/mandos/release : revision 237.7.309

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

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*

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* Everything else is

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*

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

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

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* along with this program. If not, see

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

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*

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

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

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*/

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

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#ifndef _LARGEFILE_SOURCE

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#define _LARGEFILE_SOURCE

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#endif

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#endif /* not _LARGEFILE_SOURCE */

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#ifndef _FILE_OFFSET_BITS

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#define _FILE_OFFSET_BITS 64

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#endif

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#endif /* not _FILE_OFFSET_BITS */

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#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */

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

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stdout, ferror(), remove() */

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

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stdout, ferror() */

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

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

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

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strtof(), abort() */

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sockaddr_in6, PF_INET6,

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SOCK_STREAM, uid_t, gid_t, open(),

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opendir(), DIR */

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

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

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

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inet_pton(), connect() */

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

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inet_pton(), connect(),

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getnameinfo() */

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

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#include <dirent.h> /* opendir(), struct dirent, readdir()

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*/

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

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strtoimax() */

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#include <assert.h> /* assert() */

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

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

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

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program_invocation_short_name */

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

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

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SIOCSIFFLAGS, if_indextoname(),

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if_nametoindex(), IF_NAMESIZE */

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*/

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#include <unistd.h> /* close(), SEEK_SET, off_t, write(),

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getuid(), getgid(), seteuid(),

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setgid(), pause() */

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

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setgid(), pause(), _exit(),

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unlinkat() */

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

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

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

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argp_state, struct argp,

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raise() */

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

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EX_NOHOST, EX_IOERR, EX_PROTOCOL */

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

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WEXITSTATUS(), WTERMSIG() */

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

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

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argz_delete(), argz_append(),

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argz_stringify(), argz_add(),

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argz_count() */

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#include <netdb.h> /* getnameinfo(), NI_NUMERICHOST,

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EAI_SYSTEM, gai_strerror() */

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#ifdef __linux__

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

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118

init_gnutls_session(),

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119

GNUTLS_* */

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#include <gnutls/openpgp.h>

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/* gnutls_certificate_set_openpgp_key_file(),

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GNUTLS_OPENPGP_FMT_BASE64 */

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/* gnutls_certificate_set_openpgp_key_file(),

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GNUTLS_OPENPGP_FMT_BASE64 */

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/* GPGME */

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125

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

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133

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

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134

#define SECKEY "seckey.txt"

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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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139

static const char mandos_protocol_version[] = "1";

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

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

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

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static const char sys_class_net[] = "/sys/class/net";

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char *connect_to = NULL;

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const char *hookdir = HOOKDIR;

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int hookdir_fd = -1;

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uid_t uid = 65534;

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gid_t gid = 65534;

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

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typedef struct server{

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const char *ip;

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in_port_t port;

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AvahiIfIndex if_index;

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int af;

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struct timespec last_seen;

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struct server *next;

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struct server *prev;

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} server;

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

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typedef struct {

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AvahiSimplePoll *simple_poll;

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AvahiServer *server;

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gnutls_certificate_credentials_t cred;

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164

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;

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

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

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.dh_bits = 1024, .priority = "SECURE256"

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

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/* global so signal handler can reach it*/

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AvahiSimplePoll *simple_poll;

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175

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sig_atomic_t quit_now = 0;

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177

int signal_received = 0;

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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;

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

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program_invocation_short_name);

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errno = e;

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perror(print_text);

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}

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188

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

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

190

va_list ap;

191

va_start (ap, format);

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193

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

194

program_invocation_short_name));

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

196

}

197

150

198

/*

151

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,

153

201

* "buffer_length" is how much is already used.

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202

*/

203

__attribute__((nonnull, warn_unused_result))

155

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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return 0;

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214

}

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*buffer = new_buf;

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buffer_capacity += BUFFER_SIZE;

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217

}

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218

return buffer_capacity;

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219

}

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

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__attribute__((nonnull, warn_unused_result))

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

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int af, server **current_server){

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int ret;

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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),

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.port = port,

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.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;

258

*current_server = new_server;

259

} else {

260

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

261

new_server->next = *current_server;

262

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

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new_server->prev->next = new_server;

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(*current_server)->prev = new_server;

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}

266

return true;

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}

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/*

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* Initialize GPGME.

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271

*/

170

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))

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static bool init_gpgme(const char * const seckey,

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const char * const pubkey,

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const char * const tempdir,

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mandos_context *mc){

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gpgme_error_t rc;

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gpgme_engine_info_t engine_info;

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/*

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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;

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285

int fd;

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gpgme_data_t pgp_data;

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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");

187

291

return false;

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292

}

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293

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rc = gpgme_data_new_from_fd(&pgp_data, fd);

191

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if(rc != GPG_ERR_NO_ERROR){

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

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gpgme_strsource(rc), gpgme_strerror(rc));

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

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gpgme_strsource(rc), gpgme_strerror(rc));

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return false;

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299

}

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300

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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

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ret = (int)TEMP_FAILURE_RETRY(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

}

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315

212

316

if(debug){

213

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

317

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

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318

}

215

319

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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

mandos_context *mc){

402

520

int ret;

521

unsigned int uret;

403

522

404

523

if(debug){

405

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

524

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

406

525

}

407

526

408

527

ret = gnutls_global_init();

409

528

if(ret != GNUTLS_E_SUCCESS){

410

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

411

safer_gnutls_strerror(ret));

529

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

530

safer_gnutls_strerror(ret));

412

531

return -1;

413

532

}

414

533

421

540

}

422

541

423

542

/* OpenPGP credentials */

424

gnutls_certificate_allocate_credentials(&mc.cred);

543

ret = gnutls_certificate_allocate_credentials(&mc->cred);

425

544

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));

545

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

546

safer_gnutls_strerror(ret));

431

547

gnutls_global_deinit();

432

548

return -1;

433

549

}

434

550

435

551

if(debug){

436

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

437

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

438

seckeyfilename);

552

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

553

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

554

pubkeyfilename,

555

seckeyfilename);

439

556

}

440

557

441

558

ret = gnutls_certificate_set_openpgp_key_file

442

(mc.cred, pubkeyfilename, seckeyfilename,

559

(mc->cred, pubkeyfilename, seckeyfilename,

443

560

GNUTLS_OPENPGP_FMT_BASE64);

444

561

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));

562

fprintf_plus(stderr,

563

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

564

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

565

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

566

safer_gnutls_strerror(ret));

450

567

goto globalfail;

451

568

}

452

569

453

570

/* GnuTLS server initialization */

454

ret = gnutls_dh_params_init(&mc.dh_params);

571

ret = gnutls_dh_params_init(&mc->dh_params);

455

572

if(ret != GNUTLS_E_SUCCESS){

456

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

457

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

573

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

574

" initialization: %s\n",

575

safer_gnutls_strerror(ret));

458

576

goto globalfail;

459

577

}

460

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

578

if(mc->dh_bits == 0){

579

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

580

/* Try to read the private key file */

581

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

582

{

583

int secfile = open(seckeyfilename, O_RDONLY);

584

size_t buffer_capacity = 0;

585

while(true){

586

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

587

(size_t)buffer.size,

588

(size_t)buffer_capacity);

589

if(buffer_capacity == 0){

590

perror_plus("incbuffer");

591

free(buffer.data);

592

buffer.data = NULL;

593

break;

594

}

595

ssize_t bytes_read = read(secfile, buffer.data + buffer.size,

596

BUFFER_SIZE);

597

/* EOF */

598

if(bytes_read == 0){

599

break;

600

}

601

/* check bytes_read for failure */

602

if(bytes_read < 0){

603

perror_plus("read");

604

free(buffer.data);

605

buffer.data = NULL;

606

break;

607

}

608

buffer.size += (unsigned int)bytes_read;

609

}

610

close(secfile);

611

}

612

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

613

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

614

if(buffer.data != NULL){

615

{

616

gnutls_openpgp_privkey_t privkey = NULL;

617

ret = gnutls_openpgp_privkey_init(&privkey);

618

if(ret != GNUTLS_E_SUCCESS){

619

fprintf_plus(stderr, "Error initializing OpenPGP key"

620

" structure: %s", safer_gnutls_strerror(ret));

621

free(buffer.data);

622

buffer.data = NULL;

623

} else {

624

ret = gnutls_openpgp_privkey_import(privkey, &buffer,

625

GNUTLS_OPENPGP_FMT_BASE64,

626

"", 0);

