[u/mdw/putty] / unix / uxser.c

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

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

#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <termios.h>

#include "putty.h"
#include "tree234.h"

#define SERIAL_MAX_BACKLOG 4096

typedef struct serial_backend_data {
    void *frontend;
    int fd;
    int finished;
    int inbufsize;
    bufchain output_data;
} *Serial;

/*
 * We store our serial backends in a tree sorted by fd, so that
 * when we get an uxsel notification we know which backend instance
 * is the owner of the serial port that caused it.
 */
static int serial_compare_by_fd(void *av, void *bv)
{
    Serial a = (Serial)av;
    Serial b = (Serial)bv;

    if (a->fd < b->fd)
	return -1;
    else if (a->fd > b->fd)
	return +1;
    return 0;
}

static int serial_find_by_fd(void *av, void *bv)
{
    int a = *(int *)av;
    Serial b = (Serial)bv;

    if (a < b->fd)
	return -1;
    else if (a > b->fd)
	return +1;
    return 0;
}

static tree234 *serial_by_fd = NULL;

static int serial_select_result(int fd, int event);
static void serial_uxsel_setup(Serial serial);
static void serial_try_write(Serial serial);

static const char *serial_configure(Serial serial, Config *cfg)
{
    struct termios options;
    int bflag, bval;
    const char *str;
    char *msg;

    if (serial->fd < 0)
	return "Unable to reconfigure already-closed serial connection";

    tcgetattr(serial->fd, &options);

    /*
     * Find the appropriate baud rate flag.
     */
#define SETBAUD(x) (bflag = B ## x, bval = x)
#define CHECKBAUD(x) do { if (cfg->serspeed >= x) SETBAUD(x); } while (0)
    SETBAUD(50);
#ifdef B75
    CHECKBAUD(75);
#endif
#ifdef B110
    CHECKBAUD(110);
#endif
#ifdef B134
    CHECKBAUD(134);
#endif
#ifdef B150
    CHECKBAUD(150);
#endif
#ifdef B200
    CHECKBAUD(200);
#endif
#ifdef B300
    CHECKBAUD(300);
#endif
#ifdef B600
    CHECKBAUD(600);
#endif
#ifdef B1200
    CHECKBAUD(1200);
#endif
#ifdef B1800
    CHECKBAUD(1800);
#endif
#ifdef B2400
    CHECKBAUD(2400);
#endif
#ifdef B4800
    CHECKBAUD(4800);
#endif
#ifdef B9600
    CHECKBAUD(9600);
#endif
#ifdef B19200
    CHECKBAUD(19200);
#endif
#ifdef B38400
    CHECKBAUD(38400);
#endif
#ifdef B57600
    CHECKBAUD(57600);
#endif
#ifdef B76800
    CHECKBAUD(76800);
#endif
#ifdef B115200
    CHECKBAUD(115200);
#endif
#ifdef B153600
    CHECKBAUD(153600);
#endif
#ifdef B230400
    CHECKBAUD(230400);
#endif
#ifdef B307200
    CHECKBAUD(307200);
#endif
#ifdef B460800
    CHECKBAUD(460800);
#endif
#ifdef B500000
    CHECKBAUD(500000);
#endif
#ifdef B576000
    CHECKBAUD(576000);
#endif
#ifdef B921600
    CHECKBAUD(921600);
#endif
#ifdef B1000000
    CHECKBAUD(1000000);
#endif
#ifdef B1152000
    CHECKBAUD(1152000);
#endif
#ifdef B1500000
    CHECKBAUD(1500000);
#endif
#ifdef B2000000
    CHECKBAUD(2000000);
#endif
#ifdef B2500000
    CHECKBAUD(2500000);
#endif
#ifdef B3000000
    CHECKBAUD(3000000);
#endif
#ifdef B3500000
    CHECKBAUD(3500000);
#endif
#ifdef B4000000
    CHECKBAUD(4000000);
#endif
#undef CHECKBAUD
#undef SETBAUD
    cfsetispeed(&options, bflag);
    cfsetospeed(&options, bflag);
    msg = dupprintf("Configuring baud rate %d", bval);
    logevent(serial->frontend, msg);
    sfree(msg);

