[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;
    int out_len;
    bool handshake_done;
    guint timer_tag;
} 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;
}

/*
 * 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));

    if (t->timer_tag) {
        g_source_remove(t->timer_tag);
        t->timer_tag = 0;
    }
    t->timer_tag = g_timeout_add_seconds(600, 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->out_len = 0;
    t->handshake_done = false;
    if (t->timer_tag) {
        g_source_remove(t->timer_tag);
        t->timer_tag = 0;
    }

    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_tag = g_timeout_add_seconds(600, 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 int read_payload_3270(EmulatedCcw3270Device *dev, uint32_t cda,
                             uint16_t count)
{
    Terminal3270 *t = TERMINAL_3270(dev);
    int len;

    len = MIN(count, t->in_len);
    cpu_physical_memory_write(cda, 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,
                              uint32_t cda, uint16_t count)
{
    Terminal3270 *t = TERMINAL_3270(dev);
    int retval = 0;

    assert(count <= (OUTPUT_BUFFER_SIZE - 3) / 2);

    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[0] = cmd;
    cpu_physical_memory_read(cda, &t->outv[1], count);
    t->out_len = count + 1;

    t->out_len = insert_IAC_escape_char(t->outv, t->out_len);
    t->outv[t->out_len++] = IAC;
    t->outv[t->out_len++] = IAC_EOR;

    retval = qemu_chr_fe_write_all(&t->chr, t->outv, t->out_len);
    return (retval <= 0) ? 0 : (retval - 3);
}

