/*
 * Copyright 2000, International Business Machines Corporation and others.
 * All Rights Reserved.
 * 
 * This software has been released under the terms of the IBM Public
 * License.  For details, see the LICENSE file in the top-level source
 * directory or online at http://www.openafs.org/dl/license10.html
 */

#include <afs/param.h>
#include <afs/stds.h>

#include <windows.h>
#include <nb30.h>
#include <winsock2.h>
#include <stdlib.h>
#include <stdio.h>
#include <malloc.h>
#include <osi.h>
#include <string.h>

#include "afsd.h"

osi_rwlock_t cm_cellLock;

/* function called as callback proc from cm_SearchCellFile.  Return 0 to
 * continue processing.  
 *
 * At the present time the return value is ignored by the caller.
 */
long cm_AddCellProc(void *rockp, struct sockaddr_in *addrp, char *hostnamep)
{
    cm_server_t *tsp;
    cm_serverRef_t *tsrp;
    cm_cell_t *cellp;
    cm_cell_rock_t *cellrockp = (cm_cell_rock_t *)rockp;
    afs_uint32 probe;
        
    cellp = cellrockp->cellp;
    probe = !(cellrockp->flags & CM_FLAG_NOPROBE);

    /* if this server was previously created by fs setserverprefs */
    if ( tsp = cm_FindServer(addrp, CM_SERVER_VLDB))
    {
        if ( !tsp->cellp )
            tsp->cellp = cellp;
        else if (tsp->cellp != cellp) {
            osi_Log3(afsd_logp, "found a vlserver %s associated with two cells named %s and %s",
                     osi_LogSaveString(afsd_logp,hostnamep),
                     osi_LogSaveString(afsd_logp,tsp->cellp->name), 
                     osi_LogSaveString(afsd_logp,cellp->name));
        }
    }       
    else
        tsp = cm_NewServer(addrp, CM_SERVER_VLDB, cellp, probe ? 0 : CM_FLAG_NOPROBE);

    /* Insert the vlserver into a sorted list, sorted by server rank */
    tsrp = cm_NewServerRef(tsp, 0);
    cm_InsertServerList(&cellp->vlServersp, tsrp);
    /* drop the allocation reference */
    lock_ObtainWrite(&cm_serverLock);
    tsrp->refCount--;
    lock_ReleaseWrite(&cm_serverLock);

    return 0;
}

/* if it's from DNS, see if it has expired 
 * and check to make sure we have a valid set of volume servers
 * this function must be called with a Write Lock on cm_cellLock
 */
cm_cell_t *cm_UpdateCell(cm_cell_t * cp, afs_uint32 flags)
{
    long code = 0;
    cm_cell_rock_t rock;

    if (cp == NULL)
        return NULL;

    lock_ObtainMutex(&cp->mx);
    if ((cp->vlServersp == NULL 
#ifdef AFS_FREELANCE_CLIENT
          && !(cp->flags & CM_CELLFLAG_FREELANCE)
#endif
          ) || (time(0) > cp->timeout)
#ifdef AFS_AFSDB_ENV
        || (cm_dnsEnabled && (cp->flags & CM_CELLFLAG_DNS) &&
         ((cp->flags & CM_CELLFLAG_VLSERVER_INVALID)))
#endif
            ) 
    {
        lock_ReleaseMutex(&cp->mx);

        /* must empty cp->vlServersp */
        if (cp->vlServersp) {
            cm_FreeServerList(&cp->vlServersp, CM_FREESERVERLIST_DELETE);
            cp->vlServersp = NULL;
        }

        rock.cellp = cp;
        rock.flags = flags;
        code = cm_SearchCellFile(cp->name, NULL, cm_AddCellProc, &rock);
        if (code == 0) {
            lock_ObtainMutex(&cp->mx);
	    cp->timeout = time(0) + 7200;
            lock_ReleaseMutex(&cp->mx);
        }
#ifdef AFS_AFSDB_ENV
        else {
            if (cm_dnsEnabled) {
                int ttl;

                code = cm_SearchCellByDNS(cp->name, NULL, &ttl, cm_AddCellProc, &rock);
                if (code == 0) {   /* got cell from DNS */
                    lock_ObtainMutex(&cp->mx);
                    cp->flags |= CM_CELLFLAG_DNS;
                    cp->flags &= ~CM_CELLFLAG_VLSERVER_INVALID;
		    cp->timeout = time(0) + ttl;
                    lock_ReleaseMutex(&cp->mx);
#ifdef DEBUG
                    fprintf(stderr, "cell %s: ttl=%d\n", cp->name, ttl);
#endif
		} else {
                    /* if we fail to find it this time, we'll just do nothing and leave the
                     * current entry alone 
		     */
                    lock_ObtainMutex(&cp->mx);
                    cp->flags |= CM_CELLFLAG_VLSERVER_INVALID;
                    lock_ReleaseMutex(&cp->mx);
                }
	    }
	}
#endif /* AFS_AFSDB_ENV */
    } else {
        lock_ReleaseMutex(&cp->mx);
    }
    return code ? NULL : cp;
}

