system/dev/misc/pty/pty-core.h

// Copyright 2017 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#pragma once

#include <stdint.h>
#include <threads.h>

#include <ddk/device.h>

#include <zircon/compiler.h>
#include <zircon/listnode.h>

__BEGIN_CDECLS;

typedef struct pty_server pty_server_t;
typedef struct pty_client pty_client_t;

struct pty_server {
    zx_device_t* mxdev;

    // lock covers server and all its clients
    mtx_t lock;

    // track server lifetime
    int32_t refcount;

    // pending OOB events
    uint32_t events;

    // list of all clients
    list_node_t clients;

    // active client receives inbound data
    pty_client_t* active;

    // control client receives events
    pty_client_t* control;

    // called when data is written by active client
    // pty_server's lock is held across this call
    // (it is not legal to call back into any pty_server_*() functions)
    zx_status_t (*recv)(pty_server_t* ps, const void* data, size_t len, size_t* actual);

    // if non-null, called for unhandled client ioctl ops
    // no lock is held across this call
    zx_status_t (*ioctl)(pty_server_t* ps, uint32_t op,
                     const void* cmd, size_t cmdlen,
                     void* out, size_t outlen, size_t* out_actual);

    // called when pty_server_t should be deleted
    // if NULL, free(ps) is called instead
    void (*release)(pty_server_t* ps);

    // window size in character cells
    uint32_t width;
    uint32_t height;
};

// this initializes everything *except* the embedded zx_device_t
void pty_server_init(pty_server_t* ps);

// write data through to active client
// if atomic is true, the send will be all-or-nothing
// if atomic is true ^c, etc processing is not done
zx_status_t pty_server_send(pty_server_t* ps, const void* data, size_t len, bool atomic, size_t* actual);

// If the recv callback returns ZX_ERR_SHOULD_WAIT, pty_server_resume()
// must be called when it is possible to call it successfully again.
// ps->lock must be held.
void pty_server_resume_locked(pty_server_t* ps);

void pty_server_set_window_size(pty_server_t* ps, uint32_t w, uint32_t h);

// device ops for pty_server
// the zx_device_t here must be the one embedded in pty_server_t
zx_status_t pty_server_openat(void* ctx, zx_device_t** out, const char* path, uint32_t flags);
void pty_server_release(void* ctx);

__END_CDECLS;