util-linux/volume_id/get_devname.c - busybox - Git at Google

 /* vi: set sw=4 ts=4: */
 /*
  * Support functions for mounting devices by label/uuid
  *
  * Copyright (C) 2006 by Jason Schoon <floydpink@gmail.com>
  * Some portions cribbed from e2fsprogs, util-linux, dosfstools
  *
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */

 #include "volume_id_internal.h"

 //#define BLKGETSIZE64 _IOR(0x12,114,size_t)

 static struct uuidCache_s {
 	struct uuidCache_s *next;
 //	int major, minor;
 	char *device;
 	char *label;
 	char *uc_uuid; /* prefix makes it easier to grep for */
 } *uuidCache;

 /* Returns !0 on error.
  * Otherwise, returns malloc'ed strings for label and uuid
  * (and they can't be NULL, although they can be "") */
 #if !ENABLE_FEATURE_VOLUMEID_ISO9660
 #define get_label_uuid(device, label, uuid, iso_only) \
 	get_label_uuid(device, label, uuid)
 #endif
 static int
 get_label_uuid(const char *device, char **label, char **uuid, int iso_only)
 {
 	int rv = 1;
 	uint64_t size;
 	struct volume_id *vid;

 	vid = volume_id_open_node(device);
 	if (!vid)
 		return rv;

 	if (ioctl(vid->fd, BLKGETSIZE64, &size) != 0)
 		size = 0;

 #if ENABLE_FEATURE_VOLUMEID_ISO9660
 	if ((iso_only ?
 	     volume_id_probe_iso9660(vid, 0) :
 	     volume_id_probe_all(vid, 0, size)
 	    ) != 0
 	) {
 		goto ret;
 	}
 #else
 	if (volume_id_probe_all(vid, 0, size) != 0) {
 		goto ret;
 	}
 #endif

 	if (vid->label[0] != '\0' || vid->uuid[0] != '\0') {
 		*label = xstrndup(vid->label, sizeof(vid->label));
 		*uuid  = xstrndup(vid->uuid, sizeof(vid->uuid));
 		dbg("found label '%s', uuid '%s' on %s", *label, *uuid, device);
 		rv = 0;
 	}
  ret:
 	free_volume_id(vid);
 	return rv;
 }

 /* NB: we take ownership of (malloc'ed) label and uuid */
 static void
 uuidcache_addentry(char *device, /*int major, int minor,*/ char *label, char *uuid)
 {
 	struct uuidCache_s *last;

 	if (!uuidCache) {
 		last = uuidCache = xzalloc(sizeof(*uuidCache));
 	} else {
 		for (last = uuidCache; last->next; last = last->next)
 			continue;
 		last->next = xzalloc(sizeof(*uuidCache));
 		last = last->next;
 	}
 	/*last->next = NULL; - xzalloc did it*/
 //	last->major = major;
 //	last->minor = minor;
 	last->device = device;
 	last->label = label;
 	last->uc_uuid = uuid;
 }

 /* If get_label_uuid() on device_name returns success,
  * add a cache entry for this device.
  * If device node does not exist, it will be temporarily created. */
 #if !ENABLE_FEATURE_VOLUMEID_ISO9660
 #define uuidcache_check_device(device_name, ma, mi, iso_only) \
 	uuidcache_check_device(device_name, ma, mi)
 #endif
 static void
 uuidcache_check_device(const char *device_name, int ma, int mi, int iso_only)
 {
 	char *device, *last_slash;
 	char *uuid, *label;
 	char *ptr;
 	int must_remove = 0;
 	int added = 0;

 	last_slash = NULL;
 	device = xasprintf("/dev/%s", device_name);
 	if (access(device, F_OK) != 0) {
 		/* device does not exist, temporarily create */
 		int slash_cnt = 0;

