[u/mdw/putty] / windows / winser.c

/*
 * Serial back end (Windows-specific).
 */

#include <stdio.h>
#include <stdlib.h>
#include <limits.h>

#include "putty.h"

#define SERIAL_MAX_BACKLOG 4096

typedef struct serial_backend_data {
    HANDLE port;
    struct handle *out, *in;
    void *frontend;
    int bufsize;
    long clearbreak_time;
    int break_in_progress;
} *Serial;

static void serial_terminate(Serial serial)
{
    if (serial->out) {
	handle_free(serial->out);
	serial->out = NULL;
    }
    if (serial->in) {
	handle_free(serial->in);
	serial->in = NULL;
    }
    if (serial->port != INVALID_HANDLE_VALUE) {
	if (serial->break_in_progress)
	    ClearCommBreak(serial->port);
	CloseHandle(serial->port);
	serial->port = INVALID_HANDLE_VALUE;
    }
}

static int serial_gotdata(struct handle *h, void *data, int len)
{
    Serial serial = (Serial)handle_get_privdata(h);
    if (len <= 0) {
	const char *error_msg;

	/*
	 * Currently, len==0 should never happen because we're
	 * ignoring EOFs. However, it seems not totally impossible
	 * that this same back end might be usable to talk to named
	 * pipes or some other non-serial device, in which case EOF
	 * may become meaningful here.
	 */
	if (len == 0)
	    error_msg = "End of file reading from serial device";
	else
	    error_msg = "Error reading from serial device";

	serial_terminate(serial);

	notify_remote_exit(serial->frontend);

	logevent(serial->frontend, error_msg);

	connection_fatal(serial->frontend, "%s", error_msg);

	return 0;		       /* placate optimiser */
    } else {
	return from_backend(serial->frontend, 0, data, len);
    }
}

static void serial_sentdata(struct handle *h, int new_backlog)
{
    Serial serial = (Serial)handle_get_privdata(h);
    if (new_backlog < 0) {
	const char *error_msg = "Error writing to serial device";

	serial_terminate(serial);

	notify_remote_exit(serial->frontend);

	logevent(serial->frontend, error_msg);

	connection_fatal(serial->frontend, "%s", error_msg);
    } else {
	serial->bufsize = new_backlog;
    }
}

static const char *serial_configure(Serial serial, HANDLE serport, Config *cfg)
{
    DCB dcb;
    COMMTIMEOUTS timeouts;

    /*
     * Set up the serial port parameters. If we can't even
     * GetCommState, we ignore the problem on the grounds that the
     * user might have pointed us at some other type of two-way
     * device instead of a serial port.
     */
    if (GetCommState(serport, &dcb)) {
	char *msg;
	const char *str;

	/*
	 * Boilerplate.
	 */
	dcb.fBinary = TRUE;
	dcb.fDtrControl = DTR_CONTROL_ENABLE;
	dcb.fDsrSensitivity = FALSE;
	dcb.fTXContinueOnXoff = FALSE;
	dcb.fOutX = FALSE;
	dcb.fInX = FALSE;
	dcb.fErrorChar = FALSE;
	dcb.fNull = FALSE;
	dcb.fRtsControl = RTS_CONTROL_ENABLE;
	dcb.fAbortOnError = FALSE;
	dcb.fOutxCtsFlow = FALSE;
	dcb.fOutxDsrFlow = FALSE;

	/*
	 * Configurable parameters.
	 */
	dcb.BaudRate = cfg->serspeed;
	msg = dupprintf("Configuring baud rate %d", cfg->serspeed);
	logevent(serial->frontend, msg);
	sfree(msg);

	dcb.ByteSize = cfg->serdatabits;
	msg = dupprintf("Configuring %d data bits", cfg->serdatabits);
	logevent(serial->frontend, msg);
	sfree(msg);

	switch (cfg->serstopbits) {
	  case 2: dcb.StopBits = ONESTOPBIT; str = "1"; break;
	  case 3: dcb.StopBits = ONE5STOPBITS; str = "1.5"; break;
	  case 4: dcb.StopBits = TWOSTOPBITS; str = "2"; break;
	  default: return "Invalid number of stop bits (need 1, 1.5 or 2)";
	}
	msg = dupprintf("Configuring %s data bits", str);
	logevent(serial->frontend, msg);
	sfree(msg);

