/mandos/trunk : revision 524

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

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stdout, ferror(), remove() */

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

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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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sockaddr_in6, PF_INET6,

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SOCK_STREAM, uid_t, gid_t, open(),

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opendir(), DIR */

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

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

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

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inet_pton(), connect() */

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

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*/

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#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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setgid(), pause() */

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

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raise() */

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#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,

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EX_NOHOST, EX_IOERR, EX_PROTOCOL */

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

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WEXITSTATUS(), WTERMSIG() */

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

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#ifdef __linux__

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

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init_gnutls_session(),

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109

GNUTLS_* */

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#include <gnutls/openpgp.h>

114

/* gnutls_certificate_set_openpgp_key_file(),

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GNUTLS_OPENPGP_FMT_BASE64 */

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/* gnutls_certificate_set_openpgp_key_file(),

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GNUTLS_OPENPGP_FMT_BASE64 */

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/* GPGME */

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#include <gpgme.h> /* All GPGME types, constants and

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#define PATHDIR "/conf/conf.d/mandos"

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#define SECKEY "seckey.txt"

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125

#define PUBKEY "pubkey.txt"

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#define HOOKDIR "/lib/mandos/network-hooks.d"

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bool debug = false;

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static const char mandos_protocol_version[] = "1";

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const char *argp_program_bug_address = "<mandos@recompile.se>";

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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;

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uid_t uid = 65534;

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gid_t gid = 65534;

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133

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

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135

typedef struct server{

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165

173

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/* Function to use when printing errors */

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void perror_plus(const char *print_text){

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int e = errno;

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fprintf(stderr, "Mandos plugin %s: ",

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program_invocation_short_name);

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errno = e;

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perror(print_text);

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}

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172

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

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

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va_list ap;

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va_start (ap, format);

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

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program_invocation_short_name));

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

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}

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192

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/*

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* Make additional room in "buffer" for at least BUFFER_SIZE more

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

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* "buffer_length" is how much is already used.

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*/

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size_t incbuffer(char **buffer, size_t buffer_length,

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size_t buffer_capacity){

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size_t buffer_capacity){

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180

if(buffer_length + BUFFER_SIZE > buffer_capacity){

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

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if(buffer == NULL){

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188

}

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

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

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int af){

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int add_server(const char *ip, uint16_t port,

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AvahiIfIndex if_index,

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int af){

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int ret;

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

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if(new_server == NULL){

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197

perror_plus("malloc");

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return false;

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return -1;

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}

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*new_server = (server){ .ip = strdup(ip),

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.port = port,

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.if_index = if_index,

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.af = af };

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.port = port,

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.if_index = if_index,

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.af = af };

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if(new_server->ip == NULL){

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perror_plus("strdup");

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return false;

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return -1;

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207

}

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/* Special case of first server */

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if (mc.current_server == NULL){

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

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221

if(ret == -1){

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222

perror_plus("clock_gettime");

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return false;

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return -1;

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}

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return true;

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return 0;

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}

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/*

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* Initialize GPGME.

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*/

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

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const char *tempdir){

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static bool init_gpgme(const char *seckey,

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const char *pubkey, const char *tempdir){

251

233

gpgme_error_t rc;

252

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gpgme_engine_info_t engine_info;

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269

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rc = gpgme_data_new_from_fd(&pgp_data, fd);

270

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if(rc != GPG_ERR_NO_ERROR){

271

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

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gpgme_strsource(rc), gpgme_strerror(rc));

253

fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",

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gpgme_strsource(rc), gpgme_strerror(rc));

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return false;

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256

}

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257

276

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rc = gpgme_op_import(mc.ctx, pgp_data);

277

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if(rc != GPG_ERR_NO_ERROR){

278

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

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gpgme_strsource(rc), gpgme_strerror(rc));

260

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

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gpgme_strsource(rc), gpgme_strerror(rc));

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return false;

281

263

}

282

264

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271

}

290

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if(debug){

292

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

274

fprintf(stderr, "Initializing GPGME\n");

293

275

}

294

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/* Init GPGME */

296

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gpgme_check_version(NULL);

297

279

rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);

298

280

if(rc != GPG_ERR_NO_ERROR){

299

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

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gpgme_strsource(rc), gpgme_strerror(rc));

281

fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",

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gpgme_strsource(rc), gpgme_strerror(rc));

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return false;

302

284

}

303

285

304

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/* Set GPGME home directory for the OpenPGP engine only */

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rc = gpgme_get_engine_info(&engine_info);

306

288

if(rc != GPG_ERR_NO_ERROR){

307

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

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gpgme_strsource(rc), gpgme_strerror(rc));

289

fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",

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gpgme_strsource(rc), gpgme_strerror(rc));

309

291

return false;

310

292

}

311

293

while(engine_info != NULL){

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299

engine_info = engine_info->next;

318

300

}

319

301

if(engine_info == NULL){

320

fprintf_plus(stderr, "Could not set GPGME home dir to %s\n",

321

tempdir);

302

fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);

322

303

return false;

323

304

}

324

305

325

306

/* Create new GPGME "context" */

326

307

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

327

308

if(rc != GPG_ERR_NO_ERROR){

328

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

329

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

330

gpgme_strerror(rc));

309

fprintf(stderr, "bad gpgme_new: %s: %s\n",

310

gpgme_strsource(rc), gpgme_strerror(rc));

331

311

return false;

332

312

}

333

313

352

332

ssize_t plaintext_length = 0;

353

333

354

334

if(debug){

355

fprintf_plus(stderr, "Trying to decrypt OpenPGP data\n");

335

fprintf(stderr, "Trying to decrypt OpenPGP data\n");

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336

}

357

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/* Create new GPGME data buffer from memory cryptotext */

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rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,

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340

0);

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341

if(rc != GPG_ERR_NO_ERROR){

362

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

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gpgme_strsource(rc), gpgme_strerror(rc));

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fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",

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gpgme_strsource(rc), gpgme_strerror(rc));

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return -1;

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}

366

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367

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/* Create new empty GPGME data buffer for the plaintext */

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rc = gpgme_data_new(&dh_plain);

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if(rc != GPG_ERR_NO_ERROR){

370

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

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"bad gpgme_data_new: %s: %s\n",

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gpgme_strsource(rc), gpgme_strerror(rc));

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fprintf(stderr, "bad gpgme_data_new: %s: %s\n",

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gpgme_strsource(rc), gpgme_strerror(rc));

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gpgme_data_release(dh_crypto);

374

353

return -1;

375

354

}

378

357

data buffer */

379

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

380

359

if(rc != GPG_ERR_NO_ERROR){

381

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

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gpgme_strsource(rc), gpgme_strerror(rc));

