2 * 386-specific Win32 dll<->dll snooping functions
4 * Copyright 1998 Marcus Meissner
15 #include "builtin32.h"
19 #include "selectors.h"
20 #include "stackframe.h"
21 #include "debugtools.h"
23 DEFAULT_DEBUG_CHANNEL(snoop
);
25 char **debug_snoop_excludelist
= NULL
, **debug_snoop_includelist
= NULL
;
29 extern void WINAPI
SNOOP_Entry();
30 extern void WINAPI
SNOOP_Return();
32 #ifdef NEED_UNDERSCORE_PREFIX
40 typedef struct tagSNOOP_FUN
{
42 BYTE lcall
; /* 0xe8 call snoopentry (relative) */
43 /* NOTE: If you move snoopentry OR nrofargs fix the relative offset
46 DWORD snoopentry
; /* SNOOP_Entry relative */
53 typedef struct tagSNOOP_DLL
{
58 struct tagSNOOP_DLL
*next
;
60 typedef struct tagSNOOP_RETURNENTRY
{
62 BYTE lcall
; /* 0xe8 call snoopret relative*/
63 /* NOTE: If you move snoopret OR origreturn fix the relative offset
66 DWORD snoopret
; /* SNOOP_Ret relative */
72 DWORD
*args
; /* saved args across a stdcall */
75 typedef struct tagSNOOP_RETURNENTRIES
{
76 SNOOP_RETURNENTRY entry
[4092/sizeof(SNOOP_RETURNENTRY
)];
77 struct tagSNOOP_RETURNENTRIES
*next
;
78 } SNOOP_RETURNENTRIES
;
82 static SNOOP_DLL
*firstdll
= NULL
;
83 static SNOOP_RETURNENTRIES
*firstrets
= NULL
;
85 /***********************************************************************
86 * SNOOP_ShowDebugmsgSnoop
88 * Simple function to decide if a particular debugging message is
91 int SNOOP_ShowDebugmsgSnoop(const char *dll
, int ord
, const char *fname
) {
93 if(debug_snoop_excludelist
|| debug_snoop_includelist
) {
96 int len
, len2
, itemlen
, show
;
98 if(debug_snoop_excludelist
) {
100 listitem
= debug_snoop_excludelist
;
103 listitem
= debug_snoop_includelist
;
107 sprintf(buf
, "%s.%d", dll
, ord
);
109 for(; *listitem
; listitem
++) {
110 itemlen
= strlen(*listitem
);
111 if((itemlen
== len
&& !strncmp(*listitem
, buf
, len
)) ||
112 (itemlen
== len2
&& !strncmp(*listitem
, buf
, len2
)) ||
113 !strcmp(*listitem
, fname
)) {
124 SNOOP_RegisterDLL(HMODULE hmod
,LPCSTR name
,DWORD nrofordinals
) {
125 SNOOP_DLL
**dll
= &(firstdll
);
128 if (!TRACE_ON(snoop
)) return;
130 if ((*dll
)->hmod
== hmod
)
131 return; /* already registered */
132 dll
= &((*dll
)->next
);
134 *dll
= (SNOOP_DLL
*)HeapAlloc(GetProcessHeap(),HEAP_ZERO_MEMORY
,sizeof(SNOOP_DLL
));
137 (*dll
)->nrofordinals
= nrofordinals
;
138 (*dll
)->name
= HEAP_strdupA(GetProcessHeap(),0,name
);
139 if ((s
=strrchr((*dll
)->name
,'.')))
141 (*dll
)->funs
= VirtualAlloc(NULL
,nrofordinals
*sizeof(SNOOP_FUN
),MEM_COMMIT
|MEM_RESERVE
,PAGE_EXECUTE_READWRITE
);
142 memset((*dll
)->funs
,0,nrofordinals
*sizeof(SNOOP_FUN
));
144 HeapFree(GetProcessHeap(),0,*dll
);
145 FIXME("out of memory\n");
151 SNOOP_GetProcAddress(HMODULE hmod
,LPCSTR name
,DWORD ordinal
,FARPROC origfun
) {
152 SNOOP_DLL
*dll
= firstdll
;
155 IMAGE_SECTION_HEADER
*pe_seg
= PE_SECTIONS(hmod
);
157 if (!TRACE_ON(snoop
)) return origfun
;
158 if (!*(LPBYTE
)origfun
) /* 0x00 is an imposs. opcode, poss. dataref. */
160 for (j
=0;j
<PE_HEADER(hmod
)->FileHeader
.NumberOfSections
;j
++)
161 /* 0x42 is special ELF loader tag */
162 if ((pe_seg
[j
].VirtualAddress
==0x42) ||
163 (((DWORD
)origfun
-hmod
>=pe_seg
[j
].VirtualAddress
)&&
164 ((DWORD
)origfun
-hmod
<pe_seg
[j
].VirtualAddress
+
165 pe_seg
[j
].SizeOfRawData
169 /* If we looked through all sections (and didn't find one)
170 * or if the sectionname contains "data", we return the
171 * original function since it is most likely a datareference.
