usr/src/lib/libdevid/deviceid.c - illumos-gate - Gitiles

 /*
  * CDDL HEADER START
  *
  * The contents of this file are subject to the terms of the
  * Common Development and Distribution License, Version 1.0 only
  * (the "License").  You may not use this file except in compliance
  * with the License.
  *
  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  * or http://www.opensolaris.org/os/licensing.
  * See the License for the specific language governing permissions
  * and limitations under the License.
  *
  * When distributing Covered Code, include this CDDL HEADER in each
  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  * If applicable, add the following below this CDDL HEADER, with the
  * fields enclosed by brackets "[]" replaced with your own identifying
  * information: Portions Copyright [yyyy] [name of copyright owner]
  *
  * CDDL HEADER END
  */

 /*
  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  * Copyright 2017 Nexenta Systems, Inc.
  */

 #include <unistd.h>
 #include <stdlib.h>
 #include <errno.h>
 #include <ftw.h>
 #include <string.h>
 #include <thread.h>
 #include <synch.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <sys/modctl.h>
 #include <strings.h>

 #include <libdevinfo.h>
 #include "libdevid.h"

 /*
  * Get Device Id from an open file descriptor
  */
 int
 devid_get(int fd, ddi_devid_t *devidp)
 {
 	int		len = 0;
 	dev_t		dev;
 	struct stat	statb;
 	ddi_devid_t	mydevid;

 	if (fstat(fd, &statb) != 0)
 		return (-1);

 	/* If not char or block device, then error */
 	if (!S_ISCHR(statb.st_mode) && !S_ISBLK(statb.st_mode))
 		return (-1);

 	/* Get the device id size */
 	dev = statb.st_rdev;
 	if (modctl(MODSIZEOF_DEVID, dev, &len) != 0)
 		return (-1);

 	/* Allocate space to return device id */
 	if ((mydevid = (ddi_devid_t)malloc(len)) == NULL)
 		return (-1);

 	/* Get the device id */
 	if (modctl(MODGETDEVID, dev, len, mydevid) != 0) {
 		free(mydevid);
 		return (-1);
 	}

 	/* Return the device id copy */
 	*devidp = mydevid;
 	return (0);
 }

 /*
  * Get the minor name
  */
 int
 devid_get_minor_name(int fd, char **minor_namep)
 {
 	int		len = 0;
 	dev_t		dev;
 	int		spectype;
 	char		*myminor_name;
 	struct stat	statb;

 	if (fstat(fd, &statb) != 0)
 		return (-1);

 	/* If not a char or block device, then return an error */
 	if (!S_ISCHR(statb.st_mode) && !S_ISBLK(statb.st_mode))
 		return (-1);

 	spectype = statb.st_mode & S_IFMT;
 	dev = statb.st_rdev;

 	/* Get the minor name size */
 	if (modctl(MODSIZEOF_MINORNAME, dev, spectype, &len) != 0)
 		return (-1);

 	/* Allocate space for the minor name */
 	if ((myminor_name = (char *)malloc(len)) == NULL)
 		return (-1);

 	/* Get the minor name */
 	if (modctl(MODGETMINORNAME, dev, spectype, len, myminor_name) != 0) {
 		free(myminor_name);
 		return (-1);
 	}

 	/* return the minor name copy */
 	*minor_namep = myminor_name;
 	return (0);
 }

 char *
 devid_str_from_path(const char *path)
 {
 	int		fd;
 	ddi_devid_t	devid;
 	char		*minor, *ret = NULL;

 	if ((fd = open(path, O_RDONLY)) < 0)
 		return (NULL);

 	if (devid_get(fd, &devid) == 0) {
 		if (devid_get_minor_name(fd, &minor) != 0)
 			minor = NULL;
 		ret = devid_str_encode(devid, minor);
 		if (minor != NULL)
 			devid_str_free(minor);
 		devid_free(devid);
 	}
 	(void) close(fd);

 	return (ret);
 }

 /* list element of devid_nmlist_t information */
 struct nmlist {
 	struct nmlist	*nl_next;
 	char		*nl_devname;
 	dev_t		nl_dev;
 };

