/mandos/release : revision 237.7.325

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

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

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

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

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asprintf(), strcpy() */

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

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

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sockaddr_in6, PF_INET6,

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SOCK_STREAM, uid_t, gid_t, open(),

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opendir(), DIR */

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

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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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118

init_gnutls_session(),

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119

GNUTLS_* */

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120

#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"

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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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bool debug = false;

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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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/* 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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161

typedef struct {

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AvahiSimplePoll *simple_poll;

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162

AvahiServer *server;

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163

gnutls_certificate_credentials_t cred;

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unsigned int dh_bits;

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gnutls_dh_params_t dh_params;

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166

const char *priority;

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gpgme_ctx_t ctx;

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server *current_server;

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char *interfaces;

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size_t interfaces_size;

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171

} mandos_context;

141

172

142

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

143

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*/

174

AvahiSimplePoll *simple_poll;

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175

147

176

sig_atomic_t quit_now = 0;

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177

int signal_received = 0;

149

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179

/* Function to use when printing errors */

180

void perror_plus(const char *print_text){

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int e = errno;

182

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

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program_invocation_short_name);

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errno = e;

185

perror(print_text);

186

}

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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

150

198

/*

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199

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

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200

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

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201

* "buffer_length" is how much is already used.

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202

*/

203

__attribute__((nonnull, warn_unused_result))

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204

size_t incbuffer(char **buffer, size_t buffer_length,

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size_t buffer_capacity){

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size_t buffer_capacity){

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206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

158

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

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if(buffer == NULL){

207

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

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if(new_buf == NULL){

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int old_errno = errno;

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free(*buffer);

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errno = old_errno;

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*buffer = NULL;

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213

return 0;

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214

}

215

*buffer = new_buf;

162

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buffer_capacity += BUFFER_SIZE;

163

217

}

164

218

return buffer_capacity;

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219

}

166

220

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

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__attribute__((nonnull, warn_unused_result))

223

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

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int af, server **current_server){

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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,

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.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;

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*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;

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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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return true;

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}

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/*

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* Initialize GPGME.

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271

*/

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static bool init_gpgme(const char *seckey,

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const char *pubkey, const char *tempdir){

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__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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gpgme_error_t rc;

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gpgme_engine_info_t engine_info;

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279

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280

/*

177

281

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

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282

*/

179

bool import_key(const char *filename){

283

bool import_key(const char * const filename){

180

284

int ret;

181

285

int fd;

182

286

gpgme_data_t pgp_data;

183

287

184

288

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

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289

if(fd == -1){

186

perror("open");

290

perror_plus("open");

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291

return false;

188

292

}

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190

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rc = gpgme_data_new_from_fd(&pgp_data, fd);

191

295

if(rc != GPG_ERR_NO_ERROR){

192

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",

297

gpgme_strsource(rc), gpgme_strerror(rc));

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return false;

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299

}

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300

197

rc = gpgme_op_import(mc.ctx, pgp_data);

301

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

198

302

if(rc != GPG_ERR_NO_ERROR){

199

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",

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gpgme_strsource(rc), gpgme_strerror(rc));

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305

return false;

202

306

}

203

307

204

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

308

ret = close(fd);

205

309

if(ret == -1){

206

perror("close");

310

perror_plus("close");

207

311

}

208

312

gpgme_data_release(pgp_data);

209

313

return true;

210

314

}

211

315

212

316

if(debug){

213

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

317

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

214

318

}

215

319

216

320

/* Init GPGME */

217

321

gpgme_check_version(NULL);

218

322

rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);

219

323

if(rc != GPG_ERR_NO_ERROR){

220

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

221

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));

222

326

return false;

223

327

}

224

328

225

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

329

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

226

330

rc = gpgme_get_engine_info(&engine_info);

227

331

if(rc != GPG_ERR_NO_ERROR){

228

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

229

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));

230

334

return false;

231

335

}

232

336

while(engine_info != NULL){

238

342

engine_info = engine_info->next;

239

343

}

240

344

if(engine_info == NULL){

241

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);

242

347

return false;

243

348

}

244

349

245

350

/* Create new GPGME "context" */

246

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

351

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

247

352

if(rc != GPG_ERR_NO_ERROR){

248

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

249

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));

250

356

return false;

251

357

}

252

358

261

367

* Decrypt OpenPGP data.

262

368

* Returns -1 on error

263

369

*/

370

__attribute__((nonnull, warn_unused_result))

264

371

static ssize_t pgp_packet_decrypt(const char *cryptotext,

265

372

size_t crypto_size,

266

char **plaintext){

373

char **plaintext,

374

mandos_context *mc){

267

375

gpgme_data_t dh_crypto, dh_plain;

268

376

gpgme_error_t rc;

269

377

ssize_t ret;

271

379

ssize_t plaintext_length = 0;

272

380

273

381

if(debug){

274

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

382

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

275

383

}

276

384

277

385

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

278

386

rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,

279

387

0);

280

388

if(rc != GPG_ERR_NO_ERROR){

281

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

282

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));

283

391

return -1;

284

392

}

285

393

286

394

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

287

395

rc = gpgme_data_new(&dh_plain);

288

396

if(rc != GPG_ERR_NO_ERROR){

289

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

290

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));

291

400

gpgme_data_release(dh_crypto);

292

401

return -1;

293

402

}

294

403

295

404

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

296

405

data buffer */

297

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

406

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

298

407

if(rc != GPG_ERR_NO_ERROR){

299

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

300

gpgme_strsource(rc), gpgme_strerror(rc));

408

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

409

gpgme_strsource(rc), gpgme_strerror(rc));

301

410

plaintext_length = -1;

302

411

if(debug){

303

412

gpgme_decrypt_result_t result;

304

result = gpgme_op_decrypt_result(mc.ctx);

413

result = gpgme_op_decrypt_result(mc->ctx);

305

414

if(result == NULL){

306

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

415

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

307

416

} else {

308

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

309

result->unsupported_algorithm);

310

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

311

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);

312

421

if(result->file_name != NULL){

313

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

422

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

314

423

}

315

424

gpgme_recipient_t recipient;

316

425

recipient = result->recipients;

317

426

while(recipient != NULL){

318

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

319

gpgme_pubkey_algo_name(recipient->pubkey_algo));

320

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

321

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

322

recipient->status == GPG_ERR_NO_SECKEY

323

? "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");

324

434

recipient = recipient->next;

325

435

}

326

436

}

329

439

}

330

440

331

441

if(debug){

332

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

442

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

333

443

}

334

444

335

445

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

336

446

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

337

perror("gpgme_data_seek");

447

perror_plus("gpgme_data_seek");

338

448

plaintext_length = -1;

339

449

goto decrypt_end;

340

450

}

342

452

*plaintext = NULL;

343

453

while(true){

344

454

plaintext_capacity = incbuffer(plaintext,

345

(size_t)plaintext_length,

346

plaintext_capacity);

455

(size_t)plaintext_length,

456

plaintext_capacity);

347

457

if(plaintext_capacity == 0){

348

perror("incbuffer");

349

plaintext_length = -1;

350

goto decrypt_end;

458

perror_plus("incbuffer");

459

plaintext_length = -1;

460

goto decrypt_end;

351

461

}

352

462

353

463

ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,

358

468

break;

359

469

}

360

470

if(ret < 0){

361

perror("gpgme_data_read");

471

perror_plus("gpgme_data_read");

362

472

plaintext_length = -1;

363

473

goto decrypt_end;

364

474

}

366

476

}

367

477

368

478

if(debug){

369

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

479

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

370

480

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

371

481

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

372

482

}

383

493

return plaintext_length;

384

494

}

385

495

386

static const char * safer_gnutls_strerror(int value){

387

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

388

-Wunreachable-code */

389

if(ret == NULL)

390

ret = "(unknown)";

391

return ret;

496

__attribute__((warn_unused_result, const))

497

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

498

if(str == NULL)

499

return "(unknown)";

500

return str;

501

}

502

503

__attribute__((warn_unused_result))

504

static const char *safer_gnutls_strerror(int value){

505

const char *ret = gnutls_strerror(value);

506

return safe_string(ret);

392

507

}

393

508

394

509

/* GnuTLS log function callback */

510

__attribute__((nonnull))

395

511

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

396

512

const char* string){

397

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

513

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

398

514

}

399

515

516

__attribute__((nonnull, warn_unused_result))

400

517

static int init_gnutls_global(const char *pubkeyfilename,

401

const char *seckeyfilename){

518

const char *seckeyfilename,

519

const char *dhparamsfilename,

520

mandos_context *mc){

402

521

int ret;

522

unsigned int uret;

403

523

404

524

if(debug){

405

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

525

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

406

526

}

407

527

408

528

ret = gnutls_global_init();

409

529

if(ret != GNUTLS_E_SUCCESS){

410

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

411

safer_gnutls_strerror(ret));

530

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

531

safer_gnutls_strerror(ret));

412

532

return -1;

413

533

}

414

534

421

541

}

422

542

423

543

/* OpenPGP credentials */

424

gnutls_certificate_allocate_credentials(&mc.cred);

544

ret = gnutls_certificate_allocate_credentials(&mc->cred);

425

545

if(ret != GNUTLS_E_SUCCESS){

426

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

427

from

428

-Wunreachable-code

429

*/

430

safer_gnutls_strerror(ret));

546

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

547

safer_gnutls_strerror(ret));

431

548

gnutls_global_deinit();

432

549

return -1;

433

550

}

434

551

435

552

if(debug){

436

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

437

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

438

seckeyfilename);

553

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

554

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

555

pubkeyfilename,

556

seckeyfilename);

439

557

}

440

558

441

559

ret = gnutls_certificate_set_openpgp_key_file

442

(mc.cred, pubkeyfilename, seckeyfilename,

560

(mc->cred, pubkeyfilename, seckeyfilename,

443

561

GNUTLS_OPENPGP_FMT_BASE64);

444

562

if(ret != GNUTLS_E_SUCCESS){

445

fprintf(stderr,

446

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

447

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

448

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

449

safer_gnutls_strerror(ret));

563

fprintf_plus(stderr,

564

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

565

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

566

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

567

safer_gnutls_strerror(ret));

450

568

goto globalfail;

