--- /dev/null
+#ifndef UTIL_LINUX_LOOPDEV_H
+#define UTIL_LINUX_LOOPDEV_H
+
+/*
+ * loop_info.lo_encrypt_type
+ */
+#define LO_CRYPT_NONE 0
+#define LO_CRYPT_XOR 1
+#define LO_CRYPT_DES 2
+#define LO_CRYPT_CRYPTOAPI 18
+
+#define LOOP_SET_FD 0x4C00
+#define LOOP_CLR_FD 0x4C01
+/*
+ * Obsolete (kernel < 2.6)
+ *
+ * #define LOOP_SET_STATUS 0x4C02
+ * #define LOOP_GET_STATUS 0x4C03
+ */
+#define LOOP_SET_STATUS64 0x4C04
+#define LOOP_GET_STATUS64 0x4C05
+/* #define LOOP_CHANGE_FD 0x4C06 */
+#define LOOP_SET_CAPACITY 0x4C07
+
+/*
+ * loop_info.lo_flags
+ */
+enum {
+ LO_FLAGS_READ_ONLY = 1,
+ LO_FLAGS_USE_AOPS = 2,
+ LO_FLAGS_AUTOCLEAR = 4, /* New in 2.6.25 */
+};
+
+#define LO_NAME_SIZE 64
+#define LO_KEY_SIZE 32
+
+/*
+ * Linux LOOP_{SET,GET}_STATUS64 ioclt struct
+ */
+struct loop_info64 {
+ uint64_t lo_device;
+ uint64_t lo_inode;
+ uint64_t lo_rdevice;
+ uint64_t lo_offset;
+ uint64_t lo_sizelimit; /* bytes, 0 == max available */
+ uint32_t lo_number;
+ uint32_t lo_encrypt_type;
+ uint32_t lo_encrypt_key_size;
+ uint32_t lo_flags;
+ uint8_t lo_file_name[LO_NAME_SIZE];
+ uint8_t lo_crypt_name[LO_NAME_SIZE];
+ uint8_t lo_encrypt_key[LO_KEY_SIZE];
+ uint64_t lo_init[2];
+};
+
+#define LOOPDEV_MAJOR 7 /* loop major number */
+#define LOOPDEV_DEFAULT_NNODES 8 /* default number of loop devices */
+
+struct loopdev_iter {
+ FILE *proc; /* /proc/partitions */
+ int ncur; /* current position */
+ int *minors; /* ary of minor numbers (when scan whole /dev) */
+ int nminors; /* number of items in *minors */
+ int ct_perm; /* count permission problems */
+ int ct_succ; /* count number of detected devices */
+
+ int done:1; /* scanning done */
+ int default_check:1;/* check first LOOPDEV_NLOOPS */
+ int flags; /* LOOPITER_FL_* flags */
+};
+
+enum {
+ LOOPITER_FL_FREE = (1 << 0),
+ LOOPITER_FL_USED = (1 << 1)
+};
+
+/*
+ * handler for work with loop devices
+ */
+struct loopdev_cxt {
+ char device[128]; /* device path (e.g. /dev/loop<N>) */
+ char *filename; /* backing file for loopcxt_set_... */
+ int fd; /* open(/dev/looo<N>) */
+
+ int flags; /* LOOPDEV_FL_* flags */
+ int has_info:1; /* .info contains data */
+ int extra_check:1; /* unusual stuff for iterator */
+
+ struct sysfs_cxt sysfs; /* pointer to /sys/dev/block/<maj:min>/ */
+ struct loop_info64 info; /* for GET/SET ioctl */
+ struct loopdev_iter iter; /* scans /sys or /dev for used/free devices */
+};
+
+/*
+ * loopdev_cxt.flags
+ */
+enum {
+ LOOPDEV_FL_RDONLY = (1 << 0), /* default */
+ LOOPDEV_FL_RDWR = (1 << 1), /* necessary for loop setup only */
+ LOOPDEV_FL_OFFSET = (1 << 4),
+ LOOPDEV_FL_NOSYSFS = (1 << 5),
+ LOOPDEV_FL_NOIOCTL = (1 << 6),
+ LOOPDEV_FL_DEVSUBDIR = (1 << 7)
+};
+
+/*
+ * High-level
+ */
+extern int is_loopdev(const char *device);
+extern int loopdev_is_autoclear(const char *device);
+extern char *loopdev_get_backing_file(const char *device);
+extern int loopdev_is_used(const char *device, const char *filename,
+ uint64_t offset, int flags);
+extern char *loopdev_find_by_backing_file(const char *filename,
+ uint64_t offset, int flags);
+extern int loopcxt_find_unused(struct loopdev_cxt *lc);
+extern int loopdev_delete(const char *device);
+
+/*
+ * Low-level
+ */
+extern int loopcxt_init(struct loopdev_cxt *lc, int flags);
+extern void loopcxt_deinit(struct loopdev_cxt *lc);
+
+extern int loopcxt_set_device(struct loopdev_cxt *lc, const char *device);
+extern char *loopcxt_strdup_device(struct loopdev_cxt *lc);
