2 * 386-specific Win16 dll<->dll snooping functions
4 * Copyright 1998 Marcus Meissner
15 #include "selectors.h"
16 #include "stackframe.h"
23 void WINAPI SNOOP16_Entry(CONTEXT *context);
24 void WINAPI SNOOP16_Return(CONTEXT *context);
25 extern void CallFrom16_p_regs_();
27 /* Generic callfrom16_p_regs function entry.
29 * pushl $DOS3Call DWORD fun32
31 * .long CallFrom16_p_regs_ DWORD addr
32 * .long 0x90900023 WORD seg;nop;nop
35 typedef struct tagSNOOP16_FUN {
37 BYTE lcall; /* 0x9a call absolute with segment */
45 typedef struct tagSNOOP16_DLL {
50 struct tagSNOOP16_DLL *next;
53 typedef struct tagSNOOP16_RETURNENTRY {
55 BYTE lcall; /* 0x9a call absolute with segment */
62 WORD *args; /* saved args across a stdcall */
63 } SNOOP16_RETURNENTRY;
65 typedef struct tagSNOOP16_RETURNENTRIES {
66 SNOOP16_RETURNENTRY entry[65500/sizeof(SNOOP16_RETURNENTRY)];
68 struct tagSNOOP16_RETURNENTRIES *next;
69 } SNOOP16_RETURNENTRIES;
71 typedef struct tagSNOOP16_RELAY {
73 BYTE prefix; /* 0x66 , 32bit prefix */
74 BYTE pushbp; /* 0x55 */
75 BYTE pushl; /* 0x68 */
76 DWORD realfun; /* SNOOP16_Return */
77 BYTE lcall; /* 0x9a call absolute with segment */
85 static SNOOP16_DLL *firstdll = NULL;
86 static SNOOP16_RETURNENTRIES *firstrets = NULL;
87 static SNOOP16_RELAY *snr;
88 static HANDLE16 xsnr = 0;
91 SNOOP16_RegisterDLL(NE_MODULE *pModule,LPCSTR name) {
92 SNOOP16_DLL **dll = &(firstdll);
95 if (!TRACE_ON(snoop)) return;
97 xsnr=GLOBAL_Alloc(GMEM_ZEROINIT,2*sizeof(*snr),0,TRUE,TRUE,FALSE);
98 snr = GlobalLock16(xsnr);
100 snr[0].pushbp = 0x55;
102 snr[0].realfun = (DWORD)SNOOP16_Entry;
104 snr[0].callfromregs = (DWORD)CallFrom16_p_regs_;
106 snr[1].prefix = 0x66;
107 snr[1].pushbp = 0x55;
109 snr[1].realfun = (DWORD)SNOOP16_Return;
111 snr[1].callfromregs = (DWORD)CallFrom16_p_regs_;
115 if ((*dll)->hmod == pModule->self)
116 return; /* already registered */
117 dll = &((*dll)->next);
119 *dll = (SNOOP16_DLL*)HeapAlloc(SystemHeap,HEAP_ZERO_MEMORY,sizeof(SNOOP16_DLL));
121 (*dll)->hmod = pModule->self;
122 if ((s=strrchr(name,'\\')))
124 (*dll)->name = HEAP_strdupA(SystemHeap,0,name);
125 if ((s=strrchr((*dll)->name,'.')))
