cryptsetup-generator.c revision b4d0195b0598df76d30f006507fa8466f5a5d330
/*-*- 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 General Public License as published by
the Free Software Foundation; either version 2 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
General Public License for more details.
You should have received a copy of the GNU 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"
const char *arg_dest = "/tmp";
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");
if (!(n = unit_name_build_escape("cryptsetup", name, ".service"))) {
r = -ENOMEM;
log_error("Failed to allocate unit name.");
goto fail;
}
if (asprintf(&p, "%s/%s", arg_dest, n) < 0) {
r = -ENOMEM;
log_error("Failed to allocate unit file name.");
goto fail;
}
if (!(u = fstab_node_to_udev_node(device))) {
r = -ENOMEM;
log_error("Failed to allocate device node.");
goto fail;
}
if (!(d = unit_name_from_path(u, ".device"))) {
r = -ENOMEM;
log_error("Failed to allocate device name.");
goto fail;
}
if (!(f = fopen(p, "wxe"))) {
r = -errno;
log_error("Failed to create unit file: %m");
goto fail;
}
fprintf(f,
"[Unit]\n"
"Description=Cryptography Setup for %%I\n"
"Conflicts=umount.target\n"
"DefaultDependencies=no\n"
"BindTo=%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")))
fprintf(f,
"After=systemd-random-seed-load.service\n");
else
fprintf(f,
"Before=local-fs.target\n");
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 = -ENOMEM;
goto fail;
}
if (!noauto) {
if (asprintf(&to, "%s/%s.wants/%s", arg_dest, d, n) < 0) {
r = -ENOMEM;
goto fail;
}
mkdir_parents(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;
if (!nofail)
asprintf(&to, "%s/cryptsetup.target.requires/%s", arg_dest, n);
else
asprintf(&to, "%s/cryptsetup.target.wants/%s", arg_dest, n);
if (!to) {
r = -ENOMEM;
goto fail;
}
mkdir_parents(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);
if (asprintf(&to, "%s/dev-mapper-%s.device.requires/%s", arg_dest, e, n) < 0) {
r = -ENOMEM;
goto fail;
}
mkdir_parents(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;
}
int main(int argc, char *argv[]) {
FILE *f;
int r = EXIT_SUCCESS;
unsigned n = 0;
if (argc > 2) {
log_error("This program takes one or no arguments.");
return EXIT_FAILURE;
}
if (argc > 1)
arg_dest = argv[1];
log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
log_parse_environment();
log_open();
umask(0022);
if (!(f = fopen("/etc/crypttab", "re"))) {
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;
if ((k = sscanf(l, "%ms %ms %ms %ms", &name, &device, &password, &options)) < 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:
return r;
}