src/libelf-0.8.13/lib/gelftrans.c

/*
gelftrans.c - gelf_* translation functions.
Copyright (C) 2000 - 2001 Michael Riepe

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.

This library 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
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/

#include <private.h>

#if __LIBELF64

#ifndef lint
static const char rcsid[] = "@(#) $Id: gelftrans.c,v 1.10 2008/05/23 08:15:34 michael Exp $";
#endif /* lint */

#define check_and_copy(type, d, s, name, eret)		\
    do {						\
	if (sizeof((d)->name) < sizeof((s)->name)	\
	 && (type)(s)->name != (s)->name) {		\
	    seterr(ERROR_BADVALUE);			\
	    return (eret);				\
	}						\
	(d)->name = (type)(s)->name;			\
    } while (0)

/*
 * These macros are missing on some Linux systems
 */
#if !defined(ELF32_R_SYM) || !defined(ELF32_R_TYPE) || !defined(ELF32_R_INFO)
# undef ELF32_R_SYM
# undef ELF32_R_TYPE
# undef ELF32_R_INFO
# define ELF32_R_SYM(i)		((i)>>8)
# define ELF32_R_TYPE(i)	((unsigned char)(i))
# define ELF32_R_INFO(s,t)	(((s)<<8)+(unsigned char)(t))
#endif /* !defined(...) */

#if !defined(ELF64_R_SYM) || !defined(ELF64_R_TYPE) || !defined(ELF64_R_INFO)
# undef ELF64_R_SYM
# undef ELF64_R_TYPE
# undef ELF64_R_INFO
# define ELF64_R_SYM(i)		((i)>>32)
# define ELF64_R_TYPE(i)	((i)&0xffffffffL)
# define ELF64_R_INFO(s,t)	(((Elf64_Xword)(s)<<32)+((t)&0xffffffffL))
#endif /* !defined(...) */

static char*
get_addr_and_class(const Elf_Data *data, int ndx, Elf_Type type, unsigned *cls) {
    Scn_Data *sd = (Scn_Data*)data;
    Elf_Scn *scn;
    Elf *elf;
    size_t n;

    if (!sd) {
	return NULL;
    }
    elf_assert(sd->sd_magic == DATA_MAGIC);
    scn = sd->sd_scn;
    elf_assert(scn);
    elf_assert(scn->s_magic == SCN_MAGIC);
    elf = scn->s_elf;
    elf_assert(elf);
    elf_assert(elf->e_magic == ELF_MAGIC);
    if (elf->e_kind != ELF_K_ELF) {
	seterr(ERROR_NOTELF);
	return NULL;
    }
    if (!valid_class(elf->e_class)) {
	seterr(ERROR_UNKNOWN_CLASS);
	return NULL;
    }
    if (data->d_type != type) {
	seterr(ERROR_BADTYPE);
	return NULL;
    }
    n = _msize(elf->e_class, data->d_version, type);
    if (n == 0) {
	seterr(ERROR_UNIMPLEMENTED);
	return NULL;
    }
    if (ndx < 0 || data->d_size < (ndx + 1) * n) {
	seterr(ERROR_BADINDEX);
	return NULL;
    }
    if (!data->d_buf) {
	seterr(ERROR_NULLBUF);
	return NULL;
    }
    if (cls) {
	*cls = elf->e_class;
    }
    return (char*)data->d_buf + n * ndx;
}

GElf_Sym*
gelf_getsym(Elf_Data *src, int ndx, GElf_Sym *dst) {
    GElf_Sym buf;
    unsigned cls;
    char *tmp;

    if (!dst) {
	dst = &buf;
    }
    tmp = get_addr_and_class(src, ndx, ELF_T_SYM, &cls);
    if (!tmp) {
	return NULL;
    }
    if (cls == ELFCLASS64) {
	*dst = *(Elf64_Sym*)tmp;
    }
    else if (cls == ELFCLASS32) {
	Elf32_Sym *src = (Elf32_Sym*)tmp;

	check_and_copy(GElf_Word,     dst, src, st_name,  NULL);
	check_and_copy(unsigned char, dst, src, st_info,  NULL);
	check_and_copy(unsigned char, dst, src, st_other, NULL);
	check_and_copy(GElf_Half,     dst, src, st_shndx, NULL);
	check_and_copy(GElf_Addr,     dst, src, st_value, NULL);
	check_and_copy(GElf_Xword,    dst, src, st_size,  NULL);
    }
    else {
	seterr(ERROR_UNIMPLEMENTED);
	return NULL;
    }
    if (dst == &buf) {
	dst = (GElf_Sym*)malloc(sizeof(GElf_Sym));
	if (!dst) {
	    seterr(ERROR_MEM_SYM);
	    return NULL;
	}
	*dst = buf;
    }
    return dst;
}

