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 term_width, term_height;
  23     void *frontend;
  24 } *Rlogin;
  25
  26 static void rlogin_size(void *handle, int width, int height);
  27
  28 static void c_write(Rlogin rlogin, char *buf, int len)
  29 {
  30     int backlog = from_backend(rlogin->frontend, 0, buf, len);
  31     sk_set_frozen(rlogin->s, backlog > RLOGIN_MAX_BACKLOG);
  32 }
  33
  34 static int rlogin_closing(Plug plug, char *error_msg, int error_code,
  35                           int calling_back)
  36 {
  37     Rlogin rlogin = (Rlogin) plug;
  38     if (rlogin->s) {
  39         sk_close(rlogin->s);
  40         rlogin->s = NULL;
  41     }
  42     if (error_msg) {
  43         /* A socket error has occurred. */
  44         logevent(rlogin->frontend, error_msg);
  45         connection_fatal("%s", error_msg);
  46     }                                  /* Otherwise, the remote side closed the connection normally. */
  47     return 0;
  48 }
  49
  50 static int rlogin_receive(Plug plug, int urgent, char *data, int len)
  51 {
  52     Rlogin rlogin = (Rlogin) plug;
  53     if (urgent == 2) {
  54         char c;
  55
  56         c = *data++;
  57         len--;
  58         if (c == '\x80')
  59             rlogin_size(rlogin, rlogin->term_width, rlogin->term_height);
  60         /*
  61          * We should flush everything (aka Telnet SYNCH) if we see
  62          * 0x02, and we should turn off and on _local_ flow control
  63          * on 0x10 and 0x20 respectively. I'm not convinced it's
  64          * worth it...
  65          */
  66     } else {
  67         /*
  68          * Main rlogin protocol. This is really simple: the first
  69          * byte is expected to be NULL and is ignored, and the rest
  70          * is printed.
  71          */
  72         static int firstbyte = 1;
  73         if (firstbyte) {
  74             if (data[0] == '\0') {
  75                 data++;
  76                 len--;
  77             }
  78             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 = smalloc(sizeof(*rlogin));
 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     *backend_handle = rlogin;
 120
 121     /*
 122      * Try to find host.
 123      */
 124     {
 125         char *buf;
 126         buf = dupprintf("Looking up host \"%s\"", host);
 127         logevent(rlogin->frontend, buf);
 128         sfree(buf);
 129     }
 130     addr = name_lookup(host, port, realhost, cfg);
 131     if ((err = sk_addr_error(addr)) != NULL)
 132         return err;
 133
 134     if (port < 0)
 135         port = 513;                    /* default rlogin port */
 136
 137     /*
 138      * Open socket.
 139      */
 140     {
 141         char *buf, addrbuf[100];
 142         sk_getaddr(addr, addrbuf, 100);
 143         buf = dupprintf("Connecting to %s port %d", addrbuf, port);
 144         logevent(rlogin->frontend, buf);
 145         sfree(buf);
 146     }
 147     rlogin->s = new_connection(addr, *realhost, port, 1, 0,
 148                                nodelay, (Plug) rlogin, cfg);
 149     if ((err = sk_socket_error(rlogin->s)) != NULL)
 150         return err;
 151
 152     sk_addr_free(addr);
 153
 154     /*
 155      * Send local username, remote username, terminal/speed
 156      */
 157
 158     {
 159         char z = 0;
 160         char *p;
 161         sk_write(rlogin->s, &z, 1);
 162         sk_write(rlogin->s, cfg->localusername,
 163                  strlen(cfg->localusername));
 164         sk_write(rlogin->s, &z, 1);
 165         sk_write(rlogin->s, cfg->username,
 166                  strlen(cfg->username));
 167         sk_write(rlogin->s, &z, 1);
 168         sk_write(rlogin->s, cfg->termtype,
 169                  strlen(cfg->termtype));
 170         sk_write(rlogin->s, "/", 1);
 171         for (p = cfg->termspeed; isdigit(*p); p++) continue;
 172         sk_write(rlogin->s, cfg->termspeed, p - cfg->termspeed);
 173         rlogin->bufsize = sk_write(rlogin->s, &z, 1);
 174     }
 175
 176     return NULL;
 177 }
 178
 179 /*
 180  * Stub routine (we don't have any need to reconfigure this backend).
