arch/um/drivers/fd.c

   1 /*
   2  * Copyright (C) 2001 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <unistd.h>
   9 #include <termios.h>
  10 #include <errno.h>
  11 #include "user.h"
  12 #include "user_util.h"
  13 #include "chan_user.h"
  14 #include "os.h"
  15 #include "um_malloc.h"
  16
  17 struct fd_chan {
  18         int fd;
  19         int raw;
  20         struct termios tt;
  21         char str[sizeof("1234567890\0")];
  22 };
  23
  24 static 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("fd_init : channel type 'fd' must specify a file "
  32                        "descriptor\n");
  33                 return(NULL);
  34         }
  35         str++;
  36         n = strtoul(str, &end, 0);
  37         if((*end != '\0') || (end == str)){
  38                 printk("fd_init : couldn't parse file descriptor '%s'\n", str);
  39                 return(NULL);
  40         }
  41         data = um_kmalloc(sizeof(*data));
  42         if(data == NULL) return(NULL);
  43         *data = ((struct fd_chan) { .fd         = n,
  44                                     .raw        = opts->raw });
  45         return(data);
  46 }
  47
  48 static int fd_open(int input, int output, int primary, void *d, char **dev_out)
  49 {
  50         struct fd_chan *data = d;
  51         int err;
  52
  53         if(data->raw && isatty(data->fd)){
  54                 CATCH_EINTR(err = tcgetattr(data->fd, &data->tt));
  55                 if(err)
  56                         return(err);
  57
  58                 err = raw(data->fd);
  59                 if(err)
  60                         return(err);
  61         }
  62         sprintf(data->str, "%d", data->fd);
  63         *dev_out = data->str;
  64         return(data->fd);
  65 }
  66
  67 static void fd_close(int fd, void *d)
  68 {
  69         struct fd_chan *data = d;
  70         int err;
  71
  72         if(data->raw && isatty(fd)){
  73                 CATCH_EINTR(err = tcsetattr(fd, TCSAFLUSH, &data->tt));
  74                 if(err)
  75                         printk("Failed to restore terminal state - "
  76                                "errno = %d\n", -err);
  77                 data->raw = 0;
  78         }
  79 }
  80
  81 const struct chan_ops fd_ops = {
  82         .type           = "fd",
  83         .init           = fd_init,
  84         .open           = fd_open,
  85         .close          = fd_close,
  86         .read           = generic_read,
  87         .write          = generic_write,
  88         .console_write  = generic_console_write,
  89         .window_size    = generic_window_size,
  90         .free           = generic_free,
  91         .winch          = 1,
  92 };
  93
  94 /*
  95  * Overrides for Emacs so that we follow Linus's tabbing style.
  96  * Emacs will notice this stuff at the end of the file and automatically
  97  * adjust the settings for this buffer only.  This must remain at the end
  98  * of the file.
  99  * ---------------------------------------------------------------------------
 100  * Local variables:
 101  * c-file-style: "linux"
 102  * End:
 103  */