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;
	33	int out_len;
	34	bool handshake_done;
e65a2720	35	guint timer_tag;
b8476205 YC	36	} Terminal3270;
	37
	38	#define TYPE_TERMINAL_3270 "x-terminal3270"
2dc95b4c JL	39	#define TERMINAL_3270(obj) \
	40	OBJECT_CHECK(Terminal3270, (obj), TYPE_TERMINAL_3270)
	41
	42	static int terminal_can_read(void *opaque)
	43	{
	44	Terminal3270 *t = opaque;
	45
	46	return INPUT_BUFFER_SIZE - t->in_len;
	47	}
	48
	49	/*
	50	* Protocol handshake done,
	51	* signal guest by an unsolicited DE irq.
	52	*/
	53	static void TN3270_handshake_done(Terminal3270 *t)
	54	{
	55	CcwDevice *ccw_dev = CCW_DEVICE(t);
	56	SubchDev *sch = ccw_dev->sch;
	57
	58	t->handshake_done = true;
	59	sch->curr_status.scsw.dstat = SCSW_DSTAT_DEVICE_END;
	60	css_conditional_io_interrupt(sch);
	61	}
	62
e65a2720 JL	63	/*
	64	* Called when the interval is timeout to detect
	65	* if the client is still alive by Timing Mark.
	66	*/
	67	static gboolean send_timing_mark_cb(gpointer opaque)
	68	{
	69	Terminal3270 *t = opaque;
	70	const uint8_t timing[] = {0xff, 0xfd, 0x06};
	71
	72	qemu_chr_fe_write_all(&t->chr, timing, sizeof(timing));
	73	return true;
	74	}
	75
2dc95b4c JL	76	/*
	77	* Receive inbound data from socket.
	78	* For data given to guest, drop the data boundary IAC, IAC_EOR.
	79	* TODO:
	80	* Using "Reset" key on x3270 may result multiple commands in one packet.
	81	* This usually happens when the user meets a poor traffic of the network.
	82	* As of now, for such case, we simply terminate the connection,
	83	* and we should come back here later with a better solution.
	84	*/
	85	static void terminal_read(void opaque, const uint8_t buf, int size)
	86	{
	87	Terminal3270 *t = opaque;
	88	CcwDevice *ccw_dev = CCW_DEVICE(t);
	89	SubchDev *sch = ccw_dev->sch;
	90	int end;
	91
	92	assert(size <= (INPUT_BUFFER_SIZE - t->in_len));
	93
e65a2720 JL	94	if (t->timer_tag) {
	95	g_source_remove(t->timer_tag);
	96	t->timer_tag = 0;
	97	}
	98	t->timer_tag = g_timeout_add_seconds(600, send_timing_mark_cb, t);
	99
2dc95b4c JL	100	memcpy(&t->inv[t->in_len], buf, size);
	101	t->in_len += size;
	102	if (t->in_len < 2) {
	103	return;
	104	}
	105
	106	if (!t->handshake_done) {
	107	/*
	108	* Receiving Terminal Type is the last step of handshake.
	109	* The data format: IAC SB Terminal-Type IS <terminal type> IAC SE
	110	* The code for Terminal-Type is 0x18, for IS is 0.
	111	* Simply check the data format and mark handshake_done.
	112	*/
	113	if (t->in_len > 6 && t->inv[2] == 0x18 && t->inv[3] == 0x0 &&
	114	t->inv[t->in_len - 2] == IAC && t->inv[t->in_len - 1] == IAC_SE) {
	115	TN3270_handshake_done(t);
	116	t->in_len = 0;
	117	}
	118	return;
	119	}
	120
	121	for (end = 0; end < t->in_len - 1; end++) {
	122	if (t->inv[end] == IAC && t->inv[end + 1] == IAC_EOR) {
	123	break;
	124	}
	125	}
	126	if (end == t->in_len - 2) {
	127	/* Data is valid for consuming. */
	128	t->in_len -= 2;
	129	sch->curr_status.scsw.dstat = SCSW_DSTAT_ATTENTION;
	130	css_conditional_io_interrupt(sch);
	131	} else if (end < t->in_len - 2) {
	132	/* "Reset" key is used. */
	133	qemu_chr_fe_disconnect(&t->chr);
	134	} else {
	135	/* Gathering data. */
	136	return;
	137	}
	138	}
b8476205	139
4996241a JL	140	static void chr_event(void *opaque, int event)
	141	{
	142	Terminal3270 *t = opaque;
	143	CcwDevice *ccw_dev = CCW_DEVICE(t);
	144	SubchDev *sch = ccw_dev->sch;
	145
	146	/* Ensure the initial status correct, always reset them. */
	147	t->in_len = 0;
	148	t->out_len = 0;
	149	t->handshake_done = false;
e65a2720 JL	150	if (t->timer_tag) {
	151	g_source_remove(t->timer_tag);
	152	t->timer_tag = 0;
	153	}
4996241a JL	154
	155	switch (event) {
	156	case CHR_EVENT_OPENED:
	157	/*
	158	* 3270 does handshake firstly by the negotiate options in
	159	* char-socket.c. Once qemu receives the terminal-type of the
	160	* client, mark handshake done and trigger everything rolling again.
	161	*/
e65a2720	162	t->timer_tag = g_timeout_add_seconds(600, send_timing_mark_cb, t);
