/mandos/trunk : revision 738.1.5

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

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*

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* Everything else is

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*

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

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

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* along with this program. If not, see

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

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*

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* Contact the authors at <mandos@fukt.bsnet.se>.

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

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*/

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

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#ifndef _LARGEFILE_SOURCE

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#define _LARGEFILE_SOURCE

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#endif

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#endif /* not _LARGEFILE_SOURCE */

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#ifndef _FILE_OFFSET_BITS

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#define _FILE_OFFSET_BITS 64

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#endif

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#endif /* not _FILE_OFFSET_BITS */

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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(), remove() */

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

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stdout, ferror() */

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

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

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

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strtof(), abort() */

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sockaddr_in6, PF_INET6,

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SOCK_STREAM, uid_t, gid_t, open(),

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opendir(), DIR */

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

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

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

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inet_pton(), connect() */

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

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

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

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program_invocation_short_name */

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

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

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SIOCSIFFLAGS, if_indextoname(),

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if_nametoindex(), IF_NAMESIZE */

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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() */

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

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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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#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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119

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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125

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

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133

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

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134

#define SECKEY "seckey.txt"

124

135

#define PUBKEY "pubkey.txt"

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

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137

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138

bool debug = false;

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139

static const char mandos_protocol_version[] = "1";

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const char *argp_program_version = "mandos-client " VERSION;

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

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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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149

/* 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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AvahiIfIndex if_index;

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int af;

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struct timespec last_seen;

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struct server *next;

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struct server *prev;

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} server;

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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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162

AvahiServer *server;

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gnutls_certificate_credentials_t cred;

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164

unsigned int dh_bits;

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165

gnutls_dh_params_t dh_params;

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const char *priority;

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167

gpgme_ctx_t ctx;

168

server *current_server;

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char *interfaces;

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size_t interfaces_size;

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171

} mandos_context;

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172

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

145

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

146

.dh_bits = 1024, .priority = "SECURE256"

147

":!CTYPE-X.509:+CTYPE-OPENPGP" };

173

/* global so signal handler can reach it*/

174

AvahiSimplePoll *simple_poll;

148

175

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176

sig_atomic_t quit_now = 0;

150

177

int signal_received = 0;

151

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179

/* Function to use when printing errors */

180

void perror_plus(const char *print_text){

181

int e = errno;

182

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

183

program_invocation_short_name);

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errno = e;

185

perror(print_text);

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}

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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

152

198

/*

153

199

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

154

200

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

155

201

* "buffer_length" is how much is already used.

156

202

*/

203

__attribute__((nonnull, warn_unused_result))

157

204

size_t incbuffer(char **buffer, size_t buffer_length,

158

size_t buffer_capacity){

205

size_t buffer_capacity){

159

206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

160

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

161

if(buffer == NULL){

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;

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*buffer = NULL;

162

213

return 0;

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214

}

215

*buffer = new_buf;

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buffer_capacity += BUFFER_SIZE;

165

217

}

166

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return buffer_capacity;

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219

}

168

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

222

__attribute__((nonnull, warn_unused_result))

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

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int af, server **current_server){

225

int ret;

226

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

227

if(new_server == NULL){

228

perror_plus("malloc");

229

return false;

230

}

231

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

232

.port = port,

233

.if_index = if_index,

234

.af = af };

235

if(new_server->ip == NULL){

236

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;

253

}

254

/* Special case of first server */

255

if(*current_server == NULL){

256

new_server->next = new_server;

257

new_server->prev = new_server;

258

*current_server = new_server;

259

} else {

260

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

261

new_server->next = *current_server;

262

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

263

new_server->prev->next = new_server;

264

(*current_server)->prev = new_server;

265

}

266

return true;

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}

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/*

170

270

* Initialize GPGME.

171

271

*/

172

static bool init_gpgme(const char *seckey,

173

const char *pubkey, const char *tempdir){

272

__attribute__((nonnull, warn_unused_result))

273

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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277

gpgme_error_t rc;

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gpgme_engine_info_t engine_info;

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177

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/*

179

281

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

180

282

*/

181

bool import_key(const char *filename){

283

bool import_key(const char * const filename){

182

284

int ret;

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285

int fd;

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286

gpgme_data_t pgp_data;

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fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));

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289

if(fd == -1){

188

perror("open");

290

perror_plus("open");

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291

return false;

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292

}

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293

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rc = gpgme_data_new_from_fd(&pgp_data, fd);

193

295

if(rc != GPG_ERR_NO_ERROR){

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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));

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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return false;

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}

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rc = gpgme_op_import(mc.ctx, pgp_data);

301

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

200

302

if(rc != GPG_ERR_NO_ERROR){

201

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

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gpgme_strsource(rc), gpgme_strerror(rc));

303

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

304

gpgme_strsource(rc), gpgme_strerror(rc));

203

305

return false;

204

306

}

205

307

206

308

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

207

309

if(ret == -1){

208

perror("close");

310

perror_plus("close");

209

311

}

210

312

gpgme_data_release(pgp_data);

211

313

return true;

212

314

}

213

315

214

316

if(debug){

215

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

317

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

216

318

}

217

319

218

320

/* Init GPGME */

219

321

gpgme_check_version(NULL);

220

322

rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);

221

323

if(rc != GPG_ERR_NO_ERROR){

222

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

223

gpgme_strsource(rc), gpgme_strerror(rc));

324

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

325

gpgme_strsource(rc), gpgme_strerror(rc));

224

326

return false;

225

327

}

226

328

227

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

329

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

228

330

rc = gpgme_get_engine_info(&engine_info);

229

331

if(rc != GPG_ERR_NO_ERROR){

230

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

231

gpgme_strsource(rc), gpgme_strerror(rc));

332

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

333

gpgme_strsource(rc), gpgme_strerror(rc));

232

334

return false;

233

335

}

234

336

while(engine_info != NULL){

240

342

engine_info = engine_info->next;

241

343

}

242

344

if(engine_info == NULL){

243

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

345

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

346

tempdir);

244

347

return false;

245

348

}

246

349

247

350

/* Create new GPGME "context" */

248

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

351

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

249

352

if(rc != GPG_ERR_NO_ERROR){

250

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

251

gpgme_strsource(rc), gpgme_strerror(rc));

353

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

354

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

355

gpgme_strerror(rc));

252

356

return false;

253

357

}

254

358

263

367

* Decrypt OpenPGP data.

264

368

* Returns -1 on error

265

369

*/

370

__attribute__((nonnull, warn_unused_result))

266

371

static ssize_t pgp_packet_decrypt(const char *cryptotext,

267

372

size_t crypto_size,

268

char **plaintext){

373

char **plaintext,

374

mandos_context *mc){

269

375

gpgme_data_t dh_crypto, dh_plain;

270

376

gpgme_error_t rc;

271

377

ssize_t ret;

273

379

ssize_t plaintext_length = 0;

274

380

275

381

if(debug){

276

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

382

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

277

383

}

278

384

279

385

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

280

386

rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,

281

387

0);

282

388

if(rc != GPG_ERR_NO_ERROR){

283

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

284

gpgme_strsource(rc), gpgme_strerror(rc));

389

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

390

gpgme_strsource(rc), gpgme_strerror(rc));

285

391

return -1;

286

392

}

287

393

288

394

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

289

395

rc = gpgme_data_new(&dh_plain);

290

396

if(rc != GPG_ERR_NO_ERROR){

291

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

292

gpgme_strsource(rc), gpgme_strerror(rc));

397

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

398

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

399

gpgme_strsource(rc), gpgme_strerror(rc));

293

400

gpgme_data_release(dh_crypto);

294

401

return -1;

295

402

}

296

403

297

404

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

298

405

data buffer */

299

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

406

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

300

407

if(rc != GPG_ERR_NO_ERROR){

301

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

302

gpgme_strsource(rc), gpgme_strerror(rc));

408

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

409

gpgme_strsource(rc), gpgme_strerror(rc));

303

410

plaintext_length = -1;

304

411

if(debug){

305

412

gpgme_decrypt_result_t result;

306

result = gpgme_op_decrypt_result(mc.ctx);

413

result = gpgme_op_decrypt_result(mc->ctx);

307

414

if(result == NULL){

308

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

415

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

309

416

} else {

310

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

311

result->unsupported_algorithm);

312

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

313

result->wrong_key_usage);

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);

314

421

if(result->file_name != NULL){

315

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

422

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

316

423

}

317

424

gpgme_recipient_t recipient;

318

425

recipient = result->recipients;

319

426

while(recipient != NULL){

320

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

321

gpgme_pubkey_algo_name(recipient->pubkey_algo));

322

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

323

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

324

recipient->status == GPG_ERR_NO_SECKEY

325

? "No" : "Yes");

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");

326

434

recipient = recipient->next;

327

435

}

328

436

}

331

439

}

332

440

333

441

if(debug){

334

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

442

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

335

443

}

336

444

337

445

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

338

446

if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){

339

perror("gpgme_data_seek");

447

perror_plus("gpgme_data_seek");

340

448

plaintext_length = -1;

341

449

goto decrypt_end;

342

450

}

344

452

*plaintext = NULL;

345

453

while(true){

346

454

plaintext_capacity = incbuffer(plaintext,

347

(size_t)plaintext_length,

348

plaintext_capacity);

455

(size_t)plaintext_length,

456

plaintext_capacity);

349

457

if(plaintext_capacity == 0){

350

perror("incbuffer");

351

plaintext_length = -1;

352

goto decrypt_end;

458

perror_plus("incbuffer");

459

plaintext_length = -1;

460

goto decrypt_end;

353

461

}

354

462

355

463

ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,

360

468

break;

361

469

}

362

470

if(ret < 0){

363

perror("gpgme_data_read");

471

perror_plus("gpgme_data_read");

364

472

plaintext_length = -1;

365

473

goto decrypt_end;

366

474

}

368

476

}

369

477

370

478

if(debug){

371

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

479

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

372

480

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

373

481

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

374

482

}

385

493

return plaintext_length;

386

494

}

387

495

388

static const char * safer_gnutls_strerror(int value){

389

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

390

-Wunreachable-code */

496

__attribute__((warn_unused_result))

497

static const char *safer_gnutls_strerror(int value){

498

const char *ret = gnutls_strerror(value);

