Systemd/src/shared/dissect-image.h
Lennart Poettering 4623e8e6ac nspawn/dissect: automatically discover dm-verity verity partitions
This adds support for discovering and making use of properly tagged dm-verity
data integrity partitions. This extends both systemd-nspawn and systemd-dissect
with a new --root-hash= switch that takes the root hash to use for the root
partition, and is otherwise fully automatic.

Verity partitions are discovered automatically by GPT table type UUIDs, as
listed in
https://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/
(which I updated prior to this change, to include new UUIDs for this purpose.

mkosi with https://github.com/systemd/mkosi/pull/39 applied may generate images
that carry the necessary integrity data. With that PR and this commit, the
following simply lines suffice to boot up an integrity-protected container image:

```
 # mkdir test
 # cd test
 # mkosi --verity
 # systemd-nspawn -i ./image.raw -bn
```

Note that mkosi writes the image file to "image.raw" next to a a file
"image.roothash" that contains the root hash. systemd-nspawn will look for that
file and use it if it exists, in case --root-hash= is not specified explicitly.
2016-12-07 18:38:41 +01:00

91 lines
3.6 KiB
C

#pragma once
/***
This file is part of systemd.
Copyright 2016 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 <http://www.gnu.org/licenses/>.
***/
#include <stdbool.h>
#include "macro.h"
typedef struct DissectedImage DissectedImage;
typedef struct DissectedPartition DissectedPartition;
typedef struct DecryptedImage DecryptedImage;
struct DissectedPartition {
bool found:1;
bool rw:1;
int partno; /* -1 if there was no partition and the images contains a file system directly */
int architecture; /* Intended architecture: either native, secondary or unset (-1). */
char *fstype;
char *node;
char *decrypted_node;
char *decrypted_fstype;
};
enum {
PARTITION_ROOT,
PARTITION_ROOT_SECONDARY, /* Secondary architecture */
PARTITION_HOME,
PARTITION_SRV,
PARTITION_ESP,
PARTITION_SWAP,
PARTITION_ROOT_VERITY, /* verity data for the PARTITION_ROOT partition */
PARTITION_ROOT_SECONDARY_VERITY, /* verity data for the PARTITION_ROOT_SECONDARY partition */
_PARTITION_DESIGNATOR_MAX,
_PARTITION_DESIGNATOR_INVALID = -1
};
static inline int PARTITION_VERITY_OF(int p) {
if (p == PARTITION_ROOT)
return PARTITION_ROOT_VERITY;
if (p == PARTITION_ROOT_SECONDARY)
return PARTITION_ROOT_SECONDARY_VERITY;
return _PARTITION_DESIGNATOR_INVALID;
}
typedef enum DissectImageFlags {
DISSECT_IMAGE_READ_ONLY = 1,
DISSECT_IMAGE_DISCARD_ON_LOOP = 2, /* Turn on "discard" if on loop device and file system supports it */
DISSECT_IMAGE_DISCARD = 4, /* Turn on "discard" if file system supports it, on all block devices */
DISSECT_IMAGE_DISCARD_ON_CRYPTO = 8, /* Turn on "discard" also on crypto devices */
} DissectImageFlags;
struct DissectedImage {
bool encrypted:1;
bool verity:1; /* verity available and usable */
bool can_verity:1; /* verity available, but not necessarily used */
DissectedPartition partitions[_PARTITION_DESIGNATOR_MAX];
};
int dissect_image(int fd, const void *root_hash, size_t root_hash_size, DissectedImage **ret);
DissectedImage* dissected_image_unref(DissectedImage *m);
DEFINE_TRIVIAL_CLEANUP_FUNC(DissectedImage*, dissected_image_unref);
int dissected_image_decrypt(DissectedImage *m, const char *passphrase, const void *root_hash, size_t root_hash_size, DissectImageFlags flags, DecryptedImage **ret);
int dissected_image_decrypt_interactively(DissectedImage *m, const char *passphrase, const void *root_hash, size_t root_hash_size, DissectImageFlags flags, DecryptedImage **ret);
int dissected_image_mount(DissectedImage *m, const char *dest, DissectImageFlags flags);
DecryptedImage* decrypted_image_unref(DecryptedImage *p);
DEFINE_TRIVIAL_CLEANUP_FUNC(DecryptedImage*, decrypted_image_unref);
int decrypted_image_relinquish(DecryptedImage *d);
const char* partition_designator_to_string(int i) _const_;
int partition_designator_from_string(const char *name) _pure_;