summaryrefslogtreecommitdiff
path: root/ext/libelf/libelf_ehdr.c
diff options
context:
space:
mode:
Diffstat (limited to 'ext/libelf/libelf_ehdr.c')
-rw-r--r--ext/libelf/libelf_ehdr.c201
1 files changed, 201 insertions, 0 deletions
diff --git a/ext/libelf/libelf_ehdr.c b/ext/libelf/libelf_ehdr.c
new file mode 100644
index 000000000..c90394681
--- /dev/null
+++ b/ext/libelf/libelf_ehdr.c
@@ -0,0 +1,201 @@
+/*-
+ * 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.
+ *
+ * $FreeBSD: src/lib/libelf/libelf_ehdr.c,v 1.2 2006/12/25 02:22:22 jkoshy Exp $
+ */
+
+#include <assert.h>
+#include "gelf.h"
+#include "libelf.h"
+#include <stdlib.h>
+
+#include "_libelf.h"
+
+/*
+ * Retrieve counts for sections, phdrs and the section string table index
+ * from section header #0 of the ELF object.
+ */
+static int
+_libelf_load_extended(Elf *e, int ec, uint64_t shoff, uint16_t phnum,
+ uint16_t strndx)
+{
+ Elf_Scn *scn;
+ size_t fsz;
+ void (*xlator)(char *_d, char *_s, size_t _c, int _swap);
+ uint32_t shtype;
+
+ assert(STAILQ_EMPTY(&e->e_u.e_elf.e_scn));
+
+ fsz = _libelf_fsize(ELF_T_SHDR, ec, e->e_version, 1);
+ assert(fsz > 0);
+
+ if (e->e_rawsize < shoff + fsz) { /* raw file too small */
+ LIBELF_SET_ERROR(HEADER, 0);
+ return (0);
+ }
+
+ if ((scn = _libelf_allocate_scn(e, (size_t) 0)) == NULL)
+ return (0);
+
+ xlator = _libelf_get_translator(ELF_T_SHDR, ELF_TOMEMORY, ec);
+ (*xlator)((char *) &scn->s_shdr, e->e_rawfile + shoff, (size_t) 1,
+ e->e_byteorder != LIBELF_PRIVATE(byteorder));
+
+#define GET_SHDR_MEMBER(M) ((ec == ELFCLASS32) ? scn->s_shdr.s_shdr32.M : \
+ scn->s_shdr.s_shdr64.M)
+
+ if ((shtype = GET_SHDR_MEMBER(sh_type)) != SHT_NULL) {
+ LIBELF_SET_ERROR(SECTION, 0);
+ return (0);
+ }
+
+ e->e_u.e_elf.e_nscn = GET_SHDR_MEMBER(sh_size);
+ e->e_u.e_elf.e_nphdr = (phnum != PN_XNUM) ? phnum :
+ GET_SHDR_MEMBER(sh_info);
+ e->e_u.e_elf.e_strndx = (strndx != SHN_XINDEX) ? strndx :
+ GET_SHDR_MEMBER(sh_link);
+#undef GET_SHDR_MEMBER
+
+ return (1);
+}
+
+#define EHDR_INIT(E,SZ) do { \
+ Elf##SZ##_Ehdr *eh = (E); \
+ eh->e_ident[EI_MAG0] = ELFMAG0; \
+ eh->e_ident[EI_MAG1] = ELFMAG1; \
+ eh->e_ident[EI_MAG2] = ELFMAG2; \
+ eh->e_ident[EI_MAG3] = ELFMAG3; \
+ eh->e_ident[EI_CLASS] = ELFCLASS##SZ; \
+ eh->e_ident[EI_DATA] = ELFDATANONE; \
+ eh->e_ident[EI_VERSION] = LIBELF_PRIVATE(version); \
+ eh->e_machine = EM_NONE; \
+ eh->e_type = ELF_K_NONE; \
+ eh->e_version = LIBELF_PRIVATE(version); \
+ } while (0)
+
+void *
+_libelf_ehdr(Elf *e, int ec, int allocate)
+{
+ void *ehdr;
+ size_t fsz, msz;
