if1632/snoop.c

   1 /*
   2  * 386-specific Win16 dll<->dll snooping functions
   3  *
   4  * Copyright 1998 Marcus Meissner
   5  */
   6
   7 #include <assert.h>
   8 #include <string.h>
   9 #include <stdio.h>
  10 #include "winbase.h"
  11 #include "windef.h"
  12 #include "winnt.h"
  13 #include "heap.h"
  14 #include "global.h"
  15 #include "selectors.h"
  16 #include "stackframe.h"
  17 #include "builtin16.h"
  18 #include "toolhelp.h"
  19 #include "snoop.h"
  20 #include "debugtools.h"
  21
  22 DEFAULT_DEBUG_CHANNEL(snoop);
  23
  24 #ifdef __i386__
  25
  26 #include "pshpack1.h"
  27
  28 void WINAPI SNOOP16_Entry(FARPROC proc, LPBYTE args, CONTEXT86 *context);
  29 void WINAPI SNOOP16_Return(FARPROC proc, LPBYTE args, CONTEXT86 *context);
  30
  31 typedef struct tagSNOOP16_FUN {
  32         /* code part */
  33         BYTE            lcall;          /* 0x9a call absolute with segment */
  34         DWORD           snr;
  35         /* unreached */
  36         int             nrofargs;
  37         FARPROC16       origfun;
  38         char            *name;
  39 } SNOOP16_FUN;
  40
  41 typedef struct tagSNOOP16_DLL {
  42         HMODULE16       hmod;
  43         HANDLE16        funhandle;
  44         SNOOP16_FUN     *funs;
  45         LPCSTR          name;
  46         struct tagSNOOP16_DLL   *next;
  47 } SNOOP16_DLL;
  48
  49 typedef struct tagSNOOP16_RETURNENTRY {
  50         /* code part */
  51         BYTE            lcall;          /* 0x9a call absolute with segment */
  52         DWORD           snr;
  53         /* unreached */
  54         FARPROC16       origreturn;
  55         SNOOP16_DLL     *dll;
  56         DWORD           ordinal;
  57         WORD            origSP;
  58         WORD            *args;          /* saved args across a stdcall */
  59 } SNOOP16_RETURNENTRY;
  60
  61 typedef struct tagSNOOP16_RETURNENTRIES {
  62         SNOOP16_RETURNENTRY entry[65500/sizeof(SNOOP16_RETURNENTRY)];
  63         HANDLE16        rethandle;
  64         struct tagSNOOP16_RETURNENTRIES *next;
  65 } SNOOP16_RETURNENTRIES;
  66
  67 typedef struct tagSNOOP16_RELAY {
  68         WORD            pushbp;         /* 0x5566 */
  69         BYTE            pusheax;        /* 0x50 */
  70         WORD            pushax;         /* 0x5066 */
  71         BYTE            pushl;          /* 0x68 */
  72         DWORD           realfun;        /* SNOOP16_Return */
  73         BYTE            lcall;          /* 0x9a call absolute with segment */
  74         DWORD           callfromregs;
  75         WORD            seg;
  76         WORD            lret;           /* 0xcb66 */
  77 } SNOOP16_RELAY;
  78
  79 #include "poppack.h"
  80
  81 static  SNOOP16_DLL             *firstdll = NULL;
  82 static  SNOOP16_RETURNENTRIES   *firstrets = NULL;
  83 static  SNOOP16_RELAY           *snr;
  84 static  HANDLE16                xsnr = 0;
  85
  86 void
  87 SNOOP16_RegisterDLL(NE_MODULE *pModule,LPCSTR name) {
  88         SNOOP16_DLL     **dll = &(firstdll);
  89         char            *s;
  90
  91         if (!TRACE_ON(snoop)) return;
  92         if (!snr) {
  93                 xsnr=GLOBAL_Alloc(GMEM_ZEROINIT,2*sizeof(*snr),0,TRUE,TRUE,FALSE);
  94                 snr = GlobalLock16(xsnr);
  95                 snr[0].pushbp   = 0x5566;
  96                 snr[0].pusheax  = 0x50;
  97                 snr[0].pushax   = 0x5066;
  98                 snr[0].pushl    = 0x68;
  99                 snr[0].realfun  = (DWORD)SNOOP16_Entry;
 100                 snr[0].lcall    = 0x9a;
