cryptsetup-generator.c revision bde29068aa3815c88190a91e9867605a0aeaf9c4
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
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 <string.h>
#include <errno.h>
#include <unistd.h>
#include "log.h"
#include "util.h"
#include "unit-name.h"
#include "mkdir.h"
#include "strv.h"
#include "fileio.h"
#include "path-util.h"
static const char *arg_dest = "/tmp";
static bool arg_enabled = true;
static bool arg_read_crypttab = true;
static char **arg_disks = NULL;
static char **arg_options = NULL;
static char *arg_keyfile = NULL;
static bool has_option(const char *haystack, const char *needle) {
const char *f = haystack;
size_t l;
assert(needle);
if (!haystack)
return false;
l = strlen(needle);
while ((f = strstr(f, needle))) {
if (f > haystack && f[-1] != ',') {
f++;
continue;
}
if (f[l] != 0 && f[l] != ',') {
f++;
continue;
}
return true;
}
return false;
}
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, *to = NULL, *e = NULL;
_cleanup_fclose_ FILE *f = NULL;
bool noauto, nofail, tmp, swap;
char *from;
int r;
assert(name);
assert(device);
noauto = has_option(options, "noauto");
nofail = has_option(options, "nofail");
tmp = has_option(options, "tmp");
swap = has_option(options, "swap");
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();
n = unit_name_build("systemd-cryptsetup", e, ".service");
if (!n)
return log_oom();
p = strjoin(arg_dest, "/", n, NULL);
if (!p)
return log_oom();
u = fstab_node_to_udev_node(device);
if (!u)
return log_oom();
d = unit_name_from_path(u, ".device");
if (!d)
return log_oom();
f = fopen(p, "wxe");
if (!f) {
log_error("Failed to create unit file %s: %m", p);
return -errno;
}
fputs(
"# 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"
"BindsTo=dev-mapper-%i.device\n"
"IgnoreOnIsolate=true\n"
"After=systemd-readahead-collect.service systemd-readahead-replay.service cryptsetup-pre.target\n",
f);
if (!nofail)
fprintf(f,
"Before=cryptsetup.target\n");
if (password) {
if (STR_IN_SET(password, "/dev/urandom", "/dev/random", "/dev/hw_random"))
fputs("After=systemd-random-seed.service\n", f);
else if (!streq(password, "-") && !streq(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 (is_device_path(uu)) {
_cleanup_free_ char *dd;
dd = unit_name_from_path(uu, ".device");
if (!dd)
return log_oom();
fprintf(f, "After=%1$s\nRequires=%1$s\n", dd);
} else
fprintf(f, "RequiresMountsFor=%s\n", password);
}
}
}
if (is_device_path(u))
fprintf(f,
"BindsTo=%s\n"
"After=%s\n"
"Before=umount.target\n",
d, d);
else
fprintf(f,
"RequiresMountsFor=%s\n",
u);
fprintf(f,
"\n[Service]\n"
"Type=oneshot\n"
"RemainAfterExit=yes\n"
"TimeoutSec=0\n" /* the binary handles timeouts anyway */
"ExecStart=" SYSTEMD_CRYPTSETUP_PATH " attach '%s' '%s' '%s' '%s'\n"
"ExecStop=" SYSTEMD_CRYPTSETUP_PATH " detach '%s'\n",
name, u, strempty(password), strempty(options),
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);
fflush(f);
if (ferror(f)) {
log_error("Failed to write file %s: %m", p);
return -errno;
}
from = strappenda("../", n);
if (!noauto) {
to = strjoin(arg_dest, "/", d, ".wants/", n, NULL);
if (!to)
return log_oom();
mkdir_parents_label(to, 0755);
if (symlink(from, to) < 0) {
log_error("Failed to create symlink %s: %m", to);
return -errno;
}
free(to);
if (!nofail)
to = strjoin(arg_dest, "/cryptsetup.target.requires/", n, NULL);
else
to = strjoin(arg_dest, "/cryptsetup.target.wants/", n, NULL);
if (!to)
return log_oom();
mkdir_parents_label(to, 0755);
if (symlink(from, to) < 0) {
log_error("Failed to create symlink %s: %m", to);
return -errno;
}
}
free(to);
to = strjoin(arg_dest, "/dev-mapper-", e, ".device.requires/", n, NULL);
if (!to)
return log_oom();
mkdir_parents_label(to, 0755);
if (symlink(from, to) < 0) {
log_error("Failed to create symlink %s: %m", to);
return -errno;
}
if (!noauto && !nofail) {
free(p);
p = strjoin(arg_dest, "/dev-mapper-", e, ".device.d/50-job-timeout-sec-0.conf", NULL);
if (!p)
return log_oom();
mkdir_parents_label(p, 0755);
r = write_string_file(p,
"# Automatically generated by systemd-cryptsetup-generator\n\n"
"[Unit]\n"
"JobTimeoutSec=0\n"); /* the binary handles timeouts anyway */
if (r < 0) {
log_error("Failed to write device drop-in: %s", strerror(-r));
return r;
}
}
return 0;
}
static int parse_proc_cmdline_item(const char *key, const char *value) {
int r;
if (STR_IN_SET(key, "luks", "rd.luks") && value) {
r = parse_boolean(value);
if (r < 0)