627

if(ret != GNUTLS_E_SUCCESS){

628

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

629

safer_gnutls_strerror(ret));

630

privkey = NULL;

631

}

632

free(buffer.data);

633

buffer.data = NULL;

634

if(privkey != NULL){

635

/* Use private key to suggest an appropriate sec_param */

636

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

637

gnutls_openpgp_privkey_deinit(privkey);

638

if(debug){

639

fprintf_plus(stderr, "This OpenPGP key implies using a"

640

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

641

safe_string(gnutls_sec_param_get_name

642

(sec_param)));

643

}

644

}

645

}

646

}

647

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

648

/* Err on the side of caution */

649

sec_param = GNUTLS_SEC_PARAM_ULTRA;

650

if(debug){

651

fprintf_plus(stderr, "Falling back to security parameter"

652

" \"%s\"\n",

653

safe_string(gnutls_sec_param_get_name

654

(sec_param)));

655

}

656

}

657

}

658

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

659

if(uret != 0){

660

mc->dh_bits = uret;

661

if(debug){

662

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

663

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

664

safe_string(gnutls_sec_param_get_name

665

(sec_param)),

666

mc->dh_bits);

667

}

668

} else {

669

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

670

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

671

safe_string(gnutls_sec_param_get_name(sec_param)),

672

safer_gnutls_strerror(ret));

673

goto globalfail;

674

}

675

} else if(debug){

676

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

677

mc->dh_bits);

678

}

679

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

461

680

if(ret != GNUTLS_E_SUCCESS){

462

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

463

safer_gnutls_strerror(ret));

681

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

682

" %s\n", mc->dh_bits, safer_gnutls_strerror(ret));

464

683

goto globalfail;

465

684

}

466

685

467

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

686

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

468

687

469

688

return 0;

470

689

471

690

globalfail:

472

691

473

gnutls_certificate_free_credentials(mc.cred);

692

gnutls_certificate_free_credentials(mc->cred);

474

693

gnutls_global_deinit();

475

gnutls_dh_params_deinit(mc.dh_params);

694

gnutls_dh_params_deinit(mc->dh_params);

476

695

return -1;

477

696

}

478

697

479

static int init_gnutls_session(gnutls_session_t *session){

698

__attribute__((nonnull, warn_unused_result))

699

static int init_gnutls_session(gnutls_session_t *session,

700

mandos_context *mc){

480

701

int ret;

481

702

/* GnuTLS session creation */

482

703

do {

486

707

}

487

708

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

488

709

if(ret != GNUTLS_E_SUCCESS){

489

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

490

safer_gnutls_strerror(ret));

710

fprintf_plus(stderr,

711

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

712

safer_gnutls_strerror(ret));

491

713

}

492

714

493

715

{

494

716

const char *err;

495

717

do {

496

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

718

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

497

719

if(quit_now){

498

720

gnutls_deinit(*session);

499

721

return -1;

500

722

}

501

723

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

502

724

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));

725

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

726

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

727

safer_gnutls_strerror(ret));

506

728

gnutls_deinit(*session);

507

729

return -1;

508

730

}

510

732

511

733

do {

512

734

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

513

mc.cred);

735

mc->cred);

514

736

if(quit_now){

515

737

gnutls_deinit(*session);

516

738

return -1;

517

739

}

518

740

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

519

741

if(ret != GNUTLS_E_SUCCESS){

520

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

521

safer_gnutls_strerror(ret));

742

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

743

safer_gnutls_strerror(ret));

522

744

gnutls_deinit(*session);

523

745

return -1;

524

746

}

526

748

/* ignore client certificate if any. */

527

749

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

528

750

529

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

751

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

530

752

531

753

return 0;

532

754

}

535

757

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

536

758

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

537

759

760

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

761

__attribute__((warn_unused_result))

762

error_t raise_privileges(void){

763

error_t old_errno = errno;

764

error_t ret_errno = 0;

765

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

766

ret_errno = errno;

767

}

768

errno = old_errno;

769

return ret_errno;

770

}

771

772

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

773

__attribute__((warn_unused_result))

774

error_t raise_privileges_permanently(void){

775

error_t old_errno = errno;

776

error_t ret_errno = raise_privileges();

777

if(ret_errno != 0){

778

errno = old_errno;

779

return ret_errno;

780

}

781

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

782

ret_errno = errno;

783

}

784

errno = old_errno;

785

return ret_errno;

786

}

787

788

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

789

__attribute__((warn_unused_result))

790

error_t lower_privileges(void){

791

error_t old_errno = errno;

792

error_t ret_errno = 0;

793

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

794

ret_errno = errno;

795

}

796

errno = old_errno;

797

return ret_errno;

798

}

799

800

/* Lower privileges permanently */

801

__attribute__((warn_unused_result))

802

error_t lower_privileges_permanently(void){

803

error_t old_errno = errno;

804

error_t ret_errno = 0;

805

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

806

ret_errno = errno;

807

}

808

errno = old_errno;

809

return ret_errno;

810

}

811

812

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

813

__attribute__((nonnull, warn_unused_result))

814

static bool add_delete_local_route(const bool add,

815

const char *address,

816

AvahiIfIndex if_index){

817

int ret;

818

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

819

char add_arg[] = "add";

820

char delete_arg[] = "delete";

821

char debug_flag[] = "--debug";

822

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

823

if(pluginhelperdir == NULL){

824

if(debug){

825

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

826

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

827

}

828

return false;

829

}

830

831

char interface[IF_NAMESIZE];

832

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

833

perror_plus("if_indextoname");

834

return false;

835

}

836

837

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

838

if(devnull == -1){

839

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

840

return false;

841

}

842

pid_t pid = fork();

843

if(pid == 0){

844

/* Child */

845

/* Raise privileges */

846

errno = raise_privileges_permanently();

847

if(errno != 0){

848

perror_plus("Failed to raise privileges");

849

/* _exit(EX_NOPERM); */

850

} else {

851

/* Set group */

852

errno = 0;

853

ret = setgid(0);

854

if(ret == -1){

855

perror_plus("setgid");

856

_exit(EX_NOPERM);

857

}

858

/* Reset supplementary groups */

859

errno = 0;

860

ret = setgroups(0, NULL);

861

if(ret == -1){

862

perror_plus("setgroups");

863

_exit(EX_NOPERM);

864

}

865

}

866

ret = dup2(devnull, STDIN_FILENO);

867

if(ret == -1){

868

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

869

_exit(EX_OSERR);

870

}

871

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

872

if(ret == -1){

873

perror_plus("close");

874

_exit(EX_OSERR);

875

}

876

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

877

if(ret == -1){

878

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

879

_exit(EX_OSERR);

880

}

881

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

882

O_RDONLY

883

| O_DIRECTORY

884

| O_PATH

885

| O_CLOEXEC));

886

if(helperdir_fd == -1){

887

perror_plus("open");

888

_exit(EX_UNAVAILABLE);

889

}

890

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

891

helper, O_RDONLY));

892

if(helper_fd == -1){

893

perror_plus("openat");

894

_exit(EX_UNAVAILABLE);

895

}

896

TEMP_FAILURE_RETRY(close(helperdir_fd));

897

#ifdef __GNUC__

898

#pragma GCC diagnostic push

899

#pragma GCC diagnostic ignored "-Wcast-qual"

900

#endif

901

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

902

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

903

interface, debug ? debug_flag : NULL, NULL },

904

environ) == -1){

905

#ifdef __GNUC__

906

#pragma GCC diagnostic pop

907

#endif

908

perror_plus("fexecve");

909

_exit(EXIT_FAILURE);

910

}

911

}

912

if(pid == -1){

913

perror_plus("fork");

914

return false;

915

}

916

int status;

917

pid_t pret = -1;

918

errno = 0;

919

do {

920

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

921

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

922

int errno_raising = 0;

923

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

924

errno_raising = errno;

925

perror_plus("Failed to raise privileges in order to"

926

" kill helper program");

927

}

928

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

929

perror_plus("kill");

930

}

931

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

932

perror_plus("Failed to lower privileges after killing"

933

" helper program");

934

}

935

return false;

936

}

937

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

938

if(pret == -1){

939

perror_plus("waitpid");

940

return false;

