relay32/snoop.c

   1 /*
   2  * 386-specific Win32 dll<->dll snooping functions
   3  *
   4  * Copyright 1998 Marcus Meissner
   5  */
   6
   7 #include "config.h"
   8
   9 #include <assert.h>
  10 #include <stdio.h>
  11 #include <string.h>
  12 #include "winbase.h"
  13 #include "wingdi.h"
  14 #include "winuser.h"
  15 #include "winnt.h"
  16 #include "heap.h"
  17 #include "builtin32.h"
  18 #include "snoop.h"
  19 #include "neexe.h"
  20 #include "selectors.h"
  21 #include "stackframe.h"
  22 #include "debugtools.h"
  23 #include "wine/exception.h"
  24
  25 DEFAULT_DEBUG_CHANNEL(snoop);
  26
  27 static WINE_EXCEPTION_FILTER(page_fault)
  28 {
  29     if (GetExceptionCode() == EXCEPTION_ACCESS_VIOLATION)
  30         return EXCEPTION_EXECUTE_HANDLER;
  31     return EXCEPTION_CONTINUE_SEARCH;
  32 }
  33
  34 char **debug_snoop_excludelist = NULL, **debug_snoop_includelist = NULL;
  35
  36 #ifdef __i386__
  37
  38 extern void WINAPI SNOOP_Entry();
  39 extern void WINAPI SNOOP_Return();
  40
  41 #ifdef NEED_UNDERSCORE_PREFIX
  42 # define PREFIX "_"
  43 #else
  44 # define PREFIX
  45 #endif
  46
  47 #include "pshpack1.h"
  48
  49 typedef struct tagSNOOP_FUN {
  50         /* code part */
  51         BYTE            lcall;          /* 0xe8 call snoopentry (relative) */
  52         /* NOTE: If you move snoopentry OR nrofargs fix the relative offset
  53          * calculation!
  54          */
  55         DWORD           snoopentry;     /* SNOOP_Entry relative */
  56         /* unreached */
  57         int             nrofargs;
  58         FARPROC origfun;
  59         char            *name;
  60 } SNOOP_FUN;
  61
  62 typedef struct tagSNOOP_DLL {
  63         HMODULE hmod;
  64         SNOOP_FUN       *funs;
  65         LPCSTR          name;
  66         int             nrofordinals;
  67         struct tagSNOOP_DLL     *next;
  68 } SNOOP_DLL;
  69 typedef struct tagSNOOP_RETURNENTRY {
  70         /* code part */
  71         BYTE            lcall;          /* 0xe8 call snoopret relative*/
  72         /* NOTE: If you move snoopret OR origreturn fix the relative offset
  73          * calculation!
  74          */
  75         DWORD           snoopret;       /* SNOOP_Ret relative */
  76         /* unreached */
  77         FARPROC origreturn;
  78         SNOOP_DLL       *dll;
  79         DWORD           ordinal;
  80         DWORD           origESP;
  81         DWORD           *args;          /* saved args across a stdcall */
  82 } SNOOP_RETURNENTRY;
  83
  84 typedef struct tagSNOOP_RETURNENTRIES {
  85         SNOOP_RETURNENTRY entry[4092/sizeof(SNOOP_RETURNENTRY)];
  86         struct tagSNOOP_RETURNENTRIES   *next;
  87 } SNOOP_RETURNENTRIES;
  88
  89 #include "poppack.h"
  90
  91 static  SNOOP_DLL               *firstdll = NULL;
  92 static  SNOOP_RETURNENTRIES     *firstrets = NULL;
  93
  94 /***********************************************************************
  95  *          SNOOP_ShowDebugmsgSnoop
  96  *
  97  * Simple function to decide if a particular debugging message is
  98  * wanted.
