if1632/snoop.c

   1 /*
   2  * 386-specific Win16 dll<->dll snooping functions
   3  *
   4  * Copyright 1998 Marcus Meissner
   5  */
   6
   7 #ifdef __i386__
   8
   9 #include <assert.h>
  10 #include "windows.h"
  11 #include "winbase.h"
  12 #include "winnt.h"
  13 #include "heap.h"
  14 #include "global.h"
  15 #include "selectors.h"
  16 #include "stackframe.h"
  17 #include "snoop.h"
  18 #include "debugstr.h"
  19 #include "debug.h"
  20
  21 #pragma pack(1)
  22
  23 void WINAPI SNOOP16_Entry(CONTEXT *context);
  24 void WINAPI SNOOP16_Return(CONTEXT *context);
  25 extern void CallFrom16_p_regs_();
  26
  27 /* Generic callfrom16_p_regs function entry.
  28  *      pushw %bp                       0x55
  29  *      pushl $DOS3Call                 DWORD fun32
  30  *      .byte 0x9a                      0x9a
  31  *      .long CallFrom16_p_regs_        DWORD addr
  32  *      .long 0x90900023                WORD seg;nop;nop
  33  */
  34
  35 typedef struct tagSNOOP16_FUN {
  36         /* code part */
  37         BYTE            lcall;          /* 0x9a call absolute with segment */
  38         DWORD           snr;
  39         /* unreached */
  40         int             nrofargs;
  41         FARPROC16       origfun;
  42         char            *name;
  43 } SNOOP16_FUN;
  44
  45 typedef struct tagSNOOP16_DLL {
  46         HMODULE16       hmod;
  47         HANDLE16        funhandle;
  48         SNOOP16_FUN     *funs;
  49         LPCSTR          name;
  50         struct tagSNOOP16_DLL   *next;
  51 } SNOOP16_DLL;
  52
  53 typedef struct tagSNOOP16_RETURNENTRY {
  54         /* code part */
  55         BYTE            lcall;          /* 0x9a call absolute with segment */
  56         DWORD           snr;
  57         /* unreached */
  58         FARPROC16       origreturn;
  59         SNOOP16_DLL     *dll;
  60         DWORD           ordinal;
  61         WORD            origSP;
  62         WORD            *args;          /* saved args across a stdcall */
  63 } SNOOP16_RETURNENTRY;
  64
  65 typedef struct tagSNOOP16_RETURNENTRIES {
  66         SNOOP16_RETURNENTRY entry[65500/sizeof(SNOOP16_RETURNENTRY)];
  67         HANDLE16        rethandle;
  68         struct tagSNOOP16_RETURNENTRIES *next;
  69 } SNOOP16_RETURNENTRIES;
  70
  71 typedef struct tagSNOOP16_RELAY {
  72         /* code part */
  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 */
  78         DWORD           callfromregs;
  79         WORD            seg;
  80         /* unreached */
  81 } SNOOP16_RELAY;
  82
  83 #pragma pack(4)
  84
  85 static  SNOOP16_DLL             *firstdll = NULL;
  86 static  SNOOP16_RETURNENTRIES   *firstrets = NULL;
  87 static  SNOOP16_RELAY           *snr;
  88 static  HANDLE16                xsnr = 0;
  89
  90 void
  91 SNOOP16_RegisterDLL(NE_MODULE *pModule,LPCSTR name) {
  92         SNOOP16_DLL     **dll = &(firstdll);
  93         char            *s;
  94
  95         if (!TRACE_ON(snoop)) return;
  96         if (!snr) {
  97                 xsnr=GLOBAL_Alloc(GMEM_ZEROINIT,2*sizeof(*snr),0,TRUE,TRUE,FALSE);
  98                 snr = GlobalLock16(xsnr);
  99                 snr[0].prefix   = 0x66;
 100                 snr[0].pushbp   = 0x55;
 101                 snr[0].pushl    = 0x68;
 102                 snr[0].realfun  = (DWORD)SNOOP16_Entry;