/* load up a cell structure from the cell database, AFS_CELLSERVDB */
cm_cell_t *cm_GetCell(char *namep, afs_uint32 flags)
{
    return cm_GetCell_Gen(namep, NULL, flags);
}

void cm_FreeCell(cm_cell_t *cellp)
{
    if (cellp->vlServersp)
        cm_FreeServerList(&cellp->vlServersp, CM_FREESERVERLIST_DELETE);
    cellp->name[0] = '\0';    

    cellp->freeNextp = cm_data.freeCellsp;
    cm_data.freeCellsp = cellp;
}

cm_cell_t *cm_GetCell_Gen(char *namep, char *newnamep, afs_uint32 flags)
{
    cm_cell_t *cp, *cp2;
    long code;
    char fullname[CELL_MAXNAMELEN]="";
    int  hasWriteLock = 0;
    int  hasMutex = 0;
    afs_uint32 hash;
    cm_cell_rock_t rock;

    if (!strcmp(namep,SMB_IOCTL_FILENAME_NOSLASH))
        return NULL;

    hash = CM_CELL_NAME_HASH(namep);

    lock_ObtainRead(&cm_cellLock);
    for (cp = cm_data.cellNameHashTablep[hash]; cp; cp=cp->nameNextp) {
        if (cm_stricmp_utf8(namep, cp->name) == 0) {
            strncpy(fullname, cp->name, CELL_MAXNAMELEN);
            fullname[CELL_MAXNAMELEN-1] = '\0';
            break;
        }
    }

    if (!cp) {
        for (cp = cm_data.allCellsp; cp; cp=cp->allNextp) {
            if (strnicmp(namep, cp->name, strlen(namep)) == 0) {
                strncpy(fullname, cp->name, CELL_MAXNAMELEN);
                fullname[CELL_MAXNAMELEN-1] = '\0';
                break;
            }
        }   
    }

    if (cp) {
        lock_ReleaseRead(&cm_cellLock);
        cm_UpdateCell(cp, flags);
    } else if (flags & CM_FLAG_CREATE) {
        lock_ConvertRToW(&cm_cellLock);
        hasWriteLock = 1;

        /* when we dropped the lock the cell could have been added
         * to the list so check again while holding the write lock 
         */
        for (cp = cm_data.cellNameHashTablep[hash]; cp; cp=cp->nameNextp) {
            if (cm_stricmp_utf8(namep, cp->name) == 0) {
                strncpy(fullname, cp->name, CELL_MAXNAMELEN);
                fullname[CELL_MAXNAMELEN-1] = '\0';
                break;
            }
        }   

        if (cp)
            goto done;

        for (cp = cm_data.allCellsp; cp; cp=cp->allNextp) {
            if (strnicmp(namep, cp->name, strlen(namep)) == 0) {
                strncpy(fullname, cp->name, CELL_MAXNAMELEN);
                fullname[CELL_MAXNAMELEN-1] = '\0';
                break;
            }
        }   

        if (cp) {
            lock_ObtainMutex(&cp->mx);
            cm_AddCellToNameHashTable(cp);
            cm_AddCellToIDHashTable(cp);           
            lock_ReleaseMutex(&cp->mx);
            goto done;
        }

        if ( cm_data.freeCellsp != NULL ) {
            cp = cm_data.freeCellsp;
            cm_data.freeCellsp = cp->freeNextp;

            /* 
             * The magic, cellID, and mx fields are already set.
             */
        } else {
            if ( cm_data.currentCells >= cm_data.maxCells )
                osi_panic("Exceeded Max Cells", __FILE__, __LINE__);

            /* don't increment currentCells until we know that we 
             * are going to keep this entry 
             */
            cp = &cm_data.cellBaseAddress[cm_data.currentCells];
            memset(cp, 0, sizeof(cm_cell_t));
            cp->magic = CM_CELL_MAGIC;

