/* SPDX-License-Identifier: GPL-2.0+ */ /* * compose persistent device path * * Copyright (C) 2009-2011 Kay Sievers * * 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 . */ #include #include #include #include #include #include #include #include #include #include "alloc-util.h" #include "dirent-util.h" #include "fd-util.h" #include "string-util.h" #include "sysexits.h" #include "udev.h" #include "udev-util.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 = pre; pre = NULL; } } /* ** 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 *udev; struct udev_device *targetdev; _cleanup_udev_device_unref_ struct udev_device *fcdev = NULL; const char *port; _cleanup_free_ char *lun = NULL; assert(parent); assert(path); udev = udev_device_get_udev(parent); targetdev = udev_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_target"); if (!targetdev) return NULL; fcdev = udev_device_new_from_subsystem_sysname(udev, "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 *udev; struct udev_device *targetdev, *target_parent; _cleanup_udev_device_unref_ struct udev_device *sasdev = NULL; const char *sas_address; _cleanup_free_ char *lun = NULL; assert(parent); assert(path); udev = udev_device_get_udev(parent); 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(udev, "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 *udev; struct udev_device *targetdev, *target_parent, *port, *expander; _cleanup_udev_device_unref_ 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); udev = udev_device_get_udev(parent); 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( udev, "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( udev, "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( udev, "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 *udev; struct udev_device *transportdev; _cleanup_udev_device_unref_ struct udev_device *sessiondev = NULL, *conndev = NULL; const char *target, *connname, *addr, *port; _cleanup_free_ char *lun = NULL; assert(parent); assert(path); udev = udev_device_get_udev(parent); /* 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(udev, "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(udev, "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 *udev; struct udev_device *targetdev, *target_parent; _cleanup_udev_device_unref_ struct udev_device *atadev = NULL; const char *port_no; assert(parent); assert(path); udev = udev_device_get_udev(parent); 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) 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) { struct udev_device *hostdev; struct udev_device *vmbusdev; const char *guid_str; _cleanup_free_ 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); 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); return handle_scsi_default(parent, path); } 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); 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 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 && 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, };