391

499

if(ret == NULL)

392

500

ret = "(unknown)";

393

501

return ret;

394

502

}

395

503

396

504

/* GnuTLS log function callback */

505

__attribute__((nonnull))

397

506

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

398

507

const char* string){

399

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

508

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

400

509

}

401

510

511

__attribute__((nonnull, warn_unused_result))

402

512

static int init_gnutls_global(const char *pubkeyfilename,

403

const char *seckeyfilename){

513

const char *seckeyfilename,

514

mandos_context *mc){

404

515

int ret;

405

516

406

517

if(debug){

407

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

518

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

408

519

}

409

520

410

521

ret = gnutls_global_init();

411

522

if(ret != GNUTLS_E_SUCCESS){

412

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

413

safer_gnutls_strerror(ret));

523

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

524

safer_gnutls_strerror(ret));

414

525

return -1;

415

526

}

416

527

423

534

}

424

535

425

536

/* OpenPGP credentials */

426

gnutls_certificate_allocate_credentials(&mc.cred);

537

ret = gnutls_certificate_allocate_credentials(&mc->cred);

427

538

if(ret != GNUTLS_E_SUCCESS){

428

fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning

429

from

430

-Wunreachable-code

431

*/

432

safer_gnutls_strerror(ret));

539

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

540

safer_gnutls_strerror(ret));

433

541

gnutls_global_deinit();

434

542

return -1;

435

543

}

436

544

437

545

if(debug){

438

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

439

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

440

seckeyfilename);

546

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

547

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

548

pubkeyfilename,

549

seckeyfilename);

441

550

}

442

551

443

552

ret = gnutls_certificate_set_openpgp_key_file

444

(mc.cred, pubkeyfilename, seckeyfilename,

553

(mc->cred, pubkeyfilename, seckeyfilename,

445

554

GNUTLS_OPENPGP_FMT_BASE64);

446

555

if(ret != GNUTLS_E_SUCCESS){

447

fprintf(stderr,

448

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

449

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

450

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

451

safer_gnutls_strerror(ret));

556

fprintf_plus(stderr,

557

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

558

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

559

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

560

safer_gnutls_strerror(ret));

452

561

goto globalfail;

453

562

}

454

563

455

564

/* GnuTLS server initialization */

456

ret = gnutls_dh_params_init(&mc.dh_params);

565

ret = gnutls_dh_params_init(&mc->dh_params);

457

566

if(ret != GNUTLS_E_SUCCESS){

458

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

459

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

567

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

568

" initialization: %s\n",

569

safer_gnutls_strerror(ret));

460

570

goto globalfail;

461

571

}

462

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

572

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

463

573

if(ret != GNUTLS_E_SUCCESS){

464

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

465

safer_gnutls_strerror(ret));

574

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

575

safer_gnutls_strerror(ret));

466

576

goto globalfail;

467

577

}

468

578

469

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

579

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

470

580

471

581

return 0;

472

582

473

583

globalfail:

474

584

475

gnutls_certificate_free_credentials(mc.cred);

585

gnutls_certificate_free_credentials(mc->cred);

476

586

gnutls_global_deinit();

477

gnutls_dh_params_deinit(mc.dh_params);

587

gnutls_dh_params_deinit(mc->dh_params);

478

588

return -1;

479

589

}

480

590

481

static int init_gnutls_session(gnutls_session_t *session){

591

__attribute__((nonnull, warn_unused_result))

592

static int init_gnutls_session(gnutls_session_t *session,

593

mandos_context *mc){

482

594

int ret;

483

595

/* GnuTLS session creation */

484

596

do {

488

600

}

489

601

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

490

602

if(ret != GNUTLS_E_SUCCESS){

491

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

492

safer_gnutls_strerror(ret));

603

fprintf_plus(stderr,

604

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

605

safer_gnutls_strerror(ret));

493

606

}

494

607

495

608

{

496

609

const char *err;

497

610

do {

498

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

611

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

499

612

if(quit_now){

500

613

gnutls_deinit(*session);

501

614

return -1;

502

615

}

503

616

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

504

617

if(ret != GNUTLS_E_SUCCESS){

505

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

506

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

507

safer_gnutls_strerror(ret));

618

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

619

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

620

safer_gnutls_strerror(ret));

508

621

gnutls_deinit(*session);

509

622

return -1;

510

623

}

512

625

513

626

do {

514

627

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

515

mc.cred);

628

mc->cred);

516

629

if(quit_now){

517

630

gnutls_deinit(*session);

518

631

return -1;

519

632

}

520

633

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

521

634

if(ret != GNUTLS_E_SUCCESS){

522

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

523

safer_gnutls_strerror(ret));

635

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

636

safer_gnutls_strerror(ret));

524

637

gnutls_deinit(*session);

525

638

return -1;

526

639

}

528

641

/* ignore client certificate if any. */

529

642

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

530

643

531

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

644

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

532

645

533

646

return 0;

534

647

}

537

650

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

538

651

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

539

652

653

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

654

__attribute__((warn_unused_result))

655

error_t raise_privileges(void){

656

error_t old_errno = errno;

657

error_t ret_errno = 0;

658

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

659

ret_errno = errno;

660

}

661

errno = old_errno;

662

return ret_errno;

663

}

664

665

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

666

__attribute__((warn_unused_result))

667

error_t raise_privileges_permanently(void){

668

error_t old_errno = errno;

669

error_t ret_errno = raise_privileges();

670

if(ret_errno != 0){

671

errno = old_errno;

672

return ret_errno;

673

}

674

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

675

ret_errno = errno;

676

}

677

errno = old_errno;

678

return ret_errno;

679

}

680

681

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

682

__attribute__((warn_unused_result))

683

error_t lower_privileges(void){

684

error_t old_errno = errno;

685

error_t ret_errno = 0;

686

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

687

ret_errno = errno;

688

}

689

errno = old_errno;

690

return ret_errno;

691

}

692

693

/* Lower privileges permanently */

694

__attribute__((warn_unused_result))

695

error_t lower_privileges_permanently(void){

696

error_t old_errno = errno;

697

error_t ret_errno = 0;

698

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

699

ret_errno = errno;

700

}

701

errno = old_errno;

702

return ret_errno;

703

}

704

705

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

706

__attribute__((nonnull, warn_unused_result))

707

static bool add_remove_local_route(const bool add,

708

const char *address,

709

AvahiIfIndex if_index){

710

int ret;

711

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

712

char add_arg[] = "add";

713

char delete_arg[] = "delete";

714

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

715

if(pluginhelperdir == NULL){

716

if(debug){

717

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

718

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

719

}

720

return false;

721

}

722

723

char interface[IF_NAMESIZE];

724

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

725

perror_plus("if_indextoname");

726

return false;

727

}

728

729

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

730

if(devnull == -1){

731

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

732

return false;

733

}

734

pid_t pid = fork();

735

if(pid == 0){

736

/* Child */

737

/* Raise privileges */

738

errno = raise_privileges_permanently();

739

if(errno != 0){

740

perror_plus("Failed to raise privileges");

741

/* _exit(EX_NOPERM); */

742

} else {

743

/* Set group */

744

errno = 0;

745

ret = setgid(0);

746

if(ret == -1){

747

perror_plus("setgid");

748

_exit(EX_NOPERM);

749

}

750

/* Reset supplementary groups */

751

errno = 0;

752

ret = setgroups(0, NULL);

753

if(ret == -1){

754

perror_plus("setgroups");

755

_exit(EX_NOPERM);

756

}

757

}

758

ret = dup2(devnull, STDIN_FILENO);

759

if(ret == -1){

760

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

761

_exit(EX_OSERR);

762

}

763

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

764

if(ret == -1){

765

perror_plus("close");

766

_exit(EX_OSERR);

767

}

768

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

769

if(ret == -1){

770

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

771

_exit(EX_OSERR);

772

}

773

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

774

O_RDONLY

775

| O_DIRECTORY

776

| O_PATH

777

| O_CLOEXEC));

778

if(helperdir_fd == -1){

779

perror_plus("open");

780

_exit(EX_UNAVAILABLE);

781

}

782

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

783

helper, O_RDONLY));

784

if(helper_fd == -1){

785

perror_plus("openat");

786

_exit(EX_UNAVAILABLE);

787

}

788

TEMP_FAILURE_RETRY(close(helperdir_fd));

789

#ifdef __GNUC__

790

#pragma GCC diagnostic push

791

#pragma GCC diagnostic ignored "-Wcast-qual"

792

#endif

793

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

794

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

795

interface, NULL }, environ) == -1){

796

#ifdef __GNUC__

797

#pragma GCC diagnostic pop

798

#endif

799

perror_plus("fexecve");

800

_exit(EXIT_FAILURE);

801

}

802

}

803

if(pid == -1){

804

perror_plus("fork");

805

return false;

806

}

807

int status;

808

pid_t pret = -1;

809

errno = 0;

810

do {

811

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

812

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

813

int errno_raising = 0;

814

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

815

errno_raising = errno;

816

perror_plus("Failed to raise privileges in order to"

817

" kill helper program");

818

}

819

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

820

perror_plus("kill");

821

}

822

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

823

perror_plus("Failed to lower privileges after killing"

824

" helper program");

825

}

826

return false;

827

}

828

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

829

if(pret == -1){

830

perror_plus("waitpid");

831

return false;

832

}

833

if(WIFEXITED(status)){

834

if(WEXITSTATUS(status) != 0){

835

fprintf_plus(stderr, "Error: iprouteadddel exited"

836

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

837

return false;

838

}

839

return true;

840

}

841

if(WIFSIGNALED(status)){

842

fprintf_plus(stderr, "Error: iprouteadddel died by"

843

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

844

return false;

845

}

846

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

847

return false;

848

}

849

850

__attribute__((nonnull, warn_unused_result))

851

static bool add_local_route(const char *address,

852

AvahiIfIndex if_index){

853

return add_remove_local_route(true, address, if_index);

