relay32/snoop.c

   1 /*
   2  * 386-specific Win32 dll<->dll snooping functions
   3  *
   4  * Copyright 1998 Marcus Meissner
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include "config.h"
  22 #include "wine/port.h"
  23
  24 #include <assert.h>
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include "winbase.h"
  28 #include "winnt.h"
  29 #include "winternl.h"
  30 #include "snoop.h"
  31 #include "stackframe.h"
  32 #include "wine/debug.h"
  33 #include "wine/exception.h"
  34 #include "msvcrt/excpt.h"
  35
  36 WINE_DEFAULT_DEBUG_CHANNEL(snoop);
  37
  38 static WINE_EXCEPTION_FILTER(page_fault)
  39 {
  40     if (GetExceptionCode() == EXCEPTION_ACCESS_VIOLATION ||
  41         GetExceptionCode() == EXCEPTION_PRIV_INSTRUCTION)
  42         return EXCEPTION_EXECUTE_HANDLER;
  43     return EXCEPTION_CONTINUE_SEARCH;
  44 }
  45
  46 extern const char **debug_snoop_excludelist;
  47 extern const char **debug_snoop_includelist;
  48
  49 #ifdef __i386__
  50
  51 extern void WINAPI SNOOP_Entry();
  52 extern void WINAPI SNOOP_Return();
  53
  54 #include "pshpack1.h"
  55
  56 typedef struct tagSNOOP_FUN {
  57         /* code part */
  58         BYTE            lcall;          /* 0xe8 call snoopentry (relative) */
  59         /* NOTE: If you move snoopentry OR nrofargs fix the relative offset
  60          * calculation!
  61          */
  62         DWORD           snoopentry;     /* SNOOP_Entry relative */
  63         /* unreached */
  64         int             nrofargs;
  65         FARPROC origfun;
  66         char            *name;
  67 } SNOOP_FUN;
  68
  69 typedef struct tagSNOOP_DLL {
  70         HMODULE hmod;
  71         SNOOP_FUN       *funs;
  72         DWORD           ordbase;
  73         DWORD           nrofordinals;
  74         struct tagSNOOP_DLL     *next;
  75         char name[1];
  76 } SNOOP_DLL;
  77
  78 typedef struct tagSNOOP_RETURNENTRY {
  79         /* code part */
  80         BYTE            lcall;          /* 0xe8 call snoopret relative*/
  81         /* NOTE: If you move snoopret OR origreturn fix the relative offset
  82          * calculation!
  83          */
  84         DWORD           snoopret;       /* SNOOP_Ret relative */
  85         /* unreached */
  86         FARPROC origreturn;
  87         SNOOP_DLL       *dll;
  88         DWORD           ordinal;
  89         DWORD           origESP;
  90         DWORD           *args;          /* saved args across a stdcall */
  91 } SNOOP_RETURNENTRY;
  92
  93 typedef struct tagSNOOP_RETURNENTRIES {
  94         SNOOP_RETURNENTRY entry[4092/sizeof(SNOOP_RETURNENTRY)];
  95         struct tagSNOOP_RETURNENTRIES   *next;
  96 } SNOOP_RETURNENTRIES;
  97
  98 #include "poppack.h"
  99
 100 static  SNOOP_DLL               *firstdll = NULL;
 101 static  SNOOP_RETURNENTRIES     *firstrets = NULL;
 102
 103 /***********************************************************************
 104  *          SNOOP_ShowDebugmsgSnoop
 105  *
 106  * Simple function to decide if a particular debugging message is
 107  * wanted.
