/*
* Copyright (c) 2003
* Bill Paul <wpaul@windriver.com>. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Bill Paul.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL Bill Paul OR THE VOICES IN HIS HEAD
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* This file contains routines for relocating and dynamically linking
* executable object code files in the Windows(r) PE (Portable Executable)
* format. In Windows, anything with a .EXE, .DLL or .SYS extention is
* considered an executable, and all such files have some structures in
* common. The PE format was apparently based largely on COFF but has
* mutated significantly over time. We are mainly concerned with .SYS files,
* so this module implements only enough routines to be able to parse the
* headers and sections of a .SYS object file and perform the necessary
* relocations and jump table patching to allow us to call into it
* (and to have it call back to us). Note that while this module
* can handle fixups for imported symbols, it knows nothing about
* exporting them.
*/
#include <sys/param.h>
#include <sys/types.h>
#include <sys/errno.h>
#ifdef _KERNEL
#include <sys/systm.h>
#else
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#endif
#include <compat/ndis/pe_var.h>
static u_int32_t pe_functbl_match(image_patch_table *, char *);
/*
* Check for an MS-DOS executable header. All Windows binaries
* have a small MS-DOS executable prepended to them to print out
* the "This program requires Windows" message. Even .SYS files
* have this header, in spite of the fact that you're can't actually
* run them directly.
*/
int
pe_get_dos_header(imgbase, hdr)
vm_offset_t imgbase;
image_dos_header *hdr;
{
uint16_t signature;
if (imgbase == 0 || hdr == NULL)
return (EINVAL);
signature = *(uint16_t *)imgbase;
if (signature != IMAGE_DOS_SIGNATURE)
return (ENOEXEC);
bcopy ((char *)imgbase, (char *)hdr, sizeof(image_dos_header));
return(0);
}
/*
* Verify that this image has a Windows NT PE signature.
*/
int
pe_is_nt_image(imgbase)
vm_offset_t imgbase;
{
uint32_t signature;
image_dos_header *dos_hdr;
if (imgbase == 0)
return (EINVAL);
signature = *(uint16_t *)imgbase;
if (signature == IMAGE_DOS_SIGNATURE) {
dos_hdr = (image_dos_header *)imgbase;
signature = *(uint32_t *)(imgbase + dos_hdr->idh_lfanew);
if (signature == IMAGE_NT_SIGNATURE)
return(0);
}
return(ENOEXEC);
}
/*
* Return a copy of the optional header. This contains the
* executable entry point and the directory listing which we
* need to find the relocations and imports later.
*/
int
pe_get_optional_header(imgbase, hdr)
vm_offset_t imgbase;
image_optional_header *hdr;
{
image_dos_header *dos_hdr;
image_nt_header *nt_hdr;
if (imgbase == 0 || hdr == NULL)
return(EINVAL);
if (pe_is_nt_image(imgbase))
return (EINVAL);
dos_hdr = (image_dos_header *)(imgbase);
nt_hdr = (image_nt_header *)(imgbase + dos_hdr->idh_lfanew);
bcopy ((char *)&nt_hdr->inh_optionalhdr, (char *)hdr,
sizeof(image_optional_header));
return(0);
}
/*
* Return a copy of the file header. Contains the number of
* sections in this image.
*/
int
pe_get_file_header(imgbase, hdr)
vm_offset_t imgbase;
image_file_header *hdr;
{
image_dos_header *dos_hdr;
image_nt_header *nt_hdr;
if (imgbase == 0 || hdr == NULL)
return(EINVAL);
if (pe_is_nt_image(imgbase))
return (EINVAL);
dos_hdr = (image_dos_header *)imgbase;
nt_hdr = (image_nt_header *)(imgbase + dos_hdr->idh_lfanew);
bcopy ((char *)&nt_hdr->inh_filehdr, (char *)hdr,
sizeof(image_file_header));
return(0);
}
/*
* Return the header of the first section in this image (usually
* .text).