854

}

855

856

__attribute__((nonnull, warn_unused_result))

857

static bool remove_local_route(const char *address,

858

AvahiIfIndex if_index){

859

return add_remove_local_route(false, address, if_index);

860

}

861

540

862

/* Called when a Mandos server is found */

541

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

863

__attribute__((nonnull, warn_unused_result))

864

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

542

865

AvahiIfIndex if_index,

543

int af){

866

int af, mandos_context *mc){

544

867

int ret, tcp_sd = -1;

545

868

ssize_t sret;

546

union {

547

struct sockaddr_in in;

548

struct sockaddr_in6 in6;

549

} to;

869

struct sockaddr_storage to;

550

870

char *buffer = NULL;

551

871

char *decrypted_buffer = NULL;

552

872

size_t buffer_length = 0;

555

875

int retval = -1;

556

876

gnutls_session_t session;

557

877

int pf; /* Protocol family */

878

bool route_added = false;

558

879

559

880

errno = 0;

560

881

571

892

pf = PF_INET;

572

893

break;

573

894

default:

574

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

895

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

575

896

errno = EINVAL;

576

897

return -1;

577

898

}

578

899

579

ret = init_gnutls_session(&session);

900

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

901

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

902

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

903

bool match = false;

904

{

905

char *interface = NULL;

906

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

907

interface))){

908

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

909

match = true;

910

break;

911

}

912

}

913

}

914

if(not match){

915

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

916

connect to the server */

917

if(debug){

918

char interface[IF_NAMESIZE];

919

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

920

perror_plus("if_indextoname");

921

} else {

922

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

923

" \"%s\"\n",

924

if_indextoname((unsigned int)if_index,

925

interface));

926

}

927

}

928

return -1;

929

}

930

}

931

932

ret = init_gnutls_session(&session, mc);

580

933

if(ret != 0){

581

934

return -1;

582

935

}

583

936

584

937

if(debug){

585

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

586

"\n", ip, port);

938

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

939

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

587

940

}

588

941

589

tcp_sd = socket(pf, SOCK_STREAM, 0);

942

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

590

943

if(tcp_sd < 0){

591

944

int e = errno;

592

perror("socket");

945

perror_plus("socket");

593

946

errno = e;

594

947

goto mandos_end;

595

948

}

601

954

602

955

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

603

956

if(af == AF_INET6){

604

to.in6.sin6_family = (sa_family_t)af;

605

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

957

((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;

958

ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);

606

959

} else { /* IPv4 */

607

to.in.sin_family = (sa_family_t)af;

608

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

960

((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;

961

ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);

609

962

}

610

963

if(ret < 0 ){

611

964

int e = errno;

612

perror("inet_pton");

965

perror_plus("inet_pton");

613

966

errno = e;

614

967

goto mandos_end;

615

968

}

616

969

if(ret == 0){

617

970

int e = errno;

618

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

971

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

619

972

errno = e;

620

973

goto mandos_end;

621

974

}

622

975

if(af == AF_INET6){

623

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

624

-Wconversion and

625

-Wunreachable-code */

626

627

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

628

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

629

-Wunreachable-code*/

976

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

977

if(IN6_IS_ADDR_LINKLOCAL

978

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

630

979

if(if_index == AVAHI_IF_UNSPEC){

631

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

632

" without a network interface\n");

980

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

981

" incomplete without a network interface\n");

633

982

errno = EINVAL;

634

983

goto mandos_end;

635

984

}

636

985

/* Set the network interface number as scope */

637

to.in6.sin6_scope_id = (uint32_t)if_index;

986

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

638

987

}

639

988

} else {

640

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

641

-Wconversion and

642

-Wunreachable-code */

989

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

643

990

}

644

991

645

992

if(quit_now){

651

998

if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){

652

999

char interface[IF_NAMESIZE];

653

1000

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

654

perror("if_indextoname");

1001

perror_plus("if_indextoname");

655

1002

} else {

656

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

657

ip, interface, port);

1003

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

1004

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

658

1005

}

659

1006

} else {

660

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

661

port);

1007

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

1008

ip, (uintmax_t)port);

662

1009

}

663

1010

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

664

1011

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

665

const char *pcret;

666

if(af == AF_INET6){

667

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

668

sizeof(addrstr));

669

} else {

670

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

671

sizeof(addrstr));

672

}

673

if(pcret == NULL){

674

perror("inet_ntop");

675

} else {

676

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

677

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

678

}

679

}

680

}

681

682

if(quit_now){

683

errno = EINTR;

684

goto mandos_end;

685

}

686

687

if(af == AF_INET6){

688

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

689

} else {

690

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

691

}

692

if(ret < 0){

693

int e = errno;

694

perror("connect");

695

errno = e;

696

goto mandos_end;

697

}

698

699

if(quit_now){

700

errno = EINTR;

701

goto mandos_end;

1012

if(af == AF_INET6){

1013

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

1014

sizeof(struct sockaddr_in6),

1015

addrstr, sizeof(addrstr), NULL, 0,

1016

NI_NUMERICHOST);

1017

} else {

1018

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

1019

sizeof(struct sockaddr_in),

1020

addrstr, sizeof(addrstr), NULL, 0,

1021

NI_NUMERICHOST);

1022

}

1023

if(ret == EAI_SYSTEM){

1024

perror_plus("getnameinfo");

1025

} else if(ret != 0) {

1026

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

1027

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

1028

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

1029

}

1030

}

1031

1032

if(quit_now){

1033

errno = EINTR;

1034

goto mandos_end;

1035

}

1036

1037

while(true){

1038

if(af == AF_INET6){

1039

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

1040

sizeof(struct sockaddr_in6));

1041

} else {

1042

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

1043

sizeof(struct sockaddr_in));

1044

}

1045

if(ret < 0){

1046

if(errno == ENETUNREACH

1047

and if_index != AVAHI_IF_UNSPEC

1048

and connect_to == NULL

1049

and not route_added and

1050

((af == AF_INET6 and not

1051

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1052

&to)->sin6_addr)))

1053

or (af == AF_INET and

1054

/* Not a a IPv4LL address */

1055

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

1056

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

1057

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

1058

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

1059

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

1060

connect to a Mandos server announced by Avahi on a server

1061

host with a global address. Work around this by retrying

1062

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

1063

1064

Avahi bug reference:

1065

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

1066

https://bugs.debian.org/587961

1067

*/

1068

int e = errno;

1069

route_added = add_local_route(ip, if_index);

1070

if(route_added){

1071

continue;

1072

}

1073

errno = e;

1074

}

1075

if(errno != ECONNREFUSED or debug){

1076

int e = errno;

1077

perror_plus("connect");

1078

errno = e;

1079

}

1080

goto mandos_end;

1081

}

1082

1083

if(quit_now){

1084

errno = EINTR;

1085

goto mandos_end;

1086

}

1087

break;

702

1088

}

703

1089

704

1090

const char *out = mandos_protocol_version;

706

1092

while(true){

707

1093

size_t out_size = strlen(out);

708

1094

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

709

out_size - written));

1095

out_size - written));

710

1096

if(ret == -1){

711

1097

int e = errno;

712

perror("write");

1098

perror_plus("write");

713

1099

errno = e;

714

1100

goto mandos_end;

715

1101

}

732

1118

}

733

1119

734

1120

if(debug){

735

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

1121

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

736

1122

}

737

1123

738

1124

if(quit_now){

740

1126

goto mandos_end;

741

1127

}

742

1128

743

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1129

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

1130

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

1131

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

1132

gnutls_transport_set_ptr(session,

1133

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

744

1134

745

1135

if(quit_now){

746

1136

errno = EINTR;

757

1147

758

1148

if(ret != GNUTLS_E_SUCCESS){

759

1149

if(debug){

760

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

1150

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

761

1151

gnutls_perror(ret);

762

1152

}

763

1153

errno = EPROTO;

767

1157

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

768

1158

769

1159

if(debug){

770

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

771

ip);

1160

fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"

1161

" %s\n", ip);

772

1162

}

773

1163

774

1164

while(true){

779

1169

}

780

1170

781

1171

buffer_capacity = incbuffer(&buffer, buffer_length,

782

buffer_capacity);

1172

buffer_capacity);

783

1173

if(buffer_capacity == 0){

784

1174

int e = errno;

785

perror("incbuffer");

1175

perror_plus("incbuffer");

786

1176

errno = e;

787

1177

goto mandos_end;

788

1178

}

812

1202

}

813

1203

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

814

1204

if(ret < 0){

815

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

1205

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

1206

"***\n");

816

1207

gnutls_perror(ret);

817

1208

errno = EPROTO;

818

1209

goto mandos_end;

819

1210

}

820

1211

break;

821

1212

default:

822

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

823

" encrypted session with Mandos server\n");

1213

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

1214

" encrypted session with Mandos server\n");

824

1215

gnutls_bye(session, GNUTLS_SHUT_RDWR);

825

1216

errno = EIO;

826

1217

goto mandos_end;

831

1222

}

832

1223

833

1224

if(debug){

834

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

1225

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

835

1226

}

836

1227

837

1228

if(quit_now){

849

1240

850

1241

if(buffer_length > 0){

851

1242

ssize_t decrypted_buffer_size;

852

decrypted_buffer_size = pgp_packet_decrypt(buffer,

853

buffer_length,

854

&decrypted_buffer);

1243

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1244

&decrypted_buffer, mc);

855

1245

if(decrypted_buffer_size >= 0){

856

1246

857

1247

written = 0;

867

1257

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

868

1258

int e = errno;

869

1259

if(debug){

870

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

871

strerror(errno));

1260

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

1261

strerror(errno));

872

1262

}

873

1263

errno = e;

874

1264

goto mandos_end;

883

1273

884

1274

mandos_end:

885

1275

{

1276

if(route_added){

1277

if(not remove_local_route(ip, if_index)){

1278

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

1279

" interface %d", ip, if_index);

1280

}

1281

}

886

1282

int e = errno;

887

1283

free(decrypted_buffer);

888

1284

free(buffer);

893

1289

if(e == 0){

894

1290

e = errno;

895

1291

}

896

perror("close");

1292

perror_plus("close");

897

1293

}

898

1294

gnutls_deinit(session);

