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GELF_XLATETOF(3) FreeBSD Library Functions Manual GELF_XLATETOF(3)
NAME
elf32_xlate, elf64_xlate, gelf_xlate - translate data between files and
memory
LIBRARY
ELF Access Library (libelf, -lelf)
SYNOPSIS
#include <libelf.h>
Elf_Data *
elf32_xlatetof(Elf_Data *dst, Elf_Data *src, unsigned int file_encoding);
Elf_Data *
elf32_xlatetom(Elf_Data *dst, Elf_Data *src, unsigned int file_encoding);
Elf_Data *
elf64_xlatetof(Elf_Data *dst, Elf_Data *src, unsigned int file_encoding);
Elf_Data *
elf64_xlatetom(Elf_Data *dst, Elf_Data *src, unsigned int file_encoding);
#include <gelf.h>
Elf_Data *
gelf_xlatetof(Elf *elf, Elf_Data *dst, Elf_Data *src,
unsigned int file_encoding);
Elf_Data *
gelf_xlatetom(Elf *elf, Elf_Data *dst, Elf_Data *src,
unsigned int file_encoding);
DESCRIPTION
These functions translate between the file and memory representations of
ELF data structures. The in-memory representation of an ELF data
structure would conform to the byte ordering and data alignment
restrictions dictated by the host processor. As described in elf(3), the
file representation of this data structure could use a different byte
ordering from that of the host, or could use a different layout within
the file.
Functions elf32_xlatetom(), elf64_xlatetom(), and gelf_xlatetom()
translate data from file representations to native, in-memory
representations. Functions elf32_xlatetof(), elf64_xlatetof(), and
gelf_xlatetof() translate data from in-memory representations to file
representations.
Argument src denotes an Elf_Data descriptor describing the source to be
translated. The following elements of the descriptor need to be set
before invoking these functions:
d_buf Set to a valid pointer value denoting the beginning of the
data area to be translated.
d_size Set to the total size in bytes of the source data area to
be translated.
supported.
Argument dst describes the destination buffer. The following elements of
the Elf_Data descriptor need to be set before invoking these functions:
d_buf Set to a valid pointer value that denotes the start of the
destination buffer that will hold translated data. This
value may be the same as that of the source buffer, in
which case an in-place conversion will be attempted.
d_size Set to the size of the destination buffer in bytes. This
value will be modified if the function call succeeds.
d_version Set to the desired version number of the destination.
Currently only version EV_CURRENT is supported.
These translations routines allow the source and destination buffers to
coincide, in which case an in-place translation will be done if the
destination is large enough to hold the translated data. Other kinds of
overlap between the source and destination buffers are not permitted.
On successful completion of the translation request the following fields
of the dst descriptor would be modified:
d_size Set to the size in bytes of the translated data.
d_type Set to the d_type value of the source data descriptor.
Argument file_encoding specifies the encoding in which the file objects
are represented. It must be one of:
ELFDATANONE File objects use the library's native byte ordering.
ELFDATA2LSB File objects use a little-endian ordering.
ELFDATA2MSB File objects use a big-endian ordering.
The functions gelf_xlatetof() and gelf_xlatetom() select the appropriate
translation scheme based on the properties of argument elf.
RETURN VALUES
These functions return argument dst if successful, or NULL in case of an
error.
EXAMPLES
To translate a GElf_Rel structure to its LSB file representation use:
Elf_Data dst, src;
GElf_Rel rel;
Elf *e;
e = ...; /* See elf_begin(3). */
/* Set up the 'src' descriptor. */
memset(&src, 0, sizeof src);
src.d_buf = &rel;
src.d_size = sizeof(rel);
src.d_type = ELF_T_REL;
src.d_version = EV_CURRENT;
if (gelf_xlatetof(e, &dst, &src, ELFDATA2LSB) == NULL) {
printf("error: %s", elf_errmsg(0));
}
ERRORS
These functions may fail with the following errors:
[ELF_E_ARGUMENT] One of arguments src, dst or elf was NULL.
[ELF_E_ARGUMENT] Arguments src and dst were equal.
[ELF_E_ARGUMENT] The desired encoding parameter was not one of
ELFDATANONE, ELFDATA2LSB or ELFDATA2MSB.
[ELF_E_ARGUMENT] The d_type field of argument src specified an
unsupported type.
[ELF_E_DATA] The src argument specified a buffer size that was not
an integral multiple of its underlying type.
[ELF_E_DATA] The dst argument specified a buffer size that was too
small.
[ELF_E_DATA] Argument dst specified a destination buffer that
overlaps with the source buffer.
[ELF_E_DATA] The destination buffer for a conversion to memory had
an alignment inappropriate for the underlying ELF type.
[ELF_E_DATA] The source buffer for a conversion to file had an
alignment inappropriate for the underlying ELF type.
[ELF_E_UNIMPL] The version numbers for arguments dst and src were not
identical.
[ELF_E_UNIMPL] The argument src requested conversion for a type which
is not currently supported.
[ELF_E_VERSION] Argument src specified an unsupported version number.
SEE ALSO
elf(3), elf_getdata(3), gelf(3)
FreeBSD 14.0-RELEASE-p11 October 11, 2018 FreeBSD 14.0-RELEASE-p11