/*-
* Copyright (c) 2016 Kai Wang
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 THE AUTHOR OR CONTRIBUTORS 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/param.h>
#include <err.h>
#include <gelf.h>
#include <libpe.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "elfcopy.h"
ELFTC_VCSID("$Id: pe.c 3508 2016-12-27 06:19:39Z kaiwang27 $");
/* Convert ELF object to Portable Executable (PE). */
void
create_pe(struct elfcopy *ecp, int ifd, int ofd)
{
Elf *e;
Elf_Scn *scn;
Elf_Data *d;
GElf_Ehdr eh;
GElf_Shdr sh;
PE *pe;
PE_Scn *ps;
PE_SecHdr psh;
PE_CoffHdr pch;
PE_OptHdr poh;
PE_Object po;
PE_Buffer *pb;
const char *name;
size_t indx;
time_t timestamp;
int elferr;
if (ecp->otf == ETF_EFI || ecp->oem == EM_X86_64)
po = PE_O_PE32P;
else
po = PE_O_PE32;
if ((e = elf_begin(ifd, ELF_C_READ, NULL)) == NULL)
errx(EXIT_FAILURE, "elf_begin() failed: %s",
elf_errmsg(-1));
if (gelf_getehdr(e, &eh) == NULL)
errx(EXIT_FAILURE, "gelf_getehdr() failed: %s",
elf_errmsg(-1));
if (elf_getshstrndx(e, &indx) == 0)
errx(EXIT_FAILURE, "elf_getshstrndx() failed: %s",
elf_errmsg(-1));
if ((pe = pe_init(ofd, PE_C_WRITE, po)) == NULL)
err(EXIT_FAILURE, "pe_init() failed");
/* Setup PE COFF header. */
memset(&pch, 0, sizeof(pch));
switch (ecp->oem) {
case EM_386:
pch.ch_machine = IMAGE_FILE_MACHINE_I386;
break;
case EM_X86_64:
pch.ch_machine = IMAGE_FILE_MACHINE_AMD64;
break;
default:
pch.ch_machine = IMAGE_FILE_MACHINE_UNKNOWN;
break;
}
if (elftc_timestamp(×tamp) != 0)
err(EXIT_FAILURE, "elftc_timestamp");
pch.ch_timestamp = (uint32_t) timestamp;
if (pe_update_coff_header(pe, &pch) < 0)
err(EXIT_FAILURE, "pe_update_coff_header() failed");
/* Setup PE optional header. */
memset(&poh, 0, sizeof(poh));
if (ecp->otf == ETF_EFI)
poh.oh_subsystem = IMAGE_SUBSYSTEM_EFI_APPLICATION;
poh.oh_entry = (uint32_t) eh.e_entry;
/*
* Default section alignment and file alignment. (Here the
* section alignment is set to the default page size of the
* archs supported. We should use different section alignment
* for some arch. (e.g. IA64)
*/
poh.oh_secalign = 0x1000;
poh.oh_filealign = 0x200;
/* Copy sections. */
scn = NULL;
while ((scn = elf_nextscn(e, scn)) != NULL) {
/*
* Read in ELF section.
*/
if (gelf_getshdr(scn, &sh) == NULL) {
warnx("gelf_getshdr() failed: %s", elf_errmsg(-1));
(void) elf_errno();
continue;
}
if ((name = elf_strptr(e, indx, sh.sh_name)) ==
NULL) {
warnx("elf_strptr() failed: %s", elf_errmsg(-1));
(void) elf_errno();
continue;
}
/* Skip sections unneeded. */
if (strcmp(name, ".shstrtab") == 0 ||
strcmp(name, ".symtab") == 0 ||
strcmp(name, ".strtab") == 0)
continue;
if ((d = elf_getdata(scn, NULL)) == NULL) {
warnx("elf_getdata() failed: %s", elf_errmsg(-1));
(void) elf_errno();
continue;
}
if (strcmp(name, ".text") == 0) {
poh.oh_textbase = (uint32_t) sh.sh_addr;
poh.oh_textsize = (uint32_t) roundup(sh.sh_size,
poh.oh_filealign);
} else {
if (po == PE_O_PE32 && strcmp(name, ".data") == 0)
poh.oh_database = sh.sh_addr;
if (sh.sh_type == SHT_NOBITS)
poh.oh_bsssize += (uint32_t)
roundup(sh.sh_size, poh.oh_filealign);
else if (sh.sh_flags & SHF_ALLOC)
poh.oh_datasize += (uint32_t)
roundup(sh.sh_size, poh.oh_filealign);
}
/*
* Create PE/COFF section.
*/
if ((ps = pe_newscn(pe)) == NULL) {
warn("pe_newscn() failed");
continue;
}
/*
* Setup PE/COFF section header. The section name is not
* NUL-terminated if its length happens to be 8. Long
* section name should be truncated for PE image according
* to the PE/COFF specification.
*/
memset(&psh, 0, sizeof(psh));
strncpy(psh.sh_name, name, sizeof(psh.sh_name));
psh.sh_addr = sh.sh_addr;
psh.sh_virtsize = sh.sh_size;
if (sh.sh_type != SHT_NOBITS)
psh.sh_rawsize = roundup(sh.sh_size, poh.oh_filealign);
else
psh.sh_char |= IMAGE_SCN_CNT_UNINITIALIZED_DATA;
/*
* Translate ELF section flags to PE/COFF section flags.
*/
psh.sh_char |= IMAGE_SCN_MEM_READ;
if (sh.sh_flags & SHF_WRITE)
psh.sh_char |= IMAGE_SCN_MEM_WRITE;
if (sh.sh_flags & SHF_EXECINSTR)
psh.sh_char |= IMAGE_SCN_MEM_EXECUTE |
IMAGE_SCN_CNT_CODE;
if ((sh.sh_flags & SHF_ALLOC) && (psh.sh_char & 0xF0) == 0)
psh.sh_char |= IMAGE_SCN_CNT_INITIALIZED_DATA;
/* Mark relocation section "discardable". */
if (strcmp(name, ".reloc") == 0)
psh.sh_char |= IMAGE_SCN_MEM_DISCARDABLE;
if (pe_update_section_header(ps, &psh) < 0) {
warn("pe_update_section_header() failed");
continue;
}
/* Copy section content. */
if ((pb = pe_newbuffer(ps)) == NULL) {
warn("pe_newbuffer() failed");
continue;
}
pb->pb_align = 1;
pb->pb_off = 0;
if (sh.sh_type != SHT_NOBITS) {
pb->pb_size = roundup(sh.sh_size, poh.oh_filealign);
if ((pb->pb_buf = calloc(1, pb->pb_size)) == NULL) {
warn("calloc failed");
continue;
}
memcpy(pb->pb_buf, d->d_buf, sh.sh_size);
}
}
elferr = elf_errno();
if (elferr != 0)
warnx("elf_nextscn() failed: %s", elf_errmsg(elferr));
/* Update PE optional header. */
if (pe_update_opt_header(pe, &poh) < 0)
err(EXIT_FAILURE, "pe_update_opt_header() failed");
/* Write out PE/COFF object. */
if (pe_update(pe) < 0)
err(EXIT_FAILURE, "pe_update() failed");
pe_finish(pe);
elf_end(e);
}