1295

errno = e;

899

1296

if(quit_now){

900

e = EINTR;

1297

errno = EINTR;

901

1298

retval = -1;

902

1299

}

903

errno = e;

904

1300

}

905

1301

return retval;

906

1302

}

907

1303

1304

__attribute__((nonnull))

908

1305

static void resolve_callback(AvahiSServiceResolver *r,

909

1306

AvahiIfIndex interface,

910

1307

AvahiProtocol proto,

918

1315

AVAHI_GCC_UNUSED AvahiStringList *txt,

919

1316

AVAHI_GCC_UNUSED AvahiLookupResultFlags

920

1317

flags,

921

AVAHI_GCC_UNUSED void* userdata){

922

assert(r);

1318

void *mc){

1319

if(r == NULL){

1320

return;

1321

}

923

1322

924

1323

/* Called whenever a service has been resolved successfully or

925

1324

timed out */

926

1325

927

1326

if(quit_now){

1327

avahi_s_service_resolver_free(r);

928

1328

return;

929

1329

}

930

1330

931

1331

switch(event){

932

1332

default:

933

1333

case AVAHI_RESOLVER_FAILURE:

934

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

935

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

936

avahi_strerror(avahi_server_errno(mc.server)));

1334

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

1335

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

1336

domain,

1337

avahi_strerror(avahi_server_errno

1338

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

937

1339

break;

938

1340

939

1341

case AVAHI_RESOLVER_FOUND:

941

1343

char ip[AVAHI_ADDRESS_STR_MAX];

942

1344

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

943

1345

if(debug){

944

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

945

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

946

ip, (intmax_t)interface, port);

1346

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

1347

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

1348

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

947

1349

}

948

int ret = start_mandos_communication(ip, port, interface,

949

avahi_proto_to_af(proto));

1350

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

1351

interface,

1352

avahi_proto_to_af(proto),

1353

mc);

950

1354

if(ret == 0){

951

avahi_simple_poll_quit(mc.simple_poll);

1355

avahi_simple_poll_quit(simple_poll);

1356

} else {

1357

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

1358

avahi_proto_to_af(proto),

1359

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

1360

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

1361

" list\n", name);

1362

}

952

1363

}

953

1364

}

954

1365

}

964

1375

const char *domain,

965

1376

AVAHI_GCC_UNUSED AvahiLookupResultFlags

966

1377

flags,

967

AVAHI_GCC_UNUSED void* userdata){

968

assert(b);

1378

void *mc){

1379

if(b == NULL){

1380

return;

1381

}

969

1382

970

1383

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

971

1384

is removed from the LAN */

978

1391

default:

979

1392

case AVAHI_BROWSER_FAILURE:

980

1393

981

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

982

avahi_strerror(avahi_server_errno(mc.server)));

983

avahi_simple_poll_quit(mc.simple_poll);

1394

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

1395

avahi_strerror(avahi_server_errno

1396

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

1397

avahi_simple_poll_quit(simple_poll);

984

1398

return;

985

1399

986

1400

case AVAHI_BROWSER_NEW:

989

1403

the callback function is called the Avahi server will free the

990

1404

resolver for us. */

991

1405

992

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

993

name, type, domain, protocol, 0,

994

resolve_callback, NULL) == NULL)

995

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

996

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

1406

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

1407

interface, protocol, name, type,

1408

domain, protocol, 0,

1409

resolve_callback, mc) == NULL)

1410

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

1411

" %s\n", name,

1412

avahi_strerror(avahi_server_errno

1413

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

997

1414

break;

998

1415

999

1416

case AVAHI_BROWSER_REMOVE:

1002

1419

case AVAHI_BROWSER_ALL_FOR_NOW:

1003

1420

case AVAHI_BROWSER_CACHE_EXHAUSTED:

1004

1421

if(debug){

1005

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

1422

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

1423

" searching...\n");

1006

1424

}

1007

1425

break;

1008

1426

}

1009

1427

}

1010

1428

1011

/* stop main loop after sigterm has been called */

1429

/* Signal handler that stops main loop after SIGTERM */

1012

1430

static void handle_sigterm(int sig){

1013

1431

if(quit_now){

1014

1432

return;

1016

1434

quit_now = 1;

1017

1435

signal_received = sig;

1018

1436

int old_errno = errno;

1019

if(mc.simple_poll != NULL){

1020

avahi_simple_poll_quit(mc.simple_poll);

1437

/* set main loop to exit */

1438

if(simple_poll != NULL){

1439

avahi_simple_poll_quit(simple_poll);

1021

1440

}

1022

1441

errno = old_errno;

1023

1442

}

1024

1443

1444

__attribute__((nonnull, warn_unused_result))

1445

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

1446

int ret;

1447

error_t ret_errno;

1448

1449

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

1450

if(s < 0){

1451

ret_errno = errno;

1452

perror_plus("socket");

1453

errno = ret_errno;

1454

return false;

1455

}

1456

strcpy(ifr->ifr_name, ifname);

1457

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1458

if(ret == -1){

1459

if(debug){

1460

ret_errno = errno;

1461

perror_plus("ioctl SIOCGIFFLAGS");

1462

errno = ret_errno;

1463

}

1464

return false;

1465

}

1466

return true;

1467

}

1468

1469

__attribute__((nonnull, warn_unused_result))

1470

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

1471

1472

/* Reject the loopback device */

1473

if(ifr->ifr_flags & IFF_LOOPBACK){

1474

if(debug){

1475

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

1476

ifname);

1477

}

1478

return false;

1479

}

1480

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

1481

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

1482

if(debug){

1483

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

1484

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

1485

}

1486

return true;

1487

}

1488

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

1489

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

1490

if(debug){

1491

fprintf_plus(stderr, "Rejecting non-broadcast interface"

1492

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

1493

}

1494

return false;

1495

}

1496

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

1497

if(ifr->ifr_flags & IFF_NOARP){

1498

if(debug){

1499

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

1500

ifname);

1501

}

1502

return false;

1503

}

1504

1505

/* Accept this device */

1506

if(debug){

1507

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

1508

}

1509

return true;

1510

}

1511

1025

1512

/*

1026

1513

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

1027

1514

* corresponds to an acceptable network device.

1028

1515

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

1029

1516

*/

1517

__attribute__((nonnull, warn_unused_result))

1030

1518

int good_interface(const struct dirent *if_entry){

1031

ssize_t ssret;

1032

char *flagname = NULL;

1033

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

1034

if_entry->d_name);

1035

if(ret < 0){

1036

perror("asprintf");

1037

return 0;

1038

}

1039

1519

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

1040

1520

return 0;

1041

1521

}

1042

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

1043

if(flags_fd == -1){

1044

perror("open");

1045

return 0;

1046

}

1047

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

1048

/* read line from flags_fd */

1049

ssize_t to_read = (sizeof(ifreq_flags)*2)+3; /* "0x1003\n" */

1050

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

1051

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

1052

if(flagstring == NULL){

1053

perror("malloc");

1054

close(flags_fd);

1055

return 0;

1056

}

1057

while(to_read > 0){

1058

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

1059

(size_t)to_read));

1060

if(ssret == -1){

1061

perror("read");

1062

free(flagstring);

1063

close(flags_fd);

1064

return 0;

1065

}

1066

to_read -= ssret;

1067

if(ssret == 0){

1522

1523

struct ifreq ifr;

1524

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

1525

if(debug){

1526

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

1527

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

1528

}

1529

return 0;

1530

}

1531

1532

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

1533

return 0;

1534

}

1535

return 1;

1536

}

1537

1538

/*

1539

* This function determines if a network interface is up.

1540

*/

1541

__attribute__((nonnull, warn_unused_result))

1542

bool interface_is_up(const char *interface){

1543

struct ifreq ifr;

1544

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

1545

if(debug){

1546

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

1547

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

1548

}

1549

return false;

1550

}

1551

1552

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

1553

}

1554

1555

/*

1556

* This function determines if a network interface is running

1557

*/

1558

__attribute__((nonnull, warn_unused_result))

1559

bool interface_is_running(const char *interface){

1560

struct ifreq ifr;

1561

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

1562

if(debug){

1563

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

1564

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

1565

}

1566

return false;

1567

}

1568

1569

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

1570

}

1571

1572

__attribute__((nonnull, pure, warn_unused_result))

1573

int notdotentries(const struct dirent *direntry){

1574

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

1575

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

1576

and (direntry->d_name[1] == '\0'

1577

or (direntry->d_name[1] == '.'

1578

and direntry->d_name[2] == '\0'))){

1579

return 0;

1580

}

1581

return 1;

1582

}

1583

1584

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

1585

__attribute__((nonnull, warn_unused_result))

1586

int runnable_hook(const struct dirent *direntry){

1587

int ret;

1588

size_t sret;

1589

struct stat st;

1590

1591

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

1592

/* Empty name? */

1593

return 0;

1594

}

1595

1596

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

1597

"abcdefghijklmnopqrstuvwxyz"

1598

"0123456789"

1599

"_.-");

1600

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

1601

/* Contains non-allowed characters */

1602

if(debug){

1603

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

1604

direntry->d_name);

1605

}

1606

return 0;

1607

}

1608

1609

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

1610

if(ret == -1){

1611

if(debug){

1612

perror_plus("Could not stat hook");

1613

}

1614

return 0;

1615

}

1616

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

1617

/* Not a regular file */

1618

if(debug){

1619

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

1620

direntry->d_name);

1621

}

1622

return 0;

1623

}

1624

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

1625

/* Not executable */

1626

if(debug){

1627

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

1628

direntry->d_name);

1629

}

1630

return 0;

1631

}

1632

if(debug){

1633

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

1634

direntry->d_name);

1635

}

1636

return 1;

1637

}

1638

1639

__attribute__((nonnull, warn_unused_result))

1640

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1641

mandos_context *mc){

1642

int ret;

1643

struct timespec now;

1644

struct timespec waited_time;

1645

intmax_t block_time;

1646

1647

while(true){

1648

if(mc->current_server == NULL){

1649

if(debug){

1650

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

1651

" No timeout!\n");

1652

}

1653

ret = avahi_simple_poll_iterate(s, -1);

