blob: 411793092518ed0f9525f75f332cd703b6d4e13c [file] [log] [blame] [raw]
/* SPDX-License-Identifier: LGPL-2.1+ */
#include <errno.h>
#include <stdio_ext.h>
#include "alloc-util.h"
#include "dropin.h"
#include "escape.h"
#include "fd-util.h"
#include "fileio.h"
#include "fstab-util.h"
#include "generator.h"
#include "hashmap.h"
#include "id128-util.h"
#include "log.h"
#include "mkdir.h"
#include "parse-util.h"
#include "path-util.h"
#include "proc-cmdline.h"
#include "specifier.h"
#include "string-util.h"
#include "strv.h"
#include "unit-name.h"
#include "util.h"
typedef struct crypto_device {
char *uuid;
char *keyfile;
char *keydev;
char *name;
char *options;
bool create;
} crypto_device;
static const char *arg_dest = "/tmp";
static bool arg_enabled = true;
static bool arg_read_crypttab = true;
static bool arg_whitelist = false;
static Hashmap *arg_disks = NULL;
static char *arg_default_options = NULL;
static char *arg_default_keyfile = NULL;
static int split_keyspec(const char *keyspec, char **ret_keyfile, char **ret_keydev) {
_cleanup_free_ char *keyfile = NULL, *keydev = NULL;
const char *c;
assert(ret_keyfile);
assert(ret_keydev);
if (!keyspec) {
*ret_keyfile = *ret_keydev = NULL;
return 0;
}
c = strrchr(keyspec, ':');
if (c) {
/* The keydev part has to be either an absolute path to device node (/dev/something,
* /dev/foo/something, or even possibly /dev/foo/something:part), or a fstab device
* specification starting with LABEL= or similar. The keyfile part has the same syntax.
*
* Let's try to guess if the second part looks like a keydev specification, or just part of a
* filename with a colon. fstab_node_to_udev_node() will convert the fstab device syntax to
* an absolute path. If we didn't get an absolute path, assume that it is just part of the
* first keyfile argument. */
keydev = fstab_node_to_udev_node(c + 1);
if (!keydev)
return log_oom();
if (path_is_absolute(keydev))
keyfile = strndup(keyspec, c-keyspec);
else {
log_debug("Keyspec argument contains a colon, but \"%s\" doesn't look like a device specification.\n"
"Assuming that \"%s\" is a single device specification.",
c + 1, keyspec);
keydev = mfree(keydev);
c = NULL;
}
}
if (!c)
/* No keydev specified */
keyfile = strdup(keyspec);
if (!keyfile)
return log_oom();
*ret_keyfile = TAKE_PTR(keyfile);
*ret_keydev = TAKE_PTR(keydev);
return 0;
}
static int generate_keydev_mount(const char *name, const char *keydev, const char *keydev_timeout, bool canfail, char **unit, char **mount) {
_cleanup_free_ char *u = NULL, *where = NULL, *name_escaped = NULL, *device_unit = NULL;
_cleanup_fclose_ FILE *f = NULL;
int r;
usec_t timeout_us;
assert(name);
assert(keydev);
assert(unit);
assert(mount);
r = mkdir_parents("/run/systemd/cryptsetup", 0755);
if (r < 0)
return r;
r = mkdir("/run/systemd/cryptsetup", 0700);
if (r < 0 && errno != EEXIST)
return -errno;
name_escaped = cescape(name);
if (!name_escaped)
return -ENOMEM;
where = strjoin("/run/systemd/cryptsetup/keydev-", name_escaped);
if (!where)
return -ENOMEM;
r = mkdir(where, 0700);
if (r < 0 && errno != EEXIST)
return -errno;
r = unit_name_from_path(where, ".mount", &u);
if (r < 0)
return r;
r = generator_open_unit_file(arg_dest, NULL, u, &f);
if (r < 0)
return r;
fprintf(f,
"[Unit]\n"
"DefaultDependencies=no\n\n"
"[Mount]\n"
"What=%s\n"
"Where=%s\n"
"Options=ro%s\n", keydev, where, canfail ? ",nofail" : "");
if (keydev_timeout) {
r = parse_sec_fix_0(keydev_timeout, &timeout_us);
if (r >= 0) {
r = unit_name_from_path(keydev, ".device", &device_unit);
if (r < 0)
return log_error_errno(r, "Failed to generate unit name: %m");
r = write_drop_in_format(arg_dest, device_unit, 90, "device-timeout",
"# Automatically generated by systemd-cryptsetup-generator \n\n"
"[Unit]\nJobRunningTimeoutSec=%s", keydev_timeout);
if (r < 0)