	switch (cfg->serparity) {
	  case SER_PAR_NONE: dcb.Parity = NOPARITY; str = "no"; break;
	  case SER_PAR_ODD: dcb.Parity = ODDPARITY; str = "odd"; break;
	  case SER_PAR_EVEN: dcb.Parity = EVENPARITY; str = "even"; break;
	  case SER_PAR_MARK: dcb.Parity = MARKPARITY; str = "mark"; break;
	  case SER_PAR_SPACE: dcb.Parity = SPACEPARITY; str = "space"; break;
	}
	msg = dupprintf("Configuring %s parity", str);
	logevent(serial->frontend, msg);
	sfree(msg);

	switch (cfg->serflow) {
	  case SER_FLOW_NONE:
	    str = "no";
	    break;
	  case SER_FLOW_XONXOFF:
	    dcb.fOutX = dcb.fInX = TRUE;
	    str = "XON/XOFF";
	    break;
	  case SER_FLOW_RTSCTS:
	    dcb.fRtsControl = RTS_CONTROL_HANDSHAKE;
	    dcb.fOutxCtsFlow = TRUE;
	    str = "RTS/CTS";
	    break;
	  case SER_FLOW_DSRDTR:
	    dcb.fDtrControl = DTR_CONTROL_HANDSHAKE;
	    dcb.fOutxDsrFlow = TRUE;
	    str = "DSR/DTR";
	    break;
	}
	msg = dupprintf("Configuring %s flow control", str);
	logevent(serial->frontend, msg);
	sfree(msg);

	if (!SetCommState(serport, &dcb))
	    return "Unable to configure serial port";

	timeouts.ReadIntervalTimeout = 1;
	timeouts.ReadTotalTimeoutMultiplier = 0;
	timeouts.ReadTotalTimeoutConstant = 0;
	timeouts.WriteTotalTimeoutMultiplier = 0;
	timeouts.WriteTotalTimeoutConstant = 0;
	if (!SetCommTimeouts(serport, &timeouts))
	    return "Unable to configure serial timeouts";
    }

    return NULL;
}

/*
 * Called to set up the serial connection.
 * 
 * Returns an error message, or NULL on success.
 *
 * Also places the canonical host name into `realhost'. It must be
 * freed by the caller.
 */
static const char *serial_init(void *frontend_handle, void **backend_handle,
			       Config *cfg,
			       char *host, int port, char **realhost, int nodelay,
			       int keepalive)
{
    Serial serial;
    HANDLE serport;
    const char *err;

    serial = snew(struct serial_backend_data);
    serial->port = INVALID_HANDLE_VALUE;
    serial->out = serial->in = NULL;
    serial->bufsize = 0;
    serial->break_in_progress = FALSE;
    *backend_handle = serial;

    serial->frontend = frontend_handle;

    {
	char *msg = dupprintf("Opening serial device %s", cfg->serline);
	logevent(serial->frontend, msg);
    }

    {
	/*
	 * Munge the string supplied by the user into a Windows filename.
	 *
	 * Windows supports opening a few "legacy" devices (including
	 * COM1-9) by specifying their names verbatim as a filename to
	 * open. (Thus, no files can ever have these names. See
	 * <http://msdn2.microsoft.com/en-us/library/aa365247.aspx>
	 * ("Naming a File") for the complete list of reserved names.)
	 *
	 * However, this doesn't let you get at devices COM10 and above.
	 * For that, you need to specify a filename like "\\.\COM10".
	 * This is also necessary for special serial and serial-like
	 * devices such as \\.\WCEUSBSH001. It also works for the "legacy"
	 * names, so you can do \\.\COM1 (verified as far back as Win95).
	 * See <http://msdn2.microsoft.com/en-us/library/aa363858.aspx>
	 * (CreateFile() docs).
	 *
	 * So, we believe that prepending "\\.\" should always be the
	 * Right Thing. However, just in case someone finds something to
	 * talk to that doesn't exist under there, if the serial line
	 * contains a backslash, we use it verbatim. (This also lets
	 * existing configurations using \\.\ continue working.)
	 */
	char *serfilename =
	    dupprintf("%s%s",
		      strchr(cfg->serline, '\\') ? "" : "\\\\.\\",
		      cfg->serline);
	serport = CreateFile(serfilename, GENERIC_READ | GENERIC_WRITE, 0, NULL,
			     OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
	sfree(serfilename);
    }

