libelf/src/elf32.c

/* @LICENSE(UNSW_OZPLB) */

/*
 * Australian Public Licence B (OZPLB)
 *
 * Version 1-0
 *
 * Copyright (c) 2004 University of New South Wales
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 * Developed by: Operating Systems and Distributed Systems Group (DiSy)
 *               University of New South Wales
 *               http://www.disy.cse.unsw.edu.au
 *
 * Permission is granted by University of New South Wales, free of charge, to
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 */
#include <elf/elf.h>
#include <elf/elf32.h>
#include <inttypes.h>
#include <string.h>

/* ELF header functions */
int elf32_checkFile(elf_t *elf)
{
    if (elf->elfSize < sizeof(Elf32_Ehdr)) {
        return -1; /* file smaller than ELF header */
    }

    if (elf_check_magic(elf->elfFile) < 0) {
        return -1; /* not an ELF file */
    }

    Elf32_Ehdr *header = elf->elfFile;
    if (header->e_ident[EI_CLASS] != ELFCLASS32) {
        return -1; /* not a 32-bit ELF */
    }

    if (header->e_phentsize != sizeof(Elf32_Phdr)) {
        return -1; /* unexpected program header size */
    }

    if (header->e_shentsize != sizeof(Elf32_Shdr)) {
        return -1; /* unexpected section header size */
    }

    if (header->e_shstrndx >= header->e_shnum) {
        return -1; /* invalid section header string table section */
    }

    elf->elfClass = header->e_ident[EI_CLASS];
    return 0; /* elf header looks OK */
}

int elf32_checkProgramHeaderTable(elf_t *elf)
{
    Elf32_Ehdr *header = elf->elfFile;
    size_t ph_end = header->e_phoff + header->e_phentsize * header->e_phnum;
    if (elf->elfSize < ph_end || ph_end < header->e_phoff) {
        return -1; /* invalid program header table */
    }

    return 0;
}

int elf32_checkSectionTable(elf_t *elf)
{
    Elf32_Ehdr *header = elf->elfFile;
    size_t sh_end = header->e_shoff + header->e_shentsize * header->e_shnum;
    if (elf->elfSize < sh_end || sh_end < header->e_shoff) {
        return -1; /* invalid section header table */
    }

    return 0;
}