941

}

942

if(WIFEXITED(status)){

943

if(WEXITSTATUS(status) != 0){

944

fprintf_plus(stderr, "Error: iprouteadddel exited"

945

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

946

return false;

947

}

948

return true;

949

}

950

if(WIFSIGNALED(status)){

951

fprintf_plus(stderr, "Error: iprouteadddel died by"

952

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

953

return false;

954

}

955

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

956

return false;

957

}

958

959

__attribute__((nonnull, warn_unused_result))

960

static bool add_local_route(const char *address,

961

AvahiIfIndex if_index){

962

if(debug){

963

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

964

}

965

return add_delete_local_route(true, address, if_index);

966

}

967

968

__attribute__((nonnull, warn_unused_result))

969

static bool delete_local_route(const char *address,

970

AvahiIfIndex if_index){

971

if(debug){

972

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

973

}

974

return add_delete_local_route(false, address, if_index);

975

}

976

538

977

/* Called when a Mandos server is found */

539

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

978

__attribute__((nonnull, warn_unused_result))

979

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

540

980

AvahiIfIndex if_index,

541

int af){

981

int af, mandos_context *mc){

542

982

int ret, tcp_sd = -1;

543

983

ssize_t sret;

544

union {

545

struct sockaddr_in in;

546

struct sockaddr_in6 in6;

547

} to;

984

struct sockaddr_storage to;

548

985

char *buffer = NULL;

549

986

char *decrypted_buffer = NULL;

550

987

size_t buffer_length = 0;

553

990

int retval = -1;

554

991

gnutls_session_t session;

555

992

int pf; /* Protocol family */

993

bool route_added = false;

556

994

557

995

errno = 0;

558

996

569

1007

pf = PF_INET;

570

1008

break;

571

1009

default:

572

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

1010

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

573

1011

errno = EINVAL;

574

1012

return -1;

575

1013

}

576

1014

577

ret = init_gnutls_session(&session);

1015

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

1016

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

1017

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

1018

bool match = false;

1019

{

1020

char *interface = NULL;

1021

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

1022

interface))){

1023

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

1024

match = true;

1025

break;

1026

}

1027

}

1028

}

1029

if(not match){

1030

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

1031

connect to the server */

1032

if(debug){

1033

char interface[IF_NAMESIZE];

1034

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

1035

perror_plus("if_indextoname");

1036

} else {

1037

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

1038

" \"%s\"\n",

1039

if_indextoname((unsigned int)if_index,

1040

interface));

1041

}

1042

}

1043

return -1;

1044

}

1045

}

1046

1047

ret = init_gnutls_session(&session, mc);

578

1048

if(ret != 0){

579

1049

return -1;

580

1050

}

581

1051

582

1052

if(debug){

583

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

584

"\n", ip, port);

1053

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

1054

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

585

1055

}

586

1056

587

tcp_sd = socket(pf, SOCK_STREAM, 0);

1057

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

588

1058

if(tcp_sd < 0){

589

1059

int e = errno;

590

perror("socket");

1060

perror_plus("socket");

591

1061

errno = e;

592

1062

goto mandos_end;

593

1063

}

599

1069

600

1070

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

601

1071

if(af == AF_INET6){

602

to.in6.sin6_family = (sa_family_t)af;

603

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

1072

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

1073

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

604

1074

} else { /* IPv4 */

605

to.in.sin_family = (sa_family_t)af;

606

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

1075

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

1076

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

607

1077

}

608

1078

if(ret < 0 ){

609

1079

int e = errno;

610

perror("inet_pton");

1080

perror_plus("inet_pton");

611

1081

errno = e;

612

1082

goto mandos_end;

613

1083

}

614

1084

if(ret == 0){

615

1085

int e = errno;

616

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

1086

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

617

1087

errno = e;

618

1088

goto mandos_end;

619

1089

}

620

1090

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*/

1091

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

1092

if(IN6_IS_ADDR_LINKLOCAL

1093

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

628

1094

if(if_index == AVAHI_IF_UNSPEC){

629

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

630

" without a network interface\n");

1095

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

1096

" incomplete without a network interface\n");

631

1097

errno = EINVAL;

632

1098

goto mandos_end;

633

1099

}

634

1100

/* Set the network interface number as scope */

635

to.in6.sin6_scope_id = (uint32_t)if_index;

1101

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

636

1102

}

637

1103

} else {

638

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

639

-Wconversion and

640

-Wunreachable-code */

1104

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

641

1105

}

642

1106

643

1107

if(quit_now){

649

1113

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

650

1114

char interface[IF_NAMESIZE];

651

1115

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

652

perror("if_indextoname");

1116

perror_plus("if_indextoname");

653

1117

} else {

654

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

655

ip, interface, port);

1118

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

1119

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

656

1120

}

657

1121

} else {

658

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

659

port);

1122

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

1123

ip, (uintmax_t)port);

660

1124

}

661

1125

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

662

1126

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;

1127

if(af == AF_INET6){

1128

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

1129

sizeof(struct sockaddr_in6),

1130

addrstr, sizeof(addrstr), NULL, 0,

1131

NI_NUMERICHOST);

1132

} else {

1133

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

1134

sizeof(struct sockaddr_in),

1135

addrstr, sizeof(addrstr), NULL, 0,

1136

NI_NUMERICHOST);

1137

}

1138

if(ret == EAI_SYSTEM){

1139

perror_plus("getnameinfo");

1140

} else if(ret != 0) {

1141

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

1142

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

1143

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

1144

}

1145

}

1146

1147

if(quit_now){

1148

errno = EINTR;

1149

goto mandos_end;

1150

}

1151

1152

while(true){

1153

if(af == AF_INET6){

1154

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

1155

sizeof(struct sockaddr_in6));

1156

} else {

1157

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

1158

sizeof(struct sockaddr_in));

1159

}

1160

if(ret < 0){

1161

if(errno == ENETUNREACH

1162

and if_index != AVAHI_IF_UNSPEC

1163

and connect_to == NULL

1164

and not route_added and

1165

((af == AF_INET6 and not

1166

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1167

&to)->sin6_addr)))

1168

or (af == AF_INET and

1169

/* Not a a IPv4LL address */

1170

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

1171

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

1172

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

1173

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

1174

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

1175

connect to a Mandos server announced by Avahi on a server

1176

host with a global address. Work around this by retrying

1177

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

1178

1179

Avahi bug reference:

1180

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

1181

https://bugs.debian.org/587961

1182

*/

1183

if(debug){

1184

fprintf_plus(stderr, "Mandos server unreachable, trying"

1185

" direct route\n");

1186

}

1187

int e = errno;

1188

route_added = add_local_route(ip, if_index);

1189

if(route_added){

1190

continue;

1191

}

1192

errno = e;

1193

}

1194

if(errno != ECONNREFUSED or debug){

1195

int e = errno;

1196

perror_plus("connect");

1197

errno = e;

1198

}

1199

goto mandos_end;

1200

}

1201

1202

if(quit_now){

1203

errno = EINTR;

1204

goto mandos_end;

1205

}

1206

break;

700

1207

}

701

1208

702

1209

const char *out = mandos_protocol_version;

704

1211

while(true){

705

1212

size_t out_size = strlen(out);

706

1213

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

707

out_size - written));

1214

out_size - written));

708

1215

if(ret == -1){

709

1216

int e = errno;

710

perror("write");

1217

perror_plus("write");

711

1218

errno = e;

712

1219

goto mandos_end;

713

1220

}

730

1237

}

731

1238

732

1239

if(debug){

733

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

1240

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

734

1241

}

735

1242

736

1243

if(quit_now){

738

1245

goto mandos_end;

739

1246

}

740

1247

741

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1248

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

1249

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

1250

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

1251

gnutls_transport_set_ptr(session,

1252

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

742

1253

743

1254

if(quit_now){

744

1255

errno = EINTR;

755

1266

756

1267

if(ret != GNUTLS_E_SUCCESS){

757

1268

if(debug){

758

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

1269

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

759

1270

gnutls_perror(ret);

760

1271

}

761

1272

errno = EPROTO;

765

1276

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

766

1277

767

1278

if(debug){

768

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

769

ip);

1279

fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"

1280

" %s\n", ip);

770

1281

}

771

1282

772

1283

while(true){

777

1288

}

778

1289

779

1290

buffer_capacity = incbuffer(&buffer, buffer_length,

780

buffer_capacity);

1291

buffer_capacity);

