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

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3
   4 #include "putty.h"
   5
   6 #ifndef FALSE
   7 #define FALSE 0
   8 #endif
   9 #ifndef TRUE
  10 #define TRUE 1
  11 #endif
  12
  13 #define RAW_MAX_BACKLOG 4096
  14
  15 typedef struct raw_backend_data {
  16     const struct plug_function_table *fn;
  17     /* the above field _must_ be first in the structure */
  18
  19     Socket s;
  20     int bufsize;
  21     void *frontend;
  22 } *Raw;
  23
  24 static void raw_size(void *handle, int width, int height);
  25
  26 static void c_write(Raw raw, char *buf, int len)
  27 {
  28     int backlog = from_backend(raw->frontend, 0, buf, len);
  29     sk_set_frozen(raw->s, backlog > RAW_MAX_BACKLOG);
  30 }
  31
  32 static int raw_closing(Plug plug, const char *error_msg, int error_code,
  33                        int calling_back)
  34 {
  35     Raw raw = (Raw) plug;
  36
  37     if (raw->s) {
  38         sk_close(raw->s);
  39         raw->s = NULL;
  40         notify_remote_exit(raw->frontend);
  41     }
  42     if (error_msg) {
  43         /* A socket error has occurred. */
  44         logevent(raw->frontend, error_msg);
  45         connection_fatal(raw->frontend, "%s", error_msg);
  46     }                                  /* Otherwise, the remote side closed the connection normally. */
  47     return 0;
  48 }
  49
  50 static int raw_receive(Plug plug, int urgent, char *data, int len)
  51 {
  52     Raw raw = (Raw) plug;
  53     c_write(raw, data, len);
  54     return 1;
  55 }
  56
  57 static void raw_sent(Plug plug, int bufsize)
  58 {
  59     Raw raw = (Raw) plug;
  60     raw->bufsize = bufsize;
  61 }
  62
  63 /*
  64  * Called to set up the raw connection.
  65  *
  66  * Returns an error message, or NULL on success.
  67  *
  68  * Also places the canonical host name into `realhost'. It must be
  69  * freed by the caller.
  70  */
  71 static const char *raw_init(void *frontend_handle, void **backend_handle,
  72                             Config *cfg,
  73                             char *host, int port, char **realhost, int nodelay,
  74                             int keepalive)
  75 {
  76     static const struct plug_function_table fn_table = {
  77         raw_closing,
  78         raw_receive,
  79         raw_sent
  80     };
  81     SockAddr addr;
  82     const char *err;
  83     Raw raw;
  84
  85     raw = snew(struct raw_backend_data);
  86     raw->fn = &fn_table;
  87     raw->s = NULL;
  88     *backend_handle = raw;
  89
  90     raw->frontend = frontend_handle;
  91
  92     /*
  93      * Try to find host.
  94      */
  95     {
  96         char *buf;
  97         buf = dupprintf("Looking up host \"%s\"", host);
  98         logevent(raw->frontend, buf);
  99         sfree(buf);
 100     }
 101     addr = name_lookup(host, port, realhost, cfg);
 102     if ((err = sk_addr_error(addr)) != NULL) {
 103         sk_addr_free(addr);
 104         return err;
 105     }
 106
 107     if (port < 0)
 108         port = 23;                     /* default telnet port */
 109
 110     /*
 111      * Open socket.
 112      */
 113     {
 114         char *buf, addrbuf[100];
 115         sk_getaddr(addr, addrbuf, 100);
 116         buf = dupprintf("Connecting to %s port %d", addrbuf, port);
 117         logevent(raw->frontend, buf);
 118         sfree(buf);
 119     }
 120     raw->s = new_connection(addr, *realhost, port, 0, 1, nodelay, keepalive,
 121                             (Plug) raw, cfg);
 122     if ((err = sk_socket_error(raw->s)) != NULL)
 123         return err;
 124
 125     return NULL;
 126 }
 127
 128 static void raw_free(void *handle)
 129 {
 130     Raw raw = (Raw) handle;
 131
 132     if (raw->s)
 133         sk_close(raw->s);
 134     sfree(raw);
 135 }
 136
 137 /*
 138  * Stub routine (we don't have any need to reconfigure this backend).
 139  */
 140 static void raw_reconfig(void *handle, Config *cfg)
 141 {
 142 }
 143
 144 /*
 145  * Called to send data down the raw connection.
 146  */
 147 static int raw_send(void *handle, char *buf, int len)
 148 {
 149     Raw raw = (Raw) handle;
 150
 151     if (raw->s == NULL)
 152         return 0;
 153
 154     raw->bufsize = sk_write(raw->s, buf, len);
 155
 156     return raw->bufsize;
 157 }
 158
 159 /*
 160  * Called to query the current socket sendability status.
 161  */
 162 static int raw_sendbuffer(void *handle)
 163 {
 164     Raw raw = (Raw) handle;
 165     return raw->bufsize;
 166 }
 167
 168 /*
 169  * Called to set the size of the window
 170  */
 171 static void raw_size(void *handle, int width, int height)
 172 {
 173     /* Do nothing! */
 174     return;
 175 }
 176
 177 /*
 178  * Send raw special codes.
 179  */
 180 static void raw_special(void *handle, Telnet_Special code)
 181 {
 182     /* Do nothing! */
 183     return;
 184 }
 185
 186 /*
 187  * Return a list of the special codes that make sense in this
 188  * protocol.
 189  */
 190 static const struct telnet_special *raw_get_specials(void *handle)
 191 {
 192     return NULL;
 193 }
 194
 195 static Socket raw_socket(void *handle)
 196 {
 197     Raw raw = (Raw) handle;
 198     return raw->s;
 199 }
 200
 201 static int raw_sendok(void *handle)
 202 {
 203     return 1;
 204 }
 205
 206 static void raw_unthrottle(void *handle, int backlog)
 207 {
 208     Raw raw = (Raw) handle;
 209     sk_set_frozen(raw->s, backlog > RAW_MAX_BACKLOG);
 210 }
 211
 212 static int raw_ldisc(void *handle, int option)
 213 {
 214     if (option == LD_EDIT || option == LD_ECHO)
 215         return 1;
 216     return 0;
 217 }
 218
 219 static void raw_provide_ldisc(void *handle, void *ldisc)
 220 {
 221     /* This is a stub. */
 222 }
 223
 224 static void raw_provide_logctx(void *handle, void *logctx)
 225 {
 226     /* This is a stub. */
 227 }
 228
 229 static int raw_exitcode(void *handle)
 230 {
 231     Raw raw = (Raw) handle;
 232     if (raw->s != NULL)
 233         return -1;                     /* still connected */
 234     else
 235         /* Exit codes are a meaningless concept in the Raw protocol */
 236         return 0;
 237 }
 238
 239 Backend raw_backend = {
 240     raw_init,
 241     raw_free,
 242     raw_reconfig,
 243     raw_send,
 244     raw_sendbuffer,
 245     raw_size,
 246     raw_special,
 247     raw_get_specials,
 248     raw_socket,
 249     raw_exitcode,
 250     raw_sendok,
 251     raw_ldisc,
 252     raw_provide_ldisc,
 253     raw_provide_logctx,
 254     raw_unthrottle,
 255     1
 256 };