 108  */
 109 int SNOOP_ShowDebugmsgSnoop(const char *dll, int ord, const char *fname) {
 110
 111   if(debug_snoop_excludelist || debug_snoop_includelist) {
 112     const char **listitem;
 113     char buf[80];
 114     int len, len2, itemlen, show;
 115
 116     if(debug_snoop_excludelist) {
 117       show = 1;
 118       listitem = debug_snoop_excludelist;
 119     } else {
 120       show = 0;
 121       listitem = debug_snoop_includelist;
 122     }
 123     len = strlen(dll);
 124     assert(len < 64);
 125     sprintf(buf, "%s.%d", dll, ord);
 126     len2 = strlen(buf);
 127     for(; *listitem; listitem++) {
 128       itemlen = strlen(*listitem);
 129       if((itemlen == len && !strncasecmp(*listitem, buf, len)) ||
 130          (itemlen == len2 && !strncasecmp(*listitem, buf, len2)) ||
 131          !strcasecmp(*listitem, fname)) {
 132         show = !show;
 133        break;
 134       }
 135     }
 136     return show;
 137   }
 138   return 1;
 139 }
 140
 141 void
 142 SNOOP_RegisterDLL(HMODULE hmod,LPCSTR name,DWORD ordbase,DWORD nrofordinals) {
 143         SNOOP_DLL       **dll = &(firstdll);
 144         char            *s;
 145
 146     TRACE("hmod=%x, name=%s, ordbase=%ld, nrofordinals=%ld\n",
 147            hmod, name, ordbase, nrofordinals);
 148
 149         if (!TRACE_ON(snoop)) return;
 150         while (*dll) {
 151                 if ((*dll)->hmod == hmod)
 152                 {
 153                     /* another dll, loaded at the same address */
 154                     VirtualFree((*dll)->funs, (*dll)->nrofordinals*sizeof(SNOOP_FUN), MEM_RELEASE);
 155                     break;
 156                 }
 157                 dll = &((*dll)->next);
 158         }
 159         *dll = HeapReAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, *dll, sizeof(SNOOP_DLL)+strlen(name));
 160         (*dll)->hmod    = hmod;
 161         (*dll)->ordbase = ordbase;
 162         (*dll)->nrofordinals = nrofordinals;
 163         strcpy( (*dll)->name, name );
 164         if ((s=strrchr((*dll)->name,'.')))
 165                 *s='\0';
 166         (*dll)->funs = VirtualAlloc(NULL,nrofordinals*sizeof(SNOOP_FUN),MEM_COMMIT|MEM_RESERVE,PAGE_EXECUTE_READWRITE);
 167         memset((*dll)->funs,0,nrofordinals*sizeof(SNOOP_FUN));
 168         if (!(*dll)->funs) {
 169                 HeapFree(GetProcessHeap(),0,*dll);
 170                 FIXME("out of memory\n");
 171                 return;
 172         }
 173 }
 174
 175 FARPROC
 176 SNOOP_GetProcAddress(HMODULE hmod,LPCSTR name,DWORD ordinal,FARPROC origfun) {
 177         SNOOP_DLL                       *dll = firstdll;
 178         SNOOP_FUN                       *fun;
 179         IMAGE_SECTION_HEADER *sec;
 180
 181         if (!TRACE_ON(snoop)) return origfun;
 182         if (!*(LPBYTE)origfun) /* 0x00 is an imposs. opcode, poss. dataref. */
 183                 return origfun;
 184
 185         sec = RtlImageRvaToSection( RtlImageNtHeader(hmod), hmod, (char *)origfun - (char *)hmod );
 186
 187         if (!sec || !(sec->Characteristics & IMAGE_SCN_CNT_CODE))
 188             return origfun;  /* most likely a data reference */
 189
 190         while (dll) {
 191                 if (hmod == dll->hmod)
 192                         break;
 193                 dll=dll->next;
 194         }
 195         if (!dll)       /* probably internal */
 196                 return origfun;
 197         if (!SNOOP_ShowDebugmsgSnoop(dll->name,ordinal,name))
 198                 return origfun;
 199         assert(ordinal < dll->nrofordinals);
 200         fun = dll->funs+ordinal;
 201         if (!fun->name)
 202           {
 203             fun->name = HeapAlloc(GetProcessHeap(),0,strlen(name)+1);
 204             strcpy( fun->name, name );
 205             fun->lcall  = 0xe8;
 206             /* NOTE: origreturn struct member MUST come directly after snoopentry */
