/* Compute simple checksum from permanent parts of the ELF file. Copyright (C) 2002, 2003, 2004, 2005, 2009 Red Hat, Inc. This file is part of Red Hat elfutils. Written by Ulrich Drepper , 2002. Red Hat elfutils is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. Red Hat elfutils is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with Red Hat elfutils; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. In addition, as a special exception, Red Hat, Inc. gives You the additional right to link the code of Red Hat elfutils with code licensed under any Open Source Initiative certified open source license (http://www.opensource.org/licenses/index.php) which requires the distribution of source code with any binary distribution and to distribute linked combinations of the two. Non-GPL Code permitted under this exception must only link to the code of Red Hat elfutils through those well defined interfaces identified in the file named EXCEPTION found in the source code files (the "Approved Interfaces"). The files of Non-GPL Code may instantiate templates or use macros or inline functions from the Approved Interfaces without causing the resulting work to be covered by the GNU General Public License. Only Red Hat, Inc. may make changes or additions to the list of Approved Interfaces. Red Hat's grant of this exception is conditioned upon your not adding any new exceptions. If you wish to add a new Approved Interface or exception, please contact Red Hat. You must obey the GNU General Public License in all respects for all of the Red Hat elfutils code and other code used in conjunction with Red Hat elfutils except the Non-GPL Code covered by this exception. If you modify this file, you may extend this exception to your version of the file, but you are not obligated to do so. If you do not wish to provide this exception without modification, you must delete this exception statement from your version and license this file solely under the GPL without exception. Red Hat elfutils is an included package of the Open Invention Network. An included package of the Open Invention Network is a package for which Open Invention Network licensees cross-license their patents. No patent license is granted, either expressly or impliedly, by designation as an included package. Should you wish to participate in the Open Invention Network licensing program, please visit www.openinventionnetwork.com . */ #ifdef HAVE_CONFIG_H # include #endif #include #include #include #include #include #include "gelf.h" #include "libelfP.h" #include "elf-knowledge.h" #ifndef LIBELFBITS # define LIBELFBITS 32 #endif /* The SECTION_STRIP_P macro wants to call into libebl which we cannot do and do not have to do here. Provide a dummy replacement. */ #define ebl_debugscn_p(ebl, name) true #define process_block(crc, data) \ __libelf_crc32 (crc, data->d_buf, data->d_size) long int elfw2(LIBELFBITS,checksum) (elf) Elf *elf; { size_t shstrndx; Elf_Scn *scn; long int result = 0; unsigned char *ident; bool same_byte_order; if (elf == NULL) return -1l; /* Find the section header string table. */ if (INTUSE(elf_getshdrstrndx) (elf, &shstrndx) < 0) { /* This can only happen if the ELF handle is not for real. */ __libelf_seterrno (ELF_E_INVALID_HANDLE); return -1l; } /* Determine whether the byte order of the file and that of the host is the same. */ ident = elf->state.ELFW(elf,LIBELFBITS).ehdr->e_ident; same_byte_order = ((ident[EI_DATA] == ELFDATA2LSB && __BYTE_ORDER == __LITTLE_ENDIAN) || (ident[EI_DATA] == ELFDATA2MSB && __BYTE_ORDER == __BIG_ENDIAN)); /* If we don't have native byte order, we will likely need to convert the data with xlate functions. We do it upfront instead of relocking mid-iteration. */ if (!likely (same_byte_order)) rwlock_wrlock (elf->lock); else rwlock_rdlock (elf->lock); /* Iterate over all sections to find those which are not strippable. */ scn = NULL; while ((scn = INTUSE(elf_nextscn) (elf, scn)) != NULL) { GElf_Shdr shdr_mem; GElf_Shdr *shdr; Elf_Data *data; /* Get the section header. */ shdr = INTUSE(gelf_getshdr) (scn, &shdr_mem); if (shdr == NULL) { __libelf_seterrno (ELF_E_INVALID_SECTION_HEADER); result = -1l; goto out; } if (SECTION_STRIP_P (shdr, INTUSE(elf_strptr) (elf, shstrndx, shdr->sh_name), true)) /* The section can be stripped. Don't use it. */ continue; /* Do not look at NOBITS sections. */ if (shdr->sh_type == SHT_NOBITS) continue; /* To compute the checksum we need to get to the data. For repeatable results we must use the external format. The data we get with 'elf'getdata' might be changed for endianess reasons. Therefore we use 'elf_rawdata' if possible. But this function can fail if the data was constructed by the program. In this case we have to use 'elf_getdata' and eventually convert the data to the external format. */ data = INTUSE(elf_rawdata) (scn, NULL); if (data != NULL) { /* The raw data is available. */ result = process_block (result, data); /* Maybe the user added more data. These blocks cannot be read using 'elf_rawdata'. Simply proceed with looking for more data block with 'elf_getdata'. */ } /* Iterate through the list of data blocks. */ while ((data = INTUSE(elf_getdata) (scn, data)) != NULL) /* If the file byte order is the same as the host byte order process the buffer directly. If the data is just a stream of bytes which the library will not convert we can use it as well. */ if (likely (same_byte_order) || data->d_type == ELF_T_BYTE) result = process_block (result, data); else { /* Convert the data to file byte order. */ if (INTUSE(elfw2(LIBELFBITS,xlatetof)) (data, data, ident[EI_DATA]) == NULL) { result = -1l; goto out; } result = process_block (result, data); /* And convert it back. */ if (INTUSE(elfw2(LIBELFBITS,xlatetom)) (data, data, ident[EI_DATA]) == NULL) { result = -1l; goto out; } } } out: rwlock_unlock (elf->lock); return result; } INTDEF(elfw2(LIBELFBITS,checksum))