release/src/router/dropbear/svr-runopts.c

   1 /*
   2  * Dropbear - a SSH2 server
   3  *
   4  * Copyright (c) 2002,2003 Matt Johnston
   5  * All rights reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy
   8  * of this software and associated documentation files (the "Software"), to deal
   9  * in the Software without restriction, including without limitation the rights
  10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11  * copies of the Software, and to permit persons to whom the Software is
  12  * furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in
  15  * all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23  * SOFTWARE. */
  24
  25 #include "includes.h"
  26 #include "runopts.h"
  27 #include "signkey.h"
  28 #include "buffer.h"
  29 #include "dbutil.h"
  30 #include "algo.h"
  31
  32 svr_runopts svr_opts; /* GLOBAL */
  33
  34 static void printhelp(const char * progname);
  35 static void addportandaddress(char* spec);
  36
  37 static void printhelp(const char * progname) {
  38
  39         fprintf(stderr, "Dropbear sshd v%s\n"
  40                                         "Usage: %s [options]\n"
  41                                         "Options are:\n"
  42                                         "-b bannerfile  Display the contents of bannerfile"
  43                                         " before user login\n"
  44                                         "               (default: none)\n"
  45 #ifdef DROPBEAR_DSS
  46                                         "-d dsskeyfile  Use dsskeyfile for the DSS host key\n"
  47                                         "               (default: %s)\n"
  48 #endif
  49 #ifdef DROPBEAR_RSA
  50                                         "-r rsakeyfile  Use rsakeyfile for the RSA host key\n"
  51                                         "               (default: %s)\n"
  52 #endif
  53                                         "-F             Don't fork into background\n"
  54 #ifdef DISABLE_SYSLOG
  55                                         "(Syslog support not compiled in, using stderr)\n"
  56 #else
  57                                         "-E             Log to stderr rather than syslog\n"
  58 #endif
  59 #ifdef DO_MOTD
  60                                         "-m             Don't display the motd on login\n"
  61 #endif
  62                                         "-w             Disallow root logins\n"
  63 #if defined(ENABLE_SVR_PASSWORD_AUTH) || defined(ENABLE_SVR_PAM_AUTH)
  64                                         "-s             Disable password logins\n"
  65                                         "-g             Disable password logins for root\n"
  66 #endif
  67 #ifdef ENABLE_SVR_LOCALTCPFWD
  68                                         "-j             Disable local port forwarding\n"
  69 #endif
  70 #ifdef ENABLE_SVR_REMOTETCPFWD
  71                                         "-k             Disable remote port forwarding\n"
  72                                         "-a             Allow connections to forwarded ports from any host\n"
  73 #endif
  74                                         "-p [address:]port\n"
  75                                         "               Listen on specified tcp port (and optionally address),\n"
  76                                         "               up to %d can be specified\n"
  77                                         "               (default port is %s if none specified)\n"
  78                                         "-P PidFile     Create pid file PidFile\n"
  79                                         "               (default %s)\n"
  80 #ifdef INETD_MODE
  81                                         "-i             Start for inetd\n"
  82 #endif
  83                                         "-W <receive_window_buffer> (default %d, larger may be faster, max 1MB)\n"
  84                                         "-K <keepalive>  (0 is never, default %d, in seconds)\n"
  85                                         "-I <idle_timeout>  (0 is never, default %d, in seconds)\n"
  86 #ifdef DEBUG_TRACE
  87                                         "-v             verbose (compiled with DEBUG_TRACE)\n"
  88 #endif
  89                                         ,DROPBEAR_VERSION, progname,