    options.c_cflag &= ~CSIZE;
    switch (cfg->serdatabits) {
      case 5: options.c_cflag |= CS5; break;
      case 6: options.c_cflag |= CS6; break;
      case 7: options.c_cflag |= CS7; break;
      case 8: options.c_cflag |= CS8; break;
      default: return "Invalid number of data bits (need 5, 6, 7 or 8)";
    }
    msg = dupprintf("Configuring %d data bits", cfg->serdatabits);
    logevent(serial->frontend, msg);
    sfree(msg);

    if (cfg->serstopbits >= 4) {
	options.c_cflag |= CSTOPB;
    } else {
	options.c_cflag &= ~CSTOPB;
    }
    msg = dupprintf("Configuring %d stop bits",
		    (options.c_cflag & CSTOPB ? 2 : 1));
    logevent(serial->frontend, msg);
    sfree(msg);

    options.c_iflag &= ~(IXON|IXOFF);
#ifdef CRTSCTS
    options.c_cflag &= ~CRTSCTS;
#endif
#ifdef CNEW_RTSCTS
    options.c_cflag &= ~CNEW_RTSCTS;
#endif
    if (cfg->serflow == SER_FLOW_XONXOFF) {
	options.c_iflag |= IXON | IXOFF;
	str = "XON/XOFF";
    } else if (cfg->serflow == SER_FLOW_RTSCTS) {
#ifdef CRTSCTS
	options.c_cflag |= CRTSCTS;
#endif
#ifdef CNEW_RTSCTS
	options.c_cflag |= CNEW_RTSCTS;
#endif
	str = "RTS/CTS";
    } else
	str = "no";
    msg = dupprintf("Configuring %s flow control", str);
    logevent(serial->frontend, msg);
    sfree(msg);

    /* Parity */
    if (cfg->serparity == SER_PAR_ODD) {
	options.c_cflag |= PARENB;
	options.c_cflag |= PARODD;
	str = "odd";
    } else if (cfg->serparity == SER_PAR_EVEN) {
	options.c_cflag |= PARENB;
	options.c_cflag &= ~PARODD;
	str = "even";
    } else {
	options.c_cflag &= ~PARENB;
	str = "no";
    }
    msg = dupprintf("Configuring %s parity", str);
    logevent(serial->frontend, msg);
    sfree(msg);

    options.c_cflag |= CLOCAL | CREAD;
    options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
    options.c_iflag &= ~(ISTRIP | IGNCR | INLCR | ICRNL
#ifdef IUCLC
			 | IUCLC
#endif
			 );
    options.c_oflag &= ~(OPOST
#ifdef ONLCR
			 | ONLCR
#endif
#ifdef OCRNL
			 | OCRNL
#endif
#ifdef ONOCR
			 | ONOCR
#endif
#ifdef ONLRET
			 | ONLRET
#endif
			 );
    options.c_cc[VMIN] = 1;
    options.c_cc[VTIME] = 0;

    if (tcsetattr(serial->fd, TCSANOW, &options) < 0)
	return "Unable to configure serial port";

    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;
    const char *err;

    serial = snew(struct serial_backend_data);
    *backend_handle = serial;

    serial->frontend = frontend_handle;
    serial->finished = FALSE;
    serial->inbufsize = 0;
    bufchain_init(&serial->output_data);

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

    serial->fd = open(cfg->serline, O_RDWR | O_NOCTTY | O_NDELAY | O_NONBLOCK);
    if (serial->fd < 0)
	return "Unable to open serial port";

    cloexec(serial->fd);

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

    *realhost = dupstr(cfg->serline);

    if (!serial_by_fd)
	serial_by_fd = newtree234(serial_compare_by_fd);
    add234(serial_by_fd, serial);

    serial_uxsel_setup(serial);

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

    return NULL;
}

static void serial_close(Serial serial)
{
    if (serial->fd >= 0) {
	close(serial->fd);
	serial->fd = -1;
    }
}

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

    serial_close(serial);

    bufchain_clear(&serial->output_data);

    sfree(serial);
}

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

    err = serial_configure(serial, cfg);

