| /* |
| * 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 |
| */ |
| |
| #include <stdio.h> |
| #include <string.h> |
| #include <ctype.h> |
| #include <fcntl.h> |
| #include <unistd.h> |
| #include "sundries.h" /* for xstrdup */ |
| #include "linux_fs.h" |
| #include "mount_by_label.h" |
| #include "nls.h" |
| |
| #define PROC_PARTITIONS "/proc/partitions" |
| #define DEVLABELDIR "/dev" |
| |
| 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 = 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 xstrdup(uc->device); |
| break; |
| case VOL: |
| if (!strcmp(t, uc->label)) |
| return xstrdup(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); |
| } |
| |
| 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: |
| die(EX_USAGE, _("mount: bad UUID")); |
| return NULL; /* just for gcc */ |
| } |
| |
| 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; |
| } |