*/
int
pe_get_section_header(imgbase, hdr)
vm_offset_t imgbase;
image_section_header *hdr;
{
image_dos_header *dos_hdr;
image_nt_header *nt_hdr;
image_section_header *sect_hdr;
if (imgbase == 0 || hdr == NULL)
return(EINVAL);
if (pe_is_nt_image(imgbase))
return (EINVAL);
dos_hdr = (image_dos_header *)imgbase;
nt_hdr = (image_nt_header *)(imgbase + dos_hdr->idh_lfanew);
sect_hdr = (image_section_header *)((vm_offset_t)nt_hdr +
sizeof(image_nt_header));
bcopy ((char *)sect_hdr, (char *)hdr, sizeof(image_section_header));
return(0);
}
/*
* Return the number of sections in this executable, or 0 on error.
*/
int
pe_numsections(imgbase)
vm_offset_t imgbase;
{
image_file_header file_hdr;
if (pe_get_file_header(imgbase, &file_hdr))
return(0);
return (file_hdr.ifh_numsections);
}
/*
* Return the base address that this image was linked for.
* This helps us calculate relocation addresses later.
*/
vm_offset_t
pe_imagebase(imgbase)
vm_offset_t imgbase;
{
image_optional_header optional_hdr;
if (pe_get_optional_header(imgbase, &optional_hdr))
return(0);
return (optional_hdr.ioh_imagebase);
}
/*
* Return the offset of a given directory structure within the
* image. Directories reside within sections.
*/
vm_offset_t
pe_directory_offset(imgbase, diridx)
vm_offset_t imgbase;
uint32_t diridx;
{
image_optional_header opt_hdr;
vm_offset_t dir;
if (pe_get_optional_header(imgbase, &opt_hdr))
return(0);
if (diridx >= opt_hdr.ioh_rva_size_cnt)
return(0);
dir = opt_hdr.ioh_datadir[diridx].idd_vaddr;
return(pe_translate_addr(imgbase, dir));
}
vm_offset_t
pe_translate_addr(imgbase, rva)
vm_offset_t imgbase;
uint32_t rva;
{
image_optional_header opt_hdr;
image_section_header *sect_hdr;
image_dos_header *dos_hdr;
image_nt_header *nt_hdr;
int i = 0, sections, fixedlen;
if (pe_get_optional_header(imgbase, &opt_hdr))
return(0);
sections = pe_numsections(imgbase);
dos_hdr = (image_dos_header *)imgbase;
nt_hdr = (image_nt_header *)(imgbase + dos_hdr->idh_lfanew);
sect_hdr = (image_section_header *)((vm_offset_t)nt_hdr +
sizeof(image_nt_header));
/*
* The test here is to see if the RVA falls somewhere
* inside the section, based on the section's start RVA
* and its length. However it seems sometimes the
* virtual length isn't enough to cover the entire
* area of the section. We fudge by taking into account
* the section alignment and rounding the section length
* up to a page boundary.
*/
while (i++ < sections) {
fixedlen = sect_hdr->ish_misc.ish_vsize;
fixedlen += ((opt_hdr.ioh_sectalign - 1) -
sect_hdr->ish_misc.ish_vsize) &
(opt_hdr.ioh_sectalign - 1);
if (sect_hdr->ish_vaddr <= (u_int32_t)rva &&
(sect_hdr->ish_vaddr + fixedlen) >
(u_int32_t)rva)
break;
sect_hdr++;
}
if (i > sections)
return(0);
return((vm_offset_t)(imgbase + rva - sect_hdr->ish_vaddr +
sect_hdr->ish_rawdataaddr));
}
/*
* Get the section header for a particular section. Note that
* section names can be anything, but there are some standard
* ones (.text, .data, .rdata, .reloc).
