/mandos/trunk : revision 534

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* "browse_callback", and parts of "main".

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*

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* Everything else is

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*

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* This file is part of Mandos.

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*

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* Mandos is free software: you can redistribute it and/or modify it

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* under the terms of the GNU General Public License as published by

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* the Free Software Foundation, either version 3 of the License, or

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* (at your option) any later version.

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*

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* Mandos is distributed in the hope that it will be useful, but

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*

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* This program is free software: you can redistribute it and/or

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* modify it under the terms of the GNU General Public License as

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* published by the Free Software Foundation, either version 3 of the

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* License, or (at your option) any later version.

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*

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* This program is distributed in the hope that it will be useful, but

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* WITHOUT ANY WARRANTY; without even the implied warranty of

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22

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

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23

* General Public License for more details.

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*

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* You should have received a copy of the GNU General Public License

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* along with Mandos. If not, see <http://www.gnu.org/licenses/>.

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* along with this program. If not, see

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* <http://www.gnu.org/licenses/>.

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*

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* Contact the authors at <mandos@recompile.se>.

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*/

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/* Needed by GPGME, specifically gpgme_data_seek() */

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#ifndef _LARGEFILE_SOURCE

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#define _LARGEFILE_SOURCE

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#endif /* not _LARGEFILE_SOURCE */

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#endif

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#ifndef _FILE_OFFSET_BITS

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#define _FILE_OFFSET_BITS 64

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#endif /* not _FILE_OFFSET_BITS */

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#endif

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#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */

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#include <stdio.h> /* fprintf(), stderr, fwrite(),

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stdout, ferror() */

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#include <stdint.h> /* uint16_t, uint32_t, intptr_t */

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stdout, ferror(), remove() */

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#include <stdint.h> /* uint16_t, uint32_t */

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#include <stddef.h> /* NULL, size_t, ssize_t */

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#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),

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strtof(), abort() */

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#include <stdbool.h> /* bool, false, true */

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#include <string.h> /* strcmp(), strlen(), strerror(),

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asprintf(), strncpy(), strsignal()

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*/

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#include <string.h> /* memset(), strcmp(), strlen(),

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strerror(), asprintf(), strcpy() */

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51

#include <sys/ioctl.h> /* ioctl */

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#include <sys/types.h> /* socket(), inet_pton(), sockaddr,

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sockaddr_in6, PF_INET6,

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opendir(), DIR */

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#include <sys/stat.h> /* open(), S_ISREG */

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#include <sys/socket.h> /* socket(), struct sockaddr_in6,

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inet_pton(), connect(),

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getnameinfo() */

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#include <fcntl.h> /* open(), unlinkat(), AT_REMOVEDIR */

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inet_pton(), connect() */

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#include <fcntl.h> /* open() */

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#include <dirent.h> /* opendir(), struct dirent, readdir()

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61

*/

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62

#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,

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strtoimax() */

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#include <errno.h> /* perror(), errno, EINTR, EINVAL,

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EAI_SYSTEM, ENETUNREACH,

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EHOSTUNREACH, ECONNREFUSED, EPROTO,

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EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

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ENOTEMPTY,

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#include <assert.h> /* assert() */

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#include <errno.h> /* perror(), errno,

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program_invocation_short_name */

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#include <time.h> /* nanosleep(), time(), sleep() */

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#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,

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73

*/

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74

#include <unistd.h> /* close(), SEEK_SET, off_t, write(),

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getuid(), getgid(), seteuid(),

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setgid(), pause(), _exit(),

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unlinkat() */

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#include <arpa/inet.h> /* inet_pton(), htons() */

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setgid(), pause(), _exit() */

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#include <arpa/inet.h> /* inet_pton(), htons, inet_ntop() */

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#include <iso646.h> /* not, or, and */

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79

#include <argp.h> /* struct argp_option, error_t, struct

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argp_state, struct argp,

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#include <sys/wait.h> /* waitpid(), WIFEXITED(),

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WEXITSTATUS(), WTERMSIG() */

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90

#include <grp.h> /* setgroups() */

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#include <argz.h> /* argz_add_sep(), argz_next(),

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argz_delete(), argz_append(),

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argz_stringify(), argz_add(),

101

argz_count() */

102

#include <netdb.h> /* getnameinfo(), NI_NUMERICHOST,

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EAI_SYSTEM, gai_strerror() */

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#ifdef __linux__

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#include <sys/klog.h> /* klogctl() */

148

135

static const char sys_class_net[] = "/sys/class/net";

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char *connect_to = NULL;

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const char *hookdir = HOOKDIR;

151

int hookdir_fd = -1;

152

uid_t uid = 65534;

153

gid_t gid = 65534;

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138

155

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/* Doubly linked list that need to be circularly linked when used */

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typedef struct server{

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const char *ip;

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in_port_t port;

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uint16_t port;

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AvahiIfIndex if_index;

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int af;

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struct timespec last_seen;

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149

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/* Used for passing in values through the Avahi callback functions */

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typedef struct {

152

AvahiSimplePoll *simple_poll;

168

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AvahiServer *server;

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gnutls_certificate_credentials_t cred;

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unsigned int dh_bits;

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157

const char *priority;

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gpgme_ctx_t ctx;

174

159

server *current_server;

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char *interfaces;

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size_t interfaces_size;

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} mandos_context;

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161

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/* global so signal handler can reach it*/

180

AvahiSimplePoll *simple_poll;

162

/* global context so signal handler can reach it*/

163

mandos_context mc = { .simple_poll = NULL, .server = NULL,

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.dh_bits = 1024, .priority = "SECURE256"

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":!CTYPE-X.509:+CTYPE-OPENPGP",

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.current_server = NULL };

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167

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sig_atomic_t quit_now = 0;

183

169

int signal_received = 0;

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177

perror(print_text);

192

178

}

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179

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__attribute__((format (gnu_printf, 2, 3), nonnull))

180

__attribute__((format (gnu_printf, 2, 3)))

195

181

int fprintf_plus(FILE *stream, const char *format, ...){

196

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va_list ap;

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va_start (ap, format);

198

184

199

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TEMP_FAILURE_RETRY(fprintf(stream, "Mandos plugin %s: ",

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program_invocation_short_name));

201

return (int)TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));

187

return TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));

202

188

}

203

189

204

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/*

206

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* bytes. "buffer_capacity" is how much is currently allocated,

207

193

* "buffer_length" is how much is already used.

208

194

*/

209

__attribute__((nonnull, warn_unused_result))

210

195

size_t incbuffer(char **buffer, size_t buffer_length,

211

196

size_t buffer_capacity){

212

197

if(buffer_length + BUFFER_SIZE > buffer_capacity){

213

char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);

214

if(new_buf == NULL){

215

int old_errno = errno;

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free(*buffer);

217

errno = old_errno;

218

*buffer = NULL;

198

*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);

199

if(buffer == NULL){

219

200

return 0;

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201

}

221

*buffer = new_buf;

222

202

buffer_capacity += BUFFER_SIZE;

223

203

}

224

204

return buffer_capacity;

225

205

}

226

206

227

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/* Add server to set of servers to retry periodically */

228

__attribute__((nonnull, warn_unused_result))

229

bool add_server(const char *ip, in_port_t port, AvahiIfIndex if_index,

230

int af, server **current_server){

208

bool add_server(const char *ip, uint16_t port, AvahiIfIndex if_index,

209

int af){

231

210

int ret;

232

211

server *new_server = malloc(sizeof(server));

233

212

if(new_server == NULL){

240

219

.af = af };

241

220

if(new_server->ip == NULL){

242

221

perror_plus("strdup");

243

free(new_server);

244

return false;

245

}

246

ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));

247

if(ret == -1){

248

perror_plus("clock_gettime");

249

#ifdef __GNUC__

250

#pragma GCC diagnostic push

251

#pragma GCC diagnostic ignored "-Wcast-qual"

252

#endif

253

free((char *)(new_server->ip));

254

#ifdef __GNUC__

255

#pragma GCC diagnostic pop

256

#endif

257

free(new_server);

258

222

return false;

259

223

}

260

224

/* Special case of first server */

261

if(*current_server == NULL){

225

if (mc.current_server == NULL){

262

226

new_server->next = new_server;

263

227

new_server->prev = new_server;

264

*current_server = new_server;

228

mc.current_server = new_server;

229

/* Place the new server last in the list */

265

230

} else {

266

/* Place the new server last in the list */

267

new_server->next = *current_server;

268

new_server->prev = (*current_server)->prev;

231

new_server->next = mc.current_server;

232

new_server->prev = mc.current_server->prev;

269

233

new_server->prev->next = new_server;

270

(*current_server)->prev = new_server;

234

mc.current_server->prev = new_server;

235

}

236

ret = clock_gettime(CLOCK_MONOTONIC, &mc.current_server->last_seen);

237

if(ret == -1){

238

perror_plus("clock_gettime");

239

return false;

271

240

}

272

241

return true;

273

242

}

275

244

/*

276

245

* Initialize GPGME.

277

246

*/

278

__attribute__((nonnull, warn_unused_result))

279

static bool init_gpgme(const char * const seckey,

280

const char * const pubkey,

281

const char * const tempdir,

282

mandos_context *mc){

247

static bool init_gpgme(const char *seckey, const char *pubkey,

248

const char *tempdir){

283

249

gpgme_error_t rc;

284

250

gpgme_engine_info_t engine_info;

285

251

252

286

253

/*

287

254

* Helper function to insert pub and seckey to the engine keyring.

288

255

*/

289

bool import_key(const char * const filename){

256

bool import_key(const char *filename){

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257

int ret;

291

258

int fd;

292

259

gpgme_data_t pgp_data;

304

271

return false;

305

272

}

306

273

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rc = gpgme_op_import(mc->ctx, pgp_data);

274

rc = gpgme_op_import(mc.ctx, pgp_data);

308

275

if(rc != GPG_ERR_NO_ERROR){

309

276

fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",

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gpgme_strsource(rc), gpgme_strerror(rc));

311

278

return false;

312

279

}

313

280

314

ret = close(fd);

281

ret = (int)TEMP_FAILURE_RETRY(close(fd));

315

282

if(ret == -1){

316

283

perror_plus("close");

317

284

}

354

321

}

355

322

356

323

/* Create new GPGME "context" */

357

rc = gpgme_new(&(mc->ctx));

324

rc = gpgme_new(&(mc.ctx));

358

325

if(rc != GPG_ERR_NO_ERROR){

359

326

fprintf_plus(stderr, "Mandos plugin mandos-client: "

360

327

"bad gpgme_new: %s: %s\n", gpgme_strsource(rc),

373

340

* Decrypt OpenPGP data.

374

341

* Returns -1 on error

375

342

*/

376

__attribute__((nonnull, warn_unused_result))

377

343

static ssize_t pgp_packet_decrypt(const char *cryptotext,

378

344

size_t crypto_size,

379

char **plaintext,

380

mandos_context *mc){

345

char **plaintext){

381

346

gpgme_data_t dh_crypto, dh_plain;

382

347

gpgme_error_t rc;

383

348

ssize_t ret;

409

374

410

375

/* Decrypt data from the cryptotext data buffer to the plaintext

411

376

data buffer */

412

rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);

377

rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);

413

378

if(rc != GPG_ERR_NO_ERROR){

414

379

fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",

415

380

gpgme_strsource(rc), gpgme_strerror(rc));

416

381

plaintext_length = -1;

417

382

if(debug){

418

383

gpgme_decrypt_result_t result;

419

result = gpgme_op_decrypt_result(mc->ctx);

384

result = gpgme_op_decrypt_result(mc.ctx);

420

385

if(result == NULL){

421

386

fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");

422

387

} else {

499

464

return plaintext_length;

500

465

}

501

466

502

__attribute__((warn_unused_result, const))

503

static const char *safe_string(const char *str){

504

if(str == NULL)

505

return "(unknown)";

506

return str;

507

}

508

509

__attribute__((warn_unused_result))

510

static const char *safer_gnutls_strerror(int value){

511

const char *ret = gnutls_strerror(value);

512

return safe_string(ret);

467

static const char * safer_gnutls_strerror(int value){

468

const char *ret = gnutls_strerror(value); /* Spurious warning from

469

-Wunreachable-code */

470

if(ret == NULL)

471

ret = "(unknown)";

472

return ret;

513

473

}

514

474

515

475

/* GnuTLS log function callback */

516

__attribute__((nonnull))

517

476

static void debuggnutls(__attribute__((unused)) int level,

518

477

const char* string){

519

478

fprintf_plus(stderr, "GnuTLS: %s", string);

520

479

}

521

480

522

__attribute__((nonnull(1, 2, 4), warn_unused_result))

523

481

static int init_gnutls_global(const char *pubkeyfilename,

524

const char *seckeyfilename,

525

const char *dhparamsfilename,

526

mandos_context *mc){

482

const char *seckeyfilename){

527

483

int ret;

528

unsigned int uret;

529

484

530

485

if(debug){

531

486

fprintf_plus(stderr, "Initializing GnuTLS\n");

532

487

}

533

488

489

ret = gnutls_global_init();

490

if(ret != GNUTLS_E_SUCCESS){

491

fprintf_plus(stderr, "GnuTLS global_init: %s\n",

492

safer_gnutls_strerror(ret));

493

return -1;

494

}

495

534

496

if(debug){

535

497

/* "Use a log level over 10 to enable all debugging options."