            /* the cellID cannot be 0 */
            cp->cellID = ++cm_data.currentCells;

            /* otherwise we found the cell, and so we're nearly done */
            lock_InitializeMutex(&cp->mx, "cm_cell_t mutex", LOCK_HIERARCHY_CELL);
        }

        lock_ReleaseWrite(&cm_cellLock);
        hasWriteLock = 0;

        rock.cellp = cp;
        rock.flags = flags;
        code = cm_SearchCellFile(namep, fullname, cm_AddCellProc, &rock);
        if (code) {
            osi_Log3(afsd_logp,"in cm_GetCell_gen cm_SearchCellFile(%s) returns code= %d fullname= %s", 
                      osi_LogSaveString(afsd_logp,namep), code, osi_LogSaveString(afsd_logp,fullname));

#ifdef AFS_AFSDB_ENV
            if (cm_dnsEnabled) {
                int ttl;

                code = cm_SearchCellByDNS(namep, fullname, &ttl, cm_AddCellProc, &rock);
                if ( code ) {
                    osi_Log3(afsd_logp,"in cm_GetCell_gen cm_SearchCellByDNS(%s) returns code= %d fullname= %s", 
                             osi_LogSaveString(afsd_logp,namep), code, osi_LogSaveString(afsd_logp,fullname));
                    cm_FreeCell(cp);
                    cp = NULL;
                    goto done;
                } else {   /* got cell from DNS */
                    lock_ObtainMutex(&cp->mx);
                    hasMutex = 1;
                    cp->flags |= CM_CELLFLAG_DNS;
                    cp->flags &= ~CM_CELLFLAG_VLSERVER_INVALID;
                    cp->timeout = time(0) + ttl;
                }
            } 
            else 
#endif
            {
                cm_FreeCell(cp);
                cp = NULL;
                goto done;
	    }
        } else {
            lock_ObtainMutex(&cp->mx);
            hasMutex = 1;
	    cp->timeout = time(0) + 7200;	/* two hour timeout */
	}

        /* we have now been given the fullname of the cell.  It may
         * be that we already have a cell with that name.  If so,
         * we should use it instead of completing the allocation
         * of a new cm_cell_t 
         */
        hash = CM_CELL_NAME_HASH(fullname);
        for (cp2 = cm_data.cellNameHashTablep[hash]; cp2; cp2=cp2->nameNextp) {
            if (cm_stricmp_utf8(fullname, cp2->name) == 0) {
                break;
            }
        }   

        if (cp2) {
            if (hasMutex) {
                lock_ReleaseMutex(&cp->mx);
                hasMutex = 0;
            }
            cm_FreeCell(cp);
            cp = cp2;
            goto done;
        }

        /* randomise among those vlservers having the same rank*/ 
        cm_RandomizeServer(&cp->vlServersp);

        if (!hasMutex)
            lock_ObtainMutex(&cp->mx);
        /* copy in name */
        strncpy(cp->name, fullname, CELL_MAXNAMELEN);
        cp->name[CELL_MAXNAMELEN-1] = '\0';

        cm_AddCellToNameHashTable(cp);
        cm_AddCellToIDHashTable(cp);           
        lock_ReleaseMutex(&cp->mx);
        hasMutex = 0;

        /* append cell to global list */
        if (cm_data.allCellsp == NULL) {
            cm_data.allCellsp = cp;
        } else {
            for (cp2 = cm_data.allCellsp; cp2->allNextp; cp2=cp2->allNextp)
                ;
            cp2->allNextp = cp;
        }
        cp->allNextp = NULL;

    } else {
        lock_ReleaseRead(&cm_cellLock);
    }
  done:
    if (hasMutex && cp)
        lock_ReleaseMutex(&cp->mx);
    if (hasWriteLock)
        lock_ReleaseWrite(&cm_cellLock);
    
