/*
 * 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"
#include "snmp-tc.h"
#include "read_config.h"
#include "default_store.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;

void
vacm_save(const char *token, const char *type)
{
  struct vacm_viewEntry *vptr;
  struct vacm_accessEntry *aptr;
  struct vacm_groupEntry *gptr;
  
  for (vptr = viewList; vptr != NULL; vptr = vptr->next) {
    if (vptr->viewStorageType == ST_NONVOLATILE)
      vacm_save_view(vptr, token, type);
  }
        
  for (aptr = accessList; aptr != NULL; aptr = aptr->next) {
    if (aptr->storageType == ST_NONVOLATILE)
      vacm_save_access(aptr, token, type);
  }
      
  for (gptr = groupList; gptr != NULL; gptr = gptr->next) {
    if (gptr->storageType == ST_NONVOLATILE)
      vacm_save_group(gptr, token, type);
  }
}

/* vacm_save_view(): saves a view entry to the persistent cache */
void
vacm_save_view(struct vacm_viewEntry *view, const char *token, const char *type)
{
  char line[4096];
  char *cptr;

  memset(line, 0, sizeof(line));
  sprintf(line, "%s%s %d %d %d ", token,"View", view->viewStatus, view->viewStorageType, view->viewType);
  cptr = &line[strlen(line)]; /* the NULL */
  
  cptr = read_config_save_octet_string(cptr, (u_char *)view->viewName+1,
                                              view->viewName[0]+1);
  *cptr++ = ' ';
  cptr = read_config_save_objid(cptr, view->viewSubtree, view->viewSubtreeLen);
  *cptr++ = ' ';
  cptr = read_config_save_octet_string(cptr, (u_char *)view->viewMask,
											view->viewMaskLen);
    
  read_config_store(type, line);
}

void
vacm_parse_config_view(const char *token, char *line)
{
  struct vacm_viewEntry view;
  struct vacm_viewEntry *vptr;
  char *viewName=(char *)&view.viewName;
  oid *viewSubtree=(oid *)&view.viewSubtree;
  u_char *viewMask;
  size_t len;
  
  view.viewStatus=atoi(line); 
  line=skip_token(line);
  view.viewStorageType=atoi(line);
  line=skip_token(line);
  view.viewType=atoi(line);
  line=skip_token(line);
  line = read_config_read_octet_string(line, (u_char **)&viewName,&len);
  view.viewSubtreeLen=MAX_OID_LEN;
  line = read_config_read_objid(line, (oid **)&viewSubtree,&view.viewSubtreeLen);

  vptr=vacm_createViewEntry(view.viewName,view.viewSubtree,view.viewSubtreeLen);
  if(!vptr)
	return;

  vptr->viewStatus=view.viewStatus;
  vptr->viewStorageType=view.viewStorageType;
  vptr->viewType=view.viewType;
  viewMask=(u_char *)vptr->viewMask;
  line = read_config_read_octet_string(line,(u_char **)&viewMask,&vptr->viewMaskLen); 
}

/* vacm_save_access(): saves an access entry to the persistent cache */
void
vacm_save_access(struct vacm_accessEntry *access, const char *token, const char *type)
{
  char line[4096];
  char *cptr;

  memset(line, 0, sizeof(line));
  sprintf(line, "%s%s %d %d %d %d %d ", token,"Access", access->status, access->storageType, access->securityModel
								  , access->securityLevel, access->contextMatch);
  cptr = &line[strlen(line)]; /* the NULL */
  cptr = read_config_save_octet_string(cptr, (u_char *)access->groupName+1,
                                       access->groupName[0]+1);
  *cptr++ = ' ';                                       
  cptr = read_config_save_octet_string(cptr, (u_char *)access->contextPrefix+1,
                                       access->contextPrefix[0]+1);
  
  *cptr++ = ' ';                                       
  cptr = read_config_save_octet_string(cptr, (u_char *)access->readView,
                                       strlen(access->readView)+1);
  *cptr++ = ' ';                                       
  cptr = read_config_save_octet_string(cptr, (u_char *)access->writeView,
                                       strlen(access->writeView)+1);
  *cptr++ = ' ';                                       
  cptr = read_config_save_octet_string(cptr, (u_char *)access->notifyView,
                                       strlen(access->notifyView)+1);