log_warning("Failed to parse luks switch %s. Ignoring.", value);
else
arg_enabled = r;
} else if (STR_IN_SET(key, "luks.crypttab", "rd.luks.crypttab") && value) {
r = parse_boolean(value);
if (r < 0)
log_warning("Failed to parse luks crypttab switch %s. Ignoring.", value);
else
arg_read_crypttab = r;
} else if (STR_IN_SET(key, "luks.uuid", "rd.luks.uuid") && value) {
if (strv_extend(&arg_disks, value) < 0)
return log_oom();
} else if (STR_IN_SET(key, "luks.options", "rd.luks.options") && value) {
if (strv_extend(&arg_options, value) < 0)
return log_oom();
} else if (STR_IN_SET(key, "luks.key", "rd.luks.key") && value) {
free(arg_keyfile);
arg_keyfile = strdup(value);
if (!arg_keyfile)
return log_oom();
}
return 0;
}
int main(int argc, char *argv[]) {
_cleanup_strv_free_ char **disks_done = NULL;
_cleanup_fclose_ FILE *f = NULL;
unsigned n = 0;
int r = EXIT_FAILURE, r2 = EXIT_FAILURE;
char **i;
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);
if (parse_proc_cmdline(parse_proc_cmdline_item) < 0)
goto cleanup;
if (!arg_enabled) {
r = r2 = EXIT_SUCCESS;
goto cleanup;
}
strv_uniq(arg_disks);
if (arg_read_crypttab) {
struct stat st;
f = fopen("/etc/crypttab", "re");
if (!f) {
if (errno == ENOENT)
r = EXIT_SUCCESS;
else
log_error("Failed to open /etc/crypttab: %m");
goto next;
}
if (fstat(fileno(f), &st) < 0) {
log_error("Failed to stat /etc/crypttab: %m");
goto next;
}
/* If we readd support for specifying passphrases
* directly in crypttabe we should upgrade the warning
* below, though possibly only if a passphrase is
* specified directly. */
if (st.st_mode & 0005)
log_debug("/etc/crypttab is world-readable. This is usually not a good idea.");
for (;;) {
char line[LINE_MAX], *l;
_cleanup_free_ char *name = NULL, *device = NULL, *password = NULL, *options = NULL;
int k;
if (!fgets(line, sizeof(line), f))
break;
n++;
l = strstrip(line);
if (*l == '#' || *l == 0)
continue;
k = sscanf(l, "%ms %ms %ms %ms", &name, &device, &password, &options);
if (k < 2 || k > 4) {
log_error("Failed to parse /etc/crypttab:%u, ignoring.", n);
continue;
}
/*
If options are specified on the kernel commandline, let them override
the ones from crypttab.
*/
STRV_FOREACH(i, arg_options) {
_cleanup_free_ char *proc_uuid = NULL, *proc_options = NULL;
const char *p = *i;
k = sscanf(p, "%m[0-9a-fA-F-]=%ms", &proc_uuid, &proc_options);
if (k == 2 && streq(proc_uuid, device + 5)) {
free(options);
options = strdup(p);
if (!proc_options) {
log_oom();
goto cleanup;
}
}
}
if (arg_disks) {
/*
If luks UUIDs are specified on the kernel command line, use them as a filter
for /etc/crypttab and only generate units for those.
*/
STRV_FOREACH(i, arg_disks) {
_cleanup_free_ char *proc_device = NULL, *proc_name = NULL;
const char *p = *i;
if (startswith(p, "luks-"))
p += 5;
proc_name = strappend("luks-", p);
proc_device = strappend("UUID=", p);
if (!proc_name || !proc_device) {
log_oom();
goto cleanup;
}
if (streq(proc_device, device) || streq(proc_name, name)) {
if (create_disk(name, device, password, options) < 0)
goto cleanup;
if (strv_extend(&disks_done, p) < 0) {
log_oom();
goto cleanup;
}
}
}
} else if (create_disk(name, device, password, options) < 0)
goto cleanup;
}
}
r = EXIT_SUCCESS;
next:
STRV_FOREACH(i, arg_disks) {
/*
Generate units for those UUIDs, which were specified
on the kernel command line and not yet written.
*/
_cleanup_free_ char *name = NULL, *device = NULL, *options = NULL;
const char *p = *i;
if (startswith(p, "luks-"))
p += 5;
if (strv_contains(disks_done, p))
continue;
name = strappend("luks-", p);
device = strappend("UUID=", p);
if (!name || !device) {
log_oom();
goto cleanup;
}
if (arg_options) {
/*
If options are specified on the kernel commandline, use them.
*/
char **j;
STRV_FOREACH(j, arg_options) {
_cleanup_free_ char *proc_uuid = NULL, *proc_options = NULL;
const char *s = *j;
int k;
k = sscanf(s, "%m[0-9a-fA-F-]=%ms", &proc_uuid, &proc_options);
if (k == 2) {
if (streq(proc_uuid, device + 5)) {
free(options);
options = proc_options;
proc_options = NULL;
}
} else if (!options) {
/*
Fall back to options without a specified UUID
*/
options = strdup(s);
if (!options) {
log_oom();
goto cleanup;
};
}
}
}
if (!options) {
options = strdup("timeout=0");
if (!options) {
log_oom();
goto cleanup;
}
}
if (create_disk(name, device, arg_keyfile, options) < 0)
goto cleanup;
}
r2 = EXIT_SUCCESS;
cleanup:
strv_free(arg_disks);
strv_free(arg_options);
free(arg_keyfile);
return r != EXIT_SUCCESS ? r : r2;
}