/mandos/trunk : revision 518.2.2

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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

32

/* 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(), strcpy() */

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

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

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#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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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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getnameinfo() */

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

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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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*/

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

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strtoimax() */

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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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*/

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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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unlinkat() */

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

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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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argp_state, struct argp,

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

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argz_delete(), argz_append(),

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argz_stringify(), argz_add(),

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argz_count() */

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#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() */

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init_gnutls_session(),

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109

GNUTLS_* */

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#include <gnutls/openpgp.h>

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/* 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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#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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int hookdir_fd = -1;

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uid_t uid = 65534;

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gid_t gid = 65534;

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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;

159

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

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typedef struct {

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AvahiSimplePoll *simple_poll;

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AvahiServer *server;

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gnutls_certificate_credentials_t cred;

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150

unsigned int dh_bits;

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const char *priority;

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gpgme_ctx_t ctx;

168

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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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156

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/* global so signal handler can reach it*/

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AvahiSimplePoll *simple_poll;

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

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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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162

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163

sig_atomic_t quit_now = 0;

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int signal_received = 0;

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/* Function to use when printing errors */

180

167

void perror_plus(const char *print_text){

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int e = errno;

182

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

183

169

program_invocation_short_name);

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errno = e;

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170

perror(print_text);

186

171

}

187

172

188

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

189

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

190

va_list ap;

191

va_start (ap, format);

192

193

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

194

program_invocation_short_name));

195

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

196

}

197

198

173

/*

199

174

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

200

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

201

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* "buffer_length" is how much is already used.

202

177

*/

203

__attribute__((nonnull, warn_unused_result))

204

178

size_t incbuffer(char **buffer, size_t buffer_length,

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size_t buffer_capacity){

179

size_t buffer_capacity){

206

180

if(buffer_length + BUFFER_SIZE > buffer_capacity){

207

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

208

if(new_buf == NULL){

209

int old_errno = errno;

210

free(*buffer);

211

errno = old_errno;

212

*buffer = NULL;

181

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

182

if(buffer == NULL){

213

183

return 0;

214

184

}

215

*buffer = new_buf;

216

185

buffer_capacity += BUFFER_SIZE;

217

186

}

218

187

return buffer_capacity;

219

188

}

220

189

221

190

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

222

__attribute__((nonnull, warn_unused_result))

223

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

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int af, server **current_server){

191

int add_server(const char *ip, uint16_t port,

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AvahiIfIndex if_index,

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int af){

225

194

int ret;

226

195

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

227

196

if(new_server == NULL){

228

197

perror_plus("malloc");

229

return false;

198

return -1;

230

199

}

231

200

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

232

.port = port,

233

.if_index = if_index,

234

.af = af };

201

.port = port,

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.if_index = if_index,

203

.af = af };

235

204

if(new_server->ip == NULL){

236

205

perror_plus("strdup");

237

free(new_server);

238

return false;

239

}

240

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

241

if(ret == -1){

242

perror_plus("clock_gettime");

243

#ifdef __GNUC__

244

#pragma GCC diagnostic push

245

#pragma GCC diagnostic ignored "-Wcast-qual"

246

#endif

247

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

248

#ifdef __GNUC__

249

#pragma GCC diagnostic pop

250

#endif

251

free(new_server);

252

return false;

206

return -1;

253

207

}

254

208

/* Special case of first server */

255

if(*current_server == NULL){

209

if (mc.current_server == NULL){

256

210

new_server->next = new_server;

257

211

new_server->prev = new_server;

258

*current_server = new_server;

212

mc.current_server = new_server;

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

259

214

} else {

260

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

261

new_server->next = *current_server;

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

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new_server->next = mc.current_server;

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

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217

new_server->prev->next = new_server;

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(*current_server)->prev = new_server;

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}

266

return true;

218

mc.current_server->prev = new_server;

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}

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

221

if(ret == -1){

222

perror_plus("clock_gettime");

223

return -1;

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}

225

return 0;

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226

}

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227

269

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/*

270

229

* Initialize GPGME.

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*/

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__attribute__((nonnull, warn_unused_result))

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static bool init_gpgme(const char * const seckey,

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const char * const pubkey,

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const char * const tempdir,

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mandos_context *mc){

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static bool init_gpgme(const char *seckey,

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const char *pubkey, const char *tempdir){

277

233

gpgme_error_t rc;

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gpgme_engine_info_t engine_info;

279

235

236

280

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/*

281

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

282

239

*/

283

bool import_key(const char * const filename){

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bool import_key(const char *filename){

284

241

int ret;

285

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int fd;

286

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gpgme_data_t pgp_data;

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294

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rc = gpgme_data_new_from_fd(&pgp_data, fd);

295

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if(rc != GPG_ERR_NO_ERROR){

296

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

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gpgme_strsource(rc), gpgme_strerror(rc));

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

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gpgme_strsource(rc), gpgme_strerror(rc));

298

255

return false;

299

256

}

300

257

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

258

rc = gpgme_op_import(mc.ctx, pgp_data);

302

259

if(rc != GPG_ERR_NO_ERROR){

303

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",

261

gpgme_strsource(rc), gpgme_strerror(rc));

305

262

return false;

306

263

}

307

264

308

ret = close(fd);

265

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

309

266

if(ret == -1){

310

267

perror_plus("close");

311

268

}

314

271

}

315

272

316

273

if(debug){

317

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

274

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

318

275

}

319

276

320

277

/* Init GPGME */

321

278

gpgme_check_version(NULL);

322

279

rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);

323

280

if(rc != GPG_ERR_NO_ERROR){

324

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

325

gpgme_strsource(rc), gpgme_strerror(rc));

281

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

282

gpgme_strsource(rc), gpgme_strerror(rc));

326

283

return false;

327

284

}

328

285

329

286

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

330

287

rc = gpgme_get_engine_info(&engine_info);

331

288

if(rc != GPG_ERR_NO_ERROR){

332

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

333

gpgme_strsource(rc), gpgme_strerror(rc));

289

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

290

gpgme_strsource(rc), gpgme_strerror(rc));

334

291

return false;

335

292

}

336

293

while(engine_info != NULL){

342

299

engine_info = engine_info->next;

343

300

}

344

301

if(engine_info == NULL){

345

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

346

tempdir);

302

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

347

303

return false;

348

304

}

349

305

350

306

/* Create new GPGME "context" */

351

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

307

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

352

308

if(rc != GPG_ERR_NO_ERROR){

353

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

354

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

355

gpgme_strerror(rc));

309

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

310

gpgme_strsource(rc), gpgme_strerror(rc));

356

311

return false;

357

312

}

358

313

367

322

* Decrypt OpenPGP data.

368

323

* Returns -1 on error

369

324

*/

370

__attribute__((nonnull, warn_unused_result))

371

325

static ssize_t pgp_packet_decrypt(const char *cryptotext,

372

326

size_t crypto_size,

373

char **plaintext,

374

mandos_context *mc){

327

char **plaintext){

375

328

gpgme_data_t dh_crypto, dh_plain;

376

329

gpgme_error_t rc;

377

330

ssize_t ret;

379

332

ssize_t plaintext_length = 0;

380

333

381

334

if(debug){

382

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

335

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

383

336

}

384

337

385

338

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

386

339

rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,

387

340

0);

388

341

if(rc != GPG_ERR_NO_ERROR){

389

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

390

gpgme_strsource(rc), gpgme_strerror(rc));

342

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

343

gpgme_strsource(rc), gpgme_strerror(rc));

391

344

return -1;

392

345

}

393

346

394

347

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

395

348

rc = gpgme_data_new(&dh_plain);

396

349

if(rc != GPG_ERR_NO_ERROR){

397

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

398

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

399

gpgme_strsource(rc), gpgme_strerror(rc));

350

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

351

gpgme_strsource(rc), gpgme_strerror(rc));

400

352

gpgme_data_release(dh_crypto);

401

353

return -1;

402

354

}

403

355

404

356

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

405

357

data buffer */

406

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

358

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

407

359

if(rc != GPG_ERR_NO_ERROR){

408

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

409

gpgme_strsource(rc), gpgme_strerror(rc));

360

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

361

gpgme_strsource(rc), gpgme_strerror(rc));

410

362

plaintext_length = -1;

411

363

if(debug){

412

364

gpgme_decrypt_result_t result;

413

result = gpgme_op_decrypt_result(mc->ctx);

365

result = gpgme_op_decrypt_result(mc.ctx);

414

366

if(result == NULL){

415

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

367

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

416

368

} else {

417

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

418

result->unsupported_algorithm);

419

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

420

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);

421

373

if(result->file_name != NULL){

422

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

374

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

423

375

}

424

376

gpgme_recipient_t recipient;

425

377

recipient = result->recipients;

426

378

while(recipient != NULL){

427

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

428

gpgme_pubkey_algo_name

429

(recipient->pubkey_algo));

430

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

431

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

432

recipient->status == GPG_ERR_NO_SECKEY

433

? "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");

434

385

recipient = recipient->next;