127 (*dll)->funhandle = GlobalHandleToSel(GLOBAL_Alloc(GMEM_ZEROINIT,65535,0,TRUE,FALSE,FALSE));
128 (*dll)->funs = GlobalLock16((*dll)->funhandle);
130 HeapFree(SystemHeap,0,*dll);
131 FIXME(snoop,"out of memory\n");
134 memset((*dll)->funs,0,65535);
138 SNOOP16_GetProcAddress16(HMODULE16 hmod,DWORD ordinal,FARPROC16 origfun) {
139 SNOOP16_DLL *dll = firstdll;
141 NE_MODULE *pModule = NE_GetPtr(hmod);
145 if (!TRACE_ON(snoop) || !pModule || !HIWORD(origfun))
147 if (!*(LPBYTE)PTR_SEG_TO_LIN(origfun)) /* 0x00 is an imposs. opcode, poss. dataref. */
150 if (hmod == dll->hmod)
154 if (!dll) /* probably internal */
156 if (ordinal>65535/sizeof(SNOOP16_FUN))
158 fun = dll->funs+ordinal;
161 fun->snr = MAKELONG(0,xsnr);
162 fun->origfun = origfun;
164 return (FARPROC16)(SEGPTR)MAKELONG(((char*)fun-(char*)dll->funs),dll->funhandle);
165 cpnt = (unsigned char *)pModule + pModule->name_table;
167 cpnt += *cpnt + 1 + sizeof(WORD);
168 if (*(WORD*)(cpnt+*cpnt+1) == ordinal) {
169 sprintf(name,"%.*s",*cpnt,cpnt+1);
173 /* Now search the non-resident names table */
175 if (!*cpnt && pModule->nrname_handle) {
176 cpnt = (char *)GlobalLock16( pModule->nrname_handle );
178 cpnt += *cpnt + 1 + sizeof(WORD);
179 if (*(WORD*)(cpnt+*cpnt+1) == ordinal) {
180 sprintf(name,"%.*s",*cpnt,cpnt+1);
186 fun->name = HEAP_strdupA(SystemHeap,0,name);
188 fun->name = HEAP_strdupA(SystemHeap,0,"");
189 /* more magic. do not try to snoop thunk data entries (MMSYSTEM) */
190 if (strchr(fun->name,'_')) {
191 char *s=strchr(fun->name,'_');
193 if (!strncasecmp(s,"_thunkdata",10)) {
194 HeapFree(SystemHeap,0,fun->name);
200 fun->snr = MAKELONG(0,xsnr);
201 fun->origfun = origfun;
203 return (FARPROC16)(SEGPTR)MAKELONG(((char*)fun-(char*)dll->funs),dll->funhandle);
206 #define CALLER1REF (*(DWORD*)(PTR_SEG_OFF_TO_LIN(SS_reg(context),SP_reg(context)+4)))
207 void WINAPI SNOOP16_Entry(CONTEXT *context) {
209 DWORD entry=(DWORD)PTR_SEG_OFF_TO_LIN(CS_reg(context),IP_reg(context))-5;
210 WORD xcs = CS_reg(context);
211 SNOOP16_DLL *dll = firstdll;
212 SNOOP16_FUN *fun = NULL;
213 SNOOP16_RETURNENTRIES **rets = &firstrets;
214 SNOOP16_RETURNENTRY *ret;
218 if (xcs == dll->funhandle) {
219 fun = (SNOOP16_FUN*)entry;
220 ordinal = fun-dll->funs;
226 FIXME(snoop,"entrypoint 0x%08lx not found\n",entry);
229 /* guess cdecl ... */
230 if (fun->nrofargs<0) {
231 /* Typical cdecl return frame is:
233 * which has (for xxxxxxxx up to 255 the opcode "83 C4 xx".
