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                          char *host, int port, char **realhost, int nodelay)
 102 {
 103     static const struct plug_function_table fn_table = {
 104         rlogin_closing,
 105         rlogin_receive,
 106         rlogin_sent
 107     };
 108     SockAddr addr;
 109     char *err;
 110     Rlogin rlogin;
 111
 112     rlogin = smalloc(sizeof(*rlogin));
 113     rlogin->fn = &fn_table;
 114     rlogin->s = NULL;
 115     rlogin->frontend = frontend_handle;
 116     rlogin->term_width = cfg.width;
 117     rlogin->term_height = cfg.height;
 118     *backend_handle = rlogin;
 119
 120     /*
 121      * Try to find host.
 122      */
 123     {
 124         char *buf;
 125         buf = dupprintf("Looking up host \"%s\"", host);
 126         logevent(rlogin->frontend, buf);
 127         sfree(buf);
 128     }
 129     addr = name_lookup(host, port, realhost);
 130     if ((err = sk_addr_error(addr)))
 131         return err;
 132
 133     if (port < 0)
 134         port = 513;                    /* default rlogin port */
 135
 136     /*
 137      * Open socket.
 138      */
 139     {
 140         char *buf, addrbuf[100];
 141         sk_getaddr(addr, addrbuf, 100);
 142         buf = dupprintf("Connecting to %s port %d", addrbuf, port);
 143         logevent(rlogin->frontend, buf);
 144         sfree(buf);
 145     }
 146     rlogin->s = new_connection(addr, *realhost, port, 1, 0,
 147                                nodelay, (Plug) rlogin);
 148     if ((err = sk_socket_error(rlogin->s)))
 149         return err;
 150
 151     sk_addr_free(addr);
 152
 153     /*
 154      * Send local username, remote username, terminal/speed
 155      */
 156
 157     {
 158         char z = 0;
 159         char *p;
 160         sk_write(rlogin->s, &z, 1);
 161         sk_write(rlogin->s, cfg.localusername, strlen(cfg.localusername));
 162         sk_write(rlogin->s, &z, 1);
 163         sk_write(rlogin->s, cfg.username, strlen(cfg.username));
 164         sk_write(rlogin->s, &z, 1);
 165         sk_write(rlogin->s, cfg.termtype, strlen(cfg.termtype));
 166         sk_write(rlogin->s, "/", 1);
 167         for (p = cfg.termspeed; isdigit(*p); p++);
 168         sk_write(rlogin->s, cfg.termspeed, p - cfg.termspeed);
 169         rlogin->bufsize = sk_write(rlogin->s, &z, 1);
 170     }
 171
 172     return NULL;
 173 }
 174
 175 /*
 176  * Called to send data down the rlogin connection.
 177  */
 178 static int rlogin_send(void *handle, char *buf, int len)
 179 {
 180     Rlogin rlogin = (Rlogin) handle;
 181
 182     if (rlogin->s == NULL)
 183         return 0;
 184
 185     rlogin->bufsize = sk_write(rlogin->s, buf, len);
 186
 187     return rlogin->bufsize;
 188 }
 189
 190 /*
 191  * Called to query the current socket sendability status.
 192  */
 193 static int rlogin_sendbuffer(void *handle)
 194 {
 195     Rlogin rlogin = (Rlogin) handle;
 196     return rlogin->bufsize;
 197 }
 198
 199 /*
 200  * Called to set the size of the window
 201  */
 202 static void rlogin_size(void *handle, int width, int height)
 203 {
 204     Rlogin rlogin = (Rlogin) handle;
 205     char b[12] = { '\xFF', '\xFF', 0x73, 0x73, 0, 0, 0, 0, 0, 0, 0, 0 };
 206
 207     rlogin->term_width = width;
 208     rlogin->term_height = height;
 209
 210     if (rlogin->s == NULL)
 211         return;
 212
 213     b[6] = rlogin->term_width >> 8;
 214     b[7] = rlogin->term_width & 0xFF;
 215     b[4] = rlogin->term_height >> 8;
 216     b[5] = rlogin->term_height & 0xFF;
 217     rlogin->bufsize = sk_write(rlogin->s, b, 12);
 218     return;
 219 }
 220
 221 /*
 222  * Send rlogin special codes.
 223  */
 224 static void rlogin_special(void *handle, Telnet_Special code)
 225 {
 226     /* Do nothing! */
 227     return;
 228 }
 229
 230 static Socket rlogin_socket(void *handle)
 231 {
 232     Rlogin rlogin = (Rlogin) handle;
 233     return rlogin->s;
 234 }
 235
 236 static int rlogin_sendok(void *handle)
 237 {
 238     /* Rlogin rlogin = (Rlogin) handle; */
 239     return 1;
 240 }
 241
 242 static void rlogin_unthrottle(void *handle, int backlog)
 243 {
 244     Rlogin rlogin = (Rlogin) handle;
 245     sk_set_frozen(rlogin->s, backlog > RLOGIN_MAX_BACKLOG);
 246 }
 247
 248 static int rlogin_ldisc(void *handle, int option)
 249 {
 250     /* Rlogin rlogin = (Rlogin) handle; */
 251     return 0;
 252 }
 253
 254 static void rlogin_provide_ldisc(void *handle, void *ldisc)
 255 {
 256     /* This is a stub. */
 257 }
 258
 259 static void rlogin_provide_logctx(void *handle, void *logctx)
 260 {
 261     /* This is a stub. */
 262 }
 263
 264 static int rlogin_exitcode(void *handle)
 265 {
 266     /* Rlogin rlogin = (Rlogin) handle; */
 267     /* If we ever implement RSH, we'll probably need to do this properly */
 268     return 0;
 269 }
 270
 271 Backend rlogin_backend = {
 272     rlogin_init,
 273     rlogin_send,
 274     rlogin_sendbuffer,
 275     rlogin_size,
 276     rlogin_special,
 277     rlogin_socket,
 278     rlogin_exitcode,
 279     rlogin_sendok,
 280     rlogin_ldisc,
 281     rlogin_provide_ldisc,
 282     rlogin_provide_logctx,
 283     rlogin_unthrottle,
 284     1
 285 };