return log_error_errno(r, "Failed to write device drop-in: %m");
} else
log_warning_errno(r, "Failed to parse %s, ignoring: %m", keydev_timeout);
}
r = fflush_and_check(f);
if (r < 0)
return r;
*unit = TAKE_PTR(u);
*mount = TAKE_PTR(where);
return 0;
}
static int create_disk(
const char *name,
const char *device,
const char *password,
const char *keydev,
const char *options) {
_cleanup_free_ char *n = NULL, *d = NULL, *u = NULL, *e = NULL,
*keydev_mount = NULL, *keyfile_timeout_value = NULL, *password_escaped = NULL,
*filtered = NULL, *u_escaped = NULL, *filtered_escaped = NULL, *name_escaped = NULL;
_cleanup_fclose_ FILE *f = NULL;
const char *dmname;
bool noauto, nofail, tmp, swap, netdev;
int r, keyfile_can_timeout;
assert(name);
assert(device);
noauto = fstab_test_yes_no_option(options, "noauto\0" "auto\0");
nofail = fstab_test_yes_no_option(options, "nofail\0" "fail\0");
tmp = fstab_test_option(options, "tmp\0");
swap = fstab_test_option(options, "swap\0");
netdev = fstab_test_option(options, "_netdev\0");
keyfile_can_timeout = fstab_filter_options(options, "keyfile-timeout\0", NULL, &keyfile_timeout_value, NULL);
if (keyfile_can_timeout < 0)
return log_error_errno(keyfile_can_timeout, "Failed to parse keyfile-timeout= option value: %m");
if (tmp && swap) {
log_error("Device '%s' cannot be both 'tmp' and 'swap'. Ignoring.", name);
return -EINVAL;
}
name_escaped = specifier_escape(name);
if (!name_escaped)
return log_oom();
e = unit_name_escape(name);
if (!e)
return log_oom();
u = fstab_node_to_udev_node(device);
if (!u)
return log_oom();
r = unit_name_build("systemd-cryptsetup", e, ".service", &n);
if (r < 0)
return log_error_errno(r, "Failed to generate unit name: %m");
u_escaped = specifier_escape(u);
if (!u_escaped)
return log_oom();
r = unit_name_from_path(u, ".device", &d);
if (r < 0)
return log_error_errno(r, "Failed to generate unit name: %m");
if (keydev && !password) {
log_error("Key device is specified, but path to the password file is missing.");
return -EINVAL;
}
r = generator_open_unit_file(arg_dest, NULL, n, &f);
if (r < 0)
return r;
fprintf(f,
"[Unit]\n"
"Description=Cryptography Setup for %%I\n"
"Documentation=man:crypttab(5) man:systemd-cryptsetup-generator(8) man:systemd-cryptsetup@.service(8)\n"
"SourcePath=/etc/crypttab\n"
"DefaultDependencies=no\n"
"Conflicts=umount.target\n"
"IgnoreOnIsolate=true\n"
"After=%s\n",
netdev ? "remote-fs-pre.target" : "cryptsetup-pre.target");
if (password) {
password_escaped = specifier_escape(password);
if (!password_escaped)
return log_oom();
}
if (keydev) {
_cleanup_free_ char *unit = NULL, *p = NULL;
r = generate_keydev_mount(name, keydev, keyfile_timeout_value, keyfile_can_timeout > 0, &unit, &keydev_mount);
if (r < 0)
return log_error_errno(r, "Failed to generate keydev mount unit: %m");
p = prefix_root(keydev_mount, password_escaped);
if (!p)
return log_oom();
free_and_replace(password_escaped, p);
fprintf(f, "After=%s\n", unit);
if (keyfile_can_timeout > 0)
fprintf(f, "Wants=%s\n", unit);
else
fprintf(f, "Requires=%s\n", unit);
}
if (!nofail)
fprintf(f,
"Before=%s\n",
netdev ? "remote-cryptsetup.target" : "cryptsetup.target");
if (password && !keydev) {
if (STR_IN_SET(password, "/dev/urandom", "/dev/random", "/dev/hw_random"))
fputs("After=systemd-random-seed.service\n", f);
else if (!STR_IN_SET(password, "-", "none")) {
_cleanup_free_ char *uu;
uu = fstab_node_to_udev_node(password);
if (!uu)
return log_oom();
if (!path_equal(uu, "/dev/null")) {
if (path_startswith(uu, "/dev/")) {
_cleanup_free_ char *dd = NULL;
r = unit_name_from_path(uu, ".device", &dd);
if (r < 0)
return log_error_errno(r, "Failed to generate unit name: %m");
fprintf(f, "After=%1$s\nRequires=%1$s\n", dd);
} else
fprintf(f, "RequiresMountsFor=%s\n", password_escaped);
}
}
}
