cryptsetup-generator.c revision 74576bea7a50740f1aec423bac5e20f8ca7a8592
/*-*- 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 "virt.h"
#include "strv.h"
static const char *arg_dest = "/tmp";
static bool arg_enabled = true;
static bool arg_read_crypttab = true;
static char **arg_proc_cmdline_disks = 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) {
char *p = NULL, *n = NULL, *d = NULL, *u = NULL, *from = NULL, *to = NULL, *e = NULL;
int r;
FILE *f = NULL;
bool noauto, nofail;
assert(name);
assert(device);
noauto = has_option(options, "noauto");
nofail = has_option(options, "nofail");
n = unit_name_from_path_instance("systemd-cryptsetup", name, ".service");
if (!n) {
r = log_oom();
goto fail;
}
p = strjoin(arg_dest, "/", n, NULL);
if (!p) {
r = log_oom();
goto fail;
}
u = fstab_node_to_udev_node(device);
if (!u) {
r = log_oom();
goto fail;
}
d = unit_name_from_path(u, ".device");
if (!d) {
r = log_oom();
goto fail;
}
f = fopen(p, "wxe");
if (!f) {
r = -errno;
log_error("Failed to create unit file: %m");
goto fail;
}
fprintf(f,
"# Automatically generated by systemd-cryptsetup-generator\n\n"
"[Unit]\n"
"Description=Cryptography Setup for %%I\n"
"Documentation=man:systemd-cryptsetup@.service(8) man:crypttab(5)\n"
"SourcePath=/etc/crypttab\n"
"Conflicts=umount.target\n"
"DefaultDependencies=no\n"
"BindsTo=%s dev-mapper-%%i.device\n"
"After=systemd-readahead-collect.service systemd-readahead-replay.service %s\n"
"Before=umount.target\n",
d, d);
if (!nofail)
fprintf(f,
"Before=cryptsetup.target\n");
if (password && (streq(password, "/dev/urandom") ||
streq(password, "/dev/random") ||
streq(password, "/dev/hw_random")))
fputs("After=systemd-random-seed-load.service\n", f);
else
fputs("Before=local-fs.target\n", f);
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 (has_option(options, "tmp"))
fprintf(f,
"ExecStartPost=/sbin/mke2fs '/dev/mapper/%s'\n",
name);
if (has_option(options, "swap"))
fprintf(f,
"ExecStartPost=/sbin/mkswap '/dev/mapper/%s'\n",
name);
fflush(f);
if (ferror(f)) {
r = -errno;
log_error("Failed to write file: %m");
goto fail;
}
if (asprintf(&from, "../%s", n) < 0) {
r = log_oom();
goto fail;
}
if (!noauto) {
to = strjoin(arg_dest, "/", d, ".wants/", n, NULL);
if (!to) {
r = log_oom();
goto fail;
}
mkdir_parents_label(to, 0755);
if (symlink(from, to) < 0) {
log_error("Failed to create symlink '%s' to '%s': %m", from, to);
r = -errno;
goto fail;
}
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) {
r = log_oom();
goto fail;
}
mkdir_parents_label(to, 0755);
if (symlink(from, to) < 0) {
log_error("Failed to create symlink '%s' to '%s': %m", from, to);
r = -errno;
goto fail;
}
free(to);
to = NULL;
}
e = unit_name_escape(name);
to = strjoin(arg_dest, "/dev-mapper-", e, ".device.requires/", n, NULL);
if (!to) {
r = log_oom();
goto fail;
}
mkdir_parents_label(to, 0755);
if (symlink(from, to) < 0) {
log_error("Failed to create symlink '%s' to '%s': %m", from, to);
r = -errno;
goto fail;
}
r = 0;
fail:
free(p);
free(n);
free(d);
free(e);
free(from);
free(to);
if (f)
fclose(f);
return r;
}
static int parse_proc_cmdline(void) {
char *line, *w, *state;
int r;
size_t l;
if (detect_container(NULL) > 0)
return 0;
r = read_one_line_file("/proc/cmdline", &line);
if (r < 0) {
log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(-r));
return 0;
}
FOREACH_WORD_QUOTED(w, l, line, state) {
char *word;
word = strndup(w, l);
if (!word) {
r = log_oom();
goto finish;
}
if (startswith(word, "luks=")) {
r = parse_boolean(word + 5);
if (r < 0)
log_warning("Failed to parse luks switch %s. Ignoring.", word + 5);
else
arg_enabled = r;
} else if (startswith(word, "rd.luks=")) {
if (in_initrd()) {
r = parse_boolean(word + 8);
if (r < 0)
log_warning("Failed to parse luks switch %s. Ignoring.", word + 8);
else
arg_enabled = r;
}
} else if (startswith(word, "luks.crypttab=")) {
r = parse_boolean(word + 14);
if (r < 0)
log_warning("Failed to parse luks crypttab switch %s. Ignoring.", word + 14);
else
arg_read_crypttab = r;
} else if (startswith(word, "rd.luks.crypttab=")) {
if (in_initrd()) {
r = parse_boolean(word + 17);
if (r < 0)
log_warning("Failed to parse luks crypttab switch %s. Ignoring.", word + 17);
else
arg_read_crypttab = r;
}
} else if (startswith(word, "luks.uuid=")) {
char **t;
t = strv_append(arg_proc_cmdline_disks, word + 10);
if (!t) {
r = log_oom();
goto finish;
}
strv_free(arg_proc_cmdline_disks);
arg_proc_cmdline_disks = t;
} else if (startswith(word, "rd.luks.uuid=")) {
if (in_initrd()) {
char **t;
t = strv_append(arg_proc_cmdline_disks, word + 13);
if (!t) {
r = log_oom();
goto finish;
}
strv_free(arg_proc_cmdline_disks);
arg_proc_cmdline_disks = t;
}
} else if (startswith(word, "luks.") ||
(in_initrd() && startswith(word, "rd.luks."))) {
log_warning("Unknown kernel switch %s. Ignoring.", word);
}
free(word);
}
r = 0;
finish:
free(line);
return r;
}
int main(int argc, char *argv[]) {
FILE *f = NULL;
int r = EXIT_SUCCESS;
unsigned n = 0;
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() < 0)
return EXIT_FAILURE;
if (!arg_enabled) {
r = EXIT_SUCCESS;
goto finish;
}
STRV_FOREACH(i, arg_proc_cmdline_disks) {
char *name, *device;
const char *p = *i;
if (startswith(p, "luks-"))
p += 5;
name = strappend("luks-", p);
device = strappend("UUID=", p);
if (!name || !device) {
log_oom();
r = EXIT_FAILURE;
free(name);
free(device);
goto finish;
}
if (create_disk(name, device, NULL, NULL) < 0)
r = EXIT_FAILURE;
free(name);
free(device);
}
if (!arg_read_crypttab)
return r;
f = fopen("/etc/crypttab", "re");
if (!f) {
if (errno == ENOENT)
r = EXIT_SUCCESS;
else {
r = EXIT_FAILURE;
log_error("Failed to open /etc/crypttab: %m");
}
goto finish;
}
for (;;) {
char line[LINE_MAX], *l;
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);
r = EXIT_FAILURE;
goto next;
}
if (create_disk(name, device, password, options) < 0)
r = EXIT_FAILURE;
next:
free(name);
free(device);
free(password);
free(options);
}
finish:
if (f)
fclose(f);
strv_free(arg_proc_cmdline_disks);
return r;
}