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 "windows.h"
  10 #include "winbase.h"
  11 #include "winnt.h"
  12 #include "heap.h"
  13 #include "builtin32.h"
  14 #include "snoop.h"
  15 #include "peexe.h"
  16 #include "selectors.h"
  17 #include "stackframe.h"
  18 #include "debugstr.h"
  19 #include "debug.h"
  20
  21 #ifdef __i386__
  22
  23 char **debug_snoop_excludelist = NULL, **debug_snoop_includelist = NULL;
  24
  25 #ifdef NEED_UNDERSCORE_PREFIX
  26 # define PREFIX "_"
  27 #else
  28 # define PREFIX
  29 #endif
  30
  31 /* Well, not exactly extern since they are in the same file (in the lines
  32  * below). But the C Compiler doesn't see them there, so we have to help a bit.
  33  */
  34 extern void SNOOP_Return();
  35 extern void SNOOP_Entry();
  36 __asm__(".align 4\n\t"
  37         ".globl "PREFIX"SNOOP_Entry\n\t"
  38         ".type "PREFIX"SNOOP_Entry,@function\n\t"
  39         PREFIX"SNOOP_Entry:\n\t"
  40         "pushl $"PREFIX"__regs_SNOOP_Entry\n\t"
  41         "pushl $"PREFIX"CALL32_Regs\n\t"
  42         "ret\n\t"
  43         ".align 4\n\t"
  44         ".globl "PREFIX"SNOOP_Return\n\t"
  45         ".type "PREFIX"SNOOP_Return,@function\n\t"
  46         PREFIX"SNOOP_Return:\n\t"
  47         "pushl $"PREFIX"__regs_SNOOP_Return\n\t"
  48         "pushl $"PREFIX"CALL32_Regs\n\t"
  49         "ret"
  50 );
  51
  52 #pragma pack(1)
  53
  54 typedef struct tagSNOOP_FUN {
  55         /* code part */
  56         BYTE            lcall;          /* 0xe8 call snoopentry (relative) */
  57         /* NOTE: If you move snoopentry OR nrofargs fix the relative offset
  58          * calculation!
  59          */
  60         DWORD           snoopentry;     /* SNOOP_Entry relative */
  61         /* unreached */
  62         int             nrofargs;
  63         FARPROC32       origfun;
  64         char            *name;
  65 } SNOOP_FUN;
  66
  67 typedef struct tagSNOOP_DLL {
  68         HMODULE32       hmod;
  69         SNOOP_FUN       *funs;
  70         LPCSTR          name;
  71         int             nrofordinals;
  72         struct tagSNOOP_DLL     *next;
  73 } SNOOP_DLL;
  74 typedef struct tagSNOOP_RETURNENTRY {
  75         /* code part */
  76         BYTE            lcall;          /* 0xe8 call snoopret relative*/
  77         /* NOTE: If you move snoopret OR origreturn fix the relative offset
  78          * calculation!
  79          */
  80         DWORD           snoopret;       /* SNOOP_Ret relative */
  81         /* unreached */
  82         FARPROC32       origreturn;
  83         SNOOP_DLL       *dll;
  84         DWORD           ordinal;
  85         DWORD           origESP;
  86         DWORD           *args;          /* saved args across a stdcall */
  87 } SNOOP_RETURNENTRY;
  88
  89 typedef struct tagSNOOP_RETURNENTRIES {
  90         SNOOP_RETURNENTRY entry[4092/sizeof(SNOOP_RETURNENTRY)];
  91         struct tagSNOOP_RETURNENTRIES   *next;
  92 } SNOOP_RETURNENTRIES;
  93
  94 #pragma pack(4)
  95
  96 static  SNOOP_DLL               *firstdll = NULL;
  97 static  SNOOP_RETURNENTRIES     *firstrets = NULL;
  98
  99 /***********************************************************************
 100  *          SNOOP_ShowDebugmsgSnoop
 101  *
 102  * Simple function to decide if a particular debugging message is
 103  * wanted.
