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 "winbase.h"
  10 #include "winnt.h"
  11 #include "heap.h"
  12 #include "global.h"
  13 #include "selectors.h"
  14 #include "stackframe.h"
  15 #include "snoop.h"
  16 #include "debugstr.h"
  17 #include "debug.h"
  18
  19 DEFAULT_DEBUG_CHANNEL(snoop)
  20
  21 #ifdef __i386__
  22
  23 #include "pshpack1.h"
  24
  25 void WINAPI SNOOP16_Entry(CONTEXT *context);
  26 void WINAPI SNOOP16_Return(CONTEXT *context);
  27 extern void CallFrom16_p_regs_();
  28
  29 /* Generic callfrom16_p_regs function entry.
  30  *      pushw %bp                       0x55
  31  *      pushl $DOS3Call                 DWORD fun32
  32  *      .byte 0x9a                      0x9a
  33  *      .long CallFrom16_p_regs_        DWORD addr
  34  *      .long 0x90900023                WORD seg;nop;nop
  35  */
  36
  37 typedef struct tagSNOOP16_FUN {
  38         /* code part */
  39         BYTE            lcall;          /* 0x9a call absolute with segment */
  40         DWORD           snr;
  41         /* unreached */
  42         int             nrofargs;
  43         FARPROC16       origfun;
  44         char            *name;
  45 } SNOOP16_FUN;
  46
  47 typedef struct tagSNOOP16_DLL {
  48         HMODULE16       hmod;
  49         HANDLE16        funhandle;
  50         SNOOP16_FUN     *funs;
  51         LPCSTR          name;
  52         struct tagSNOOP16_DLL   *next;
  53 } SNOOP16_DLL;
  54
  55 typedef struct tagSNOOP16_RETURNENTRY {
  56         /* code part */
  57         BYTE            lcall;          /* 0x9a call absolute with segment */
  58         DWORD           snr;
  59         /* unreached */
  60         FARPROC16       origreturn;
  61         SNOOP16_DLL     *dll;
  62         DWORD           ordinal;
  63         WORD            origSP;
  64         WORD            *args;          /* saved args across a stdcall */
  65 } SNOOP16_RETURNENTRY;
  66
  67 typedef struct tagSNOOP16_RETURNENTRIES {
  68         SNOOP16_RETURNENTRY entry[65500/sizeof(SNOOP16_RETURNENTRY)];
  69         HANDLE16        rethandle;
  70         struct tagSNOOP16_RETURNENTRIES *next;
  71 } SNOOP16_RETURNENTRIES;
  72
  73 typedef struct tagSNOOP16_RELAY {
  74         /* code part */
  75         BYTE            prefix;         /* 0x66 , 32bit prefix */
  76         BYTE            pushbp;         /* 0x55 */
  77         BYTE            pushl;          /* 0x68 */
  78         DWORD           realfun;        /* SNOOP16_Return */
  79         BYTE            lcall;          /* 0x9a call absolute with segment */
  80         DWORD           callfromregs;
  81         WORD            seg;
  82         /* unreached */
  83 } SNOOP16_RELAY;
  84
  85 #include "poppack.h"
  86
  87 static  SNOOP16_DLL             *firstdll = NULL;
  88 static  SNOOP16_RETURNENTRIES   *firstrets = NULL;
  89 static  SNOOP16_RELAY           *snr;
  90 static  HANDLE16                xsnr = 0;
  91
  92 void
  93 SNOOP16_RegisterDLL(NE_MODULE *pModule,LPCSTR name) {
  94         SNOOP16_DLL     **dll = &(firstdll);
  95         char            *s;
  96
  97         if (!TRACE_ON(snoop)) return;
  98         if (!snr) {
  99                 xsnr=GLOBAL_Alloc(GMEM_ZEROINIT,2*sizeof(*snr),0,TRUE,TRUE,FALSE);
 100                 snr = GlobalLock16(xsnr);
 101                 snr[0].prefix   = 0x66;
 102                 snr[0].pushbp   = 0x55;
 103                 snr[0].pushl    = 0x68;
 104                 snr[0].realfun  = (DWORD)SNOOP16_Entry;
