chardev/char-fe.c - qemu - Git at Google

 /*
  * 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 "qemu/error-report.h"
 #include "qapi/error.h"
 #include "qapi/qmp/qerror.h"
 #include "sysemu/replay.h"

 #include "chardev/char-fe.h"
 #include "chardev/char-io.h"
 #include "chardev/char-mux.h"

 int qemu_chr_fe_write(CharBackend *be, const uint8_t *buf, int len)
 {
     Chardev *s = be->chr;

     if (!s) {
         return 0;
     }

     return qemu_chr_write(s, buf, len, false);
 }

 int qemu_chr_fe_write_all(CharBackend *be, const uint8_t *buf, int len)
 {
     Chardev *s = be->chr;

     if (!s) {
         return 0;
     }

     return qemu_chr_write(s, buf, len, true);
 }

 int qemu_chr_fe_read_all(CharBackend *be, uint8_t *buf, int len)
 {
     Chardev *s = be->chr;
     int offset = 0, counter = 10;
     int res;

     if (!s || !CHARDEV_GET_CLASS(s)->chr_sync_read) {
         return 0;
     }

     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_PLAY) {
         return replay_char_read_all_load(buf);
     }

     while (offset < len) {
     retry:
         res = CHARDEV_GET_CLASS(s)->chr_sync_read(s, buf + offset,
                                                   len - offset);
         if (res == -1 && errno == EAGAIN) {
             g_usleep(100);
             goto retry;
         }

         if (res == 0) {
             break;
         }

         if (res < 0) {
             if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_RECORD) {
                 replay_char_read_all_save_error(res);
             }
             return res;
         }

         offset += res;

         if (!counter--) {
             break;
         }
     }

     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_RECORD) {
         replay_char_read_all_save_buf(buf, offset);
     }
     return offset;
 }

 int qemu_chr_fe_ioctl(CharBackend *be, int cmd, void *arg)
 {
     Chardev *s = be->chr;
     int res;

     if (!s || !CHARDEV_GET_CLASS(s)->chr_ioctl || qemu_chr_replay(s)) {
         res = -ENOTSUP;
     } else {
         res = CHARDEV_GET_CLASS(s)->chr_ioctl(s, cmd, arg);
     }

     return res;
 }

 int qemu_chr_fe_get_msgfd(CharBackend *be)
 {
     Chardev *s = be->chr;
     int fd;
     int res = (qemu_chr_fe_get_msgfds(be, &fd, 1) == 1) ? fd : -1;
     if (s && qemu_chr_replay(s)) {
         error_report("Replay: get msgfd is not supported "
                      "for serial devices yet");
         exit(1);
     }
     return res;
 }

 int qemu_chr_fe_get_msgfds(CharBackend *be, int *fds, int len)
 {
     Chardev *s = be->chr;

     if (!s) {
         return -1;
     }

     return CHARDEV_GET_CLASS(s)->get_msgfds ?
         CHARDEV_GET_CLASS(s)->get_msgfds(s, fds, len) : -1;
 }

 int qemu_chr_fe_set_msgfds(CharBackend *be, int *fds, int num)
 {
     Chardev *s = be->chr;

     if (!s) {
         return -1;
     }

     return CHARDEV_GET_CLASS(s)->set_msgfds ?
         CHARDEV_GET_CLASS(s)->set_msgfds(s, fds, num) : -1;
 }

 void qemu_chr_fe_accept_input(CharBackend *be)
 {
     Chardev *s = be->chr;

     if (!s) {
         return;
     }

     if (CHARDEV_GET_CLASS(s)->chr_accept_input) {
         CHARDEV_GET_CLASS(s)->chr_accept_input(s);
     }
     qemu_notify_event();
 }

 void qemu_chr_fe_printf(CharBackend *be, const char *fmt, ...)
 {
     char buf[CHR_READ_BUF_LEN];
     va_list ap;
     va_start(ap, fmt);
     vsnprintf(buf, sizeof(buf), fmt, ap);
     /* XXX this blocks entire thread. Rewrite to use
      * qemu_chr_fe_write and background I/O callbacks */
     qemu_chr_fe_write_all(be, (uint8_t *)buf, strlen(buf));
     va_end(ap);
 }