int
gelf_update_sym(Elf_Data *dst, int ndx, GElf_Sym *src) {
    unsigned cls;
    char *tmp;

    tmp = get_addr_and_class(dst, ndx, ELF_T_SYM, &cls);
    if (!tmp) {
	return 0;
    }
    if (cls == ELFCLASS64) {
	*(Elf64_Sym*)tmp = *src;
    }
    else if (cls == ELFCLASS32) {
	Elf32_Sym *dst = (Elf32_Sym*)tmp;

	check_and_copy(Elf32_Word,    dst, src, st_name,  0);
	check_and_copy(Elf32_Addr,    dst, src, st_value, 0);
	check_and_copy(Elf32_Word,    dst, src, st_size,  0);
	check_and_copy(unsigned char, dst, src, st_info,  0);
	check_and_copy(unsigned char, dst, src, st_other, 0);
	check_and_copy(Elf32_Half,    dst, src, st_shndx, 0);
    }
    else {
	seterr(ERROR_UNIMPLEMENTED);
	return 0;
    }
    return 1;
}

GElf_Dyn*
gelf_getdyn(Elf_Data *src, int ndx, GElf_Dyn *dst) {
    GElf_Dyn buf;
    unsigned cls;
    char *tmp;

    if (!dst) {
	dst = &buf;
    }
    tmp = get_addr_and_class(src, ndx, ELF_T_DYN, &cls);
    if (!tmp) {
	return NULL;
    }
    if (cls == ELFCLASS64) {
	*dst = *(Elf64_Dyn*)tmp;
    }
    else if (cls == ELFCLASS32) {
	Elf32_Dyn *src = (Elf32_Dyn*)tmp;

	check_and_copy(GElf_Sxword, dst, src, d_tag,      NULL);
	check_and_copy(GElf_Xword,  dst, src, d_un.d_val, NULL);
    }
    else {
	seterr(ERROR_UNIMPLEMENTED);
	return NULL;
    }
    if (dst == &buf) {
	dst = (GElf_Dyn*)malloc(sizeof(GElf_Dyn));
	if (!dst) {
	    seterr(ERROR_MEM_DYN);
	    return NULL;
	}
	*dst = buf;
    }
    return dst;
}

int
gelf_update_dyn(Elf_Data *dst, int ndx, GElf_Dyn *src) {
    unsigned cls;
    char *tmp;

    tmp = get_addr_and_class(dst, ndx, ELF_T_DYN, &cls);
    if (!tmp) {
	return 0;
    }
    if (cls == ELFCLASS64) {
	*(Elf64_Dyn*)tmp = *src;
    }
    else if (cls == ELFCLASS32) {
	Elf32_Dyn *dst = (Elf32_Dyn*)tmp;

	check_and_copy(Elf32_Sword, dst, src, d_tag,      0);
	check_and_copy(Elf32_Word,  dst, src, d_un.d_val, 0);
    }
    else {
	seterr(ERROR_UNIMPLEMENTED);
	return 0;
    }
    return 1;
}

GElf_Rela*
gelf_getrela(Elf_Data *src, int ndx, GElf_Rela *dst) {
    GElf_Rela buf;
    unsigned cls;
    char *tmp;

    if (!dst) {
	dst = &buf;
    }
    tmp = get_addr_and_class(src, ndx, ELF_T_RELA, &cls);
    if (!tmp) {
	return NULL;
    }
    if (cls == ELFCLASS64) {
	*dst = *(Elf64_Rela*)tmp;
    }
    else if (cls == ELFCLASS32) {
	Elf32_Rela *src = (Elf32_Rela*)tmp;

	check_and_copy(GElf_Addr,   dst, src, r_offset, NULL);
	dst->r_info = ELF64_R_INFO((Elf64_Xword)ELF32_R_SYM(src->r_info),
				   (Elf64_Xword)ELF32_R_TYPE(src->r_info));
	check_and_copy(GElf_Sxword, dst, src, r_addend, NULL);
    }
    else {
	seterr(ERROR_UNIMPLEMENTED);
	return NULL;
    }
    if (dst == &buf) {
	dst = (GElf_Rela*)malloc(sizeof(GElf_Rela));
	if (!dst) {
	    seterr(ERROR_MEM_RELA);
	    return NULL;
	}
	*dst = buf;
    }
    return dst;
}