+extern const char *loopcxt_get_device(struct loopdev_cxt *lc);
+extern struct sysfs_cxt *loopcxt_get_sysfs(struct loopdev_cxt *lc);
+extern int loopcxt_get_fd(struct loopdev_cxt *lc);
+
+extern int loopcxt_init_iterator(struct loopdev_cxt *lc, int flags);
+extern int loopcxt_deinit_iterator(struct loopdev_cxt *lc);
+extern int loopcxt_next(struct loopdev_cxt *lc);
+
+extern int loopcxt_setup_device(struct loopdev_cxt *lc);
+extern int loopcxt_delete_device(struct loopdev_cxt *lc);
+
+int loopcxt_set_offset(struct loopdev_cxt *lc, uint64_t offset);
+int loopcxt_set_sizelimit(struct loopdev_cxt *lc, uint64_t sizelimit);
+int loopcxt_set_flags(struct loopdev_cxt *lc, uint32_t flags);
+int loopcxt_set_backing_file(struct loopdev_cxt *lc, const char *filename);
+int loopcxt_set_encryption(struct loopdev_cxt *lc,
+ const char *encryption,
+ const char *password);
+
+extern char *loopcxt_get_backing_file(struct loopdev_cxt *lc);
+extern int loopcxt_get_offset(struct loopdev_cxt *lc, uint64_t *offset);
+extern int loopcxt_get_sizelimit(struct loopdev_cxt *lc, uint64_t *size);
+extern int loopcxt_is_autoclear(struct loopdev_cxt *lc);
+extern int loopcxt_find_by_backing_file(struct loopdev_cxt *lc,
+ const char *filename,
+ uint64_t offset, int flags);
+
+#endif /* UTIL_LINUX_LOOPDEV_H */
--- /dev/null
+/*
+ * Copyright (C) 2011 Karel Zak <kzak@redhat.com>
+ *
+ * -- based on mount/losetup.c
+ *
+ * Simple library for work with loop devices.
+ *
+ * - requires kernel 2.6.x
+ * - reads info from /sys/block/loop<N>/loop/<attr> (new kernels)
+ * - reads info by ioctl
+ * - supports *unlimited* number of loop devices
+ * - supports /dev/loop<N> as well as /dev/loop/<N>
+ * - minimize overhead (fd, loopinfo, ... are shared for all operations)
+ * - setup (associate device and backing file)
+ * - delete (dis-associate file)
+ * - old LOOP_{SET,GET}_STATUS (32bit) ioctls are unsupported
+ * - extendible
+ */
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <ctype.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <sys/sysmacros.h>
+#include <inttypes.h>
+#include <dirent.h>
+#include <linux/posix_types.h>
+
+#include "linux_version.h"
+#include "c.h"
+#include "sysfs.h"
+#include "pathnames.h"
+#include "loopdev.h"
+#include "canonicalize.h"
+
+#define loopcxt_ioctl_enabled(_lc) (!((_lc)->flags & LOOPDEV_FL_NOIOCTL))
+
+/*
+ * @lc: context
+ * @device: device name, absolute device path or NULL to reset the current setting
+ *
+ * Sets device, absolute paths (e.g. "/dev/loop<N>") are unchanged, device
+ * names ("loop<N>") are converted to the path (/dev/loop<N> or to
+ * /dev/loop/<N>)
+ *
+ * Returns: <0 on error, 0 on success
+ */
+int loopcxt_set_device(struct loopdev_cxt *lc, const char *device)
+{
+ if (!lc)
+ return -EINVAL;
+
+ if (lc->fd >= 0)
+ close(lc->fd);
+ lc->fd = -1;
+ lc->has_info = 0;
+ *lc->device = '\0';
+
+ /* set new */
+ if (device) {
+ if (*device != '/') {
+ const char *dir = _PATH_DEV;
+
+ /* compose device name for /dev/loop<n> or /dev/loop/<n> */
+ if (lc->flags & LOOPDEV_FL_DEVSUBDIR) {
+ if (strlen(device) < 5)
+ return -1;
+ device += 4;
+ dir = _PATH_DEV_LOOP "/"; /* _PATH_DEV uses tailing slash */
+ }
+ snprintf(lc->device, sizeof(lc->device), "%s%s",
+ dir, device);
+ } else {
+ strncpy(lc->device, device, sizeof(lc->device));
+ lc->device[sizeof(lc->device) - 1] = '\0';
+ }
+ }
+
+ sysfs_deinit(&lc->sysfs);
+ return 0;
+}
+
+/*
+ * @lc: context
+ * @flags: LOOPDEV_FL_* flags
+ *
+ * Initilize loop handler.
