/* Copyright (C) 1990, 1989 Transarc Corporation - All rights reserved */
/*
 * P_R_P_Q_# (C) COPYRIGHT IBM CORPORATION 1988
 * LICENSED MATERIALS - PROPERTY OF IBM
 * REFER TO COPYRIGHT INSTRUCTIONS FORM NUMBER G120-2083
 */


/*	
             Sherri Nichols
             Information Technology Center
       November, 1988

       Modified May, 1989 by Jeff Schiller to keep disk file in
       network byte order

*/

#include <afs/param.h>
#include <afs/stds.h>
#include <sys/types.h>
#include <stdio.h>
#ifdef AFS_HPUX_ENV
#include <string.h>
#else
#include <strings.h>
#endif
#include <lock.h>
#include <netinet/in.h>
#include <ubik.h>
#include <rx/xdr.h>
#include <afs/com_err.h>
#include "ptserver.h"
#include "pterror.h"

RCSID ("$Header$")

extern struct ubik_dbase *dbase;
extern struct afsconf_dir *prdir;
extern int pr_noAuth;

static char *whoami = "ptserver";

/* CorrectUserName - Check to make sure a user name is OK.  It must not include
 *   either a colon (or it would look like a group) or an atsign (or it would
 *   look like a foreign user).  The length is checked as well to make sure
 *   that the user name, an atsign, and the local cell name will fit in
 *   PR_MAXNAMELEN.  This is so this user can fit in another cells database as
 *   a foreign user with our cell name tacked on.  This is a predicate, so it
 *   return one if name is OK and zero if name is bogus. */

static int CorrectUserName (name)
  char *name;
{
    extern int pr_realmNameLen;

#ifdef CROSS_CELL
    if (index (name, ':') || index(name, '\n')) return 0;
#else
    if (index (name, ':') || index(name, '@') || index(name, '\n')) return 0;
#endif
    if (strlen (name) >= PR_MAXNAMELEN - pr_realmNameLen - 1) return 0; 
    return 1;
}

/* CorrectGroupName - Like the above but handles more complicated cases caused
 * by including the ownership in the name.  The interface works by calculating
 * the correct name based on a given name and owner.  This allows easy use by
 * rename, which then compares the correct name with the requested new name. */

static long CorrectGroupName (ut, aname, cid, oid, cname)
  struct ubik_trans *ut;
  char aname[PR_MAXNAMELEN];		/* name for group */
  long cid;				/* caller id */
  long oid;				/* owner of group */
  char cname[PR_MAXNAMELEN];		/* correct name for group */
{
    long  code;
    int   admin;
    char *prefix;			/* ptr to group owner part */
    char *suffix;			/* ptr to group name part */
    char  name[PR_MAXNAMELEN];		/* correct name for group */
    struct prentry tentry;

    if (strlen (aname) >= PR_MAXNAMELEN) return PRBADNAM;
    admin = pr_noAuth || (cid==SYSADMINID) || IsAMemberOf(ut, cid, SYSADMINID);

    if (oid == 0) oid = cid;

    /* Determine the correct prefix for the name. */
    if (oid == SYSADMINID) prefix = "system";
    else {
	long loc = FindByID (ut, oid);
	if (loc == 0) {
	    /* let admin create groups owned by non-existent ids (probably
             * setting a group to own itself).  Check that they look like
             * groups (with a colon) or otherwise are good user names. */
	    if (admin) {
		strcpy (cname, aname);
		goto done;
	    }
	    return PRNOENT;
	}
	code = pr_Read (ut, 0, loc, &tentry, sizeof(tentry));
	if (code) return code;
	if (ntohl(tentry.flags) & PRGRP) {
	    if ((tentry.count == 0) && !admin) return PRGROUPEMPTY;
	    /* terminate prefix at colon if there is one */
	    if (prefix = index(tentry.name, ':')) *prefix = 0;
	}
	prefix = tentry.name;
    }
    /* only sysadmin allow to use 'system:' prefix */
    if ((strcmp (prefix, "system") == 0) && !admin) return PRPERM;

    strcpy (name, aname);		/* in case aname & cname are same */
    suffix = index(name, ':');
    if (suffix == 0) {
	/* sysadmin can make groups w/o ':', but they must still look like
         * legal user names. */
	if (!admin) return PRBADNAM;
	strcpy (cname, name);
    }
    else {
	if (strlen(prefix)+strlen(suffix) >= PR_MAXNAMELEN) return PRBADNAM;
	strcpy (cname, prefix);
	strcat (cname, suffix);
    }
  done:
    /* check for legal name with either group rules or user rules */
    if (suffix = index(cname, ':')) {
	/* check for confusing characters */
#ifdef CROSS_CELL
	if (index(cname, '\n') ||	/* restrict so recreate can work */
	    index(suffix+1, ':'))	/* avoid multiple colons */
	    return PRBADNAM;
#else
	if (index(cname, '@') ||	/* avoid confusion w/ foreign users */
	    index(cname, '\n') ||	/* restrict so recreate can work */
	    index(suffix+1, ':'))	/* avoid multiple colons */
	    return PRBADNAM;
#endif
    } else {
	if (!CorrectUserName (cname)) return PRBADNAM;
    }
    return 0;
}

int AccessOK (ut, cid, tentry, mem, any)
  struct ubik_trans *ut;
  long cid;				/* caller id */
  struct prentry *tentry;		/* object being accessed */
  int mem;				/* check membership in aid, if group */
  int any;				/* if set return true */
{   long flags;
    long oid;
    long aid;

    if (pr_noAuth) return 1;
    if (cid == SYSADMINID) return 1;	/* special case fileserver */
    if (tentry) {
	flags = tentry->flags;
	oid = tentry->owner;
	aid = tentry->id;
    } else {
	flags = oid = aid = 0;
    }
    if (!(flags & PRACCESS))		/* provide default access */
	if (flags & PRGRP)
	    flags |= PRP_GROUP_DEFAULT;
	else
	    flags |= PRP_USER_DEFAULT;

