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         l = strlen(needle);
  37
  38         while ((f = strstr(f, needle))) {
  39
  40                 if (f > haystack && f[-1] != ',') {
  41                         f++;
  42                         continue;
  43                 }
  44
  45                 if (f[l] != 0 && f[l] == ',') {
  46                         f++;
  47                         continue;
  48                 }
  49
  50                 return true;
  51         }
  52
  53         return false;
  54 }
  55
  56 static int create_disk(
  57                 const char *name,
  58                 const char *device,
  59                 const char *password,
  60                 const char *options) {
  61
  62         char *p = NULL, *n = NULL, *d = NULL, *u = NULL, *from = NULL, *to = NULL, *e = NULL;
  63         int r;
  64         FILE *f = NULL;
  65
  66         assert(name);
  67         assert(device);
  68
  69         if (!(n = unit_name_build_escape("cryptsetup", name, ".service"))) {
  70                 r = -ENOMEM;
  71                 log_error("Failed to allocate unit name.");
  72                 goto fail;
  73         }
  74
  75         if (asprintf(&p, "%s/%s", arg_dest, n) < 0) {
  76                 r = -ENOMEM;
  77                 log_error("Failed to allocate unit file name.");
  78                 goto fail;
  79         }
  80
  81         if (!(u = fstab_node_to_udev_node(device))) {
  82                 r = -ENOMEM;
  83                 log_error("Failed to allocate device node.");
  84                 goto fail;
  85         }
  86
  87         if (!(d = unit_name_from_path(u, ".device"))) {
  88                 r = -ENOMEM;
  89                 log_error("Failed to allocate device name.");
  90                 goto fail;
  91         }
  92
  93         if (!(f = fopen(p, "wxe"))) {
  94                 r = -errno;
  95                 log_error("Failed to create unit file: %m");
  96                 goto fail;
  97         }
  98
  99         fprintf(f,
 100                 "[Unit]\n"
 101                 "Description=Cryptography Setup for %%I\n"
 102                 "DefaultDependencies=no\n"
 103                 "BindTo=%s dev-mapper-%%i.device\n"
 104                 "After=systemd-readahead-collect.service systemd-readahead-replay.service %s\n"
 105                 "Before=dev-mapper-%%i.device shutdown.target cryptsetup.target\n",
 106                 d, d);
 107
 108         if (password && (streq(password, "/dev/urandom") ||
 109                          streq(password, "/dev/random") ||
 110                          streq(password, "/dev/hw_random")))
 111                 fprintf(f,
 112                         "After=systemd-random-seed-load.service\n");
 113
 114         fprintf(f,
 115                 "\n[Service]\n"
 116                 "Type=oneshot\n"
 117                 "RemainAfterExit=yes\n"
 118                 "TimeoutSec=0\n" /* the binary handles timeouts anyway */
 119                 "ExecStart=" SYSTEMD_CRYPTSETUP_PATH " attach '%s' '%s' '%s' '%s'\n"
 120                 "ExecStop=" SYSTEMD_CRYPTSETUP_PATH " detach '%s'\n",
 121                 name, u, strempty(password), strempty(options),
 122                 name);
 123
 124         if (options && has_option(options, "tmp"))
 125                 fprintf(f,
 126                         "ExecStartPost=/sbin/mke2fs '/dev/mapper/%s'\n",
 127                         name);
 128
 129         if (options && has_option(options, "swap"))
 130                 fprintf(f,
 131                         "ExecStartPost=/sbin/mkswap '/dev/mapper/%s'\n",
 132                         name);
 133
 134         fflush(f);
 135
 136         if (ferror(f)) {
 137                 r = -errno;
 138                 log_error("Failed to write file: %m");
 139                 goto fail;
 140         }
 141
 142         if (asprintf(&from, "../%s", n) < 0) {
 143                 r = -ENOMEM;
 144                 goto fail;
 145         }
 146
 147         if (!options || !has_option(options, "noauto")) {
 148
 149                 if (asprintf(&to, "%s/%s.wants/%s", arg_dest, d, n) < 0) {
 150                         r = -ENOMEM;
 151                         goto fail;
 152                 }
 153
 154                 mkdir_parents(to, 0755);
 155
 156                 if (symlink(from, to) < 0) {
 157                         log_error("Failed to create symlink '%s' to '%s': %m", from, to);
 158                         r = -errno;
 159                         goto fail;
 160                 }
 161
 162                 free(to);
 163                 to = NULL;
 164
 165                 if (!options || !has_option(options, "nofail")) {
 166
 167                         if (asprintf(&to, "%s/cryptsetup.target.wants/%s", arg_dest, 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         }
 181
 182         free(to);
 183         to = NULL;
 184
 185         e = unit_name_escape(name);
 186         if (asprintf(&to, "%s/dev-mapper-%s.device.requires/%s", arg_dest, e, n) < 0) {
 187                 r = -ENOMEM;
 188                 goto fail;
 189         }
 190
 191         mkdir_parents(to, 0755);
 192
 193         if (symlink(from, to) < 0) {
 194                 log_error("Failed to create symlink '%s' to '%s': %m", from, to);
 195                 r = -errno;
 196                 goto fail;
 197         }
 198
 199         r = 0;
 200
 201 fail:
 202         free(p);
 203         free(n);
 204         free(d);
 205         free(e);
 206
 207         free(from);
 208         free(to);
 209
 210         if (f)
 211                 fclose(f);
 212
 213         return r;
 214 }
 215
 216 int main(int argc, char *argv[]) {
 217         FILE *f;
 218         int r = EXIT_SUCCESS;
 219         unsigned n = 0;
 220
 221         if (argc > 2) {
 222                 log_error("This program takes one or no arguments.");
 223                 return EXIT_FAILURE;
 224         }
 225
 226         if (argc > 1)
 227                 arg_dest = argv[1];
 228
 229         log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
 230         log_parse_environment();
 231         log_open();
 232
 233         if (!(f = fopen("/etc/crypttab", "re"))) {
 234
 235                 if (errno == ENOENT)
 236                         r = EXIT_SUCCESS;
 237                 else {
 238                         r = EXIT_FAILURE;
 239                         log_error("Failed to open /etc/crypttab: %m");
 240                 }
 241
 242                 goto finish;
 243         }
 244
 245         for (;;) {
 246                 char line[LINE_MAX], *l;
 247                 char *name = NULL, *device = NULL, *password = NULL, *options = NULL;
 248                 int k;
 249
 250                 if (!(fgets(line, sizeof(line), f)))
 251                         break;
 252
 253                 n++;
 254
 255                 l = strstrip(line);
 256                 if (*l == '#' || *l == 0)
 257                         continue;
 258
 259                 if ((k = sscanf(l, "%ms %ms %ms %ms", &name, &device, &password, &options)) < 2 || k > 4) {
 260                         log_error("Failed to parse /etc/crypttab:%u, ignoring.", n);
 261                         r = EXIT_FAILURE;
 262                         goto next;
 263                 }
 264
 265                 if (create_disk(name, device, password, options) < 0)
 266                         r = EXIT_FAILURE;
 267
 268         next:
 269                 free(name);
 270                 free(device);
 271                 free(password);
 272                 free(options);
 273         }
 274
 275 finish:
 276         return r;
 277 }