+ *
+ * Returns: <0 on error, 0 on success.
+ */
+int loopcxt_init(struct loopdev_cxt *lc, int flags)
+{
+ if (!lc)
+ return -EINVAL;
+
+ memset(lc, 0, sizeof(*lc));
+ lc->flags = flags;
+ loopcxt_set_device(lc, NULL);
+
+ if (!(lc->flags && LOOPDEV_FL_NOSYSFS) &&
+ get_linux_version() >= KERNEL_VERSION(2,6,37))
+ /*
+ * Use only sysfs for basic information about loop devices
+ */
+ lc->flags |= LOOPDEV_FL_NOIOCTL;
+
+ return 0;
+}
+
+/*
+ * @lc: context
+ *
+ * Deinitialize loop context
+ */
+void loopcxt_deinit(struct loopdev_cxt *lc)
+{
+ if (!lc)
+ return;
+
+ free(lc->filename);
+ lc->filename = NULL;
+
+ loopcxt_set_device(lc, NULL);
+ loopcxt_deinit_iterator(lc);
+}
+
+/*
+ * @lc: context
+ *
+ * Returns newly allocated device path.
+ */
+char *loopcxt_strdup_device(struct loopdev_cxt *lc)
+{
+ if (!lc || !*lc->device)
+ return NULL;
+ return strdup(lc->device);
+}
+
+/*
+ * @lc: context
+ *
+ * Returns pointer device name in the @lc struct.
+ */
+const char *loopcxt_get_device(struct loopdev_cxt *lc)
+{
+ return lc ? lc->device : NULL;
+}
+
+/*
+ * @lc: context
+ *
+ * Returns pointer to the sysfs context (see lib/sysfs.c)
+ */
+struct sysfs_cxt *loopcxt_get_sysfs(struct loopdev_cxt *lc)
+{
+ if (!lc || !*lc->device || (lc->flags & LOOPDEV_FL_NOSYSFS))
+ return NULL;
+
+ if (!lc->sysfs.devno) {
+ dev_t devno = sysfs_devname_to_devno(lc->device, NULL);
+ if (!devno)
+ return NULL;
+
+ if (sysfs_init(&lc->sysfs, devno, NULL))
+ return NULL;
+ }
+ return &lc->sysfs;
+}
+
+/*
+ * @lc: context
+ *
+ * Returns: file descriptor to the open loop device or <0 on error. The mode
+ * depends on LOOPDEV_FL_{RDWR,RDONLY} context flags. Default is
+ * read-only.
+ */
+int loopcxt_get_fd(struct loopdev_cxt *lc)
+{
+ if (!lc || !*lc->device)
+ return -1;
+
+ if (lc->fd < 0)
+ lc->fd = open(lc->device, lc->flags & LOOPDEV_FL_RDWR ?
+ O_RDWR : O_RDONLY);
+ return lc->fd;
+}
+
+/*
+ * @lc: context
+ * @flags: LOOPITER_FL_* flags
+ *
+ * Iterator allows to scan list of the free or used loop devices.
+ *
+ * Returns: <0 on error, 0 on success
+ */
+int loopcxt_init_iterator(struct loopdev_cxt *lc, int flags)
+{
+ struct loopdev_iter *iter;
+ struct stat st;
+
+ if (!lc)
+ return -EINVAL;
+
+ iter = &lc->iter;
+
+ /* always zeroize
+ */
+ memset(iter, 0, sizeof(*iter));
+ iter->ncur = -1;
+ iter->flags = flags;
+ iter->default_check = 1;
+
+ if (!lc->extra_check) {
+ /*
+ * Check for /dev/loop/<N> subdirectory
+ */
+ if (!(lc->flags && LOOPDEV_FL_DEVSUBDIR) &&
+ stat(_PATH_DEV_LOOP, &st) == 0 && S_ISDIR(st.st_mode))
+ lc->flags |= LOOPDEV_FL_DEVSUBDIR;
+
+ lc->extra_check = 1;
+ }
+ return 0;
+}
+
+/*
+ * @lc: context
+ *
+ * Returns: <0 on error, 0 on success
+ */
+int loopcxt_deinit_iterator(struct loopdev_cxt *lc)
+{
+ struct loopdev_iter *iter = &lc->iter;
+
+ if (!lc)
+ return -EINVAL;
+
+ iter = &lc->iter;
+
+ free(iter->minors);
+ if (iter->proc)
+ fclose(iter->proc);
+ iter->minors = NULL;
+ iter->proc = NULL;
+ iter->done = 1;
+ return 0;
+}
+
+/*
+ * Same as loopcxt_set_device, but also checks if the device is
+ * associeted with any file.
+ *
+ * Returns: <0 on error, 0 on success, 1 device does not match with
+ * LOOPITER_FL_{USED,FREE} flags.