    if (flags & any) return 1;
    if (oid) {
	if ((cid == oid) ||
	    IsAMemberOf (ut, cid, oid)) return 1;
    }
    if (aid > 0) {			/* checking on a user */
	if (aid == cid) return 1;
    } else if (aid < 0) {		/* checking on group */
	if ((flags & mem) && IsAMemberOf (ut, cid, aid)) return 1;
    }
    if (IsAMemberOf (ut, cid, SYSADMINID)) return 1;
    return 0;				/* no access */
}

long CreateEntry (at, aname, aid, idflag, flag, oid, creator)  
  register struct ubik_trans *at;
  char aname[PR_MAXNAMELEN];
  long *aid;
  long idflag;
  long flag;
  long oid;
  long creator;
{
    /* get and init a new entry */
    register long code;
    long newEntry;
    struct prentry tentry;
    
    bzero(&tentry, sizeof(tentry));

    if ((oid == 0) || (oid == ANONYMOUSID)) oid = creator;

    if (flag & PRGRP) {
	code = CorrectGroupName (at, aname, creator, oid, tentry.name);
	if (code) return code;
	if (strcmp (aname, tentry.name) != 0)  return PRBADNAM;
    } else {				/* non-group must not have colon */
	if (!CorrectUserName(aname)) return PRBADNAM;
	strcpy (tentry.name, aname);
    }

    if (FindByName(at,aname)) return PREXIST;

    newEntry = AllocBlock(at);
    if (!newEntry) return PRDBFAIL;
#ifdef PR_REMEMBER_TIMES
    tentry.createTime = time(0);
#endif
    if (flag & PRGRP) {
	tentry.flags |= PRGRP;
	tentry.owner = oid;
    }
    else if (flag & PRFOREIGN) {
	tentry.flags |= PRFOREIGN;
	tentry.owner = oid;
    }
    else tentry.owner = SYSADMINID;

#ifdef CROSS_CELL
#define ADD_TO_AUTHUSER_GROUP 1
#define AUTHUSER_GROUP "system:authuser"
    {
	char * atsign;

	if (!(atsign= index(aname,'@'))) {	/* No @ so local cell*/
	    if (idflag)
		tentry.id = *aid;
	    else {
		code= AllocID(at,flag,&tentry.id);
		if (code != PRSUCCESS) return code;
	    }
	} else {
	    /*foreign cells are represented by the group system:authuser@cell*/
	    if (flag & PRGRP) {
		/* it's a new foreign cell so the format
		 * must be AUTHUSER_GROUP@cellname  */
		int badFormat;
		
		*atsign = '\0';
		badFormat = strcmp(AUTHUSER_GROUP, aname);
		*atsign = '@';
		if (badFormat) return PRBADNAM;
		if (idflag)
		    tentry.id = *aid;
		else {
		    code= AllocID(at,flag,&tentry.id);
		    if (code != PRSUCCESS) return code;
		}
	    } else {
		/* it's a foreign cell entry */
		char *cellGroup;
		long pos;
		struct prentry centry;
		extern long allocNextId();
		extern long AddToEntry();
		
		cellGroup = (char *) malloc (strlen(AUTHUSER_GROUP) +
					     strlen(atsign) +1);
		strcpy(cellGroup, AUTHUSER_GROUP);
		strcat(cellGroup, atsign);
		pos = FindByName(at,cellGroup);
		
		/* if the group doesn't exist don't allow user creation */
		if (!pos) return PRBADNAM;
		
		code = pr_Read (at, 0, pos, &centry, sizeof(centry));
		if (code) return code;
		tentry.cellid = ntohl(centry.id);
		/* cellid is the id of the group representing the cell */
		
		if (idflag) {
		    if (!inRange(&centry,*aid))
                        return PRBADARG;	/* the id specified is not in
						 * the id space of the group */
		    tentry.id = *aid;
		} else
		    /* allocNextID() will allocate the next id
		     * in that cell's space */
		    tentry.id = allocNextId(&centry);

		/* charge the cell group for the new user and test quota */
		if (!(ntohl(centry.flags) & PRQUOTA)) {
                    /* quota uninitialized, so initialize it now */
                    centry.flags = htonl (ntohl(centry.flags) | PRQUOTA);
                    centry.ngroups = htonl(30);
		}

		centry.ngroups = htonl(ntohl(centry.ngroups) - 1);
		if (ntohl(centry.ngroups) < 0)
		    if (!pr_noAuth) return PRNOMORE;
		
#if !ADD_TO_AUTHUSER_GROUP
		centry.count = htonl(ntohl(centry.ngroups) +1);
		/* keep count of how many people are in the group. */
#endif
		
		code = pr_Write (at, 0, pos, &centry, sizeof(centry));
		/* write updated entry for group */

		/* Now add the new user entry to the database */
		
		tentry.creator = creator;
		*aid = tentry.id;
		code = pr_WriteEntry(at, 0, newEntry, &tentry);
		if (code) return PRDBFAIL;
		code = AddToIDHash(at,*aid,newEntry);
		if (code != PRSUCCESS) return code;
		code = AddToNameHash(at,aname,newEntry);
		if (code != PRSUCCESS) return code;
		if (inc_header_word (at, foreigncount, 1)) return PRDBFAIL;
		
#if ADD_TO_AUTHUSER_GROUP
		
		/* Now add the entry to the authuser group for this cell.
		 * We will reread the entries for the user and the group
		 * instead of modifying them before writing them in the
		 * previous steps. Although not very efficient, much simpler */