 		if ((ma | mi) < 0)
 			goto ret; /* we don't know major:minor! */

 		ptr = device;
 		while (*ptr)
 			if (*ptr++ == '/')
 				slash_cnt++;
 		if (slash_cnt > 2) {
 // BUG: handles only slash_cnt == 3 case
 			last_slash = strrchr(device, '/');
 			*last_slash = '\0';
 			if (mkdir(device, 0644)) {
 				bb_perror_msg("can't create directory %s", device);
 				*last_slash = '/';
 				last_slash = NULL; /* prevents rmdir */
 			} else {
 				*last_slash = '/';
 			}
 		}
 		mknod(device, S_IFBLK | 0600, makedev(ma, mi));
 		must_remove = 1;
 	}

 	uuid = NULL;
 	label = NULL;
 	if (get_label_uuid(device, &label, &uuid, iso_only) == 0) {
 		uuidcache_addentry(device, /*ma, mi,*/ label, uuid);
 		/* "device" is owned by cache now, don't free */
 		added = 1;
 	}

 	if (must_remove)
 		unlink(device);
 	if (last_slash) {
 		*last_slash = '\0';
 		rmdir(device);
 	}
  ret:
 	if (!added)
 		free(device);
 }

 /* Run uuidcache_check_device() for every device mentioned
  * in /proc/partitions */
 static void
 uuidcache_init_partitions(void)
 {
 	char line[100];
 	int ma, mi;
 	unsigned long long sz;
 	FILE *procpt;
 	int firstPass;
 	int handleOnFirst;
 	char *chptr;

 	procpt = xfopen("/proc/partitions", "r");
 /*
 # cat /proc/partitions
 major minor  #blocks  name

    8     0  293036184 sda
    8     1    6835626 sda1
    8     2          1 sda2
    8     5     979933 sda5
    8     6   15623181 sda6
    8     7   97659103 sda7
    8     8  171935631 sda8
 */
 	for (firstPass = 1; firstPass >= 0; firstPass--) {
 		fseek(procpt, 0, SEEK_SET);

 		while (fgets(line, sizeof(line), procpt)) {
 			/* The original version of this code used sscanf, but
 			   diet's sscanf is quite limited */
 			chptr = line;
 			if (*chptr != ' ') continue;
 			chptr = skip_whitespace(chptr);

 			ma = bb_strtou(chptr, &chptr, 0);
 			if (ma < 0) continue;
 			chptr = skip_whitespace(chptr);

 			mi = bb_strtou(chptr, &chptr, 0);
 			if (mi < 0) continue;
 			chptr = skip_whitespace(chptr);

 			sz = bb_strtoull(chptr, &chptr, 0);
 			if ((long long)sz == -1LL) continue;
 			chptr = skip_whitespace(chptr);

 			/* skip extended partitions (heuristic: size 1) */
 			if (sz == 1)
 				continue;

 			*strchrnul(chptr, '\n') = '\0';
 			/* now chptr => device name */
 			dbg("/proc/partitions: maj:%d min:%d sz:%llu name:'%s'",
 						ma, mi, sz, chptr);
 			if (!chptr[0])
 				continue;

 			/* look only at md devices on first pass */
 			handleOnFirst = (chptr[0] == 'm' && chptr[1] == 'd');
 			if (firstPass != handleOnFirst)
 				continue;

 			/* heuristic: partition name ends in a digit */
 			if (isdigit(chptr[strlen(chptr) - 1])) {
 				uuidcache_check_device(chptr, ma, mi, 0);
 			}
 		}
 	}

 	fclose(procpt);
 }

 static void
 dev_get_major_minor(char *device_name, int *major, int *minor)
 {
 	char dev[16];
 	char *dev_path;
 	char *colon;
 	int sz;

 	dev_path = xasprintf("/sys/block/%s/dev", device_name);
 	sz = open_read_close(dev_path, dev, sizeof(dev) - 1);
 	if (sz < 0)
 		goto ret;
 	dev[sz] = '\0';

 	colon = strchr(dev, ':');
 	if (!colon)
 		goto ret;
 	*major = bb_strtou(dev, NULL, 10);
 	*minor = bb_strtou(colon + 1, NULL, 10);

  ret:
 	free(dev_path);
 	return;
 }

 static void
 uuidcache_init_cdroms(void)
 {
 #define PROC_CDROMS "/proc/sys/dev/cdrom/info"
 	char line[100];
 	int ma, mi;
 	FILE *proccd;

