/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2013 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see .
***/
#include
#include
#include "strv.h"
#include "utf8.h"
#include "btrfs-util.h"
#include "path-util.h"
#include "copy.h"
#include "machine-image.h"
static const char image_search_path[] =
"/var/lib/machines\0"
"/var/lib/container\0"
"/usr/local/lib/machines\0"
"/usr/lib/machines\0";
Image *image_unref(Image *i) {
if (!i)
return NULL;
free(i->name);
free(i->path);
free(i);
return NULL;
}
static int image_new(
ImageType t,
const char *pretty,
const char *path,
const char *filename,
bool read_only,
usec_t crtime,
usec_t mtime,
Image **ret) {
_cleanup_(image_unrefp) Image *i = NULL;
assert(t >= 0);
assert(t < _IMAGE_TYPE_MAX);
assert(pretty);
assert(filename);
assert(ret);
i = new0(Image, 1);
if (!i)
return -ENOMEM;
i->type = t;
i->read_only = read_only;
i->crtime = crtime;
i->mtime = mtime;
i->size = i->size_exclusive = (uint64_t) -1;
i->limit = i->limit_exclusive = (uint64_t) -1;
i->name = strdup(pretty);
if (!i->name)
return -ENOMEM;
if (path)
i->path = strjoin(path, "/", filename, NULL);
else
i->path = strdup(filename);
if (!i->path)
return -ENOMEM;
path_kill_slashes(i->path);
*ret = i;
i = NULL;
return 0;
}
static int image_make(
const char *pretty,
int dfd,
const char *path,
const char *filename,
Image **ret) {
struct stat st;
bool read_only;
int r;
assert(filename);
/* We explicitly *do* follow symlinks here, since we want to
* allow symlinking trees into /var/lib/container/, and treat
* them normally. */
if (fstatat(dfd, filename, &st, 0) < 0)
return -errno;
read_only =
(path && path_startswith(path, "/usr")) ||
(faccessat(dfd, filename, W_OK, AT_EACCESS) < 0 && errno == EROFS);
if (S_ISDIR(st.st_mode)) {
if (!ret)
return 1;
if (!pretty)
pretty = filename;
/* btrfs subvolumes have inode 256 */
if (st.st_ino == 256) {
_cleanup_close_ int fd = -1;
struct statfs sfs;
fd = openat(dfd, filename, O_CLOEXEC|O_NOCTTY|O_DIRECTORY);
if (fd < 0)
return -errno;
if (fstatfs(fd, &sfs) < 0)
return -errno;
if (F_TYPE_EQUAL(sfs.f_type, BTRFS_SUPER_MAGIC)) {
BtrfsSubvolInfo info;
BtrfsQuotaInfo quota;
/* It's a btrfs subvolume */
r = btrfs_subvol_get_info_fd(fd, &info);
if (r < 0)
return r;
r = image_new(IMAGE_SUBVOLUME,
pretty,
path,
filename,
info.read_only || read_only,
info.otime,
0,
ret);
if (r < 0)
return r;
r = btrfs_subvol_get_quota_fd(fd, "a);
if (r >= 0) {
(*ret)->size = quota.referred;
(*ret)->size_exclusive = quota.exclusive;
(*ret)->limit = quota.referred_max;
(*ret)->limit_exclusive = quota.exclusive_max;
}
return 1;
}
}
/* It's just a normal directory. */
r = image_new(IMAGE_DIRECTORY,
pretty,
path,
filename,
read_only,
0,
0,
ret);
if (r < 0)
return r;
return 1;
} else if (S_ISREG(st.st_mode) && endswith(filename, ".gpt")) {
usec_t crtime = 0;
/* It's a GPT block device */
if (!ret)
return 1;
fd_getcrtime_at(dfd, filename, &crtime, 0);
if (!pretty)
pretty = strndupa(filename, strlen(filename) - 4);
r = image_new(IMAGE_GPT,
pretty,
path,
filename,
!(st.st_mode & 0222) || read_only,
crtime,
timespec_load(&st.st_mtim),
ret);
if (r < 0)
return r;
(*ret)->size = (*ret)->size_exclusive = st.st_blocks * 512;
(*ret)->limit = (*ret)->limit_exclusive = st.st_size;
return 1;
}
return 0;
}
int image_find(const char *name, Image **ret) {
const char *path;
int r;
assert(name);
/* There are no images with invalid names */
if (!image_name_is_valid(name))
return 0;
NULSTR_FOREACH(path, image_search_path) {
_cleanup_closedir_ DIR *d = NULL;
d = opendir(path);
if (!d) {
if (errno == ENOENT)
continue;
return -errno;
}
r = image_make(NULL, dirfd(d), path, name, ret);
if (r == 0 || r == -ENOENT) {
_cleanup_free_ char *gpt = NULL;
gpt = strappend(name, ".gpt");
if (!gpt)
