/* Parse user and group ids

   Copyright (C) 1997, 1999, 2008 Free Software Foundation, Inc.

   Written by Miles Bader <miles@gnu.ai.mit.edu>

   This program 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 2, or (at
   your option) any later version.

   This program 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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */

#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <argp.h>
#include <pwd.h>
#include <grp.h>
#include <errno.h>

#include "ugids.h"

#define OA OPTION_ARG_OPTIONAL

static const struct argp_option options[] =
{
  {"user",	'u', "USER",  0, "Add USER to the effective uids"},
  {"avail-user",'U', "USER",  0, "Add USER to the available uids"},
  {"group",     'g', "GROUP", 0, "Add GROUP to the effective groups"},
  {"avail-group",'G',"GROUP", 0, "Add GROUP to the available groups"},
  { 0 }
};

static error_t
parse_opt (int key, char *arg, struct argp_state *state)
{
  char id_lookup_buf[1024];
  struct ugids_argp_params *params = state->input;
  struct ugids *ugids = params->ugids;

  switch (key)
    {
      uid_t uid;

    case 'u':
    case 'U':
    case ARGP_KEY_ARG:
    case ARGP_KEY_END:
      if (key == ARGP_KEY_ARG && !params->parse_user_args)
	/* Let someone else parse this argument.  */
	return ARGP_ERR_UNKNOWN;

      if (key == ARGP_KEY_END)
	{
	  if (ugids_is_empty (ugids))
	    {
	      if (params->default_user >= 0)
		uid = params->default_user;
	      else if (params->require_ids)
		{
		  argp_error (state, "No ids specified");
		  return EINVAL;
		}
	      else
		break;
	    }
	  else
	    break;
	}
      else if (isdigit (*arg))
	uid = atoi (arg);
      else if (strcmp (arg, "-") == 0)
	break;
      else
	{
	  struct passwd _pw, *pw;
	  int err;
	  err = getpwnam_r (arg, &_pw, id_lookup_buf,
		    sizeof id_lookup_buf, &pw);
	  if (err == 0)
	    {
	      if (pw == NULL)
		{
		  argp_failure (state, 10, 0, "%s: Unknown user", arg);
		  return EINVAL;
		}

	      uid = pw->pw_uid;
	    }
	  else
	    {
	      argp_failure (state, 12, err,
		    "Could not get uid for user: %s", arg);
	      return err;
	    }
	}

      if (key == ARGP_KEY_ARG || key == ARGP_KEY_END)
	{
	  /* A user arg, which means add the user, and any appropriate
	     groups. */
	  if (!params->user_args_are_effective
	      && !params->user_args_are_available)
	    return ugids_set_posix_user (ugids, uid);
	  else
	    {
	      error_t err = 0;
	      if (params->user_args_are_effective)
		err = ugids_add_user (ugids, uid, 0);
	      if (!err && params->user_args_are_available)
		err = ugids_add_user (ugids, uid, 1);
	      return err;
	    }
	}
      else
	/* Add an individual specific effective/auxiliary uid.  */
	return ugids_add_uid (ugids, uid, key == 'U');

    case 'g':
    case 'G':
      if (isdigit (*arg))
	return ugids_add_gid (ugids, atoi (arg), key == 'G');
      else
	{
	  struct group _gr, *gr;
	  int err = getgrnam_r (arg, &_gr, id_lookup_buf,
		    sizeof id_lookup_buf, &gr);
	  if (err == 0)
	    {
	      if (gr == NULL)
		{
		  argp_failure (state, 11, 0, "%s: Unknown group", arg);
		  return EINVAL;
		}

	      return ugids_add_gid (ugids, gr->gr_gid, key == 'G');
	    }
	      else
		{
		  argp_failure (state, 13, err,
			"Could not get gid for group: %s", arg);
		  return err;
		}
	}

    default:
      return ARGP_ERR_UNKNOWN;
    }
  return 0;
}

/* Filtering of help output strings for UGIDS_ARGP.  */
static char *
help_filter (int key, const char *text, void *input)
{
  struct ugids_argp_params *params = input;

  /* Describe the optional behavior of parsing normal args as ugids.  */
  if (key == ARGP_KEY_HELP_ARGS_DOC && params->parse_user_args)
    return strdup ("[USER...]");

  return (char *)text;
}

/* A parser for selecting a set of ugids.  */
struct argp ugids_argp = { options, parse_opt, 0, 0, 0, help_filter };