536

498

* - GnuTLS manual

540

502

}

541

503

542

504

/* OpenPGP credentials */

543

ret = gnutls_certificate_allocate_credentials(&mc->cred);

505

ret = gnutls_certificate_allocate_credentials(&mc.cred);

544

506

if(ret != GNUTLS_E_SUCCESS){

545

507

fprintf_plus(stderr, "GnuTLS memory error: %s\n",

546

508

safer_gnutls_strerror(ret));

509

gnutls_global_deinit();

547

510

return -1;

548

511

}

549

512

555

518

}

556

519

557

520

ret = gnutls_certificate_set_openpgp_key_file

558

(mc->cred, pubkeyfilename, seckeyfilename,

521

(mc.cred, pubkeyfilename, seckeyfilename,

559

522

GNUTLS_OPENPGP_FMT_BASE64);

560

523

if(ret != GNUTLS_E_SUCCESS){

561

524

fprintf_plus(stderr,

567

530

}

568

531

569

532

/* GnuTLS server initialization */

570

ret = gnutls_dh_params_init(&mc->dh_params);

533

ret = gnutls_dh_params_init(&mc.dh_params);

571

534

if(ret != GNUTLS_E_SUCCESS){

572

535

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

573

536

" initialization: %s\n",

574

537

safer_gnutls_strerror(ret));

575

538

goto globalfail;

576

539

}

577

/* If a Diffie-Hellman parameters file was given, try to use it */

578

if(dhparamsfilename != NULL){

579

gnutls_datum_t params = { .data = NULL, .size = 0 };

580

do {

581

int dhpfile = open(dhparamsfilename, O_RDONLY);

582

if(dhpfile == -1){

583

perror_plus("open");

584

dhparamsfilename = NULL;

585

break;

586

}

587

size_t params_capacity = 0;

588

while(true){

589

params_capacity = incbuffer((char **)&params.data,

590

(size_t)params.size,

591

(size_t)params_capacity);

592

if(params_capacity == 0){

593

perror_plus("incbuffer");

594

free(params.data);

595

params.data = NULL;

596

dhparamsfilename = NULL;

597

break;

598

}

599

ssize_t bytes_read = read(dhpfile,

600

params.data + params.size,

601

BUFFER_SIZE);

602

/* EOF */

603

if(bytes_read == 0){

604

break;

605

}

606

/* check bytes_read for failure */

607

if(bytes_read < 0){

608

perror_plus("read");

609

free(params.data);

610

params.data = NULL;

611

dhparamsfilename = NULL;

612

break;

613

}

614

params.size += (unsigned int)bytes_read;

615

}

616

if(params.data == NULL){

617

dhparamsfilename = NULL;

618

}

619

if(dhparamsfilename == NULL){

620

break;

621

}

622

ret = gnutls_dh_params_import_pkcs3(mc->dh_params, &params,

623

GNUTLS_X509_FMT_PEM);

624

if(ret != GNUTLS_E_SUCCESS){

625

fprintf_plus(stderr, "Failed to parse DH parameters in file"

626

" \"%s\": %s\n", dhparamsfilename,

627

safer_gnutls_strerror(ret));

628

dhparamsfilename = NULL;

629

}

630

free(params.data);

631

} while(false);

632

}

633

if(dhparamsfilename == NULL){

634

if(mc->dh_bits == 0){

635

/* Find out the optimal number of DH bits */

636

/* Try to read the private key file */

637

gnutls_datum_t buffer = { .data = NULL, .size = 0 };

638

do {

639

int secfile = open(seckeyfilename, O_RDONLY);

640

if(secfile == -1){

641

perror_plus("open");

642

break;

643

}

644

size_t buffer_capacity = 0;

645

while(true){

646

buffer_capacity = incbuffer((char **)&buffer.data,

647

(size_t)buffer.size,

648

(size_t)buffer_capacity);

649

if(buffer_capacity == 0){

650

perror_plus("incbuffer");

651

free(buffer.data);

652

buffer.data = NULL;

653

break;

654

}

655

ssize_t bytes_read = read(secfile,

656

buffer.data + buffer.size,

657

BUFFER_SIZE);

658

/* EOF */

659

if(bytes_read == 0){

660

break;

661

}

662

/* check bytes_read for failure */

663

if(bytes_read < 0){

664

perror_plus("read");

665

free(buffer.data);

666

buffer.data = NULL;

667

break;

668

}

669

buffer.size += (unsigned int)bytes_read;

670

}

671

close(secfile);

672

} while(false);

673

/* If successful, use buffer to parse private key */

674

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

675

if(buffer.data != NULL){

676

{

677

gnutls_openpgp_privkey_t privkey = NULL;

678

ret = gnutls_openpgp_privkey_init(&privkey);

679

if(ret != GNUTLS_E_SUCCESS){

680

fprintf_plus(stderr, "Error initializing OpenPGP key"

681

" structure: %s",

682

safer_gnutls_strerror(ret));

683

free(buffer.data);

684

buffer.data = NULL;

685

} else {

686

ret = gnutls_openpgp_privkey_import

687

(privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);

688

if(ret != GNUTLS_E_SUCCESS){

689

fprintf_plus(stderr, "Error importing OpenPGP key : %s",

690

safer_gnutls_strerror(ret));

691

privkey = NULL;

692

}

693

free(buffer.data);

694

buffer.data = NULL;

695

if(privkey != NULL){

696

/* Use private key to suggest an appropriate

697

sec_param */

698

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

699

gnutls_openpgp_privkey_deinit(privkey);

700

if(debug){

701

fprintf_plus(stderr, "This OpenPGP key implies using"

702

" a GnuTLS security parameter \"%s\".\n",

703

safe_string(gnutls_sec_param_get_name

704

(sec_param)));

705

}

706

}

707

}

708

}

709

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

710

/* Err on the side of caution */

711

sec_param = GNUTLS_SEC_PARAM_ULTRA;

712

if(debug){

713

fprintf_plus(stderr, "Falling back to security parameter"

714

" \"%s\"\n",

715

safe_string(gnutls_sec_param_get_name

716

(sec_param)));

717

}

718

}

719

}

720

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

721

if(uret != 0){

722

mc->dh_bits = uret;

723

if(debug){

724

fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"

725

" implies %u DH bits; using that.\n",

726

safe_string(gnutls_sec_param_get_name

727

(sec_param)),

728

mc->dh_bits);

729

}

730

} else {

731

fprintf_plus(stderr, "Failed to get implied number of DH"

732

" bits for security parameter \"%s\"): %s\n",

733

safe_string(gnutls_sec_param_get_name

734

(sec_param)),

735

safer_gnutls_strerror(ret));

736

goto globalfail;

737

}

738

} else if(debug){

739

fprintf_plus(stderr, "DH bits explicitly set to %u\n",

740

mc->dh_bits);

741

}

742

ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);

743

if(ret != GNUTLS_E_SUCCESS){

744

fprintf_plus(stderr, "Error in GnuTLS prime generation (%u"

745

" bits): %s\n", mc->dh_bits,

746

safer_gnutls_strerror(ret));

747

goto globalfail;

748

}

749

}

750

gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);

540

ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);

541

if(ret != GNUTLS_E_SUCCESS){

542

fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",

543

safer_gnutls_strerror(ret));

544

goto globalfail;

545

}

546

547

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

751

548

752

549

return 0;

753

550

754

551

globalfail:

755

552

756

gnutls_certificate_free_credentials(mc->cred);

757

gnutls_dh_params_deinit(mc->dh_params);

553

gnutls_certificate_free_credentials(mc.cred);

554

gnutls_global_deinit();

555

gnutls_dh_params_deinit(mc.dh_params);

758

556

return -1;

759

557

}

760

558

761

__attribute__((nonnull, warn_unused_result))

762

static int init_gnutls_session(gnutls_session_t *session,

763

mandos_context *mc){

559

static int init_gnutls_session(gnutls_session_t *session){

764

560

int ret;

765

561

/* GnuTLS session creation */

766

562

do {

778

574

{

779

575

const char *err;

780

576

do {

781

ret = gnutls_priority_set_direct(*session, mc->priority, &err);

577

ret = gnutls_priority_set_direct(*session, mc.priority, &err);

782

578

if(quit_now){

783

579

gnutls_deinit(*session);

784

580

return -1;

795

591

796

592

do {

797

593

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

798

mc->cred);

594

mc.cred);

799

595

if(quit_now){

800

596

gnutls_deinit(*session);

801

597

return -1;

811

607

/* ignore client certificate if any. */

812

608

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

813

609

610

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

611

814

612

return 0;

815

613

}

816

614

818

616

static void empty_log(__attribute__((unused)) AvahiLogLevel level,

819

617

__attribute__((unused)) const char *txt){}

820

618

821

/* Set effective uid to 0, return errno */

822

__attribute__((warn_unused_result))

823

int raise_privileges(void){

824

int old_errno = errno;

825

int ret = 0;

826

if(seteuid(0) == -1){

827

ret = errno;

828

}

829

errno = old_errno;

830

return ret;

831

}

832

833

/* Set effective and real user ID to 0. Return errno. */

834

__attribute__((warn_unused_result))

835

int raise_privileges_permanently(void){

836

int old_errno = errno;

837

int ret = raise_privileges();

838

if(ret != 0){

839

errno = old_errno;

840

return ret;

841

}

842

if(setuid(0) == -1){

843

ret = errno;

844

}

845

errno = old_errno;

846

return ret;

847

}

848

849

/* Set effective user ID to unprivileged saved user ID */

850

__attribute__((warn_unused_result))

851

int lower_privileges(void){

852

int old_errno = errno;

853

int ret = 0;

854

if(seteuid(uid) == -1){

855

ret = errno;

856

}

857

errno = old_errno;

858

return ret;

859

}

860

861

/* Lower privileges permanently */

862

__attribute__((warn_unused_result))

863

int lower_privileges_permanently(void){

864

int old_errno = errno;

865

int ret = 0;

866

if(setuid(uid) == -1){

867

ret = errno;

868

}

869

errno = old_errno;

870

return ret;

871

}

872

873

/* Helper function to add_local_route() and delete_local_route() */

874

__attribute__((nonnull, warn_unused_result))

875

static bool add_delete_local_route(const bool add,

876

const char *address,

877

AvahiIfIndex if_index){

878

int ret;

879

char helper[] = "mandos-client-iprouteadddel";

880

char add_arg[] = "add";

881

char delete_arg[] = "delete";

882

char debug_flag[] = "--debug";

883

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

884

if(pluginhelperdir == NULL){

885

if(debug){

886

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

887

" variable not set; cannot run helper\n");

888

}

889

return false;

890

}

891

892

char interface[IF_NAMESIZE];

893

if(if_indextoname((unsigned int)if_index, interface) == NULL){

894

perror_plus("if_indextoname");

895

return false;

896

}

897

898

int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));

899

if(devnull == -1){

900

perror_plus("open(\"/dev/null\", O_RDONLY)");

901

return false;

902

}

903

pid_t pid = fork();