if (path_startswith(u, "/dev/")) {
fprintf(f,
"BindsTo=%s\n"
"After=%s\n"
"Before=umount.target\n",
d, d);
if (swap)
fputs("Before=dev-mapper-%i.swap\n",
f);
} else
fprintf(f,
"RequiresMountsFor=%s\n",
u_escaped);
r = generator_write_timeouts(arg_dest, device, name, options, &filtered);
if (r < 0)
return r;
if (filtered) {
filtered_escaped = specifier_escape(filtered);
if (!filtered_escaped)
return log_oom();
}
fprintf(f,
"\n[Service]\n"
"Type=oneshot\n"
"RemainAfterExit=yes\n"
"TimeoutSec=0\n" /* the binary handles timeouts anyway */
"KeyringMode=shared\n" /* make sure we can share cached keys among instances */
"ExecStart=" SYSTEMD_CRYPTSETUP_PATH " attach '%s' '%s' '%s' '%s'\n"
"ExecStop=" SYSTEMD_CRYPTSETUP_PATH " detach '%s'\n",
name_escaped, u_escaped, strempty(password_escaped), strempty(filtered_escaped),
name_escaped);
if (tmp)
fprintf(f,
"ExecStartPost=/sbin/mke2fs '/dev/mapper/%s'\n",
name_escaped);
if (swap)
fprintf(f,
"ExecStartPost=/sbin/mkswap '/dev/mapper/%s'\n",
name_escaped);
if (keydev)
fprintf(f,
"ExecStartPost=-" UMOUNT_PATH " %s\n\n",
keydev_mount);
r = fflush_and_check(f);
if (r < 0)
return log_error_errno(r, "Failed to write unit file %s: %m", n);
if (!noauto) {
r = generator_add_symlink(arg_dest, d, "wants", n);
if (r < 0)
return r;
r = generator_add_symlink(arg_dest,
netdev ? "remote-cryptsetup.target" : "cryptsetup.target",
nofail ? "wants" : "requires", n);
if (r < 0)
return r;
}
dmname = strjoina("dev-mapper-", e, ".device");
r = generator_add_symlink(arg_dest, dmname, "requires", n);
if (r < 0)
return r;
if (!noauto && !nofail) {
r = write_drop_in(arg_dest, dmname, 90, "device-timeout",
"# Automatically generated by systemd-cryptsetup-generator \n\n"
"[Unit]\nJobTimeoutSec=0");
if (r < 0)
return log_error_errno(r, "Failed to write device drop-in: %m");
}
return 0;
}
static void crypt_device_free(crypto_device *d) {
free(d->uuid);
free(d->keyfile);
free(d->keydev);
free(d->name);
free(d->options);
free(d);
}
static crypto_device *get_crypto_device(const char *uuid) {
int r;
crypto_device *d;
assert(uuid);
d = hashmap_get(arg_disks, uuid);
if (!d) {
d = new0(struct crypto_device, 1);
if (!d)
return NULL;
d->create = false;
d->keyfile = d->options = d->name = NULL;
d->uuid = strdup(uuid);
if (!d->uuid)
return mfree(d);
r = hashmap_put(arg_disks, d->uuid, d);
if (r < 0) {
free(d->uuid);
return mfree(d);
}
}
return d;
}
static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
_cleanup_free_ char *uuid = NULL, *uuid_value = NULL;
crypto_device *d;
int r;
if (streq(key, "luks")) {
r = value ? parse_boolean(value) : 1;
if (r < 0)
log_warning("Failed to parse luks= kernel command line switch %s. Ignoring.", value);
else
arg_enabled = r;
} else if (streq(key, "luks.crypttab")) {
r = value ? parse_boolean(value) : 1;
if (r < 0)
log_warning("Failed to parse luks.crypttab= kernel command line switch %s. Ignoring.", value);
else
arg_read_crypttab = r;
} else if (streq(key, "luks.uuid")) {
if (proc_cmdline_value_missing(key, value))
return 0;
d = get_crypto_device(startswith(value, "luks-") ? value+5 : value);
if (!d)
return log_oom();
d->create = arg_whitelist = true;
} else if (streq(key, "luks.options")) {
if (proc_cmdline_value_missing(key, value))
return 0;
r = sscanf(value, "%m[0-9a-fA-F-]=%ms", &uuid, &uuid_value);
if (r == 2) {
d = get_crypto_device(uuid);
if (!d)
return log_oom();
free_and_replace(d->options, uuid_value);
} else if (free_and_strdup(&arg_default_options, value) < 0)
return log_oom();
} else if (streq(key, "luks.key")) {
size_t n;
_cleanup_free_ char *keyfile = NULL, *keydev = NULL;
const char *keyspec;
if (proc_cmdline_value_missing(key, value))
return 0;
n = strspn(value, LETTERS DIGITS "-");
if (value[n] != '=') {
if (free_and_strdup(&arg_default_keyfile, value) < 0)
return log_oom();
return 0;