 105                 snr[0].lcall    = 0x9a;
 106                 snr[0].callfromregs = (DWORD)CallFrom16_p_regs_;
 107                 GET_CS(snr[0].seg);
 108                 snr[1].prefix   = 0x66;
 109                 snr[1].pushbp   = 0x55;
 110                 snr[1].pushl    = 0x68;
 111                 snr[1].realfun  = (DWORD)SNOOP16_Return;
 112                 snr[1].lcall    = 0x9a;
 113                 snr[1].callfromregs = (DWORD)CallFrom16_p_regs_;
 114                 GET_CS(snr[1].seg);
 115         }
 116         while (*dll) {
 117                 if ((*dll)->hmod == pModule->self)
 118                         return; /* already registered */
 119                 dll = &((*dll)->next);
 120         }
 121         *dll = (SNOOP16_DLL*)HeapAlloc(SystemHeap,HEAP_ZERO_MEMORY,sizeof(SNOOP16_DLL));
 122         (*dll)->next    = NULL;
 123         (*dll)->hmod    = pModule->self;
 124         if ((s=strrchr(name,'\\')))
 125                 name = s+1;
 126         (*dll)->name    = HEAP_strdupA(SystemHeap,0,name);
 127         if ((s=strrchr((*dll)->name,'.')))
 128                 *s='\0';
 129         (*dll)->funhandle = GlobalHandleToSel16(GLOBAL_Alloc(GMEM_ZEROINIT,65535,0,TRUE,FALSE,FALSE));
 130         (*dll)->funs = GlobalLock16((*dll)->funhandle);
 131         if (!(*dll)->funs) {
 132                 HeapFree(SystemHeap,0,*dll);
 133                 FIXME(snoop,"out of memory\n");
 134                 return;
 135         }
 136         memset((*dll)->funs,0,65535);
 137 }
 138
 139 FARPROC16
 140 SNOOP16_GetProcAddress16(HMODULE16 hmod,DWORD ordinal,FARPROC16 origfun) {
 141         SNOOP16_DLL                     *dll = firstdll;
 142         SNOOP16_FUN                     *fun;
 143         NE_MODULE                       *pModule = NE_GetPtr(hmod);
 144         unsigned char                   *cpnt;
 145         char                            name[200];
 146
 147         if (!TRACE_ON(snoop) || !pModule || !HIWORD(origfun))
 148                 return origfun;
 149         if (!*(LPBYTE)PTR_SEG_TO_LIN(origfun)) /* 0x00 is an imposs. opcode, poss. dataref. */
 150                 return origfun;
 151         while (dll) {
 152                 if (hmod == dll->hmod)
 153                         break;
 154                 dll=dll->next;
 155         }
 156         if (!dll)       /* probably internal */
 157                 return origfun;
 158         if (ordinal>65535/sizeof(SNOOP16_FUN))
 159                 return origfun;
 160         fun = dll->funs+ordinal;
 161         /* already done? */
 162         fun->lcall      = 0x9a;
 163         fun->snr        = MAKELONG(0,xsnr);
 164         fun->origfun    = origfun;
 165         if (fun->name)
 166                 return (FARPROC16)(SEGPTR)MAKELONG(((char*)fun-(char*)dll->funs),dll->funhandle);
 167         cpnt = (unsigned char *)pModule + pModule->name_table;
 168         while (*cpnt) {
 169                 cpnt += *cpnt + 1 + sizeof(WORD);
 170                 if (*(WORD*)(cpnt+*cpnt+1) == ordinal) {
 171                         sprintf(name,"%.*s",*cpnt,cpnt+1);
 172                         break;
 173                 }
 174         }
 175         /* Now search the non-resident names table */
 176
 177         if (!*cpnt && pModule->nrname_handle) {
 178                 cpnt = (char *)GlobalLock16( pModule->nrname_handle );
 179                 while (*cpnt) {
 180                         cpnt += *cpnt + 1 + sizeof(WORD);
