#include <errno.h>

#include <string.h>

#include <unistd.h>

#include "dropin.h"

#include "fileio.h"

#include "generator.h"

#include "hashmap.h"

#include "log.h"

#include "mkdir.h"

#include "path-util.h"

#include "strv.h"

#include "unit-name.h"

#include "util.h"

typedef struct crypto_device {

char *uuid;

char *keyfile;

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 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,

*filtered = 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)

return log_error_errno(errno, "Failed to create unit file %s: %m", p);

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=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);

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 */

"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);

fflush(f);

if (ferror(f))

return log_error_errno(errno, "Failed to write file %s: %m", p);

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)

return log_error_errno(errno, "Failed to create symlink %s: %m", to);

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)

return log_error_errno(errno, "Failed to create symlink %s: %m", to);

}

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)

return log_error_errno(errno, "Failed to create symlink %s: %m", to);

if (!noauto && !nofail) {

_cleanup_free_ char *dmname;

dmname = strjoin("dev-mapper-", e, ".device", NULL);

if (!dmname)

return log_oom();

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->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 = NULL;

d->uuid = strdup(uuid);

if (!d->uuid) {

free(d);

return NULL;

}

r = hashmap_put(arg_disks, d->uuid, d);

if (r < 0) {

free(d->uuid);

free(d);

return NULL;

}

}

return d;

}

static int parse_proc_cmdline_item(const char *key, const char *value) {

int r;

crypto_device *d;

_cleanup_free_ char *uuid = NULL, *uuid_value = NULL;

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) {

d = get_crypto_device(startswith(value, "luks-") ? value+5 : value);

if (!d)

return log_oom();

d->create = arg_whitelist = true;

} else if (STR_IN_SET(key, "luks.options", "rd.luks.options") && value) {

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(d->options);

d->options = uuid_value;

uuid_value = NULL;

} else if (free_and_strdup(&arg_default_options, value) < 0)

return log_oom();

} else if (STR_IN_SET(key, "luks.key", "rd.luks.key") && value) {

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(d->keyfile);

d->keyfile = uuid_value;

uuid_value = NULL;

} else if (free_and_strdup(&arg_default_keyfile, value))

return log_oom();

}

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;

}

/* If we readd support for specifying passphrases

if (st.st_mode & 0005)

log_debug("/etc/crypttab is world-readable. This is usually not a good idea.");

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 (*l == '#' || *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 *name = NULL, *device = NULL;

if (!d->create)

continue;

name = strappend("luks-", d->uuid);

if (!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(name, device, d->keyfile ?: arg_default_keyfile, options);

if (r < 0)

return r;

}

return 0;

}

int main(int argc, char *argv[]) {

int r = EXIT_FAILURE;

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)

goto cleanup;

r = parse_proc_cmdline(parse_proc_cmdline_item);

if (r < 0) {

log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");

r = EXIT_FAILURE;

}

if (!arg_enabled) {

r = EXIT_SUCCESS;

goto cleanup;

}

if (add_crypttab_devices() < 0)

goto cleanup;

if (add_proc_cmdline_devices() < 0)

goto cleanup;

r = EXIT_SUCCESS;

cleanup:

free_arg_disks();

free(arg_default_options);

free(arg_default_keyfile);

return r;

}