[qemu.git] / chardev / char-pty.c

/*
 * QEMU System Emulator
 *
 * Copyright (c) 2003-2008 Fabrice Bellard
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu-common.h"
#include "chardev/char.h"
#include "io/channel-file.h"
#include "qemu/sockets.h"
#include "qemu/error-report.h"

#include "chardev/char-io.h"

#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__)      \
    || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \
    || defined(__GLIBC__)

typedef struct {
    Chardev parent;
    QIOChannel *ioc;
    int read_bytes;

    /* Protected by the Chardev chr_write_lock.  */
    int connected;
    GSource *timer_src;
    GSource *open_source;
} PtyChardev;

#define PTY_CHARDEV(obj) OBJECT_CHECK(PtyChardev, (obj), TYPE_CHARDEV_PTY)

static void pty_chr_update_read_handler_locked(Chardev *chr);
static void pty_chr_state(Chardev *chr, int connected);

static void pty_chr_timer_cancel(PtyChardev *s)
{
    if (s->timer_src) {
        g_source_destroy(s->timer_src);
        g_source_unref(s->timer_src);
        s->timer_src = NULL;
    }
}

static void pty_chr_open_src_cancel(PtyChardev *s)
{
    if (s->open_source) {
        g_source_destroy(s->open_source);
        g_source_unref(s->open_source);
        s->open_source = NULL;
    }
}

static gboolean pty_chr_timer(gpointer opaque)
{
    struct Chardev *chr = CHARDEV(opaque);
    PtyChardev *s = PTY_CHARDEV(opaque);

    qemu_mutex_lock(&chr->chr_write_lock);
    pty_chr_timer_cancel(s);
    pty_chr_open_src_cancel(s);
    if (!s->connected) {
        /* Next poll ... */
        pty_chr_update_read_handler_locked(chr);
    }
    qemu_mutex_unlock(&chr->chr_write_lock);
    return FALSE;
}

/* Called with chr_write_lock held.  */
static void pty_chr_rearm_timer(Chardev *chr, int ms)
{
    PtyChardev *s = PTY_CHARDEV(chr);
    char *name;

    pty_chr_timer_cancel(s);
    name = g_strdup_printf("pty-timer-%s", chr->label);
    s->timer_src = qemu_chr_timeout_add_ms(chr, ms, pty_chr_timer, chr);
    g_source_set_name(s->timer_src, name);
    g_free(name);
}

/* Called with chr_write_lock held.  */
static void pty_chr_update_read_handler_locked(Chardev *chr)
{
    PtyChardev *s = PTY_CHARDEV(chr);
    GPollFD pfd;
    int rc;
    QIOChannelFile *fioc = QIO_CHANNEL_FILE(s->ioc);

    pfd.fd = fioc->fd;
    pfd.events = G_IO_OUT;
    pfd.revents = 0;
    do {
        rc = g_poll(&pfd, 1, 0);
    } while (rc == -1 && errno == EINTR);
    assert(rc >= 0);

    if (pfd.revents & G_IO_HUP) {
        pty_chr_state(chr, 0);
    } else {
        pty_chr_state(chr, 1);
    }
}

static void pty_chr_update_read_handler(Chardev *chr)
{
    qemu_mutex_lock(&chr->chr_write_lock);
    pty_chr_update_read_handler_locked(chr);
    qemu_mutex_unlock(&chr->chr_write_lock);
}

/* Called with chr_write_lock held.  */
static int char_pty_chr_write(Chardev *chr, const uint8_t *buf, int len)
{
    PtyChardev *s = PTY_CHARDEV(chr);

    if (!s->connected) {
        /* guest sends data, check for (re-)connect */
        pty_chr_update_read_handler_locked(chr);
        if (!s->connected) {
            return len;
        }
    }
    return io_channel_send(s->ioc, buf, len);
}

static GSource *pty_chr_add_watch(Chardev *chr, GIOCondition cond)
{
    PtyChardev *s = PTY_CHARDEV(chr);
    if (!s->connected) {
        return NULL;
    }
    return qio_channel_create_watch(s->ioc, cond);
}

static int pty_chr_read_poll(void *opaque)
{
    Chardev *chr = CHARDEV(opaque);
    PtyChardev *s = PTY_CHARDEV(opaque);

