relay32/snoop.c

   1 /*
   2  * 386-specific Win32 dll<->dll snooping functions
   3  *
   4  * Copyright 1998 Marcus Meissner
   5  */
   6
   7
   8 #include <assert.h>
   9 #include <string.h>
  10 #include "winbase.h"
  11 #include "winnt.h"
  12 #include "heap.h"
  13 #include "builtin32.h"
  14 #include "snoop.h"
  15 #include "neexe.h"
  16 #include "peexe.h"
  17 #include "selectors.h"
  18 #include "stackframe.h"
  19 #include "debugstr.h"
  20 #include "debug.h"
  21
  22 DEFAULT_DEBUG_CHANNEL(snoop)
  23
  24 char **debug_snoop_excludelist = NULL, **debug_snoop_includelist = NULL;
  25
  26 #ifdef __i386__
  27
  28 #ifdef NEED_UNDERSCORE_PREFIX
  29 # define PREFIX "_"
  30 #else
  31 # define PREFIX
  32 #endif
  33
  34 /* Well, not exactly extern since they are in the same file (in the lines
  35  * below). But the C Compiler doesn't see them there, so we have to help a bit.
  36  */
  37 extern void SNOOP_Return();
  38 extern void SNOOP_Entry();
  39 __asm__(".align 4\n\t"
  40         ".globl "PREFIX"SNOOP_Entry\n\t"
  41         ".type "PREFIX"SNOOP_Entry,@function\n\t"
  42         PREFIX"SNOOP_Entry:\n\t"
  43         "pushl $"PREFIX"__regs_SNOOP_Entry\n\t"
  44         "pushl $"PREFIX"CALL32_Regs\n\t"
  45         "ret\n\t"
  46         ".align 4\n\t"
  47         ".globl "PREFIX"SNOOP_Return\n\t"
  48         ".type "PREFIX"SNOOP_Return,@function\n\t"
  49         PREFIX"SNOOP_Return:\n\t"
  50         "pushl $"PREFIX"__regs_SNOOP_Return\n\t"
  51         "pushl $"PREFIX"CALL32_Regs\n\t"
  52         "ret"
  53 );
  54
  55 #include "pshpack1.h"
  56
  57 typedef struct tagSNOOP_FUN {
  58         /* code part */
  59         BYTE            lcall;          /* 0xe8 call snoopentry (relative) */
  60         /* NOTE: If you move snoopentry OR nrofargs fix the relative offset
  61          * calculation!
  62          */
  63         DWORD           snoopentry;     /* SNOOP_Entry relative */
  64         /* unreached */
  65         int             nrofargs;
  66         FARPROC origfun;
  67         char            *name;
  68 } SNOOP_FUN;
  69
  70 typedef struct tagSNOOP_DLL {
  71         HMODULE hmod;
  72         SNOOP_FUN       *funs;
  73         LPCSTR          name;
  74         int             nrofordinals;
  75         struct tagSNOOP_DLL     *next;
  76 } SNOOP_DLL;
  77 typedef struct tagSNOOP_RETURNENTRY {
  78         /* code part */
  79         BYTE            lcall;          /* 0xe8 call snoopret relative*/
  80         /* NOTE: If you move snoopret OR origreturn fix the relative offset
  81          * calculation!
  82          */
  83         DWORD           snoopret;       /* SNOOP_Ret relative */
  84         /* unreached */
  85         FARPROC origreturn;
  86         SNOOP_DLL       *dll;
  87         DWORD           ordinal;
  88         DWORD           origESP;
  89         DWORD           *args;          /* saved args across a stdcall */
  90 } SNOOP_RETURNENTRY;
  91
  92 typedef struct tagSNOOP_RETURNENTRIES {
  93         SNOOP_RETURNENTRY entry[4092/sizeof(SNOOP_RETURNENTRY)];
  94         struct tagSNOOP_RETURNENTRIES   *next;
  95 } SNOOP_RETURNENTRIES;
  96
  97 #include "poppack.h"
  98
  99 static  SNOOP_DLL               *firstdll = NULL;
 100 static  SNOOP_RETURNENTRIES     *firstrets = NULL;
 101
 102 /***********************************************************************
 103  *          SNOOP_ShowDebugmsgSnoop
 104  *
 105  * Simple function to decide if a particular debugging message is
 106  * wanted.
