//==========================================================================
//
//      ./lib/current/src/vacm.c
//
//
//==========================================================================
//####COPYRIGHTBEGIN####
//                                                                          
// -------------------------------------------                              
// The contents of this file are subject to the Red Hat eCos Public License 
// Version 1.1 (the "License"); you may not use this file except in         
// compliance with the License.  You may obtain a copy of the License at    
// http://www.redhat.com/                                                   
//                                                                          
// Software distributed under the License is distributed on an "AS IS"      
// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the 
// License for the specific language governing rights and limitations under 
// the License.                                                             
//                                                                          
// The Original Code is eCos - Embedded Configurable Operating System,      
// released September 30, 1998.                                             
//                                                                          
// The Initial Developer of the Original Code is Red Hat.                   
// Portions created by Red Hat are                                          
// Copyright (C) 1998, 1999, 2000 Red Hat, Inc.                             
// All Rights Reserved.                                                     
// -------------------------------------------                              
//                                                                          
//####COPYRIGHTEND####
//####UCDSNMPCOPYRIGHTBEGIN####
//
// -------------------------------------------
//
// Portions of this software may have been derived from the UCD-SNMP
// project,  <http://ucd-snmp.ucdavis.edu/>  from the University of
// California at Davis, which was originally based on the Carnegie Mellon
// University SNMP implementation.  Portions of this software are therefore
// covered by the appropriate copyright disclaimers included herein.
//
// The release used was version 4.1.2 of May 2000.  "ucd-snmp-4.1.2"
// -------------------------------------------
//
//####UCDSNMPCOPYRIGHTEND####
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):    hmt
// Contributors: hmt
// Date:         2000-05-30
// Purpose:      Port of UCD-SNMP distribution to eCos.
// Description:  
//              
//
//####DESCRIPTIONEND####
//
//==========================================================================
/********************************************************************
       Copyright 1989, 1991, 1992 by Carnegie Mellon University

			  Derivative Work -
Copyright 1996, 1998, 1999, 2000 The Regents of the University of California

			 All Rights Reserved

Permission to use, copy, modify and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appears in all copies and
that both that copyright notice and this permission notice appear in
supporting documentation, and that the name of CMU and The Regents of
the University of California not be used in advertising or publicity
pertaining to distribution of the software without specific written
permission.

CMU AND THE REGENTS OF THE UNIVERSITY OF CALIFORNIA DISCLAIM ALL
WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL CMU OR
THE REGENTS OF THE UNIVERSITY OF CALIFORNIA BE LIABLE FOR ANY SPECIAL,
INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
FROM THE LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*********************************************************************/
/*
 * vacm.c
 *
 * SNMPv3 View-based Access Control Model
 */

#include <config.h>

#if HAVE_STDLIB_H
#include <stdlib.h>
#endif
#if HAVE_STRING_H
#include <string.h>
#else
#include <strings.h>
#endif
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <sys/types.h>
#include <stdio.h>
#if TIME_WITH_SYS_TIME
# ifdef WIN32
#  include <sys/timeb.h>
# else
#  include <sys/time.h>
# endif
# include <time.h>
#else
# if HAVE_SYS_TIME_H
#  include <sys/time.h>
# else
#  include <time.h>
# endif
#endif

#if HAVE_WINSOCK_H
#include <winsock.h>
#endif

#if HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif

#if HAVE_DMALLOC_H
#include <dmalloc.h>
#endif

#include "asn1.h"
#include "snmp.h"
#include "snmp_api.h"
#include "vacm.h"
#include "snmp_debug.h"

static struct vacm_viewEntry *viewList = NULL, *viewScanPtr = NULL;
static struct vacm_accessEntry *accessList = NULL, *accessScanPtr = NULL;
static struct vacm_groupEntry *groupList = NULL, *groupScanPtr = NULL;

struct vacm_viewEntry *
vacm_getViewEntry(const char *viewName,
		  oid *viewSubtree,
		  size_t viewSubtreeLen)
{
    struct vacm_viewEntry *vp, *vpret = NULL;
    char view[VACMSTRINGLEN];
    int found, glen;