451

569

}

452

570

453

571

/* GnuTLS server initialization */

454

ret = gnutls_dh_params_init(&mc.dh_params);

455

if(ret != GNUTLS_E_SUCCESS){

456

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

457

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

458

goto globalfail;

459

}

460

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

461

if(ret != GNUTLS_E_SUCCESS){

462

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

463

safer_gnutls_strerror(ret));

464

goto globalfail;

465

}

466

467

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

572

ret = gnutls_dh_params_init(&mc->dh_params);

573

if(ret != GNUTLS_E_SUCCESS){

574

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

575

" initialization: %s\n",

576

safer_gnutls_strerror(ret));

577

goto globalfail;

578

}

579

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

580

if(dhparamsfilename != NULL){

581

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

582

do {

583

int dhpfile = open(dhparamsfilename, O_RDONLY);

584

if(dhpfile == -1){

585

perror_plus("open");

586

dhparamsfilename = NULL;

587

break;

588

}

589

size_t params_capacity = 0;

590

while(true){

591

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

592

(size_t)params.size,

593

(size_t)params_capacity);

594

if(params_capacity == 0){

595

perror_plus("incbuffer");

596

free(params.data);

597

params.data = NULL;

598

dhparamsfilename = NULL;

599

break;

600

}

601

ssize_t bytes_read = read(dhpfile,

602

params.data + params.size,

603

BUFFER_SIZE);

604

/* EOF */

605

if(bytes_read == 0){

606

break;

607

}

608

/* check bytes_read for failure */

609

if(bytes_read < 0){

610

perror_plus("read");

611

free(params.data);

612

params.data = NULL;

613

dhparamsfilename = NULL;

614

break;

615

}

616

params.size += (unsigned int)bytes_read;

617

}

618

if(params.data == NULL){

619

dhparamsfilename = NULL;

620

}

621

if(dhparamsfilename == NULL){

622

break;

623

}

624

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

625

GNUTLS_X509_FMT_PEM);

626

if(ret != GNUTLS_E_SUCCESS){

627

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

628

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

629

safer_gnutls_strerror(ret));

630

dhparamsfilename = NULL;

631

}

632

} while(false);

633

}

634

if(dhparamsfilename == NULL){

635

if(mc->dh_bits == 0){

636

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

637

/* Try to read the private key file */

638

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

639

do {

640

int secfile = open(seckeyfilename, O_RDONLY);

641

if(secfile == -1){

642

perror_plus("open");

643

break;

644

}

645

size_t buffer_capacity = 0;

646

while(true){

647

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

648

(size_t)buffer.size,

649

(size_t)buffer_capacity);

650

if(buffer_capacity == 0){

651

perror_plus("incbuffer");

652

free(buffer.data);

653

buffer.data = NULL;

654

break;

655

}

656

ssize_t bytes_read = read(secfile,

657

buffer.data + buffer.size,

658

BUFFER_SIZE);

659

/* EOF */

660

if(bytes_read == 0){

661

break;

662

}

663

/* check bytes_read for failure */

664

if(bytes_read < 0){

665

perror_plus("read");

666

free(buffer.data);

667

buffer.data = NULL;

668

break;

669

}

670

buffer.size += (unsigned int)bytes_read;

671

}

672

close(secfile);

673

} while(false);

674

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

675

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

676

if(buffer.data != NULL){

677

{

678

gnutls_openpgp_privkey_t privkey = NULL;

679

ret = gnutls_openpgp_privkey_init(&privkey);

680

if(ret != GNUTLS_E_SUCCESS){

681

fprintf_plus(stderr, "Error initializing OpenPGP key"

682

" structure: %s",

683

safer_gnutls_strerror(ret));

684

free(buffer.data);

685

buffer.data = NULL;

686

} else {

687

ret = gnutls_openpgp_privkey_import

688

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

689

if(ret != GNUTLS_E_SUCCESS){

690

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

691

safer_gnutls_strerror(ret));

692

privkey = NULL;

693

}

694

free(buffer.data);

695

buffer.data = NULL;

696

if(privkey != NULL){

697

/* Use private key to suggest an appropriate

698

sec_param */

699

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

700

gnutls_openpgp_privkey_deinit(privkey);

701

if(debug){

702

fprintf_plus(stderr, "This OpenPGP key implies using"

703

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

704

safe_string(gnutls_sec_param_get_name

705

(sec_param)));

706

}

707

}

708

}

709

}

710

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

711

/* Err on the side of caution */

712

sec_param = GNUTLS_SEC_PARAM_ULTRA;

713

if(debug){

714

fprintf_plus(stderr, "Falling back to security parameter"

715

" \"%s\"\n",

716

safe_string(gnutls_sec_param_get_name

717

(sec_param)));

718

}

719

}

720

}

721

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

722

if(uret != 0){

723

mc->dh_bits = uret;

724

if(debug){

725

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

726

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

727

safe_string(gnutls_sec_param_get_name

728

(sec_param)),

729

mc->dh_bits);

730

}

731

} else {

732

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

733

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

734

safe_string(gnutls_sec_param_get_name

735

(sec_param)),

736

safer_gnutls_strerror(ret));

737

goto globalfail;

738

}

739

} else if(debug){

740

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

741

mc->dh_bits);

742

}

743

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

744

if(ret != GNUTLS_E_SUCCESS){

745

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

746

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

747

safer_gnutls_strerror(ret));

748

goto globalfail;

749

}

750

}

751

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

468

752

469

753

return 0;

470

754

471

755

globalfail:

472

756

473

gnutls_certificate_free_credentials(mc.cred);

757

gnutls_certificate_free_credentials(mc->cred);

474

758

gnutls_global_deinit();

475

gnutls_dh_params_deinit(mc.dh_params);

759

gnutls_dh_params_deinit(mc->dh_params);

476

760

return -1;

477

761

}

478

762

479

static int init_gnutls_session(gnutls_session_t *session){

763

__attribute__((nonnull, warn_unused_result))

764

static int init_gnutls_session(gnutls_session_t *session,

765

mandos_context *mc){

480

766

int ret;

481

767

/* GnuTLS session creation */

482

768

do {

486

772

}

487

773

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

488

774

if(ret != GNUTLS_E_SUCCESS){

489

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

490

safer_gnutls_strerror(ret));

775

fprintf_plus(stderr,

776

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

777

safer_gnutls_strerror(ret));

491

778

}

492

779

493

780

{

494

781

const char *err;

495

782

do {

496

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

783

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

497

784

if(quit_now){

498

785

gnutls_deinit(*session);

499

786

return -1;

500

787

}

501

788

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

502

789

if(ret != GNUTLS_E_SUCCESS){

503

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

504

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

505

safer_gnutls_strerror(ret));

790

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

791

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

792

safer_gnutls_strerror(ret));

506

793

gnutls_deinit(*session);

507

794

return -1;

508

795

}

510

797

511

798

do {

512

799

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

513

mc.cred);

800

mc->cred);

514

801

if(quit_now){

515

802

gnutls_deinit(*session);

516

803

return -1;

517

804

}

518

805

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

519

806

if(ret != GNUTLS_E_SUCCESS){

520

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

521

safer_gnutls_strerror(ret));

807

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

808

safer_gnutls_strerror(ret));

522

809

gnutls_deinit(*session);

523

810

return -1;

524

811

}

526

813

/* ignore client certificate if any. */

527

814

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

528

815

529

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

530

531

816

return 0;

532

817

}

533

818

535

820

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

536

821

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

537

822

823

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

824

__attribute__((warn_unused_result))

825

error_t raise_privileges(void){

826

error_t old_errno = errno;

827

error_t ret_errno = 0;

828

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

829

ret_errno = errno;

830

}

831

errno = old_errno;

832

return ret_errno;

833

}

834

835

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

836

__attribute__((warn_unused_result))

837

error_t raise_privileges_permanently(void){

838

error_t old_errno = errno;

839

error_t ret_errno = raise_privileges();

840

if(ret_errno != 0){

841

errno = old_errno;

842

return ret_errno;

843

}

844

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

845

ret_errno = errno;

846

}

847

errno = old_errno;

848

return ret_errno;

849

}

850

851

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

852

__attribute__((warn_unused_result))

853

error_t lower_privileges(void){

854

error_t old_errno = errno;

855

error_t ret_errno = 0;

856

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

857

ret_errno = errno;

858

}

859

errno = old_errno;

860

return ret_errno;

861

}

862

863

/* Lower privileges permanently */

864

__attribute__((warn_unused_result))

865

error_t lower_privileges_permanently(void){

866

error_t old_errno = errno;

867

error_t ret_errno = 0;

868

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

869

ret_errno = errno;

870

}

871

errno = old_errno;

872

return ret_errno;

873

}

874

875

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

876

__attribute__((nonnull, warn_unused_result))

877

static bool add_delete_local_route(const bool add,

878

const char *address,

879

AvahiIfIndex if_index){

880

int ret;

881

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

882

char add_arg[] = "add";

883

char delete_arg[] = "delete";

884

char debug_flag[] = "--debug";

885

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

886

if(pluginhelperdir == NULL){

887

if(debug){

888

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

889

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

890

}

891

return false;

892

}

893

894

char interface[IF_NAMESIZE];

895

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

896

perror_plus("if_indextoname");

897

return false;

898

}

899

900

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

901

if(devnull == -1){

902

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

903

return false;

904

}

905

pid_t pid = fork();

906

if(pid == 0){

907

/* Child */

908

/* Raise privileges */

909

errno = raise_privileges_permanently();

910

if(errno != 0){

911

perror_plus("Failed to raise privileges");

912

/* _exit(EX_NOPERM); */

913

} else {

914

/* Set group */

915

errno = 0;

916

ret = setgid(0);

917

if(ret == -1){

918

perror_plus("setgid");

919

_exit(EX_NOPERM);

920

}

921

/* Reset supplementary groups */

922

errno = 0;

923

ret = setgroups(0, NULL);

924

if(ret == -1){

925

perror_plus("setgroups");

926

_exit(EX_NOPERM);

927

}

928

}

929

ret = dup2(devnull, STDIN_FILENO);

930

if(ret == -1){

931

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

932

_exit(EX_OSERR);

