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