360

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

361

gpgme_strsource(rc), gpgme_strerror(rc));

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362

plaintext_length = -1;

384

363

if(debug){

385

364

gpgme_decrypt_result_t result;

386

365

result = gpgme_op_decrypt_result(mc.ctx);

387

366

if(result == NULL){

388

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

367

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

389

368

} else {

390

fprintf_plus(stderr, "Unsupported algorithm: %s\n",

391

result->unsupported_algorithm);

392

fprintf_plus(stderr, "Wrong key usage: %u\n",

393

result->wrong_key_usage);

369

fprintf(stderr, "Unsupported algorithm: %s\n",

370

result->unsupported_algorithm);

371

fprintf(stderr, "Wrong key usage: %u\n",

372

result->wrong_key_usage);

394

373

if(result->file_name != NULL){

395

fprintf_plus(stderr, "File name: %s\n", result->file_name);

374

fprintf(stderr, "File name: %s\n", result->file_name);

396

375

}

397

376

gpgme_recipient_t recipient;

398

377

recipient = result->recipients;

399

378

while(recipient != NULL){

400

fprintf_plus(stderr, "Public key algorithm: %s\n",

401

gpgme_pubkey_algo_name

402

(recipient->pubkey_algo));

403

fprintf_plus(stderr, "Key ID: %s\n", recipient->keyid);

404

fprintf_plus(stderr, "Secret key available: %s\n",

405

recipient->status == GPG_ERR_NO_SECKEY

406

? "No" : "Yes");

379

fprintf(stderr, "Public key algorithm: %s\n",

380

gpgme_pubkey_algo_name(recipient->pubkey_algo));

381

fprintf(stderr, "Key ID: %s\n", recipient->keyid);

382

fprintf(stderr, "Secret key available: %s\n",

383

recipient->status == GPG_ERR_NO_SECKEY

384

? "No" : "Yes");

407

385

recipient = recipient->next;

408

386

}

409

387

}

412

390

}

413

391

414

392

if(debug){

415

fprintf_plus(stderr, "Decryption of OpenPGP data succeeded\n");

393

fprintf(stderr, "Decryption of OpenPGP data succeeded\n");

416

394

}

417

395

418

396

/* Seek back to the beginning of the GPGME plaintext data buffer */

425

403

*plaintext = NULL;

426

404

while(true){

427

405

plaintext_capacity = incbuffer(plaintext,

428

(size_t)plaintext_length,

429

plaintext_capacity);

406

(size_t)plaintext_length,

407

plaintext_capacity);

430

408

if(plaintext_capacity == 0){

431

perror_plus("incbuffer");

432

plaintext_length = -1;

433

goto decrypt_end;

409

perror_plus("incbuffer");

410

plaintext_length = -1;

411

goto decrypt_end;

434

412

}

435

413

436

414

ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,

449

427

}

450

428

451

429

if(debug){

452

fprintf_plus(stderr, "Decrypted password is: ");

430

fprintf(stderr, "Decrypted password is: ");

453

431

for(ssize_t i = 0; i < plaintext_length; i++){

454

432

fprintf(stderr, "%02hhX ", (*plaintext)[i]);

455

433

}

477

455

/* GnuTLS log function callback */

478

456

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

479

457

const char* string){

480

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

458

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

481

459

}

482

460

483

461

static int init_gnutls_global(const char *pubkeyfilename,

485

463

int ret;

486

464

487

465

if(debug){

488

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

466

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

489

467

}

490

468

491

469

ret = gnutls_global_init();

492

470

if(ret != GNUTLS_E_SUCCESS){

493

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

494

safer_gnutls_strerror(ret));

471

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

472

safer_gnutls_strerror(ret));

495

473

return -1;

496

474

}

497

475

506

484

/* OpenPGP credentials */

507

485

ret = gnutls_certificate_allocate_credentials(&mc.cred);

508

486

if(ret != GNUTLS_E_SUCCESS){

509

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

510

safer_gnutls_strerror(ret));

487

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

488

safer_gnutls_strerror(ret));

511

489

gnutls_global_deinit();

512

490

return -1;

513

491

}

514

492

515

493

if(debug){

516

fprintf_plus(stderr, "Attempting to use OpenPGP public key %s and"

517

" secret key %s as GnuTLS credentials\n",

518

pubkeyfilename,

519

seckeyfilename);

494

fprintf(stderr, "Attempting to use OpenPGP public key %s and"

495

" secret key %s as GnuTLS credentials\n", pubkeyfilename,

496

seckeyfilename);

520

497

}

521

498

522

499

ret = gnutls_certificate_set_openpgp_key_file

523

500

(mc.cred, pubkeyfilename, seckeyfilename,

524

501

GNUTLS_OPENPGP_FMT_BASE64);

525

502

if(ret != GNUTLS_E_SUCCESS){

526

fprintf_plus(stderr,

527

"Error[%d] while reading the OpenPGP key pair ('%s',"

528

" '%s')\n", ret, pubkeyfilename, seckeyfilename);

529

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

530

safer_gnutls_strerror(ret));

503

fprintf(stderr,

504

"Error[%d] while reading the OpenPGP key pair ('%s',"

505

" '%s')\n", ret, pubkeyfilename, seckeyfilename);

506

fprintf(stderr, "The GnuTLS error is: %s\n",

507

safer_gnutls_strerror(ret));

531

508

goto globalfail;

532

509

}

533

510

534

511

/* GnuTLS server initialization */

535

512

ret = gnutls_dh_params_init(&mc.dh_params);

536

513

if(ret != GNUTLS_E_SUCCESS){

537

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

538

" initialization: %s\n",

539

safer_gnutls_strerror(ret));

514

fprintf(stderr, "Error in GnuTLS DH parameter initialization:"

515

" %s\n", safer_gnutls_strerror(ret));

540

516

goto globalfail;

541

517

}

542

518

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

543

519

if(ret != GNUTLS_E_SUCCESS){

544

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

545

safer_gnutls_strerror(ret));

520

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

521

safer_gnutls_strerror(ret));

546

522

goto globalfail;

547

523

}

548

524

568

544

}

569

545

} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);

570

546

if(ret != GNUTLS_E_SUCCESS){

571

fprintf_plus(stderr,

572

"Error in GnuTLS session initialization: %s\n",

573

safer_gnutls_strerror(ret));

547

fprintf(stderr, "Error in GnuTLS session initialization: %s\n",

548

safer_gnutls_strerror(ret));

574

549

}

575

550

576

551

{

583

558

}

584

559

} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);