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

static int serial_select_result(int fd, int event)
{
    Serial serial;
    char buf[4096];
    int ret;
    int finished = FALSE;

    serial = find234(serial_by_fd, &fd, serial_find_by_fd);

    if (!serial)
	return 1;		       /* spurious event; keep going */

    if (event == 1) {
	ret = read(serial->fd, buf, sizeof(buf));

	if (ret == 0) {
	    /*
	     * Shouldn't happen on a real serial port, but I'm open
	     * to the idea that there might be two-way devices we
	     * can treat _like_ serial ports which can return EOF.
	     */
	    finished = TRUE;
	} else if (ret < 0) {
#ifdef EAGAIN
	    if (errno == EAGAIN)
		return 1;	       /* spurious */
#endif
#ifdef EWOULDBLOCK
	    if (errno == EWOULDBLOCK)
		return 1;	       /* spurious */
#endif
	    perror("read serial port");
	    exit(1);
	} else if (ret > 0) {
	    serial->inbufsize = from_backend(serial->frontend, 0, buf, ret);
	    serial_uxsel_setup(serial); /* might acquire backlog and freeze */
	}
    } else if (event == 2) {
	/*
	 * Attempt to send data down the pty.
	 */
	serial_try_write(serial);
    }

    if (finished) {
	serial_close(serial);

	serial->finished = TRUE;

	notify_remote_exit(serial->frontend);
    }

    return !finished;
}

static void serial_uxsel_setup(Serial serial)
{
    int rwx = 0;

    if (serial->inbufsize <= SERIAL_MAX_BACKLOG)
	rwx |= 1;
    if (bufchain_size(&serial->output_data))
        rwx |= 2;                      /* might also want to write to it */
    uxsel_set(serial->fd, rwx, serial_select_result);
}

static void serial_try_write(Serial serial)
{
    void *data;
    int len, ret;

    assert(serial->fd >= 0);

    while (bufchain_size(&serial->output_data) > 0) {
        bufchain_prefix(&serial->output_data, &data, &len);
	ret = write(serial->fd, data, len);

        if (ret < 0 && (errno == EWOULDBLOCK)) {
            /*
             * We've sent all we can for the moment.
             */
            break;
        }
	if (ret < 0) {
	    perror("write serial port");
	    exit(1);
	}
	bufchain_consume(&serial->output_data, ret);
    }

    serial_uxsel_setup(serial);
}

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

    if (serial->fd < 0)
	return 0;

    bufchain_add(&serial->output_data, buf, len);
    serial_try_write(serial);

    return bufchain_size(&serial->output_data);
}

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

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

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

    if (serial->fd >= 0 && code == TS_BRK) {
	tcsendbreak(serial->fd, 0);
	logevent(serial->frontend, "Sending serial break at user request");
    }

    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;
    serial->inbufsize = backlog;
    serial_uxsel_setup(serial);
}

