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 char **debug_snoop_excludelist = NULL, **debug_snoop_includelist = NULL;
  23
  24 #ifdef __i386__
  25
  26 #ifdef NEED_UNDERSCORE_PREFIX
  27 # define PREFIX "_"
  28 #else
  29 # define PREFIX
  30 #endif
  31
  32 /* Well, not exactly extern since they are in the same file (in the lines
  33  * below). But the C Compiler doesn't see them there, so we have to help a bit.
  34  */
  35 extern void SNOOP_Return();
  36 extern void SNOOP_Entry();
  37 __asm__(".align 4\n\t"
  38         ".globl "PREFIX"SNOOP_Entry\n\t"
  39         ".type "PREFIX"SNOOP_Entry,@function\n\t"
  40         PREFIX"SNOOP_Entry:\n\t"
  41         "pushl $"PREFIX"__regs_SNOOP_Entry\n\t"
  42         "pushl $"PREFIX"CALL32_Regs\n\t"
  43         "ret\n\t"
  44         ".align 4\n\t"
  45         ".globl "PREFIX"SNOOP_Return\n\t"
  46         ".type "PREFIX"SNOOP_Return,@function\n\t"
  47         PREFIX"SNOOP_Return:\n\t"
  48         "pushl $"PREFIX"__regs_SNOOP_Return\n\t"
  49         "pushl $"PREFIX"CALL32_Regs\n\t"
  50         "ret"
  51 );
  52
  53 #pragma pack(1)
  54
  55 typedef struct tagSNOOP_FUN {
  56         /* code part */
  57         BYTE            lcall;          /* 0xe8 call snoopentry (relative) */
  58         /* NOTE: If you move snoopentry OR nrofargs fix the relative offset
  59          * calculation!
  60          */
  61         DWORD           snoopentry;     /* SNOOP_Entry relative */
  62         /* unreached */
  63         int             nrofargs;
  64         FARPROC origfun;
  65         char            *name;
  66 } SNOOP_FUN;
  67
  68 typedef struct tagSNOOP_DLL {
  69         HMODULE hmod;
  70         SNOOP_FUN       *funs;
  71         LPCSTR          name;
  72         int             nrofordinals;
  73         struct tagSNOOP_DLL     *next;
  74 } SNOOP_DLL;
  75 typedef struct tagSNOOP_RETURNENTRY {
  76         /* code part */
  77         BYTE            lcall;          /* 0xe8 call snoopret relative*/
  78         /* NOTE: If you move snoopret OR origreturn fix the relative offset
  79          * calculation!
  80          */
  81         DWORD           snoopret;       /* SNOOP_Ret relative */
  82         /* unreached */
  83         FARPROC origreturn;
  84         SNOOP_DLL       *dll;
  85         DWORD           ordinal;
  86         DWORD           origESP;
  87         DWORD           *args;          /* saved args across a stdcall */
  88 } SNOOP_RETURNENTRY;
  89
  90 typedef struct tagSNOOP_RETURNENTRIES {
  91         SNOOP_RETURNENTRY entry[4092/sizeof(SNOOP_RETURNENTRY)];
  92         struct tagSNOOP_RETURNENTRIES   *next;
  93 } SNOOP_RETURNENTRIES;
  94
  95 #pragma pack(4)
  96
  97 static  SNOOP_DLL               *firstdll = NULL;
  98 static  SNOOP_RETURNENTRIES     *firstrets = NULL;
  99
 100 /***********************************************************************
 101  *          SNOOP_ShowDebugmsgSnoop
 102  *
 103  * Simple function to decide if a particular debugging message is
 104  * wanted.
