/*-
 * 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.
 *
 * $Id: _libelf.h,v 1.3 2020/05/18 06:46:23 jsg Exp $
 */

#ifndef __LIBELF_H_
#define __LIBELF_H_

#include <sys/queue.h>

#include "_libelf_config.h"

#include "_elftc.h"

/*
 * Library-private data structures.
 */

#define LIBELF_MSG_SIZE 256

struct _libelf_globals {
        int             libelf_arch;
        unsigned int    libelf_byteorder;
        int             libelf_class;
        int             libelf_error;
        int             libelf_fillchar;
        unsigned int    libelf_version;
        unsigned char   libelf_msg[LIBELF_MSG_SIZE];
};

extern struct _libelf_globals _libelf;

#define LIBELF_PRIVATE(N)       (_libelf.libelf_##N)

#define LIBELF_ELF_ERROR_MASK                   0xFF
#define LIBELF_OS_ERROR_SHIFT                   8

#define LIBELF_ERROR(E, O) (((E) & LIBELF_ELF_ERROR_MASK) |     \
        ((O) << LIBELF_OS_ERROR_SHIFT))

#define LIBELF_SET_ERROR(E, O) do {                                     \
                LIBELF_PRIVATE(error) = LIBELF_ERROR(ELF_E_##E, (O));   \
        } while (0)

#define LIBELF_ADJUST_AR_SIZE(S)        (((S) + 1U) & ~1U)

/*
 * Flags for library internal use.  These use the upper 16 bits of the
 * `e_flags' field.
 */
#define LIBELF_F_API_MASK       0x00FFFFU  /* Flags defined by the API. */
#define LIBELF_F_AR_HEADER      0x010000U  /* translated header available */
#define LIBELF_F_AR_VARIANT_SVR4 0x020000U /* BSD style ar(1) archive */
#define LIBELF_F_DATA_MALLOCED  0x040000U /* whether data was malloc'ed */
#define LIBELF_F_RAWFILE_MALLOC 0x080000U /* whether e_rawfile was malloc'ed */
#define LIBELF_F_RAWFILE_MMAP   0x100000U /* whether e_rawfile was mmap'ed */
#define LIBELF_F_SHDRS_LOADED   0x200000U /* whether all shdrs were read in */
#define LIBELF_F_SPECIAL_FILE   0x400000U /* non-regular file */

struct _Elf {
        int             e_activations;  /* activation count */
        unsigned int    e_byteorder;    /* ELFDATA* */
        int             e_class;        /* ELFCLASS*  */
        Elf_Cmd         e_cmd;          /* ELF_C_* used at creation time */
        int             e_fd;           /* associated file descriptor */
        unsigned int    e_flags;        /* ELF_F_* & LIBELF_F_* flags */
        Elf_Kind        e_kind;         /* ELF_K_* */
        Elf             *e_parent;      /* non-NULL for archive members */
        unsigned char   *e_rawfile;     /* uninterpreted bytes */
        off_t           e_rawsize;      /* size of uninterpreted bytes */
        unsigned int    e_version;      /* file version */

        /*
         * Header information for archive members.  See the
         * LIBELF_F_AR_HEADER flag.
         */
        union {
                Elf_Arhdr       *e_arhdr;       /* translated header */
                unsigned char   *e_rawhdr;      /* untranslated header */
        } e_hdr;

        union {
                struct {                /* ar(1) archives */
                        off_t   e_next; /* set by elf_rand()/elf_next() */
                        int     e_nchildren;
                        unsigned char *e_rawstrtab; /* file name strings */
                        size_t  e_rawstrtabsz;
                        unsigned char *e_rawsymtab;     /* symbol table */
                        size_t  e_rawsymtabsz;
                        Elf_Arsym *e_symtab;
                        size_t  e_symtabsz;
                } e_ar;
                struct {                /* regular ELF files */
                        union {
                                Elf32_Ehdr *e_ehdr32;
                                Elf64_Ehdr *e_ehdr64;
                        } e_ehdr;
                        union {
                                Elf32_Phdr *e_phdr32;
                                Elf64_Phdr *e_phdr64;
                        } e_phdr;
                        STAILQ_HEAD(, _Elf_Scn) e_scn;  /* section list */
                        size_t  e_nphdr;        /* number of Phdr entries */
                        size_t  e_nscn;         /* number of sections */
                        size_t  e_strndx;       /* string table section index */
                } e_elf;
        } e_u;
};

