/*
 * NE modules
 *
 * Copyright 1993 Robert J. Amstadt
 * Copyright 1995 Alexandre Julliard
 */

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <ctype.h>
#include <string.h>
#include <errno.h>
#include "neexe.h"
#include "dlls.h"
#include "windows.h"
#include "arch.h"
#include "selectors.h"
#include "callback.h"
#include "module.h"
#include "stackframe.h"
#include "stddebug.h"
#include "debug.h"


/***********************************************************************
 *           NE_LoadSegment
 */
BOOL NE_LoadSegment( HMODULE hModule, WORD segnum )
{
    NE_MODULE *pModule;
    SEGTABLEENTRY *pSegTable, *pSeg;
    WORD *pModuleTable;
    WORD count, i, module, offset;
    DWORD address;
    int fd;
    struct relocation_entry_s *rep, *reloc_entries;
    BYTE *func_name;

    char buffer[100];
    int ordinal, additive;
    unsigned short *sp;

    if (!(pModule = (NE_MODULE *)GlobalLock( hModule ))) return FALSE;
    pSegTable = NE_SEG_TABLE( pModule );
    pSeg = pSegTable + segnum - 1;
    pModuleTable = NE_MODULE_TABLE( pModule );

    if (!pSeg->filepos) return TRUE;  /* No file image, just return */

    fd = MODULE_OpenFile( hModule );
    dprintf_module( stddeb, "Loading segment %d, selector=%04x\n",
                    segnum, pSeg->selector );
    lseek( fd, pSeg->filepos << pModule->alignment, SEEK_SET );
    read( fd, GlobalLock( pSeg->selector ), pSeg->size ? pSeg->size : 0x10000);

    if (!(pSeg->flags & NE_SEGFLAGS_RELOC_DATA))
        return TRUE;  /* No relocation data, we are done */

    read( fd, &count, sizeof(count) );
    if (!count) return TRUE;

    dprintf_fixup( stddeb, "Fixups for %*.*s, segment %d, selector %04x\n",
                   *((BYTE *)pModule + pModule->name_table),
                   *((BYTE *)pModule + pModule->name_table),
                   (char *)pModule + pModule->name_table + 1,
                   segnum, pSeg->selector );

    reloc_entries = (struct relocation_entry_s *)malloc(count * sizeof(struct relocation_entry_s));
    if (read( fd, reloc_entries, count * sizeof(struct relocation_entry_s)) !=
            count * sizeof(struct relocation_entry_s))
    {
        dprintf_fixup( stddeb, "Unable to read relocation information\n" );
        return FALSE;
    }

    /*
     * Go through the relocation table on entry at a time.
     */
    rep = reloc_entries;
    for (i = 0; i < count; i++, rep++)
    {
	/*
	 * Get the target address corresponding to this entry.
	 */

	/* If additive, there is no target chain list. Instead, add source
	   and target */
	additive = rep->relocation_type & NE_RELFLAG_ADDITIVE;
	rep->relocation_type &= 0x3;
	
	switch (rep->relocation_type)
	{
	  case NE_RELTYPE_ORDINAL:
            module = pModuleTable[rep->target1-1];
	    ordinal = rep->target2;
            address = MODULE_GetEntryPoint( module, ordinal );
            if (!address)
            {
                NE_MODULE *pTarget = (NE_MODULE *)GlobalLock( module );
                if (!pTarget)
                    fprintf( stderr, "Module not found: %04x, reference %d of module %*.*s\n",
                             module, rep->target1, 
                             *((BYTE *)pModule + pModule->name_table),
                             *((BYTE *)pModule + pModule->name_table),
                             (char *)pModule + pModule->name_table + 1 );
                else
                    fprintf( stderr, "Warning: no handler for %*.*s.%d, setting to 0:0\n",
                            *((BYTE *)pTarget + pTarget->name_table),
                            *((BYTE *)pTarget + pTarget->name_table),
                            (char *)pTarget + pTarget->name_table + 1,
                            ordinal );
            }
            if (debugging_fixup)
            {
                NE_MODULE *pTarget = (NE_MODULE *)GlobalLock( module );
                fprintf( stddeb,"%d: %*.*s.%d=%04x:%04x\n", i + 1, 
                         *((BYTE *)pTarget + pTarget->name_table),
                         *((BYTE *)pTarget + pTarget->name_table),
                         (char *)pTarget + pTarget->name_table + 1,
                         ordinal, HIWORD(address), LOWORD(address) );
            }
	    break;
	    
