+/* This file is part of centaur.
+ *
+ * centaur is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License 2 as
+ * published by the Free Software Foundation.
+
+ * centaur 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 centaur. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*!
+ * @file types.h
+ * @brief libelfu's Elfu* types.
+ *
+ * libelfu provides an abstraction of the data in ELF files
+ * to more closely model the dependencies between them, and
+ * thus to facilitate consistent editing.
+ */
+
#ifndef __LIBELFU_TYPES_H__
#define __LIBELFU_TYPES_H__
-typedef enum {
- ELFU_ERROR = -1,
- ELFU_FALSE = 0,
- ELFU_TRUE = 1
-} ELFU_BOOL;
+#include <sys/queue.h>
+
+#include <elf.h>
+#include <gelf.h>
+
+
+/*!
+ * ELFU model of a symbol table entry.
+ */
+typedef struct ElfuSym {
+ /*! Offset into linked string table */
+ GElf_Word name;
+
+
+ /*! Explicit value */
+ GElf_Addr value;
+
+ /*! Size of object referenced */
+ GElf_Word size;
+
+
+ /*! Binding type (GLOBAL, LOCAL, ...) */
+ unsigned char bind;
+
+ /*! Type (FUNC, SECTION, ...) */
+ unsigned char type;
+
+ /*! Always 0, currently meaningless (see ELF spec) */
+ unsigned char other;
+
+
+ /*! If non-null, the section referenced. */
+ struct ElfuScn *scnptr;
+
+ /*! If scnptr is invalid, then this is ABS, COMMON, or UNDEF. */
+ int shndx;
+
+
+ /*! Entry in a symbol table */
+ CIRCLEQ_ENTRY(ElfuSym) elem;
+} ElfuSym;
+
+
+
+/*!
+ * ELFU model of a symbol table.
+ */
+typedef struct ElfuSymtab {
+ /*! All parsed symbols */
+ CIRCLEQ_HEAD(Syms, ElfuSym) syms;
+} ElfuSymtab;
+
+
+
+
+
+/*!
+ * ELFU model of a relocation entry.
+ */
+typedef struct ElfuRel {
+ /*! Location to patch */
+ GElf_Addr offset;
+
+
+ /*! Symbol to calculate value for */
+ GElf_Word sym;
+
+ /*! Relocation type (machine specific) */
+ unsigned char type;
+
+
+ /*! addendUsed == 0: Use addend from relocation destination (REL).
+ * addendUsed != 0: Use explicit addend (RELA). */
+ int addendUsed;
+
+ /*! Explicit addend in RELA tables */
+ GElf_Sword addend;
+
+
+ /*! Element in table */
+ CIRCLEQ_ENTRY(ElfuRel) elem;
+} ElfuRel;
+
+
+
+/*!
+ * ELFU model of a relocation table.
+ */
+typedef struct ElfuReltab {
+ /*! All parsed relocation entries */
+ CIRCLEQ_HEAD(Rels, ElfuRel) rels;
+} ElfuReltab;
+
+
+
+
+
+
+
+/*!
+ * ELFU model of an ELF section.
+ *
+ * Several members of the SHDR are repeated in abstract form and take
+ * precedence if present. For example, if linkptr is non-NULL then
+ * it points to another section and the SHDR's numeric sh_link member
+ * is to be ignored and recomputed by the layouter.
+ */
+typedef struct ElfuScn {
+ /*! SHDR as per ELF specification.
+ * Several values are ignored or recomputed from other members of
+ * ElfuScn. */
+ GElf_Shdr shdr;
+
+ /*! malloc()ed buffer containing this section's flat data backbuffer.
+ * Present for all sections that occupy space in the file. */
+ char *databuf;
+
+
+ /*! Pointer to a section, meaning dependent on sh_type.
+ * Preferred over sh_link if non-null. */
+ struct ElfuScn *linkptr;
+
+ /*! Pointer to a section, meaning dependent on sh_type.
+ * Preferred over sh_info if non-null. */
+ struct ElfuScn *infoptr;
+
+
+ /*! If this section is a clone of another section, then this
+ * points to that other section.
+ * Used during code injection to facilitate relocation. */
+ struct ElfuScn *oldptr;
+
+
+ /*! Translated contents of a symbol table. */
+ struct ElfuSymtab symtab;
+
+ /*! Translated contents of a relocation table. */
+ struct ElfuReltab reltab;
+
+
+ /*! Element linking this section into an ElfuPhdr's childScnList,
+ * or into an ElfuElf's orphanScnList. */
+ CIRCLEQ_ENTRY(ElfuScn) elemChildScn;
+} ElfuScn;
+
+
+
+/*!
+ * ELFU model of an ELF PHDR.
+ */
+typedef struct ElfuPhdr {
+ /*! PHDR as per ELF specification. */
+ GElf_Phdr phdr;
+
+
+ /*! Sections to be shifted in file/memory together with this PHDR */
+ CIRCLEQ_HEAD(ChildScnList, ElfuScn) childScnList;
+
+ /*! PHDRs to be shifted in file/memory together with this PHDR */
+ CIRCLEQ_HEAD(ChildPhdrList, ElfuPhdr) childPhdrList;
+
+
+ /*! Element linking this section into an ElfuPhdr's childPhdrList */
+ CIRCLEQ_ENTRY(ElfuPhdr) elemChildPhdr;
+
+ /*! Element linking this section into an ElfuElf's phdrList */
+ CIRCLEQ_ENTRY(ElfuPhdr) elem;
+} ElfuPhdr;
+
+
+
+/*!
+ * ELFU model of an ELF file header
+ */
+typedef struct {
+ /*! The ELF class -- ELFCLASS32/ELFCLASS64 */
+ int elfclass;
+
+ /*! EHDR as per ELF specification */
+ GElf_Ehdr ehdr;
+
+
+ /*! PHDRs that are not dependent on others.
+ * Usually, LOAD and GNU_STACK. */
+ CIRCLEQ_HEAD(PhdrList, ElfuPhdr) phdrList;
+
+ /*! Sections not in any PHDR, and thus not loaded at runtime.
+ * Usually .symtab, .strtab, .shstrtab, .debug_*, ... */
+ CIRCLEQ_HEAD(OrphanScnList, ElfuScn) orphanScnList;
+
+
+ /*! Pointer to ElfuScn containing .shstrtab.
+ * Parsed from EHDR for convenience. */
+ ElfuScn *shstrtab;
+
+ /*! Pointer to ElfuScn containing .symtab.
+ * Parsed from list of sections for convenience. */
+ ElfuScn *symtab;
+} ElfuElf;
#endif
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