435

386

}

436

387

}

439

390

}

440

391

441

392

if(debug){

442

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

393

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

443

394

}

444

395

445

396

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

452

403

*plaintext = NULL;

453

404

while(true){

454

405

plaintext_capacity = incbuffer(plaintext,

455

(size_t)plaintext_length,

456

plaintext_capacity);

406

(size_t)plaintext_length,

407

plaintext_capacity);

457

408

if(plaintext_capacity == 0){

458

perror_plus("incbuffer");

459

plaintext_length = -1;

460

goto decrypt_end;

409

perror_plus("incbuffer");

410

plaintext_length = -1;

411

goto decrypt_end;

461

412

}

462

413

463

414

ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,

476

427

}

477

428

478

429

if(debug){

479

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

430

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

480

431

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

481

432

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

482

433

}

493

444

return plaintext_length;

494

445

}

495

446

496

__attribute__((warn_unused_result, const))

497

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

498

if(str == NULL)

499

return "(unknown)";

500

return str;

501

}

502

503

__attribute__((warn_unused_result))

504

static const char *safer_gnutls_strerror(int value){

505

const char *ret = gnutls_strerror(value);

506

return safe_string(ret);

447

static const char * safer_gnutls_strerror(int value){

448

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

449

-Wunreachable-code */

450

if(ret == NULL)

451

ret = "(unknown)";

452

return ret;

507

453

}

508

454

509

455

/* GnuTLS log function callback */

510

__attribute__((nonnull))

511

456

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

512

457

const char* string){

513

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

458

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

514

459

}

515

460

516

__attribute__((nonnull, warn_unused_result))

517

461

static int init_gnutls_global(const char *pubkeyfilename,

518

const char *seckeyfilename,

519

const char *dhparamsfilename,

520

mandos_context *mc){

462

const char *seckeyfilename){

521

463

int ret;

522

unsigned int uret;

523

464

524

465

if(debug){

525

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

466

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

526

467

}

527

468

528

469

ret = gnutls_global_init();

529

470

if(ret != GNUTLS_E_SUCCESS){

530

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

531

safer_gnutls_strerror(ret));

471

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

472

safer_gnutls_strerror(ret));

532

473

return -1;

533

474

}

534

475

541

482

}

542

483

543

484

/* OpenPGP credentials */

544

ret = gnutls_certificate_allocate_credentials(&mc->cred);

485

ret = gnutls_certificate_allocate_credentials(&mc.cred);

545

486

if(ret != GNUTLS_E_SUCCESS){

546

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

547

safer_gnutls_strerror(ret));

487

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

488

safer_gnutls_strerror(ret));

548

489

gnutls_global_deinit();

549

490

return -1;

550

491

}

551

492

552

493

if(debug){

553

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

554

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

555

pubkeyfilename,

556

seckeyfilename);

494

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

495

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

496

seckeyfilename);

557

497

}

558

498

559

499

ret = gnutls_certificate_set_openpgp_key_file

560

(mc->cred, pubkeyfilename, seckeyfilename,

500

(mc.cred, pubkeyfilename, seckeyfilename,

561

501

GNUTLS_OPENPGP_FMT_BASE64);

562

502

if(ret != GNUTLS_E_SUCCESS){

563

fprintf_plus(stderr,

564

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

565

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

566

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

567

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));

568

508

goto globalfail;

569

509

}

570

510

571

511

/* GnuTLS server initialization */

572

ret = gnutls_dh_params_init(&mc->dh_params);

573

if(ret != GNUTLS_E_SUCCESS){

574

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

575

" initialization: %s\n",

576

safer_gnutls_strerror(ret));

577

goto globalfail;

578

}

579

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

580

if(dhparamsfilename != NULL){

581

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

582

do {

583

int dhpfile = open(dhparamsfilename, O_RDONLY);

584

if(dhpfile == -1){

585

perror_plus("open");

586

dhparamsfilename = NULL;

587

break;

588

}

589

size_t params_capacity = 0;

590

while(true){

591

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

592

(size_t)params.size,

593

(size_t)params_capacity);

594

if(params_capacity == 0){

595

perror_plus("incbuffer");

596

free(params.data);

597

params.data = NULL;

598

dhparamsfilename = NULL;

599

break;

600

}

601

ssize_t bytes_read = read(dhpfile,

602

params.data + params.size,

603

BUFFER_SIZE);

604

/* EOF */

605

if(bytes_read == 0){

606

break;

607

}

608

/* check bytes_read for failure */

609

if(bytes_read < 0){

610

perror_plus("read");

611

free(params.data);

612

params.data = NULL;

613

dhparamsfilename = NULL;

614

break;

615

}

616

params.size += (unsigned int)bytes_read;

617

}

618

if(params.data == NULL){

619

dhparamsfilename = NULL;

620

}

621

if(dhparamsfilename == NULL){

622

break;

623

}

624

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

625

GNUTLS_X509_FMT_PEM);

626

if(ret != GNUTLS_E_SUCCESS){

627

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

628

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

629

safer_gnutls_strerror(ret));

630

dhparamsfilename = NULL;

631

}

632

} while(false);

633

}

634

if(dhparamsfilename == NULL){

635

if(mc->dh_bits == 0){

636

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

637

/* Try to read the private key file */

638

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

639

do {

640

int secfile = open(seckeyfilename, O_RDONLY);

641

if(secfile == -1){

642

perror_plus("open");

643

break;

644

}

645

size_t buffer_capacity = 0;

646

while(true){

647

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

648

(size_t)buffer.size,

649

(size_t)buffer_capacity);

650

if(buffer_capacity == 0){

651

perror_plus("incbuffer");

652

free(buffer.data);

653

buffer.data = NULL;

654

break;

655

}

656

ssize_t bytes_read = read(secfile,

657

buffer.data + buffer.size,

658

BUFFER_SIZE);

659

/* EOF */

660

if(bytes_read == 0){

661

break;

662

}

663

/* check bytes_read for failure */

664

if(bytes_read < 0){

665

perror_plus("read");

666

free(buffer.data);

667

buffer.data = NULL;

668

break;

669

}

670

buffer.size += (unsigned int)bytes_read;

671

}

672

close(secfile);

673

} while(false);

674

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

675

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

676

if(buffer.data != NULL){

677

{

678

gnutls_openpgp_privkey_t privkey = NULL;

679

ret = gnutls_openpgp_privkey_init(&privkey);

680

if(ret != GNUTLS_E_SUCCESS){

681

fprintf_plus(stderr, "Error initializing OpenPGP key"

682

" structure: %s",

683

safer_gnutls_strerror(ret));

684

free(buffer.data);

685

buffer.data = NULL;

686

} else {

687

ret = gnutls_openpgp_privkey_import

688

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

689

if(ret != GNUTLS_E_SUCCESS){

690

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

691

safer_gnutls_strerror(ret));

692

privkey = NULL;

693

}

694

free(buffer.data);

695

buffer.data = NULL;

696

if(privkey != NULL){

697

/* Use private key to suggest an appropriate

698

sec_param */

699

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

700

gnutls_openpgp_privkey_deinit(privkey);

701

if(debug){

702

fprintf_plus(stderr, "This OpenPGP key implies using"

703

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

704

safe_string(gnutls_sec_param_get_name

705

(sec_param)));

706

}

707

}

708

}

709

}

710

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

711

/* Err on the side of caution */

712

sec_param = GNUTLS_SEC_PARAM_ULTRA;

713

if(debug){

714

fprintf_plus(stderr, "Falling back to security parameter"

715

" \"%s\"\n",

716

safe_string(gnutls_sec_param_get_name

717

(sec_param)));

718

}

719

}

720

}

721

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

722

if(uret != 0){

723

mc->dh_bits = uret;

724

if(debug){

725

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

726

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

727

safe_string(gnutls_sec_param_get_name

728

(sec_param)),

729

mc->dh_bits);

730

}

731

} else {

732

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

733

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

734

safe_string(gnutls_sec_param_get_name

735

(sec_param)),

736

safer_gnutls_strerror(ret));

737

goto globalfail;

738

}

739

} else if(debug){

740

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

741

mc->dh_bits);

742

}

743

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

744

if(ret != GNUTLS_E_SUCCESS){

745

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

746

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

747

safer_gnutls_strerror(ret));

748

goto globalfail;

749

}

750

}

751

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

512

ret = gnutls_dh_params_init(&mc.dh_params);

513

if(ret != GNUTLS_E_SUCCESS){

514

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

515

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

516

goto globalfail;

517

}

518

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

519

if(ret != GNUTLS_E_SUCCESS){

520

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

521

safer_gnutls_strerror(ret));

522

goto globalfail;

523

}

524

525

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

752

526

753

527

return 0;

754

528

755

529

globalfail:

756

530

757

gnutls_certificate_free_credentials(mc->cred);

531

gnutls_certificate_free_credentials(mc.cred);

758

532

gnutls_global_deinit();

759

gnutls_dh_params_deinit(mc->dh_params);

533

gnutls_dh_params_deinit(mc.dh_params);