    s->read_bytes = qemu_chr_be_can_write(chr);
    return s->read_bytes;
}

static gboolean pty_chr_read(QIOChannel *chan, GIOCondition cond, void *opaque)
{
    Chardev *chr = CHARDEV(opaque);
    PtyChardev *s = PTY_CHARDEV(opaque);
    gsize len;
    uint8_t buf[CHR_READ_BUF_LEN];
    ssize_t ret;

    len = sizeof(buf);
    if (len > s->read_bytes) {
        len = s->read_bytes;
    }
    if (len == 0) {
        return TRUE;
    }
    ret = qio_channel_read(s->ioc, (char *)buf, len, NULL);
    if (ret <= 0) {
        pty_chr_state(chr, 0);
        return FALSE;
    } else {
        pty_chr_state(chr, 1);
        qemu_chr_be_write(chr, buf, ret);
    }
    return TRUE;
}

static gboolean qemu_chr_be_generic_open_func(gpointer opaque)
{
    Chardev *chr = CHARDEV(opaque);
    PtyChardev *s = PTY_CHARDEV(opaque);

    s->open_source = NULL;
    qemu_chr_be_event(chr, CHR_EVENT_OPENED);
    return FALSE;
}

/* Called with chr_write_lock held.  */
static void pty_chr_state(Chardev *chr, int connected)
{
    PtyChardev *s = PTY_CHARDEV(chr);

    if (!connected) {
        pty_chr_open_src_cancel(s);
        remove_fd_in_watch(chr);
        s->connected = 0;
        /* (re-)connect poll interval for idle guests: once per second.
         * We check more frequently in case the guests sends data to
         * the virtual device linked to our pty. */
        pty_chr_rearm_timer(chr, 1000);
    } else {
        pty_chr_timer_cancel(s);
        if (!s->connected) {
            g_assert(s->open_source == NULL);
            s->open_source = g_idle_source_new();
            s->connected = 1;
            g_source_set_callback(s->open_source,
                                  qemu_chr_be_generic_open_func,
                                  chr, NULL);
            g_source_attach(s->open_source, chr->gcontext);
        }
        if (!chr->gsource) {
            chr->gsource = io_add_watch_poll(chr, s->ioc,
                                               pty_chr_read_poll,
                                               pty_chr_read,
                                               chr, chr->gcontext);
        }
    }
}

static void char_pty_finalize(Object *obj)
{
    Chardev *chr = CHARDEV(obj);
    PtyChardev *s = PTY_CHARDEV(obj);

    qemu_mutex_lock(&chr->chr_write_lock);
    pty_chr_state(chr, 0);
    object_unref(OBJECT(s->ioc));
    pty_chr_timer_cancel(s);
    qemu_mutex_unlock(&chr->chr_write_lock);
    qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
}

static void char_pty_open(Chardev *chr,
                          ChardevBackend *backend,
                          bool *be_opened,
                          Error **errp)
{
    PtyChardev *s;
    int master_fd, slave_fd;
    char pty_name[PATH_MAX];
    char *name;

    master_fd = qemu_openpty_raw(&slave_fd, pty_name);
    if (master_fd < 0) {
        error_setg_errno(errp, errno, "Failed to create PTY");
        return;
    }

    close(slave_fd);
    qemu_set_nonblock(master_fd);

    chr->filename = g_strdup_printf("pty:%s", pty_name);
    error_report("char device redirected to %s (label %s)",
                 pty_name, chr->label);

    s = PTY_CHARDEV(chr);
    s->ioc = QIO_CHANNEL(qio_channel_file_new_fd(master_fd));
    name = g_strdup_printf("chardev-pty-%s", chr->label);
    qio_channel_set_name(QIO_CHANNEL(s->ioc), name);
    g_free(name);
    s->timer_src = NULL;
    *be_opened = false;
}

static void char_pty_class_init(ObjectClass *oc, void *data)
{
    ChardevClass *cc = CHARDEV_CLASS(oc);

    cc->open = char_pty_open;
    cc->chr_write = char_pty_chr_write;
    cc->chr_update_read_handler = pty_chr_update_read_handler;
    cc->chr_add_watch = pty_chr_add_watch;
}

static const TypeInfo char_pty_type_info = {
    .name = TYPE_CHARDEV_PTY,
    .parent = TYPE_CHARDEV,
    .instance_size = sizeof(PtyChardev),
    .instance_finalize = char_pty_finalize,
    .class_init = char_pty_class_init,
};

