2 * 386-specific Win32 dll<->dll snooping functions
4 * Copyright 1998 Marcus Meissner
16 #include "selectors.h"
17 #include "stackframe.h"
18 #include "debugtools.h"
19 #include "wine/exception.h"
21 DEFAULT_DEBUG_CHANNEL(snoop
);
23 static WINE_EXCEPTION_FILTER(page_fault
)
25 if (GetExceptionCode() == EXCEPTION_ACCESS_VIOLATION
||
26 GetExceptionCode() == EXCEPTION_PRIV_INSTRUCTION
)
27 return EXCEPTION_EXECUTE_HANDLER
;
28 return EXCEPTION_CONTINUE_SEARCH
;
31 char **debug_snoop_excludelist
= NULL
, **debug_snoop_includelist
= NULL
;
35 extern void WINAPI
SNOOP_Entry();
36 extern void WINAPI
SNOOP_Return();
38 #ifdef NEED_UNDERSCORE_PREFIX
46 typedef struct tagSNOOP_FUN
{
48 BYTE lcall
; /* 0xe8 call snoopentry (relative) */
49 /* NOTE: If you move snoopentry OR nrofargs fix the relative offset
52 DWORD snoopentry
; /* SNOOP_Entry relative */
59 typedef struct tagSNOOP_DLL
{
64 struct tagSNOOP_DLL
*next
;
66 typedef struct tagSNOOP_RETURNENTRY
{
68 BYTE lcall
; /* 0xe8 call snoopret relative*/
69 /* NOTE: If you move snoopret OR origreturn fix the relative offset
72 DWORD snoopret
; /* SNOOP_Ret relative */
78 DWORD
*args
; /* saved args across a stdcall */
81 typedef struct tagSNOOP_RETURNENTRIES
{
82 SNOOP_RETURNENTRY entry
[4092/sizeof(SNOOP_RETURNENTRY
)];
83 struct tagSNOOP_RETURNENTRIES
*next
;
84 } SNOOP_RETURNENTRIES
;
88 static SNOOP_DLL
*firstdll
= NULL
;
89 static SNOOP_RETURNENTRIES
*firstrets
= NULL
;
91 /***********************************************************************
92 * SNOOP_ShowDebugmsgSnoop
94 * Simple function to decide if a particular debugging message is
97 int SNOOP_ShowDebugmsgSnoop(const char *dll
, int ord
, const char *fname
) {
99 if(debug_snoop_excludelist
|| debug_snoop_includelist
) {
102 int len
, len2
, itemlen
, show
;
104 if(debug_snoop_excludelist
) {
106 listitem
= debug_snoop_excludelist
;
109 listitem
= debug_snoop_includelist
;
113 sprintf(buf
, "%s.%d", dll
, ord
);
115 for(; *listitem
; listitem
++) {
116 itemlen
= strlen(*listitem
);
117 if((itemlen
== len
&& !strncmp(*listitem
, buf
, len
)) ||
118 (itemlen
== len2
&& !strncmp(*listitem
, buf
, len2
)) ||
119 !strcmp(*listitem
, fname
)) {
130 SNOOP_RegisterDLL(HMODULE hmod
,LPCSTR name
,DWORD nrofordinals
) {
131 SNOOP_DLL
**dll
= &(firstdll
);
134 if (!TRACE_ON(snoop
)) return;
136 if ((*dll
)->hmod
== hmod
)
137 return; /* already registered */
138 dll
= &((*dll
)->next
);
140 *dll
= (SNOOP_DLL
*)HeapAlloc(GetProcessHeap(),HEAP_ZERO_MEMORY
,sizeof(SNOOP_DLL
));
143 (*dll
)->nrofordinals
= nrofordinals
;
144 (*dll
)->name
= HEAP_strdupA(GetProcessHeap(),0,name
);
145 if ((s
=strrchr((*dll
)->name
,'.')))
