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

   1 /*
   2  * "Raw" backend.
   3  */
   4
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7
   8 #include "putty.h"
   9
  10 #ifndef FALSE
  11 #define FALSE 0
  12 #endif
  13 #ifndef TRUE
  14 #define TRUE 1
  15 #endif
  16
  17 #define RAW_MAX_BACKLOG 4096
  18
  19 typedef struct raw_backend_data {
  20     const struct plug_function_table *fn;
  21     /* the above field _must_ be first in the structure */
  22
  23     Socket s;
  24     int bufsize;
  25     void *frontend;
  26     int sent_console_eof, sent_socket_eof;
  27 } *Raw;
  28
  29 static void raw_size(void *handle, int width, int height);
  30
  31 static void c_write(Raw raw, char *buf, int len)
  32 {
  33     int backlog = from_backend(raw->frontend, 0, buf, len);
  34     sk_set_frozen(raw->s, backlog > RAW_MAX_BACKLOG);
  35 }
  36
  37 static void raw_log(Plug plug, int type, SockAddr addr, int port,
  38                     const char *error_msg, int error_code)
  39 {
  40     Raw raw = (Raw) plug;
  41     char addrbuf[256], *msg;
  42
  43     sk_getaddr(addr, addrbuf, lenof(addrbuf));
  44
  45     if (type == 0)
  46         msg = dupprintf("Connecting to %s port %d", addrbuf, port);
  47     else
  48         msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
  49
  50     logevent(raw->frontend, msg);
  51 }
  52
  53 static void raw_check_close(Raw raw)
  54 {
  55     /*
  56      * Called after we send EOF on either the socket or the console.
  57      * Its job is to wind up the session once we have sent EOF on both.
  58      */
  59     if (raw->sent_console_eof && raw->sent_socket_eof) {
  60         if (raw->s) {
  61             sk_close(raw->s);
  62             raw->s = NULL;
  63             notify_remote_exit(raw->frontend);
  64         }
  65     }
  66 }
  67
  68 static int raw_closing(Plug plug, const char *error_msg, int error_code,
  69                        int calling_back)
  70 {
  71     Raw raw = (Raw) plug;
  72
  73     if (error_msg) {
  74         /* A socket error has occurred. */
  75         if (raw->s) {
  76             sk_close(raw->s);
  77             raw->s = NULL;
  78             notify_remote_exit(raw->frontend);
  79         }
  80         logevent(raw->frontend, error_msg);
  81         connection_fatal(raw->frontend, "%s", error_msg);
  82     } else {
  83         /* Otherwise, the remote side closed the connection normally. */
  84         if (!raw->sent_console_eof && from_backend_eof(raw->frontend)) {
  85             /*
  86              * The front end wants us to close the outgoing side of the
  87              * connection as soon as we see EOF from the far end.
  88              */
  89             if (!raw->sent_socket_eof) {
  90                 if (raw->s)
  91                     sk_write_eof(raw->s);
  92                 raw->sent_socket_eof= TRUE;
  93             }
  94         }
  95         raw->sent_console_eof = TRUE;
  96         raw_check_close(raw);
  97     }
  98     return 0;
  99 }
 100
 101 static int raw_receive(Plug plug, int urgent, char *data, int len)
 102 {
 103     Raw raw = (Raw) plug;
 104     c_write(raw, data, len);
 105     return 1;
 106 }
 107
 108 static void raw_sent(Plug plug, int bufsize)
 109 {
 110     Raw raw = (Raw) plug;
 111     raw->bufsize = bufsize;
 112 }
 113
 114 /*
 115  * Called to set up the raw connection.
 116  *
 117  * Returns an error message, or NULL on success.
 118  *
 119  * Also places the canonical host name into `realhost'. It must be
 120  * freed by the caller.
 121  */
 122 static const char *raw_init(void *frontend_handle, void **backend_handle,
 123                             Conf *conf,
 124                             char *host, int port, char **realhost, int nodelay,
 125                             int keepalive)
 126 {
 127     static const struct plug_function_table fn_table = {
 128         raw_log,
 129         raw_closing,
 130         raw_receive,
 131         raw_sent
 132     };
 133     SockAddr addr;
 134     const char *err;
 135     Raw raw;
 136     int addressfamily;
 137     char *loghost;
 138
 139     raw = snew(struct raw_backend_data);
 140     raw->fn = &fn_table;
 141     raw->s = NULL;
 142     *backend_handle = raw;
 143     raw->sent_console_eof = raw->sent_socket_eof = FALSE;
 144
 145     raw->frontend = frontend_handle;
 146
 147     addressfamily = conf_get_int(conf, CONF_addressfamily);
 148     /*
 149      * Try to find host.
 150      */
 151     {
 152         char *buf;
 153         buf = dupprintf("Looking up host \"%s\"%s", host,
 154                         (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
 155                          (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" :
 156                           "")));
 157         logevent(raw->frontend, buf);
 158         sfree(buf);
 159     }
 160     addr = name_lookup(host, port, realhost, conf, addressfamily);
 161     if ((err = sk_addr_error(addr)) != NULL) {
 162         sk_addr_free(addr);
 163         return err;
 164     }
 165
 166     if (port < 0)
 167         port = 23;                     /* default telnet port */
 168
 169     /*
 170      * Open socket.