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->fd >= 0)
        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
aef05b78	1	/*
	2	* Serial back end (Unix-specific).
	3	*/
	4
aef05b78	5	#include <stdio.h>
	6	#include <stdlib.h>
	7	#include <assert.h>
	8	#include <limits.h>
	9
	10	#include <errno.h>
	11	#include <unistd.h>
	12	#include <fcntl.h>
	13	#include <termios.h>
	14
	15	#include "putty.h"
	16	#include "tree234.h"
	17
	18	#define SERIAL_MAX_BACKLOG 4096
	19
	20	typedef struct serial_backend_data {
	21	void *frontend;
	22	int fd;
	23	int finished;
	24	int inbufsize;
	25	bufchain output_data;
	26	} *Serial;
	27
	28	/*
	29	* We store our serial backends in a tree sorted by fd, so that
	30	* when we get an uxsel notification we know which backend instance
	31	* is the owner of the serial port that caused it.
	32	*/
	33	static int serial_compare_by_fd(void av, void bv)
	34	{
	35	Serial a = (Serial)av;
	36	Serial b = (Serial)bv;
	37
	38	if (a->fd < b->fd)
	39	return -1;
	40	else if (a->fd > b->fd)
	41	return +1;
	42	return 0;
	43	}
	44
	45	static int serial_find_by_fd(void av, void bv)
	46	{
	47	int a = (int )av;
	48	Serial b = (Serial)bv;
	49
	50	if (a < b->fd)
	51	return -1;
	52	else if (a > b->fd)
	53	return +1;
	54	return 0;
	55	}
	56
	57	static tree234 *serial_by_fd = NULL;
	58
	59	static int serial_select_result(int fd, int event);
	60	static void serial_uxsel_setup(Serial serial);
	61	static void serial_try_write(Serial serial);
	62
	63	static const char serial_configure(Serial serial, Config cfg)
	64	{
	65	struct termios options;
	66	int bflag, bval;
	67	const char *str;
	68	char *msg;
69
70	if (serial->fd < 0)
71	return "Unable to reconfigure already-closed serial connection";
72
73	tcgetattr(serial->fd, &options);
74
75	/*
76	* Find the appropriate baud rate flag.
77	*/
78	#define SETBAUD(x) (bflag = B ## x, bval = x)
79	#define CHECKBAUD(x) do { if (cfg->serspeed >= x) SETBAUD(x); } while (0)
80	SETBAUD(50);
81	#ifdef B75
82	CHECKBAUD(75);
83	#endif
84	#ifdef B110
85	CHECKBAUD(110);
86	#endif
87	#ifdef B134
88	CHECKBAUD(134);
89	#endif
90	#ifdef B150
91	CHECKBAUD(150);
92	#endif
93	#ifdef B200
94	CHECKBAUD(200);
95	#endif
96	#ifdef B300
97	CHECKBAUD(300);
98	#endif
99	#ifdef B600
100	CHECKBAUD(600);
101	#endif
102	#ifdef B1200
103	CHECKBAUD(1200);
104	#endif
105	#ifdef B1800
106	CHECKBAUD(1800);
107	#endif
108	#ifdef B2400
109	CHECKBAUD(2400);
110	#endif
111	#ifdef B4800
112	CHECKBAUD(4800);
113	#endif
114	#ifdef B9600
115	CHECKBAUD(9600);
116	#endif
117	#ifdef B19200
118	CHECKBAUD(19200);
119	#endif
120	#ifdef B38400
121	CHECKBAUD(38400);
122	#endif
123	#ifdef B57600
124	CHECKBAUD(57600);
125	#endif
126	#ifdef B76800
127	CHECKBAUD(76800);
128	#endif
129	#ifdef B115200
130	CHECKBAUD(115200);
131	#endif
25d0ab1e	132	#ifdef B153600
	133	CHECKBAUD(153600);
	134	#endif
aef05b78	135	#ifdef B230400
	136	CHECKBAUD(230400);
	137	#endif
25d0ab1e	138	#ifdef B307200
	139	CHECKBAUD(307200);
	140	#endif
	141	#ifdef B460800
	142	CHECKBAUD(460800);
	143	#endif
	144	#ifdef B500000
	145	CHECKBAUD(500000);
	146	#endif
	147	#ifdef B576000
	148	CHECKBAUD(576000);
	149	#endif
	150	#ifdef B921600
	151	CHECKBAUD(921600);
	152	#endif
	153	#ifdef B1000000
	154	CHECKBAUD(1000000);
	155	#endif
	156	#ifdef B1152000
	157	CHECKBAUD(1152000);
	158	#endif
	159	#ifdef B1500000
	160	CHECKBAUD(1500000);
	161	#endif
	162	#ifdef B2000000
	163	CHECKBAUD(2000000);
	164	#endif
	165	#ifdef B2500000