 /* add list element to end of nmlist headed by *nlhp */
 struct nmlist *
 nmlist_add(struct nmlist **nlhp, char *path)
 {
 	struct stat	statb;
 	dev_t		dev;
 	struct nmlist	*nl;

 	/* stat and get the devt for char or block */
 	if ((stat(path, &statb) == 0) &&
 	    (S_ISCHR(statb.st_mode) || S_ISBLK(statb.st_mode)))
 		dev = statb.st_rdev;
 	else
 		dev = NODEV;

 	/* find the end of the list */
 	for (; (nl = *nlhp) != NULL; nlhp = &nl->nl_next)
 		;

 	/* allocate and initialize new entry */
 	if ((nl = malloc(sizeof (*nl))) == NULL)
 		return (NULL);

 	if ((nl->nl_devname = strdup(path)) == NULL) {
 		free(nl);
 		return (NULL);
 	}
 	nl->nl_next = NULL;
 	nl->nl_dev = dev;

 	/* link new entry at end */
 	*nlhp = nl;
 	return (nl);
 }

 /* information needed by devlink_callback to call nmlist_add */
 struct devlink_cbinfo {
 	struct nmlist	**cbi_nlhp;
 	char		*cbi_search_path;
 	int		cbi_error;
 };

 /* di_devlink callback to add a /dev entry to nmlist */
 static int
 devlink_callback(di_devlink_t dl, void *arg)
 {
 	struct devlink_cbinfo	*cbip = (struct devlink_cbinfo *)arg;
 	char			*devpath = (char *)di_devlink_path(dl);

 	if (strncmp(devpath, cbip->cbi_search_path,
 	    strlen(cbip->cbi_search_path)) == 0) {
 		if (nmlist_add(cbip->cbi_nlhp, devpath) == NULL) {
 			cbip->cbi_error = 1;
 			return (DI_WALK_TERMINATE);
 		}
 	}
 	return (DI_WALK_CONTINUE);
 }

 /*
  * Resolve /dev names to DI_PRIMARY_LINK, DI_SECONDARY_LINK, or both.
  * The default is to resolve to just the DI_PRIMARY_LINK.
  */
 int			devid_deviceid_to_nmlist_link = DI_PRIMARY_LINK;

 /*
  * Options for the devid_deviceid_to_nmlist implementation:
  *
  *   DEVICEID_NMLIST_SLINK -	reduce overhead by reuse the previous
  *				di_devlink_init.
  */
 #define	DEVICEID_NMLIST_SLINK	1
 int			devid_deviceid_to_nmlist_flg = 0;
 static di_devlink_handle_t devid_deviceid_to_nmlist_dlh = NULL;	/* SLINK */

 #define	DEVICEID_NMLIST_NRETRY	10

 /*
  * Convert the specified devid/minor_name into a devid_nmlist_t array
  * with names that resolve into /devices or /dev depending on search_path.
  *
  * The man page indicates that:
  *
  *     This function traverses the file tree, starting at search_path.
  *
  * This is not true, we reverse engineer the paths relative to
  * the specified search path to avoid attaching all devices.
  */
 int
 devid_deviceid_to_nmlist(char *search_path, ddi_devid_t devid, char *minor_name,
     devid_nmlist_t **retlist)
 {
 	char			*cp;
 	int			dev;
 	char			*paths = NULL;
 	char			*path;
 	int			lens;
 	di_devlink_handle_t	dlh = NULL;
 	int			ret = -1;
 	struct devlink_cbinfo	cbi;
 	struct nmlist		*nlh = NULL;
 	struct nmlist		*nl;
 	devid_nmlist_t		*rl;
 	int			nret;
 	int			nagain = 0;
 	int			err = 0;

 	*retlist = NULL;