 105  */
 106 int SNOOP_ShowDebugmsgSnoop(const char *dll, int ord, const char *fname) {
 107
 108   if(debug_snoop_excludelist || debug_snoop_includelist) {
 109     char **listitem;
 110     char buf[80];
 111     int len, len2, itemlen, show;
 112
 113     if(debug_snoop_excludelist) {
 114       show = 1;
 115       listitem = debug_snoop_excludelist;
 116     } else {
 117       show = 0;
 118       listitem = debug_snoop_includelist;
 119     }
 120     len = strlen(dll);
 121     assert(len < 64);
 122     sprintf(buf, "%s.%d", dll, ord);
 123     len2 = strlen(buf);
 124     for(; *listitem; listitem++) {
 125       itemlen = strlen(*listitem);
 126       if((itemlen == len && !strncmp(*listitem, buf, len)) ||
 127          (itemlen == len2 && !strncmp(*listitem, buf, len2)) ||
 128          !strcmp(*listitem, fname)) {
 129         show = !show;
 130        break;
 131       }
 132     }
 133     return show;
 134   }
 135   return 1;
 136 }
 137
 138 void
 139 SNOOP_RegisterDLL(HMODULE hmod,LPCSTR name,DWORD nrofordinals) {
 140         SNOOP_DLL       **dll = &(firstdll);
 141         char            *s;
 142
 143         if (!TRACE_ON(snoop)) return;
 144         while (*dll) {
 145                 if ((*dll)->hmod == hmod)
 146                         return; /* already registered */
 147                 dll = &((*dll)->next);
 148         }
 149         *dll = (SNOOP_DLL*)HeapAlloc(SystemHeap,HEAP_ZERO_MEMORY,sizeof(SNOOP_DLL));
 150         (*dll)->next    = NULL;
 151         (*dll)->hmod    = hmod;
 152         (*dll)->nrofordinals = nrofordinals;
 153         (*dll)->name    = HEAP_strdupA(SystemHeap,0,name);
 154         if ((s=strrchr((*dll)->name,'.')))
 155                 *s='\0';
 156         (*dll)->funs = VirtualAlloc(NULL,nrofordinals*sizeof(SNOOP_FUN),MEM_COMMIT|MEM_RESERVE,PAGE_EXECUTE_READWRITE);
 157         memset((*dll)->funs,0,nrofordinals*sizeof(SNOOP_FUN));
 158         if (!(*dll)->funs) {
 159                 HeapFree(SystemHeap,0,*dll);
 160                 FIXME(snoop,"out of memory\n");
 161                 return;
 162         }
 163 }
 164
 165 FARPROC
 166 SNOOP_GetProcAddress(HMODULE hmod,LPCSTR name,DWORD ordinal,FARPROC origfun) {
 167         SNOOP_DLL                       *dll = firstdll;
 168         SNOOP_FUN                       *fun;
 169         int                             j;
 170         IMAGE_SECTION_HEADER            *pe_seg = PE_SECTIONS(hmod);
 171
 172         if (!TRACE_ON(snoop)) return origfun;
 173         if (!*(LPBYTE)origfun) /* 0x00 is an imposs. opcode, poss. dataref. */
 174                 return origfun;
 175         for (j=0;j<PE_HEADER(hmod)->FileHeader.NumberOfSections;j++)
 176                 /* 0x42 is special ELF loader tag */
 177                 if ((pe_seg[j].VirtualAddress==0x42) ||
 178                     (((DWORD)origfun-hmod>=pe_seg[j].VirtualAddress)&&
 179                      ((DWORD)origfun-hmod <pe_seg[j].VirtualAddress+
 180                                    pe_seg[j].SizeOfRawData
 181                    ))
 182                 )
 183                         break;
 184         /* If we looked through all sections (and didn't find one)
 185          * or if the sectionname contains "data", we return the
 186          * original function since it is most likely a datareference.