+ */
+static int loopiter_set_device(struct loopdev_cxt *lc, const char *device)
+{
+ int rc = loopcxt_set_device(lc, device);
+ int used;
+
+ if (rc)
+ return rc;
+
+ if (!(lc->iter.flags & LOOPITER_FL_USED) &&
+ !(lc->iter.flags & LOOPITER_FL_FREE))
+ return 0; /* caller does not care about device status */
+
+ used = loopcxt_get_offset(lc, NULL) == 0;
+
+ if ((lc->iter.flags & LOOPITER_FL_USED) && used)
+ return 0;
+
+ if ((lc->iter.flags & LOOPITER_FL_FREE) && !used)
+ return 0;
+
+ loopcxt_set_device(lc, NULL);
+ return 1;
+}
+
+static int cmpnum(const void *p1, const void *p2)
+{
+ return (* (int *) p1) > (* (int *) p2);
+}
+
+/*
+ * The classic scandir() is more expensive and less portable.
+ * We needn't full loop device names -- loop numbers (loop<N>)
+ * are enough.
+ */
+static int loop_scandir(const char *dirname, int **ary, int hasprefix)
+{
+ DIR *dir;
+ struct dirent *d;
+ unsigned int n, count = 0, arylen = 0;
+
+ if (!dirname || !ary)
+ return 0;
+ dir = opendir(dirname);
+ if (!dir)
+ return 0;
+
+ free(*ary);
+ *ary = NULL;
+
+ while((d = readdir(dir))) {
+#ifdef _DIRENT_HAVE_D_TYPE
+ if (d->d_type != DT_BLK && d->d_type != DT_UNKNOWN &&
+ d->d_type != DT_LNK)
+ continue;
+#endif
+ if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
+ continue;
+
+ if (hasprefix) {
+ /* /dev/loop<N> */
+ if (sscanf(d->d_name, "loop%u", &n) != 1)
+ continue;
+ } else {
+ /* /dev/loop/<N> */
+ char *end = NULL;
+
+ n = strtol(d->d_name, &end, 10);
+ if (d->d_name == end || (end && *end) || errno)
+ continue;
+ }
+ if (n < LOOPDEV_DEFAULT_NNODES)
+ continue; /* ignore loop<0..7> */
+
+ if (count + 1 > arylen) {
+ int *tmp;
+
+ arylen += 1;
+
+ tmp = realloc(*ary, arylen * sizeof(int));
+ if (!tmp) {
+ free(*ary);
+ return -1;
+ }
+ *ary = tmp;
+ }
+ (*ary)[count++] = n;
+ }
+ if (count)
+ qsort(*ary, count, sizeof(int), cmpnum);
+
+ closedir(dir);
+ return count;
+}
+
+/*
+ * @lc: context, has to initialized by loopcxt_init_iterator()
+ *
+ * Returns: 0 on success, -1 on error, 1 at the end of scanning. The details
+ * about the current loop device are available by
+ * loopcxt_get_{fd,backing_file,device,offset, ...} functions.
+ */
+int loopcxt_next(struct loopdev_cxt *lc)
+{
+ struct loopdev_iter *iter;
+
+ if (!lc)
+ return -EINVAL;
+ iter = &lc->iter;
+ if (iter->done)
+ return 1;
+
+ /* A) Look for used loop devices in /proc/partitions ("losetup -a" only)
+ */
+ if (iter->flags & LOOPITER_FL_USED) {
+ char buf[BUFSIZ];
+
+ if (!iter->proc)
+ iter->proc = fopen(_PATH_PROC_PARTITIONS, "r");
+
+ while (iter->proc && fgets(buf, sizeof(buf), iter->proc)) {
+ unsigned int m;
+ char name[128];
+
+ if (sscanf(buf, " %u %*s %*s %128[^\n ]",
+ &m, name) != 2 || m != LOOPDEV_MAJOR)
+ continue;
+
+ if (loopiter_set_device(lc, name) == 0)
+ return 0;
+ }
+
+ goto done;
+ }
+
+ /* B) Classic way, try first eight loop devices (default number
+ * of loop devices). This is enough for 99% of all cases.
+ */
+ if (iter->default_check) {
+ for (++iter->ncur; iter->ncur < LOOPDEV_DEFAULT_NNODES;
+ iter->ncur++) {
+ char name[16];
+ snprintf(name, sizeof(name), "loop%d", iter->ncur);
+
+ if (loopiter_set_device(lc, name) == 0)
+ return 0;
+ }
+ iter->default_check = 0;
+ }
+
+ /* C) the worst possibility, scan whole /dev or /dev/loop/<N>
+ */
+ if (!iter->minors) {
+ iter->nminors = (lc->flags & LOOPDEV_FL_DEVSUBDIR) ?
