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     sfree(msg);
  54 }
  55
  56 static void raw_check_close(Raw raw)
  57 {
  58     /*
  59      * Called after we send EOF on either the socket or the console.
  60      * Its job is to wind up the session once we have sent EOF on both.
  61      */
  62     if (raw->sent_console_eof && raw->sent_socket_eof) {
  63         if (raw->s) {
  64             sk_close(raw->s);
  65             raw->s = NULL;
  66             notify_remote_exit(raw->frontend);
  67         }
  68     }
  69 }
  70
  71 static int raw_closing(Plug plug, const char *error_msg, int error_code,
  72                        int calling_back)
  73 {
  74     Raw raw = (Raw) plug;
  75
  76     if (error_msg) {
  77         /* A socket error has occurred. */
  78         if (raw->s) {
  79             sk_close(raw->s);
  80             raw->s = NULL;
  81             raw->closed_on_socket_error = TRUE;
  82             notify_remote_exit(raw->frontend);
  83         }
  84         logevent(raw->frontend, error_msg);
  85         connection_fatal(raw->frontend, "%s", error_msg);
  86     } else {
  87         /* Otherwise, the remote side closed the connection normally. */
  88         if (!raw->sent_console_eof && from_backend_eof(raw->frontend)) {
  89             /*
  90              * The front end wants us to close the outgoing side of the
  91              * connection as soon as we see EOF from the far end.
  92              */
  93             if (!raw->sent_socket_eof) {
  94                 if (raw->s)
  95                     sk_write_eof(raw->s);
  96                 raw->sent_socket_eof= TRUE;
  97             }
  98         }
  99         raw->sent_console_eof = TRUE;
 100         raw_check_close(raw);
 101     }
 102     return 0;
 103 }
 104
 105 static int raw_receive(Plug plug, int urgent, char *data, int len)
 106 {
 107     Raw raw = (Raw) plug;
 108     c_write(raw, data, len);
 109     return 1;
 110 }
 111
 112 static void raw_sent(Plug plug, int bufsize)
 113 {
 114     Raw raw = (Raw) plug;
 115     raw->bufsize = bufsize;
 116 }
 117
 118 /*
 119  * Called to set up the raw connection.
 120  *
 121  * Returns an error message, or NULL on success.
 122  *
 123  * Also places the canonical host name into `realhost'. It must be
 124  * freed by the caller.
 125  */
 126 static const char *raw_init(void *frontend_handle, void **backend_handle,
 127                             Conf *conf,
 128                             char *host, int port, char **realhost, int nodelay,
 129                             int keepalive)
 130 {
 131     static const struct plug_function_table fn_table = {
 132         raw_log,
 133         raw_closing,
 134         raw_receive,
 135         raw_sent
 136     };
 137     SockAddr addr;
 138     const char *err;
 139     Raw raw;
 140     int addressfamily;
 141     char *loghost;
 142
 143     raw = snew(struct raw_backend_data);
 144     raw->fn = &fn_table;
 145     raw->s = NULL;
 146     raw->closed_on_socket_error = FALSE;
 147     *backend_handle = raw;
 148     raw->sent_console_eof = raw->sent_socket_eof = FALSE;
 149
 150     raw->frontend = frontend_handle;
 151
 152     addressfamily = conf_get_int(conf, CONF_addressfamily);
 153     /*
 154      * Try to find host.
 155      */
 156     {
 157         char *buf;
 158         buf = dupprintf("Looking up host \"%s\"%s", host,
 159                         (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
 160                          (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" :
 161                           "")));
 162         logevent(raw->frontend, buf);
 163         sfree(buf);
 164     }
 165     addr = name_lookup(host, port, realhost, conf, addressfamily);
 166     if ((err = sk_addr_error(addr)) != NULL) {
 167         sk_addr_free(addr);
 168         return err;
 169     }
 170
 171     if (port < 0)
 172         port = 23;                     /* default telnet port */
 173
 174     /*
 175      * Open socket.
 176      */
 177     raw->s = new_connection(addr, *realhost, port, 0, 1, nodelay, keepalive,
 178                             (Plug) raw, conf);
 179     if ((err = sk_socket_error(raw->s)) != NULL)
 180         return err;
 181
 182     loghost = conf_get_str(conf, CONF_loghost);
 183     if (*loghost) {
 184         char *colon;
 185
 186         sfree(*realhost);
 187         *realhost = dupstr(loghost);
 188         colon = strrchr(*realhost, ':');
 189         if (colon) {
 190             /*
 191              * FIXME: if we ever update this aspect of ssh.c for
 192              * IPv6 literal management, this should change in line
 193              * with it.