 	/* verify valid search path starts with "/devices" or "/dev" */
 	if ((strcmp(search_path, "/devices") == 0) ||
 	    (strncmp(search_path, "/devices/", 9) == 0))
 		dev = 0;
 	else if ((strcmp(search_path, "/dev") == 0) ||
 	    (strncmp(search_path, "/dev/", 5) == 0))
 		dev = 1;
 	else {
 		errno = EINVAL;
 		return (-1);
 	}


 	/* translate devid/minor_name to /devices paths */
 again:	if (modctl(MODDEVID2PATHS, devid, minor_name, 0, &lens, NULL) != 0)
 		goto out;
 	if ((paths = (char *)malloc(lens)) == NULL)
 		goto out;
 	if (modctl(MODDEVID2PATHS, devid, minor_name, 0, &lens, paths) != 0) {
 		if ((errno == EAGAIN) && (nagain++ < DEVICEID_NMLIST_NRETRY)) {
 			free(paths);
 			paths = NULL;
 			goto again;
 		}
 		goto out;
 	}

 	/*
 	 * initialize for /devices path to /dev path translation. To reduce
 	 * overhead we reuse the last snapshot if DEVICEID_NMLIST_SLINK is set.
 	 */
 	if (dev) {
 		dlh = devid_deviceid_to_nmlist_dlh;
 		if (dlh &&
 		    !(devid_deviceid_to_nmlist_flg & DEVICEID_NMLIST_SLINK)) {
 			(void) di_devlink_fini(&dlh);
 			dlh = devid_deviceid_to_nmlist_dlh = NULL;
 		}
 		if ((dlh == NULL) &&
 		    ((dlh = di_devlink_init(NULL, 0)) == NULL))
 				goto out;
 	}

 	/*
 	 * iterate over all the devtspectype resolutions of the devid and
 	 * convert them into the appropriate path form and add items to return
 	 * to the nmlist list;
 	 */
 	for (path = paths; *path; path += strlen(path) + 1) {
 		if (dev) {
 			/* add /dev entries */
 			cbi.cbi_nlhp = &nlh;
 			cbi.cbi_search_path = search_path;
 			cbi.cbi_error = 0;

 			(void) di_devlink_walk(dlh, NULL, path,
 			    devid_deviceid_to_nmlist_link,
 			    (void *)&cbi, devlink_callback);
 			if (cbi.cbi_error)
 				goto out;
 		} else {
 			/* add /devices entry */
 			cp = malloc(strlen("/devices") + strlen(path) + 1);
 			(void) strcpy(cp, "/devices");
 			(void) strcat(cp, path);
 			if (strncmp(cp, search_path,
 			    strlen(search_path)) == 0) {
 				if (nmlist_add(&nlh, cp) == NULL) {
 					free(cp);
 					goto out;
 				}
 			}
 			free(cp);
 		}
 	}

 	/* convert from nmlist to retlist array */
 	for (nl = nlh, nret = 0; nl; nl = nl->nl_next)
 		nret++;
 	if (nret == 0) {
 		err = ENODEV;
 		goto out;
 	}
 	if ((*retlist = calloc(nret + 1, sizeof (devid_nmlist_t))) == NULL) {
 		err = ENOMEM;
 		goto out;
 	}
 	for (nl = nlh, rl = *retlist; nl; nl = nl->nl_next, rl++) {
 		rl->devname = nl->nl_devname;
 		rl->dev = nl->nl_dev;
 	}
 	rl->devname = NULL;
 	rl->dev = NODEV;

 	ret = 0;

 out:
 	while ((nl = nlh) != NULL) {	/* free the nmlist */
 		nlh = nl->nl_next;
 		free(nl);
 	}
 	if (paths)
 		free(paths);
 	if (dlh) {
 		if ((ret == 0) &&
 		    (devid_deviceid_to_nmlist_flg & DEVICEID_NMLIST_SLINK))
 			devid_deviceid_to_nmlist_dlh = dlh;
 		else
 			(void) di_devlink_fini(&dlh);
 	}
 	if (ret && *retlist)
 		free(*retlist);
 	if (ret && err != 0)
 		errno = err;
 	return (ret);
 }

