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