linux/arch/um/drivers/fd.c
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   1/*
   2 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
   3 * Licensed under the GPL
   4 */
   5
   6#include <stdio.h>
   7#include <stdlib.h>
   8#include <unistd.h>
   9#include <errno.h>
  10#include <termios.h>
  11#include "chan_user.h"
  12#include "os.h"
  13#include "um_malloc.h"
  14
  15struct fd_chan {
  16        int fd;
  17        int raw;
  18        struct termios tt;
  19        char str[sizeof("1234567890\0")];
  20};
  21
  22static void *fd_init(char *str, int device, const struct chan_opts *opts)
  23{
  24        struct fd_chan *data;
  25        char *end;
  26        int n;
  27
  28        if (*str != ':') {
  29                printk(UM_KERN_ERR "fd_init : channel type 'fd' must specify a "
  30                       "file descriptor\n");
  31                return NULL;
  32        }
  33        str++;
  34        n = strtoul(str, &end, 0);
  35        if ((*end != '\0') || (end == str)) {
  36                printk(UM_KERN_ERR "fd_init : couldn't parse file descriptor "
  37                       "'%s'\n", str);
  38                return NULL;
  39        }
  40
  41        data = uml_kmalloc(sizeof(*data), UM_GFP_KERNEL);
  42        if (data == NULL)
  43                return NULL;
  44
  45        *data = ((struct fd_chan) { .fd         = n,
  46                                    .raw        = opts->raw });
  47        return data;
  48}
  49
  50static int fd_open(int input, int output, int primary, void *d, char **dev_out)
  51{
  52        struct fd_chan *data = d;
  53        int err;
  54
  55        if (data->raw && isatty(data->fd)) {
  56                CATCH_EINTR(err = tcgetattr(data->fd, &data->tt));
  57                if (err)
  58                        return err;
  59
  60                err = raw(data->fd);
  61                if (err)
  62                        return err;
  63        }
  64        sprintf(data->str, "%d", data->fd);
  65        *dev_out = data->str;
  66        return data->fd;
  67}
  68
  69static void fd_close(int fd, void *d)
  70{
  71        struct fd_chan *data = d;
  72        int err;
  73
  74        if (!data->raw || !isatty(fd))
  75                return;
  76
  77        CATCH_EINTR(err = tcsetattr(fd, TCSAFLUSH, &data->tt));
  78        if (err)
  79                printk(UM_KERN_ERR "Failed to restore terminal state - "
  80                       "errno = %d\n", -err);
  81        data->raw = 0;
  82}
  83
  84const struct chan_ops fd_ops = {
  85        .type           = "fd",
  86        .init           = fd_init,
  87        .open           = fd_open,
  88        .close          = fd_close,
  89        .read           = generic_read,
  90        .write          = generic_write,
  91        .console_write  = generic_console_write,
  92        .window_size    = generic_window_size,
  93        .free           = generic_free,
  94        .winch          = 1,
  95};
  96
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