 187          */
 188         if (    (j==PE_HEADER(hmod)->FileHeader.NumberOfSections)       ||
 189                 (strstr(pe_seg[j].Name,"data"))                         ||
 190                 !(pe_seg[j].Characteristics & IMAGE_SCN_CNT_CODE)
 191         )
 192                 return origfun;
 193
 194         while (dll) {
 195                 if (hmod == dll->hmod)
 196                         break;
 197                 dll=dll->next;
 198         }
 199         if (!dll)       /* probably internal */
 200                 return origfun;
 201         if (!SNOOP_ShowDebugmsgSnoop(dll->name,ordinal,name))
 202                 return origfun;
 203         assert(ordinal<dll->nrofordinals);
 204         fun = dll->funs+ordinal;
 205         if (!fun->name) fun->name = HEAP_strdupA(SystemHeap,0,name);
 206         fun->lcall      = 0xe8;
 207         /* NOTE: origreturn struct member MUST come directly after snoopentry */
 208         fun->snoopentry = (char*)SNOOP_Entry-((char*)(&fun->nrofargs));
 209         fun->origfun    = origfun;
 210         fun->nrofargs   = -1;
 211         return (FARPROC)&(fun->lcall);
 212 }
 213
 214 static char*
 215 SNOOP_PrintArg(DWORD x) {
 216         static char     buf[200];
 217         int             i,nostring;
 218         MEMORY_BASIC_INFORMATION        mbi;
 219
 220         if (    !HIWORD(x)                                      ||
 221                 !VirtualQuery((LPVOID)x,&mbi,sizeof(mbi))       ||
 222                 !mbi.Type
 223         ) {
 224                 sprintf(buf,"%08lx",x);
 225                 return buf;
 226         }
 227         i=0;nostring=0;
 228         if (!IsBadStringPtrA((LPSTR)x,80)) {
 229                 while (i<80) {
 230                         LPBYTE  s=(LPBYTE)x;
 231
 232                         if (s[i]==0) break;
 233                         if (s[i]<0x20) {nostring=1;break;}
 234                         if (s[i]>=0x80) {nostring=1;break;}
 235                         i++;
 236                 }
 237                 if (!nostring) {
 238                         if (i>5) {
 239                                 sprintf(buf,"%08lx \"",x);
 240                                 strncat(buf,(LPSTR)x,198-strlen(buf)-2);
 241                                 strcat(buf,"\"");
 242                                 return buf;
 243                         }
 244                 }
 245         }
 246         i=0;nostring=0;
 247         if (!IsBadStringPtrW((LPWSTR)x,80)) {
 248                 while (i<80) {
 249                         LPWSTR  s=(LPWSTR)x;
 250
 251                         if (s[i]==0) break;
 252                         if (s[i]<0x20) {nostring=1;break;}
 253                         if (s[i]>0x100) {nostring=1;break;}
 254                         i++;
 255                 }
 256                 if (!nostring) {
 257                         if (i>5) {
 258                                 sprintf(buf,"%08lx L",x);
 259                                 strcat(buf,debugstr_wn((LPWSTR)x,198-strlen(buf)-2));
 260                                 return buf;
 261                         }
 262                 }
 263         }
 264         sprintf(buf,"%08lx",x);
 265         return buf;
 266 }
 267
 268 #define CALLER1REF (*(DWORD*)(ESP_reg(context)+4))
 269 REGS_ENTRYPOINT(SNOOP_Entry) {
 270         DWORD           ordinal=0,entry = EIP_reg(context)-5;
 271         SNOOP_DLL       *dll = firstdll;
 272         SNOOP_FUN       *fun = NULL;
 273         SNOOP_RETURNENTRIES     **rets = &firstrets;
 274         SNOOP_RETURNENTRY       *ret;
 275         int             i,max;
 276
 277         while (dll) {
 278                 if (    ((char*)entry>=(char*)dll->funs)        &&
 279                         ((char*)entry<=(char*)(dll->funs+dll->nrofordinals))
 280                 ) {
 281                         fun = (SNOOP_FUN*)entry;
 282                         ordinal = fun-dll->funs;
 283                         break;
 284                 }
 285                 dll=dll->next;
 286         }
 287         if (!dll) {
 288                 FIXME(snoop,"entrypoint 0x%08lx not found\n",entry);
 289                 return; /* oops */
 290         }
 291         /* guess cdecl ... */
 292         if (fun->nrofargs<0) {
 293                 /* Typical cdecl return frame is:
 294                  *      add esp, xxxxxxxx
 295                  * which has (for xxxxxxxx up to 255 the opcode "83 C4 xx".