+ loop_scandir(_PATH_DEV_LOOP, &iter->minors, 0) :
+ loop_scandir(_PATH_DEV, &iter->minors, 1);
+ iter->ncur = -1;
+ }
+ for (++iter->ncur; iter->ncur < iter->nminors; iter->ncur++) {
+ char name[16];
+ snprintf(name, sizeof(name), "loop%d", iter->minors[iter->ncur]);
+
+ if (loopiter_set_device(lc, name) == 0)
+ return 0;
+ }
+done:
+ loopcxt_deinit_iterator(lc);
+ return 1;
+}
+
+/*
+ * @device: path to device
+ */
+int is_loopdev(const char *device)
+{
+ struct stat st;
+
+ if (!device)
+ return 0;
+
+ return (stat(device, &st) == 0 &&
+ S_ISBLK(st.st_mode) &&
+ major(st.st_rdev) == LOOPDEV_MAJOR);
+}
+
+/*
+ * @lc: context
+ *
+ * Returns result from LOOP_GET_STAT64 ioctl or NULL on error.
+ */
+struct loop_info64 *loopcxt_get_info(struct loopdev_cxt *lc)
+{
+ int fd;
+
+ if (!lc)
+ return NULL;
+ if (lc->has_info)
+ return &lc->info;
+
+ fd = loopcxt_get_fd(lc);
+ if (fd < 0)
+ return NULL;
+
+ if (ioctl(fd, LOOP_GET_STATUS64, &lc->info) == 0) {
+ lc->has_info = 1;
+ return &lc->info;
+ }
+
+ return NULL;
+}
+
+/*
+ * @lc: context
+ *
+ * Returns (allocated) string with path to the file assicieted
+ * with the current loop device.
+ */
+char *loopcxt_get_backing_file(struct loopdev_cxt *lc)
+{
+ struct sysfs_cxt *sysfs = loopcxt_get_sysfs(lc);
+ char *res = NULL;
+
+ if (sysfs)
+ res = sysfs_strdup(sysfs, "loop/backing_file");
+
+ if (!res && loopcxt_ioctl_enabled(lc)) {
+ struct loop_info64 *lo = loopcxt_get_info(lc);
+
+ if (lo) {
+ lo->lo_file_name[LO_NAME_SIZE - 2] = '*';
+ lo->lo_file_name[LO_NAME_SIZE - 1] = '\0';
+ res = strdup((char *) lo->lo_file_name);
+ }
+ }
+ return res;
+}
+
+/*
+ * @lc: context
+ * @offset: returns offset number for the given device
+ *
+ * Returns: <0 on error, 0 on success
+ */
+int loopcxt_get_offset(struct loopdev_cxt *lc, uint64_t *offset)
+{
+ struct sysfs_cxt *sysfs = loopcxt_get_sysfs(lc);
+ int rc = -EINVAL;
+
+ if (sysfs)
+ rc = sysfs_read_u64(sysfs, "loop/offset", offset);
+
+ if (rc && loopcxt_ioctl_enabled(lc)) {
+ struct loop_info64 *lo = loopcxt_get_info(lc);
+ if (lo) {
+ if (offset)
+ *offset = lo->lo_offset;
+ return 0;
+ }
+ }
+
+ return rc;
+}
+
+/*
+ * @lc: context
+ * @sizelimit: returns size limit for the given device
+ *
+ * Returns: <0 on error, 0 on success
+ */
+int loopcxt_get_sizelimit(struct loopdev_cxt *lc, uint64_t *size)
+{
+ struct sysfs_cxt *sysfs = loopcxt_get_sysfs(lc);
+ int rc = -EINVAL;
+
+ if (sysfs)
+ rc = sysfs_read_u64(sysfs, "loop/sizelimit", size);
+
+ if (rc && loopcxt_ioctl_enabled(lc)) {
+ struct loop_info64 *lo = loopcxt_get_info(lc);
+ if (lo) {
+ if (size)
+ *size = lo->lo_sizelimit;
+ return 0;
+ }
+ }
+
+ return rc;
+}
+
+/*
+ * @lc: context
+ *
+ * Returns: 1 of the autoclear flags is set.
+ */
+int loopcxt_is_autoclear(struct loopdev_cxt *lc)
+{
+ struct sysfs_cxt *sysfs = loopcxt_get_sysfs(lc);
+
+ if (sysfs) {
+ int fl;
+ if (sysfs_read_int(sysfs, "loop/autoclear", &fl) == 0)
+ return fl;
+ }
+
+ if (loopcxt_ioctl_enabled(lc)) {
+ struct loop_info64 *lo = loopcxt_get_info(lc);
+ if (lo)
+ return lo->lo_flags & LO_FLAGS_AUTOCLEAR;
+ }
+ return 0;
+}
+
+int loopcxt_set_offset(struct loopdev_cxt *lc, uint64_t offset)
+{
+ if (!lc)
+ return -EINVAL;
+ lc->info.lo_offset = offset;
+ return 0;
+}
+
+int loopcxt_set_sizelimit(struct loopdev_cxt *lc, uint64_t sizelimit)
+{
+ if (!lc)
+ return -EINVAL;
+ lc->info.lo_sizelimit = sizelimit;
+ return 0;
+}
+
+/*
+ * @lc: context
+ * @flags: kernel LO_FLAGS_{READ_ONLY,USE_AOPS,AUTOCLEAR} flags
+ *
+ * Returns: 0 on success, <0 on error.
