#ifndef QEMU_CHAR_FE_H
#define QEMU_CHAR_FE_H
#include "chardev/char.h"
typedef void IOEventHandler(void *opaque, int event);
typedef int BackendChangeHandler(void *opaque);
/* This is the backend as seen by frontend, the actual backend is
* Chardev */
struct CharBackend {
Chardev *chr;
IOEventHandler *chr_event;
IOCanReadHandler *chr_can_read;
IOReadHandler *chr_read;
BackendChangeHandler *chr_be_change;
void *opaque;
int tag;
int fe_open;
};
/**
* qemu_chr_fe_init:
*
* Initializes a front end for the given CharBackend and
* Chardev. Call qemu_chr_fe_deinit() to remove the association and
* release the driver.
*
* Returns: false on error.
*/
bool qemu_chr_fe_init(CharBackend *b, Chardev *s, Error **errp);
/**
* qemu_chr_fe_deinit:
* @b: a CharBackend
* @del: if true, delete the chardev backend
*
* Dissociate the CharBackend from the Chardev.
*
* Safe to call without associated Chardev.
*/
void qemu_chr_fe_deinit(CharBackend *b, bool del);
/**
* qemu_chr_fe_get_driver:
*
* Returns: the driver associated with a CharBackend or NULL if no
* associated Chardev.
* Note: avoid this function as the driver should never be accessed directly,
* especially by the frontends that support chardevice hotswap.
* Consider qemu_chr_fe_backend_connected() to check for driver existence
*/
Chardev *qemu_chr_fe_get_driver(CharBackend *be);
/**
* qemu_chr_fe_backend_connected:
*
* Returns: true if there is a chardevice associated with @be.
*/
bool qemu_chr_fe_backend_connected(CharBackend *be);
/**
* qemu_chr_fe_backend_open:
*
* Returns: true if chardevice associated with @be is open.
*/
bool qemu_chr_fe_backend_open(CharBackend *be);
/**
* qemu_chr_fe_set_handlers:
* @b: a CharBackend
* @fd_can_read: callback to get the amount of data the frontend may
* receive
* @fd_read: callback to receive data from char
* @fd_event: event callback
* @be_change: backend change callback; passing NULL means hot backend change
* is not supported and will not be attempted
* @opaque: an opaque pointer for the callbacks
* @context: a main loop context or NULL for the default
* @set_open: whether to call qemu_chr_fe_set_open() implicitely when
* any of the handler is non-NULL
*
* Set the front end char handlers. The front end takes the focus if
* any of the handler is non-NULL.
*
* Without associated Chardev, nothing is changed.
*/
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);
/**
* qemu_chr_fe_take_focus:
*
* Take the focus (if the front end is muxed).
*
* Without associated Chardev, nothing is changed.
*/
void qemu_chr_fe_take_focus(CharBackend *b);
/**
* qemu_chr_fe_accept_input:
*
* Notify that the frontend is ready to receive data
*/
void qemu_chr_fe_accept_input(CharBackend *be);
/**
* qemu_chr_fe_disconnect:
*
* Close a fd accepted by character backend.
* Without associated Chardev, do nothing.
*/
void qemu_chr_fe_disconnect(CharBackend *be);
/**
* qemu_chr_fe_wait_connected:
*
* Wait for characted backend to be connected, return < 0 on error or
* if no associated Chardev.
*/
int qemu_chr_fe_wait_connected(CharBackend *be, Error **errp);
/**
* qemu_chr_fe_set_echo:
* @echo: true to enable echo, false to disable echo
*
* Ask the backend to override its normal echo setting. This only really
* applies to the stdio backend and is used by the QMP server such that you
* can see what you type if you try to type QMP commands.
* Without associated Chardev, do nothing.
*/
void qemu_chr_fe_set_echo(CharBackend *be, bool echo);
/**
* qemu_chr_fe_set_open:
*
* Set character frontend open status. This is an indication that the
* front end is ready (or not) to begin doing I/O.
* Without associated Chardev, do nothing.
