/*
 * Copyright (C) 1996-1998 Ilya Ryzhenkov (orangy@inetlab.com)
 * This file maintains some DLM API
 */
#include "helpdefs.h"
#include "dlmimage.h"
#include "dlm_sym.h"
#include "dlm_rslv.h"
#include "dlm.h"

static const char *_dlm_version="DLM Engine version 2.02";

TDlm *_dlm_find_for_addr(unsigned long eip)
{
 TDlm* dlm;
 unsigned long base;
 _sym_dlmsearch();
 while ((dlm=_sym_dlmnext()))
  {
    base=(unsigned long)dlm->Base;
    if (base<=eip && base+dlm->VSize>=eip) break;
  }
 return dlm;
}

/* this function creates classes by their names */
void _dlm_sig_invalid_new(unsigned long eip,char *name);
#define NEW_ERR _dlm_sig_invalid_new(retaddr,name);
#define NEW_TOLERANCE 32
void *_dlm_new_named(unsigned long size,char *name,void*p)
{
 static char buf[512];
 void *(*stdnew)(unsigned long size);
 unsigned long tmp,base=0,idx,min,i,namelen,newsize=0,*szptr;
 char *basename,*mangle;
 unsigned long retaddr=*((unsigned long*)&size-1),*patchplace,patchvalue;
 TDlm *dlm=_dlm_find_for_addr(retaddr);

 if (!dlm) NEW_ERR else base=(unsigned long)dlm->Base;

 min=retaddr+NEW_TOLERANCE;
 idx=0xFFFFFFFF;
 for  (i=0; i<dlm->NumRel; i++)
   {
    tmp=dlm->Relocs[i].r_vaddr+base;
    if (tmp>=retaddr && tmp<min) { min=tmp; idx=i; }
   }
 if (idx==0xFFFFFFFF) NEW_ERR
 /* idx is now index of relocation */
 /* now getting sizeof(named class) */
 strcpy(buf,"__SYSDLM_sizeof_");
 strcat(buf,name);
 szptr=(unsigned long *)_sym_find_export(buf,0);
 if (szptr) newsize=*szptr; else NEW_ERR

 /* now patching code with constructor call */
 /* first generate constructor name */
 basename=strdup(dlm->Strings+dlm->Symbols[dlm->Relocs[idx].r_symndx].e_name);
 if (strncmp(basename,"___",3)) NEW_ERR
 namelen=strtol(basename+3,&mangle,0);
 if (!namelen) NEW_ERR
 mangle+=namelen;
 sprintf(buf,"___%ld%s%s",strlen(name),name,mangle);

 /* now buf contains required construtor name and dlm->Relocs[idx].r_vaddr+base is
    a place to patch */
 patchplace=(unsigned long *)(dlm->Relocs[idx].r_vaddr+base);
 patchvalue=(unsigned int)_sym_find_export(buf,0);
 if (!patchvalue) NEW_ERR
 /* this must be call, so assume REL32 */
 *patchplace=patchvalue-base-dlm->Relocs[idx].r_vaddr-4;

// printf("Patched at 0x%x to 0x%x\n",patchplace,patchvalue);
 /* now the code is ready to call constructor for named class instead of base class */
 stdnew=(typeof(stdnew))_sym_find_export("___builtin_new",0);
 if (!stdnew) NEW_ERR
 free(basename);
 return stdnew(newsize);
}

void *_dlm_lookup(char *name)
{
 return _sym_find_export(name,0);
}

int _dlm_isloaded(char *path)
{
 return (_sym_find_dlm(path))?1:0;
}

unsigned long _dlm_extra_size(char *name)
{
 int i;
 TDlm *dlm;
 void *symadr;
 symadr=_sym_find_export(name,0);
 if (!symadr) return 0;

 dlm=_dlm_find_for_addr((unsigned long)symadr);
 if (!dlm) return 0;

 for (i=0; i<dlm->NumSect; i++)
   if (!strncmp(".extra",dlm->Sections[i].s_name,8))
    if (dlm->Sections[i].s_vaddr+dlm->Base == symadr)
      return dlm->Sections[i].s_size;
 return 0;
}

void _dlm_dup_fail(char *name, TDlm* dlm);
int _dlm_export_user(char *name, void *addr)
{
 void *symaddr;
 symaddr=_sym_find_export(name,0);
 if (symaddr && ((dlmflags&DLMFLAG_DUP)==DLMFLAG_DUP_FAIL))
   _dlm_dup_fail(name,(TDlm*)-1);

 if (!symaddr || ((dlmflags&DLMFLAG_DUP)!=DLMFLAG_DUP_IGNORE))
 {
  if (_sym_add_export(name,addr,(TDlm*)-1))
   {
    if (!symaddr || ((dlmflags&DLMFLAG_DUP)==DLMFLAG_DUP_OVRIDE))
	   _dlm_resolve_to_sym(name);
   } else { ERR(NOMEM); return 0; }
 }
 return 1;
}

int _dlm_remove_user(char *name)
{
 int res;
 res=_sym_del_export(name,(TDlm*)-1);
 if (res) _dlm_resolve_to_sym(name);
 return res;
}