904

if(pid == 0){

905

/* Child */

906

/* Raise privileges */

907

errno = raise_privileges_permanently();

908

if(errno != 0){

909

perror_plus("Failed to raise privileges");

910

/* _exit(EX_NOPERM); */

911

} else {

912

/* Set group */

913

errno = 0;

914

ret = setgid(0);

915

if(ret == -1){

916

perror_plus("setgid");

917

_exit(EX_NOPERM);

918

}

919

/* Reset supplementary groups */

920

errno = 0;

921

ret = setgroups(0, NULL);

922

if(ret == -1){

923

perror_plus("setgroups");

924

_exit(EX_NOPERM);

925

}

926

}

927

ret = dup2(devnull, STDIN_FILENO);

928

if(ret == -1){

929

perror_plus("dup2(devnull, STDIN_FILENO)");

930

_exit(EX_OSERR);

931

}

932

ret = close(devnull);

933

if(ret == -1){

934

perror_plus("close");

935

_exit(EX_OSERR);

936

}

937

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

938

if(ret == -1){

939

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

940

_exit(EX_OSERR);

941

}

942

int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,

943

O_RDONLY

944

| O_DIRECTORY

945

| O_PATH

946

| O_CLOEXEC));

947

if(helperdir_fd == -1){

948

perror_plus("open");

949

_exit(EX_UNAVAILABLE);

950

}

951

int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,

952

helper, O_RDONLY));

953

if(helper_fd == -1){

954

perror_plus("openat");

955

close(helperdir_fd);

956

_exit(EX_UNAVAILABLE);

957

}

958

close(helperdir_fd);

959

#ifdef __GNUC__

960

#pragma GCC diagnostic push

961

#pragma GCC diagnostic ignored "-Wcast-qual"

962

#endif

963

if(fexecve(helper_fd, (char *const [])

964

{ helper, add ? add_arg : delete_arg, (char *)address,

965

interface, debug ? debug_flag : NULL, NULL },

966

environ) == -1){

967

#ifdef __GNUC__

968

#pragma GCC diagnostic pop

969

#endif

970

perror_plus("fexecve");

971

_exit(EXIT_FAILURE);

972

}

973

}

974

if(pid == -1){

975

perror_plus("fork");

976

return false;

977

}

978

int status;

979

pid_t pret = -1;

980

errno = 0;

981

do {

982

pret = waitpid(pid, &status, 0);

983

if(pret == -1 and errno == EINTR and quit_now){

984

int errno_raising = 0;

985

if((errno = raise_privileges()) != 0){

986

errno_raising = errno;

987

perror_plus("Failed to raise privileges in order to"

988

" kill helper program");

989

}

990

if(kill(pid, SIGTERM) == -1){

991

perror_plus("kill");

992

}

993

if((errno_raising == 0) and (errno = lower_privileges()) != 0){

994

perror_plus("Failed to lower privileges after killing"

995

" helper program");

996

}

997

return false;

998

}

999

} while(pret == -1 and errno == EINTR);

1000

if(pret == -1){

1001

perror_plus("waitpid");

1002

return false;

1003

}

1004

if(WIFEXITED(status)){

1005

if(WEXITSTATUS(status) != 0){

1006

fprintf_plus(stderr, "Error: iprouteadddel exited"

1007

" with status %d\n", WEXITSTATUS(status));

1008

return false;

1009

}

1010

return true;

1011

}

1012

if(WIFSIGNALED(status)){

1013

fprintf_plus(stderr, "Error: iprouteadddel died by"

1014

" signal %d\n", WTERMSIG(status));

1015

return false;

1016

}

1017

fprintf_plus(stderr, "Error: iprouteadddel crashed\n");

1018

return false;

1019

}

1020

1021

__attribute__((nonnull, warn_unused_result))

1022

static bool add_local_route(const char *address,

1023

AvahiIfIndex if_index){

1024

if(debug){

1025

fprintf_plus(stderr, "Adding route to %s\n", address);

1026

}

1027

return add_delete_local_route(true, address, if_index);

1028

}

1029

1030

__attribute__((nonnull, warn_unused_result))

1031

static bool delete_local_route(const char *address,

1032

AvahiIfIndex if_index){

1033

if(debug){

1034

fprintf_plus(stderr, "Removing route to %s\n", address);

1035

}

1036

return add_delete_local_route(false, address, if_index);

1037

}

1038

1039

619

/* Called when a Mandos server is found */

1040

__attribute__((nonnull, warn_unused_result))

1041

static int start_mandos_communication(const char *ip, in_port_t port,

620

static int start_mandos_communication(const char *ip, uint16_t port,

1042

621

AvahiIfIndex if_index,

1043

int af, mandos_context *mc){

622

int af){

1044

623

int ret, tcp_sd = -1;

1045

624

ssize_t sret;

1046

struct sockaddr_storage to;

625

union {

626

struct sockaddr_in in;

627

struct sockaddr_in6 in6;

628

} to;

1047

629

char *buffer = NULL;

1048

630

char *decrypted_buffer = NULL;

1049

631

size_t buffer_length = 0;

1052

634

int retval = -1;

1053

635

gnutls_session_t session;

1054

636

int pf; /* Protocol family */

1055

bool route_added = false;

1056

637

1057

638

errno = 0;

1058

639

1074

655

return -1;

1075

656

}

1076

657

1077

/* If the interface is specified and we have a list of interfaces */

1078

if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){

1079

/* Check if the interface is one of the interfaces we are using */

1080

bool match = false;

1081

{

1082

char *interface = NULL;

1083

while((interface = argz_next(mc->interfaces,

1084

mc->interfaces_size,

1085

interface))){

1086

if(if_nametoindex(interface) == (unsigned int)if_index){

1087

match = true;

1088

break;

1089

}

1090

}

1091

}

1092

if(not match){

1093

/* This interface does not match any in the list, so we don't

1094

connect to the server */

1095

if(debug){

1096

char interface[IF_NAMESIZE];

1097

if(if_indextoname((unsigned int)if_index, interface) == NULL){

1098

perror_plus("if_indextoname");

1099

} else {

1100

fprintf_plus(stderr, "Skipping server on non-used interface"

1101

" \"%s\"\n",

1102

if_indextoname((unsigned int)if_index,

1103

interface));

1104

}

1105

}

1106

return -1;

1107

}

1108

}

1109

1110

ret = init_gnutls_session(&session, mc);

658

ret = init_gnutls_session(&session);

1111

659

if(ret != 0){

1112

660

return -1;

1113

661

}

1114

662

1115

663

if(debug){

1116

664

fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"

1117

PRIuMAX "\n", ip, (uintmax_t)port);

665

PRIu16 "\n", ip, port);

1118

666

}

1119

667

1120

tcp_sd = socket(pf, SOCK_STREAM | SOCK_CLOEXEC, 0);

668

tcp_sd = socket(pf, SOCK_STREAM, 0);

1121

669

if(tcp_sd < 0){

1122

670

int e = errno;

1123

671

perror_plus("socket");

1130

678

goto mandos_end;

1131

679

}

1132

680

681

memset(&to, 0, sizeof(to));

1133

682

if(af == AF_INET6){

1134

struct sockaddr_in6 *to6 = (struct sockaddr_in6 *)&to;

1135

*to6 = (struct sockaddr_in6){ .sin6_family = (sa_family_t)af };

1136

ret = inet_pton(af, ip, &to6->sin6_addr);

683

to.in6.sin6_family = (sa_family_t)af;

684

ret = inet_pton(af, ip, &to.in6.sin6_addr);

1137

685

} else { /* IPv4 */

1138

struct sockaddr_in *to4 = (struct sockaddr_in *)&to;

1139

*to4 = (struct sockaddr_in){ .sin_family = (sa_family_t)af };

1140

ret = inet_pton(af, ip, &to4->sin_addr);

686

to.in.sin_family = (sa_family_t)af;

687

ret = inet_pton(af, ip, &to.in.sin_addr);

1141

688

}

1142

689

if(ret < 0 ){

1143

690

int e = errno;

1152

699

goto mandos_end;

1153

700

}

1154

701

if(af == AF_INET6){

1155

((struct sockaddr_in6 *)&to)->sin6_port = htons(port);

1156

if(IN6_IS_ADDR_LINKLOCAL

1157

(&((struct sockaddr_in6 *)&to)->sin6_addr)){

702

to.in6.sin6_port = htons(port); /* Spurious warnings from

703

-Wconversion and

704

-Wunreachable-code */

705

706

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

707

(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and

708

-Wunreachable-code*/

1158

709

if(if_index == AVAHI_IF_UNSPEC){

1159

710

fprintf_plus(stderr, "An IPv6 link-local address is"

1160

711

" incomplete without a network interface\n");

1162

713

goto mandos_end;

1163

714

}

1164

715

/* Set the network interface number as scope */

1165

((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;

716

to.in6.sin6_scope_id = (uint32_t)if_index;

1166

717

}

1167

718

} else {

1168

((struct sockaddr_in *)&to)->sin_port = htons(port);

719

to.in.sin_port = htons(port); /* Spurious warnings from

720

-Wconversion and

721

-Wunreachable-code */

1169

722

}

1170

723

1171

724

if(quit_now){

1179

732

if(if_indextoname((unsigned int)if_index, interface) == NULL){

1180

733

perror_plus("if_indextoname");

1181

734

} else {

1182

fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX

1183

"\n", ip, interface, (uintmax_t)port);

735

fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIu16

736

"\n", ip, interface, port);

1184

737

}

1185

738

} else {

1186

fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",

1187

ip, (uintmax_t)port);

739

fprintf_plus(stderr, "Connection to: %s, port %" PRIu16 "\n",

740

ip, port);

1188

741

}

1189

742

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1190

743

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1191

if(af == AF_INET6){

1192

ret = getnameinfo((struct sockaddr *)&to,

1193

sizeof(struct sockaddr_in6),

1194

addrstr, sizeof(addrstr), NULL, 0,

1195

NI_NUMERICHOST);

1196

} else {

1197

ret = getnameinfo((struct sockaddr *)&to,

1198

sizeof(struct sockaddr_in),

1199

addrstr, sizeof(addrstr), NULL, 0,

1200

NI_NUMERICHOST);

1201

}

1202

if(ret == EAI_SYSTEM){

1203

perror_plus("getnameinfo");

1204

} else if(ret != 0) {

1205

fprintf_plus(stderr, "getnameinfo: %s", gai_strerror(ret));

1206

} else if(strcmp(addrstr, ip) != 0){

1207

fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);

1208

}

1209

}

1210

1211

if(quit_now){

1212

errno = EINTR;

1213

goto mandos_end;

1214

}

1215

1216

while(true){

1217

if(af == AF_INET6){

1218

ret = connect(tcp_sd, (struct sockaddr *)&to,

1219

sizeof(struct sockaddr_in6));

1220

} else {

1221

ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */

1222

sizeof(struct sockaddr_in));

1223

}

1224

if(ret < 0){

1225

if(((errno == ENETUNREACH) or (errno == EHOSTUNREACH))

1226

and if_index != AVAHI_IF_UNSPEC

1227

and connect_to == NULL

1228

and not route_added and

1229

((af == AF_INET6 and not

1230

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1231

&to)->sin6_addr)))

1232

or (af == AF_INET and

1233

/* Not a a IPv4LL address */

1234

(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)

1235

& 0xFFFF0000L) != 0xA9FE0000L))){

1236

/* Work around Avahi bug - Avahi does not announce link-local

1237

addresses if it has a global address, so local hosts with

1238

*only* a link-local address (e.g. Mandos clients) cannot

1239

connect to a Mandos server announced by Avahi on a server

1240

host with a global address. Work around this by retrying

1241

with an explicit route added with the server's address.