*/
void qemu_chr_fe_set_open(CharBackend *be, int fe_open);
/**
* qemu_chr_fe_printf:
* @fmt: see #printf
*
* Write to a character backend using a printf style interface. This
* function is thread-safe. It does nothing without associated
* Chardev.
*/
void qemu_chr_fe_printf(CharBackend *be, const char *fmt, ...)
GCC_FMT_ATTR(2, 3);
/**
* qemu_chr_fe_add_watch:
* @cond: the condition to poll for
* @func: the function to call when the condition happens
* @user_data: the opaque pointer to pass to @func
*
* If the backend is connected, create and add a #GSource that fires
* when the given condition (typically G_IO_OUT|G_IO_HUP or G_IO_HUP)
* is active; return the #GSource's tag. If it is disconnected,
* or without associated Chardev, return 0.
*
* Returns: the source tag
*/
guint qemu_chr_fe_add_watch(CharBackend *be, GIOCondition cond,
GIOFunc func, void *user_data);
/**
* qemu_chr_fe_write:
* @buf: the data
* @len: the number of bytes to send
*
* Write data to a character backend from the front end. This function
* will send data from the front end to the back end. This function
* is thread-safe.
*
* Returns: the number of bytes consumed (0 if no associated Chardev)
*/
int qemu_chr_fe_write(CharBackend *be, const uint8_t *buf, int len);
/**
* qemu_chr_fe_write_all:
* @buf: the data
* @len: the number of bytes to send
*
* Write data to a character backend from the front end. This function will
* send data from the front end to the back end. Unlike @qemu_chr_fe_write,
* this function will block if the back end cannot consume all of the data
* attempted to be written. This function is thread-safe.
*
* Returns: the number of bytes consumed (0 if no associated Chardev)
*/
int qemu_chr_fe_write_all(CharBackend *be, const uint8_t *buf, int len);
/**
* qemu_chr_fe_read_all:
* @buf: the data buffer
* @len: the number of bytes to read
*
* Read data to a buffer from the back end.
*
* Returns: the number of bytes read (0 if no associated Chardev)
*/
int qemu_chr_fe_read_all(CharBackend *be, uint8_t *buf, int len);
/**
* qemu_chr_fe_ioctl:
* @cmd: see CHR_IOCTL_*
* @arg: the data associated with @cmd
*
* Issue a device specific ioctl to a backend. This function is thread-safe.
*
* Returns: if @cmd is not supported by the backend or there is no
* associated Chardev, -ENOTSUP, otherwise the return
* value depends on the semantics of @cmd
*/
int qemu_chr_fe_ioctl(CharBackend *be, int cmd, void *arg);
/**
* qemu_chr_fe_get_msgfd:
*
* For backends capable of fd passing, return the latest file descriptor passed
* by a client.
*
* Returns: -1 if fd passing isn't supported or there is no pending file
* descriptor. If a file descriptor is returned, subsequent calls to
* this function will return -1 until a client sends a new file
* descriptor.
*/
int qemu_chr_fe_get_msgfd(CharBackend *be);
/**
* qemu_chr_fe_get_msgfds:
*
* For backends capable of fd passing, return the number of file received
* descriptors and fills the fds array up to num elements
*
* Returns: -1 if fd passing isn't supported or there are no pending file
* descriptors. If file descriptors are returned, subsequent calls to
* this function will return -1 until a client sends a new set of file
* descriptors.
*/
int qemu_chr_fe_get_msgfds(CharBackend *be, int *fds, int num);
/**
* qemu_chr_fe_set_msgfds:
*
* For backends capable of fd passing, set an array of fds to be passed with
* the next send operation.
* A subsequent call to this function before calling a write function will
* result in overwriting the fd array with the new value without being send.
* Upon writing the message the fd array is freed.
*
* Returns: -1 if fd passing isn't supported or no associated Chardev.
*/
int qemu_chr_fe_set_msgfds(CharBackend *be, int *fds, int num);
#endif /* QEMU_CHAR_FE_H */
