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