		/* First update the group entry */
		pos = FindByID(at,tentry.cellid);
		if (!pos) return PRBADNAM;
		code = pr_ReadEntry (at, 0, pos, &centry);
		if (code) return code;
		code = AddToEntry(at, &centry,pos,*aid);
		if (code) return code;
		/* and now the user entry */
		pos = FindByID(at,*aid);
		if (!pos) return PRBADNAM;
		code = pr_ReadEntry(at, 0, pos, &tentry);
		if (code) return code;
		code = AddToEntry(at, &tentry,pos,tentry.cellid);
		if (code) return code;
		
#endif
		
		/* Ok we're done */
		return PRSUCCESS;
	    }
	}
    }

#else	/* !CROSS_CELL */

    if (idflag) 
	tentry.id = *aid;
    else {
	code= AllocID(at,flag,&tentry.id);
	if (code != PRSUCCESS) return code;
    }
#endif	/* !CROSS_CELL */

    if (flag & PRGRP) {
	/* group ids are negative */
	if (tentry.id < (long)ntohl(cheader.maxGroup)) {
	    code = set_header_word (at, maxGroup, htonl(tentry.id));
	    if (code) return PRDBFAIL;
	}
    }
    else if (flag & PRFOREIGN) {
	if (tentry.id > (long)ntohl(cheader.maxForeign)) {
	    code = set_header_word (at, maxForeign, htonl(tentry.id));
	    if (code) return PRDBFAIL;
	}
    }
    else {
	if (tentry.id > (long)ntohl(cheader.maxID)) {
	    code = set_header_word (at, maxID, htonl(tentry.id));
	    if (code) return PRDBFAIL;
	}
    }
    /* PRACCESS is off until set, defaults provided in AccessOK */
    if (flag == 0) {			/* only normal users get quota */
	tentry.flags |= PRQUOTA;
	tentry.ngroups = tentry.nusers = 20;
    }

    if (flag & (PRGRP | PRFOREIGN)) {
	long loc = FindByID (at, creator);
	struct prentry centry;
	long *nP;			/* ptr to entry to be decremented */
	long  n;			/* quota to check */

	if (loc) { /* this should only fail during initialization */
	    code = pr_Read (at, 0, loc, &centry, sizeof(centry));
	    if (code) return code;

	    if (flag & PRGRP) nP = &centry.ngroups;
	    else if (flag & PRFOREIGN) nP = &centry.nusers;
	    else nP = 0;
	    
	    if (nP) {
		if (!(ntohl(centry.flags) & PRQUOTA)) {
		    /* quota uninitialized, so do it now */
		    centry.flags = htonl (ntohl(centry.flags) | PRQUOTA);
		    centry.ngroups = centry.nusers = htonl(20);
		}
		n = ntohl(*nP);
		if (n <= 0) {
		    if (!pr_noAuth &&
			!IsAMemberOf (at, creator, SYSADMINID))
			return PRNOMORE;
		}
		else {			/* don't use up admin user's quota */
		    int admin = ((creator == SYSADMINID) ||
				 IsAMemberOf (at, creator, SYSADMINID));
		    if (!admin) *nP = htonl(n-1);
		}
	    }
	    code = pr_Write (at, 0, loc, &centry, sizeof(centry));
	    if (code) return code;
	} /* if (loc) */
    } /* need to check creation quota */
    tentry.creator = creator;
    *aid = tentry.id;
    code = pr_WriteEntry(at, 0, newEntry, &tentry);
    if (code) return PRDBFAIL;
    code = AddToIDHash(at,*aid,newEntry);
    if (code != PRSUCCESS) return code;
    code = AddToNameHash(at,aname,newEntry);
    if (code != PRSUCCESS) return code;
    if (tentry.flags & PRGRP) {
	code = AddToOwnerChain(at,tentry.id,oid);
	if (code) return code;
    }
    if (tentry.flags & PRGRP) {
	if (inc_header_word (at, groupcount, 1)) return PRDBFAIL;
    }
    else if (tentry.flags & PRFOREIGN) {
	if (inc_header_word (at, foreigncount, 1)) return PRDBFAIL;
    }
    else if (tentry.flags & PRINST) {
	if (inc_header_word (at, instcount, 1)) return PRDBFAIL;
    }
    else {
	if (inc_header_word (at, usercount, 1)) return PRDBFAIL;
    }
    return PRSUCCESS;
}
    

/* RemoveFromEntry - remove aid from bid's entries list, freeing a continuation
 * entry if appropriate */

long RemoveFromEntry (at, aid, bid)
  register struct ubik_trans *at;
  register long aid;
  register long bid;
{
    register long code;
    struct prentry tentry;
    struct contentry centry;
    struct contentry hentry;
    long temp;
    long i,j;
    long nptr;
    long hloc;
    
    if (aid == bid) return PRINCONSISTENT;
    bzero(&hentry,sizeof(hentry));
    temp = FindByID(at,bid);
    if (temp == 0) return PRNOENT;
    code = pr_ReadEntry(at, 0, temp, &tentry);
    if (code != 0) return code;
#ifdef PR_REMEMBER_TIMES
    tentry.removeTime = time(0);
#endif
    for (i=0;i<PRSIZE;i++) {
	if (tentry.entries[i] == aid) {  
	    tentry.entries[i] = PRBADID;
	    tentry.count--;
	    code = pr_WriteEntry(at,0,temp,&tentry);
            if (code != 0) return code;
	    return PRSUCCESS;
	}
	if (tentry.entries[i] == 0)   /* found end of list */
	    return PRNOENT;
    }
    hloc = 0;
    nptr = tentry.next;
    while (nptr != NULL) {
	code = pr_ReadCoEntry(at,0,nptr,&centry);
	if (code != 0) return code;
	if ((centry.id != bid) || !(centry.flags & PRCONT)) return PRDBBAD;
	for (i=0;i<COSIZE;i++) {
	    if (centry.entries[i] == aid) {
		centry.entries[i] = PRBADID;
		for (j=0;j<COSIZE;j++)
		    if (centry.entries[j] != PRBADID &&
			centry.entries[j] != 0) break;
		if (j == COSIZE) {   /* can free this block */
		    if (hloc == 0) {
			tentry.next = centry.next;
		    }
		    else {
			hentry.next = centry.next;
			code = pr_WriteCoEntry (at, 0, hloc, &hentry);
			if (code != 0) return code;
		    }
		    code = FreeBlock (at, nptr);
		    if (code) return code;
		}
		else { /* can't free it yet */
		    code = pr_WriteCoEntry(at,0,nptr,&centry);
		    if (code != 0) return code;
		}
		tentry.count--;
		code = pr_WriteEntry(at,0,temp,&tentry);
		if (code) return PRDBFAIL;
		return 0;
	    }
	    if (centry.entries[i] == 0) return PRNOENT;
	} /* for all coentry slots */
	hloc = nptr;
	nptr = centry.next;
	bcopy(&centry,&hentry,sizeof(centry));
    } /* while there are coentries */
    return PRNOENT;
}