 	proccd = fopen(PROC_CDROMS, "r");
 	if (!proccd) {
 //		static smallint warn = 0;
 //		if (!warn) {
 //			warn = 1;
 //			bb_error_msg("can't open %s, UUID and LABEL "
 //				"conversion cannot be done for CD-Roms",
 //				PROC_CDROMS);
 //		}
 		return;
 	}

 	while (fgets(line, sizeof(line), proccd)) {
 		static const char drive_name_string[] ALIGN1 = "drive name:";

 		if (strncmp(line, drive_name_string, sizeof(drive_name_string) - 1) == 0) {
 			char *device_name;

 			device_name = strtok(skip_whitespace(line + sizeof(drive_name_string) - 1), " \t\n");
 			while (device_name && device_name[0]) {
 				ma = mi = -1;
 				dev_get_major_minor(device_name, &ma, &mi);
 				uuidcache_check_device(device_name, ma, mi, 1);
 				device_name = strtok(NULL, " \t\n");
 			}
 			break;
 		}
 	}

 	fclose(proccd);
 }

 static void
 uuidcache_init(void)
 {
 	if (uuidCache)
 		return;

 	uuidcache_init_partitions();
 	uuidcache_init_cdroms();
 }

 #define UUID   1
 #define VOL    2

 #ifdef UNUSED
 static char *
 get_spec_by_x(int n, const char *t, int *majorPtr, int *minorPtr)
 {
 	struct uuidCache_s *uc;

 	uuidcache_init();
 	uc = uuidCache;

 	while (uc) {
 		switch (n) {
 		case UUID:
 			if (strcmp(t, uc->uc_uuid) == 0) {
 				*majorPtr = uc->major;
 				*minorPtr = uc->minor;
 				return uc->device;
 			}
 			break;
 		case VOL:
 			if (strcmp(t, uc->label) == 0) {
 				*majorPtr = uc->major;
 				*minorPtr = uc->minor;
 				return uc->device;
 			}
 			break;
 		}
 		uc = uc->next;
 	}
 	return NULL;
 }

 static unsigned char
 fromhex(char c)
 {
 	if (isdigit(c))
 		return (c - '0');
 	return ((c|0x20) - 'a' + 10);
 }

 static char *
 get_spec_by_uuid(const char *s, int *major, int *minor)
 {
 	unsigned char uuid[16];
 	int i;

 	if (strlen(s) != 36 || s[8] != '-' || s[13] != '-'
 	 || s[18] != '-' || s[23] != '-'
 	) {
 		goto bad_uuid;
 	}
 	for (i = 0; i < 16; i++) {
 		if (*s == '-')
 			s++;
 		if (!isxdigit(s[0]) || !isxdigit(s[1]))
 			goto bad_uuid;
 		uuid[i] = ((fromhex(s[0]) << 4) | fromhex(s[1]));
 		s += 2;
 	}
 	return get_spec_by_x(UUID, (char *)uuid, major, minor);

  bad_uuid:
 	fprintf(stderr, _("mount: bad UUID"));
 	return 0;
 }

 static char *
 get_spec_by_volume_label(const char *s, int *major, int *minor)
 {
 	return get_spec_by_x(VOL, s, major, minor);
 }

 static int display_uuid_cache(void)
 {
 	struct uuidCache_s *u;
 	size_t i;

 	uuidcache_init();

 	u = uuidCache;
 	while (u) {
 		printf("%s %s %s\n", u->device, u->label, u->uc_uuid);
 		u = u->next;
 	}

 	return 0;
 }
 #endif // UNUSED


 /* Used by mount and findfs */

 char *get_devname_from_label(const char *spec)
 {
 	struct uuidCache_s *uc;
 	int spec_len = strlen(spec);

 	uuidcache_init();
 	uc = uuidCache;
 	while (uc) {
 // FIXME: empty label ("LABEL=") matches anything??!
 		if (uc->label[0] && strncmp(spec, uc->label, spec_len) == 0) {
 			return xstrdup(uc->device);
 		}
 		uc = uc->next;
 	}
 	return NULL;
 }

