src/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
  30 const char *arg_dest = "/tmp";
  31
  32 static bool has_option(const char *haystack, const char *needle) {
  33         const char *f = haystack;
  34         size_t l;
  35
  36         assert(needle);
  37
  38         if (!haystack)
  39                 return false;
  40
  41         l = strlen(needle);
  42
  43         while ((f = strstr(f, needle))) {
  44
  45                 if (f > haystack && f[-1] != ',') {
  46                         f++;
  47                         continue;
  48                 }
  49
  50                 if (f[l] != 0 && f[l] != ',') {
  51                         f++;
  52                         continue;
  53                 }
  54
  55                 return true;
  56         }
  57
  58         return false;
  59 }
  60
  61 static int create_disk(
  62                 const char *name,
  63                 const char *device,
  64                 const char *password,
  65                 const char *options) {
  66
  67         char *p = NULL, *n = NULL, *d = NULL, *u = NULL, *from = NULL, *to = NULL, *e = NULL;
  68         int r;
  69         FILE *f = NULL;
  70         bool noauto, nofail;
  71
  72         assert(name);
  73         assert(device);
  74
  75         noauto = has_option(options, "noauto");
  76         nofail = has_option(options, "nofail");
  77
  78         if (!(n = unit_name_build_escape("cryptsetup", name, ".service"))) {
  79                 r = -ENOMEM;
  80                 log_error("Failed to allocate unit name.");
  81                 goto fail;
  82         }
  83
  84         if (asprintf(&p, "%s/%s", arg_dest, n) < 0) {
  85                 r = -ENOMEM;
  86                 log_error("Failed to allocate unit file name.");
  87                 goto fail;
  88         }
  89
  90         if (!(u = fstab_node_to_udev_node(device))) {
  91                 r = -ENOMEM;
  92                 log_error("Failed to allocate device node.");
  93                 goto fail;
  94         }
  95
  96         if (!(d = unit_name_from_path(u, ".device"))) {
  97                 r = -ENOMEM;
  98                 log_error("Failed to allocate device name.");
  99                 goto fail;
 100         }
 101
 102         if (!(f = fopen(p, "wxe"))) {
 103                 r = -errno;
 104                 log_error("Failed to create unit file: %m");
 105                 goto fail;
 106         }
 107
 108         fprintf(f,
 109                 "[Unit]\n"
 110                 "Description=Cryptography Setup for %%I\n"
 111                 "Conflicts=umount.target\n"
 112                 "DefaultDependencies=no\n"
 113                 "BindTo=%s dev-mapper-%%i.device\n"
 114                 "After=systemd-readahead-collect.service systemd-readahead-replay.service %s\n"
 115                 "Before=umount.target\n"
 116                 "Before=local-fs.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
 129         fprintf(f,
 130                 "\n[Service]\n"
 131                 "Type=oneshot\n"
 132                 "RemainAfterExit=yes\n"
 133                 "TimeoutSec=0\n" /* the binary handles timeouts anyway */
 134                 "ExecStart=" SYSTEMD_CRYPTSETUP_PATH " attach '%s' '%s' '%s' '%s'\n"
 135                 "ExecStop=" SYSTEMD_CRYPTSETUP_PATH " detach '%s'\n",
 136                 name, u, strempty(password), strempty(options),
 137                 name);
 138
 139         if (has_option(options, "tmp"))
 140                 fprintf(f,
 141                         "ExecStartPost=/sbin/mke2fs '/dev/mapper/%s'\n",
 142                         name);
 143
 144         if (has_option(options, "swap"))
 145                 fprintf(f,
 146                         "ExecStartPost=/sbin/mkswap '/dev/mapper/%s'\n",
 147                         name);
 148
 149         fflush(f);
 150
 151         if (ferror(f)) {
 152                 r = -errno;
 153                 log_error("Failed to write file: %m");
 154                 goto fail;
 155         }
 156
 157         if (asprintf(&from, "../%s", n) < 0) {
 158                 r = -ENOMEM;
 159                 goto fail;