/* DeleteEntry - delete the entry in tentry at loc, removing it from all
 * groups, putting groups owned by it on orphan chain, and freeing the space */

long DeleteEntry (at, tentry, loc)
  register struct ubik_trans *at;
  struct prentry *tentry;
  long loc;
{
    register long code;
    struct contentry centry;
    register long  i;
    long nptr;

#ifdef CROSS_CELL
    if (index(tentry->name,'@')) {
	if (tentry->flags & PRGRP) {
	    /* If there are still foreign user accounts from that cell
	     * don't delete the group */
	    if (tentry->count) return PRBADARG;
	} else {
	    /* It's a user adjust the group quota upwards */
	    long loc = FindByID (at, tentry->cellid);
	    struct prentry centry;
	    if (loc) {
		code = pr_Read (at, 0, loc, &centry, sizeof(centry));
		if (code) return code;
		if (ntohl(centry.flags) & PRQUOTA) {
                    centry.ngroups = htonl(ntohl(centry.ngroups) + 1);
		}
#if !ADD_TO_AUTHUSER_GROUP
		/* if this is a foreign cell entry then decrement the number of
		 * existing users in the prentry of the authuser group for that
		 * cell
		 */
		centry.count = htonl(ntohl(centry.count) - 1);
#endif
		code = pr_Write (at, 0, loc, &centry, sizeof(centry));
		if (code) return code;
	    }
        }
    }
#endif /* CROSS_CELL */
    
    /* First remove the entire membership list */
    for (i=0;i<PRSIZE;i++) {
	if (tentry->entries[i] == PRBADID) continue;
	if (tentry->entries[i] == 0) break;
	code = RemoveFromEntry (at, tentry->id, tentry->entries[i]);
	if (code) return code;
    }
    nptr = tentry->next;
    while (nptr != NULL) {
	code = pr_ReadCoEntry(at,0,nptr,&centry);
	if (code != 0) return PRDBFAIL;
	for (i=0;i<COSIZE;i++) {
	    if (centry.entries[i] == PRBADID) continue;
	    if (centry.entries[i] == 0) break;
	    code = RemoveFromEntry (at, tentry->id, centry.entries[i]);
	    if (code) return code;
	}
	code = FreeBlock (at, nptr);	/* free continuation block */
	if (code) return code;
	nptr = centry.next;
    }

    /* Remove us from other's owned chain.  Note that this will zero our owned
     * field (on disk) so this step must follow the above step in case we are
     * on our own owned list. */
    if (tentry->flags & PRGRP) {
	if (tentry->owner) {
	    code = RemoveFromOwnerChain (at, tentry->id, tentry->owner);
	    if (code) return code;
	}
	else {
	    code = RemoveFromOrphan (at, tentry->id);
	    if (code) return code;
	}
    }

    code = RemoveFromIDHash(at,tentry->id,&loc);
    if (code != PRSUCCESS) return code;
    code = RemoveFromNameHash(at,tentry->name,&loc);
    if (code != PRSUCCESS) return code;

    if (tentry->flags & (PRGRP | PRFOREIGN)) {
	long loc = FindByID (at, tentry->creator);
	struct prentry centry;
	int admin;
	if (loc) {
	    code = pr_Read (at, 0, loc, &centry, sizeof(centry));
	    if (code) return code;
	    admin = ((tentry->creator == SYSADMINID) ||
		     IsAMemberOf (at, tentry->creator, SYSADMINID));
	    if (ntohl(centry.flags) & PRQUOTA) {
		if ((tentry->flags & PRGRP) &&
		    !(admin && (ntohl(centry.ngroups) >= 20))) {
		    centry.ngroups = htonl(ntohl(centry.ngroups) + 1);
		} else if ((tentry->flags & PRFOREIGN) &&
			   !(admin && (ntohl(centry.nusers) >= 20))) {
		    centry.nusers = htonl(ntohl(centry.nusers) + 1);
		}
	    }
	    code = pr_Write (at, 0, loc, &centry, sizeof(centry));
	    if (code) return code;
	}
    }

    if (tentry->flags & PRGRP) {
	if (inc_header_word (at, groupcount, -1)) return PRDBFAIL;
    }
    else if (tentry->flags & PRFOREIGN) {
	if (inc_header_word (at, foreigncount, -1)) return PRDBFAIL;
    }
    else if (tentry->flags & PRINST) {
	if (inc_header_word (at, instcount, -1)) return PRDBFAIL;
    }
    else {
	if (inc_header_word (at, usercount, -1)) return PRDBFAIL;
    }
    code = FreeBlock(at, loc);
    return code;
}

