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