diff options
Diffstat (limited to 'util-linux/volume_id/get_devname.c')
| -rw-r--r-- | util-linux/volume_id/get_devname.c | 254 |
1 files changed, 254 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..d82808f --- /dev/null +++ b/util-linux/volume_id/get_devname.c @@ -0,0 +1,254 @@ +/* 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) + +static struct uuidCache_s { + struct uuidCache_s *next; +// int major, minor; + char *device; + char *label; + char *uc_uuid; /* prefix makes it easier to grep for */ +} *uuidCache; + +/* Returns !0 on error. + * Otherwise, returns malloc'ed strings for label and uuid + * (and they can't be NULL, although they can be ""). + * NB: closes fd. */ +static int +get_label_uuid(int fd, char **label, char **uuid) +{ + int rv = 1; + uint64_t size; + struct volume_id *vid; + + /* fd is owned by vid now */ + vid = volume_id_open_node(fd); + + if (ioctl(/*vid->*/fd, BLKGETSIZE64, &size) != 0) + size = 0; + + if (volume_id_probe_all(vid, 0, size) != 0) + goto ret; + + if (vid->label[0] != '\0' || vid->uuid[0] != '\0') { + *label = xstrndup(vid->label, sizeof(vid->label)); + *uuid = xstrndup(vid->uuid, sizeof(vid->uuid)); + dbg("found label '%s', uuid '%s' on %s", *label, *uuid, device); + rv = 0; + } + ret: + free_volume_id(vid); /* also closes fd */ + return rv; +} + +/* NB: we take ownership of (malloc'ed) label and uuid */ +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->major = major; +// last->minor = minor; + last->device = device; + last->label = label; + last->uc_uuid = uuid; +} + +/* If get_label_uuid() on device_name returns success, + * add a cache entry for this device. + * If device node does not exist, it will be temporarily created. */ +static int FAST_FUNC +uuidcache_check_device(const char *device, + struct stat *statbuf, + void *userData UNUSED_PARAM, + int depth UNUSED_PARAM) +{ + char *uuid = uuid; /* for compiler */ + char *label = label; + int fd; + + if (!S_ISBLK(statbuf->st_mode)) + return TRUE; + + fd = open(device, O_RDONLY); + if (fd < 0) + return TRUE; + + /* get_label_uuid() closes fd in all cases (success & failure) */ + if (get_label_uuid(fd, &label, &uuid) == 0) { + /* uuidcache_addentry() takes ownership of all three params */ + uuidcache_addentry(xstrdup(device), /*ma, mi,*/ label, uuid); + } + return TRUE; +} + +static void +uuidcache_init(void) +{ + if (uuidCache) + return; + + /* We were scanning /proc/partitions + * and /proc/sys/dev/cdrom/info here. + * Missed volume managers. I see that "standard" blkid uses these: + * /dev/mapper/control + * /proc/devices + * /proc/evms/volumes + * /proc/lvm/VGs + * This is unacceptably complex. Let's just scan /dev. + * (Maybe add scanning of /sys/block/XXX/dev for devices + * somehow not having their /dev/XXX entries created?) */ + + recursive_action("/dev", ACTION_RECURSE, + uuidcache_check_device, /* file_action */ + NULL, /* dir_action */ + NULL, /* userData */ + 0 /* depth */); +} + +#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 (strcmp(t, uc->uc_uuid) == 0) { + *majorPtr = uc->major; + *minorPtr = uc->minor; + return uc->device; + } + break; + case VOL: + if (strcmp(t, uc->label) == 0) { + *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'); + return ((c|0x20) - '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); +} +#endif // UNUSED + +/* Used by blkid */ +void display_uuid_cache(void) +{ + struct uuidCache_s *u; + + uuidcache_init(); + u = uuidCache; + while (u) { + printf("%s:", u->device); + if (u->label[0]) + printf(" LABEL=\"%s\"", u->label); + if (u->uc_uuid[0]) + printf(" UUID=\"%s\"", u->uc_uuid); + bb_putchar('\n'); + u = u->next; + } +} + +/* 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) { +// FIXME: empty label ("LABEL=") matches anything??! + if (uc->label[0] && strncmp(spec, uc->label, spec_len) == 0) { + 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) { + /* case of hex numbers doesn't matter */ + if (strcasecmp(spec, uc->uc_uuid) == 0) { + return xstrdup(uc->device); + } + uc = uc->next; + } + return NULL; +} |