585

560

if(ret != GNUTLS_E_SUCCESS){

586

fprintf_plus(stderr, "Syntax error at: %s\n", err);

587

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

588

safer_gnutls_strerror(ret));

561

fprintf(stderr, "Syntax error at: %s\n", err);

562

fprintf(stderr, "GnuTLS error: %s\n",

563

safer_gnutls_strerror(ret));

589

564

gnutls_deinit(*session);

590

565

return -1;

591

566

}

600

575

}

601

576

} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);

602

577

if(ret != GNUTLS_E_SUCCESS){

603

fprintf_plus(stderr, "Error setting GnuTLS credentials: %s\n",

604

safer_gnutls_strerror(ret));

578

fprintf(stderr, "Error setting GnuTLS credentials: %s\n",

579

safer_gnutls_strerror(ret));

605

580

gnutls_deinit(*session);

606

581

return -1;

607

582

}

652

627

pf = PF_INET;

653

628

break;

654

629

default:

655

fprintf_plus(stderr, "Bad address family: %d\n", af);

630

fprintf(stderr, "Bad address family: %d\n", af);

656

631

errno = EINVAL;

657

632

return -1;

658

633

}

663

638

}

664

639

665

640

if(debug){

666

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

667

PRIu16 "\n", ip, port);

641

fprintf(stderr, "Setting up a TCP connection to %s, port %" PRIu16

642

"\n", ip, port);

668

643

}

669

644

670

645

tcp_sd = socket(pf, SOCK_STREAM, 0);

696

671

}

697

672

if(ret == 0){

698

673

int e = errno;

699

fprintf_plus(stderr, "Bad address: %s\n", ip);

674

fprintf(stderr, "Bad address: %s\n", ip);

700

675

errno = e;

701

676

goto mandos_end;

702

677

}

707

682

708

683

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

709

684

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

710

-Wunreachable-code*/

685

-Wunreachable-code*/

711

686

if(if_index == AVAHI_IF_UNSPEC){

712

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

713

" incomplete without a network interface\n");

687

fprintf(stderr, "An IPv6 link-local address is incomplete"

688

" without a network interface\n");

714

689

errno = EINVAL;

715

690

goto mandos_end;

716

691

}

734

709

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

735

710

perror_plus("if_indextoname");

736

711

} else {

737

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

738

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

712

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

713

ip, interface, port);

739

714

}

740

715

} else {

741

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

742

ip, port);

716

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

717

port);

743

718

}

744

719

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

745

720

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

755

730

perror_plus("inet_ntop");

756

731

} else {

757

732

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

758

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

733

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

759

734

}

760

735

}

761

736

}

789

764

while(true){

790

765

size_t out_size = strlen(out);

791

766

ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,

792

out_size - written));

767

out_size - written));

793

768

if(ret == -1){

794

769

int e = errno;

795

770

perror_plus("write");

815

790

}

816

791

817

792

if(debug){

818

fprintf_plus(stderr, "Establishing TLS session with %s\n", ip);

793

fprintf(stderr, "Establishing TLS session with %s\n", ip);

819

794

}

820

795

821

796

if(quit_now){

823

798

goto mandos_end;

824

799

}

825

800

826

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

827

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

828

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

829

gnutls_transport_set_ptr(session,

830

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

801

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

802

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

831

803

832

804

if(quit_now){

833

805

errno = EINTR;

844

816

845

817

if(ret != GNUTLS_E_SUCCESS){

846

818

if(debug){

847

fprintf_plus(stderr, "*** GnuTLS Handshake failed ***\n");

819

fprintf(stderr, "*** GnuTLS Handshake failed ***\n");

848

820

gnutls_perror(ret);

849

821

}

850

822

errno = EPROTO;

854

826

/* Read OpenPGP packet that contains the wanted password */

855

827

856

828

if(debug){

857

fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"

858

" %s\n", ip);

829

fprintf(stderr, "Retrieving OpenPGP encrypted password from %s\n",

830

ip);

859

831

}

860

832

861

833

while(true){

866

838

}

867

839

868

840

buffer_capacity = incbuffer(&buffer, buffer_length,

869

buffer_capacity);

841

buffer_capacity);

870

842

if(buffer_capacity == 0){

871

843

int e = errno;

872

844

perror_plus("incbuffer");

899

871

}

900

872

} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);

901

873

if(ret < 0){

902

fprintf_plus(stderr, "*** GnuTLS Re-handshake failed "

903

"***\n");

874

fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");

904

875

gnutls_perror(ret);

905

876

errno = EPROTO;

906

877

goto mandos_end;

907

878

}

908

879

break;

909

880

default:

910

fprintf_plus(stderr, "Unknown error while reading data from"

911

" encrypted session with Mandos server\n");

881

fprintf(stderr, "Unknown error while reading data from"

882

" encrypted session with Mandos server\n");

912

883

gnutls_bye(session, GNUTLS_SHUT_RDWR);

913

884

errno = EIO;

914

885

goto mandos_end;

919

890

}

920

891

921

892

if(debug){

922

fprintf_plus(stderr, "Closing TLS session\n");

893

fprintf(stderr, "Closing TLS session\n");

923

894

}

924

895

925

896

if(quit_now){

937

908

938

909

if(buffer_length > 0){

939

910

ssize_t decrypted_buffer_size;

940

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

911

decrypted_buffer_size = pgp_packet_decrypt(buffer,

912

buffer_length,

941

913

&decrypted_buffer);

942

914

if(decrypted_buffer_size >= 0){

943

915

954

926

if(ret == 0 and ferror(stdout)){

955

927

int e = errno;

956

928

if(debug){

957

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

958

strerror(errno));

929

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

930

strerror(errno));

959

931

}

960

932

errno = e;

961

933

goto mandos_end;

1018

990

switch(event){

1019

991

default:

1020

992

case AVAHI_RESOLVER_FAILURE:

1021

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

1022

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

1023

domain,

1024

avahi_strerror(avahi_server_errno(mc.server)));

993

fprintf(stderr, "(Avahi Resolver) Failed to resolve service '%s'"

994

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

995

avahi_strerror(avahi_server_errno(mc.server)));

1025

996

break;

1026

997

1027

998

case AVAHI_RESOLVER_FOUND:

1029

1000

char ip[AVAHI_ADDRESS_STR_MAX];

1030

1001

avahi_address_snprint(ip, sizeof(ip), address);

1031

1002

if(debug){

1032

fprintf_plus(stderr, "Mandos server \"%s\" found on %s (%s, %"

1033

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

1034

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

1003

fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %"

1004

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

1005

ip, (intmax_t)interface, port);