  90 #ifdef DROPBEAR_DSS
  91                                         DSS_PRIV_FILENAME,
  92 #endif
  93 #ifdef DROPBEAR_RSA
  94                                         RSA_PRIV_FILENAME,
  95 #endif
  96                                         DROPBEAR_MAX_PORTS, DROPBEAR_DEFPORT, DROPBEAR_PIDFILE,
  97                                         DEFAULT_RECV_WINDOW, DEFAULT_KEEPALIVE, DEFAULT_IDLE_TIMEOUT);
  98 }
  99
 100 void svr_getopts(int argc, char ** argv) {
 101
 102         unsigned int i;
 103         char ** next = 0;
 104         int nextisport = 0;
 105         char* recv_window_arg = NULL;
 106         char* keepalive_arg = NULL;
 107         char* idle_timeout_arg = NULL;
 108
 109         /* see printhelp() for options */
 110         svr_opts.rsakeyfile = NULL;
 111         svr_opts.dsskeyfile = NULL;
 112         svr_opts.bannerfile = NULL;
 113         svr_opts.banner = NULL;
 114         svr_opts.forkbg = 1;
 115         svr_opts.norootlogin = 0;
 116         svr_opts.noauthpass = 0;
 117         svr_opts.norootpass = 0;
 118         svr_opts.inetdmode = 0;
 119         svr_opts.portcount = 0;
 120         svr_opts.hostkey = NULL;
 121         svr_opts.pidfile = DROPBEAR_PIDFILE;
 122 #ifdef ENABLE_SVR_LOCALTCPFWD
 123         svr_opts.nolocaltcp = 0;
 124 #endif
 125 #ifdef ENABLE_SVR_REMOTETCPFWD
 126         svr_opts.noremotetcp = 0;
 127 #endif
 128 #ifndef DISABLE_ZLIB
 129         opts.enable_compress = 1;
 130 #endif
 131         /* not yet
 132         opts.ipv4 = 1;
 133         opts.ipv6 = 1;
 134         */
 135 #ifdef DO_MOTD
 136         svr_opts.domotd = 1;
 137 #endif
 138 #ifndef DISABLE_SYSLOG
 139         svr_opts.usingsyslog = 1;
 140 #endif
 141         opts.recv_window = DEFAULT_RECV_WINDOW;
 142         opts.keepalive_secs = DEFAULT_KEEPALIVE;
 143         opts.idle_timeout_secs = DEFAULT_IDLE_TIMEOUT;
 144
 145 #ifdef ENABLE_SVR_REMOTETCPFWD
 146         opts.listen_fwd_all = 0;
 147 #endif
 148
 149         for (i = 1; i < (unsigned int)argc; i++) {
 150                 if (nextisport) {
 151                         addportandaddress(argv[i]);
 152                         nextisport = 0;
 153                         continue;
 154                 }
 155
 156                 if (next) {
 157                         *next = argv[i];
 158                         if (*next == NULL) {
 159                                 dropbear_exit("Invalid null argument");
 160                         }
 161                         next = 0x00;
 162                         continue;
 163                 }
 164
 165                 if (argv[i][0] == '-') {
 166                         switch (argv[i][1]) {
 167                                 case 'b':
 168                                         next = &svr_opts.bannerfile;
 169                                         break;
 170 #ifdef DROPBEAR_DSS
 171                                 case 'd':
 172                                         next = &svr_opts.dsskeyfile;
 173                                         break;
 174 #endif
 175 #ifdef DROPBEAR_RSA
 176                                 case 'r':
 177                                         next = &svr_opts.rsakeyfile;
 178                                         break;
 179 #endif
 180                                 case 'F':
 181                                         svr_opts.forkbg = 0;
 182                                         break;
 183 #ifndef DISABLE_SYSLOG
 184                                 case 'E':
 185                                         svr_opts.usingsyslog = 0;
 186                                         break;
 187 #endif
 188 #ifdef ENABLE_SVR_LOCALTCPFWD
 189                                 case 'j':
 190                                         svr_opts.nolocaltcp = 1;
 191                                         break;
 192 #endif
 193 #ifdef ENABLE_SVR_REMOTETCPFWD
 194                                 case 'k':
 195                                         svr_opts.noremotetcp = 1;
 196                                         break;
 197                                 case 'a':
 198                                         opts.listen_fwd_all = 1;
 199                                         break;
 200 #endif
 201 #ifdef INETD_MODE
 202                                 case 'i':
