| /* |
| * get_device_by_label.h |
| * |
| * Copyright 1999 by Andries Brouwer |
| * Copyright 1999, 2000 by Theodore Ts'o |
| * |
| * This file may be redistributed under the terms of the GNU Public |
| * License. |
| * |
| * Taken from aeb's mount, 990619 |
| * Updated from aeb's mount, 20000725 |
| * Added call to ext2fs_find_block_device, so that we can find devices |
| * even if devfs (ugh) is compiled in, but not mounted, since |
| * this messes up /proc/partitions, by TYT. |
| */ |
| |
| #include <stdio.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <ctype.h> |
| #include <fcntl.h> |
| #include <unistd.h> |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #ifdef HAVE_SYS_MKDEV_H |
| #include <sys/mkdev.h> |
| #endif |
| #ifdef HAVE_SYS_SYSMACROS_H |
| #include <sys/sysmacros.h> |
| #endif |
| #include "nls-enable.h" |
| #include "get_device_by_label.h" |
| #include "fsck.h" |
| |
| /* function prototype from libext2 */ |
| extern char *ext2fs_find_block_device(dev_t device); |
| |
| #define PROC_PARTITIONS "/proc/partitions" |
| #define DEVLABELDIR "/dev" |
| |
| #define EXT2_SUPER_MAGIC 0xEF53 |
| struct ext2_super_block { |
| unsigned char s_dummy1[56]; |
| unsigned char s_magic[2]; |
| unsigned char s_dummy2[46]; |
| unsigned char s_uuid[16]; |
| unsigned char s_volume_name[16]; |
| }; |
| #define ext2magic(s) ((unsigned int) s.s_magic[0] + (((unsigned int) s.s_magic[1]) << 8)) |
| |
| 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) |
| || (ext2magic(e2sb) != 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 = calloc(sizeof(e2sb.s_volume_name) + 1, 1); |
| memcpy(*label, e2sb.s_volume_name, sizeof(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, *devname; |
| char device[110]; |
| dev_t dev; |
| struct stat statbuf; |
| 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])) { |
| /* |
| * We first look in /dev for the device, but |
| * if we don't find it, or if the stat |
| * information doesn't check out, we use |
| * ext2fs_find_block_device to find it. |
| */ |
| sprintf(device, "%s/%s", DEVLABELDIR, ptname); |
| dev = makedev(ma, mi); |
| if ((stat(device, &statbuf) < 0) || |
| (statbuf.st_rdev != dev)) { |
| devname = ext2fs_find_block_device(dev); |
| } else |
| devname = string_copy(device); |
| if (!devname) |
| continue; |
| if (!get_label_uuid(devname, &label, uuid)) |
| uuidcache_addentry(devname, label, uuid); |
| else |
| free(devname); |
| } |
| } |
| } |
| |
| 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 string_copy(uc->device); |
| break; |
| case VOL: |
| if (!strcmp(t, uc->label)) |
| return string_copy(uc->device); |
| break; |
| } |
| uc = uc->next; |
| } |
| return NULL; |
| } |
| |
| static char fromhex(char c) |
| { |
| if (isdigit(c)) |
| return (c - '0'); |
| else if (islower(c)) |
| return (c - 'a' + 10); |
| else |
| return (c - 'A' + 10); |
| } |
| |
| char * |
| get_spec_by_uuid(const char *s) |
| { |
| 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: |
| fprintf(stderr, _("WARNING: %s: bad UUID"), s); |
| return NULL; |
| } |
| |
| char * |
| get_spec_by_volume_label(const char *s) { |
| return get_spec_by_x(VOL, s); |
| } |
| |
| const char * |
| get_volume_label_by_spec(const char *spec) { |
| struct uuidCache_s *uc; |
| |
| uuidcache_init(); |
| uc = uuidCache; |
| |
| while(uc) { |
| if (!strcmp(spec, uc->device)) |
| return uc->label; |
| uc = uc->next; |
| } |
| return NULL; |
| } |