 160         }
 161
 162         if (!noauto) {
 163
 164                 if (asprintf(&to, "%s/%s.wants/%s", arg_dest, d, n) < 0) {
 165                         r = -ENOMEM;
 166                         goto fail;
 167                 }
 168
 169                 mkdir_parents(to, 0755);
 170
 171                 if (symlink(from, to) < 0) {
 172                         log_error("Failed to create symlink '%s' to '%s': %m", from, to);
 173                         r = -errno;
 174                         goto fail;
 175                 }
 176
 177                 free(to);
 178                 to = NULL;
 179
 180                 if (!nofail)
 181                         asprintf(&to, "%s/cryptsetup.target.requires/%s", arg_dest, n);
 182                 else
 183                         asprintf(&to, "%s/cryptsetup.target.wants/%s", arg_dest, n);
 184
 185                 if (!to) {
 186                         r = -ENOMEM;
 187                         goto fail;
 188                 }
 189
 190                 mkdir_parents(to, 0755);
 191
 192                 if (symlink(from, to) < 0) {
 193                         log_error("Failed to create symlink '%s' to '%s': %m", from, to);
 194                         r = -errno;
 195                         goto fail;
 196                 }
 197         }
 198
 199         free(to);
 200         to = NULL;
 201
 202         e = unit_name_escape(name);
 203         if (asprintf(&to, "%s/dev-mapper-%s.device.requires/%s", arg_dest, e, n) < 0) {
 204                 r = -ENOMEM;
 205                 goto fail;
 206         }
 207
 208         mkdir_parents(to, 0755);
 209
 210         if (symlink(from, to) < 0) {
 211                 log_error("Failed to create symlink '%s' to '%s': %m", from, to);
 212                 r = -errno;
 213                 goto fail;
 214         }
 215
 216         r = 0;
 217
 218 fail:
 219         free(p);
 220         free(n);
 221         free(d);
 222         free(e);
 223
 224         free(from);
 225         free(to);
 226
 227         if (f)
 228                 fclose(f);
 229
 230         return r;
 231 }
 232
 233 int main(int argc, char *argv[]) {
 234         FILE *f;
 235         int r = EXIT_SUCCESS;
 236         unsigned n = 0;
 237
 238         if (argc > 2) {
 239                 log_error("This program takes one or no arguments.");
 240                 return EXIT_FAILURE;
 241         }
 242
 243         if (argc > 1)
 244                 arg_dest = argv[1];
 245
 246         log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
 247         log_parse_environment();
 248         log_open();
 249
 250         umask(0022);
 251
 252         if (!(f = fopen("/etc/crypttab", "re"))) {
 253
 254                 if (errno == ENOENT)
 255                         r = EXIT_SUCCESS;
 256                 else {
 257                         r = EXIT_FAILURE;
 258                         log_error("Failed to open /etc/crypttab: %m");
 259                 }
 260
 261                 goto finish;
 262         }
 263
 264         for (;;) {
 265                 char line[LINE_MAX], *l;
 266                 char *name = NULL, *device = NULL, *password = NULL, *options = NULL;
 267                 int k;
 268
 269                 if (!(fgets(line, sizeof(line), f)))
 270                         break;
 271
 272                 n++;
 273
 274                 l = strstrip(line);
 275                 if (*l == '#' || *l == 0)
 276                         continue;
 277
 278                 if ((k = sscanf(l, "%ms %ms %ms %ms", &name, &device, &password, &options)) < 2 || k > 4) {
 279                         log_error("Failed to parse /etc/crypttab:%u, ignoring.", n);
 280                         r = EXIT_FAILURE;
 281                         goto next;
 282                 }
 283
 284                 if (create_disk(name, device, password, options) < 0)
 285                         r = EXIT_FAILURE;
 286
 287         next:
 288                 free(name);
 289                 free(device);
 290                 free(password);
 291                 free(options);
 292         }
 293
 294 finish:
 295         return r;
 296 }