}
uuid = strndup(value, n);
if (!uuid)
return log_oom();
if (!id128_is_valid(uuid)) {
log_warning("Failed to parse luks.key= kernel command line switch. UUID is invalid, ignoring.");
return 0;
}
d = get_crypto_device(uuid);
if (!d)
return log_oom();
keyspec = value + n + 1;
r = split_keyspec(keyspec, &keyfile, &keydev);
if (r < 0)
return r;
free_and_replace(d->keyfile, keyfile);
free_and_replace(d->keydev, keydev);
} else if (streq(key, "luks.name")) {
if (proc_cmdline_value_missing(key, value))
return 0;
r = sscanf(value, "%m[0-9a-fA-F-]=%ms", &uuid, &uuid_value);
if (r == 2) {
d = get_crypto_device(uuid);
if (!d)
return log_oom();
d->create = arg_whitelist = true;
free_and_replace(d->name, uuid_value);
} else
log_warning("Failed to parse luks name switch %s. Ignoring.", value);
}
return 0;
}
static int add_crypttab_devices(void) {
struct stat st;
unsigned crypttab_line = 0;
_cleanup_fclose_ FILE *f = NULL;
if (!arg_read_crypttab)
return 0;
f = fopen("/etc/crypttab", "re");
if (!f) {
if (errno != ENOENT)
log_error_errno(errno, "Failed to open /etc/crypttab: %m");
return 0;
}
(void) __fsetlocking(f, FSETLOCKING_BYCALLER);
if (fstat(fileno(f), &st) < 0) {
log_error_errno(errno, "Failed to stat /etc/crypttab: %m");
return 0;
}
for (;;) {
int r, k;
char line[LINE_MAX], *l, *uuid;
crypto_device *d = NULL;
_cleanup_free_ char *name = NULL, *device = NULL, *keydev = NULL, *keyfile = NULL, *keyspec = NULL, *options = NULL;
if (!fgets(line, sizeof(line), f))
break;
crypttab_line++;
l = strstrip(line);
if (IN_SET(*l, 0, '#'))
continue;
k = sscanf(l, "%ms %ms %ms %ms", &name, &device, &keyspec, &options);
if (k < 2 || k > 4) {
log_error("Failed to parse /etc/crypttab:%u, ignoring.", crypttab_line);
continue;
}
uuid = startswith(device, "UUID=");
if (!uuid)
uuid = path_startswith(device, "/dev/disk/by-uuid/");
if (!uuid)
uuid = startswith(name, "luks-");
if (uuid)
d = hashmap_get(arg_disks, uuid);
if (arg_whitelist && !d) {
log_info("Not creating device '%s' because it was not specified on the kernel command line.", name);
continue;
}
r = split_keyspec(keyspec, &keyfile, &keydev);
if (r < 0)
return r;
r = create_disk(name, device, keyfile, keydev, (d && d->options) ? d->options : options);
if (r < 0)
return r;
if (d)
d->create = false;
}
return 0;
}
static int add_proc_cmdline_devices(void) {
int r;
Iterator i;
crypto_device *d;
HASHMAP_FOREACH(d, arg_disks, i) {
const char *options;
_cleanup_free_ char *device = NULL;
if (!d->create)
continue;
if (!d->name) {
d->name = strappend("luks-", d->uuid);
if (!d->name)
return log_oom();
}
device = strappend("UUID=", d->uuid);
if (!device)
return log_oom();
if (d->options)
options = d->options;
else if (arg_default_options)
options = arg_default_options;
else
options = "timeout=0";
r = create_disk(d->name, device, d->keyfile ?: arg_default_keyfile, d->keydev, options);
if (r < 0)
return r;
}
return 0;
}
int main(int argc, char *argv[]) {
int r;
if (argc > 1 && argc != 4) {
log_error("This program takes three or no arguments.");
return EXIT_FAILURE;
}
if (argc > 1)
arg_dest = argv[1];
log_set_prohibit_ipc(true);
log_set_target(LOG_TARGET_AUTO);
log_parse_environment();
log_open();
umask(0022);
arg_disks = hashmap_new(&string_hash_ops);
if (!arg_disks) {
r = log_oom();
goto finish;
}
r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, PROC_CMDLINE_STRIP_RD_PREFIX);
if (r < 0) {
log_warning_errno(r, "Failed to parse kernel command line: %m");
goto finish;
}
if (!arg_enabled) {
r = 0;
goto finish;
}
r = add_crypttab_devices();
if (r < 0)
goto finish;
r = add_proc_cmdline_devices();
if (r < 0)
goto finish;
r = 0;
finish:
hashmap_free_with_destructor(arg_disks, crypt_device_free);
free(arg_default_options);
free(arg_default_keyfile);
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}