fd.c

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/*
 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
 * Licensed under the GPL
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <termios.h>
#include "chan_user.h"
#include <os.h>
#include <um_malloc.h>

struct fd_chan {
    int fd;
    int raw;
    struct termios tt;
    char str[sizeof("1234567890\0")];
};

static void *fd_init(char *str, int device, const struct chan_opts *opts)
{
    struct fd_chan *data;
    char *end;
    int n;

    if (*str != ':') {
        printk(UM_KERN_ERR "fd_init : channel type 'fd' must specify a "
               "file descriptor\n");
        return NULL;
    }
    str++;
    n = strtoul(str, &end, 0);
    if ((*end != '\0') || (end == str)) {
        printk(UM_KERN_ERR "fd_init : couldn't parse file descriptor "
               "'%s'\n", str);
        return NULL;
    }

    data = uml_kmalloc(sizeof(*data), UM_GFP_KERNEL);
    if (data == NULL)
        return NULL;

    *data = ((struct fd_chan) { .fd     = n,
                    .raw    = opts->raw });
    return data;
}

static int fd_open(int input, int output, int primary, void *d, char **dev_out)
{
    struct fd_chan *data = d;
    int err;

    if (data->raw && isatty(data->fd)) {
        CATCH_EINTR(err = tcgetattr(data->fd, &data->tt));
        if (err)
            return err;

        err = raw(data->fd);
        if (err)
            return err;
    }
    sprintf(data->str, "%d", data->fd);
    *dev_out = data->str;
    return data->fd;
}

static void fd_close(int fd, void *d)
{
    struct fd_chan *data = d;
    int err;

    if (!data->raw || !isatty(fd))
        return;

    CATCH_EINTR(err = tcsetattr(fd, TCSAFLUSH, &data->tt));
    if (err)
        printk(UM_KERN_ERR "Failed to restore terminal state - "
               "errno = %d\n", -err);
    data->raw = 0;
}

const struct chan_ops fd_ops = {
    .type       = "fd",
    .init       = fd_init,
    .open       = fd_open,
    .close      = fd_close,
    .read       = generic_read,
    .write      = generic_write,
    .console_write  = generic_console_write,
    .window_size    = generic_window_size,
    .free       = generic_free,
    .winch      = 1,
};