	166	CHECKBAUD(2500000);
	167	#endif
	168	#ifdef B3000000
	169	CHECKBAUD(3000000);
	170	#endif
	171	#ifdef B3500000
	172	CHECKBAUD(3500000);
	173	#endif
	174	#ifdef B4000000
	175	CHECKBAUD(4000000);
	176	#endif
aef05b78	177	#undef CHECKBAUD
	178	#undef SETBAUD
	179	cfsetispeed(&options, bflag);
	180	cfsetospeed(&options, bflag);
	181	msg = dupprintf("Configuring baud rate %d", bval);
	182	logevent(serial->frontend, msg);
	183	sfree(msg);
	184
	185	options.c_cflag &= ~CSIZE;
	186	switch (cfg->serdatabits) {
	187	case 5: options.c_cflag \|= CS5; break;
	188	case 6: options.c_cflag \|= CS6; break;
	189	case 7: options.c_cflag \|= CS7; break;
	190	case 8: options.c_cflag \|= CS8; break;
	191	default: return "Invalid number of data bits (need 5, 6, 7 or 8)";
	192	}
	193	msg = dupprintf("Configuring %d data bits", cfg->serdatabits);
	194	logevent(serial->frontend, msg);
	195	sfree(msg);
	196
	197	if (cfg->serstopbits >= 4) {
	198	options.c_cflag \|= CSTOPB;
	199	} else {
	200	options.c_cflag &= ~CSTOPB;
	201	}
	202	msg = dupprintf("Configuring %d stop bits",
	203	(options.c_cflag & CSTOPB ? 2 : 1));
	204	logevent(serial->frontend, msg);
	205	sfree(msg);
	206
e26f8aa1	207	options.c_iflag &= ~(IXON\|IXOFF);
	208	#ifdef CRTSCTS
	209	options.c_cflag &= ~CRTSCTS;
	210	#endif
	211	#ifdef CNEW_RTSCTS
	212	options.c_cflag &= ~CNEW_RTSCTS;
	213	#endif
aef05b78	214	if (cfg->serflow == SER_FLOW_XONXOFF) {
e26f8aa1	215	options.c_iflag \|= IXON \| IXOFF;
aef05b78	216	str = "XON/XOFF";
	217	} else if (cfg->serflow == SER_FLOW_RTSCTS) {
	218	#ifdef CRTSCTS
	219	options.c_cflag \|= CRTSCTS;
	220	#endif
	221	#ifdef CNEW_RTSCTS
	222	options.c_cflag \|= CNEW_RTSCTS;
	223	#endif
	224	str = "RTS/CTS";
	225	} else
	226	str = "no";
	227	msg = dupprintf("Configuring %s flow control", str);
	228	logevent(serial->frontend, msg);
	229	sfree(msg);
	230
	231	/* Parity */
	232	if (cfg->serparity == SER_PAR_ODD) {
	233	options.c_cflag \|= PARENB;
	234	options.c_cflag \|= PARODD;
	235	str = "odd";
	236	} else if (cfg->serparity == SER_PAR_EVEN) {
	237	options.c_cflag \|= PARENB;
	238	options.c_cflag &= ~PARODD;
	239	str = "even";
	240	} else {
	241	options.c_cflag &= ~PARENB;
	242	str = "no";
	243	}
	244	msg = dupprintf("Configuring %s parity", str);
	245	logevent(serial->frontend, msg);
	246	sfree(msg);
	247
	248	options.c_cflag \|= CLOCAL \| CREAD;
	249	options.c_lflag &= ~(ICANON \| ECHO \| ECHOE \| ISIG);
9a41f8d3	250	options.c_iflag &= ~(ISTRIP \| IGNCR \| INLCR \| ICRNL
	251	#ifdef IUCLC
	252	\| IUCLC
	253	#endif
	254	);
	255	options.c_oflag &= ~(OPOST
	256	#ifdef ONLCR
	257	\| ONLCR
	258	#endif
e8c03e4c	259	#ifdef OCRNL
	260	\| OCRNL
	261	#endif
	262	#ifdef ONOCR
	263	\| ONOCR
	264	#endif
	265	#ifdef ONLRET
	266	\| ONLRET
	267	#endif
	268	);
aef05b78	269	options.c_cc[VMIN] = 1;
	270	options.c_cc[VTIME] = 0;
	271
	272	if (tcsetattr(serial->fd, TCSANOW, &options) < 0)
	273	return "Unable to configure serial port";
	274
	275	return NULL;
	276	}
	277
	278	/*
	279	* Called to set up the serial connection.
	280	*
	281	* Returns an error message, or NULL on success.
	282	*
	283	* Also places the canonical host name into `realhost'. It must be
	284	* freed by the caller.
	285	*/
	286	static const char serial_init(void frontend_handle, void **backend_handle,
	287	Config *cfg,
	288	char host, int port, char *realhost, int nodelay,
	289	int keepalive)
	290	{
	291	Serial serial;
	292	const char *err;
	293
	294	serial = snew(struct serial_backend_data);
