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/*!
* @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__
#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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