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

type_init(register_types);

#endif
Commit	Line	Data
c3b7d620 MAL	1	/*
	2	* QEMU System Emulator
	3	*
	4	* Copyright (c) 2003-2008 Fabrice Bellard
	5	*
	6	* Permission is hereby granted, free of charge, to any person obtaining a copy
	7	* of this software and associated documentation files (the "Software"), to deal
	8	* in the Software without restriction, including without limitation the rights
	9	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	10	* copies of the Software, and to permit persons to whom the Software is
	11	* furnished to do so, subject to the following conditions:
	12	*
	13	* The above copyright notice and this permission notice shall be included in
	14	* all copies or substantial portions of the Software.
	15	*
	16	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	17	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	18	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	19	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	20	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	21	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	22	* THE SOFTWARE.
	23	*/
	24	#include "qemu/osdep.h"
	25	#include "qapi/error.h"
	26	#include "qemu-common.h"
8228e353	27	#include "chardev/char.h"
c3b7d620 MAL	28	#include "io/channel-file.h"
	29	#include "qemu/sockets.h"
	30	#include "qemu/error-report.h"
	31
8228e353	32	#include "chardev/char-io.h"
c3b7d620 MAL	33
	34	#if defined(__linux__) \|\| defined(__sun__) \|\| defined(__FreeBSD__) \
	35	\|\| defined(__NetBSD__) \|\| defined(__OpenBSD__) \|\| defined(__DragonFly__) \
	36	\|\| defined(__GLIBC__)
	37
	38	typedef struct {
	39	Chardev parent;
	40	QIOChannel *ioc;
	41	int read_bytes;
	42
	43	/* Protected by the Chardev chr_write_lock. */
	44	int connected;
2c716ba1	45	GSource *timer_src;
938eb9e9	46	GSource *open_source;
c3b7d620 MAL	47	} PtyChardev;
	48
	49	#define PTY_CHARDEV(obj) OBJECT_CHECK(PtyChardev, (obj), TYPE_CHARDEV_PTY)
	50
	51	static void pty_chr_update_read_handler_locked(Chardev *chr);
	52	static void pty_chr_state(Chardev *chr, int connected);
	53
4e4b5734 PX	54	static void pty_chr_timer_cancel(PtyChardev *s)
	55	{
	56	if (s->timer_src) {
	57	g_source_destroy(s->timer_src);
	58	g_source_unref(s->timer_src);
	59	s->timer_src = NULL;
	60	}
	61	}
	62
	63	static void pty_chr_open_src_cancel(PtyChardev *s)
	64	{
	65	if (s->open_source) {
	66	g_source_destroy(s->open_source);
	67	g_source_unref(s->open_source);
	68	s->open_source = NULL;
	69	}
	70	}
	71
c3b7d620 MAL	72	static gboolean pty_chr_timer(gpointer opaque)
	73	{
	74	struct Chardev *chr = CHARDEV(opaque);
	75	PtyChardev *s = PTY_CHARDEV(opaque);
	76
	77	qemu_mutex_lock(&chr->chr_write_lock);
4e4b5734 PX	78	pty_chr_timer_cancel(s);
4e4b5734 PX	79	pty_chr_open_src_cancel(s);
c3b7d620 MAL	80	if (!s->connected) {
	81	/* Next poll ... */
	82	pty_chr_update_read_handler_locked(chr);
	83	}
	84	qemu_mutex_unlock(&chr->chr_write_lock);
	85	return FALSE;
	86	}
	87
	88	/* Called with chr_write_lock held. */
