/* Examine a pre-existing object file and extract its ELF header.
*/
static void readreferenceheader(char const *filename)
{
FILE *file;
file = fopen(filename, "rb");
if (!file)
fail("%s: %s", filename, strerror(errno));
if (!elfrw_read_Ehdr(file, &refehdr))
fail("%s: %s", filename, strerror(errno));
fclose(file);
output64 = refehdr.e_ident[EI_CLASS] == ELFCLASS64;
}
/* Read in the ELF header proper, and verify that its contents conform
* to what the program can decipher.
*/
static int readelfhdr(void)
{
if (elfrw_read_Ehdr(thefile, &elffhdr) != 1) {
if (ferror(thefile))
return err(NULL);
else
return err("%s: not an ELF file.", thefilename);
}
if (!checkelfident(elffhdr.e_ident))
return FALSE;
switch (elffhdr.e_type) {
case ET_REL:
case ET_EXEC:
case ET_DYN:
case ET_CORE:
break;
default:
return err("%s: unknown ELF file type (type = %u).",
thefilename, elffhdr.e_type);
}
if (elffhdr.e_ehsize != sizeof(Elf32_Ehdr) &&
elffhdr.e_ehsize != sizeof(Elf64_Ehdr))
return err("%s: warning: unrecognized ELF header size: %d.",
thefilename, elffhdr.e_ehsize);
if (elffhdr.e_version != EV_CURRENT)
return err("%s: unrecognized ELF header version: %u.",
thefilename, (unsigned int)elffhdr.e_version);
if (elffhdr.e_phoff != 0) {
if (elffhdr.e_phentsize != sizeof(Elf32_Phdr) &&
elffhdr.e_phentsize != sizeof(Elf64_Phdr))
err("%s: unrecognized program header entry size: %u.",
thefilename, elffhdr.e_phentsize);
else
proghdrs = 1;
}
if (elffhdr.e_shoff != 0) {
if (elffhdr.e_shentsize != sizeof(Elf32_Shdr) &&
elffhdr.e_shentsize != sizeof(Elf64_Shdr))
err("%s: unrecognized section header entry size: %u.",
thefilename, elffhdr.e_shentsize);
else
secthdrs = 1;
}
return TRUE;
}