 101                 snr[0].callfromregs = (DWORD)CallFrom16Register;
 102                 snr[0].seg      = __get_cs();
 103                 snr[0].lret     = 0xcb66;
 104
 105                 snr[1].pushbp   = 0x5566;
 106                 snr[1].pusheax  = 0x50;
 107                 snr[1].pushax   = 0x5066;
 108                 snr[1].pushl    = 0x68;
 109                 snr[1].realfun  = (DWORD)SNOOP16_Return;
 110                 snr[1].lcall    = 0x9a;
 111                 snr[1].callfromregs = (DWORD)CallFrom16Register;
 112                 snr[1].seg      = __get_cs();
 113                 snr[1].lret     = 0xcb66;
 114         }
 115         while (*dll) {
 116                 if ((*dll)->hmod == pModule->self)
 117                         return; /* already registered */
 118                 dll = &((*dll)->next);
 119         }
 120         *dll = (SNOOP16_DLL*)HeapAlloc(GetProcessHeap(),HEAP_ZERO_MEMORY,sizeof(SNOOP16_DLL));
 121         (*dll)->next    = NULL;
 122         (*dll)->hmod    = pModule->self;
 123         if ((s=strrchr(name,'\\')))
 124                 name = s+1;
 125         (*dll)->name    = HEAP_strdupA(GetProcessHeap(),0,name);
 126         if ((s=strrchr((*dll)->name,'.')))
 127                 *s='\0';
 128         (*dll)->funhandle = GlobalHandleToSel16(GLOBAL_Alloc(GMEM_ZEROINIT,65535,0,TRUE,FALSE,FALSE));
 129         (*dll)->funs = GlobalLock16((*dll)->funhandle);
 130         if (!(*dll)->funs) {
 131                 HeapFree(GetProcessHeap(),0,*dll);
 132                 FIXME("out of memory\n");
 133                 return;
 134         }
 135         memset((*dll)->funs,0,65535);
 136 }
 137
 138 FARPROC16
 139 SNOOP16_GetProcAddress16(HMODULE16 hmod,DWORD ordinal,FARPROC16 origfun) {
 140         SNOOP16_DLL                     *dll = firstdll;
 141         SNOOP16_FUN                     *fun;
 142         NE_MODULE                       *pModule = NE_GetPtr(hmod);
 143         unsigned char                   *cpnt;
 144         char                            name[200];
 145
 146         if (!TRACE_ON(snoop) || !pModule || !HIWORD(origfun))
 147                 return origfun;
 148         if (!*(LPBYTE)PTR_SEG_TO_LIN(origfun)) /* 0x00 is an imposs. opcode, poss. dataref. */
 149                 return origfun;
 150         while (dll) {
 151                 if (hmod == dll->hmod)
 152                         break;
 153                 dll=dll->next;
 154         }
 155         if (!dll)       /* probably internal */
 156                 return origfun;
 157         if (ordinal>65535/sizeof(SNOOP16_FUN))
 158                 return origfun;
 159         fun = dll->funs+ordinal;
 160         /* already done? */
 161         fun->lcall      = 0x9a;
 162         fun->snr        = MAKELONG(0,xsnr);
 163         fun->origfun    = origfun;
 164         if (fun->name)
 165                 return (FARPROC16)(SEGPTR)MAKELONG(((char*)fun-(char*)dll->funs),dll->funhandle);
 166         cpnt = (unsigned char *)pModule + pModule->name_table;
 167         while (*cpnt) {
 168                 cpnt += *cpnt + 1 + sizeof(WORD);
 169                 if (*(WORD*)(cpnt+*cpnt+1) == ordinal) {
 170                         sprintf(name,"%.*s",*cpnt,cpnt+1);
 171                         break;
 172                 }
 173         }
 174         /* Now search the non-resident names table */
 175
 176         if (!*cpnt && pModule->nrname_handle) {
 177                 cpnt = (char *)GlobalLock16( pModule->nrname_handle );
 178                 while (*cpnt) {
