path_id: implement in C using libudev

TODO

@@ -1,4 +1,5 @@
 
+  o kill path_id.sh (add fc, sas, iscsi to C version)
   o add tests for kernel provided DEVNAME logic
   o drop modprobe floppy alias (SUSE), it will be in the module (2.6.30)
   o remove MMC rules, they got a modalias now (2.6.30)

extras/path_id/.gitignore

@@ -0,0 +1 @@
+path_id

extras/path_id/Makefile.am

@@ -2,7 +2,19 @@ include $(top_srcdir)/Makefile.am.inc
 
 udevhomedir = $(udev_prefix)/lib/udev
 dist_udevhome_SCRIPTS = \
+	path_id.sh
+
+udevhome_PROGRAMS = \
 	path_id
 
+path_id_SOURCES = \
+	path_id.c \
+	../../udev/lib/libudev.h \
+	../../udev/lib/libudev.c \
+	../../udev/lib/libudev-device.c \
+	../../udev/lib/libudev-enumerate.c \
+	../../udev/lib/libudev-list.c \
+	../../udev/lib/libudev-util.c
+
 dist_man_MANS = \
 	path_id.8

extras/path_id/path_id.c

@@ -0,0 +1,365 @@
+/*
+ * compose persisistent device path
+ *
+ * Copyright (C) 2009 Kay Sievers <kay.sievers@vrfy.org>
+ *
+ * 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 <libudev.h>
+#include <../../udev/udev.h>
+
+int debug;
+
+static void log_fn(struct udev *udev, int priority,
+		   const char *file, int line, const char *fn,
+		   const char *format, va_list args)
+{
+	if (debug) {
+		fprintf(stderr, "%s: ", fn != NULL ? fn : file);
+		vfprintf(stderr, format, args);
+	} else {
+		vsyslog(priority, format, args);
+	}
+}
+
+static int path_prepend(char **path, const char *fmt, ...)
+{
+	va_list va;
+	char *old;
+	char *pre;
+	int err;
+
+	old = *path;
+
+	va_start(va, fmt);
+	err = vasprintf(&pre, fmt, va);
+	va_end(va);
+	if (err < 0)
+		return err;
+
+	if (old != NULL) {
+		err = asprintf(path, "%s-%s", pre, old);
+		if (err < 0)
+			return err;
+		free(pre);
+	} else {
+		*path = pre;
+	}
+
+	free(old);
+	return 0;
+}
+
+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 || strcmp(subsystem, subsys) != 0)
+			break;
+		dev = parent;
+		parent = udev_device_get_parent(parent);
+	}
+	return dev;
+}
+
+/* find smallest number of instances of <syspath>/<name><number> */
+static int base_number(const char *syspath, const char *name)
+{
+	char *base;
+	char *pos;
+	DIR *dir;
+	struct dirent *dent;
+	size_t len;
+	int number = -1;
+
+	base = strdup(syspath);
+	if (base == NULL)
+		goto out;
+
+	pos = strrchr(base, '/');
+	if (pos == NULL)
+		goto out;
+	pos[0] = '\0';
+
+	len = strlen(name);
+	dir = opendir(base);
+	if (dir == 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 (strncmp(dent->d_name, name, len) != 0)
+			continue;
+		i = strtoul(&dent->d_name[len], &rest, 10);
+		if (rest[0] != '\0')
+			continue;
+		if (number == -1 || i < number)
+			number = i;
+	}
+	closedir(dir);
+out:
+	free(base);
+	return number;
+}
+
+static struct udev_device *handle_scsi(struct udev_device *dev, char **path)
+{
+	const char *devtype;
+	struct udev_device *hostdev;
+	const char *name;
+	int host, bus, target, lun;
+	int base;
+
+	devtype = udev_device_get_devtype(dev);
+	if (devtype == NULL || strcmp(devtype, "scsi_device") != 0)
+		return dev;
+
+	hostdev = udev_device_get_parent_with_subsystem_devtype(dev, "scsi", "scsi_host");
+	if (hostdev == NULL)
+		return dev;
+
+	name = udev_device_get_sysname(dev);
+	if (sscanf(name, "%d:%d:%d:%d", &host, &bus, &target, &lun) != 4)
+		return dev;
+
+	/* rebase host offset to get the local relative number */
+	base = base_number(udev_device_get_syspath(hostdev), "host");
+	if (base < 0)
+		return dev;
+	host -= base;
+
+	path_prepend(path, "scsi-%u:%u:%u:%u", host, bus, target, lun);
+	dev = skip_subsystem(dev, "scsi");
+	return dev;
+}
+
+static void handle_scsi_tape(struct udev_device *dev, char **suffix)
+{
+	const char *name;
+
+	name = udev_device_get_sysname(dev);
+	if (strncmp(name, "nst", 3) == 0 && strchr("lma", name[3]) != NULL)
+		asprintf(suffix, "nst%c", name[3]);
+	else if (strncmp(name, "st", 2) == 0 && strchr("lma", name[2]) != NULL)
+		asprintf(suffix, "st%c", name[2]);
+}
+
+static struct udev_device *handle_usb(struct udev_device *dev, char **path)
+{
+	const char *devtype;