933

}

934

ret = close(devnull);

935

if(ret == -1){

936

perror_plus("close");

937

_exit(EX_OSERR);

938

}

939

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

940

if(ret == -1){

941

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

942

_exit(EX_OSERR);

943

}

944

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

945

O_RDONLY

946

| O_DIRECTORY

947

| O_PATH

948

| O_CLOEXEC));

949

if(helperdir_fd == -1){

950

perror_plus("open");

951

_exit(EX_UNAVAILABLE);

952

}

953

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

954

helper, O_RDONLY));

955

if(helper_fd == -1){

956

perror_plus("openat");

957

close(helperdir_fd);

958

_exit(EX_UNAVAILABLE);

959

}

960

close(helperdir_fd);

961

#ifdef __GNUC__

962

#pragma GCC diagnostic push

963

#pragma GCC diagnostic ignored "-Wcast-qual"

964

#endif

965

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

966

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

967

interface, debug ? debug_flag : NULL, NULL },

968

environ) == -1){

969

#ifdef __GNUC__

970

#pragma GCC diagnostic pop

971

#endif

972

perror_plus("fexecve");

973

_exit(EXIT_FAILURE);

974

}

975

}

976

if(pid == -1){

977

perror_plus("fork");

978

return false;

979

}

980

int status;

981

pid_t pret = -1;

982

errno = 0;

983

do {

984

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

985

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

986

int errno_raising = 0;

987

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

988

errno_raising = errno;

989

perror_plus("Failed to raise privileges in order to"

990

" kill helper program");

991

}

992

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

993

perror_plus("kill");

994

}

995

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

996

perror_plus("Failed to lower privileges after killing"

997

" helper program");

998

}

999

return false;

1000

}

1001

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

1002

if(pret == -1){

1003

perror_plus("waitpid");

1004

return false;

1005

}

1006

if(WIFEXITED(status)){

1007

if(WEXITSTATUS(status) != 0){

1008

fprintf_plus(stderr, "Error: iprouteadddel exited"

1009

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

1010

return false;

1011

}

1012

return true;

1013

}

1014

if(WIFSIGNALED(status)){

1015

fprintf_plus(stderr, "Error: iprouteadddel died by"

1016

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

1017

return false;

1018

}

1019

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

1020

return false;

1021

}

1022

1023

__attribute__((nonnull, warn_unused_result))

1024

static bool add_local_route(const char *address,

1025

AvahiIfIndex if_index){

1026

if(debug){

1027

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

1028

}

1029

return add_delete_local_route(true, address, if_index);

1030

}

1031

1032

__attribute__((nonnull, warn_unused_result))

1033

static bool delete_local_route(const char *address,

1034

AvahiIfIndex if_index){

1035

if(debug){

1036

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

1037

}

1038

return add_delete_local_route(false, address, if_index);

1039

}

1040

538

1041

/* Called when a Mandos server is found */

539

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

1042

__attribute__((nonnull, warn_unused_result))

1043

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

540

1044

AvahiIfIndex if_index,

541

int af){

1045

int af, mandos_context *mc){

542

1046

int ret, tcp_sd = -1;

543

1047

ssize_t sret;

544

union {

545

struct sockaddr_in in;

546

struct sockaddr_in6 in6;

547

} to;

1048

struct sockaddr_storage to;

548

1049

char *buffer = NULL;

549

1050

char *decrypted_buffer = NULL;

550

1051

size_t buffer_length = 0;

553

1054

int retval = -1;

554

1055

gnutls_session_t session;

555

1056

int pf; /* Protocol family */

1057

bool route_added = false;

556

1058

557

1059

errno = 0;

558

1060

569

1071

pf = PF_INET;

570

1072

break;

571

1073

default:

572

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

1074

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

573

1075

errno = EINVAL;

574

1076

return -1;

575

1077

}

576

1078

577

ret = init_gnutls_session(&session);

1079

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

1080

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

1081

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

1082

bool match = false;

1083

{

1084

char *interface = NULL;

1085

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

1086

interface))){

1087

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

1088

match = true;

1089

break;

1090

}

1091

}

1092

}

1093

if(not match){

1094

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

1095

connect to the server */

1096

if(debug){

1097

char interface[IF_NAMESIZE];

1098

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

1099

perror_plus("if_indextoname");

1100

} else {

1101

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

1102

" \"%s\"\n",

1103

if_indextoname((unsigned int)if_index,

1104

interface));

1105

}

1106

}

1107

return -1;

1108

}

1109

}

1110

1111

ret = init_gnutls_session(&session, mc);

578

1112

if(ret != 0){

579

1113

return -1;

580

1114

}

581

1115

582

1116

if(debug){

583

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

584

"\n", ip, port);

1117

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

1118

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

585

1119

}

586

1120

587

tcp_sd = socket(pf, SOCK_STREAM, 0);

1121

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

588

1122

if(tcp_sd < 0){

589

1123

int e = errno;

590

perror("socket");

1124

perror_plus("socket");

591

1125

errno = e;

592

1126

goto mandos_end;

593

1127

}

597

1131

goto mandos_end;

598

1132

}

599

1133

600

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

601

1134

if(af == AF_INET6){

602

to.in6.sin6_family = (sa_family_t)af;

603

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

1135

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

1136

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

1137

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

604

1138

} else { /* IPv4 */

605

to.in.sin_family = (sa_family_t)af;

606

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

1139

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

1140

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

1141

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

607

1142

}

608

1143

if(ret < 0 ){

609

1144

int e = errno;

610

perror("inet_pton");

1145

perror_plus("inet_pton");

611

1146

errno = e;

612

1147

goto mandos_end;

613

1148

}

614

1149

if(ret == 0){

615

1150

int e = errno;

616

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

1151

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

617

1152

errno = e;

618

1153

goto mandos_end;

619

1154

}

620

1155

if(af == AF_INET6){

621

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

622

-Wconversion and

623

-Wunreachable-code */

624

625

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

626

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

627

-Wunreachable-code*/

1156

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

1157

if(IN6_IS_ADDR_LINKLOCAL

1158

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

628

1159

if(if_index == AVAHI_IF_UNSPEC){

629

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

630

" without a network interface\n");

1160

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

1161

" incomplete without a network interface\n");

631

1162

errno = EINVAL;

632

1163

goto mandos_end;

633

1164

}

634

1165

/* Set the network interface number as scope */

635

to.in6.sin6_scope_id = (uint32_t)if_index;

1166

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

636

1167

}

637

1168

} else {

638

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

639

-Wconversion and

640

-Wunreachable-code */

1169

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

641

1170

}

642

1171

643

1172

if(quit_now){

649

1178

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

650

1179

char interface[IF_NAMESIZE];

651

1180

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

652

perror("if_indextoname");

1181

perror_plus("if_indextoname");

653

1182

} else {

654

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

655

ip, interface, port);

1183

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

1184

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

656

1185

}

657

1186

} else {

658

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

659

port);

1187

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

1188

ip, (uintmax_t)port);

660

1189

}

661

1190

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

662

1191

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

663

const char *pcret;

664

if(af == AF_INET6){

665

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

666

sizeof(addrstr));

667

} else {

668

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

669

sizeof(addrstr));

670

}

671

if(pcret == NULL){

672

perror("inet_ntop");

673

} else {

674

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

675

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

676

}

677

}

678

}

679

680

if(quit_now){

681

errno = EINTR;

682

goto mandos_end;

683

}

684

685

if(af == AF_INET6){

686

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

687

} else {

688

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

689

}

690

if(ret < 0){

691

int e = errno;

692

perror("connect");

693

errno = e;

694

goto mandos_end;

695

}

696

697

if(quit_now){

698

errno = EINTR;

699

goto mandos_end;

1192

if(af == AF_INET6){

1193

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

1194

sizeof(struct sockaddr_in6),

1195

addrstr, sizeof(addrstr), NULL, 0,

1196

NI_NUMERICHOST);

1197

} else {

1198

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

1199

sizeof(struct sockaddr_in),

1200

addrstr, sizeof(addrstr), NULL, 0,

1201

NI_NUMERICHOST);

1202

}

1203

if(ret == EAI_SYSTEM){

1204

perror_plus("getnameinfo");

1205

} else if(ret != 0) {

1206

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

1207

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

1208

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

1209

}

1210

}

1211

1212

if(quit_now){

1213

errno = EINTR;

1214

goto mandos_end;

1215

}

1216

1217

while(true){

1218

if(af == AF_INET6){

1219

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

1220

sizeof(struct sockaddr_in6));

1221

} else {

1222

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

1223

sizeof(struct sockaddr_in));

1224

}

1225

if(ret < 0){

1226

if(errno == ENETUNREACH

1227

and if_index != AVAHI_IF_UNSPEC

1228

and connect_to == NULL

1229

and not route_added and

1230

((af == AF_INET6 and not

1231

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1232

&to)->sin6_addr)))

1233

or (af == AF_INET and

1234

/* Not a a IPv4LL address */

1235

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

1236

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

1237

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

1238

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

1239

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

1240

connect to a Mandos server announced by Avahi on a server

1241

host with a global address. Work around this by retrying

1242

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

1243

1244

Avahi bug reference:

1245

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

1246

https://bugs.debian.org/587961

1247

*/

1248

if(debug){

1249

fprintf_plus(stderr, "Mandos server unreachable, trying"

1250

" direct route\n");

1251

}

1252

int e = errno;

1253

route_added = add_local_route(ip, if_index);

1254

if(route_added){

1255

continue;

1256

}

1257

errno = e;

1258

}

1259

if(errno != ECONNREFUSED or debug){

1260

int e = errno;

1261

perror_plus("connect");

1262

errno = e;

1263

}

1264

goto mandos_end;

1265

}

1266

1267

if(quit_now){

1268

errno = EINTR;

1269

goto mandos_end;

1270

}

1271

break;

700

1272

}

701

1273

702

1274

const char *out = mandos_protocol_version;

704

1276

while(true){

705

1277

size_t out_size = strlen(out);

706

1278

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

707

out_size - written));

1279

out_size - written));

708

1280

if(ret == -1){

709

1281

int e = errno;

710

perror("write");

1282

perror_plus("write");

711

1283

errno = e;