760

534

return -1;

761

535

}

762

536

763

__attribute__((nonnull, warn_unused_result))

764

static int init_gnutls_session(gnutls_session_t *session,

765

mandos_context *mc){

537

static int init_gnutls_session(gnutls_session_t *session){

766

538

int ret;

767

539

/* GnuTLS session creation */

768

540

do {

772

544

}

773

545

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

774

546

if(ret != GNUTLS_E_SUCCESS){

775

fprintf_plus(stderr,

776

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

777

safer_gnutls_strerror(ret));

547

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

548

safer_gnutls_strerror(ret));

778

549

}

779

550

780

551

{

781

552

const char *err;

782

553

do {

783

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

554

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

784

555

if(quit_now){

785

556

gnutls_deinit(*session);

786

557

return -1;

787

558

}

788

559

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

789

560

if(ret != GNUTLS_E_SUCCESS){

790

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

791

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

792

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));

793

564

gnutls_deinit(*session);

794

565

return -1;

795

566

}

797

568

798

569

do {

799

570

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

800

mc->cred);

571

mc.cred);

801

572

if(quit_now){

802

573

gnutls_deinit(*session);

803

574

return -1;

804

575

}

805

576

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

806

577

if(ret != GNUTLS_E_SUCCESS){

807

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

808

safer_gnutls_strerror(ret));

578

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

579

safer_gnutls_strerror(ret));

809

580

gnutls_deinit(*session);

810

581

return -1;

811

582

}

813

584

/* ignore client certificate if any. */

814

585

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

815

586

587

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

588

816

589

return 0;

817

590

}

818

591

820

593

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

821

594

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

822

595

823

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

824

__attribute__((warn_unused_result))

825

error_t raise_privileges(void){

826

error_t old_errno = errno;

827

error_t ret_errno = 0;

828

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

829

ret_errno = errno;

830

}

831

errno = old_errno;

832

return ret_errno;

833

}

834

835

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

836

__attribute__((warn_unused_result))

837

error_t raise_privileges_permanently(void){

838

error_t old_errno = errno;

839

error_t ret_errno = raise_privileges();

840

if(ret_errno != 0){

841

errno = old_errno;

842

return ret_errno;

843

}

844

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

845

ret_errno = errno;

846

}

847

errno = old_errno;

848

return ret_errno;

849

}

850

851

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

852

__attribute__((warn_unused_result))

853

error_t lower_privileges(void){

854

error_t old_errno = errno;

855

error_t ret_errno = 0;

856

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

857

ret_errno = errno;

858

}

859

errno = old_errno;

860

return ret_errno;

861

}

862

863

/* Lower privileges permanently */

864

__attribute__((warn_unused_result))

865

error_t lower_privileges_permanently(void){

866

error_t old_errno = errno;

867

error_t ret_errno = 0;

868

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

869

ret_errno = errno;

870

}

871

errno = old_errno;

872

return ret_errno;

873

}

874

875

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

876

__attribute__((nonnull, warn_unused_result))

877

static bool add_delete_local_route(const bool add,

878

const char *address,

879

AvahiIfIndex if_index){

880

int ret;

881

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

882

char add_arg[] = "add";

883

char delete_arg[] = "delete";

884

char debug_flag[] = "--debug";

885

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

886

if(pluginhelperdir == NULL){

887

if(debug){

888

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

889

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

890

}

891

return false;

892

}

893

894

char interface[IF_NAMESIZE];

895

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

896

perror_plus("if_indextoname");

897

return false;

898

}

899

900

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

901

if(devnull == -1){

902

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

903

return false;

904

}

905

pid_t pid = fork();

906

if(pid == 0){

907

/* Child */

908

/* Raise privileges */

909

errno = raise_privileges_permanently();

910

if(errno != 0){

911

perror_plus("Failed to raise privileges");

912

/* _exit(EX_NOPERM); */

913

} else {

914

/* Set group */

915

errno = 0;

916

ret = setgid(0);

917

if(ret == -1){

918

perror_plus("setgid");

919

_exit(EX_NOPERM);

920

}

921

/* Reset supplementary groups */

922

errno = 0;

923

ret = setgroups(0, NULL);

924

if(ret == -1){

925

perror_plus("setgroups");

926

_exit(EX_NOPERM);

927

}

928

}

929

ret = dup2(devnull, STDIN_FILENO);

930

if(ret == -1){

931

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

932

_exit(EX_OSERR);

933

}

934

ret = close(devnull);

935

if(ret == -1){

936

perror_plus("close");

937

_exit(EX_OSERR);

938

}

939

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

940

if(ret == -1){

941

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

942

_exit(EX_OSERR);

943

}

944

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

945

O_RDONLY

946

| O_DIRECTORY

947

| O_PATH

948

| O_CLOEXEC));

949

if(helperdir_fd == -1){

950

perror_plus("open");

951

_exit(EX_UNAVAILABLE);

952

}

953

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

954

helper, O_RDONLY));

955

if(helper_fd == -1){

956

perror_plus("openat");

957

close(helperdir_fd);

958

_exit(EX_UNAVAILABLE);

959

}

960

close(helperdir_fd);

961

#ifdef __GNUC__

962

#pragma GCC diagnostic push

963

#pragma GCC diagnostic ignored "-Wcast-qual"

964

#endif

965

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

966

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

967

interface, debug ? debug_flag : NULL, NULL },

968

environ) == -1){

969

#ifdef __GNUC__

970

#pragma GCC diagnostic pop

971

#endif

972

perror_plus("fexecve");

973

_exit(EXIT_FAILURE);

974

}

975

}

976

if(pid == -1){

977

perror_plus("fork");

978

return false;

979

}

980

int status;

981

pid_t pret = -1;

982

errno = 0;

983

do {

984

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

985

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

986

int errno_raising = 0;

987

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

988

errno_raising = errno;

989

perror_plus("Failed to raise privileges in order to"

990

" kill helper program");

991

}

992

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

993

perror_plus("kill");

994

}

995

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

996

perror_plus("Failed to lower privileges after killing"

997

" helper program");

998

}

999

return false;

1000

}

1001

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

1002

if(pret == -1){

1003

perror_plus("waitpid");

1004

return false;

1005

}

1006

if(WIFEXITED(status)){

1007

if(WEXITSTATUS(status) != 0){

1008

fprintf_plus(stderr, "Error: iprouteadddel exited"

1009

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

1010

return false;

1011

}

1012

return true;

1013

}

1014

if(WIFSIGNALED(status)){

1015

fprintf_plus(stderr, "Error: iprouteadddel died by"

1016

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

1017

return false;

1018

}

1019

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

1020

return false;

1021

}

1022

1023

__attribute__((nonnull, warn_unused_result))

1024

static bool add_local_route(const char *address,

1025

AvahiIfIndex if_index){

1026

if(debug){

1027

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

1028

}

1029

return add_delete_local_route(true, address, if_index);

1030

}

1031

1032

__attribute__((nonnull, warn_unused_result))

1033

static bool delete_local_route(const char *address,

1034

AvahiIfIndex if_index){

1035

if(debug){

1036

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

1037

}

1038

return add_delete_local_route(false, address, if_index);

1039

}

1040

1041

596

/* Called when a Mandos server is found */

1042

__attribute__((nonnull, warn_unused_result))

1043

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

597

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

1044

598

AvahiIfIndex if_index,

1045

int af, mandos_context *mc){

599

int af){

1046

600

int ret, tcp_sd = -1;

1047

601

ssize_t sret;

1048

struct sockaddr_storage to;

602

union {

603

struct sockaddr_in in;

604

struct sockaddr_in6 in6;

605

} to;

1049

606

char *buffer = NULL;

1050

607

char *decrypted_buffer = NULL;

1051

608

size_t buffer_length = 0;

1054

611

int retval = -1;

1055

612

gnutls_session_t session;

1056

613

int pf; /* Protocol family */

1057

bool route_added = false;

1058

614

1059

615

errno = 0;

1060

616

1071

627

pf = PF_INET;

1072

628

break;

1073

629

default:

1074

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

630

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

1075

631

errno = EINVAL;

1076

632

return -1;

1077

633

}

1078

634

1079

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

1080

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

1081

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

1082

bool match = false;

1083

{

1084

char *interface = NULL;

1085

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

1086

interface))){

1087

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

1088

match = true;

1089

break;

1090

}

1091

}

1092

}

1093

if(not match){

1094

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

1095

connect to the server */

1096

if(debug){

1097

char interface[IF_NAMESIZE];

1098

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

1099

perror_plus("if_indextoname");

1100

} else {

1101

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

1102

" \"%s\"\n",

1103

if_indextoname((unsigned int)if_index,

1104

interface));

1105

}

1106

}

1107

return -1;

1108

}

1109

}

1110

1111

ret = init_gnutls_session(&session, mc);

635

ret = init_gnutls_session(&session);

1112

636

if(ret != 0){

1113

637

return -1;

1114

638

}

1115

639

1116

640

if(debug){

1117

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

1118

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

641

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

642

"\n", ip, port);