+ */
+int loopcxt_set_flags(struct loopdev_cxt *lc, uint32_t flags)
+{
+ if (!lc)
+ return -EINVAL;
+ lc->info.lo_flags = flags;
+ return 0;
+}
+
+/*
+ * @lc: context
+ * @filename: backing file path (the path will be canonicalized)
+ *
+ * Returns: 0 on success, <0 on error.
+ */
+int loopcxt_set_backing_file(struct loopdev_cxt *lc, const char *filename)
+{
+ if (!lc)
+ return -EINVAL;
+
+ lc->filename = canonicalize_path(filename);
+ if (!lc->filename)
+ return -errno;
+
+ strncpy((char *)lc->info.lo_file_name, lc->filename, LO_NAME_SIZE);
+ lc->info.lo_file_name[LO_NAME_SIZE- 1] = '\0';
+
+ return 0;
+}
+
+static int digits_only(const char *s)
+{
+ while (*s)
+ if (!isdigit(*s++))
+ return 0;
+ return 1;
+}
+
+/*
+ * @lc: context
+ * @encryption: encryption name / type (see lopsetup man page)
+ * @password
+ *
+ * Note that the encyption functionality is deprecated an unmaintained. Use
+ * cryptsetup (it also supports AES-loops).
+ *
+ * Returns: 0 on success, <0 on error.
+ */
+int loopcxt_set_encryption(struct loopdev_cxt *lc,
+ const char *encryption,
+ const char *password)
+{
+ if (!lc)
+ return -EINVAL;
+
+ if (encryption && *encryption) {
+ if (digits_only(encryption)) {
+ lc->info.lo_encrypt_type = atoi(encryption);
+ } else {
+ lc->info.lo_encrypt_type = LO_CRYPT_CRYPTOAPI;
+ snprintf((char *)lc->info.lo_crypt_name, LO_NAME_SIZE,
+ "%s", encryption);
+ }
+ }
+
+ switch (lc->info.lo_encrypt_type) {
+ case LO_CRYPT_NONE:
+ lc->info.lo_encrypt_key_size = 0;
+ break;
+ default:
+ memset(lc->info.lo_encrypt_key, 0, LO_KEY_SIZE);
+ strncpy((char *)lc->info.lo_encrypt_key, password, LO_KEY_SIZE);
+ lc->info.lo_encrypt_key[LO_KEY_SIZE - 1] = '\0';
+ lc->info.lo_encrypt_key_size = LO_KEY_SIZE;
+ break;
+ }
+ return 0;
+}
+
+/*
+ * @cl: context
+ *
+ * Associate the current device (see loopcxt_{set,get}_device()) with
+ * a file (see loopcxt_set_backing_file()).
+ *
+ * Default is open backing file and device in read-write mode, see
+ * LOOPDEV_FL_{RDONLY,RDWR} and loopcxt_init(). The LO_FLAGS_READ_ONLY lo_flag
+ * will be set automatically according to LOOPDEV_FL_ flags.
+ *
+ * Returns: <0 on error, 0 on success.