712

1284

goto mandos_end;

713

1285

}

730

1302

}

731

1303

732

1304

if(debug){

733

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

1305

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

734

1306

}

735

1307

736

1308

if(quit_now){

738

1310

goto mandos_end;

739

1311

}

740

1312

741

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1313

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

1314

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

1315

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

1316

gnutls_transport_set_ptr(session,

1317

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

742

1318

743

1319

if(quit_now){

744

1320

errno = EINTR;

755

1331

756

1332

if(ret != GNUTLS_E_SUCCESS){

757

1333

if(debug){

758

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

1334

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

759

1335

gnutls_perror(ret);

760

1336

}

761

1337

errno = EPROTO;

765

1341

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

766

1342

767

1343

if(debug){

768

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

769

ip);

1344

fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"

1345

" %s\n", ip);

770

1346

}

771

1347

772

1348

while(true){

777

1353

}

778

1354

779

1355

buffer_capacity = incbuffer(&buffer, buffer_length,

780

buffer_capacity);

1356

buffer_capacity);

781

1357

if(buffer_capacity == 0){

782

1358

int e = errno;

783

perror("incbuffer");

1359

perror_plus("incbuffer");

784

1360

errno = e;

785

1361

goto mandos_end;

786

1362

}

810

1386

}

811

1387

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

812

1388

if(ret < 0){

813

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

1389

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

1390

"***\n");

814

1391

gnutls_perror(ret);

815

1392

errno = EPROTO;

816

1393

goto mandos_end;

817

1394

}

818

1395

break;

819

1396

default:

820

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

821

" encrypted session with Mandos server\n");

1397

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

1398

" encrypted session with Mandos server\n");

822

1399

gnutls_bye(session, GNUTLS_SHUT_RDWR);

823

1400

errno = EIO;

824

1401

goto mandos_end;

829

1406

}

830

1407

831

1408

if(debug){

832

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

1409

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

833

1410

}

834

1411

835

1412

if(quit_now){

847

1424

848

1425

if(buffer_length > 0){

849

1426

ssize_t decrypted_buffer_size;

850

decrypted_buffer_size = pgp_packet_decrypt(buffer,

851

buffer_length,

852

&decrypted_buffer);

1427

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1428

&decrypted_buffer, mc);

853

1429

if(decrypted_buffer_size >= 0){

854

1430

855

1431

written = 0;

865

1441

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

866

1442

int e = errno;

867

1443

if(debug){

868

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

869

strerror(errno));

1444

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

1445

strerror(errno));

870

1446

}

871

1447

errno = e;

872

1448

goto mandos_end;

881

1457

882

1458

mandos_end:

883

1459

{

1460

if(route_added){

1461

if(not delete_local_route(ip, if_index)){

1462

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

1463

" interface %d", ip, if_index);

1464

}

1465

}

884

1466

int e = errno;

885

1467

free(decrypted_buffer);

886

1468

free(buffer);

887

1469

if(tcp_sd >= 0){

888

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

1470

ret = close(tcp_sd);

889

1471

}

890

1472

if(ret == -1){

891

1473

if(e == 0){

892

1474

e = errno;

893

1475

}

894

perror("close");

1476

perror_plus("close");

895

1477

}

896

1478

gnutls_deinit(session);

1479

errno = e;

897

1480

if(quit_now){

898

e = EINTR;

1481

errno = EINTR;

899

1482

retval = -1;

900

1483

}

901

errno = e;

902

1484

}

903

1485

return retval;

904

1486

}

905

1487

1488

__attribute__((nonnull))

906

1489

static void resolve_callback(AvahiSServiceResolver *r,

907

1490

AvahiIfIndex interface,

908

1491

AvahiProtocol proto,

916

1499

AVAHI_GCC_UNUSED AvahiStringList *txt,

917

1500

AVAHI_GCC_UNUSED AvahiLookupResultFlags

918

1501

flags,

919

AVAHI_GCC_UNUSED void* userdata){

920

assert(r);

1502

void *mc){

1503

if(r == NULL){

1504

return;

1505

}

921

1506

922

1507

/* Called whenever a service has been resolved successfully or

923

1508

timed out */

924

1509

925

1510

if(quit_now){

1511

avahi_s_service_resolver_free(r);

926

1512

return;

927

1513

}

928

1514

929

1515

switch(event){

930

1516

default:

931

1517

case AVAHI_RESOLVER_FAILURE:

932

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

933

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

934

avahi_strerror(avahi_server_errno(mc.server)));

1518

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

1519

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

1520

domain,

1521

avahi_strerror(avahi_server_errno

1522

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

935

1523

break;

936

1524

937

1525

case AVAHI_RESOLVER_FOUND:

939

1527

char ip[AVAHI_ADDRESS_STR_MAX];

940

1528

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

941

1529

if(debug){

942

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

943

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

944

ip, (intmax_t)interface, port);

1530

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

1531

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

1532

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

945

1533

}

946

int ret = start_mandos_communication(ip, port, interface,

947

avahi_proto_to_af(proto));

1534

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

1535

interface,

1536

avahi_proto_to_af(proto),

1537

mc);

948

1538

if(ret == 0){

949

avahi_simple_poll_quit(mc.simple_poll);

1539

avahi_simple_poll_quit(simple_poll);

1540

} else {

1541

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

1542

avahi_proto_to_af(proto),

1543

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

1544

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

1545

" list\n", name);

1546

}

950

1547

}

951

1548

}

952

1549

}

962

1559

const char *domain,

963

1560

AVAHI_GCC_UNUSED AvahiLookupResultFlags

964

1561

flags,

965

AVAHI_GCC_UNUSED void* userdata){

966

assert(b);

1562

void *mc){

1563

if(b == NULL){

1564

return;

1565

}

967

1566

968

1567

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

969

1568

is removed from the LAN */

976

1575

default:

977

1576

case AVAHI_BROWSER_FAILURE:

978

1577

979

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

980

avahi_strerror(avahi_server_errno(mc.server)));

981

avahi_simple_poll_quit(mc.simple_poll);

1578

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

1579

avahi_strerror(avahi_server_errno

1580

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

1581

avahi_simple_poll_quit(simple_poll);

982

1582

return;

983

1583

984

1584

case AVAHI_BROWSER_NEW:

987

1587

the callback function is called the Avahi server will free the

988

1588

resolver for us. */

989

1589

990

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

991

name, type, domain, protocol, 0,

992

resolve_callback, NULL) == NULL)

993

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

994

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

1590

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

1591

interface, protocol, name, type,

1592

domain, protocol, 0,

1593

resolve_callback, mc) == NULL)

1594

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

1595

" %s\n", name,

1596

avahi_strerror(avahi_server_errno

1597

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

995

1598

break;

996

1599

997

1600

case AVAHI_BROWSER_REMOVE:

1000

1603

case AVAHI_BROWSER_ALL_FOR_NOW:

1001

1604

case AVAHI_BROWSER_CACHE_EXHAUSTED:

1002

1605

if(debug){

1003

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

1606

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

1607

" searching...\n");

1004

1608

}

1005

1609

break;

1006

1610

}

1007

1611

}

1008

1612

1009

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

1613

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

1010

1614

static void handle_sigterm(int sig){

1011

1615

if(quit_now){

1012

1616

return;

1014

1618

quit_now = 1;

1015

1619

signal_received = sig;

1016

1620

int old_errno = errno;

1017

if(mc.simple_poll != NULL){

1018

avahi_simple_poll_quit(mc.simple_poll);

1019

}

1020

errno = old_errno;

1621

/* set main loop to exit */

1622

if(simple_poll != NULL){

1623

avahi_simple_poll_quit(simple_poll);

1624

}

1625

errno = old_errno;

1626

}

1627

1628

__attribute__((nonnull, warn_unused_result))

1629

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

1630

int ret;

1631

error_t ret_errno;

1632

1633

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

1634

if(s < 0){

1635

ret_errno = errno;

1636

perror_plus("socket");

1637

errno = ret_errno;

1638

return false;

1639

}

1640

strcpy(ifr->ifr_name, ifname);

1641

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1642

if(ret == -1){

1643

if(debug){

1644

ret_errno = errno;

1645

perror_plus("ioctl SIOCGIFFLAGS");

1646

errno = ret_errno;

1647

}

1648

return false;

1649

}

1650

return true;

1651

}

1652

1653

__attribute__((nonnull, warn_unused_result))

1654

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

1655

1656

/* Reject the loopback device */

1657

if(ifr->ifr_flags & IFF_LOOPBACK){

1658

if(debug){

1659

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

1660

ifname);

1661

}

1662

return false;

1663

}

1664

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

1665

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

1666

if(debug){

1667

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

1668

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

1669

}

1670

return true;

1671

}

1672

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

1673

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

1674

if(debug){

1675

fprintf_plus(stderr, "Rejecting non-broadcast interface"

1676

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

1677

}

1678

return false;

1679

}

1680

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

1681

if(ifr->ifr_flags & IFF_NOARP){

1682

if(debug){

1683

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

1684

ifname);

1685

}

1686

return false;

1687

}

1688

1689

/* Accept this device */

1690

if(debug){

1691

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

1692

}

1693

return true;

1694

}

1695

1696

/*

1697

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

1698

* corresponds to an acceptable network device.

1699

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

1700

*/

1701

__attribute__((nonnull, warn_unused_result))

1702

int good_interface(const struct dirent *if_entry){

1703

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

1704

return 0;

1705

}

1706

1707

struct ifreq ifr;

1708

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

1709

if(debug){

1710

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

1711

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

1712

}

1713

return 0;

1714

}

1715

1716

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

1717

return 0;

1718

}

1719

return 1;

1720

}

1721

1722

/*

1723

* This function determines if a network interface is up.