 181                         if (*(WORD*)(cpnt+*cpnt+1) == ordinal) {
 182                                     sprintf(name,"%.*s",*cpnt,cpnt+1);
 183                                     break;
 184                         }
 185                 }
 186         }
 187         if (*cpnt)
 188                 fun->name = HEAP_strdupA(SystemHeap,0,name);
 189         else
 190                 fun->name = HEAP_strdupA(SystemHeap,0,"");
 191         if (!SNOOP_ShowDebugmsgSnoop(dll->name, ordinal, fun->name))
 192                 return origfun;
 193
 194         /* more magic. do not try to snoop thunk data entries (MMSYSTEM) */
 195         if (strchr(fun->name,'_')) {
 196                 char *s=strchr(fun->name,'_');
 197
 198                 if (!strncasecmp(s,"_thunkdata",10)) {
 199                         HeapFree(SystemHeap,0,fun->name);
 200                         fun->name = NULL;
 201                         return origfun;
 202                 }
 203         }
 204         fun->lcall      = 0x9a;
 205         fun->snr        = MAKELONG(0,xsnr);
 206         fun->origfun    = origfun;
 207         fun->nrofargs   = -1;
 208         return (FARPROC16)(SEGPTR)MAKELONG(((char*)fun-(char*)dll->funs),dll->funhandle);
 209 }
 210
 211 #define CALLER1REF (*(DWORD*)(PTR_SEG_OFF_TO_LIN(SS_reg(context),SP_reg(context)+4)))
 212 void WINAPI SNOOP16_Entry(CONTEXT *context) {
 213         DWORD           ordinal=0;
 214         DWORD           entry=(DWORD)PTR_SEG_OFF_TO_LIN(CS_reg(context),IP_reg(context))-5;
 215         WORD            xcs = CS_reg(context);
 216         SNOOP16_DLL     *dll = firstdll;
 217         SNOOP16_FUN     *fun = NULL;
 218         SNOOP16_RETURNENTRIES   **rets = &firstrets;
 219         SNOOP16_RETURNENTRY     *ret;
 220         int             i,max;
 221
 222         while (dll) {
 223                 if (xcs == dll->funhandle) {
 224                         fun = (SNOOP16_FUN*)entry;
 225                         ordinal = fun-dll->funs;
 226                         break;
 227                 }
 228                 dll=dll->next;
 229         }
 230         if (!dll) {
 231                 FIXME(snoop,"entrypoint 0x%08lx not found\n",entry);
 232                 return; /* oops */
 233         }
 234         while (*rets) {
 235                 for (i=0;i<sizeof((*rets)->entry)/sizeof((*rets)->entry[0]);i++)
 236                         if (!(*rets)->entry[i].origreturn)
 237                                 break;
 238                 if (i!=sizeof((*rets)->entry)/sizeof((*rets)->entry[0]))
 239                         break;
 240                 rets = &((*rets)->next);
 241         }
 242         if (!*rets) {
 243                 HANDLE16        hand = GlobalHandleToSel16(GLOBAL_Alloc(GMEM_ZEROINIT,65535,0,TRUE,FALSE,FALSE));
 244                 *rets = GlobalLock16(hand);
 245                 memset(*rets,0,65535);
 246                 (*rets)->rethandle = hand;
 247                 i = 0;  /* entry 0 is free */
 248         }
 249         ret = &((*rets)->entry[i]);
 250         ret->lcall      = 0x9a;
 251         ret->snr        = MAKELONG(sizeof(SNOOP16_RELAY),xsnr);
 252         ret->origreturn = (FARPROC16)CALLER1REF;
 253         CALLER1REF      = MAKELONG((char*)&(ret->lcall)-(char*)((*rets)->entry),(*rets)->rethandle);
 254         ret->dll        = dll;
 255         ret->args       = NULL;
 256         ret->ordinal    = ordinal;
 257         ret->origSP     = SP_reg(context);
 258
 259         IP_reg(context)= LOWORD(fun->origfun);