1035

1006

}

1036

1007

int ret = start_mandos_communication(ip, port, interface,

1037

1008

avahi_proto_to_af(proto));

1038

1009

if(ret == 0){

1039

1010

avahi_simple_poll_quit(mc.simple_poll);

1040

1011

} else {

1041

if(not add_server(ip, port, interface,

1042

avahi_proto_to_af(proto))){

1043

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

1044

" list\n", name);

1045

}

1012

ret = add_server(ip, port, interface,

1013

avahi_proto_to_af(proto));

1046

1014

}

1047

1015

}

1048

1016

}

1072

1040

default:

1073

1041

case AVAHI_BROWSER_FAILURE:

1074

1042

1075

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

1076

avahi_strerror(avahi_server_errno(mc.server)));

1043

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

1044

avahi_strerror(avahi_server_errno(mc.server)));

1077

1045

avahi_simple_poll_quit(mc.simple_poll);

1078

1046

return;

1079

1047

1086

1054

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

1087

1055

name, type, domain, protocol, 0,

1088

1056

resolve_callback, NULL) == NULL)

1089

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

1090

" %s\n", name,

1091

avahi_strerror(avahi_server_errno(mc.server)));

1057

fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",

1058

name, avahi_strerror(avahi_server_errno(mc.server)));

1092

1059

break;

1093

1060

1094

1061

case AVAHI_BROWSER_REMOVE:

1097

1064

case AVAHI_BROWSER_ALL_FOR_NOW:

1098

1065

case AVAHI_BROWSER_CACHE_EXHAUSTED:

1099

1066

if(debug){

1100

fprintf_plus(stderr, "No Mandos server found, still"

1101

" searching...\n");

1067

fprintf(stderr, "No Mandos server found, still searching...\n");

1102

1068

}

1103

1069

break;

1104

1070

}

1119

1085

errno = old_errno;

1120

1086

}

1121

1087

1122

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

1123

int ret;

1124

1125

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

1126

if(s < 0){

1127

perror_plus("socket");

1128

return false;

1129

}

1130

strcpy(ifr->ifr_name, ifname);

1131

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1132

if(ret == -1){

1088

/*

1089

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

1090

* corresponds to an acceptable network device.

1091

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

1092

*/

1093

int good_interface(const struct dirent *if_entry){

1094

ssize_t ssret;

1095

char *flagname = NULL;

1096

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

1097

return 0;

1098

}

1099

int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,

1100

if_entry->d_name);

1101

if(ret < 0){

1102

perror_plus("asprintf");

1103

return 0;

1104

}

1105

int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));

1106

if(flags_fd == -1){

1107

perror_plus("open");

1108

free(flagname);

1109

return 0;

1110

}

1111

free(flagname);

1112

typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */

1113

/* read line from flags_fd */

1114

ssize_t to_read = 2+(sizeof(ifreq_flags)*2)+1; /* "0x1003\n" */

1115

char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */

1116

flagstring[(size_t)to_read] = '\0';

1117

if(flagstring == NULL){

1118

perror_plus("malloc");

1119

close(flags_fd);

1120

return 0;

1121

}

1122

while(to_read > 0){

1123

ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,

1124

(size_t)to_read));

1125

if(ssret == -1){

1126

perror_plus("read");

1127

free(flagstring);

1128

close(flags_fd);

1129

return 0;

1130

}

1131

to_read -= ssret;

1132

if(ssret == 0){

1133

break;

1134

}

1135

}

1136

close(flags_fd);

1137

intmax_t tmpmax;

1138

char *tmp;

1139

errno = 0;

1140

tmpmax = strtoimax(flagstring, &tmp, 0);

1141

if(errno != 0 or tmp == flagstring or (*tmp != '\0'

1142

and not (isspace(*tmp)))

1143

or tmpmax != (ifreq_flags)tmpmax){

1133

1144

if(debug){

1134

perror_plus("ioctl SIOCGIFFLAGS");

1145

fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",

1146

flagstring, if_entry->d_name);

1135

1147

}

1136

return false;

1148

free(flagstring);

1149

return 0;

1137

1150

}

1138

return true;

1139

}

1140

1141

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

1142

1151

free(flagstring);

1152

ifreq_flags flags = (ifreq_flags)tmpmax;

1143

1153

/* Reject the loopback device */

1144

if(ifr->ifr_flags & IFF_LOOPBACK){

1154

if(flags & IFF_LOOPBACK){

1145

1155

if(debug){

1146

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

1147

ifname);

1156

fprintf(stderr, "Rejecting loopback interface \"%s\"\n",

1157

if_entry->d_name);

1148

1158

}

1149

return false;

1159

return 0;

1150

1160

}

1151

1161

/* Accept point-to-point devices only if connect_to is specified */

1152

if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){

1162

if(connect_to != NULL and (flags & IFF_POINTOPOINT)){

1153

1163

if(debug){

1154

fprintf_plus(stderr, "Accepting point-to-point interface"

1155

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

1164

fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",

1165

if_entry->d_name);

1156

1166

}

1157

return true;

1167

return 1;

1158

1168

}

1159

1169

/* Otherwise, reject non-broadcast-capable devices */

1160

if(not (ifr->ifr_flags & IFF_BROADCAST)){

1170

if(not (flags & IFF_BROADCAST)){

1161

1171

if(debug){

1162

fprintf_plus(stderr, "Rejecting non-broadcast interface"

1163

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

1172

fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",

1173

if_entry->d_name);

1164

1174

}

1165

return false;

1175

return 0;

1166

1176

}

1167

1177

/* Reject non-ARP interfaces (including dummy interfaces) */

1168

if(ifr->ifr_flags & IFF_NOARP){

1178

if(flags & IFF_NOARP){

1169

1179

if(debug){

1170

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

1171

ifname);

1180

fprintf(stderr, "Rejecting non-ARP interface \"%s\"\n",

1181

if_entry->d_name);

1172

1182

}

1173

return false;

1183

return 0;

1174

1184

}

1175

1176

1185

/* Accept this device */

1177

1186

if(debug){

1178

fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);

1179

}

1180

return true;

1181

}

1182

1183

/*

1184

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

1185

* corresponds to an acceptable network device.

1186

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

1187

*/

1188

int good_interface(const struct dirent *if_entry){

1189

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

1190

return 0;

1191

}

1192

1193

struct ifreq ifr;

1194

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

1195

if(debug){

1196

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

1197

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

1198

}

1199

return 0;

1200

}

1201

1202

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

1203

return 0;

1204

}

1205

return 1;

1206

}

1207

1208

/*

1209

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

1210

* corresponds to an acceptable network device which is up.

