[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, Conf *conf)
{
    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 = conf_get_int(conf, CONF_serspeed);
	msg = dupprintf("Configuring baud rate %d", dcb.BaudRate);
	logevent(serial->frontend, msg);
	sfree(msg);

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

	switch (conf_get_int(conf, CONF_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 (conf_get_int(conf, CONF_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 (conf_get_int(conf, CONF_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,
			       Conf *conf, char *host, int port,
			       char **realhost, int nodelay, int keepalive)
{
    Serial serial;
    HANDLE serport;
    const char *err;
    char *serline;

    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;

    serline = conf_get_str(conf, CONF_serline);
    {
	char *msg = dupprintf("Opening serial device %s", 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(serline, '\\') ? "" : "\\\\.\\", 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, conf);
    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(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, Conf *conf)
{
    Serial serial = (Serial) handle;
    const char *err;

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

    /*
     * 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, unsigned 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,
    0
};
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
4a693cfc	90	static const char serial_configure(Serial serial, HANDLE serport, Conf conf)
d3b85d02	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	*/
4a693cfc	124	dcb.BaudRate = conf_get_int(conf, CONF_serspeed);
4a693cfc	125	msg = dupprintf("Configuring baud rate %d", dcb.BaudRate);
d3b85d02	126	logevent(serial->frontend, msg);
	127	sfree(msg);
	128
4a693cfc	129	dcb.ByteSize = conf_get_int(conf, CONF_serdatabits);
4a693cfc	130	msg = dupprintf("Configuring %d data bits", dcb.ByteSize);
d3b85d02	131	logevent(serial->frontend, msg);
	132	sfree(msg);
	133
4a693cfc	134	switch (conf_get_int(conf, CONF_serstopbits)) {
d3b85d02	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
4a693cfc	144	switch (conf_get_int(conf, CONF_serparity)) {
d3b85d02	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
4a693cfc	155	switch (conf_get_int(conf, CONF_serflow)) {
d3b85d02	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,
4a693cfc	202	Conf conf, char host, int port,
4a693cfc	203	char **realhost, int nodelay, int keepalive)
d3b85d02	204	{
	205	Serial serial;
	206	HANDLE serport;
	207	const char *err;
4a693cfc	208	char *serline;
d3b85d02	209
d3b85d02	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
4a693cfc	219	serline = conf_get_str(conf, CONF_serline);
d3b85d02	220	{
4a693cfc	221	char *msg = dupprintf("Opening serial device %s", serline);
d3b85d02	222	logevent(serial->frontend, msg);
	223	}
	224
934dbf05	225	{
	226	/*
	227	* Munge the string supplied by the user into a Windows filename.
	228	*
	229	* Windows supports opening a few "legacy" devices (including
	230	* COM1-9) by specifying their names verbatim as a filename to
	231	* open. (Thus, no files can ever have these names. See
	232	* <http://msdn2.microsoft.com/en-us/library/aa365247.aspx>
	233	* ("Naming a File") for the complete list of reserved names.)
	234	*
	235	* However, this doesn't let you get at devices COM10 and above.
	236	* For that, you need to specify a filename like "\\.\COM10".
	237	* This is also necessary for special serial and serial-like
	238	* devices such as \\.\WCEUSBSH001. It also works for the "legacy"
	239	* names, so you can do \\.\COM1 (verified as far back as Win95).
	240	* See <http://msdn2.microsoft.com/en-us/library/aa363858.aspx>
	241	* (CreateFile() docs).
	242	*
	243	* So, we believe that prepending "\\.\" should always be the
	244	* Right Thing. However, just in case someone finds something to
	245	* talk to that doesn't exist under there, if the serial line
	246	* contains a backslash, we use it verbatim. (This also lets
	247	* existing configurations using \\.\ continue working.)
	248	*/
	249	char *serfilename =
4a693cfc	250	dupprintf("%s%s", strchr(serline, '\\') ? "" : "\\\\.\\", serline);
934dbf05	251	serport = CreateFile(serfilename, GENERIC_READ \| GENERIC_WRITE, 0, NULL,
	252	OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
	253	sfree(serfilename);
	254	}
	255
d3b85d02	256	if (serport == INVALID_HANDLE_VALUE)
	257	return "Unable to open serial port";
	258
4a693cfc	259	err = serial_configure(serial, serport, conf);
d3b85d02	260	if (err)
	261	return err;
	262
	263	serial->port = serport;
	264	serial->out = handle_output_new(serport, serial_sentdata, serial,
	265	HANDLE_FLAG_OVERLAPPED);
	266	serial->in = handle_input_new(serport, serial_gotdata, serial,
