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