[qemu.git] / hw / char / terminal3270.c

/*
 * Terminal 3270 implementation
 *
 * Copyright 2017 IBM Corp.
 *
 * Authors: Yang Chen <[email protected]>
 *          Jing Liu <[email protected]>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or (at
 * your option) any later version. See the COPYING file in the top-level
 * directory.
 */

#include "qemu/osdep.h"
#include "qapi/error.h"
#include "chardev/char-fe.h"
#include "hw/s390x/3270-ccw.h"

/* Enough spaces for different window sizes. */
#define INPUT_BUFFER_SIZE  1000
/*
 * 1 for header, 1024*2 for datastream, 2 for tail
 * Reserve enough spaces for telnet IAC escape.
 */
#define OUTPUT_BUFFER_SIZE 2051

typedef struct Terminal3270 {
    EmulatedCcw3270Device cdev;
    CharBackend chr;
    uint8_t inv[INPUT_BUFFER_SIZE];
    uint8_t outv[OUTPUT_BUFFER_SIZE];
    int in_len;
    bool handshake_done;
    GSource *timer_src;
} Terminal3270;

#define TYPE_TERMINAL_3270 "x-terminal3270"
#define TERMINAL_3270(obj) \
        OBJECT_CHECK(Terminal3270, (obj), TYPE_TERMINAL_3270)

static int terminal_can_read(void *opaque)
{
    Terminal3270 *t = opaque;

    return INPUT_BUFFER_SIZE - t->in_len;
}

static void terminal_timer_cancel(Terminal3270 *t)
{
    if (t->timer_src) {
        g_source_destroy(t->timer_src);
        g_source_unref(t->timer_src);
        t->timer_src = NULL;
    }
}

/*
 * Protocol handshake done,
 * signal guest by an unsolicited DE irq.
 */
static void TN3270_handshake_done(Terminal3270 *t)
{
    CcwDevice *ccw_dev = CCW_DEVICE(t);
    SubchDev *sch = ccw_dev->sch;

    t->handshake_done = true;
    sch->curr_status.scsw.dstat = SCSW_DSTAT_DEVICE_END;
    css_conditional_io_interrupt(sch);
}

/*
 * Called when the interval is timeout to detect
 * if the client is still alive by Timing Mark.
 */
static gboolean send_timing_mark_cb(gpointer opaque)
{
    Terminal3270 *t = opaque;
    const uint8_t timing[] = {0xff, 0xfd, 0x06};

    qemu_chr_fe_write_all(&t->chr, timing, sizeof(timing));
    return true;
}

/*
 * Receive inbound data from socket.
 * For data given to guest, drop the data boundary IAC, IAC_EOR.
 * TODO:
 * Using "Reset" key on x3270 may result multiple commands in one packet.
 * This usually happens when the user meets a poor traffic of the network.
 * As of now, for such case, we simply terminate the connection,
 * and we should come back here later with a better solution.
 */
static void terminal_read(void *opaque, const uint8_t *buf, int size)
{
    Terminal3270 *t = opaque;
    CcwDevice *ccw_dev = CCW_DEVICE(t);
    SubchDev *sch = ccw_dev->sch;
    int end;

    assert(size <= (INPUT_BUFFER_SIZE - t->in_len));

    terminal_timer_cancel(t);
    t->timer_src = qemu_chr_timeout_add_ms(t->chr.chr, 600 * 1000,
                                           send_timing_mark_cb, t);
    memcpy(&t->inv[t->in_len], buf, size);
    t->in_len += size;
    if (t->in_len < 2) {
        return;
    }

    if (!t->handshake_done) {
        /*
         * Receiving Terminal Type is the last step of handshake.
         * The data format: IAC SB Terminal-Type IS <terminal type> IAC SE
         * The code for Terminal-Type is 0x18, for IS is 0.
         * Simply check the data format and mark handshake_done.
         */
        if (t->in_len > 6 && t->inv[2] == 0x18 && t->inv[3] == 0x0 &&
            t->inv[t->in_len - 2] == IAC && t->inv[t->in_len - 1] == IAC_SE) {
            TN3270_handshake_done(t);
            t->in_len = 0;
        }
        return;
    }

