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 } *Rlogin;
  31
  32 static void rlogin_size(void *handle, int width, int height);
  33
  34 static void c_write(Rlogin rlogin, char *buf, int len)
  35 {
  36     int backlog = from_backend(rlogin->frontend, 0, buf, len);
  37     sk_set_frozen(rlogin->s, backlog > RLOGIN_MAX_BACKLOG);
  38 }
  39
  40 static void rlogin_log(Plug plug, int type, SockAddr addr, int port,
  41                        const char *error_msg, int error_code)
  42 {
  43     Rlogin rlogin = (Rlogin) plug;
  44     char addrbuf[256], *msg;
  45
  46     sk_getaddr(addr, addrbuf, lenof(addrbuf));
  47
  48     if (type == 0)
  49         msg = dupprintf("Connecting to %s port %d", addrbuf, port);
  50     else
  51         msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
  52
  53     logevent(rlogin->frontend, msg);
  54 }
  55
  56 static int rlogin_closing(Plug plug, const char *error_msg, int error_code,
  57                           int calling_back)
  58 {
  59     Rlogin rlogin = (Rlogin) plug;
  60     if (rlogin->s) {
  61         sk_close(rlogin->s);
  62         rlogin->s = NULL;
  63         notify_remote_exit(rlogin->frontend);
  64     }
  65     if (error_msg) {
  66         /* A socket error has occurred. */
  67         logevent(rlogin->frontend, error_msg);
  68         connection_fatal(rlogin->frontend, "%s", error_msg);
  69     }                                  /* Otherwise, the remote side closed the connection normally. */
  70     return 0;
  71 }
  72
  73 static int rlogin_receive(Plug plug, int urgent, char *data, int len)
  74 {
  75     Rlogin rlogin = (Rlogin) plug;
  76     if (urgent == 2) {
  77         char c;
  78
  79         c = *data++;
  80         len--;
  81         if (c == '\x80') {
  82             rlogin->cansize = 1;
  83             rlogin_size(rlogin, rlogin->term_width, rlogin->term_height);
  84         }
  85         /*
  86          * We should flush everything (aka Telnet SYNCH) if we see
  87          * 0x02, and we should turn off and on _local_ flow control
  88          * on 0x10 and 0x20 respectively. I'm not convinced it's
  89          * worth it...
  90          */
  91     } else {
  92         /*
  93          * Main rlogin protocol. This is really simple: the first
  94          * byte is expected to be NULL and is ignored, and the rest
  95          * is printed.
  96          */
  97         if (rlogin->firstbyte) {
  98             if (data[0] == '\0') {
  99                 data++;
 100                 len--;
 101             }
 102             rlogin->firstbyte = 0;
 103         }
 104         if (len > 0)
 105             c_write(rlogin, data, len);
 106     }
 107     return 1;
 108 }
 109
 110 static void rlogin_sent(Plug plug, int bufsize)
 111 {
 112     Rlogin rlogin = (Rlogin) plug;
 113     rlogin->bufsize = bufsize;
 114 }
 115
 116 /*
 117  * Called to set up the rlogin connection.
 118  *
 119  * Returns an error message, or NULL on success.
 120  *
 121  * Also places the canonical host name into `realhost'. It must be
 122  * freed by the caller.
 123  */
 124 static const char *rlogin_init(void *frontend_handle, void **backend_handle,
 125                                Config *cfg,
 126                                char *host, int port, char **realhost,
 127                                int nodelay, int keepalive)
 128 {
 129     static const struct plug_function_table fn_table = {
 130         rlogin_log,
 131         rlogin_closing,
 132         rlogin_receive,
 133         rlogin_sent
 134     };
 135     SockAddr addr;
 136     const char *err;
 137     Rlogin rlogin;
 138
 139     rlogin = snew(struct rlogin_tag);
 140     rlogin->fn = &fn_table;
 141     rlogin->s = NULL;
 142     rlogin->frontend = frontend_handle;
 143     rlogin->term_width = cfg->width;
 144     rlogin->term_height = cfg->height;
 145     rlogin->firstbyte = 1;
 146     rlogin->cansize = 0;
 147     *backend_handle = rlogin;
 148
 149     /*
 150      * Try to find host.
 151      */
 152     {
 153         char *buf;
 154         buf = dupprintf("Looking up host \"%s\"%s", host,
 155                         (cfg->addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
 156                          (cfg->addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" :
 157                           "")));
 158         logevent(rlogin->frontend, buf);
 159         sfree(buf);
 160     }
 161     addr = name_lookup(host, port, realhost, cfg, cfg->addressfamily);
 162     if ((err = sk_addr_error(addr)) != NULL) {
 163         sk_addr_free(addr);
 164         return err;
 165     }
 166
 167     if (port < 0)
 168         port = 513;                    /* default rlogin port */
 169
 170     /*
 171      * Open socket.