	  case NE_RELTYPE_NAME:
            module = pModuleTable[rep->target1-1];
            func_name = (char *)pModule + pModule->import_table + rep->target2;
            memcpy( buffer, func_name+1, *func_name );
            buffer[*func_name] = '\0';
            func_name = buffer;
            ordinal = MODULE_GetOrdinal( module, func_name );

            address = MODULE_GetEntryPoint( module, ordinal );

            if (!address)
            {
                NE_MODULE *pTarget = (NE_MODULE *)GlobalLock( module );
                fprintf( stderr, "Warning: no handler for %*.*s.%s, setting to 0:0\n",
                        *((BYTE *)pTarget + pTarget->name_table),
                        *((BYTE *)pTarget + pTarget->name_table),
                        (char *)pTarget + pTarget->name_table + 1, func_name );
            }
            if (debugging_fixup)
            {
                NE_MODULE *pTarget = (NE_MODULE *)GlobalLock( module );
                fprintf( stddeb,"%d: %*.*s.%s=%04x:%04x\n", i + 1, 
                         *((BYTE *)pTarget + pTarget->name_table),
                         *((BYTE *)pTarget + pTarget->name_table),
                         (char *)pTarget + pTarget->name_table + 1,
                         func_name, HIWORD(address), LOWORD(address) );
            }
	    break;
	    
	  case NE_RELTYPE_INTERNAL:
	    if (rep->target1 == 0x00ff)
	    {
		address  = MODULE_GetEntryPoint( hModule, rep->target2 );
	    }
	    else
	    {
                address = MAKELONG( rep->target2, pSegTable[rep->target1-1].selector );
	    }
	    
	    dprintf_fixup(stddeb,"%d: %04x:%04x\n", 
			  i + 1, HIWORD(address), LOWORD(address) );
	    break;

	  case NE_RELTYPE_OSFIXUP:
	    /* Relocation type 7:
	     *
	     *    These appear to be used as fixups for the Windows
	     * floating point emulator.  Let's just ignore them and
	     * try to use the hardware floating point.  Linux should
	     * successfully emulate the coprocessor if it doesn't
	     * exist.
	     */
	    dprintf_fixup(stddeb,
                   "%d: ADDR TYPE %d,  TYPE %d,  OFFSET %04x,  ",
		   i + 1, rep->address_type, rep->relocation_type, 
		   rep->offset);
	    dprintf_fixup(stddeb,"TARGET %04x %04x\n", 
		   rep->target1, rep->target2);
	    continue;
	    
	  default:
	    dprintf_fixup(stddeb,
		   "%d: ADDR TYPE %d,  TYPE %d,  OFFSET %04x,  ",
		   i + 1, rep->address_type, rep->relocation_type, 
		   rep->offset);
	    dprintf_fixup(stddeb,"TARGET %04x %04x\n", 
		    rep->target1, rep->target2);
	    free(reloc_entries);
	    return FALSE;
	}

	offset  = rep->offset;

	switch (rep->address_type)
	{
	  case NE_RADDR_LOWBYTE:
            do {
                sp = PTR_SEG_OFF_TO_LIN( pSeg->selector, offset );
                dprintf_fixup(stddeb,"    %04x:%04x:%04x BYTE%s\n",
                              pSeg->selector, offset, *sp, additive ? " additive":"");
                offset = *sp;
		if(additive)
                    *(unsigned char*)sp = (unsigned char)((address+offset) & 0xFF);
		else
                    *(unsigned char*)sp = (unsigned char)(address & 0xFF);
            }
            while (offset != 0xffff && !additive);
            break;

	  case NE_RADDR_OFFSET16:
	    do {
                sp = PTR_SEG_OFF_TO_LIN( pSeg->selector, offset );
		dprintf_fixup(stddeb,"    %04x:%04x:%04x OFFSET16%s\n",
                              pSeg->selector, offset, *sp, additive ? " additive" : "" );
		offset = *sp;
		*sp = LOWORD(address);
		if (additive) *sp += offset;
	    } 
	    while (offset != 0xffff && !additive);
	    break;
	    