1119

643

}

1120

644

1121

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

645

tcp_sd = socket(pf, SOCK_STREAM, 0);

1122

646

if(tcp_sd < 0){

1123

647

int e = errno;

1124

648

perror_plus("socket");

1131

655

goto mandos_end;

1132

656

}

1133

657

658

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

1134

659

if(af == AF_INET6){

1135

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

1136

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

1137

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

660

to.in6.sin6_family = (sa_family_t)af;

661

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

1138

662

} else { /* IPv4 */

1139

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

1140

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

1141

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

663

to.in.sin_family = (sa_family_t)af;

664

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

1142

665

}

1143

666

if(ret < 0 ){

1144

667

int e = errno;

1148

671

}

1149

672

if(ret == 0){

1150

673

int e = errno;

1151

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

674

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

1152

675

errno = e;

1153

676

goto mandos_end;

1154

677

}

1155

678

if(af == AF_INET6){

1156

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

1157

if(IN6_IS_ADDR_LINKLOCAL

1158

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

679

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

680

-Wconversion and

681

-Wunreachable-code */

682

683

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

684

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

685

-Wunreachable-code*/

1159

686

if(if_index == AVAHI_IF_UNSPEC){

1160

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

1161

" incomplete without a network interface\n");

687

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

688

" without a network interface\n");

1162

689

errno = EINVAL;

1163

690

goto mandos_end;

1164

691

}

1165

692

/* Set the network interface number as scope */

1166

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

693

to.in6.sin6_scope_id = (uint32_t)if_index;

1167

694

}

1168

695

} else {

1169

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

696

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

697

-Wconversion and

698

-Wunreachable-code */

1170

699

}

1171

700

1172

701

if(quit_now){

1180

709

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

1181

710

perror_plus("if_indextoname");

1182

711

} else {

1183

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

1184

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

712

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

713

ip, interface, port);

1185

714

}

1186

715

} else {

1187

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

1188

ip, (uintmax_t)port);

716

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

717

port);

1189

718

}

1190

719

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1191

720

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1192

if(af == AF_INET6){

1193

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

1194

sizeof(struct sockaddr_in6),

1195

addrstr, sizeof(addrstr), NULL, 0,

1196

NI_NUMERICHOST);

1197

} else {

1198

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

1199

sizeof(struct sockaddr_in),

1200

addrstr, sizeof(addrstr), NULL, 0,

1201

NI_NUMERICHOST);

1202

}

1203

if(ret == EAI_SYSTEM){

1204

perror_plus("getnameinfo");

1205

} else if(ret != 0) {

1206

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

1207

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

1208

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

1209

}

1210

}

1211

1212

if(quit_now){

1213

errno = EINTR;

1214

goto mandos_end;

1215

}

1216

1217

while(true){

1218

if(af == AF_INET6){

1219

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

1220

sizeof(struct sockaddr_in6));

1221

} else {

1222

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

1223

sizeof(struct sockaddr_in));

1224

}

1225

if(ret < 0){

1226

if(errno == ENETUNREACH

1227

and if_index != AVAHI_IF_UNSPEC

1228

and connect_to == NULL

1229

and not route_added and

1230

((af == AF_INET6 and not

1231

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1232

&to)->sin6_addr)))

1233

or (af == AF_INET and

1234

/* Not a a IPv4LL address */

1235

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

1236

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

1237

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

1238

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

1239

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

1240

connect to a Mandos server announced by Avahi on a server

1241

host with a global address. Work around this by retrying

1242

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

1243

1244

Avahi bug reference:

1245

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

1246

https://bugs.debian.org/587961

1247

*/

1248

if(debug){

1249

fprintf_plus(stderr, "Mandos server unreachable, trying"

1250

" direct route\n");

1251

}

1252

int e = errno;

1253

route_added = add_local_route(ip, if_index);

1254

if(route_added){

1255

continue;

1256

}

1257

errno = e;

1258

}

1259

if(errno != ECONNREFUSED or debug){

1260

int e = errno;

1261

perror_plus("connect");

1262

errno = e;

1263

}

1264

goto mandos_end;

1265

}

1266

1267

if(quit_now){

1268

errno = EINTR;

1269

goto mandos_end;

1270

}

1271

break;

721

const char *pcret;

722

if(af == AF_INET6){

723

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

724

sizeof(addrstr));

725

} else {

726

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

727

sizeof(addrstr));

728

}

729

if(pcret == NULL){

730

perror_plus("inet_ntop");

731

} else {

732

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

733

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

734

}

735

}

736

}

737

738

if(quit_now){

739

errno = EINTR;

740

goto mandos_end;

741

}

742

743

if(af == AF_INET6){

744

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

745

} else {

746

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

747

}

748

if(ret < 0){

749

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

750

int e = errno;

751

perror_plus("connect");

752

errno = e;

753

}

754

goto mandos_end;

755

}

756

757

if(quit_now){

758

errno = EINTR;

759

goto mandos_end;

1272

760

}

1273

761

1274

762

const char *out = mandos_protocol_version;

1276

764

while(true){

1277

765

size_t out_size = strlen(out);

1278

766

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

1279

out_size - written));

767

out_size - written));

1280

768

if(ret == -1){

1281

769

int e = errno;

1282

770

perror_plus("write");

1302

790

}

1303

791

1304

792

if(debug){

1305

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

793

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

1306

794

}

1307

795

1308

796

if(quit_now){

1310

798

goto mandos_end;

1311

799

}

1312

800

1313

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

1314

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

1315

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

1316

gnutls_transport_set_ptr(session,

1317

(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);

1318

803

1319

804

if(quit_now){

1320

805

errno = EINTR;

1331

816

1332

817

if(ret != GNUTLS_E_SUCCESS){

1333

818

if(debug){

1334

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

819

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

1335

820

gnutls_perror(ret);

1336

821

}

1337

822

errno = EPROTO;

1341

826

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

1342

827

1343

828

if(debug){

1344

fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"

1345

" %s\n", ip);

829

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

830

ip);

1346

831

}

1347

832

1348

833

while(true){

1353

838

}

1354

839

1355

840

buffer_capacity = incbuffer(&buffer, buffer_length,

1356

buffer_capacity);

841

buffer_capacity);

1357

842

if(buffer_capacity == 0){

1358

843

int e = errno;

1359

844

perror_plus("incbuffer");

1386

871

}

1387

872

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

1388

873

if(ret < 0){

1389

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

1390

"***\n");

874

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

1391

875

gnutls_perror(ret);

1392

876

errno = EPROTO;

1393

877

goto mandos_end;

1394

878

}

1395

879

break;

1396

880

default:

1397

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

1398

" encrypted session with Mandos server\n");

881

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

882

" encrypted session with Mandos server\n");

1399

883

gnutls_bye(session, GNUTLS_SHUT_RDWR);

1400

884

errno = EIO;

1401

885

goto mandos_end;

1406

890

}

1407

891

1408

892

if(debug){

1409

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

893

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

1410

894

}

1411

895

1412

896

if(quit_now){

1424

908

1425

909

if(buffer_length > 0){

1426

910

ssize_t decrypted_buffer_size;

1427

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1428

&decrypted_buffer, mc);

911

decrypted_buffer_size = pgp_packet_decrypt(buffer,

912

buffer_length,

913

&decrypted_buffer);

1429

914

if(decrypted_buffer_size >= 0){

1430

915

1431

916

written = 0;

1441

926

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

1442

927

int e = errno;

1443

928

if(debug){

1444

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

1445

strerror(errno));

929

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

930

strerror(errno));

1446

931

}

1447

932

errno = e;

1448

933

goto mandos_end;

1457

942

1458

943

mandos_end:

1459

944

{

1460

if(route_added){

1461

if(not delete_local_route(ip, if_index)){

1462

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

1463

" interface %d", ip, if_index);

1464

}

1465

}

1466

945

int e = errno;

1467

946

free(decrypted_buffer);

1468

947

free(buffer);

1469

948

if(tcp_sd >= 0){

1470

ret = close(tcp_sd);

949

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

1471

950

}

1472

951

if(ret == -1){

1473

952

if(e == 0){

1485

964

return retval;

1486

965

}

1487

966

1488

__attribute__((nonnull))

1489

967

static void resolve_callback(AvahiSServiceResolver *r,

1490

968

AvahiIfIndex interface,

1491

969

AvahiProtocol proto,

1499

977

AVAHI_GCC_UNUSED AvahiStringList *txt,

1500

978

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1501

979

flags,

1502

void *mc){

1503

if(r == NULL){

1504

return;

1505

}

980

AVAHI_GCC_UNUSED void* userdata){

981

assert(r);

1506

982

1507

983

/* Called whenever a service has been resolved successfully or

1508

984

timed out */

1509

985

1510

986

if(quit_now){

1511

avahi_s_service_resolver_free(r);

1512

987

return;

1513

988

}

1514

989

1515

990

switch(event){

1516

991

default:

1517

992

case AVAHI_RESOLVER_FAILURE:

1518

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

1519

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

1520

domain,

1521

avahi_strerror(avahi_server_errno

1522

(((mandos_context*)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)));

1523

996

break;

1524

997

1525

998

case AVAHI_RESOLVER_FOUND:

1527

1000

char ip[AVAHI_ADDRESS_STR_MAX];

1528

1001

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

1529

1002

if(debug){

1530

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

1531

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

1532

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);

1533

1006

}

1534

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

1535

interface,

1536

avahi_proto_to_af(proto),

1537

mc);

1007

int ret = start_mandos_communication(ip, port, interface,

1008

avahi_proto_to_af(proto));

1538

1009

if(ret == 0){

1539

avahi_simple_poll_quit(simple_poll);

1010

avahi_simple_poll_quit(mc.simple_poll);

1540

1011

} else {

1541

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

1542

avahi_proto_to_af(proto),

1543

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

1544

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

1545

" list\n", name);

1546

}

1012

ret = add_server(ip, port, interface,

1013

avahi_proto_to_af(proto));

1547

1014

}

1548

1015

}

1549

1016

}

1559

1026

const char *domain,

1560

1027

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1561

1028

flags,

1562

void *mc){

1563

if(b == NULL){

1564

return;

1565

}

1029

AVAHI_GCC_UNUSED void* userdata){

1030

assert(b);

1566

1031

1567

1032

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

1568

1033

is removed from the LAN */

1575

1040

default:

1576

1041

case AVAHI_BROWSER_FAILURE:

1577

1042

1578

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

1579

avahi_strerror(avahi_server_errno

1580

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

1581

avahi_simple_poll_quit(simple_poll);

1043

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

1044

avahi_strerror(avahi_server_errno(mc.server)));

1045

avahi_simple_poll_quit(mc.simple_poll);

1582

1046

return;

1583

1047

1584

1048

case AVAHI_BROWSER_NEW:

1587

1051

the callback function is called the Avahi server will free the

1588

1052

resolver for us. */

1589

1053

1590

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

1591

interface, protocol, name, type,

1592

domain, protocol, 0,

1593

resolve_callback, mc) == NULL)

1594

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

1595

" %s\n", name,

1596

avahi_strerror(avahi_server_errno

1597

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

1054

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

1055

name, type, domain, protocol, 0,

1056

resolve_callback, NULL) == NULL)

1057

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

1058

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

1598

1059

break;

1599

1060

1600

1061

case AVAHI_BROWSER_REMOVE:

1603

1064

case AVAHI_BROWSER_ALL_FOR_NOW:

1604

1065

case AVAHI_BROWSER_CACHE_EXHAUSTED:

1605

1066

if(debug){

1606

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

1607

" searching...\n");

1067

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

1608

1068

}

1609

1069

break;

1610

1070

}

1619

1079

signal_received = sig;

1620

1080

int old_errno = errno;

1621

1081

/* set main loop to exit */

1622

if(simple_poll != NULL){

1623

avahi_simple_poll_quit(simple_poll);

1082

if(mc.simple_poll != NULL){

1083

avahi_simple_poll_quit(mc.simple_poll);

1624

1084

}

1625

1085

errno = old_errno;

1626

1086

}

1627

1087

1628

__attribute__((nonnull, warn_unused_result))

1629

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

1630

int ret;

1631

error_t ret_errno;

1632

1633

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

1634

if(s < 0){

1635

ret_errno = errno;

1636

perror_plus("socket");

1637

errno = ret_errno;

1638

return false;

1639

}

1640

strcpy(ifr->ifr_name, ifname);

1641

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1642

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){

1643

1144

if(debug){

1644

ret_errno = errno;

1645

perror_plus("ioctl SIOCGIFFLAGS");

1646

errno = ret_errno;

1145

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

1146

flagstring, if_entry->d_name);

1647

1147

}

1648

return false;

1148

free(flagstring);

1149

return 0;

1649

1150

}

1650

return true;

1651

}

1652

1653

__attribute__((nonnull, warn_unused_result))

1654

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

1655

1151

free(flagstring);

1152

ifreq_flags flags = (ifreq_flags)tmpmax;

1656

1153

/* Reject the loopback device */

1657

if(ifr->ifr_flags & IFF_LOOPBACK){

1154

if(flags & IFF_LOOPBACK){

1658

1155

if(debug){

1659

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

1660

ifname);

1156

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

1157

if_entry->d_name);

1661

1158

}

1662

return false;

1159

return 0;

1663

1160

}

1664

1161

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

1665

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

1162

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

1666

1163

if(debug){

1667

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

1668

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

1164

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

1165

if_entry->d_name);

1669

1166

}

1670

return true;

1167

return 1;

1671

1168

}

1672

1169

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

1673

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

1170

if(not (flags & IFF_BROADCAST)){

1674

1171

if(debug){

1675

fprintf_plus(stderr, "Rejecting non-broadcast interface"

1676

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

1172

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

1173

if_entry->d_name);

1677

1174

}

1678

return false;

1175

return 0;

1679

1176

}

1680

1177

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

1681

if(ifr->ifr_flags & IFF_NOARP){

1178

if(flags & IFF_NOARP){

1682

1179

if(debug){

1683

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

1684

ifname);

1180

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

1181

if_entry->d_name);

1685

1182

}

1686

return false;

1183

return 0;

1687

1184

}

1688

1689

1185

/* Accept this device */

1690

1186

if(debug){

1691

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

1692

}

1693

return true;

1694

}

1695

1696

/*

1697

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

1698

* corresponds to an acceptable network device.

1699

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

1700

*/

1701

__attribute__((nonnull, warn_unused_result))

1702

int good_interface(const struct dirent *if_entry){

1703

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

1704

return 0;

1705

}

1706

1707

struct ifreq ifr;

1708

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

1709

if(debug){

1710

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

1711

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

1712

}

1713

return 0;

1714

}

1715

1716

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

1717

return 0;

1187

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

1188

if_entry->d_name);

1718

1189

}

1719

1190

return 1;

1720

1191

}

1721

1192

1722

/*

1723

* This function determines if a network interface is up.

1724

*/

1725

__attribute__((nonnull, warn_unused_result))

1726

bool interface_is_up(const char *interface){

1727

struct ifreq ifr;

1728

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

1729

if(debug){

1730

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

1731

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

1732

}

1733

return false;

1734

}

1735

1736

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

1737

}

1738

1739

/*

1740

* This function determines if a network interface is running

1741

*/

1742

__attribute__((nonnull, warn_unused_result))

1743

bool interface_is_running(const char *interface){

1744

struct ifreq ifr;

1745

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

1746

if(debug){

1747

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

1748

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

1749

}

1750

return false;

1751

}

1752

1753

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

1754

}

1755

1756

__attribute__((nonnull, pure, warn_unused_result))

1757

1193

int notdotentries(const struct dirent *direntry){

1758

1194

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

1759

1195

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

1765

1201

return 1;

1766

1202

}

1767

1203

1768

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

1769

__attribute__((nonnull, warn_unused_result))

1770

int runnable_hook(const struct dirent *direntry){

1771

int ret;

1772

size_t sret;

1773

struct stat st;

1774

1775

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

1776

/* Empty name? */

1777

return 0;

1778

}

1779

1780

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

1781

"abcdefghijklmnopqrstuvwxyz"

1782

"0123456789"

1783

"_.-");

1784

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

1785

/* Contains non-allowed characters */

1786

if(debug){

1787

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

1788

direntry->d_name);

1789

}

1790

return 0;

1791

}

1792

1793

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

1794

if(ret == -1){

1795

if(debug){

1796

perror_plus("Could not stat hook");

1797

}

1798

return 0;

1799

}

1800

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

1801

/* Not a regular file */

1802

if(debug){

1803

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

1804

direntry->d_name);

1805

}

1806

return 0;

1807

}

1808

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

1809

/* Not executable */

1810

if(debug){

1811

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

1812

direntry->d_name);

1813

}

1814

return 0;

1815

}

1816

if(debug){

1817

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

1818

direntry->d_name);

1819

}

1820

return 1;

1821

}

1822

1823

__attribute__((nonnull, warn_unused_result))

1824

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1825

mandos_context *mc){

1204

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1826

1205

int ret;

1827

1206

struct timespec now;

1828

1207

struct timespec waited_time;

1829

1208

intmax_t block_time;

1830

1209

1831

1210

while(true){

1832

if(mc->current_server == NULL){

1833

if(debug){

1834

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

1835

" No timeout!\n");

1211

if(mc.current_server == NULL){

1212

if (debug){

1213

fprintf(stderr,

1214

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

1836

1215

}

1837

1216

ret = avahi_simple_poll_iterate(s, -1);

1838

1217

} else {

1839

if(debug){

1840

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

1841

" it, or wait\n");

1218

if (debug){

1219

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

1220

" or wait\n");

1842

1221

}

1843

1222

/* the current time */

1844

1223

ret = clock_gettime(CLOCK_MONOTONIC, &now);

