glibc/nis/nis_defaults.c

/* Copyright (c) 1997-2023 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <sys/types.h>
#include <rpc/rpc.h>
#include <rpcsvc/nis.h>
#include <shlib-compat.h>

#define DEFAULT_TTL 43200

/*
** Some functions for parsing the -D param and NIS_DEFAULTS Environ
*/
static nis_name
searchXYX (char *str, const char *what)
{
  assert (strlen (what) == 6);
  assert (strncmp (str, what, 6) == 0);
  str += 6;			/* Points to the begin of the parameters.  */

  int i = 0;
  while (str[i] != '\0' && str[i] != ':')
    ++i;
  if (i == 0)			/* only "<WHAT>=" ? */
    return strdup ("");

  return strndup (str, i);
}


static nis_name
searchgroup (char *str)
{
  return searchXYX (str, "group=");
}


static nis_name
searchowner (char *str)
{
  return searchXYX (str, "owner=");
}


static uint32_t
searchttl (char *str)
{
  char buf[strlen (str) + 1];
  char *cptr, *dptr;
  uint32_t time;
  int i;

  dptr = strstr (str, "ttl=");
  if (dptr == NULL)		/* should (could) not happen */
    return DEFAULT_TTL;;

  dptr += 4;			/* points to the begin of the new ttl */
  i = 0;
  while (dptr[i] != '\0' && dptr[i] != ':')
    i++;
  if (i == 0)			/* only "ttl=" ? */
    return DEFAULT_TTL;

  strncpy (buf, dptr, i);
  buf[i] = '\0';
  time = 0;

  dptr = buf;
  cptr = strchr (dptr, 'd');
  if (cptr != NULL)
    {
      *cptr = '\0';
      cptr++;
      time += atoi (dptr) * 60 * 60 * 24;
      dptr = cptr;
    }

  cptr = strchr (dptr, 'h');
  if (cptr != NULL)
    {
      *cptr = '\0';
      cptr++;
      time += atoi (dptr) * 60 * 60;
      dptr = cptr;
    }

  cptr = strchr (dptr, 'm');
  if (cptr != NULL)
    {
      *cptr = '\0';
      cptr++;
      time += atoi (dptr) * 60;
      dptr = cptr;
    }

  cptr = strchr (dptr, 's');
  if (cptr != NULL)
    *cptr = '\0';

  time += atoi (dptr);

  return time;
}

static unsigned int
searchaccess (char *str, unsigned int access)
{
  char buf[strlen (str) + 1];
  char *cptr;
  unsigned int result = access;
  int i;
  int n, o, g, w;

  cptr = strstr (str, "access=");
  if (cptr == NULL)
    return 0;

  cptr += 7;			/* points to the begin of the access string */
  i = 0;
  while (cptr[i] != '\0' && cptr[i] != ':')
    i++;
  if (i == 0)			/* only "access=" ? */
    return 0;

  strncpy (buf, cptr, i);
  buf[i] = '\0';