1211

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

1212

*/

1213

int up_interface(const struct dirent *if_entry){

1214

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

1215

return 0;

1216

}

1217

1218

struct ifreq ifr;

1219

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

1220

if(debug){

1221

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

1222

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

1223

}

1224

return 0;

1225

}

1226

1227

/* Reject down interfaces */

1228

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

1229

if(debug){

1230

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

1231

if_entry->d_name);

1232

}

1233

return 0;

1234

}

1235

1236

/* Reject non-running interfaces */

1237

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

1238

if(debug){

1239

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

1240

if_entry->d_name);

1241

}

1242

return 0;

1243

}

1244

1245

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

1246

return 0;

1187

fprintf(stderr, "Interface \"%s\" is acceptable\n",

1188

if_entry->d_name);

1247

1189

}

1248

1190

return 1;

1249

1191

}

1259

1201

return 1;

1260

1202

}

1261

1203

1262

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

1263

int runnable_hook(const struct dirent *direntry){

1264

int ret;

1265

size_t sret;

1266

struct stat st;

1267

1268

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

1269

/* Empty name? */

1270

return 0;

1271

}

1272

1273

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

1274

"abcdefghijklmnopqrstuvwxyz"

1275

"0123456789"

1276

"_-");

1277

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

1278

/* Contains non-allowed characters */

1279

if(debug){

1280

fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",

1281

direntry->d_name);

1282

}

1283

return 0;

1284

}

1285

1286

char *fullname = NULL;

1287

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

1288

if(ret < 0){

1289

perror_plus("asprintf");

1290

return 0;

1291

}

1292

1293

ret = stat(fullname, &st);

1294

if(ret == -1){

1295

if(debug){

1296

perror_plus("Could not stat hook");

1297

}

1298

return 0;

1299

}

1300

if(not (S_ISREG(st.st_mode))){

1301

/* Not a regular file */

1302

if(debug){

1303

fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",

1304

direntry->d_name);

1305

}

1306

return 0;

1307

}

1308

if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){

1309

/* Not executable */

1310

if(debug){

1311

fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",

1312

direntry->d_name);

1313

}

1314

return 0;

1315

}

1316

if(debug){

1317

fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",

1318

direntry->d_name);

1319

}

1320

return 1;

1321

}

1322

1323

1204

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1324

1205

int ret;

1325

1206

struct timespec now;

1329

1210

while(true){

1330

1211

if(mc.current_server == NULL){

1331

1212

if (debug){

1332

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

1333

" No timeout!\n");

1213

fprintf(stderr,

1214

"Wait until first server is found. No timeout!\n");

1334

1215

}

1335

1216

ret = avahi_simple_poll_iterate(s, -1);

1336

1217

} else {

1337

1218

if (debug){

1338

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

1339

" it, or wait\n");

1219

fprintf(stderr, "Check current_server if we should run it,"

1220

" or wait\n");

1340

1221

}

1341

1222

/* the current time */

1342

1223

ret = clock_gettime(CLOCK_MONOTONIC, &now);

1358

1239

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

1359

1240

1360

1241

if (debug){

1361

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

1362

block_time);

1242

fprintf(stderr, "Blocking for %" PRIdMAX " ms\n", block_time);

1363

1243

}

1364

1244

1365

1245

if(block_time <= 0){

1385

1265

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

1386

1266

}

1387

1267

if(ret != 0){

1388

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

1268

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

1389

1269

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

1390

1270

}

1391

1271

}

1392

1272

}

1393

1273

}

1394

1274

1395

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

1396

int raise_privileges(void){

1397

int old_errno = errno;

1398

int ret_errno = 0;

1399

errno = 0;

1400

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

1401

perror_plus("seteuid");

1402

}

1403

ret_errno = errno;

1404

errno = old_errno;

1405

return ret_errno;

1406

}

1407

1408

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

1409

int raise_privileges_permanently(void){

1410

int old_errno = errno;

1411

int ret_errno = raise_privileges();

1412

if(ret_errno != 0){

1413

errno = old_errno;

1414

return ret_errno;

1415

}

1416

errno = 0;

1417

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

1418

perror_plus("seteuid");

1419

}

1420

ret_errno = errno;

1421

errno = old_errno;

1422

return ret_errno;

1423

}

1424

1425

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

1426

int lower_privileges(void){

1427

int old_errno = errno;

1428

int ret_errno = 0;

1429

errno = 0;

1430

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

1431

perror_plus("seteuid");

1432

}

1433

ret_errno = errno;

1434

errno = old_errno;

1435

return ret_errno;

1436

}

1437

1438

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

1439

const float delay){

1440

struct dirent **direntries;

1441

struct dirent *direntry;

1442

int ret;

1443

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

1444

alphasort);

1445

if(numhooks == -1){

1446

perror_plus("scandir");

1447

} else {

1448

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

1449

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

1450

direntry = direntries[i];

1451

char *fullname = NULL;

1452

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

1453

if(ret < 0){

1454

perror_plus("asprintf");

1455

continue;

1456

}

1457

if(debug){

1458

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

1459

direntry->d_name);

1460

}

1461

pid_t hook_pid = fork();

1462

if(hook_pid == 0){

1463

/* Child */

1464

/* Raise privileges */

1465

raise_privileges_permanently();

1466

/* Set group */

1467

errno = 0;

1468

ret = setgid(0);

1469

if(ret == -1){

1470

perror_plus("setgid");

1471

}

1472

/* Reset supplementary groups */

1473

errno = 0;

1474

ret = setgroups(0, NULL);

1475

if(ret == -1){

1476

perror_plus("setgroups");

1477

}

1478

dup2(devnull, STDIN_FILENO);

1479

close(devnull);

1480

dup2(STDERR_FILENO, STDOUT_FILENO);

1481

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

1482

if(ret == -1){

1483

perror_plus("setenv");

1484

_exit(EX_OSERR);

1485

}

1486

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

1487

if(ret == -1){

1488

perror_plus("setenv");

1489

_exit(EX_OSERR);

1490

}

1491

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

1492

if(ret == -1){

1493

perror_plus("setenv");

1494

_exit(EX_OSERR);

1495

}

1496

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

1497

if(ret == -1){

1498

perror_plus("setenv");

1499

_exit(EX_OSERR);

1500

}

1501

char *delaystring;

1502

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

1503

if(ret == -1){

1504

perror_plus("asprintf");

1505

_exit(EX_OSERR);

1506

}

1507

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

1508

if(ret == -1){

1509

free(delaystring);

1510

perror_plus("setenv");

1511

_exit(EX_OSERR);

