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