/* AddToEntry - add aid to entry's entries list, alloc'ing a continuation block
 * if needed.
 *
 * Note the entry is written out by this routine. */

long AddToEntry (tt, entry, loc, aid)
  struct ubik_trans *tt;
  struct prentry *entry;
  long loc;
  long aid;
{
    register long code;
    long i;
    struct contentry nentry;
    struct contentry aentry;
    long nptr;
    long last;				/* addr of last cont. block */
    long first = 0;
    long cloc;
    long slot = -1;

    if (entry->id == aid) return PRINCONSISTENT;
#ifdef PR_REMEMBER_TIMES
    entry->addTime = time(0);
#endif
    for (i=0;i<PRSIZE;i++) {
	if (entry->entries[i] == aid)
	    return PRIDEXIST;
	if (entry->entries[i] == PRBADID) { /* remember this spot */
	    first = 1;
	    slot = i;
	}
	else if (entry->entries[i] == 0) { /* end of the line */
	    if (slot == -1) {
		first = 1;
		slot = i;
	    }
	    break;
	}
    }
    last = 0;
    nptr = entry->next;
    while (nptr != NULL) {
 	code = pr_ReadCoEntry(tt,0,nptr,&nentry);
	if (code != 0) return code;
	last = nptr;
	if (!(nentry.flags & PRCONT)) return PRDBFAIL;
	for (i=0;i<COSIZE;i++) {
	    if (nentry.entries[i] == aid)
		return PRIDEXIST;
	    if (nentry.entries[i] == PRBADID) {
		if (slot == -1) {
		    slot = i;
		    cloc = nptr;
		}
	    }
	    else if (nentry.entries[i] == 0) {
		if (slot == -1) {
		    slot = i;
		    cloc = nptr;
		}
		break;
	    }
	}
	nptr = nentry.next;
    }
    if (slot != -1) {			/* we found a place */
	entry->count++;
	if (first) {  /* place is in first block */
	    entry->entries[slot] = aid;
	    code = pr_WriteEntry (tt, 0, loc, entry);
	    if (code != 0) return code;
	    return PRSUCCESS;
	}
	code = pr_WriteEntry (tt, 0, loc, entry);
	if (code) return code;
	code = pr_ReadCoEntry(tt,0,cloc,&aentry);
	if (code != 0) return code;
	aentry.entries[slot] = aid;
	code = pr_WriteCoEntry(tt,0,cloc,&aentry);
	if (code != 0) return code;
	return PRSUCCESS;
    }
    /* have to allocate a continuation block if we got here */
    nptr = AllocBlock(tt);
    if (last) {
	/* then we should tack new block after last block in cont. chain */
	nentry.next = nptr;
	code = pr_WriteCoEntry(tt,0,last,&nentry);
	if (code != 0) return code;
    }
    else {
	entry->next = nptr;
    }
    bzero(&aentry,sizeof(aentry));
    aentry.flags |= PRCONT;
    aentry.id = entry->id;
    aentry.next = NULL;
    aentry.entries[0] = aid;
    code = pr_WriteCoEntry(tt,0,nptr,&aentry);
    if (code != 0) return code;
    /* don't forget to update count, here! */
    entry->count++;
    code = pr_WriteEntry (tt, 0, loc, entry);
    return code;
	
}

long AddToPRList (alist, sizeP, id)
  prlist *alist;
  int *sizeP;
  long id;
{
    if (alist->prlist_len >= PR_MAXGROUPS) return PRTOOMANY;
    if (alist->prlist_len >= *sizeP) {
	*sizeP = *sizeP + 100;
	if (*sizeP > PR_MAXGROUPS) *sizeP = PR_MAXGROUPS;
	alist->prlist_val =
	    (long *) ((alist->prlist_val) ?
		      realloc (alist->prlist_val, (*sizeP)*sizeof(long)) :
		      malloc ((*sizeP)*sizeof(long)));
    }
    alist->prlist_val[alist->prlist_len++] = id;
    return 0;
}

long GetList (at, tentry, alist, add)
  struct ubik_trans *at;
  struct prentry *tentry;
  prlist *alist;
  long add;
{
    register long code;
    long i;
    struct contentry centry;
    long nptr;
    int size;
    int count = 0;
    extern long IDCmp();

    size = 0;
    alist->prlist_val = 0;
    alist->prlist_len = 0;

    for (i=0;i<PRSIZE;i++) {
	if (tentry->entries[i] == PRBADID) continue;
	if (tentry->entries[i] == 0) break;
	code = AddToPRList (alist, &size, tentry->entries[i]);
	if (code) return code;
    }

    nptr = tentry->next;
    while (nptr != NULL) {
	/* look through cont entries */
	code = pr_ReadCoEntry(at,0,nptr,&centry);
	if (code != 0) return code;
	for (i=0;i<COSIZE;i++) {
	    if (centry.entries[i] == PRBADID) continue;
	    if (centry.entries[i] == 0) break;
	    code = AddToPRList (alist, &size, centry.entries[i]);
	    if (code) return code;
	}
	nptr = centry.next;
	if (count++ > 50) IOMGR_Poll(), count = 0;
    }

    if (add) { /* this is for a CPS, so tack on appropriate stuff */
	if (tentry->id != ANONYMOUSID && tentry->id != ANYUSERID) {
#ifdef CROSS_CELL
	    if ((code = AddToPRList (alist, &size, ANYUSERID)) ||
		(code = AddAuthGroup(tentry, alist, &size)) ||
		(code = AddToPRList (alist, &size, tentry->id))) return code;
#else
	    if ((code = AddToPRList (alist, &size, ANYUSERID)) ||
		(code = AddToPRList (alist, &size, AUTHUSERID)) ||
		(code = AddToPRList (alist, &size, tentry->id))) return code;
#endif
	}
	else {
	    if ((code = AddToPRList (alist, &size, ANYUSERID)) ||
		(code = AddToPRList (alist, &size, tentry->id))) return code;
	}
    }
    if (alist->prlist_len > 100) IOMGR_Poll();
    qsort(alist->prlist_val,alist->prlist_len,sizeof(long),IDCmp);
    return PRSUCCESS;
}

