blob: 040a1aa4084b4dbdeff1a0adf4860e3ab210ce36 [file] [log] [blame] [raw]
/***
This file is part of systemd.
Copyright 2010 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 <errno.h>
#include "alloc-util.h"
#include "dropin.h"
#include "fd-util.h"
#include "fileio.h"
#include "fstab-util.h"
#include "generator.h"
#include "hashmap.h"
#include "log.h"
#include "mkdir.h"
#include "parse-util.h"
#include "path-util.h"
#include "proc-cmdline.h"
#include "string-util.h"
#include "strv.h"
#include "unit-name.h"
#include "util.h"
typedef struct crypto_device {
char *uuid;
char *keyfile;
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 create_disk(
const char *name,
const char *device,
const char *password,
const char *options) {
_cleanup_free_ char *p = NULL, *n = NULL, *d = NULL, *u = NULL, *e = NULL,
*filtered = NULL;
_cleanup_fclose_ FILE *f = NULL;
const char *dmname;
bool noauto, nofail, tmp, swap, netdev;
int r;
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");
if (tmp && swap) {
log_error("Device '%s' cannot be both 'tmp' and 'swap'. Ignoring.", name);
return -EINVAL;
}
e = unit_name_escape(name);
if (!e)
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");
p = strjoin(arg_dest, "/", n);
if (!p)
return log_oom();
u = fstab_node_to_udev_node(device);
if (!u)
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");
f = fopen(p, "wxe");
if (!f)
return log_error_errno(errno, "Failed to create unit file %s: %m", p);
fprintf(f,
"# Automatically generated by systemd-cryptsetup-generator\n\n"
"[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 (!nofail)
fprintf(f,
"Before=%s\n",
netdev ? "remote-cryptsetup.target" : "cryptsetup.target");
if (password) {
if (STR_IN_SET(password, "/dev/urandom", "/dev/random", "/dev/hw_random"))
fputs_unlocked("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);
}
}
}
if (path_startswith(u, "/dev/")) {
fprintf(f,
"BindsTo=%s\n"
"After=%s\n"
"Before=umount.target\n",
d, d);
if (swap)
fputs_unlocked("Before=dev-mapper-%i.swap\n",
f);
} else
fprintf(f,
"RequiresMountsFor=%s\n",
u);
r = generator_write_timeouts(arg_dest, device, name, options, &filtered);
if (r < 0)
return r;
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, u, strempty(password), strempty(filtered),
name);
if (tmp)
fprintf(f,
"ExecStartPost=/sbin/mke2fs '/dev/mapper/%s'\n",
name);
if (swap)
fprintf(f,
"ExecStartPost=/sbin/mkswap '/dev/mapper/%s'\n",
name);
r = fflush_and_check(f);
if (r < 0)
return log_error_errno(r, "Failed to write file %s: %m", p);
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 free_arg_disks(void) {
crypto_device *d;
while ((d = hashmap_steal_first(arg_disks))) {
free(d->uuid);
free(d->keyfile);
free(d->name);
free(d->options);
free(d);
}
hashmap_free(arg_disks);
}
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")) {
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->keyfile, uuid_value);
} else if (free_and_strdup(&arg_default_keyfile, value) < 0)
return log_oom();
} 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(d->name);
d->name = uuid_value;
uuid_value = NULL;
} 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;
}
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, *keyfile = 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, &keyfile, &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 = create_disk(name, device, keyfile, (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, 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_target(LOG_TARGET_SAFE);
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:
free_arg_disks();
free(arg_default_options);
free(arg_default_keyfile);
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}