/mandos/release : revision 237.7.150

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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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#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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#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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*/

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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 <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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*/

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

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

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

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

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raise() */

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

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EX_NOHOST, EX_IOERR, EX_PROTOCOL */

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

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WEXITSTATUS(), WTERMSIG() */

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

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#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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#ifdef __linux__

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

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114

init_gnutls_session(),

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115

GNUTLS_* */

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116

#include <gnutls/openpgp.h>

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/* gnutls_certificate_set_openpgp_key_file(),

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GNUTLS_OPENPGP_FMT_BASE64 */

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/* gnutls_certificate_set_openpgp_key_file(),

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GNUTLS_OPENPGP_FMT_BASE64 */

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/* GPGME */

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

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129

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

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130

#define SECKEY "seckey.txt"

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#define PUBKEY "pubkey.txt"

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

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bool debug = false;

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135

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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139

char *connect_to = NULL;

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const char *hookdir = HOOKDIR;

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uid_t uid = 65534;

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gid_t gid = 65534;

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144

/* 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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156

typedef struct {

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AvahiSimplePoll *simple_poll;

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157

AvahiServer *server;

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gnutls_certificate_credentials_t cred;

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159

unsigned int dh_bits;

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gnutls_dh_params_t dh_params;

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161

const char *priority;

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162

gpgme_ctx_t ctx;

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server *current_server;

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} mandos_context;

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165

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

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

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.dh_bits = 1024, .priority = "SECURE256"

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

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/* global so signal handler can reach it*/

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AvahiSimplePoll *simple_poll;

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168

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sig_atomic_t quit_now = 0;

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int signal_received = 0;

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172

/* Function to use when printing errors */

173

void perror_plus(const char *print_text){

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int e = errno;

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

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program_invocation_short_name);

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errno = e;

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perror(print_text);

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}

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

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

183

va_list ap;

184

va_start (ap, format);

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186

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

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program_invocation_short_name));

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

189

}

190

152

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/*

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

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193

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

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194

* "buffer_length" is how much is already used.

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195

*/

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size_t incbuffer(char **buffer, size_t buffer_length,

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size_t buffer_capacity){

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size_t buffer_capacity){

159

198

if(buffer_length + BUFFER_SIZE > buffer_capacity){

160

199

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

161

200

if(buffer == NULL){

166

205

return buffer_capacity;

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}

168

207

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

209

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

210

int af, server **current_server){

211

int ret;

212

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

213

if(new_server == NULL){

214

perror_plus("malloc");

215

return false;

216

}

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

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.port = port,

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.if_index = if_index,

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.af = af };

221

if(new_server->ip == NULL){

222

perror_plus("strdup");

223

return false;

224

}

225

/* Special case of first server */

226

if(*current_server == NULL){

227

new_server->next = new_server;

228

new_server->prev = new_server;

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*current_server = new_server;

230

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

231

} else {

232

new_server->next = *current_server;

233

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

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new_server->prev->next = new_server;

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(*current_server)->prev = new_server;

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}

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

238

if(ret == -1){

239

perror_plus("clock_gettime");

240

return false;

241

}

242

return true;

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}

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169

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/*

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246

* Initialize GPGME.

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247

*/

172

static bool init_gpgme(const char *seckey,

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const char *pubkey, const char *tempdir){

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

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const char *tempdir, mandos_context *mc){

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gpgme_error_t rc;

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251

gpgme_engine_info_t engine_info;

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252

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/*

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254

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

180

255

*/

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261

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

187

262

if(fd == -1){

188

perror("open");

263

perror_plus("open");

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264

return false;

190

265

}

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266

192

267

rc = gpgme_data_new_from_fd(&pgp_data, fd);

193

268

if(rc != GPG_ERR_NO_ERROR){

194

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

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gpgme_strsource(rc), gpgme_strerror(rc));

269

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

270

gpgme_strsource(rc), gpgme_strerror(rc));

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return false;

197

272

}

198

273

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rc = gpgme_op_import(mc.ctx, pgp_data);

274

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

200

275

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));

276

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

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gpgme_strsource(rc), gpgme_strerror(rc));

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return false;

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279

}

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

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282

if(ret == -1){

208

perror("close");

283

perror_plus("close");

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284

}

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gpgme_data_release(pgp_data);

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286

return true;

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}

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if(debug){

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

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

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}

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/* Init GPGME */

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gpgme_check_version(NULL);

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rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);

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if(rc != GPG_ERR_NO_ERROR){

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

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gpgme_strsource(rc), gpgme_strerror(rc));

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

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gpgme_strsource(rc), gpgme_strerror(rc));

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return false;

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300

}

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301

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

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

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rc = gpgme_get_engine_info(&engine_info);

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if(rc != GPG_ERR_NO_ERROR){

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

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gpgme_strsource(rc), gpgme_strerror(rc));

305

fprintf_plus(stderr, "bad gpgme_get_engine_info: %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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while(engine_info != NULL){

240

315

engine_info = engine_info->next;

241

316

}

242

317

if(engine_info == NULL){

243

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

318

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

319

tempdir);

244

320

return false;

245

321

}

246

322

247

323

/* Create new GPGME "context" */

248

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

324

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

249

325

if(rc != GPG_ERR_NO_ERROR){

250

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

251

gpgme_strsource(rc), gpgme_strerror(rc));

326

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

327

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

328

gpgme_strerror(rc));

252

329

return false;

253

330

}

254

331

265

342

*/

266

343

static ssize_t pgp_packet_decrypt(const char *cryptotext,

267

344

size_t crypto_size,

268

char **plaintext){

345

char **plaintext,

346

mandos_context *mc){

269

347

gpgme_data_t dh_crypto, dh_plain;

270

348

gpgme_error_t rc;

271

349

ssize_t ret;

273

351

ssize_t plaintext_length = 0;

274

352

275

353

if(debug){

276

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

354

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

277

355

}

278

356

279

357

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

280

358

rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,

281

359

0);

282

360

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));

361

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

362

gpgme_strsource(rc), gpgme_strerror(rc));

285

363

return -1;

286

364

}

287

365

288

366

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

289

367

rc = gpgme_data_new(&dh_plain);

290

368

if(rc != GPG_ERR_NO_ERROR){

291

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

292

gpgme_strsource(rc), gpgme_strerror(rc));

369

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

370

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

371

gpgme_strsource(rc), gpgme_strerror(rc));

293

372

gpgme_data_release(dh_crypto);

294

373

return -1;

295

374

}

296

375

297

376

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

298

377

data buffer */

299

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

378

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

300

379

if(rc != GPG_ERR_NO_ERROR){

301

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

302

gpgme_strsource(rc), gpgme_strerror(rc));

380

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

381

gpgme_strsource(rc), gpgme_strerror(rc));

303

382

plaintext_length = -1;

304

383

if(debug){

305

384

gpgme_decrypt_result_t result;

306

result = gpgme_op_decrypt_result(mc.ctx);

385

result = gpgme_op_decrypt_result(mc->ctx);

307

386

if(result == NULL){

308

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

387

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

309

388

} 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);

389

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

390

result->unsupported_algorithm);

391

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

392

result->wrong_key_usage);

314

393

if(result->file_name != NULL){

315

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

394

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

316

395

}

317

396

gpgme_recipient_t recipient;

318

397

recipient = result->recipients;

319

398

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");

399

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

400

gpgme_pubkey_algo_name

401

(recipient->pubkey_algo));

402

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

403

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

404

recipient->status == GPG_ERR_NO_SECKEY

405

? "No" : "Yes");

326

406

recipient = recipient->next;

327

407

}

328

408

}

331

411

}

332

412

333

413

if(debug){

334

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

414

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

335

415

}

336

416

337

417

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

338

418

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

339

perror("gpgme_data_seek");

419

perror_plus("gpgme_data_seek");

340

420

plaintext_length = -1;

341

421

goto decrypt_end;

342

422

}

344

424

*plaintext = NULL;

345

425

while(true){

346

426

plaintext_capacity = incbuffer(plaintext,

347

(size_t)plaintext_length,

348

plaintext_capacity);

427

(size_t)plaintext_length,

428

plaintext_capacity);

