/*
  Copyright (C) 1995-2023 Free Software Foundation, Inc.

  This file is part of GNU Inetutils.

  GNU Inetutils is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or (at
  your option) any later version.

  GNU Inetutils is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see `http://www.gnu.org/licenses/'. */

/*
 * Copyright (c) 1985, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <config.h>

#include <sys/types.h>
#include <sys/stat.h>

#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdarg.h>
#include <error.h>

#include "ftp_var.h"
#include <libinetutils.h>
#include <xalloc.h>

static int token (void);
static FILE *cfile;

/* protect agains os headers */
#undef	DEFAULT
#define DEFAULT	1
#undef	LOGIN
#define LOGIN	2
#undef	PASSWD
#define PASSWD	3
#undef	ACCOUNT
#define ACCOUNT 4
#undef  MACDEF
#define MACDEF  5
#undef	ID
#define ID	10
#undef	MACHINE
#define MACHINE	11

static char tokval[BUFSIZ];

static struct toktab
{
  char *tokstr;
  int tval;
} toktab[] = {
  {
   "default", DEFAULT},
  {
   "login", LOGIN},
  {
   "password", PASSWD},
  {
   "passwd", PASSWD},
  {
   "account", ACCOUNT},
  {
   "machine", MACHINE},
  {
   "macdef", MACDEF},
  {
   NULL, 0}
};

int
remote_userpass (char *host, char **aname, char **apass, char **aacct)
{
  char *hdir, buf[BUFSIZ], *tmp;
  char *myname, *mydomain;
  int t, c, usedefault = 0;
  size_t i;
  struct stat stb;

  hdir = getenv ("HOME");
  if (hdir == NULL)
    hdir = ".";
  snprintf (buf, sizeof buf, "%s/.netrc", hdir);

  /* The switch `-N/--netrc' would have set this.  */
  if (!netrc)
    netrc = getenv ("NETRC");

  if (netrc && netrc[0])
    snprintf (buf, sizeof buf, "%s", netrc);

  cfile = fopen (buf, "r");
  if (cfile == NULL)
    {
      if (errno != ENOENT)
	error (0, errno, "%s", buf);
      return (0);
    }

  /* The .netrc is now opened and is thus fixed.
   * Check that it is a regular file, and not a
   * soft link in particular.
   */
  if (lstat (buf, &stb) < 0)
    {
      error (0, errno, "%s", buf);
      fclose (cfile);
      return (-1);
    }

  if (!S_ISREG (stb.st_mode))
    {
      if (S_ISLNK (stb.st_mode))
	error (0, 0, "the .netrc file is symbolic link: %s", buf);
      else
	error (0, 0, "the .netrc file is no regular file: %s", buf);

      fclose (cfile);
      return (-1);
    }

  myname = localhost ();
  if (!myname)
    myname = xstrdup ("");

  mydomain = strchr (myname, '.');
  if (mydomain == NULL)
    mydomain = "";

next:
  while ((t = token ()))
    switch (t)
      {
      case DEFAULT:
	usedefault = 1;
	/* FALL THROUGH */

      case MACHINE:
	if (!usedefault)
	  {
	    if (token () != ID)
	      continue;
	    /*
	     * Allow match either for user's input host name
	     * or official hostname.  Also allow match of
	     * incompletely-specified host in local domain.  */
	    if (strcasecmp (host, tokval) == 0)
	      goto match;
	    if (strcasecmp (hostname, tokval) == 0)
	      goto match;
	    tmp = strchr (hostname, '.');
	    if (tmp != NULL
		&& strcasecmp (tmp, mydomain) == 0
		&& strncasecmp (hostname, tokval, tmp - hostname) == 0
		&& tokval[tmp - hostname] == '\0')
	      goto match;
	    tmp = strchr (host, '.');
	    if (tmp != NULL
		&& strcasecmp (tmp, mydomain) == 0
		&& strncasecmp (host, tokval, tmp - host) == 0
		&& tokval[tmp - host] == '\0')
	      goto match;
	    continue;
	  }
      match:
	while ((t = token ()) && t != MACHINE && t != DEFAULT)
	  switch (t)
	    {
	    case LOGIN:
	      if (token ())
		{
		  if (*aname == 0)
		    {
		      *aname = xmalloc ((unsigned) strlen (tokval) + 1);
		      strcpy (*aname, tokval);
		    }
		  else
		    {
		      if (strcmp (*aname, tokval))
			goto next;
		    }
		}
	      break;
	    case PASSWD:
	      if ((*aname == NULL || strcmp (*aname, "anonymous"))
		  && fstat (fileno (cfile), &stb) >= 0
		  && (stb.st_mode & 077) != 0)
		{
		  error (0, 0, "Error: .netrc file is readable by others.");
		  error (0, 0,
			 "Remove password or make file unreadable by others.");
		  goto bad;
		}
	      if (token () && *apass == 0)
		{
		  *apass = xmalloc ((unsigned) strlen (tokval) + 1);
		  strcpy (*apass, tokval);
		}
	      break;
	    case ACCOUNT:
	      if (fstat (fileno (cfile), &stb) >= 0
		  && (stb.st_mode & 077) != 0)
		{
		  error (0, 0, "Error: .netrc file is readable by others.");
		  error (0, 0,
			 "Remove account or make file unreadable by others.");
		  goto bad;
		}
	      if (token () && *aacct == 0)
		{
		  *aacct = xmalloc ((unsigned) strlen (tokval) + 1);
		  strcpy (*aacct, tokval);
		}
	      break;
	    case MACDEF:
	      if (proxy)
		goto done;

