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 #include <limits.h>
   8
   9 #include "putty.h"
  10
  11 #ifndef FALSE
  12 #define FALSE 0
  13 #endif
  14 #ifndef TRUE
  15 #define TRUE 1
  16 #endif
  17
  18 #define RAW_MAX_BACKLOG 4096
  19
  20 typedef struct raw_backend_data {
  21     const struct plug_function_table *fn;
  22     /* the above field _must_ be first in the structure */
  23
  24     Socket s;
  25     int closed_on_socket_error;
  26     int bufsize;
  27     void *frontend;
  28     int sent_console_eof, sent_socket_eof;
  29 } *Raw;
  30
  31 static void raw_size(void *handle, int width, int height);
  32
  33 static void c_write(Raw raw, char *buf, int len)
  34 {
  35     int backlog = from_backend(raw->frontend, 0, buf, len);
  36     sk_set_frozen(raw->s, backlog > RAW_MAX_BACKLOG);
  37 }
  38
  39 static void raw_log(Plug plug, int type, SockAddr addr, int port,
  40                     const char *error_msg, int error_code)
  41 {
  42     Raw raw = (Raw) plug;
  43     char addrbuf[256], *msg;
  44
  45     sk_getaddr(addr, addrbuf, lenof(addrbuf));
  46
  47     if (type == 0)
  48         msg = dupprintf("Connecting to %s port %d", addrbuf, port);
  49     else
  50         msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
  51
  52     logevent(raw->frontend, msg);
  53 }
  54
  55 static void raw_check_close(Raw raw)
  56 {
  57     /*
  58      * Called after we send EOF on either the socket or the console.
  59      * Its job is to wind up the session once we have sent EOF on both.
  60      */
  61     if (raw->sent_console_eof && raw->sent_socket_eof) {
  62         if (raw->s) {
  63             sk_close(raw->s);
  64             raw->s = NULL;
  65             notify_remote_exit(raw->frontend);
  66         }
  67     }
  68 }
  69
  70 static int raw_closing(Plug plug, const char *error_msg, int error_code,
  71                        int calling_back)
  72 {
  73     Raw raw = (Raw) plug;
  74
  75     if (error_msg) {
  76         /* A socket error has occurred. */
  77         if (raw->s) {
  78             sk_close(raw->s);
  79             raw->s = NULL;
  80             raw->closed_on_socket_error = TRUE;
  81             notify_remote_exit(raw->frontend);
  82         }
  83         logevent(raw->frontend, error_msg);
  84         connection_fatal(raw->frontend, "%s", error_msg);
  85     } else {
  86         /* Otherwise, the remote side closed the connection normally. */
  87         if (!raw->sent_console_eof && from_backend_eof(raw->frontend)) {
  88             /*
  89              * The front end wants us to close the outgoing side of the
  90              * connection as soon as we see EOF from the far end.
  91              */
  92             if (!raw->sent_socket_eof) {
  93                 if (raw->s)
  94                     sk_write_eof(raw->s);
  95                 raw->sent_socket_eof= TRUE;
  96             }
  97         }
  98         raw->sent_console_eof = TRUE;
  99         raw_check_close(raw);
 100     }
 101     return 0;
 102 }
 103
 104 static int raw_receive(Plug plug, int urgent, char *data, int len)
 105 {
 106     Raw raw = (Raw) plug;
 107     c_write(raw, data, len);
 108     return 1;
 109 }
 110
 111 static void raw_sent(Plug plug, int bufsize)
 112 {
 113     Raw raw = (Raw) plug;
 114     raw->bufsize = bufsize;
 115 }
 116
 117 /*
 118  * Called to set up the raw connection.
 119  *
 120  * Returns an error message, or NULL on success.
 121  *
 122  * Also places the canonical host name into `realhost'. It must be
 123  * freed by the caller.
 124  */
 125 static const char *raw_init(void *frontend_handle, void **backend_handle,
 126                             Conf *conf,
 127                             char *host, int port, char **realhost, int nodelay,
 128                             int keepalive)
 129 {
 130     static const struct plug_function_table fn_table = {
 131         raw_log,
 132         raw_closing,
 133         raw_receive,
 134         raw_sent
 135     };
 136     SockAddr addr;
 137     const char *err;
 138     Raw raw;
 139     int addressfamily;
 140     char *loghost;
 141
 142     raw = snew(struct raw_backend_data);
 143     raw->fn = &fn_table;
 144     raw->s = NULL;
 145     raw->closed_on_socket_error = FALSE;
 146     *backend_handle = raw;
 147     raw->sent_console_eof = raw->sent_socket_eof = FALSE;
 148
 149     raw->frontend = frontend_handle;
 150
 151     addressfamily = conf_get_int(conf, CONF_addressfamily);
 152     /*
 153      * Try to find host.
 154      */
 155     {
 156         char *buf;
 157         buf = dupprintf("Looking up host \"%s\"%s", host,
 158                         (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
 159                          (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" :
 160                           "")));
 161         logevent(raw->frontend, buf);
 162         sfree(buf);
 163     }
 164     addr = name_lookup(host, port, realhost, conf, addressfamily);
 165     if ((err = sk_addr_error(addr)) != NULL) {
 166         sk_addr_free(addr);
 167         return err;
 168     }
 169
 170     if (port < 0)
 171         port = 23;                     /* default telnet port */
 172
 173     /*
 174      * Open socket.