	295	*backend_handle = serial;
	296
	297	serial->frontend = frontend_handle;
	298	serial->finished = FALSE;
	299	serial->inbufsize = 0;
	300	bufchain_init(&serial->output_data);
	301
	302	{
	303	char *msg = dupprintf("Opening serial device %s", cfg->serline);
	304	logevent(serial->frontend, msg);
	305	}
	306
	307	serial->fd = open(cfg->serline, O_RDWR \| O_NOCTTY \| O_NDELAY \| O_NONBLOCK);
	308	if (serial->fd < 0)
	309	return "Unable to open serial port";
	310
db9b7dce	311	cloexec(serial->fd);
89e97516	312
aef05b78	313	err = serial_configure(serial, cfg);
	314	if (err)
	315	return err;
	316
	317	*realhost = dupstr(cfg->serline);
	318
	319	if (!serial_by_fd)
	320	serial_by_fd = newtree234(serial_compare_by_fd);
	321	add234(serial_by_fd, serial);
	322
	323	serial_uxsel_setup(serial);
	324
45ef7ce3	325	/*
	326	* Specials are always available.
	327	*/
	328	update_specials_menu(serial->frontend);
	329
aef05b78	330	return NULL;
	331	}
	332
	333	static void serial_close(Serial serial)
	334	{
	335	if (serial->fd >= 0) {
	336	close(serial->fd);
	337	serial->fd = -1;
	338	}
	339	}
	340
	341	static void serial_free(void *handle)
	342	{
	343	Serial serial = (Serial) handle;
	344
	345	serial_close(serial);
	346
	347	bufchain_clear(&serial->output_data);
	348
	349	sfree(serial);
	350	}
	351
	352	static void serial_reconfig(void handle, Config cfg)
	353	{
	354	Serial serial = (Serial) handle;
	355	const char *err;
	356
	357	err = serial_configure(serial, cfg);
	358
	359	/*
	360	* FIXME: what should we do if err returns something?
	361	*/
	362	}
	363
	364	static int serial_select_result(int fd, int event)
	365	{
	366	Serial serial;
	367	char buf[4096];
	368	int ret;
	369	int finished = FALSE;
	370
	371	serial = find234(serial_by_fd, &fd, serial_find_by_fd);
	372
	373	if (!serial)
	374	return 1; /* spurious event; keep going */
	375
	376	if (event == 1) {
	377	ret = read(serial->fd, buf, sizeof(buf));
	378
	379	if (ret == 0) {
	380	/*
	381	* Shouldn't happen on a real serial port, but I'm open
	382	* to the idea that there might be two-way devices we
	383	* can treat _like_ serial ports which can return EOF.
	384	*/
	385	finished = TRUE;
	386	} else if (ret < 0) {
0620c88a	387	#ifdef EAGAIN
	388	if (errno == EAGAIN)
	389	return 1; /* spurious */
	390	#endif
	391	#ifdef EWOULDBLOCK
	392	if (errno == EWOULDBLOCK)
	393	return 1; /* spurious */
	394	#endif
aef05b78	395	perror("read serial port");
	396	exit(1);
	397	} else if (ret > 0) {
	398	serial->inbufsize = from_backend(serial->frontend, 0, buf, ret);
	399	serial_uxsel_setup(serial); /* might acquire backlog and freeze */
	400	}
	401	} else if (event == 2) {
	402	/*
	403	* Attempt to send data down the pty.
	404	*/
	405	serial_try_write(serial);
	406	}
	407
	408	if (finished) {
	409	serial_close(serial);
	410
	411	serial->finished = TRUE;
	412
	413	notify_remote_exit(serial->frontend);
	414	}
	415
	416	return !finished;
	417	}
	418
	419	static void serial_uxsel_setup(Serial serial)
	420	{
	421	int rwx = 0;
	422
	423	if (serial->inbufsize <= SERIAL_MAX_BACKLOG)
	424	rwx \|= 1;
	425	if (bufchain_size(&serial->output_data))
	426	rwx \|= 2; /* might also want to write to it */
	427	uxsel_set(serial->fd, rwx, serial_select_result);
	428	}
	429
	430	static void serial_try_write(Serial serial)
	431	{
	432	void *data;
	433	int len, ret;
	434
	435	assert(serial->fd >= 0);
	436
	437	while (bufchain_size(&serial->output_data) > 0) {