*/
int
pe_get_section(imgbase, hdr, name)
vm_offset_t imgbase;
image_section_header *hdr;
const char *name;
{
image_dos_header *dos_hdr;
image_nt_header *nt_hdr;
image_section_header *sect_hdr;
int i, sections;
if (imgbase == 0 || hdr == NULL)
return(EINVAL);
if (pe_is_nt_image(imgbase))
return (EINVAL);
sections = pe_numsections(imgbase);
dos_hdr = (image_dos_header *)imgbase;
nt_hdr = (image_nt_header *)(imgbase + dos_hdr->idh_lfanew);
sect_hdr = (image_section_header *)((vm_offset_t)nt_hdr +
sizeof(image_nt_header));
for (i = 0; i < sections; i++) {
if (!strcmp ((char *)§_hdr->ish_name, name)) {
bcopy((char *)sect_hdr, (char *)hdr,
sizeof(image_section_header));
return(0);
} else
sect_hdr++;
}
return (ENOEXEC);
}
/*
* Apply the base relocations to this image. The relocation table
* resides within the .reloc section. Relocations are specified in
* blocks which refer to a particular page. We apply the relocations
* one page block at a time.
*/
int
pe_relocate(imgbase)
vm_offset_t imgbase;
{
image_section_header sect;
image_base_reloc *relhdr;
uint16_t rel, *sloc;
uint32_t base, delta, *lloc;
int i, count;
vm_offset_t txt;
base = pe_imagebase(imgbase);
pe_get_section(imgbase, §, ".text");
txt = pe_translate_addr(imgbase, sect.ish_vaddr);
delta = (uint32_t)(txt) - base - sect.ish_vaddr;
pe_get_section(imgbase, §, ".reloc");
relhdr = (image_base_reloc *)(imgbase + sect.ish_rawdataaddr);
do {
count = (relhdr->ibr_blocksize -
(sizeof(uint32_t) * 2)) / sizeof(uint16_t);
for (i = 0; i < count; i++) {
rel = relhdr->ibr_rel[i];
switch (IMR_RELTYPE(rel)) {
case IMAGE_REL_BASED_ABSOLUTE:
break;
case IMAGE_REL_BASED_HIGHLOW:
lloc = (uint32_t *)pe_translate_addr(imgbase,
relhdr->ibr_vaddr + IMR_RELOFFSET(rel));
*lloc = pe_translate_addr(imgbase,
(*lloc - base));
break;
case IMAGE_REL_BASED_HIGH:
sloc = (uint16_t *)pe_translate_addr(imgbase,
relhdr->ibr_vaddr + IMR_RELOFFSET(rel));
*sloc += (delta & 0xFFFF0000) >> 16;
break;
case IMAGE_REL_BASED_LOW:
sloc = (uint16_t *)pe_translate_addr(imgbase,
relhdr->ibr_vaddr + IMR_RELOFFSET(rel));
*sloc += (delta & 0xFFFF);
break;
default:
printf ("[%d]reloc type: %d\n",i,
IMR_RELTYPE(rel));
break;
}
}
relhdr = (image_base_reloc *)((vm_offset_t)relhdr +
relhdr->ibr_blocksize);
} while (relhdr->ibr_blocksize);
return(0);
}
/*
* Return the import descriptor for a particular module. An image
* may be linked against several modules, typically HAL.dll, ntoskrnl.exe
* and NDIS.SYS. For each module, there is a list of imported function
* names and their addresses.
*/
int
pe_get_import_descriptor(imgbase, desc, module)
vm_offset_t imgbase;
image_import_descriptor *desc;
char *module;
{
vm_offset_t offset;
image_import_descriptor *imp_desc;
char *modname;
if (imgbase == 0 || module == NULL || desc == NULL)
return(EINVAL);
offset = pe_directory_offset(imgbase, IMAGE_DIRECTORY_ENTRY_IMPORT);
if (offset == 0)
return (ENOENT);
imp_desc = (void *)offset;
while (imp_desc->iid_nameaddr) {
modname = (char *)pe_translate_addr(imgbase,
imp_desc->iid_nameaddr);
if (!strncmp(module, modname, strlen(module))) {
bcopy((char *)imp_desc, (char *)desc,
sizeof(image_import_descriptor));
return(0);
}
imp_desc++;
}
return (ENOENT);
}
int
pe_get_messagetable(imgbase, md)
vm_offset_t imgbase;
message_resource_data **md;
{
image_resource_directory *rdir, *rtype;
image_resource_directory_entry *dent, *dent2;
image_resource_data_entry *rent;
vm_offset_t offset;
int i;
if (imgbase == 0)
return(EINVAL);