349

429

if(plaintext_capacity == 0){

350

perror("incbuffer");

351

plaintext_length = -1;

352

goto decrypt_end;

430

perror_plus("incbuffer");

431

plaintext_length = -1;

432

goto decrypt_end;

353

433

}

354

434

355

435

ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,

360

440

break;

361

441

}

362

442

if(ret < 0){

363

perror("gpgme_data_read");

443

perror_plus("gpgme_data_read");

364

444

plaintext_length = -1;

365

445

goto decrypt_end;

366

446

}

368

448

}

369

449

370

450

if(debug){

371

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

451

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

372

452

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

373

453

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

374

454

}

386

466

}

387

467

388

468

static const char * safer_gnutls_strerror(int value){

389

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

390

-Wunreachable-code */

469

const char *ret = gnutls_strerror(value);

391

470

if(ret == NULL)

392

471

ret = "(unknown)";

393

472

return ret;

396

475

/* GnuTLS log function callback */

397

476

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

398

477

const char* string){

399

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

478

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

400

479

}

401

480

402

481

static int init_gnutls_global(const char *pubkeyfilename,

403

const char *seckeyfilename){

482

const char *seckeyfilename,

483

mandos_context *mc){

404

484

int ret;

405

485

406

486

if(debug){

407

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

487

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

408

488

}

409

489

410

490

ret = gnutls_global_init();

411

491

if(ret != GNUTLS_E_SUCCESS){

412

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

413

safer_gnutls_strerror(ret));

492

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

493

safer_gnutls_strerror(ret));

414

494

return -1;

415

495

}

416

496

423

503

}

424

504

425

505

/* OpenPGP credentials */

426

ret = gnutls_certificate_allocate_credentials(&mc.cred);

506

ret = gnutls_certificate_allocate_credentials(&mc->cred);

427

507

if(ret != GNUTLS_E_SUCCESS){

428

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

429

safer_gnutls_strerror(ret));

508

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

509

safer_gnutls_strerror(ret));

430

510

gnutls_global_deinit();

431

511

return -1;

432

512

}

433

513

434

514

if(debug){

435

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

436

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

437

seckeyfilename);

515

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

516

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

517

pubkeyfilename,

518

seckeyfilename);

438

519

}

439

520

440

521

ret = gnutls_certificate_set_openpgp_key_file

441

(mc.cred, pubkeyfilename, seckeyfilename,

522

(mc->cred, pubkeyfilename, seckeyfilename,

442

523

GNUTLS_OPENPGP_FMT_BASE64);

443

524

if(ret != GNUTLS_E_SUCCESS){

444

fprintf(stderr,

445

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

446

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

447

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

448

safer_gnutls_strerror(ret));

525

fprintf_plus(stderr,

526

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

527

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

528

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

529

safer_gnutls_strerror(ret));

449

530

goto globalfail;

450

531

}

451

532

452

533

/* GnuTLS server initialization */

453

ret = gnutls_dh_params_init(&mc.dh_params);

534

ret = gnutls_dh_params_init(&mc->dh_params);

454

535

if(ret != GNUTLS_E_SUCCESS){

455

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

456

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

536

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

537

" initialization: %s\n",

538

safer_gnutls_strerror(ret));

457

539

goto globalfail;

458

540

}

459

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

541

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

460

542

if(ret != GNUTLS_E_SUCCESS){

461

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

462

safer_gnutls_strerror(ret));

543

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

544

safer_gnutls_strerror(ret));

463

545

goto globalfail;

464

546

}

465

547

466

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

548

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

467

549

468

550

return 0;

469

551

470

552

globalfail:

471

553

472

gnutls_certificate_free_credentials(mc.cred);

554

gnutls_certificate_free_credentials(mc->cred);

473

555

gnutls_global_deinit();

474

gnutls_dh_params_deinit(mc.dh_params);

556

gnutls_dh_params_deinit(mc->dh_params);

475

557

return -1;

476

558

}

477

559

478

static int init_gnutls_session(gnutls_session_t *session){

560

static int init_gnutls_session(gnutls_session_t *session,

561

mandos_context *mc){

479

562

int ret;

480

563

/* GnuTLS session creation */

481

564

do {

485

568

}

486

569

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

487

570

if(ret != GNUTLS_E_SUCCESS){

488

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

489

safer_gnutls_strerror(ret));

571

fprintf_plus(stderr,

572

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

573

safer_gnutls_strerror(ret));

490

574

}

491

575

492

576

{

493

577

const char *err;

494

578

do {

495

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

579

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

496

580

if(quit_now){

497

581

gnutls_deinit(*session);

498

582

return -1;

499

583

}

500

584

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

501

585

if(ret != GNUTLS_E_SUCCESS){

502

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

503

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

504

safer_gnutls_strerror(ret));

586

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

587

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

588

safer_gnutls_strerror(ret));

505

589

gnutls_deinit(*session);

506

590

return -1;

507

591

}

509

593

510

594

do {

511

595

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

512

mc.cred);

596

mc->cred);

513

597

if(quit_now){

514

598

gnutls_deinit(*session);

515

599

return -1;

516

600

}

517

601

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

518

602

if(ret != GNUTLS_E_SUCCESS){

519

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

520

safer_gnutls_strerror(ret));

603

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

604

safer_gnutls_strerror(ret));

521

605

gnutls_deinit(*session);

522

606

return -1;

523

607

}

525

609

/* ignore client certificate if any. */

526

610

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

527

611

528

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

612

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

529

613

530

614

return 0;

531

615

}

535

619

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

536

620

537

621

/* Called when a Mandos server is found */

538

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

622

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

539

623

AvahiIfIndex if_index,

540

int af){

624

int af, mandos_context *mc){

541

625

int ret, tcp_sd = -1;

542

626

ssize_t sret;

543

627

union {

568

652

pf = PF_INET;

569

653

break;

570

654

default:

571

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

655

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

572

656

errno = EINVAL;

573

657

return -1;

574

658

}

575

659

576

ret = init_gnutls_session(&session);

660

ret = init_gnutls_session(&session, mc);

577

661

if(ret != 0){

578

662

return -1;

579

663

}

580

664

581

665

if(debug){

582

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

583

"\n", ip, port);

666

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

667

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

584

668

}

585

669

586

670

tcp_sd = socket(pf, SOCK_STREAM, 0);

587

671

if(tcp_sd < 0){

588

672

int e = errno;

589

perror("socket");

673

perror_plus("socket");

590

674

errno = e;

591

675

goto mandos_end;

592

676

}

606

690

}

607

691

if(ret < 0 ){

608

692

int e = errno;

609

perror("inet_pton");

693

perror_plus("inet_pton");

610

694

errno = e;

611

695

goto mandos_end;

612

696

}

613

697

if(ret == 0){

614

698

int e = errno;

615

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

699

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

616

700

errno = e;

617

701

goto mandos_end;

618

702

}

619

703

if(af == AF_INET6){

620

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

621

-Wconversion and

622

-Wunreachable-code */

623

704

to.in6.sin6_port = htons(port);

624

705

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

625

706

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

626

-Wunreachable-code*/

707

-Wunreachable-code*/

627

708

if(if_index == AVAHI_IF_UNSPEC){

628

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

629

" without a network interface\n");

709

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

710

" incomplete without a network interface\n");

630

711

errno = EINVAL;

631

712

goto mandos_end;

632

713

}

648

729

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

649

730

char interface[IF_NAMESIZE];

650

731

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

651

perror("if_indextoname");

732

perror_plus("if_indextoname");

652

733

} else {

653

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

654

ip, interface, port);

734

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

735

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

655

736

}

656

737

} else {

657

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

658

port);

738

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

739

ip, (uintmax_t)port);

659

740

}

660

741

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

661

742

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

668

749

sizeof(addrstr));

669

750

}

670

751

if(pcret == NULL){

671

perror("inet_ntop");

752

perror_plus("inet_ntop");

672

753

} else {

673

754

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

674

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

755

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

675

756

}

676

757

}

677

758

}

689

770

if(ret < 0){

690

771

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

691

772

int e = errno;

692

perror("connect");