    if (serport == INVALID_HANDLE_VALUE)
	return "Unable to open serial port";

    err = serial_configure(serial, serport, cfg);
    if (err)
	return err;

    serial->port = serport;
    serial->out = handle_output_new(serport, serial_sentdata, serial,
				    HANDLE_FLAG_OVERLAPPED);
    serial->in = handle_input_new(serport, serial_gotdata, serial,
				  HANDLE_FLAG_OVERLAPPED |
				  HANDLE_FLAG_IGNOREEOF |
				  HANDLE_FLAG_UNITBUFFER);

    *realhost = dupstr(cfg->serline);

    /*
     * Specials are always available.
     */
    update_specials_menu(serial->frontend);

    return NULL;
}

static void serial_free(void *handle)
{
    Serial serial = (Serial) handle;

    serial_terminate(serial);
    expire_timer_context(serial);
    sfree(serial);
}

static void serial_reconfig(void *handle, Config *cfg)
{
    Serial serial = (Serial) handle;
    const char *err;

    err = serial_configure(serial, serial->port, cfg);

    /*
     * FIXME: what should we do if err returns something?
     */
}

/*
 * Called to send data down the serial connection.
 */
static int serial_send(void *handle, char *buf, int len)
{
    Serial serial = (Serial) handle;

    if (serial->out == NULL)
	return 0;

    serial->bufsize = handle_write(serial->out, buf, len);
    return serial->bufsize;
}

/*
 * Called to query the current sendability status.
 */
static int serial_sendbuffer(void *handle)
{
    Serial serial = (Serial) handle;
    return serial->bufsize;
}

/*
 * Called to set the size of the window
 */
static void serial_size(void *handle, int width, int height)
{
    /* Do nothing! */
    return;
}

static void serbreak_timer(void *ctx, long now)
{
    Serial serial = (Serial)ctx;

    if (now >= serial->clearbreak_time && serial->port) {
	ClearCommBreak(serial->port);
	serial->break_in_progress = FALSE;
	logevent(serial->frontend, "Finished serial break");
    }
}

/*
 * Send serial special codes.
 */
static void serial_special(void *handle, Telnet_Special code)
{
    Serial serial = (Serial) handle;

    if (serial->port && code == TS_BRK) {
	logevent(serial->frontend, "Starting serial break at user request");
	SetCommBreak(serial->port);
	/*
	 * To send a serial break on Windows, we call SetCommBreak
	 * to begin the break, then wait a bit, and then call
	 * ClearCommBreak to finish it. Hence, I must use timing.c
	 * to arrange a callback when it's time to do the latter.
	 * 
	 * SUS says that a default break length must be between 1/4
	 * and 1/2 second. FreeBSD apparently goes with 2/5 second,
	 * and so will I. 
	 */
	serial->clearbreak_time =
	    schedule_timer(TICKSPERSEC * 2 / 5, serbreak_timer, serial);
	serial->break_in_progress = TRUE;
    }

    return;
}

/*
 * Return a list of the special codes that make sense in this
 * protocol.
 */
static const struct telnet_special *serial_get_specials(void *handle)
{
    static const struct telnet_special specials[] = {
	{"Break", TS_BRK},
	{NULL, TS_EXITMENU}
    };
    return specials;
}

static int serial_connected(void *handle)
{
    return 1;			       /* always connected */
}

static int serial_sendok(void *handle)
{
    return 1;
}

static void serial_unthrottle(void *handle, int backlog)
{
    Serial serial = (Serial) handle;
    if (serial->in)
	handle_unthrottle(serial->in, backlog);
}

static int serial_ldisc(void *handle, int option)
{
    /*
     * Local editing and local echo are off by default.
     */
    return 0;
}

static void serial_provide_ldisc(void *handle, void *ldisc)
{
    /* This is a stub. */
}

static void serial_provide_logctx(void *handle, void *logctx)
{
    /* This is a stub. */
}

static int serial_exitcode(void *handle)
{
    Serial serial = (Serial) handle;
    if (serial->port != INVALID_HANDLE_VALUE)
        return -1;                     /* still connected */
    else
        /* Exit codes are a meaningless concept with serial ports */
        return INT_MAX;
}

