git.distorted.org.uk Git - u/mdw/putty/blob - rlogin.c

   1 /*
   2  * Rlogin backend.
   3  */
   4
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <ctype.h>
   8
   9 #include "putty.h"
  10
  11 #ifndef FALSE
  12 #define FALSE 0
  13 #endif
  14 #ifndef TRUE
  15 #define TRUE 1
  16 #endif
  17
  18 #define RLOGIN_MAX_BACKLOG 4096
  19
  20 typedef struct rlogin_tag {
  21     const struct plug_function_table *fn;
  22     /* the above field _must_ be first in the structure */
  23
  24     Socket s;
  25     int bufsize;
  26     int firstbyte;
  27     int cansize;
  28     int term_width, term_height;
  29     void *frontend;
  30
  31     Conf *conf;
  32
  33     /* In case we need to read a username from the terminal before starting */
  34     prompts_t *prompt;
  35 } *Rlogin;
  36
  37 static void rlogin_size(void *handle, int width, int height);
  38
  39 static void c_write(Rlogin rlogin, char *buf, int len)
  40 {
  41     int backlog = from_backend(rlogin->frontend, 0, buf, len);
  42     sk_set_frozen(rlogin->s, backlog > RLOGIN_MAX_BACKLOG);
  43 }
  44
  45 static void rlogin_log(Plug plug, int type, SockAddr addr, int port,
  46                        const char *error_msg, int error_code)
  47 {
  48     Rlogin rlogin = (Rlogin) plug;
  49     char addrbuf[256], *msg;
  50
  51     sk_getaddr(addr, addrbuf, lenof(addrbuf));
  52
  53     if (type == 0)
  54         msg = dupprintf("Connecting to %s port %d", addrbuf, port);
  55     else
  56         msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
  57
  58     logevent(rlogin->frontend, msg);
  59 }
  60
  61 static int rlogin_closing(Plug plug, const char *error_msg, int error_code,
  62                           int calling_back)
  63 {
  64     Rlogin rlogin = (Rlogin) plug;
  65
  66     /*
  67      * We don't implement independent EOF in each direction for Telnet
  68      * connections; as soon as we get word that the remote side has
  69      * sent us EOF, we wind up the whole connection.
  70      */
  71
  72     if (rlogin->s) {
  73         sk_close(rlogin->s);
  74         rlogin->s = NULL;
  75         notify_remote_exit(rlogin->frontend);
  76     }
  77     if (error_msg) {
  78         /* A socket error has occurred. */
  79         logevent(rlogin->frontend, error_msg);
  80         connection_fatal(rlogin->frontend, "%s", error_msg);
  81     }                                  /* Otherwise, the remote side closed the connection normally. */
  82     return 0;
  83 }
  84
  85 static int rlogin_receive(Plug plug, int urgent, char *data, int len)
  86 {
  87     Rlogin rlogin = (Rlogin) plug;
  88     if (urgent == 2) {
  89         char c;
  90
  91         c = *data++;
  92         len--;
  93         if (c == '\x80') {
  94             rlogin->cansize = 1;
  95             rlogin_size(rlogin, rlogin->term_width, rlogin->term_height);
  96         }
  97         /*
  98          * We should flush everything (aka Telnet SYNCH) if we see
  99          * 0x02, and we should turn off and on _local_ flow control
 100          * on 0x10 and 0x20 respectively. I'm not convinced it's
 101          * worth it...
 102          */
 103     } else {
 104         /*
 105          * Main rlogin protocol. This is really simple: the first
 106          * byte is expected to be NULL and is ignored, and the rest
 107          * is printed.
 108          */
 109         if (rlogin->firstbyte) {
 110             if (data[0] == '\0') {
 111                 data++;
 112                 len--;
 113             }
 114             rlogin->firstbyte = 0;
 115         }
 116         if (len > 0)
 117             c_write(rlogin, data, len);
 118     }
 119     return 1;
 120 }
 121
 122 static void rlogin_sent(Plug plug, int bufsize)
 123 {
 124     Rlogin rlogin = (Rlogin) plug;
 125     rlogin->bufsize = bufsize;
 126 }
 127
 128 static void rlogin_startup(Rlogin rlogin, const char *ruser)
 129 {
 130     char z = 0;
 131     char *p;
 132
 133     sk_write(rlogin->s, &z, 1);
 134     p = conf_get_str(rlogin->conf, CONF_localusername);
 135     sk_write(rlogin->s, p, strlen(p));
 136     sk_write(rlogin->s, &z, 1);
 137     sk_write(rlogin->s, ruser, strlen(ruser));
 138     sk_write(rlogin->s, &z, 1);
 139     p = conf_get_str(rlogin->conf, CONF_termtype);
 140     sk_write(rlogin->s, p, strlen(p));
 141     sk_write(rlogin->s, "/", 1);
 142     p = conf_get_str(rlogin->conf, CONF_termspeed);
 143     sk_write(rlogin->s, p, strspn(p, "0123456789"));
 144     rlogin->bufsize = sk_write(rlogin->s, &z, 1);
 145
 146     rlogin->prompt = NULL;
 147 }
 148
 149 /*
 150  * Called to set up the rlogin connection.
