/*  DNR.c - DNR library for MPW

    (c) Copyright 1988 by Apple Computer.  All rights reserved

    Modifications by Jim Matthews, Dartmouth College, 5/91

    Further modifications by Steve Falkenburg, Apple MacDTS 8/91

*/

#include <OSUtils.h>

#include <Errors.h>

#include <Files.h>

#include <Resources.h>

#include <Memory.h>

#include <Traps.h>

#include <GestaltEqu.h>

#include <Folders.h>

#include <ToolUtils.h>

#define OPENRESOLVER    1L                  /* need to make these longs explicit, even though... */

#define CLOSERESOLVER   2L                  /* ...the prototype below would do it normally.  This*/

#define STRTOADDR       3L                  /* ...is a workaround for a bug in Think C 4.0.5.    */

#define ADDRTOSTR       4L

#define ENUMCACHE       5L

#define ADDRTONAME      6L

#define HINFO           7L

#define MXINFO          8L

Handle codeHndl = nil;

typedef OSErr (*OSErrProcPtr)(long,...);    /* added proto for Think C compatibility -->SJF<-- */

OSErrProcPtr dnr = nil;                     /* ... otherwise, first arg would be passed as short*/

TrapType GetTrapType(theTrap)

unsigned long theTrap;

{

    if (BitAnd(theTrap, 0x0800) > 0)

        return(ToolTrap);

    else

        return(OSTrap);

    }

Boolean TrapAvailable(trap)

unsigned long trap;

{

TrapType trapType = ToolTrap;

unsigned long numToolBoxTraps;

    if (NGetTrapAddress(_InitGraf, ToolTrap) == NGetTrapAddress(0xAA6E, ToolTrap))

        numToolBoxTraps = 0x200;

    else

        numToolBoxTraps = 0x400;

    trapType = GetTrapType(trap);

    if (trapType == ToolTrap) {

        trap = BitAnd(trap, 0x07FF);

        if (trap >= numToolBoxTraps)

            trap = _Unimplemented;

        }

    return(NGetTrapAddress(trap, trapType) != NGetTrapAddress(_Unimplemented, ToolTrap));

}

void GetSystemFolder(short *vRefNumP, long *dirIDP)

{

    SysEnvRec info;

    long wdProcID;

    SysEnvirons(1, &info);

    if (GetWDInfo(info.sysVRefNum, vRefNumP, dirIDP, &wdProcID) != noErr) {

        *vRefNumP = 0;

        *dirIDP = 0;

        }

    }

void GetCPanelFolder(short *vRefNumP, long *dirIDP)

{

    Boolean hasFolderMgr = false;

    long feature;

    if (TrapAvailable(_GestaltDispatch)) if (Gestalt(gestaltFindFolderAttr, &feature) == noErr) hasFolderMgr = true;

    if (!hasFolderMgr) {

        GetSystemFolder(vRefNumP, dirIDP);

        return;

        }

    else {

        if (FindFolder(kOnSystemDisk, kControlPanelFolderType, kDontCreateFolder, vRefNumP, dirIDP) != noErr) {

            *vRefNumP = 0;

            *dirIDP = 0;

            }

        }

    }

/* SearchFolderForDNRP is called to search a folder for files that might 

    contain the 'dnrp' resource */

short SearchFolderForDNRP(long targetType, long targetCreator, short vRefNum, long dirID)

{

    HParamBlockRec fi;

    Str255 filename;

    short refnum;

    fi.fileParam.ioCompletion = nil;

    fi.fileParam.ioNamePtr = filename;

    fi.fileParam.ioVRefNum = vRefNum;

    fi.fileParam.ioDirID = dirID;

    fi.fileParam.ioFDirIndex = 1;

    while (PBHGetFInfo(&fi, false) == noErr) {

        /* scan system folder for driver resource files of specific type & creator */

        if (fi.fileParam.ioFlFndrInfo.fdType == targetType &&

            fi.fileParam.ioFlFndrInfo.fdCreator == targetCreator) {

            /* found the MacTCP driver file? */

            refnum = HOpenResFile(vRefNum, dirID, filename, fsRdPerm);

            if (GetIndResource('dnrp', 1) == NULL)

                CloseResFile(refnum);

            else

                return refnum;

            }

        /* check next file in system folder */

        fi.fileParam.ioFDirIndex++;

        fi.fileParam.ioDirID = dirID;   /* PBHGetFInfo() clobbers ioDirID */

        }

    return(-1);

    }   

/* OpenOurRF is called to open the MacTCP driver resources */

short OpenOurRF()

{

    short refnum;

    short vRefNum;

    long dirID;