 181  */
 182 static void rlogin_reconfig(void *handle, Config *cfg)
 183 {
 184 }
 185
 186 /*
 187  * Called to send data down the rlogin connection.
 188  */
 189 static int rlogin_send(void *handle, char *buf, int len)
 190 {
 191     Rlogin rlogin = (Rlogin) handle;
 192
 193     if (rlogin->s == NULL)
 194         return 0;
 195
 196     rlogin->bufsize = sk_write(rlogin->s, buf, len);
 197
 198     return rlogin->bufsize;
 199 }
 200
 201 /*
 202  * Called to query the current socket sendability status.
 203  */
 204 static int rlogin_sendbuffer(void *handle)
 205 {
 206     Rlogin rlogin = (Rlogin) handle;
 207     return rlogin->bufsize;
 208 }
 209
 210 /*
 211  * Called to set the size of the window
 212  */
 213 static void rlogin_size(void *handle, int width, int height)
 214 {
 215     Rlogin rlogin = (Rlogin) handle;
 216     char b[12] = { '\xFF', '\xFF', 0x73, 0x73, 0, 0, 0, 0, 0, 0, 0, 0 };
 217
 218     rlogin->term_width = width;
 219     rlogin->term_height = height;
 220
 221     if (rlogin->s == NULL)
 222         return;
 223
 224     b[6] = rlogin->term_width >> 8;
 225     b[7] = rlogin->term_width & 0xFF;
 226     b[4] = rlogin->term_height >> 8;
 227     b[5] = rlogin->term_height & 0xFF;
 228     rlogin->bufsize = sk_write(rlogin->s, b, 12);
 229     return;
 230 }
 231
 232 /*
 233  * Send rlogin special codes.
 234  */
 235 static void rlogin_special(void *handle, Telnet_Special code)
 236 {
 237     /* Do nothing! */
 238     return;
 239 }
 240
 241 static Socket rlogin_socket(void *handle)
 242 {
 243     Rlogin rlogin = (Rlogin) handle;
 244     return rlogin->s;
 245 }
 246
 247 static int rlogin_sendok(void *handle)
 248 {
 249     /* Rlogin rlogin = (Rlogin) handle; */
 250     return 1;
 251 }
 252
 253 static void rlogin_unthrottle(void *handle, int backlog)
 254 {
 255     Rlogin rlogin = (Rlogin) handle;
 256     sk_set_frozen(rlogin->s, backlog > RLOGIN_MAX_BACKLOG);
 257 }
 258
 259 static int rlogin_ldisc(void *handle, int option)
 260 {
 261     /* Rlogin rlogin = (Rlogin) handle; */
 262     return 0;
 263 }
 264
 265 static void rlogin_provide_ldisc(void *handle, void *ldisc)
 266 {
 267     /* This is a stub. */
 268 }
 269
 270 static void rlogin_provide_logctx(void *handle, void *logctx)
 271 {
 272     /* This is a stub. */
 273 }
 274
 275 static int rlogin_exitcode(void *handle)
 276 {
 277     /* Rlogin rlogin = (Rlogin) handle; */
 278     /* If we ever implement RSH, we'll probably need to do this properly */
 279     return 0;
 280 }
 281
 282 Backend rlogin_backend = {
 283     rlogin_init,
 284     rlogin_reconfig,
 285     rlogin_send,
 286     rlogin_sendbuffer,
 287     rlogin_size,
 288     rlogin_special,
 289     rlogin_socket,
 290     rlogin_exitcode,
 291     rlogin_sendok,
 292     rlogin_ldisc,
 293     rlogin_provide_ldisc,
 294     rlogin_provide_logctx,
 295     rlogin_unthrottle,
 296     1
 297 };