LXR linux/arch/um/drivers/fd.c

   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 "kern_constants.h"
  13#include "os.h"
  14#include "um_malloc.h"
  15#include "user.h"
  16
  17struct fd_chan {
  18        int fd;
  19        int raw;
  20        struct termios tt;
  21        char str[sizeof("1234567890\0")];
  22};
  23
  24static void *fd_init(char *str, int device, const struct chan_opts *opts)
  25{
  26        struct fd_chan *data;
  27        char *end;
  28        int n;
  29
  30        if (*str != ':') {
  31                printk(UM_KERN_ERR "fd_init : channel type 'fd' must specify a "
  32                       "file descriptor\n");
  33                return NULL;
  34        }
  35        str++;
  36        n = strtoul(str, &end, 0);
  37        if ((*end != '\0') || (end == str)) {
  38                printk(UM_KERN_ERR "fd_init : couldn't parse file descriptor "
  39                       "'%s'\n", str);
  40                return NULL;
  41        }
  42
  43        data = uml_kmalloc(sizeof(*data), UM_GFP_KERNEL);
  44        if (data == NULL)
  45                return NULL;
  46
  47        *data = ((struct fd_chan) { .fd         = n,
  48                                    .raw        = opts->raw });
  49        return data;
  50}
  51
  52static int fd_open(int input, int output, int primary, void *d, char **dev_out)
  53{
  54        struct fd_chan *data = d;
  55        int err;
  56
  57        if (data->raw && isatty(data->fd)) {
  58                CATCH_EINTR(err = tcgetattr(data->fd, &data->tt));
  59                if (err)
  60                        return err;
  61
  62                err = raw(data->fd);
  63                if (err)
  64                        return err;
  65        }
  66        sprintf(data->str, "%d", data->fd);
  67        *dev_out = data->str;
  68        return data->fd;
  69}
  70
  71static void fd_close(int fd, void *d)
  72{
  73        struct fd_chan *data = d;
  74        int err;
  75
  76        if (!data->raw || !isatty(fd))
  77                return;
  78
  79        CATCH_EINTR(err = tcsetattr(fd, TCSAFLUSH, &data->tt));
  80        if (err)
  81                printk(UM_KERN_ERR "Failed to restore terminal state - "
  82                       "errno = %d\n", -err);
  83        data->raw = 0;
  84}
  85
  86const struct chan_ops fd_ops = {
  87        .type           = "fd",
  88        .init           = fd_init,
  89        .open           = fd_open,
  90        .close          = fd_close,
  91        .read           = generic_read,
  92        .write          = generic_write,
  93        .console_write  = generic_console_write,
  94        .window_size    = generic_window_size,
  95        .free           = generic_free,
  96        .winch          = 1,
  97};
  98