.\" $NetBSD: gelf_newehdr.3,v 1.1.1.1 2009/12/19 05:43:40 thorpej Exp $ .\" .\" Copyright (c) 2006,2007 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 Joseph Koshy ``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 Joseph Koshy 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. .\" .\" $FreeBSD: src/lib/libelf/gelf_newehdr.3,v 1.4.2.1.2.1 2009/10/25 01:10:29 kensmith Exp $ .\" .Dd October 22, 2007 .Os .Dt GELF_NEWEHDR 3 .Sh NAME .Nm elf32_newehdr , .Nm elf64_newehdr , .Nm gelf_newehdr .Nd retrieve or allocate the object file header .Sh LIBRARY .Lb libelf .Sh SYNOPSIS .In libelf.h .Ft "Elf32_Ehdr *" .Fn elf32_newehdr "Elf *elf" .Ft "Elf64_Ehdr *" .Fn elf64_newehdr "Elf *elf" .In gelf.h .Ft "void *" .Fn gelf_newehdr "Elf *elf" "int elfclass" .Sh DESCRIPTION These functions retrieve the ELF header from the ELF descriptor .Ar elf , allocating a new header if needed. File data structures are translated to their in-memory representations as described in .Xr elf 3 . .Pp Function .Fn elf32_newehdr returns a pointer to a 32 bit .Vt Elf32_Ehdr structure. Function .Fn elf64_newehdr returns a pointer to a 64 bit .Vt Elf64_Ehdr structure. .Pp When argument .Ar elfclass has value .Dv ELFCLASS32 , function .Fn gelf_newehdr returns the value returned by .Fn elf32_newehdr "elf" . When argument .Ar elfclass has value .Dv ELFCLASS64 it returns the value returned by .Fn elf64_newehdr "elf" . .Pp If a fresh header structure is allocated, the members of the structure are initialized as follows: .Bl -tag -width indent .It Va "e_ident[EI_MAG0..EI_MAG3]" Identification bytes at offsets .Dv EI_MAG0 , .Dv EI_MAG1 , .Dv EI_MAG2 and .Dv EI_MAG3 are set to the ELF signature. .It Va "e_ident[EI_CLASS]" The identification byte at offset .Dv EI_CLASS is set to the ELF class associated with the function being called or to argument .Ar elfclass for function .Fn gelf_newehdr . .It Va "e_ident[EI_DATA]" The identification byte at offset .Dv EI_DATA is set to .Dv ELFDATANONE . .It Va "e_ident[EI_VERSION]" The identification byte at offset .Dv EI_VERSION is set to the ELF library's operating version set by a prior call to .Xr elf_version 3 . .It Va e_machine is set to .Dv EM_NONE . .It Va e_type is set to .Dv ELF_K_NONE . .It Va e_version is set to the ELF library's operating version set by a prior call to .Xr elf_version 3 . .El .Pp Other members of the header are set to zero. The application is responsible for changing these values as needed before calling .Fn elf_update . .Pp If successful, these three functions set the .Dv ELF_F_DIRTY flag on ELF descriptor .Ar elf . .Sh RETURN VALUES These functions return a pointer to a translated header descriptor if successful, or NULL on failure. .Sh ERRORS These functions can fail with the following errors: .Bl -tag -width "[ELF_E_RESOURCE]" .It Bq Er ELF_E_ARGUMENT The argument .Ar elf was null. .It Bq Er ELF_E_ARGUMENT Argument .Ar elf was not a descriptor for an ELF object. .It Bq Er ELF_E_ARGUMENT Argument .Ar elfclass had an unsupported value. .It Bq Er ELF_E_ARGUMENT The class of the ELF descriptor .Ar elf did not match that of the requested operation. .It Bq Er ELF_E_ARGUMENT For function .Fn gelf_newehdr , the class of argument .Ar elf was not .Dv ELFCLASSNONE and did not match the argument .Ar elfclass . .It Bq Er ELF_E_CLASS The ELF class of descriptor .Ar elf did not match that of the API function being called. .It Bq Er ELF_E_HEADER A malformed ELF header was detected. .It Bq Er ELF_E_RESOURCE An out of memory condition was detected during execution. .It Bq Er ELF_E_SECTION The ELF descriptor in argument .Ar elf did not adhere to the conventions used for extended numbering. .It Bq Er ELF_E_VERSION The ELF descriptor .Ar elf had an unsupported ELF version number. .El .Sh SEE ALSO .Xr elf 3 , .Xr elf32_getehdr 3 , .Xr elf64_getehdr 3 , .Xr elf_flagdata 3 , .Xr elf_getident 3 , .Xr elf_update 3 , .Xr elf_version 3 , .Xr gelf 3 , .Xr gelf_getehdr 3 , .Xr elf 5