    for (end = 0; end < t->in_len - 1; end++) {
        if (t->inv[end] == IAC && t->inv[end + 1] == IAC_EOR) {
            break;
        }
    }
    if (end == t->in_len - 2) {
        /* Data is valid for consuming. */
        t->in_len -= 2;
        sch->curr_status.scsw.dstat = SCSW_DSTAT_ATTENTION;
        css_conditional_io_interrupt(sch);
    } else if (end < t->in_len - 2) {
        /* "Reset" key is used. */
        qemu_chr_fe_disconnect(&t->chr);
    } else {
        /* Gathering data. */
        return;
    }
}

static void chr_event(void *opaque, int event)
{
    Terminal3270 *t = opaque;
    CcwDevice *ccw_dev = CCW_DEVICE(t);
    SubchDev *sch = ccw_dev->sch;

    /* Ensure the initial status correct, always reset them. */
    t->in_len = 0;
    t->handshake_done = false;
    terminal_timer_cancel(t);

    switch (event) {
    case CHR_EVENT_OPENED:
        /*
         * 3270 does handshake firstly by the negotiate options in
         * char-socket.c. Once qemu receives the terminal-type of the
         * client, mark handshake done and trigger everything rolling again.
         */
        t->timer_src = qemu_chr_timeout_add_ms(t->chr.chr, 600 * 1000,
                                               send_timing_mark_cb, t);
        break;
    case CHR_EVENT_CLOSED:
        sch->curr_status.scsw.dstat = SCSW_DSTAT_DEVICE_END;
        css_conditional_io_interrupt(sch);
        break;
    }
}

static void terminal_init(EmulatedCcw3270Device *dev, Error **errp)
{
    Terminal3270 *t = TERMINAL_3270(dev);
    static bool terminal_available;

    if (terminal_available) {
        error_setg(errp, "Multiple 3270 terminals are not supported.");
        return;
    }
    terminal_available = true;
    qemu_chr_fe_set_handlers(&t->chr, terminal_can_read,
                             terminal_read, chr_event, NULL, t, NULL, true);
}

static inline CcwDataStream *get_cds(Terminal3270 *t)
{
    return &(CCW_DEVICE(&t->cdev)->sch->cds);
}

static int read_payload_3270(EmulatedCcw3270Device *dev)
{
    Terminal3270 *t = TERMINAL_3270(dev);
    int len;

    len = MIN(ccw_dstream_avail(get_cds(t)), t->in_len);
    ccw_dstream_write_buf(get_cds(t), t->inv, len);
    t->in_len -= len;

    return len;
}

/* TN3270 uses binary transmission, which needs escape IAC to IAC IAC */
static int insert_IAC_escape_char(uint8_t *outv, int out_len)
{
    int IAC_num = 0, new_out_len, i, j;

    for (i = 0; i < out_len; i++) {
        if (outv[i] == IAC) {
            IAC_num++;
        }
    }
    if (IAC_num == 0) {
        return out_len;
    }
    new_out_len = out_len + IAC_num;
    for (i = out_len - 1, j = new_out_len - 1; j > i && i >= 0; i--, j--) {
        outv[j] = outv[i];
        if (outv[i] == IAC) {
            outv[--j] = IAC;
        }
    }
    return new_out_len;
}