 107  */
 108 int SNOOP_ShowDebugmsgSnoop(const char *dll, int ord, const char *fname) {
 109
 110   if(debug_snoop_excludelist || debug_snoop_includelist) {
 111     char **listitem;
 112     char buf[80];
 113     int len, len2, itemlen, show;
 114
 115     if(debug_snoop_excludelist) {
 116       show = 1;
 117       listitem = debug_snoop_excludelist;
 118     } else {
 119       show = 0;
 120       listitem = debug_snoop_includelist;
 121     }
 122     len = strlen(dll);
 123     assert(len < 64);
 124     sprintf(buf, "%s.%d", dll, ord);
 125     len2 = strlen(buf);
 126     for(; *listitem; listitem++) {
 127       itemlen = strlen(*listitem);
 128       if((itemlen == len && !strncmp(*listitem, buf, len)) ||
 129          (itemlen == len2 && !strncmp(*listitem, buf, len2)) ||
 130          !strcmp(*listitem, fname)) {
 131         show = !show;
 132        break;
 133       }
 134     }
 135     return show;
 136   }
 137   return 1;
 138 }
 139
 140 void
 141 SNOOP_RegisterDLL(HMODULE hmod,LPCSTR name,DWORD nrofordinals) {
 142         SNOOP_DLL       **dll = &(firstdll);
 143         char            *s;
 144
 145         if (!TRACE_ON(snoop)) return;
 146         while (*dll) {
 147                 if ((*dll)->hmod == hmod)
 148                         return; /* already registered */
 149                 dll = &((*dll)->next);
 150         }
 151         *dll = (SNOOP_DLL*)HeapAlloc(SystemHeap,HEAP_ZERO_MEMORY,sizeof(SNOOP_DLL));
 152         (*dll)->next    = NULL;
 153         (*dll)->hmod    = hmod;
 154         (*dll)->nrofordinals = nrofordinals;
 155         (*dll)->name    = HEAP_strdupA(SystemHeap,0,name);
 156         if ((s=strrchr((*dll)->name,'.')))
 157                 *s='\0';
 158         (*dll)->funs = VirtualAlloc(NULL,nrofordinals*sizeof(SNOOP_FUN),MEM_COMMIT|MEM_RESERVE,PAGE_EXECUTE_READWRITE);
 159         memset((*dll)->funs,0,nrofordinals*sizeof(SNOOP_FUN));
 160         if (!(*dll)->funs) {
 161                 HeapFree(SystemHeap,0,*dll);
 162                 FIXME(snoop,"out of memory\n");
 163                 return;
 164         }
 165 }
 166
 167 FARPROC
 168 SNOOP_GetProcAddress(HMODULE hmod,LPCSTR name,DWORD ordinal,FARPROC origfun) {
 169         SNOOP_DLL                       *dll = firstdll;
 170         SNOOP_FUN                       *fun;
 171         int                             j;
 172         IMAGE_SECTION_HEADER            *pe_seg = PE_SECTIONS(hmod);
 173
 174         if (!TRACE_ON(snoop)) return origfun;
 175         if (!*(LPBYTE)origfun) /* 0x00 is an imposs. opcode, poss. dataref. */
 176                 return origfun;
 177         for (j=0;j<PE_HEADER(hmod)->FileHeader.NumberOfSections;j++)
 178                 /* 0x42 is special ELF loader tag */
 179                 if ((pe_seg[j].VirtualAddress==0x42) ||
 180                     (((DWORD)origfun-hmod>=pe_seg[j].VirtualAddress)&&
 181                      ((DWORD)origfun-hmod <pe_seg[j].VirtualAddress+
 182                                    pe_seg[j].SizeOfRawData
 183                    ))
 184                 )
 185                         break;
 186         /* If we looked through all sections (and didn't find one)
 187          * or if the sectionname contains "data", we return the
 188          * original function since it is most likely a datareference.