  n = o = g = w = 0;
  cptr = buf;
  if (*cptr == ',') /* Fix for stupid Solaris scripts */
    ++cptr;
  while (*cptr != '\0')
    {
      switch (*cptr)
	{
	case 'n':
	  n = 1;
	  break;
	case 'o':
	  o = 1;
	  break;
	case 'g':
	  g = 1;
	  break;
	case 'w':
	  w = 1;
	  break;
	case 'a':
	  o = g = w = 1;
	  break;
	case '-':
	  cptr++;		/* Remove "-" from beginning */
	  while (*cptr != '\0' && *cptr != ',')
	    {
	      switch (*cptr)
		{
		case 'r':
		  if (n)
		    result = result & ~(NIS_READ_ACC << 24);
		  if (o)
		    result = result & ~(NIS_READ_ACC << 16);
		  if (g)
		    result = result & ~(NIS_READ_ACC << 8);
		  if (w)
		    result = result & ~(NIS_READ_ACC);
		  break;
		case 'm':
		  if (n)
		    result = result & ~(NIS_MODIFY_ACC << 24);
		  if (o)
		    result = result & ~(NIS_MODIFY_ACC << 16);
		  if (g)
		    result = result & ~(NIS_MODIFY_ACC << 8);
		  if (w)
		    result = result & ~(NIS_MODIFY_ACC);
		  break;
		case 'c':
		  if (n)
		    result = result & ~(NIS_CREATE_ACC << 24);
		  if (o)
		    result = result & ~(NIS_CREATE_ACC << 16);
		  if (g)
		    result = result & ~(NIS_CREATE_ACC << 8);
		  if (w)
		    result = result & ~(NIS_CREATE_ACC);
		  break;
		case 'd':
		  if (n)
		    result = result & ~(NIS_DESTROY_ACC << 24);
		  if (o)
		    result = result & ~(NIS_DESTROY_ACC << 16);
		  if (g)
		    result = result & ~(NIS_DESTROY_ACC << 8);
		  if (w)
		    result = result & ~(NIS_DESTROY_ACC);
		  break;
		default:
		  return (~0U);
		}
	      cptr++;
	    }
	  n = o = g = w = 0;
	  break;
	case '+':
	  cptr++;		/* Remove "+" from beginning */
	  while (*cptr != '\0' && *cptr != ',')
	    {
	      switch (*cptr)
		{
		case 'r':
		  if (n)
		    result = result | (NIS_READ_ACC << 24);
		  if (o)
		    result = result | (NIS_READ_ACC << 16);
		  if (g)
		    result = result | (NIS_READ_ACC << 8);
		  if (w)
		    result = result | (NIS_READ_ACC);
		  break;
		case 'm':
		  if (n)
		    result = result | (NIS_MODIFY_ACC << 24);
		  if (o)
		    result = result | (NIS_MODIFY_ACC << 16);
		  if (g)
		    result = result | (NIS_MODIFY_ACC << 8);
		  if (w)
		    result = result | (NIS_MODIFY_ACC);
		  break;
		case 'c':
		  if (n)
		    result = result | (NIS_CREATE_ACC << 24);
		  if (o)
		    result = result | (NIS_CREATE_ACC << 16);
		  if (g)
		    result = result | (NIS_CREATE_ACC << 8);
		  if (w)
		    result = result | (NIS_CREATE_ACC);
		  break;
		case 'd':
		  if (n)
		    result = result | (NIS_DESTROY_ACC << 24);
		  if (o)
		    result = result | (NIS_DESTROY_ACC << 16);
		  if (g)
		    result = result | (NIS_DESTROY_ACC << 8);
		  if (w)
		    result = result | (NIS_DESTROY_ACC);
		  break;
		default:
		  return (~0U);
		}
	      cptr++;
	    }
	  n = o = g = w = 0;
	  break;
	case '=':
	  cptr++;		/* Remove "=" from beginning */
	  /* Clear */
	  if (n)
	    result = result & ~((NIS_READ_ACC + NIS_MODIFY_ACC
				 + NIS_CREATE_ACC + NIS_DESTROY_ACC) << 24);