int
gelf_update_rela(Elf_Data *dst, int ndx, GElf_Rela *src) {
    unsigned cls;
    char *tmp;

    tmp = get_addr_and_class(dst, ndx, ELF_T_RELA, &cls);
    if (!tmp) {
	return 0;
    }
    if (cls == ELFCLASS64) {
	*(Elf64_Rela*)tmp = *src;
    }
    else if (cls == ELFCLASS32) {
	Elf32_Rela *dst = (Elf32_Rela*)tmp;

	check_and_copy(Elf32_Addr,  dst, src, r_offset, 0);
	if (ELF64_R_SYM(src->r_info) > 0xffffffUL
	 || ELF64_R_TYPE(src->r_info) > 0xffUL) {
	    seterr(ERROR_BADVALUE);
	    return 0;
	}
	dst->r_info = ELF32_R_INFO((Elf32_Word)ELF64_R_SYM(src->r_info),
				  (Elf32_Word)ELF64_R_TYPE(src->r_info));
	check_and_copy(Elf32_Sword, dst, src, r_addend, 0);
    }
    else {
	seterr(ERROR_UNIMPLEMENTED);
	return 0;
    }
    return 1;
}

GElf_Rel*
gelf_getrel(Elf_Data *src, int ndx, GElf_Rel *dst) {
    GElf_Rel buf;
    unsigned cls;
    char *tmp;

    if (!dst) {
	dst = &buf;
    }
    tmp = get_addr_and_class(src, ndx, ELF_T_REL, &cls);
    if (!tmp) {
	return NULL;
    }
    if (cls == ELFCLASS64) {
	*dst = *(Elf64_Rel*)tmp;
    }
    else if (cls == ELFCLASS32) {
	Elf32_Rel *src = (Elf32_Rel*)tmp;

	check_and_copy(GElf_Addr, dst, src, r_offset, NULL);
	dst->r_info = ELF64_R_INFO((Elf64_Xword)ELF32_R_SYM(src->r_info),
				   (Elf64_Xword)ELF32_R_TYPE(src->r_info));
    }
    else {
	seterr(ERROR_UNIMPLEMENTED);
	return NULL;
    }
    if (dst == &buf) {
	dst = (GElf_Rel*)malloc(sizeof(GElf_Rel));
	if (!dst) {
	    seterr(ERROR_MEM_REL);
	    return NULL;
	}
	*dst = buf;
    }
    return dst;
}

int
gelf_update_rel(Elf_Data *dst, int ndx, GElf_Rel *src) {
    unsigned cls;
    char *tmp;

    tmp = get_addr_and_class(dst, ndx, ELF_T_REL, &cls);
    if (!tmp) {
	return 0;
    }
    if (cls == ELFCLASS64) {
	*(Elf64_Rel*)tmp = *src;
    }
    else if (cls == ELFCLASS32) {
	Elf32_Rel *dst = (Elf32_Rel*)tmp;

	check_and_copy(Elf32_Addr, dst, src, r_offset, 0);
	if (ELF64_R_SYM(src->r_info) > 0xffffffUL
	 || ELF64_R_TYPE(src->r_info) > 0xffUL) {
	    seterr(ERROR_BADVALUE);
	    return 0;
	}
	dst->r_info = ELF32_R_INFO((Elf32_Word)ELF64_R_SYM(src->r_info),
				   (Elf32_Word)ELF64_R_TYPE(src->r_info));
    }
    else {
	seterr(ERROR_UNIMPLEMENTED);
	return 0;
    }
    return 1;
}

#if 0

GElf_Syminfo*
gelf_getsyminfo(Elf_Data *src, int ndx, GElf_Syminfo *dst) {
    seterr(ERROR_UNIMPLEMENTED);
    return NULL;
}

int
gelf_update_syminfo(Elf_Data *dst, int ndx, GElf_Syminfo *src) {
    seterr(ERROR_UNIMPLEMENTED);
    return 0;
}

GElf_Move*
gelf_getmove(Elf_Data *src, int ndx, GElf_Move *src) {
    seterr(ERROR_UNIMPLEMENTED);
    return NULL;
}

int
gelf_update_move(Elf_Data *dst, int ndx, GElf_Move *src) {
    seterr(ERROR_UNIMPLEMENTED);
    return 0;
}

#endif

#endif /* __LIBELF64 */