    /* fullname is not valid if cp == NULL */
    if (newnamep) {
        if (cp) {
            strncpy(newnamep, fullname, CELL_MAXNAMELEN);
            newnamep[CELL_MAXNAMELEN-1]='\0';
        } else {
            newnamep[0] = '\0';
        }
    }
    return cp;
}

cm_cell_t *cm_FindCellByID(afs_int32 cellID, afs_uint32 flags)
{
    cm_cell_t *cp;
    afs_uint32 hash;

    lock_ObtainRead(&cm_cellLock);

    hash = CM_CELL_ID_HASH(cellID);

    for (cp = cm_data.cellIDHashTablep[hash]; cp; cp=cp->idNextp) {
        if (cellID == cp->cellID) 
            break;
    }
    lock_ReleaseRead(&cm_cellLock);	

    if (cp)
        cm_UpdateCell(cp, flags);

    return cp;
}

long 
cm_ValidateCell(void)
{
    cm_cell_t * cellp;
    afs_uint32 count;

    for (cellp = cm_data.allCellsp, count = 0; cellp; cellp=cellp->allNextp, count++) {
        if ( cellp->magic != CM_CELL_MAGIC ) {
            afsi_log("cm_ValidateCell failure: cellp->magic != CM_CELL_MAGIC");
            fprintf(stderr, "cm_ValidateCell failure: cellp->magic != CM_CELL_MAGIC\n");
            return -1;
        }
        if ( count != 0 && cellp == cm_data.allCellsp ||
             count > cm_data.maxCells ) {
            afsi_log("cm_ValidateCell failure: cm_data.allCellsp infinite loop");
            fprintf(stderr, "cm_ValidateCell failure: cm_data.allCellsp infinite loop\n");
            return -2;
        }
    }

    for (cellp = cm_data.freeCellsp; cellp; cellp=cellp->freeNextp, count++) {
        if ( count != 0 && cellp == cm_data.freeCellsp ||
             count > cm_data.maxCells ) {
            afsi_log("cm_ValidateCell failure: cm_data.freeCellsp infinite loop");
            fprintf(stderr, "cm_ValidateCell failure: cm_data.freeCellsp infinite loop\n");
            return -3;
        }
    }

    if ( count != cm_data.currentCells ) {
        afsi_log("cm_ValidateCell failure: count != cm_data.currentCells");
        fprintf(stderr, "cm_ValidateCell failure: count != cm_data.currentCells\n");
        return -4;
    }
    
    return 0;
}


long 
cm_ShutdownCell(void)
{
    cm_cell_t * cellp;

    for (cellp = cm_data.allCellsp; cellp; cellp=cellp->allNextp)
        lock_FinalizeMutex(&cellp->mx);

    return 0;
}


void cm_InitCell(int newFile, long maxCells)
{
    static osi_once_t once;
        
    if (osi_Once(&once)) {
        cm_cell_t * cellp;

        lock_InitializeRWLock(&cm_cellLock, "cell global lock", LOCK_HIERARCHY_CELL_GLOBAL);

        if ( newFile ) {
            cm_data.allCellsp = NULL;
            cm_data.currentCells = 0;
            cm_data.maxCells = maxCells;
            memset(cm_data.cellNameHashTablep, 0, sizeof(cm_cell_t *) * cm_data.cellHashTableSize);
            memset(cm_data.cellIDHashTablep, 0, sizeof(cm_cell_t *) * cm_data.cellHashTableSize);
        
#ifdef AFS_FREELANCE_CLIENT
            /* Generate a dummy entry for the Freelance cell whether or not 
             * freelance mode is being used in this session 
             */

            cellp = &cm_data.cellBaseAddress[cm_data.currentCells++];
            memset(cellp, 0, sizeof(cm_cell_t));
            cellp->magic = CM_CELL_MAGIC;

            lock_InitializeMutex(&cellp->mx, "cm_cell_t mutex", LOCK_HIERARCHY_CELL);

            /* copy in name */
            strncpy(cellp->name, "Freelance.Local.Cell", CELL_MAXNAMELEN); /*safe*/
            cellp->name[CELL_MAXNAMELEN-1] = '\0';

            /* thread on global list */
            cellp->allNextp = cm_data.allCellsp;
            cm_data.allCellsp = cellp;
                
            cellp->cellID = AFS_FAKE_ROOT_CELL_ID;
            cellp->vlServersp = NULL;
            cellp->flags = CM_CELLFLAG_FREELANCE;

            lock_ObtainMutex(&cellp->mx);
            cm_AddCellToNameHashTable(cellp);
            cm_AddCellToIDHashTable(cellp);           
            lock_ReleaseMutex(&cellp->mx);
#endif  
        } else {
            for (cellp = cm_data.allCellsp; cellp; cellp=cellp->allNextp) {
                lock_InitializeMutex(&cellp->mx, "cm_cell_t mutex", LOCK_HIERARCHY_CELL);
                cellp->vlServersp = NULL;
                cellp->flags |= CM_CELLFLAG_VLSERVER_INVALID;
            }
        }

