static Socket s = NULL;
+static void *frontend;
+static int telnet_term_width, telnet_term_height;
+
#define IAC 255 /* interpret as command: */
#define DONT 254 /* you are not to use option */
#define DO 253 /* please, you use option */
&o_we_sga, &o_they_sga, NULL
};
+#define TELNET_MAX_BACKLOG 4096
+
static int echoing = TRUE, editing = TRUE;
static int activated = FALSE;
-
+static int telnet_bufsize;
static int in_synch;
static int sb_opt, sb_len;
static char *sb_buf = NULL;
static void c_write1(int c)
{
+ int backlog;
char cc = (char) c;
- from_backend(0, &cc, 1);
+ backlog = from_backend(frontend, 0, &cc, 1);
+ sk_set_frozen(s, backlog > TELNET_MAX_BACKLOG);
}
static void log_option(char *sender, int cmd, int option)
b[0] = IAC;
b[1] = cmd;
b[2] = option;
- sk_write(s, b, 3);
+ telnet_bufsize = sk_write(s, b, 3);
log_option("client", cmd, option);
}
echoing = !enabled;
else if (o->option == TELOPT_SGA && o->send == DO)
editing = !enabled;
- ldisc_send(NULL, 0); /* cause ldisc to notice the change */
+ ldisc_send(NULL, 0, 0); /* cause ldisc to notice the change */
/* Ensure we get the minimum options */
if (!activated) {
n = 4 + strlen(cfg.termspeed);
b[n] = IAC;
b[n + 1] = SE;
- sk_write(s, b, n + 2);
+ telnet_bufsize = sk_write(s, b, n + 2);
logevent("server:\tSB TSPEED SEND");
sprintf(logbuf, "client:\tSB TSPEED IS %s", cfg.termspeed);
logevent(logbuf);
'a' : cfg.termtype[n]);
b[n + 4] = IAC;
b[n + 5] = SE;
- sk_write(s, b, n + 6);
+ telnet_bufsize = sk_write(s, b, n + 6);
b[n + 4] = 0;
logevent("server:\tSB TTYPE SEND");
sprintf(logbuf, "client:\tSB TTYPE IS %s", b + 4);
}
b[n++] = IAC;
b[n++] = SE;
- sk_write(s, b, n);
+ telnet_bufsize = sk_write(s, b, n);
sprintf(logbuf, "client:\tSB %s IS %s", telopt(sb_opt),
n == 6 ? "<nothing>" : "<stuff>");
logevent(logbuf);
}
static enum {
- TOPLEVEL, SEENIAC, SEENWILL, SEENWONT, SEENDO, SEENDONT,
+ TOP_LEVEL, SEENIAC, SEENWILL, SEENWONT, SEENDO, SEENDONT,
SEENSB, SUBNEGOT, SUBNEG_IAC, SEENCR
-} telnet_state = TOPLEVEL;
+} telnet_state = TOP_LEVEL;
static void do_telnet_read(char *buf, int len)
{
int c = (unsigned char) *buf++;
switch (telnet_state) {
- case TOPLEVEL:
+ case TOP_LEVEL:
case SEENCR:
if (c == NUL && telnet_state == SEENCR)
- telnet_state = TOPLEVEL;
+ telnet_state = TOP_LEVEL;
else if (c == IAC)
telnet_state = SEENIAC;
else {
if (c == CR)
telnet_state = SEENCR;
else
- telnet_state = TOPLEVEL;
+ telnet_state = TOP_LEVEL;
}
break;
case SEENIAC:
telnet_state = SEENSB;
else if (c == DM) {
in_synch = 0;
- telnet_state = TOPLEVEL;
+ telnet_state = TOP_LEVEL;
} else {
/* ignore everything else; print it if it's IAC */
if (c == IAC) {
c_write1(c);
}
- telnet_state = TOPLEVEL;
+ telnet_state = TOP_LEVEL;
}
break;
case SEENWILL:
proc_rec_opt(WILL, c);
- telnet_state = TOPLEVEL;
+ telnet_state = TOP_LEVEL;
break;
case SEENWONT:
proc_rec_opt(WONT, c);
- telnet_state = TOPLEVEL;
+ telnet_state = TOP_LEVEL;
break;
case SEENDO:
proc_rec_opt(DO, c);