1849

1228

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

1850

1229

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

1851

1230

waited_time.tv_sec = (now.tv_sec

1852

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

1231

- mc.current_server->last_seen.tv_sec);

1853

1232

waited_time.tv_nsec = (now.tv_nsec

1854

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

1233

- mc.current_server->last_seen.tv_nsec);

1855

1234

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

1856

1235

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

1857

1236

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

1859

1238

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

1860

1239

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

1861

1240

1862

if(debug){

1863

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

1864

block_time);

1241

if (debug){

1242

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

1865

1243

}

1866

1244

1867

1245

if(block_time <= 0){

1868

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

1869

mc->current_server->port,

1870

mc->current_server->if_index,

1871

mc->current_server->af, mc);

1246

ret = start_mandos_communication(mc.current_server->ip,

1247

mc.current_server->port,

1248

mc.current_server->if_index,

1249

mc.current_server->af);

1872

1250

if(ret == 0){

1873

avahi_simple_poll_quit(s);

1251

avahi_simple_poll_quit(mc.simple_poll);

1874

1252

return 0;

1875

1253

}

1876

1254

ret = clock_gettime(CLOCK_MONOTONIC,

1877

&mc->current_server->last_seen);

1255

&mc.current_server->last_seen);

1878

1256

if(ret == -1){

1879

1257

perror_plus("clock_gettime");

1880

1258

return -1;

1881

1259

}

1882

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

1260

mc.current_server = mc.current_server->next;

1883

1261

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

1884

1262

servers, but don't block */

1885

1263

}

1887

1265

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

1888

1266

}

1889

1267

if(ret != 0){

1890

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

1268

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

1891

1269

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

1892

1270

}

1893

1271

}

1894

1272

}

1895

1273

}

1896

1274

1897

__attribute__((nonnull))

1898

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

1899

const float delay){

1900

struct dirent **direntries = NULL;

1901

if(hookdir_fd == -1){

1902

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1903

| O_CLOEXEC);

1904

if(hookdir_fd == -1){

1905

if(errno == ENOENT){

1906

if(debug){

1907

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

1908

" found\n", hookdir);

1909

}

1910

} else {

1911

perror_plus("open");

1912

}

1913

return;

1914

}

1915

}

1916

#ifdef __GLIBC__

1917

#if __GLIBC_PREREQ(2, 15)

1918

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

1919

runnable_hook, alphasort);

1920

#else /* not __GLIBC_PREREQ(2, 15) */

1921

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

1922

alphasort);

1923

#endif /* not __GLIBC_PREREQ(2, 15) */

1924

#else /* not __GLIBC__ */

1925

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

1926

alphasort);

1927

#endif /* not __GLIBC__ */

1928

if(numhooks == -1){

1929

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){

1991

perror_plus("asprintf");

1992

_exit(EX_OSERR);

1993

}

1994

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

1995

if(ret == -1){

1996

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

error_t bring_up_interface(const char *const interface,

2089

const float delay){

2090

error_t 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

error_t ret_errno = 0, ioctl_errno = 0;

2107

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

2108

ret_errno = errno;

2109

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

2110

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

2111

errno = old_errno;

2112

return ret_errno;

2113

}

2114

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

2115

2116

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

2117

if(sd == -1){

2118

ret_errno = errno;

2119

perror_plus("socket");

2120

errno = old_errno;

2121

return ret_errno;

2122

}

2123

2124

if(quit_now){

2125

ret = close(sd);

2126

if(ret == -1){

2127

perror_plus("close");

2128

}

2129

errno = old_errno;

2130

return EINTR;

2131

}

2132

2133

if(debug){

2134

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

2135

interface);

2136

}

2137

2138

/* Raise privileges */

2139

ret_errno = raise_privileges();

2140

if(ret_errno != 0){

2141

errno = ret_errno;

2142

perror_plus("Failed to raise privileges");

2143

}

2144

2145

#ifdef __linux__

2146

int ret_linux;

2147

bool restore_loglevel = false;

2148

if(ret_errno == 0){

2149

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2150

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

2151

ret_linux = klogctl(8, NULL, 5);

2152

if(ret_linux == -1){

2153

perror_plus("klogctl");

2154

} else {

2155

restore_loglevel = true;

2156

}

2157

}

2158

#endif /* __linux__ */

2159

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

2160

ioctl_errno = errno;

2161

#ifdef __linux__

2162

if(restore_loglevel){

2163

ret_linux = klogctl(7, NULL, 0);

2164

if(ret_linux == -1){

2165

perror_plus("klogctl");

2166

}

2167

}

2168

#endif /* __linux__ */

2169

2170

/* If raise_privileges() succeeded above */

2171

if(ret_errno == 0){

2172

/* Lower privileges */

2173

ret_errno = lower_privileges();

2174

if(ret_errno != 0){

2175

errno = ret_errno;

2176

perror_plus("Failed to lower privileges");

2177

}

2178

}

2179

2180

/* Close the socket */

2181

ret = close(sd);

2182

if(ret == -1){

2183

perror_plus("close");

2184

}

2185

2186

if(ret_setflags == -1){

2187

errno = ioctl_errno;

2188

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2189

errno = old_errno;

2190

return ioctl_errno;

2191

}

2192

} else if(debug){

2193

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

2194

interface);

2195

}

2196

2197

/* Sleep checking until interface is running.

2198

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

2199

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

2200

if(interface_is_running(interface)){

2201

break;

2202

}

2203

struct timespec sleeptime = { .tv_nsec = 250000000 };

2204

ret = nanosleep(&sleeptime, NULL);

2205

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

2206

perror_plus("nanosleep");

2207

}

2208

}

2209

2210

errno = old_errno;

2211

return 0;

2212

}

2213

2214

__attribute__((nonnull, warn_unused_result))

2215

error_t take_down_interface(const char *const interface){

2216

error_t old_errno = errno;

2217

struct ifreq network;

2218

unsigned int if_index = if_nametoindex(interface);

2219

if(if_index == 0){

2220

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

2221

errno = old_errno;

2222

return ENXIO;

2223

}

2224

if(interface_is_up(interface)){

2225

error_t ret_errno = 0, ioctl_errno = 0;

2226

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

2227

ret_errno = errno;

2228

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

2229

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

2230

errno = old_errno;

2231

return ret_errno;

2232

}

2233

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

2234

2235

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

2236

if(sd == -1){

2237

ret_errno = errno;

2238

perror_plus("socket");

2239

errno = old_errno;

2240

return ret_errno;

2241

}

2242

2243

if(debug){

2244

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

2245

interface);

2246

}

2247

2248

/* Raise privileges */

2249

ret_errno = raise_privileges();

2250

if(ret_errno != 0){

2251

errno = ret_errno;

2252

perror_plus("Failed to raise privileges");

2253

}

2254

2255

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

2256

ioctl_errno = errno;

2257

2258

/* If raise_privileges() succeeded above */

2259

if(ret_errno == 0){

2260

/* Lower privileges */

2261

ret_errno = lower_privileges();

2262

if(ret_errno != 0){

2263

errno = ret_errno;

2264

perror_plus("Failed to lower privileges");

2265

}

2266

}

2267

2268

/* Close the socket */

2269

int ret = close(sd);

2270

if(ret == -1){

2271

perror_plus("close");

2272

}

2273

2274

if(ret_setflags == -1){

2275

errno = ioctl_errno;

2276

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2277

errno = old_errno;

2278

return ioctl_errno;

2279

}

2280

} else if(debug){

2281

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

2282

interface);

2283

}

2284

2285

errno = old_errno;

2286

return 0;

2287

}

2288

2289

1275

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

2290

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

2291

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

2292

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

2293

.current_server = NULL, .interfaces = NULL,

2294

.interfaces_size = 0 };

2295

1276

AvahiSServiceBrowser *sb = NULL;

2296

error_t ret_errno;

1277

int error;

2297

1278

int ret;

2298

1279

intmax_t tmpmax;

2299

1280

char *tmp;

2300

1281

int exitcode = EXIT_SUCCESS;

2301

char *interfaces_to_take_down = NULL;

2302

size_t interfaces_to_take_down_size = 0;

2303

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

2304

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

2305

char *tempdir = NULL;

1282

const char *interface = "";

1283

struct ifreq network;

1284

int sd = -1;

1285

bool take_down_interface = false;

1286

uid_t uid;

1287

gid_t gid;

1288

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

1289

bool tempdir_created = false;

2306

1290

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2307

1291

const char *seckey = PATHDIR "/" SECKEY;

2308

1292

const char *pubkey = PATHDIR "/" PUBKEY;

2309

const char *dh_params_file = NULL;

2310

char *interfaces_hooks = NULL;

2311

1293

2312

1294

bool gnutls_initialized = false;

2313

1295

bool gpgme_initialized = false;

