support for mount by label (not yet tested)

Also adds findfs applet. Closes bug 1143.

1 files changed, 399 insertions, 0 deletions

diff --git a/util-linux/volume_id/get_devname.c b/util-linux/volume_id/get_devname.c
new file mode 100644
index 0000000..75060b0
--- /dev/null
+++ b/util-linux/volume_id/get_devname.c
@@ -0,0 +1,399 @@
+/* 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;
+}