1724

*/

1725

__attribute__((nonnull, warn_unused_result))

1726

bool interface_is_up(const char *interface){

1727

struct ifreq ifr;

1728

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

1729

if(debug){

1730

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

1731

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

1732

}

1733

return false;

1734

}

1735

1736

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

1737

}

1738

1739

/*

1740

* This function determines if a network interface is running

1741

*/

1742

__attribute__((nonnull, warn_unused_result))

1743

bool interface_is_running(const char *interface){

1744

struct ifreq ifr;

1745

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

1746

if(debug){

1747

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

1748

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

1749

}

1750

return false;

1751

}

1752

1753

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

1754

}

1755

1756

__attribute__((nonnull, pure, warn_unused_result))

1757

int notdotentries(const struct dirent *direntry){

1758

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

1759

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

1760

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

1761

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

1762

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

1763

return 0;

1764

}

1765

return 1;

1766

}

1767

1768

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

1769

__attribute__((nonnull, warn_unused_result))

1770

int runnable_hook(const struct dirent *direntry){

1771

int ret;

1772

size_t sret;

1773

struct stat st;

1774

1775

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

1776

/* Empty name? */

1777

return 0;

1778

}

1779

1780

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

1781

"abcdefghijklmnopqrstuvwxyz"

1782

"0123456789"

1783

"_.-");

1784

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

1785

/* Contains non-allowed characters */

1786

if(debug){

1787

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

1788

direntry->d_name);

1789

}

1790

return 0;

1791

}

1792

1793

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

1794

if(ret == -1){

1795

if(debug){

1796

perror_plus("Could not stat hook");

1797

}

1798

return 0;

1799

}

1800

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

1801

/* Not a regular file */

1802

if(debug){

1803

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

1804

direntry->d_name);

1805

}

1806

return 0;

1807

}

1808

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

1809

/* Not executable */

1810

if(debug){

1811

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

1812

direntry->d_name);

1813

}

1814

return 0;

1815

}

1816

if(debug){

1817

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

1818

direntry->d_name);

1819

}

1820

return 1;

1821

}

1822

1823

__attribute__((nonnull, warn_unused_result))

1824

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1825

mandos_context *mc){

1826

int ret;

1827

struct timespec now;

1828

struct timespec waited_time;

1829

intmax_t block_time;

1830

1831

while(true){

1832

if(mc->current_server == NULL){

1833

if(debug){

1834

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

1835

" No timeout!\n");

1836

}

1837

ret = avahi_simple_poll_iterate(s, -1);

1838

} else {

1839

if(debug){

1840

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

1841

" it, or wait\n");

1842

}

1843

/* the current time */

1844

ret = clock_gettime(CLOCK_MONOTONIC, &now);

1845

if(ret == -1){

1846

perror_plus("clock_gettime");

1847

return -1;

1848

}

1849

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

1850

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

1851

waited_time.tv_sec = (now.tv_sec

1852

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

1853

waited_time.tv_nsec = (now.tv_nsec

1854

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

1855

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

1856

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

1857

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

1858

block_time = ((retry_interval

1859

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

1860

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

1861

1862

if(debug){

1863

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

1864

block_time);

1865

}

1866

1867

if(block_time <= 0){

1868

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

1869

mc->current_server->port,

1870

mc->current_server->if_index,

1871

mc->current_server->af, mc);

1872

if(ret == 0){

1873

avahi_simple_poll_quit(s);

1874

return 0;

1875

}

1876

ret = clock_gettime(CLOCK_MONOTONIC,

1877

&mc->current_server->last_seen);

1878

if(ret == -1){

1879

perror_plus("clock_gettime");

1880

return -1;

1881

}

1882

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

1883

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

1884

servers, but don't block */

1885

}

1886

1887

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

1888

}

1889

if(ret != 0){

1890

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

1891

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

1892

}

1893

}

1894

}

1895

}

1896

1897

__attribute__((nonnull))

1898

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

1899

const float delay){

1900

struct dirent **direntries = NULL;

1901

if(hookdir_fd == -1){

1902

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1903

| O_CLOEXEC);

1904

if(hookdir_fd == -1){

1905

if(errno == ENOENT){

1906

if(debug){

1907

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

1908

" found\n", hookdir);

1909

}

1910

} else {

1911

perror_plus("open");

1912

}

1913

return;

1914

}

1915

}

1916

#ifdef __GLIBC__

1917

#if __GLIBC_PREREQ(2, 15)

1918

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

1919

runnable_hook, alphasort);

1920

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

1921

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

1922

alphasort);

1923

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

1924

#else /* not __GLIBC__ */

1925

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

1926

alphasort);

1927

#endif /* not __GLIBC__ */

1928

if(numhooks == -1){

1929

perror_plus("scandir");

1930

return;

1931

}

1932

struct dirent *direntry;

1933

int ret;

1934

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

1935

if(devnull == -1){

1936

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

1937

return;

1938

}

1939

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

1940

direntry = direntries[i];

1941

if(debug){

1942

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

1943

direntry->d_name);

1944

}

1945

pid_t hook_pid = fork();

1946

if(hook_pid == 0){

1947

/* Child */

1948

/* Raise privileges */

1949

errno = raise_privileges_permanently();

1950

if(errno != 0){

1951

perror_plus("Failed to raise privileges");

1952

_exit(EX_NOPERM);

1953

}

1954

/* Set group */

1955

errno = 0;

1956

ret = setgid(0);

1957

if(ret == -1){

1958

perror_plus("setgid");

1959

_exit(EX_NOPERM);

1960

}

1961

/* Reset supplementary groups */

1962

errno = 0;

1963

ret = setgroups(0, NULL);

1964

if(ret == -1){

1965

perror_plus("setgroups");

1966

_exit(EX_NOPERM);

1967

}

1968

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

1969

if(ret == -1){

1970

perror_plus("setenv");

1971

_exit(EX_OSERR);

1972

}

1973

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

1974

if(ret == -1){

1975

perror_plus("setenv");

1976

_exit(EX_OSERR);

1977

}

1978

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

1979

if(ret == -1){

1980

perror_plus("setenv");

1981

_exit(EX_OSERR);

1982

}

1983

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

1984

if(ret == -1){

1985

perror_plus("setenv");

1986

_exit(EX_OSERR);

1987

}

1988

char *delaystring;

1989

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

1990

if(ret == -1){

1991

perror_plus("asprintf");

1992

_exit(EX_OSERR);

1993

}

1994

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

1995

if(ret == -1){

1996

free(delaystring);

1997

perror_plus("setenv");

1998

_exit(EX_OSERR);

1999

}

2000

free(delaystring);

2001

if(connect_to != NULL){

2002

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

2003

if(ret == -1){

2004

perror_plus("setenv");

2005

_exit(EX_OSERR);

2006

}

2007

}

2008

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

2009

direntry->d_name,

2010

O_RDONLY));

2011

if(hook_fd == -1){

2012

perror_plus("openat");

2013

_exit(EXIT_FAILURE);

2014

}

2015

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

2016

perror_plus("close");

2017

_exit(EXIT_FAILURE);

2018

}

2019

ret = dup2(devnull, STDIN_FILENO);

2020

if(ret == -1){

2021

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

2022

_exit(EX_OSERR);

2023

}

2024

ret = close(devnull);

2025

if(ret == -1){

2026

perror_plus("close");

2027

_exit(EX_OSERR);

2028

}

2029

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2030

if(ret == -1){

2031

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

2032

_exit(EX_OSERR);

2033

}

2034

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

2035

environ) == -1){

2036

perror_plus("fexecve");

2037

_exit(EXIT_FAILURE);

2038

}

2039

} else {

2040

if(hook_pid == -1){

2041

perror_plus("fork");

2042

free(direntry);

2043

continue;

2044

}

2045

int status;

2046

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

2047

perror_plus("waitpid");

2048

free(direntry);

2049

continue;

2050

}

2051

if(WIFEXITED(status)){

2052

if(WEXITSTATUS(status) != 0){

2053

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

2054

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

2055

WEXITSTATUS(status));

2056

free(direntry);

2057

continue;

2058

}

2059

} else if(WIFSIGNALED(status)){

2060

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

2061

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

2062

WTERMSIG(status));

2063

free(direntry);

2064

continue;

2065

} else {

2066

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

2067

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

2068

free(direntry);

2069

continue;

2070

}

2071

}

2072

if(debug){

2073

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

2074

direntry->d_name);

2075

}

2076

free(direntry);

2077

}

2078

free(direntries);

2079

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

2080

perror_plus("close");

2081

} else {

2082

hookdir_fd = -1;

2083

}

2084

close(devnull);

2085

}

2086

2087

__attribute__((nonnull, warn_unused_result))

2088

error_t bring_up_interface(const char *const interface,

2089

const float delay){

2090

error_t old_errno = errno;

2091

int ret;

2092

struct ifreq network;

2093

unsigned int if_index = if_nametoindex(interface);

2094

if(if_index == 0){

2095

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

2096

errno = old_errno;

2097

return ENXIO;

2098

}

2099

2100

if(quit_now){

2101

errno = old_errno;

2102

return EINTR;

2103

}

2104

2105

if(not interface_is_up(interface)){

2106

error_t ret_errno = 0, ioctl_errno = 0;

2107

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

2108

ret_errno = errno;

2109

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

2110

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

2111

errno = old_errno;

2112

return ret_errno;

2113

}

2114

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

2115

2116

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

2117

if(sd == -1){

2118

ret_errno = errno;

2119

perror_plus("socket");

2120

errno = old_errno;

2121

return ret_errno;

2122

}

2123

2124

if(quit_now){

2125

ret = close(sd);

2126

if(ret == -1){

2127

perror_plus("close");

2128

}

2129

errno = old_errno;

2130

return EINTR;

2131

}

2132

2133

if(debug){

2134

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

2135

interface);

2136

}

2137

2138

/* Raise privileges */

2139

ret_errno = raise_privileges();

2140

if(ret_errno != 0){

2141

errno = ret_errno;

2142

perror_plus("Failed to raise privileges");

2143

}

2144

2145

#ifdef __linux__

2146

int ret_linux;

2147

bool restore_loglevel = false;

2148

if(ret_errno == 0){

2149

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2150

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

2151

ret_linux = klogctl(8, NULL, 5);

2152

if(ret_linux == -1){

2153

perror_plus("klogctl");

2154

} else {

2155

restore_loglevel = true;

2156

}

2157

}

2158

#endif /* __linux__ */

2159

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

2160

ioctl_errno = errno;

2161

#ifdef __linux__

2162

if(restore_loglevel){

2163

ret_linux = klogctl(7, NULL, 0);

2164

if(ret_linux == -1){

2165

perror_plus("klogctl");

2166

}

2167

}

2168

#endif /* __linux__ */

2169

2170

/* If raise_privileges() succeeded above */

2171

if(ret_errno == 0){

2172

/* Lower privileges */

2173

ret_errno = lower_privileges();

2174

if(ret_errno != 0){

2175

errno = ret_errno;

2176

perror_plus("Failed to lower privileges");

2177

}

2178

}

2179

2180

/* Close the socket */

2181

ret = close(sd);

2182

if(ret == -1){

2183

perror_plus("close");

2184

}

2185

2186

if(ret_setflags == -1){

2187

errno = ioctl_errno;

2188

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2189

errno = old_errno;

2190

return ioctl_errno;

2191

}

2192

} else if(debug){

2193

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

2194

interface);

2195

}

2196

2197

/* Sleep checking until interface is running.

