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
  71         assert(name);
  72         assert(device);
  73
  74         if (!(n = unit_name_build_escape("cryptsetup", name, ".service"))) {
  75                 r = -ENOMEM;
  76                 log_error("Failed to allocate unit name.");
  77                 goto fail;
  78         }
  79
  80         if (asprintf(&p, "%s/%s", arg_dest, n) < 0) {
  81                 r = -ENOMEM;
  82                 log_error("Failed to allocate unit file name.");
  83                 goto fail;
  84         }
  85
  86         if (!(u = fstab_node_to_udev_node(device))) {
  87                 r = -ENOMEM;
  88                 log_error("Failed to allocate device node.");
  89                 goto fail;
  90         }
  91
  92         if (!(d = unit_name_from_path(u, ".device"))) {
  93                 r = -ENOMEM;
  94                 log_error("Failed to allocate device name.");
  95                 goto fail;
  96         }
  97
  98         if (!(f = fopen(p, "wxe"))) {
  99                 r = -errno;
 100                 log_error("Failed to create unit file: %m");
 101                 goto fail;
 102         }
 103
 104         fprintf(f,
 105                 "[Unit]\n"
 106                 "Description=Cryptography Setup for %%I\n"
 107                 "DefaultDependencies=no\n"
 108                 "BindTo=%s dev-mapper-%%i.device\n"
 109                 "After=systemd-readahead-collect.service systemd-readahead-replay.service %s\n"
 110                 "Before=dev-mapper-%%i.device shutdown.target cryptsetup.target\n",
 111                 d, d);
 112
 113         if (password && (streq(password, "/dev/urandom") ||
 114                          streq(password, "/dev/random") ||
 115                          streq(password, "/dev/hw_random")))
 116                 fprintf(f,
 117                         "After=systemd-random-seed-load.service\n");
 118
 119         fprintf(f,
 120                 "\n[Service]\n"
 121                 "Type=oneshot\n"
 122                 "RemainAfterExit=yes\n"
 123                 "TimeoutSec=0\n" /* the binary handles timeouts anyway */
 124                 "ExecStart=" SYSTEMD_CRYPTSETUP_PATH " attach '%s' '%s' '%s' '%s'\n"
 125                 "ExecStop=" SYSTEMD_CRYPTSETUP_PATH " detach '%s'\n",
 126                 name, u, strempty(password), strempty(options),
 127                 name);
 128
 129         if (has_option(options, "tmp"))
 130                 fprintf(f,
 131                         "ExecStartPost=/sbin/mke2fs '/dev/mapper/%s'\n",
 132                         name);
 133
 134         if (has_option(options, "swap"))
 135                 fprintf(f,
 136                         "ExecStartPost=/sbin/mkswap '/dev/mapper/%s'\n",
 137                         name);
 138
 139         fflush(f);
 140
 141         if (ferror(f)) {
 142                 r = -errno;
 143                 log_error("Failed to write file: %m");
 144                 goto fail;
 145         }
 146
 147         if (asprintf(&from, "../%s", n) < 0) {
 148                 r = -ENOMEM;
 149                 goto fail;
 150         }
 151
 152         if (!has_option(options, "noauto")) {
 153
 154                 if (asprintf(&to, "%s/%s.wants/%s", arg_dest, d, n) < 0) {
 155                         r = -ENOMEM;
 156                         goto fail;
 157                 }
 158
 159                 mkdir_parents(to, 0755);
 160
 161                 if (symlink(from, to) < 0) {
 162                         log_error("Failed to create symlink '%s' to '%s': %m", from, to);
 163                         r = -errno;
 164                         goto fail;
 165                 }
 166
 167                 free(to);
 168                 to = NULL;
 169
 170                 if (!has_option(options, "nofail")) {
 171
 172                         if (asprintf(&to, "%s/cryptsetup.target.wants/%s", arg_dest, n) < 0) {
 173                                 r = -ENOMEM;
 174                                 goto fail;
 175                         }
 176
 177                         mkdir_parents(to, 0755);
 178
 179                         if (symlink(from, to) < 0) {
 180                                 log_error("Failed to create symlink '%s' to '%s': %m", from, to);
 181                                 r = -errno;
 182                                 goto fail;
 183                         }
 184                 }
 185         }
 186
 187         free(to);
 188         to = NULL;
 189
 190         e = unit_name_escape(name);
 191         if (asprintf(&to, "%s/dev-mapper-%s.device.requires/%s", arg_dest, e, n) < 0) {
 192                 r = -ENOMEM;
 193                 goto fail;
 194         }
 195
 196         mkdir_parents(to, 0755);
 197
 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         r = 0;
 205
 206 fail:
 207         free(p);
 208         free(n);
 209         free(d);
 210         free(e);
 211
 212         free(from);
 213         free(to);
 214
 215         if (f)
 216                 fclose(f);
 217
 218         return r;
 219 }
 220
 221 int main(int argc, char *argv[]) {
 222         FILE *f;
 223         int r = EXIT_SUCCESS;
 224         unsigned n = 0;
 225
 226         if (argc > 2) {
 227                 log_error("This program takes one or no arguments.");
 228                 return EXIT_FAILURE;
 229         }
 230
 231         if (argc > 1)
 232                 arg_dest = argv[1];
 233
 234         log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
 235         log_parse_environment();
 236         log_open();
 237
 238         if (!(f = fopen("/etc/crypttab", "re"))) {
 239
 240                 if (errno == ENOENT)
 241                         r = EXIT_SUCCESS;
 242                 else {
 243                         r = EXIT_FAILURE;
 244                         log_error("Failed to open /etc/crypttab: %m");
 245                 }
 246
 247                 goto finish;
 248         }
 249
 250         for (;;) {
 251                 char line[LINE_MAX], *l;
 252                 char *name = NULL, *device = NULL, *password = NULL, *options = NULL;
 253                 int k;
 254
 255                 if (!(fgets(line, sizeof(line), f)))
 256                         break;
 257
 258                 n++;
 259
 260                 l = strstrip(line);
 261                 if (*l == '#' || *l == 0)
 262                         continue;
 263
 264                 if ((k = sscanf(l, "%ms %ms %ms %ms", &name, &device, &password, &options)) < 2 || k > 4) {
 265                         log_error("Failed to parse /etc/crypttab:%u, ignoring.", n);
 266                         r = EXIT_FAILURE;
 267                         goto next;
 268                 }
 269
 270                 if (create_disk(name, device, password, options) < 0)
 271                         r = EXIT_FAILURE;
 272
 273         next:
 274                 free(name);
 275                 free(device);
 276                 free(password);
 277                 free(options);
 278         }
 279
 280 finish:
 281         return r;
 282 }