4996241a JL	163	break;
	164	case CHR_EVENT_CLOSED:
	165	sch->curr_status.scsw.dstat = SCSW_DSTAT_DEVICE_END;
	166	css_conditional_io_interrupt(sch);
	167	break;
	168	}
	169	}
	170
b8476205 YC	171	static void terminal_init(EmulatedCcw3270Device dev, Error *errp)
b8476205 YC	172	{
2dc95b4c	173	Terminal3270 *t = TERMINAL_3270(dev);
b8476205 YC	174	static bool terminal_available;
	175
	176	if (terminal_available) {
	177	error_setg(errp, "Multiple 3270 terminals are not supported.");
	178	return;
	179	}
	180	terminal_available = true;
2dc95b4c	181	qemu_chr_fe_set_handlers(&t->chr, terminal_can_read,
81517ba3	182	terminal_read, chr_event, NULL, t, NULL, true);
2dc95b4c JL	183	}
	184
	185	static int read_payload_3270(EmulatedCcw3270Device *dev, uint32_t cda,
	186	uint16_t count)
	187	{
	188	Terminal3270 *t = TERMINAL_3270(dev);
	189	int len;
	190
	191	len = MIN(count, t->in_len);
	192	cpu_physical_memory_write(cda, t->inv, len);
	193	t->in_len -= len;
	194
	195	return len;
	196	}
	197
	198	/* TN3270 uses binary transmission, which needs escape IAC to IAC IAC */
	199	static int insert_IAC_escape_char(uint8_t *outv, int out_len)
	200	{
	201	int IAC_num = 0, new_out_len, i, j;
	202
	203	for (i = 0; i < out_len; i++) {
	204	if (outv[i] == IAC) {
	205	IAC_num++;
	206	}
	207	}
	208	if (IAC_num == 0) {
	209	return out_len;
	210	}
	211	new_out_len = out_len + IAC_num;
	212	for (i = out_len - 1, j = new_out_len - 1; j > i && i >= 0; i--, j--) {
	213	outv[j] = outv[i];
	214	if (outv[i] == IAC) {
	215	outv[--j] = IAC;
	216	}
	217	}
	218	return new_out_len;
b8476205 YC	219	}
b8476205 YC	220
2dc95b4c JL	221	/*
	222	* Write 3270 outbound to socket.
	223	* Return the count of 3270 data field if succeeded, zero if failed.
	224	*/
	225	static int write_payload_3270(EmulatedCcw3270Device *dev, uint8_t cmd,
	226	uint32_t cda, uint16_t count)
	227	{
	228	Terminal3270 *t = TERMINAL_3270(dev);
	229	int retval = 0;
	230
	231	assert(count <= (OUTPUT_BUFFER_SIZE - 3) / 2);
	232
	233	if (!t->handshake_done) {
e65a2720 JL	234	if (!(t->outv[0] == IAC && t->outv[1] != IAC)) {
	235	/*
	236	* Before having finished 3270 negotiation,
	237	* sending outbound data except protocol options is prohibited.
	238	*/
	239	return 0;
	240	}
2dc95b4c	241	}
30650701	242	if (!qemu_chr_fe_backend_connected(&t->chr)) {
2dc95b4c JL	243	/* We just say we consumed all data if there's no backend. */
	244	return count;
	245	}
	246	t->outv[0] = cmd;
	247	cpu_physical_memory_read(cda, &t->outv[1], count);
	248	t->out_len = count + 1;
	249
	250	t->out_len = insert_IAC_escape_char(t->outv, t->out_len);
	251	t->outv[t->out_len++] = IAC;
	252	t->outv[t->out_len++] = IAC_EOR;
	253
	254	retval = qemu_chr_fe_write_all(&t->chr, t->outv, t->out_len);
	255	return (retval <= 0) ? 0 : (retval - 3);
	256	}
	257
	258	static Property terminal_properties[] = {
	259	DEFINE_PROP_CHR("chardev", Terminal3270, chr),
	260	DEFINE_PROP_END_OF_LIST(),
	261	};
	262
9e8b3009 JL	263	static const VMStateDescription terminal3270_vmstate = {
	264	.name = TYPE_TERMINAL_3270,
	265	.unmigratable = 1,
	266	};
	267
b8476205 YC	268	static void terminal_class_init(ObjectClass klass, void data)
b8476205 YC	269	{
2dc95b4c	270	DeviceClass *dc = DEVICE_CLASS(klass);
b8476205 YC	271	EmulatedCcw3270Class *ck = EMULATED_CCW_3270_CLASS(klass);
b8476205 YC	272
2dc95b4c	273	dc->props = terminal_properties;
9e8b3009	274	dc->vmsd = &terminal3270_vmstate;
b8476205	275	ck->init = terminal_init;
2dc95b4c JL	276	ck->read_payload_3270 = read_payload_3270;
2dc95b4c JL	277	ck->write_payload_3270 = write_payload_3270;
b8476205 YC	278	}
	279
	280	static const TypeInfo ccw_terminal_info = {
	281	.name = TYPE_TERMINAL_3270,
	282	.parent = TYPE_EMULATED_CCW_3270,
	283	.instance_size = sizeof(Terminal3270),
	284	.class_init = terminal_class_init,
	285	.class_size = sizeof(EmulatedCcw3270Class),
	286	};
	287
	288	static void register_types(void)
	289	{
	290	type_register_static(&ccw_terminal_info);
	291	}
	292
	293	type_init(register_types)