	  if (o)
	    result = result & ~((NIS_READ_ACC + NIS_MODIFY_ACC
				 + NIS_CREATE_ACC + NIS_DESTROY_ACC) << 16);
	  if (g)
	    result = result & ~((NIS_READ_ACC + NIS_MODIFY_ACC
				 + NIS_CREATE_ACC + NIS_DESTROY_ACC) << 8);
	  if (w)
	    result = result & ~(NIS_READ_ACC + NIS_MODIFY_ACC
				+ NIS_CREATE_ACC + NIS_DESTROY_ACC);
	  while (*cptr != '\0' && *cptr != ',')
	    {
	      switch (*cptr)
		{
		case 'r':
		  if (n)
		    result = result | (NIS_READ_ACC << 24);
		  if (o)
		    result = result | (NIS_READ_ACC << 16);
		  if (g)
		    result = result | (NIS_READ_ACC << 8);
		  if (w)
		    result = result | (NIS_READ_ACC);
		  break;
		case 'm':
		  if (n)
		    result = result | (NIS_MODIFY_ACC << 24);
		  if (o)
		    result = result | (NIS_MODIFY_ACC << 16);
		  if (g)
		    result = result | (NIS_MODIFY_ACC << 8);
		  if (w)
		    result = result | (NIS_MODIFY_ACC);
		  break;
		case 'c':
		  if (n)
		    result = result | (NIS_CREATE_ACC << 24);
		  if (o)
		    result = result | (NIS_CREATE_ACC << 16);
		  if (g)
		    result = result | (NIS_CREATE_ACC << 8);
		  if (w)
		    result = result | (NIS_CREATE_ACC);
		  break;
		case 'd':
		  if (n)
		    result = result | (NIS_DESTROY_ACC << 24);
		  if (o)
		    result = result | (NIS_DESTROY_ACC << 16);
		  if (g)
		    result = result | (NIS_DESTROY_ACC << 8);
		  if (w)
		    result = result | (NIS_DESTROY_ACC);
		  break;
		default:
		  return result = (~0U);
		}
	      cptr++;
	    }
	  n = o = g = w = 0;
	  break;
	default:
	  return result = (~0U);
	}
      if (*cptr != '\0')
	cptr++;
    }

  return result;
}


nis_name
__nis_default_owner (char *defaults)
{
  char *default_owner = NULL;

  char *cptr = defaults;
  if (cptr == NULL)
    cptr = getenv ("NIS_DEFAULTS");

  if (cptr != NULL)
    {
      char *dptr = strstr (cptr, "owner=");
      if (dptr != NULL)
	{
	  char *p = searchowner (dptr);
	  if (p == NULL)
	    return NULL;
	  default_owner = strdupa (p);
	  free (p);
	}
    }

  return strdup (default_owner ?: nis_local_principal ());
}
libnsl_hidden_nolink_def (__nis_default_owner, GLIBC_2_1)


nis_name
__nis_default_group (char *defaults)
{
  char *default_group = NULL;

  char *cptr = defaults;
  if (cptr == NULL)
    cptr = getenv ("NIS_DEFAULTS");

  if (cptr != NULL)
    {
      char *dptr = strstr (cptr, "group=");
      if (dptr != NULL)
	{
	  char *p = searchgroup (dptr);
	  if (p == NULL)
	    return NULL;
	  default_group = strdupa (p);
	  free (p);
	}
    }

  return strdup (default_group ?: nis_local_group ());
}
libnsl_hidden_nolink_def (__nis_default_group, GLIBC_2_1)


uint32_t
__nis_default_ttl (char *defaults)
{
  char *cptr, *dptr;

  if (defaults != NULL)
    {
      dptr = strstr (defaults, "ttl=");
      if (dptr != NULL)
	return searchttl (defaults);
    }

  cptr = getenv ("NIS_DEFAULTS");
  if (cptr == NULL)
    return DEFAULT_TTL;

  dptr = strstr (cptr, "ttl=");
  if (dptr == NULL)
    return DEFAULT_TTL;

  return searchttl (cptr);
}
libnsl_hidden_nolink_def (__nis_default_ttl, GLIBC_2_1)

/* Default access rights are ----rmcdr---r---, but we could change
   this with the NIS_DEFAULTS variable. */
unsigned int
__nis_default_access (char *param, unsigned int defaults)
{
  unsigned int result;
  char *cptr;

  if (defaults == 0)
    result = 0 | OWNER_DEFAULT | GROUP_DEFAULT | WORLD_DEFAULT;
  else
    result = defaults;

  if (param != NULL && strstr (param, "access=") != NULL)
    result = searchaccess (param, result);
  else
    {
      cptr = getenv ("NIS_DEFAULTS");
      if (cptr != NULL && strstr (cptr, "access=") != NULL)
	result = searchaccess (cptr, result);
    }

  return result;
}
libnsl_hidden_nolink_def (__nis_default_access, GLIBC_2_1)