    /* first search Control Panels for MacTCP 1.1 */

    GetCPanelFolder(&vRefNum, &dirID);

    refnum = SearchFolderForDNRP('cdev', 'ztcp', vRefNum, dirID);

    if (refnum != -1) return(refnum);

    /* next search System Folder for MacTCP 1.0.x */

    GetSystemFolder(&vRefNum, &dirID);

    refnum = SearchFolderForDNRP('cdev', 'mtcp', vRefNum, dirID);

    if (refnum != -1) return(refnum);

    /* finally, search Control Panels for MacTCP 1.0.x */

    GetCPanelFolder(&vRefNum, &dirID);

    refnum = SearchFolderForDNRP('cdev', 'mtcp', vRefNum, dirID);

    if (refnum != -1) return(refnum);

    return -1;

    }   

OSErr OpenResolver(fileName)

char *fileName;

{

    short refnum;

    OSErr rc;

    long rezSize;

    if (dnr != nil)

        /* resolver already loaded in */

        return(noErr);

    /* open the MacTCP driver to get DNR resources. Search for it based on

       creator & type rather than simply file name */   

    refnum = OpenOurRF();

    /* ignore failures since the resource may have been installed in the 

       System file if running on a Mac 512Ke */

    /* load in the DNR resource package */

    codeHndl = GetIndResource('dnrp', 1);

    if (codeHndl == nil) {

        /* can't open DNR */

        return(ResError());

        }

    DetachResource(codeHndl);

    if (refnum != -1) {

        CloseResFile(refnum);

        }

    /* lock the DNR resource since it cannot be reloated while opened */

    MoveHHi(codeHndl);

    HLock(codeHndl);

    dnr = (OSErrProcPtr) *codeHndl;

    /* call open resolver */

    rc = (*dnr)(OPENRESOLVER, fileName);

    if (rc != noErr) {

        /* problem with open resolver, flush it */

        HUnlock(codeHndl);

        DisposHandle(codeHndl);

        dnr = nil;

        }

    return(rc);

    }

OSErr CloseResolver()

{

    if (dnr == nil)

        /* resolver not loaded error */

        return(notOpenErr);

    /* call close resolver */

    (void) (*dnr)(CLOSERESOLVER);

    /* release the DNR resource package */

    HUnlock(codeHndl);

    DisposHandle(codeHndl);

    dnr = nil;

    return(noErr);

    }

OSErr StrToAddr(hostName, rtnStruct, resultproc, userDataPtr)

char *hostName;

struct hostInfo *rtnStruct;

long resultproc;

char *userDataPtr;

{

    if (dnr == nil)

        /* resolver not loaded error */

        return(notOpenErr);

    return((*dnr)(STRTOADDR, hostName, rtnStruct, resultproc, userDataPtr));

    }

OSErr AddrToStr(addr, addrStr)

unsigned long addr;

char *addrStr;                                  

{

    if (dnr == nil)

        /* resolver not loaded error */

        return(notOpenErr);

    (*dnr)(ADDRTOSTR, addr, addrStr);

    return(noErr);

    }

OSErr EnumCache(resultproc, userDataPtr)

long resultproc;

char *userDataPtr;

{

    if (dnr == nil)

        /* resolver not loaded error */

        return(notOpenErr);

    return((*dnr)(ENUMCACHE, resultproc, userDataPtr));

    }

OSErr AddrToName(addr, rtnStruct, resultproc, userDataPtr)

unsigned long addr;

struct hostInfo *rtnStruct;

long resultproc;

char *userDataPtr;                                  

{

    if (dnr == nil)

        /* resolver not loaded error */

        return(notOpenErr);

    return((*dnr)(ADDRTONAME, addr, rtnStruct, resultproc, userDataPtr));

    }

extern OSErr HInfo(hostName, returnRecPtr, resultProc, userDataPtr)

char *hostName;

struct returnRec *returnRecPtr;

long resultProc;

char *userDataPtr;

{

    if (dnr == nil)

        /* resolver not loaded error */

        return(notOpenErr);

    return((*dnr)(HINFO, hostName, returnRecPtr, resultProc, userDataPtr));

    }

extern OSErr MXInfo(hostName, returnRecPtr, resultProc, userDataPtr)

char *hostName;

struct returnRec *returnRecPtr;

long resultProc;

char *userDataPtr;

{

    if (dnr == nil)

        /* resolver not loaded error */

        return(notOpenErr);

    return((*dnr)(MXINFO, hostName, returnRecPtr, resultProc, userDataPtr));

    }   /* removed ; (causes syntax err in Think C 5.0 */