 179                         cpnt += *cpnt + 1 + sizeof(WORD);
 180                         if (*(WORD*)(cpnt+*cpnt+1) == ordinal) {
 181                                     sprintf(name,"%.*s",*cpnt,cpnt+1);
 182                                     break;
 183                         }
 184                 }
 185         }
 186         if (*cpnt)
 187                 fun->name = HEAP_strdupA(GetProcessHeap(),0,name);
 188         else
 189                 fun->name = HEAP_strdupA(GetProcessHeap(),0,"");
 190         if (!SNOOP_ShowDebugmsgSnoop(dll->name, ordinal, fun->name))
 191                 return origfun;
 192
 193         /* more magic. do not try to snoop thunk data entries (MMSYSTEM) */
 194         if (strchr(fun->name,'_')) {
 195                 char *s=strchr(fun->name,'_');
 196
 197                 if (!strncasecmp(s,"_thunkdata",10)) {
 198                         HeapFree(GetProcessHeap(),0,fun->name);
 199                         fun->name = NULL;
 200                         return origfun;
 201                 }
 202         }
 203         fun->lcall      = 0x9a;
 204         fun->snr        = MAKELONG(0,xsnr);
 205         fun->origfun    = origfun;
 206         fun->nrofargs   = -1;
 207         return (FARPROC16)(SEGPTR)MAKELONG(((char*)fun-(char*)dll->funs),dll->funhandle);
 208 }
 209
 210 #define CALLER1REF (*(DWORD*)(PTR_SEG_OFF_TO_LIN(SS_reg(context),LOWORD(ESP_reg(context))+4)))
 211 void WINAPI SNOOP16_Entry(FARPROC proc, LPBYTE args, CONTEXT86 *context) {
 212         DWORD           ordinal=0;
 213         DWORD           entry=(DWORD)PTR_SEG_OFF_TO_LIN(CS_reg(context),LOWORD(EIP_reg(context)))-5;
 214         WORD            xcs = CS_reg(context);
 215         SNOOP16_DLL     *dll = firstdll;
 216         SNOOP16_FUN     *fun = NULL;
 217         SNOOP16_RETURNENTRIES   **rets = &firstrets;
 218         SNOOP16_RETURNENTRY     *ret;
 219         int             i,max;
 220
 221         while (dll) {
 222                 if (xcs == dll->funhandle) {
 223                         fun = (SNOOP16_FUN*)entry;
 224                         ordinal = fun-dll->funs;
 225                         break;
 226                 }
 227                 dll=dll->next;
 228         }
 229         if (!dll) {
 230                 FIXME("entrypoint 0x%08lx not found\n",entry);
 231                 return; /* oops */
 232         }
 233         while (*rets) {
 234                 for (i=0;i<sizeof((*rets)->entry)/sizeof((*rets)->entry[0]);i++)
 235                         if (!(*rets)->entry[i].origreturn)
 236                                 break;
 237                 if (i!=sizeof((*rets)->entry)/sizeof((*rets)->entry[0]))
 238                         break;
 239                 rets = &((*rets)->next);
 240         }
 241         if (!*rets) {
 242                 HANDLE16        hand = GlobalHandleToSel16(GLOBAL_Alloc(GMEM_ZEROINIT,65535,0,TRUE,FALSE,FALSE));
 243                 *rets = GlobalLock16(hand);
 244                 memset(*rets,0,65535);
 245                 (*rets)->rethandle = hand;
 246                 i = 0;  /* entry 0 is free */
 247         }
 248         ret = &((*rets)->entry[i]);
 249         ret->lcall      = 0x9a;
 250         ret->snr        = MAKELONG(sizeof(SNOOP16_RELAY),xsnr);
 251         ret->origreturn = (FARPROC16)CALLER1REF;
 252         CALLER1REF      = MAKELONG((char*)&(ret->lcall)-(char*)((*rets)->entry),(*rets)->rethandle);
 253         ret->dll        = dll;
 254         ret->args       = NULL;
 255         ret->ordinal    = ordinal;