    glen = (int)strlen(viewName);
    if (glen < 0 || glen >= VACM_MAX_STRING)
        return NULL;
    view[0] = glen;
    strcpy(view+1, viewName);
    for(vp = viewList; vp; vp = vp->next){
        if (!memcmp(view, vp->viewName,glen+1)
	    && viewSubtreeLen >= vp->viewSubtreeLen) {
	    int mask = 0x80, maskpos = 0;
	    int oidpos;
            found = 1;
	    for (oidpos = 0; found && oidpos < (int)vp->viewSubtreeLen; oidpos++) {
		if ((vp->viewMask[maskpos] & mask) != 0) {
		    if (viewSubtree[oidpos] != vp->viewSubtree[oidpos])
                        found = 0;
		}
		if (mask == 1) {
		    mask = 0x80;
		    maskpos++;
		}
		else mask >>= 1;
	    }
            if (found) {
              /* match successful, keep this node if its longer than
                 the previous or (equal and lexicographically greater
                 than the previous). */
              if (vpret == NULL || vp->viewSubtreeLen > vpret->viewSubtreeLen ||
                  (vp->viewSubtreeLen == vpret->viewSubtreeLen &&
                   snmp_oid_compare(vp->viewSubtree, vp->viewSubtreeLen,
                                    vpret->viewSubtree,
                                    vpret->viewSubtreeLen) > 0))
                vpret = vp;
            }
	}
    }
    DEBUGMSGTL(("vacm:getView", ", %s", (vpret)?"found":"none"));
    return vpret;
}

void
vacm_scanViewInit (void)
{
    viewScanPtr = viewList;
}

struct vacm_viewEntry *
vacm_scanViewNext (void)
{
    struct vacm_viewEntry *returnval = viewScanPtr;
    if (viewScanPtr) viewScanPtr = viewScanPtr->next;
    return returnval;
}

struct vacm_viewEntry *
vacm_createViewEntry(const char *viewName,
		     oid *viewSubtree,
		     size_t viewSubtreeLen)
{
    struct vacm_viewEntry *vp, *lp, *op = NULL;
    int cmp, glen;

    glen = (int)strlen(viewName);
    if (glen < 0 || glen >= VACM_MAX_STRING)
        return NULL;
    vp = (struct vacm_viewEntry *)calloc(1, sizeof(struct vacm_viewEntry));
    if (vp == NULL)
        return NULL;
    vp->reserved = (struct vacm_viewEntry *)calloc(1, sizeof(struct vacm_viewEntry));
    if (vp->reserved == NULL) {
        free(vp);
        return NULL;
    }

    vp->viewName[0] = glen;
    strcpy(vp->viewName+1, viewName);
    memcpy(vp->viewSubtree, viewSubtree, viewSubtreeLen * sizeof(oid));
    vp->viewSubtreeLen = viewSubtreeLen;

    lp = viewList;
    while (lp) {
	cmp = memcmp(lp->viewName, vp->viewName, glen+1);
	if (cmp > 0) break;
	if (cmp < 0) goto next;
	
next:
	op = lp;
	lp = lp->next;
    }
    vp->next = lp;
    if (op) op->next = vp;
    else viewList = vp;
    return vp;
}

void
vacm_destroyViewEntry(const char *viewName,
		      oid *viewSubtree,
		      size_t viewSubtreeLen)
{
    struct vacm_viewEntry *vp, *lastvp = NULL;

    if (viewList && !strcmp(viewList->viewName+1, viewName)
	&& viewList->viewSubtreeLen == viewSubtreeLen
	&& !memcmp((char *)viewList->viewSubtree, (char *)viewSubtree,
		 viewSubtreeLen * sizeof(oid))){
	vp = viewList;
	viewList = viewList->next;
    } else {
	for (vp = viewList; vp; vp = vp->next){
	    if (!strcmp(vp->viewName+1, viewName)
		&& vp->viewSubtreeLen  == viewSubtreeLen 
		&& !memcmp((char *)vp->viewSubtree, (char *)viewSubtree,
			 viewSubtreeLen * sizeof(oid)))
		break;
	    lastvp = vp;
	}
	if (!vp)
	    return;
	lastvp->next = vp->next;
    }
    if (vp->reserved)
	free(vp->reserved);
    free(vp);
    return;
}

