src/cryptsetup/cryptsetup-generator.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <string.h>
  23 #include <errno.h>
  24 #include <unistd.h>
  25
  26 #include "log.h"
  27 #include "util.h"
  28 #include "unit-name.h"
  29 #include "mkdir.h"
  30
  31 const char *arg_dest = "/tmp";
  32
  33 static bool has_option(const char *haystack, const char *needle) {
  34         const char *f = haystack;
  35         size_t l;
  36
  37         assert(needle);
  38
  39         if (!haystack)
  40                 return false;
  41
  42         l = strlen(needle);
  43
  44         while ((f = strstr(f, needle))) {
  45
  46                 if (f > haystack && f[-1] != ',') {
  47                         f++;
  48                         continue;
  49                 }
  50
  51                 if (f[l] != 0 && f[l] != ',') {
  52                         f++;
  53                         continue;
  54                 }
  55
  56                 return true;
  57         }
  58
  59         return false;
  60 }
  61
  62 static int create_disk(
  63                 const char *name,
  64                 const char *device,
  65                 const char *password,
  66                 const char *options) {
  67
  68         char *p = NULL, *n = NULL, *d = NULL, *u = NULL, *from = NULL, *to = NULL, *e = NULL;
  69         int r;
  70         FILE *f = NULL;
  71         bool noauto, nofail;
  72
  73         assert(name);
  74         assert(device);
  75
  76         noauto = has_option(options, "noauto");
  77         nofail = has_option(options, "nofail");
  78
  79         if (!(n = unit_name_build_escape("cryptsetup", name, ".service"))) {
  80                 r = -ENOMEM;
  81                 log_error("Failed to allocate unit name.");
  82                 goto fail;
  83         }
  84
  85         if (asprintf(&p, "%s/%s", arg_dest, n) < 0) {
  86                 r = -ENOMEM;
  87                 log_error("Failed to allocate unit file name.");
  88                 goto fail;
  89         }
  90
  91         if (!(u = fstab_node_to_udev_node(device))) {
  92                 r = -ENOMEM;
  93                 log_error("Failed to allocate device node.");
  94                 goto fail;
  95         }
  96
  97         if (!(d = unit_name_from_path(u, ".device"))) {
  98                 r = -ENOMEM;
  99                 log_error("Failed to allocate device name.");
 100                 goto fail;
 101         }
 102
 103         if (!(f = fopen(p, "wxe"))) {
 104                 r = -errno;
 105                 log_error("Failed to create unit file: %m");
 106                 goto fail;
 107         }
 108
 109         fprintf(f,
 110                 "[Unit]\n"
 111                 "Description=Cryptography Setup for %%I\n"
 112                 "Conflicts=umount.target\n"
 113                 "DefaultDependencies=no\n"
 114                 "BindTo=%s dev-mapper-%%i.device\n"
 115                 "After=systemd-readahead-collect.service systemd-readahead-replay.service %s\n"
 116                 "Before=umount.target\n",
 117                 d, d);
 118
 119         if (!nofail)
 120                 fprintf(f,
 121                         "Before=cryptsetup.target\n");
 122
 123         if (password && (streq(password, "/dev/urandom") ||
 124                          streq(password, "/dev/random") ||
 125                          streq(password, "/dev/hw_random")))
 126                 fprintf(f,
 127                         "After=systemd-random-seed-load.service\n");
 128         else
 129                 fprintf(f,
 130                         "Before=local-fs.target\n");
 131
 132         fprintf(f,
 133                 "\n[Service]\n"
 134                 "Type=oneshot\n"
 135                 "RemainAfterExit=yes\n"
 136                 "TimeoutSec=0\n" /* the binary handles timeouts anyway */
 137                 "ExecStart=" SYSTEMD_CRYPTSETUP_PATH " attach '%s' '%s' '%s' '%s'\n"
 138                 "ExecStop=" SYSTEMD_CRYPTSETUP_PATH " detach '%s'\n",
 139                 name, u, strempty(password), strempty(options),
 140                 name);
 141
 142         if (has_option(options, "tmp"))
 143                 fprintf(f,
 144                         "ExecStartPost=/sbin/mke2fs '/dev/mapper/%s'\n",
 145                         name);
 146
 147         if (has_option(options, "swap"))
 148                 fprintf(f,
 149                         "ExecStartPost=/sbin/mkswap '/dev/mapper/%s'\n",