	438	bufchain_prefix(&serial->output_data, &data, &len);
	439	ret = write(serial->fd, data, len);
	440
	441	if (ret < 0 && (errno == EWOULDBLOCK)) {
	442	/*
	443	* We've sent all we can for the moment.
	444	*/
	445	break;
	446	}
	447	if (ret < 0) {
	448	perror("write serial port");
	449	exit(1);
	450	}
	451	bufchain_consume(&serial->output_data, ret);
	452	}
	453
	454	serial_uxsel_setup(serial);
	455	}
	456
	457	/*
	458	* Called to send data down the serial connection.
459	*/
460	static int serial_send(void handle, char buf, int len)
461	{
462	Serial serial = (Serial) handle;
463
464	if (serial->fd < 0)
465	return 0;
466
467	bufchain_add(&serial->output_data, buf, len);
468	serial_try_write(serial);
469
470	return bufchain_size(&serial->output_data);
471	}
472
473	/*
474	* Called to query the current sendability status.
475	*/
476	static int serial_sendbuffer(void *handle)
477	{
478	Serial serial = (Serial) handle;
479	return bufchain_size(&serial->output_data);
480	}
481
482	/*
483	* Called to set the size of the window
484	*/
485	static void serial_size(void *handle, int width, int height)
486	{
487	/* Do nothing! */
488	return;
489	}
490
491	/*
492	* Send serial special codes.
493	*/
494	static void serial_special(void *handle, Telnet_Special code)
495	{
45ef7ce3	496	Serial serial = (Serial) handle;
	497
	498	if (serial->fd >= 0 && code == TS_BRK) {
	499	tcsendbreak(serial->fd, 0);
	500	logevent(serial->frontend, "Sending serial break at user request");
	501	}
	502
aef05b78	503	return;
	504	}
	505
	506	/*
	507	* Return a list of the special codes that make sense in this
	508	* protocol.
	509	*/
	510	static const struct telnet_special serial_get_specials(void handle)
	511	{
45ef7ce3	512	static const struct telnet_special specials[] = {
	513	{"Break", TS_BRK},
	514	{NULL, TS_EXITMENU}
	515	};
	516	return specials;
aef05b78	517	}
	518
	519	static int serial_connected(void *handle)
	520	{
	521	return 1; /* always connected */
	522	}
	523
	524	static int serial_sendok(void *handle)
	525	{
	526	return 1;
	527	}
	528
	529	static void serial_unthrottle(void *handle, int backlog)
	530	{
	531	Serial serial = (Serial) handle;
	532	serial->inbufsize = backlog;
	533	serial_uxsel_setup(serial);
	534	}
	535
	536	static int serial_ldisc(void *handle, int option)
	537	{
	538	/*
	539	* Local editing and local echo are off by default.
	540	*/
	541	return 0;
	542	}
	543
	544	static void serial_provide_ldisc(void handle, void ldisc)
	545	{
	546	/* This is a stub. */
	547	}
	548
	549	static void serial_provide_logctx(void handle, void logctx)
	550	{
	551	/* This is a stub. */
	552	}
	553
	554	static int serial_exitcode(void *handle)
	555	{
	556	Serial serial = (Serial) handle;
	557	if (serial->fd >= 0)
	558	return -1; /* still connected */
	559	else
	560	/* Exit codes are a meaningless concept with serial ports */
	561	return INT_MAX;
	562	}
	563
	564	/*
	565	* cfg_info for Serial does nothing at all.
	566	*/
	567	static int serial_cfg_info(void *handle)
	568	{
	569	return 0;
	570	}
	571
	572	Backend serial_backend = {
	573	serial_init,
	574	serial_free,
	575	serial_reconfig,
	576	serial_send,
	577	serial_sendbuffer,
	578	serial_size,
	579	serial_special,
	580	serial_get_specials,
581	serial_connected,
582	serial_exitcode,
583	serial_sendok,
584	serial_ldisc,
585	serial_provide_ldisc,
586	serial_provide_logctx,
587	serial_unthrottle,
588	serial_cfg_info,
9e164d82	589	"serial",
9e164d82	590	PROT_SERIAL,
a4451dd1	591	0
aef05b78	592	};