long GetOwnedChain (ut, next, alist)
  struct ubik_trans *ut;
  long next;
  prlist *alist;
{   register long code;
    struct prentry tentry;
    int size;
    int count = 0;
    extern long IDCmp();

    size = 0;
    alist->prlist_val = 0;
    alist->prlist_len = 0;

    while (next) {
	code = pr_Read (ut, 0, next, &tentry, sizeof(tentry));
	if (code) return code;
	code = AddToPRList (alist, &size, ntohl(tentry.id));
	if (code) return code;
	next = ntohl(tentry.nextOwned);
	if (count++ > 50) IOMGR_Poll(), count = 0;
    }
    if (alist->prlist_len > 100) IOMGR_Poll();
    qsort(alist->prlist_val,alist->prlist_len,sizeof(long),IDCmp);
    return PRSUCCESS;
}

long GetMax(at,uid,gid)
register struct ubik_trans *at;
long *uid;
long *gid;
{
    *uid = ntohl(cheader.maxID);
    *gid = ntohl(cheader.maxGroup);
    return PRSUCCESS;
}

long SetMax(at,id,flag)
register struct ubik_trans *at;
long id;
long flag;
{
    register long code;
    if (flag & PRGRP) {
	cheader.maxGroup = htonl(id);
	code = pr_Write(at,0,16,(char *)&cheader.maxGroup,sizeof(cheader.maxGroup));
	if (code != 0) return code;
    }
    else {
	cheader.maxID = htonl(id);
	code = pr_Write(at,0,20,(char *)&cheader.maxID,sizeof(cheader.maxID));
	if (code != 0) return code;
    }
    return PRSUCCESS;
}

int pr_noAuth;

long Initdb()
{
    long code;
    struct ubik_trans *tt;
    long len;
    static long initd=0;
#if 0
    static struct ubik_version curver;
    struct ubik_version newver;
#endif

    /* init the database.  We'll try reading it, but if we're starting from scratch, we'll have to do a write transaction. */

    pr_noAuth = afsconf_GetNoAuthFlag(prdir);

    code = ubik_BeginTransReadAny(dbase,UBIK_READTRANS, &tt);
    if (code) return code;
    code = ubik_SetLock(tt,1,1,LOCKREAD);
    if (code) {
	ubik_AbortTrans(tt);
	return code;
    }
    if (!initd) {
	initd = 1;
#if 0
	bzero(&curver,sizeof(curver));
#endif
    } else if (!ubik_CacheUpdate (tt)) {
	code = ubik_EndTrans(tt);
	return code;
    }
#if 0
    code = ubik_GetVersion(tt,&newver);
    if (vcmp(curver,newver) == 0) {
	/* same version */
	code = ubik_EndTrans(tt);
	if (code) return code;
	return PRSUCCESS;
    }
    bcopy(&newver,&curver,sizeof(struct ubik_version));
#endif

    len = sizeof(cheader);
    code = pr_Read(tt, 0, 0, (char *) &cheader, len);
    if (code != 0) {
	com_err (whoami, code, "couldn't read header");
	ubik_AbortTrans(tt);
	return code;
    }
    if ((ntohl(cheader.version) == PRDBVERSION) &&
	ntohl(cheader.headerSize) == sizeof(cheader) &&
	ntohl(cheader.eofPtr) != NULL &&
	FindByID(tt,ANONYMOUSID) != 0){
	/* database exists, so we don't have to build it */
	code = ubik_EndTrans(tt);
	if (code) return code;
	return PRSUCCESS;
    }
    /* else we need to build a database */
    code = ubik_EndTrans(tt);
    if (code) return code;

    /* Only rebuild database if the db was deleted (the header is zero) and we
       are running noAuth. */
    {   char *bp = (char *)&cheader;
	int i;
	for (i=0; i<sizeof(cheader); i++)
	    if (bp[i])  {
		code = PRDBBAD;
		com_err (whoami, code,
			 "Can't rebuild database because it is not empty");
		return code;
	    }
    }
    if (!pr_noAuth) {
	code = PRDBBAD;
	com_err (whoami, code,
		 "Can't rebuild database because not running NoAuth");
	return code;
    }

    code = ubik_BeginTrans(dbase,UBIK_WRITETRANS, &tt);
    if (code) return code;

    code = ubik_SetLock(tt,1,1,LOCKWRITE);
    if (code) {
	ubik_AbortTrans(tt);
	return code;
    }

    /* before doing a rebuild, check again that the dbase looks bad, because
     * the previous check was only under a ReadAny transaction, and there could
     * actually have been a good database out there.  Now that we have a
     * real write transaction, make sure things are still bad.
     */
    if ((ntohl(cheader.version) == PRDBVERSION) &&
	ntohl(cheader.headerSize) == sizeof(cheader) &&
	ntohl(cheader.eofPtr) != NULL &&
	FindByID(tt,ANONYMOUSID) != 0){
	/* database exists, so we don't have to build it */
	code = ubik_EndTrans(tt);
	if (code) return code;
	return PRSUCCESS;
    }

    /* Initialize the database header */
    if ((code = set_header_word (tt, version, htonl(PRDBVERSION))) ||
	(code = set_header_word (tt, headerSize, htonl(sizeof(cheader)))) ||
	(code = set_header_word (tt, eofPtr, cheader.headerSize))) {
	com_err (whoami, code, "couldn't write header words");
	ubik_AbortTrans(tt);
	return code;
    }

#define InitialGroup(id,name) do {    \
    long temp = (id);		      \
    long flag = (id) < 0 ? PRGRP : 0; \
    code = CreateEntry		      \
	(tt, (name), &temp, /*idflag*/1, flag, SYSADMINID, SYSADMINID); \
    if (code) {			      \
	com_err (whoami, code, "couldn't create %s with id %di.", 	\
		 (name), (id));	      \
	ubik_AbortTrans(tt);	      \
	return code;		      \
    }				      \
} while (0)