1654

} else {

1655

if(debug){

1656

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

1657

" it, or wait\n");

1658

}

1659

/* the current time */

1660

ret = clock_gettime(CLOCK_MONOTONIC, &now);

1661

if(ret == -1){

1662

perror_plus("clock_gettime");

1663

return -1;

1664

}

1665

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

1666

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

1667

waited_time.tv_sec = (now.tv_sec

1668

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

1669

waited_time.tv_nsec = (now.tv_nsec

1670

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

1671

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

1672

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

1673

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

1674

block_time = ((retry_interval

1675

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

1676

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

1677

1678

if(debug){

1679

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

1680

block_time);

1681

}

1682

1683

if(block_time <= 0){

1684

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

1685

mc->current_server->port,

1686

mc->current_server->if_index,

1687

mc->current_server->af, mc);

1688

if(ret == 0){

1689

avahi_simple_poll_quit(s);

1690

return 0;

1691

}

1692

ret = clock_gettime(CLOCK_MONOTONIC,

1693

&mc->current_server->last_seen);

1694

if(ret == -1){

1695

perror_plus("clock_gettime");

1696

return -1;

1697

}

1698

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

1699

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

1700

servers, but don't block */

1701

}

1702

1703

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

1704

}

1705

if(ret != 0){

1706

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

1707

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

1708

}

1709

}

1710

}

1711

}

1712

1713

__attribute__((nonnull))

1714

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

1715

const float delay){

1716

struct dirent **direntries = NULL;

1717

if(hookdir_fd == -1){

1718

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1719

| O_CLOEXEC);

1720

if(hookdir_fd == -1){

1721

if(errno == ENOENT){

1722

if(debug){

1723

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

1724

" found\n", hookdir);

1725

}

1726

} else {

1727

perror_plus("open");

1728

}

1729

return;

1730

}

1731

}

1732

#ifdef __GLIBC__

1733

#if __GLIBC_PREREQ(2, 15)

1734

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

1735

runnable_hook, alphasort);

1736

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

1737

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

1738

alphasort);

1739

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

1740

#else /* not __GLIBC__ */

1741

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

1742

alphasort);

1743

#endif /* not __GLIBC__ */

1744

if(numhooks == -1){

1745

perror_plus("scandir");

1746

return;

1747

}

1748

struct dirent *direntry;

1749

int ret;

1750

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

1751

if(devnull == -1){

1752

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

1753

return;

1754

}

1755

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

1756

direntry = direntries[i];

1757

if(debug){

1758

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

1759

direntry->d_name);

1760

}

1761

pid_t hook_pid = fork();

1762

if(hook_pid == 0){

1763

/* Child */

1764

/* Raise privileges */

1765

errno = raise_privileges_permanently();

1766

if(errno != 0){

1767

perror_plus("Failed to raise privileges");

1768

_exit(EX_NOPERM);

1769

}

1770

/* Set group */

1771

errno = 0;

1772

ret = setgid(0);

1773

if(ret == -1){

1774

perror_plus("setgid");

1775

_exit(EX_NOPERM);

1776

}

1777

/* Reset supplementary groups */

1778

errno = 0;

1779

ret = setgroups(0, NULL);

1780

if(ret == -1){

1781

perror_plus("setgroups");

1782

_exit(EX_NOPERM);

1783

}

1784

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

1785

if(ret == -1){

1786

perror_plus("setenv");

1787

_exit(EX_OSERR);

1788

}

1789

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

1790

if(ret == -1){

1791

perror_plus("setenv");

1792

_exit(EX_OSERR);

1793

}

1794

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

1795

if(ret == -1){

1796

perror_plus("setenv");

1797

_exit(EX_OSERR);

1798

}

1799

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

1800

if(ret == -1){

1801

perror_plus("setenv");

1802

_exit(EX_OSERR);

1803

}

1804

char *delaystring;

1805

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

1806

if(ret == -1){

1807

perror_plus("asprintf");

1808

_exit(EX_OSERR);

1809

}

1810

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

1811

if(ret == -1){

1812

free(delaystring);

1813

perror_plus("setenv");

1814

_exit(EX_OSERR);

1815

}

1816

free(delaystring);

1817

if(connect_to != NULL){

1818

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

1819

if(ret == -1){

1820

perror_plus("setenv");

1821

_exit(EX_OSERR);

1822

}

1823

}

1824

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

1825

direntry->d_name,

1826

O_RDONLY));

1827

if(hook_fd == -1){

1828

perror_plus("openat");

1829

_exit(EXIT_FAILURE);

1830

}

1831

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

1832

perror_plus("close");

1833

_exit(EXIT_FAILURE);

1834

}

1835

ret = dup2(devnull, STDIN_FILENO);

1836

if(ret == -1){

1837

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

1838

_exit(EX_OSERR);

1839

}

1840

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

1841

if(ret == -1){

1842

perror_plus("close");

1843

_exit(EX_OSERR);

1844

}

1845

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1846

if(ret == -1){

1847

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

1848

_exit(EX_OSERR);

1849

}

1850

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

1851

environ) == -1){

1852

perror_plus("fexecve");

1853

_exit(EXIT_FAILURE);

1854

}

1855

} else {

1856

if(hook_pid == -1){

1857

perror_plus("fork");

1858

free(direntry);

1859

continue;

1860

}

1861

int status;

1862

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

1863

perror_plus("waitpid");

1864

free(direntry);

1865

continue;

1866

}

1867

if(WIFEXITED(status)){

1868

if(WEXITSTATUS(status) != 0){

1869

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

1870

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

1871

WEXITSTATUS(status));

1872

free(direntry);

1873

continue;

1874

}

1875

} else if(WIFSIGNALED(status)){

1876

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

1877

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

1878

WTERMSIG(status));

1879

free(direntry);

1880

continue;

1881

} else {

1882

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

1883

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

1884

free(direntry);

1885

continue;

1886

}

1887

}

1888

if(debug){

1889

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

1890

direntry->d_name);

1891

}

1892

free(direntry);

1893

}

1894

free(direntries);

1895

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

1896

perror_plus("close");

1897

} else {

1898

hookdir_fd = -1;

1899

}

1900

close(devnull);

1901

}

1902

1903

__attribute__((nonnull, warn_unused_result))

1904

error_t bring_up_interface(const char *const interface,

1905

const float delay){

1906

error_t old_errno = errno;

1907

int ret;

1908

struct ifreq network;

1909

unsigned int if_index = if_nametoindex(interface);

1910

if(if_index == 0){

1911

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

1912

errno = old_errno;

1913

return ENXIO;

1914

}

1915

1916

if(quit_now){

1917

errno = old_errno;

1918

return EINTR;

1919

}

1920

1921

if(not interface_is_up(interface)){

1922

error_t ret_errno = 0, ioctl_errno = 0;

1923

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

1924

ret_errno = errno;

1925

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

1926

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

1927

errno = old_errno;

1928

return ret_errno;

1929

}

1930

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

1931

1932

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

1933

if(sd == -1){

1934

ret_errno = errno;

1935

perror_plus("socket");

1936

errno = old_errno;

1937

return ret_errno;

1938

}

1939

1940

if(quit_now){

1941

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

1942

if(ret == -1){

1943

perror_plus("close");

1944

}

1945

errno = old_errno;

1946

return EINTR;

1947

}

1948

1949

if(debug){

1950

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

1951

interface);

1952

}

1953

1954

/* Raise privileges */

1955

ret_errno = raise_privileges();

1956

if(ret_errno != 0){

1957

errno = ret_errno;

1958

perror_plus("Failed to raise privileges");

1959

}

1960

1961

#ifdef __linux__

1962

int ret_linux;

1963

bool restore_loglevel = false;

1964

if(ret_errno == 0){

1965

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1966

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

1967

ret_linux = klogctl(8, NULL, 5);

1968

if(ret_linux == -1){

1969

perror_plus("klogctl");

1970

} else {

1971

restore_loglevel = true;

1972

}

1973

}

1974

#endif /* __linux__ */

1975

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

1976

ioctl_errno = errno;

1977

#ifdef __linux__

1978

if(restore_loglevel){

1979

ret_linux = klogctl(7, NULL, 0);

1980

if(ret_linux == -1){

1981

perror_plus("klogctl");

1982

}

1983

}

1984

#endif /* __linux__ */

1985

1986

/* If raise_privileges() succeeded above */

1987

if(ret_errno == 0){

1988

/* Lower privileges */

1989

ret_errno = lower_privileges();

1990

if(ret_errno != 0){

1991

errno = ret_errno;

1992

perror_plus("Failed to lower privileges");

1993

}

1994

}

1995

1996

/* Close the socket */

1997

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

1998

if(ret == -1){

1999

perror_plus("close");

2000

}

2001

2002

if(ret_setflags == -1){

2003

errno = ioctl_errno;

2004

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2005

errno = old_errno;

2006

return ioctl_errno;

2007

}

2008

} else if(debug){

2009

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

2010

interface);

2011

}

2012

2013

/* Sleep checking until interface is running.