773

perror_plus("connect");

693

774

errno = e;

694

775

}

695

776

goto mandos_end;

705

786

while(true){

706

787

size_t out_size = strlen(out);

707

788

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

708

out_size - written));

789

out_size - written));

709

790

if(ret == -1){

710

791

int e = errno;

711

perror("write");

792

perror_plus("write");

712

793

errno = e;

713

794

goto mandos_end;

714

795

}

731

812

}

732

813

733

814

if(debug){

734

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

815

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

735

816

}

736

817

737

818

if(quit_now){

739

820

goto mandos_end;

740

821

}

741

822

742

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

823

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

824

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

825

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

826

gnutls_transport_set_ptr(session,

827

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

743

828

744

829

if(quit_now){

745

830

errno = EINTR;

756

841

757

842

if(ret != GNUTLS_E_SUCCESS){

758

843

if(debug){

759

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

844

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

760

845

gnutls_perror(ret);

761

846

}

762

847

errno = EPROTO;

766

851

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

767

852

768

853

if(debug){

769

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

770

ip);

854

fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"

855

" %s\n", ip);

771

856

}

772

857

773

858

while(true){

778

863

}

779

864

780

865

buffer_capacity = incbuffer(&buffer, buffer_length,

781

buffer_capacity);

866

buffer_capacity);

782

867

if(buffer_capacity == 0){

783

868

int e = errno;

784

perror("incbuffer");

869

perror_plus("incbuffer");

785

870

errno = e;

786

871

goto mandos_end;

787

872

}

811

896

}

812

897

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

813

898

if(ret < 0){

814

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

899

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

900

"***\n");

815

901

gnutls_perror(ret);

816

902

errno = EPROTO;

817

903

goto mandos_end;

818

904

}

819

905

break;

820

906

default:

821

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

822

" encrypted session with Mandos server\n");

907

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

908

" encrypted session with Mandos server\n");

823

909

gnutls_bye(session, GNUTLS_SHUT_RDWR);

824

910

errno = EIO;

825

911

goto mandos_end;

830

916

}

831

917

832

918

if(debug){

833

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

919

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

834

920

}

835

921

836

922

if(quit_now){

848

934

849

935

if(buffer_length > 0){

850

936

ssize_t decrypted_buffer_size;

851

decrypted_buffer_size = pgp_packet_decrypt(buffer,

852

buffer_length,

853

&decrypted_buffer);

937

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

938

&decrypted_buffer, mc);

854

939

if(decrypted_buffer_size >= 0){

855

940

856

941

written = 0;

866

951

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

867

952

int e = errno;

868

953

if(debug){

869

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

870

strerror(errno));

954

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

955

strerror(errno));

871

956

}

872

957

errno = e;

873

958

goto mandos_end;

892

977

if(e == 0){

893

978

e = errno;

894

979

}

895

perror("close");

980

perror_plus("close");

896

981

}

897

982

gnutls_deinit(session);

983

errno = e;

898

984

if(quit_now){

899

e = EINTR;

985

errno = EINTR;

900

986

retval = -1;

901

987

}

902

errno = e;

903

988

}

904

989

return retval;

905

990

}

917

1002

AVAHI_GCC_UNUSED AvahiStringList *txt,

918

1003

AVAHI_GCC_UNUSED AvahiLookupResultFlags

919

1004

flags,

920

AVAHI_GCC_UNUSED void* userdata){

921

assert(r);

1005

void* mc){

1006

if(r == NULL){

1007

return;

1008

}

922

1009

923

1010

/* Called whenever a service has been resolved successfully or

924

1011

timed out */

930

1017

switch(event){

931

1018

default:

932

1019

case AVAHI_RESOLVER_FAILURE:

933

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

934

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

935

avahi_strerror(avahi_server_errno(mc.server)));

1020

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

1021

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

1022

domain,

1023

avahi_strerror(avahi_server_errno

1024

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

936

1025

break;

937

1026

938

1027

case AVAHI_RESOLVER_FOUND:

940

1029

char ip[AVAHI_ADDRESS_STR_MAX];

941

1030

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

942

1031

if(debug){

943

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

944

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

945

ip, (intmax_t)interface, port);

1032

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

1033

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

1034

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

946

1035

}

947

int ret = start_mandos_communication(ip, port, interface,

948

avahi_proto_to_af(proto));

1036

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

1037

interface,

1038

avahi_proto_to_af(proto),

1039

mc);

949

1040

if(ret == 0){

950

avahi_simple_poll_quit(mc.simple_poll);

1041

avahi_simple_poll_quit(simple_poll);

1042

} else {

1043

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

1044

avahi_proto_to_af(proto),

1045

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

1046

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

1047

" list\n", name);

1048

}

951

1049

}

952

1050

}

953

1051

}

963

1061

const char *domain,

964

1062

AVAHI_GCC_UNUSED AvahiLookupResultFlags

965

1063

flags,

966

AVAHI_GCC_UNUSED void* userdata){

967

assert(b);

1064

void* mc){

1065

if(b == NULL){

1066

return;

1067

}

968

1068

969

1069

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

970

1070

is removed from the LAN */

977

1077

default:

978

1078

case AVAHI_BROWSER_FAILURE:

979

1079

980

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

981

avahi_strerror(avahi_server_errno(mc.server)));

982

avahi_simple_poll_quit(mc.simple_poll);

1080

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

1081

avahi_strerror(avahi_server_errno

1082

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

1083

avahi_simple_poll_quit(simple_poll);

983

1084

return;

984

1085

985

1086

case AVAHI_BROWSER_NEW:

988

1089

the callback function is called the Avahi server will free the

989

1090

resolver for us. */

990

1091

991

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

992

name, type, domain, protocol, 0,

993

resolve_callback, NULL) == NULL)

994

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

995

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

1092

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

1093

interface, protocol, name, type,

1094

domain, protocol, 0,

1095

resolve_callback, mc) == NULL)

1096

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

1097

" %s\n", name,

1098

avahi_strerror(avahi_server_errno

1099

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

996

1100

break;

997

1101

998

1102

case AVAHI_BROWSER_REMOVE:

1001

1105

case AVAHI_BROWSER_ALL_FOR_NOW:

1002

1106

case AVAHI_BROWSER_CACHE_EXHAUSTED:

1003

1107

if(debug){

1004

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

1108

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

1109

" searching...\n");

1005

1110

}

1006

1111

break;

1007

1112

}

1008

1113

}

1009

1114

1010

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

1115

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

1011

1116

static void handle_sigterm(int sig){

1012

1117

if(quit_now){

1013

1118

return;

1015

1120

quit_now = 1;

1016

1121

signal_received = sig;

1017

1122

int old_errno = errno;

1018

if(mc.simple_poll != NULL){

1019

avahi_simple_poll_quit(mc.simple_poll);

1123

/* set main loop to exit */

1124

if(simple_poll != NULL){

1125

avahi_simple_poll_quit(simple_poll);

1020

1126

}

1021

1127

errno = old_errno;

1022

1128

}

1023

1129

1130

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

1131

int ret;

1132

error_t ret_errno;

1133

1134

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

1135

if(s < 0){

1136

ret_errno = errno;

1137

perror_plus("socket");

1138

errno = ret_errno;

1139

return false;

1140

}

1141

strcpy(ifr->ifr_name, ifname);

1142

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1143

if(ret == -1){

1144

if(debug){

1145

ret_errno = errno;

1146

perror_plus("ioctl SIOCGIFFLAGS");

1147

errno = ret_errno;

1148

}

1149

return false;

1150

}

1151

return true;

1152

}

1153

1154

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

1155

1156

/* Reject the loopback device */

1157

if(ifr->ifr_flags & IFF_LOOPBACK){

1158

if(debug){

1159

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

1160

ifname);

1161

}

1162

return false;

1163

}

1164

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

1165

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

1166

if(debug){

1167

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

1168

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

1169

}

1170

return true;

1171

}

1172

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

1173

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

1174

if(debug){

1175

fprintf_plus(stderr, "Rejecting non-broadcast interface"

1176

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

1177

}

1178

return false;

1179

}

1180

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

1181

if(ifr->ifr_flags & IFF_NOARP){

1182

if(debug){

1183

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

1184

ifname);

1185

}

1186

return false;

1187

}

1188

1189

/* Accept this device */

1190

if(debug){

1191

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

1192

}

1193

return true;

1194

}

1195

1024

1196

/*

1025

1197

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

1026

1198

* corresponds to an acceptable network device.