/*
 * cfg_info for Serial does nothing at all.
 */
static int serial_cfg_info(void *handle)
{
    return 0;
}

Backend serial_backend = {
    serial_init,
    serial_free,
    serial_reconfig,
    serial_send,
    serial_sendbuffer,
    serial_size,
    serial_special,
    serial_get_specials,
    serial_connected,
    serial_exitcode,
    serial_sendok,
    serial_ldisc,
    serial_provide_ldisc,
    serial_provide_logctx,
    serial_unthrottle,
    serial_cfg_info,
    "serial",
    PROT_SERIAL,
    1
};
Commit	Line	Data
d3b85d02	1	/*
	2	* Serial back end (Windows-specific).
	3	*/
	4
d3b85d02	5	#include <stdio.h>
	6	#include <stdlib.h>
	7	#include <limits.h>
	8
	9	#include "putty.h"
	10
	11	#define SERIAL_MAX_BACKLOG 4096
	12
	13	typedef struct serial_backend_data {
	14	HANDLE port;
	15	struct handle out, in;
	16	void *frontend;
	17	int bufsize;
45ef7ce3	18	long clearbreak_time;
45ef7ce3	19	int break_in_progress;
d3b85d02	20	} *Serial;
	21
	22	static void serial_terminate(Serial serial)
	23	{
	24	if (serial->out) {
	25	handle_free(serial->out);
	26	serial->out = NULL;
	27	}
	28	if (serial->in) {
	29	handle_free(serial->in);
	30	serial->in = NULL;
	31	}
4a0b6d61	32	if (serial->port != INVALID_HANDLE_VALUE) {
45ef7ce3	33	if (serial->break_in_progress)
45ef7ce3	34	ClearCommBreak(serial->port);
d3b85d02	35	CloseHandle(serial->port);
4a0b6d61	36	serial->port = INVALID_HANDLE_VALUE;
d3b85d02	37	}
	38	}
	39
	40	static int serial_gotdata(struct handle h, void data, int len)
	41	{
	42	Serial serial = (Serial)handle_get_privdata(h);
	43	if (len <= 0) {
	44	const char *error_msg;
	45
	46	/*
	47	* Currently, len==0 should never happen because we're
	48	* ignoring EOFs. However, it seems not totally impossible
	49	* that this same back end might be usable to talk to named
	50	* pipes or some other non-serial device, in which case EOF
	51	* may become meaningful here.
	52	*/
	53	if (len == 0)
	54	error_msg = "End of file reading from serial device";
	55	else
	56	error_msg = "Error reading from serial device";
	57
	58	serial_terminate(serial);
	59
	60	notify_remote_exit(serial->frontend);
	61
	62	logevent(serial->frontend, error_msg);
	63
	64	connection_fatal(serial->frontend, "%s", error_msg);
	65
	66	return 0; /* placate optimiser */
	67	} else {
	68	return from_backend(serial->frontend, 0, data, len);
	69	}
	70	}
	71
	72	static void serial_sentdata(struct handle *h, int new_backlog)
	73	{
	74	Serial serial = (Serial)handle_get_privdata(h);
	75	if (new_backlog < 0) {
	76	const char *error_msg = "Error writing to serial device";
	77
	78	serial_terminate(serial);
	79
	80	notify_remote_exit(serial->frontend);
	81
	82	logevent(serial->frontend, error_msg);
	83
	84	connection_fatal(serial->frontend, "%s", error_msg);
	85	} else {
	86	serial->bufsize = new_backlog;
	87	}
	88	}
	89
	90	static const char serial_configure(Serial serial, HANDLE serport, Config cfg)
	91	{
	92	DCB dcb;
	93	COMMTIMEOUTS timeouts;
	94
	95	/*
	96	* Set up the serial port parameters. If we can't even
	97	* GetCommState, we ignore the problem on the grounds that the
	98	* user might have pointed us at some other type of two-way
	99	* device instead of a serial port.
	100	*/
101	if (GetCommState(serport, &dcb)) {
102	char *msg;
103	const char *str;
104
105	/*
106	* Boilerplate.
107	*/
108	dcb.fBinary = TRUE;
109	dcb.fDtrControl = DTR_CONTROL_ENABLE;