 296                  * (after that 81 C2 xx xx xx xx)
 297                  */
 298                 LPBYTE  reteip = (LPBYTE)CALLER1REF;
 299
 300                 if (reteip) {
 301                         if ((reteip[0]==0x83)&&(reteip[1]==0xc4))
 302                                 fun->nrofargs=reteip[2]/4;
 303                 }
 304         }
 305
 306
 307         while (*rets) {
 308                 for (i=0;i<sizeof((*rets)->entry)/sizeof((*rets)->entry[0]);i++)
 309                         if (!(*rets)->entry[i].origreturn)
 310                                 break;
 311                 if (i!=sizeof((*rets)->entry)/sizeof((*rets)->entry[0]))
 312                         break;
 313                 rets = &((*rets)->next);
 314         }
 315         if (!*rets) {
 316                 *rets = VirtualAlloc(NULL,4096,MEM_COMMIT|MEM_RESERVE,PAGE_EXECUTE_READWRITE);
 317                 memset(*rets,0,4096);
 318                 i = 0;  /* entry 0 is free */
 319         }
 320         ret = &((*rets)->entry[i]);
 321         ret->lcall      = 0xe8;
 322         /* NOTE: origreturn struct member MUST come directly after snoopret */
 323         ret->snoopret   = ((char*)SNOOP_Return)-(char*)(&ret->origreturn);
 324         ret->origreturn = (FARPROC)CALLER1REF;
 325         CALLER1REF      = (DWORD)&ret->lcall;
 326         ret->dll        = dll;
 327         ret->args       = NULL;
 328         ret->ordinal    = ordinal;
 329         ret->origESP    = ESP_reg(context);
 330
 331         EIP_reg(context)= (DWORD)fun->origfun;
 332
 333         DPRINTF("Call %s.%ld: %s(",dll->name,ordinal,fun->name);
 334         if (fun->nrofargs>0) {
 335                 max = fun->nrofargs; if (max>16) max=16;
 336                 for (i=0;i<max;i++)
 337                         DPRINTF("%s%s",SNOOP_PrintArg(*(DWORD*)(ESP_reg(context)+8+sizeof(DWORD)*i)),(i<fun->nrofargs-1)?",":"");
 338                 if (max!=fun->nrofargs)
 339                         DPRINTF(" ...");
 340         } else if (fun->nrofargs<0) {
 341                 DPRINTF("<unknown, check return>");
 342                 ret->args = HeapAlloc(SystemHeap,0,16*sizeof(DWORD));
 343                 memcpy(ret->args,(LPBYTE)(ESP_reg(context)+8),sizeof(DWORD)*16);
 344         }
 345         DPRINTF(") ret=%08lx fs=%04lx\n",(DWORD)ret->origreturn,FS_reg(context));
 346 }
 347
 348 REGS_ENTRYPOINT(SNOOP_Return) {
 349         SNOOP_RETURNENTRY       *ret = (SNOOP_RETURNENTRY*)(EIP_reg(context)-5);
 350
 351         /* We haven't found out the nrofargs yet. If we called a cdecl
 352          * function it is too late anyway and we can just set '0' (which
 353          * will be the difference between orig and current ESP
 354          * If stdcall -> everything ok.
 355          */
 356         if (ret->dll->funs[ret->ordinal].nrofargs<0)
 357                 ret->dll->funs[ret->ordinal].nrofargs=(ESP_reg(context)-ret->origESP-4)/4;
 358         EIP_reg(context) = (DWORD)ret->origreturn;
 359         if (ret->args) {
 360                 int     i,max;
 361
 362                 DPRINTF("Ret  %s.%ld: %s(",ret->dll->name,ret->ordinal,ret->dll->funs[ret->ordinal].name);
 363                 max = ret->dll->funs[ret->ordinal].nrofargs;
 364                 if (max>16) max=16;
 365
 366                 for (i=0;i<max;i++)
 367                         DPRINTF("%s%s",SNOOP_PrintArg(ret->args[i]),(i<max-1)?",":"");
 368                 DPRINTF(") retval = %08lx ret=%08lx fs=%04lx\n",
 369                         EAX_reg(context),(DWORD)ret->origreturn,FS_reg(context)
 370                 );
 371                 HeapFree(SystemHeap,0,ret->args);
 372                 ret->args = NULL;
 373         } else
 374                 DPRINTF("Ret  %s.%ld: %s() retval = %08lx ret=%08lx fs=%04lx\n",
 375                         ret->dll->name,ret->ordinal,ret->dll->funs[ret->ordinal].name,
 376                         EAX_reg(context),(DWORD)ret->origreturn,FS_reg(context)
 377                 );
 378         ret->origreturn = NULL; /* mark as empty */
 379 }
 380 #else   /* !__i386__ */
 381 void SNOOP_RegisterDLL(HMODULE hmod,LPCSTR name,DWORD nrofordinals) {
 382         FIXME(snoop,"snooping works only on i386 for now.\n");
 383         return;
 384 }
 385
 386 FARPROC SNOOP_GetProcAddress(HMODULE hmod,LPCSTR name,DWORD ordinal,FARPROC origfun) {
 387         return origfun;
 388 }
 389 #endif  /* !__i386__ */