 /*
  * Free Device Id Name List
  */
 void
 devid_free_nmlist(devid_nmlist_t *list)
 {
 	devid_nmlist_t *p = list;

 	if (list == NULL)
 		return;

 	/* Free all the device names */
 	while (p->devname != NULL) {
 		free(p->devname);
 		p++;
 	}

 	/* Free the array */
 	free(list);
 }
	/*
	* CDDL HEADER START
	*
	* The contents of this file are subject to the terms of the
	* Common Development and Distribution License, Version 1.0 only
	* (the "License"). You may not use this file except in compliance
	* with the License.
	*
	* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
	* or http://www.opensolaris.org/os/licensing.
	* See the License for the specific language governing permissions
	* and limitations under the License.
	*
	* When distributing Covered Code, include this CDDL HEADER in each
	* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
	* If applicable, add the following below this CDDL HEADER, with the
	* fields enclosed by brackets "[]" replaced with your own identifying
	* information: Portions Copyright [yyyy] [name of copyright owner]
	*
	* CDDL HEADER END
	*/

	/*
	* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
	* Use is subject to license terms.
	* Copyright 2017 Nexenta Systems, Inc.
	*/

	#include <unistd.h>
	#include <stdlib.h>
	#include <errno.h>
	#include <ftw.h>
	#include <string.h>
	#include <thread.h>
	#include <synch.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <fcntl.h>
	#include <sys/modctl.h>
	#include <strings.h>

	#include <libdevinfo.h>
	#include "libdevid.h"

	/*
	* Get Device Id from an open file descriptor
	*/
	int
	devid_get(int fd, ddi_devid_t *devidp)
	{
	int len = 0;
	dev_t dev;
	struct stat statb;
	ddi_devid_t mydevid;

	if (fstat(fd, &statb) != 0)
	return (-1);

	/* If not char or block device, then error */
	if (!S_ISCHR(statb.st_mode) && !S_ISBLK(statb.st_mode))
	return (-1);

	/* Get the device id size */
	dev = statb.st_rdev;
	if (modctl(MODSIZEOF_DEVID, dev, &len) != 0)
	return (-1);

	/* Allocate space to return device id */
	if ((mydevid = (ddi_devid_t)malloc(len)) == NULL)
	return (-1);

	/* Get the device id */
	if (modctl(MODGETDEVID, dev, len, mydevid) != 0) {
	free(mydevid);
	return (-1);
	}

	/* Return the device id copy */
	*devidp = mydevid;
	return (0);
	}

	/*
	* Get the minor name
	*/
	int
	devid_get_minor_name(int fd, char **minor_namep)
	{
	int len = 0;
	dev_t dev;
	int spectype;
	char *myminor_name;
	struct stat statb;

	if (fstat(fd, &statb) != 0)
	return (-1);

	/* If not a char or block device, then return an error */
	if (!S_ISCHR(statb.st_mode) && !S_ISBLK(statb.st_mode))
	return (-1);

	spectype = statb.st_mode & S_IFMT;
	dev = statb.st_rdev;

	/* Get the minor name size */
	if (modctl(MODSIZEOF_MINORNAME, dev, spectype, &len) != 0)
	return (-1);

	/* Allocate space for the minor name */
	if ((myminor_name = (char *)malloc(len)) == NULL)
	return (-1);

	/* Get the minor name */
	if (modctl(MODGETMINORNAME, dev, spectype, len, myminor_name) != 0) {
	free(myminor_name);
	return (-1);
	}

	/* return the minor name copy */
	*minor_namep = myminor_name;
	return (0);
	}

	char *
	devid_str_from_path(const char *path)
	{
	int fd;
	ddi_devid_t devid;
	char minor, ret = NULL;

	if ((fd = open(path, O_RDONLY)) < 0)
	return (NULL);

	if (devid_get(fd, &devid) == 0) {
	if (devid_get_minor_name(fd, &minor) != 0)
	minor = NULL;
	ret = devid_str_encode(devid, minor);
	if (minor != NULL)
	devid_str_free(minor);
	devid_free(devid);
	}
	(void) close(fd);

	return (ret);
	}

	/* list element of devid_nmlist_t information */
	struct nmlist {
	struct nmlist *nl_next;
	char *nl_devname;
	dev_t nl_dev;
	};