	89	static void pty_chr_rearm_timer(Chardev *chr, int ms)
	90	{
	91	PtyChardev *s = PTY_CHARDEV(chr);
	92	char *name;
	93
2c716ba1 PX	94	pty_chr_timer_cancel(s);
	95	name = g_strdup_printf("pty-timer-%s", chr->label);
	96	s->timer_src = qemu_chr_timeout_add_ms(chr, ms, pty_chr_timer, chr);
	97	g_source_set_name(s->timer_src, name);
c3b7d620 MAL	98	g_free(name);
	99	}
	100
	101	/* Called with chr_write_lock held. */
	102	static void pty_chr_update_read_handler_locked(Chardev *chr)
	103	{
	104	PtyChardev *s = PTY_CHARDEV(chr);
	105	GPollFD pfd;
	106	int rc;
	107	QIOChannelFile *fioc = QIO_CHANNEL_FILE(s->ioc);
	108
	109	pfd.fd = fioc->fd;
	110	pfd.events = G_IO_OUT;
	111	pfd.revents = 0;
	112	do {
	113	rc = g_poll(&pfd, 1, 0);
	114	} while (rc == -1 && errno == EINTR);
	115	assert(rc >= 0);
	116
	117	if (pfd.revents & G_IO_HUP) {
	118	pty_chr_state(chr, 0);
	119	} else {
	120	pty_chr_state(chr, 1);
	121	}
	122	}
	123
bb86d05f	124	static void pty_chr_update_read_handler(Chardev *chr)
c3b7d620 MAL	125	{
	126	qemu_mutex_lock(&chr->chr_write_lock);
	127	pty_chr_update_read_handler_locked(chr);
	128	qemu_mutex_unlock(&chr->chr_write_lock);
	129	}
	130
	131	/* Called with chr_write_lock held. */
	132	static int char_pty_chr_write(Chardev chr, const uint8_t buf, int len)
	133	{
	134	PtyChardev *s = PTY_CHARDEV(chr);
	135
	136	if (!s->connected) {
	137	/* guest sends data, check for (re-)connect */
	138	pty_chr_update_read_handler_locked(chr);
	139	if (!s->connected) {
1c64fdbc	140	return len;
c3b7d620 MAL	141	}
	142	}
	143	return io_channel_send(s->ioc, buf, len);
	144	}
	145
	146	static GSource pty_chr_add_watch(Chardev chr, GIOCondition cond)
	147	{
	148	PtyChardev *s = PTY_CHARDEV(chr);
	149	if (!s->connected) {
	150	return NULL;
	151	}
	152	return qio_channel_create_watch(s->ioc, cond);
	153	}
	154
	155	static int pty_chr_read_poll(void *opaque)
	156	{
	157	Chardev *chr = CHARDEV(opaque);
	158	PtyChardev *s = PTY_CHARDEV(opaque);
	159
	160	s->read_bytes = qemu_chr_be_can_write(chr);
	161	return s->read_bytes;
	162	}
	163
	164	static gboolean pty_chr_read(QIOChannel chan, GIOCondition cond, void opaque)
	165	{
	166	Chardev *chr = CHARDEV(opaque);
	167	PtyChardev *s = PTY_CHARDEV(opaque);
	168	gsize len;
	169	uint8_t buf[CHR_READ_BUF_LEN];
	170	ssize_t ret;
	171
	172	len = sizeof(buf);
	173	if (len > s->read_bytes) {
	174	len = s->read_bytes;
	175	}
	176	if (len == 0) {
	177	return TRUE;
	178	}
	179	ret = qio_channel_read(s->ioc, (char *)buf, len, NULL);
	180	if (ret <= 0) {
	181	pty_chr_state(chr, 0);
	182	return FALSE;
	183	} else {
	184	pty_chr_state(chr, 1);
	185	qemu_chr_be_write(chr, buf, ret);
	186	}
	187	return TRUE;
	188	}
	189
	190	static gboolean qemu_chr_be_generic_open_func(gpointer opaque)
	191	{
	192	Chardev *chr = CHARDEV(opaque);
	193	PtyChardev *s = PTY_CHARDEV(opaque);
	194
938eb9e9	195	s->open_source = NULL;
63618135	196	qemu_chr_be_event(chr, CHR_EVENT_OPENED);
c3b7d620 MAL	197	return FALSE;
	198	}
	199
	200	/* Called with chr_write_lock held. */
	201	static void pty_chr_state(Chardev *chr, int connected)
	202	{