	      while (((c = getc (cfile)) != EOF && c == ' ') || c == '\t')
		;
	      if (c == EOF || c == '\n')
		{
		  printf ("Missing macdef name argument.\n");
		  goto bad;
		}
	      if (macnum == 16)
		{
		  printf ("Limit of 16 macros have already been defined\n");
		  goto bad;
		}
	      tmp = macros[macnum].mac_name;
	      *tmp++ = c;
	      for (i = 0; i < (sizeof (macros[macnum].mac_name) - 1)
		   && (c = getc (cfile)) != EOF && !isspace (c); ++i)
		{
		  *tmp++ = c;
		}
	      if (c == EOF)
		{
		  printf ("Macro definition missing null line terminator.\n");
		  goto bad;
		}
	      *tmp = '\0';
	      if (c != '\n')
		{
		  while ((c = getc (cfile)) != EOF && c != '\n');
		}
	      if (c == EOF)
		{
		  printf ("Macro definition missing null line terminator.\n");
		  goto bad;
		}
	      if (macnum == 0)
		{
		  macros[macnum].mac_start = macbuf;
		}
	      else
		{
		  macros[macnum].mac_start = macros[macnum - 1].mac_end + 1;
		}
	      tmp = macros[macnum].mac_start;
	      while (tmp < macbuf + sizeof (macbuf))
		{
		  if ((c = getc (cfile)) == EOF)
		    {
		      printf
			("Macro definition missing null line terminator.\n");
		      goto bad;
		    }
		  *tmp = c;
		  if (*tmp == '\n')
		    {
		      if (*(tmp - 1) == '\0')
			{
			  macros[macnum++].mac_end = tmp - 1;
			  break;
			}
		      *tmp = '\0';
		    }
		  tmp++;
		}
	      if (tmp == macbuf + sizeof (macbuf))
		{
		  printf ("4K macro buffer exceeded\n");
		  goto bad;
		}
	      break;
	    default:
	      error (0, 0, "Unknown .netrc keyword %s", tokval);
	      break;
	    }
	goto done;
      }
done:
  fclose (cfile);
  free (myname);
  return (0);
bad:
  fclose (cfile);
  free (myname);
  return (-1);
}

static int
token (void)
{
  char *cp;
  int c;
  struct toktab *t;

  if (feof (cfile) || ferror (cfile))
    return (0);
  while ((c = getc (cfile)) != EOF &&
	 (c == '\n' || c == '\t' || c == ' ' || c == ','))
    continue;
  if (c == EOF)
    return (0);
  cp = tokval;
  if (c == '"')
    {
      while ((c = getc (cfile)) != EOF && c != '"')
	{
	  if (c == '\\')
	    c = getc (cfile);
	  *cp++ = c;
	}
    }
  else
    {
      *cp++ = c;
      while ((c = getc (cfile)) != EOF
	     && c != '\n' && c != '\t' && c != ' ' && c != ',')
	{
	  if (c == '\\')
	    c = getc (cfile);
	  *cp++ = c;
	}
    }
  *cp = 0;
  if (tokval[0] == 0)
    return (0);
  for (t = toktab; t->tokstr; t++)
    if (!strcmp (t->tokstr, tokval))
      return (t->tval);
  return (ID);
}