2365

1347

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

2366

1348

" Diffie-Hellman key exchange",

2367

1349

.group = 2 },

2368

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

2369

.arg = "FILE",

2370

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

2371

" for the Diffie-Hellman key exchange",

2372

.group = 2 },

2373

1350

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

2374

1351

.arg = "STRING",

2375

1352

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

2380

1357

.group = 2 },

2381

1358

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

2382

1359

.arg = "SECONDS",

2383

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

2384

.group = 2 },

2385

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

2386

.arg = "DIR",

2387

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

1360

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

2388

1361

.group = 2 },

2389

1362

/*

2390

1363

* These reproduce what we would get without ARGP_NO_HELP

2409

1382

connect_to = arg;

2410

1383

break;

2411

1384

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

2412

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

2413

arg, (int)',');

2414

if(ret_errno != 0){

2415

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

2416

}

1385

interface = arg;

2417

1386

break;

2418

1387

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

2419

1388

seckey = arg;

2430

1399

}

2431

1400

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

2432

1401

break;

2433

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

2434

dh_params_file = arg;

2435

break;

2436

1402

case 130: /* --priority */

2437

1403

mc.priority = arg;

2438

1404

break;

2451

1417

argp_error(state, "Bad retry interval");

2452

1418

}

2453

1419

break;

2454

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

2455

hookdir = arg;

2456

break;

2457

1420

/*

2458

1421

* These reproduce what we would get without ARGP_NO_HELP

2459

1422

*/

2465

1428

argp_state_help(state, state->out_stream,

2466

1429

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

2467

1430

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

2468

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

1431

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

2469

1432

exit(argp_err_exit_status);

2470

1433

break;

2471

1434

default:

2494

1457

goto end;

2495

1458

}

2496

1459

}

2497

1460

2498

1461

{

2499

1462

/* Work around Debian bug #633582:

2500

1463

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

2501

2502

/* Re-raise privileges */

2503

ret_errno = raise_privileges();

2504

if(ret_errno != 0){

2505

errno = ret_errno;

2506

perror_plus("Failed to raise privileges");

2507

} else {

2508

struct stat st;

2509

2510

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

2511

int seckey_fd = open(seckey, O_RDONLY);

2512

if(seckey_fd == -1){

2513

perror_plus("open");

2514

} else {

2515

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

2516

if(ret == -1){

2517

perror_plus("fstat");

2518

} else {

2519

if(S_ISREG(st.st_mode)

2520

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

2521

ret = fchown(seckey_fd, uid, gid);

2522

if(ret == -1){

2523

perror_plus("fchown");

2524

}

2525

}

2526

}

2527

close(seckey_fd);

2528

}

2529

}

2530

2531

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

2532

int pubkey_fd = open(pubkey, O_RDONLY);

2533

if(pubkey_fd == -1){

2534

perror_plus("open");

2535

} else {

2536

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

2537

if(ret == -1){

2538

perror_plus("fstat");

2539

} else {

2540

if(S_ISREG(st.st_mode)

2541

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

2542

ret = fchown(pubkey_fd, uid, gid);

2543

if(ret == -1){

2544

perror_plus("fchown");

2545

}

2546

}

2547

}

2548

close(pubkey_fd);

2549

}

2550

}

2551

2552

if(dh_params_file != NULL

2553

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

2554

int dhparams_fd = open(dh_params_file, O_RDONLY);

2555

if(dhparams_fd == -1){

2556

perror_plus("open");

2557

} else {

2558

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

2559

if(ret == -1){

2560

perror_plus("fstat");

2561

} else {

2562

if(S_ISREG(st.st_mode)

2563

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

2564

ret = fchown(dhparams_fd, uid, gid);

2565

if(ret == -1){

2566

perror_plus("fchown");

2567

}

2568

}

2569

}

2570

close(dhparams_fd);

2571

}

2572

}

2573

2574

/* Lower privileges */

2575

ret_errno = lower_privileges();

2576

if(ret_errno != 0){

2577

errno = ret_errno;

2578

perror_plus("Failed to lower privileges");

2579

}

2580

}

2581

}

2582

2583

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

2584

{

2585

char *interface = NULL;

2586

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

2587

interface))){

2588

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

2589

and if_nametoindex(interface) == 0){

2590

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

2591

fprintf_plus(stderr, "Not using nonexisting interface"

2592

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

2593

}

2594

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

2595

interface = NULL;

2596

}

2597

}

2598

}

2599

2600

/* Run network hooks */

2601

{

2602

if(mc.interfaces != NULL){

2603

interfaces_hooks = malloc(mc.interfaces_size);

2604

if(interfaces_hooks == NULL){

2605

perror_plus("malloc");

2606

goto end;

2607

}

2608

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

2609

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

2610

}

2611

run_network_hooks("start", interfaces_hooks != NULL ?

2612

interfaces_hooks : "", delay);

1464

struct stat st;

1465

1466

/* Re-raise priviliges */

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

}

2613

1519

}

2614

1520

2615

1521

if(not debug){

2616

1522

avahi_set_log_function(empty_log);

2617

1523

}

1524

1525

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

1526

struct dirent **direntries;

1527

ret = scandir(sys_class_net, &direntries, good_interface,

1528

alphasort);

1529

if(ret >= 1){

1530

/* Pick the first good interface */

1531

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

1532

if(debug){

1533

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

1534

}

1535

if(interface == NULL){

1536

perror_plus("malloc");

1537

free(direntries);

1538

exitcode = EXIT_FAILURE;

1539

goto end;

1540

}

1541

free(direntries);

1542

} else {

1543

free(direntries);

1544

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

1545

exitcode = EXIT_FAILURE;

1546

goto end;

1547

}

1548

}

2618

1549

2619

1550

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

2620

1551

from the signal handler */

2621

1552

/* Initialize the pseudo-RNG for Avahi */

2622

1553

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

2623

simple_poll = avahi_simple_poll_new();

2624

if(simple_poll == NULL){

2625

fprintf_plus(stderr,

2626

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

1554

mc.simple_poll = avahi_simple_poll_new();

1555

if(mc.simple_poll == NULL){

1556

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

2627

1557

exitcode = EX_UNAVAILABLE;

2628

1558

goto end;

2629

1559

}

2691

1621

}

2692

1622

}

2693

1623

2694

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

2695

if(mc.interfaces == NULL){

2696

struct dirent **direntries = NULL;

2697

/* Look for any good interfaces */

2698

ret = scandir(sys_class_net, &direntries, good_interface,

2699

alphasort);

2700

if(ret >= 1){

2701

/* Add all found interfaces to interfaces list */

2702

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

2703

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

2704

direntries[i]->d_name);

2705

if(ret_errno != 0){

2706

errno = ret_errno;

2707

perror_plus("argz_add");

2708

free(direntries[i]);

2709

continue;

2710

}

2711

if(debug){

2712

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

2713

direntries[i]->d_name);

2714

}

2715

free(direntries[i]);

2716

}

2717

free(direntries);

1624

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

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

}

2718

1760

} else {

2719

if(ret == 0){

2720

free(direntries);

2721

}

2722

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

2723

exitcode = EXIT_FAILURE;

2724

goto end;

2725

}

2726

}

2727

2728

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

2729

{

2730

char *interface = NULL;

2731

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

2732

interface))){

2733

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

2734

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

2735

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

2736

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

2737

interface);

2738

interface = NULL;

2739

while((interface = argz_next(mc.interfaces,

2740

mc.interfaces_size, interface))){

2741

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

2742

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

2743

interface);

2744

interface = NULL;

2745

}

2746

}

2747

break;

2748

}

2749

bool interface_was_up = interface_is_up(interface);

2750

errno = bring_up_interface(interface, delay);

2751

if(not interface_was_up){

2752

if(errno != 0){

2753

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

2754

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

2755

} else {

2756

errno = argz_add(&interfaces_to_take_down,

2757

&interfaces_to_take_down_size,

2758

interface);

2759

if(errno != 0){

2760

perror_plus("argz_add");

2761

}

2762

}

2763

}

2764

}

2765

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

2766

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

2767

}

2768

}

2769

2770

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

2771

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

2772

if(debug){

2773

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

2774

mc.interfaces);

2775

}

2776

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

1761

/* Lower privileges permanently */

1762

ret = setuid(uid);

1763

if(ret == -1){

1764

perror_plus("setuid");

1765

}

1766

}

2777

1767

}

2778

1768

2779

1769

if(quit_now){

2780

1770

goto end;

2781

1771

}

2782

1772

2783

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

1773

ret = init_gnutls_global(pubkey, seckey);

2784

1774

if(ret == -1){

2785

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

1775

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

2786

1776

exitcode = EX_UNAVAILABLE;

2787

1777

goto end;

2788

1778

} else {

2793

1783

goto end;

2794

1784

}

2795

1785

2796

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

2797

tempdir = mkdtemp(run_tempdir);

2798

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

2799

if(debug){

2800

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

2801

run_tempdir, old_tempdir);

2802

}

2803

tempdir = mkdtemp(old_tempdir);

2804

}

2805

if(tempdir == NULL){

1786

if(mkdtemp(tempdir) == NULL){

2806

1787

perror_plus("mkdtemp");

2807

1788

goto end;

2808

1789

}

1790

tempdir_created = true;