 104  */
 105 int SNOOP_ShowDebugmsgSnoop(const char *dll, int ord, const char *fname) {
 106
 107   if(debug_snoop_excludelist || debug_snoop_includelist) {
 108     char **listitem;
 109     char buf[80];
 110     int len, len2, itemlen, show;
 111
 112     if(debug_snoop_excludelist) {
 113       show = 1;
 114       listitem = debug_snoop_excludelist;
 115     } else {
 116       show = 0;
 117       listitem = debug_snoop_includelist;
 118     }
 119     len = strlen(dll);
 120     assert(len < 64);
 121     sprintf(buf, "%s.%d", dll, ord);
 122     len2 = strlen(buf);
 123     for(; *listitem; listitem++) {
 124       itemlen = strlen(*listitem);
 125       if((itemlen == len && !strncmp(*listitem, buf, len)) ||
 126          (itemlen == len2 && !strncmp(*listitem, buf, len2)) ||
 127          !strcmp(*listitem, fname)) {
 128         show = !show;
 129        break;
 130       }
 131     }
 132     return show;
 133   }
 134   return 1;
 135 }
 136
 137 void
 138 SNOOP_RegisterDLL(HMODULE32 hmod,LPCSTR name,DWORD nrofordinals) {
 139         SNOOP_DLL       **dll = &(firstdll);
 140         char            *s;
 141
 142         if (!TRACE_ON(snoop)) return;
 143         while (*dll) {
 144                 if ((*dll)->hmod == hmod)
 145                         return; /* already registered */
 146                 dll = &((*dll)->next);
 147         }
 148         *dll = (SNOOP_DLL*)HeapAlloc(SystemHeap,HEAP_ZERO_MEMORY,sizeof(SNOOP_DLL));
 149         (*dll)->next    = NULL;
 150         (*dll)->hmod    = hmod;
 151         (*dll)->nrofordinals = nrofordinals;
 152         (*dll)->name    = HEAP_strdupA(SystemHeap,0,name);
 153         if ((s=strrchr((*dll)->name,'.')))
 154                 *s='\0';
 155         (*dll)->funs = VirtualAlloc(NULL,nrofordinals*sizeof(SNOOP_FUN),MEM_COMMIT|MEM_RESERVE,PAGE_EXECUTE_READWRITE);
 156         memset((*dll)->funs,0,nrofordinals*sizeof(SNOOP_FUN));
 157         if (!(*dll)->funs) {
 158                 HeapFree(SystemHeap,0,*dll);
 159                 FIXME(snoop,"out of memory\n");
 160                 return;
 161         }
 162 }
 163
 164 FARPROC32
 165 SNOOP_GetProcAddress32(HMODULE32 hmod,LPCSTR name,DWORD ordinal,FARPROC32 origfun) {
 166         SNOOP_DLL                       *dll = firstdll;
 167         SNOOP_FUN                       *fun;
 168         int                             j;
 169         IMAGE_SECTION_HEADER            *pe_seg = PE_SECTIONS(hmod);
 170
 171         if (!TRACE_ON(snoop)) return origfun;
 172         if (!*(LPBYTE)origfun) /* 0x00 is an imposs. opcode, poss. dataref. */
 173                 return origfun;
 174         for (j=0;j<PE_HEADER(hmod)->FileHeader.NumberOfSections;j++)
 175                 /* 0x42 is special ELF loader tag */
 176                 if ((pe_seg[j].VirtualAddress==0x42) ||
 177                     (((DWORD)origfun-hmod>=pe_seg[j].VirtualAddress)&&
 178                      ((DWORD)origfun-hmod <pe_seg[j].VirtualAddress+
 179                                    pe_seg[j].SizeOfRawData
 180                    ))
 181                 )
 182                         break;
 183         /* If we looked through all sections (and didn't find one)
 184          * or if the sectionname contains "data", we return the
 185          * original function since it is most likely a datareference.