    InitialGroup (SYSADMINID, "system:administrators");
    InitialGroup (ANYUSERID, "system:anyuser");
    InitialGroup (AUTHUSERID, "system:authuser");
    InitialGroup (ANONYMOUSID, "anonymous");

    /* Well, we don't really want the max id set to anonymousid, so we'll set
     * it back to 0 */
    code = set_header_word (tt, maxID, 0); /* correct in any byte order */
    if (code) {
	com_err (whoami, code, "couldn't reset max id");
	ubik_AbortTrans(tt);
	return code;
    }

    code = ubik_EndTrans(tt);
    if (code) return code;
    return PRSUCCESS;
}

/*
 * FUNCTION
 * 	fixOwnerChain
 *
 * DESCRIPTION
 * This function follows the "owned" and "nextOwned" chains and verifies
 * that the data is consistent.  The chain is only traversed as far as is
 * necessary for efficiency reasons:
 * o Follow the "nextOwned" chain only if we had to adjust ourself
 *   (either renaming ourself or adjusting the owner id)
 * o Follow the "owned" chain if we had to adjust ourself (see above), or
 *   we are the parent that started this mess (tentry->id == oldid/newid)
 */

long fixOwnerChain(at,loc,tentry,oldid,newid)
    struct ubik_trans *at;
    struct prentry *tentry;
    long loc, oldid, newid;
{
    char name[PR_MAXNAMELEN];
    struct prentry nentry;
    long pos;
    register long code;
    int nextOwn = 0;

    if (newid && oldid != newid) {
	if (tentry->owner == oldid) tentry->owner = newid;
	if (tentry->creator == oldid) tentry->creator = newid;

	/* If our owner has changed, continue along the nextOwned chain */
	if (tentry->owner == newid) nextOwn=1;
    }
    
    strcpy(name, tentry->name);
    code=CorrectGroupName(at,name,tentry->creator,tentry->owner,tentry->name);
    if (code) return code;
    if (strcmp(name, tentry->name)) {

	/* If we had to rename ourself, there are probably others
	 * along the nextOwned chain that have to do the same.  */
	nextOwn = 1;

	pos = FindByName(at,tentry->name);
	if (pos) return PREXIST;

	code = RemoveFromNameHash (at, name, &loc);
	if (code) return code;
	code = AddToNameHash(at,tentry->name,loc);
	if (code) return code;
    }

    code = pr_WriteEntry(at, 0, loc, tentry);
    if (code) return code;

    if ((loc = tentry->owned) &&
	(nextOwn || (newid && tentry->id == newid) || (tentry->id == oldid))) {

	code = pr_ReadEntry(at,0,loc,&nentry);
	if (code) return code;
	code = fixOwnerChain(at, loc, &nentry, oldid, newid);
	if (code) return code;
    }

    if (nextOwn && (loc = tentry->nextOwned)) {

	code = pr_ReadEntry(at,0,loc,&nentry);
	if (code) return code;
	code = fixOwnerChain(at, loc, &nentry, oldid, newid);
	if (code) return code;
    }
    return PRSUCCESS;
}

long ChangeEntry (at, aid, cid, name, oid, newid)
  struct ubik_trans *at;
  long aid;
  long cid;
  char *name;
  long oid;
  long newid;
{
    register long code, nptr, i;
    long pos;
    struct prentry tentry, gentry;
    struct contentry centry;
    long loc;
    long oldowner;
    char holder[PR_MAXNAMELEN];
    char temp[PR_MAXNAMELEN];
    char oldname[PR_MAXNAMELEN];
#if CROSS_CELL
    char *atsign;
#endif

    bzero(holder,PR_MAXNAMELEN);
    bzero(temp,PR_MAXNAMELEN);
    loc = FindByID(at,aid);
    if (!loc) return PRNOENT;
    code = pr_ReadEntry(at,0,loc,&tentry);
    if (code) return PRDBFAIL;
    if (tentry.owner != cid &&
	!IsAMemberOf(at,cid,SYSADMINID) &&
	!IsAMemberOf(at,cid,tentry.owner) &&
	!pr_noAuth) return PRPERM;
#ifdef PR_REMEMBER_TIMES
    tentry.changeTime = time(0);
#endif

    /* we're actually trying to change the id */
    if (aid != newid && newid != 0) {
	if (!IsAMemberOf(at,cid,SYSADMINID) && !pr_noAuth) return PRPERM;
	pos = FindByID(at,newid);
	if (pos) return PRIDEXIST;  /* new id already in use! */
	if ((aid < 0 && newid > 0) || (aid > 0 && newid < 0)) return PRPERM;
	/* if new id is not in use, rehash things */
	code = RemoveFromIDHash(at,aid,&loc);
	if (code != PRSUCCESS) return code;
	tentry.id = newid;
	code = pr_WriteEntry(at,0,loc,&tentry);
	if (code) return code;
	code = AddToIDHash(at,tentry.id,loc);
	if (code) return code;
	/* get current data */
	code = pr_ReadEntry(at,0,loc,&tentry);
	if (code) return PRDBFAIL;

        for (i=0;i<PRSIZE;i++) {
	    if (tentry.entries[i] == PRBADID) continue;
	    if (tentry.entries[i] == 0) break;
	    if (pos = FindByID(at, tentry.entries[i])) {
		code = pr_ReadEntry(at,0,pos,&gentry);
		if (code) return PRDBFAIL;
		code = AddToEntry(at,&gentry,pos,newid);
		if (code) return PRDBFAIL;
		code = RemoveFromEntry(at,aid,tentry.entries[i]);
		if (code) return PRDBFAIL;
	    } else {
		fprintf(stderr, "ChangeEntry: %d: Couldn't locate group %d\n",
		    newid, tentry.entries[i]);
		return PRDBFAIL;
	    }
	}
	nptr = tentry.next;
	while (nptr) {
	    /* look through cont entries */
	    code = pr_ReadCoEntry(at,0,nptr,&centry);
	    if (code != 0) return code;
	    for (i=0;i<COSIZE;i++) {
		if (centry.entries[i] == PRBADID) continue;
		if (centry.entries[i] == 0) break;
		if (pos = FindByID(at, centry.entries[i])) {
		    code = pr_ReadEntry(at,0,pos,&gentry);
		    if (code) return PRDBFAIL;
		    code = AddToEntry(at,&gentry,pos,newid);
		    if (code) return PRDBFAIL;
		    code = RemoveFromEntry(at,aid,centry.entries[i]);
		    if (code) return PRDBFAIL;
		} else
		    return PRDBFAIL;
	    }
	    nptr = centry.next;
	}
    }