 Chardev *qemu_chr_fe_get_driver(CharBackend *be)
 {
     /* this is unsafe for the users that support chardev hotswap */
     assert(be->chr_be_change == NULL);
     return be->chr;
 }

 bool qemu_chr_fe_backend_connected(CharBackend *be)
 {
     return !!be->chr;
 }

 bool qemu_chr_fe_backend_open(CharBackend *be)
 {
     return be->chr && be->chr->be_open;
 }

 bool qemu_chr_fe_init(CharBackend *b, Chardev *s, Error **errp)
 {
     int tag = 0;

     if (s) {
         if (CHARDEV_IS_MUX(s)) {
             MuxChardev *d = MUX_CHARDEV(s);

             if (d->mux_cnt >= MAX_MUX) {
                 goto unavailable;
             }

             d->backends[d->mux_cnt] = b;
             tag = d->mux_cnt++;
         } else if (s->be) {
             goto unavailable;
         } else {
             s->be = b;
         }
     }

     b->fe_open = false;
     b->tag = tag;
     b->chr = s;
     return true;

 unavailable:
     error_setg(errp, QERR_DEVICE_IN_USE, s->label);
     return false;
 }

 void qemu_chr_fe_deinit(CharBackend *b, bool del)
 {
     assert(b);

     if (b->chr) {
         qemu_chr_fe_set_handlers(b, NULL, NULL, NULL, NULL, NULL, NULL, true);
         if (b->chr->be == b) {
             b->chr->be = NULL;
         }
         if (CHARDEV_IS_MUX(b->chr)) {
             MuxChardev *d = MUX_CHARDEV(b->chr);
             d->backends[b->tag] = NULL;
         }
         if (del) {
             object_unparent(OBJECT(b->chr));
         }
         b->chr = NULL;
     }
 }

 void qemu_chr_fe_set_handlers(CharBackend *b,
                               IOCanReadHandler *fd_can_read,
                               IOReadHandler *fd_read,
                               IOEventHandler *fd_event,
                               BackendChangeHandler *be_change,
                               void *opaque,
                               GMainContext *context,
                               bool set_open)
 {
     Chardev *s;
     int fe_open;

     s = b->chr;
     if (!s) {
         return;
     }

     if (!opaque && !fd_can_read && !fd_read && !fd_event) {
         fe_open = 0;
         remove_fd_in_watch(s);
     } else {
         fe_open = 1;
     }
     b->chr_can_read = fd_can_read;
     b->chr_read = fd_read;
     b->chr_event = fd_event;
     b->chr_be_change = be_change;
     b->opaque = opaque;

     qemu_chr_be_update_read_handlers(s, context);

     if (set_open) {
         qemu_chr_fe_set_open(b, fe_open);
     }

     if (fe_open) {
         qemu_chr_fe_take_focus(b);
         /* We're connecting to an already opened device, so let's make sure we
            also get the open event */
         if (s->be_open) {
             qemu_chr_be_event(s, CHR_EVENT_OPENED);
         }
     }

     if (CHARDEV_IS_MUX(s)) {
         mux_chr_set_handlers(s, context);
     }
 }

 void qemu_chr_fe_take_focus(CharBackend *b)
 {
     if (!b->chr) {
         return;
     }

     if (CHARDEV_IS_MUX(b->chr)) {
         mux_set_focus(b->chr, b->tag);
     }
 }

 int qemu_chr_fe_wait_connected(CharBackend *be, Error **errp)
 {
     if (!be->chr) {
         error_setg(errp, "missing associated backend");
         return -1;
     }

     return qemu_chr_wait_connected(be->chr, errp);
 }

 void qemu_chr_fe_set_echo(CharBackend *be, bool echo)
 {
     Chardev *chr = be->chr;

     if (chr && CHARDEV_GET_CLASS(chr)->chr_set_echo) {
         CHARDEV_GET_CLASS(chr)->chr_set_echo(chr, echo);
     }
 }

 void qemu_chr_fe_set_open(CharBackend *be, int fe_open)
 {
     Chardev *chr = be->chr;

     if (!chr) {
         return;
     }

     if (be->fe_open == fe_open) {
         return;
     }
     be->fe_open = fe_open;
     if (CHARDEV_GET_CLASS(chr)->chr_set_fe_open) {
         CHARDEV_GET_CLASS(chr)->chr_set_fe_open(chr, fe_open);
     }
 }

 guint qemu_chr_fe_add_watch(CharBackend *be, GIOCondition cond,
                             GIOFunc func, void *user_data)
 {
     Chardev *s = be->chr;
     GSource *src;
     guint tag;

     if (!s || CHARDEV_GET_CLASS(s)->chr_add_watch == NULL) {
         return 0;
     }

     src = CHARDEV_GET_CLASS(s)->chr_add_watch(s, cond);
     if (!src) {
         return 0;
     }

     g_source_set_callback(src, (GSourceFunc)func, user_data, NULL);
     tag = g_source_attach(src, s->gcontext);
     g_source_unref(src);

     return tag;
 }

 void qemu_chr_fe_disconnect(CharBackend *be)
 {
     Chardev *chr = be->chr;

     if (chr && CHARDEV_GET_CLASS(chr)->chr_disconnect) {
         CHARDEV_GET_CLASS(chr)->chr_disconnect(chr);
     }
 }
	/*
	* 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 "qemu/error-report.h"
	#include "qapi/error.h"
	#include "qapi/qmp/qerror.h"
	#include "sysemu/replay.h"