 189          */
 190         if (    (j==PE_HEADER(hmod)->FileHeader.NumberOfSections)       ||
 191                 (strstr(pe_seg[j].Name,"data"))                         ||
 192                 !(pe_seg[j].Characteristics & IMAGE_SCN_CNT_CODE)
 193         )
 194                 return origfun;
 195
 196         while (dll) {
 197                 if (hmod == dll->hmod)
 198                         break;
 199                 dll=dll->next;
 200         }
 201         if (!dll)       /* probably internal */
 202                 return origfun;
 203         if (!SNOOP_ShowDebugmsgSnoop(dll->name,ordinal,name))
 204                 return origfun;
 205         assert(ordinal<dll->nrofordinals);
 206         fun = dll->funs+ordinal;
 207         if (!fun->name) fun->name = HEAP_strdupA(SystemHeap,0,name);
 208         fun->lcall      = 0xe8;
 209         /* NOTE: origreturn struct member MUST come directly after snoopentry */
 210         fun->snoopentry = (char*)SNOOP_Entry-((char*)(&fun->nrofargs));
 211         fun->origfun    = origfun;
 212         fun->nrofargs   = -1;
 213         return (FARPROC)&(fun->lcall);
 214 }
 215
 216 static char*
 217 SNOOP_PrintArg(DWORD x) {
 218         static char     buf[200];
 219         int             i,nostring;
 220         MEMORY_BASIC_INFORMATION        mbi;
 221
 222         if (    !HIWORD(x)                                      ||
 223                 !VirtualQuery((LPVOID)x,&mbi,sizeof(mbi))       ||
 224                 !mbi.Type
 225         ) {
 226                 sprintf(buf,"%08lx",x);
 227                 return buf;
 228         }
 229         i=0;nostring=0;
 230         if (!IsBadStringPtrA((LPSTR)x,80)) {
 231                 while (i<80) {
 232                         LPBYTE  s=(LPBYTE)x;
 233
 234                         if (s[i]==0) break;
 235                         if (s[i]<0x20) {nostring=1;break;}
 236                         if (s[i]>=0x80) {nostring=1;break;}
 237                         i++;
 238                 }
 239                 if (!nostring) {
 240                         if (i>5) {
 241                                 sprintf(buf,"%08lx \"",x);
 242                                 strncat(buf,(LPSTR)x,198-strlen(buf)-2);
 243                                 strcat(buf,"\"");
 244                                 return buf;
 245                         }
 246                 }
 247         }
 248         i=0;nostring=0;
 249         if (!IsBadStringPtrW((LPWSTR)x,80)) {
 250                 while (i<80) {
 251                         LPWSTR  s=(LPWSTR)x;
 252
 253                         if (s[i]==0) break;
 254                         if (s[i]<0x20) {nostring=1;break;}
 255                         if (s[i]>0x100) {nostring=1;break;}
 256                         i++;
 257                 }
 258                 if (!nostring) {
 259                         if (i>5) {
 260                                 sprintf(buf,"%08lx L",x);
 261                                 strcat(buf,debugstr_wn((LPWSTR)x,198-strlen(buf)-2));
 262                                 return buf;
 263                         }
 264                 }
 265         }
 266         sprintf(buf,"%08lx",x);
 267         return buf;
 268 }
 269
 270 #define CALLER1REF (*(DWORD*)(ESP_reg(context)+4))
 271 REGS_ENTRYPOINT(SNOOP_Entry) {
 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(snoop,"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)+8+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(SystemHeap,0,16*sizeof(DWORD));
 345                 memcpy(ret->args,(LPBYTE)(ESP_reg(context)+8),sizeof(DWORD)*16);
 346         }
 347         DPRINTF(") ret=%08lx fs=%04lx\n",(DWORD)ret->origreturn,FS_reg(context));
 348 }
 349
 350 REGS_ENTRYPOINT(SNOOP_Return) {
 351         SNOOP_RETURNENTRY       *ret = (SNOOP_RETURNENTRY*)(EIP_reg(context)-5);
 352
 353         /* We haven't found out the nrofargs yet. If we called a cdecl
 354          * function it is too late anyway and we can just set '0' (which
 355          * will be the difference between orig and current ESP
 356          * If stdcall -> everything ok.
 357          */
 358         if (ret->dll->funs[ret->ordinal].nrofargs<0)
 359                 ret->dll->funs[ret->ordinal].nrofargs=(ESP_reg(context)-ret->origESP-4)/4;
 360         EIP_reg(context) = (DWORD)ret->origreturn;
 361         if (ret->args) {
 362                 int     i,max;
 363
 364                 DPRINTF("Ret  %s.%ld: %s(",ret->dll->name,ret->ordinal,ret->dll->funs[ret->ordinal].name);
 365                 max = ret->dll->funs[ret->ordinal].nrofargs;
 366                 if (max>16) max=16;
 367
 368                 for (i=0;i<max;i++)
 369                         DPRINTF("%s%s",SNOOP_PrintArg(ret->args[i]),(i<max-1)?",":"");
 370                 DPRINTF(") retval = %08lx ret=%08lx fs=%04lx\n",
 371                         EAX_reg(context),(DWORD)ret->origreturn,FS_reg(context)
 372                 );
 373                 HeapFree(SystemHeap,0,ret->args);
 374                 ret->args = NULL;
 375         } else
 376                 DPRINTF("Ret  %s.%ld: %s() retval = %08lx ret=%08lx fs=%04lx\n",
 377                         ret->dll->name,ret->ordinal,ret->dll->funs[ret->ordinal].name,
 378                         EAX_reg(context),(DWORD)ret->origreturn,FS_reg(context)
 379                 );
 380         ret->origreturn = NULL; /* mark as empty */
 381 }
 382 #else   /* !__i386__ */
 383 void SNOOP_RegisterDLL(HMODULE hmod,LPCSTR name,DWORD nrofordinals) {
 384         FIXME(snoop,"snooping works only on i386 for now.\n");
 385         return;
 386 }
 387
 388 FARPROC SNOOP_GetProcAddress(HMODULE hmod,LPCSTR name,DWORD ordinal,FARPROC origfun) {
 389         return origfun;
 390 }
 391 #endif  /* !__i386__ */