/*
 * Write 3270 outbound to socket.
 * Return the count of 3270 data field if succeeded, zero if failed.
 */
static int write_payload_3270(EmulatedCcw3270Device *dev, uint8_t cmd)
{
    Terminal3270 *t = TERMINAL_3270(dev);
    int retval = 0;
    int count = ccw_dstream_avail(get_cds(t));
    int bound = (OUTPUT_BUFFER_SIZE - 3) / 2;
    int len = MIN(count, bound);
    int out_len = 0;

    if (!t->handshake_done) {
        if (!(t->outv[0] == IAC && t->outv[1] != IAC)) {
            /*
             * Before having finished 3270 negotiation,
             * sending outbound data except protocol options is prohibited.
             */
            return 0;
        }
    }
    if (!qemu_chr_fe_backend_connected(&t->chr)) {
        /* We just say we consumed all data if there's no backend. */
        return count;
    }

    t->outv[out_len++] = cmd;
    do {
        ccw_dstream_read_buf(get_cds(t), &t->outv[out_len], len);
        count = ccw_dstream_avail(get_cds(t));
        out_len += len;

        out_len = insert_IAC_escape_char(t->outv, out_len);
        if (!count) {
            t->outv[out_len++] = IAC;
            t->outv[out_len++] = IAC_EOR;
        }
        retval = qemu_chr_fe_write_all(&t->chr, t->outv, out_len);
        len = MIN(count, bound);
        out_len = 0;
    } while (len && retval >= 0);
    return (retval <= 0) ? 0 : get_cds(t)->count;
}

static Property terminal_properties[] = {
    DEFINE_PROP_CHR("chardev", Terminal3270, chr),
    DEFINE_PROP_END_OF_LIST(),
};

static const VMStateDescription terminal3270_vmstate = {
    .name = TYPE_TERMINAL_3270,
    .unmigratable = 1,
};

static void terminal_class_init(ObjectClass *klass, void *data)
{
    DeviceClass *dc = DEVICE_CLASS(klass);
    EmulatedCcw3270Class *ck = EMULATED_CCW_3270_CLASS(klass);

    dc->props = terminal_properties;
    dc->vmsd = &terminal3270_vmstate;
    ck->init = terminal_init;
    ck->read_payload_3270 = read_payload_3270;
    ck->write_payload_3270 = write_payload_3270;
}

static const TypeInfo ccw_terminal_info = {
    .name = TYPE_TERMINAL_3270,
    .parent = TYPE_EMULATED_CCW_3270,
    .instance_size = sizeof(Terminal3270),
    .class_init = terminal_class_init,
    .class_size = sizeof(EmulatedCcw3270Class),
};

static void register_types(void)
{
    type_register_static(&ccw_terminal_info);
}