  99  */
 100 int SNOOP_ShowDebugmsgSnoop(const char *dll, int ord, const char *fname) {
 101
 102   if(debug_snoop_excludelist || debug_snoop_includelist) {
 103     char **listitem;
 104     char buf[80];
 105     int len, len2, itemlen, show;
 106
 107     if(debug_snoop_excludelist) {
 108       show = 1;
 109       listitem = debug_snoop_excludelist;
 110     } else {
 111       show = 0;
 112       listitem = debug_snoop_includelist;
 113     }
 114     len = strlen(dll);
 115     assert(len < 64);
 116     sprintf(buf, "%s.%d", dll, ord);
 117     len2 = strlen(buf);
 118     for(; *listitem; listitem++) {
 119       itemlen = strlen(*listitem);
 120       if((itemlen == len && !strncmp(*listitem, buf, len)) ||
 121          (itemlen == len2 && !strncmp(*listitem, buf, len2)) ||
 122          !strcmp(*listitem, fname)) {
 123         show = !show;
 124        break;
 125       }
 126     }
 127     return show;
 128   }
 129   return 1;
 130 }
 131
 132 void
 133 SNOOP_RegisterDLL(HMODULE hmod,LPCSTR name,DWORD nrofordinals) {
 134         SNOOP_DLL       **dll = &(firstdll);
 135         char            *s;
 136
 137         if (!TRACE_ON(snoop)) return;
 138         while (*dll) {
 139                 if ((*dll)->hmod == hmod)
 140                         return; /* already registered */
 141                 dll = &((*dll)->next);
 142         }
 143         *dll = (SNOOP_DLL*)HeapAlloc(GetProcessHeap(),HEAP_ZERO_MEMORY,sizeof(SNOOP_DLL));
 144         (*dll)->next    = NULL;
 145         (*dll)->hmod    = hmod;
 146         (*dll)->nrofordinals = nrofordinals;
 147         (*dll)->name    = HEAP_strdupA(GetProcessHeap(),0,name);
 148         if ((s=strrchr((*dll)->name,'.')))
 149                 *s='\0';
 150         (*dll)->funs = VirtualAlloc(NULL,nrofordinals*sizeof(SNOOP_FUN),MEM_COMMIT|MEM_RESERVE,PAGE_EXECUTE_READWRITE);
 151         memset((*dll)->funs,0,nrofordinals*sizeof(SNOOP_FUN));
 152         if (!(*dll)->funs) {
 153                 HeapFree(GetProcessHeap(),0,*dll);
 154                 FIXME("out of memory\n");
 155                 return;
 156         }
 157 }
 158
 159 FARPROC
 160 SNOOP_GetProcAddress(HMODULE hmod,LPCSTR name,DWORD ordinal,FARPROC origfun) {
 161         SNOOP_DLL                       *dll = firstdll;
 162         SNOOP_FUN                       *fun;
 163         int                             j;
 164         IMAGE_SECTION_HEADER            *pe_seg = PE_SECTIONS(hmod);
 165
 166         if (!TRACE_ON(snoop)) return origfun;
 167         if (!*(LPBYTE)origfun) /* 0x00 is an imposs. opcode, poss. dataref. */
 168                 return origfun;
 169         for (j=0;j<PE_HEADER(hmod)->FileHeader.NumberOfSections;j++)
 170                 /* 0x42 is special ELF loader tag */
 171                 if ((pe_seg[j].VirtualAddress==0x42) ||
 172                     (((DWORD)origfun-hmod>=pe_seg[j].VirtualAddress)&&
 173                      ((DWORD)origfun-hmod <pe_seg[j].VirtualAddress+
 174                                    pe_seg[j].SizeOfRawData
 175                    ))
 176                 )
 177                         break;
 178         /* If we looked through all sections (and didn't find one)
 179          * or if the sectionname contains "data", we return the
 180          * original function since it is most likely a datareference.
 181          */
 182         if (    (j==PE_HEADER(hmod)->FileHeader.NumberOfSections)       ||
 183                 (strstr(pe_seg[j].Name,"data"))                         ||
 184                 !(pe_seg[j].Characteristics & IMAGE_SCN_CNT_CODE)
 185         )
 186                 return origfun;
 187
 188         while (dll) {
 189                 if (hmod == dll->hmod)
 190                         break;
 191                 dll=dll->next;
 192         }
 193         if (!dll)       /* probably internal */
 194                 return origfun;
 195         if (!SNOOP_ShowDebugmsgSnoop(dll->name,ordinal,name))
 196                 return origfun;