 207             fun->snoopentry     = (char*)SNOOP_Entry-((char*)(&fun->nrofargs));
 208             fun->origfun        = origfun;
 209             fun->nrofargs       = -1;
 210           }
 211         return (FARPROC)&(fun->lcall);
 212 }
 213
 214 static void SNOOP_PrintArg(DWORD x)
 215 {
 216     int i,nostring;
 217
 218     DPRINTF("%08lx",x);
 219     if ( !HIWORD(x) ) return; /* trivial reject to avoid faults */
 220     __TRY
 221     {
 222         LPBYTE s=(LPBYTE)x;
 223         i=0;nostring=0;
 224         while (i<80) {
 225             if (s[i]==0) break;
 226             if (s[i]<0x20) {nostring=1;break;}
 227             if (s[i]>=0x80) {nostring=1;break;}
 228             i++;
 229         }
 230         if (!nostring && i > 5)
 231             DPRINTF(" %s",debugstr_an((LPSTR)x,i));
 232         else  /* try unicode */
 233         {
 234             LPWSTR s=(LPWSTR)x;
 235             i=0;nostring=0;
 236             while (i<80) {
 237                 if (s[i]==0) break;
 238                 if (s[i]<0x20) {nostring=1;break;}
 239                 if (s[i]>0x100) {nostring=1;break;}
 240                 i++;
 241             }
 242             if (!nostring && i > 5) DPRINTF(" %s",debugstr_wn((LPWSTR)x,i));
 243         }
 244     }
 245     __EXCEPT(page_fault)
 246     {
 247     }
 248     __ENDTRY
 249 }
 250
 251 #define CALLER1REF (*(DWORD*)context->Esp)
 252
 253 void WINAPI SNOOP_DoEntry( CONTEXT86 *context )
 254 {
 255         DWORD           ordinal=0,entry = context->Eip - 5;
 256         SNOOP_DLL       *dll = firstdll;
 257         SNOOP_FUN       *fun = NULL;
 258         SNOOP_RETURNENTRIES     **rets = &firstrets;
 259         SNOOP_RETURNENTRY       *ret;
 260         int             i=0, max;
 261
 262         while (dll) {
 263                 if (    ((char*)entry>=(char*)dll->funs)        &&
 264                         ((char*)entry<=(char*)(dll->funs+dll->nrofordinals))
 265                 ) {
 266                         fun = (SNOOP_FUN*)entry;
 267                         ordinal = fun-dll->funs;
 268                         break;
 269                 }
 270                 dll=dll->next;
 271         }
 272         if (!dll) {
 273                 FIXME("entrypoint 0x%08lx not found\n",entry);
 274                 return; /* oops */
 275         }
 276         /* guess cdecl ... */
 277         if (fun->nrofargs<0) {
 278                 /* Typical cdecl return frame is:
 279                  *      add esp, xxxxxxxx
 280                  * which has (for xxxxxxxx up to 255 the opcode "83 C4 xx".
 281                  * (after that 81 C2 xx xx xx xx)
 282                  */
 283                 LPBYTE  reteip = (LPBYTE)CALLER1REF;
 284
 285                 if (reteip) {
 286                         if ((reteip[0]==0x83)&&(reteip[1]==0xc4))
 287                                 fun->nrofargs=reteip[2]/4;
 288                 }
 289         }
 290
 291
 292         while (*rets) {
 293                 for (i=0;i<sizeof((*rets)->entry)/sizeof((*rets)->entry[0]);i++)
 294                         if (!(*rets)->entry[i].origreturn)
 295                                 break;
 296                 if (i!=sizeof((*rets)->entry)/sizeof((*rets)->entry[0]))
 297                         break;
 298                 rets = &((*rets)->next);
 299         }
 300         if (!*rets) {
 301                 *rets = VirtualAlloc(NULL,4096,MEM_COMMIT|MEM_RESERVE,PAGE_EXECUTE_READWRITE);
 302                 memset(*rets,0,4096);
 303                 i = 0;  /* entry 0 is free */
 304         }
 305         ret = &((*rets)->entry[i]);
 306         ret->lcall      = 0xe8;
 307         /* NOTE: origreturn struct member MUST come directly after snoopret */
 308         ret->snoopret   = ((char*)SNOOP_Return)-(char*)(&ret->origreturn);