 char *get_devname_from_uuid(const char *spec)
 {
 	struct uuidCache_s *uc;

 	uuidcache_init();
 	uc = uuidCache;
 	while (uc) {
 		/* case of hex numbers doesn't matter */
 		if (strcasecmp(spec, uc->uc_uuid) == 0) {
 			return xstrdup(uc->device);
 		}
 		uc = uc->next;
 	}
 	return NULL;
 }
	/* vi: set sw=4 ts=4: */
	/*
	* Support functions for mounting devices by label/uuid
	*
	* Copyright (C) 2006 by Jason Schoon <floydpink@gmail.com>
	* Some portions cribbed from e2fsprogs, util-linux, dosfstools
	*
	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
	*/

	#include "volume_id_internal.h"

	//#define BLKGETSIZE64 _IOR(0x12,114,size_t)

	static struct uuidCache_s {
	struct uuidCache_s *next;
	// int major, minor;
	char *device;
	char *label;
	char uc_uuid; / prefix makes it easier to grep for */
	} *uuidCache;

	/* Returns !0 on error.
	* Otherwise, returns malloc'ed strings for label and uuid
	* (and they can't be NULL, although they can be "") */
	#if !ENABLE_FEATURE_VOLUMEID_ISO9660
	#define get_label_uuid(device, label, uuid, iso_only) \
	get_label_uuid(device, label, uuid)
	#endif
	static int
	get_label_uuid(const char device, char label, char *uuid, int iso_only)
	{
	int rv = 1;
	uint64_t size;
	struct volume_id *vid;

	vid = volume_id_open_node(device);
	if (!vid)
	return rv;

	if (ioctl(vid->fd, BLKGETSIZE64, &size) != 0)
	size = 0;

	#if ENABLE_FEATURE_VOLUMEID_ISO9660
	if ((iso_only ?
	volume_id_probe_iso9660(vid, 0) :
	volume_id_probe_all(vid, 0, size)
	) != 0
	) {
	goto ret;
	}
	#else
	if (volume_id_probe_all(vid, 0, size) != 0) {
	goto ret;
	}
	#endif

	if (vid->label[0] != '\0' \|\| vid->uuid[0] != '\0') {
	*label = xstrndup(vid->label, sizeof(vid->label));
	*uuid = xstrndup(vid->uuid, sizeof(vid->uuid));
	dbg("found label '%s', uuid '%s' on %s", label, uuid, device);
	rv = 0;
	}
	ret:
	free_volume_id(vid);
	return rv;
	}

	/* NB: we take ownership of (malloc'ed) label and uuid */
	static void
	uuidcache_addentry(char device, /int major, int minor,/ char label, char *uuid)
	{
	struct uuidCache_s *last;

	if (!uuidCache) {
	last = uuidCache = xzalloc(sizeof(*uuidCache));
	} else {
	for (last = uuidCache; last->next; last = last->next)
	continue;
	last->next = xzalloc(sizeof(*uuidCache));
	last = last->next;
	}
	/last->next = NULL; - xzalloc did it/
	// last->major = major;
	// last->minor = minor;
	last->device = device;
	last->label = label;
	last->uc_uuid = uuid;
	}

	/* If get_label_uuid() on device_name returns success,
	* add a cache entry for this device.
	* If device node does not exist, it will be temporarily created. */
	#if !ENABLE_FEATURE_VOLUMEID_ISO9660
	#define uuidcache_check_device(device_name, ma, mi, iso_only) \
	uuidcache_check_device(device_name, ma, mi)
	#endif
	static void
	uuidcache_check_device(const char *device_name, int ma, int mi, int iso_only)
	{
	char device, last_slash;
	char uuid, label;
	char *ptr;
	int must_remove = 0;
	int added = 0;

	last_slash = NULL;
	device = xasprintf("/dev/%s", device_name);
	if (access(device, F_OK) != 0) {
	/* device does not exist, temporarily create */
	int slash_cnt = 0;