1242

1243

Avahi bug reference:

1244

https://lists.freedesktop.org/archives/avahi/2010-February/001833.html

1245

https://bugs.debian.org/587961

1246

*/

1247

if(debug){

1248

fprintf_plus(stderr, "Mandos server unreachable, trying"

1249

" direct route\n");

1250

}

1251

int e = errno;

1252

route_added = add_local_route(ip, if_index);

1253

if(route_added){

1254

continue;

1255

}

1256

errno = e;

1257

}

1258

if(errno != ECONNREFUSED or debug){

1259

int e = errno;

1260

perror_plus("connect");

1261

errno = e;

1262

}

1263

goto mandos_end;

1264

}

1265

1266

if(quit_now){

1267

errno = EINTR;

1268

goto mandos_end;

1269

}

1270

break;

744

const char *pcret;

745

if(af == AF_INET6){

746

pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,

747

sizeof(addrstr));

748

} else {

749

pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,

750

sizeof(addrstr));

751

}

752

if(pcret == NULL){

753

perror_plus("inet_ntop");

754

} else {

755

if(strcmp(addrstr, ip) != 0){

756

fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);

757

}

758

}

759

}

760

761

if(quit_now){

762

errno = EINTR;

763

goto mandos_end;

764

}

765

766

if(af == AF_INET6){

767

ret = connect(tcp_sd, &to.in6, sizeof(to));

768

} else {

769

ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */

770

}

771

if(ret < 0){

772

if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){

773

int e = errno;

774

perror_plus("connect");

775

errno = e;

776

}

777

goto mandos_end;

778

}

779

780

if(quit_now){

781

errno = EINTR;

782

goto mandos_end;

1271

783

}

1272

784

1273

785

const char *out = mandos_protocol_version;

1309

821

goto mandos_end;

1310

822

}

1311

823

1312

/* This casting via intptr_t is to eliminate warning about casting

1313

an int to a pointer type. This is exactly how the GnuTLS Guile

1314

function "set-session-transport-fd!" does it. */

1315

gnutls_transport_set_ptr(session,

1316

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

824

/* Spurious warning from -Wint-to-pointer-cast */

825

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1317

826

1318

827

if(quit_now){

1319

828

errno = EINTR;

1424

933

if(buffer_length > 0){

1425

934

ssize_t decrypted_buffer_size;

1426

935

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1427

&decrypted_buffer, mc);

936

&decrypted_buffer);

1428

937

if(decrypted_buffer_size >= 0){

1429

938

1430

clearerr(stdout);

1431

939

written = 0;

1432

940

while(written < (size_t) decrypted_buffer_size){

1433

941

if(quit_now){

1449

957

}

1450

958

written += (size_t)ret;

1451

959

}

1452

ret = fflush(stdout);

1453

if(ret != 0){

1454

int e = errno;

1455

if(debug){

1456

fprintf_plus(stderr, "Error writing encrypted data: %s\n",

1457

strerror(errno));

1458

}

1459

errno = e;

1460

goto mandos_end;

1461

}

1462

960

retval = 0;

1463

961

}

1464

962

}

1467

965

1468

966

mandos_end:

1469

967

{

1470

if(route_added){

1471

if(not delete_local_route(ip, if_index)){

1472

fprintf_plus(stderr, "Failed to delete local route to %s on"

1473

" interface %d", ip, if_index);

1474

}

1475

}

1476

968

int e = errno;

1477

969

free(decrypted_buffer);

1478

970

free(buffer);

1479

971

if(tcp_sd >= 0){

1480

ret = close(tcp_sd);

972

ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));

1481

973

}

1482

974

if(ret == -1){

1483

975

if(e == 0){

1508

1000

AVAHI_GCC_UNUSED AvahiStringList *txt,

1509

1001

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1510

1002

flags,

1511

void *mc){

1512

if(r == NULL){

1513

return;

1514

}

1003

AVAHI_GCC_UNUSED void* userdata){

1004

assert(r);

1515

1005

1516

1006

/* Called whenever a service has been resolved successfully or

1517

1007

timed out */

1518

1008

1519

1009

if(quit_now){

1520

avahi_s_service_resolver_free(r);

1521

1010

return;

1522

1011

}

1523

1012

1527

1016

fprintf_plus(stderr, "(Avahi Resolver) Failed to resolve service "

1528

1017

"'%s' of type '%s' in domain '%s': %s\n", name, type,

1529

1018

domain,

1530

avahi_strerror(avahi_server_errno

1531

(((mandos_context*)mc)->server)));

1019

avahi_strerror(avahi_server_errno(mc.server)));

1532

1020

break;

1533

1021

1534

1022

case AVAHI_RESOLVER_FOUND:

1540

1028

PRIdMAX ") on port %" PRIu16 "\n", name,

1541

1029

host_name, ip, (intmax_t)interface, port);

1542

1030

}

1543

int ret = start_mandos_communication(ip, (in_port_t)port,

1544

interface,

1545

avahi_proto_to_af(proto),

1546

mc);

1031

int ret = start_mandos_communication(ip, port, interface,

1032

avahi_proto_to_af(proto));

1547

1033

if(ret == 0){

1548

avahi_simple_poll_quit(simple_poll);

1034

avahi_simple_poll_quit(mc.simple_poll);

1549

1035

} else {

1550

if(not add_server(ip, (in_port_t)port, interface,

1551

avahi_proto_to_af(proto),

1552

&((mandos_context*)mc)->current_server)){

1036

if(not add_server(ip, port, interface,

1037

avahi_proto_to_af(proto))){

1553

1038

fprintf_plus(stderr, "Failed to add server \"%s\" to server"

1554

1039

" list\n", name);

1555

1040

}

1568

1053

const char *domain,

1569

1054

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1570

1055

flags,

1571

void *mc){

1572

if(b == NULL){

1573

return;

1574

}

1056

AVAHI_GCC_UNUSED void* userdata){

1057

assert(b);

1575

1058

1576

1059

/* Called whenever a new services becomes available on the LAN or

1577

1060

is removed from the LAN */

1585

1068

case AVAHI_BROWSER_FAILURE:

1586

1069

1587

1070

fprintf_plus(stderr, "(Avahi browser) %s\n",

1588

avahi_strerror(avahi_server_errno

1589

(((mandos_context*)mc)->server)));

1590

avahi_simple_poll_quit(simple_poll);

1071

avahi_strerror(avahi_server_errno(mc.server)));

1072

avahi_simple_poll_quit(mc.simple_poll);

1591

1073

return;

1592

1074

1593

1075

case AVAHI_BROWSER_NEW:

1596

1078

the callback function is called the Avahi server will free the

1597

1079

resolver for us. */

1598

1080

1599

if(avahi_s_service_resolver_new(((mandos_context*)mc)->server,

1600

interface, protocol, name, type,

1601

domain, protocol, 0,

1602

resolve_callback, mc) == NULL)

1081

if(avahi_s_service_resolver_new(mc.server, interface, protocol,

1082

name, type, domain, protocol, 0,

1083

resolve_callback, NULL) == NULL)

1603

1084

fprintf_plus(stderr, "Avahi: Failed to resolve service '%s':"

1604

1085

" %s\n", name,

1605

avahi_strerror(avahi_server_errno

1606

(((mandos_context*)mc)->server)));

1086

avahi_strerror(avahi_server_errno(mc.server)));

1607

1087

break;

1608

1088

1609

1089

case AVAHI_BROWSER_REMOVE:

1628

1108

signal_received = sig;

1629

1109

int old_errno = errno;

1630

1110

/* set main loop to exit */

1631

if(simple_poll != NULL){

1632

avahi_simple_poll_quit(simple_poll);

1111

if(mc.simple_poll != NULL){

1112

avahi_simple_poll_quit(mc.simple_poll);

1633

1113

}

1634

1114

errno = old_errno;

1635

1115

}

1636

1116

1637

__attribute__((nonnull, warn_unused_result))

1638

1117

bool get_flags(const char *ifname, struct ifreq *ifr){

1639

1118

int ret;

1640

int old_errno;

1641

1119

1642

1120

int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1643

1121

if(s < 0){

1644

old_errno = errno;

1645

1122

perror_plus("socket");

1646

errno = old_errno;

1647

1123

return false;

1648

1124

}

1649

strncpy(ifr->ifr_name, ifname, IF_NAMESIZE);

1650

ifr->ifr_name[IF_NAMESIZE-1] = '\0'; /* NUL terminate */

1125

strcpy(ifr->ifr_name, ifname);

1651

1126

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1652

1127

if(ret == -1){

1653

1128

if(debug){

1654

old_errno = errno;

1655

1129

perror_plus("ioctl SIOCGIFFLAGS");

1656

errno = old_errno;

1657

1130

}

1658

1131

return false;

1659

1132

}

1660

1133

return true;

1661

1134

}

1662

1135

1663

__attribute__((nonnull, warn_unused_result))

1664

1136

bool good_flags(const char *ifname, const struct ifreq *ifr){

1665

1137

1666

1138

/* Reject the loopback device */

1708

1180

* corresponds to an acceptable network device.

1709

1181

* (This function is passed to scandir(3) as a filter function.)

1710

1182

*/

1711

__attribute__((nonnull, warn_unused_result))

1712

1183

int good_interface(const struct dirent *if_entry){

1713

1184

if(if_entry->d_name[0] == '.'){

1714

1185

return 0;

1730

1201

}

1731

1202

1732

1203

/*

1733

* This function determines if a network interface is up.

1734

*/

1735

__attribute__((nonnull, warn_unused_result))

1736

bool interface_is_up(const char *interface){

1737

struct ifreq ifr;

1738

if(not get_flags(interface, &ifr)){

1739

if(debug){

1740

fprintf_plus(stderr, "Failed to get flags for interface "

1741

"\"%s\"\n", interface);

1742

}

1743

return false;

1744

}

1745

1746

return (bool)(ifr.ifr_flags & IFF_UP);

1747

}

1748

1749

/*

1750

* This function determines if a network interface is running

1751

*/

1752

__attribute__((nonnull, warn_unused_result))

1753

bool interface_is_running(const char *interface){

1754

struct ifreq ifr;

1755

if(not get_flags(interface, &ifr)){

1756

if(debug){

1757

fprintf_plus(stderr, "Failed to get flags for interface "

1758

"\"%s\"\n", interface);

1759

}

1760

return false;

1761

}

1762

1763

return (bool)(ifr.ifr_flags & IFF_RUNNING);

1764

}

1765

1766

__attribute__((nonnull, pure, warn_unused_result))

1204

* This function determines if a directory entry in /sys/class/net

1205

* corresponds to an acceptable network device which is up.

1206

* (This function is passed to scandir(3) as a filter function.)

1207

*/

1208

int up_interface(const struct dirent *if_entry){

1209

if(if_entry->d_name[0] == '.'){

1210

return 0;

1211

}

1212

1213

struct ifreq ifr;

1214

if(not get_flags(if_entry->d_name, &ifr)){

1215

if(debug){

1216

fprintf_plus(stderr, "Failed to get flags for interface "

1217

"\"%s\"\n", if_entry->d_name);

1218

}

1219

return 0;

1220

}

1221

1222

/* Reject down interfaces */

1223

if(not (ifr.ifr_flags & IFF_UP)){

1224

if(debug){

1225

fprintf_plus(stderr, "Rejecting down interface \"%s\"\n",

1226

if_entry->d_name);

1227

}

1228

return 0;

1229

}

1230

1231

/* Reject non-running interfaces */

1232

if(not (ifr.ifr_flags & IFF_RUNNING)){

1233

if(debug){

1234

fprintf_plus(stderr, "Rejecting non-running interface \"%s\"\n",

1235

if_entry->d_name);

1236

}

1237

return 0;

1238

}

1239

1240

if(not good_flags(if_entry->d_name, &ifr)){

1241

return 0;

1242

}

1243

return 1;

1244

}

1245

1767

1246

int notdotentries(const struct dirent *direntry){

1768

1247

/* Skip "." and ".." */

1769

1248

if(direntry->d_name[0] == '.'

