1 files changed, 276 insertions, 0 deletions
diff --git a/lib/libelf/elf_data.c b/lib/libelf/elf_data.c
new file mode 100644
index 00000000000..a8178b3ccc4
--- /dev/null
+++ b/lib/libelf/elf_data.c
@@ -0,0 +1,276 @@
+/*-
+ * Copyright (c) 2006,2008,2011 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 <assert.h>
+#include <errno.h>
+#include <libelf.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "_libelf.h"
+
+ELFTC_VCSID("$Id: elf_data.c,v 1.1 2019/02/01 05:27:37 jsg Exp $");
+
+Elf_Data *
+elf_getdata(Elf_Scn *s, Elf_Data *ed)
+{
+	Elf *e;
+	unsigned int sh_type;
+	int elfclass, elftype;
+	size_t count, fsz, msz;
+	struct _Libelf_Data *d;
+	uint64_t sh_align, sh_offset, sh_size;
+	_libelf_translator_function *xlate;
+
+	d = (struct _Libelf_Data *) ed;
+
+	if (s == NULL || (e = s->s_elf) == NULL ||
+	    (d != NULL && s != d->d_scn)) {
+		LIBELF_SET_ERROR(ARGUMENT, 0);
+		return (NULL);
+	}
+
+	assert(e->e_kind == ELF_K_ELF);
+
+	if (d == NULL && (d = STAILQ_FIRST(&s->s_data)) != NULL)
+		return (&d->d_data);
+
+	if (d != NULL)
+		return (&STAILQ_NEXT(d, d_next)->d_data);
+
+	if (e->e_rawfile == NULL) {
+		/*
+		 * In the ELF_C_WRITE case, there is no source that
+		 * can provide data for the section.
+		 */
+		LIBELF_SET_ERROR(ARGUMENT, 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 > e->e_rawsize || sh_size > e->e_rawsize - sh_offset))) {
+		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);
+	}
+
+	if (sh_size / fsz > SIZE_MAX) {
+		LIBELF_SET_ERROR(RANGE, 0);
+		return (NULL);
+	}
+
+	count = (size_t) (sh_size / fsz);
+
+	msz = _libelf_msize(elftype, elfclass, e->e_version);
+
+	if (count > 0 && msz > SIZE_MAX / count) {
+		LIBELF_SET_ERROR(RANGE, 0);
+		return (NULL);
+	}
+
+	assert(msz > 0);
+	assert(count <= SIZE_MAX);
+	assert(msz * count <= SIZE_MAX);
+
+	if ((d = _libelf_allocate_data(s)) == NULL)
+		return (NULL);
+
+	d->d_data.d_buf     = NULL;
+	d->d_data.d_off     = 0;
+	d->d_data.d_align   = sh_align;
+	d->d_data.d_size    = msz * count;
+	d->d_data.d_type    = elftype;
+	d->d_data.d_version = e->e_version;
+
+	if (sh_type == SHT_NOBITS || sh_size == 0) {
+	        STAILQ_INSERT_TAIL(&s->s_data, d, d_next);
+		return (&d->d_data);
+        }
+
+	if ((d->d_data.d_buf = malloc(msz * count)) == NULL) {
+		(void) _libelf_release_data(d);
+		LIBELF_SET_ERROR(RESOURCE, 0);
+		return (NULL);
+	}
+
+	d->d_flags  |= LIBELF_F_DATA_MALLOCED;
+
+	xlate = _libelf_get_translator(elftype, ELF_TOMEMORY, elfclass,
+	    _libelf_elfmachine(e));
+	if (!(*xlate)(d->d_data.d_buf, (size_t) d->d_data.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->d_data);
+}
+
+Elf_Data *
+elf_newdata(Elf_Scn *s)
+{
+	Elf *e;
+	struct _Libelf_Data *d;
+
+	if (s == NULL || (e = s->s_elf) == NULL) {
+		LIBELF_SET_ERROR(ARGUMENT, 0);
+		return (NULL);
+	}
+
+	assert(e->e_kind == ELF_K_ELF);
+
+	/*
+	 * 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_data.d_align = 1;
+	d->d_data.d_buf = NULL;
+	d->d_data.d_off = (uint64_t) ~0;
+	d->d_data.d_size = 0;
+	d->d_data.d_type = ELF_T_BYTE;
+	d->d_data.d_version = LIBELF_PRIVATE(version);
+
+	(void) elf_flagscn(s, ELF_C_SET, ELF_F_DIRTY);
+
+	return (&d->d_data);
+}
+
+/*
+ * Retrieve a data descriptor for raw (untranslated) data for section
+ * `s'.
+ */
+
+Elf_Data *
+elf_rawdata(Elf_Scn *s, Elf_Data *ed)
+{
+	Elf *e;
+	int elf_class;
+	uint32_t sh_type;
+	struct _Libelf_Data *d;
+	uint64_t sh_align, sh_offset, sh_size;
+
+	if (s == NULL || (e = s->s_elf) == NULL || e->e_rawfile == NULL) {
+		LIBELF_SET_ERROR(ARGUMENT, 0);
+		return (NULL);
+	}
+
+	assert(e->e_kind == ELF_K_ELF);
+
+	d = (struct _Libelf_Data *) ed;
+
+	if (d == NULL && (d = STAILQ_FIRST(&s->s_rawdata)) != NULL)
+		return (&d->d_data);
+
+	if (d != NULL)
+		return (&STAILQ_NEXT(d, d_next)->d_data);
+
+	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 (sh_type != SHT_NOBITS &&
+	    (sh_offset > e->e_rawsize || sh_size > e->e_rawsize - sh_offset)) {
+		LIBELF_SET_ERROR(SECTION, 0);
+		return (NULL);
+	}
+
+	if ((d = _libelf_allocate_data(s)) == NULL)
+		return (NULL);
+
+	d->d_data.d_buf = (sh_type == SHT_NOBITS || sh_size == 0) ? NULL :
+	    e->e_rawfile + sh_offset;
+	d->d_data.d_off     = 0;
+	d->d_data.d_align   = sh_align;
+	d->d_data.d_size    = sh_size;
+	d->d_data.d_type    = ELF_T_BYTE;
+	d->d_data.d_version = e->e_version;
+
+	STAILQ_INSERT_TAIL(&s->s_rawdata, d, d_next);
+
+	return (&d->d_data);
+}