+ */
+int loopcxt_setup_device(struct loopdev_cxt *lc)
+{
+ int file_fd, dev_fd, mode, rc = -1;
+
+ if (!lc || !*lc->device || !lc->filename)
+ return -EINVAL;
+
+ /*
+ * Open backing file and device
+ */
+ mode = (lc->flags & LOOPDEV_FL_RDONLY) ? O_RDONLY : O_RDWR;
+
+ if ((file_fd = open(lc->filename, mode)) < 0) {
+ if (mode != O_RDONLY && (errno == EROFS || errno == EACCES))
+ file_fd = open(lc->filename, mode = O_RDONLY);
+
+ if (file_fd < 0)
+ return -errno;
+ }
+
+ if (mode == O_RDONLY) {
+ lc->flags |= LOOPDEV_FL_RDONLY;
+ lc->info.lo_flags |= LO_FLAGS_READ_ONLY;
+ } else
+ lc->flags |= LOOPDEV_FL_RDWR;
+
+ dev_fd = loopcxt_get_fd(lc);
+ if (dev_fd < 0) {
+ rc = -errno;
+ goto err;
+ }
+
+ /*
+ * Set FD
+ */
+ if (ioctl(dev_fd, LOOP_SET_FD, file_fd) < 0) {
+ rc = -errno;
+ goto err;
+ }
+ close(file_fd);
+ file_fd = -1;
+
+ if (ioctl(dev_fd, LOOP_SET_STATUS64, &lc->info))
+ goto err;
+
+ memset(&lc->info, 0, sizeof(lc->info));
+ lc->has_info = 0;
+
+ return 0;
+err:
+ if (file_fd >= 0)
+ close(file_fd);
+ if (dev_fd >= 0)
+ ioctl(dev_fd, LOOP_CLR_FD, 0);
+
+ return rc;
+}
+
+int loopcxt_delete_device(struct loopdev_cxt *lc)
+{
+ int fd = loopcxt_get_fd(lc);
+
+ if (fd < 0)
+ return -EINVAL;
+
+ if (ioctl(fd, LOOP_CLR_FD, 0) < 0)
+ return -errno;
+ return 0;
+}
+
+int loopcxt_find_unused(struct loopdev_cxt *lc)
+{
+ int rc;
+
+ rc = loopcxt_init_iterator(lc, LOOPITER_FL_FREE);
+ if (rc)
+ return rc;
+
+ rc = loopcxt_next(lc);
+ loopcxt_deinit_iterator(lc);
+
+ return rc;
+}
+
+
+
+/*
+ * Return: TRUE/FALSE
+ */
+int loopdev_is_autoclear(const char *device)
+{
+ struct loopdev_cxt lc;
+ int rc;
+
+ if (!device)
+ return 0;
+
+ loopcxt_init(&lc, 0);
+ loopcxt_set_device(&lc, device);
+ rc = loopcxt_is_autoclear(&lc);
+ loopcxt_deinit(&lc);
+
+ return rc;
+}
+
+char *loopdev_get_backing_file(const char *device)
+{
+ struct loopdev_cxt lc;
+ char *res;
+
+ if (!device)
+ return NULL;
+
+ loopcxt_init(&lc, 0);
+ loopcxt_set_device(&lc, device);
+ res = loopcxt_get_backing_file(&lc);
+ loopcxt_deinit(&lc);
+
+ return res;
+}
+
+/*
+ * Returns: TRUE/FALSE
+ */
+int loopdev_is_used(const char *device, const char *filename,
+ uint64_t offset, int flags)
+{
+ struct loopdev_cxt lc;
+ char *backing = NULL;
+ int rc = 0;
+
+ if (!device)
+ return 0;
+
+ loopcxt_init(&lc, 0);
+ loopcxt_set_device(&lc, device);
+
+ backing = loopcxt_get_backing_file(&lc);
+ if (!backing)
+ goto done;
+ if (filename && strcmp(filename, backing) != 0)
+ goto done;
+ if (flags & LOOPDEV_FL_OFFSET) {
+ uint64_t off;
+
+ if (loopcxt_get_offset(&lc, &off) != 0 || off != offset)
+ goto done;
+ }
+
+ rc = 1;
+done:
+ free(backing);
+ loopcxt_deinit(&lc);
+
+ return rc;
+}
+
+int loopdev_delete(const char *device)
+{
+ struct loopdev_cxt lc;
+ int rc;
+
+ loopcxt_init(&lc, 0);
+ rc = loopcxt_set_device(&lc, device);
+ if (!rc)
+ rc = loopcxt_delete_device(&lc);
+ loopcxt_deinit(&lc);
+ return rc;
+}
+
+/*
+ * Returns: 0 = success, < 0 error, 1 not found
+ */
+int loopcxt_find_by_backing_file(struct loopdev_cxt *lc, const char *filename,
+ uint64_t offset, int flags)
+{
+ int rc;
+
+ if (!filename)
+ return -EINVAL;
+
+ rc = loopcxt_init_iterator(lc, LOOPITER_FL_USED);
+ if (rc)
+ return rc;
+
+ while((rc = loopcxt_next(lc)) == 0) {
+ char *backing = loopcxt_get_backing_file(lc);
+
+ if (!backing || strcmp(backing, filename)) {
+ free(backing);
+ continue;
+ }
+
+ free(backing);
+
+ if (flags & LOOPDEV_FL_OFFSET) {
+ uint64_t off;
+ if (loopcxt_get_offset(lc, &off) != 0 || offset != off)
+ continue;
+ }
+
+ rc = 0;
+ break;
+ }
+
+ loopcxt_deinit_iterator(lc);
+ return rc;
+}
+
+/*
+ * Returns allocated string with device name