173 if ( (j
==PE_HEADER(hmod
)->FileHeader
.NumberOfSections
) ||
174 (strstr(pe_seg
[j
].Name
,"data")) ||
175 !(pe_seg
[j
].Characteristics
& IMAGE_SCN_CNT_CODE
)
180 if (hmod
== dll
->hmod
)
184 if (!dll
) /* probably internal */
186 if (!SNOOP_ShowDebugmsgSnoop(dll
->name
,ordinal
,name
))
188 assert(ordinal
<dll
->nrofordinals
);
189 fun
= dll
->funs
+ordinal
;
190 if (!fun
->name
) fun
->name
= HEAP_strdupA(GetProcessHeap(),0,name
);
192 /* NOTE: origreturn struct member MUST come directly after snoopentry */
193 fun
->snoopentry
= (char*)SNOOP_Entry
-((char*)(&fun
->nrofargs
));
194 fun
->origfun
= origfun
;
196 return (FARPROC
)&(fun
->lcall
);
200 SNOOP_PrintArg(DWORD x
) {
201 static char buf
[200];
203 MEMORY_BASIC_INFORMATION mbi
;
206 !VirtualQuery((LPVOID
)x
,&mbi
,sizeof(mbi
)) ||
209 sprintf(buf
,"%08lx",x
);
212 if (!IsBadStringPtrA((LPSTR
)x
,80)) {
217 if (s
[i
]<0x20) {nostring
=1;break;}
218 if (s
[i
]>=0x80) {nostring
=1;break;}
223 wsnprintfA(buf
,sizeof(buf
),"%08lx %s",x
,debugstr_an((LPSTR
)x
,sizeof(buf
)-10));
228 if (!IsBadStringPtrW((LPWSTR
)x
,80)) {
233 if (s
[i
]<0x20) {nostring
=1;break;}
234 if (s
[i
]>0x100) {nostring
=1;break;}
239 wsnprintfA(buf
,sizeof(buf
),"%08lx %s",x
,debugstr_wn((LPWSTR
)x
,sizeof(buf
)-10));
244 sprintf(buf
,"%08lx",x
);
248 #define CALLER1REF (*(DWORD*)ESP_reg(context))
250 void WINAPI
SNOOP_DoEntry( CONTEXT86
*context
);
251 DEFINE_REGS_ENTRYPOINT_0( SNOOP_Entry
, SNOOP_DoEntry
);
252 void WINAPI
SNOOP_DoEntry( CONTEXT86
*context
)
254 DWORD ordinal
=0,entry
= EIP_reg(context
)-5;
255 SNOOP_DLL
*dll
= firstdll
;
256 SNOOP_FUN
*fun
= NULL
;
257 SNOOP_RETURNENTRIES
**rets
= &firstrets
;
258 SNOOP_RETURNENTRY
*ret
;
262 if ( ((char*)entry
>=(char*)dll
->funs
) &&
263 ((char*)entry
<=(char*)(dll
->funs
+dll
->nrofordinals
))
265 fun
= (SNOOP_FUN
*)entry
;
266 ordinal
= fun
-dll
->funs
;
272 FIXME("entrypoint 0x%08lx not found\n",entry
);
275 /* guess cdecl ... */
276 if (fun
->nrofargs
<0) {
277 /* Typical cdecl return frame is:
279 * which has (for xxxxxxxx up to 255 the opcode "83 C4 xx".