2014

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

2015

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

2016

if(interface_is_running(interface)){

1068

2017

break;

1069

2018

}

1070

}

1071

close(flags_fd);

1072

intmax_t tmpmax;

1073

char *tmp;

1074

errno = 0;

1075

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

1076

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

1077

and not (isspace(*tmp)))

1078

or tmpmax != (ifreq_flags)tmpmax){

1079

if(debug){

1080

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

1081

flagstring, if_entry->d_name);

1082

}

1083

free(flagstring);

1084

return 0;

1085

}

1086

free(flagstring);

1087

ifreq_flags flags = (ifreq_flags)tmpmax;

1088

/* Reject the loopback device */

1089

if(flags & IFF_LOOPBACK){

1090

if(debug){

1091

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

1092

if_entry->d_name);

1093

}

1094

return 0;

1095

}

1096

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

1097

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

1098

if(debug){

1099

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

1100

if_entry->d_name);

1101

}

1102

return 1;

1103

}

1104

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

1105

if(not (flags & IFF_BROADCAST)){

1106

if(debug){

1107

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

1108

if_entry->d_name);

1109

}

1110

return 0;

1111

}

1112

/* Accept this device */

1113

if(debug){

1114

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

1115

if_entry->d_name);

1116

}

1117

return 1;

2019

struct timespec sleeptime = { .tv_nsec = 250000000 };

2020

ret = nanosleep(&sleeptime, NULL);

2021

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

2022

perror_plus("nanosleep");

2023

}

2024

}

2025

2026

errno = old_errno;

2027

return 0;

2028

}

2029

2030

__attribute__((nonnull, warn_unused_result))

2031

error_t take_down_interface(const char *const interface){

2032

error_t old_errno = errno;

2033

struct ifreq network;

2034

unsigned int if_index = if_nametoindex(interface);

2035

if(if_index == 0){

2036

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

2037

errno = old_errno;

2038

return ENXIO;

2039

}

2040

if(interface_is_up(interface)){

2041

error_t ret_errno = 0, ioctl_errno = 0;

2042

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

2043

ret_errno = errno;

2044

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

2045

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

2046

errno = old_errno;

2047

return ret_errno;

2048

}

2049

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

2050

2051

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

2052

if(sd == -1){

2053

ret_errno = errno;

2054

perror_plus("socket");

2055

errno = old_errno;

2056

return ret_errno;

2057

}

2058

2059

if(debug){

2060

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

2061

interface);

2062

}

2063

2064

/* Raise privileges */

2065

ret_errno = raise_privileges();

2066

if(ret_errno != 0){

2067

errno = ret_errno;

2068

perror_plus("Failed to raise privileges");

2069

}

2070

2071

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

2072

ioctl_errno = errno;

2073

2074

/* If raise_privileges() succeeded above */

2075

if(ret_errno == 0){

2076

/* Lower privileges */

2077

ret_errno = lower_privileges();

2078

if(ret_errno != 0){

2079

errno = ret_errno;

2080

perror_plus("Failed to lower privileges");

2081

}

2082

}

2083

2084

/* Close the socket */

2085

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

2086

if(ret == -1){

2087

perror_plus("close");

2088

}

2089

2090

if(ret_setflags == -1){

2091

errno = ioctl_errno;

2092

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2093

errno = old_errno;

2094

return ioctl_errno;

2095

}

2096

} else if(debug){

2097

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

2098

interface);

2099

}

2100

2101

errno = old_errno;

2102

return 0;

1118

2103

}

1119

2104

1120

2105

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

2106

mandos_context mc = { .server = NULL, .dh_bits = 1024,

2107

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

2108

"+CTYPE-OPENPGP", .current_server = NULL,

2109

.interfaces = NULL, .interfaces_size = 0 };

1121

2110

AvahiSServiceBrowser *sb = NULL;

1122

int error;

2111

error_t ret_errno;

1123

2112

int ret;

1124

2113

intmax_t tmpmax;

1125

2114

char *tmp;

1126

2115

int exitcode = EXIT_SUCCESS;

1127

const char *interface = "";

1128

struct ifreq network;

1129

int sd = -1;

1130

bool take_down_interface = false;

1131

uid_t uid;

1132

gid_t gid;

1133

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

1134

bool tempdir_created = false;

2116

char *interfaces_to_take_down = NULL;

2117

size_t interfaces_to_take_down_size = 0;

2118

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

2119

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

2120

char *tempdir = NULL;

1135

2121

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1136

2122

const char *seckey = PATHDIR "/" SECKEY;

1137

2123

const char *pubkey = PATHDIR "/" PUBKEY;

2124

char *interfaces_hooks = NULL;

1138

2125

1139

2126

bool gnutls_initialized = false;

1140

2127

bool gpgme_initialized = false;

1141

2128

float delay = 2.5f;

2129

double retry_interval = 10; /* 10s between trying a server and

2130

retrying the same server again */

1142

2131

1143

2132

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

1144

2133

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1150

2139

errno = 0;

1151

2140

ret = setgid(gid);

1152

2141

if(ret == -1){

1153

perror("setgid");

2142

perror_plus("setgid");

1154

2143

}

1155

2144

1156

2145

/* Lower user privileges (temporarily) */

1157

2146

errno = 0;

1158

2147

ret = seteuid(uid);

1159

2148

if(ret == -1){

1160

perror("seteuid");

2149

perror_plus("seteuid");

1161

2150

}

1162

2151

1163

2152

if(quit_now){

1198

2187

.arg = "SECONDS",

1199

2188

.doc = "Maximum delay to wait for interface startup",

1200

2189

.group = 2 },

2190

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

2191

.arg = "SECONDS",

2192

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

2193

.group = 2 },

2194

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

2195

.arg = "DIR",

2196

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

2197

.group = 2 },

1201

2198

/*

1202

2199

* These reproduce what we would get without ARGP_NO_HELP

1203

2200

*/

1221

2218

connect_to = arg;

1222

2219

break;

1223

2220

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

1224

interface = arg;

2221

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

2222

arg, (int)',');

2223

if(ret_errno != 0){

2224

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

2225

}

1225

2226

break;

1226

2227

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

1227

2228

seckey = arg;

1247

2248

if(errno != 0 or tmp == arg or *tmp != '\0'){

1248

2249

argp_error(state, "Bad delay");

1249

2250

}

2251

case 132: /* --retry */

2252

errno = 0;

2253

retry_interval = strtod(arg, &tmp);

2254

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

2255

or (retry_interval * 1000) > INT_MAX

2256

or retry_interval < 0){

2257

argp_error(state, "Bad retry interval");

2258

}

2259

break;

2260

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

2261

hookdir = arg;

1250

2262

break;

1251

2263

/*

1252

2264

* These reproduce what we would get without ARGP_NO_HELP

1259

2271

argp_state_help(state, state->out_stream,

1260

2272

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1261

2273

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

1262

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

2274

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

1263

2275

exit(argp_err_exit_status);

1264

2276

break;

1265

2277

default:

1280

2292

case ENOMEM:

1281

2293

default:

1282

2294

errno = ret;

1283

perror("argp_parse");

2295

perror_plus("argp_parse");

1284

2296

exitcode = EX_OSERR;

1285

2297

goto end;

1286

2298

case EINVAL:

1289

2301

}

1290

2302

}

1291

2303

2304

{

2305

/* Work around Debian bug #633582:

2306

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

2307

2308

/* Re-raise privileges */

2309

ret_errno = raise_privileges();

2310

if(ret_errno != 0){

2311

errno = ret_errno;

2312

perror_plus("Failed to raise privileges");

2313

} else {

2314

struct stat st;

2315

2316

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

2317

int seckey_fd = open(seckey, O_RDONLY);

2318

if(seckey_fd == -1){

2319

perror_plus("open");

2320

} else {

2321

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

2322

if(ret == -1){

2323

perror_plus("fstat");

2324

} else {

2325

if(S_ISREG(st.st_mode)

2326

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

2327

ret = fchown(seckey_fd, uid, gid);

2328

if(ret == -1){

2329

perror_plus("fchown");

2330

}

2331

}

2332

}

2333

TEMP_FAILURE_RETRY(close(seckey_fd));

2334

}

2335

}

2336

2337

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

2338

int pubkey_fd = open(pubkey, O_RDONLY);

2339

if(pubkey_fd == -1){

2340

perror_plus("open");

2341

} else {

2342

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

2343

if(ret == -1){

2344

perror_plus("fstat");

2345

} else {

2346

if(S_ISREG(st.st_mode)

2347

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

2348

ret = fchown(pubkey_fd, uid, gid);

2349

if(ret == -1){

2350

perror_plus("fchown");

2351

}

2352

}

2353

}

2354

TEMP_FAILURE_RETRY(close(pubkey_fd));

2355

}

2356

}

2357

2358

/* Lower privileges */

2359

ret_errno = lower_privileges();

2360

if(ret_errno != 0){

2361

errno = ret_errno;

2362

perror_plus("Failed to lower privileges");

2363

}

2364

}

2365

}

2366

2367

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

2368

{

2369

char *interface = NULL;

2370

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

2371

interface))){

2372

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

2373

and if_nametoindex(interface) == 0){

2374

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

2375

fprintf_plus(stderr, "Not using nonexisting interface"

2376

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

2377

}

2378

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

2379

interface = NULL;

2380

}

2381

}

2382

}

2383

2384

/* Run network hooks */

2385

{

2386

if(mc.interfaces != NULL){

2387

interfaces_hooks = malloc(mc.interfaces_size);

2388

if(interfaces_hooks == NULL){

2389

perror_plus("malloc");

2390

goto end;

2391

}

2392

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

2393

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

2394

}

2395

run_network_hooks("start", interfaces_hooks != NULL ?

2396

interfaces_hooks : "", delay);

2397

}

2398

1292

2399

if(not debug){

1293

2400

avahi_set_log_function(empty_log);

1294

2401

}

1295

1296

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

1297

struct dirent **direntries;

1298

ret = scandir(sys_class_net, &direntries, good_interface,

1299

alphasort);

1300

if(ret >= 1){

1301

/* Pick the first good interface */

1302

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

1303

if(debug){

1304

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

1305

}

1306

if(interface == NULL){

1307

perror("malloc");

1308

free(direntries);

1309

exitcode = EXIT_FAILURE;

1310

goto end;

1311

}

1312

free(direntries);

1313

} else {

1314

free(direntries);

1315

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

1316

exitcode = EXIT_FAILURE;

1317

goto end;

1318

}

1319

}

1320

2402

1321

2403

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

1322

2404

from the signal handler */

1323

2405

/* Initialize the pseudo-RNG for Avahi */

1324

2406

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

1325

mc.simple_poll = avahi_simple_poll_new();

1326

if(mc.simple_poll == NULL){

1327

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

2407

simple_poll = avahi_simple_poll_new();

2408

if(simple_poll == NULL){

2409

fprintf_plus(stderr,

2410

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

1328

2411

exitcode = EX_UNAVAILABLE;

1329

2412

goto end;

1330

2413

}

1332

2415

sigemptyset(&sigterm_action.sa_mask);

1333

2416

ret = sigaddset(&sigterm_action.sa_mask, SIGINT);

1334

2417

if(ret == -1){

1335

perror("sigaddset");