type_init(register_types)
Commit	Line	Data
b8476205 YC	1	/*
	2	* Terminal 3270 implementation
	3	*
	4	* Copyright 2017 IBM Corp.
	5	*
	6	* Authors: Yang Chen <[email protected]>
	7	* Jing Liu <[email protected]>
	8	*
	9	* This work is licensed under the terms of the GNU GPL, version 2 or (at
	10	* your option) any later version. See the COPYING file in the top-level
	11	* directory.
	12	*/
	13
	14	#include "qemu/osdep.h"
2dc95b4c	15	#include "qapi/error.h"
4d43a603	16	#include "chardev/char-fe.h"
b8476205 YC	17	#include "hw/s390x/3270-ccw.h"
b8476205 YC	18
2dc95b4c JL	19	/* Enough spaces for different window sizes. */
	20	#define INPUT_BUFFER_SIZE 1000
	21	/*
	22	* 1 for header, 1024*2 for datastream, 2 for tail
	23	* Reserve enough spaces for telnet IAC escape.
	24	*/
	25	#define OUTPUT_BUFFER_SIZE 2051
	26
b8476205 YC	27	typedef struct Terminal3270 {
b8476205 YC	28	EmulatedCcw3270Device cdev;
2dc95b4c JL	29	CharBackend chr;
	30	uint8_t inv[INPUT_BUFFER_SIZE];
	31	uint8_t outv[OUTPUT_BUFFER_SIZE];
	32	int in_len;
2dc95b4c	33	bool handshake_done;
2c716ba1	34	GSource *timer_src;
b8476205 YC	35	} Terminal3270;
	36
	37	#define TYPE_TERMINAL_3270 "x-terminal3270"
2dc95b4c JL	38	#define TERMINAL_3270(obj) \
	39	OBJECT_CHECK(Terminal3270, (obj), TYPE_TERMINAL_3270)
	40
	41	static int terminal_can_read(void *opaque)
	42	{
	43	Terminal3270 *t = opaque;
	44
	45	return INPUT_BUFFER_SIZE - t->in_len;
	46	}
	47
2c716ba1 PX	48	static void terminal_timer_cancel(Terminal3270 *t)
	49	{
	50	if (t->timer_src) {
	51	g_source_destroy(t->timer_src);
	52	g_source_unref(t->timer_src);
	53	t->timer_src = NULL;
	54	}
	55	}
	56
2dc95b4c JL	57	/*
	58	* Protocol handshake done,
	59	* signal guest by an unsolicited DE irq.
	60	*/
	61	static void TN3270_handshake_done(Terminal3270 *t)
	62	{
	63	CcwDevice *ccw_dev = CCW_DEVICE(t);
	64	SubchDev *sch = ccw_dev->sch;
	65
	66	t->handshake_done = true;
	67	sch->curr_status.scsw.dstat = SCSW_DSTAT_DEVICE_END;
	68	css_conditional_io_interrupt(sch);
	69	}
	70
e65a2720 JL	71	/*
	72	* Called when the interval is timeout to detect
	73	* if the client is still alive by Timing Mark.
	74	*/
	75	static gboolean send_timing_mark_cb(gpointer opaque)
	76	{
	77	Terminal3270 *t = opaque;
	78	const uint8_t timing[] = {0xff, 0xfd, 0x06};
	79
	80	qemu_chr_fe_write_all(&t->chr, timing, sizeof(timing));
	81	return true;
	82	}
	83
2dc95b4c JL	84	/*
	85	* Receive inbound data from socket.
	86	* For data given to guest, drop the data boundary IAC, IAC_EOR.
	87	* TODO:
	88	* Using "Reset" key on x3270 may result multiple commands in one packet.
	89	* This usually happens when the user meets a poor traffic of the network.
	90	* As of now, for such case, we simply terminate the connection,
	91	* and we should come back here later with a better solution.
	92	*/
	93	static void terminal_read(void opaque, const uint8_t buf, int size)
	94	{
	95	Terminal3270 *t = opaque;
	96	CcwDevice *ccw_dev = CCW_DEVICE(t);
	97	SubchDev *sch = ccw_dev->sch;
	98	int end;
	99
	100	assert(size <= (INPUT_BUFFER_SIZE - t->in_len));
	101
2c716ba1 PX	102	terminal_timer_cancel(t);
	103	t->timer_src = qemu_chr_timeout_add_ms(t->chr.chr, 600 * 1000,
	104	send_timing_mark_cb, t);