 175      */
 176     raw->s = new_connection(addr, *realhost, port, 0, 1, nodelay, keepalive,
 177                             (Plug) raw, conf);
 178     if ((err = sk_socket_error(raw->s)) != NULL)
 179         return err;
 180
 181     loghost = conf_get_str(conf, CONF_loghost);
 182     if (*loghost) {
 183         char *colon;
 184
 185         sfree(*realhost);
 186         *realhost = dupstr(loghost);
 187         colon = strrchr(*realhost, ':');
 188         if (colon) {
 189             /*
 190              * FIXME: if we ever update this aspect of ssh.c for
 191              * IPv6 literal management, this should change in line
 192              * with it.
 193              */
 194             *colon++ = '\0';
 195         }
 196     }
 197
 198     return NULL;
 199 }
 200
 201 static void raw_free(void *handle)
 202 {
 203     Raw raw = (Raw) handle;
 204
 205     if (raw->s)
 206         sk_close(raw->s);
 207     sfree(raw);
 208 }
 209
 210 /*
 211  * Stub routine (we don't have any need to reconfigure this backend).
 212  */
 213 static void raw_reconfig(void *handle, Conf *conf)
 214 {
 215 }
 216
 217 /*
 218  * Called to send data down the raw connection.
 219  */
 220 static int raw_send(void *handle, char *buf, int len)
 221 {
 222     Raw raw = (Raw) handle;
 223
 224     if (raw->s == NULL)
 225         return 0;
 226
 227     raw->bufsize = sk_write(raw->s, buf, len);
 228
 229     return raw->bufsize;
 230 }
 231
 232 /*
 233  * Called to query the current socket sendability status.
 234  */
 235 static int raw_sendbuffer(void *handle)
 236 {
 237     Raw raw = (Raw) handle;
 238     return raw->bufsize;
 239 }
 240
 241 /*
 242  * Called to set the size of the window
 243  */
 244 static void raw_size(void *handle, int width, int height)
 245 {
 246     /* Do nothing! */
 247     return;
 248 }
 249
 250 /*
 251  * Send raw special codes. We only handle outgoing EOF here.
 252  */
 253 static void raw_special(void *handle, Telnet_Special code)
 254 {
 255     Raw raw = (Raw) handle;
 256     if (code == TS_EOF && raw->s) {
 257         sk_write_eof(raw->s);
 258         raw->sent_socket_eof= TRUE;
 259         raw_check_close(raw);
 260     }
 261
 262     return;
 263 }
 264
 265 /*
 266  * Return a list of the special codes that make sense in this
 267  * protocol.
 268  */
 269 static const struct telnet_special *raw_get_specials(void *handle)
 270 {
 271     return NULL;
 272 }
 273
 274 static int raw_connected(void *handle)
 275 {
 276     Raw raw = (Raw) handle;
 277     return raw->s != NULL;
 278 }
 279
 280 static int raw_sendok(void *handle)
 281 {
 282     return 1;
 283 }
 284
 285 static void raw_unthrottle(void *handle, int backlog)
 286 {
 287     Raw raw = (Raw) handle;
 288     sk_set_frozen(raw->s, backlog > RAW_MAX_BACKLOG);
 289 }
 290
 291 static int raw_ldisc(void *handle, int option)
 292 {
 293     if (option == LD_EDIT || option == LD_ECHO)
 294         return 1;
 295     return 0;
 296 }
 297
 298 static void raw_provide_ldisc(void *handle, void *ldisc)
 299 {
 300     /* This is a stub. */
 301 }
 302
 303 static void raw_provide_logctx(void *handle, void *logctx)
 304 {
 305     /* This is a stub. */
 306 }
 307
 308 static int raw_exitcode(void *handle)
 309 {
 310     Raw raw = (Raw) handle;
 311     if (raw->s != NULL)
 312         return -1;                     /* still connected */
 313     else if (raw->closed_on_socket_error)
 314         return INT_MAX;     /* a socket error counts as an unclean exit */
 315     else
 316         /* Exit codes are a meaningless concept in the Raw protocol */
 317         return 0;
 318 }
 319
 320 /*
 321  * cfg_info for Raw does nothing at all.
 322  */
 323 static int raw_cfg_info(void *handle)
 324 {
 325     return 0;
 326 }
 327
 328 Backend raw_backend = {
 329     raw_init,
 330     raw_free,
 331     raw_reconfig,
 332     raw_send,
 333     raw_sendbuffer,
 334     raw_size,
 335     raw_special,
 336     raw_get_specials,
 337     raw_connected,
 338     raw_exitcode,
 339     raw_sendok,
 340     raw_ldisc,
 341     raw_provide_ldisc,
 342     raw_provide_logctx,
 343     raw_unthrottle,
 344     raw_cfg_info,
 345     "raw",
 346     PROT_RAW,
 347     0
 348 };