 197         assert(ordinal<dll->nrofordinals);
 198         fun = dll->funs+ordinal;
 199         if (!fun->name) fun->name = HEAP_strdupA(GetProcessHeap(),0,name);
 200         fun->lcall      = 0xe8;
 201         /* NOTE: origreturn struct member MUST come directly after snoopentry */
 202         fun->snoopentry = (char*)SNOOP_Entry-((char*)(&fun->nrofargs));
 203         fun->origfun    = origfun;
 204         fun->nrofargs   = -1;
 205         return (FARPROC)&(fun->lcall);
 206 }
 207
 208 static char*
 209 SNOOP_PrintArg(DWORD x) {
 210         static char     buf[200];
 211         int             i,nostring;
 212         char * ret=0;
 213         MEMORY_BASIC_INFORMATION        mbi;
 214
 215         if (    !HIWORD(x)                                      ||
 216                 !VirtualQuery((LPVOID)x,&mbi,sizeof(mbi))       ||
 217                 !mbi.Type
 218         ) {
 219                 sprintf(buf,"%08lx",x);
 220                 return buf;
 221         }
 222         __TRY{
 223                 LPBYTE  s=(LPBYTE)x;
 224                 i=0;nostring=0;
 225                 while (i<80) {
 226                         if (s[i]==0) break;
 227                         if (s[i]<0x20) {nostring=1;break;}
 228                         if (s[i]>=0x80) {nostring=1;break;}
 229                         i++;
 230                 }
 231                 if (!nostring) {
 232                         if (i>5) {
 233                                 wsnprintfA(buf,sizeof(buf),"%08lx %s",x,debugstr_an((LPSTR)x,sizeof(buf)-10));
 234                                 ret=buf;
 235                         }
 236                 }
 237         }
 238         __EXCEPT(page_fault){}
 239         __ENDTRY
 240         if (ret)
 241           return ret;
 242         __TRY{
 243                 LPWSTR  s=(LPWSTR)x;
 244                 i=0;nostring=0;
 245                 while (i<80) {
 246                         if (s[i]==0) break;
 247                         if (s[i]<0x20) {nostring=1;break;}
 248                         if (s[i]>0x100) {nostring=1;break;}
 249                         i++;
 250                 }
 251                 if (!nostring) {
 252                         if (i>5) {
 253                                 wsnprintfA(buf,sizeof(buf),"%08lx %s",x,debugstr_wn((LPWSTR)x,sizeof(buf)-10));
 254                                 ret=buf;
 255                         }
 256                 }
 257         }
 258         __EXCEPT(page_fault){}
 259         __ENDTRY
 260         if (ret)
 261           return ret;
 262         sprintf(buf,"%08lx",x);
 263         return buf;
 264 }
 265
 266 #define CALLER1REF (*(DWORD*)ESP_reg(context))
 267
 268 void WINAPI SNOOP_DoEntry( CONTEXT86 *context );
 269 DEFINE_REGS_ENTRYPOINT_0( SNOOP_Entry, SNOOP_DoEntry );
 270 void WINAPI SNOOP_DoEntry( CONTEXT86 *context )
 271 {
 272         DWORD           ordinal=0,entry = EIP_reg(context)-5;
 273         SNOOP_DLL       *dll = firstdll;
 274         SNOOP_FUN       *fun = NULL;
 275         SNOOP_RETURNENTRIES     **rets = &firstrets;
 276         SNOOP_RETURNENTRY       *ret;
 277         int             i,max;
 278
 279         while (dll) {
 280                 if (    ((char*)entry>=(char*)dll->funs)        &&
 281                         ((char*)entry<=(char*)(dll->funs+dll->nrofordinals))
 282                 ) {
 283                         fun = (SNOOP_FUN*)entry;
 284                         ordinal = fun-dll->funs;
 285                         break;
 286                 }
 287                 dll=dll->next;
 288         }
 289         if (!dll) {
 290                 FIXME("entrypoint 0x%08lx not found\n",entry);
 291                 return; /* oops */
 292         }
 293         /* guess cdecl ... */
 294         if (fun->nrofargs<0) {
 295                 /* Typical cdecl return frame is:
 296                  *      add esp, xxxxxxxx
 297                  * which has (for xxxxxxxx up to 255 the opcode "83 C4 xx".