110	dcb.fDsrSensitivity = FALSE;
111	dcb.fTXContinueOnXoff = FALSE;
112	dcb.fOutX = FALSE;
113	dcb.fInX = FALSE;
114	dcb.fErrorChar = FALSE;
115	dcb.fNull = FALSE;
116	dcb.fRtsControl = RTS_CONTROL_ENABLE;
117	dcb.fAbortOnError = FALSE;
118	dcb.fOutxCtsFlow = FALSE;
119	dcb.fOutxDsrFlow = FALSE;
120
121	/*
122	* Configurable parameters.
123	*/
124	dcb.BaudRate = cfg->serspeed;
125	msg = dupprintf("Configuring baud rate %d", cfg->serspeed);
126	logevent(serial->frontend, msg);
127	sfree(msg);
128
129	dcb.ByteSize = cfg->serdatabits;
130	msg = dupprintf("Configuring %d data bits", cfg->serdatabits);
131	logevent(serial->frontend, msg);
132	sfree(msg);
133
134	switch (cfg->serstopbits) {
135	case 2: dcb.StopBits = ONESTOPBIT; str = "1"; break;
136	case 3: dcb.StopBits = ONE5STOPBITS; str = "1.5"; break;
137	case 4: dcb.StopBits = TWOSTOPBITS; str = "2"; break;
138	default: return "Invalid number of stop bits (need 1, 1.5 or 2)";
139	}
140	msg = dupprintf("Configuring %s data bits", str);
141	logevent(serial->frontend, msg);
142	sfree(msg);
143
144	switch (cfg->serparity) {
145	case SER_PAR_NONE: dcb.Parity = NOPARITY; str = "no"; break;
146	case SER_PAR_ODD: dcb.Parity = ODDPARITY; str = "odd"; break;
147	case SER_PAR_EVEN: dcb.Parity = EVENPARITY; str = "even"; break;
148	case SER_PAR_MARK: dcb.Parity = MARKPARITY; str = "mark"; break;
149	case SER_PAR_SPACE: dcb.Parity = SPACEPARITY; str = "space"; break;
150	}
151	msg = dupprintf("Configuring %s parity", str);
152	logevent(serial->frontend, msg);
153	sfree(msg);
154
155	switch (cfg->serflow) {
156	case SER_FLOW_NONE:
157	str = "no";
158	break;
159	case SER_FLOW_XONXOFF:
160	dcb.fOutX = dcb.fInX = TRUE;
161	str = "XON/XOFF";
162	break;
163	case SER_FLOW_RTSCTS:
164	dcb.fRtsControl = RTS_CONTROL_HANDSHAKE;
165	dcb.fOutxCtsFlow = TRUE;
166	str = "RTS/CTS";
167	break;
168	case SER_FLOW_DSRDTR:
169	dcb.fDtrControl = DTR_CONTROL_HANDSHAKE;
170	dcb.fOutxDsrFlow = TRUE;
171	str = "DSR/DTR";
172	break;
173	}
174	msg = dupprintf("Configuring %s flow control", str);
175	logevent(serial->frontend, msg);
176	sfree(msg);
177
178	if (!SetCommState(serport, &dcb))
179	return "Unable to configure serial port";
180
181	timeouts.ReadIntervalTimeout = 1;
182	timeouts.ReadTotalTimeoutMultiplier = 0;
183	timeouts.ReadTotalTimeoutConstant = 0;
184	timeouts.WriteTotalTimeoutMultiplier = 0;
185	timeouts.WriteTotalTimeoutConstant = 0;
186	if (!SetCommTimeouts(serport, &timeouts))
187	return "Unable to configure serial timeouts";
188	}
189
190	return NULL;
191	}
192
193	/*
194	* Called to set up the serial connection.
195	*
196	* Returns an error message, or NULL on success.
197	*
198	* Also places the canonical host name into `realhost'. It must be
199	* freed by the caller.
200	*/
201	static const char serial_init(void frontend_handle, void **backend_handle,
202	Config *cfg,
203	char host, int port, char *realhost, int nodelay,
204	int keepalive)
205	{
206	Serial serial;
207	HANDLE serport;
208	const char *err;
209
210	serial = snew(struct serial_backend_data);
4a0b6d61	211	serial->port = INVALID_HANDLE_VALUE;
d3b85d02	212	serial->out = serial->in = NULL;
dcf640d6	213	serial->bufsize = 0;
45ef7ce3	214	serial->break_in_progress = FALSE;
d3b85d02	215	*backend_handle = serial;
	216
	217	serial->frontend = frontend_handle;
	218
	219	{
e5a76e12	220	char *msg = dupprintf("Opening serial device %s", cfg->serline);