void vacm_destroyAllViewEntries (void)
{
    struct vacm_viewEntry *vp;
    while ((vp = viewList)) {
	viewList = vp->next;
	if (vp->reserved) free(vp->reserved);
	free(vp);
    }
}

struct vacm_groupEntry *
vacm_getGroupEntry(int securityModel,
		   const char *securityName)
{
    struct vacm_groupEntry *vp;
    char secname[VACMSTRINGLEN];
    int glen;

    glen = (int)strlen(securityName);
    if (glen < 0 || glen >= VACM_MAX_STRING)
        return NULL;
    secname[0] = glen;
    strcpy(secname+1, securityName);

    for (vp = groupList; vp; vp = vp->next) {
	if ((securityModel == vp->securityModel || vp->securityModel == SNMP_SEC_MODEL_ANY)
	    && !memcmp(vp->securityName, secname,glen+1))
	return vp;
    }
    return NULL;
}

void
vacm_scanGroupInit (void)
{
    groupScanPtr = groupList;
}

struct vacm_groupEntry *
vacm_scanGroupNext (void)
{
    struct vacm_groupEntry *returnval = groupScanPtr;
    if (groupScanPtr) groupScanPtr = groupScanPtr->next;
    return returnval;
}

struct vacm_groupEntry *
vacm_createGroupEntry(int securityModel,
		      const char *securityName)
{
    struct vacm_groupEntry *gp, *lg, *og;
    int cmp, glen;

    glen = (int)strlen(securityName);
    if (glen < 0 || glen >= VACM_MAX_STRING)
        return NULL;
    gp = (struct vacm_groupEntry *)calloc(1, sizeof(struct vacm_groupEntry));
    if (gp == NULL)
        return NULL;
    gp->reserved = (struct vacm_groupEntry *)calloc(1, sizeof(struct vacm_groupEntry));
    if (gp->reserved == NULL) {
        free(gp);
        return NULL;
    }

    gp->securityModel = securityModel;
    gp->securityName[0] = glen;
    strcpy(gp->securityName+1, securityName);

    lg = groupList;
    og = NULL;
    while (lg) {
	if (lg->securityModel > securityModel) break;
	if (lg->securityModel == securityModel && 
	    (cmp = memcmp(lg->securityName, gp->securityName, glen+1)) > 0) break;
	/* if (lg->securityModel == securityModel && cmp == 0) abort(); */
	og = lg; lg = lg->next;
    }
    gp->next = lg;
    if (og == NULL) groupList = gp;
    else og->next = gp;
    return gp;
}

void
vacm_destroyGroupEntry(int securityModel,
		       const char *securityName)
{
    struct vacm_groupEntry *vp, *lastvp = NULL;

    if (groupList && groupList->securityModel == securityModel
	&& !strcmp(groupList->securityName+1, securityName)) {
	vp = groupList;
	groupList = groupList->next;
    } else {
	for (vp = groupList; vp; vp = vp->next){
	    if (vp->securityModel == securityModel
		&& !strcmp(vp->securityName+1, securityName))
		break;
	    lastvp = vp;
	}
	if (!vp)
	    return;
	lastvp->next = vp->next;
    }
    if (vp->reserved)
	free(vp->reserved);
    free(vp);
    return;
}

void vacm_destroyAllGroupEntries (void)
{
    struct vacm_groupEntry *gp;
    while ((gp = groupList)) {
	groupList = gp->next;
	if (gp->reserved) free(gp->reserved);
	free(gp);
    }
}

struct vacm_accessEntry *
vacm_getAccessEntry(const char *groupName, 
		    const char *contextPrefix,
		    int securityModel, 
		    int securityLevel)
{
    struct vacm_accessEntry *vp;
    char group[VACMSTRINGLEN];
    char context[VACMSTRINGLEN];
    int glen, clen;

    glen = (int)strlen(groupName);
    if (glen < 0 || glen >= VACM_MAX_STRING)
        return NULL;
    clen = (int)strlen(contextPrefix);
    if (clen < 0 || clen >= VACM_MAX_STRING)
        return NULL;