	203	PtyChardev *s = PTY_CHARDEV(chr);
	204
	205	if (!connected) {
4e4b5734	206	pty_chr_open_src_cancel(s);
b19456dd	207	remove_fd_in_watch(chr);
c3b7d620 MAL	208	s->connected = 0;
	209	/* (re-)connect poll interval for idle guests: once per second.
	210	* We check more frequently in case the guests sends data to
	211	* the virtual device linked to our pty. */
	212	pty_chr_rearm_timer(chr, 1000);
	213	} else {
2c716ba1	214	pty_chr_timer_cancel(s);
c3b7d620	215	if (!s->connected) {
938eb9e9 PX	216	g_assert(s->open_source == NULL);
938eb9e9 PX	217	s->open_source = g_idle_source_new();
c3b7d620	218	s->connected = 1;
938eb9e9 PX	219	g_source_set_callback(s->open_source,
	220	qemu_chr_be_generic_open_func,
	221	chr, NULL);
	222	g_source_attach(s->open_source, chr->gcontext);
c3b7d620	223	}
b19456dd HZ	224	if (!chr->gsource) {
b19456dd HZ	225	chr->gsource = io_add_watch_poll(chr, s->ioc,
c3b7d620 MAL	226	pty_chr_read_poll,
c3b7d620 MAL	227	pty_chr_read,
6bbb6c06	228	chr, chr->gcontext);
c3b7d620 MAL	229	}
	230	}
	231	}
	232
	233	static void char_pty_finalize(Object *obj)
	234	{
	235	Chardev *chr = CHARDEV(obj);
	236	PtyChardev *s = PTY_CHARDEV(obj);
	237
	238	qemu_mutex_lock(&chr->chr_write_lock);
	239	pty_chr_state(chr, 0);
	240	object_unref(OBJECT(s->ioc));
2c716ba1	241	pty_chr_timer_cancel(s);
c3b7d620 MAL	242	qemu_mutex_unlock(&chr->chr_write_lock);
	243	qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
	244	}
	245
	246	static void char_pty_open(Chardev *chr,
	247	ChardevBackend *backend,
	248	bool *be_opened,
	249	Error **errp)
	250	{
	251	PtyChardev *s;
	252	int master_fd, slave_fd;
	253	char pty_name[PATH_MAX];
	254	char *name;
	255
	256	master_fd = qemu_openpty_raw(&slave_fd, pty_name);
	257	if (master_fd < 0) {
	258	error_setg_errno(errp, errno, "Failed to create PTY");
	259	return;
	260	}
	261
	262	close(slave_fd);
	263	qemu_set_nonblock(master_fd);
	264
	265	chr->filename = g_strdup_printf("pty:%s", pty_name);
	266	error_report("char device redirected to %s (label %s)",
	267	pty_name, chr->label);
	268
	269	s = PTY_CHARDEV(chr);
	270	s->ioc = QIO_CHANNEL(qio_channel_file_new_fd(master_fd));
	271	name = g_strdup_printf("chardev-pty-%s", chr->label);
	272	qio_channel_set_name(QIO_CHANNEL(s->ioc), name);
	273	g_free(name);
2c716ba1	274	s->timer_src = NULL;
c3b7d620 MAL	275	*be_opened = false;
	276	}
	277
	278	static void char_pty_class_init(ObjectClass oc, void data)
	279	{
	280	ChardevClass *cc = CHARDEV_CLASS(oc);
	281
	282	cc->open = char_pty_open;
	283	cc->chr_write = char_pty_chr_write;
	284	cc->chr_update_read_handler = pty_chr_update_read_handler;
	285	cc->chr_add_watch = pty_chr_add_watch;
	286	}
	287
	288	static const TypeInfo char_pty_type_info = {
	289	.name = TYPE_CHARDEV_PTY,
	290	.parent = TYPE_CHARDEV,
	291	.instance_size = sizeof(PtyChardev),
	292	.instance_finalize = char_pty_finalize,
	293	.class_init = char_pty_class_init,
	294	};
	295
	296	static void register_types(void)
	297	{
	298	type_register_static(&char_pty_type_info);
	299	}
	300
	301	type_init(register_types);
	302
	303	#endif