+ */
+char *loopdev_find_by_backing_file(const char *filename, uint64_t offset, int flags)
+{
+ struct loopdev_cxt lc;
+ char *res = NULL;
+
+ if (!filename)
+ return NULL;
+
+ loopcxt_init(&lc, 0);
+ if (loopcxt_find_by_backing_file(&lc, filename, offset, flags))
+ res = loopcxt_strdup_device(&lc);
+ loopcxt_deinit(&lc);
+
+ return res;
+}
+
+
+#ifdef TEST_PROGRAM_LOOPDEV
+#include <errno.h>
+#include <err.h>
+#include <stdlib.h>
+
+static void test_loop_info(const char *device, int flags)
+{
+ struct loopdev_cxt lc;
+ char *p;
+ uint64_t u64;
+
+ loopcxt_init(&lc, flags);
+ if (loopcxt_set_device(&lc, device))
+ err(EXIT_FAILURE, "failed to set device");
+
+ p = loopcxt_get_backing_file(&lc);
+ printf("\tBACKING FILE: %s\n", p);
+ free(p);
+
+ if (loopcxt_get_offset(&lc, &u64) == 0)
+ printf("\tOFFSET: %jd\n", u64);
+
+ if (loopcxt_get_sizelimit(&lc, &u64) == 0)
+ printf("\tSIZE LIMIT: %jd\n", u64);
+
+ printf("\tAUTOCLEAR: %s\n", loopcxt_is_autoclear(&lc) ? "YES" : "NOT");
+
+ loopcxt_deinit(&lc);
+}
+
+static void test_loop_scan(int flags)
+{
+ struct loopdev_cxt lc;
+ int rc;
+
+ loopcxt_init(&lc, 0);
+
+ if (loopcxt_init_iterator(&lc, flags))
+ err(EXIT_FAILURE, "iterator initlization failed");
+
+ while((rc = loopcxt_next(&lc)) == 0) {
+ const char *device = loopcxt_get_device(&lc);
+
+ if (flags & LOOPITER_FL_USED) {
+ char *backing = loopcxt_get_backing_file(&lc);
+ printf("\t%s: %s\n", device, backing);
+ free(backing);
+ } else
+ printf("\t%s\n", device);
+ }
+
+ if (rc < 0)
+ err(EXIT_FAILURE, "loopdevs scanning failed");
+
+ loopcxt_deinit(&lc);
+}
+
+static int test_loop_setup(const char *filename, const char *device)
+{
+ struct loopdev_cxt lc;
+ int rc = 0;
+
+ loopcxt_init(&lc, 0);
+
+ if (loopcxt_set_backing_file(&lc, filename))
+ err(EXIT_FAILURE, "failed to set backing file");
+
+ if (device) {
+ rc = loopcxt_set_device(&lc, device);
+ if (rc)
+ err(EXIT_FAILURE, "failed to set device: %s", device);
+ }
+
+ do {
+ if (!device) {
+ rc = loopcxt_find_unused(&lc);
+ if (rc)
+ err(EXIT_FAILURE, "failed to found unused device");
+ printf("Trying to use '%s'\n", loopcxt_get_device(&lc));
+ }
+
+ rc = loopcxt_setup_device(&lc);
+ if (rc == 0)
+ break; /* success */
+
+ if (device || rc != -EBUSY)
+ err(EXIT_FAILURE, "failed to setup device for %s",
+ lc.filename);
+
+ printf("device stolen...trying again\n");
+ } while (1);
+
+ loopcxt_deinit(&lc);
+
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ if (argc < 2)
+ goto usage;
+
+ if (argc == 3 && strcmp(argv[1], "--info") == 0) {
+ printf("---sysfs & ioctl:---\n");
+ test_loop_info(argv[2], 0);
+ printf("---sysfs only:---\n");
+ test_loop_info(argv[2], LOOPDEV_FL_NOIOCTL);
+ printf("---ioctl only:---\n");
+ test_loop_info(argv[2], LOOPDEV_FL_NOSYSFS);
+
+ } else if (argc == 2 && strcmp(argv[1], "--used") == 0) {
+ printf("---all used devices---\n");
+ test_loop_scan(LOOPITER_FL_USED);
+
+ } else if (argc == 2 && strcmp(argv[1], "--free") == 0) {
+ printf("---all free devices---\n");
+ test_loop_scan(LOOPITER_FL_FREE);
+
+ } else if (argc >= 3 && strcmp(argv[1], "--setup") == 0) {
+ test_loop_setup(argv[2], argv[3]);
+
+ } else if (argc == 3 && strcmp(argv[1], "--delete") == 0) {
+ if (loopdev_delete(argv[2]))
+ errx(EXIT_FAILURE, "failed to deinitialize device %s", argv[2]);
+ } else
+ goto usage;
+
+ return EXIT_SUCCESS;
+
+usage:
+ errx(EXIT_FAILURE, "usage: \n"
+ " %1$s --info <device>\n"
+ " %1$s --free\n"
+ " %1$s --used\n"
+ " %1$s --setup <filename> [<device>]\n"
+ " %1$s --delete\n",
+ argv[0]);
+}
+
+#endif /* TEST_PROGRAM */
projects / thirdparty / util-linux.git / commitdiff