+	const char *str;
+	const char *port;
+
+	devtype = udev_device_get_devtype(dev);
+	if (devtype == NULL || strcmp(devtype, "usb_interface") != 0)
+		return dev;
+
+	str = udev_device_get_sysname(dev);
+	port = strchr(str, '-');
+	if (port == NULL)
+		return dev;
+	port++;
+
+	dev = skip_subsystem(dev, "usb");
+	path_prepend(path, "usb-0:%s", port);
+	return dev;
+}
+
+static struct udev_device *handle_firewire(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 *id;
+
+		id = udev_device_get_sysattr_value(scsi_dev, "ieee1394_id");
+		if (id != NULL)
+			path_prepend(path, "ieee1394-0x%s", id);
+	}
+
+	parent = skip_subsystem(parent, "firewire");
+	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;
+}
+
+int main(int argc, char **argv)
+{
+	static const struct option options[] = {
+		{ "debug", no_argument, NULL, 'd' },
+		{ "help", no_argument, NULL, 'h' },
+		{}
+	};
+	struct udev *udev;
+	struct udev_device *dev;
+	struct udev_device *parent;
+	char syspath[UTIL_PATH_SIZE];
+	const char *devpath;
+	char *path;
+	char *path_suffix;
+	int rc = 1;
+
+	udev = udev_new();
+	if (udev == NULL)
+		goto exit;
+
+	logging_init("usb_id");
+	udev_set_log_fn(udev, log_fn);
+
+	while (1) {
+		int option;
+
+		option = getopt_long(argc, argv, "dh", options, NULL);
+		if (option == -1)
+			break;
+
+		switch (option) {
+		case 'd':
+			debug = 1;
+			if (udev_get_log_priority(udev) < LOG_INFO)
+				udev_set_log_priority(udev, LOG_INFO);
+			break;
+		case 'h':
+			printf("Usage: path_id [--debug] [--help] <devpath>\n"
+			       "  --debug    print debug information\n"
+			       "  --help      print this help text\n\n");
+		default:
+			rc = 1;
+			goto exit;
+		}
+	}
+
+	devpath = argv[optind];
+	if (devpath == NULL) {
+		fprintf(stderr, "No device specified\n");
+		rc = 2;
+		goto exit;
+	}
+
+	util_strscpyl(syspath, sizeof(syspath), udev_get_sys_path(udev), devpath, NULL);
+	dev = udev_device_new_from_syspath(udev, syspath);
+	if (dev == NULL) {
+		fprintf(stderr, "unable to access '%s'\n", devpath);
+		rc = 3;
+		goto exit;
+	}
+
+	path = NULL;
+	path_suffix = NULL;
+
+	parent = dev;
+	while (parent != NULL) {
+		const char *subsys;
+
+		subsys = udev_device_get_subsystem(parent);
+
+		if (subsys == NULL) {
+			;
+		} else if (strcmp(subsys, "scsi_tape") == 0) {
+			handle_scsi_tape(parent, &path_suffix);
+		} else if (strcmp(subsys, "scsi") == 0) {
+			parent = handle_scsi(parent, &path);
+		} else if (strcmp(subsys, "fc_transport") == 0) {
+			; //handle_fc();
+		} else if (strcmp(subsys, "sas_end_device") == 0) {
+			; //handle_sas();
+		} else if (strcmp(subsys, "iscsi_session") == 0) {
+			; //handle_iscsi()
+		} else if (strcmp(subsys, "ccw") == 0) {
+			handle_ccw(parent, dev, &path);
+		} else if (strcmp(subsys, "cciss") == 0) {
+			; //handle_cciss();
+		} else if (strcmp(subsys, "usb") == 0) {
+			parent = handle_usb(parent, &path);
+		} else if (strcmp(subsys, "serio") == 0) {
+			path_prepend(&path, "serio-%s", udev_device_get_sysnum(parent));
+			parent = skip_subsystem(parent, "serio");
+		} else if (strcmp(subsys, "firewire") == 0 || strcmp(subsys, "ieee1394") == 0) {
+			parent = handle_firewire(parent, dev, &path);
+		} else if (strcmp(subsys, "pci") == 0) {
+			path_prepend(&path, "pci-%s", udev_device_get_sysname(parent));
+			parent = skip_subsystem(parent, "pci");
+		} else if (strcmp(subsys, "platform") == 0) {
+			path_prepend(&path, "platform-%s", udev_device_get_sysname(parent));
+			parent = skip_subsystem(parent, "platform");
+		} else if (strcmp(subsys, "xen") == 0) {
+			path_prepend(&path, "xen-%s", udev_device_get_sysname(parent));
+			parent = skip_subsystem(parent, "xen");
+		}
+
+		parent = udev_device_get_parent(parent);
+	}
+
+	if (path != NULL) {
+		if (path_suffix != NULL) {
+			printf("ID_PATH=%s%s\n", path, path_suffix);
+			free(path_suffix);
+		} else {
+			printf("ID_PATH=%s\n", path);
+		}
+		free(path);
+		rc = 0;
+	}
+
+	udev_device_unref(dev);
+exit:
+	udev_unref(udev);
+	logging_close();
+	return rc;
+}

