blob: ca38f56087911f283165d6207ca69e67ec616c1c [file] [log] [blame] [raw]
/* 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 <unistd.h>
#include "alloc-util.h"
#include "dirent-util.h"
#include "fd-util.h"
#include "libudev-util.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 int format_lun_number(sd_device *dev, char **path) {
const char *sysnum;
unsigned long lun;
int r;
r = sd_device_get_sysnum(dev, &sysnum);
if (r < 0)
return r;
if (!sysnum)
return -ENOENT;
lun = strtoul(sysnum, 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);
return 0;
}
static sd_device *skip_subsystem(sd_device *dev, const char *subsys) {
sd_device *parent;
assert(dev);
assert(subsys);
for (parent = dev; ; ) {
const char *subsystem;
if (sd_device_get_subsystem(parent, &subsystem) < 0)
break;
if (!streq(subsystem, subsys))
break;
dev = parent;
if (sd_device_get_parent(dev, &parent) < 0)
break;
}
return dev;
}
static sd_device *handle_scsi_fibre_channel(sd_device *parent, char **path) {
sd_device *targetdev;
_cleanup_(sd_device_unrefp) sd_device *fcdev = NULL;
const char *port, *sysname;
_cleanup_free_ char *lun = NULL;
assert(parent);
assert(path);
if (sd_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_target", &targetdev) < 0)
return NULL;
if (sd_device_get_sysname(targetdev, &sysname) < 0)
return NULL;
if (sd_device_new_from_subsystem_sysname(&fcdev, "fc_transport", sysname) < 0)
return NULL;
if (sd_device_get_sysattr_value(fcdev, "port_name", &port) < 0)
return NULL;
format_lun_number(parent, &lun);
path_prepend(path, "fc-%s-%s", port, lun);
return parent;
}
static sd_device *handle_scsi_sas_wide_port(sd_device *parent, char **path) {
sd_device *targetdev, *target_parent;
_cleanup_(sd_device_unrefp) sd_device *sasdev = NULL;
const char *sas_address, *sysname;
_cleanup_free_ char *lun = NULL;
assert(parent);
assert(path);
if (sd_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_target", &targetdev) < 0)
return NULL;
if (sd_device_get_parent(targetdev, &target_parent) < 0)
return NULL;
if (sd_device_get_sysname(target_parent, &sysname) < 0)
return NULL;
if (sd_device_new_from_subsystem_sysname(&sasdev, "sas_device", sysname) < 0)
return NULL;
if (sd_device_get_sysattr_value(sasdev, "sas_address", &sas_address) < 0)
return NULL;
format_lun_number(parent, &lun);
path_prepend(path, "sas-%s-%s", sas_address, lun);
return parent;
}
static sd_device *handle_scsi_sas(sd_device *parent, char **path) {
sd_device *targetdev, *target_parent, *port, *expander;
_cleanup_(sd_device_unrefp) sd_device *target_sasdev = NULL, *expander_sasdev = NULL, *port_sasdev = NULL;
const char *sas_address = NULL;
const char *phy_id;
const char *phy_count, *sysname;
_cleanup_free_ char *lun = NULL;
assert(parent);
assert(path);
if (sd_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_target", &targetdev) < 0)
return NULL;
if (sd_device_get_parent(targetdev, &target_parent) < 0)
return NULL;
if (sd_device_get_sysname(target_parent, &sysname) < 0)
return NULL;
/* Get sas device */
if (sd_device_new_from_subsystem_sysname(&target_sasdev, "sas_device", sysname) < 0)
return NULL;
/* The next parent is sas port */
if (sd_device_get_parent(target_parent, &port) < 0)