- telnet_state = TOPLEVEL;
+ telnet_state = TOP_LEVEL;
break;
case SEENDONT:
proc_rec_opt(DONT, c);
- telnet_state = TOPLEVEL;
+ telnet_state = TOP_LEVEL;
break;
case SEENSB:
sb_opt = c;
goto subneg_addchar; /* yes, it's a hack, I know, but... */
else {
process_subneg();
- telnet_state = TOPLEVEL;
+ telnet_state = TOP_LEVEL;
}
break;
}
static int telnet_closing(Plug plug, char *error_msg, int error_code,
int calling_back)
{
- sk_close(s);
- s = NULL;
+ if (s) {
+ sk_close(s);
+ s = NULL;
+ }
if (error_msg) {
/* A socket error has occurred. */
- connection_fatal(error_msg);
+ logevent(error_msg);
+ connection_fatal("%s", error_msg);
} /* Otherwise, the remote side closed the connection normally. */
return 0;
}
return 1;
}
+static void telnet_sent(Plug plug, int bufsize)
+{
+ telnet_bufsize = bufsize;
+}
+
/*
* Called to set up the Telnet connection.
*
* Returns an error message, or NULL on success.
*
- * Also places the canonical host name into `realhost'.
+ * Also places the canonical host name into `realhost'. It must be
+ * freed by the caller.
*/
-static char *telnet_init(char *host, int port, char **realhost)
+static char *telnet_init(void *frontend_handle,
+ char *host, int port, char **realhost, int nodelay)
{
static struct plug_function_table fn_table = {
telnet_closing,
- telnet_receive
+ telnet_receive,
+ telnet_sent
}, *fn_table_ptr = &fn_table;
SockAddr addr;
char *err;
+ frontend = frontend_handle;
+ telnet_term_width = cfg.width;
+ telnet_term_height = cfg.height;
+
/*
* Try to find host.
*/
+ {
+ char buf[200];
+ sprintf(buf, "Looking up host \"%.170s\"", host);
+ logevent(buf);
+ }
addr = sk_namelookup(host, realhost);
if ((err = sk_addr_error(addr)))
return err;
/*
* Open socket.
*/
- s = sk_new(addr, port, 0, 1, &fn_table_ptr);
+ {
+ char buf[200], addrbuf[100];
+ sk_getaddr(addr, addrbuf, 100);
+ sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
+ logevent(buf);
+ }
+ s = new_connection(addr, *realhost, port, 0, 1, nodelay, &fn_table_ptr);
if ((err = sk_socket_error(s)))
return err;
/*
* Called to send data down the Telnet connection.
*/
-static void telnet_send(char *buf, int len)
+static int telnet_send(char *buf, int len)
{
char *p;
static unsigned char iac[2] = { IAC, IAC };
static unsigned char cr[2] = { CR, NUL };
+#if 0
static unsigned char nl[2] = { CR, LF };
+#endif
if (s == NULL)
- return;
+ return 0;
p = buf;
while (p < buf + len) {
while (iswritable((unsigned char) *p) && p < buf + len)
p++;
- sk_write(s, q, p - q);
+ telnet_bufsize = sk_write(s, q, p - q);
while (p < buf + len && !iswritable((unsigned char) *p)) {
- sk_write(s, (unsigned char) *p == IAC ? iac : nl, 2);
+ telnet_bufsize =
+ sk_write(s, (unsigned char) *p == IAC ? iac : cr, 2);
p++;
}
}
+
+ return telnet_bufsize;
+}
+
+/*
+ * Called to query the current socket sendability status.
+ */
+static int telnet_sendbuffer(void)
+{
+ return telnet_bufsize;
}
/*
* Called to set the size of the window from Telnet's POV.