 103                 snr[0].lcall    = 0x9a;
 104                 snr[0].callfromregs = (DWORD)CallFrom16_p_regs_;
 105                 GET_CS(snr[0].seg);
 106                 snr[1].prefix   = 0x66;
 107                 snr[1].pushbp   = 0x55;
 108                 snr[1].pushl    = 0x68;
 109                 snr[1].realfun  = (DWORD)SNOOP16_Return;
 110                 snr[1].lcall    = 0x9a;
 111                 snr[1].callfromregs = (DWORD)CallFrom16_p_regs_;
 112                 GET_CS(snr[1].seg);
 113         }
 114         while (*dll) {
 115                 if ((*dll)->hmod == pModule->self)
 116                         return; /* already registered */
 117                 dll = &((*dll)->next);
 118         }
 119         *dll = (SNOOP16_DLL*)HeapAlloc(SystemHeap,HEAP_ZERO_MEMORY,sizeof(SNOOP16_DLL));
 120         (*dll)->next    = NULL;
 121         (*dll)->hmod    = pModule->self;
 122         if ((s=strrchr(name,'\\')))
 123                 name = s+1;
 124         (*dll)->name    = HEAP_strdupA(SystemHeap,0,name);
 125         if ((s=strrchr((*dll)->name,'.')))
 126                 *s='\0';
 127         (*dll)->funhandle = GlobalHandleToSel(GLOBAL_Alloc(GMEM_ZEROINIT,65535,0,TRUE,FALSE,FALSE));
 128         (*dll)->funs = GlobalLock16((*dll)->funhandle);
 129         if (!(*dll)->funs) {
 130                 HeapFree(SystemHeap,0,*dll);
 131                 FIXME(snoop,"out of memory\n");
 132                 return;
 133         }
 134         memset((*dll)->funs,0,65535);
 135 }
 136
 137 FARPROC16
 138 SNOOP16_GetProcAddress16(HMODULE16 hmod,DWORD ordinal,FARPROC16 origfun) {
 139         SNOOP16_DLL                     *dll = firstdll;
 140         SNOOP16_FUN                     *fun;
 141         NE_MODULE                       *pModule = NE_GetPtr(hmod);
 142         unsigned char                   *cpnt;
 143         char                            name[200];
 144
 145         if (!TRACE_ON(snoop) || !pModule || !HIWORD(origfun))
 146                 return origfun;
 147         if (!*(LPBYTE)PTR_SEG_TO_LIN(origfun)) /* 0x00 is an imposs. opcode, poss. dataref. */
 148                 return origfun;
 149         while (dll) {
 150                 if (hmod == dll->hmod)
 151                         break;
 152                 dll=dll->next;
 153         }
 154         if (!dll)       /* probably internal */
 155                 return origfun;
 156         if (ordinal>65535/sizeof(SNOOP16_FUN))
 157                 return origfun;
 158         fun = dll->funs+ordinal;
 159         /* already done? */
 160         fun->lcall      = 0x9a;
 161         fun->snr        = MAKELONG(0,xsnr);
 162         fun->origfun    = origfun;
 163         if (fun->name)
 164                 return (FARPROC16)(SEGPTR)MAKELONG(((char*)fun-(char*)dll->funs),dll->funhandle);
 165         cpnt = (unsigned char *)pModule + pModule->name_table;
 166         while (*cpnt) {
 167                 cpnt += *cpnt + 1 + sizeof(WORD);
 168                 if (*(WORD*)(cpnt+*cpnt+1) == ordinal) {
 169                         sprintf(name,"%.*s",*cpnt,cpnt+1);
 170                         break;
 171                 }
 172         }
 173         /* Now search the non-resident names table */
 174
 175         if (!*cpnt && pModule->nrname_handle) {
 176                 cpnt = (char *)GlobalLock16( pModule->nrname_handle );