235 LPBYTE reteip = (LPBYTE)PTR_SEG_TO_LIN(CALLER1REF);
237 if ((reteip[0]==0x83)&&(reteip[1]==0xc4))
238 fun->nrofargs=reteip[2]/2;
242 for (i=0;i<sizeof((*rets)->entry)/sizeof((*rets)->entry[0]);i++)
243 if (!(*rets)->entry[i].origreturn)
245 if (i!=sizeof((*rets)->entry)/sizeof((*rets)->entry[0]))
247 rets = &((*rets)->next);
250 HANDLE16 hand = GlobalHandleToSel(GLOBAL_Alloc(GMEM_ZEROINIT,65535,0,TRUE,FALSE,FALSE));
251 *rets = GlobalLock16(hand);
252 memset(*rets,0,65535);
253 (*rets)->rethandle = hand;
254 i = 0; /* entry 0 is free */
256 ret = &((*rets)->entry[i]);
258 ret->snr = MAKELONG(sizeof(SNOOP16_RELAY),xsnr);
259 ret->origreturn = (FARPROC16)CALLER1REF;
260 CALLER1REF = MAKELONG((char*)&(ret->lcall)-(char*)((*rets)->entry),(*rets)->rethandle);
263 ret->ordinal = ordinal;
264 ret->origSP = SP_reg(context);
266 IP_reg(context)= LOWORD(fun->origfun);
267 CS_reg(context)= HIWORD(fun->origfun);
269 DPRINTF("Call %s.%ld: %s(",dll->name,ordinal,fun->name);
270 if (fun->nrofargs>0) {
271 max = fun->nrofargs; if (max>16) max=16;
273 DPRINTF("%04x%s",*(WORD*)(PTR_SEG_OFF_TO_LIN(SS_reg(context),SP_reg(context))+8+sizeof(WORD)*i),i?",":"");
274 if (max!=fun->nrofargs)
276 } else if (fun->nrofargs<0) {
277 DPRINTF("<unknown, check return>");
278 ret->args = HeapAlloc(SystemHeap,0,16*sizeof(WORD));
279 memcpy(ret->args,(LPBYTE)(PTR_SEG_OFF_TO_LIN(SS_reg(context),SP_reg(context))+8),sizeof(WORD)*16);
281 DPRINTF(") ret=%04x:%04x\n",HIWORD((DWORD)(*rets)->entry[i].origreturn),LOWORD((DWORD)(*rets)->entry[i].origreturn));
284 void WINAPI SNOOP16_Return(CONTEXT *context) {
285 SNOOP16_RETURNENTRY *ret = (SNOOP16_RETURNENTRY*)(PTR_SEG_OFF_TO_LIN(CS_reg(context),IP_reg(context))-5);
287 /* We haven't found out the nrofargs yet. If we called a cdecl
288 * function it is too late anyway and we can just set '0' (which
289 * will be the difference between orig and current SP
290 * If pascal -> everything ok.
292 if (ret->dll->funs[ret->ordinal].nrofargs<0)
293 ret->dll->funs[ret->ordinal].nrofargs=(SP_reg(context)-ret->origSP-4)/2;
294 IP_reg(context) = LOWORD(ret->origreturn);
295 CS_reg(context) = HIWORD(ret->origreturn);
299 DPRINTF("Ret %s.%ld: %s(",ret->dll->name,ret->ordinal,ret->dll->funs[ret->ordinal].name);
300 max = ret->dll->funs[ret->ordinal].nrofargs;
304 DPRINTF("%04x%s",ret->args[i],i?",":"");
305 DPRINTF(") retval = %04x:%04x ret=%04x:%04x\n",
306 DX_reg(context),AX_reg(context),HIWORD(ret->origreturn),LOWORD(ret->origreturn)
308 HeapFree(SystemHeap,0,ret->args);
311 DPRINTF("Ret %s.%ld: %s() retval = %04x:%04x ret=%04x:%04x\n",
312 ret->dll->name,ret->ordinal,ret->dll->funs[ret->ordinal].name,
313 DX_reg(context),AX_reg(context),HIWORD(ret->origreturn),LOWORD(ret->origreturn)
315 ret->origreturn = NULL; /* mark as empty */
317 #else /* !__i386__ */
318 void SNOOP16_RegisterDLL(NE_MODULE *pModule,LPCSTR name) {
319 FIXME(snoop,"snooping works only on i386 for now.\n");
323 FARPROC16 SNOOP16_GetProcAddress16(HMODULE16 hmod,DWORD ordinal,FARPROC16 origfun) {
326 #endif /* !__i386__ */
330 fnSNOOP16_GetProcAddress16=SNOOP16_GetProcAddress16;
331 fnSNOOP16_RegisterDLL=SNOOP16_RegisterDLL;