/*
   * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   * Licensed under the GPL.
   */

  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>

  #include <errno.h>

  #include <fcntl.h>
  #include <string.h>

  #include <sys/termios.h>
  #include <sys/wait.h>

  #include <net_user.h>
  #include <os.h>

  #include "slip.h"

  #include <um_malloc.h>

  static int slip_user_init(void *data, void *dev)

  {
  	struct slip_data *pri = data;
  
  	pri->dev = dev;

  	return 0;

  }
  
  static int set_up_tty(int fd)
  {
  	int i;
  	struct termios tios;
  
  	if (tcgetattr(fd, &tios) < 0) {

  		printk(UM_KERN_ERR "could not get initial terminal "
  		       "attributes
  ");
  		return -1;

  	}
  
  	tios.c_cflag = CS8 | CREAD | HUPCL | CLOCAL;
  	tios.c_iflag = IGNBRK | IGNPAR;
  	tios.c_oflag = 0;
  	tios.c_lflag = 0;
  	for (i = 0; i < NCCS; i++)
  		tios.c_cc[i] = 0;
  	tios.c_cc[VMIN] = 1;
  	tios.c_cc[VTIME] = 0;
  
  	cfsetospeed(&tios, B38400);
  	cfsetispeed(&tios, B38400);
  
  	if (tcsetattr(fd, TCSAFLUSH, &tios) < 0) {

  		printk(UM_KERN_ERR "failed to set terminal attributes
  ");
  		return -1;

  	}

  	return 0;

  }
  
  struct slip_pre_exec_data {
  	int stdin;
  	int stdout;
  	int close_me;
  };
  
  static void slip_pre_exec(void *arg)
  {
  	struct slip_pre_exec_data *data = arg;

  	if (data->stdin >= 0)
  		dup2(data->stdin, 0);

  	dup2(data->stdout, 1);

  	if (data->close_me >= 0)
  		close(data->close_me);

  }
  
  static int slip_tramp(char **argv, int fd)
  {
  	struct slip_pre_exec_data pe_data;
  	char *output;

  	int pid, fds[2], err, output_len;

  
  	err = os_pipe(fds, 1, 0);

  	if (err < 0) {
  		printk(UM_KERN_ERR "slip_tramp : pipe failed, err = %d
  ",
  		       -err);

  		goto out;

  	}
  
  	err = 0;
  	pe_data.stdin = fd;
  	pe_data.stdout = fds[1];
  	pe_data.close_me = fds[0];

  	err = run_helper(slip_pre_exec, &pe_data, argv);

  	if (err < 0)

  		goto out_close;
  	pid = err;

  	output_len = UM_KERN_PAGE_SIZE;

  	output = uml_kmalloc(output_len, UM_GFP_KERNEL);

  	if (output == NULL) {
  		printk(UM_KERN_ERR "slip_tramp : failed to allocate output "
  		       "buffer
  ");

  		os_kill_process(pid, 1);
  		err = -ENOMEM;

  		goto out_close;

  	}

  	close(fds[1]);

  	read_output(fds[0], output, output_len);
  	printk("%s", output);

  	err = helper_wait(pid);

  	close(fds[0]);

  	kfree(output);
  	return err;
  
  out_close:

  	close(fds[0]);
  	close(fds[1]);

  out:
  	return err;

  }
  
  static int slip_open(void *data)
  {
  	struct slip_data *pri = data;
  	char version_buf[sizeof("nnnnn\0")];
  	char gate_buf[sizeof("nnn.nnn.nnn.nnn\0")];

  	char *argv[] = { "uml_net", version_buf, "slip", "up", gate_buf,

  			 NULL };
  	int sfd, mfd, err;

  	err = get_pty();

  	if (err < 0) {
  		printk(UM_KERN_ERR "slip-open : Failed to open pty, err = %d
  ",
  		       -err);

  		goto out;

  	}

  	mfd = err;

  	err = open(ptsname(mfd), O_RDWR, 0);
  	if (err < 0) {
  		printk(UM_KERN_ERR "Couldn't open tty for slip line, "
  		       "err = %d
  ", -err);

  		goto out_close;

  	}

  	sfd = err;

  	if (set_up_tty(sfd))

  		goto out_close2;

  	pri->slave = sfd;

  	pri->slip.pos = 0;
  	pri->slip.esc = 0;

  	if (pri->gate_addr != NULL) {

  		sprintf(version_buf, "%d", UML_NET_VERSION);
  		strcpy(gate_buf, pri->gate_addr);
  
  		err = slip_tramp(argv, sfd);

  		if (err < 0) {
  			printk(UM_KERN_ERR "slip_tramp failed - err = %d
  ",
  			       -err);

  			goto out_close2;

  		}
  		err = os_get_ifname(pri->slave, pri->name);

  		if (err < 0) {
  			printk(UM_KERN_ERR "get_ifname failed, err = %d
  ",
  			       -err);

  			goto out_close2;

  		}
  		iter_addresses(pri->dev, open_addr, pri->name);
  	}
  	else {
  		err = os_set_slip(sfd);

  		if (err < 0) {
  			printk(UM_KERN_ERR "Failed to set slip discipline "
  			       "encapsulation - err = %d
  ", -err);

  			goto out_close2;

  		}
  	}

  	return mfd;

  out_close2:

  	close(sfd);

  out_close:

  	close(mfd);

  out:
  	return err;

  }
  
  static void slip_close(int fd, void *data)
  {
  	struct slip_data *pri = data;
  	char version_buf[sizeof("nnnnn\0")];

  	char *argv[] = { "uml_net", version_buf, "slip", "down", pri->name,

  			 NULL };
  	int err;

  	if (pri->gate_addr != NULL)

  		iter_addresses(pri->dev, close_addr, pri->name);
  
  	sprintf(version_buf, "%d", UML_NET_VERSION);
  
  	err = slip_tramp(argv, pri->slave);

  	if (err != 0)
  		printk(UM_KERN_ERR "slip_tramp failed - errno = %d
  ", -err);
  	close(fd);
  	close(pri->slave);

  	pri->slave = -1;
  }
  
  int slip_user_read(int fd, void *buf, int len, struct slip_data *pri)
  {

  	return slip_proto_read(fd, buf, len, &pri->slip);

  }
  
  int slip_user_write(int fd, void *buf, int len, struct slip_data *pri)
  {

  	return slip_proto_write(fd, buf, len, &pri->slip);

  }

  static void slip_add_addr(unsigned char *addr, unsigned char *netmask,
  			  void *data)
  {
  	struct slip_data *pri = data;

  	if (pri->slave < 0)
  		return;

  	open_addr(addr, netmask, pri->name);
  }
  
  static void slip_del_addr(unsigned char *addr, unsigned char *netmask,
  			    void *data)
  {
  	struct slip_data *pri = data;

  	if (pri->slave < 0)
  		return;

  	close_addr(addr, netmask, pri->name);
  }

  const struct net_user_info slip_user_info = {

  	.init		= slip_user_init,
  	.open		= slip_open,
  	.close	 	= slip_close,
  	.remove	 	= NULL,

  	.add_address	= slip_add_addr,
  	.delete_address = slip_del_addr,

  	.mtu		= BUF_SIZE,
  	.max_packet	= BUF_SIZE,

  };