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