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

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <ctype.h>
   4
   5 #include "putty.h"
   6
   7 #ifndef FALSE
   8 #define FALSE 0
   9 #endif
  10 #ifndef TRUE
  11 #define TRUE 1
  12 #endif
  13
  14 #define RLOGIN_MAX_BACKLOG 4096
  15
  16 typedef struct rlogin_tag {
  17     const struct plug_function_table *fn;
  18     /* the above field _must_ be first in the structure */
  19
  20     Socket s;
  21     int bufsize;
  22     int firstbyte;
  23     int cansize;
  24     int term_width, term_height;
  25     void *frontend;
  26 } *Rlogin;
  27
  28 static void rlogin_size(void *handle, int width, int height);
  29
  30 static void c_write(Rlogin rlogin, char *buf, int len)
  31 {
  32     int backlog = from_backend(rlogin->frontend, 0, buf, len);
  33     sk_set_frozen(rlogin->s, backlog > RLOGIN_MAX_BACKLOG);
  34 }
  35
  36 static void rlogin_log(Plug plug, int type, SockAddr addr, int port,
  37                        const char *error_msg, int error_code)
  38 {
  39     Rlogin rlogin = (Rlogin) plug;
  40     char addrbuf[256], *msg;
  41
  42     sk_getaddr(addr, addrbuf, lenof(addrbuf));
  43
  44     if (type == 0)
  45         msg = dupprintf("Connecting to %s port %d", addrbuf, port);
  46     else
  47         msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
  48
  49     logevent(rlogin->frontend, msg);
  50 }
  51
  52 static int rlogin_closing(Plug plug, const char *error_msg, int error_code,
  53                           int calling_back)
  54 {
  55     Rlogin rlogin = (Rlogin) plug;
  56     if (rlogin->s) {
  57         sk_close(rlogin->s);
  58         rlogin->s = NULL;
  59         notify_remote_exit(rlogin->frontend);
  60     }
  61     if (error_msg) {
  62         /* A socket error has occurred. */
  63         logevent(rlogin->frontend, error_msg);
  64         connection_fatal(rlogin->frontend, "%s", error_msg);
  65     }                                  /* Otherwise, the remote side closed the connection normally. */
  66     return 0;
  67 }
  68
  69 static int rlogin_receive(Plug plug, int urgent, char *data, int len)
  70 {
  71     Rlogin rlogin = (Rlogin) plug;
  72     if (urgent == 2) {
  73         char c;
  74
  75         c = *data++;
  76         len--;
  77         if (c == '\x80') {
  78             rlogin->cansize = 1;
  79             rlogin_size(rlogin, rlogin->term_width, rlogin->term_height);
  80         }
  81         /*
  82          * We should flush everything (aka Telnet SYNCH) if we see
  83          * 0x02, and we should turn off and on _local_ flow control
  84          * on 0x10 and 0x20 respectively. I'm not convinced it's
  85          * worth it...
  86          */
  87     } else {
  88         /*
  89          * Main rlogin protocol. This is really simple: the first
  90          * byte is expected to be NULL and is ignored, and the rest
  91          * is printed.
  92          */
  93         if (rlogin->firstbyte) {
  94             if (data[0] == '\0') {
  95                 data++;
  96                 len--;
  97             }
  98             rlogin->firstbyte = 0;
  99         }
 100         if (len > 0)
 101             c_write(rlogin, data, len);
 102     }
 103     return 1;
 104 }
 105
 106 static void rlogin_sent(Plug plug, int bufsize)
 107 {
 108     Rlogin rlogin = (Rlogin) plug;
 109     rlogin->bufsize = bufsize;
 110 }
 111
 112 /*
 113  * Called to set up the rlogin connection.
 114  *
 115  * Returns an error message, or NULL on success.
 116  *
 117  * Also places the canonical host name into `realhost'. It must be
 118  * freed by the caller.
 119  */
 120 static const char *rlogin_init(void *frontend_handle, void **backend_handle,
 121                                Config *cfg,
 122                                char *host, int port, char **realhost,
 123                                int nodelay, int keepalive)
 124 {
 125     static const struct plug_function_table fn_table = {
 126         rlogin_log,
 127         rlogin_closing,
 128         rlogin_receive,
 129         rlogin_sent
 130     };
 131     SockAddr addr;
 132     const char *err;
 133     Rlogin rlogin;
 134
 135     rlogin = snew(struct rlogin_tag);
 136     rlogin->fn = &fn_table;
 137     rlogin->s = NULL;
 138     rlogin->frontend = frontend_handle;
 139     rlogin->term_width = cfg->width;
 140     rlogin->term_height = cfg->height;
 141     rlogin->firstbyte = 1;
 142     rlogin->cansize = 0;
 143     *backend_handle = rlogin;
 144
 145     /*
 146      * Try to find host.
 147      */
 148     {
 149         char *buf;
 150         buf = dupprintf("Looking up host \"%s\"%s", host,
 151                         (cfg->addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
 152                          (cfg->addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" :
 153                           "")));
 154         logevent(rlogin->frontend, buf);
 155         sfree(buf);
 156     }
 157     addr = name_lookup(host, port, realhost, cfg, cfg->addressfamily);
 158     if ((err = sk_addr_error(addr)) != NULL) {
 159         sk_addr_free(addr);
 160         return err;
 161     }
 162
 163     if (port < 0)
 164         port = 513;                    /* default rlogin port */
 165
 166     /*
 167      * Open socket.