 256         ret->origSP     = LOWORD(ESP_reg(context));
 257
 258         EIP_reg(context)= LOWORD(fun->origfun);
 259         CS_reg(context) = HIWORD(fun->origfun);
 260
 261
 262         DPRINTF("CALL %s.%ld: %s(",dll->name,ordinal,fun->name);
 263         if (fun->nrofargs>0) {
 264                 max = fun->nrofargs;
 265                 if (max>16) max=16;
 266                 for (i=max;i--;)
 267                         DPRINTF("%04x%s",*(WORD*)((char *) PTR_SEG_OFF_TO_LIN(SS_reg(context),LOWORD(ESP_reg(context)))+8+sizeof(WORD)*i),i?",":"");
 268                 if (max!=fun->nrofargs)
 269                         DPRINTF(" ...");
 270         } else if (fun->nrofargs<0) {
 271                 DPRINTF("<unknown, check return>");
 272                 ret->args = HeapAlloc(GetProcessHeap(),0,16*sizeof(WORD));
 273                 memcpy(ret->args,(LPBYTE)((char *) PTR_SEG_OFF_TO_LIN(SS_reg(context),LOWORD(ESP_reg(context)))+8),sizeof(WORD)*16);
 274         }
 275         DPRINTF(") ret=%04x:%04x\n",HIWORD(ret->origreturn),LOWORD(ret->origreturn));
 276 }
 277
 278 void WINAPI SNOOP16_Return(FARPROC proc, LPBYTE args, CONTEXT86 *context) {
 279         SNOOP16_RETURNENTRY     *ret = (SNOOP16_RETURNENTRY*)((char *) PTR_SEG_OFF_TO_LIN(CS_reg(context),LOWORD(EIP_reg(context)))-5);
 280
 281         /* We haven't found out the nrofargs yet. If we called a cdecl
 282          * function it is too late anyway and we can just set '0' (which
 283          * will be the difference between orig and current SP
 284          * If pascal -> everything ok.
 285          */
 286         if (ret->dll->funs[ret->ordinal].nrofargs<0) {
 287                 ret->dll->funs[ret->ordinal].nrofargs=(LOWORD(ESP_reg(context))-ret->origSP-4)/2;
 288         }
 289         EIP_reg(context) = LOWORD(ret->origreturn);
 290         CS_reg(context)  = HIWORD(ret->origreturn);
 291         if (ret->args) {
 292                 int     i,max;
 293
 294                 DPRINTF("RET  %s.%ld: %s(",ret->dll->name,ret->ordinal,ret->dll->funs[ret->ordinal].name);
 295                 max = ret->dll->funs[ret->ordinal].nrofargs;
 296                 if (max>16)
 297                         max=16;
 298                 if (max<0)
 299                         max=0;
 300
 301                 for (i=max;i--;)
 302                         DPRINTF("%04x%s",ret->args[i],i?",":"");
 303                 if (max!=ret->dll->funs[ret->ordinal].nrofargs)
 304                         DPRINTF(" ...");
 305                 DPRINTF(") retval = %04x:%04x ret=%04x:%04x\n",
 306                         DX_reg(context),AX_reg(context),HIWORD(ret->origreturn),LOWORD(ret->origreturn)
 307                 );
 308                 HeapFree(GetProcessHeap(),0,ret->args);
 309                 ret->args = NULL;
 310         } else
 311                 DPRINTF("RET  %s.%ld: %s() retval = %04x:%04x ret=%04x:%04x\n",
 312                         ret->dll->name,ret->ordinal,ret->dll->funs[ret->ordinal].name,
 313                         DX_reg(context),AX_reg(context),HIWORD(ret->origreturn),LOWORD(ret->origreturn)
 314                 );
 315         ret->origreturn = NULL; /* mark as empty */
 316 }
 317 #else   /* !__i386__ */
 318 void SNOOP16_RegisterDLL(NE_MODULE *pModule,LPCSTR name) {
 319         FIXME("snooping works only on i386 for now.\n");
 320         return;
 321 }
 322
 323 FARPROC16 SNOOP16_GetProcAddress16(HMODULE16 hmod,DWORD ordinal,FARPROC16 origfun) {
 324         return origfun;
 325 }
 326 #endif  /* !__i386__ */
 327