1027

1199

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

1028

1200

*/

1029

1201

int good_interface(const struct dirent *if_entry){

1030

ssize_t ssret;

1031

char *flagname = NULL;

1032

1202

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

1033

1203

return 0;

1034

1204

}

1035

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

1036

if_entry->d_name);

1205

1206

struct ifreq ifr;

1207

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

1208

if(debug){

1209

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

1210

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

1211

}

1212

return 0;

1213

}

1214

1215

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

1216

return 0;

1217

}

1218

return 1;

1219

}

1220

1221

/*

1222

* This function determines if a network interface is up.

1223

*/

1224

bool interface_is_up(const char *interface){

1225

struct ifreq ifr;

1226

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

1227

if(debug){

1228

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

1229

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

1230

}

1231

return false;

1232

}

1233

1234

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

1235

}

1236

1237

/*

1238

* This function determines if a network interface is running

1239

*/

1240

bool interface_is_running(const char *interface){

1241

struct ifreq ifr;

1242

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

1243

if(debug){

1244

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

1245

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

1246

}

1247

return false;

1248

}

1249

1250

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

1251

}

1252

1253

int notdotentries(const struct dirent *direntry){

1254

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

1255

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

1256

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

1257

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

1258

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

1259

return 0;

1260

}

1261

return 1;

1262

}

1263

1264

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

1265

int runnable_hook(const struct dirent *direntry){

1266

int ret;

1267

size_t sret;

1268

struct stat st;

1269

1270

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

1271

/* Empty name? */

1272

return 0;

1273

}

1274

1275

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

1276

"abcdefghijklmnopqrstuvwxyz"

1277

"0123456789"

1278

"_-");

1279

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

1280

/* Contains non-allowed characters */

1281

if(debug){

1282

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

1283

direntry->d_name);

1284

}

1285

return 0;

1286

}

1287

1288

char *fullname = NULL;

1289

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

1037

1290

if(ret < 0){

1038

perror("asprintf");

1039

return 0;

1040

}

1041

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

1042

if(flags_fd == -1){

1043

perror("open");

1044

free(flagname);

1045

return 0;

1046

}

1047

free(flagname);

1048

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

1049

/* read line from flags_fd */

1050

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

1051

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

1052

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

1053

if(flagstring == NULL){

1054

perror("malloc");

1055

close(flags_fd);

1056

return 0;

1057

}

1058

while(to_read > 0){

1059

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

1060

(size_t)to_read));

1061

if(ssret == -1){

1062

perror("read");

1063

free(flagstring);

1064

close(flags_fd);

1065

return 0;

1066

}

1067

to_read -= ssret;

1068

if(ssret == 0){

1291

perror_plus("asprintf");

1292

return 0;

1293

}

1294

1295

ret = stat(fullname, &st);

1296

if(ret == -1){

1297

if(debug){

1298

perror_plus("Could not stat hook");

1299

}

1300

return 0;

1301

}

1302

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

1303

/* Not a regular file */

1304

if(debug){

1305

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

1306

direntry->d_name);

1307

}

1308

return 0;

1309

}

1310

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

1311

/* Not executable */

1312

if(debug){

1313

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

1314

direntry->d_name);

1315

}

1316

return 0;

1317

}

1318

if(debug){

1319

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

1320

direntry->d_name);

1321

}

1322

return 1;

1323

}

1324

1325

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1326

mandos_context *mc){

1327

int ret;

1328

struct timespec now;

1329

struct timespec waited_time;

1330

intmax_t block_time;

1331

1332

while(true){

1333

if(mc->current_server == NULL){

1334

if (debug){

1335

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

1336

" No timeout!\n");

1337

}

1338

ret = avahi_simple_poll_iterate(s, -1);

1339

} else {

1340

if (debug){

1341

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

1342

" it, or wait\n");

1343

}

1344

/* the current time */

1345

ret = clock_gettime(CLOCK_MONOTONIC, &now);

1346

if(ret == -1){

1347

perror_plus("clock_gettime");

1348

return -1;

1349

}

1350

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

1351

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

1352

waited_time.tv_sec = (now.tv_sec

1353

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

1354

waited_time.tv_nsec = (now.tv_nsec

1355

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

1356

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

1357

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

1358

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

1359

block_time = ((retry_interval

1360

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

1361

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

1362

1363

if (debug){

1364

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

1365

block_time);

1366

}

1367

1368

if(block_time <= 0){

1369

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

1370

mc->current_server->port,

1371

mc->current_server->if_index,

1372

mc->current_server->af, mc);

1373

if(ret == 0){

1374

avahi_simple_poll_quit(s);

1375

return 0;

1376

}

1377

ret = clock_gettime(CLOCK_MONOTONIC,

1378

&mc->current_server->last_seen);

1379

if(ret == -1){

1380

perror_plus("clock_gettime");

1381

return -1;

1382

}

1383

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

1384

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

1385

servers, but don't block */

1386

}

1387

1388

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

1389

}

1390

if(ret != 0){

1391

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

1392

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

1393

}

1394

}

1395

}

1396

}

1397

1398

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

1399

error_t raise_privileges(void){

1400

error_t old_errno = errno;

1401

error_t ret_errno = 0;

1402

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

1403

ret_errno = errno;

1404

perror_plus("seteuid");

1405

}

1406

errno = old_errno;

1407

return ret_errno;

1408

}

1409

1410

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

1411

error_t raise_privileges_permanently(void){

1412

error_t old_errno = errno;

1413

error_t ret_errno = raise_privileges();

1414

if(ret_errno != 0){

1415

errno = old_errno;

1416

return ret_errno;

1417

}

1418

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

1419

ret_errno = errno;

1420

perror_plus("seteuid");

1421

}

1422

errno = old_errno;

1423

return ret_errno;

1424

}

1425

1426

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

1427

error_t lower_privileges(void){

1428

error_t old_errno = errno;

1429

error_t ret_errno = 0;

1430

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

1431

ret_errno = errno;

1432

perror_plus("seteuid");

1433

}

1434

errno = old_errno;

1435

return ret_errno;

1436

}

1437

1438

/* Lower privileges permanently */

1439

error_t lower_privileges_permanently(void){

1440

error_t old_errno = errno;

1441

error_t ret_errno = 0;

1442

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

1443

ret_errno = errno;

1444

perror_plus("setuid");

1445

}

1446

errno = old_errno;

1447

return ret_errno;

1448

}

1449

1450

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

1451

const float delay){

1452

struct dirent **direntries;

1453

struct dirent *direntry;

1454

int ret;

1455

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

1456

alphasort);

1457

if(numhooks == -1){

1458

if(errno == ENOENT){

1459

if(debug){

1460

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

1461

" found\n", hookdir);

1462

}

1463

} else {

1464

perror_plus("scandir");

1465

}

1466

} else {

1467

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

1468

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

1469

direntry = direntries[i];

1470

char *fullname = NULL;

1471

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

1472

if(ret < 0){

1473

perror_plus("asprintf");

1474

continue;

1475

}

1476

if(debug){

1477

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

1478

direntry->d_name);

1479

}

1480

pid_t hook_pid = fork();

1481

if(hook_pid == 0){

1482

/* Child */

1483

/* Raise privileges */

1484

raise_privileges_permanently();

1485

/* Set group */

1486

errno = 0;

1487

ret = setgid(0);

1488

if(ret == -1){

1489

perror_plus("setgid");

1490

}

1491

/* Reset supplementary groups */

1492

errno = 0;

1493

ret = setgroups(0, NULL);

1494

if(ret == -1){

1495

perror_plus("setgroups");

1496

}

1497

dup2(devnull, STDIN_FILENO);

1498

close(devnull);

1499

dup2(STDERR_FILENO, STDOUT_FILENO);

1500

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

1501

if(ret == -1){

1502

perror_plus("setenv");