 186          */
 187         if (    (j==PE_HEADER(hmod)->FileHeader.NumberOfSections)       ||
 188                 (strstr(pe_seg[j].Name,"data"))                         ||
 189                 !(pe_seg[j].Characteristics & IMAGE_SCN_CNT_CODE)
 190         )
 191                 return origfun;
 192
 193         while (dll) {
 194                 if (hmod == dll->hmod)
 195                         break;
 196                 dll=dll->next;
 197         }
 198         if (!dll)       /* probably internal */
 199                 return origfun;
 200         if (!SNOOP_ShowDebugmsgSnoop(dll->name,ordinal,name))
 201                 return origfun;
 202         assert(ordinal<dll->nrofordinals);
 203         fun = dll->funs+ordinal;
 204         if (!fun->name) fun->name = HEAP_strdupA(SystemHeap,0,name);
 205         fun->lcall      = 0xe8;
 206         /* NOTE: origreturn struct member MUST come directly after snoopentry */
 207         fun->snoopentry = (char*)SNOOP_Entry-((char*)(&fun->nrofargs));
 208         fun->origfun    = origfun;
 209         fun->nrofargs   = -1;
 210         return (FARPROC32)&(fun->lcall);
 211 }
 212
 213 static char*
 214 SNOOP_PrintArg(DWORD x) {
 215         static char     buf[200];
 216         int             i,nostring;
 217         MEMORY_BASIC_INFORMATION        mbi;
 218
 219         if (    !HIWORD(x)                                      ||
 220                 !VirtualQuery((LPVOID)x,&mbi,sizeof(mbi))       ||
 221                 !mbi.Type
 222         ) {
 223                 sprintf(buf,"%08lx",x);
 224                 return buf;
 225         }
 226         i=0;nostring=0;
 227         if (!IsBadStringPtr32A((LPSTR)x,80)) {
 228                 while (i<80) {
 229                         LPBYTE  s=(LPBYTE)x;
 230
 231                         if (s[i]==0) break;
 232                         if (s[i]<0x20) {nostring=1;break;}
 233                         if (s[i]>=0x80) {nostring=1;break;}
 234                         i++;
 235                 }
 236                 if (!nostring) {
 237                         if (i>5) {
 238                                 sprintf(buf,"%08lx \"",x);
 239                                 strncat(buf,(LPSTR)x,198-strlen(buf)-2);
 240                                 strcat(buf,"\"");
 241                                 return buf;
 242                         }
 243                 }
 244         }
 245         i=0;nostring=0;
 246         if (!IsBadStringPtr32W((LPWSTR)x,80)) {
 247                 while (i<80) {
 248                         LPWSTR  s=(LPWSTR)x;
 249
 250                         if (s[i]==0) break;
 251                         if (s[i]<0x20) {nostring=1;break;}
 252                         if (s[i]>0x100) {nostring=1;break;}
 253                         i++;
 254                 }
 255                 if (!nostring) {
 256                         if (i>5) {
 257                                 sprintf(buf,"%08lx L",x);
 258                                 strcat(buf,debugstr_wn((LPWSTR)x,198-strlen(buf)-2));
 259                                 return buf;
 260                         }
 261                 }
 262         }
 263         sprintf(buf,"%08lx",x);
 264         return buf;
 265 }
 266
 267 #define CALLER1REF (*(DWORD*)(ESP_reg(context)+4))
 268 REGS_ENTRYPOINT(SNOOP_Entry) {
 269         DWORD           ordinal=0,entry = EIP_reg(context)-5;
 270         SNOOP_DLL       *dll = firstdll;
 271         SNOOP_FUN       *fun = NULL;
 272         SNOOP_RETURNENTRIES     **rets = &firstrets;
 273         SNOOP_RETURNENTRY       *ret;
 274         int             i,max;
 275
 276         while (dll) {
 277                 if (    ((char*)entry>=(char*)dll->funs)        &&
 278                         ((char*)entry<=(char*)(dll->funs+dll->nrofordinals))
 279                 ) {
 280                         fun = (SNOOP_FUN*)entry;
 281                         ordinal = fun-dll->funs;
 282                         break;
 283                 }
 284                 dll=dll->next;
 285         }
 286         if (!dll) {
 287                 FIXME(snoop,"entrypoint 0x%08lx not found\n",entry);
 288                 return; /* oops */
 289         }
 290         /* guess cdecl ... */
 291         if (fun->nrofargs<0) {
 292                 /* Typical cdecl return frame is:
 293                  *      add esp, xxxxxxxx
 294                  * which has (for xxxxxxxx up to 255 the opcode "83 C4 xx".