  read_config_store(type, line);									  
}

void
vacm_parse_config_access(const char *token, char *line)
{
  struct vacm_accessEntry access;
  struct vacm_accessEntry *aptr;
  char *contextPrefix=(char *)&access.contextPrefix;
  char *groupName=(char *)&access.groupName;
  char *readView,*writeView,*notifyView;
  size_t len;
    
  access.status=atoi(line);
  line=skip_token(line);
  access.storageType=atoi(line);
  line=skip_token(line);
  access.securityModel=atoi(line);
  line=skip_token(line);
  access.securityLevel=atoi(line);
  line=skip_token(line);
  access.contextMatch=atoi(line);
  line=skip_token(line);
  line = read_config_read_octet_string(line, (u_char **)&groupName,&len);  
  line = read_config_read_octet_string(line, (u_char **)&contextPrefix,&len);  
  
  aptr=vacm_createAccessEntry(access.groupName,access.contextPrefix,
							access.securityModel,access.securityLevel);
  if(!aptr)
	return;
  
  aptr->status=access.status;  
  aptr->storageType=access.storageType;  
  aptr->securityModel=access.securityModel;  
  aptr->securityLevel=access.securityLevel;  
  aptr->contextMatch=access.contextMatch;
  readView=(char *)aptr->readView;
  line = read_config_read_octet_string(line,(u_char **)&readView,&len);  
  writeView=(char *)aptr->writeView;
  line = read_config_read_octet_string(line,(u_char **)&writeView,&len);     
  notifyView=(char *)aptr->notifyView;
  line = read_config_read_octet_string(line,(u_char **)&notifyView,&len);     
}

/* vacm_save_group(): saves a group entry to the persistent cache */
void
vacm_save_group(struct vacm_groupEntry *group, const char *token, const char *type)
{
  char line[4096];
  char *cptr;

  memset(line, 0, sizeof(line));
  sprintf(line, "%s%s %d %d %d ", token,"Group", group->status, group->storageType, group->securityModel);
  cptr = &line[strlen(line)]; /* the NULL */
  
  cptr = read_config_save_octet_string(cptr, (u_char *)group->securityName+1,
                                       group->securityName[0]+1);
  *cptr++ = ' ';
  cptr = read_config_save_octet_string(cptr, (u_char *)group->groupName,
                                       strlen(group->groupName)+1);
  
  read_config_store(type, line);
}

void
vacm_parse_config_group(const char *token, char *line)
{
  struct vacm_groupEntry group;
  struct vacm_groupEntry *gptr;
  char *securityName=(char *)&group.securityName;
  char *groupName;
  size_t len;
  
  group.status=atoi(line);
  line=skip_token(line);
  group.storageType=atoi(line);
  line=skip_token(line);
  group.securityModel=atoi(line);
  line=skip_token(line);
  line = read_config_read_octet_string(line, (u_char **)&securityName,&len);
    
  gptr=vacm_createGroupEntry(group.securityModel,group.securityName);
  if(!gptr)
	return;
	
  gptr->status=group.status;
  gptr->storageType=group.storageType;    
  groupName=(char *)gptr->groupName;
  line = read_config_read_octet_string(line, (u_char **)&groupName,&len);  
}

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-1;
                 oidpos++) {
		if ((vp->viewMask[maskpos] & mask) != 0) {
		    if (viewSubtree[oidpos] != vp->viewSubtree[oidpos+1])
                        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+1, vp->viewSubtreeLen-1,
                                    vpret->viewSubtree+1,
                                    vpret->viewSubtreeLen-1) > 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,cmp2, 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);
    vp->viewSubtree[0] = viewSubtreeLen;
    memcpy(vp->viewSubtree+1, viewSubtree, viewSubtreeLen * sizeof(oid));
    vp->viewSubtreeLen = viewSubtreeLen+1;

    lp = viewList;
    while (lp) {
	cmp = memcmp(lp->viewName, vp->viewName, glen+1);
	cmp2 = snmp_oid_compare(lp->viewSubtree, lp->viewSubtreeLen,
	                        vp->viewSubtree, vp->viewSubtreeLen);
	if (cmp == 0 && cmp2 > 0) break;
	if (cmp > 0) break;
	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);
    }
}

int
store_vacm(int majorID, int minorID, void *serverarg, void *clientarg)
{
/* figure out our application name */
  char *appname = (char *) clientarg;
  if (appname == NULL)
      appname = ds_get_string(DS_LIBRARY_ID, DS_LIB_APPTYPE);

  /* save the VACM MIB */
  vacm_save("vacm",appname);
  return SNMPERR_SUCCESS;
}

/* 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;
}