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