	#include "chardev/char-fe.h"
	#include "chardev/char-io.h"
	#include "chardev/char-mux.h"

	int qemu_chr_fe_write(CharBackend be, const uint8_t buf, int len)
	{
	Chardev *s = be->chr;

	if (!s) {
	return 0;
	}

	return qemu_chr_write(s, buf, len, false);
	}

	int qemu_chr_fe_write_all(CharBackend be, const uint8_t buf, int len)
	{
	Chardev *s = be->chr;

	if (!s) {
	return 0;
	}

	return qemu_chr_write(s, buf, len, true);
	}

	int qemu_chr_fe_read_all(CharBackend be, uint8_t buf, int len)
	{
	Chardev *s = be->chr;
	int offset = 0, counter = 10;
	int res;

	if (!s \|\| !CHARDEV_GET_CLASS(s)->chr_sync_read) {
	return 0;
	}

	if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_PLAY) {
	return replay_char_read_all_load(buf);
	}

	while (offset < len) {
	retry:
	res = CHARDEV_GET_CLASS(s)->chr_sync_read(s, buf + offset,
	len - offset);
	if (res == -1 && errno == EAGAIN) {
	g_usleep(100);
	goto retry;
	}

	if (res == 0) {
	break;
	}

	if (res < 0) {
	if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_RECORD) {
	replay_char_read_all_save_error(res);
	}
	return res;
	}

	offset += res;

	if (!counter--) {
	break;
	}
	}

	if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_RECORD) {
	replay_char_read_all_save_buf(buf, offset);
	}
	return offset;
	}

	int qemu_chr_fe_ioctl(CharBackend be, int cmd, void arg)
	{
	Chardev *s = be->chr;
	int res;

	if (!s \|\| !CHARDEV_GET_CLASS(s)->chr_ioctl \|\| qemu_chr_replay(s)) {
	res = -ENOTSUP;
	} else {
	res = CHARDEV_GET_CLASS(s)->chr_ioctl(s, cmd, arg);
	}

	return res;
	}

	int qemu_chr_fe_get_msgfd(CharBackend *be)
	{
	Chardev *s = be->chr;
	int fd;
	int res = (qemu_chr_fe_get_msgfds(be, &fd, 1) == 1) ? fd : -1;
	if (s && qemu_chr_replay(s)) {
	error_report("Replay: get msgfd is not supported "
	"for serial devices yet");
	exit(1);
	}
	return res;
	}

	int qemu_chr_fe_get_msgfds(CharBackend be, int fds, int len)
	{
	Chardev *s = be->chr;

	if (!s) {
	return -1;
	}

	return CHARDEV_GET_CLASS(s)->get_msgfds ?
	CHARDEV_GET_CLASS(s)->get_msgfds(s, fds, len) : -1;
	}

	int qemu_chr_fe_set_msgfds(CharBackend be, int fds, int num)
	{
	Chardev *s = be->chr;

	if (!s) {
	return -1;
	}

	return CHARDEV_GET_CLASS(s)->set_msgfds ?
	CHARDEV_GET_CLASS(s)->set_msgfds(s, fds, num) : -1;
	}

	void qemu_chr_fe_accept_input(CharBackend *be)
	{
	Chardev *s = be->chr;

	if (!s) {
	return;
	}

	if (CHARDEV_GET_CLASS(s)->chr_accept_input) {
	CHARDEV_GET_CLASS(s)->chr_accept_input(s);
	}
	qemu_notify_event();
	}

	void qemu_chr_fe_printf(CharBackend be, const char fmt, ...)
	{
	char buf[CHR_READ_BUF_LEN];
	va_list ap;
	va_start(ap, fmt);
	vsnprintf(buf, sizeof(buf), fmt, ap);
	/* XXX this blocks entire thread. Rewrite to use
	* qemu_chr_fe_write and background I/O callbacks */
	qemu_chr_fe_write_all(be, (uint8_t *)buf, strlen(buf));
	va_end(ap);
	}