 151  *
 152  * Returns an error message, or NULL on success.
 153  *
 154  * Also places the canonical host name into `realhost'. It must be
 155  * freed by the caller.
 156  */
 157 static const char *rlogin_init(void *frontend_handle, void **backend_handle,
 158                                Conf *conf,
 159                                char *host, int port, char **realhost,
 160                                int nodelay, int keepalive)
 161 {
 162     static const struct plug_function_table fn_table = {
 163         rlogin_log,
 164         rlogin_closing,
 165         rlogin_receive,
 166         rlogin_sent
 167     };
 168     SockAddr addr;
 169     const char *err;
 170     Rlogin rlogin;
 171     char *ruser;
 172     int addressfamily;
 173     char *loghost;
 174
 175     rlogin = snew(struct rlogin_tag);
 176     rlogin->fn = &fn_table;
 177     rlogin->s = NULL;
 178     rlogin->frontend = frontend_handle;
 179     rlogin->term_width = conf_get_int(conf, CONF_width);
 180     rlogin->term_height = conf_get_int(conf, CONF_height);
 181     rlogin->firstbyte = 1;
 182     rlogin->cansize = 0;
 183     rlogin->prompt = NULL;
 184     rlogin->conf = conf_copy(conf);
 185     *backend_handle = rlogin;
 186
 187     addressfamily = conf_get_int(conf, CONF_addressfamily);
 188     /*
 189      * Try to find host.
 190      */
 191     {
 192         char *buf;
 193         buf = dupprintf("Looking up host \"%s\"%s", host,
 194                         (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
 195                          (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" :
 196                           "")));
 197         logevent(rlogin->frontend, buf);
 198         sfree(buf);
 199     }
 200     addr = name_lookup(host, port, realhost, conf, addressfamily);
 201     if ((err = sk_addr_error(addr)) != NULL) {
 202         sk_addr_free(addr);
 203         return err;
 204     }
 205
 206     if (port < 0)
 207         port = 513;                    /* default rlogin port */
 208
 209     /*
 210      * Open socket.
 211      */
 212     rlogin->s = new_connection(addr, *realhost, port, 1, 0,
 213                                nodelay, keepalive, (Plug) rlogin, conf);
 214     if ((err = sk_socket_error(rlogin->s)) != NULL)
 215         return err;
 216
 217     loghost = conf_get_str(conf, CONF_loghost);
 218     if (*loghost) {
 219         char *colon;
 220
 221         sfree(*realhost);
 222         *realhost = dupstr(loghost);
 223         colon = strrchr(*realhost, ':');
 224         if (colon) {
 225             /*
 226              * FIXME: if we ever update this aspect of ssh.c for
 227              * IPv6 literal management, this should change in line
 228              * with it.
 229              */
 230             *colon++ = '\0';
 231         }
 232     }
 233
 234     /*
 235      * Send local username, remote username, terminal type and
 236      * terminal speed - unless we don't have the remote username yet,
 237      * in which case we prompt for it and may end up deferring doing
 238      * anything else until the local prompt mechanism returns.
 239      */
 240     if ((ruser = get_remote_username(conf)) != NULL) {
 241         rlogin_startup(rlogin, ruser);
 242         sfree(ruser);
 243     } else {
 244         int ret;
 245
 246         rlogin->prompt = new_prompts(rlogin->frontend);
 247         rlogin->prompt->to_server = TRUE;
 248         rlogin->prompt->name = dupstr("Rlogin login name");
 249         add_prompt(rlogin->prompt, dupstr("rlogin username: "), TRUE);
 250         ret = get_userpass_input(rlogin->prompt, NULL, 0);
 251         if (ret >= 0) {
 252             rlogin_startup(rlogin, rlogin->prompt->prompts[0]->result);
 253         }
 254     }
 255
 256     return NULL;
 257 }
 258
 259 static void rlogin_free(void *handle)
 260 {
 261     Rlogin rlogin = (Rlogin) handle;
 262
 263     if (rlogin->prompt)
 264         free_prompts(rlogin->prompt);
 265     if (rlogin->s)
 266         sk_close(rlogin->s);
 267     conf_free(rlogin->conf);
 268     sfree(rlogin);
 269 }
 270
 271 /*
 272  * Stub routine (we don't have any need to reconfigure this backend).
 273  */
 274 static void rlogin_reconfig(void *handle, Conf *conf)
 275 {
 276 }
 277
 278 /*
 279  * Called to send data down the rlogin connection.