 171      */
 172     raw->s = new_connection(addr, *realhost, port, 0, 1, nodelay, keepalive,
 173                             (Plug) raw, conf);
 174     if ((err = sk_socket_error(raw->s)) != NULL)
 175         return err;
 176
 177     loghost = conf_get_str(conf, CONF_loghost);
 178     if (*loghost) {
 179         char *colon;
 180
 181         sfree(*realhost);
 182         *realhost = dupstr(loghost);
 183         colon = strrchr(*realhost, ':');
 184         if (colon) {
 185             /*
 186              * FIXME: if we ever update this aspect of ssh.c for
 187              * IPv6 literal management, this should change in line
 188              * with it.
 189              */
 190             *colon++ = '\0';
 191         }
 192     }
 193
 194     return NULL;
 195 }
 196
 197 static void raw_free(void *handle)
 198 {
 199     Raw raw = (Raw) handle;
 200
 201     if (raw->s)
 202         sk_close(raw->s);
 203     sfree(raw);
 204 }
 205
 206 /*
 207  * Stub routine (we don't have any need to reconfigure this backend).
 208  */
 209 static void raw_reconfig(void *handle, Conf *conf)
 210 {
 211 }
 212
 213 /*
 214  * Called to send data down the raw connection.
 215  */
 216 static int raw_send(void *handle, char *buf, int len)
 217 {
 218     Raw raw = (Raw) handle;
 219
 220     if (raw->s == NULL)
 221         return 0;
 222
 223     raw->bufsize = sk_write(raw->s, buf, len);
 224
 225     return raw->bufsize;
 226 }
 227
 228 /*
 229  * Called to query the current socket sendability status.
 230  */
 231 static int raw_sendbuffer(void *handle)
 232 {
 233     Raw raw = (Raw) handle;
 234     return raw->bufsize;
 235 }
 236
 237 /*
 238  * Called to set the size of the window
 239  */
 240 static void raw_size(void *handle, int width, int height)
 241 {
 242     /* Do nothing! */
 243     return;
 244 }
 245
 246 /*
 247  * Send raw special codes. We only handle outgoing EOF here.
 248  */
 249 static void raw_special(void *handle, Telnet_Special code)
 250 {
 251     Raw raw = (Raw) handle;
 252     if (code == TS_EOF && raw->s) {
 253         sk_write_eof(raw->s);
 254         raw->sent_socket_eof= TRUE;
 255         raw_check_close(raw);
 256     }
 257
 258     return;
 259 }
 260
 261 /*
 262  * Return a list of the special codes that make sense in this
 263  * protocol.
 264  */
 265 static const struct telnet_special *raw_get_specials(void *handle)
 266 {
 267     return NULL;
 268 }
 269
 270 static int raw_connected(void *handle)
 271 {
 272     Raw raw = (Raw) handle;
 273     return raw->s != NULL;
 274 }
 275
 276 static int raw_sendok(void *handle)
 277 {
 278     return 1;
 279 }
 280
 281 static void raw_unthrottle(void *handle, int backlog)
 282 {
 283     Raw raw = (Raw) handle;
 284     sk_set_frozen(raw->s, backlog > RAW_MAX_BACKLOG);
 285 }
 286
 287 static int raw_ldisc(void *handle, int option)
 288 {
 289     if (option == LD_EDIT || option == LD_ECHO)
 290         return 1;
 291     return 0;
 292 }
 293
 294 static void raw_provide_ldisc(void *handle, void *ldisc)
 295 {
 296     /* This is a stub. */
 297 }
 298
 299 static void raw_provide_logctx(void *handle, void *logctx)
 300 {
 301     /* This is a stub. */
 302 }
 303
 304 static int raw_exitcode(void *handle)
 305 {
 306     Raw raw = (Raw) handle;
 307     if (raw->s != NULL)
 308         return -1;                     /* still connected */
 309     else
 310         /* Exit codes are a meaningless concept in the Raw protocol */
 311         return 0;
 312 }
 313
 314 /*
 315  * cfg_info for Raw does nothing at all.
 316  */
 317 static int raw_cfg_info(void *handle)
 318 {
 319     return 0;
 320 }
 321
 322 Backend raw_backend = {
 323     raw_init,
 324     raw_free,
 325     raw_reconfig,
 326     raw_send,
 327     raw_sendbuffer,
 328     raw_size,
 329     raw_special,
 330     raw_get_specials,
 331     raw_connected,
 332     raw_exitcode,
 333     raw_sendok,
 334     raw_ldisc,
 335     raw_provide_ldisc,
 336     raw_provide_logctx,
 337     raw_unthrottle,
 338     raw_cfg_info,
 339     "raw",
 340     PROT_RAW,
 341     0
 342 };