offset = pe_directory_offset(imgbase, IMAGE_DIRECTORY_ENTRY_RESOURCE);
if (offset == 0)
return (ENOENT);
rdir = (image_resource_directory *)offset;
dent = (image_resource_directory_entry *)(offset +
sizeof(image_resource_directory));
for (i = 0; i < rdir->ird_id_entries; i++){
if (dent->irde_name != RT_MESSAGETABLE) {
dent++;
continue;
}
dent2 = dent;
while (dent2->irde_dataoff & RESOURCE_DIR_FLAG) {
rtype = (image_resource_directory *)(offset +
(dent2->irde_dataoff & ~RESOURCE_DIR_FLAG));
dent2 = (image_resource_directory_entry *)
((uintptr_t)rtype +
sizeof(image_resource_directory));
}
rent = (image_resource_data_entry *)(offset +
dent2->irde_dataoff);
*md = (message_resource_data *)pe_translate_addr(imgbase,
rent->irde_offset);
return(0);
}
return(ENOENT);
}
int
pe_get_message(imgbase, id, str, len, flags)
vm_offset_t imgbase;
uint32_t id;
char **str;
int *len;
uint16_t *flags;
{
message_resource_data *md = NULL;
message_resource_block *mb;
message_resource_entry *me;
uint32_t i;
pe_get_messagetable(imgbase, &md);
if (md == NULL)
return(ENOENT);
mb = (message_resource_block *)((uintptr_t)md +
sizeof(message_resource_data));
for (i = 0; i < md->mrd_numblocks; i++) {
if (id >= mb->mrb_lowid && id <= mb->mrb_highid) {
me = (message_resource_entry *)((uintptr_t)md +
mb->mrb_entryoff);
for (i = id - mb->mrb_lowid; i > 0; i--)
me = (message_resource_entry *)((uintptr_t)me +
me->mre_len);
*str = me->mre_text;
*len = me->mre_len;
*flags = me->mre_flags;
return(0);
}
mb++;
}
return(ENOENT);
}
/*
* Find the function that matches a particular name. This doesn't
* need to be particularly speedy since it's only run when loading
* a module for the first time.
*/
static vm_offset_t
pe_functbl_match(functbl, name)
image_patch_table *functbl;
char *name;
{
image_patch_table *p;
if (functbl == NULL || name == NULL)
return(0);
p = functbl;
while (p->ipt_name != NULL) {
if (!strcmp(p->ipt_name, name))
return((uint32_t)p->ipt_func);
p++;
}
printf ("no match for %s\n", name);
return((vm_offset_t)p->ipt_func);
}
/*
* Patch the imported function addresses for a given module.
* The caller must specify the module name and provide a table
* of function pointers that will be patched into the jump table.
* Note that there are actually two copies of the jump table: one
* copy is left alone. In a .SYS file, the jump tables are usually
* merged into the INIT segment.
*
* Note: Windows uses the _stdcall calling convention. This means
* that the callback functions provided in the function table must
* be declared using __attribute__((__stdcall__)), otherwise the
* Windows code will likely screw up the %esp register and cause
* us to jump to an invalid address when it returns.
*/
int
pe_patch_imports(imgbase, module, functbl)
vm_offset_t imgbase;
char *module;
image_patch_table *functbl;
{
image_import_descriptor imp_desc;
char *fname;
vm_offset_t *nptr, *fptr;
vm_offset_t func;
if (imgbase == 0 || module == NULL || functbl == NULL)
return(EINVAL);
if (pe_get_import_descriptor(imgbase, &imp_desc, module))
return(ENOEXEC);
nptr = (vm_offset_t *)pe_translate_addr(imgbase,
imp_desc.iid_import_name_table_addr);
fptr = (vm_offset_t *)pe_translate_addr(imgbase,
imp_desc.iid_import_address_table_addr);
while (nptr != NULL && pe_translate_addr(imgbase, *nptr)) {
fname = (char *)pe_translate_addr(imgbase, (*nptr) + 2);
func = pe_functbl_match(functbl, fname);
if (func)
*fptr = func;
#ifdef notdef
if (*fptr == 0)
return(ENOENT);
#endif
nptr++;
fptr++;
}
return(0);
}