	/* add list element to end of nmlist headed by nlhp /
	struct nmlist *
	nmlist_add(struct nmlist *nlhp, char path)
	{
	struct stat statb;
	dev_t dev;
	struct nmlist *nl;

	/* stat and get the devt for char or block */
	if ((stat(path, &statb) == 0) &&
	(S_ISCHR(statb.st_mode) \|\| S_ISBLK(statb.st_mode)))
	dev = statb.st_rdev;
	else
	dev = NODEV;

	/* find the end of the list */
	for (; (nl = *nlhp) != NULL; nlhp = &nl->nl_next)
	;

	/* allocate and initialize new entry */
	if ((nl = malloc(sizeof (*nl))) == NULL)
	return (NULL);

	if ((nl->nl_devname = strdup(path)) == NULL) {
	free(nl);
	return (NULL);
	}
	nl->nl_next = NULL;
	nl->nl_dev = dev;

	/* link new entry at end */
	*nlhp = nl;
	return (nl);
	}

	/* information needed by devlink_callback to call nmlist_add */
	struct devlink_cbinfo {
	struct nmlist **cbi_nlhp;
	char *cbi_search_path;
	int cbi_error;
	};

	/* di_devlink callback to add a /dev entry to nmlist */
	static int
	devlink_callback(di_devlink_t dl, void *arg)
	{
	struct devlink_cbinfo cbip = (struct devlink_cbinfo )arg;
	char devpath = (char )di_devlink_path(dl);

	if (strncmp(devpath, cbip->cbi_search_path,
	strlen(cbip->cbi_search_path)) == 0) {
	if (nmlist_add(cbip->cbi_nlhp, devpath) == NULL) {
	cbip->cbi_error = 1;
	return (DI_WALK_TERMINATE);
	}
	}
	return (DI_WALK_CONTINUE);
	}

	/*
	* Resolve /dev names to DI_PRIMARY_LINK, DI_SECONDARY_LINK, or both.
	* The default is to resolve to just the DI_PRIMARY_LINK.
	*/
	int devid_deviceid_to_nmlist_link = DI_PRIMARY_LINK;

	/*
	* Options for the devid_deviceid_to_nmlist implementation:
	*
	* DEVICEID_NMLIST_SLINK - reduce overhead by reuse the previous
	* di_devlink_init.
	*/
	#define DEVICEID_NMLIST_SLINK 1
	int devid_deviceid_to_nmlist_flg = 0;
	static di_devlink_handle_t devid_deviceid_to_nmlist_dlh = NULL; /* SLINK */

	#define DEVICEID_NMLIST_NRETRY 10

	/*
	* Convert the specified devid/minor_name into a devid_nmlist_t array
	* with names that resolve into /devices or /dev depending on search_path.
	*
	* The man page indicates that:
	*
	* This function traverses the file tree, starting at search_path.
	*
	* This is not true, we reverse engineer the paths relative to
	* the specified search path to avoid attaching all devices.
	*/
	int
	devid_deviceid_to_nmlist(char search_path, ddi_devid_t devid, char minor_name,
	devid_nmlist_t **retlist)
	{
	char *cp;
	int dev;
	char *paths = NULL;
	char *path;
	int lens;
	di_devlink_handle_t dlh = NULL;
	int ret = -1;
	struct devlink_cbinfo cbi;
	struct nmlist *nlh = NULL;
	struct nmlist *nl;
	devid_nmlist_t *rl;
	int nret;
	int nagain = 0;
	int err = 0;

	*retlist = NULL;

