util-linux/volume_id/get_devname.c - codeaurora/busybox - Gitiles

 /* 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)

 #define PROC_PARTITIONS "/proc/partitions"
 #define PROC_CDROMS	"/proc/sys/dev/cdrom/info"
 #define DEVLABELDIR	"/dev"
 #define SYS_BLOCK	"/sys/block"

 static struct uuidCache_s {
 	struct uuidCache_s *next;
 	char uuid[16];
 	char *device;
 	char *label;
 	int major, minor;
 } *uuidCache;

 /* for now, only ext2, ext3 and xfs are supported */
 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 (ioctl(vid->fd, BLKGETSIZE64, &size) != 0) {
 		size = 0;
 	}

 #if ENABLE_FEATURE_VOLUMEID_ISO9660
 	if (iso_only ?
 	    volume_id_probe_iso9660(vid, 0) != 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') {
 		*label = xstrndup(vid->label, sizeof(vid->label));
 		*uuid  = xstrndup(vid->uuid, sizeof(vid->uuid));
 		printf("Found label %s on %s (uuid:%s)\n", *label, device, *uuid);
 		rv = 0;
 	}
  ret:
 	free_volume_id(vid);
 	return rv;
 }

 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->label = label;
 	last->device = device;
 	last->major = major;
 	last->minor = minor;
 	memcpy(last->uuid, uuid, sizeof(last->uuid));
 }

 static void
 uuidcache_check_device(const char *device_name, int ma, int mi, int iso_only)
 {
 	char device[110];
 	char *uuid = NULL, *label = NULL;
 	char *ptr;
 	char *deviceDir = NULL;
 	int mustRemove = 0;
 	int mustRemoveDir = 0;
 	int i;

 	sprintf(device, "%s/%s", DEVLABELDIR, device_name);
 	if (access(device, F_OK)) {
 		ptr = device;
 		i = 0;
 		while (*ptr)
 			if (*ptr++ == '/')
 				i++;
 		if (i > 2) {
 			deviceDir = alloca(strlen(device) + 1);
 			strcpy(deviceDir, device);
 			ptr = deviceDir + (strlen(device) - 1);
 			while (*ptr != '/')
 				*ptr-- = '\0';
 			if (mkdir(deviceDir, 0644)) {
 				printf("mkdir: cannot create directory %s: %d\n", deviceDir, errno);
 			} else {
 				mustRemoveDir = 1;
 			}
 		}

 		mknod(device, S_IFBLK | 0600, makedev(ma, mi));
 		mustRemove = 1;
 	}
 	if (!get_label_uuid(device, &label, &uuid, iso_only))
 		uuidcache_addentry(strdup(device), ma, mi,
 				   label, uuid);

 	if (mustRemove) unlink(device);
 	if (mustRemoveDir) rmdir(deviceDir);
 }

 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++;

 			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 */
 			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 int
 dev_get_major_minor(char *device_name, int *major, int *minor)
 {
 	char * dev_path;
 	int fd;
 	char dev[7];
 	char *major_ptr, *minor_ptr;

 	dev_path = alloca(strlen(SYS_BLOCK) + strlen(device_name) + 6);
 	sprintf(dev_path, "%s/%s/dev", SYS_BLOCK, device_name);

 	fd = open(dev_path, O_RDONLY);
 	if (fd < 0) return 1;
 	full_read(fd, dev, sizeof(dev));
 	close(fd);

 	major_ptr = dev;
 	minor_ptr = strchr(dev, ':');
 	if (!minor_ptr) return 1;
 	*minor_ptr++ = '\0';

 	*major = strtol(major_ptr, NULL, 10);
 	*minor = strtol(minor_ptr, NULL, 10);

 	return 0;
 }

 static void
 uuidcache_init_cdroms(void)
 {
 	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("mount: could not open %s, so UUID and LABEL "
 				"conversion cannot be done for CD-Roms.",
 				PROC_CDROMS);
 		}
 		return;
 	}

 	while (fgets(line, sizeof(line), proccd)) {
 		const char *drive_name_string = "drive name:\t\t";
 		if (!strncmp(line, drive_name_string, strlen(drive_name_string))) {
 			char *device_name;
 			device_name = strtok(line + strlen(drive_name_string), "\t\n");
 			while (device_name) {
 				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 (!memcmp(t, uc->uuid, sizeof(uc->uuid))) {
 				*majorPtr = uc->major;
 				*minorPtr = uc->minor;
 				return uc->device;
 			}
 			break;
 		case VOL:
 			if (!strcmp(t, uc->label)) {
 				*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');
 	if (islower(c))
 		return (c - 'a' + 10);
 	return (c - '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 ", u->device, u->label);
 		for (i = 0; i < sizeof(u->uuid); i++) {
 			if (i == 4 || i == 6 || i == 8 || i == 10)
 				printf("-");
 			printf("%x", u->uuid[i] & 0xff);
 		}
 		printf("\n");
 		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) {
 		if (uc->label && !strncmp(spec, uc->label, spec_len)) {
 			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) {
 		if (!memcmp(spec, uc->uuid, sizeof(uc->uuid))) {
 			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)