1512

}

1513

free(delaystring);

1514

if(connect_to != NULL){

1515

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

1516

if(ret == -1){

1517

perror_plus("setenv");

1518

_exit(EX_OSERR);

1519

}

1520

}

1521

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

1522

perror_plus("execl");

1523

_exit(EXIT_FAILURE);

1524

}

1525

} else {

1526

int status;

1527

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

1528

perror_plus("waitpid");

1529

free(fullname);

1530

continue;

1531

}

1532

if(WIFEXITED(status)){

1533

if(WEXITSTATUS(status) != 0){

1534

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

1535

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

1536

WEXITSTATUS(status));

1537

free(fullname);

1538

continue;

1539

}

1540

} else if(WIFSIGNALED(status)){

1541

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

1542

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

1543

WTERMSIG(status));

1544

free(fullname);

1545

continue;

1546

} else {

1547

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

1548

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

1549

free(fullname);

1550

continue;

1551

}

1552

}

1553

free(fullname);

1554

if(debug){

1555

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

1556

direntry->d_name);

1557

}

1558

}

1559

close(devnull);

1560

}

1561

return true;

1562

}

1563

1564

int bring_up_interface(const char * const interface, const float delay){

1565

int sd = -1;

1566

int old_errno = errno;

1567

int ret_errno = 0;

1568

int ret;

1569

struct ifreq network;

1570

AvahiIfIndex if_index = (AvahiIfIndex)if_nametoindex(interface);

1571

if(if_index == 0){

1572

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

1573

errno = old_errno;

1574

return ENXIO;

1575

}

1576

1577

if(quit_now){

1578

errno = old_errno;

1579

return EINTR;

1580

}

1581

1582

/* Re-raise priviliges */

1583

raise_privileges();

1584

1585

#ifdef __linux__

1586

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1587

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

1588

ret = klogctl(8, NULL, 5);

1589

bool restore_loglevel = true;

1590

if(ret == -1){

1591

restore_loglevel = false;

1592

perror_plus("klogctl");

1593

}

1594

#endif /* __linux__ */

1595

1596

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1597

if(sd < 0){

1598

ret_errno = errno;

1599

perror_plus("socket");

1600

#ifdef __linux__

1601

if(restore_loglevel){

1602

ret = klogctl(7, NULL, 0);

1603

if(ret == -1){

1604

perror_plus("klogctl");

1605

}

1606

}

1607

#endif /* __linux__ */

1608

/* Lower privileges */

1609

lower_privileges();

1610

errno = old_errno;

1611

return ret_errno;

1612

}

1613

strcpy(network.ifr_name, interface);

1614

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

1615

if(ret == -1){

1616

ret_errno = errno;

1617

perror_plus("ioctl SIOCGIFFLAGS");

1618

#ifdef __linux__

1619

if(restore_loglevel){

1620

ret = klogctl(7, NULL, 0);

1621

if(ret == -1){

1622

perror_plus("klogctl");

1623

}

1624

}

1625

#endif /* __linux__ */

1626

/* Lower privileges */

1627

lower_privileges();

1628

errno = old_errno;

1629

return ret_errno;

1630

}

1631

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

1632

network.ifr_flags |= IFF_UP;

1633

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

1634

if(ret == -1){

1635

ret_errno = errno;

1636

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1637

#ifdef __linux__

1638

if(restore_loglevel){

1639

ret = klogctl(7, NULL, 0);

1640

if(ret == -1){

1641

perror_plus("klogctl");

1642

}

1643

}

1644

#endif /* __linux__ */

1645

/* Lower privileges */

1646

lower_privileges();

1647

errno = old_errno;

1648

return ret_errno;

1649

}

1650

}

1651

/* Sleep checking until interface is running.

1652

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

1653

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

1654

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

1655

if(ret == -1){

1656

perror_plus("ioctl SIOCGIFFLAGS");

1657

} else if(network.ifr_flags & IFF_RUNNING){

1658

break;

1659

}

1660

struct timespec sleeptime = { .tv_nsec = 250000000 };

1661

ret = nanosleep(&sleeptime, NULL);

1662

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

1663

perror_plus("nanosleep");

1664

}

1665

}

1666

/* Close the socket */

1667

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

1668

if(ret == -1){

1669

perror_plus("close");

1670

}

1671

#ifdef __linux__

1672

if(restore_loglevel){

1673

/* Restores kernel loglevel to default */

1674

ret = klogctl(7, NULL, 0);

1675

if(ret == -1){

1676

perror_plus("klogctl");

1677

}

1678

}

1679

#endif /* __linux__ */

1680

/* Lower privileges */

1681

lower_privileges();

1682

errno = old_errno;

1683

return 0;

1684

}

1685

1686

1275

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

1687

1276

AvahiSServiceBrowser *sb = NULL;

1688

1277

int error;

1694

1283

struct ifreq network;

1695

1284

int sd = -1;

1696

1285

bool take_down_interface = false;

1286

uid_t uid;

1287

gid_t gid;

1697

1288

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

1698

1289

bool tempdir_created = false;

1699

1290

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1766

1357

.group = 2 },

1767

1358

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

1768

1359

.arg = "SECONDS",

1769

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

1770

.group = 2 },

1771

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

1772

.arg = "DIR",

1773

.doc = "Directory where network hooks are located",

1360

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

1774

1361

.group = 2 },

1775

1362

/*

1776

1363

* These reproduce what we would get without ARGP_NO_HELP

1830

1417

argp_error(state, "Bad retry interval");

1831

1418

}

1832

1419

break;

1833

case 133: /* --network-hook-dir */

1834

hookdir = arg;

1835

break;

1836

1420

/*

1837

1421

* These reproduce what we would get without ARGP_NO_HELP

1838

1422

*/

1844

1428

argp_state_help(state, state->out_stream,

1845

1429

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1846

1430

case 'V': /* --version */

1847

fprintf_plus(state->out_stream, "%s\n", argp_program_version);

1431

fprintf(state->out_stream, "%s\n", argp_program_version);

1848

1432

exit(argp_err_exit_status);

1849

1433

break;

1850

1434

default:

1877

1461

{

1878

1462

/* Work around Debian bug #633582:

1879

1463

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

1464

struct stat st;

1880

1465

1881

1466

/* Re-raise priviliges */

1882

if(raise_privileges() == 0){

1883

struct stat st;

1884

1885

if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){

1886

int seckey_fd = open(seckey, O_RDONLY);

1887

if(seckey_fd == -1){

1888

perror_plus("open");

1889

} else {

1890

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

1891

if(ret == -1){

1892

perror_plus("fstat");

