/* * 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 <stdio.h> #include <stdlib.h> #include <stdarg.h> #include <unistd.h> #include <string.h> #include <ctype.h> #include <fcntl.h> #include <errno.h> #include <dirent.h> #include <getopt.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; 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; 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); if (lun) free(lun); out: udev_device_unref(fcdev); 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 *sasdev; const char *sas_address; char *lun = NULL; 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); if (lun) free(lun); out: udev_device_unref(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; /* 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); if (lun) free(lun); out: udev_device_unref(sessiondev); udev_device_unref(conndev); 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; 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; 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) { 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); 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); goto out; } if (strstr(name, "/end_device-") != NULL) { parent = handle_scsi_sas(parent, path); goto out; } if (strstr(name, "/session") != NULL) { parent = handle_scsi_iscsi(parent, path); goto out; } /* * We do not support the ATA transport class, it uses global counters * to name the ata devices which numbers spread across multiple * controllers. * * The real link numbers are not exported. Also, possible chains of ports * behind port multipliers cannot be composed that way. * * Until all that is solved at the kernel level, there are no by-path/ * links for ATA devices. */ if (strstr(name, "/ata") != NULL) { parent = NULL; 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; } static struct udev_device *handle_ccw(struct udev_device *parent, struct udev_device *dev, char **path) { struct udev_device *scsi_dev; scsi_dev = udev_device_get_parent_with_subsystem_devtype(dev, "scsi", "scsi_device"); if (scsi_dev != NULL) { const char *wwpn; const char *lun; const char *hba_id; hba_id = udev_device_get_sysattr_value(scsi_dev, "hba_id"); wwpn = udev_device_get_sysattr_value(scsi_dev, "wwpn"); lun = udev_device_get_sysattr_value(scsi_dev, "fcp_lun"); if (hba_id != NULL && lun != NULL && wwpn != NULL) { path_prepend(path, "ccw-%s-zfcp-%s:%s", hba_id, wwpn, lun); goto out; } } path_prepend(path, "ccw-%s", udev_device_get_sysname(parent)); out: parent = skip_subsystem(parent, "ccw"); 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; /* S390 ccw bus */ parent = udev_device_get_parent_with_subsystem_devtype(dev, "ccw", NULL); if (parent != NULL) { handle_ccw(parent, dev, &path); goto out; } /* 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_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, "scm")) { path_prepend(&path, "scm-%s", udev_device_get_sysname(parent)); parent = skip_subsystem(parent, "scm"); supported_transport = true; supported_parent = true; } parent = udev_device_get_parent(parent); } /* * Do return devices with have an unknown type of parent device, they * might produce conflicting IDs below multiple independent parent * devices. */ if (!supported_parent) { free(path); path = NULL; } /* * Do not return a have-only a single-parent block devices, some * have entire hidden buses behind it, and not create predictable * IDs that way. */ if (streq(udev_device_get_subsystem(dev), "block") && !supported_transport) { free(path); path = NULL; } out: 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, };