	Chardev qemu_chr_fe_get_driver(CharBackend be)
	{
	/* this is unsafe for the users that support chardev hotswap */
	assert(be->chr_be_change == NULL);
	return be->chr;
	}

	bool qemu_chr_fe_backend_connected(CharBackend *be)
	{
	return !!be->chr;
	}

	bool qemu_chr_fe_backend_open(CharBackend *be)
	{
	return be->chr && be->chr->be_open;
	}

	bool qemu_chr_fe_init(CharBackend b, Chardev s, Error **errp)
	{
	int tag = 0;

	if (s) {
	if (CHARDEV_IS_MUX(s)) {
	MuxChardev *d = MUX_CHARDEV(s);

	if (d->mux_cnt >= MAX_MUX) {
	goto unavailable;
	}

	d->backends[d->mux_cnt] = b;
	tag = d->mux_cnt++;
	} else if (s->be) {
	goto unavailable;
	} else {
	s->be = b;
	}
	}

	b->fe_open = false;
	b->tag = tag;
	b->chr = s;
	return true;

	unavailable:
	error_setg(errp, QERR_DEVICE_IN_USE, s->label);
	return false;
	}

	void qemu_chr_fe_deinit(CharBackend *b, bool del)
	{
	assert(b);

	if (b->chr) {
	qemu_chr_fe_set_handlers(b, NULL, NULL, NULL, NULL, NULL, NULL, true);
	if (b->chr->be == b) {
	b->chr->be = NULL;
	}
	if (CHARDEV_IS_MUX(b->chr)) {
	MuxChardev *d = MUX_CHARDEV(b->chr);
	d->backends[b->tag] = NULL;
	}
	if (del) {
	object_unparent(OBJECT(b->chr));
	}
	b->chr = NULL;
	}
	}

	void qemu_chr_fe_set_handlers(CharBackend *b,
	IOCanReadHandler *fd_can_read,
	IOReadHandler *fd_read,
	IOEventHandler *fd_event,
	BackendChangeHandler *be_change,
	void *opaque,
	GMainContext *context,
	bool set_open)
	{
	Chardev *s;
	int fe_open;

	s = b->chr;
	if (!s) {
	return;
	}

	if (!opaque && !fd_can_read && !fd_read && !fd_event) {
	fe_open = 0;
	remove_fd_in_watch(s);
	} else {
	fe_open = 1;
	}
	b->chr_can_read = fd_can_read;
	b->chr_read = fd_read;
	b->chr_event = fd_event;
	b->chr_be_change = be_change;
	b->opaque = opaque;

	qemu_chr_be_update_read_handlers(s, context);

	if (set_open) {
	qemu_chr_fe_set_open(b, fe_open);
	}

	if (fe_open) {
	qemu_chr_fe_take_focus(b);
	/* We're connecting to an already opened device, so let's make sure we
	also get the open event */
	if (s->be_open) {
	qemu_chr_be_event(s, CHR_EVENT_OPENED);
	}
	}

	if (CHARDEV_IS_MUX(s)) {
	mux_chr_set_handlers(s, context);
	}
	}

	void qemu_chr_fe_take_focus(CharBackend *b)
	{
	if (!b->chr) {
	return;
	}

	if (CHARDEV_IS_MUX(b->chr)) {
	mux_set_focus(b->chr, b->tag);
	}
	}

	int qemu_chr_fe_wait_connected(CharBackend be, Error *errp)
	{
	if (!be->chr) {
	error_setg(errp, "missing associated backend");
	return -1;
	}

	return qemu_chr_wait_connected(be->chr, errp);
	}

	void qemu_chr_fe_set_echo(CharBackend *be, bool echo)
	{
	Chardev *chr = be->chr;

	if (chr && CHARDEV_GET_CLASS(chr)->chr_set_echo) {
	CHARDEV_GET_CLASS(chr)->chr_set_echo(chr, echo);
	}
	}

	void qemu_chr_fe_set_open(CharBackend *be, int fe_open)
	{
	Chardev *chr = be->chr;

	if (!chr) {
	return;
	}

	if (be->fe_open == fe_open) {
	return;
	}
	be->fe_open = fe_open;
	if (CHARDEV_GET_CLASS(chr)->chr_set_fe_open) {
	CHARDEV_GET_CLASS(chr)->chr_set_fe_open(chr, fe_open);
	}
	}

	guint qemu_chr_fe_add_watch(CharBackend *be, GIOCondition cond,
	GIOFunc func, void *user_data)
	{
	Chardev *s = be->chr;
	GSource *src;
	guint tag;

	if (!s \|\| CHARDEV_GET_CLASS(s)->chr_add_watch == NULL) {
	return 0;
	}

	src = CHARDEV_GET_CLASS(s)->chr_add_watch(s, cond);
	if (!src) {
	return 0;
	}

	g_source_set_callback(src, (GSourceFunc)func, user_data, NULL);
	tag = g_source_attach(src, s->gcontext);
	g_source_unref(src);

	return tag;
	}

	void qemu_chr_fe_disconnect(CharBackend *be)
	{
	Chardev *chr = be->chr;

	if (chr && CHARDEV_GET_CLASS(chr)->chr_disconnect) {
	CHARDEV_GET_CLASS(chr)->chr_disconnect(chr);
	}
	}