	  case NE_RADDR_POINTER32:
	    do {
                sp = PTR_SEG_OFF_TO_LIN( pSeg->selector, offset );
		dprintf_fixup(stddeb,"    %04x:%04x:%04x POINTER32%s\n",
                              pSeg->selector, offset, *sp, additive ? " additive" : "" );
		offset = *sp;
		*sp    = LOWORD(address);
		if (additive) *sp += offset;
		*(sp+1) = HIWORD(address);
	    } 
	    while (offset != 0xffff && !additive);
	    break;
	    
	  case NE_RADDR_SELECTOR:
	    do {
                sp = PTR_SEG_OFF_TO_LIN( pSeg->selector, offset );
		dprintf_fixup(stddeb,"    %04x:%04x:%04x SELECTOR%s\n",
                              pSeg->selector, offset, *sp, additive ? " additive" : "" );
		offset = *sp;
		*sp    = HIWORD(address);
		/* Borland creates additive records with offset zero. Strange, but OK */
		if(additive && offset)
        	fprintf(stderr,"Additive selector to %4.4x.Please report\n",offset);
	    } 
	    while (offset != 0xffff && !additive);
	    break;
	    
	  default:
	    dprintf_fixup(stddeb,
		   "%d: ADDR TYPE %d,  TYPE %d,  OFFSET %04x,  ",
		   i + 1, rep->address_type, rep->relocation_type, 
		   rep->offset);
	    dprintf_fixup(stddeb,
		   "TARGET %04x %04x\n", rep->target1, rep->target2);
	    free(reloc_entries);
	    return FALSE;
	}
    }

    free(reloc_entries);
    return TRUE;
}


/***********************************************************************
 *           NE_FixupPrologs
 *
 * Fixup the exported functions prologs.
 */
void NE_FixupPrologs( HMODULE hModule )
{
    NE_MODULE *pModule;
    SEGTABLEENTRY *pSegTable;
    WORD dgroup = 0;
    WORD sel;
    BYTE *p, *fixup_ptr, count;

    pModule = (NE_MODULE *)GlobalLock( hModule );
    pSegTable = NE_SEG_TABLE(pModule);
    if (pModule->flags & NE_FFLAGS_SINGLEDATA)
        dgroup = pSegTable[pModule->dgroup-1].selector;

    dprintf_module( stddeb, "MODULE_FixupPrologs(%04x)\n", hModule );
    p = (BYTE *)pModule + pModule->entry_table;
    while (*p)
    {
        if (p[1] == 0)  /* Unused entry */
        {
            p += 2;  /* Skip it */
            continue;
        }
        if (p[1] == 0xfe)  /* Constant entry */
        {
            p += 2 + *p * 3;  /* Skip it */
            continue;
        }

        /* Now fixup the entries of this bundle */
        count = *p;
        sel = p[1];
        p += 2;
        while (count-- > 0)
        {
            dprintf_module( stddeb,"Flags: %04x, sel %02x ", *p, sel);
            /* According to the output generated by TDUMP, the flags mean:
             * 0x0001 function is exported
	     * 0x0002 Single data (seems to occur only in DLLs)
	     */
	    if (sel == 0xff) { /* moveable */
		dprintf_module( stddeb, "(%02x) o %04x ", p[3], *(WORD *)(p+4) );
		fixup_ptr = (char *)GET_SEL_BASE(pSegTable[p[3]-1].selector) + *(WORD *)(p + 4);
	    } else { /* fixed */
		dprintf_module( stddeb, "offset %04x ", *(WORD *)(p+1) );
		fixup_ptr = (char *)GET_SEL_BASE(pSegTable[sel-1].selector) + *(WORD *)(p + 1);
	    }
	    dprintf_module( stddeb, "Signature: %02x %02x %02x,ff %x\n",
			   fixup_ptr[0], fixup_ptr[1], fixup_ptr[2],
			   pModule->flags );
            if (*p & 0x0001)
            {
                /* Verify the signature */
                if (((fixup_ptr[0] == 0x1e && fixup_ptr[1] == 0x58)
                     || (fixup_ptr[0] == 0x8c && fixup_ptr[1] == 0xd8))
                    && fixup_ptr[2] == 0x90)
                {
                    if (*p & 0x0002)
                    {
			if (pModule->flags & NE_FFLAGS_MULTIPLEDATA) {
			    /* can this happen? */
			    fprintf( stderr, "FixupPrologs got confused\n" );
			}
                        *fixup_ptr = 0xb8;	/* MOV AX, */
                        *(WORD *)(fixup_ptr+1) = dgroup;
                    }
                    else
                    {
			if (pModule->flags & NE_FFLAGS_MULTIPLEDATA) {
			    fixup_ptr[0] = 0x90; /* non-library: NOPs */
			    fixup_ptr[1] = 0x90;
			    fixup_ptr[2] = 0x90;
			}
                    }
                } else {
		    dprintf_fixup( stddeb, "Unknown signature\n" );
		}
            }
	    else
	      dprintf_module( stddeb,"\n");
            p += (sel == 0xff) ? 6 : 3;  
        }
    }
}


