arch/um/drivers/pty.c

   1 /*
   2  * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <stdio.h>
   7 #include <unistd.h>
   8 #include <string.h>
   9 #include <errno.h>
  10 #include <fcntl.h>
  11 #include <termios.h>
  12 #include "chan_user.h"
  13 #include "user.h"
  14 #include "user_util.h"
  15 #include "kern_util.h"
  16
  17 struct pty_chan {
  18         void (*announce)(char *dev_name, int dev);
  19         int dev;
  20         int raw;
  21         struct termios tt;
  22         char dev_name[sizeof("/dev/pts/0123456\0")];
  23 };
  24
  25 void *pty_chan_init(char *str, int device, struct chan_opts *opts)
  26 {
  27         struct pty_chan *data;
  28
  29         if((data = um_kmalloc(sizeof(*data))) == NULL) return(NULL);
  30         *data = ((struct pty_chan) { .announce          = opts->announce,
  31                                      .dev               = device,
  32                                      .raw               = opts->raw });
  33         return(data);
  34 }
  35
  36 int pts_open(int input, int output, int primary, void *d, char **dev_out)
  37 {
  38         struct pty_chan *data = d;
  39         char *dev;
  40         int fd;
  41
  42         if((fd = get_pty()) < 0){
  43                 printk("open_pts : Failed to open pts\n");
  44                 return(-errno);
  45         }
  46         if(data->raw){
  47                 tcgetattr(fd, &data->tt);
  48                 raw(fd, 0);
  49         }
  50
  51         dev = ptsname(fd);
  52         sprintf(data->dev_name, "%s", dev);
  53         *dev_out = data->dev_name;
  54         if(data->announce) (*data->announce)(dev, data->dev);
  55         return(fd);
  56 }
  57
  58 int getmaster(char *line)
  59 {
  60         struct stat stb;
  61         char *pty, *bank, *cp;
  62         int master;
  63
  64         pty = &line[strlen("/dev/ptyp")];
  65         for (bank = "pqrs"; *bank; bank++) {
  66                 line[strlen("/dev/pty")] = *bank;
  67                 *pty = '0';
  68                 if (stat(line, &stb) < 0)
  69                         break;
  70                 for (cp = "0123456789abcdef"; *cp; cp++) {
  71                         *pty = *cp;
  72                         master = open(line, O_RDWR);
  73                         if (master >= 0) {
  74                                 char *tp = &line[strlen("/dev/")];
  75                                 int ok;
  76
  77                                 /* verify slave side is usable */
  78                                 *tp = 't';
  79                                 ok = access(line, R_OK|W_OK) == 0;
  80                                 *tp = 'p';
  81                                 if (ok) return(master);
  82                                 (void) close(master);
  83                         }
  84                 }
  85         }
  86         return(-1);
  87 }
  88
  89 int pty_open(int input, int output, int primary, void *d, char **dev_out)
  90 {
  91         struct pty_chan *data = d;
  92         int fd;
  93         char dev[sizeof("/dev/ptyxx\0")] = "/dev/ptyxx";
  94
  95         fd = getmaster(dev);
  96         if(fd < 0) return(-errno);
  97
  98         if(data->raw) raw(fd, 0);
  99         if(data->announce) (*data->announce)(dev, data->dev);
 100
 101         sprintf(data->dev_name, "%s", dev);
 102         *dev_out = data->dev_name;
 103         return(fd);
 104 }
 105
 106 int pty_console_write(int fd, const char *buf, int n, void *d)
 107 {
 108         struct pty_chan *data = d;
 109
 110         return(generic_console_write(fd, buf, n, &data->tt));
 111 }
 112
 113 struct chan_ops pty_ops = {
 114         .type           = "pty",
 115         .init           = pty_chan_init,
 116         .open           = pty_open,
 117         .close          = generic_close,
 118         .read           = generic_read,
 119         .write          = generic_write,
 120         .console_write  = pty_console_write,
 121         .window_size    = generic_window_size,
 122         .free           = generic_free,
 123         .winch          = 0,
 124 };
 125
 126 struct chan_ops pts_ops = {
 127         .type           = "pts",
 128         .init           = pty_chan_init,
 129         .open           = pts_open,
 130         .close          = generic_close,
 131         .read           = generic_read,
 132         .write          = generic_write,
 133         .console_write  = pty_console_write,
 134         .window_size    = generic_window_size,
 135         .free           = generic_free,
 136         .winch          = 0,
 137 };
 138
 139 /*
 140  * Overrides for Emacs so that we follow Linus's tabbing style.
 141  * Emacs will notice this stuff at the end of the file and automatically
 142  * adjust the settings for this buffer only.  This must remain at the end
 143  * of the file.
 144  * ---------------------------------------------------------------------------
 145  * Local variables:
 146  * c-file-style: "linux"
 147  * End:
 148  */