Quelle  ssl.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
/* 
 * Copyright (C) 2000, 2002 Jeff Dike (jdike@karaya.com)
 */

#include <linux/fs.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/major.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/console.h>
#include <asm/termbits.h>
#include <asm/irq.h>
#include "chan.h"
#include <init.h>
#include <irq_user.h>
#include "mconsole_kern.h"

static const int ssl_version = 1;

#define NR_PORTS 64

static void ssl_announce(char *dev_name, int dev)
{
 printk(KERN_INFO "Serial line %d assigned device '%s'\n", dev,
        dev_name);
}

/* Almost const, except that xterm_title may be changed in an initcall */
static struct chan_opts opts = {
 .announce  = ssl_announce,
 .xterm_title = "Serial Line #%d",
 .raw  = 1,
};

static int ssl_config(char *str, char **error_out);
static int ssl_get_config(char *dev, char *str, int size, char **error_out);
static int ssl_remove(int n, char **error_out);


/* Const, except for .mc.list */
static struct line_driver driver = {
 .name    = "UML serial line",
 .device_name   = "ttyS",
 .major    = TTY_MAJOR,
 .minor_start   = 64,
 .type     = TTY_DRIVER_TYPE_SERIAL,
 .subtype    = 0,
 .read_irq_name   = "ssl",
 .write_irq_name  = "ssl-write",
 .mc  = {
  .list  = LIST_HEAD_INIT(driver.mc.list),
  .name    = "ssl",
  .config  = ssl_config,
  .get_config  = ssl_get_config,
  .id  = line_id,
  .remove  = ssl_remove,
 },
};

/* The array is initialized by line_init, at initcall time.  The
 * elements are locked individually as needed.
 */
static char *conf[NR_PORTS];
static char *def_conf = CONFIG_SSL_CHAN;
static struct line serial_lines[NR_PORTS];

static int ssl_config(char *str, char **error_out)
{
 return line_config(serial_lines, ARRAY_SIZE(serial_lines), str, &opts,
      error_out);
}

static int ssl_get_config(char *dev, char *str, int size, char **error_out)
{
 return line_get_config(dev, serial_lines, ARRAY_SIZE(serial_lines), str,
          size, error_out);
}

static int ssl_remove(int n, char **error_out)
{
 return line_remove(serial_lines, ARRAY_SIZE(serial_lines), n,
      error_out);
}

static int ssl_install(struct tty_driver *driver, struct tty_struct *tty)
{
 return line_install(driver, tty, &serial_lines[tty->index]);
}

static const struct tty_operations ssl_ops = {
 .open     = line_open,
 .close     = line_close,
 .write     = line_write,
 .write_room  = line_write_room,
 .chars_in_buffer  = line_chars_in_buffer,
 .flush_buffer   = line_flush_buffer,
 .flush_chars   = line_flush_chars,
 .throttle   = line_throttle,
 .unthrottle   = line_unthrottle,
 .install  = ssl_install,
 .hangup   = line_hangup,
};

/* Changed by ssl_init and referenced by ssl_exit, which are both serialized
 * by being an initcall and exitcall, respectively.
 */
static int ssl_init_done;

static void ssl_console_write(struct console *c, const char *string,
         unsigned len)
{
 struct line *line = &serial_lines[c->index];
 unsigned long flags;

 spin_lock_irqsave(&line->lock, flags);
 console_write_chan(line->chan_out, string, len);
 spin_unlock_irqrestore(&line->lock, flags);
}

static struct tty_driver *ssl_console_device(struct console *c, int *index)
{
 *index = c->index;
 return driver.driver;
}

static int ssl_console_setup(struct console *co, char *options)
{
 struct line *line = &serial_lines[co->index];

 return console_open_chan(line, co);
}

/* No locking for register_console call - relies on single-threaded initcalls */
static struct console ssl_cons = {
 .name  = "ttyS",
 .write  = ssl_console_write,
 .device  = ssl_console_device,
 .setup  = ssl_console_setup,
 .flags  = CON_PRINTBUFFER|CON_ANYTIME,
 .index  = -1,
};

static int ssl_init(void)
{
 char *new_title;
 int err;
 int i;

 printk(KERN_INFO "Initializing software serial port version %d\n",
        ssl_version);

 err = register_lines(&driver, &ssl_ops, serial_lines,
        ARRAY_SIZE(serial_lines));
 if (err)
  return err;

 new_title = add_xterm_umid(opts.xterm_title);
 if (new_title != NULL)
  opts.xterm_title = new_title;

 for (i = 0; i < NR_PORTS; i++) {
  char *error;
  char *s = conf[i];
  if (!s)
   s = def_conf;
  if (setup_one_line(serial_lines, i, s, &opts, &error))
   printk(KERN_ERR "setup_one_line failed for "
          "device %d : %s\n", i, error);
 }

 ssl_init_done = 1;
 register_console(&ssl_cons);
 return 0;
}
late_initcall(ssl_init);

static void ssl_exit(void)
{
 if (!ssl_init_done)
  return;
 close_lines(serial_lines, ARRAY_SIZE(serial_lines));
}
__uml_exitcall(ssl_exit);

static int ssl_chan_setup(char *str)
{
 line_setup(conf, NR_PORTS, &def_conf, str, "serial line");
 return 1;
}

__setup("ssl", ssl_chan_setup);
__channel_help(ssl_chan_setup, "ssl");

static int ssl_non_raw_setup(char *str)
{
 opts.raw = 0;
 return 1;
}
__setup("ssl-non-raw", ssl_non_raw_setup);
__uml_help(ssl_non_raw_setup,
"ssl-non-raw\n"
" Set serial lines to non-raw mode.\n\n"
);