2dc95b4c JL	105	memcpy(&t->inv[t->in_len], buf, size);
	106	t->in_len += size;
	107	if (t->in_len < 2) {
	108	return;
	109	}
	110
	111	if (!t->handshake_done) {
	112	/*
	113	* Receiving Terminal Type is the last step of handshake.
	114	* The data format: IAC SB Terminal-Type IS <terminal type> IAC SE
	115	* The code for Terminal-Type is 0x18, for IS is 0.
	116	* Simply check the data format and mark handshake_done.
	117	*/
	118	if (t->in_len > 6 && t->inv[2] == 0x18 && t->inv[3] == 0x0 &&
	119	t->inv[t->in_len - 2] == IAC && t->inv[t->in_len - 1] == IAC_SE) {
	120	TN3270_handshake_done(t);
	121	t->in_len = 0;
	122	}
	123	return;
	124	}
	125
	126	for (end = 0; end < t->in_len - 1; end++) {
	127	if (t->inv[end] == IAC && t->inv[end + 1] == IAC_EOR) {
	128	break;
	129	}
	130	}
	131	if (end == t->in_len - 2) {
	132	/* Data is valid for consuming. */
	133	t->in_len -= 2;
	134	sch->curr_status.scsw.dstat = SCSW_DSTAT_ATTENTION;
	135	css_conditional_io_interrupt(sch);
	136	} else if (end < t->in_len - 2) {
	137	/* "Reset" key is used. */
	138	qemu_chr_fe_disconnect(&t->chr);
	139	} else {
	140	/* Gathering data. */
	141	return;
	142	}
	143	}
b8476205	144
4996241a JL	145	static void chr_event(void *opaque, int event)
	146	{
	147	Terminal3270 *t = opaque;
	148	CcwDevice *ccw_dev = CCW_DEVICE(t);
	149	SubchDev *sch = ccw_dev->sch;
	150
	151	/* Ensure the initial status correct, always reset them. */
	152	t->in_len = 0;
4996241a	153	t->handshake_done = false;
2c716ba1	154	terminal_timer_cancel(t);
4996241a JL	155
	156	switch (event) {
	157	case CHR_EVENT_OPENED:
	158	/*
	159	* 3270 does handshake firstly by the negotiate options in
	160	* char-socket.c. Once qemu receives the terminal-type of the
	161	* client, mark handshake done and trigger everything rolling again.
	162	*/
2c716ba1 PX	163	t->timer_src = qemu_chr_timeout_add_ms(t->chr.chr, 600 * 1000,
2c716ba1 PX	164	send_timing_mark_cb, t);
4996241a JL	165	break;
	166	case CHR_EVENT_CLOSED:
	167	sch->curr_status.scsw.dstat = SCSW_DSTAT_DEVICE_END;
	168	css_conditional_io_interrupt(sch);
	169	break;
	170	}
	171	}
	172
b8476205 YC	173	static void terminal_init(EmulatedCcw3270Device dev, Error *errp)
b8476205 YC	174	{
2dc95b4c	175	Terminal3270 *t = TERMINAL_3270(dev);
b8476205 YC	176	static bool terminal_available;
	177
	178	if (terminal_available) {
	179	error_setg(errp, "Multiple 3270 terminals are not supported.");
	180	return;
	181	}
	182	terminal_available = true;
2dc95b4c	183	qemu_chr_fe_set_handlers(&t->chr, terminal_can_read,
81517ba3	184	terminal_read, chr_event, NULL, t, NULL, true);
2dc95b4c JL	185	}
2dc95b4c JL	186
1baa2eb0 HP	187	static inline CcwDataStream get_cds(Terminal3270 t)
	188	{
	189	return &(CCW_DEVICE(&t->cdev)->sch->cds);
	190	}
	191
	192	static int read_payload_3270(EmulatedCcw3270Device *dev)
2dc95b4c JL	193	{
	194	Terminal3270 *t = TERMINAL_3270(dev);
	195	int len;
	196
1baa2eb0 HP	197	len = MIN(ccw_dstream_avail(get_cds(t)), t->in_len);
1baa2eb0 HP	198	ccw_dstream_write_buf(get_cds(t), t->inv, len);
2dc95b4c JL	199	t->in_len -= len;
	200
	201	return len;
	202	}
	203
	204	/* TN3270 uses binary transmission, which needs escape IAC to IAC IAC */
	205	static int insert_IAC_escape_char(uint8_t *outv, int out_len)