2198

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

2199

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

2200

if(interface_is_running(interface)){

2201

break;

2202

}

2203

struct timespec sleeptime = { .tv_nsec = 250000000 };

2204

ret = nanosleep(&sleeptime, NULL);

2205

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

2206

perror_plus("nanosleep");

2207

}

2208

}

2209

2210

errno = old_errno;

2211

return 0;

2212

}

2213

2214

__attribute__((nonnull, warn_unused_result))

2215

error_t take_down_interface(const char *const interface){

2216

error_t old_errno = errno;

2217

struct ifreq network;

2218

unsigned int if_index = if_nametoindex(interface);

2219

if(if_index == 0){

2220

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

2221

errno = old_errno;

2222

return ENXIO;

2223

}

2224

if(interface_is_up(interface)){

2225

error_t ret_errno = 0, ioctl_errno = 0;

2226

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

2227

ret_errno = errno;

2228

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

2229

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

2230

errno = old_errno;

2231

return ret_errno;

2232

}

2233

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

2234

2235

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

2236

if(sd == -1){

2237

ret_errno = errno;

2238

perror_plus("socket");

2239

errno = old_errno;

2240

return ret_errno;

2241

}

2242

2243

if(debug){

2244

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

2245

interface);

2246

}

2247

2248

/* Raise privileges */

2249

ret_errno = raise_privileges();

2250

if(ret_errno != 0){

2251

errno = ret_errno;

2252

perror_plus("Failed to raise privileges");

2253

}

2254

2255

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

2256

ioctl_errno = errno;

2257

2258

/* If raise_privileges() succeeded above */

2259

if(ret_errno == 0){

2260

/* Lower privileges */

2261

ret_errno = lower_privileges();

2262

if(ret_errno != 0){

2263

errno = ret_errno;

2264

perror_plus("Failed to lower privileges");

2265

}

2266

}

2267

2268

/* Close the socket */

2269

int ret = close(sd);

2270

if(ret == -1){

2271

perror_plus("close");

2272

}

2273

2274

if(ret_setflags == -1){

2275

errno = ioctl_errno;

2276

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2277

errno = old_errno;

2278

return ioctl_errno;

2279

}

2280

} else if(debug){

2281

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

2282

interface);

2283

}

2284

2285

errno = old_errno;

2286

return 0;

1021

2287

}

1022

2288

1023

2289

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

2290

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

2291

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

2292

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

2293

.current_server = NULL, .interfaces = NULL,

2294

.interfaces_size = 0 };

1024

2295

AvahiSServiceBrowser *sb = NULL;

1025

int error;

2296

error_t ret_errno;

1026

2297

int ret;

1027

2298

intmax_t tmpmax;

1028

2299

char *tmp;

1029

2300

int exitcode = EXIT_SUCCESS;

1030

const char *interface = "eth0";

1031

struct ifreq network;

1032

int sd = -1;

1033

bool take_down_interface = false;

1034

uid_t uid;

1035

gid_t gid;

1036

char *connect_to = NULL;

1037

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

1038

bool tempdir_created = false;

2301

char *interfaces_to_take_down = NULL;

2302

size_t interfaces_to_take_down_size = 0;

2303

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

2304

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

2305

char *tempdir = NULL;

1039

2306

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1040

2307

const char *seckey = PATHDIR "/" SECKEY;

1041

2308

const char *pubkey = PATHDIR "/" PUBKEY;

2309

const char *dh_params_file = NULL;

2310

char *interfaces_hooks = NULL;

1042

2311

1043

2312

bool gnutls_initialized = false;

1044

2313

bool gpgme_initialized = false;

1045

2314

float delay = 2.5f;

2315

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

2316

retrying the same server again */

1046

2317

1047

2318

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

1048

2319

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1054

2325

errno = 0;

1055

2326

ret = setgid(gid);

1056

2327

if(ret == -1){

1057

perror("setgid");

2328

perror_plus("setgid");

1058

2329

}

1059

2330

1060

2331

/* Lower user privileges (temporarily) */

1061

2332

errno = 0;

1062

2333

ret = seteuid(uid);

1063

2334

if(ret == -1){

1064

perror("seteuid");

2335

perror_plus("seteuid");

1065

2336

}

1066

2337

1067

2338

if(quit_now){

1094

2365

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

1095

2366

" Diffie-Hellman key exchange",

1096

2367

.group = 2 },

2368

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

2369

.arg = "FILE",

2370

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

2371

" for the Diffie-Hellman key exchange",

2372

.group = 2 },

1097

2373

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

1098

2374

.arg = "STRING",

1099

2375

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

1102

2378

.arg = "SECONDS",

1103

2379

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

1104

2380

.group = 2 },

2381

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

2382

.arg = "SECONDS",

2383

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

2384

.group = 2 },

2385

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

2386

.arg = "DIR",

2387

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

2388

.group = 2 },

1105

2389

/*

1106

2390

* These reproduce what we would get without ARGP_NO_HELP

1107

2391

*/

1125

2409

connect_to = arg;

1126

2410

break;

1127

2411

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

1128

interface = arg;

2412

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

2413

arg, (int)',');

2414

if(ret_errno != 0){

2415

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

2416

}

1129

2417

break;

1130

2418

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

1131

2419

seckey = arg;

1142

2430

}

1143

2431

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

1144

2432

break;

2433

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

2434

dh_params_file = arg;

2435

break;

1145

2436

case 130: /* --priority */

1146

2437

mc.priority = arg;

1147

2438

break;

1151

2442

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

1152

2443

argp_error(state, "Bad delay");

1153

2444

}

2445

case 132: /* --retry */

2446

errno = 0;

2447

retry_interval = strtod(arg, &tmp);

2448

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

2449

or (retry_interval * 1000) > INT_MAX

2450

or retry_interval < 0){

2451

argp_error(state, "Bad retry interval");

2452

}

2453

break;

2454

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

2455

hookdir = arg;

1154

2456

break;

1155

2457

/*

1156

2458

* These reproduce what we would get without ARGP_NO_HELP

1163

2465

argp_state_help(state, state->out_stream,

1164

2466

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1165

2467

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

1166

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

2468

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

1167

2469

exit(argp_err_exit_status);

1168

2470

break;

1169

2471

default:

1184

2486

case ENOMEM:

1185

2487

default:

1186

2488

errno = ret;

1187

perror("argp_parse");

2489

perror_plus("argp_parse");

1188

2490

exitcode = EX_OSERR;

1189

2491

goto end;

1190

2492

case EINVAL:

1193

2495

}

1194

2496

}

1195

2497

2498

{

2499

/* Work around Debian bug #633582:

2500

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

2501

2502

/* Re-raise privileges */

2503

ret_errno = raise_privileges();

2504

if(ret_errno != 0){

2505

errno = ret_errno;

2506

perror_plus("Failed to raise privileges");

2507

} else {

2508

struct stat st;

2509

2510

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

2511

int seckey_fd = open(seckey, O_RDONLY);

2512

if(seckey_fd == -1){

2513

perror_plus("open");

2514

} else {

2515

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

2516

if(ret == -1){

2517

perror_plus("fstat");

2518

} else {

2519

if(S_ISREG(st.st_mode)

2520

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

2521

ret = fchown(seckey_fd, uid, gid);

2522

if(ret == -1){

2523

perror_plus("fchown");

2524

}

2525

}

2526

}

2527

close(seckey_fd);

2528

}

2529

}

2530

2531

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

2532

int pubkey_fd = open(pubkey, O_RDONLY);

2533

if(pubkey_fd == -1){

2534

perror_plus("open");

2535

} else {

2536

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

2537

if(ret == -1){

2538

perror_plus("fstat");

2539

} else {

2540

if(S_ISREG(st.st_mode)

2541

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

2542

ret = fchown(pubkey_fd, uid, gid);

2543

if(ret == -1){

2544

perror_plus("fchown");

2545

}

2546

}

2547

}

2548

close(pubkey_fd);

2549

}

2550

}

2551

2552

if(dh_params_file != NULL

2553

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

2554

int dhparams_fd = open(dh_params_file, O_RDONLY);

2555

if(dhparams_fd == -1){

2556

perror_plus("open");

2557

} else {

2558

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

2559

if(ret == -1){

2560

perror_plus("fstat");

2561

} else {

2562

if(S_ISREG(st.st_mode)

2563

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

2564

ret = fchown(dhparams_fd, uid, gid);

2565

if(ret == -1){

2566

perror_plus("fchown");

2567

}

2568

}

2569

}

2570

close(dhparams_fd);

2571

}

2572

}

2573

2574

/* Lower privileges */

2575

ret_errno = lower_privileges();

2576

if(ret_errno != 0){

2577

errno = ret_errno;

2578

perror_plus("Failed to lower privileges");

2579

}

2580

}

2581

}

2582

2583

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

2584

{

2585

char *interface = NULL;

2586

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

2587

interface))){

2588

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

2589

and if_nametoindex(interface) == 0){

2590

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

2591

fprintf_plus(stderr, "Not using nonexisting interface"

2592

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

2593

}

2594

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

2595

interface = NULL;

2596

}

2597

}

2598

}

2599

2600

/* Run network hooks */

2601

{

2602

if(mc.interfaces != NULL){

2603

interfaces_hooks = malloc(mc.interfaces_size);

2604

if(interfaces_hooks == NULL){

2605

perror_plus("malloc");

2606

goto end;

2607

}

2608

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

2609

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

2610

}

2611

run_network_hooks("start", interfaces_hooks != NULL ?