1776

1255

}

1777

1256

1778

1257

/* Is this directory entry a runnable program? */

1779

__attribute__((nonnull, warn_unused_result))

1780

1258

int runnable_hook(const struct dirent *direntry){

1781

1259

int ret;

1782

1260

size_t sret;

1790

1268

sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

1791

1269

"abcdefghijklmnopqrstuvwxyz"

1792

1270

"0123456789"

1793

"_.-");

1271

"_-");

1794

1272

if((direntry->d_name)[sret] != '\0'){

1795

1273

/* Contains non-allowed characters */

1796

1274

if(debug){

1800

1278

return 0;

1801

1279

}

1802

1280

1803

ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);

1281

char *fullname = NULL;

1282

ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);

1283

if(ret < 0){

1284

perror_plus("asprintf");

1285

return 0;

1286

}

1287

1288

ret = stat(fullname, &st);

1804

1289

if(ret == -1){

1805

1290

if(debug){

1806

1291

perror_plus("Could not stat hook");

1830

1315

return 1;

1831

1316

}

1832

1317

1833

__attribute__((nonnull, warn_unused_result))

1834

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1835

mandos_context *mc){

1318

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1836

1319

int ret;

1837

1320

struct timespec now;

1838

1321

struct timespec waited_time;

1839

1322

intmax_t block_time;

1840

1323

1841

1324

while(true){

1842

if(mc->current_server == NULL){

1843

if(debug){

1325

if(mc.current_server == NULL){

1326

if (debug){

1844

1327

fprintf_plus(stderr, "Wait until first server is found."

1845

1328

" No timeout!\n");

1846

1329

}

1847

1330

ret = avahi_simple_poll_iterate(s, -1);

1848

1331

} else {

1849

if(debug){

1332

if (debug){

1850

1333

fprintf_plus(stderr, "Check current_server if we should run"

1851

1334

" it, or wait\n");

1852

1335

}

1859

1342

/* Calculating in ms how long time between now and server

1860

1343

who we visted longest time ago. Now - last seen. */

1861

1344

waited_time.tv_sec = (now.tv_sec

1862

- mc->current_server->last_seen.tv_sec);

1345

- mc.current_server->last_seen.tv_sec);

1863

1346

waited_time.tv_nsec = (now.tv_nsec

1864

- mc->current_server->last_seen.tv_nsec);

1347

- mc.current_server->last_seen.tv_nsec);

1865

1348

/* total time is 10s/10,000ms.

1866

1349

Converting to s from ms by dividing by 1,000,

1867

1350

and ns to ms by dividing by 1,000,000. */

1869

1352

- ((intmax_t)waited_time.tv_sec * 1000))

1870

1353

- ((intmax_t)waited_time.tv_nsec / 1000000));

1871

1354

1872

if(debug){

1355

if (debug){

1873

1356

fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",

1874

1357

block_time);

1875

1358

}

1876

1359

1877

1360

if(block_time <= 0){

1878

ret = start_mandos_communication(mc->current_server->ip,

1879

mc->current_server->port,

1880

mc->current_server->if_index,

1881

mc->current_server->af, mc);

1361

ret = start_mandos_communication(mc.current_server->ip,

1362

mc.current_server->port,

1363

mc.current_server->if_index,

1364

mc.current_server->af);

1882

1365

if(ret == 0){

1883

avahi_simple_poll_quit(s);

1366

avahi_simple_poll_quit(mc.simple_poll);

1884

1367

return 0;

1885

1368

}

1886

1369

ret = clock_gettime(CLOCK_MONOTONIC,

1887

&mc->current_server->last_seen);

1370

&mc.current_server->last_seen);

1888

1371

if(ret == -1){

1889

1372

perror_plus("clock_gettime");

1890

1373

return -1;

1891

1374

}

1892

mc->current_server = mc->current_server->next;

1375

mc.current_server = mc.current_server->next;

1893

1376

block_time = 0; /* Call avahi to find new Mandos

1894

1377

servers, but don't block */

1895

1378

}

1897

1380

ret = avahi_simple_poll_iterate(s, (int)block_time);

1898

1381

}

1899

1382

if(ret != 0){

1900

if(ret > 0 or errno != EINTR){

1383

if (ret > 0 or errno != EINTR){

1901

1384

return (ret != 1) ? ret : 0;

1902

1385

}

1903

1386

}

1904

1387

}

1905

1388

}

1906

1389

1907

__attribute__((nonnull))

1908

void run_network_hooks(const char *mode, const char *interface,

1390

bool run_network_hooks(const char *mode, const char *interface,

1909

1391

const float delay){

1910

struct dirent **direntries = NULL;

1911

if(hookdir_fd == -1){

1912

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1913

| O_CLOEXEC);

1914

if(hookdir_fd == -1){

1915

if(errno == ENOENT){

1916

if(debug){

1917

fprintf_plus(stderr, "Network hook directory \"%s\" not"

1918

" found\n", hookdir);

1919

}

1920

} else {

1921

perror_plus("open");

1922

}

1923

return;

1924

}

1925

}

1926

int numhooks = scandirat(hookdir_fd, ".", &direntries,

1927

runnable_hook, alphasort);

1392

struct dirent **direntries;

1393

struct dirent *direntry;

1394

int ret;

1395

int numhooks = scandir(hookdir, &direntries, runnable_hook,

1396

alphasort);

1928

1397

if(numhooks == -1){

1929

1398

perror_plus("scandir");

1930

return;

1931

}

1932

struct dirent *direntry;

1933

int ret;

1934

int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));

1935

if(devnull == -1){

1936

perror_plus("open(\"/dev/null\", O_RDONLY)");

1937

return;

1938

}

1939

for(int i = 0; i < numhooks; i++){

1940

direntry = direntries[i];

1941

if(debug){

1942

fprintf_plus(stderr, "Running network hook \"%s\"\n",

1943

direntry->d_name);

1944

}

1945

pid_t hook_pid = fork();

1946

if(hook_pid == 0){

1947

/* Child */

1948

/* Raise privileges */

1949

errno = raise_privileges_permanently();

1950

if(errno != 0){

1951

perror_plus("Failed to raise privileges");

1952

_exit(EX_NOPERM);

1953

}

1954

/* Set group */

1955

errno = 0;

1956

ret = setgid(0);

1957

if(ret == -1){

1958

perror_plus("setgid");

1959

_exit(EX_NOPERM);

1960

}

1961

/* Reset supplementary groups */

1962

errno = 0;

1963

ret = setgroups(0, NULL);

1964

if(ret == -1){

1965

perror_plus("setgroups");

1966

_exit(EX_NOPERM);

1967

}

1968

ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);

1969

if(ret == -1){

1970

perror_plus("setenv");

1971

_exit(EX_OSERR);

1972

}

1973

ret = setenv("DEVICE", interface, 1);

1974

if(ret == -1){

1975

perror_plus("setenv");

1976

_exit(EX_OSERR);

1977

}

1978

ret = setenv("VERBOSITY", debug ? "1" : "0", 1);

1979

if(ret == -1){

1980

perror_plus("setenv");

1981

_exit(EX_OSERR);

1982

}

1983

ret = setenv("MODE", mode, 1);

1984

if(ret == -1){

1985

perror_plus("setenv");

1986

_exit(EX_OSERR);

1987

}

1988

char *delaystring;

1989

ret = asprintf(&delaystring, "%f", (double)delay);

1990

if(ret == -1){

1399

} else {

1400

int devnull = open("/dev/null", O_RDONLY);

1401

for(int i = 0; i < numhooks; i++){

1402

direntry = direntries[i];

1403

char *fullname = NULL;

1404

ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);

1405

if(ret < 0){

1991

1406

perror_plus("asprintf");

1992

_exit(EX_OSERR);

1993

}

1994

ret = setenv("DELAY", delaystring, 1);

1995

if(ret == -1){

1407

continue;

1408

}

1409

if(debug){

1410

fprintf_plus(stderr, "Running network hook \"%s\"\n",

1411

direntry->d_name);

1412

}

1413

pid_t hook_pid = fork();

1414

if(hook_pid == 0){

1415

/* Child */

1416

/* Raise privileges */

1417

errno = 0;

1418

ret = seteuid(0);

1419

if(ret == -1){

1420

perror_plus("seteuid");

1421

}

1422

/* Raise privileges even more */

1423

errno = 0;

1424

ret = setuid(0);

1425

if(ret == -1){

1426

perror_plus("setuid");

1427

}

1428

/* Set group */

1429

errno = 0;

1430

ret = setgid(0);

1431

if(ret == -1){

1432

perror_plus("setgid");

1433

}

1434

/* Reset supplementary groups */

1435

errno = 0;

1436

ret = setgroups(0, NULL);

1437

if(ret == -1){

1438

perror_plus("setgroups");

1439

}

1440

dup2(devnull, STDIN_FILENO);

1441

close(devnull);

1442

dup2(STDERR_FILENO, STDOUT_FILENO);

1443

ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);

1444

if(ret == -1){

1445

perror_plus("setenv");

1446

_exit(EX_OSERR);

1447

}

1448

ret = setenv("DEVICE", interface, 1);

1449

if(ret == -1){

1450

perror_plus("setenv");

1451

_exit(EX_OSERR);

1452

}

1453

ret = setenv("VERBOSE", debug ? "1" : "0", 1);

1454

if(ret == -1){

1455

perror_plus("setenv");

1456

_exit(EX_OSERR);

1457

}

1458

ret = setenv("MODE", mode, 1);

1459

if(ret == -1){

1460

perror_plus("setenv");

1461

_exit(EX_OSERR);

1462

}

1463

char *delaystring;

1464

ret = asprintf(&delaystring, "%f", delay);

1465

if(ret == -1){

1466

perror_plus("asprintf");

1467

_exit(EX_OSERR);

1468

}

1469

ret = setenv("DELAY", delaystring, 1);

1470

if(ret == -1){

1471

free(delaystring);

1472

perror_plus("setenv");

1473

_exit(EX_OSERR);

1474

}

1996

1475

free(delaystring);

1997

perror_plus("setenv");

1998

_exit(EX_OSERR);

1999

}

2000

free(delaystring);

2001

if(connect_to != NULL){

2002

ret = setenv("CONNECT", connect_to, 1);

2003

if(ret == -1){

2004

perror_plus("setenv");

2005

_exit(EX_OSERR);

2006

}

2007

}

2008

int hook_fd = (int)TEMP_FAILURE_RETRY(openat(hookdir_fd,

2009

direntry->d_name,

2010

O_RDONLY));

2011

if(hook_fd == -1){

2012

perror_plus("openat");

2013

_exit(EXIT_FAILURE);

2014

}

2015

if(close(hookdir_fd) == -1){

2016

perror_plus("close");

2017

_exit(EXIT_FAILURE);

2018

}

2019

ret = dup2(devnull, STDIN_FILENO);

2020

if(ret == -1){

2021

perror_plus("dup2(devnull, STDIN_FILENO)");

2022

_exit(EX_OSERR);

2023

}

2024

ret = close(devnull);

2025

if(ret == -1){

2026

perror_plus("close");

2027

_exit(EX_OSERR);

2028

}

2029

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2030

if(ret == -1){

2031

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

2032

_exit(EX_OSERR);

2033

}

2034

if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },

2035

environ) == -1){

2036

perror_plus("fexecve");

2037

_exit(EXIT_FAILURE);

2038

}

2039

} else {

2040

if(hook_pid == -1){

2041

perror_plus("fork");

2042

free(direntry);

2043

continue;

2044

}

2045

int status;

2046

if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){

2047

perror_plus("waitpid");

2048

free(direntry);

2049

continue;

2050

}

2051

if(WIFEXITED(status)){

2052

if(WEXITSTATUS(status) != 0){

2053

fprintf_plus(stderr, "Warning: network hook \"%s\" exited"

2054

" with status %d\n", direntry->d_name,

2055

WEXITSTATUS(status));

2056

free(direntry);

2057

continue;

2058

}

2059

} else if(WIFSIGNALED(status)){

2060

fprintf_plus(stderr, "Warning: network hook \"%s\" died by"

2061

" signal %d\n", direntry->d_name,

2062

WTERMSIG(status));

2063

free(direntry);

2064

continue;

2065

} else {

2066

fprintf_plus(stderr, "Warning: network hook \"%s\""

2067

" crashed\n", direntry->d_name);

2068

free(direntry);

2069

continue;

2070

}

2071

}

2072

if(debug){

2073

fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",

2074

direntry->d_name);

2075

}

2076

free(direntry);

2077

}

2078

free(direntries);

2079

if(close(hookdir_fd) == -1){

2080

perror_plus("close");

2081

} else {

2082

hookdir_fd = -1;

2083

}

2084

close(devnull);

2085

}

2086

2087

__attribute__((nonnull, warn_unused_result))

2088

int bring_up_interface(const char *const interface,

2089

const float delay){

2090

int old_errno = errno;

2091

int ret;