2418

perror_plus("sigaddset");

1336

2419

exitcode = EX_OSERR;

1337

2420

goto end;

1338

2421

}

1339

2422

ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);

1340

2423

if(ret == -1){

1341

perror("sigaddset");

2424

perror_plus("sigaddset");

1342

2425

exitcode = EX_OSERR;

1343

2426

goto end;

1344

2427

}

1345

2428

ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);

1346

2429

if(ret == -1){

1347

perror("sigaddset");

2430

perror_plus("sigaddset");

1348

2431

exitcode = EX_OSERR;

1349

2432

goto end;

1350

2433

}

1354

2437

*/

1355

2438

ret = sigaction(SIGINT, NULL, &old_sigterm_action);

1356

2439

if(ret == -1){

1357

perror("sigaction");

2440

perror_plus("sigaction");

1358

2441

return EX_OSERR;

1359

2442

}

1360

2443

if(old_sigterm_action.sa_handler != SIG_IGN){

1361

2444

ret = sigaction(SIGINT, &sigterm_action, NULL);

1362

2445

if(ret == -1){

1363

perror("sigaction");

2446

perror_plus("sigaction");

1364

2447

exitcode = EX_OSERR;

1365

2448

goto end;

1366

2449

}

1367

2450

}

1368

2451

ret = sigaction(SIGHUP, NULL, &old_sigterm_action);

1369

2452

if(ret == -1){

1370

perror("sigaction");

2453

perror_plus("sigaction");

1371

2454

return EX_OSERR;

1372

2455

}

1373

2456

if(old_sigterm_action.sa_handler != SIG_IGN){

1374

2457

ret = sigaction(SIGHUP, &sigterm_action, NULL);

1375

2458

if(ret == -1){

1376

perror("sigaction");

2459

perror_plus("sigaction");

1377

2460

exitcode = EX_OSERR;

1378

2461

goto end;

1379

2462

}

1380

2463

}

1381

2464

ret = sigaction(SIGTERM, NULL, &old_sigterm_action);

1382

2465

if(ret == -1){

1383

perror("sigaction");

2466

perror_plus("sigaction");

1384

2467

return EX_OSERR;

1385

2468

}

1386

2469

if(old_sigterm_action.sa_handler != SIG_IGN){

1387

2470

ret = sigaction(SIGTERM, &sigterm_action, NULL);

1388

2471

if(ret == -1){

1389

perror("sigaction");

1390

exitcode = EX_OSERR;

1391

goto end;

1392

}

1393

}

1394

1395

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

1396

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

1397

if_index = (AvahiIfIndex) if_nametoindex(interface);

1398

if(if_index == 0){

1399

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

1400

exitcode = EX_UNAVAILABLE;

1401

goto end;

1402

}

1403

1404

if(quit_now){

1405

goto end;

1406

}

1407

1408

/* Re-raise priviliges */

1409

errno = 0;

1410

ret = seteuid(0);

1411

if(ret == -1){

1412

perror("seteuid");

1413

}

1414

1415

#ifdef __linux__

1416

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1417

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

1418

ret = klogctl(8, NULL, 5);

1419

bool restore_loglevel = true;

1420

if(ret == -1){

1421

restore_loglevel = false;

1422

perror("klogctl");

1423

}

1424

#endif /* __linux__ */

1425

1426

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1427

if(sd < 0){

1428

perror("socket");

1429

exitcode = EX_OSERR;

1430

#ifdef __linux__

1431

if(restore_loglevel){

1432

ret = klogctl(7, NULL, 0);

1433

if(ret == -1){

1434

perror("klogctl");

1435

}

1436

}

1437

#endif /* __linux__ */

1438

/* Lower privileges */

1439

errno = 0;

1440

ret = seteuid(uid);

1441

if(ret == -1){

1442

perror("seteuid");

1443

}

1444

goto end;

1445

}

1446

strcpy(network.ifr_name, interface);

1447

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

1448

if(ret == -1){

1449

perror("ioctl SIOCGIFFLAGS");

1450

#ifdef __linux__

1451

if(restore_loglevel){

1452

ret = klogctl(7, NULL, 0);

1453

if(ret == -1){

1454

perror("klogctl");

1455

}

1456

}

1457

#endif /* __linux__ */

1458

exitcode = EX_OSERR;

1459

/* Lower privileges */

1460

errno = 0;

1461

ret = seteuid(uid);

1462

if(ret == -1){

1463

perror("seteuid");

1464

}

1465

goto end;

1466

}

1467

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

1468

network.ifr_flags |= IFF_UP;

1469

take_down_interface = true;

1470

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

1471

if(ret == -1){

1472

take_down_interface = false;

1473

perror("ioctl SIOCSIFFLAGS +IFF_UP");

1474

exitcode = EX_OSERR;

1475

#ifdef __linux__

1476

if(restore_loglevel){

1477

ret = klogctl(7, NULL, 0);

1478

if(ret == -1){

1479

perror("klogctl");

2472

perror_plus("sigaction");

2473

exitcode = EX_OSERR;

2474

goto end;

2475

}

2476

}

2477

2478

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

2479

if(mc.interfaces == NULL){

2480

struct dirent **direntries = NULL;

2481

/* Look for any good interfaces */

2482

ret = scandir(sys_class_net, &direntries, good_interface,

2483

alphasort);

2484

if(ret >= 1){

2485

/* Add all found interfaces to interfaces list */

2486

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

2487

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

2488

direntries[i]->d_name);

2489

if(ret_errno != 0){

2490

errno = ret_errno;

2491

perror_plus("argz_add");

2492

free(direntries[i]);

2493

continue;

2494

}

2495

if(debug){

2496

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

2497

direntries[i]->d_name);

2498

}

2499

free(direntries[i]);

2500

}

2501

free(direntries);

2502

} else {

2503

if(ret == 0){

2504

free(direntries);

2505

}

2506

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

2507

exitcode = EXIT_FAILURE;

2508

goto end;

2509

}

2510

}

2511

2512

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

2513

{

2514

char *interface = NULL;

2515

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

2516

interface))){

2517

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

2518

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

2519

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

2520

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

2521

interface);

2522

interface = NULL;

2523

while((interface = argz_next(mc.interfaces,

2524

mc.interfaces_size, interface))){

2525

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

2526

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

2527

interface);

2528

interface = NULL;

1480

2529

}

1481

2530

}

1482

#endif /* __linux__ */

1483

/* Lower privileges */

1484

errno = 0;

1485

ret = seteuid(uid);

1486

if(ret == -1){

1487

perror("seteuid");

1488

}

1489

goto end;

1490

}

1491

}

1492

/* sleep checking until interface is running */

1493

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

1494

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

1495

if(ret == -1){

1496

perror("ioctl SIOCGIFFLAGS");

1497

} else if(network.ifr_flags & IFF_RUNNING){

1498

2531

break;

1499

2532

}

1500

struct timespec sleeptime = { .tv_nsec = 250000000 };

1501

ret = nanosleep(&sleeptime, NULL);

1502

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

1503

perror("nanosleep");

1504

}

1505

}

1506

if(not take_down_interface){

1507

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

1508

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

1509

if(ret == -1){

1510

perror("close");

1511

}

1512

}

1513

#ifdef __linux__

1514

if(restore_loglevel){

1515

/* Restores kernel loglevel to default */

1516

ret = klogctl(7, NULL, 0);

1517

if(ret == -1){

1518

perror("klogctl");

1519

}

1520

}

1521

#endif /* __linux__ */

1522

/* Lower privileges */

1523

errno = 0;

1524

if(take_down_interface){

1525

/* Lower privileges */

1526

ret = seteuid(uid);

1527

if(ret == -1){

1528

perror("seteuid");

1529

}

1530

} else {

1531

/* Lower privileges permanently */

1532

ret = setuid(uid);

1533

if(ret == -1){

1534

perror("setuid");

1535

}

1536

}

2533

bool interface_was_up = interface_is_up(interface);

2534

errno = bring_up_interface(interface, delay);

2535

if(not interface_was_up){

2536

if(errno != 0){

2537

perror_plus("Failed to bring up interface");

2538

} else {

2539

errno = argz_add(&interfaces_to_take_down,

2540

&interfaces_to_take_down_size,

2541

interface);

2542

if(errno != 0){

2543

perror_plus("argz_add");

2544

}

2545

}

2546

}

2547

}

2548

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

2549

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

2550

}

2551

}

2552

2553

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

2554

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

2555

if(debug){

2556

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

2557

mc.interfaces);

2558

}

2559

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

1537

2560

}

1538

2561

1539

2562

if(quit_now){

1540

2563

goto end;

1541

2564

}

1542

2565

1543

ret = init_gnutls_global(pubkey, seckey);

2566

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

1544

2567

if(ret == -1){

1545

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

2568

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

1546

2569

exitcode = EX_UNAVAILABLE;

1547

2570

goto end;

1548

2571

} else {

1553

2576

goto end;

1554

2577

}

1555

2578

1556

tempdir_created = true;

1557

if(mkdtemp(tempdir) == NULL){

1558

tempdir_created = false;

1559

perror("mkdtemp");

2579

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

2580

tempdir = mkdtemp(run_tempdir);

2581

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

2582

if(debug){

2583

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

2584

run_tempdir, old_tempdir);

2585

}

2586

tempdir = mkdtemp(old_tempdir);

2587

}

2588

if(tempdir == NULL){

2589

perror_plus("mkdtemp");

1560

2590

goto end;

1561

2591

}

1562

2592

1564

2594

goto end;

1565

2595

}

1566

2596

1567

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

1568

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

2597

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

2598

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

1569

2599

exitcode = EX_UNAVAILABLE;

1570

2600

goto end;

1571

2601

} else {

1580

2610

/* Connect directly, do not use Zeroconf */

1581

2611

/* (Mainly meant for debugging) */

1582

2612

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

2613

1583

2614

if(address == NULL){

1584

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

2615

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

1585

2616

exitcode = EX_USAGE;

1586

2617

goto end;

1587

2618

}

1590

2621

goto end;

1591

2622

}

1592

2623

1593

uint16_t port;

2624

in_port_t port;

