Systemd/src/dissect/dissect.c

346 lines
13 KiB
C

/* SPDX-License-Identifier: LGPL-2.1+ */
#include <fcntl.h>
#include <getopt.h>
#include <linux/loop.h>
#include <stdio.h>
#include "architecture.h"
#include "dissect-image.h"
#include "hexdecoct.h"
#include "log.h"
#include "loop-util.h"
#include "main-func.h"
#include "parse-util.h"
#include "path-util.h"
#include "string-util.h"
#include "strv.h"
#include "user-util.h"
#include "util.h"
static enum {
ACTION_DISSECT,
ACTION_MOUNT,
} arg_action = ACTION_DISSECT;
static const char *arg_image = NULL;
static const char *arg_path = NULL;
static DissectImageFlags arg_flags = DISSECT_IMAGE_REQUIRE_ROOT|DISSECT_IMAGE_DISCARD_ON_LOOP|DISSECT_IMAGE_RELAX_VAR_CHECK|DISSECT_IMAGE_FSCK;
static void *arg_root_hash = NULL;
static char *arg_verity_data = NULL;
static size_t arg_root_hash_size = 0;
static char *arg_root_hash_sig_path = NULL;
static void *arg_root_hash_sig = NULL;
static size_t arg_root_hash_sig_size = 0;
STATIC_DESTRUCTOR_REGISTER(arg_root_hash, freep);
STATIC_DESTRUCTOR_REGISTER(arg_verity_data, freep);
STATIC_DESTRUCTOR_REGISTER(arg_root_hash_sig_path, freep);
STATIC_DESTRUCTOR_REGISTER(arg_root_hash_sig, freep);
static void help(void) {
printf("%s [OPTIONS...] IMAGE\n"
"%s [OPTIONS...] --mount IMAGE PATH\n"
"Dissect a file system OS image.\n\n"
" -h --help Show this help\n"
" --version Show package version\n"
" -m --mount Mount the image to the specified directory\n"
" -r --read-only Mount read-only\n"
" --fsck=BOOL Run fsck before mounting\n"
" --discard=MODE Choose 'discard' mode (disabled, loop, all, crypto)\n"
" --root-hash=HASH Specify root hash for verity\n"
" --root-hash-sig=SIG Specify pkcs7 signature of root hash for verity\n"
" as a DER encoded PKCS7, either as a path to a file\n"
" or as an ASCII base64 encoded string prefixed by\n"
" 'base64:'\n"
" --verity-data=PATH Specify data file with hash tree for verity if it is\n"
" not embedded in IMAGE\n",
program_invocation_short_name,
program_invocation_short_name);
}
static int parse_argv(int argc, char *argv[]) {
enum {
ARG_VERSION = 0x100,
ARG_DISCARD,
ARG_ROOT_HASH,
ARG_FSCK,
ARG_VERITY_DATA,
ARG_ROOT_HASH_SIG,
};
static const struct option options[] = {
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, ARG_VERSION },
{ "mount", no_argument, NULL, 'm' },
{ "read-only", no_argument, NULL, 'r' },
{ "discard", required_argument, NULL, ARG_DISCARD },
{ "root-hash", required_argument, NULL, ARG_ROOT_HASH },
{ "fsck", required_argument, NULL, ARG_FSCK },
{ "verity-data", required_argument, NULL, ARG_VERITY_DATA },
{ "root-hash-sig", required_argument, NULL, ARG_ROOT_HASH_SIG },
{}
};
int c, r;
assert(argc >= 0);
assert(argv);
while ((c = getopt_long(argc, argv, "hmr", options, NULL)) >= 0) {
switch (c) {
case 'h':
help();
return 0;
case ARG_VERSION:
return version();
case 'm':
arg_action = ACTION_MOUNT;
break;
case 'r':
arg_flags |= DISSECT_IMAGE_READ_ONLY;
break;
case ARG_DISCARD: {
DissectImageFlags flags;
if (streq(optarg, "disabled"))
flags = 0;
else if (streq(optarg, "loop"))
flags = DISSECT_IMAGE_DISCARD_ON_LOOP;
else if (streq(optarg, "all"))
flags = DISSECT_IMAGE_DISCARD_ON_LOOP | DISSECT_IMAGE_DISCARD;
else if (streq(optarg, "crypt"))
flags = DISSECT_IMAGE_DISCARD_ANY;
else
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
"Unknown --discard= parameter: %s",
optarg);
arg_flags = (arg_flags & ~DISSECT_IMAGE_DISCARD_ANY) | flags;
break;
}
case ARG_ROOT_HASH: {
void *p;
size_t l;
r = unhexmem(optarg, strlen(optarg), &p, &l);
if (r < 0)
return log_error_errno(r, "Failed to parse root hash '%s': %m", optarg);
if (l < sizeof(sd_id128_t)) {
log_error("Root hash must be at least 128bit long: %s", optarg);
free(p);
return -EINVAL;
}
free(arg_root_hash);
arg_root_hash = p;
arg_root_hash_size = l;
break;
}
case ARG_VERITY_DATA:
r = parse_path_argument_and_warn(optarg, false, &arg_verity_data);
if (r < 0)
return r;
break;
case ARG_ROOT_HASH_SIG: {
char *value;
if ((value = startswith(optarg, "base64:"))) {
void *p;
size_t l;
r = unbase64mem(value, strlen(value), &p, &l);
if (r < 0)
return log_error_errno(r, "Failed to parse root hash signature '%s': %m", optarg);
free_and_replace(arg_root_hash_sig, p);