 298                  * (after that 81 C2 xx xx xx xx)
 299                  */
 300                 LPBYTE  reteip = (LPBYTE)CALLER1REF;
 301
 302                 if (reteip) {
 303                         if ((reteip[0]==0x83)&&(reteip[1]==0xc4))
 304                                 fun->nrofargs=reteip[2]/4;
 305                 }
 306         }
 307
 308
 309         while (*rets) {
 310                 for (i=0;i<sizeof((*rets)->entry)/sizeof((*rets)->entry[0]);i++)
 311                         if (!(*rets)->entry[i].origreturn)
 312                                 break;
 313                 if (i!=sizeof((*rets)->entry)/sizeof((*rets)->entry[0]))
 314                         break;
 315                 rets = &((*rets)->next);
 316         }
 317         if (!*rets) {
 318                 *rets = VirtualAlloc(NULL,4096,MEM_COMMIT|MEM_RESERVE,PAGE_EXECUTE_READWRITE);
 319                 memset(*rets,0,4096);
 320                 i = 0;  /* entry 0 is free */
 321         }
 322         ret = &((*rets)->entry[i]);
 323         ret->lcall      = 0xe8;
 324         /* NOTE: origreturn struct member MUST come directly after snoopret */
 325         ret->snoopret   = ((char*)SNOOP_Return)-(char*)(&ret->origreturn);
 326         ret->origreturn = (FARPROC)CALLER1REF;
 327         CALLER1REF      = (DWORD)&ret->lcall;
 328         ret->dll        = dll;
 329         ret->args       = NULL;
 330         ret->ordinal    = ordinal;
 331         ret->origESP    = ESP_reg(context);
 332
 333         EIP_reg(context)= (DWORD)fun->origfun;
 334
 335         DPRINTF("Call %s.%ld: %s(",dll->name,ordinal,fun->name);
 336         if (fun->nrofargs>0) {
 337                 max = fun->nrofargs; if (max>16) max=16;
 338                 for (i=0;i<max;i++)
 339                         DPRINTF("%s%s",SNOOP_PrintArg(*(DWORD*)(ESP_reg(context)+4+sizeof(DWORD)*i)),(i<fun->nrofargs-1)?",":"");
 340                 if (max!=fun->nrofargs)
 341                         DPRINTF(" ...");
 342         } else if (fun->nrofargs<0) {
 343                 DPRINTF("<unknown, check return>");
 344                 ret->args = HeapAlloc(GetProcessHeap(),0,16*sizeof(DWORD));
 345                 memcpy(ret->args,(LPBYTE)(ESP_reg(context)+4),sizeof(DWORD)*16);
 346         }
 347         DPRINTF(") ret=%08lx fs=%04lx\n",(DWORD)ret->origreturn,FS_reg(context));
 348 }
 349
 350 void WINAPI SNOOP_DoReturn( CONTEXT86 *context );
 351 DEFINE_REGS_ENTRYPOINT_0( SNOOP_Return, SNOOP_DoReturn );
 352 void WINAPI SNOOP_DoReturn( CONTEXT86 *context )
 353 {
 354         SNOOP_RETURNENTRY       *ret = (SNOOP_RETURNENTRY*)(EIP_reg(context)-5);
 355
 356         /* We haven't found out the nrofargs yet. If we called a cdecl
 357          * function it is too late anyway and we can just set '0' (which
 358          * will be the difference between orig and current ESP
 359          * If stdcall -> everything ok.
 360          */
 361         if (ret->dll->funs[ret->ordinal].nrofargs<0)
 362                 ret->dll->funs[ret->ordinal].nrofargs=(ESP_reg(context)-ret->origESP-4)/4;
 363         EIP_reg(context) = (DWORD)ret->origreturn;
 364         if (ret->args) {
 365                 int     i,max;
 366
 367                 DPRINTF("Ret  %s.%ld: %s(",ret->dll->name,ret->ordinal,ret->dll->funs[ret->ordinal].name);
 368                 max = ret->dll->funs[ret->ordinal].nrofargs;
 369                 if (max>16) max=16;
 370
 371                 for (i=0;i<max;i++)
 372                         DPRINTF("%s%s",SNOOP_PrintArg(ret->args[i]),(i<max-1)?",":"");
 373                 DPRINTF(") retval = %08lx ret=%08lx fs=%04lx\n",
 374                         EAX_reg(context),(DWORD)ret->origreturn,FS_reg(context)
 375                 );
 376                 HeapFree(GetProcessHeap(),0,ret->args);
 377                 ret->args = NULL;
 378         } else
 379                 DPRINTF("Ret  %s.%ld: %s() retval = %08lx ret=%08lx fs=%04lx\n",
 380                         ret->dll->name,ret->ordinal,ret->dll->funs[ret->ordinal].name,
 381                         EAX_reg(context),(DWORD)ret->origreturn,FS_reg(context)
 382                 );
 383         ret->origreturn = NULL; /* mark as empty */
 384 }
 385 #else   /* !__i386__ */
 386 void SNOOP_RegisterDLL(HMODULE hmod,LPCSTR name,DWORD nrofordinals) {
 387         FIXME("snooping works only on i386 for now.\n");
 388         return;
 389 }
 390
 391 FARPROC SNOOP_GetProcAddress(HMODULE hmod,LPCSTR name,DWORD ordinal,FARPROC origfun) {
 392         return origfun;
 393 }
 394 #endif  /* !__i386__ */