147 (*dll
)->funs
= VirtualAlloc(NULL
,nrofordinals
*sizeof(SNOOP_FUN
),MEM_COMMIT
|MEM_RESERVE
,PAGE_EXECUTE_READWRITE
);
148 memset((*dll
)->funs
,0,nrofordinals
*sizeof(SNOOP_FUN
));
150 HeapFree(GetProcessHeap(),0,*dll
);
151 FIXME("out of memory\n");
157 SNOOP_GetProcAddress(HMODULE hmod
,LPCSTR name
,DWORD ordinal
,FARPROC origfun
) {
158 SNOOP_DLL
*dll
= firstdll
;
161 IMAGE_SECTION_HEADER
*pe_seg
= PE_SECTIONS(hmod
);
163 if (!TRACE_ON(snoop
)) return origfun
;
164 if (!*(LPBYTE
)origfun
) /* 0x00 is an imposs. opcode, poss. dataref. */
166 for (j
=0;j
<PE_HEADER(hmod
)->FileHeader
.NumberOfSections
;j
++)
167 /* 0x42 is special ELF loader tag */
168 if ((pe_seg
[j
].VirtualAddress
==0x42) ||
169 (((DWORD
)origfun
-hmod
>=pe_seg
[j
].VirtualAddress
)&&
170 ((DWORD
)origfun
-hmod
<pe_seg
[j
].VirtualAddress
+
171 pe_seg
[j
].SizeOfRawData
175 /* If we looked through all sections (and didn't find one)
176 * or if the sectionname contains "data", we return the
177 * original function since it is most likely a datareference.
179 if ( (j
==PE_HEADER(hmod
)->FileHeader
.NumberOfSections
) ||
180 (strstr(pe_seg
[j
].Name
,"data")) ||
181 !(pe_seg
[j
].Characteristics
& IMAGE_SCN_CNT_CODE
)
186 if (hmod
== dll
->hmod
)
190 if (!dll
) /* probably internal */
192 if (!SNOOP_ShowDebugmsgSnoop(dll
->name
,ordinal
,name
))
194 assert(ordinal
< dll
->nrofordinals
);
195 fun
= dll
->funs
+ordinal
;
196 if (!fun
->name
) fun
->name
= HEAP_strdupA(GetProcessHeap(),0,name
);
198 /* NOTE: origreturn struct member MUST come directly after snoopentry */
199 fun
->snoopentry
= (char*)SNOOP_Entry
-((char*)(&fun
->nrofargs
));
200 fun
->origfun
= origfun
;
202 return (FARPROC
)&(fun
->lcall
);
206 SNOOP_PrintArg(DWORD x
) {
207 static char buf
[200];
209 char * volatile ret
=0;
211 if ( !HIWORD(x
) ) { /* trivial reject to avoid faults */
212 sprintf(buf
,"%08lx",x
);
220 if (s
[i
]<0x20) {nostring
=1;break;}
221 if (s
[i
]>=0x80) {nostring
=1;break;}
226 snprintf(buf
,sizeof(buf
),"%08lx %s",x
,debugstr_an((LPSTR
)x
,sizeof(buf
)-10));
231 __EXCEPT(page_fault
){}
240 if (s
[i
]<0x20) {nostring
=1;break;}
241 if (s
[i
]>0x100) {nostring
=1;break;}
246 snprintf(buf
,sizeof(buf
),"%08lx %s",x
,debugstr_wn((LPWSTR
)x
,sizeof(buf
)-10));
251 __EXCEPT(page_fault
){}
255 sprintf(buf
,"%08lx",x
);
259 #define CALLER1REF (*(DWORD*)context->Esp)
261 void WINAPI
SNOOP_DoEntry( CONTEXT86
*context
);
262 DEFINE_REGS_ENTRYPOINT_0( SNOOP_Entry
, SNOOP_DoEntry
);
263 void WINAPI
SNOOP_DoEntry( CONTEXT86
*context
)
265 DWORD ordinal
=0,entry
= context
->Eip
- 5;
266 SNOOP_DLL
*dll
= firstdll
;
267 SNOOP_FUN
*fun
= NULL
;
268 SNOOP_RETURNENTRIES
**rets
= &firstrets
;
269 SNOOP_RETURNENTRY
*ret
;
273 if ( ((char*)entry
>=(char*)dll
->funs
) &&
274 ((char*)entry
<=(char*)(dll
->funs
+dll
->nrofordinals
))
276 fun
= (SNOOP_FUN
*)entry
;
277 ordinal
= fun
-dll
->funs
;
283 FIXME("entrypoint 0x%08lx not found\n",entry
);
286 /* guess cdecl ... */
287 if (fun
->nrofargs
<0) {
288 /* Typical cdecl return frame is:
290 * which has (for xxxxxxxx up to 255 the opcode "83 C4 xx".