280 * (after that 81 C2 xx xx xx xx)
282 LPBYTE reteip
= (LPBYTE
)CALLER1REF
;
285 if ((reteip
[0]==0x83)&&(reteip
[1]==0xc4))
286 fun
->nrofargs
=reteip
[2]/4;
292 for (i
=0;i
<sizeof((*rets
)->entry
)/sizeof((*rets
)->entry
[0]);i
++)
293 if (!(*rets
)->entry
[i
].origreturn
)
295 if (i
!=sizeof((*rets
)->entry
)/sizeof((*rets
)->entry
[0]))
297 rets
= &((*rets
)->next
);
300 *rets
= VirtualAlloc(NULL
,4096,MEM_COMMIT
|MEM_RESERVE
,PAGE_EXECUTE_READWRITE
);
301 memset(*rets
,0,4096);
302 i
= 0; /* entry 0 is free */
304 ret
= &((*rets
)->entry
[i
]);
306 /* NOTE: origreturn struct member MUST come directly after snoopret */
307 ret
->snoopret
= ((char*)SNOOP_Return
)-(char*)(&ret
->origreturn
);
308 ret
->origreturn
= (FARPROC
)CALLER1REF
;
309 CALLER1REF
= (DWORD
)&ret
->lcall
;
312 ret
->ordinal
= ordinal
;
313 ret
->origESP
= ESP_reg(context
);
315 EIP_reg(context
)= (DWORD
)fun
->origfun
;
317 DPRINTF("Call %s.%ld: %s(",dll
->name
,ordinal
,fun
->name
);
318 if (fun
->nrofargs
>0) {
319 max
= fun
->nrofargs
; if (max
>16) max
=16;
321 DPRINTF("%s%s",SNOOP_PrintArg(*(DWORD
*)(ESP_reg(context
)+4+sizeof(DWORD
)*i
)),(i
<fun
->nrofargs
-1)?",":"");
322 if (max
!=fun
->nrofargs
)
324 } else if (fun
->nrofargs
<0) {
325 DPRINTF("<unknown, check return>");
326 ret
->args
= HeapAlloc(GetProcessHeap(),0,16*sizeof(DWORD
));
327 memcpy(ret
->args
,(LPBYTE
)(ESP_reg(context
)+4),sizeof(DWORD
)*16);
329 DPRINTF(") ret=%08lx fs=%04lx\n",(DWORD
)ret
->origreturn
,FS_reg(context
));
332 void WINAPI
SNOOP_DoReturn( CONTEXT86
*context
);
333 DEFINE_REGS_ENTRYPOINT_0( SNOOP_Return
, SNOOP_DoReturn
);
334 void WINAPI
SNOOP_DoReturn( CONTEXT86
*context
)
336 SNOOP_RETURNENTRY
*ret
= (SNOOP_RETURNENTRY
*)(EIP_reg(context
)-5);
338 /* We haven't found out the nrofargs yet. If we called a cdecl
339 * function it is too late anyway and we can just set '0' (which
340 * will be the difference between orig and current ESP
341 * If stdcall -> everything ok.
343 if (ret
->dll
->funs
[ret
->ordinal
].nrofargs
<0)
344 ret
->dll
->funs
[ret
->ordinal
].nrofargs
=(ESP_reg(context
)-ret
->origESP
-4)/4;
345 EIP_reg(context
) = (DWORD
)ret
->origreturn
;
349 DPRINTF("Ret %s.%ld: %s(",ret
->dll
->name
,ret
->ordinal
,ret
->dll
->funs
[ret
->ordinal
].name
);
350 max
= ret
->dll
->funs
[ret
->ordinal
].nrofargs
;
354 DPRINTF("%s%s",SNOOP_PrintArg(ret
->args
[i
]),(i
<max
-1)?",":"");
355 DPRINTF(") retval = %08lx ret=%08lx fs=%04lx\n",
356 EAX_reg(context
),(DWORD
)ret
->origreturn
,FS_reg(context
)
358 HeapFree(GetProcessHeap(),0,ret
->args
);
361 DPRINTF("Ret %s.%ld: %s() retval = %08lx ret=%08lx fs=%04lx\n",
362 ret
->dll
->name
,ret
->ordinal
,ret
->dll
->funs
[ret
->ordinal
].name
,
363 EAX_reg(context
),(DWORD
)ret
->origreturn
,FS_reg(context
)
365 ret
->origreturn
= NULL
; /* mark as empty */
367 #else /* !__i386__ */
368 void SNOOP_RegisterDLL(HMODULE hmod
,LPCSTR name
,DWORD nrofordinals
) {
369 FIXME("snooping works only on i386 for now.\n");
373 FARPROC
SNOOP_GetProcAddress(HMODULE hmod
,LPCSTR name
,DWORD ordinal
,FARPROC origfun
) {
376 #endif /* !__i386__ */