return NULL;
if (sd_device_get_sysname(port, &sysname) < 0)
return NULL;
/* Get port device */
if (sd_device_new_from_subsystem_sysname(&port_sasdev, "sas_port", sysname) < 0)
return NULL;
if (sd_device_get_sysattr_value(port_sasdev, "num_phys", &phy_count) < 0)
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 */
if (sd_device_get_sysattr_value(target_sasdev, "phy_identifier", &phy_id) < 0)
return NULL;
/* The port's parent is either hba or expander */
if (sd_device_get_parent(port, &expander) < 0)
return NULL;
if (sd_device_get_sysname(expander, &sysname) < 0)
return NULL;
/* Get expander device */
if (sd_device_new_from_subsystem_sysname(&expander_sasdev, "sas_device", sysname) >= 0) {
/* Get expander's address */
if (sd_device_get_sysattr_value(expander_sasdev, "sas_address", &sas_address) < 0)
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 sd_device *handle_scsi_iscsi(sd_device *parent, char **path) {
sd_device *transportdev;
_cleanup_(sd_device_unrefp) sd_device *sessiondev = NULL, *conndev = NULL;
const char *target, *connname, *addr, *port;
_cleanup_free_ char *lun = NULL;
const char *sysname, *sysnum;
assert(parent);
assert(path);
/* find iscsi session */
for (transportdev = parent; ; ) {
if (sd_device_get_parent(transportdev, &transportdev) < 0)
return NULL;
if (sd_device_get_sysname(transportdev, &sysname) < 0)
return NULL;
if (startswith(sysname, "session"))
break;
}
/* find iscsi session device */
if (sd_device_new_from_subsystem_sysname(&sessiondev, "iscsi_session", sysname) < 0)
return NULL;
if (sd_device_get_sysattr_value(sessiondev, "targetname", &target) < 0)
return NULL;
if (sd_device_get_sysnum(transportdev, &sysnum) < 0 || !sysnum)
return NULL;
connname = strjoina("connection", sysnum, ":0");
if (sd_device_new_from_subsystem_sysname(&conndev, "iscsi_connection", connname) < 0)
return NULL;
if (sd_device_get_sysattr_value(conndev, "persistent_address", &addr) < 0)
return NULL;
if (sd_device_get_sysattr_value(conndev, "persistent_port", &port) < 0)
return NULL;
format_lun_number(parent, &lun);
path_prepend(path, "ip-%s:%s-iscsi-%s-%s", addr, port, target, lun);
return parent;
}
static sd_device *handle_scsi_ata(sd_device *parent, char **path) {
sd_device *targetdev, *target_parent;
_cleanup_(sd_device_unrefp) sd_device *atadev = NULL;
const char *port_no, *sysname;
assert(parent);
assert(path);
if (sd_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_host", &targetdev) < 0)
return NULL;
if (sd_device_get_parent(targetdev, &target_parent) < 0)
return NULL;
if (sd_device_get_sysname(target_parent, &sysname) < 0)
return NULL;
if (sd_device_new_from_subsystem_sysname(&atadev, "ata_port", sysname) < 0)
return NULL;
if (sd_device_get_sysattr_value(atadev, "port_no", &port_no) < 0)
return NULL;
path_prepend(path, "ata-%s", port_no);
return parent;
}
static sd_device *handle_scsi_default(sd_device *parent, char **path) {
sd_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);
if (sd_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_host", &hostdev) < 0)
return NULL;
if (sd_device_get_sysname(parent, &name) < 0)
return NULL;
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.