 172      */
 173     rlogin->s = new_connection(addr, *realhost, port, 1, 0,
 174                                nodelay, keepalive, (Plug) rlogin, cfg);
 175     if ((err = sk_socket_error(rlogin->s)) != NULL)
 176         return err;
 177
 178     /*
 179      * Send local username, remote username, terminal/speed
 180      */
 181
 182     {
 183         char z = 0;
 184         char *p;
 185         char ruser[sizeof(cfg->username)];
 186         (void) get_remote_username(cfg, ruser, sizeof(ruser));
 187         sk_write(rlogin->s, &z, 1);
 188         sk_write(rlogin->s, cfg->localusername,
 189                  strlen(cfg->localusername));
 190         sk_write(rlogin->s, &z, 1);
 191         sk_write(rlogin->s, ruser,
 192                  strlen(ruser));
 193         sk_write(rlogin->s, &z, 1);
 194         sk_write(rlogin->s, cfg->termtype,
 195                  strlen(cfg->termtype));
 196         sk_write(rlogin->s, "/", 1);
 197         for (p = cfg->termspeed; isdigit((unsigned char)*p); p++) continue;
 198         sk_write(rlogin->s, cfg->termspeed, p - cfg->termspeed);
 199         rlogin->bufsize = sk_write(rlogin->s, &z, 1);
 200     }
 201
 202     if (*cfg->loghost) {
 203         char *colon;
 204
 205         sfree(*realhost);
 206         *realhost = dupstr(cfg->loghost);
 207         colon = strrchr(*realhost, ':');
 208         if (colon) {
 209             /*
 210              * FIXME: if we ever update this aspect of ssh.c for
 211              * IPv6 literal management, this should change in line
 212              * with it.
 213              */
 214             *colon++ = '\0';
 215         }
 216     }
 217
 218     return NULL;
 219 }
 220
 221 static void rlogin_free(void *handle)
 222 {
 223     Rlogin rlogin = (Rlogin) handle;
 224
 225     if (rlogin->s)
 226         sk_close(rlogin->s);
 227     sfree(rlogin);
 228 }
 229
 230 /*
 231  * Stub routine (we don't have any need to reconfigure this backend).
 232  */
 233 static void rlogin_reconfig(void *handle, Config *cfg)
 234 {
 235 }
 236
 237 /*
 238  * Called to send data down the rlogin connection.
 239  */
 240 static int rlogin_send(void *handle, char *buf, int len)
 241 {
 242     Rlogin rlogin = (Rlogin) handle;
 243
 244     if (rlogin->s == NULL)
 245         return 0;
 246
 247     rlogin->bufsize = sk_write(rlogin->s, buf, len);
 248
 249     return rlogin->bufsize;
 250 }
 251
 252 /*
 253  * Called to query the current socket sendability status.
 254  */
 255 static int rlogin_sendbuffer(void *handle)
 256 {
 257     Rlogin rlogin = (Rlogin) handle;
 258     return rlogin->bufsize;
 259 }
 260
 261 /*
 262  * Called to set the size of the window
 263  */
 264 static void rlogin_size(void *handle, int width, int height)
 265 {
 266     Rlogin rlogin = (Rlogin) handle;
 267     char b[12] = { '\xFF', '\xFF', 0x73, 0x73, 0, 0, 0, 0, 0, 0, 0, 0 };
 268
 269     rlogin->term_width = width;
 270     rlogin->term_height = height;
 271
 272     if (rlogin->s == NULL || !rlogin->cansize)
 273         return;
 274
 275     b[6] = rlogin->term_width >> 8;
 276     b[7] = rlogin->term_width & 0xFF;
 277     b[4] = rlogin->term_height >> 8;
 278     b[5] = rlogin->term_height & 0xFF;
 279     rlogin->bufsize = sk_write(rlogin->s, b, 12);
 280     return;
 281 }
 282
 283 /*
 284  * Send rlogin special codes.
 285  */
 286 static void rlogin_special(void *handle, Telnet_Special code)
 287 {
 288     /* Do nothing! */
 289     return;
 290 }
 291
 292 /*
 293  * Return a list of the special codes that make sense in this
 294  * protocol.
 295  */
 296 static const struct telnet_special *rlogin_get_specials(void *handle)
 297 {
 298     return NULL;
 299 }
 300
 301 static int rlogin_connected(void *handle)
 302 {
 303     Rlogin rlogin = (Rlogin) handle;
 304     return rlogin->s != NULL;
 305 }
 306
 307 static int rlogin_sendok(void *handle)
 308 {
 309     /* Rlogin rlogin = (Rlogin) handle; */
 310     return 1;
 311 }
 312
 313 static void rlogin_unthrottle(void *handle, int backlog)
 314 {
 315     Rlogin rlogin = (Rlogin) handle;
 316     sk_set_frozen(rlogin->s, backlog > RLOGIN_MAX_BACKLOG);
 317 }
 318
 319 static int rlogin_ldisc(void *handle, int option)
 320 {
 321     /* Rlogin rlogin = (Rlogin) handle; */
 322     return 0;
 323 }
 324
 325 static void rlogin_provide_ldisc(void *handle, void *ldisc)
 326 {
 327     /* This is a stub. */
 328 }
 329
 330 static void rlogin_provide_logctx(void *handle, void *logctx)
 331 {
 332     /* This is a stub. */
 333 }
 334
 335 static int rlogin_exitcode(void *handle)
 336 {
 337     Rlogin rlogin = (Rlogin) handle;
 338     if (rlogin->s != NULL)
 339         return -1;                     /* still connected */
 340     else
 341         /* If we ever implement RSH, we'll probably need to do this properly */
 342         return 0;
 343 }
 344
 345 /*
 346  * cfg_info for rlogin does nothing at all.
 347  */
 348 static int rlogin_cfg_info(void *handle)
 349 {
 350     return 0;
 351 }
 352
 353 Backend rlogin_backend = {
 354     rlogin_init,
 355     rlogin_free,
 356     rlogin_reconfig,
 357     rlogin_send,
 358     rlogin_sendbuffer,
 359     rlogin_size,
 360     rlogin_special,
 361     rlogin_get_specials,
 362     rlogin_connected,
 363     rlogin_exitcode,
 364     rlogin_sendok,
 365     rlogin_ldisc,
 366     rlogin_provide_ldisc,
 367     rlogin_provide_logctx,
 368     rlogin_unthrottle,
 369     rlogin_cfg_info,
 370     "rlogin",
 371     PROT_RLOGIN,
 372     513
 373 };