 280  */
 281 static int rlogin_send(void *handle, char *buf, int len)
 282 {
 283     Rlogin rlogin = (Rlogin) handle;
 284
 285     if (rlogin->s == NULL)
 286         return 0;
 287
 288     if (rlogin->prompt) {
 289         /*
 290          * We're still prompting for a username, and aren't talking
 291          * directly to the network connection yet.
 292          */
 293         int ret = get_userpass_input(rlogin->prompt,
 294                                      (unsigned char *)buf, len);
 295         if (ret >= 0) {
 296             rlogin_startup(rlogin, rlogin->prompt->prompts[0]->result);
 297             /* that nulls out rlogin->prompt, so then we'll start sending
 298              * data down the wire in the obvious way */
 299         }
 300     } else {
 301         rlogin->bufsize = sk_write(rlogin->s, buf, len);
 302     }
 303
 304     return rlogin->bufsize;
 305 }
 306
 307 /*
 308  * Called to query the current socket sendability status.
 309  */
 310 static int rlogin_sendbuffer(void *handle)
 311 {
 312     Rlogin rlogin = (Rlogin) handle;
 313     return rlogin->bufsize;
 314 }
 315
 316 /*
 317  * Called to set the size of the window
 318  */
 319 static void rlogin_size(void *handle, int width, int height)
 320 {
 321     Rlogin rlogin = (Rlogin) handle;
 322     char b[12] = { '\xFF', '\xFF', 0x73, 0x73, 0, 0, 0, 0, 0, 0, 0, 0 };
 323
 324     rlogin->term_width = width;
 325     rlogin->term_height = height;
 326
 327     if (rlogin->s == NULL || !rlogin->cansize)
 328         return;
 329
 330     b[6] = rlogin->term_width >> 8;
 331     b[7] = rlogin->term_width & 0xFF;
 332     b[4] = rlogin->term_height >> 8;
 333     b[5] = rlogin->term_height & 0xFF;
 334     rlogin->bufsize = sk_write(rlogin->s, b, 12);
 335     return;
 336 }
 337
 338 /*
 339  * Send rlogin special codes.
 340  */
 341 static void rlogin_special(void *handle, Telnet_Special code)
 342 {
 343     /* Do nothing! */
 344     return;
 345 }
 346
 347 /*
 348  * Return a list of the special codes that make sense in this
 349  * protocol.
 350  */
 351 static const struct telnet_special *rlogin_get_specials(void *handle)
 352 {
 353     return NULL;
 354 }
 355
 356 static int rlogin_connected(void *handle)
 357 {
 358     Rlogin rlogin = (Rlogin) handle;
 359     return rlogin->s != NULL;
 360 }
 361
 362 static int rlogin_sendok(void *handle)
 363 {
 364     /* Rlogin rlogin = (Rlogin) handle; */
 365     return 1;
 366 }
 367
 368 static void rlogin_unthrottle(void *handle, int backlog)
 369 {
 370     Rlogin rlogin = (Rlogin) handle;
 371     sk_set_frozen(rlogin->s, backlog > RLOGIN_MAX_BACKLOG);
 372 }
 373
 374 static int rlogin_ldisc(void *handle, int option)
 375 {
 376     /* Rlogin rlogin = (Rlogin) handle; */
 377     return 0;
 378 }
 379
 380 static void rlogin_provide_ldisc(void *handle, void *ldisc)
 381 {
 382     /* This is a stub. */
 383 }
 384
 385 static void rlogin_provide_logctx(void *handle, void *logctx)
 386 {
 387     /* This is a stub. */
 388 }
 389
 390 static int rlogin_exitcode(void *handle)
 391 {
 392     Rlogin rlogin = (Rlogin) handle;
 393     if (rlogin->s != NULL)
 394         return -1;                     /* still connected */
 395     else
 396         /* If we ever implement RSH, we'll probably need to do this properly */
 397         return 0;
 398 }
 399
 400 /*
 401  * cfg_info for rlogin does nothing at all.
 402  */
 403 static int rlogin_cfg_info(void *handle)
 404 {
 405     return 0;
 406 }
 407
 408 Backend rlogin_backend = {
 409     rlogin_init,
 410     rlogin_free,
 411     rlogin_reconfig,
 412     rlogin_send,
 413     rlogin_sendbuffer,
 414     rlogin_size,
 415     rlogin_special,
 416     rlogin_get_specials,
 417     rlogin_connected,
 418     rlogin_exitcode,
 419     rlogin_sendok,
 420     rlogin_ldisc,
 421     rlogin_provide_ldisc,
 422     rlogin_provide_logctx,
 423     rlogin_unthrottle,
 424     rlogin_cfg_info,
 425     "rlogin",
 426     PROT_RLOGIN,
 427     513
 428 };