	if ((ma \| mi) < 0)
	goto ret; /* we don't know major:minor! */

	ptr = device;
	while (*ptr)
	if (*ptr++ == '/')
	slash_cnt++;
	if (slash_cnt > 2) {
	// BUG: handles only slash_cnt == 3 case
	last_slash = strrchr(device, '/');
	*last_slash = '\0';
	if (mkdir(device, 0644)) {
	bb_perror_msg("can't create directory %s", device);
	*last_slash = '/';
	last_slash = NULL; /* prevents rmdir */
	} else {
	*last_slash = '/';
	}
	}
	mknod(device, S_IFBLK \| 0600, makedev(ma, mi));
	must_remove = 1;
	}

	uuid = NULL;
	label = NULL;
	if (get_label_uuid(device, &label, &uuid, iso_only) == 0) {
	uuidcache_addentry(device, /ma, mi,/ label, uuid);
	/* "device" is owned by cache now, don't free */
	added = 1;
	}

	if (must_remove)
	unlink(device);
	if (last_slash) {
	*last_slash = '\0';
	rmdir(device);
	}
	ret:
	if (!added)
	free(device);
	}

	/* Run uuidcache_check_device() for every device mentioned
	* in /proc/partitions */
	static void
	uuidcache_init_partitions(void)
	{
	char line[100];
	int ma, mi;
	unsigned long long sz;
	FILE *procpt;
	int firstPass;
	int handleOnFirst;
	char *chptr;

	procpt = xfopen("/proc/partitions", "r");
	/*
	# cat /proc/partitions
	major minor #blocks name

	8 0 293036184 sda
	8 1 6835626 sda1
	8 2 1 sda2
	8 5 979933 sda5
	8 6 15623181 sda6
	8 7 97659103 sda7
	8 8 171935631 sda8
	*/
	for (firstPass = 1; firstPass >= 0; firstPass--) {
	fseek(procpt, 0, SEEK_SET);

	while (fgets(line, sizeof(line), procpt)) {
	/* The original version of this code used sscanf, but
	diet's sscanf is quite limited */
	chptr = line;
	if (*chptr != ' ') continue;
	chptr = skip_whitespace(chptr);

	ma = bb_strtou(chptr, &chptr, 0);
	if (ma < 0) continue;
	chptr = skip_whitespace(chptr);

	mi = bb_strtou(chptr, &chptr, 0);
	if (mi < 0) continue;
	chptr = skip_whitespace(chptr);

	sz = bb_strtoull(chptr, &chptr, 0);
	if ((long long)sz == -1LL) continue;
	chptr = skip_whitespace(chptr);

	/* skip extended partitions (heuristic: size 1) */
	if (sz == 1)
	continue;

	*strchrnul(chptr, '\n') = '\0';
	/* now chptr => device name */
	dbg("/proc/partitions: maj:%d min:%d sz:%llu name:'%s'",
	ma, mi, sz, chptr);
	if (!chptr[0])
	continue;

	/* look only at md devices on first pass */
	handleOnFirst = (chptr[0] == 'm' && chptr[1] == 'd');
	if (firstPass != handleOnFirst)
	continue;

	/* heuristic: partition name ends in a digit */
	if (isdigit(chptr[strlen(chptr) - 1])) {
	uuidcache_check_device(chptr, ma, mi, 0);
	}
	}
	}

	fclose(procpt);
	}

	static void
	dev_get_major_minor(char device_name, int major, int *minor)
	{
	char dev[16];
	char *dev_path;
	char *colon;
	int sz;

	dev_path = xasprintf("/sys/block/%s/dev", device_name);
	sz = open_read_close(dev_path, dev, sizeof(dev) - 1);
	if (sz < 0)
	goto ret;
	dev[sz] = '\0';

	colon = strchr(dev, ':');
	if (!colon)
	goto ret;
	*major = bb_strtou(dev, NULL, 10);
	*minor = bb_strtou(colon + 1, NULL, 10);

	ret:
	free(dev_path);
	return;
	}

	static void
	uuidcache_init_cdroms(void)
	{
	#define PROC_CDROMS "/proc/sys/dev/cdrom/info"
	char line[100];
	int ma, mi;
	FILE *proccd;