#ifdef CROSS_CELL
    atsign = index(tentry.name, '@'); /* check for foreign entry */
#endif

    /* Change the owner */
    if (tentry.owner != oid && oid) {
	/* only groups can have their owner's changed */
	if (!(tentry.flags & PRGRP)) return PRPERM;
#ifdef CROSS_CELL
	/* don't allow modifications to foreign cell group owners */
	if (atsign) return PRPERM;
#endif
	oldowner = tentry.owner;
	tentry.owner = oid;
	/* The entry must be written through first so Remove and Add routines
         * can operate on disk data */
	code = pr_WriteEntry(at,0,loc,(char *)&tentry);
	if (code) return PRDBFAIL;
	if (tentry.flags & PRGRP) {
	    /* switch owner chains */
	    if (oldowner)		/* if it has an owner */
		code = RemoveFromOwnerChain(at,tentry.id,oldowner);
	    else			/* must be an orphan */
		code = RemoveFromOrphan(at,tentry.id);
	    if (code) return code;
	    code = AddToOwnerChain(at,tentry.id,tentry.owner);
	    if (code) return code;
	}
	/* fix up the name */
	if ((tentry.flags & PRGRP) && (strlen(name) == 0)) name = tentry.name;
	/* get current data */
	code = pr_ReadEntry(at,0,loc,&tentry);
	if (code) return PRDBFAIL;
    }

    /* Change the name, if name is a ptr to tentry.name then this name change
     * is due to a chown, otherwise caller has specified a new name */
    if ((name == tentry.name) ||
	(*name && (strcmp (tentry.name, name) != 0))) {
	strncpy (oldname, tentry.name, PR_MAXNAMELEN);
	if (tentry.flags & PRGRP) {
#ifdef CROSS_CELL
	    if (atsign) return PRPERM;
#endif
	    code = CorrectGroupName (at, name, cid, tentry.owner, tentry.name);
	    if (code) return code;

	    if (name == tentry.name) {	/* owner fixup */
		if (strcmp (oldname, tentry.name) == 0) goto nameOK;
	    } else {			/* new name, caller must be correct */
		if (strcmp (name, tentry.name) != 0) return PRBADNAM;
	    }
	} else {
#ifdef CROSS_CELL
	    /* Allow a foreign name change only if the cellname part is
	     * the same */
            char *newatsign;

            newatsign = index (name, '@');
            if (newatsign != atsign){ /* if they are the same no problem*/
		/* if the pointers are not equal the strings better be */
		if ((atsign == 0) || (newatsign == 0) ||
                    strcmp (atsign,newatsign)) return PRPERM;
            }
#endif
            if (!CorrectUserName(name)) return PRBADNAM;
        }

	pos = FindByName(at,name);
	if (pos) return PREXIST;
	code = RemoveFromNameHash (at, oldname, &loc);
	if (code != PRSUCCESS) return code;
	strncpy (tentry.name, name, PR_MAXNAMELEN);
	code = pr_WriteEntry(at,0,loc,(char *)&tentry);
	if (code) return PRDBFAIL;
	code = AddToNameHash(at,tentry.name,loc);
	if (code != PRSUCCESS) return code;
nameOK:;
    }
    return (fixOwnerChain(at, loc, &tentry, aid, newid));
}

#ifdef CROSS_CELL
long allocNextId(cellEntry)
struct prentry *cellEntry;
{
    /* Id's for foreign cell entries are constructed as follows:
     * The 16 low order bits are the group id of the cell and the
     * top 16 bits identify the particular users in that cell */

    long id;

    id = (ntohl(cellEntry -> nusers) +1);
    cellEntry -> nusers = htonl(id);
    /* use the field nusers to keep the last used id in that
     * foreign cell's group.
     *
     * Note: It would seem more appropriate to use ngroup for
     * that and nusers to enforce the quota, however pts does not
     * have an option to change foreign users quota yet. */
    id = (id << 16) | ((ntohl(cellEntry-> id)) & 0x0000ffff);
    return id;
}

int inRange(cellEntry,aid)
struct prentry *cellEntry;
long aid;
{
    unsigned long id,cellid,groupid;

    /* The only thing that we want to make sure here is that the id
     * is in the legal range of this group. If it is a duplicate we
     * don't care since it will get in a different check. */
    cellid = aid & 0x0000ffff;
    groupid =  (ntohl(cellEntry-> id)) & 0x0000ffff;
    if (cellid != groupid) return 0;		/* not in range */

    /* if we got here we're ok but we need to update the nusers field
     * in order to get the id correct the next time that we try to
     * allocate it automatically. */
    id = aid >> 16;
    if (id > ntohl(cellEntry -> nusers))
	cellEntry -> nusers = htonl(id);
    return 1;
}

AddAuthGroup(tentry, alist, size)
    struct prentry *tentry;
    prlist *alist;
    long *size;
{
    if (!(index(tentry->name, '@')))
	return (AddToPRList (alist, size, AUTHUSERID));
#if ADD_TO_AUTHUSER_GROUP
    return PRSUCCESS;
#else
    return (AddToPRList (alist, size, tentry->cellid));
#endif
}
#endif	/* CROSS_CELL */