2612

interfaces_hooks : "", delay);

2613

}

2614

1196

2615

if(not debug){

1197

2616

avahi_set_log_function(empty_log);

1198

2617

}

1201

2620

from the signal handler */

1202

2621

/* Initialize the pseudo-RNG for Avahi */

1203

2622

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

1204

mc.simple_poll = avahi_simple_poll_new();

1205

if(mc.simple_poll == NULL){

1206

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

2623

simple_poll = avahi_simple_poll_new();

2624

if(simple_poll == NULL){

2625

fprintf_plus(stderr,

2626

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

1207

2627

exitcode = EX_UNAVAILABLE;

1208

2628

goto end;

1209

2629

}

1211

2631

sigemptyset(&sigterm_action.sa_mask);

1212

2632

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

1213

2633

if(ret == -1){

1214

perror("sigaddset");

2634

perror_plus("sigaddset");

1215

2635

exitcode = EX_OSERR;

1216

2636

goto end;

1217

2637

}

1218

2638

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

1219

2639

if(ret == -1){

1220

perror("sigaddset");

2640

perror_plus("sigaddset");

1221

2641

exitcode = EX_OSERR;

1222

2642

goto end;

1223

2643

}

1224

2644

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

1225

2645

if(ret == -1){

1226

perror("sigaddset");

2646

perror_plus("sigaddset");

1227

2647

exitcode = EX_OSERR;

1228

2648

goto end;

1229

2649

}

1233

2653

*/

1234

2654

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

1235

2655

if(ret == -1){

1236

perror("sigaction");

2656

perror_plus("sigaction");

1237

2657

return EX_OSERR;

1238

2658

}

1239

2659

if(old_sigterm_action.sa_handler != SIG_IGN){

1240

2660

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

1241

2661

if(ret == -1){

1242

perror("sigaction");

2662

perror_plus("sigaction");

1243

2663

exitcode = EX_OSERR;

1244

2664

goto end;

1245

2665

}

1246

2666

}

1247

2667

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

1248

2668

if(ret == -1){

1249

perror("sigaction");

2669

perror_plus("sigaction");

1250

2670

return EX_OSERR;

1251

2671

}

1252

2672

if(old_sigterm_action.sa_handler != SIG_IGN){

1253

2673

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

1254

2674

if(ret == -1){

1255

perror("sigaction");

2675

perror_plus("sigaction");

1256

2676

exitcode = EX_OSERR;

1257

2677

goto end;

1258

2678

}

1259

2679

}

1260

2680

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

1261

2681

if(ret == -1){

1262

perror("sigaction");

2682

perror_plus("sigaction");

1263

2683

return EX_OSERR;

1264

2684

}

1265

2685

if(old_sigterm_action.sa_handler != SIG_IGN){

1266

2686

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

1267

2687

if(ret == -1){

1268

perror("sigaction");

1269

exitcode = EX_OSERR;

1270

goto end;

1271

}

1272

}

1273

1274

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

1275

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

1276

if_index = (AvahiIfIndex) if_nametoindex(interface);

1277

if(if_index == 0){

1278

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

1279

exitcode = EX_UNAVAILABLE;

1280

goto end;

1281

}

1282

1283

if(quit_now){

1284

goto end;

1285

}

1286

1287

/* Re-raise priviliges */

1288

errno = 0;

1289

ret = seteuid(0);

1290

if(ret == -1){

1291

perror("seteuid");

1292

}

1293

1294

#ifdef __linux__

1295

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1296

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

1297

ret = klogctl(8, NULL, 5);

1298

bool restore_loglevel = true;

1299

if(ret == -1){

1300

restore_loglevel = false;

1301

perror("klogctl");

1302

}

1303

#endif /* __linux__ */

1304

1305

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1306

if(sd < 0){

1307

perror("socket");

1308

exitcode = EX_OSERR;

1309

#ifdef __linux__

1310

if(restore_loglevel){

1311

ret = klogctl(7, NULL, 0);

1312

if(ret == -1){

1313

perror("klogctl");

1314

}

1315

}

1316

#endif /* __linux__ */

1317

/* Lower privileges */

1318

errno = 0;

1319

ret = seteuid(uid);

1320

if(ret == -1){

1321

perror("seteuid");

1322

}

1323

goto end;

1324

}

1325

strcpy(network.ifr_name, interface);

1326

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

1327

if(ret == -1){

1328

perror("ioctl SIOCGIFFLAGS");

1329

#ifdef __linux__

1330

if(restore_loglevel){

1331

ret = klogctl(7, NULL, 0);

1332

if(ret == -1){

1333

perror("klogctl");

1334

}

1335

}

1336

#endif /* __linux__ */

1337

exitcode = EX_OSERR;

1338

/* Lower privileges */

1339

errno = 0;

1340

ret = seteuid(uid);

1341

if(ret == -1){

1342

perror("seteuid");

1343

}

1344

goto end;

1345

}

1346

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

1347

network.ifr_flags |= IFF_UP;

1348

take_down_interface = true;

1349

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

1350

if(ret == -1){

1351

take_down_interface = false;

1352

perror("ioctl SIOCSIFFLAGS");

1353

exitcode = EX_OSERR;

1354

#ifdef __linux__

1355

if(restore_loglevel){

1356

ret = klogctl(7, NULL, 0);

1357

if(ret == -1){

1358

perror("klogctl");

2688

perror_plus("sigaction");

2689

exitcode = EX_OSERR;

2690

goto end;

2691

}

2692

}

2693

2694

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

2695

if(mc.interfaces == NULL){

2696

struct dirent **direntries = NULL;

2697

/* Look for any good interfaces */

2698

ret = scandir(sys_class_net, &direntries, good_interface,

2699

alphasort);

2700

if(ret >= 1){

2701

/* Add all found interfaces to interfaces list */

2702

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

2703

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

2704

direntries[i]->d_name);

2705

if(ret_errno != 0){

2706

errno = ret_errno;

2707

perror_plus("argz_add");

2708

free(direntries[i]);

2709

continue;

2710

}

2711

if(debug){

2712

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

2713

direntries[i]->d_name);

2714

}

2715

free(direntries[i]);

2716

}

2717

free(direntries);

2718

} else {

2719

if(ret == 0){

2720

free(direntries);

2721

}

2722

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

2723

exitcode = EXIT_FAILURE;

2724

goto end;

2725

}

2726

}

2727

2728

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

2729

{

2730

char *interface = NULL;

2731

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

2732

interface))){

2733

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

2734

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

2735

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

2736

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

2737

interface);

2738

interface = NULL;

2739

while((interface = argz_next(mc.interfaces,

2740

mc.interfaces_size, interface))){

2741

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

2742

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

2743

interface);

2744

interface = NULL;

1359

2745

}

1360

2746

}

1361

#endif /* __linux__ */

1362

/* Lower privileges */

1363

errno = 0;

1364

ret = seteuid(uid);

1365

if(ret == -1){

1366

perror("seteuid");

1367

}

1368

goto end;

1369

}

1370

}

1371

/* sleep checking until interface is running */

1372

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

1373

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

1374

if(ret == -1){

1375

perror("ioctl SIOCGIFFLAGS");

1376

} else if(network.ifr_flags & IFF_RUNNING){

1377

2747

break;

1378

2748

}

1379

struct timespec sleeptime = { .tv_nsec = 250000000 };

1380

ret = nanosleep(&sleeptime, NULL);

1381

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

1382

perror("nanosleep");

1383

}

1384

}

1385

if(not take_down_interface){

1386

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

1387

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

1388

if(ret == -1){

1389

perror("close");

1390

}

1391

}

1392

#ifdef __linux__

1393

if(restore_loglevel){

1394

/* Restores kernel loglevel to default */

1395

ret = klogctl(7, NULL, 0);

1396

if(ret == -1){

1397

perror("klogctl");

1398

}

1399

}

1400

#endif /* __linux__ */

1401

/* Lower privileges */

1402

errno = 0;

1403

if(take_down_interface){

1404

/* Lower privileges */

1405

ret = seteuid(uid);

1406

if(ret == -1){

1407

perror("seteuid");

1408

}

1409

} else {

1410

/* Lower privileges permanently */

1411

ret = setuid(uid);

1412

if(ret == -1){

1413

perror("setuid");

1414

}

1415

}

2749

bool interface_was_up = interface_is_up(interface);

2750

errno = bring_up_interface(interface, delay);

2751

if(not interface_was_up){

2752

if(errno != 0){

2753

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

2754

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

2755

} else {

2756

errno = argz_add(&interfaces_to_take_down,

2757

&interfaces_to_take_down_size,

2758

interface);

2759

if(errno != 0){

2760

perror_plus("argz_add");

2761

}

2762

}

2763

}

2764

}

2765

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

2766

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

2767

}

2768

}

2769

2770

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

2771

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

2772

if(debug){

2773

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

2774

mc.interfaces);

2775

}

2776

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

1416

2777

}

1417

2778

1418

2779

if(quit_now){

1419

2780

goto end;

1420

2781

}

1421

2782

1422

ret = init_gnutls_global(pubkey, seckey);

2783

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

1423

2784

if(ret == -1){

1424

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

2785

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

1425

2786

exitcode = EX_UNAVAILABLE;

1426

2787

goto end;

1427

2788

} else {

1432

2793

goto end;

1433

2794

}

1434

2795

1435

tempdir_created = true;

1436

if(mkdtemp(tempdir) == NULL){

1437

tempdir_created = false;

1438

perror("mkdtemp");

2796

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

2797

tempdir = mkdtemp(run_tempdir);

2798

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

2799

if(debug){

2800

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

2801

run_tempdir, old_tempdir);

2802

}

2803

tempdir = mkdtemp(old_tempdir);

2804

}

2805

if(tempdir == NULL){

2806

perror_plus("mkdtemp");

1439

2807

goto end;

1440

2808

}

1441

2809

1443

2811

goto end;

1444

2812

}

1445

2813

1446

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

1447

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

2814

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

2815

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

1448

2816

exitcode = EX_UNAVAILABLE;