/*
 * The internal descriptor wrapping the "Elf_Data" type.
 */
struct _Libelf_Data {
        Elf_Data        d_data;         /* The exported descriptor. */
        Elf_Scn         *d_scn;         /* The containing section */
        unsigned int    d_flags;
        STAILQ_ENTRY(_Libelf_Data) d_next;
};

struct _Elf_Scn {
        union {
                Elf32_Shdr      s_shdr32;
                Elf64_Shdr      s_shdr64;
        } s_shdr;
        STAILQ_HEAD(, _Libelf_Data) s_data;     /* translated data */
        STAILQ_HEAD(, _Libelf_Data) s_rawdata;  /* raw data */
        STAILQ_ENTRY(_Elf_Scn) s_next;
        struct _Elf     *s_elf;         /* parent ELF descriptor */
        unsigned int    s_flags;        /* flags for the section as a whole */
        size_t          s_ndx;          /* index# for this section */
        uint64_t        s_offset;       /* managed by elf_update() */
        uint64_t        s_rawoff;       /* original offset in the file */
        uint64_t        s_size;         /* managed by elf_update() */
};


enum {
        ELF_TOFILE,
        ELF_TOMEMORY
};


/*
 * The LIBELF_COPY macros are used to copy fields from a GElf_*
 * structure to their 32-bit counterparts, while checking for out of
 * range values.
 *
 * - LIBELF_COPY_U32 :: copy an unsigned 32 bit field.
 * - LIBELF_COPY_S32 :: copy a signed 32 bit field.
 */

#define LIBELF_COPY_U32(DST, SRC, NAME) do {                    \
                if ((SRC)->NAME > UINT32_MAX) {                 \
                        LIBELF_SET_ERROR(RANGE, 0);             \
                        return (0);                             \
                }                                               \
                (DST)->NAME = (SRC)->NAME & 0xFFFFFFFFU;        \
        } while (0)

#define LIBELF_COPY_S32(DST, SRC, NAME) do {                    \
                if ((SRC)->NAME > INT32_MAX ||                  \
                    (SRC)->NAME < INT32_MIN) {                  \
                        LIBELF_SET_ERROR(RANGE, 0);             \
                        return (0);                             \
                }                                               \
                (DST)->NAME = (int32_t) (SRC)->NAME;            \
        } while (0)


/*
 * Function Prototypes.
 */

typedef int _libelf_translator_function(unsigned char *_dst, size_t dsz,
    unsigned char *_src, size_t _cnt, int _byteswap);

#ifdef __cplusplus
extern "C" {
#endif
struct _Libelf_Data *_libelf_allocate_data(Elf_Scn *_s);
Elf     *_libelf_allocate_elf(void);
Elf_Scn *_libelf_allocate_scn(Elf *_e, size_t _ndx);
Elf_Arhdr *_libelf_ar_gethdr(Elf *_e);
Elf     *_libelf_ar_open(Elf *_e, int _reporterror);
Elf     *_libelf_ar_open_member(int _fd, Elf_Cmd _c, Elf *_ar);
Elf_Arsym *_libelf_ar_process_bsd_symtab(Elf *_ar, size_t *_dst);
Elf_Arsym *_libelf_ar_process_svr4_symtab(Elf *_ar, size_t *_dst);
long     _libelf_checksum(Elf *_e, int _elfclass);
void    *_libelf_ehdr(Elf *_e, int _elfclass, int _allocate);
int     _libelf_elfmachine(Elf *_e);
unsigned int _libelf_falign(Elf_Type _t, int _elfclass);
size_t  _libelf_fsize(Elf_Type _t, int _elfclass, unsigned int _version,
    size_t count);
_libelf_translator_function *_libelf_get_translator(Elf_Type _t,
    int _direction, int _elfclass, int _elfmachine);
void    *_libelf_getphdr(Elf *_e, int _elfclass);
void    *_libelf_getshdr(Elf_Scn *_scn, int _elfclass);
void    _libelf_init_elf(Elf *_e, Elf_Kind _kind);
int     _libelf_load_section_headers(Elf *e, void *ehdr);
unsigned int _libelf_malign(Elf_Type _t, int _elfclass);
Elf     *_libelf_memory(unsigned char *_image, size_t _sz, int _reporterror);
size_t  _libelf_msize(Elf_Type _t, int _elfclass, unsigned int _version);
void    *_libelf_newphdr(Elf *_e, int _elfclass, size_t _count);
Elf     *_libelf_open_object(int _fd, Elf_Cmd _c, int _reporterror);
struct _Libelf_Data *_libelf_release_data(struct _Libelf_Data *_d);
void    _libelf_release_elf(Elf *_e);
Elf_Scn *_libelf_release_scn(Elf_Scn *_s);
int     _libelf_setphnum(Elf *_e, void *_eh, int _elfclass, size_t _phnum);
int     _libelf_setshnum(Elf *_e, void *_eh, int _elfclass, size_t _shnum);
int     _libelf_setshstrndx(Elf *_e, void *_eh, int _elfclass,
    size_t _shstrndx);
Elf_Data *_libelf_xlate(Elf_Data *_d, const Elf_Data *_s,
    unsigned int _encoding, int _elfclass, int _elfmachine, int _direction);
int     _libelf_xlate_shtype(uint32_t _sht);
#ifdef __cplusplus
}
#endif

#endif  /* __LIBELF_H_ */