 203                                         svr_opts.inetdmode = 1;
 204                                         break;
 205 #endif
 206                                 case 'p':
 207                                   nextisport = 1;
 208                                   break;
 209                                 case 'P':
 210                                         next = &svr_opts.pidfile;
 211                                         break;
 212 #ifdef DO_MOTD
 213                                 /* motd is displayed by default, -m turns it off */
 214                                 case 'm':
 215                                         svr_opts.domotd = 0;
 216                                         break;
 217 #endif
 218                                 case 'w':
 219                                         svr_opts.norootlogin = 1;
 220                                         break;
 221                                 case 'W':
 222                                         next = &recv_window_arg;
 223                                         break;
 224                                 case 'K':
 225                                         next = &keepalive_arg;
 226                                         break;
 227                                 case 'I':
 228                                         next = &idle_timeout_arg;
 229                                         break;
 230 #if defined(ENABLE_SVR_PASSWORD_AUTH) || defined(ENABLE_SVR_PAM_AUTH)
 231                                 case 's':
 232                                         svr_opts.noauthpass = 1;
 233                                         break;
 234                                 case 'g':
 235                                         svr_opts.norootpass = 1;
 236                                         break;
 237 #endif
 238                                 case 'h':
 239                                         printhelp(argv[0]);
 240                                         exit(EXIT_FAILURE);
 241                                         break;
 242                                 case 'u':
 243                                         /* backwards compatibility with old urandom option */
 244                                         break;
 245 #ifdef DEBUG_TRACE
 246                                 case 'v':
 247                                         debug_trace = 1;
 248                                         break;
 249 #endif
 250                                 default:
 251                                         fprintf(stderr, "Unknown argument %s\n", argv[i]);
 252                                         printhelp(argv[0]);
 253                                         exit(EXIT_FAILURE);
 254                                         break;
 255                         }
 256                 }
 257         }
 258
 259         /* Set up listening ports */
 260         if (svr_opts.portcount == 0) {
 261                 svr_opts.ports[0] = m_strdup(DROPBEAR_DEFPORT);
 262                 svr_opts.addresses[0] = m_strdup(DROPBEAR_DEFADDRESS);
 263                 svr_opts.portcount = 1;
 264         }
 265
 266         if (svr_opts.dsskeyfile == NULL) {
 267                 svr_opts.dsskeyfile = DSS_PRIV_FILENAME;
 268         }
 269         if (svr_opts.rsakeyfile == NULL) {
 270                 svr_opts.rsakeyfile = RSA_PRIV_FILENAME;
 271         }
 272
 273         if (svr_opts.bannerfile) {
 274                 struct stat buf;
 275                 if (stat(svr_opts.bannerfile, &buf) != 0) {
 276                         dropbear_exit("Error opening banner file '%s'",
 277                                         svr_opts.bannerfile);
 278                 }
 279
 280                 if (buf.st_size > MAX_BANNER_SIZE) {
 281                         dropbear_exit("Banner file too large, max is %d bytes",
 282                                         MAX_BANNER_SIZE);
 283                 }
 284
 285                 svr_opts.banner = buf_new(buf.st_size);
 286                 if (buf_readfile(svr_opts.banner, svr_opts.bannerfile)!=DROPBEAR_SUCCESS) {
 287                         dropbear_exit("Error reading banner file '%s'",
 288                                         svr_opts.bannerfile);
 289                 }
 290                 buf_setpos(svr_opts.banner, 0);