1594

2625

errno = 0;

1595

2626

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

1596

2627

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

1597

or tmpmax != (uint16_t)tmpmax){

1598

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

2628

or tmpmax != (in_port_t)tmpmax){

2629

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

1599

2630

exitcode = EX_USAGE;

1600

2631

goto end;

1601

2632

}

1602

2633

1603

2634

if(quit_now){

1604

2635

goto end;

1605

2636

}

1606

2637

1607

port = (uint16_t)tmpmax;

2638

port = (in_port_t)tmpmax;

1608

2639

*address = '\0';

1609

address = connect_to;

1610

2640

/* Colon in address indicates IPv6 */

1611

2641

int af;

1612

if(strchr(address, ':') != NULL){

2642

if(strchr(connect_to, ':') != NULL){

1613

2643

af = AF_INET6;

2644

/* Accept [] around IPv6 address - see RFC 5952 */

2645

if(connect_to[0] == '[' and address[-1] == ']')

2646

{

2647

connect_to++;

2648

address[-1] = '\0';

2649

}

1614

2650

} else {

1615

2651

af = AF_INET;

1616

2652

}

2653

address = connect_to;

1617

2654

1618

2655

if(quit_now){

1619

2656

goto end;

1620

2657

}

1621

2658

1622

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

1623

if(ret < 0){

1624

switch(errno){

1625

case ENETUNREACH:

1626

case EHOSTDOWN:

1627

case EHOSTUNREACH:

1628

exitcode = EX_NOHOST;

1629

break;

1630

case EINVAL:

1631

exitcode = EX_USAGE;

1632

break;

1633

case EIO:

1634

exitcode = EX_IOERR;

1635

break;

1636

case EPROTO:

1637

exitcode = EX_PROTOCOL;

1638

break;

1639

default:

1640

exitcode = EX_OSERR;

1641

break;

1642

}

1643

} else {

2659

while(not quit_now){

2660

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

2661

&mc);

2662

if(quit_now or ret == 0){

2663

break;

2664

}

2665

if(debug){

2666

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

2667

(int)retry_interval);

2668

}

2669

sleep((unsigned int)retry_interval);

2670

}

2671

2672

if(not quit_now){

1644

2673

exitcode = EXIT_SUCCESS;

1645

2674

}

2675

1646

2676

goto end;

1647

2677

}

1648

2678

1660

2690

config.publish_domain = 0;

1661

2691

1662

2692

/* Allocate a new server */

1663

mc.server = avahi_server_new(avahi_simple_poll_get

1664

(mc.simple_poll), &config, NULL,

1665

NULL, &error);

2693

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2694

&config, NULL, NULL, &ret_errno);

1666

2695

1667

2696

/* Free the Avahi configuration data */

1668

2697

avahi_server_config_free(&config);

1670

2699

1671

2700

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

1672

2701

if(mc.server == NULL){

1673

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

1674

avahi_strerror(error));

2702

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

2703

avahi_strerror(ret_errno));

1675

2704

exitcode = EX_UNAVAILABLE;

1676

2705

goto end;

1677

2706

}

1683

2712

/* Create the Avahi service browser */

1684

2713

sb = avahi_s_service_browser_new(mc.server, if_index,

1685

2714

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1686

NULL, 0, browse_callback, NULL);

2715

NULL, 0, browse_callback,

2716

(void *)&mc);

1687

2717

if(sb == NULL){

1688

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

1689

avahi_strerror(avahi_server_errno(mc.server)));

2718

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

2719

avahi_strerror(avahi_server_errno(mc.server)));

1690

2720

exitcode = EX_UNAVAILABLE;

1691

2721

goto end;

1692

2722

}

1698

2728

/* Run the main loop */

1699

2729

1700

2730

if(debug){

1701

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

2731

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

1702

2732

}

1703

2733

1704

avahi_simple_poll_loop(mc.simple_poll);

2734

ret = avahi_loop_with_timeout(simple_poll,

2735

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

2736

if(debug){

2737

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

2738

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

2739

}

1705

2740

1706

2741

end:

1707

2742

1708

2743

if(debug){

1709

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

2744

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

1710

2745

}

1711

2746

1712

2747

/* Cleanup things */

2748

free(mc.interfaces);

2749

1713

2750

if(sb != NULL)

1714

2751

avahi_s_service_browser_free(sb);

1715

2752

1716

2753

if(mc.server != NULL)

1717

2754

avahi_server_free(mc.server);

1718

2755

1719

if(mc.simple_poll != NULL)

1720

avahi_simple_poll_free(mc.simple_poll);

2756

if(simple_poll != NULL)

2757

avahi_simple_poll_free(simple_poll);

1721

2758

1722

2759

if(gnutls_initialized){

1723

2760

gnutls_certificate_free_credentials(mc.cred);

1729

2766

gpgme_release(mc.ctx);

1730

2767

}

1731

2768

1732

/* Take down the network interface */

1733

if(take_down_interface){

1734

/* Re-raise priviliges */

1735

errno = 0;

1736

ret = seteuid(0);

1737

if(ret == -1){

1738

perror("seteuid");

1739

}

1740

if(geteuid() == 0){

1741

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

1742

if(ret == -1){

1743

perror("ioctl SIOCGIFFLAGS");

1744

} else if(network.ifr_flags & IFF_UP) {

1745

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

1746

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

1747

if(ret == -1){

1748

perror("ioctl SIOCSIFFLAGS -IFF_UP");

1749

}

1750

}

1751

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

1752

if(ret == -1){

1753

perror("close");

1754

}

1755

/* Lower privileges permanently */

1756

errno = 0;

1757

ret = setuid(uid);

1758

if(ret == -1){

1759

perror("setuid");

1760

}

1761

}

1762

}

1763

1764

/* Removes the temp directory used by GPGME */

1765

if(tempdir_created){

1766

DIR *d;

1767

struct dirent *direntry;

1768

d = opendir(tempdir);

1769

if(d == NULL){

1770

if(errno != ENOENT){

1771

perror("opendir");

1772

}

1773

} else {

1774

while(true){

1775

direntry = readdir(d);

1776

if(direntry == NULL){

1777

break;

1778

}

1779

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

1780

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

1781

and (direntry->d_name[1] == '\0'

1782

or (direntry->d_name[1] == '.'

1783

and direntry->d_name[2] == '\0'))){

1784

continue;

1785

}

1786

char *fullname = NULL;

1787

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

1788

direntry->d_name);

1789

if(ret < 0){

1790

perror("asprintf");

1791

continue;

1792

}

1793

ret = remove(fullname);

1794

if(ret == -1){

1795

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

1796

strerror(errno));

1797

}

1798

free(fullname);

1799

}

1800

closedir(d);

1801

}

1802

ret = rmdir(tempdir);

1803

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

1804

perror("rmdir");

2769

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

2770

has seen */

2771

if(mc.current_server != NULL){

2772

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

2773

while(mc.current_server != NULL){

2774

server *next = mc.current_server->next;

2775

#ifdef __GNUC__

2776

#pragma GCC diagnostic push

2777

#pragma GCC diagnostic ignored "-Wcast-qual"

2778

#endif

2779

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

2780

#ifdef __GNUC__

2781

#pragma GCC diagnostic pop

2782

#endif

2783

free(mc.current_server);

2784

mc.current_server = next;

2785

}

2786

}

2787

2788

/* Re-raise privileges */

2789

{

2790

ret_errno = raise_privileges();

2791

if(ret_errno != 0){

2792

errno = ret_errno;

2793

perror_plus("Failed to raise privileges");

2794

} else {

2795

2796

/* Run network hooks */

2797

run_network_hooks("stop", interfaces_hooks != NULL ?

2798

interfaces_hooks : "", delay);

2799

2800

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

2801

{

2802

char *interface = NULL;

2803

while((interface=argz_next(interfaces_to_take_down,

2804

interfaces_to_take_down_size,

2805

interface))){

2806

ret_errno = take_down_interface(interface);

2807

if(ret_errno != 0){

2808

errno = ret_errno;

2809

perror_plus("Failed to take down interface");

2810

}

2811

}

2812

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

2813

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

2814

" down\n");

2815

}

2816

}

2817

}

2818

2819

ret_errno = lower_privileges_permanently();

2820

if(ret_errno != 0){

2821

errno = ret_errno;

2822

perror_plus("Failed to lower privileges permanently");

2823

}

2824

}

2825

2826

free(interfaces_to_take_down);

2827

free(interfaces_hooks);

2828

2829

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

2830

if(tempdir != NULL){

2831

struct dirent **direntries = NULL;

2832

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

2833

| O_NOFOLLOW

2834

| O_DIRECTORY

2835

| O_PATH));

2836

if(tempdir_fd == -1){

2837

perror_plus("open");

2838

} else {

2839

#ifdef __GLIBC__

2840

#if __GLIBC_PREREQ(2, 15)

2841

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

2842

notdotentries, alphasort);

2843

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

2844

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

2845

alphasort);

2846

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

2847

#else /* not __GLIBC__ */

2848

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

2849

alphasort);

2850

#endif /* not __GLIBC__ */

2851

if(numentries >= 0){

2852

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

2853

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

2854

if(ret == -1){

2855

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

2856

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

2857

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

2858

}

2859

free(direntries[i]);

2860

}

2861

2862

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

2863

free(direntries);

2864

if(numentries == -1){

2865

perror_plus("scandir");

2866

}

2867

ret = rmdir(tempdir);

2868

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

2869

perror_plus("rmdir");

2870

}

2871

}

2872

TEMP_FAILURE_RETRY(close(tempdir_fd));

1805

2873

}

1806

2874

}

1807

2875

1812

2880

&old_sigterm_action,

1813

2881

NULL));

1814

2882

if(ret == -1){

1815

perror("sigaction");

2883

perror_plus("sigaction");

1816

2884

}

1817

2885

do {

1818

2886

ret = raise(signal_received);

1819

2887

} while(ret != 0 and errno == EINTR);

1820

2888

if(ret != 0){

1821

perror("raise");

2889

perror_plus("raise");

1822

2890

abort();

1823

2891

}

1824

2892

TEMP_FAILURE_RETRY(pause());