2092

struct ifreq network;

2093

unsigned int if_index = if_nametoindex(interface);

2094

if(if_index == 0){

2095

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

2096

errno = old_errno;

2097

return ENXIO;

2098

}

2099

2100

if(quit_now){

2101

errno = old_errno;

2102

return EINTR;

2103

}

2104

2105

if(not interface_is_up(interface)){

2106

int ret_errno = 0;

2107

int ioctl_errno = 0;

2108

if(not get_flags(interface, &network)){

2109

ret_errno = errno;

2110

fprintf_plus(stderr, "Failed to get flags for interface "

2111

"\"%s\"\n", interface);

2112

errno = old_errno;

2113

return ret_errno;

2114

}

2115

network.ifr_flags |= IFF_UP; /* set flag */

2116

2117

int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

2118

if(sd == -1){

2119

ret_errno = errno;

2120

perror_plus("socket");

2121

errno = old_errno;

2122

return ret_errno;

2123

}

2124

2125

if(quit_now){

2126

ret = close(sd);

2127

if(ret == -1){

2128

perror_plus("close");

2129

}

2130

errno = old_errno;

2131

return EINTR;

2132

}

2133

2134

if(debug){

2135

fprintf_plus(stderr, "Bringing up interface \"%s\"\n",

2136

interface);

2137

}

2138

2139

/* Raise privileges */

2140

ret_errno = raise_privileges();

2141

if(ret_errno != 0){

2142

errno = ret_errno;

2143

perror_plus("Failed to raise privileges");

2144

}

2145

2146

#ifdef __linux__

2147

int ret_linux;

2148

bool restore_loglevel = false;

2149

if(ret_errno == 0){

2150

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2151

messages about the network interface to mess up the prompt */

2152

ret_linux = klogctl(8, NULL, 5);

2153

if(ret_linux == -1){

2154

perror_plus("klogctl");

2155

} else {

2156

restore_loglevel = true;

2157

}

2158

}

2159

#endif /* __linux__ */

2160

int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);

2161

ioctl_errno = errno;

2162

#ifdef __linux__

2163

if(restore_loglevel){

2164

ret_linux = klogctl(7, NULL, 0);

2165

if(ret_linux == -1){

2166

perror_plus("klogctl");

2167

}

2168

}

2169

#endif /* __linux__ */

2170

2171

/* If raise_privileges() succeeded above */

2172

if(ret_errno == 0){

2173

/* Lower privileges */

2174

ret_errno = lower_privileges();

2175

if(ret_errno != 0){

2176

errno = ret_errno;

2177

perror_plus("Failed to lower privileges");

2178

}

2179

}

2180

2181

/* Close the socket */

2182

ret = close(sd);

2183

if(ret == -1){

2184

perror_plus("close");

2185

}

2186

2187

if(ret_setflags == -1){

2188

errno = ioctl_errno;

2189

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2190

errno = old_errno;

2191

return ioctl_errno;

2192

}

2193

} else if(debug){

2194

fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",

2195

interface);

2196

}

2197

2198

/* Sleep checking until interface is running.

2199

Check every 0.25s, up to total time of delay */

2200

for(int i = 0; i < delay * 4; i++){

2201

if(interface_is_running(interface)){

2202

break;

2203

}

2204

struct timespec sleeptime = { .tv_nsec = 250000000 };

2205

ret = nanosleep(&sleeptime, NULL);

2206

if(ret == -1 and errno != EINTR){

2207

perror_plus("nanosleep");

2208

}

2209

}

2210

2211

errno = old_errno;

2212

return 0;

2213

}

2214

2215

__attribute__((nonnull, warn_unused_result))

2216

int take_down_interface(const char *const interface){

2217

int old_errno = errno;

2218

struct ifreq network;

2219

unsigned int if_index = if_nametoindex(interface);

2220

if(if_index == 0){

2221

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

2222

errno = old_errno;

2223

return ENXIO;

2224

}

2225

if(interface_is_up(interface)){

2226

int ret_errno = 0;

2227

int ioctl_errno = 0;

2228

if(not get_flags(interface, &network) and debug){

2229

ret_errno = errno;

2230

fprintf_plus(stderr, "Failed to get flags for interface "

2231

"\"%s\"\n", interface);

2232

errno = old_errno;

2233

return ret_errno;

2234

}

2235

network.ifr_flags &= ~(short)IFF_UP; /* clear flag */

2236

2237

int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

2238

if(sd == -1){

2239

ret_errno = errno;

2240

perror_plus("socket");

2241

errno = old_errno;

2242

return ret_errno;

2243

}

2244

2245

if(debug){

2246

fprintf_plus(stderr, "Taking down interface \"%s\"\n",

2247

interface);

2248

}

2249

2250

/* Raise privileges */

2251

ret_errno = raise_privileges();

2252

if(ret_errno != 0){

2253

errno = ret_errno;

2254

perror_plus("Failed to raise privileges");

2255

}

2256

2257

int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);

2258

ioctl_errno = errno;

2259

2260

/* If raise_privileges() succeeded above */

2261

if(ret_errno == 0){

2262

/* Lower privileges */

2263

ret_errno = lower_privileges();

2264

if(ret_errno != 0){

2265

errno = ret_errno;

2266

perror_plus("Failed to lower privileges");

2267

}

2268

}

2269

2270

/* Close the socket */

2271

int ret = close(sd);

2272

if(ret == -1){

2273

perror_plus("close");

2274

}

2275

2276

if(ret_setflags == -1){

2277

errno = ioctl_errno;

2278

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2279

errno = old_errno;

2280

return ioctl_errno;

2281

}

2282

} else if(debug){

2283

fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",

2284

interface);

2285

}

2286

2287

errno = old_errno;

2288

return 0;

1476

if(execl(fullname, direntry->d_name, mode, NULL) == -1){

1477

perror_plus("execl");

1478

_exit(EXIT_FAILURE);

1479

}

1480

} else {

1481

int status;

1482

if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){

1483

perror_plus("waitpid");

1484

free(fullname);

1485

continue;

1486

}

1487

if(WIFEXITED(status)){

1488

if(WEXITSTATUS(status) != 0){

1489

fprintf_plus(stderr, "Warning: network hook \"%s\" exited"

1490

" with status %d\n", direntry->d_name,

1491

WEXITSTATUS(status));

1492

free(fullname);

1493

continue;

1494

}

1495

} else if(WIFSIGNALED(status)){

1496

fprintf_plus(stderr, "Warning: network hook \"%s\" died by"

1497

" signal %d\n", direntry->d_name,

1498

WTERMSIG(status));

1499

free(fullname);

1500

continue;

1501

} else {

1502

fprintf_plus(stderr, "Warning: network hook \"%s\""

1503

" crashed\n", direntry->d_name);

1504

free(fullname);

1505

continue;

1506

}

1507

}

1508

free(fullname);

1509

if(debug){

1510

fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",

1511

direntry->d_name);

1512

}

1513

}

1514

close(devnull);

1515

}

1516

return true;

2289

1517

}

2290

1518

2291

1519

int main(int argc, char *argv[]){

2292

mandos_context mc = { .server = NULL, .dh_bits = 0,

2293

.priority = "SECURE256:!CTYPE-X.509"

2294

":+CTYPE-OPENPGP:!RSA:+SIGN-DSA-SHA256",

2295

.current_server = NULL, .interfaces = NULL,

2296

.interfaces_size = 0 };

2297

1520

AvahiSServiceBrowser *sb = NULL;

2298

error_t ret_errno;

1521

int error;

2299

1522

int ret;

2300

1523

intmax_t tmpmax;

2301

1524

char *tmp;

2302

1525

int exitcode = EXIT_SUCCESS;

2303

char *interfaces_to_take_down = NULL;

2304

size_t interfaces_to_take_down_size = 0;

2305

char run_tempdir[] = "/run/tmp/mandosXXXXXX";

2306

char old_tempdir[] = "/tmp/mandosXXXXXX";

2307

char *tempdir = NULL;

1526

const char *interface = "";

1527

struct ifreq network;

1528

int sd = -1;

1529

bool take_down_interface = false;

1530

uid_t uid;

1531

gid_t gid;

1532

char tempdir[] = "/tmp/mandosXXXXXX";

1533

bool tempdir_created = false;

2308

1534

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2309

1535

const char *seckey = PATHDIR "/" SECKEY;

2310

1536

const char *pubkey = PATHDIR "/" PUBKEY;

2311

const char *dh_params_file = NULL;

2312

char *interfaces_hooks = NULL;

2313

1537

2314

1538

bool gnutls_initialized = false;

2315

1539

bool gpgme_initialized = false;

2367

1591

.doc = "Bit length of the prime number used in the"

2368

1592

" Diffie-Hellman key exchange",

2369

1593

.group = 2 },

2370

{ .name = "dh-params", .key = 134,

2371

.arg = "FILE",

2372

.doc = "PEM-encoded PKCS#3 file with pre-generated parameters"

2373

" for the Diffie-Hellman key exchange",

2374

.group = 2 },

2375

1594

{ .name = "priority", .key = 130,

2376

1595

.arg = "STRING",

2377

1596

.doc = "GnuTLS priority string for the TLS handshake",

2382

1601

.group = 2 },

2383

1602

{ .name = "retry", .key = 132,

2384

1603

.arg = "SECONDS",

2385

.doc = "Retry interval used when denied by the Mandos server",

1604

.doc = "Retry interval used when denied by the mandos server",

2386

1605

.group = 2 },

2387

1606

{ .name = "network-hook-dir", .key = 133,

2388

1607

.arg = "DIR",

2411

1630

connect_to = arg;

2412

1631

break;

2413

1632

case 'i': /* --interface */

2414

ret_errno = argz_add_sep(&mc.interfaces, &mc.interfaces_size,

2415

arg, (int)',');

2416

if(ret_errno != 0){

2417

argp_error(state, "%s", strerror(ret_errno));

2418

}

1633

interface = arg;

2419

1634

break;

2420

1635

case 's': /* --seckey */

2421

1636

seckey = arg;

2432

1647

}

2433

1648

mc.dh_bits = (typeof(mc.dh_bits))tmpmax;

2434

1649

break;

2435

case 134: /* --dh-params */

2436

dh_params_file = arg;

2437

break;

2438

1650

case 130: /* --priority */

2439

1651

mc.priority = arg;

2440

1652

break;

2480

1692

.args_doc = "",

2481

1693

.doc = "Mandos client -- Get and decrypt"

2482

1694

" passwords from a Mandos server" };

2483

ret_errno = argp_parse(&argp, argc, argv,

2484

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2485

switch(ret_errno){

1695

ret = argp_parse(&argp, argc, argv,

1696

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1697

switch(ret){

2486

1698

case 0:

2487

1699

break;

2488

1700

case ENOMEM:

2489

1701

default:

2490

errno = ret_errno;

1702

errno = ret;

2491

1703

perror_plus("argp_parse");

2492

1704

exitcode = EX_OSERR;

2493

1705

goto end;

2496

1708

goto end;

2497

1709

}

2498

1710

}

2499

1711

2500

1712

{

2501

1713

/* Work around Debian bug #633582:

2502

<https://bugs.debian.org/633582> */

1714

<http://bugs.debian.org/633582> */

2503

1715

2504

/* Re-raise privileges */

2505

ret = raise_privileges();

2506

if(ret != 0){

2507

errno = ret;

2508

perror_plus("Failed to raise privileges");

1716

/* Re-raise priviliges */

1717

errno = 0;

1718

ret = seteuid(0);

1719

if(ret == -1){

1720

perror_plus("seteuid");

2509

1721

} else {

2510

1722

struct stat st;

2511

1723

2526

1738

}

2527

1739

}

2528

1740

}

2529

close(seckey_fd);

1741

TEMP_FAILURE_RETRY(close(seckey_fd));

2530

1742

}

2531

1743

}

2532

1744

2533

1745

if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){

2534

1746

int pubkey_fd = open(pubkey, O_RDONLY);

2535

1747

if(pubkey_fd == -1){

2547

1759

}

2548

1760

}

2549

1761

}

2550

close(pubkey_fd);

2551

}

2552

}

2553

2554

if(dh_params_file != NULL

2555

and strcmp(dh_params_file, PATHDIR "/dhparams.pem" ) == 0){

2556

int dhparams_fd = open(dh_params_file, O_RDONLY);