1893

} else {

1894

if(S_ISREG(st.st_mode)

1895

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

1896

ret = fchown(seckey_fd, uid, gid);

1897

if(ret == -1){

1898

perror_plus("fchown");

1899

}

1900

}

1901

}

1902

TEMP_FAILURE_RETRY(close(seckey_fd));

1903

}

1904

}

1905

1906

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

1907

int pubkey_fd = open(pubkey, O_RDONLY);

1908

if(pubkey_fd == -1){

1909

perror_plus("open");

1910

} else {

1911

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

1912

if(ret == -1){

1913

perror_plus("fstat");

1914

} else {

1915

if(S_ISREG(st.st_mode)

1916

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

1917

ret = fchown(pubkey_fd, uid, gid);

1918

if(ret == -1){

1919

perror_plus("fchown");

1920

}

1921

}

1922

}

1923

TEMP_FAILURE_RETRY(close(pubkey_fd));

1924

}

1925

}

1926

1927

/* Lower privileges */

1928

errno = 0;

1929

ret = seteuid(uid);

1930

if(ret == -1){

1931

perror_plus("seteuid");

1932

}

1933

}

1934

}

1935

1936

/* Run network hooks */

1937

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

1938

goto end;

1467

errno = 0;

1468

ret = seteuid(0);

1469

if(ret == -1){

1470

perror_plus("seteuid");

1471

}

1472

1473

if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){

1474

int seckey_fd = open(seckey, O_RDONLY);

1475

if(seckey_fd == -1){

1476

perror_plus("open");

1477

} else {

1478

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

1479

if(ret == -1){

1480

perror_plus("fstat");

1481

} else {

1482

if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){

1483

ret = fchown(seckey_fd, uid, gid);

1484

if(ret == -1){

1485

perror_plus("fchown");

1486

}

1487

}

1488

}

1489

TEMP_FAILURE_RETRY(close(seckey_fd));

1490

}

1491

}

1492

1493

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

1494

int pubkey_fd = open(pubkey, O_RDONLY);

1495

if(pubkey_fd == -1){

1496

perror_plus("open");

1497

} else {

1498

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

1499

if(ret == -1){

1500

perror_plus("fstat");

1501

} else {

1502

if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){

1503

ret = fchown(pubkey_fd, uid, gid);

1504

if(ret == -1){

1505

perror_plus("fchown");

1506

}

1507

}

1508

}

1509

TEMP_FAILURE_RETRY(close(pubkey_fd));

1510

}

1511

}

1512

1513

/* Lower privileges */

1514

errno = 0;

1515

ret = seteuid(uid);

1516

if(ret == -1){

1517

perror_plus("seteuid");

1518

}

1939

1519

}

1940

1520

1941

1521

if(not debug){

1942

1522

avahi_set_log_function(empty_log);

1943

1523

}

1944

1524

1945

1525

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

1946

1526

struct dirent **direntries;

1947

/* First look for interfaces that are up */

1948

ret = scandir(sys_class_net, &direntries, up_interface,

1527

ret = scandir(sys_class_net, &direntries, good_interface,

1949

1528

alphasort);

1950

if(ret == 0){

1951

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

1952

free(direntries);

1953

ret = scandir(sys_class_net, &direntries, good_interface,

1954

alphasort);

1955

}

1956

1529

if(ret >= 1){

1957

/* Pick the first interface returned */

1530

/* Pick the first good interface */

1958

1531

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

1959

1532

if(debug){

1960

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

1533

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

1961

1534

}

1962

1535

if(interface == NULL){

1963

1536

perror_plus("malloc");

1968

1541

free(direntries);

1969

1542

} else {

1970

1543

free(direntries);

1971

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

1544

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

1972

1545

exitcode = EXIT_FAILURE;

1973

1546

goto end;

1974

1547

}

1980

1553

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

1981

1554

mc.simple_poll = avahi_simple_poll_new();

1982

1555

if(mc.simple_poll == NULL){

1983

fprintf_plus(stderr,

1984

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

1556

fprintf(stderr, "Avahi: Failed to create simple poll object.\n");

1985

1557

exitcode = EX_UNAVAILABLE;

1986

1558

goto end;

1987

1559

}

2050

1622

}

2051

1623

2052

1624

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

2053

if((interface[0] != '\0') and (strcmp(interface, "none") != 0)){

2054

ret = bring_up_interface(interface, delay);

2055

if(ret != 0){

2056

errno = ret;

2057

perror_plus("Failed to bring up interface");

1625

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

1626

if_index = (AvahiIfIndex) if_nametoindex(interface);

1627

if(if_index == 0){

1628

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

1629

exitcode = EX_UNAVAILABLE;

1630

goto end;

1631

}

1632

1633

if(quit_now){

1634

goto end;

1635

}

1636

1637

/* Re-raise priviliges */

1638

errno = 0;

1639

ret = seteuid(0);

1640

if(ret == -1){

1641

perror_plus("seteuid");

1642

}

1643

1644

#ifdef __linux__

1645

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1646

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

1647

ret = klogctl(8, NULL, 5);

1648

bool restore_loglevel = true;

1649

if(ret == -1){

1650

restore_loglevel = false;

1651

perror_plus("klogctl");

1652

}

1653

#endif /* __linux__ */

1654

1655

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1656

if(sd < 0){

1657

perror_plus("socket");

1658

exitcode = EX_OSERR;

1659

#ifdef __linux__

1660

if(restore_loglevel){

1661

ret = klogctl(7, NULL, 0);

1662

if(ret == -1){

1663

perror_plus("klogctl");

1664

}

1665

}

1666

#endif /* __linux__ */

1667

/* Lower privileges */

1668

errno = 0;

1669

ret = seteuid(uid);

1670

if(ret == -1){

1671

perror_plus("seteuid");

1672

}

1673

goto end;

1674

}

1675

strcpy(network.ifr_name, interface);

1676

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

1677

if(ret == -1){

1678

perror_plus("ioctl SIOCGIFFLAGS");

1679

#ifdef __linux__

1680

if(restore_loglevel){

1681

ret = klogctl(7, NULL, 0);

1682

if(ret == -1){

1683

perror_plus("klogctl");

1684

}

1685

}

1686

#endif /* __linux__ */

1687

exitcode = EX_OSERR;

1688

/* Lower privileges */

1689

errno = 0;

1690

ret = seteuid(uid);

1691

if(ret == -1){

1692

perror_plus("seteuid");

1693

}

1694

goto end;

1695

}

1696

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

1697

network.ifr_flags |= IFF_UP;

1698

take_down_interface = true;

1699

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

1700

if(ret == -1){

1701

take_down_interface = false;

1702

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1703

exitcode = EX_OSERR;

1704

#ifdef __linux__

1705

if(restore_loglevel){

1706

ret = klogctl(7, NULL, 0);

1707

if(ret == -1){

1708

perror_plus("klogctl");

1709

}

1710

}

1711

#endif /* __linux__ */

1712

/* Lower privileges */

1713

errno = 0;

1714

ret = seteuid(uid);

1715

if(ret == -1){

1716

perror_plus("seteuid");

1717

}

1718

goto end;

1719

}

1720

}

1721

/* Sleep checking until interface is running.