 295                  * (after that 81 C2 xx xx xx xx)
 296                  */
 297                 LPBYTE  reteip = (LPBYTE)CALLER1REF;
 298
 299                 if (reteip) {
 300                         if ((reteip[0]==0x83)&&(reteip[1]==0xc4))
 301                                 fun->nrofargs=reteip[2]/4;
 302                 }
 303         }
 304
 305
 306         while (*rets) {
 307                 for (i=0;i<sizeof((*rets)->entry)/sizeof((*rets)->entry[0]);i++)
 308                         if (!(*rets)->entry[i].origreturn)
 309                                 break;
 310                 if (i!=sizeof((*rets)->entry)/sizeof((*rets)->entry[0]))
 311                         break;
 312                 rets = &((*rets)->next);
 313         }
 314         if (!*rets) {
 315                 *rets = VirtualAlloc(NULL,4096,MEM_COMMIT|MEM_RESERVE,PAGE_EXECUTE_READWRITE);
 316                 memset(*rets,0,4096);
 317                 i = 0;  /* entry 0 is free */
 318         }
 319         ret = &((*rets)->entry[i]);
 320         ret->lcall      = 0xe8;
 321         /* NOTE: origreturn struct member MUST come directly after snoopret */
 322         ret->snoopret   = ((char*)SNOOP_Return)-(char*)(&ret->origreturn);
 323         ret->origreturn = (FARPROC32)CALLER1REF;
 324         CALLER1REF      = (DWORD)&ret->lcall;
 325         ret->dll        = dll;
 326         ret->args       = NULL;
 327         ret->ordinal    = ordinal;
 328         ret->origESP    = ESP_reg(context);
 329
 330         EIP_reg(context)= (DWORD)fun->origfun;
 331
 332         DPRINTF("Call %s.%ld: %s(",dll->name,ordinal,fun->name);
 333         if (fun->nrofargs>0) {
 334                 max = fun->nrofargs; if (max>16) max=16;
 335                 for (i=0;i<max;i++)
 336                         DPRINTF("%s%s",SNOOP_PrintArg(*(DWORD*)(ESP_reg(context)+8+sizeof(DWORD)*i)),(i<fun->nrofargs-1)?",":"");
 337                 if (max!=fun->nrofargs)
 338                         DPRINTF(" ...");
 339         } else if (fun->nrofargs<0) {
 340                 DPRINTF("<unknown, check return>");
 341                 ret->args = HeapAlloc(SystemHeap,0,16*sizeof(DWORD));
 342                 memcpy(ret->args,(LPBYTE)(ESP_reg(context)+8),sizeof(DWORD)*16);
 343         }
 344         DPRINTF(") ret=%08lx fs=%04lx\n",(DWORD)ret->origreturn,FS_reg(context));
 345 }
 346
 347 REGS_ENTRYPOINT(SNOOP_Return) {
 348         SNOOP_RETURNENTRY       *ret = (SNOOP_RETURNENTRY*)(EIP_reg(context)-5);
 349
 350         /* We haven't found out the nrofargs yet. If we called a cdecl
 351          * function it is too late anyway and we can just set '0' (which
 352          * will be the difference between orig and current ESP
 353          * If stdcall -> everything ok.
 354          */
 355         if (ret->dll->funs[ret->ordinal].nrofargs<0)
 356                 ret->dll->funs[ret->ordinal].nrofargs=(ESP_reg(context)-ret->origESP-4)/4;
 357         EIP_reg(context) = (DWORD)ret->origreturn;
 358         if (ret->args) {
 359                 int     i,max;
 360
 361                 DPRINTF("Ret  %s.%ld: %s(",ret->dll->name,ret->ordinal,ret->dll->funs[ret->ordinal].name);
 362                 max = ret->dll->funs[ret->ordinal].nrofargs;
 363                 if (max>16) max=16;
 364
 365                 for (i=0;i<max;i++)
 366                         DPRINTF("%s%s",SNOOP_PrintArg(ret->args[i]),(i<max-1)?",":"");
 367                 DPRINTF(") retval = %08lx ret=%08lx fs=%04lx\n",
 368                         EAX_reg(context),(DWORD)ret->origreturn,FS_reg(context)
 369                 );
 370                 HeapFree(SystemHeap,0,ret->args);
 371                 ret->args = NULL;
 372         } else
 373                 DPRINTF("Ret  %s.%ld: %s() retval = %08lx ret=%08lx fs=%04lx\n",
 374                         ret->dll->name,ret->ordinal,ret->dll->funs[ret->ordinal].name,
 375                         EAX_reg(context),(DWORD)ret->origreturn,FS_reg(context)
 376                 );
 377         ret->origreturn = NULL; /* mark as empty */
 378 }
 379 #else   /* !__i386__ */
 380 void SNOOP_RegisterDLL(HMODULE32 hmod,LPCSTR name,DWORD nrofordinals) {
 381         FIXME(snoop,"snooping works only on i386 for now.\n");
 382         return;
 383 }
 384
 385 FARPROC32 SNOOP_GetProcAddress32(HMODULE32 hmod,LPCSTR name,DWORD ordinal,FARPROC32 origfun) {
 386         return origfun;
 387 }
 388 #endif  /* !__i386__ */