text: /*-
   * Copyright (c) 2006 Joseph Koshy
   * 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/cdefs.h>
  __FBSDID("$FreeBSD: releng/10.1/lib/libelf/elf_data.c 246978 2013-02-19 03:23:13Z markj $");
  
  #include <assert.h>
  #include <errno.h>
  #include <libelf.h>
  #include <stdlib.h>
  
  #include "_libelf.h"
  
  
  Elf_Data *
  elf_getdata(Elf_Scn *s, Elf_Data *d)
  {
  	Elf *e;
  	size_t fsz, msz, count;
  	int elfclass, elftype;
  	unsigned int sh_type;
  	uint64_t sh_align, sh_offset, sh_size;
  	int (*xlate)(char *_d, size_t _dsz, char *_s, size_t _c, int _swap);
  
  	if (s == NULL || (e = s->s_elf) == NULL || e->e_kind != ELF_K_ELF ||
  	    (d != NULL && s != d->d_scn)) {
  		LIBELF_SET_ERROR(ARGUMENT, 0);
  		return (NULL);
  	}
  
  	if (d == NULL && (d = STAILQ_FIRST(&s->s_data)) != NULL)
  		return (d);
  
  	if (d != NULL)
  		return (STAILQ_NEXT(d, d_next));
  
  	if (e->e_rawfile == NULL) {
  		LIBELF_SET_ERROR(SEQUENCE, 0);
  		return (NULL);
  	}
  
  	elfclass = e->e_class;
  
  	assert(elfclass == ELFCLASS32 || elfclass == ELFCLASS64);
  
  	if (elfclass == ELFCLASS32) {
  		sh_type   = s->s_shdr.s_shdr32.sh_type;
  		sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset;
  		sh_size   = (uint64_t) s->s_shdr.s_shdr32.sh_size;
  		sh_align  = (uint64_t) s->s_shdr.s_shdr32.sh_addralign;
  	} else {
  		sh_type   = s->s_shdr.s_shdr64.sh_type;
  		sh_offset = s->s_shdr.s_shdr64.sh_offset;
  		sh_size   = s->s_shdr.s_shdr64.sh_size;
  		sh_align  = s->s_shdr.s_shdr64.sh_addralign;
  	}
  
  	if (sh_type == SHT_NULL) {
  		LIBELF_SET_ERROR(SECTION, 0);
  		return (NULL);
  	}
  
  	if ((elftype = _libelf_xlate_shtype(sh_type)) < ELF_T_FIRST ||
  	    elftype > ELF_T_LAST || (sh_type != SHT_NOBITS &&
  	    sh_offset + sh_size > (uint64_t) e->e_rawsize)) {
  		LIBELF_SET_ERROR(SECTION, 0);
  		return (NULL);
  	}
  
  	if ((fsz = (elfclass == ELFCLASS32 ? elf32_fsize : elf64_fsize)
              (elftype, (size_t) 1, e->e_version)) == 0) {
  		LIBELF_SET_ERROR(UNIMPL, 0);
  		return (NULL);
  	}
  
  	if (sh_size % fsz) {
  		LIBELF_SET_ERROR(SECTION, 0);
  		return (NULL);
  	}
  
  	count = sh_size / fsz;
  
  	msz = _libelf_msize(elftype, elfclass, e->e_version);
  
  	assert(msz > 0);
  
  	if ((d = _libelf_allocate_data(s)) == NULL)
  		return (NULL);
  
  	d->d_buf     = NULL;
  	d->d_off     = 0;
  	d->d_align   = sh_align;
  	d->d_size    = msz * count;
  	d->d_type    = elftype;
  	d->d_version = e->e_version;
  
  	if (sh_type == SHT_NOBITS || sh_size == 0) {
  	        STAILQ_INSERT_TAIL(&s->s_data, d, d_next);
  		return (d);
          }
  
  	if ((d->d_buf = malloc(msz*count)) == NULL) {
  		(void) _libelf_release_data(d);
  		LIBELF_SET_ERROR(RESOURCE, 0);
  		return (NULL);
  	}
  
  	d->d_flags  |= LIBELF_F_MALLOCED;
  
  	xlate = _libelf_get_translator(elftype, ELF_TOMEMORY, elfclass);
  	if (!(*xlate)(d->d_buf, d->d_size, e->e_rawfile + sh_offset, count,
  	    e->e_byteorder != LIBELF_PRIVATE(byteorder))) {
  		_libelf_release_data(d);
  		LIBELF_SET_ERROR(DATA, 0);
  		return (NULL);
  	}
  