 309         ret->origreturn = (FARPROC)CALLER1REF;
 310         CALLER1REF      = (DWORD)&ret->lcall;
 311         ret->dll        = dll;
 312         ret->args       = NULL;
 313         ret->ordinal    = ordinal;
 314         ret->origESP    = context->Esp;
 315
 316         context->Eip = (DWORD)fun->origfun;
 317
 318         DPRINTF("%08lx:CALL %s.%ld: %s(",GetCurrentThreadId(),dll->name,dll->ordbase+ordinal,fun->name);
 319         if (fun->nrofargs>0) {
 320                 max = fun->nrofargs; if (max>16) max=16;
 321                 for (i=0;i<max;i++)
 322                 {
 323                     SNOOP_PrintArg(*(DWORD*)(context->Esp + 4 + sizeof(DWORD)*i));
 324                     if (i<fun->nrofargs-1) DPRINTF(",");
 325                 }
 326                 if (max!=fun->nrofargs)
 327                         DPRINTF(" ...");
 328         } else if (fun->nrofargs<0) {
 329                 DPRINTF("<unknown, check return>");
 330                 ret->args = HeapAlloc(GetProcessHeap(),0,16*sizeof(DWORD));
 331                 memcpy(ret->args,(LPBYTE)(context->Esp + 4),sizeof(DWORD)*16);
 332         }
 333         DPRINTF(") ret=%08lx\n",(DWORD)ret->origreturn);
 334 }
 335
 336
 337 void WINAPI SNOOP_DoReturn( CONTEXT86 *context )
 338 {
 339         SNOOP_RETURNENTRY       *ret = (SNOOP_RETURNENTRY*)(context->Eip - 5);
 340
 341         /* We haven't found out the nrofargs yet. If we called a cdecl
 342          * function it is too late anyway and we can just set '0' (which
 343          * will be the difference between orig and current ESP
 344          * If stdcall -> everything ok.
 345          */
 346         if (ret->dll->funs[ret->ordinal].nrofargs<0)
 347                 ret->dll->funs[ret->ordinal].nrofargs=(context->Esp - ret->origESP-4)/4;
 348         context->Eip = (DWORD)ret->origreturn;
 349         if (ret->args) {
 350                 int     i,max;
 351
 352                 DPRINTF("%08lx:RET  %s.%ld: %s(",
 353                         GetCurrentThreadId(),
 354                         ret->dll->name,ret->dll->ordbase+ret->ordinal,ret->dll->funs[ret->ordinal].name);
 355                 max = ret->dll->funs[ret->ordinal].nrofargs;
 356                 if (max>16) max=16;
 357
 358                 for (i=0;i<max;i++)
 359                 {
 360                     SNOOP_PrintArg(ret->args[i]);
 361                     if (i<max-1) DPRINTF(",");
 362                 }
 363                 DPRINTF(") retval = %08lx ret=%08lx\n",
 364                         context->Eax,(DWORD)ret->origreturn );
 365                 HeapFree(GetProcessHeap(),0,ret->args);
 366                 ret->args = NULL;
 367         } else
 368                 DPRINTF("%08lx:RET  %s.%ld: %s() retval = %08lx ret=%08lx\n",
 369                         GetCurrentThreadId(),
 370                         ret->dll->name,ret->dll->ordbase+ret->ordinal,ret->dll->funs[ret->ordinal].name,
 371                         context->Eax, (DWORD)ret->origreturn);
 372         ret->origreturn = NULL; /* mark as empty */
 373 }
 374
 375 /* assembly wrappers that save the context */
 376 __ASM_GLOBAL_FUNC( SNOOP_Entry,
 377                    "call " __ASM_NAME("__wine_call_from_32_regs") "\n\t"
 378                    ".long " __ASM_NAME("SNOOP_DoEntry") ",0" );
 379 __ASM_GLOBAL_FUNC( SNOOP_Return,
 380                    "call " __ASM_NAME("__wine_call_from_32_regs") "\n\t"
 381                    ".long " __ASM_NAME("SNOOP_DoReturn") ",0" );
 382
 383 #else   /* !__i386__ */
 384 void SNOOP_RegisterDLL(HMODULE hmod,LPCSTR name,DWORD nrofordinals, DWORD dw) {
 385         if (!TRACE_ON(snoop)) return;
 386         FIXME("snooping works only on i386 for now.\n");
 387 }
 388
 389 FARPROC SNOOP_GetProcAddress(HMODULE hmod,LPCSTR name,DWORD ordinal,FARPROC origfun) {
 390         return origfun;
 391 }
 392 #endif  /* !__i386__ */