend(path, "usb-0:%s", port);
return skip_subsystem(parent, "usb");
}
static struct udev_device *handle_bcma(struct udev_device *parent, char **path) {
const char *sysname;
unsigned 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 && func)
path_prepend(path, "ap-%s-%s", type, func);
else
path_prepend(path, "ap-%s", udev_device_get_sysname(parent));
return skip_subsystem(parent, "ap");
}
static int builtin_path_id(struct udev_device *dev, int argc, char *argv[], bool test) {
struct udev_device *parent;
_cleanup_free_ 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) {
const char *subsys;
subsys = udev_device_get_subsystem(parent);
if (!subsys) {
;
} 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")) {
parent = skip_subsystem(parent, "virtio");
supported_transport = 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);
}
if (!path)
return EXIT_FAILURE;
/*
* 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)
return EXIT_FAILURE;
/*
* 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)
return EXIT_FAILURE;
{
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);
}
return EXIT_SUCCESS;
}
const struct udev_builtin udev_builtin_path_id = {
.name = "path_id",
.cmd = builtin_path_id,
.help = "Compose persistent device path",
.run_once = true,
};
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