	proccd = fopen(PROC_CDROMS, "r");
	if (!proccd) {
	// static smallint warn = 0;
	// if (!warn) {
	// warn = 1;
	// bb_error_msg("can't open %s, UUID and LABEL "
	// "conversion cannot be done for CD-Roms",
	// PROC_CDROMS);
	// }
	return;
	}

	while (fgets(line, sizeof(line), proccd)) {
	static const char drive_name_string[] ALIGN1 = "drive name:";

	if (strncmp(line, drive_name_string, sizeof(drive_name_string) - 1) == 0) {
	char *device_name;

	device_name = strtok(skip_whitespace(line + sizeof(drive_name_string) - 1), " \t\n");
	while (device_name && device_name[0]) {
	ma = mi = -1;
	dev_get_major_minor(device_name, &ma, &mi);
	uuidcache_check_device(device_name, ma, mi, 1);
	device_name = strtok(NULL, " \t\n");
	}
	break;
	}
	}

	fclose(proccd);
	}

	static void
	uuidcache_init(void)
	{
	if (uuidCache)
	return;

	uuidcache_init_partitions();
	uuidcache_init_cdroms();
	}

	#define UUID 1
	#define VOL 2

	#ifdef UNUSED
	static char *
	get_spec_by_x(int n, const char t, int majorPtr, int *minorPtr)
	{
	struct uuidCache_s *uc;

	uuidcache_init();
	uc = uuidCache;

	while (uc) {
	switch (n) {
	case UUID:
	if (strcmp(t, uc->uc_uuid) == 0) {
	*majorPtr = uc->major;
	*minorPtr = uc->minor;
	return uc->device;
	}
	break;
	case VOL:
	if (strcmp(t, uc->label) == 0) {
	*majorPtr = uc->major;
	*minorPtr = uc->minor;
	return uc->device;
	}
	break;
	}
	uc = uc->next;
	}
	return NULL;
	}

	static unsigned char
	fromhex(char c)
	{
	if (isdigit(c))
	return (c - '0');
	return ((c\|0x20) - 'a' + 10);
	}

	static char *
	get_spec_by_uuid(const char s, int major, int *minor)
	{
	unsigned char uuid[16];
	int i;

	if (strlen(s) != 36 \|\| s[8] != '-' \|\| s[13] != '-'
	\|\| s[18] != '-' \|\| s[23] != '-'
	) {
	goto bad_uuid;
	}
	for (i = 0; i < 16; i++) {
	if (*s == '-')
	s++;
	if (!isxdigit(s[0]) \|\| !isxdigit(s[1]))
	goto bad_uuid;
	uuid[i] = ((fromhex(s[0]) << 4) \| fromhex(s[1]));
	s += 2;
	}
	return get_spec_by_x(UUID, (char *)uuid, major, minor);

	bad_uuid:
	fprintf(stderr, _("mount: bad UUID"));
	return 0;
	}

	static char *
	get_spec_by_volume_label(const char s, int major, int *minor)
	{
	return get_spec_by_x(VOL, s, major, minor);
	}

	static int display_uuid_cache(void)
	{
	struct uuidCache_s *u;
	size_t i;

	uuidcache_init();

	u = uuidCache;
	while (u) {
	printf("%s %s %s\n", u->device, u->label, u->uc_uuid);
	u = u->next;
	}

	return 0;
	}
	#endif // UNUSED


	/* Used by mount and findfs */

	char get_devname_from_label(const char spec)
	{
	struct uuidCache_s *uc;
	int spec_len = strlen(spec);

	uuidcache_init();
	uc = uuidCache;
	while (uc) {
	// FIXME: empty label ("LABEL=") matches anything??!
	if (uc->label[0] && strncmp(spec, uc->label, spec_len) == 0) {
	return xstrdup(uc->device);
	}
	uc = uc->next;
	}
	return NULL;
	}

	char get_devname_from_uuid(const char spec)
	{
	struct uuidCache_s *uc;

	uuidcache_init();
	uc = uuidCache;
	while (uc) {
	/* case of hex numbers doesn't matter */
	if (strcasecmp(spec, uc->uc_uuid) == 0) {
	return xstrdup(uc->device);
	}
	uc = uc->next;
	}
	return NULL;
	}