1449

2817

goto end;

1450

2818

} else {

1459

2827

/* Connect directly, do not use Zeroconf */

1460

2828

/* (Mainly meant for debugging) */

1461

2829

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

2830

1462

2831

if(address == NULL){

1463

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

2832

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

1464

2833

exitcode = EX_USAGE;

1465

2834

goto end;

1466

2835

}

1469

2838

goto end;

1470

2839

}

1471

2840

1472

uint16_t port;

2841

in_port_t port;

1473

2842

errno = 0;

1474

2843

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

1475

2844

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

1476

or tmpmax != (uint16_t)tmpmax){

1477

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

2845

or tmpmax != (in_port_t)tmpmax){

2846

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

1478

2847

exitcode = EX_USAGE;

1479

2848

goto end;

1480

2849

}

1481

2850

1482

2851

if(quit_now){

1483

2852

goto end;

1484

2853

}

1485

2854

1486

port = (uint16_t)tmpmax;

2855

port = (in_port_t)tmpmax;

1487

2856

*address = '\0';

1488

address = connect_to;

1489

2857

/* Colon in address indicates IPv6 */

1490

2858

int af;

1491

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

2859

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

1492

2860

af = AF_INET6;

2861

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

2862

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

2863

{

2864

connect_to++;

2865

address[-1] = '\0';

2866

}

1493

2867

} else {

1494

2868

af = AF_INET;

1495

2869

}

2870

address = connect_to;

1496

2871

1497

2872

if(quit_now){

1498

2873

goto end;

1499

2874

}

1500

2875

1501

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

1502

if(ret < 0){

1503

switch(errno){

1504

case ENETUNREACH:

1505

case EHOSTDOWN:

1506

case EHOSTUNREACH:

1507

exitcode = EX_NOHOST;

1508

break;

1509

case EINVAL:

1510

exitcode = EX_USAGE;

1511

break;

1512

case EIO:

1513

exitcode = EX_IOERR;

1514

break;

1515

case EPROTO:

1516

exitcode = EX_PROTOCOL;

1517

break;

1518

default:

1519

exitcode = EX_OSERR;

1520

break;

1521

}

1522

} else {

2876

while(not quit_now){

2877

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

2878

&mc);

2879

if(quit_now or ret == 0){

2880

break;

2881

}

2882

if(debug){

2883

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

2884

(int)retry_interval);

2885

}

2886

sleep((unsigned int)retry_interval);

2887

}

2888

2889

if(not quit_now){

1523

2890

exitcode = EXIT_SUCCESS;

1524

2891

}

2892

1525

2893

goto end;

1526

2894

}

1527

2895

1539

2907

config.publish_domain = 0;

1540

2908

1541

2909

/* Allocate a new server */

1542

mc.server = avahi_server_new(avahi_simple_poll_get

1543

(mc.simple_poll), &config, NULL,

1544

NULL, &error);

2910

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2911

&config, NULL, NULL, &ret_errno);

1545

2912

1546

2913

/* Free the Avahi configuration data */

1547

2914

avahi_server_config_free(&config);

1549

2916

1550

2917

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

1551

2918

if(mc.server == NULL){

1552

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

1553

avahi_strerror(error));

2919

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

2920

avahi_strerror(ret_errno));

1554

2921

exitcode = EX_UNAVAILABLE;

1555

2922

goto end;

1556

2923

}

1562

2929

/* Create the Avahi service browser */

1563

2930

sb = avahi_s_service_browser_new(mc.server, if_index,

1564

2931

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1565

NULL, 0, browse_callback, NULL);

2932

NULL, 0, browse_callback,

2933

(void *)&mc);

1566

2934

if(sb == NULL){

1567

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

1568

avahi_strerror(avahi_server_errno(mc.server)));

2935

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

2936

avahi_strerror(avahi_server_errno(mc.server)));

1569

2937

exitcode = EX_UNAVAILABLE;

1570

2938

goto end;

1571

2939

}

1577

2945

/* Run the main loop */

1578

2946

1579

2947

if(debug){

1580

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

2948

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

1581

2949

}

1582

2950

1583

avahi_simple_poll_loop(mc.simple_poll);

2951

ret = avahi_loop_with_timeout(simple_poll,

2952

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

2953

if(debug){

2954

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

2955

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

2956

}

1584

2957

1585

2958

end:

1586

2959

1587

2960

if(debug){

1588

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

2961

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

1589

2962

}

1590

2963

1591

2964

/* Cleanup things */

2965

free(mc.interfaces);

2966

1592

2967

if(sb != NULL)

1593

2968

avahi_s_service_browser_free(sb);

1594

2969

1595

2970

if(mc.server != NULL)

1596

2971

avahi_server_free(mc.server);

1597

2972

1598

if(mc.simple_poll != NULL)

1599

avahi_simple_poll_free(mc.simple_poll);

2973

if(simple_poll != NULL)

2974

avahi_simple_poll_free(simple_poll);

1600

2975

1601

2976

if(gnutls_initialized){

1602

2977

gnutls_certificate_free_credentials(mc.cred);

1608

2983

gpgme_release(mc.ctx);

1609

2984

}

1610

2985

1611

/* Take down the network interface */

1612

if(take_down_interface){

1613

/* Re-raise priviliges */

1614

errno = 0;

1615

ret = seteuid(0);

1616

if(ret == -1){

1617

perror("seteuid");

1618

}

1619

if(geteuid() == 0){

1620

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

1621

if(ret == -1){

1622

perror("ioctl SIOCGIFFLAGS");

1623

} else if(network.ifr_flags & IFF_UP) {

1624

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

1625

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

1626

if(ret == -1){

1627

perror("ioctl SIOCSIFFLAGS");

1628

}

1629

}

1630

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

1631

if(ret == -1){

1632

perror("close");

1633

}

1634

/* Lower privileges permanently */

1635

errno = 0;

1636

ret = setuid(uid);

1637

if(ret == -1){

1638

perror("setuid");

1639

}

1640

}

1641

}

1642

1643

/* Removes the temp directory used by GPGME */

1644

if(tempdir_created){

1645

DIR *d;

1646

struct dirent *direntry;

1647

d = opendir(tempdir);

1648

if(d == NULL){

1649

if(errno != ENOENT){

1650

perror("opendir");

1651

}

1652

} else {

1653

while(true){

1654

direntry = readdir(d);

1655

if(direntry == NULL){

1656

break;

1657

}

1658

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

1659

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

1660

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

1661

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

1662

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

1663

continue;

1664

}

1665

char *fullname = NULL;

1666

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

1667

direntry->d_name);

1668

if(ret < 0){

1669

perror("asprintf");

1670

continue;

1671

}

1672

ret = remove(fullname);

1673

if(ret == -1){

1674

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

1675

strerror(errno));

1676

}

1677

free(fullname);

1678

}

1679

closedir(d);

1680

}

1681

ret = rmdir(tempdir);

1682

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

1683

perror("rmdir");

2986

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

2987

has seen */

2988

if(mc.current_server != NULL){

2989

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

2990

while(mc.current_server != NULL){

2991

server *next = mc.current_server->next;

2992

#ifdef __GNUC__

2993

#pragma GCC diagnostic push

2994

#pragma GCC diagnostic ignored "-Wcast-qual"

2995

#endif

2996

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

2997

#ifdef __GNUC__

2998

#pragma GCC diagnostic pop

2999

#endif

3000

free(mc.current_server);

3001

mc.current_server = next;

3002

}

3003

}

3004

3005

/* Re-raise privileges */

3006

{

3007

ret_errno = raise_privileges();

3008

if(ret_errno != 0){

3009

errno = ret_errno;

3010

perror_plus("Failed to raise privileges");

3011

} else {

3012

3013

/* Run network hooks */

3014

run_network_hooks("stop", interfaces_hooks != NULL ?

3015

interfaces_hooks : "", delay);

3016

3017

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

3018

{

3019

char *interface = NULL;

3020

while((interface=argz_next(interfaces_to_take_down,

3021

interfaces_to_take_down_size,

3022

interface))){

3023

ret_errno = take_down_interface(interface);

3024

if(ret_errno != 0){

3025

errno = ret_errno;

3026

perror_plus("Failed to take down interface");

3027

}

3028

}

3029

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

3030

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

3031

" down\n");

3032

}

3033

}

3034

}

3035

3036

ret_errno = lower_privileges_permanently();

3037

if(ret_errno != 0){

3038

errno = ret_errno;

3039

perror_plus("Failed to lower privileges permanently");

3040

}

3041

}

3042

3043

free(interfaces_to_take_down);

3044

free(interfaces_hooks);

3045

3046

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

3047

if(tempdir != NULL){

3048

struct dirent **direntries = NULL;

3049

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

3050

| O_NOFOLLOW

3051

| O_DIRECTORY

3052

| O_PATH));

3053

if(tempdir_fd == -1){

3054

perror_plus("open");

3055

} else {

3056

#ifdef __GLIBC__

3057

#if __GLIBC_PREREQ(2, 15)

3058

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

3059

notdotentries, alphasort);

3060

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

3061

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

3062

alphasort);

3063

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

3064

#else /* not __GLIBC__ */

3065

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

3066

alphasort);

3067

#endif /* not __GLIBC__ */

3068

if(numentries >= 0){

3069

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

3070

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

3071

if(ret == -1){

3072

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

3073

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

3074

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

3075

}

3076

free(direntries[i]);

3077

}

3078

3079

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

3080

free(direntries);

3081

if(numentries == -1){

3082

perror_plus("scandir");

3083

}

3084

ret = rmdir(tempdir);

3085

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

3086

perror_plus("rmdir");

3087

}

3088

}

3089

close(tempdir_fd);

1684

3090

}

1685

3091

}

1686

3092

1691

3097

&old_sigterm_action,

1692

3098

NULL));

1693

3099

if(ret == -1){

1694

perror("sigaction");

3100

perror_plus("sigaction");

1695

3101

}

1696

3102

do {

1697

3103

ret = raise(signal_received);

1698

3104

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

1699

3105

if(ret != 0){

1700

perror("raise");

3106

perror_plus("raise");

1701

3107

abort();

1702

3108

}

1703

3109

TEMP_FAILURE_RETRY(pause());