781

1292

if(buffer_capacity == 0){

782

1293

int e = errno;

783

perror("incbuffer");

1294

perror_plus("incbuffer");

784

1295

errno = e;

785

1296

goto mandos_end;

786

1297

}

810

1321

}

811

1322

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

812

1323

if(ret < 0){

813

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

1324

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

1325

"***\n");

814

1326

gnutls_perror(ret);

815

1327

errno = EPROTO;

816

1328

goto mandos_end;

817

1329

}

818

1330

break;

819

1331

default:

820

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

821

" encrypted session with Mandos server\n");

1332

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

1333

" encrypted session with Mandos server\n");

822

1334

gnutls_bye(session, GNUTLS_SHUT_RDWR);

823

1335

errno = EIO;

824

1336

goto mandos_end;

829

1341

}

830

1342

831

1343

if(debug){

832

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

1344

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

833

1345

}

834

1346

835

1347

if(quit_now){

847

1359

848

1360

if(buffer_length > 0){

849

1361

ssize_t decrypted_buffer_size;

850

decrypted_buffer_size = pgp_packet_decrypt(buffer,

851

buffer_length,

852

&decrypted_buffer);

1362

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1363

&decrypted_buffer, mc);

853

1364

if(decrypted_buffer_size >= 0){

854

1365

855

1366

written = 0;

865

1376

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

866

1377

int e = errno;

867

1378

if(debug){

868

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

869

strerror(errno));

1379

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

1380

strerror(errno));

870

1381

}

871

1382

errno = e;

872

1383

goto mandos_end;

881

1392

882

1393

mandos_end:

883

1394

{

1395

if(route_added){

1396

if(not delete_local_route(ip, if_index)){

1397

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

1398

" interface %d", ip, if_index);

1399

}

1400

}

884

1401

int e = errno;

885

1402

free(decrypted_buffer);

886

1403

free(buffer);

891

1408

if(e == 0){

892

1409

e = errno;

893

1410

}

894

perror("close");

1411

perror_plus("close");

895

1412

}

896

1413

gnutls_deinit(session);

1414

errno = e;

897

1415

if(quit_now){

898

e = EINTR;

1416

errno = EINTR;

899

1417

retval = -1;

900

1418

}

901

errno = e;

902

1419

}

903

1420

return retval;

904

1421

}

905

1422

1423

__attribute__((nonnull))

906

1424

static void resolve_callback(AvahiSServiceResolver *r,

907

1425

AvahiIfIndex interface,

908

1426

AvahiProtocol proto,

916

1434

AVAHI_GCC_UNUSED AvahiStringList *txt,

917

1435

AVAHI_GCC_UNUSED AvahiLookupResultFlags

918

1436

flags,

919

AVAHI_GCC_UNUSED void* userdata){

920

assert(r);

1437

void *mc){

1438

if(r == NULL){

1439

return;

1440

}

921

1441

922

1442

/* Called whenever a service has been resolved successfully or

923

1443

timed out */

924

1444

925

1445

if(quit_now){

1446

avahi_s_service_resolver_free(r);

926

1447

return;

927

1448

}

928

1449

929

1450

switch(event){

930

1451

default:

931

1452

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)));

1453

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

1454

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

1455

domain,

1456

avahi_strerror(avahi_server_errno

1457

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

935

1458

break;

936

1459

937

1460

case AVAHI_RESOLVER_FOUND:

939

1462

char ip[AVAHI_ADDRESS_STR_MAX];

940

1463

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

941

1464

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);

1465

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

1466

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

1467

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

945

1468

}

946

int ret = start_mandos_communication(ip, port, interface,

947

avahi_proto_to_af(proto));

1469

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

1470

interface,

1471

avahi_proto_to_af(proto),

1472

mc);

948

1473

if(ret == 0){

949

avahi_simple_poll_quit(mc.simple_poll);

1474

avahi_simple_poll_quit(simple_poll);

1475

} else {

1476

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

1477

avahi_proto_to_af(proto),

1478

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

1479

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

1480

" list\n", name);

1481

}

950

1482

}

951

1483

}

952

1484

}

962

1494

const char *domain,

963

1495

AVAHI_GCC_UNUSED AvahiLookupResultFlags

964

1496

flags,

965

AVAHI_GCC_UNUSED void* userdata){

966

assert(b);

1497

void *mc){

1498

if(b == NULL){

1499

return;

1500

}

967

1501

968

1502

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

969

1503

is removed from the LAN */

976

1510

default:

977

1511

case AVAHI_BROWSER_FAILURE:

978

1512

979

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

980

avahi_strerror(avahi_server_errno(mc.server)));

981

avahi_simple_poll_quit(mc.simple_poll);

1513

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

1514

avahi_strerror(avahi_server_errno

1515

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

1516

avahi_simple_poll_quit(simple_poll);

982

1517

return;

983

1518

984

1519

case AVAHI_BROWSER_NEW:

987

1522

the callback function is called the Avahi server will free the

988

1523

resolver for us. */

989

1524

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)));

1525

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

1526

interface, protocol, name, type,

1527

domain, protocol, 0,

1528

resolve_callback, mc) == NULL)

1529

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

1530

" %s\n", name,

1531

avahi_strerror(avahi_server_errno

1532

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

995

1533

break;

996

1534

997

1535

case AVAHI_BROWSER_REMOVE:

1000

1538

case AVAHI_BROWSER_ALL_FOR_NOW:

1001

1539

case AVAHI_BROWSER_CACHE_EXHAUSTED:

1002

1540

if(debug){

1003

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

1541

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

1542

" searching...\n");

1004

1543

}

1005

1544

break;

1006

1545

}

1007

1546

}

1008

1547

1009

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

1548

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

1010

1549

static void handle_sigterm(int sig){

1011

1550

if(quit_now){

1012

1551

return;

1014

1553

quit_now = 1;

1015

1554

signal_received = sig;

1016

1555

int old_errno = errno;

1017

if(mc.simple_poll != NULL){

1018

avahi_simple_poll_quit(mc.simple_poll);

1019

}

1020

errno = old_errno;

1556

/* set main loop to exit */

1557

if(simple_poll != NULL){

1558

avahi_simple_poll_quit(simple_poll);

1559

}

1560

errno = old_errno;

1561

}

1562

1563

__attribute__((nonnull, warn_unused_result))

1564

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

1565

int ret;

1566

error_t ret_errno;

1567

1568

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

1569

if(s < 0){

1570

ret_errno = errno;

1571

perror_plus("socket");

1572

errno = ret_errno;

1573

return false;

1574

}

1575

strcpy(ifr->ifr_name, ifname);

1576

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1577

if(ret == -1){

1578

if(debug){

1579

ret_errno = errno;

1580

perror_plus("ioctl SIOCGIFFLAGS");

1581

errno = ret_errno;

1582

}

1583

return false;

1584

}

1585

return true;

1586

}

1587

1588

__attribute__((nonnull, warn_unused_result))

1589

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

1590

1591

/* Reject the loopback device */

1592

if(ifr->ifr_flags & IFF_LOOPBACK){

1593

if(debug){

1594

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

1595

ifname);

1596

}

1597

return false;

1598

}

1599

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

1600

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

1601

if(debug){

1602

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

1603

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

1604

}

1605

return true;

1606

}

1607

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

1608

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

1609

if(debug){

1610

fprintf_plus(stderr, "Rejecting non-broadcast interface"

1611

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

1612

}

1613

return false;

1614

}

1615

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

1616

if(ifr->ifr_flags & IFF_NOARP){

1617

if(debug){

1618

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

1619

ifname);

1620

}

1621

return false;

1622

}

1623

1624

/* Accept this device */

1625

if(debug){

1626

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

1627

}

1628

return true;

1629

}

1630

1631

/*

1632

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

1633

* corresponds to an acceptable network device.

1634

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

1635

*/

1636

__attribute__((nonnull, warn_unused_result))

1637

int good_interface(const struct dirent *if_entry){

1638

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

1639

return 0;

1640

}

1641

1642

struct ifreq ifr;

1643

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

1644

if(debug){

1645

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

1646

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

1647

}

1648

return 0;

1649

}

1650

1651

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

1652

return 0;

1653

}

1654

return 1;

1655

}

1656

1657

/*

1658

* This function determines if a network interface is up.