2557

if(dhparams_fd == -1){

2558

perror_plus("open");

2559

} else {

2560

ret = (int)TEMP_FAILURE_RETRY(fstat(dhparams_fd, &st));

2561

if(ret == -1){

2562

perror_plus("fstat");

2563

} else {

2564

if(S_ISREG(st.st_mode)

2565

and st.st_uid == 0 and st.st_gid == 0){

2566

ret = fchown(dhparams_fd, uid, gid);

2567

if(ret == -1){

2568

perror_plus("fchown");

2569

}

2570

}

2571

}

2572

close(dhparams_fd);

2573

}

2574

}

2575

1762

TEMP_FAILURE_RETRY(close(pubkey_fd));

1763

}

1764

}

1765

2576

1766

/* Lower privileges */

2577

ret = lower_privileges();

2578

if(ret != 0){

2579

errno = ret;

2580

perror_plus("Failed to lower privileges");

2581

}

2582

}

2583

}

2584

2585

/* Remove invalid interface names (except "none") */

2586

{

2587

char *interface = NULL;

2588

while((interface = argz_next(mc.interfaces, mc.interfaces_size,

2589

interface))){

2590

if(strcmp(interface, "none") != 0

2591

and if_nametoindex(interface) == 0){

2592

if(interface[0] != '\0'){

2593

fprintf_plus(stderr, "Not using nonexisting interface"

2594

" \"%s\"\n", interface);

2595

}

2596

argz_delete(&mc.interfaces, &mc.interfaces_size, interface);

2597

interface = NULL;

1767

errno = 0;

1768

ret = seteuid(uid);

1769

if(ret == -1){

1770

perror_plus("seteuid");

2598

1771

}

2599

1772

}

2600

1773

}

2601

1774

2602

1775

/* Run network hooks */

2603

{

2604

if(mc.interfaces != NULL){

2605

interfaces_hooks = malloc(mc.interfaces_size);

2606

if(interfaces_hooks == NULL){

2607

perror_plus("malloc");

2608

goto end;

2609

}

2610

memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);

2611

argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');

2612

}

2613

run_network_hooks("start", interfaces_hooks != NULL ?

2614

interfaces_hooks : "", delay);

1776

if(not run_network_hooks("start", interface, delay)){

1777

goto end;

2615

1778

}

2616

1779

2617

1780

if(not debug){

2618

1781

avahi_set_log_function(empty_log);

2619

1782

}

2620

1783

1784

if(interface[0] == '\0'){

1785

struct dirent **direntries;

1786

/* First look for interfaces that are up */

1787

ret = scandir(sys_class_net, &direntries, up_interface,

1788

alphasort);

1789

if(ret == 0){

1790

/* No up interfaces, look for any good interfaces */

1791

free(direntries);

1792

ret = scandir(sys_class_net, &direntries, good_interface,

1793

alphasort);

1794

}

1795

if(ret >= 1){

1796

/* Pick the first interface returned */

1797

interface = strdup(direntries[0]->d_name);

1798

if(debug){

1799

fprintf_plus(stderr, "Using interface \"%s\"\n", interface);

1800

}

1801

if(interface == NULL){

1802

perror_plus("malloc");

1803

free(direntries);

1804

exitcode = EXIT_FAILURE;

1805

goto end;

1806

}

1807

free(direntries);

1808

} else {

1809

free(direntries);

1810

fprintf_plus(stderr, "Could not find a network interface\n");

1811

exitcode = EXIT_FAILURE;

1812

goto end;

1813

}

1814

}

1815

2621

1816

/* Initialize Avahi early so avahi_simple_poll_quit() can be called

2622

1817

from the signal handler */

2623

1818

/* Initialize the pseudo-RNG for Avahi */

2624

1819

srand((unsigned int) time(NULL));

2625

simple_poll = avahi_simple_poll_new();

2626

if(simple_poll == NULL){

1820

mc.simple_poll = avahi_simple_poll_new();

1821

if(mc.simple_poll == NULL){

2627

1822

fprintf_plus(stderr,

2628

1823

"Avahi: Failed to create simple poll object.\n");

2629

1824

exitcode = EX_UNAVAILABLE;

2693

1888

}

2694

1889

}

2695

1890

2696

/* If no interfaces were specified, make a list */

2697

if(mc.interfaces == NULL){

2698

struct dirent **direntries = NULL;

2699

/* Look for any good interfaces */

2700

ret = scandir(sys_class_net, &direntries, good_interface,

2701

alphasort);

2702

if(ret >= 1){

2703

/* Add all found interfaces to interfaces list */

2704

for(int i = 0; i < ret; ++i){

2705

ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,

2706

direntries[i]->d_name);

2707

if(ret_errno != 0){

2708

errno = ret_errno;

2709

perror_plus("argz_add");

2710

free(direntries[i]);

2711

continue;

2712

}

2713

if(debug){

2714

fprintf_plus(stderr, "Will use interface \"%s\"\n",

2715

direntries[i]->d_name);

2716

}

2717

free(direntries[i]);

2718

}

2719

free(direntries);

2720

} else {

2721

if(ret == 0){

2722

free(direntries);

2723

}

2724

fprintf_plus(stderr, "Could not find a network interface\n");

2725

exitcode = EXIT_FAILURE;

2726

goto end;

2727

}

2728

}

2729

2730

/* Bring up interfaces which are down, and remove any "none"s */

2731

{

2732

char *interface = NULL;

2733

while((interface = argz_next(mc.interfaces, mc.interfaces_size,

2734

interface))){

2735

/* If interface name is "none", stop bringing up interfaces.

2736

Also remove all instances of "none" from the list */

2737

if(strcmp(interface, "none") == 0){

2738

argz_delete(&mc.interfaces, &mc.interfaces_size,

2739

interface);

2740

interface = NULL;

2741

while((interface = argz_next(mc.interfaces,

2742

mc.interfaces_size, interface))){

2743

if(strcmp(interface, "none") == 0){

2744

argz_delete(&mc.interfaces, &mc.interfaces_size,

2745

interface);

2746

interface = NULL;

1891

/* If the interface is down, bring it up */

1892

if(strcmp(interface, "none") != 0){

1893

if_index = (AvahiIfIndex) if_nametoindex(interface);

1894

if(if_index == 0){

1895

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

1896

exitcode = EX_UNAVAILABLE;

1897

goto end;

1898

}

1899

1900

if(quit_now){

1901

goto end;

1902

}

1903

1904

/* Re-raise priviliges */

1905

errno = 0;

1906

ret = seteuid(0);

1907

if(ret == -1){

1908

perror_plus("seteuid");

1909

}

1910

1911

#ifdef __linux__

1912

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1913

messages about the network interface to mess up the prompt */

1914

ret = klogctl(8, NULL, 5);

1915

bool restore_loglevel = true;

1916

if(ret == -1){

1917

restore_loglevel = false;

1918

perror_plus("klogctl");

1919

}

1920

#endif /* __linux__ */

1921

1922

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1923

if(sd < 0){

1924

perror_plus("socket");

1925

exitcode = EX_OSERR;

1926

#ifdef __linux__

1927

if(restore_loglevel){

1928

ret = klogctl(7, NULL, 0);

1929

if(ret == -1){

1930

perror_plus("klogctl");

1931

}

1932

}

1933

#endif /* __linux__ */

1934

/* Lower privileges */

1935

errno = 0;

1936

ret = seteuid(uid);

1937

if(ret == -1){

1938

perror_plus("seteuid");

1939

}

1940

goto end;

1941

}

1942

strcpy(network.ifr_name, interface);

1943

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1944

if(ret == -1){

1945

perror_plus("ioctl SIOCGIFFLAGS");

1946

#ifdef __linux__

1947

if(restore_loglevel){

1948

ret = klogctl(7, NULL, 0);

1949

if(ret == -1){

1950

perror_plus("klogctl");

1951

}

1952

}

1953

#endif /* __linux__ */

1954

exitcode = EX_OSERR;

1955

/* Lower privileges */

1956

errno = 0;

1957

ret = seteuid(uid);

1958

if(ret == -1){

1959

perror_plus("seteuid");

1960

}

1961

goto end;

1962

}

1963

if((network.ifr_flags & IFF_UP) == 0){

1964

network.ifr_flags |= IFF_UP;

1965

take_down_interface = true;

1966

ret = ioctl(sd, SIOCSIFFLAGS, &network);

1967

if(ret == -1){

1968

take_down_interface = false;

1969

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1970

exitcode = EX_OSERR;

1971

#ifdef __linux__

1972

if(restore_loglevel){

1973

ret = klogctl(7, NULL, 0);

1974

if(ret == -1){

1975

perror_plus("klogctl");

2747

1976

}

2748

1977

}

1978

#endif /* __linux__ */

1979

/* Lower privileges */

1980

errno = 0;

1981

ret = seteuid(uid);

1982

if(ret == -1){

1983

perror_plus("seteuid");

1984

}

1985

goto end;

1986

}

1987

}

1988

/* Sleep checking until interface is running.

1989

Check every 0.25s, up to total time of delay */

1990

for(int i=0; i < delay * 4; i++){

1991

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1992

if(ret == -1){

1993

perror_plus("ioctl SIOCGIFFLAGS");

1994

} else if(network.ifr_flags & IFF_RUNNING){

2749

1995

break;

2750

1996

}

2751

bool interface_was_up = interface_is_up(interface);

2752

errno = bring_up_interface(interface, delay);

2753

if(not interface_was_up){

2754

if(errno != 0){

2755

fprintf_plus(stderr, "Failed to bring up interface \"%s\":"

2756

" %s\n", interface, strerror(errno));

2757

} else {

2758

errno = argz_add(&interfaces_to_take_down,

2759

&interfaces_to_take_down_size,

2760

interface);

2761

if(errno != 0){

2762

perror_plus("argz_add");

2763

}

2764

}

2765

}

2766

}

2767

if(debug and (interfaces_to_take_down == NULL)){

2768

fprintf_plus(stderr, "No interfaces were brought up\n");

2769

}

2770

}

2771

2772

/* If we only got one interface, explicitly use only that one */

2773

if(argz_count(mc.interfaces, mc.interfaces_size) == 1){

2774

if(debug){

2775

fprintf_plus(stderr, "Using only interface \"%s\"\n",

2776

mc.interfaces);

2777

}

2778

if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);

1997

struct timespec sleeptime = { .tv_nsec = 250000000 };

1998

ret = nanosleep(&sleeptime, NULL);

1999

if(ret == -1 and errno != EINTR){

2000

perror_plus("nanosleep");

2001

}

2002

}

2003

if(not take_down_interface){

2004

/* We won't need the socket anymore */

2005

ret = (int)TEMP_FAILURE_RETRY(close(sd));

2006

if(ret == -1){

2007

perror_plus("close");

2008

}

2009

}

2010

#ifdef __linux__

2011

if(restore_loglevel){

2012

/* Restores kernel loglevel to default */

2013

ret = klogctl(7, NULL, 0);

2014

if(ret == -1){

2015

perror_plus("klogctl");

2016

}

2017

}

2018

#endif /* __linux__ */

2019

/* Lower privileges */

2020

errno = 0;

2021

/* Lower privileges */

2022

ret = seteuid(uid);

2023

if(ret == -1){

2024

perror_plus("seteuid");

2025

}

2779

2026

}

2780

2027

2781

2028

if(quit_now){

2782

2029

goto end;

2783

2030

}

2784

2031

2785

ret = init_gnutls_global(pubkey, seckey, dh_params_file, &mc);

2032

ret = init_gnutls_global(pubkey, seckey);

2786

2033

if(ret == -1){

2787

2034

fprintf_plus(stderr, "init_gnutls_global failed\n");

2788

2035

exitcode = EX_UNAVAILABLE;

2795

2042

goto end;

2796

2043

}

2797

2044

2798

/* Try /run/tmp before /tmp */

2799

tempdir = mkdtemp(run_tempdir);

2800

if(tempdir == NULL and errno == ENOENT){

2801

if(debug){

2802

fprintf_plus(stderr, "Tempdir %s did not work, trying %s\n",

2803

run_tempdir, old_tempdir);