1722

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

1723

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

1724

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

1725

if(ret == -1){

1726

perror_plus("ioctl SIOCGIFFLAGS");

1727

} else if(network.ifr_flags & IFF_RUNNING){

1728

break;

1729

}

1730

struct timespec sleeptime = { .tv_nsec = 250000000 };

1731

ret = nanosleep(&sleeptime, NULL);

1732

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

1733

perror_plus("nanosleep");

1734

}

1735

}

1736

if(not take_down_interface){

1737

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

1738

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

1739

if(ret == -1){

1740

perror_plus("close");

1741

}

1742

}

1743

#ifdef __linux__

1744

if(restore_loglevel){

1745

/* Restores kernel loglevel to default */

1746

ret = klogctl(7, NULL, 0);

1747

if(ret == -1){

1748

perror_plus("klogctl");

1749

}

1750

}

1751

#endif /* __linux__ */

1752

/* Lower privileges */

1753

errno = 0;

1754

if(take_down_interface){

1755

/* Lower privileges */

1756

ret = seteuid(uid);

1757

if(ret == -1){

1758

perror_plus("seteuid");

1759

}

1760

} else {

1761

/* Lower privileges permanently */

1762

ret = setuid(uid);

1763

if(ret == -1){

1764

perror_plus("setuid");

1765

}

2058

1766

}

2059

1767

}

2060

1768

2064

1772

2065

1773

ret = init_gnutls_global(pubkey, seckey);

2066

1774

if(ret == -1){

2067

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

1775

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

2068

1776

exitcode = EX_UNAVAILABLE;

2069

1777

goto end;

2070

1778

} else {

2086

1794

}

2087

1795

2088

1796

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

2089

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

1797

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

2090

1798

exitcode = EX_UNAVAILABLE;

2091

1799

goto end;

2092

1800

} else {

2101

1809

/* Connect directly, do not use Zeroconf */

2102

1810

/* (Mainly meant for debugging) */

2103

1811

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

2104

2105

1812

if(address == NULL){

2106

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

1813

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

2107

1814

exitcode = EX_USAGE;

2108

1815

goto end;

2109

1816

}

2117

1824

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

2118

1825

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

2119

1826

or tmpmax != (uint16_t)tmpmax){

2120

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

1827

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

2121

1828

exitcode = EX_USAGE;

2122

1829

goto end;

2123

1830

}

2153

1860

break;

2154

1861

}

2155

1862

if(debug){

2156

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

2157

(int)retry_interval);

1863

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

1864

(int)retry_interval);

2158

1865

}

2159

1866

sleep((int)retry_interval);

2160

1867

}

2162

1869

if (not quit_now){

2163

1870

exitcode = EXIT_SUCCESS;

2164

1871

}

2165

1872

2166

1873

goto end;

2167

1874

}

2168

1875

2190

1897

2191

1898

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

2192

1899

if(mc.server == NULL){

2193

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

2194

avahi_strerror(error));

1900

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

1901

avahi_strerror(error));

2195

1902

exitcode = EX_UNAVAILABLE;

2196

1903

goto end;

2197

1904

}

2205

1912

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2206

1913

NULL, 0, browse_callback, NULL);

2207

1914

if(sb == NULL){

2208

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

2209

avahi_strerror(avahi_server_errno(mc.server)));

1915

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

1916

avahi_strerror(avahi_server_errno(mc.server)));

2210

1917

exitcode = EX_UNAVAILABLE;

2211

1918

goto end;

2212

1919

}

2218

1925

/* Run the main loop */

2219

1926

2220

1927

if(debug){

2221

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

1928

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

2222

1929

}

2223

1930

2224

1931

ret = avahi_loop_with_timeout(mc.simple_poll,

2225

1932

(int)(retry_interval * 1000));

2226

1933

if(debug){

2227

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

2228

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

1934

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

1935

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

2229

1936

}

2230

1937

2231

1938

end:

2232

1939

2233

1940

if(debug){

2234

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

1941

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

2235

1942

}

2236

1943

2237

1944

/* Cleanup things */

2253

1960

if(gpgme_initialized){

2254

1961

gpgme_release(mc.ctx);

2255

1962

}

2256

1963

2257

1964

/* Cleans up the circular linked list of Mandos servers the client

2258

1965

has seen */

2259

1966

if(mc.current_server != NULL){

2265

1972

}

2266

1973

}

2267

1974

2268

/* Run network hooks */

2269

run_network_hooks("stop", interface, delay);

2270

2271

/* Re-raise priviliges */

2272

{

2273

raise_privileges();

2274

2275

/* Take down the network interface */

2276

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

1975

/* Take down the network interface */

1976

if(take_down_interface){

1977

/* Re-raise priviliges */

1978

errno = 0;

1979

ret = seteuid(0);

1980

if(ret == -1){

1981

perror_plus("seteuid");

1982

}

1983

if(geteuid() == 0){

2277

1984

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

2278

1985

if(ret == -1){

2279

1986

perror_plus("ioctl SIOCGIFFLAGS");

2280

} else if(network.ifr_flags & IFF_UP){

1987

} else if(network.ifr_flags & IFF_UP) {

2281

1988

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

2282

1989

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

2283

1990

if(ret == -1){

2288

1995

if(ret == -1){

2289

1996

perror_plus("close");

2290

1997

}

1998

/* Lower privileges permanently */

1999

errno = 0;

2000

ret = setuid(uid);

2001

if(ret == -1){

2002

perror_plus("setuid");

2003

}

2291

2004

}

2292

2005

}

2293

/* Lower privileges permanently */

2294

errno = 0;

2295

ret = setuid(uid);

2296

if(ret == -1){

2297

perror_plus("setuid");

2298

}

2299

2006

2300

2007

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

2301

2008

if(tempdir_created){

2315

2022

}

2316

2023

ret = remove(fullname);

2317

2024

if(ret == -1){

2318

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

2319

strerror(errno));

2025

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

2026

strerror(errno));

2320

2027

}

2321

2028

free(fullname);

2322

2029

}