1659

*/

1660

__attribute__((nonnull, warn_unused_result))

1661

bool interface_is_up(const char *interface){

1662

struct ifreq ifr;

1663

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

1664

if(debug){

1665

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

1666

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

1667

}

1668

return false;

1669

}

1670

1671

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

1672

}

1673

1674

/*

1675

* This function determines if a network interface is running

1676

*/

1677

__attribute__((nonnull, warn_unused_result))

1678

bool interface_is_running(const char *interface){

1679

struct ifreq ifr;

1680

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

1681

if(debug){

1682

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

1683

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

1684

}

1685

return false;

1686

}

1687

1688

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

1689

}

1690

1691

__attribute__((nonnull, pure, warn_unused_result))

1692

int notdotentries(const struct dirent *direntry){

1693

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

1694

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

1695

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

1696

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

1697

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

1698

return 0;

1699

}

1700

return 1;

1701

}

1702

1703

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

1704

__attribute__((nonnull, warn_unused_result))

1705

int runnable_hook(const struct dirent *direntry){

1706

int ret;

1707

size_t sret;

1708

struct stat st;

1709

1710

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

1711

/* Empty name? */

1712

return 0;

1713

}

1714

1715

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

1716

"abcdefghijklmnopqrstuvwxyz"

1717

"0123456789"

1718

"_.-");

1719

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

1720

/* Contains non-allowed characters */

1721

if(debug){

1722

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

1723

direntry->d_name);

1724

}

1725

return 0;

1726

}

1727

1728

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

1729

if(ret == -1){

1730

if(debug){

1731

perror_plus("Could not stat hook");

1732

}

1733

return 0;

1734

}

1735

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

1736

/* Not a regular file */

1737

if(debug){

1738

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

1739

direntry->d_name);

1740

}

1741

return 0;

1742

}

1743

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

1744

/* Not executable */

1745

if(debug){

1746

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

1747

direntry->d_name);

1748

}

1749

return 0;

1750

}

1751

if(debug){

1752

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

1753

direntry->d_name);

1754

}

1755

return 1;

1756

}

1757

1758

__attribute__((nonnull, warn_unused_result))

1759

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1760

mandos_context *mc){

1761

int ret;

1762

struct timespec now;

1763

struct timespec waited_time;

1764

intmax_t block_time;

1765

1766

while(true){

1767

if(mc->current_server == NULL){

1768

if(debug){

1769

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

1770

" No timeout!\n");

1771

}

1772

ret = avahi_simple_poll_iterate(s, -1);

1773

} else {

1774

if(debug){

1775

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

1776

" it, or wait\n");

1777

}

1778

/* the current time */

1779

ret = clock_gettime(CLOCK_MONOTONIC, &now);

1780

if(ret == -1){

1781

perror_plus("clock_gettime");

1782

return -1;

1783

}

1784

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

1785

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

1786

waited_time.tv_sec = (now.tv_sec

1787

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

1788

waited_time.tv_nsec = (now.tv_nsec

1789

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

1790

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

1791

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

1792

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

1793

block_time = ((retry_interval

1794

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

1795

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

1796

1797

if(debug){

1798

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

1799

block_time);

1800

}

1801

1802

if(block_time <= 0){

1803

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

1804

mc->current_server->port,

1805

mc->current_server->if_index,

1806

mc->current_server->af, mc);

1807

if(ret == 0){

1808

avahi_simple_poll_quit(s);

1809

return 0;

1810

}

1811

ret = clock_gettime(CLOCK_MONOTONIC,

1812

&mc->current_server->last_seen);

1813

if(ret == -1){

1814

perror_plus("clock_gettime");

1815

return -1;

1816

}

1817

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

1818

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

1819

servers, but don't block */

1820

}

1821

1822

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

1823

}

1824

if(ret != 0){

1825

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

1826

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

1827

}

1828

}

1829

}

1830

}

1831

1832

__attribute__((nonnull))

1833

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

1834

const float delay){

1835

struct dirent **direntries = NULL;

1836

if(hookdir_fd == -1){

1837

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1838

| O_CLOEXEC);

1839

if(hookdir_fd == -1){

1840

if(errno == ENOENT){

1841

if(debug){

1842

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

1843

" found\n", hookdir);

1844

}

1845

} else {

1846

perror_plus("open");

1847

}

1848

return;

1849

}

1850

}

1851

#ifdef __GLIBC__

1852

#if __GLIBC_PREREQ(2, 15)

1853

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

1854

runnable_hook, alphasort);

1855

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

1856

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

1857

alphasort);

1858

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

1859

#else /* not __GLIBC__ */

1860

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

1861

alphasort);

1862

#endif /* not __GLIBC__ */

1863

if(numhooks == -1){

1864

perror_plus("scandir");

1865

return;

1866

}

1867

struct dirent *direntry;

1868

int ret;

1869

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

1870

if(devnull == -1){

1871

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

1872

return;

1873

}

1874

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

1875

direntry = direntries[i];

1876

if(debug){

1877

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

1878

direntry->d_name);

1879

}

1880

pid_t hook_pid = fork();

1881

if(hook_pid == 0){

1882

/* Child */

1883

/* Raise privileges */

1884

errno = raise_privileges_permanently();

1885

if(errno != 0){

1886

perror_plus("Failed to raise privileges");

1887

_exit(EX_NOPERM);

1888

}

1889

/* Set group */

1890

errno = 0;

1891

ret = setgid(0);

1892

if(ret == -1){

1893

perror_plus("setgid");

1894

_exit(EX_NOPERM);

1895

}

1896

/* Reset supplementary groups */

1897

errno = 0;

1898

ret = setgroups(0, NULL);

1899

if(ret == -1){

1900

perror_plus("setgroups");

1901

_exit(EX_NOPERM);

1902

}

1903

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

1904

if(ret == -1){

1905

perror_plus("setenv");

1906

_exit(EX_OSERR);

1907

}

1908

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

1909

if(ret == -1){

1910

perror_plus("setenv");

1911

_exit(EX_OSERR);

1912

}

1913

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

1914

if(ret == -1){

1915

perror_plus("setenv");

1916

_exit(EX_OSERR);

1917

}

1918

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

1919

if(ret == -1){

1920

perror_plus("setenv");

1921

_exit(EX_OSERR);

1922

}

1923

char *delaystring;

1924

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

1925

if(ret == -1){

1926

perror_plus("asprintf");

1927

_exit(EX_OSERR);

1928

}

1929

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

1930

if(ret == -1){

1931

free(delaystring);

1932

perror_plus("setenv");

1933

_exit(EX_OSERR);

1934

}

1935

free(delaystring);

1936

if(connect_to != NULL){

1937

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

1938

if(ret == -1){

1939

perror_plus("setenv");

1940

_exit(EX_OSERR);

1941

}

1942

}

1943

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

1944

direntry->d_name,

1945

O_RDONLY));

1946

if(hook_fd == -1){

1947

perror_plus("openat");

1948

_exit(EXIT_FAILURE);

1949

}

1950

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

1951

perror_plus("close");

1952

_exit(EXIT_FAILURE);

1953

}

1954

ret = dup2(devnull, STDIN_FILENO);

1955

if(ret == -1){

1956

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

1957

_exit(EX_OSERR);

1958

}

1959

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

1960

if(ret == -1){

1961

perror_plus("close");

1962

_exit(EX_OSERR);

1963

}

1964

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1965

if(ret == -1){

1966

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

1967

_exit(EX_OSERR);

1968

}

1969

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

1970

environ) == -1){

1971

perror_plus("fexecve");

1972

_exit(EXIT_FAILURE);

1973

}

1974

} else {

1975

if(hook_pid == -1){

1976

perror_plus("fork");

1977

free(direntry);

1978

continue;

1979

}

1980

int status;

1981

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

1982

perror_plus("waitpid");

1983

free(direntry);

1984

continue;

1985

}

1986

if(WIFEXITED(status)){

1987

if(WEXITSTATUS(status) != 0){

1988

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

1989

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

1990

WEXITSTATUS(status));

1991

free(direntry);

1992

continue;

1993

}

1994

} else if(WIFSIGNALED(status)){

1995

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

1996

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

1997

WTERMSIG(status));

1998

free(direntry);

1999

continue;

2000

} else {

2001

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

2002

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

2003

free(direntry);

2004

continue;

2005

}

2006

}

2007

if(debug){

2008

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

2009

direntry->d_name);