1503

_exit(EX_OSERR);

1504

}

1505

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

1506

if(ret == -1){

1507

perror_plus("setenv");

1508

_exit(EX_OSERR);

1509

}

1510

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

1511

if(ret == -1){

1512

perror_plus("setenv");

1513

_exit(EX_OSERR);

1514

}

1515

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

1516

if(ret == -1){

1517

perror_plus("setenv");

1518

_exit(EX_OSERR);

1519

}

1520

char *delaystring;

1521

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

1522

if(ret == -1){

1523

perror_plus("asprintf");

1524

_exit(EX_OSERR);

1525

}

1526

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

1527

if(ret == -1){

1528

free(delaystring);

1529

perror_plus("setenv");

1530

_exit(EX_OSERR);

1531

}

1532

free(delaystring);

1533

if(connect_to != NULL){

1534

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

1535

if(ret == -1){

1536

perror_plus("setenv");

1537

_exit(EX_OSERR);

1538

}

1539

}

1540

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

1541

perror_plus("execl");

1542

_exit(EXIT_FAILURE);

1543

}

1544

} else {

1545

int status;

1546

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

1547

perror_plus("waitpid");

1548

free(fullname);

1549

continue;

1550

}

1551

if(WIFEXITED(status)){

1552

if(WEXITSTATUS(status) != 0){

1553

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

1554

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

1555

WEXITSTATUS(status));

1556

free(fullname);

1557

continue;

1558

}

1559

} else if(WIFSIGNALED(status)){

1560

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

1561

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

1562

WTERMSIG(status));

1563

free(fullname);

1564

continue;

1565

} else {

1566

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

1567

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

1568

free(fullname);

1569

continue;

1570

}

1571

}

1572

free(fullname);

1573

if(debug){

1574

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

1575

direntry->d_name);

1576

}

1577

}

1578

close(devnull);

1579

}

1580

return true;

1581

}

1582

1583

error_t bring_up_interface(const char *const interface,

1584

const float delay){

1585

int sd = -1;

1586

error_t old_errno = errno;

1587

error_t ret_errno = 0;

1588

int ret, ret_setflags;

1589

struct ifreq network;

1590

unsigned int if_index = if_nametoindex(interface);

1591

if(if_index == 0){

1592

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

1593

errno = old_errno;

1594

return ENXIO;

1595

}

1596

1597

if(quit_now){

1598

errno = old_errno;

1599

return EINTR;

1600

}

1601

1602

if(not interface_is_up(interface)){

1603

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

1604

ret_errno = errno;

1605

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

1606

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

1607

return ret_errno;

1608

}

1609

network.ifr_flags |= IFF_UP;

1610

1611

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1612

if(sd < 0){

1613

ret_errno = errno;

1614

perror_plus("socket");

1615

errno = old_errno;

1616

return ret_errno;

1617

}

1618

1619

if(quit_now){

1620

close(sd);

1621

errno = old_errno;

1622

return EINTR;

1623

}

1624

1625

if(debug){

1626

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

1627

interface);

1628

}

1629

1630

/* Raise priviliges */

1631

raise_privileges();

1632

1633

#ifdef __linux__

1634

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1635

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

1636

int ret_linux = klogctl(8, NULL, 5);

1637

bool restore_loglevel = true;

1638

if(ret_linux == -1){

1639

restore_loglevel = false;

1640

perror_plus("klogctl");

1641

}

1642

#endif /* __linux__ */

1643

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

1644

ret_errno = errno;

1645

#ifdef __linux__

1646

if(restore_loglevel){

1647

ret_linux = klogctl(7, NULL, 0);

1648

if(ret_linux == -1){

1649

perror_plus("klogctl");

1650

}

1651

}

1652

#endif /* __linux__ */

1653

1654

/* Lower privileges */

1655

lower_privileges();

1656

1657

/* Close the socket */

1658

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

1659

if(ret == -1){

1660

perror_plus("close");

1661

}

1662

1663

if(ret_setflags == -1){

1664

errno = ret_errno;

1665

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1666

errno = old_errno;

1667

return ret_errno;

1668

}

1669

} else if(debug){

1670

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

1671

interface);

1672

}

1673

1674

/* Sleep checking until interface is running.

1675

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

1676

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

1677

if(interface_is_running(interface)){

1069

1678

break;

1070

1679

}

1071

}

1072

close(flags_fd);

1073

intmax_t tmpmax;

1074

char *tmp;

1075

errno = 0;

1076

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

1077

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

1078

and not (isspace(*tmp)))

1079

or tmpmax != (ifreq_flags)tmpmax){

1080

if(debug){

1081

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

1082

flagstring, if_entry->d_name);

1083

}

1084

free(flagstring);

1085

return 0;

1086

}

1087

free(flagstring);

1088

ifreq_flags flags = (ifreq_flags)tmpmax;

1089

/* Reject the loopback device */

1090

if(flags & IFF_LOOPBACK){

1091

if(debug){

1092

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

1093

if_entry->d_name);

1094

}

1095

return 0;

1096

}

1097

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

1098

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

1099

if(debug){

1100

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

1101

if_entry->d_name);

1102

}

1103

return 1;

1104

}

1105

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

1106

if(not (flags & IFF_BROADCAST)){

1107

if(debug){

1108

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

1109

if_entry->d_name);

1110

}

1111

return 0;

1112

}

1113

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

1114

if(flags & IFF_NOARP){

1115

if(debug){

1116

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

1117

if_entry->d_name);

1118

}

1119

return 0;

1120

}

1121

/* Accept this device */

1122

if(debug){

1123

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

1124

if_entry->d_name);

1125

}

1126

return 1;

1680

struct timespec sleeptime = { .tv_nsec = 250000000 };

1681

ret = nanosleep(&sleeptime, NULL);

1682

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

1683

perror_plus("nanosleep");

1684

}

1685

}

1686

1687

errno = old_errno;

1688

return 0;

1689

}

1690

1691

error_t take_down_interface(const char *const interface){

1692

int sd = -1;

1693

error_t old_errno = errno;

1694

error_t ret_errno = 0;

1695

int ret, ret_setflags;

1696

struct ifreq network;

1697

unsigned int if_index = if_nametoindex(interface);

1698

if(if_index == 0){

1699

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

1700

errno = old_errno;

1701

return ENXIO;

1702

}

1703

if(interface_is_up(interface)){

1704

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

1705

ret_errno = errno;

1706

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

1707

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

1708

return ret_errno;

1709

}

1710

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

1711

1712

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1713

if(sd < 0){

1714

ret_errno = errno;

1715

perror_plus("socket");

1716

errno = old_errno;

1717

return ret_errno;

1718

}

1719

1720

if(debug){

1721

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

1722

interface);

1723

}

1724

1725

/* Raise priviliges */

1726

raise_privileges();

1727

1728

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

1729

ret_errno = errno;

1730

1731

/* Lower privileges */

1732

lower_privileges();

1733

1734

/* Close the socket */

1735

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

1736

if(ret == -1){

1737

perror_plus("close");

1738

}

1739

1740

if(ret_setflags == -1){

1741

errno = ret_errno;

1742

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1743

errno = old_errno;

1744

return ret_errno;

1745

}

1746

} else if(debug){

1747

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

1748

interface);

1749

}

1750

1751

errno = old_errno;

1752

return 0;

1127

1753

}

1128

1754

1129

1755

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

1756

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

1757

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

1758

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

1130

1759

AvahiSServiceBrowser *sb = NULL;

1131

int error;

1760

error_t ret_errno;

1132

1761

int ret;

1133

1762

intmax_t tmpmax;

1134

1763

char *tmp;

1135

1764

int exitcode = EXIT_SUCCESS;

1136

const char *interface = "";

1137

struct ifreq network;

1138

int sd = -1;

1139

bool take_down_interface = false;

1140

uid_t uid;

1141

gid_t gid;

1765

char *interfaces = NULL;

1766

size_t interfaces_size = 0;

1767

char *interfaces_to_take_down = NULL;

1768

size_t interfaces_to_take_down_size = 0;

1142

1769

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

1143

1770

bool tempdir_created = false;