 168      */
 169     rlogin->s = new_connection(addr, *realhost, port, 1, 0,
 170                                nodelay, keepalive, (Plug) rlogin, cfg);
 171     if ((err = sk_socket_error(rlogin->s)) != NULL)
 172         return err;
 173
 174     /*
 175      * Send local username, remote username, terminal/speed
 176      */
 177
 178     {
 179         char z = 0;
 180         char *p;
 181         sk_write(rlogin->s, &z, 1);
 182         sk_write(rlogin->s, cfg->localusername,
 183                  strlen(cfg->localusername));
 184         sk_write(rlogin->s, &z, 1);
 185         sk_write(rlogin->s, cfg->username,
 186                  strlen(cfg->username));
 187         sk_write(rlogin->s, &z, 1);
 188         sk_write(rlogin->s, cfg->termtype,
 189                  strlen(cfg->termtype));
 190         sk_write(rlogin->s, "/", 1);
 191         for (p = cfg->termspeed; isdigit((unsigned char)*p); p++) continue;
 192         sk_write(rlogin->s, cfg->termspeed, p - cfg->termspeed);
 193         rlogin->bufsize = sk_write(rlogin->s, &z, 1);
 194     }
 195
 196     return NULL;
 197 }
 198
 199 static void rlogin_free(void *handle)
 200 {
 201     Rlogin rlogin = (Rlogin) handle;
 202
 203     if (rlogin->s)
 204         sk_close(rlogin->s);
 205     sfree(rlogin);
 206 }
 207
 208 /*
 209  * Stub routine (we don't have any need to reconfigure this backend).
 210  */
 211 static void rlogin_reconfig(void *handle, Config *cfg)
 212 {
 213 }
 214
 215 /*
 216  * Called to send data down the rlogin connection.
 217  */
 218 static int rlogin_send(void *handle, char *buf, int len)
 219 {
 220     Rlogin rlogin = (Rlogin) handle;
 221
 222     if (rlogin->s == NULL)
 223         return 0;
 224
 225     rlogin->bufsize = sk_write(rlogin->s, buf, len);
 226
 227     return rlogin->bufsize;
 228 }
 229
 230 /*
 231  * Called to query the current socket sendability status.
 232  */
 233 static int rlogin_sendbuffer(void *handle)
 234 {
 235     Rlogin rlogin = (Rlogin) handle;
 236     return rlogin->bufsize;
 237 }
 238
 239 /*
 240  * Called to set the size of the window
 241  */
 242 static void rlogin_size(void *handle, int width, int height)
 243 {
 244     Rlogin rlogin = (Rlogin) handle;
 245     char b[12] = { '\xFF', '\xFF', 0x73, 0x73, 0, 0, 0, 0, 0, 0, 0, 0 };
 246
 247     rlogin->term_width = width;
 248     rlogin->term_height = height;
 249
 250     if (rlogin->s == NULL || !rlogin->cansize)
 251         return;
 252
 253     b[6] = rlogin->term_width >> 8;
 254     b[7] = rlogin->term_width & 0xFF;
 255     b[4] = rlogin->term_height >> 8;
 256     b[5] = rlogin->term_height & 0xFF;
 257     rlogin->bufsize = sk_write(rlogin->s, b, 12);
 258     return;
 259 }
 260
 261 /*
 262  * Send rlogin special codes.
 263  */
 264 static void rlogin_special(void *handle, Telnet_Special code)
 265 {
 266     /* Do nothing! */
 267     return;
 268 }
 269
 270 /*
 271  * Return a list of the special codes that make sense in this
 272  * protocol.
 273  */
 274 static const struct telnet_special *rlogin_get_specials(void *handle)
 275 {
 276     return NULL;
 277 }
 278
 279 static Socket rlogin_socket(void *handle)
 280 {
 281     Rlogin rlogin = (Rlogin) handle;
 282     return rlogin->s;
 283 }
 284
 285 static int rlogin_sendok(void *handle)
 286 {
 287     /* Rlogin rlogin = (Rlogin) handle; */
 288     return 1;
 289 }
 290
 291 static void rlogin_unthrottle(void *handle, int backlog)
 292 {
 293     Rlogin rlogin = (Rlogin) handle;
 294     sk_set_frozen(rlogin->s, backlog > RLOGIN_MAX_BACKLOG);
 295 }
 296
 297 static int rlogin_ldisc(void *handle, int option)
 298 {
 299     /* Rlogin rlogin = (Rlogin) handle; */
 300     return 0;
 301 }
 302
 303 static void rlogin_provide_ldisc(void *handle, void *ldisc)
 304 {
 305     /* This is a stub. */
 306 }
 307
 308 static void rlogin_provide_logctx(void *handle, void *logctx)
 309 {
 310     /* This is a stub. */
 311 }
 312
 313 static int rlogin_exitcode(void *handle)
 314 {
 315     Rlogin rlogin = (Rlogin) handle;
 316     if (rlogin->s != NULL)
 317         return -1;                     /* still connected */
 318     else
 319         /* If we ever implement RSH, we'll probably need to do this properly */
 320         return 0;
 321 }
 322
 323 /*
 324  * cfg_info for rlogin does nothing at all.
 325  */
 326 static int rlogin_cfg_info(void *handle)
 327 {
 328     return 0;
 329 }
 330
 331 Backend rlogin_backend = {
 332     rlogin_init,
 333     rlogin_free,
 334     rlogin_reconfig,
 335     rlogin_send,
 336     rlogin_sendbuffer,
 337     rlogin_size,
 338     rlogin_special,
 339     rlogin_get_specials,
 340     rlogin_socket,
 341     rlogin_exitcode,
 342     rlogin_sendok,
 343     rlogin_ldisc,
 344     rlogin_provide_ldisc,
 345     rlogin_provide_logctx,
 346     rlogin_unthrottle,
 347     rlogin_cfg_info,
 348     1
 349 };