2010

}

2011

free(direntry);

2012

}

2013

free(direntries);

2014

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

2015

perror_plus("close");

2016

} else {

2017

hookdir_fd = -1;

2018

}

2019

close(devnull);

2020

}

2021

2022

__attribute__((nonnull, warn_unused_result))

2023

error_t bring_up_interface(const char *const interface,

2024

const float delay){

2025

error_t old_errno = errno;

2026

int ret;

2027

struct ifreq network;

2028

unsigned int if_index = if_nametoindex(interface);

2029

if(if_index == 0){

2030

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

2031

errno = old_errno;

2032

return ENXIO;

2033

}

2034

2035

if(quit_now){

2036

errno = old_errno;

2037

return EINTR;

2038

}

2039

2040

if(not interface_is_up(interface)){

2041

error_t ret_errno = 0, ioctl_errno = 0;

2042

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

2043

ret_errno = errno;

2044

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

2045

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

2046

errno = old_errno;

2047

return ret_errno;

2048

}

2049

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

2050

2051

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

2052

if(sd == -1){

2053

ret_errno = errno;

2054

perror_plus("socket");

2055

errno = old_errno;

2056

return ret_errno;

2057

}

2058

2059

if(quit_now){

2060

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

2061

if(ret == -1){

2062

perror_plus("close");

2063

}

2064

errno = old_errno;

2065

return EINTR;

2066

}

2067

2068

if(debug){

2069

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

2070

interface);

2071

}

2072

2073

/* Raise privileges */

2074

ret_errno = raise_privileges();

2075

if(ret_errno != 0){

2076

errno = ret_errno;

2077

perror_plus("Failed to raise privileges");

2078

}

2079

2080

#ifdef __linux__

2081

int ret_linux;

2082

bool restore_loglevel = false;

2083

if(ret_errno == 0){

2084

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2085

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

2086

ret_linux = klogctl(8, NULL, 5);

2087

if(ret_linux == -1){

2088

perror_plus("klogctl");

2089

} else {

2090

restore_loglevel = true;

2091

}

2092

}

2093

#endif /* __linux__ */

2094

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

2095

ioctl_errno = errno;

2096

#ifdef __linux__

2097

if(restore_loglevel){

2098

ret_linux = klogctl(7, NULL, 0);

2099

if(ret_linux == -1){

2100

perror_plus("klogctl");

2101

}

2102

}

2103

#endif /* __linux__ */

2104

2105

/* If raise_privileges() succeeded above */

2106

if(ret_errno == 0){

2107

/* Lower privileges */

2108

ret_errno = lower_privileges();

2109

if(ret_errno != 0){

2110

errno = ret_errno;

2111

perror_plus("Failed to lower privileges");

2112

}

2113

}

2114

2115

/* Close the socket */

2116

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

2117

if(ret == -1){

2118

perror_plus("close");

2119

}

2120

2121

if(ret_setflags == -1){

2122

errno = ioctl_errno;

2123

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2124

errno = old_errno;

2125

return ioctl_errno;

2126

}

2127

} else if(debug){

2128

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

2129

interface);

2130

}

2131

2132

/* Sleep checking until interface is running.

2133

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

2134

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

2135

if(interface_is_running(interface)){

2136

break;

2137

}

2138

struct timespec sleeptime = { .tv_nsec = 250000000 };

2139

ret = nanosleep(&sleeptime, NULL);

2140

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

2141

perror_plus("nanosleep");

2142

}

2143

}

2144

2145

errno = old_errno;

2146

return 0;

2147

}

2148

2149

__attribute__((nonnull, warn_unused_result))

2150

error_t take_down_interface(const char *const interface){

2151

error_t old_errno = errno;

2152

struct ifreq network;

2153

unsigned int if_index = if_nametoindex(interface);

2154

if(if_index == 0){

2155

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

2156

errno = old_errno;

2157

return ENXIO;

2158

}

2159

if(interface_is_up(interface)){

2160

error_t ret_errno = 0, ioctl_errno = 0;

2161

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

2162

ret_errno = errno;

2163

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

2164

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

2165

errno = old_errno;

2166

return ret_errno;

2167

}

2168

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

2169

2170

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

2171

if(sd == -1){

2172

ret_errno = errno;

2173

perror_plus("socket");

2174

errno = old_errno;

2175

return ret_errno;

2176

}

2177

2178

if(debug){

2179

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

2180

interface);

2181

}

2182

2183

/* Raise privileges */

2184

ret_errno = raise_privileges();

2185

if(ret_errno != 0){

2186

errno = ret_errno;

2187

perror_plus("Failed to raise privileges");

2188

}

2189

2190

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

2191

ioctl_errno = errno;

2192

2193

/* If raise_privileges() succeeded above */

2194

if(ret_errno == 0){

2195

/* Lower privileges */

2196

ret_errno = lower_privileges();

2197

if(ret_errno != 0){

2198

errno = ret_errno;

2199

perror_plus("Failed to lower privileges");

2200

}

2201

}

2202

2203

/* Close the socket */

2204

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

2205

if(ret == -1){

2206

perror_plus("close");

2207

}

2208

2209

if(ret_setflags == -1){

2210

errno = ioctl_errno;

2211

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2212

errno = old_errno;

2213

return ioctl_errno;

2214

}

2215

} else if(debug){

2216

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

2217

interface);

2218

}

2219

2220

errno = old_errno;

2221

return 0;

1021

2222

}

1022

2223

1023

2224

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

2225

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

2226

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

2227

"+CTYPE-OPENPGP:!RSA", .current_server = NULL,

2228

.interfaces = NULL, .interfaces_size = 0 };

1024

2229

AvahiSServiceBrowser *sb = NULL;

1025

int error;

2230

error_t ret_errno;

1026

2231

int ret;

1027

2232

intmax_t tmpmax;

1028

2233

char *tmp;

1029

2234

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;

2235

char *interfaces_to_take_down = NULL;

2236

size_t interfaces_to_take_down_size = 0;

2237

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

2238

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

2239

char *tempdir = NULL;

1039

2240

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1040

2241

const char *seckey = PATHDIR "/" SECKEY;

1041

2242

const char *pubkey = PATHDIR "/" PUBKEY;

2243

char *interfaces_hooks = NULL;

1042

2244

1043

2245

bool gnutls_initialized = false;

1044

2246

bool gpgme_initialized = false;

1045

2247

float delay = 2.5f;

2248

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

2249

retrying the same server again */

1046

2250

1047

2251

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

1048

2252

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1054

2258

errno = 0;

1055

2259

ret = setgid(gid);

1056

2260

if(ret == -1){

1057

perror("setgid");

2261

perror_plus("setgid");

1058

2262

}

1059

2263

1060

2264

/* Lower user privileges (temporarily) */

1061

2265

errno = 0;

1062

2266

ret = seteuid(uid);

1063

2267

if(ret == -1){

1064

perror("seteuid");

2268

perror_plus("seteuid");

1065

2269

}

1066

2270

1067

2271

if(quit_now){

1102

2306

.arg = "SECONDS",

1103

2307

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

1104

2308

.group = 2 },

2309

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

2310

.arg = "SECONDS",

2311

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

2312

.group = 2 },

2313

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

2314

.arg = "DIR",

2315

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

2316

.group = 2 },

1105

2317

/*

1106

2318

* These reproduce what we would get without ARGP_NO_HELP

1107

2319

*/

1125

2337

connect_to = arg;

1126

2338

break;

1127

2339

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

1128

interface = arg;

2340

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

2341

arg, (int)',');

2342

if(ret_errno != 0){

2343

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

2344

}

1129

2345

break;

1130

2346

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

1131

2347

seckey = arg;

1151

2367

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

1152

2368

argp_error(state, "Bad delay");

1153

2369

}

2370

case 132: /* --retry */

2371

errno = 0;

2372

retry_interval = strtod(arg, &tmp);

2373

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

2374

or (retry_interval * 1000) > INT_MAX

2375

or retry_interval < 0){

2376

argp_error(state, "Bad retry interval");

2377

}

2378

break;

2379

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

2380

hookdir = arg;

1154

2381

break;

1155

2382

/*

1156

2383

* These reproduce what we would get without ARGP_NO_HELP

1163

2390

argp_state_help(state, state->out_stream,

1164

2391

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1165

2392

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

1166

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

2393

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

1167

2394

exit(argp_err_exit_status);