d3b85d02	221	logevent(serial->frontend, msg);
	222	}
	223
934dbf05	224	{
	225	/*
	226	* Munge the string supplied by the user into a Windows filename.
	227	*
	228	* Windows supports opening a few "legacy" devices (including
	229	* COM1-9) by specifying their names verbatim as a filename to
	230	* open. (Thus, no files can ever have these names. See
	231	* <http://msdn2.microsoft.com/en-us/library/aa365247.aspx>
	232	* ("Naming a File") for the complete list of reserved names.)
	233	*
	234	* However, this doesn't let you get at devices COM10 and above.
	235	* For that, you need to specify a filename like "\\.\COM10".
	236	* This is also necessary for special serial and serial-like
	237	* devices such as \\.\WCEUSBSH001. It also works for the "legacy"
	238	* names, so you can do \\.\COM1 (verified as far back as Win95).
	239	* See <http://msdn2.microsoft.com/en-us/library/aa363858.aspx>
	240	* (CreateFile() docs).
	241	*
	242	* So, we believe that prepending "\\.\" should always be the
	243	* Right Thing. However, just in case someone finds something to
	244	* talk to that doesn't exist under there, if the serial line
	245	* contains a backslash, we use it verbatim. (This also lets
	246	* existing configurations using \\.\ continue working.)
	247	*/
	248	char *serfilename =
	249	dupprintf("%s%s",
	250	strchr(cfg->serline, '\\') ? "" : "\\\\.\\",
	251	cfg->serline);
	252	serport = CreateFile(serfilename, GENERIC_READ \| GENERIC_WRITE, 0, NULL,
	253	OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
	254	sfree(serfilename);
	255	}
	256
d3b85d02	257	if (serport == INVALID_HANDLE_VALUE)
	258	return "Unable to open serial port";
	259
	260	err = serial_configure(serial, serport, cfg);
	261	if (err)
	262	return err;
	263
	264	serial->port = serport;
	265	serial->out = handle_output_new(serport, serial_sentdata, serial,
	266	HANDLE_FLAG_OVERLAPPED);
	267	serial->in = handle_input_new(serport, serial_gotdata, serial,
	268	HANDLE_FLAG_OVERLAPPED \|
c606abbc	269	HANDLE_FLAG_IGNOREEOF \|
c606abbc	270	HANDLE_FLAG_UNITBUFFER);
d3b85d02	271
	272	*realhost = dupstr(cfg->serline);
	273
45ef7ce3	274	/*
	275	* Specials are always available.
	276	*/
	277	update_specials_menu(serial->frontend);
	278
d3b85d02	279	return NULL;
	280	}
	281
	282	static void serial_free(void *handle)
	283	{
	284	Serial serial = (Serial) handle;
	285
	286	serial_terminate(serial);
45ef7ce3	287	expire_timer_context(serial);
d3b85d02	288	sfree(serial);
	289	}
	290
	291	static void serial_reconfig(void handle, Config cfg)
	292	{
	293	Serial serial = (Serial) handle;
	294	const char *err;
	295
	296	err = serial_configure(serial, serial->port, cfg);
	297
	298	/*
	299	* FIXME: what should we do if err returns something?
	300	*/
	301	}
	302
	303	/*
	304	* Called to send data down the serial connection.
	305	*/
	306	static int serial_send(void handle, char buf, int len)
	307	{
	308	Serial serial = (Serial) handle;
	309
	310	if (serial->out == NULL)
	311	return 0;
	312
	313	serial->bufsize = handle_write(serial->out, buf, len);
	314	return serial->bufsize;
	315	}
	316
	317	/*
	318	* Called to query the current sendability status.
	319	*/
	320	static int serial_sendbuffer(void *handle)
	321	{
	322	Serial serial = (Serial) handle;
	323	return serial->bufsize;
	324	}
	325
	326	/*
	327	* Called to set the size of the window
	328	*/
