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 Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 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   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser 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         n = unit_name_build_escape("cryptsetup", name, ".service");
  80         if (!n) {
  81                 r = -ENOMEM;
  82                 log_error("Failed to allocate unit name.");
  83                 goto fail;
  84         }
  85
  86         p = join(arg_dest, "/", n, NULL);
  87         if (!p) {
  88                 r = -ENOMEM;
  89                 log_error("Failed to allocate unit file name.");
  90                 goto fail;
  91         }
  92
  93         u = fstab_node_to_udev_node(device);
  94         if (!u) {
  95                 r = -ENOMEM;
  96                 log_error("Failed to allocate device node.");
  97                 goto fail;
  98         }
  99
 100         d = unit_name_from_path(u, ".device");
 101         if (!d) {
 102                 r = -ENOMEM;
 103                 log_error("Failed to allocate device name.");
 104                 goto fail;
 105         }
 106
 107         f = fopen(p, "wxe");
 108         if (!f) {
 109                 r = -errno;
 110                 log_error("Failed to create unit file: %m");
 111                 goto fail;
 112         }
 113
 114         fprintf(f,
 115                 "# Automatically generated by systemd-cryptsetup-generator\n\n"
 116                 "[Unit]\n"
 117                 "Description=Cryptography Setup for %%I\n"
 118                 "Conflicts=umount.target\n"
 119                 "DefaultDependencies=no\n"
 120                 "BindTo=%s dev-mapper-%%i.device\n"
 121                 "After=systemd-readahead-collect.service systemd-readahead-replay.service %s\n"
 122                 "Before=umount.target\n",
 123                 d, d);
 124
 125         if (!nofail)
 126                 fprintf(f,
 127                         "Before=cryptsetup.target\n");
 128
 129         if (password && (streq(password, "/dev/urandom") ||
 130                          streq(password, "/dev/random") ||
 131                          streq(password, "/dev/hw_random")))
 132                 fprintf(f,
 133                         "After=systemd-random-seed-load.service\n");
 134         else
 135                 fprintf(f,
 136                         "Before=local-fs.target\n");
 137
 138         fprintf(f,
 139                 "\n[Service]\n"
 140                 "Type=oneshot\n"
 141                 "RemainAfterExit=yes\n"
 142                 "TimeoutSec=0\n" /* the binary handles timeouts anyway */
 143                 "ExecStart=" SYSTEMD_CRYPTSETUP_PATH " attach '%s' '%s' '%s' '%s'\n"
 144                 "ExecStop=" SYSTEMD_CRYPTSETUP_PATH " detach '%s'\n",
 145                 name, u, strempty(password), strempty(options),
 146                 name);
 147
 148         if (has_option(options, "tmp"))
 149                 fprintf(f,
 150                         "ExecStartPost=/sbin/mke2fs '/dev/mapper/%s'\n",
 151                         name);
 152
 153         if (has_option(options, "swap"))
 154                 fprintf(f,
 155                         "ExecStartPost=/sbin/mkswap '/dev/mapper/%s'\n",
 156                         name);
 157
 158         fflush(f);
 159
 160         if (ferror(f)) {
 161                 r = -errno;
 162                 log_error("Failed to write file: %m");
 163                 goto fail;
 164         }
 165
 166         if (asprintf(&from, "../%s", n) < 0) {
 167                 r = -ENOMEM;
 168                 goto fail;
 169         }
 170
 171         if (!noauto) {
 172
 173                 to = join(arg_dest, "/", d, ".wants/", n, NULL);
 174                 if (!to) {
 175                         r = -ENOMEM;
 176                         goto fail;
 177                 }
 178
 179                 mkdir_parents(to, 0755);
 180                 if (symlink(from, to) < 0) {
 181                         log_error("Failed to create symlink '%s' to '%s': %m", from, to);
 182                         r = -errno;
 183                         goto fail;
 184                 }
 185
 186                 free(to);
 187
 188                 if (!nofail)
 189                         to = join(arg_dest, "/cryptsetup.target.requires/", n, NULL);
 190                 else
 191                         to = join(arg_dest, "/cryptsetup.target.wants/", n, NULL);
 192                 if (!to) {
 193                         r = -ENOMEM;
 194                         goto fail;
 195                 }
 196
 197                 mkdir_parents(to, 0755);
 198                 if (symlink(from, to) < 0) {
 199                         log_error("Failed to create symlink '%s' to '%s': %m", from, to);
 200                         r = -errno;
 201                         goto fail;
 202                 }
 203
 204                 free(to);
 205                 to = NULL;
 206         }
 207
 208         e = unit_name_escape(name);
 209         to = join(arg_dest, "/dev-mapper-", e, ".device.requires/", n, NULL);
 210         if (!to) {
 211                 r = -ENOMEM;
 212                 goto fail;
 213         }
 214
 215         mkdir_parents(to, 0755);
 216         if (symlink(from, to) < 0) {
 217                 log_error("Failed to create symlink '%s' to '%s': %m", from, to);
 218                 r = -errno;
 219                 goto fail;
 220         }
 221
 222         r = 0;
 223
 224 fail:
 225         free(p);
 226         free(n);
 227         free(d);
 228         free(e);
 229
 230         free(from);
 231         free(to);
 232
 233         if (f)
 234                 fclose(f);
 235
 236         return r;
 237 }
 238
 239 int main(int argc, char *argv[]) {
 240         FILE *f;
 241         int r = EXIT_SUCCESS;
 242         unsigned n = 0;
 243
 244         if (argc > 2) {
 245                 log_error("This program takes one or no arguments.");
 246                 return EXIT_FAILURE;
 247         }
 248
 249         if (argc > 1)
 250                 arg_dest = argv[1];
 251
 252         log_set_target(LOG_TARGET_AUTO);
 253         log_parse_environment();
 254         log_open();
 255
 256         umask(0022);
 257
 258         f = fopen("/etc/crypttab", "re");
 259         if (!f) {
 260
 261                 if (errno == ENOENT)
 262                         r = EXIT_SUCCESS;
 263                 else {
 264                         r = EXIT_FAILURE;
 265                         log_error("Failed to open /etc/crypttab: %m");
 266                 }
 267
 268                 goto finish;
 269         }
 270
 271         for (;;) {
 272                 char line[LINE_MAX], *l;
 273                 char *name = NULL, *device = NULL, *password = NULL, *options = NULL;
 274                 int k;
 275
 276                 if (!fgets(line, sizeof(line), f))
 277                         break;
 278
 279                 n++;
 280
 281                 l = strstrip(line);
 282                 if (*l == '#' || *l == 0)
 283                         continue;
 284
 285                 k = sscanf(l, "%ms %ms %ms %ms", &name, &device, &password, &options);
 286                 if (k < 2 || k > 4) {
 287                         log_error("Failed to parse /etc/crypttab:%u, ignoring.", n);
 288                         r = EXIT_FAILURE;
 289                         goto next;
 290                 }
 291
 292                 if (create_disk(name, device, password, options) < 0)
 293                         r = EXIT_FAILURE;
 294
 295         next:
 296                 free(name);
 297                 free(device);
 298                 free(password);
 299                 free(options);
 300         }
 301
 302 finish:
 303         return r;
 304 }