1168

2395

break;

1169

2396

default:

1184

2411

case ENOMEM:

1185

2412

default:

1186

2413

errno = ret;

1187

perror("argp_parse");

2414

perror_plus("argp_parse");

1188

2415

exitcode = EX_OSERR;

1189

2416

goto end;

1190

2417

case EINVAL:

1193

2420

}

1194

2421

}

1195

2422

2423

{

2424

/* Work around Debian bug #633582:

2425

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

2426

2427

/* Re-raise privileges */

2428

ret_errno = raise_privileges();

2429

if(ret_errno != 0){

2430

errno = ret_errno;

2431

perror_plus("Failed to raise privileges");

2432

} else {

2433

struct stat st;

2434

2435

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

2436

int seckey_fd = open(seckey, O_RDONLY);

2437

if(seckey_fd == -1){

2438

perror_plus("open");

2439

} else {

2440

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

2441

if(ret == -1){

2442

perror_plus("fstat");

2443

} else {

2444

if(S_ISREG(st.st_mode)

2445

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

2446

ret = fchown(seckey_fd, uid, gid);

2447

if(ret == -1){

2448

perror_plus("fchown");

2449

}

2450

}

2451

}

2452

TEMP_FAILURE_RETRY(close(seckey_fd));

2453

}

2454

}

2455

2456

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

2457

int pubkey_fd = open(pubkey, O_RDONLY);

2458

if(pubkey_fd == -1){

2459

perror_plus("open");

2460

} else {

2461

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

2462

if(ret == -1){

2463

perror_plus("fstat");

2464

} else {

2465

if(S_ISREG(st.st_mode)

2466

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

2467

ret = fchown(pubkey_fd, uid, gid);

2468

if(ret == -1){

2469

perror_plus("fchown");

2470

}

2471

}

2472

}

2473

TEMP_FAILURE_RETRY(close(pubkey_fd));

2474

}

2475

}

2476

2477

/* Lower privileges */

2478

ret_errno = lower_privileges();

2479

if(ret_errno != 0){

2480

errno = ret_errno;

2481

perror_plus("Failed to lower privileges");

2482

}

2483

}

2484

}

2485

2486

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

2487

{

2488

char *interface = NULL;

2489

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

2490

interface))){

2491

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

2492

and if_nametoindex(interface) == 0){

2493

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

2494

fprintf_plus(stderr, "Not using nonexisting interface"

2495

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

2496

}

2497

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

2498

interface = NULL;

2499

}

2500

}

2501

}

2502

2503

/* Run network hooks */

2504

{

2505

if(mc.interfaces != NULL){

2506

interfaces_hooks = malloc(mc.interfaces_size);

2507

if(interfaces_hooks == NULL){

2508

perror_plus("malloc");

2509

goto end;

2510

}

2511

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

2512

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

2513

}

2514

run_network_hooks("start", interfaces_hooks != NULL ?

2515

interfaces_hooks : "", delay);

2516

}

2517

1196

2518

if(not debug){

1197

2519

avahi_set_log_function(empty_log);

1198

2520

}

1201

2523

from the signal handler */

1202

2524

/* Initialize the pseudo-RNG for Avahi */

1203

2525

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");

2526

simple_poll = avahi_simple_poll_new();

2527

if(simple_poll == NULL){

2528

fprintf_plus(stderr,

2529

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

1207

2530

exitcode = EX_UNAVAILABLE;

1208

2531

goto end;

1209

2532

}

1211

2534

sigemptyset(&sigterm_action.sa_mask);

1212

2535

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

1213

2536

if(ret == -1){

1214

perror("sigaddset");

2537

perror_plus("sigaddset");

1215

2538

exitcode = EX_OSERR;

1216

2539

goto end;

1217

2540

}

1218

2541

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

1219

2542

if(ret == -1){

1220

perror("sigaddset");

2543

perror_plus("sigaddset");

1221

2544

exitcode = EX_OSERR;

1222

2545

goto end;

1223

2546

}

1224

2547

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

1225

2548

if(ret == -1){

1226

perror("sigaddset");

2549

perror_plus("sigaddset");

1227

2550

exitcode = EX_OSERR;

1228

2551

goto end;

1229

2552

}

1233

2556

*/

1234

2557

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

1235

2558

if(ret == -1){

1236

perror("sigaction");

2559

perror_plus("sigaction");

1237

2560

return EX_OSERR;

1238

2561

}

1239

2562

if(old_sigterm_action.sa_handler != SIG_IGN){

1240

2563

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

1241

2564

if(ret == -1){

1242

perror("sigaction");

2565

perror_plus("sigaction");

1243

2566

exitcode = EX_OSERR;

1244

2567

goto end;

1245

2568

}

1246

2569

}

1247

2570

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

1248

2571

if(ret == -1){

1249

perror("sigaction");

2572

perror_plus("sigaction");

1250

2573

return EX_OSERR;

1251

2574

}

1252

2575

if(old_sigterm_action.sa_handler != SIG_IGN){

1253

2576

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

1254

2577

if(ret == -1){

1255

perror("sigaction");

2578

perror_plus("sigaction");

1256

2579

exitcode = EX_OSERR;

1257

2580

goto end;

1258

2581

}

1259

2582

}

1260

2583

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

1261

2584

if(ret == -1){

1262

perror("sigaction");

2585

perror_plus("sigaction");

1263

2586

return EX_OSERR;

1264

2587

}

1265

2588

if(old_sigterm_action.sa_handler != SIG_IGN){

1266

2589

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

1267

2590

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");

2591

perror_plus("sigaction");

2592

exitcode = EX_OSERR;

2593

goto end;

2594

}

2595

}

2596

2597

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

2598

if(mc.interfaces == NULL){

2599

struct dirent **direntries = NULL;

2600

/* Look for any good interfaces */

2601

ret = scandir(sys_class_net, &direntries, good_interface,

2602

alphasort);

2603

if(ret >= 1){

2604

/* Add all found interfaces to interfaces list */

2605

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

2606

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

2607

direntries[i]->d_name);

2608

if(ret_errno != 0){

2609

errno = ret_errno;

2610

perror_plus("argz_add");

2611

free(direntries[i]);

2612

continue;

2613

}

2614

if(debug){

2615

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

2616

direntries[i]->d_name);

2617

}

2618

free(direntries[i]);

2619

}

2620

free(direntries);

2621

} else {

2622

if(ret == 0){

2623

free(direntries);

2624

}

2625

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

2626

exitcode = EXIT_FAILURE;

2627

goto end;

2628

}

2629

}

2630

2631

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

2632

{

2633

char *interface = NULL;

2634

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

2635

interface))){

2636

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

2637

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

2638

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

2639

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

2640

interface);

2641

interface = NULL;

2642

while((interface = argz_next(mc.interfaces,

2643

mc.interfaces_size, interface))){

2644

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

2645

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

2646

interface);

2647

interface = NULL;

1359

2648

}

1360

2649

}

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

2650

break;

1378

2651

}

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

}

2652

bool interface_was_up = interface_is_up(interface);

2653

errno = bring_up_interface(interface, delay);

2654

if(not interface_was_up){

2655

if(errno != 0){

2656

perror_plus("Failed to bring up interface");

2657

} else {

2658

errno = argz_add(&interfaces_to_take_down,

2659

&interfaces_to_take_down_size,

2660

interface);

2661

if(errno != 0){

2662

perror_plus("argz_add");

2663

}

2664

}

2665

}

2666

}

2667

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

2668

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

2669

}

2670

}

2671

2672

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

2673

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

2674

if(debug){

2675

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

2676

mc.interfaces);

2677

}

2678

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

1416

2679

}

1417

2680

1418

2681

if(quit_now){

1419

2682

goto end;

1420

2683

}

1421

2684

1422

ret = init_gnutls_global(pubkey, seckey);

2685

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

1423

2686

if(ret == -1){

1424

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

2687

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

1425

2688

exitcode = EX_UNAVAILABLE;

1426

2689

goto end;

1427

2690

} else {

1432

2695

goto end;

1433

2696

}

1434

2697

1435

tempdir_created = true;

1436

if(mkdtemp(tempdir) == NULL){

1437

tempdir_created = false;

1438

perror("mkdtemp");

2698

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

2699

tempdir = mkdtemp(run_tempdir);