 177                 while (*cpnt) {
 178                         cpnt += *cpnt + 1 + sizeof(WORD);
 179                         if (*(WORD*)(cpnt+*cpnt+1) == ordinal) {
 180                                     sprintf(name,"%.*s",*cpnt,cpnt+1);
 181                                     break;
 182                         }
 183                 }
 184         }
 185         if (*cpnt)
 186                 fun->name = HEAP_strdupA(SystemHeap,0,name);
 187         else
 188                 fun->name = HEAP_strdupA(SystemHeap,0,"");
 189         fun->lcall      = 0x9a;
 190         fun->snr        = MAKELONG(0,xsnr);
 191         fun->origfun    = origfun;
 192         fun->nrofargs   = -1;
 193         return (FARPROC16)(SEGPTR)MAKELONG(((char*)fun-(char*)dll->funs),dll->funhandle);
 194 }
 195
 196 #define CALLER1REF (*(DWORD*)(PTR_SEG_OFF_TO_LIN(SS_reg(context),SP_reg(context)+4)))
 197 void WINAPI SNOOP16_Entry(CONTEXT *context) {
 198         DWORD           ordinal=0;
 199         DWORD           entry=(DWORD)PTR_SEG_OFF_TO_LIN(CS_reg(context),IP_reg(context))-5;
 200         WORD            xcs = CS_reg(context);
 201         SNOOP16_DLL     *dll = firstdll;
 202         SNOOP16_FUN     *fun = NULL;
 203         SNOOP16_RETURNENTRIES   **rets = &firstrets;
 204         SNOOP16_RETURNENTRY     *ret;
 205         int             i,max;
 206
 207         while (dll) {
 208                 if (xcs == dll->funhandle) {
 209                         fun = (SNOOP16_FUN*)entry;
 210                         ordinal = fun-dll->funs;
 211                         break;
 212                 }
 213                 dll=dll->next;
 214         }
 215         if (!dll) {
 216                 FIXME(snoop,"entrypoint 0x%08lx not found\n",entry);
 217                 return; /* oops */
 218         }
 219         /* guess cdecl ... */
 220         if (fun->nrofargs<0) {
 221                 /* Typical cdecl return frame is:
 222                  *      add esp, xxxxxxxx
 223                  * which has (for xxxxxxxx up to 255 the opcode "83 C4 xx".
 224                  */
 225                 LPBYTE  reteip = (LPBYTE)PTR_SEG_TO_LIN(CALLER1REF);
 226
 227                 if ((reteip[0]==0x83)&&(reteip[1]==0xc4))
 228                         fun->nrofargs=reteip[2]/2;
 229         }
 230
 231         while (*rets) {
 232                 for (i=0;i<sizeof((*rets)->entry)/sizeof((*rets)->entry[0]);i++)
 233                         if (!(*rets)->entry[i].origreturn)
 234                                 break;
 235                 if (i!=sizeof((*rets)->entry)/sizeof((*rets)->entry[0]))
 236                         break;
 237                 rets = &((*rets)->next);
 238         }
 239         if (!*rets) {
 240                 HANDLE16        hand = GlobalHandleToSel(GLOBAL_Alloc(GMEM_ZEROINIT,65535,0,TRUE,FALSE,FALSE));
 241                 *rets = GlobalLock16(hand);
 242                 memset(*rets,0,65535);
 243                 (*rets)->rethandle = hand;
 244                 i = 0;  /* entry 0 is free */
 245         }
 246         ret = &((*rets)->entry[i]);
 247         ret->lcall      = 0x9a;
 248         ret->snr        = MAKELONG(sizeof(SNOOP16_RELAY),xsnr);
 249         ret->origreturn = (FARPROC16)CALLER1REF;
 250         CALLER1REF      = MAKELONG((char*)&(ret->lcall)-(char*)((*rets)->entry),(*rets)->rethandle);