1144

1771

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1145

1772

const char *seckey = PATHDIR "/" SECKEY;

1146

1773

const char *pubkey = PATHDIR "/" PUBKEY;

1774

char *interfaces_hooks = NULL;

1775

size_t interfaces_hooks_size = 0;

1147

1776

1148

1777

bool gnutls_initialized = false;

1149

1778

bool gpgme_initialized = false;

1150

1779

float delay = 2.5f;

1780

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

1781

retrying the same server again */

1151

1782

1152

1783

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

1153

1784

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1159

1790

errno = 0;

1160

1791

ret = setgid(gid);

1161

1792

if(ret == -1){

1162

perror("setgid");

1793

perror_plus("setgid");

1163

1794

}

1164

1795

1165

1796

/* Lower user privileges (temporarily) */

1166

1797

errno = 0;

1167

1798

ret = seteuid(uid);

1168

1799

if(ret == -1){

1169

perror("seteuid");

1800

perror_plus("seteuid");

1170

1801

}

1171

1802

1172

1803

if(quit_now){

1207

1838

.arg = "SECONDS",

1208

1839

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

1209

1840

.group = 2 },

1841

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

1842

.arg = "SECONDS",

1843

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

1844

.group = 2 },

1845

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

1846

.arg = "DIR",

1847

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

1848

.group = 2 },

1210

1849

/*

1211

1850

* These reproduce what we would get without ARGP_NO_HELP

1212

1851

*/

1230

1869

connect_to = arg;

1231

1870

break;

1232

1871

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

1233

interface = arg;

1872

ret_errno = argz_add_sep(&interfaces, &interfaces_size, arg,

1873

(int)',');

1874

if(ret_errno != 0){

1875

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

1876

}

1234

1877

break;

1235

1878

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

1236

1879

seckey = arg;

1256

1899

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

1257

1900

argp_error(state, "Bad delay");

1258

1901

}

1902

case 132: /* --retry */

1903

errno = 0;

1904

retry_interval = strtod(arg, &tmp);

1905

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

1906

or (retry_interval * 1000) > INT_MAX

1907

or retry_interval < 0){

1908

argp_error(state, "Bad retry interval");

1909

}

1910

break;

1911

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

1912

hookdir = arg;

1259

1913

break;

1260

1914

/*

1261

1915

* These reproduce what we would get without ARGP_NO_HELP

1268

1922

argp_state_help(state, state->out_stream,

1269

1923

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1270

1924

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

1271

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

1925

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

1272

1926

exit(argp_err_exit_status);

1273

1927

break;

1274

1928

default:

1289

1943

case ENOMEM:

1290

1944

default:

1291

1945

errno = ret;

1292

perror("argp_parse");

1946

perror_plus("argp_parse");

1293

1947

exitcode = EX_OSERR;

1294

1948

goto end;

1295

1949

case EINVAL:

1297

1951

goto end;

1298

1952

}

1299

1953

}

1954

1955

{

1956

/* Work around Debian bug #633582:

1957

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

1958

1959

/* Re-raise priviliges */

1960

if(raise_privileges() == 0){

1961

struct stat st;

1962

1963

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

1964

int seckey_fd = open(seckey, O_RDONLY);

1965

if(seckey_fd == -1){

1966

perror_plus("open");

1967

} else {

1968

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

1969

if(ret == -1){

1970

perror_plus("fstat");

1971

} else {

1972

if(S_ISREG(st.st_mode)

1973

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

1974

ret = fchown(seckey_fd, uid, gid);

1975

if(ret == -1){

1976

perror_plus("fchown");

1977

}

1978

}

1979

}

1980

TEMP_FAILURE_RETRY(close(seckey_fd));

1981

}

1982

}

1983

1984

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

1985

int pubkey_fd = open(pubkey, O_RDONLY);

1986

if(pubkey_fd == -1){

1987

perror_plus("open");

1988

} else {

1989

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

1990

if(ret == -1){

1991

perror_plus("fstat");

1992

} else {

1993

if(S_ISREG(st.st_mode)

1994

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

1995

ret = fchown(pubkey_fd, uid, gid);

1996

if(ret == -1){

1997

perror_plus("fchown");

1998

}

1999

}

2000

}

2001

TEMP_FAILURE_RETRY(close(pubkey_fd));

2002

}

2003

}

2004

2005

/* Lower privileges */

2006

errno = 0;

2007

ret = seteuid(uid);

2008

if(ret == -1){

2009

perror_plus("seteuid");

2010

}

2011

}

2012

}

2013

2014

/* Remove empty interface names */

2015

{

2016

char *interface = NULL;

2017

while((interface = argz_next(interfaces, interfaces_size,

2018

interface))){

2019

if(if_nametoindex(interface) == 0){

2020

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

2021

fprintf_plus(stderr, "Not using nonexisting interface"

2022

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

2023

}

2024

argz_delete(&interfaces, &interfaces_size, interface);

2025

interface = NULL;

2026

}

2027

}

2028

}

2029

2030

/* Run network hooks */

2031

{

2032

2033

if(interfaces != NULL){

2034

interfaces_hooks = malloc(interfaces_size);

2035

if(interfaces_hooks == NULL){

2036

perror_plus("malloc");

2037

goto end;

2038

}

2039

memcpy(interfaces_hooks, interfaces, interfaces_size);

2040

interfaces_hooks_size = interfaces_size;

2041

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2042

(int)',');

2043

}

2044

if(not run_network_hooks("start", interfaces_hooks != NULL ?

2045

interfaces_hooks : "", delay)){

2046

goto end;

2047

}

2048

}

1300

2049

1301

2050

if(not debug){

1302

2051

avahi_set_log_function(empty_log);

1303

2052

}

1304

1305

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

1306

struct dirent **direntries;

1307

ret = scandir(sys_class_net, &direntries, good_interface,

1308

alphasort);

1309

if(ret >= 1){

1310

/* Pick the first good interface */

1311

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

1312

if(debug){

1313

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

1314

}

1315

if(interface == NULL){

1316

perror("malloc");

1317

free(direntries);

1318

exitcode = EXIT_FAILURE;

1319

goto end;

1320

}

1321

free(direntries);

1322

} else {

1323

free(direntries);

1324

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

1325

exitcode = EXIT_FAILURE;

1326

goto end;

1327

}

1328

}

1329

2053

1330

2054

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

1331

2055

from the signal handler */

1332

2056

/* Initialize the pseudo-RNG for Avahi */

1333

2057

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

1334

mc.simple_poll = avahi_simple_poll_new();

1335

if(mc.simple_poll == NULL){

1336

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

2058

simple_poll = avahi_simple_poll_new();

2059

if(simple_poll == NULL){

2060

fprintf_plus(stderr,

2061

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

1337

2062

exitcode = EX_UNAVAILABLE;

1338

2063

goto end;

1339

2064

}

1341

2066

sigemptyset(&sigterm_action.sa_mask);

1342

2067

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

1343

2068

if(ret == -1){

1344

perror("sigaddset");

2069

perror_plus("sigaddset");

1345

2070

exitcode = EX_OSERR;

1346

2071

goto end;

1347

2072

}

1348

2073

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

1349

2074

if(ret == -1){

1350

perror("sigaddset");

2075

perror_plus("sigaddset");

1351

2076

exitcode = EX_OSERR;

1352

2077

goto end;

1353

2078

}

1354

2079

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

1355

2080

if(ret == -1){

1356

perror("sigaddset");

2081

perror_plus("sigaddset");

1357

2082

exitcode = EX_OSERR;

1358

2083

goto end;

1359

2084

}

1363

2088

*/

1364

2089

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

1365

2090

if(ret == -1){

1366

perror("sigaction");

2091

perror_plus("sigaction");

1367

2092

return EX_OSERR;

1368

2093

}

1369

2094

if(old_sigterm_action.sa_handler != SIG_IGN){

1370

2095

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

1371

2096

if(ret == -1){

1372

perror("sigaction");

2097

perror_plus("sigaction");

1373

2098

exitcode = EX_OSERR;

1374

2099

goto end;