	/* verify valid search path starts with "/devices" or "/dev" */
	if ((strcmp(search_path, "/devices") == 0) \|\|
	(strncmp(search_path, "/devices/", 9) == 0))
	dev = 0;
	else if ((strcmp(search_path, "/dev") == 0) \|\|
	(strncmp(search_path, "/dev/", 5) == 0))
	dev = 1;
	else {
	errno = EINVAL;
	return (-1);
	}


	/* translate devid/minor_name to /devices paths */
	again: if (modctl(MODDEVID2PATHS, devid, minor_name, 0, &lens, NULL) != 0)
	goto out;
	if ((paths = (char *)malloc(lens)) == NULL)
	goto out;
	if (modctl(MODDEVID2PATHS, devid, minor_name, 0, &lens, paths) != 0) {
	if ((errno == EAGAIN) && (nagain++ < DEVICEID_NMLIST_NRETRY)) {
	free(paths);
	paths = NULL;
	goto again;
	}
	goto out;
	}

	/*
	* initialize for /devices path to /dev path translation. To reduce
	* overhead we reuse the last snapshot if DEVICEID_NMLIST_SLINK is set.
	*/
	if (dev) {
	dlh = devid_deviceid_to_nmlist_dlh;
	if (dlh &&
	!(devid_deviceid_to_nmlist_flg & DEVICEID_NMLIST_SLINK)) {
	(void) di_devlink_fini(&dlh);
	dlh = devid_deviceid_to_nmlist_dlh = NULL;
	}
	if ((dlh == NULL) &&
	((dlh = di_devlink_init(NULL, 0)) == NULL))
	goto out;
	}

	/*
	* iterate over all the devtspectype resolutions of the devid and
	* convert them into the appropriate path form and add items to return
	* to the nmlist list;
	*/
	for (path = paths; *path; path += strlen(path) + 1) {
	if (dev) {
	/* add /dev entries */
	cbi.cbi_nlhp = &nlh;
	cbi.cbi_search_path = search_path;
	cbi.cbi_error = 0;

	(void) di_devlink_walk(dlh, NULL, path,
	devid_deviceid_to_nmlist_link,
	(void *)&cbi, devlink_callback);
	if (cbi.cbi_error)
	goto out;
	} else {
	/* add /devices entry */
	cp = malloc(strlen("/devices") + strlen(path) + 1);
	(void) strcpy(cp, "/devices");
	(void) strcat(cp, path);
	if (strncmp(cp, search_path,
	strlen(search_path)) == 0) {
	if (nmlist_add(&nlh, cp) == NULL) {
	free(cp);
	goto out;
	}
	}
	free(cp);
	}
	}

	/* convert from nmlist to retlist array */
	for (nl = nlh, nret = 0; nl; nl = nl->nl_next)
	nret++;
	if (nret == 0) {
	err = ENODEV;
	goto out;
	}
	if ((*retlist = calloc(nret + 1, sizeof (devid_nmlist_t))) == NULL) {
	err = ENOMEM;
	goto out;
	}
	for (nl = nlh, rl = *retlist; nl; nl = nl->nl_next, rl++) {
	rl->devname = nl->nl_devname;
	rl->dev = nl->nl_dev;
	}
	rl->devname = NULL;
	rl->dev = NODEV;

	ret = 0;

	out:
	while ((nl = nlh) != NULL) { /* free the nmlist */
	nlh = nl->nl_next;
	free(nl);
	}
	if (paths)
	free(paths);
	if (dlh) {
	if ((ret == 0) &&
	(devid_deviceid_to_nmlist_flg & DEVICEID_NMLIST_SLINK))
	devid_deviceid_to_nmlist_dlh = dlh;
	else
	(void) di_devlink_fini(&dlh);
	}
	if (ret && *retlist)
	free(*retlist);
	if (ret && err != 0)
	errno = err;
	return (ret);
	}

	/*
	* Free Device Id Name List
	*/
	void
	devid_free_nmlist(devid_nmlist_t *list)
	{
	devid_nmlist_t *p = list;

	if (list == NULL)
	return;

	/* Free all the device names */
	while (p->devname != NULL) {
	free(p->devname);
	p++;
	}

	/* Free the array */
	free(list);
	}