*/
if (sd_device_get_syspath(hostdev, &base) < 0)
return NULL;
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 sd_device *handle_scsi_hyperv(sd_device *parent, char **path, size_t guid_str_len) {
sd_device *hostdev;
sd_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));
if (sd_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_host", &hostdev) < 0)
return NULL;
if (sd_device_get_parent(hostdev, &vmbusdev) < 0)
return NULL;
if (sd_device_get_sysattr_value(vmbusdev, "device_id", &guid_str) < 0)
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 sd_device *handle_scsi(sd_device *parent, char **path, bool *supported_parent) {
const char *devtype, *id, *name;
if (sd_device_get_devtype(parent, &devtype) < 0 ||
!streq(devtype, "scsi_device"))
return parent;
/* firewire */
if (sd_device_get_sysattr_value(parent, "ieee1394_id", &id) >= 0) {
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 */
if (sd_device_get_syspath(parent, &name) < 0)
return NULL;
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 sd_device *handle_cciss(sd_device *parent, char **path) {
const char *str;
unsigned controller, disk;
if (sd_device_get_sysname(parent, &str) < 0)
return NULL;
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(sd_device *dev, char **path) {
const char *name;
/* must be the last device in the syspath */
if (*path)
return;
if (sd_device_get_sysname(dev, &name) < 0)
return;
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 sd_device *handle_usb(sd_device *parent, char **path) {
const char *devtype, *str, *port;
if (sd_device_get_devtype(parent, &devtype) < 0)
return parent;
if (!STR_IN_SET(devtype, "usb_interface", "usb_device"))
return parent;
if (sd_device_get_sysname(parent, &str) < 0)
return parent;
port = strchr(str, '-');
if (!port)
return parent;
port++;
path_prepend(path, "usb-0:%s", port);
return skip_subsystem(parent, "usb");
}
static sd_device *handle_bcma(sd_device *parent, char **path) {
const char *sysname;
unsigned core;
if (sd_device_get_sysname(parent, &sysname) < 0)
return NULL;
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 sd_device *handle_ap(sd_device *parent, char **path) {
const char *type, *func;
assert(parent);
assert(path);
if (sd_device_get_sysattr_value(parent, "type", &type) >= 0 &&
sd_device_get_sysattr_value(parent, "ap_functions", &func) >= 0)
path_prepend(path, "ap-%s-%s", type, func);
else {
const char *sysname;
if (sd_device_get_sysname(parent, &sysname) >= 0)
path_prepend(path, "ap-%s", sysname);
}
return skip_subsystem(parent, "ap");
}
static int builtin_path_id(sd_device *dev, int argc, char *argv[], bool test) {
sd_device *parent;
_cleanup_free_ char *path = NULL;
bool supported_transport = false;
bool supported_parent = false;
const char *subsystem;
assert(dev);
/* walk up the chain of devices and compose path */
parent = dev;
while (parent) {
const char *subsys, *sysname;
if (sd_device_get_subsystem(parent, &subsys) < 0 ||
sd_device_get_sysname(parent, &sysname) < 0) {
;
} 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")) {
const char *sysnum;
if (sd_device_get_sysnum(parent, &sysnum) >= 0 && sysnum) {
path_prepend(&path, "serio-%s", sysnum);
parent = skip_subsystem(parent, "serio");
}
} else if (streq(subsys, "pci")) {
path_prepend(&path, "pci-%s", sysname);
parent = skip_subsystem(parent, "pci");
supported_parent = true;
} else if (streq(subsys, "platform")) {
path_prepend(&path, "platform-%s", sysname);
parent = skip_subsystem(parent, "platform");
supported_transport = true;
supported_parent = true;
} else if (streq(subsys, "acpi")) {
path_prepend(&path, "acpi-%s", sysname);
parent = skip_subsystem(parent, "acpi");
supported_parent = true;
} else if (streq(subsys, "xen")) {
path_prepend(&path, "xen-%s", sysname);
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", sysname);
parent = skip_subsystem(parent, "scm");
supported_transport = true;
supported_parent = true;
} else if (streq(subsys, "ccw")) {
path_prepend(&path, "ccw-%s", sysname);
parent = skip_subsystem(parent, "ccw");
supported_transport = true;
supported_parent = true;
} else if (streq(subsys, "ccwgroup")) {
path_prepend(&path, "ccwgroup-%s", sysname);
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", sysname);
parent = skip_subsystem(parent, "iucv");
supported_transport = true;
supported_parent = true;
} else if (streq(subsys, "nvme")) {
const char *nsid;
if (sd_device_get_sysattr_value(dev, "nsid", &nsid) >= 0) {
path_prepend(&path, "nvme-%s", nsid);
parent = skip_subsystem(parent, "nvme");
supported_parent = true;
supported_transport = true;
}
}
if (!parent)
break;
if (sd_device_get_parent(parent, &parent) < 0)
break;
}
if (!path)
return -ENOENT;
/*
* 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 -ENOENT;
/*
* 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 (sd_device_get_subsystem(dev, &subsystem) >= 0 &&
streq(subsystem, "block") &&
!supported_transport)
return -ENOENT;
{
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 0;
}
const UdevBuiltin udev_builtin_path_id = {
.name = "path_id",
.cmd = builtin_path_id,
.help = "Compose persistent device path",
.run_once = true,
};