arg_root_hash_sig_size = l;
arg_root_hash_sig_path = mfree(arg_root_hash_sig_path);
} else {
r = parse_path_argument_and_warn(optarg, false, &arg_root_hash_sig_path);
if (r < 0)
return r;
arg_root_hash_sig = mfree(arg_root_hash_sig);
arg_root_hash_sig_size = 0;
}
break;
}
case ARG_FSCK:
r = parse_boolean(optarg);
if (r < 0)
return log_error_errno(r, "Failed to parse --fsck= parameter: %s", optarg);
SET_FLAG(arg_flags, DISSECT_IMAGE_FSCK, r);
break;
case '?':
return -EINVAL;
default:
assert_not_reached("Unhandled option");
}
}
switch (arg_action) {
case ACTION_DISSECT:
if (optind + 1 != argc)
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
"Expected a file path as only argument.");
arg_image = argv[optind];
arg_flags |= DISSECT_IMAGE_READ_ONLY;
break;
case ACTION_MOUNT:
if (optind + 2 != argc)
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
"Expected a file path and mount point path as only arguments.");
arg_image = argv[optind];
arg_path = argv[optind + 1];
break;
default:
assert_not_reached("Unknown action.");
}
return 1;
}
static int run(int argc, char *argv[]) {
_cleanup_(loop_device_unrefp) LoopDevice *d = NULL;
_cleanup_(decrypted_image_unrefp) DecryptedImage *di = NULL;
_cleanup_(dissected_image_unrefp) DissectedImage *m = NULL;
int r;
log_parse_environment();
log_open();
r = parse_argv(argc, argv);
if (r <= 0)
return r;
r = loop_device_make_by_path(arg_image, (arg_flags & DISSECT_IMAGE_READ_ONLY) ? O_RDONLY : O_RDWR, LO_FLAGS_PARTSCAN, &d);
if (r < 0)
return log_error_errno(r, "Failed to set up loopback device: %m");
r = verity_metadata_load(arg_image, NULL, arg_root_hash ? NULL : &arg_root_hash, &arg_root_hash_size,
arg_verity_data ? NULL : &arg_verity_data,
arg_root_hash_sig_path || arg_root_hash_sig ? NULL : &arg_root_hash_sig_path);
if (r < 0)
return log_error_errno(r, "Failed to read verity artefacts for %s: %m", arg_image);
arg_flags |= arg_verity_data ? DISSECT_IMAGE_NO_PARTITION_TABLE : 0;
r = dissect_image_and_warn(d->fd, arg_image, arg_root_hash, arg_root_hash_size, arg_verity_data, arg_flags, &m);
if (r < 0)
return r;
switch (arg_action) {
case ACTION_DISSECT: {
unsigned i;
for (i = 0; i < _PARTITION_DESIGNATOR_MAX; i++) {
DissectedPartition *p = m->partitions + i;
if (!p->found)
continue;
printf("Found %s '%s' partition",
p->rw ? "writable" : "read-only",
partition_designator_to_string(i));
if (!sd_id128_is_null(p->uuid))
printf(" (UUID " SD_ID128_FORMAT_STR ")", SD_ID128_FORMAT_VAL(p->uuid));
if (p->fstype)
printf(" of type %s", p->fstype);
if (p->architecture != _ARCHITECTURE_INVALID)
printf(" for %s", architecture_to_string(p->architecture));
if (dissected_image_can_do_verity(m, i))
printf(" %s verity", dissected_image_has_verity(m, i) ? "with" : "without");
if (p->partno >= 0)
printf(" on partition #%i", p->partno);
if (p->node)
printf(" (%s)", p->node);
putchar('\n');
}
r = dissected_image_acquire_metadata(m);
if (r < 0)
return log_error_errno(r, "Failed to acquire image metadata: %m");
if (m->hostname)
printf(" Hostname: %s\n", m->hostname);
if (!sd_id128_is_null(m->machine_id))
printf("Machine ID: " SD_ID128_FORMAT_STR "\n", SD_ID128_FORMAT_VAL(m->machine_id));
if (!strv_isempty(m->machine_info)) {
char **p, **q;
STRV_FOREACH_PAIR(p, q, m->machine_info)
printf("%s %s=%s\n",
p == m->machine_info ? "Mach. Info:" : " ",
*p, *q);
}
if (!strv_isempty(m->os_release)) {
char **p, **q;
STRV_FOREACH_PAIR(p, q, m->os_release)
printf("%s %s=%s\n",
p == m->os_release ? "OS Release:" : " ",
*p, *q);
}
break;
}
case ACTION_MOUNT:
r = dissected_image_decrypt_interactively(m, NULL, arg_root_hash, arg_root_hash_size, arg_verity_data, arg_root_hash_sig_path, arg_root_hash_sig, arg_root_hash_sig_size, arg_flags, &di);
if (r < 0)
return r;
r = dissected_image_mount(m, arg_path, UID_INVALID, arg_flags);
if (r == -EUCLEAN)
return log_error_errno(r, "File system check on image failed: %m");
if (r < 0)
return log_error_errno(r, "Failed to mount image: %m");
if (di) {
r = decrypted_image_relinquish(di);
if (r < 0)
return log_error_errno(r, "Failed to relinquish DM devices: %m");
}
loop_device_relinquish(d);
break;
default:
assert_not_reached("Unknown action.");
}
return 0;
}
DEFINE_MAIN_FUNCTION(run);