1375

2100

}

1376

2101

}

1377

2102

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

1378

2103

if(ret == -1){

1379

perror("sigaction");

2104

perror_plus("sigaction");

1380

2105

return EX_OSERR;

1381

2106

}

1382

2107

if(old_sigterm_action.sa_handler != SIG_IGN){

1383

2108

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

1384

2109

if(ret == -1){

1385

perror("sigaction");

2110

perror_plus("sigaction");

1386

2111

exitcode = EX_OSERR;

1387

2112

goto end;

1388

2113

}

1389

2114

}

1390

2115

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

1391

2116

if(ret == -1){

1392

perror("sigaction");

2117

perror_plus("sigaction");

1393

2118

return EX_OSERR;

1394

2119

}

1395

2120

if(old_sigterm_action.sa_handler != SIG_IGN){

1396

2121

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

1397

2122

if(ret == -1){

1398

perror("sigaction");

2123

perror_plus("sigaction");

1399

2124

exitcode = EX_OSERR;

1400

2125

goto end;

1401

2126

}

1402

2127

}

1403

2128

1404

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

1405

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

1406

if_index = (AvahiIfIndex) if_nametoindex(interface);

1407

if(if_index == 0){

1408

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

1409

exitcode = EX_UNAVAILABLE;

1410

goto end;

1411

}

1412

1413

if(quit_now){

1414

goto end;

1415

}

1416

1417

/* Re-raise priviliges */

1418

errno = 0;

1419

ret = seteuid(0);

1420

if(ret == -1){

1421

perror("seteuid");

1422

}

1423

1424

#ifdef __linux__

1425

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1426

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

1427

ret = klogctl(8, NULL, 5);

1428

bool restore_loglevel = true;

1429

if(ret == -1){

1430

restore_loglevel = false;

1431

perror("klogctl");

1432

}

1433

#endif /* __linux__ */

1434

1435

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1436

if(sd < 0){

1437

perror("socket");

1438

exitcode = EX_OSERR;

1439

#ifdef __linux__

1440

if(restore_loglevel){

1441

ret = klogctl(7, NULL, 0);

1442

if(ret == -1){

1443

perror("klogctl");

1444

}

1445

}

1446

#endif /* __linux__ */

1447

/* Lower privileges */

1448

errno = 0;

1449

ret = seteuid(uid);

1450

if(ret == -1){

1451

perror("seteuid");

1452

}

1453

goto end;

1454

}

1455

strcpy(network.ifr_name, interface);

1456

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

1457

if(ret == -1){

1458

perror("ioctl SIOCGIFFLAGS");

1459

#ifdef __linux__

1460

if(restore_loglevel){

1461

ret = klogctl(7, NULL, 0);

1462

if(ret == -1){

1463

perror("klogctl");

1464

}

1465

}

1466

#endif /* __linux__ */

1467

exitcode = EX_OSERR;

1468

/* Lower privileges */

1469

errno = 0;

1470

ret = seteuid(uid);

1471

if(ret == -1){

1472

perror("seteuid");

1473

}

1474

goto end;

1475

}

1476

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

1477

network.ifr_flags |= IFF_UP;

1478

take_down_interface = true;

1479

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

1480

if(ret == -1){

1481

take_down_interface = false;

1482

perror("ioctl SIOCSIFFLAGS +IFF_UP");

1483

exitcode = EX_OSERR;

1484

#ifdef __linux__

1485

if(restore_loglevel){

1486

ret = klogctl(7, NULL, 0);

1487

if(ret == -1){

1488

perror("klogctl");

1489

}

1490

}

1491

#endif /* __linux__ */

1492

/* Lower privileges */

1493

errno = 0;

1494

ret = seteuid(uid);

1495

if(ret == -1){

1496

perror("seteuid");

1497

}

1498

goto end;

1499

}

1500

}

1501

/* sleep checking until interface is running */

1502

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

1503

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

1504

if(ret == -1){

1505

perror("ioctl SIOCGIFFLAGS");

1506

} else if(network.ifr_flags & IFF_RUNNING){

1507

break;

1508

}

1509

struct timespec sleeptime = { .tv_nsec = 250000000 };

1510

ret = nanosleep(&sleeptime, NULL);

1511

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

1512

perror("nanosleep");

1513

}

1514

}

1515

if(not take_down_interface){

1516

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

1517

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

1518

if(ret == -1){

1519

perror("close");

1520

}

1521

}

1522

#ifdef __linux__

1523

if(restore_loglevel){

1524

/* Restores kernel loglevel to default */

1525

ret = klogctl(7, NULL, 0);

1526

if(ret == -1){

1527

perror("klogctl");

1528

}

1529

}

1530

#endif /* __linux__ */

1531

/* Lower privileges */

1532

errno = 0;

1533

if(take_down_interface){

1534

/* Lower privileges */

1535

ret = seteuid(uid);

1536

if(ret == -1){

1537

perror("seteuid");

1538

}

2129

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

2130

if(interfaces == NULL){

2131

struct dirent **direntries;

2132

/* Look for any good interfaces */

2133

ret = scandir(sys_class_net, &direntries, good_interface,

2134

alphasort);

2135

if(ret >= 1){

2136

/* Add all found interfaces to interfaces list */

2137

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

2138

ret_errno = argz_add(&interfaces, &interfaces_size,

2139

direntries[i]->d_name);

2140

if(ret_errno != 0){

2141

perror_plus("argz_add");

2142

continue;

2143

}

2144

if(debug){

2145

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

2146

direntries[i]->d_name);

2147

}

2148

}

2149

free(direntries);

1539

2150

} else {

1540

/* Lower privileges permanently */

1541

ret = setuid(uid);

1542

if(ret == -1){

1543

perror("setuid");

2151

free(direntries);

2152

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

2153

exitcode = EXIT_FAILURE;

2154

goto end;

2155

}

2156

}

2157

2158

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

2159

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

2160

if(debug){

2161

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

2162

interfaces);

2163

}

2164

if_index = (AvahiIfIndex)if_nametoindex(interfaces);

2165

}

2166

2167

/* Bring up interfaces which are down */

2168

if(not (argz_count(interfaces, interfaces_size) == 1

2169

and strcmp(interfaces, "none") == 0)){

2170

char *interface = NULL;

2171

while((interface = argz_next(interfaces, interfaces_size,

2172

interface))){

2173

bool interface_was_up = interface_is_up(interface);

2174

ret = bring_up_interface(interface, delay);

2175

if(not interface_was_up){

2176

if(ret != 0){

2177

errno = ret;

2178

perror_plus("Failed to bring up interface");

2179

} else {

2180

ret_errno = argz_add(&interfaces_to_take_down,

2181

&interfaces_to_take_down_size,

2182

interface);

2183

}

1544

2184

}

1545

2185

}

2186

free(interfaces);

2187

interfaces = NULL;

2188

interfaces_size = 0;

2189

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

2190

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

2191

}

1546

2192

}

1547

2193

1548

2194

if(quit_now){

1549

2195

goto end;

1550

2196

}

1551

2197

1552

ret = init_gnutls_global(pubkey, seckey);

2198

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

1553

2199

if(ret == -1){

1554

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

2200

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

1555

2201

exitcode = EX_UNAVAILABLE;

1556

2202

goto end;

1557

2203

} else {

1562

2208

goto end;

1563

2209

}

1564

2210

2211

if(mkdtemp(tempdir) == NULL){

2212

perror_plus("mkdtemp");

2213

goto end;

2214

}

1565

2215

tempdir_created = true;

1566

if(mkdtemp(tempdir) == NULL){

1567

tempdir_created = false;

1568

perror("mkdtemp");

1569

goto end;

1570

}

1571

2216

1572

2217

if(quit_now){

1573

2218

goto end;

1574

2219

}

1575

2220

1576

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

1577

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

2221

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

2222

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

1578

2223

exitcode = EX_UNAVAILABLE;

1579

2224

goto end;

1580

2225

} else {

1589

2234

/* Connect directly, do not use Zeroconf */

1590

2235

/* (Mainly meant for debugging) */

1591

2236

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

2237

1592

2238

if(address == NULL){

1593

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

2239

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

1594

2240

exitcode = EX_USAGE;