/***********************************************************************
 *           NE_InitDLL
 *
 * Call the DLL initialization code
 */
static BOOL NE_InitDLL( HMODULE hModule )
{
    int cs_reg, ds_reg, ip_reg, cx_reg, di_reg, bp_reg;
    NE_MODULE *pModule;
    SEGTABLEENTRY *pSegTable;

    /* Registers at initialization must be:
     * cx     heap size
     * di     library instance
     * ds     data segment if any
     * es:si  command line (always 0)
     */

    pModule = (NE_MODULE *)GlobalLock( hModule );
    pSegTable = NE_SEG_TABLE( pModule );

    if (!(pModule->flags & NE_FFLAGS_LIBMODULE)) return TRUE; /*not a library*/
    if (!pModule->cs) return TRUE;  /* no initialization code */

    if (!(pModule->flags & NE_FFLAGS_SINGLEDATA))
    {
        if (pModule->flags & NE_FFLAGS_MULTIPLEDATA || pModule->dgroup)
        {
            /* Not SINGLEDATA */
            fprintf(stderr, "Library is not marked SINGLEDATA\n");
            exit(1);
        }
        else  /* DATA NONE DLL */
        {
            ds_reg = 0;
            cx_reg = 0;
        }
    }
    else  /* DATA SINGLE DLL */
    {
        ds_reg = pSegTable[pModule->dgroup-1].selector;
        cx_reg = pModule->heap_size;
    }

    cs_reg = pSegTable[pModule->cs-1].selector;
    ip_reg = pModule->ip;
    di_reg = ds_reg ? ds_reg : hModule;
    bp_reg = IF1632_Saved16_sp + ((WORD)&((STACK16FRAME*)1)->bp - 1);

    pModule->cs = 0;  /* Don't initialize it twice */
    dprintf_dll( stddeb, "Calling LibMain, cs:ip=%04x:%04x ds=%04x di=%04x cx=%04x\n", 
                 cs_reg, ip_reg, ds_reg, di_reg, cx_reg );
    return CallTo16_regs_( (FARPROC)(cs_reg << 16 | ip_reg), ds_reg,
                           0 /*es*/, 0 /*bp*/, 0 /*ax*/, 0 /*bx*/,
                           cx_reg, 0 /*dx*/, 0 /*si*/, di_reg );
}


/***********************************************************************
 *           NE_InitializeDLLs
 *
 * Initialize the loaded DLLs.
 */
void NE_InitializeDLLs( HMODULE hModule )
{
    NE_MODULE *pModule;
    WORD *pDLL;

    pModule = (NE_MODULE *)GlobalLock( hModule );
    if (pModule->dlls_to_init)
    {
	HANDLE to_init = pModule->dlls_to_init;
	pModule->dlls_to_init = 0;
        for (pDLL = (WORD *)GlobalLock( to_init ); *pDLL; pDLL++)
        {
            NE_InitializeDLLs( *pDLL );
            NE_InitDLL( *pDLL );
        }
        GlobalFree( to_init );
    }
    NE_InitDLL( hModule );
}