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 "chan_user.h"
  13 #include "os.h"
  14 #include "um_malloc.h"
  15
  16 struct fd_chan {
  17         int fd;
  18         int raw;
  19         struct termios tt;
  20         char str[sizeof("1234567890\0")];
  21 };
  22
  23 static void *fd_init(char *str, int device, const struct chan_opts *opts)
  24 {
  25         struct fd_chan *data;
  26         char *end;
  27         int n;
  28
  29         if(*str != ':'){
  30                 printk("fd_init : channel type 'fd' must specify a file "
  31                        "descriptor\n");
  32                 return(NULL);
  33         }
  34         str++;
  35         n = strtoul(str, &end, 0);
  36         if((*end != '\0') || (end == str)){
  37                 printk("fd_init : couldn't parse file descriptor '%s'\n", str);
  38                 return(NULL);
  39         }
  40         data = um_kmalloc(sizeof(*data));
  41         if(data == NULL) return(NULL);
  42         *data = ((struct fd_chan) { .fd         = n,
  43                                     .raw        = opts->raw });
  44         return(data);
  45 }
  46
  47 static int fd_open(int input, int output, int primary, void *d, char **dev_out)
  48 {
  49         struct fd_chan *data = d;
  50         int err;
  51
  52         if(data->raw && isatty(data->fd)){
  53                 CATCH_EINTR(err = tcgetattr(data->fd, &data->tt));
  54                 if(err)
  55                         return(err);
  56
  57                 err = raw(data->fd);
  58                 if(err)
  59                         return(err);
  60         }
  61         sprintf(data->str, "%d", data->fd);
  62         *dev_out = data->str;
  63         return(data->fd);
  64 }
  65
  66 static void fd_close(int fd, void *d)
  67 {
  68         struct fd_chan *data = d;
  69         int err;
  70
  71         if(data->raw && isatty(fd)){
  72                 CATCH_EINTR(err = tcsetattr(fd, TCSAFLUSH, &data->tt));
  73                 if(err)
  74                         printk("Failed to restore terminal state - "
  75                                "errno = %d\n", -err);
  76                 data->raw = 0;
  77         }
  78 }
  79
  80 const struct chan_ops fd_ops = {
  81         .type           = "fd",
  82         .init           = fd_init,
  83         .open           = fd_open,
  84         .close          = fd_close,
  85         .read           = generic_read,
  86         .write          = generic_write,
  87         .console_write  = generic_console_write,
  88         .window_size    = generic_window_size,
  89         .free           = generic_free,
  90         .winch          = 1,
  91 };
  92
  93 /*
  94  * Overrides for Emacs so that we follow Linus's tabbing style.
  95  * Emacs will notice this stuff at the end of the file and automatically
  96  * adjust the settings for this buffer only.  This must remain at the end
  97  * of the file.
  98  * ---------------------------------------------------------------------------
  99  * Local variables:
 100  * c-file-style: "linux"
 101  * End:
 102  */