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     }
  43     if (error_msg) {
  44         /* A socket error has occurred. */
  45         logevent(rlogin->frontend, error_msg);
  46         connection_fatal(rlogin->frontend, "%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 const char *rlogin_init(void *frontend_handle, void **backend_handle,
 101                                Config *cfg,
 102                                char *host, int port, char **realhost,
 103                                int nodelay)
 104 {
 105     static const struct plug_function_table fn_table = {
 106         rlogin_closing,
 107         rlogin_receive,
 108         rlogin_sent
 109     };
 110     SockAddr addr;
 111     const char *err;
 112     Rlogin rlogin;
 113
 114     rlogin = snew(struct rlogin_tag);
 115     rlogin->fn = &fn_table;
 116     rlogin->s = NULL;
 117     rlogin->frontend = frontend_handle;
 118     rlogin->term_width = cfg->width;
 119     rlogin->term_height = cfg->height;
 120     rlogin->firstbyte = 1;
 121     *backend_handle = rlogin;
 122
 123     /*
 124      * Try to find host.
 125      */
 126     {
 127         char *buf;
 128         buf = dupprintf("Looking up host \"%s\"", host);
 129         logevent(rlogin->frontend, buf);
 130         sfree(buf);
 131     }
 132     addr = name_lookup(host, port, realhost, cfg);
 133     if ((err = sk_addr_error(addr)) != NULL) {
 134         sk_addr_free(addr);
 135         return err;
 136     }
 137
 138     if (port < 0)
 139         port = 513;                    /* default rlogin port */
 140
 141     /*
 142      * Open socket.
 143      */
 144     {
 145         char *buf, addrbuf[100];
 146         sk_getaddr(addr, addrbuf, 100);
 147         buf = dupprintf("Connecting to %s port %d", addrbuf, port);
 148         logevent(rlogin->frontend, buf);
 149         sfree(buf);
 150     }
 151     rlogin->s = new_connection(addr, *realhost, port, 1, 0,
 152                                nodelay, (Plug) rlogin, cfg);
 153     if ((err = sk_socket_error(rlogin->s)) != NULL)
 154         return err;
 155
 156     /*
 157      * Send local username, remote username, terminal/speed
 158      */
 159
 160     {
 161         char z = 0;
 162         char *p;
 163         sk_write(rlogin->s, &z, 1);
 164         sk_write(rlogin->s, cfg->localusername,
 165                  strlen(cfg->localusername));
 166         sk_write(rlogin->s, &z, 1);
 167         sk_write(rlogin->s, cfg->username,
 168                  strlen(cfg->username));
 169         sk_write(rlogin->s, &z, 1);
 170         sk_write(rlogin->s, cfg->termtype,
 171                  strlen(cfg->termtype));
 172         sk_write(rlogin->s, "/", 1);
 173         for (p = cfg->termspeed; isdigit((unsigned char)*p); p++) continue;
 174         sk_write(rlogin->s, cfg->termspeed, p - cfg->termspeed);
 175         rlogin->bufsize = sk_write(rlogin->s, &z, 1);
 176     }
 177
 178     return NULL;
 179 }
 180
 181 static void rlogin_free(void *handle)
 182 {
 183     Rlogin rlogin = (Rlogin) handle;
 184
 185     if (rlogin->s)
 186         sk_close(rlogin->s);
 187     sfree(rlogin);
 188 }
 189
 190 /*
 191  * Stub routine (we don't have any need to reconfigure this backend).
 192  */
 193 static void rlogin_reconfig(void *handle, Config *cfg)
 194 {
 195 }
 196
 197 /*
 198  * Called to send data down the rlogin connection.
 199  */
 200 static int rlogin_send(void *handle, char *buf, int len)
 201 {
 202     Rlogin rlogin = (Rlogin) handle;
 203
 204     if (rlogin->s == NULL)
 205         return 0;
 206
 207     rlogin->bufsize = sk_write(rlogin->s, buf, len);
 208
 209     return rlogin->bufsize;
 210 }
 211
 212 /*
 213  * Called to query the current socket sendability status.
 214  */
 215 static int rlogin_sendbuffer(void *handle)
 216 {
 217     Rlogin rlogin = (Rlogin) handle;
 218     return rlogin->bufsize;
 219 }
 220
 221 /*
 222  * Called to set the size of the window
 223  */
 224 static void rlogin_size(void *handle, int width, int height)
 225 {
 226     Rlogin rlogin = (Rlogin) handle;
 227     char b[12] = { '\xFF', '\xFF', 0x73, 0x73, 0, 0, 0, 0, 0, 0, 0, 0 };
 228
 229     rlogin->term_width = width;
 230     rlogin->term_height = height;
 231
 232     if (rlogin->s == NULL)
 233         return;
 234
 235     b[6] = rlogin->term_width >> 8;
 236     b[7] = rlogin->term_width & 0xFF;
 237     b[4] = rlogin->term_height >> 8;
 238     b[5] = rlogin->term_height & 0xFF;
 239     rlogin->bufsize = sk_write(rlogin->s, b, 12);
 240     return;
 241 }
 242
 243 /*
 244  * Send rlogin special codes.
 245  */
 246 static void rlogin_special(void *handle, Telnet_Special code)
 247 {
 248     /* Do nothing! */
 249     return;
 250 }
 251
 252 /*
 253  * Return a list of the special codes that make sense in this
 254  * protocol.
 255  */
 256 static const struct telnet_special *rlogin_get_specials(void *handle)
 257 {
 258     return NULL;
 259 }
 260
 261 static Socket rlogin_socket(void *handle)
 262 {
 263     Rlogin rlogin = (Rlogin) handle;
 264     return rlogin->s;
 265 }
 266
 267 static int rlogin_sendok(void *handle)
 268 {
 269     /* Rlogin rlogin = (Rlogin) handle; */
 270     return 1;
 271 }
 272
 273 static void rlogin_unthrottle(void *handle, int backlog)
 274 {
 275     Rlogin rlogin = (Rlogin) handle;
 276     sk_set_frozen(rlogin->s, backlog > RLOGIN_MAX_BACKLOG);
 277 }
 278
 279 static int rlogin_ldisc(void *handle, int option)
 280 {
 281     /* Rlogin rlogin = (Rlogin) handle; */
 282     return 0;
 283 }
 284
 285 static void rlogin_provide_ldisc(void *handle, void *ldisc)
 286 {
 287     /* This is a stub. */
 288 }
 289
 290 static void rlogin_provide_logctx(void *handle, void *logctx)
 291 {
 292     /* This is a stub. */
 293 }
 294
 295 static int rlogin_exitcode(void *handle)
 296 {
 297     Rlogin rlogin = (Rlogin) handle;
 298     if (rlogin->s != NULL)
 299         return -1;                     /* still connected */
 300     else
 301         /* If we ever implement RSH, we'll probably need to do this properly */
 302         return 0;
 303 }
 304
 305 Backend rlogin_backend = {
 306     rlogin_init,
 307     rlogin_free,
 308     rlogin_reconfig,
 309     rlogin_send,
 310     rlogin_sendbuffer,
 311     rlogin_size,
 312     rlogin_special,
 313     rlogin_get_specials,
 314     rlogin_socket,
 315     rlogin_exitcode,
 316     rlogin_sendok,
 317     rlogin_ldisc,
 318     rlogin_provide_ldisc,
 319     rlogin_provide_logctx,
 320     rlogin_unthrottle,
 321     1
 322 };