+ uint16_t phnum, shnum, strndx;
+ uint64_t shoff;
+ void (*xlator)(char *_d, char *_s, size_t _c, int _swap);
+
+ assert(ec == ELFCLASS32 || ec == ELFCLASS64);
+
+ if (e == NULL || e->e_kind != ELF_K_ELF) {
+ LIBELF_SET_ERROR(ARGUMENT, 0);
+ return (NULL);
+ }
+
+ if (e->e_class != ELFCLASSNONE && e->e_class != ec) {
+ LIBELF_SET_ERROR(CLASS, 0);
+ return (NULL);
+ }
+
+ if (e->e_version != EV_CURRENT) {
+ LIBELF_SET_ERROR(VERSION, 0);
+ return (NULL);
+ }
+
+ if (e->e_class == ELFCLASSNONE)
+ e->e_class = ec;
+
+ if (ec == ELFCLASS32)
+ ehdr = (void *) e->e_u.e_elf.e_ehdr.e_ehdr32;
+ else
+ ehdr = (void *) e->e_u.e_elf.e_ehdr.e_ehdr64;
+
+ if (ehdr != NULL) /* already have a translated ehdr */
+ return (ehdr);
+
+ fsz = _libelf_fsize(ELF_T_EHDR, ec, e->e_version, (size_t) 1);
+ assert(fsz > 0);
+
+ if (e->e_cmd != ELF_C_WRITE && e->e_rawsize < fsz) {
+ LIBELF_SET_ERROR(HEADER, 0);
+ return (NULL);
+ }
+
+ msz = _libelf_msize(ELF_T_EHDR, ec, EV_CURRENT);
+
+ assert(msz > 0);
+
+ if ((ehdr = calloc((size_t) 1, msz)) == NULL) {
+ LIBELF_SET_ERROR(RESOURCE, 0);
+ return (NULL);
+ }
+
+ if (ec == ELFCLASS32) {
+ e->e_u.e_elf.e_ehdr.e_ehdr32 = ehdr;
+ EHDR_INIT(ehdr,32);
+ } else {
+ e->e_u.e_elf.e_ehdr.e_ehdr64 = ehdr;
+ EHDR_INIT(ehdr,64);
+ }
+
+ if (allocate)
+ e->e_flags |= ELF_F_DIRTY;
+
+ if (e->e_cmd == ELF_C_WRITE)
+ return (ehdr);
+
+ xlator = _libelf_get_translator(ELF_T_EHDR, ELF_TOMEMORY, ec);
+ (*xlator)(ehdr, e->e_rawfile, (size_t) 1,
+ e->e_byteorder != LIBELF_PRIVATE(byteorder));
+
+ /*
+ * If extended numbering is being used, read the correct
+ * number of sections and program header entries.
+ */
+ if (ec == ELFCLASS32) {
+ phnum = ((Elf32_Ehdr *) ehdr)->e_phnum;
+ shnum = ((Elf32_Ehdr *) ehdr)->e_shnum;
+ shoff = ((Elf32_Ehdr *) ehdr)->e_shoff;
+ strndx = ((Elf32_Ehdr *) ehdr)->e_shstrndx;
+ } else {
+ phnum = ((Elf64_Ehdr *) ehdr)->e_phnum;
+ shnum = ((Elf64_Ehdr *) ehdr)->e_shnum;
+ shoff = ((Elf64_Ehdr *) ehdr)->e_shoff;
+ strndx = ((Elf64_Ehdr *) ehdr)->e_shstrndx;
+ }
+
+ if (shnum >= SHN_LORESERVE ||
+ (shoff == 0LL && (shnum != 0 || phnum == PN_XNUM ||
+ strndx == SHN_XINDEX))) {
+ LIBELF_SET_ERROR(HEADER, 0);
+ return (NULL);
+ }
+
+ if (shnum != 0 || shoff == 0LL) { /* not using extended numbering */
+ e->e_u.e_elf.e_nphdr = phnum;
+ e->e_u.e_elf.e_nscn = shnum;
+ e->e_u.e_elf.e_strndx = strndx;
+ } else if (_libelf_load_extended(e, ec, shoff, phnum, strndx) == 0)
+ return (NULL);
+
+ return (ehdr);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-26 07:19:45 +0000