 150                         name);
 151
 152         fflush(f);
 153
 154         if (ferror(f)) {
 155                 r = -errno;
 156                 log_error("Failed to write file: %m");
 157                 goto fail;
 158         }
 159
 160         if (asprintf(&from, "../%s", n) < 0) {
 161                 r = -ENOMEM;
 162                 goto fail;
 163         }
 164
 165         if (!noauto) {
 166
 167                 if (asprintf(&to, "%s/%s.wants/%s", arg_dest, d, n) < 0) {
 168                         r = -ENOMEM;
 169                         goto fail;
 170                 }
 171
 172                 mkdir_parents(to, 0755);
 173
 174                 if (symlink(from, to) < 0) {
 175                         log_error("Failed to create symlink '%s' to '%s': %m", from, to);
 176                         r = -errno;
 177                         goto fail;
 178                 }
 179
 180                 free(to);
 181                 to = NULL;
 182
 183                 if (!nofail)
 184                         asprintf(&to, "%s/cryptsetup.target.requires/%s", arg_dest, n);
 185                 else
 186                         asprintf(&to, "%s/cryptsetup.target.wants/%s", arg_dest, n);
 187
 188                 if (!to) {
 189                         r = -ENOMEM;
 190                         goto fail;
 191                 }
 192
 193                 mkdir_parents(to, 0755);
 194
 195                 if (symlink(from, to) < 0) {
 196                         log_error("Failed to create symlink '%s' to '%s': %m", from, to);
 197                         r = -errno;
 198                         goto fail;
 199                 }
 200         }
 201
 202         free(to);
 203         to = NULL;
 204
 205         e = unit_name_escape(name);
 206         if (asprintf(&to, "%s/dev-mapper-%s.device.requires/%s", arg_dest, e, n) < 0) {
 207                 r = -ENOMEM;
 208                 goto fail;
 209         }
 210
 211         mkdir_parents(to, 0755);
 212
 213         if (symlink(from, to) < 0) {
 214                 log_error("Failed to create symlink '%s' to '%s': %m", from, to);
 215                 r = -errno;
 216                 goto fail;
 217         }
 218
 219         r = 0;
 220
 221 fail:
 222         free(p);
 223         free(n);
 224         free(d);
 225         free(e);
 226
 227         free(from);
 228         free(to);
 229
 230         if (f)
 231                 fclose(f);
 232
 233         return r;
 234 }
 235
 236 int main(int argc, char *argv[]) {
 237         FILE *f;
 238         int r = EXIT_SUCCESS;
 239         unsigned n = 0;
 240
 241         if (argc > 2) {
 242                 log_error("This program takes one or no arguments.");
 243                 return EXIT_FAILURE;
 244         }
 245
 246         if (argc > 1)
 247                 arg_dest = argv[1];
 248
 249         log_set_target(LOG_TARGET_AUTO);
 250         log_parse_environment();
 251         log_open();
 252
 253         umask(0022);
 254
 255         if (!(f = fopen("/etc/crypttab", "re"))) {
 256
 257                 if (errno == ENOENT)
 258                         r = EXIT_SUCCESS;
 259                 else {
 260                         r = EXIT_FAILURE;
 261                         log_error("Failed to open /etc/crypttab: %m");
 262                 }
 263
 264                 goto finish;
 265         }
 266
 267         for (;;) {
 268                 char line[LINE_MAX], *l;
 269                 char *name = NULL, *device = NULL, *password = NULL, *options = NULL;
 270                 int k;
 271
 272                 if (!(fgets(line, sizeof(line), f)))
 273                         break;
 274
 275                 n++;
 276
 277                 l = strstrip(line);
 278                 if (*l == '#' || *l == 0)
 279                         continue;
 280
 281                 if ((k = sscanf(l, "%ms %ms %ms %ms", &name, &device, &password, &options)) < 2 || k > 4) {
 282                         log_error("Failed to parse /etc/crypttab:%u, ignoring.", n);
 283                         r = EXIT_FAILURE;
 284                         goto next;
 285                 }
 286
 287                 if (create_disk(name, device, password, options) < 0)
 288                         r = EXIT_FAILURE;
 289
 290         next:
 291                 free(name);
 292                 free(device);
 293                 free(password);
 294                 free(options);
 295         }
 296
 297 finish:
 298         return r;
 299 }