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         c_write(data, len);
  72     }
  73     return 1;
  74 }
  75
  76 /*
  77  * Called to set up the rlogin connection.
  78  *
  79  * Returns an error message, or NULL on success.
  80  *
  81  * Also places the canonical host name into `realhost'. It must be
  82  * freed by the caller.
  83  */
  84 static char *rlogin_init(char *host, int port, char **realhost)
  85 {
  86     static struct plug_function_table fn_table = {
  87         rlogin_closing,
  88         rlogin_receive
  89     }, *fn_table_ptr = &fn_table;
  90
  91     SockAddr addr;
  92     char *err;
  93
  94     /*
  95      * Try to find host.
  96      */
  97     addr = sk_namelookup(host, realhost);
  98     if ((err = sk_addr_error(addr)))
  99         return err;
 100
 101     if (port < 0)
 102         port = 513;                    /* default rlogin port */
 103
 104     /*
 105      * Open socket.
 106      */
 107     s = sk_new(addr, port, 1, 0, &fn_table_ptr);
 108     if ((err = sk_socket_error(s)))
 109         return err;
 110
 111     sk_addr_free(addr);
 112
 113     /*
 114      * Send local username, remote username, terminal/speed
 115      */
 116
 117     {
 118         char z = 0;
 119         char *p;
 120         sk_write(s, &z, 1);
 121         sk_write(s, cfg.localusername, strlen(cfg.localusername));
 122         sk_write(s, &z, 1);
 123         sk_write(s, cfg.username, strlen(cfg.username));
 124         sk_write(s, &z, 1);
 125         sk_write(s, cfg.termtype, strlen(cfg.termtype));
 126         sk_write(s, "/", 1);
 127         for (p = cfg.termspeed; isdigit(*p); p++);
 128         sk_write(s, cfg.termspeed, p - cfg.termspeed);
 129         rlogin_bufsize = sk_write(s, &z, 1);
 130     }
 131
 132     return NULL;
 133 }
 134
 135 /*
 136  * Called to send data down the rlogin connection.
 137  */
 138 static int rlogin_send(char *buf, int len)
 139 {
 140     if (s == NULL)
 141         return 0;
 142
 143     rlogin_bufsize = sk_write(s, buf, len);
 144
 145     return rlogin_bufsize;
 146 }
 147
 148 /*
 149  * Called to query the current socket sendability status.
 150  */
 151 static int rlogin_sendbuffer(void)
 152 {
 153     return rlogin_bufsize;
 154 }
 155
 156 /*
 157  * Called to set the size of the window
 158  */
 159 static void rlogin_size(void)
 160 {
 161     char b[12] = { '\xFF', '\xFF', 0x73, 0x73, 0, 0, 0, 0, 0, 0, 0, 0 };
 162
 163     b[6] = cols >> 8;
 164     b[7] = cols & 0xFF;
 165     b[4] = rows >> 8;
 166     b[5] = rows & 0xFF;
 167     rlogin_bufsize = sk_write(s, b, 12);
 168     return;
 169 }
 170
 171 /*
 172  * Send rlogin special codes.
 173  */
 174 static void rlogin_special(Telnet_Special code)
 175 {
 176     /* Do nothing! */
 177     return;
 178 }
 179
 180 static Socket rlogin_socket(void)
 181 {
 182     return s;
 183 }
 184
 185 static int rlogin_sendok(void)
 186 {
 187     return 1;
 188 }
 189
 190 static void rlogin_unthrottle(int backlog)
 191 {
 192     sk_set_frozen(s, backlog > RLOGIN_MAX_BACKLOG);
 193 }
 194
 195 static int rlogin_ldisc(int option)
 196 {
 197     return 0;
 198 }
 199
 200 Backend rlogin_backend = {
 201     rlogin_init,
 202     rlogin_send,
 203     rlogin_sendbuffer,
 204     rlogin_size,
 205     rlogin_special,
 206     rlogin_socket,
 207     rlogin_sendok,
 208     rlogin_ldisc,
 209     rlogin_unthrottle,
 210     1
 211 };