 260         CS_reg(context)= HIWORD(fun->origfun);
 261
 262
 263         DPRINTF("Call %s.%ld: %s(",dll->name,ordinal,fun->name);
 264         if (fun->nrofargs>0) {
 265                 max = fun->nrofargs;
 266                 if (max>16) max=16;
 267                 for (i=max;i--;)
 268                         DPRINTF("%04x%s",*(WORD*)(PTR_SEG_OFF_TO_LIN(SS_reg(context),SP_reg(context))+8+sizeof(WORD)*i),i?",":"");
 269                 if (max!=fun->nrofargs)
 270                         DPRINTF(" ...");
 271         } else if (fun->nrofargs<0) {
 272                 DPRINTF("<unknown, check return>");
 273                 ret->args = HeapAlloc(SystemHeap,0,16*sizeof(WORD));
 274                 memcpy(ret->args,(LPBYTE)(PTR_SEG_OFF_TO_LIN(SS_reg(context),SP_reg(context))+8),sizeof(WORD)*16);
 275         }
 276         DPRINTF(") ret=%04x:%04x\n",HIWORD(ret->origreturn),LOWORD(ret->origreturn));
 277 }
 278
 279 void WINAPI SNOOP16_Return(CONTEXT *context) {
 280         SNOOP16_RETURNENTRY     *ret = (SNOOP16_RETURNENTRY*)(PTR_SEG_OFF_TO_LIN(CS_reg(context),IP_reg(context))-5);
 281
 282         /* We haven't found out the nrofargs yet. If we called a cdecl
 283          * function it is too late anyway and we can just set '0' (which
 284          * will be the difference between orig and current SP
 285          * If pascal -> everything ok.
 286          */
 287         if (ret->dll->funs[ret->ordinal].nrofargs<0) {
 288                 ret->dll->funs[ret->ordinal].nrofargs=(SP_reg(context)-ret->origSP-4)/2;
 289         }
 290         IP_reg(context) = LOWORD(ret->origreturn);
 291         CS_reg(context) = HIWORD(ret->origreturn);
 292         if (ret->args) {
 293                 int     i,max;
 294
 295                 DPRINTF("Ret  %s.%ld: %s(",ret->dll->name,ret->ordinal,ret->dll->funs[ret->ordinal].name);
 296                 max = ret->dll->funs[ret->ordinal].nrofargs;
 297                 if (max>16)
 298                         max=16;
 299                 if (max<0)
 300                         max=0;
 301
 302                 for (i=max;i--;)
 303                         DPRINTF("%04x%s",ret->args[i],i?",":"");
 304                 if (max!=ret->dll->funs[ret->ordinal].nrofargs)
 305                         DPRINTF(" ...");
 306                 DPRINTF(") retval = %04x:%04x ret=%04x:%04x\n",
 307                         DX_reg(context),AX_reg(context),HIWORD(ret->origreturn),LOWORD(ret->origreturn)
 308                 );
 309                 HeapFree(SystemHeap,0,ret->args);
 310                 ret->args = NULL;
 311         } else
 312                 DPRINTF("Ret  %s.%ld: %s() retval = %04x:%04x ret=%04x:%04x\n",
 313                         ret->dll->name,ret->ordinal,ret->dll->funs[ret->ordinal].name,
 314                         DX_reg(context),AX_reg(context),HIWORD(ret->origreturn),LOWORD(ret->origreturn)
 315                 );
 316         ret->origreturn = NULL; /* mark as empty */
 317 }
 318 #else   /* !__i386__ */
 319 void SNOOP16_RegisterDLL(NE_MODULE *pModule,LPCSTR name) {
 320         FIXME(snoop,"snooping works only on i386 for now.\n");
 321         return;
 322 }
 323
 324 FARPROC16 SNOOP16_GetProcAddress16(HMODULE16 hmod,DWORD ordinal,FARPROC16 origfun) {
 325         return origfun;
 326 }
 327 #endif  /* !__i386__ */
 328
 329 void
 330 SNOOP16_Init() {
 331         fnSNOOP16_GetProcAddress16=SNOOP16_GetProcAddress16;
 332         fnSNOOP16_RegisterDLL=SNOOP16_RegisterDLL;
 333 }