	329	static void serial_size(void *handle, int width, int height)
	330	{
	331	/* Do nothing! */
	332	return;
	333	}
	334
45ef7ce3	335	static void serbreak_timer(void *ctx, long now)
	336	{
	337	Serial serial = (Serial)ctx;
	338
	339	if (now >= serial->clearbreak_time && serial->port) {
	340	ClearCommBreak(serial->port);
	341	serial->break_in_progress = FALSE;
	342	logevent(serial->frontend, "Finished serial break");
	343	}
	344	}
	345
d3b85d02	346	/*
	347	* Send serial special codes.
	348	*/
	349	static void serial_special(void *handle, Telnet_Special code)
	350	{
45ef7ce3	351	Serial serial = (Serial) handle;
	352
	353	if (serial->port && code == TS_BRK) {
	354	logevent(serial->frontend, "Starting serial break at user request");
	355	SetCommBreak(serial->port);
	356	/*
	357	* To send a serial break on Windows, we call SetCommBreak
	358	* to begin the break, then wait a bit, and then call
	359	* ClearCommBreak to finish it. Hence, I must use timing.c
	360	* to arrange a callback when it's time to do the latter.
	361	*
	362	* SUS says that a default break length must be between 1/4
	363	* and 1/2 second. FreeBSD apparently goes with 2/5 second,
	364	* and so will I.
	365	*/
	366	serial->clearbreak_time =
	367	schedule_timer(TICKSPERSEC * 2 / 5, serbreak_timer, serial);
	368	serial->break_in_progress = TRUE;
	369	}
	370
d3b85d02	371	return;
	372	}
	373
	374	/*
	375	* Return a list of the special codes that make sense in this
	376	* protocol.
	377	*/
	378	static const struct telnet_special serial_get_specials(void handle)
	379	{
45ef7ce3	380	static const struct telnet_special specials[] = {
	381	{"Break", TS_BRK},
	382	{NULL, TS_EXITMENU}
	383	};
	384	return specials;
d3b85d02	385	}
	386
	387	static int serial_connected(void *handle)
	388	{
	389	return 1; /* always connected */
	390	}
	391
	392	static int serial_sendok(void *handle)
	393	{
	394	return 1;
	395	}
	396
	397	static void serial_unthrottle(void *handle, int backlog)
	398	{
	399	Serial serial = (Serial) handle;
	400	if (serial->in)
	401	handle_unthrottle(serial->in, backlog);
	402	}
	403
	404	static int serial_ldisc(void *handle, int option)
	405	{
	406	/*
	407	* Local editing and local echo are off by default.
	408	*/
	409	return 0;
	410	}
	411
	412	static void serial_provide_ldisc(void handle, void ldisc)
	413	{
	414	/* This is a stub. */
	415	}
	416
	417	static void serial_provide_logctx(void handle, void logctx)
	418	{
	419	/* This is a stub. */
	420	}
	421
	422	static int serial_exitcode(void *handle)
	423	{
	424	Serial serial = (Serial) handle;
4a0b6d61	425	if (serial->port != INVALID_HANDLE_VALUE)
d3b85d02	426	return -1; /* still connected */
	427	else
	428	/* Exit codes are a meaningless concept with serial ports */
	429	return INT_MAX;
	430	}
	431
	432	/*
	433	* cfg_info for Serial does nothing at all.
	434	*/
	435	static int serial_cfg_info(void *handle)
	436	{
	437	return 0;
	438	}
	439
	440	Backend serial_backend = {
	441	serial_init,
	442	serial_free,
	443	serial_reconfig,
	444	serial_send,
	445	serial_sendbuffer,
	446	serial_size,
	447	serial_special,
	448	serial_get_specials,
	449	serial_connected,
	450	serial_exitcode,
	451	serial_sendok,
	452	serial_ldisc,
	453	serial_provide_ldisc,
	454	serial_provide_logctx,
	455	serial_unthrottle,
	456	serial_cfg_info,
9e164d82	457	"serial",
9e164d82	458	PROT_SERIAL,
d3b85d02	459	1
d3b85d02	460	};