2804

}

2805

tempdir = mkdtemp(old_tempdir);

2806

}

2807

if(tempdir == NULL){

2045

if(mkdtemp(tempdir) == NULL){

2808

2046

perror_plus("mkdtemp");

2809

2047

goto end;

2810

2048

}

2049

tempdir_created = true;

2811

2050

2812

2051

if(quit_now){

2813

2052

goto end;

2814

2053

}

2815

2054

2816

if(not init_gpgme(pubkey, seckey, tempdir, &mc)){

2055

if(not init_gpgme(pubkey, seckey, tempdir)){

2817

2056

fprintf_plus(stderr, "init_gpgme failed\n");

2818

2057

exitcode = EX_UNAVAILABLE;

2819

2058

goto end;

2829

2068

/* Connect directly, do not use Zeroconf */

2830

2069

/* (Mainly meant for debugging) */

2831

2070

char *address = strrchr(connect_to, ':');

2832

2833

2071

if(address == NULL){

2834

2072

fprintf_plus(stderr, "No colon in address\n");

2835

2073

exitcode = EX_USAGE;

2840

2078

goto end;

2841

2079

}

2842

2080

2843

in_port_t port;

2081

uint16_t port;

2844

2082

errno = 0;

2845

2083

tmpmax = strtoimax(address+1, &tmp, 10);

2846

2084

if(errno != 0 or tmp == address+1 or *tmp != '\0'

2847

or tmpmax != (in_port_t)tmpmax){

2085

or tmpmax != (uint16_t)tmpmax){

2848

2086

fprintf_plus(stderr, "Bad port number\n");

2849

2087

exitcode = EX_USAGE;

2850

2088

goto end;

2851

2089

}

2852

2090

2853

2091

if(quit_now){

2854

2092

goto end;

2855

2093

}

2856

2094

2857

port = (in_port_t)tmpmax;

2095

port = (uint16_t)tmpmax;

2858

2096

*address = '\0';

2859

2097

/* Colon in address indicates IPv6 */

2860

2098

int af;

2876

2114

}

2877

2115

2878

2116

while(not quit_now){

2879

ret = start_mandos_communication(address, port, if_index, af,

2880

&mc);

2117

ret = start_mandos_communication(address, port, if_index, af);

2881

2118

if(quit_now or ret == 0){

2882

2119

break;

2883

2120

}

2885

2122

fprintf_plus(stderr, "Retrying in %d seconds\n",

2886

2123

(int)retry_interval);

2887

2124

}

2888

sleep((unsigned int)retry_interval);

2125

sleep((int)retry_interval);

2889

2126

}

2890

2127

2891

if(not quit_now){

2128

if (not quit_now){

2892

2129

exitcode = EXIT_SUCCESS;

2893

2130

}

2894

2131

2909

2146

config.publish_domain = 0;

2910

2147

2911

2148

/* Allocate a new server */

2912

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2913

&config, NULL, NULL, &ret);

2149

mc.server = avahi_server_new(avahi_simple_poll_get

2150

(mc.simple_poll), &config, NULL,

2151

NULL, &error);

2914

2152

2915

2153

/* Free the Avahi configuration data */

2916

2154

avahi_server_config_free(&config);

2919

2157

/* Check if creating the Avahi server object succeeded */

2920

2158

if(mc.server == NULL){

2921

2159

fprintf_plus(stderr, "Failed to create Avahi server: %s\n",

2922

avahi_strerror(ret));

2160

avahi_strerror(error));

2923

2161

exitcode = EX_UNAVAILABLE;

2924

2162

goto end;

2925

2163

}

2931

2169

/* Create the Avahi service browser */

2932

2170

sb = avahi_s_service_browser_new(mc.server, if_index,

2933

2171

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2934

NULL, 0, browse_callback,

2935

(void *)&mc);

2172

NULL, 0, browse_callback, NULL);

2936

2173

if(sb == NULL){

2937

2174

fprintf_plus(stderr, "Failed to create service browser: %s\n",

2938

2175

avahi_strerror(avahi_server_errno(mc.server)));

2949

2186

if(debug){

2950

2187

fprintf_plus(stderr, "Starting Avahi loop search\n");

2951

2188

}

2952

2953

ret = avahi_loop_with_timeout(simple_poll,

2954

(int)(retry_interval * 1000), &mc);

2189

2190

ret = avahi_loop_with_timeout(mc.simple_poll,

2191

(int)(retry_interval * 1000));

2955

2192

if(debug){

2956

2193

fprintf_plus(stderr, "avahi_loop_with_timeout exited %s\n",

2957

2194

(ret == 0) ? "successfully" : "with error");

2960

2197

end:

2961

2198

2962

2199

if(debug){

2963

if(signal_received){

2964

fprintf_plus(stderr, "%s exiting due to signal %d: %s\n",

2965

argv[0], signal_received,

2966

strsignal(signal_received));

2967

} else {

2968

fprintf_plus(stderr, "%s exiting\n", argv[0]);

2969

}

2200

fprintf_plus(stderr, "%s exiting\n", argv[0]);

2970

2201

}

2971

2202

2972

2203

/* Cleanup things */

2973

free(mc.interfaces);

2974

2975

2204

if(sb != NULL)

2976

2205

avahi_s_service_browser_free(sb);

2977

2206

2978

2207

if(mc.server != NULL)

2979

2208

avahi_server_free(mc.server);

2980

2209

2981

if(simple_poll != NULL)

2982

avahi_simple_poll_free(simple_poll);

2210

if(mc.simple_poll != NULL)

2211

avahi_simple_poll_free(mc.simple_poll);

2983

2212

2984

2213

if(gnutls_initialized){

2985

2214

gnutls_certificate_free_credentials(mc.cred);

2215

gnutls_global_deinit();

2986

2216

gnutls_dh_params_deinit(mc.dh_params);

2987

2217

}

2988

2218

2996

2226

mc.current_server->prev->next = NULL;

2997

2227

while(mc.current_server != NULL){

2998

2228

server *next = mc.current_server->next;

2999

#ifdef __GNUC__

3000

#pragma GCC diagnostic push

3001

#pragma GCC diagnostic ignored "-Wcast-qual"

3002

#endif

3003

free((char *)(mc.current_server->ip));

3004

#ifdef __GNUC__

3005

#pragma GCC diagnostic pop

3006

#endif

3007

2229

free(mc.current_server);

3008

2230

mc.current_server = next;

3009

2231

}

3010

2232

}

3011

2233

3012

/* Re-raise privileges */

2234

/* Run network hooks */

2235

run_network_hooks("stop", interface, delay);

2236

2237

/* Re-raise priviliges */

3013

2238

{

3014

ret = raise_privileges();

3015

if(ret != 0){

3016

errno = ret;

3017

perror_plus("Failed to raise privileges");

3018

} else {

3019

3020

/* Run network hooks */

3021

run_network_hooks("stop", interfaces_hooks != NULL ?

3022

interfaces_hooks : "", delay);

3023

3024

/* Take down the network interfaces which were brought up */

3025

{

3026

char *interface = NULL;

3027

while((interface = argz_next(interfaces_to_take_down,

3028

interfaces_to_take_down_size,

3029

interface))){

3030

ret = take_down_interface(interface);

3031

if(ret != 0){

3032

errno = ret;

3033

perror_plus("Failed to take down interface");

3034

}

3035

}

3036

if(debug and (interfaces_to_take_down == NULL)){

3037

fprintf_plus(stderr, "No interfaces needed to be taken"

3038

" down\n");

3039

}

3040

}

2239

errno = 0;

2240

ret = seteuid(0);

2241

if(ret == -1){

2242

perror_plus("seteuid");

3041

2243

}

3042

2244

3043

ret = lower_privileges_permanently();

3044

if(ret != 0){

3045

errno = ret;

3046

perror_plus("Failed to lower privileges permanently");

2245

/* Take down the network interface */

2246

if(take_down_interface and geteuid() == 0){

2247

ret = ioctl(sd, SIOCGIFFLAGS, &network);

2248

if(ret == -1){

2249

perror_plus("ioctl SIOCGIFFLAGS");

2250

} else if(network.ifr_flags & IFF_UP){

2251

network.ifr_flags &= ~(short)IFF_UP; /* clear flag */

2252

ret = ioctl(sd, SIOCSIFFLAGS, &network);

2253

if(ret == -1){

2254

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2255

}

2256

}

2257

ret = (int)TEMP_FAILURE_RETRY(close(sd));

2258

if(ret == -1){

2259

perror_plus("close");

2260

}

3047

2261

}

3048

2262

}

3049

3050

free(interfaces_to_take_down);

3051

free(interfaces_hooks);

3052

3053

void clean_dir_at(int base, const char * const dirname,

3054

uintmax_t level){

2263

/* Lower privileges permanently */

2264

errno = 0;

2265

ret = setuid(uid);

2266

if(ret == -1){

2267

perror_plus("setuid");

2268

}

2269

2270

/* Removes the GPGME temp directory and all files inside */

2271

if(tempdir_created){

3055

2272

struct dirent **direntries = NULL;

3056

int dret;

3057

int dir_fd = (int)TEMP_FAILURE_RETRY(openat(base, dirname,

3058

O_RDONLY

3059

| O_NOFOLLOW

3060

| O_DIRECTORY

3061

| O_PATH));

3062

if(dir_fd == -1){

3063

perror_plus("open");

3064

}

3065

int numentries = scandirat(dir_fd, ".", &direntries,

3066

notdotentries, alphasort);

3067

if(numentries >= 0){

2273

struct dirent *direntry = NULL;

2274

int numentries = scandir(tempdir, &direntries, notdotentries,

2275

alphasort);

2276

if (numentries > 0){

3068

2277

for(int i = 0; i < numentries; i++){

3069

if(debug){

3070

fprintf_plus(stderr, "Unlinking \"%s/%s\"\n",

3071

dirname, direntries[i]->d_name);

3072

}

3073

dret = unlinkat(dir_fd, direntries[i]->d_name, 0);

3074

if(dret == -1){

3075

if(errno == EISDIR){

3076

dret = unlinkat(dir_fd, direntries[i]->d_name,

3077

AT_REMOVEDIR);

3078

}

3079

if((dret == -1) and (errno == ENOTEMPTY)

3080

and (strcmp(direntries[i]->d_name, "private-keys-v1.d")

3081

== 0) and (level == 0)){

3082

/* Recurse only in this special case */

3083

clean_dir_at(dir_fd, direntries[i]->d_name, level+1);

3084

dret = 0;

3085

}

3086

if(dret == -1){

3087

fprintf_plus(stderr, "unlink(\"%s/%s\"): %s\n", dirname,

3088

direntries[i]->d_name, strerror(errno));

3089

}

3090

}

3091

free(direntries[i]);

3092

}

3093

3094

/* need to clean even if 0 because man page doesn't specify */

3095

free(direntries);

3096

if(numentries == -1){

3097

perror_plus("scandirat");

3098

}

3099

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3100

if(dret == -1 and errno != ENOENT){

3101

perror_plus("rmdir");

3102

}

3103

} else {

3104

perror_plus("scandirat");

3105

}

3106

close(dir_fd);

3107

}

3108

3109

/* Removes the GPGME temp directory and all files inside */

3110

if(tempdir != NULL){

3111

clean_dir_at(-1, tempdir, 0);

2278

direntry = direntries[i];

2279

char *fullname = NULL;

2280

ret = asprintf(&fullname, "%s/%s", tempdir,

2281

direntry->d_name);

2282

if(ret < 0){

2283

perror_plus("asprintf");

2284

continue;

2285

}

2286

ret = remove(fullname);

2287

if(ret == -1){

2288

fprintf_plus(stderr, "remove(\"%s\"): %s\n", fullname,

2289

strerror(errno));

2290

}

2291

free(fullname);

2292

}

2293

}

2294

2295

/* need to clean even if 0 because man page doesn't specify */

2296

free(direntries);

2297

if (numentries == -1){

2298

perror_plus("scandir");

2299

}

2300

ret = rmdir(tempdir);

2301

if(ret == -1 and errno != ENOENT){

2302

perror_plus("rmdir");

2303

}

3112

2304

}

3113

2305

3114

2306

if(quit_now){