	#define PROC_PARTITIONS "/proc/partitions"
	#define PROC_CDROMS "/proc/sys/dev/cdrom/info"
	#define DEVLABELDIR "/dev"
	#define SYS_BLOCK "/sys/block"

	static struct uuidCache_s {
	struct uuidCache_s *next;
	char uuid[16];
	char *device;
	char *label;
	int major, minor;
	} *uuidCache;

	/* for now, only ext2, ext3 and xfs are supported */
	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 (ioctl(vid->fd, BLKGETSIZE64, &size) != 0) {
	size = 0;
	}

	#if ENABLE_FEATURE_VOLUMEID_ISO9660
	if (iso_only ?
	volume_id_probe_iso9660(vid, 0) != 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') {
	*label = xstrndup(vid->label, sizeof(vid->label));
	*uuid = xstrndup(vid->uuid, sizeof(vid->uuid));
	printf("Found label %s on %s (uuid:%s)\n", label, device, uuid);
	rv = 0;
	}
	ret:
	free_volume_id(vid);
	return rv;
	}

	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->label = label;
	last->device = device;
	last->major = major;
	last->minor = minor;
	memcpy(last->uuid, uuid, sizeof(last->uuid));
	}

	static void
	uuidcache_check_device(const char *device_name, int ma, int mi, int iso_only)
	{
	char device[110];
	char uuid = NULL, label = NULL;
	char *ptr;
	char *deviceDir = NULL;
	int mustRemove = 0;
	int mustRemoveDir = 0;
	int i;

	sprintf(device, "%s/%s", DEVLABELDIR, device_name);
	if (access(device, F_OK)) {
	ptr = device;
	i = 0;
	while (*ptr)
	if (*ptr++ == '/')
	i++;
	if (i > 2) {
	deviceDir = alloca(strlen(device) + 1);
	strcpy(deviceDir, device);
	ptr = deviceDir + (strlen(device) - 1);
	while (*ptr != '/')
	*ptr-- = '\0';
	if (mkdir(deviceDir, 0644)) {
	printf("mkdir: cannot create directory %s: %d\n", deviceDir, errno);
	} else {
	mustRemoveDir = 1;
	}
	}

	mknod(device, S_IFBLK \| 0600, makedev(ma, mi));
	mustRemove = 1;
	}
	if (!get_label_uuid(device, &label, &uuid, iso_only))
	uuidcache_addentry(strdup(device), ma, mi,
	label, uuid);

	if (mustRemove) unlink(device);
	if (mustRemoveDir) rmdir(deviceDir);
	}

	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++;

	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 */
	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 int
	dev_get_major_minor(char device_name, int major, int *minor)
	{
	char * dev_path;
	int fd;
	char dev[7];
	char major_ptr, minor_ptr;

	dev_path = alloca(strlen(SYS_BLOCK) + strlen(device_name) + 6);
	sprintf(dev_path, "%s/%s/dev", SYS_BLOCK, device_name);

	fd = open(dev_path, O_RDONLY);
	if (fd < 0) return 1;
	full_read(fd, dev, sizeof(dev));
	close(fd);

	major_ptr = dev;
	minor_ptr = strchr(dev, ':');
	if (!minor_ptr) return 1;
	*minor_ptr++ = '\0';

	*major = strtol(major_ptr, NULL, 10);
	*minor = strtol(minor_ptr, NULL, 10);

	return 0;
	}

	static void
	uuidcache_init_cdroms(void)
	{
	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("mount: could not open %s, so UUID and LABEL "
	"conversion cannot be done for CD-Roms.",
	PROC_CDROMS);
	}
	return;
	}

	while (fgets(line, sizeof(line), proccd)) {
	const char *drive_name_string = "drive name:\t\t";
	if (!strncmp(line, drive_name_string, strlen(drive_name_string))) {
	char *device_name;
	device_name = strtok(line + strlen(drive_name_string), "\t\n");
	while (device_name) {
	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 (!memcmp(t, uc->uuid, sizeof(uc->uuid))) {
	*majorPtr = uc->major;
	*minorPtr = uc->minor;
	return uc->device;
	}
	break;
	case VOL:
	if (!strcmp(t, uc->label)) {
	*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');
	if (islower(c))
	return (c - 'a' + 10);
	return (c - '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 ", u->device, u->label);
	for (i = 0; i < sizeof(u->uuid); i++) {
	if (i == 4 \|\| i == 6 \|\| i == 8 \|\| i == 10)
	printf("-");
	printf("%x", u->uuid[i] & 0xff);
	}
	printf("\n");
	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) {
	if (uc->label && !strncmp(spec, uc->label, spec_len)) {
	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) {
	if (!memcmp(spec, uc->uuid, sizeof(uc->uuid))) {
	return xstrdup(uc->device);
	}
	uc = uc->next;
	}
	return NULL;
	}