rules/rules.d/60-persistent-storage-tape.rules

@@ -17,7 +17,7 @@ KERNEL=="st*[0-9]",  ENV{ID_SERIAL}=="?*", SYMLINK+="tape/by-id/$env{ID_BUS}-$en
 KERNEL=="nst*[0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="tape/by-id/$env{ID_BUS}-$env{ID_SERIAL}-nst"
 
 # by-path (parent device path)
-KERNEL=="st*[0-9]|nst*[0-9]", IMPORT{program}="path_id %p"
+KERNEL=="st*[0-9]|nst*[0-9]", IMPORT{program}="path_id.sh %p"
 KERNEL=="st*[0-9]", ENV{ID_PATH}=="?*", SYMLINK+="tape/by-path/$env{ID_PATH}"
 KERNEL=="nst*[0-9]", ENV{ID_PATH}=="?*", SYMLINK+="tape/by-path/$env{ID_PATH}"
 

rules/rules.d/60-persistent-storage.rules

@@ -47,7 +47,9 @@ KERNEL=="mspblk[0-9]", SUBSYSTEMS=="memstick", ATTRS{name}=="?*", ATTRS{serial}=
 KERNEL=="mspblk[0-9]p[0-9]", ENV{ID_NAME}=="?*", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/memstick-$env{ID_NAME}_$env{ID_SERIAL}-part%n"
 
 # by-path (parent device path)
-ENV{DEVTYPE}=="disk", DEVPATH!="*/virtual/*", IMPORT{program}="path_id %p"
+# old shell script for fc, sas, iscsi, s390, ide
+ENV{DEVTYPE}=="disk", DEVPATH=="*/css0/*|*/rport-[0-9]*|*/end_device-*|*/session[0-9]*|*/ide[0-9]*", IMPORT{program}="path_id.sh %p"
+ENV{DEVTYPE}=="disk", ENV{ID_PATH}=="", DEVPATH!="*/virtual/*", IMPORT{program}="path_id %p"
 ENV{DEVTYPE}=="disk", ENV{ID_PATH}=="?*", SYMLINK+="disk/by-path/$env{ID_PATH}"
 ENV{DEVTYPE}=="partition", ENV{ID_PATH}=="?*", SYMLINK+="disk/by-path/$env{ID_PATH}-part%n"