        osi_EndOnce(&once);
    }
}

void cm_ChangeRankCellVLServer(cm_server_t *tsp)
{
    cm_cell_t *cp;
    int code;

    cp = tsp->cellp;	/* cell that this vlserver belongs to */
    if (cp) {
	lock_ObtainMutex(&cp->mx);
	code = cm_ChangeRankServer(&cp->vlServersp, tsp);

	if ( !code ) 		/* if the server list was rearranged */
	    cm_RandomizeServer(&cp->vlServersp);

	lock_ReleaseMutex(&cp->mx);
    }
}       

int cm_DumpCells(FILE *outputFile, char *cookie, int lock)
{
    cm_cell_t *cellp;
    int zilch;
    char output[1024];

    if (lock)
        lock_ObtainRead(&cm_cellLock);

    sprintf(output, "%s - dumping cells - cm_data.currentCells=%d, cm_data.maxCells=%d\r\n", 
            cookie, cm_data.currentCells, cm_data.maxCells);
    WriteFile(outputFile, output, (DWORD)strlen(output), &zilch, NULL);

    for (cellp = cm_data.allCellsp; cellp; cellp=cellp->allNextp) {
        sprintf(output, "%s cellp=0x%p,name=%s ID=%d flags=0x%x timeout=%I64u\r\n", 
                cookie, cellp, cellp->name, cellp->cellID, cellp->flags, cellp->timeout);
        WriteFile(outputFile, output, (DWORD)strlen(output), &zilch, NULL);
    }

    sprintf(output, "%s - Done dumping cells.\r\n", cookie);
    WriteFile(outputFile, output, (DWORD)strlen(output), &zilch, NULL);

    if (lock)
        lock_ReleaseRead(&cm_cellLock);

    return(0);
}

/* call with volume write-locked and mutex held */
void cm_AddCellToNameHashTable(cm_cell_t *cellp)
{
    int i;
    
    if (cellp->flags & CM_CELLFLAG_IN_NAMEHASH)
        return;

    i = CM_CELL_NAME_HASH(cellp->name);

    cellp->nameNextp = cm_data.cellNameHashTablep[i];
    cm_data.cellNameHashTablep[i] = cellp;
    cellp->flags |= CM_CELLFLAG_IN_NAMEHASH;
}

/* call with cell write-locked and mutex held */
void cm_RemoveCellFromNameHashTable(cm_cell_t *cellp)
{
    cm_cell_t **lcellpp;
    cm_cell_t *tcellp;
    int i;
	
    if (cellp->flags & CM_CELLFLAG_IN_NAMEHASH) {
	/* hash it out first */
	i = CM_CELL_NAME_HASH(cellp->name);
	for (lcellpp = &cm_data.cellNameHashTablep[i], tcellp = cm_data.cellNameHashTablep[i];
	     tcellp;
	     lcellpp = &tcellp->nameNextp, tcellp = tcellp->nameNextp) {
	    if (tcellp == cellp) {
		*lcellpp = cellp->nameNextp;
		cellp->flags &= ~CM_CELLFLAG_IN_NAMEHASH;
                cellp->nameNextp = NULL;
		break;
	    }
	}
    }
}

/* call with cell write-locked and mutex held */
void cm_AddCellToIDHashTable(cm_cell_t *cellp)
{
    int i;
    
    if (cellp->flags & CM_CELLFLAG_IN_IDHASH)
        return;

    i = CM_CELL_ID_HASH(cellp->cellID);

    cellp->idNextp = cm_data.cellIDHashTablep[i];
    cm_data.cellIDHashTablep[i] = cellp;
    cellp->flags |= CM_CELLFLAG_IN_IDHASH;
}

/* call with cell write-locked and mutex held */
void cm_RemoveCellFromIDHashTable(cm_cell_t *cellp)
{
    cm_cell_t **lcellpp;
    cm_cell_t *tcellp;
    int i;
	
    if (cellp->flags & CM_CELLFLAG_IN_IDHASH) {
	/* hash it out first */
	i = CM_CELL_ID_HASH(cellp->cellID);
	for (lcellpp = &cm_data.cellIDHashTablep[i], tcellp = cm_data.cellIDHashTablep[i];
	     tcellp;
	     lcellpp = &tcellp->idNextp, tcellp = tcellp->idNextp) {
	    if (tcellp == cellp) {
		*lcellpp = cellp->idNextp;
		cellp->flags &= ~CM_CELLFLAG_IN_IDHASH;
                cellp->idNextp = NULL;
		break;
	    }
	}
    }
}