291 * (after that 81 C2 xx xx xx xx)
293 LPBYTE reteip
= (LPBYTE
)CALLER1REF
;
296 if ((reteip
[0]==0x83)&&(reteip
[1]==0xc4))
297 fun
->nrofargs
=reteip
[2]/4;
303 for (i
=0;i
<sizeof((*rets
)->entry
)/sizeof((*rets
)->entry
[0]);i
++)
304 if (!(*rets
)->entry
[i
].origreturn
)
306 if (i
!=sizeof((*rets
)->entry
)/sizeof((*rets
)->entry
[0]))
308 rets
= &((*rets
)->next
);
311 *rets
= VirtualAlloc(NULL
,4096,MEM_COMMIT
|MEM_RESERVE
,PAGE_EXECUTE_READWRITE
);
312 memset(*rets
,0,4096);
313 i
= 0; /* entry 0 is free */
315 ret
= &((*rets
)->entry
[i
]);
317 /* NOTE: origreturn struct member MUST come directly after snoopret */
318 ret
->snoopret
= ((char*)SNOOP_Return
)-(char*)(&ret
->origreturn
);
319 ret
->origreturn
= (FARPROC
)CALLER1REF
;
320 CALLER1REF
= (DWORD
)&ret
->lcall
;
323 ret
->ordinal
= ordinal
;
324 ret
->origESP
= context
->Esp
;
326 context
->Eip
= (DWORD
)fun
->origfun
;
328 DPRINTF("CALL %s.%ld: %s(",dll
->name
,ordinal
,fun
->name
);
329 if (fun
->nrofargs
>0) {
330 max
= fun
->nrofargs
; if (max
>16) max
=16;
332 DPRINTF("%s%s",SNOOP_PrintArg(*(DWORD
*)(context
->Esp
+ 4 + sizeof(DWORD
)*i
)),(i
<fun
->nrofargs
-1)?",":"");
333 if (max
!=fun
->nrofargs
)
335 } else if (fun
->nrofargs
<0) {
336 DPRINTF("<unknown, check return>");
337 ret
->args
= HeapAlloc(GetProcessHeap(),0,16*sizeof(DWORD
));
338 memcpy(ret
->args
,(LPBYTE
)(context
->Esp
+ 4),sizeof(DWORD
)*16);
340 DPRINTF(") ret=%08lx fs=%04lx\n",(DWORD
)ret
->origreturn
,context
->SegFs
);
343 void WINAPI
SNOOP_DoReturn( CONTEXT86
*context
);
344 DEFINE_REGS_ENTRYPOINT_0( SNOOP_Return
, SNOOP_DoReturn
);
345 void WINAPI
SNOOP_DoReturn( CONTEXT86
*context
)
347 SNOOP_RETURNENTRY
*ret
= (SNOOP_RETURNENTRY
*)(context
->Eip
- 5);
349 /* We haven't found out the nrofargs yet. If we called a cdecl
350 * function it is too late anyway and we can just set '0' (which
351 * will be the difference between orig and current ESP
352 * If stdcall -> everything ok.
354 if (ret
->dll
->funs
[ret
->ordinal
].nrofargs
<0)
355 ret
->dll
->funs
[ret
->ordinal
].nrofargs
=(context
->Esp
- ret
->origESP
-4)/4;
356 context
->Eip
= (DWORD
)ret
->origreturn
;
360 DPRINTF("RET %s.%ld: %s(",ret
->dll
->name
,ret
->ordinal
,ret
->dll
->funs
[ret
->ordinal
].name
);
361 max
= ret
->dll
->funs
[ret
->ordinal
].nrofargs
;
365 DPRINTF("%s%s",SNOOP_PrintArg(ret
->args
[i
]),(i
<max
-1)?",":"");
366 DPRINTF(") retval = %08lx ret=%08lx fs=%04lx\n",
367 context
->Eax
,(DWORD
)ret
->origreturn
,context
->SegFs
);
368 HeapFree(GetProcessHeap(),0,ret
->args
);
371 DPRINTF("RET %s.%ld: %s() retval = %08lx ret=%08lx fs=%04lx\n",
372 ret
->dll
->name
,ret
->ordinal
,ret
->dll
->funs
[ret
->ordinal
].name
,
373 context
->Eax
,(DWORD
)ret
->origreturn
,context
->SegFs
);
374 ret
->origreturn
= NULL
; /* mark as empty */
376 #else /* !__i386__ */
377 void SNOOP_RegisterDLL(HMODULE hmod
,LPCSTR name
,DWORD nrofordinals
) {
378 FIXME("snooping works only on i386 for now.\n");
382 FARPROC
SNOOP_GetProcAddress(HMODULE hmod
,LPCSTR name
,DWORD ordinal
,FARPROC origfun
) {
385 #endif /* !__i386__ */