12de3b87aSKai Wang /*-
22de3b87aSKai Wang * Copyright (c) 2006,2008 Joseph Koshy
32de3b87aSKai Wang * All rights reserved.
42de3b87aSKai Wang *
52de3b87aSKai Wang * Redistribution and use in source and binary forms, with or without
62de3b87aSKai Wang * modification, are permitted provided that the following conditions
72de3b87aSKai Wang * are met:
82de3b87aSKai Wang * 1. Redistributions of source code must retain the above copyright
92de3b87aSKai Wang * notice, this list of conditions and the following disclaimer.
102de3b87aSKai Wang * 2. Redistributions in binary form must reproduce the above copyright
112de3b87aSKai Wang * notice, this list of conditions and the following disclaimer in the
122de3b87aSKai Wang * documentation and/or other materials provided with the distribution.
132de3b87aSKai Wang *
142de3b87aSKai Wang * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
152de3b87aSKai Wang * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
162de3b87aSKai Wang * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
172de3b87aSKai Wang * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
182de3b87aSKai Wang * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
192de3b87aSKai Wang * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
202de3b87aSKai Wang * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
212de3b87aSKai Wang * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
222de3b87aSKai Wang * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
232de3b87aSKai Wang * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
242de3b87aSKai Wang * SUCH DAMAGE.
252de3b87aSKai Wang */
262de3b87aSKai Wang
272de3b87aSKai Wang #include <gelf.h>
282de3b87aSKai Wang
292de3b87aSKai Wang #include "_libelf.h"
302de3b87aSKai Wang
31*67d97fe7SEd Maste ELFTC_VCSID("$Id: libelf_checksum.c 3174 2015-03-27 17:13:41Z emaste $");
322de3b87aSKai Wang
332de3b87aSKai Wang static unsigned long
_libelf_sum(unsigned long c,const unsigned char * s,size_t size)342de3b87aSKai Wang _libelf_sum(unsigned long c, const unsigned char *s, size_t size)
352de3b87aSKai Wang {
362de3b87aSKai Wang if (s == NULL || size == 0)
372de3b87aSKai Wang return (c);
382de3b87aSKai Wang
392de3b87aSKai Wang while (size--)
402de3b87aSKai Wang c += *s++;
412de3b87aSKai Wang
422de3b87aSKai Wang return (c);
432de3b87aSKai Wang }
442de3b87aSKai Wang
45cf781b2eSEd Maste long
_libelf_checksum(Elf * e,int elfclass)462de3b87aSKai Wang _libelf_checksum(Elf *e, int elfclass)
472de3b87aSKai Wang {
482de3b87aSKai Wang size_t shn;
492de3b87aSKai Wang Elf_Scn *scn;
502de3b87aSKai Wang Elf_Data *d;
512de3b87aSKai Wang unsigned long checksum;
522de3b87aSKai Wang GElf_Ehdr eh;
532de3b87aSKai Wang GElf_Shdr shdr;
542de3b87aSKai Wang
552de3b87aSKai Wang if (e == NULL) {
562de3b87aSKai Wang LIBELF_SET_ERROR(ARGUMENT, 0);
572de3b87aSKai Wang return (0L);
582de3b87aSKai Wang }
592de3b87aSKai Wang
602de3b87aSKai Wang if (e->e_class != elfclass) {
612de3b87aSKai Wang LIBELF_SET_ERROR(CLASS, 0);
622de3b87aSKai Wang return (0L);
632de3b87aSKai Wang }
642de3b87aSKai Wang
652de3b87aSKai Wang if (gelf_getehdr(e, &eh) == NULL)
662de3b87aSKai Wang return (0);
672de3b87aSKai Wang
682de3b87aSKai Wang /*
692de3b87aSKai Wang * Iterate over all sections in the ELF file, computing the
702de3b87aSKai Wang * checksum along the way.
712de3b87aSKai Wang *
722de3b87aSKai Wang * The first section is always SHN_UNDEF and can be skipped.
732de3b87aSKai Wang * Non-allocatable sections are skipped, as are sections that
742de3b87aSKai Wang * could be affected by utilities such as strip(1).
752de3b87aSKai Wang */
762de3b87aSKai Wang
772de3b87aSKai Wang checksum = 0;
782de3b87aSKai Wang for (shn = 1; shn < e->e_u.e_elf.e_nscn; shn++) {
792de3b87aSKai Wang if ((scn = elf_getscn(e, shn)) == NULL)
802de3b87aSKai Wang return (0);
812de3b87aSKai Wang if (gelf_getshdr(scn, &shdr) == NULL)
822de3b87aSKai Wang return (0);
832de3b87aSKai Wang if ((shdr.sh_flags & SHF_ALLOC) == 0 ||
842de3b87aSKai Wang shdr.sh_type == SHT_DYNAMIC ||
852de3b87aSKai Wang shdr.sh_type == SHT_DYNSYM)
862de3b87aSKai Wang continue;
872de3b87aSKai Wang
882de3b87aSKai Wang d = NULL;
892de3b87aSKai Wang while ((d = elf_rawdata(scn, d)) != NULL)
902de3b87aSKai Wang checksum = _libelf_sum(checksum,
91cf781b2eSEd Maste (unsigned char *) d->d_buf, (size_t) d->d_size);
922de3b87aSKai Wang }
932de3b87aSKai Wang
942de3b87aSKai Wang /*
952de3b87aSKai Wang * Return a 16-bit checksum compatible with Solaris.
962de3b87aSKai Wang */
97cf781b2eSEd Maste return (long) (((checksum >> 16) & 0xFFFFUL) + (checksum & 0xFFFFUL));
982de3b87aSKai Wang }
99