+/*
+ * mount_by_label.c - aeb
+ *
+ * 1999-02-22 Arkadiusz Mi¶kiewicz <misiek@misiek.eu.org>
+ * - added Native Language Support
+ * 2000-01-20 James Antill <james@and.org>
+ * - Added error message if /proc/partitions cannot be opened
+ * 2000-05-09 Erik Troan <ewt@redhat.com>
+ * - Added cache for UUID and disk labels
+ * Wed Aug 16 2000 Erik Troan <ewt@redhat.com>
+ * - Ported to dump/restore
+ */
+
+#include <stdio.h>
+#include <sys/param.h>
+#include <string.h>
+#include <ctype.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <linux/ext2_fs.h>
+#include <ext2fs/ext2fs.h>
+#include "bylabel.h"
+
+#define PROC_PARTITIONS "/proc/partitions"
+#define DEVLABELDIR "/dev"
+
+void msg __P((const char *fmt, ...));
+
+static struct uuidCache_s {
+ struct uuidCache_s *next;
+ char uuid[16];
+ char *label;
+ char *device;
+} *uuidCache = NULL;
+
+/* for now, only ext2 is supported */
+static int
+get_label_uuid(const char *device, char **label, char *uuid) {
+
+ /* start with a test for ext2, taken from mount_guess_fstype */
+ /* should merge these later */
+ int fd;
+ struct ext2_super_block e2sb;
+
+ fd = open(device, O_RDONLY);
+ if (fd < 0)
+ return 1;
+
+ if (lseek(fd, 1024, SEEK_SET) != 1024
+ || read(fd, (char *) &e2sb, sizeof(e2sb)) != sizeof(e2sb)
+ || (e2sb.s_magic != EXT2_SUPER_MAGIC)) {
+ close(fd);
+ return 1;
+ }
+
+ close(fd);
+
+ /* superblock is ext2 - now what is its label? */
+ memcpy(uuid, e2sb.s_uuid, sizeof(e2sb.s_uuid));
+ *label = strdup(e2sb.s_volume_name);
+
+ return 0;
+}
+
+static void
+uuidcache_addentry(char *device, char *label, char *uuid) {
+ struct uuidCache_s *last;
+
+ if (!uuidCache) {
+ last = uuidCache = malloc(sizeof(*uuidCache));
+ } else {
+ for (last = uuidCache; last->next; last = last->next) ;
+ last->next = malloc(sizeof(*uuidCache));
+ last = last->next;
+ }
+ last->next = NULL;
+ last->device = device;
+ last->label = label;
+ memcpy(last->uuid, uuid, sizeof(last->uuid));
+}
+
+static void
+uuidcache_init(void) {
+ char line[100];
+ char *s;
+ int ma, mi, sz;
+ static char ptname[100];
+ FILE *procpt;
+ char uuid[16], *label;
+ char device[110];
+ int firstPass;
+ int handleOnFirst;
+
+ if (uuidCache)
+ return;
+
+ procpt = fopen(PROC_PARTITIONS, "r");
+ if (!procpt)
+ return;
+
+ for (firstPass = 1; firstPass >= 0; firstPass--) {
+ fseek(procpt, 0, SEEK_SET);
+
+ while (fgets(line, sizeof(line), procpt)) {
+ if (sscanf (line, " %d %d %d %[^\n ]",
+ &ma, &mi, &sz, ptname) != 4)
+ continue;
+
+ /* skip extended partitions (heuristic: size 1) */
+ if (sz == 1)
+ continue;
+
+ /* look only at md devices on first pass */
+ handleOnFirst = !strncmp(ptname, "md", 2);
+ if (firstPass != handleOnFirst)
+ continue;
+
+ /* skip entire disk (minor 0, 64, ... on ide;
+ 0, 16, ... on sd) */
+ /* heuristic: partition name ends in a digit */
+
+ for(s = ptname; *s; s++);
+ if (isdigit(s[-1])) {
+ /*
+ * Note: this is a heuristic only - there is no reason
+ * why these devices should live in /dev.
+ * Perhaps this directory should be specifiable by option.
+ * One might for example have /devlabel with links to /dev
+ * for the devices that may be accessed in this way.
+ * (This is useful, if the cdrom on /dev/hdc must not
+ * be accessed.)
+ */
+ sprintf(device, "%s/%s", DEVLABELDIR, ptname);
+ if (!get_label_uuid(device, &label, uuid))
+ uuidcache_addentry(strdup(device), label, uuid);
+ }
+ }
+ }
+
+ fclose(procpt);
+}
+
+#define UUID 1
+#define VOL 2
+
+static char *
+get_spec_by_x(int n, const char *t) {
+ struct uuidCache_s *uc;
+
+ uuidcache_init();
+ uc = uuidCache;
+
+ while(uc) {
+ switch (n) {
+ case UUID:
+ if (!memcmp(t, uc->uuid, sizeof(uc->uuid)))
+ return strdup(uc->device);
+ break;
+ case VOL:
+ if (!strcmp(t, uc->label))
+ return strdup(uc->device);
+ break;
+ }
+ uc = uc->next;
+ }
+ return NULL;
+}
+
+static u_char
+fromhex(char c) {
+ if (isdigit(c))
+ return (c - '0');
+ else if (islower(c))
+ return (c - 'a' + 10);
+ else
+ return (c - 'A' + 10);
+}
+
+static char *
+get_spec_by_uuid(const char *s) {
+ u_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, uuid);
+
+ bad_uuid:
+ msg("mount: bad UUID\n");
+ return NULL; /* just for gcc */
+}
+
+static char *
+get_spec_by_volume_label(const char *s) {
+ return get_spec_by_x(VOL, s);
+}
+
+const char *
+get_device_name(const char * item) {
+ const char * rc;
+
+ if (!strncmp(item, "UUID=", 5)) {
+ rc = get_spec_by_uuid(item+5);
+ }
+ else
+ if (!strncmp(item, "LABEL=", 6)) {
+ rc = get_spec_by_volume_label(item+6);
+ }
+ else {
+ rc = item;
+ }
+
+ return rc;
+}
git.wh0rd.org / dump.git / commitdiff