*/
-static void telnet_size(void)
+static void telnet_size(int width, int height)
{
unsigned char b[16];
char logbuf[50];
+ telnet_term_width = width;
+ telnet_term_height = height;
+
if (s == NULL || o_naws.state != ACTIVE)
return;
b[0] = IAC;
b[1] = SB;
b[2] = TELOPT_NAWS;
- b[3] = cols >> 8;
- b[4] = cols & 0xFF;
- b[5] = rows >> 8;
- b[6] = rows & 0xFF;
+ b[3] = telnet_term_width >> 8;
+ b[4] = telnet_term_width & 0xFF;
+ b[5] = telnet_term_height >> 8;
+ b[6] = telnet_term_height & 0xFF;
b[7] = IAC;
b[8] = SE;
- sk_write(s, b, 9);
+ telnet_bufsize = sk_write(s, b, 9);
sprintf(logbuf, "client:\tSB NAWS %d,%d",
((unsigned char) b[3] << 8) + (unsigned char) b[4],
((unsigned char) b[5] << 8) + (unsigned char) b[6]);
switch (code) {
case TS_AYT:
b[1] = AYT;
- sk_write(s, b, 2);
+ telnet_bufsize = sk_write(s, b, 2);
break;
case TS_BRK:
b[1] = BREAK;
- sk_write(s, b, 2);
+ telnet_bufsize = sk_write(s, b, 2);
break;
case TS_EC:
b[1] = EC;
- sk_write(s, b, 2);
+ telnet_bufsize = sk_write(s, b, 2);
break;
case TS_EL:
b[1] = EL;
- sk_write(s, b, 2);
+ telnet_bufsize = sk_write(s, b, 2);
break;
case TS_GA:
b[1] = GA;
- sk_write(s, b, 2);
+ telnet_bufsize = sk_write(s, b, 2);
break;
case TS_NOP:
b[1] = NOP;
- sk_write(s, b, 2);
+ telnet_bufsize = sk_write(s, b, 2);
break;
case TS_ABORT:
b[1] = ABORT;
- sk_write(s, b, 2);
+ telnet_bufsize = sk_write(s, b, 2);
break;
case TS_AO:
b[1] = AO;
- sk_write(s, b, 2);
+ telnet_bufsize = sk_write(s, b, 2);
break;
case TS_IP:
b[1] = IP;
- sk_write(s, b, 2);
+ telnet_bufsize = sk_write(s, b, 2);
break;
case TS_SUSP:
b[1] = SUSP;
- sk_write(s, b, 2);
+ telnet_bufsize = sk_write(s, b, 2);
break;
case TS_EOR:
b[1] = EOR;
- sk_write(s, b, 2);
+ telnet_bufsize = sk_write(s, b, 2);
break;
case TS_EOF:
b[1] = xEOF;
- sk_write(s, b, 2);
+ telnet_bufsize = sk_write(s, b, 2);
+ break;
+ case TS_EOL:
+ telnet_bufsize = sk_write(s, "\r\n", 2);
break;
case TS_SYNCH:
b[1] = DM;
- sk_write(s, b, 1);
- sk_write_oob(s, b + 1, 1);
+ telnet_bufsize = sk_write(s, b, 1);
+ telnet_bufsize = sk_write_oob(s, b + 1, 1);
break;
case TS_RECHO:
if (o_echo.state == INACTIVE || o_echo.state == REALLY_INACTIVE) {
case TS_PING:
if (o_they_sga.state == ACTIVE) {
b[1] = NOP;
- sk_write(s, b, 2);
+ telnet_bufsize = sk_write(s, b, 2);
}
break;
}
return 1;
}
+static void telnet_unthrottle(int backlog)
+{
+ sk_set_frozen(s, backlog > TELNET_MAX_BACKLOG);
+}
+
static int telnet_ldisc(int option)
{
if (option == LD_ECHO)
return FALSE;
}
+static int telnet_exitcode(void)
+{
+ /* Telnet doesn't transmit exit codes back to the client */
+ return 0;
+}
+
Backend telnet_backend = {
telnet_init,
telnet_send,
+ telnet_sendbuffer,
telnet_size,
telnet_special,
telnet_socket,
+ telnet_exitcode,
telnet_sendok,
telnet_ldisc,
+ telnet_unthrottle,
23
};