2809

1791

2810

1792

if(quit_now){

2811

1793

goto end;

2812

1794

}

2813

1795

2814

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

2815

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

1796

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

1797

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

2816

1798

exitcode = EX_UNAVAILABLE;

2817

1799

goto end;

2818

1800

} else {

2827

1809

/* Connect directly, do not use Zeroconf */

2828

1810

/* (Mainly meant for debugging) */

2829

1811

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

2830

2831

1812

if(address == NULL){

2832

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

1813

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

2833

1814

exitcode = EX_USAGE;

2834

1815

goto end;

2835

1816

}

2838

1819

goto end;

2839

1820

}

2840

1821

2841

in_port_t port;

1822

uint16_t port;

2842

1823

errno = 0;

2843

1824

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

2844

1825

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

2845

or tmpmax != (in_port_t)tmpmax){

2846

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

1826

or tmpmax != (uint16_t)tmpmax){

1827

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

2847

1828

exitcode = EX_USAGE;

2848

1829

goto end;

2849

1830

}

2850

1831

2851

1832

if(quit_now){

2852

1833

goto end;

2853

1834

}

2854

1835

2855

port = (in_port_t)tmpmax;

1836

port = (uint16_t)tmpmax;

2856

1837

*address = '\0';

2857

1838

/* Colon in address indicates IPv6 */

2858

1839

int af;

2874

1855

}

2875

1856

2876

1857

while(not quit_now){

2877

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

2878

&mc);

1858

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

2879

1859

if(quit_now or ret == 0){

2880

1860

break;

2881

1861

}

2882

1862

if(debug){

2883

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

2884

(int)retry_interval);

1863

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

1864

(int)retry_interval);

2885

1865

}

2886

sleep((unsigned int)retry_interval);

1866

sleep((int)retry_interval);

2887

1867

}

2888

1868

2889

if(not quit_now){

1869

if (not quit_now){

2890

1870

exitcode = EXIT_SUCCESS;

2891

1871

}

2892

1872

2893

1873

goto end;

2894

1874

}

2895

1875

2907

1887

config.publish_domain = 0;

2908

1888

2909

1889

/* Allocate a new server */

2910

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2911

&config, NULL, NULL, &ret_errno);

1890

mc.server = avahi_server_new(avahi_simple_poll_get

1891

(mc.simple_poll), &config, NULL,

1892

NULL, &error);

2912

1893

2913

1894

/* Free the Avahi configuration data */

2914

1895

avahi_server_config_free(&config);

2916

1897

2917

1898

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

2918

1899

if(mc.server == NULL){

2919

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

2920

avahi_strerror(ret_errno));

1900

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

1901

avahi_strerror(error));

2921

1902

exitcode = EX_UNAVAILABLE;

2922

1903

goto end;

2923

1904

}

2929

1910

/* Create the Avahi service browser */

2930

1911

sb = avahi_s_service_browser_new(mc.server, if_index,

2931

1912

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2932

NULL, 0, browse_callback,

2933

(void *)&mc);

1913

NULL, 0, browse_callback, NULL);

2934

1914

if(sb == NULL){

2935

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

2936

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)));

2937

1917

exitcode = EX_UNAVAILABLE;

2938

1918

goto end;

2939

1919

}

2945

1925

/* Run the main loop */

2946

1926

2947

1927

if(debug){

2948

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

1928

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

2949

1929

}

2950

2951

ret = avahi_loop_with_timeout(simple_poll,

2952

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

1930

1931

ret = avahi_loop_with_timeout(mc.simple_poll,

1932

(int)(retry_interval * 1000));

2953

1933

if(debug){

2954

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

2955

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

1934

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

1935

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

2956

1936

}

2957

1937

2958

1938

end:

2959

1939

2960

1940

if(debug){

2961

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

1941

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

2962

1942

}

2963

1943

2964

1944

/* Cleanup things */

2965

free(mc.interfaces);

2966

2967

1945

if(sb != NULL)

2968

1946

avahi_s_service_browser_free(sb);

2969

1947

2970

1948

if(mc.server != NULL)

2971

1949

avahi_server_free(mc.server);

2972

1950

2973

if(simple_poll != NULL)

2974

avahi_simple_poll_free(simple_poll);

1951

if(mc.simple_poll != NULL)

1952

avahi_simple_poll_free(mc.simple_poll);

2975

1953

2976

1954

if(gnutls_initialized){

2977

1955

gnutls_certificate_free_credentials(mc.cred);

2982

1960

if(gpgme_initialized){

2983

1961

gpgme_release(mc.ctx);

2984

1962

}

2985

1963

2986

1964

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

2987

1965

has seen */

2988

1966

if(mc.current_server != NULL){

2989

1967

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

2990

1968

while(mc.current_server != NULL){

2991

1969

server *next = mc.current_server->next;

2992

#ifdef __GNUC__

2993

#pragma GCC diagnostic push

2994

#pragma GCC diagnostic ignored "-Wcast-qual"

2995

#endif

2996

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

2997

#ifdef __GNUC__

2998

#pragma GCC diagnostic pop

2999

#endif

3000

1970

free(mc.current_server);

3001

1971

mc.current_server = next;

3002

1972

}

3003

1973

}

3004

1974

3005

/* Re-raise privileges */

3006

{

3007

ret_errno = raise_privileges();

3008

if(ret_errno != 0){

3009

errno = ret_errno;

3010

perror_plus("Failed to raise privileges");

3011

} else {

3012

3013

/* Run network hooks */

3014

run_network_hooks("stop", interfaces_hooks != NULL ?

3015

interfaces_hooks : "", delay);

3016

3017

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

3018

{

3019

char *interface = NULL;

3020

while((interface=argz_next(interfaces_to_take_down,

3021

interfaces_to_take_down_size,

3022

interface))){

3023

ret_errno = take_down_interface(interface);

3024

if(ret_errno != 0){

3025

errno = ret_errno;

3026

perror_plus("Failed to take down interface");

3027

}

3028

}

3029

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

3030

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

3031

" down\n");

3032

}

3033

}

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");

3034

1982

}

3035

3036

ret_errno = lower_privileges_permanently();

3037

if(ret_errno != 0){

3038

errno = ret_errno;

3039

perror_plus("Failed to lower privileges permanently");

1983

if(geteuid() == 0){

1984

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

1985

if(ret == -1){

1986

perror_plus("ioctl SIOCGIFFLAGS");

1987

} else if(network.ifr_flags & IFF_UP) {

1988

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

1989

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

1990

if(ret == -1){

1991

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1992

}

1993

}

1994

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

1995

if(ret == -1){

1996

perror_plus("close");

1997

}

1998

/* Lower privileges permanently */

1999

errno = 0;

2000

ret = setuid(uid);

2001

if(ret == -1){

2002

perror_plus("setuid");

2003

}

3040

2004

}

3041

2005

}

3042

2006

3043

free(interfaces_to_take_down);

3044

free(interfaces_hooks);

3045

3046

2007

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

3047

if(tempdir != NULL){

2008

if(tempdir_created){

3048

2009

struct dirent **direntries = NULL;

3049

int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY

3050

| O_NOFOLLOW

3051

| O_DIRECTORY

3052

| O_PATH));

3053

if(tempdir_fd == -1){

3054

perror_plus("open");

3055

} else {

3056

#ifdef __GLIBC__

3057

#if __GLIBC_PREREQ(2, 15)

3058

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

3059

notdotentries, alphasort);

3060

#else /* not __GLIBC_PREREQ(2, 15) */

3061

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

3062

alphasort);

3063

#endif /* not __GLIBC_PREREQ(2, 15) */

3064

#else /* not __GLIBC__ */

3065

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

3066

alphasort);

3067

#endif /* not __GLIBC__ */

3068

if(numentries >= 0){

3069

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

3070

ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);

3071

if(ret == -1){

3072

fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"

3073

" \"%s\", 0): %s\n", tempdir,

3074

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

3075

}

3076

free(direntries[i]);

3077

}

3078

3079

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

3080

free(direntries);

3081

if(numentries == -1){

3082

perror_plus("scandir");

3083

}

3084

ret = rmdir(tempdir);

3085

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

3086

perror_plus("rmdir");

3087

}

2010

struct dirent *direntry = NULL;

2011

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

2012

alphasort);

2013

if (numentries > 0){

2014

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

2015

direntry = direntries[i];

2016

char *fullname = NULL;

2017

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

2018

direntry->d_name);

2019

if(ret < 0){

2020

perror_plus("asprintf");

2021

continue;

2022

}

2023

ret = remove(fullname);

2024

if(ret == -1){

2025

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

2026

strerror(errno));

2027

}

2028

free(fullname);

3088

2029

}

3089

close(tempdir_fd);

2030

}

2031

2032

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

2033

free(direntries);

2034

if (numentries == -1){

2035

perror_plus("scandir");

2036

}

2037

ret = rmdir(tempdir);

2038

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

2039

perror_plus("rmdir");

3090

2040

}

3091

2041

}

3092

2042