git.distorted.org.uk Git - u/mdw/putty/blob - rlogin.c

   1 #include <windows.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <ctype.h>
   5
   6 #include "putty.h"
   7
   8 #ifndef FALSE
   9 #define FALSE 0
  10 #endif
  11 #ifndef TRUE
  12 #define TRUE 1
  13 #endif
  14
  15 #define RLOGIN_MAX_BACKLOG 4096
  16
  17 typedef struct rlogin_tag {
  18     const struct plug_function_table *fn;
  19     /* the above field _must_ be first in the structure */
  20
  21     Socket s;
  22     int bufsize;
  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(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         static int firstbyte = 1;
  74         if (firstbyte) {
  75             if (data[0] == '\0') {
  76                 data++;
  77                 len--;
  78             }
  79             firstbyte = 0;
  80         }
  81         if (len > 0)
  82             c_write(rlogin, data, len);
  83     }
  84     return 1;
  85 }
  86
  87 static void rlogin_sent(Plug plug, int bufsize)
  88 {
  89     Rlogin rlogin = (Rlogin) plug;
  90     rlogin->bufsize = bufsize;
  91 }
  92
  93 /*
  94  * Called to set up the rlogin connection.
  95  *
  96  * Returns an error message, or NULL on success.
  97  *
  98  * Also places the canonical host name into `realhost'. It must be
  99  * freed by the caller.
 100  */
 101 static char *rlogin_init(void *frontend_handle, void **backend_handle,
 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[200];
 126         sprintf(buf, "Looking up host \"%.170s\"", host);
 127         logevent(buf);
 128     }
 129     addr = sk_namelookup(host, 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[200], addrbuf[100];
 141         sk_getaddr(addr, addrbuf, 100);
 142         sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
 143         logevent(buf);
 144     }
 145     rlogin->s = new_connection(addr, *realhost, port, 1, 0,
 146                                nodelay, (Plug) rlogin);
 147     if ((err = sk_socket_error(rlogin->s)))
 148         return err;
 149
 150     sk_addr_free(addr);
 151
 152     /*
 153      * Send local username, remote username, terminal/speed
 154      */
 155
 156     {
 157         char z = 0;
 158         char *p;
 159         sk_write(rlogin->s, &z, 1);
 160         sk_write(rlogin->s, cfg.localusername, strlen(cfg.localusername));
 161         sk_write(rlogin->s, &z, 1);
 162         sk_write(rlogin->s, cfg.username, strlen(cfg.username));
 163         sk_write(rlogin->s, &z, 1);
 164         sk_write(rlogin->s, cfg.termtype, strlen(cfg.termtype));
 165         sk_write(rlogin->s, "/", 1);
 166         for (p = cfg.termspeed; isdigit(*p); p++);
 167         sk_write(rlogin->s, cfg.termspeed, p - cfg.termspeed);
 168         rlogin->bufsize = sk_write(rlogin->s, &z, 1);
 169     }
 170
 171     return NULL;
 172 }
 173
 174 /*
 175  * Called to send data down the rlogin connection.
 176  */
 177 static int rlogin_send(void *handle, char *buf, int len)
 178 {
 179     Rlogin rlogin = (Rlogin) handle;
 180
 181     if (rlogin->s == NULL)
 182         return 0;
 183
 184     rlogin->bufsize = sk_write(rlogin->s, buf, len);
 185
 186     return rlogin->bufsize;
 187 }
 188
 189 /*
 190  * Called to query the current socket sendability status.
 191  */
 192 static int rlogin_sendbuffer(void *handle)
 193 {
 194     Rlogin rlogin = (Rlogin) handle;
 195     return rlogin->bufsize;
 196 }
 197
 198 /*
 199  * Called to set the size of the window
 200  */
 201 static void rlogin_size(void *handle, int width, int height)
 202 {
 203     Rlogin rlogin = (Rlogin) handle;
 204     char b[12] = { '\xFF', '\xFF', 0x73, 0x73, 0, 0, 0, 0, 0, 0, 0, 0 };
 205
 206     rlogin->term_width = width;
 207     rlogin->term_height = height;
 208
 209     if (rlogin->s == NULL)
 210         return;
 211
 212     b[6] = rlogin->term_width >> 8;
 213     b[7] = rlogin->term_width & 0xFF;
 214     b[4] = rlogin->term_height >> 8;
 215     b[5] = rlogin->term_height & 0xFF;
 216     rlogin->bufsize = sk_write(rlogin->s, b, 12);
 217     return;
 218 }
 219
 220 /*
 221  * Send rlogin special codes.
 222  */
 223 static void rlogin_special(void *handle, Telnet_Special code)
 224 {
 225     /* Do nothing! */
 226     return;
 227 }
 228
 229 static Socket rlogin_socket(void *handle)
 230 {
 231     Rlogin rlogin = (Rlogin) handle;
 232     return rlogin->s;
 233 }
 234
 235 static int rlogin_sendok(void *handle)
 236 {
 237     Rlogin rlogin = (Rlogin) handle;
 238     return 1;
 239 }
 240
 241 static void rlogin_unthrottle(void *handle, int backlog)
 242 {
 243     Rlogin rlogin = (Rlogin) handle;
 244     sk_set_frozen(rlogin->s, backlog > RLOGIN_MAX_BACKLOG);
 245 }
 246
 247 static int rlogin_ldisc(void *handle, int option)
 248 {
 249     Rlogin rlogin = (Rlogin) handle;
 250     return 0;
 251 }
 252
 253 static void rlogin_provide_ldisc(void *handle, void *ldisc)
 254 {
 255     /* This is a stub. */
 256 }
 257
 258 static int rlogin_exitcode(void *handle)
 259 {
 260     Rlogin rlogin = (Rlogin) handle;
 261     /* If we ever implement RSH, we'll probably need to do this properly */
 262     return 0;
 263 }
 264
 265 Backend rlogin_backend = {
 266     rlogin_init,
 267     rlogin_send,
 268     rlogin_sendbuffer,
 269     rlogin_size,
 270     rlogin_special,
 271     rlogin_socket,
 272     rlogin_exitcode,
 273     rlogin_sendok,
 274     rlogin_ldisc,
 275     rlogin_provide_ldisc,
 276     rlogin_unthrottle,
 277     1
 278 };