return -ENOMEM;
r = image_make(NULL, dirfd(d), path, gpt, ret);
if (r == 0 || r == -ENOENT)
continue;
}
if (r < 0)
return r;
return 1;
}
if (streq(name, ".host"))
return image_make(".host", AT_FDCWD, NULL, "/", ret);
return 0;
};
int image_discover(Hashmap *h) {
const char *path;
int r;
assert(h);
NULSTR_FOREACH(path, image_search_path) {
_cleanup_closedir_ DIR *d = NULL;
struct dirent *de;
d = opendir(path);
if (!d) {
if (errno == ENOENT)
continue;
return -errno;
}
FOREACH_DIRENT_ALL(de, d, return -errno) {
_cleanup_(image_unrefp) Image *image = NULL;
if (!image_name_is_valid(de->d_name))
continue;
if (hashmap_contains(h, de->d_name))
continue;
r = image_make(NULL, dirfd(d), path, de->d_name, &image);
if (r == 0 || r == -ENOENT)
continue;
if (r < 0)
return r;
r = hashmap_put(h, image->name, image);
if (r < 0)
return r;
image = NULL;
}
}
if (!hashmap_contains(h, ".host")) {
_cleanup_(image_unrefp) Image *image = NULL;
r = image_make(".host", AT_FDCWD, NULL, "/", &image);
if (r < 0)
return r;
r = hashmap_put(h, image->name, image);
if (r < 0)
return r;
image = NULL;
}
return 0;
}
void image_hashmap_free(Hashmap *map) {
Image *i;
while ((i = hashmap_steal_first(map)))
image_unref(i);
hashmap_free(map);
}
int image_remove(Image *i) {
assert(i);
if (path_equal(i->path, "/") ||
path_startswith(i->path, "/usr"))
return -EROFS;
switch (i->type) {
case IMAGE_SUBVOLUME:
return btrfs_subvol_remove(i->path);
case IMAGE_DIRECTORY:
case IMAGE_GPT:
return rm_rf_dangerous(i->path, false, true, false);
default:
return -ENOTSUP;
}
}
int image_rename(Image *i, const char *new_name) {
_cleanup_free_ char *new_path = NULL, *nn = NULL;
int r;
assert(i);
if (!image_name_is_valid(new_name))
return -EINVAL;
if (path_equal(i->path, "/") ||
path_startswith(i->path, "/usr"))
return -EROFS;
r = image_find(new_name, NULL);
if (r < 0)
return r;
if (r > 0)
return -EEXIST;
switch (i->type) {
case IMAGE_SUBVOLUME:
case IMAGE_DIRECTORY:
new_path = file_in_same_dir(i->path, new_name);
break;
case IMAGE_GPT: {
const char *fn;
fn = strappenda(new_name, ".gpt");
new_path = file_in_same_dir(i->path, fn);
break;
}
default:
return -ENOTSUP;
}
if (!new_path)
return -ENOMEM;
nn = strdup(new_name);
if (!nn)
return -ENOMEM;
if (renameat2(AT_FDCWD, i->path, AT_FDCWD, new_path, RENAME_NOREPLACE) < 0)
return -errno;
free(i->path);
i->path = new_path;
new_path = NULL;
free(i->name);
i->name = nn;
nn = NULL;
return 0;
}
int image_clone(Image *i, const char *new_name, bool read_only) {
const char *new_path;
int r;
assert(i);
if (!image_name_is_valid(new_name))
return -EINVAL;
r = image_find(new_name, NULL);
if (r < 0)
return r;
if (r > 0)
return -EEXIST;
switch (i->type) {
case IMAGE_SUBVOLUME:
case IMAGE_DIRECTORY:
new_path = strappenda("/var/lib/container/", new_name);
r = btrfs_subvol_snapshot(i->path, new_path, read_only, true);
break;
case IMAGE_GPT:
new_path = strappenda("/var/lib/container/", new_name, ".gpt");
r = copy_file_atomic(i->path, new_path, read_only ? 0444 : 0644, false);
break;
default:
return -ENOTSUP;
}
if (r < 0)
return r;
return 0;
}
int image_read_only(Image *i, bool b) {
int r;
assert(i);
if (path_equal(i->path, "/") ||
path_startswith(i->path, "/usr"))
return -EROFS;
switch (i->type) {
case IMAGE_SUBVOLUME:
r = btrfs_subvol_set_read_only(i->path, b);
if (r < 0)
return r;
break;
case IMAGE_GPT: {
struct stat st;
if (stat(i->path, &st) < 0)
return -errno;
if (chmod(i->path, (st.st_mode & 0444) | (b ? 0000 : 0200)) < 0)
return -errno;
break;
}
case IMAGE_DIRECTORY:
default:
return -ENOTSUP;
}
return 0;
}
static const char* const image_type_table[_IMAGE_TYPE_MAX] = {
[IMAGE_DIRECTORY] = "directory",
[IMAGE_SUBVOLUME] = "subvolume",
[IMAGE_GPT] = "gpt",
};
DEFINE_STRING_TABLE_LOOKUP(image_type, ImageType);