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 } *Raw;
  27
  28 static void raw_size(void *handle, int width, int height);
  29
  30 static void c_write(Raw raw, char *buf, int len)
  31 {
  32     int backlog = from_backend(raw->frontend, 0, buf, len);
  33     sk_set_frozen(raw->s, backlog > RAW_MAX_BACKLOG);
  34 }
  35
  36 static void raw_log(Plug plug, int type, SockAddr addr, int port,
  37                     const char *error_msg, int error_code)
  38 {
  39     Raw raw = (Raw) plug;
  40     char addrbuf[256], *msg;
  41
  42     sk_getaddr(addr, addrbuf, lenof(addrbuf));
  43
  44     if (type == 0)
  45         msg = dupprintf("Connecting to %s port %d", addrbuf, port);
  46     else
  47         msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
  48
  49     logevent(raw->frontend, msg);
  50 }
  51
  52 static int raw_closing(Plug plug, const char *error_msg, int error_code,
  53                        int calling_back)
  54 {
  55     Raw raw = (Raw) plug;
  56
  57     if (raw->s) {
  58         sk_close(raw->s);
  59         raw->s = NULL;
  60         notify_remote_exit(raw->frontend);
  61     }
  62     if (error_msg) {
  63         /* A socket error has occurred. */
  64         logevent(raw->frontend, error_msg);
  65         connection_fatal(raw->frontend, "%s", error_msg);
  66     }                                  /* Otherwise, the remote side closed the connection normally. */
  67     return 0;
  68 }
  69
  70 static int raw_receive(Plug plug, int urgent, char *data, int len)
  71 {
  72     Raw raw = (Raw) plug;
  73     c_write(raw, data, len);
  74     return 1;
  75 }
  76
  77 static void raw_sent(Plug plug, int bufsize)
  78 {
  79     Raw raw = (Raw) plug;
  80     raw->bufsize = bufsize;
  81 }
  82
  83 /*
  84  * Called to set up the raw connection.
  85  *
  86  * Returns an error message, or NULL on success.
  87  *
  88  * Also places the canonical host name into `realhost'. It must be
  89  * freed by the caller.
  90  */
  91 static const char *raw_init(void *frontend_handle, void **backend_handle,
  92                             Config *cfg,
  93                             char *host, int port, char **realhost, int nodelay,
  94                             int keepalive)
  95 {
  96     static const struct plug_function_table fn_table = {
  97         raw_log,
  98         raw_closing,
  99         raw_receive,
 100         raw_sent
 101     };
 102     SockAddr addr;
 103     const char *err;
 104     Raw raw;
 105
 106     raw = snew(struct raw_backend_data);
 107     raw->fn = &fn_table;
 108     raw->s = NULL;
 109     *backend_handle = raw;
 110
 111     raw->frontend = frontend_handle;
 112
 113     /*
 114      * Try to find host.
 115      */
 116     {
 117         char *buf;
 118         buf = dupprintf("Looking up host \"%s\"%s", host,
 119                         (cfg->addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
 120                          (cfg->addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" :
 121                           "")));
 122         logevent(raw->frontend, buf);
 123         sfree(buf);
 124     }
 125     addr = name_lookup(host, port, realhost, cfg, cfg->addressfamily);
 126     if ((err = sk_addr_error(addr)) != NULL) {
 127         sk_addr_free(addr);
 128         return err;
 129     }
 130
 131     if (port < 0)
 132         port = 23;                     /* default telnet port */
 133
 134     /*
 135      * Open socket.
 136      */
 137     raw->s = new_connection(addr, *realhost, port, 0, 1, nodelay, keepalive,
 138                             (Plug) raw, cfg);
 139     if ((err = sk_socket_error(raw->s)) != NULL)
 140         return err;
 141
 142     return NULL;
 143 }
 144
 145 static void raw_free(void *handle)
 146 {
 147     Raw raw = (Raw) handle;
 148
 149     if (raw->s)
 150         sk_close(raw->s);
 151     sfree(raw);
 152 }
 153
 154 /*
 155  * Stub routine (we don't have any need to reconfigure this backend).
 156  */
 157 static void raw_reconfig(void *handle, Config *cfg)
 158 {
 159 }
 160
 161 /*
 162  * Called to send data down the raw connection.
 163  */
 164 static int raw_send(void *handle, char *buf, int len)
 165 {
 166     Raw raw = (Raw) handle;
 167
 168     if (raw->s == NULL)
 169         return 0;
 170
 171     raw->bufsize = sk_write(raw->s, buf, len);
 172
 173     return raw->bufsize;
 174 }
 175
 176 /*
 177  * Called to query the current socket sendability status.
 178  */
 179 static int raw_sendbuffer(void *handle)
 180 {
 181     Raw raw = (Raw) handle;
 182     return raw->bufsize;
 183 }
 184
 185 /*
 186  * Called to set the size of the window
 187  */
 188 static void raw_size(void *handle, int width, int height)
 189 {
 190     /* Do nothing! */
 191     return;
 192 }
 193
 194 /*
 195  * Send raw special codes.
 196  */
 197 static void raw_special(void *handle, Telnet_Special code)
 198 {
 199     /* Do nothing! */
 200     return;
 201 }
 202
 203 /*
 204  * Return a list of the special codes that make sense in this
 205  * protocol.
 206  */
 207 static const struct telnet_special *raw_get_specials(void *handle)
 208 {
 209     return NULL;
 210 }
 211
 212 static int raw_connected(void *handle)
 213 {
 214     Raw raw = (Raw) handle;
 215     return raw->s != NULL;
 216 }
 217
 218 static int raw_sendok(void *handle)
 219 {
 220     return 1;
 221 }
 222
 223 static void raw_unthrottle(void *handle, int backlog)
 224 {
 225     Raw raw = (Raw) handle;
 226     sk_set_frozen(raw->s, backlog > RAW_MAX_BACKLOG);
 227 }
 228
 229 static int raw_ldisc(void *handle, int option)
 230 {
 231     if (option == LD_EDIT || option == LD_ECHO)
 232         return 1;
 233     return 0;
 234 }
 235
 236 static void raw_provide_ldisc(void *handle, void *ldisc)
 237 {
 238     /* This is a stub. */
 239 }
 240
 241 static void raw_provide_logctx(void *handle, void *logctx)
 242 {
 243     /* This is a stub. */
 244 }
 245
 246 static int raw_exitcode(void *handle)
 247 {
 248     Raw raw = (Raw) handle;
 249     if (raw->s != NULL)
 250         return -1;                     /* still connected */
 251     else
 252         /* Exit codes are a meaningless concept in the Raw protocol */
 253         return 0;
 254 }
 255
 256 /*
 257  * cfg_info for Raw does nothing at all.
 258  */
 259 static int raw_cfg_info(void *handle)
 260 {
 261     return 0;
 262 }
 263
 264 Backend raw_backend = {
 265     raw_init,
 266     raw_free,
 267     raw_reconfig,
 268     raw_send,
 269     raw_sendbuffer,
 270     raw_size,
 271     raw_special,
 272     raw_get_specials,
 273     raw_connected,
 274     raw_exitcode,
 275     raw_sendok,
 276     raw_ldisc,
 277     raw_provide_ldisc,
 278     raw_provide_logctx,
 279     raw_unthrottle,
 280     raw_cfg_info,
 281     "raw",
 282     PROT_RAW,
 283     0
 284 };