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 static Socket s = NULL;
  18 static int rlogin_bufsize;
  19
  20 static void rlogin_size(void);
  21
  22 static void c_write(char *buf, int len)
  23 {
  24     int backlog = from_backend(0, buf, len);
  25     sk_set_frozen(s, backlog > RLOGIN_MAX_BACKLOG);
  26 }
  27
  28 static int rlogin_closing(Plug plug, char *error_msg, int error_code,
  29                           int calling_back)
  30 {
  31     if (s) {
  32         sk_close(s);
  33         s = NULL;
  34     }
  35     if (error_msg) {
  36         /* A socket error has occurred. */
  37         connection_fatal(error_msg);
  38     }                                  /* Otherwise, the remote side closed the connection normally. */
  39     return 0;
  40 }
  41
  42 static int rlogin_receive(Plug plug, int urgent, char *data, int len)
  43 {
  44     if (urgent == 2) {
  45         char c;
  46
  47         c = *data++;
  48         len--;
  49         if (c == '\x80')
  50             rlogin_size();
  51         /*
  52          * We should flush everything (aka Telnet SYNCH) if we see
  53          * 0x02, and we should turn off and on _local_ flow control
  54          * on 0x10 and 0x20 respectively. I'm not convinced it's
  55          * worth it...
  56          */
  57     } else {
  58         /*
  59          * Main rlogin protocol. This is really simple: the first
  60          * byte is expected to be NULL and is ignored, and the rest
  61          * is printed.
  62          */
  63         static int firstbyte = 1;
  64         if (firstbyte) {
  65             if (data[0] == '\0') {
  66                 data++;
  67                 len--;
  68             }
  69             firstbyte = 0;
  70         }
  71         if (len > 0)
  72             c_write(data, len);
  73     }
  74     return 1;
  75 }
  76
  77 static void rlogin_sent(Plug plug, int bufsize)
  78 {
  79     rlogin_bufsize = bufsize;
  80 }
  81
  82 /*
  83  * Called to set up the rlogin connection.
  84  *
  85  * Returns an error message, or NULL on success.
  86  *
  87  * Also places the canonical host name into `realhost'. It must be
  88  * freed by the caller.
  89  */
  90 static char *rlogin_init(char *host, int port, char **realhost, int nodelay)
  91 {
  92     static struct plug_function_table fn_table = {
  93         rlogin_closing,
  94         rlogin_receive,
  95         rlogin_sent
  96     }, *fn_table_ptr = &fn_table;
  97
  98     SockAddr addr;
  99     char *err;
 100
 101     /*
 102      * Try to find host.
 103      */
 104     {
 105         char buf[200];
 106         sprintf(buf, "Looking up host \"%.170s\"", host);
 107         logevent(buf);
 108     }
 109     addr = sk_namelookup(host, realhost);
 110     if ((err = sk_addr_error(addr)))
 111         return err;
 112
 113     if (port < 0)
 114         port = 513;                    /* default rlogin port */
 115
 116     /*
 117      * Open socket.
 118      */
 119     {
 120         char buf[200], addrbuf[100];
 121         sk_getaddr(addr, addrbuf, 100);
 122         sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
 123         logevent(buf);
 124     }
 125     s = new_connection(addr, *realhost, port, 1, 0, nodelay, &fn_table_ptr);
 126     if ((err = sk_socket_error(s)))
 127         return err;
 128
 129     sk_addr_free(addr);
 130
 131     /*
 132      * Send local username, remote username, terminal/speed
 133      */
 134
 135     {
 136         char z = 0;
 137         char *p;
 138         sk_write(s, &z, 1);
 139         sk_write(s, cfg.localusername, strlen(cfg.localusername));
 140         sk_write(s, &z, 1);
 141         sk_write(s, cfg.username, strlen(cfg.username));
 142         sk_write(s, &z, 1);
 143         sk_write(s, cfg.termtype, strlen(cfg.termtype));
 144         sk_write(s, "/", 1);
 145         for (p = cfg.termspeed; isdigit(*p); p++);
 146         sk_write(s, cfg.termspeed, p - cfg.termspeed);
 147         rlogin_bufsize = sk_write(s, &z, 1);
 148     }
 149
 150     return NULL;
 151 }
 152
 153 /*
 154  * Called to send data down the rlogin connection.
 155  */
 156 static int rlogin_send(char *buf, int len)
 157 {
 158     if (s == NULL)
 159         return 0;
 160
 161     rlogin_bufsize = sk_write(s, buf, len);
 162
 163     return rlogin_bufsize;
 164 }
 165
 166 /*
 167  * Called to query the current socket sendability status.
 168  */
 169 static int rlogin_sendbuffer(void)
 170 {
 171     return rlogin_bufsize;
 172 }
 173
 174 /*
 175  * Called to set the size of the window
 176  */
 177 static void rlogin_size(void)
 178 {
 179     char b[12] = { '\xFF', '\xFF', 0x73, 0x73, 0, 0, 0, 0, 0, 0, 0, 0 };
 180
 181     if (s == NULL)
 182         return;
 183
 184     b[6] = cols >> 8;
 185     b[7] = cols & 0xFF;
 186     b[4] = rows >> 8;
 187     b[5] = rows & 0xFF;
 188     rlogin_bufsize = sk_write(s, b, 12);
 189     return;
 190 }
 191
 192 /*
 193  * Send rlogin special codes.
 194  */
 195 static void rlogin_special(Telnet_Special code)
 196 {
 197     /* Do nothing! */
 198     return;
 199 }
 200
 201 static Socket rlogin_socket(void)
 202 {
 203     return s;
 204 }
 205
 206 static int rlogin_sendok(void)
 207 {
 208     return 1;
 209 }
 210
 211 static void rlogin_unthrottle(int backlog)
 212 {
 213     sk_set_frozen(s, backlog > RLOGIN_MAX_BACKLOG);
 214 }
 215
 216 static int rlogin_ldisc(int option)
 217 {
 218     return 0;
 219 }
 220
 221 static int rlogin_exitcode(void)
 222 {
 223     /* If we ever implement RSH, we'll probably need to do this properly */
 224     return 0;
 225 }
 226
 227 Backend rlogin_backend = {
 228     rlogin_init,
 229     rlogin_send,
 230     rlogin_sendbuffer,
 231     rlogin_size,
 232     rlogin_special,
 233     rlogin_socket,
 234     rlogin_exitcode,
 235     rlogin_sendok,
 236     rlogin_ldisc,
 237     rlogin_unthrottle,
 238     1
 239 };