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