  	STAILQ_INSERT_TAIL(&s->s_data, d, d_next);
  
  	return (d);
  }
  
  Elf_Data *
  elf_newdata(Elf_Scn *s)
  {
  	Elf *e;
  	Elf_Data *d;
  
  	if (s == NULL || (e = s->s_elf) == NULL ||
  	    e->e_kind != ELF_K_ELF) {
  		LIBELF_SET_ERROR(ARGUMENT, 0);
  		return (NULL);
  	}
  
  	/*
  	 * elf_newdata() has to append a data descriptor, so
  	 * bring in existing section data if not already present.
  	 */
  	if (e->e_rawfile && s->s_size > 0 && STAILQ_EMPTY(&s->s_data))
  		if (elf_getdata(s, NULL) == NULL)
  			return (NULL);
  
  	if ((d = _libelf_allocate_data(s)) == NULL)
  		return (NULL);
  
  	STAILQ_INSERT_TAIL(&s->s_data, d, d_next);
  
  	d->d_align = 1;
  	d->d_buf = NULL;
  	d->d_off = (uint64_t) ~0;
  	d->d_size = 0;
  	d->d_type = ELF_T_BYTE;
  	d->d_version = LIBELF_PRIVATE(version);
  
  	(void) elf_flagscn(s, ELF_C_SET, ELF_F_DIRTY);
  
  	return (d);
  }
  
  /*
   * Retrieve a data descriptor for raw (untranslated) data for section
   * `s'.
   */
  
  Elf_Data *
  elf_rawdata(Elf_Scn *s, Elf_Data *d)
  {
  	Elf *e;
  	int elf_class;
  	uint32_t sh_type;
  	uint64_t sh_align, sh_offset, sh_size;
  
  	if (s == NULL || (e = s->s_elf) == NULL ||
  	    e->e_kind != ELF_K_ELF || e->e_rawfile == NULL) {
  		LIBELF_SET_ERROR(ARGUMENT, 0);
  		return (NULL);
  	}
  
  	if (d == NULL && (d = STAILQ_FIRST(&s->s_rawdata)) != NULL)
  		return (d);
  
  	if (d != NULL)
  		return (STAILQ_NEXT(d, d_next));
  
  	elf_class = e->e_class;
  
  	assert(elf_class == ELFCLASS32 || elf_class == ELFCLASS64);
  
  	if (elf_class == ELFCLASS32) {
  		sh_type   = s->s_shdr.s_shdr32.sh_type;
  		sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset;
  		sh_size   = (uint64_t) s->s_shdr.s_shdr32.sh_size;
  		sh_align  = (uint64_t) s->s_shdr.s_shdr32.sh_addralign;
  	} else {
  		sh_type   = s->s_shdr.s_shdr64.sh_type;
  		sh_offset = s->s_shdr.s_shdr64.sh_offset;
  		sh_size   = s->s_shdr.s_shdr64.sh_size;
  		sh_align  = s->s_shdr.s_shdr64.sh_addralign;
  	}
  
  	if (sh_type == SHT_NULL) {
  		LIBELF_SET_ERROR(SECTION, 0);
  		return (NULL);
  	}
  
  	if ((d = _libelf_allocate_data(s)) == NULL)
  		return (NULL);
  
  	d->d_buf     = (sh_type == SHT_NOBITS || sh_size == 0) ? NULL :
  	    e->e_rawfile + sh_offset;
  	d->d_off     = 0;
  	d->d_align   = sh_align;
  	d->d_size    = sh_size;
  	d->d_type    = ELF_T_BYTE;
  	d->d_version = e->e_version;
  
  	STAILQ_INSERT_TAIL(&s->s_rawdata, d, d_next);
  
  	return (d);
  }
  