 291
 292         }
 293
 294         if (recv_window_arg) {
 295                 opts.recv_window = atol(recv_window_arg);
 296                 if (opts.recv_window == 0 || opts.recv_window > MAX_RECV_WINDOW) {
 297                         dropbear_exit("Bad recv window '%s'", recv_window_arg);
 298                 }
 299         }
 300
 301         if (keepalive_arg) {
 302                 unsigned int val;
 303                 if (m_str_to_uint(keepalive_arg, &val) == DROPBEAR_FAILURE) {
 304                         dropbear_exit("Bad keepalive '%s'", keepalive_arg);
 305                 }
 306                 opts.keepalive_secs = val;
 307         }
 308
 309         if (idle_timeout_arg) {
 310                 unsigned int val;
 311                 if (m_str_to_uint(idle_timeout_arg, &val) == DROPBEAR_FAILURE) {
 312                         dropbear_exit("Bad idle_timeout '%s'", idle_timeout_arg);
 313                 }
 314                 opts.idle_timeout_secs = val;
 315         }
 316 }
 317
 318 static void addportandaddress(char* spec) {
 319
 320         char *myspec = NULL;
 321
 322         if (svr_opts.portcount < DROPBEAR_MAX_PORTS) {
 323
 324                 /* We don't free it, it becomes part of the runopt state */
 325                 myspec = m_strdup(spec);
 326
 327                 /* search for ':', that separates address and port */
 328                 svr_opts.ports[svr_opts.portcount] = strchr(myspec, ':');
 329
 330                 if (svr_opts.ports[svr_opts.portcount] == NULL) {
 331                         /* no ':' -> the whole string specifies just a port */
 332                         svr_opts.ports[svr_opts.portcount] = myspec;
 333                 } else {
 334                         /* Split the address/port */
 335                         svr_opts.ports[svr_opts.portcount][0] = '\0';
 336                         svr_opts.ports[svr_opts.portcount]++;
 337                         svr_opts.addresses[svr_opts.portcount] = myspec;
 338                 }
 339
 340                 if (svr_opts.addresses[svr_opts.portcount] == NULL) {
 341                         /* no address given -> fill in the default address */
 342                         svr_opts.addresses[svr_opts.portcount] = m_strdup(DROPBEAR_DEFADDRESS);
 343                 }
 344
 345                 if (svr_opts.ports[svr_opts.portcount][0] == '\0') {
 346                         /* empty port -> exit */
 347                         dropbear_exit("Bad port");
 348                 }
 349
 350                 svr_opts.portcount++;
 351         }
 352 }
 353
 354 static void disablekey(int type, const char* filename) {
 355
 356         int i;
 357
 358         for (i = 0; sshhostkey[i].name != NULL; i++) {
 359                 if (sshhostkey[i].val == type) {
 360                         sshhostkey[i].usable = 0;
 361                         break;
 362                 }
 363         }
 364         dropbear_log(LOG_WARNING, "Failed reading '%s', disabling %s", filename,
 365                         type == DROPBEAR_SIGNKEY_DSS ? "DSS" : "RSA");
 366 }
 367
 368 /* Must be called after syslog/etc is working */
 369 void loadhostkeys() {
 370
 371         int ret;
 372         int type;
 373
 374         TRACE(("enter loadhostkeys"))
 375
 376         svr_opts.hostkey = new_sign_key();
 377
 378 #ifdef DROPBEAR_RSA
 379         type = DROPBEAR_SIGNKEY_RSA;
 380         ret = readhostkey(svr_opts.rsakeyfile, svr_opts.hostkey, &type);
 381         if (ret == DROPBEAR_FAILURE) {
 382                 disablekey(DROPBEAR_SIGNKEY_RSA, svr_opts.rsakeyfile);
 383         }
 384 #endif
 385 #ifdef DROPBEAR_DSS
 386         type = DROPBEAR_SIGNKEY_DSS;
 387         ret = readhostkey(svr_opts.dsskeyfile, svr_opts.hostkey, &type);
 388         if (ret == DROPBEAR_FAILURE) {
 389                 disablekey(DROPBEAR_SIGNKEY_DSS, svr_opts.dsskeyfile);
 390         }
 391 #endif
 392
 393         if ( 1
 394 #ifdef DROPBEAR_DSS
 395                 && svr_opts.hostkey->dsskey == NULL
 396 #endif
 397 #ifdef DROPBEAR_RSA
 398                 && svr_opts.hostkey->rsakey == NULL
 399 #endif
 400                 ) {
 401                 dropbear_exit("No hostkeys available");
 402         }
 403
 404         TRACE(("leave loadhostkeys"))
 405 }