    group[0] = glen;
    strcpy(group+1, groupName);
    context[0] = clen;
    strcpy(context+1, contextPrefix);
    for(vp = accessList; vp; vp = vp->next){
        if ((securityModel == vp->securityModel || vp->securityModel == SNMP_SEC_MODEL_ANY)
	    && securityLevel >= vp->securityLevel
	    && !memcmp(vp->groupName, group, glen+1)
	    && !memcmp(vp->contextPrefix, context, clen+1))
	  return vp;
    }
    return NULL;
}

void
vacm_scanAccessInit (void)
{
    accessScanPtr = accessList;
}

struct vacm_accessEntry *
vacm_scanAccessNext (void)
{
    struct vacm_accessEntry *returnval = accessScanPtr;
    if (accessScanPtr) accessScanPtr = accessScanPtr->next;
    return returnval;
}

struct vacm_accessEntry *
vacm_createAccessEntry(const char *groupName, 
		       const char *contextPrefix,
		       int securityModel, 
		       int securityLevel)
{
    struct vacm_accessEntry *vp, *lp, *op = NULL;
    int cmp, glen, clen;

    glen = (int)strlen(groupName);
    if (glen < 0 || glen >= VACM_MAX_STRING)
        return NULL;
    clen = (int)strlen(contextPrefix);
    if (clen < 0 || clen >= VACM_MAX_STRING)
        return NULL;
    vp = (struct vacm_accessEntry *)calloc(1, sizeof(struct vacm_accessEntry));
    if (vp == NULL)
        return NULL;
    vp->reserved = (struct vacm_accessEntry *)calloc(1, sizeof(struct vacm_accessEntry));
    if (vp->reserved == NULL) {
        free(vp);
        return NULL;
    }

    vp->securityModel = securityModel;
    vp->securityLevel = securityLevel;
    vp->groupName[0] = glen;
    strcpy(vp->groupName+1, groupName);
    vp->contextPrefix[0] = clen;
    strcpy(vp->contextPrefix+1, contextPrefix);

    lp = accessList;
    while (lp) {
	cmp = memcmp(lp->groupName, vp->groupName, glen+1);
	if (cmp > 0) break;
	if (cmp < 0) goto next;
	cmp = memcmp(lp->contextPrefix, vp->contextPrefix, clen+1);
	if (cmp > 0) break;
	if (cmp < 0) goto next;
	if (lp->securityModel > securityModel) break;
	if (lp->securityModel < securityModel) goto next;
	if (lp->securityLevel > securityLevel) break;
next:
	op = lp;
	lp = lp->next;
    }
    vp->next = lp;
    if (op == NULL) accessList = vp;
    else op->next = vp;
    return vp;
}

void
vacm_destroyAccessEntry(const char *groupName, 
			const char *contextPrefix,
			int securityModel,
			int securityLevel)
{
    struct vacm_accessEntry *vp, *lastvp = NULL;

    if (accessList && accessList->securityModel == securityModel
	&& accessList->securityModel == securityModel
	&& !strcmp(accessList->groupName+1, groupName)
	&& !strcmp(accessList->contextPrefix+1, contextPrefix)) {
	vp = accessList;
	accessList = accessList->next;
    } else {
	for (vp = accessList; vp; vp = vp->next){
	    if (vp->securityModel == securityModel
		&& vp->securityLevel == securityLevel
		&& !strcmp(vp->groupName+1, groupName)
		&& !strcmp(vp->contextPrefix+1, contextPrefix))
		break;
	    lastvp = vp;
	}
	if (!vp)
	    return;
	lastvp->next = vp->next;
    }
    if (vp->reserved)
	free(vp->reserved);
    free(vp);
    return;
}

void vacm_destroyAllAccessEntries (void)
{
    struct vacm_accessEntry *ap;
    while ((ap = accessList)) {
	accessList = ap->next;
	if (ap->reserved) free(ap->reserved);
	free(ap);
    }
}

/* returns 1 if vacm has *any* configuration entries in it (regardless
   of weather or not there is enough to make a decision based on it),
   else return 0 */
int vacm_is_configured(void) {
    if (viewList == NULL && accessList == NULL && groupList == NULL)
        return 0;
    return 1;
}