	267	HANDLE_FLAG_OVERLAPPED \|
c606abbc	268	HANDLE_FLAG_IGNOREEOF \|
c606abbc	269	HANDLE_FLAG_UNITBUFFER);
d3b85d02	270
4a693cfc	271	*realhost = dupstr(serline);
d3b85d02	272
45ef7ce3	273	/*
	274	* Specials are always available.
	275	*/
	276	update_specials_menu(serial->frontend);
	277
d3b85d02	278	return NULL;
	279	}
	280
	281	static void serial_free(void *handle)
	282	{
	283	Serial serial = (Serial) handle;
	284
	285	serial_terminate(serial);
45ef7ce3	286	expire_timer_context(serial);
d3b85d02	287	sfree(serial);
	288	}
	289
4a693cfc	290	static void serial_reconfig(void handle, Conf conf)
d3b85d02	291	{
	292	Serial serial = (Serial) handle;
	293	const char *err;
	294
4a693cfc	295	err = serial_configure(serial, serial->port, conf);
d3b85d02	296
	297	/*
	298	* FIXME: what should we do if err returns something?
	299	*/
	300	}
	301
	302	/*
	303	* Called to send data down the serial connection.
	304	*/
	305	static int serial_send(void handle, char buf, int len)
	306	{
	307	Serial serial = (Serial) handle;
	308
	309	if (serial->out == NULL)
	310	return 0;
	311
	312	serial->bufsize = handle_write(serial->out, buf, len);
	313	return serial->bufsize;
	314	}
	315
	316	/*
	317	* Called to query the current sendability status.
	318	*/
	319	static int serial_sendbuffer(void *handle)
	320	{
	321	Serial serial = (Serial) handle;
	322	return serial->bufsize;
	323	}
	324
	325	/*
	326	* Called to set the size of the window
	327	*/
	328	static void serial_size(void *handle, int width, int height)
	329	{
	330	/* Do nothing! */
	331	return;
	332	}
	333
d719927e	334	static void serbreak_timer(void *ctx, unsigned long now)
45ef7ce3	335	{
	336	Serial serial = (Serial)ctx;
	337
d719927e	338	if (now == serial->clearbreak_time && serial->port) {
45ef7ce3	339	ClearCommBreak(serial->port);
	340	serial->break_in_progress = FALSE;
	341	logevent(serial->frontend, "Finished serial break");
	342	}
	343	}
	344
d3b85d02	345	/*
	346	* Send serial special codes.
	347	*/
	348	static void serial_special(void *handle, Telnet_Special code)
	349	{
45ef7ce3	350	Serial serial = (Serial) handle;
	351
	352	if (serial->port && code == TS_BRK) {
	353	logevent(serial->frontend, "Starting serial break at user request");
	354	SetCommBreak(serial->port);
	355	/*
	356	* To send a serial break on Windows, we call SetCommBreak
	357	* to begin the break, then wait a bit, and then call
	358	* ClearCommBreak to finish it. Hence, I must use timing.c
	359	* to arrange a callback when it's time to do the latter.
	360	*
	361	* SUS says that a default break length must be between 1/4
	362	* and 1/2 second. FreeBSD apparently goes with 2/5 second,
	363	* and so will I.
	364	*/
	365	serial->clearbreak_time =
	366	schedule_timer(TICKSPERSEC * 2 / 5, serbreak_timer, serial);
	367	serial->break_in_progress = TRUE;
	368	}
	369
d3b85d02	370	return;
	371	}
	372
	373	/*
	374	* Return a list of the special codes that make sense in this
	375	* protocol.
	376	*/
	377	static const struct telnet_special serial_get_specials(void handle)
	378	{
45ef7ce3	379	static const struct telnet_special specials[] = {
	380	{"Break", TS_BRK},
	381	{NULL, TS_EXITMENU}
	382	};
	383	return specials;
d3b85d02	384	}
	385
	386	static int serial_connected(void *handle)
	387	{
	388	return 1; /* always connected */
	389	}
	390
	391	static int serial_sendok(void *handle)
	392	{
	393	return 1;
	394	}
	395
	396	static void serial_unthrottle(void *handle, int backlog)
	397	{
	398	Serial serial = (Serial) handle;
	399	if (serial->in)
	400	handle_unthrottle(serial->in, backlog);
	401	}
	402
	403	static int serial_ldisc(void *handle, int option)
	404	{
	405	/*
	406	* Local editing and local echo are off by default.
	407	*/
	408	return 0;
	409	}
	410
	411	static void serial_provide_ldisc(void handle, void ldisc)
	412	{
	413	/* This is a stub. */
	414	}
	415
	416	static void serial_provide_logctx(void handle, void logctx)
	417	{
	418	/* This is a stub. */
	419	}
	420
	421	static int serial_exitcode(void *handle)
	422	{
	423	Serial serial = (Serial) handle;
4a0b6d61	424	if (serial->port != INVALID_HANDLE_VALUE)
d3b85d02	425	return -1; /* still connected */
	426	else
	427	/* Exit codes are a meaningless concept with serial ports */
	428	return INT_MAX;
	429	}
	430
	431	/*
	432	* cfg_info for Serial does nothing at all.
	433	*/
	434	static int serial_cfg_info(void *handle)
	435	{
	436	return 0;
	437	}
	438
	439	Backend serial_backend = {
	440	serial_init,
	441	serial_free,
	442	serial_reconfig,
	443	serial_send,
	444	serial_sendbuffer,
	445	serial_size,
	446	serial_special,
	447	serial_get_specials,
	448	serial_connected,
	449	serial_exitcode,
	450	serial_sendok,
	451	serial_ldisc,
	452	serial_provide_ldisc,
	453	serial_provide_logctx,
	454	serial_unthrottle,
	455	serial_cfg_info,
9e164d82	456	"serial",
9e164d82	457	PROT_SERIAL,
a4451dd1	458	0
d3b85d02	459	};