1595

2241

goto end;

1596

2242

}

1599

2245

goto end;

1600

2246

}

1601

2247

1602

uint16_t port;

2248

in_port_t port;

1603

2249

errno = 0;

1604

2250

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

1605

2251

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

1606

or tmpmax != (uint16_t)tmpmax){

1607

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

2252

or tmpmax != (in_port_t)tmpmax){

2253

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

1608

2254

exitcode = EX_USAGE;

1609

2255

goto end;

1610

2256

}

1613

2259

goto end;

1614

2260

}

1615

2261

1616

port = (uint16_t)tmpmax;

2262

port = (in_port_t)tmpmax;

1617

2263

*address = '\0';

1618

address = connect_to;

1619

2264

/* Colon in address indicates IPv6 */

1620

2265

int af;

1621

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

2266

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

1622

2267

af = AF_INET6;

2268

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

2269

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

2270

{

2271

connect_to++;

2272

address[-1] = '\0';

2273

}

1623

2274

} else {

1624

2275

af = AF_INET;

1625

2276

}

2277

address = connect_to;

1626

2278

1627

2279

if(quit_now){

1628

2280

goto end;

1629

2281

}

1630

2282

1631

2283

while(not quit_now){

1632

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

2284

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

2285

&mc);

1633

2286

if(quit_now or ret == 0){

1634

2287

break;

1635

2288

}

1636

sleep(15);

1637

};

1638

2289

if(debug){

2290

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

2291

(int)retry_interval);

2292

}

2293

sleep((int)retry_interval);

2294

}

2295

1639

2296

if (not quit_now){

1640

2297

exitcode = EXIT_SUCCESS;

1641

2298

}

1642

2299

1643

2300

goto end;

1644

2301

}

1645

2302

1657

2314

config.publish_domain = 0;

1658

2315

1659

2316

/* Allocate a new server */

1660

mc.server = avahi_server_new(avahi_simple_poll_get

1661

(mc.simple_poll), &config, NULL,

1662

NULL, &error);

2317

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2318

&config, NULL, NULL, &ret_errno);

1663

2319

1664

2320

/* Free the Avahi configuration data */

1665

2321

avahi_server_config_free(&config);

1667

2323

1668

2324

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

1669

2325

if(mc.server == NULL){

1670

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

1671

avahi_strerror(error));

2326

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

2327

avahi_strerror(ret_errno));

1672

2328

exitcode = EX_UNAVAILABLE;

1673

2329

goto end;

1674

2330

}

1680

2336

/* Create the Avahi service browser */

1681

2337

sb = avahi_s_service_browser_new(mc.server, if_index,

1682

2338

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1683

NULL, 0, browse_callback, NULL);

2339

NULL, 0, browse_callback,

2340

(void *)&mc);

1684

2341

if(sb == NULL){

1685

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

1686

avahi_strerror(avahi_server_errno(mc.server)));

2342

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

2343

avahi_strerror(avahi_server_errno(mc.server)));

1687

2344

exitcode = EX_UNAVAILABLE;

1688

2345

goto end;

1689

2346

}

1695

2352

/* Run the main loop */

1696

2353

1697

2354

if(debug){

1698

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

1699

}

1700

1701

avahi_simple_poll_loop(mc.simple_poll);

2355

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

2356

}

2357

2358

ret = avahi_loop_with_timeout(simple_poll,

2359

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

2360

if(debug){

2361

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

2362

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

2363

}

1702

2364

1703

2365

end:

1704

2366

1705

2367

if(debug){

1706

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

2368

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

1707

2369

}

1708

2370

1709

2371

/* Cleanup things */

1713

2375

if(mc.server != NULL)

1714

2376

avahi_server_free(mc.server);

1715

2377

1716

if(mc.simple_poll != NULL)

1717

avahi_simple_poll_free(mc.simple_poll);

2378

if(simple_poll != NULL)

2379

avahi_simple_poll_free(simple_poll);

1718

2380

1719

2381

if(gnutls_initialized){

1720

2382

gnutls_certificate_free_credentials(mc.cred);

1726

2388

gpgme_release(mc.ctx);

1727

2389

}

1728

2390

1729

/* Take down the network interface */

1730

if(take_down_interface){

1731

/* Re-raise priviliges */

1732

errno = 0;

1733

ret = seteuid(0);

1734

if(ret == -1){

1735

perror("seteuid");

2391

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

2392

has seen */

2393

if(mc.current_server != NULL){

2394

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

2395

while(mc.current_server != NULL){

2396

server *next = mc.current_server->next;

2397

free(mc.current_server);

2398

mc.current_server = next;

1736

2399

}

1737

if(geteuid() == 0){

1738

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

1739

if(ret == -1){

1740

perror("ioctl SIOCGIFFLAGS");

1741

} else if(network.ifr_flags & IFF_UP) {

1742

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

1743

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

1744

if(ret == -1){

1745

perror("ioctl SIOCSIFFLAGS -IFF_UP");

2400

}

2401

2402

/* Re-raise priviliges */

2403

{

2404

raise_privileges();

2405

2406

/* Run network hooks */

2407

run_network_hooks("stop", interfaces_hooks != NULL ?

2408

interfaces_hooks : "", delay);

2409

2410

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

2411

{

2412

char *interface = NULL;

2413

while((interface=argz_next(interfaces_to_take_down,

2414

interfaces_to_take_down_size,

2415

interface))){

2416

ret_errno = take_down_interface(interface);

2417

if(ret_errno != 0){

2418

errno = ret_errno;

2419

perror_plus("Failed to take down interface");

1746

2420

}

1747

2421

}

1748

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

1749

if(ret == -1){

1750

perror("close");

1751

}

1752

/* Lower privileges permanently */

1753

errno = 0;

1754

ret = setuid(uid);

1755

if(ret == -1){

1756

perror("setuid");

2422

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

2423

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

2424

" down\n");

1757

2425

}

1758

2426

}

2427

2428

lower_privileges_permanently();

1759

2429

}

1760

2430

1761

/* Removes the temp directory used by GPGME */

2431

free(interfaces_to_take_down);

2432

free(interfaces_hooks);

2433

2434

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

1762

2435

if(tempdir_created){

1763

DIR *d;

1764

struct dirent *direntry;

1765

d = opendir(tempdir);

1766

if(d == NULL){

1767

if(errno != ENOENT){

1768

perror("opendir");

1769

}

1770

} else {

1771

while(true){

1772

direntry = readdir(d);

1773

if(direntry == NULL){

1774

break;

1775

}

1776

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

1777

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

1778

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

1779

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

1780

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

1781

continue;

1782

}

2436

struct dirent **direntries = NULL;

2437

struct dirent *direntry = NULL;

2438

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

2439

alphasort);

2440

if (numentries > 0){

2441

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

2442

direntry = direntries[i];

1783

2443

char *fullname = NULL;

1784

2444

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

1785

2445

direntry->d_name);

1786

2446

if(ret < 0){

1787

perror("asprintf");

2447

perror_plus("asprintf");

1788

2448

continue;

1789

2449

}

1790

2450

ret = remove(fullname);

1791

2451

if(ret == -1){

1792

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

1793

strerror(errno));

2452

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

2453

strerror(errno));

1794

2454

}

1795

2455

free(fullname);

1796

2456

}

1797

closedir(d);

2457

}

2458

2459

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

2460

free(direntries);

2461

if (numentries == -1){

2462

perror_plus("scandir");

1798

2463

}

1799

2464

ret = rmdir(tempdir);

1800

2465

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

1801

perror("rmdir");

2466

perror_plus("rmdir");

1802

2467

}

1803

2468

}

1804

2469

1809

2474

&old_sigterm_action,

1810

2475

NULL));

1811

2476

if(ret == -1){

1812

perror("sigaction");

2477

perror_plus("sigaction");

1813

2478

}

1814

2479

do {

1815

2480

ret = raise(signal_received);

1816

2481

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

1817

2482

if(ret != 0){

1818

perror("raise");

2483

perror_plus("raise");

1819

2484

abort();

1820

2485

}

1821

2486

TEMP_FAILURE_RETRY(pause());