 194              */
 195             *colon++ = '\0';
 196         }
 197     }
 198
 199     return NULL;
 200 }
 201
 202 static void raw_free(void *handle)
 203 {
 204     Raw raw = (Raw) handle;
 205
 206     if (raw->s)
 207         sk_close(raw->s);
 208     sfree(raw);
 209 }
 210
 211 /*
 212  * Stub routine (we don't have any need to reconfigure this backend).
 213  */
 214 static void raw_reconfig(void *handle, Conf *conf)
 215 {
 216 }
 217
 218 /*
 219  * Called to send data down the raw connection.
 220  */
 221 static int raw_send(void *handle, char *buf, int len)
 222 {
 223     Raw raw = (Raw) handle;
 224
 225     if (raw->s == NULL)
 226         return 0;
 227
 228     raw->bufsize = sk_write(raw->s, buf, len);
 229
 230     return raw->bufsize;
 231 }
 232
 233 /*
 234  * Called to query the current socket sendability status.
 235  */
 236 static int raw_sendbuffer(void *handle)
 237 {
 238     Raw raw = (Raw) handle;
 239     return raw->bufsize;
 240 }
 241
 242 /*
 243  * Called to set the size of the window
 244  */
 245 static void raw_size(void *handle, int width, int height)
 246 {
 247     /* Do nothing! */
 248     return;
 249 }
 250
 251 /*
 252  * Send raw special codes. We only handle outgoing EOF here.
 253  */
 254 static void raw_special(void *handle, Telnet_Special code)
 255 {
 256     Raw raw = (Raw) handle;
 257     if (code == TS_EOF && raw->s) {
 258         sk_write_eof(raw->s);
 259         raw->sent_socket_eof= TRUE;
 260         raw_check_close(raw);
 261     }
 262
 263     return;
 264 }
 265
 266 /*
 267  * Return a list of the special codes that make sense in this
 268  * protocol.
 269  */
 270 static const struct telnet_special *raw_get_specials(void *handle)
 271 {
 272     return NULL;
 273 }
 274
 275 static int raw_connected(void *handle)
 276 {
 277     Raw raw = (Raw) handle;
 278     return raw->s != NULL;
 279 }
 280
 281 static int raw_sendok(void *handle)
 282 {
 283     return 1;
 284 }
 285
 286 static void raw_unthrottle(void *handle, int backlog)
 287 {
 288     Raw raw = (Raw) handle;
 289     sk_set_frozen(raw->s, backlog > RAW_MAX_BACKLOG);
 290 }
 291
 292 static int raw_ldisc(void *handle, int option)
 293 {
 294     if (option == LD_EDIT || option == LD_ECHO)
 295         return 1;
 296     return 0;
 297 }
 298
 299 static void raw_provide_ldisc(void *handle, void *ldisc)
 300 {
 301     /* This is a stub. */
 302 }
 303
 304 static void raw_provide_logctx(void *handle, void *logctx)
 305 {
 306     /* This is a stub. */
 307 }
 308
 309 static int raw_exitcode(void *handle)
 310 {
 311     Raw raw = (Raw) handle;
 312     if (raw->s != NULL)
 313         return -1;                     /* still connected */
 314     else if (raw->closed_on_socket_error)
 315         return INT_MAX;     /* a socket error counts as an unclean exit */
 316     else
 317         /* Exit codes are a meaningless concept in the Raw protocol */
 318         return 0;
 319 }
 320
 321 /*
 322  * cfg_info for Raw does nothing at all.
 323  */
 324 static int raw_cfg_info(void *handle)
 325 {
 326     return 0;
 327 }
 328
 329 Backend raw_backend = {
 330     raw_init,
 331     raw_free,
 332     raw_reconfig,
 333     raw_send,
 334     raw_sendbuffer,
 335     raw_size,
 336     raw_special,
 337     raw_get_specials,
 338     raw_connected,
 339     raw_exitcode,
 340     raw_sendok,
 341     raw_ldisc,
 342     raw_provide_ldisc,
 343     raw_provide_logctx,
 344     raw_unthrottle,
 345     raw_cfg_info,
 346     "raw",
 347     PROT_RAW,
 348     0
 349 };