	206	{
	207	int IAC_num = 0, new_out_len, i, j;
	208
	209	for (i = 0; i < out_len; i++) {
	210	if (outv[i] == IAC) {
	211	IAC_num++;
	212	}
	213	}
	214	if (IAC_num == 0) {
	215	return out_len;
	216	}
	217	new_out_len = out_len + IAC_num;
	218	for (i = out_len - 1, j = new_out_len - 1; j > i && i >= 0; i--, j--) {
	219	outv[j] = outv[i];
	220	if (outv[i] == IAC) {
	221	outv[--j] = IAC;
	222	}
	223	}
	224	return new_out_len;
b8476205 YC	225	}
b8476205 YC	226
2dc95b4c JL	227	/*
	228	* Write 3270 outbound to socket.
	229	* Return the count of 3270 data field if succeeded, zero if failed.
	230	*/
1baa2eb0	231	static int write_payload_3270(EmulatedCcw3270Device *dev, uint8_t cmd)
2dc95b4c JL	232	{
	233	Terminal3270 *t = TERMINAL_3270(dev);
	234	int retval = 0;
1baa2eb0	235	int count = ccw_dstream_avail(get_cds(t));
17ec9921 HP	236	int bound = (OUTPUT_BUFFER_SIZE - 3) / 2;
	237	int len = MIN(count, bound);
	238	int out_len = 0;
2dc95b4c JL	239
2dc95b4c JL	240	if (!t->handshake_done) {
e65a2720 JL	241	if (!(t->outv[0] == IAC && t->outv[1] != IAC)) {
	242	/*
	243	* Before having finished 3270 negotiation,
	244	* sending outbound data except protocol options is prohibited.
	245	*/
	246	return 0;
	247	}
2dc95b4c	248	}
30650701	249	if (!qemu_chr_fe_backend_connected(&t->chr)) {
2dc95b4c JL	250	/* We just say we consumed all data if there's no backend. */
	251	return count;
	252	}
2dc95b4c	253
17ec9921 HP	254	t->outv[out_len++] = cmd;
	255	do {
	256	ccw_dstream_read_buf(get_cds(t), &t->outv[out_len], len);
	257	count = ccw_dstream_avail(get_cds(t));
	258	out_len += len;
2dc95b4c	259
17ec9921 HP	260	out_len = insert_IAC_escape_char(t->outv, out_len);
	261	if (!count) {
	262	t->outv[out_len++] = IAC;
	263	t->outv[out_len++] = IAC_EOR;
	264	}
	265	retval = qemu_chr_fe_write_all(&t->chr, t->outv, out_len);
	266	len = MIN(count, bound);
	267	out_len = 0;
	268	} while (len && retval >= 0);
	269	return (retval <= 0) ? 0 : get_cds(t)->count;
2dc95b4c JL	270	}
	271
	272	static Property terminal_properties[] = {
	273	DEFINE_PROP_CHR("chardev", Terminal3270, chr),
	274	DEFINE_PROP_END_OF_LIST(),
	275	};
	276
9e8b3009 JL	277	static const VMStateDescription terminal3270_vmstate = {
	278	.name = TYPE_TERMINAL_3270,
	279	.unmigratable = 1,
	280	};
	281
b8476205 YC	282	static void terminal_class_init(ObjectClass klass, void data)
b8476205 YC	283	{
2dc95b4c	284	DeviceClass *dc = DEVICE_CLASS(klass);
b8476205 YC	285	EmulatedCcw3270Class *ck = EMULATED_CCW_3270_CLASS(klass);
b8476205 YC	286
2dc95b4c	287	dc->props = terminal_properties;
9e8b3009	288	dc->vmsd = &terminal3270_vmstate;
b8476205	289	ck->init = terminal_init;
2dc95b4c JL	290	ck->read_payload_3270 = read_payload_3270;
2dc95b4c JL	291	ck->write_payload_3270 = write_payload_3270;
b8476205 YC	292	}
	293
	294	static const TypeInfo ccw_terminal_info = {
	295	.name = TYPE_TERMINAL_3270,
	296	.parent = TYPE_EMULATED_CCW_3270,
	297	.instance_size = sizeof(Terminal3270),
	298	.class_init = terminal_class_init,
	299	.class_size = sizeof(EmulatedCcw3270Class),
	300	};
	301
	302	static void register_types(void)
	303	{
	304	type_register_static(&ccw_terminal_info);
	305	}
	306
	307	type_init(register_types)