 251         ret->dll        = dll;
 252         ret->args       = NULL;
 253         ret->ordinal    = ordinal;
 254         ret->origSP     = SP_reg(context);
 255
 256         IP_reg(context)= LOWORD(fun->origfun);
 257         CS_reg(context)= HIWORD(fun->origfun);
 258
 259         DPRINTF("Call %s.%ld: %s(",dll->name,ordinal,fun->name);
 260         if (fun->nrofargs>0) {
 261                 max = fun->nrofargs; if (max>16) max=16;
 262                 for (i=max;i--;)
 263                         DPRINTF("%04x%s",*(WORD*)(PTR_SEG_OFF_TO_LIN(SS_reg(context),SP_reg(context))+8+sizeof(WORD)*i),i?",":"");
 264                 if (max!=fun->nrofargs)
 265                         DPRINTF(" ...");
 266         } else if (fun->nrofargs<0) {
 267                 DPRINTF("<unknown, check return>");
 268                 ret->args = HeapAlloc(SystemHeap,0,16*sizeof(WORD));
 269                 memcpy(ret->args,(LPBYTE)(PTR_SEG_OFF_TO_LIN(SS_reg(context),SP_reg(context))+8),sizeof(WORD)*16);
 270         }
 271         DPRINTF(") ret=%04x:%04x\n",HIWORD((DWORD)(*rets)->entry[i].origreturn),LOWORD((DWORD)(*rets)->entry[i].origreturn));
 272 }
 273
 274 void WINAPI SNOOP16_Return(CONTEXT *context) {
 275         SNOOP16_RETURNENTRY     *ret = (SNOOP16_RETURNENTRY*)(PTR_SEG_OFF_TO_LIN(CS_reg(context),IP_reg(context))-5);
 276
 277         /* We haven't found out the nrofargs yet. If we called a cdecl
 278          * function it is too late anyway and we can just set '0' (which
 279          * will be the difference between orig and current SP
 280          * If pascal -> everything ok.
 281          */
 282         if (ret->dll->funs[ret->ordinal].nrofargs<0)
 283                 ret->dll->funs[ret->ordinal].nrofargs=(SP_reg(context)-ret->origSP-4)/2;
 284         IP_reg(context) = LOWORD(ret->origreturn);
 285         CS_reg(context) = HIWORD(ret->origreturn);
 286         if (ret->args) {
 287                 int     i,max;
 288
 289                 DPRINTF("Ret  %s.%ld: %s(",ret->dll->name,ret->ordinal,ret->dll->funs[ret->ordinal].name);
 290                 max = ret->dll->funs[ret->ordinal].nrofargs;
 291                 if (max>16) max=16;
 292
 293                 for (i=max;i--;)
 294                         DPRINTF("%04x%s",ret->args[i],i?",":"");
 295                 DPRINTF(") retval = %04x:%04x ret=%04x:%04x\n",
 296                         DX_reg(context),AX_reg(context),HIWORD(ret->origreturn),LOWORD(ret->origreturn)
 297                 );
 298                 HeapFree(SystemHeap,0,ret->args);
 299                 ret->args = NULL;
 300         } else
 301                 DPRINTF("Ret  %s.%ld: %s() retval = %04x:%04x ret=%04x:%04x\n",
 302                         ret->dll->name,ret->ordinal,ret->dll->funs[ret->ordinal].name,
 303                         DX_reg(context),AX_reg(context),HIWORD(ret->origreturn),LOWORD(ret->origreturn)
 304                 );
 305         ret->origreturn = NULL; /* mark as empty */
 306 }
 307 #else   /* !__i386__ */
 308 void SNOOP16_RegisterDLL(NE_MODULE *pModule,LPCSTR name) {
 309         FIXME(snoop,"snooping works only on i386 for now.\n");
 310         return;
 311 }
 312
 313 FARPROC16 SNOOP16_GetProcAddress16(HMODULE16 hmod,DWORD ordinal,FARPROC16 origfun) {
 314         return origfun;
 315 }
 316 #endif  /* !__i386__ */