2700

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

2701

if(debug){

2702

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

2703

run_tempdir, old_tempdir);

2704

}

2705

tempdir = mkdtemp(old_tempdir);

2706

}

2707

if(tempdir == NULL){

2708

perror_plus("mkdtemp");

1439

2709

goto end;

1440

2710

}

1441

2711

1443

2713

goto end;

1444

2714

}

1445

2715

1446

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

1447

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

2716

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

2717

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

1448

2718

exitcode = EX_UNAVAILABLE;

1449

2719

goto end;

1450

2720

} else {

1459

2729

/* Connect directly, do not use Zeroconf */

1460

2730

/* (Mainly meant for debugging) */

1461

2731

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

2732

1462

2733

if(address == NULL){

1463

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

2734

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

1464

2735

exitcode = EX_USAGE;

1465

2736

goto end;

1466

2737

}

1469

2740

goto end;

1470

2741

}

1471

2742

1472

uint16_t port;

2743

in_port_t port;

1473

2744

errno = 0;

1474

2745

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

1475

2746

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

1476

or tmpmax != (uint16_t)tmpmax){

1477

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

2747

or tmpmax != (in_port_t)tmpmax){

2748

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

1478

2749

exitcode = EX_USAGE;

1479

2750

goto end;

1480

2751

}

1481

2752

1482

2753

if(quit_now){

1483

2754

goto end;

1484

2755

}

1485

2756

1486

port = (uint16_t)tmpmax;

2757

port = (in_port_t)tmpmax;

1487

2758

*address = '\0';

1488

address = connect_to;

1489

2759

/* Colon in address indicates IPv6 */

1490

2760

int af;

1491

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

2761

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

1492

2762

af = AF_INET6;

2763

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

2764

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

2765

{

2766

connect_to++;

2767

address[-1] = '\0';

2768

}

1493

2769

} else {

1494

2770

af = AF_INET;

1495

2771

}

2772

address = connect_to;

1496

2773

1497

2774

if(quit_now){

1498

2775

goto end;

1499

2776

}

1500

2777

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 {

2778

while(not quit_now){

2779

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

2780

&mc);

2781

if(quit_now or ret == 0){

2782

break;

2783

}

2784

if(debug){

2785

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

2786

(int)retry_interval);

2787

}

2788

sleep((unsigned int)retry_interval);

2789

}

2790

2791

if(not quit_now){

1523

2792

exitcode = EXIT_SUCCESS;

1524

2793

}

2794

1525

2795

goto end;

1526

2796

}

1527

2797

1539

2809

config.publish_domain = 0;

1540

2810

1541

2811

/* Allocate a new server */

1542

mc.server = avahi_server_new(avahi_simple_poll_get

1543

(mc.simple_poll), &config, NULL,

1544

NULL, &error);

2812

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2813

&config, NULL, NULL, &ret_errno);

1545

2814

1546

2815

/* Free the Avahi configuration data */

1547

2816

avahi_server_config_free(&config);

1549

2818

1550

2819

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

1551

2820

if(mc.server == NULL){

1552

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

1553

avahi_strerror(error));

2821

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

2822

avahi_strerror(ret_errno));

1554

2823

exitcode = EX_UNAVAILABLE;

1555

2824

goto end;

1556

2825

}

1562

2831

/* Create the Avahi service browser */

1563

2832

sb = avahi_s_service_browser_new(mc.server, if_index,

1564

2833

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1565

NULL, 0, browse_callback, NULL);

2834

NULL, 0, browse_callback,

2835

(void *)&mc);

1566

2836

if(sb == NULL){

1567

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

1568

avahi_strerror(avahi_server_errno(mc.server)));

2837

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

2838

avahi_strerror(avahi_server_errno(mc.server)));

1569

2839

exitcode = EX_UNAVAILABLE;

1570

2840

goto end;

1571

2841

}

1577

2847

/* Run the main loop */

1578

2848

1579

2849

if(debug){

1580

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

2850

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

1581

2851

}

1582

2852

1583

avahi_simple_poll_loop(mc.simple_poll);

2853

ret = avahi_loop_with_timeout(simple_poll,

2854

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

2855

if(debug){

2856

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

2857

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

2858

}

1584

2859

1585

2860

end:

1586

2861

1587

2862

if(debug){

1588

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

2863

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

1589

2864

}

1590

2865

1591

2866

/* Cleanup things */

2867

free(mc.interfaces);

2868

1592

2869

if(sb != NULL)

1593

2870

avahi_s_service_browser_free(sb);

1594

2871

1595

2872

if(mc.server != NULL)

1596

2873

avahi_server_free(mc.server);

1597

2874

1598

if(mc.simple_poll != NULL)

1599

avahi_simple_poll_free(mc.simple_poll);

2875

if(simple_poll != NULL)

2876

avahi_simple_poll_free(simple_poll);

1600

2877

1601

2878

if(gnutls_initialized){

1602

2879

gnutls_certificate_free_credentials(mc.cred);

1608

2885

gpgme_release(mc.ctx);

1609

2886

}

1610

2887

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");

2888

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

2889

has seen */

2890

if(mc.current_server != NULL){

2891

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

2892

while(mc.current_server != NULL){

2893

server *next = mc.current_server->next;

2894

#ifdef __GNUC__

2895

#pragma GCC diagnostic push

2896

#pragma GCC diagnostic ignored "-Wcast-qual"

2897

#endif

2898

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

2899

#ifdef __GNUC__

2900

#pragma GCC diagnostic pop

2901

#endif

2902

free(mc.current_server);

2903

mc.current_server = next;

2904

}

2905

}

2906

2907

/* Re-raise privileges */

2908

{

2909

ret_errno = raise_privileges();

2910

if(ret_errno != 0){

2911

errno = ret_errno;

2912

perror_plus("Failed to raise privileges");

2913

} else {

2914

2915

/* Run network hooks */

2916

run_network_hooks("stop", interfaces_hooks != NULL ?

2917

interfaces_hooks : "", delay);

2918

2919

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

2920

{

2921

char *interface = NULL;

2922

while((interface=argz_next(interfaces_to_take_down,

2923

interfaces_to_take_down_size,

2924

interface))){

2925

ret_errno = take_down_interface(interface);

2926

if(ret_errno != 0){

2927

errno = ret_errno;

2928

perror_plus("Failed to take down interface");

2929

}

2930

}

2931

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

2932

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

2933

" down\n");

2934

}

2935

}

2936

}

2937

2938

ret_errno = lower_privileges_permanently();

2939

if(ret_errno != 0){

2940

errno = ret_errno;

2941

perror_plus("Failed to lower privileges permanently");

2942

}

2943

}

2944

2945

free(interfaces_to_take_down);

2946

free(interfaces_hooks);

2947

2948

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

2949

if(tempdir != NULL){

2950

struct dirent **direntries = NULL;

2951

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

2952

| O_NOFOLLOW

2953

| O_DIRECTORY

2954

| O_PATH));

2955

if(tempdir_fd == -1){

2956

perror_plus("open");

2957

} else {

2958

#ifdef __GLIBC__

2959

#if __GLIBC_PREREQ(2, 15)

2960

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

2961

notdotentries, alphasort);

2962

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

2963

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

2964

alphasort);

2965

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

2966

#else /* not __GLIBC__ */

2967

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

2968

alphasort);

2969

#endif /* not __GLIBC__ */

2970

if(numentries >= 0){

2971

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

2972

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

2973

if(ret == -1){

2974

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

2975

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

2976

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

2977

}

2978

free(direntries[i]);

2979

}

2980

2981

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

2982

free(direntries);

2983

if(numentries == -1){

2984

perror_plus("scandir");

2985

}

2986

ret = rmdir(tempdir);

2987

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

2988

perror_plus("rmdir");

2989

}

2990

}

2991

TEMP_FAILURE_RETRY(close(tempdir_fd));

1684

2992

}

1685

2993

}

1686

2994

1691

2999

&old_sigterm_action,

1692

3000

NULL));

1693

3001

if(ret == -1){

1694

perror("sigaction");

3002

perror_plus("sigaction");

1695

3003

}

1696

3004

do {

1697

3005

ret = raise(signal_received);

1698

3006

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

1699

3007

if(ret != 0){

1700

perror("raise");

3008

perror_plus("raise");

1701

3009

abort();

1702

3010

}

1703

3011

TEMP_FAILURE_RETRY(pause());