/* Classification of ELF files.
Copyright (C) 2019 Red Hat, Inc.
This file is part of elfutils.
This file is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
elfutils 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <config.h>
#include <argp.h>
#include <error.h>
#include <fcntl.h>
#include <gelf.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
#include ELFUTILS_HEADER(elf)
#include ELFUTILS_HEADER(dwelf)
#include "printversion.h"
/* Name and version of program. */
ARGP_PROGRAM_VERSION_HOOK_DEF = print_version;
/* Bug report address. */
ARGP_PROGRAM_BUG_ADDRESS_DEF = PACKAGE_BUGREPORT;
/* Set by parse_opt. */
static int verbose;
/* Set by the main function. */
static const char *current_path;
/* Set by open_file. */
static int file_fd = -1;
/* Set by issue or elf_issue. */
static bool issue_found;
/* Non-fatal issue occured while processing the current_path. */
static void
issue (int e, const char *msg)
{
if (verbose >= 0)
{
if (current_path == NULL)
error (0, e, "%s", msg);
else
error (0, e, "%s '%s'", msg, current_path);
}
issue_found = true;
}
/* Non-fatal issue occured while processing the current ELF. */
static void
elf_issue (const char *msg)
{
if (verbose >= 0)
error (0, 0, "%s: %s: '%s'", msg, elf_errmsg (-1), current_path);
issue_found = true;
}
/* Set by parse_opt. */
static bool flag_only_regular_files;
static bool
open_file (void)
{
if (verbose > 1)
fprintf (stderr, "debug: processing file: %s\n", current_path);
file_fd = open (current_path, O_RDONLY | (flag_only_regular_files
? O_NOFOLLOW : 0));
if (file_fd < 0)
{
if (!flag_only_regular_files || errno != ELOOP)
issue (errno, N_("opening"));
return false;
}
struct stat st;
if (fstat (file_fd, &st) != 0)
{
issue (errno, N_("reading"));
return false;
}
/* Don't even bother with directories. */
if (S_ISDIR (st.st_mode)
|| (flag_only_regular_files && !S_ISREG (st.st_mode)))
return false;
return true;
}
static void
close_file (void)
{
if (file_fd >= 0)
{
close (file_fd);
file_fd = -1;
}
}
/* Set by open_elf. */
static Elf *elf;
/* Set by parse_opt. */
static bool flag_compressed;
static bool
open_elf (void)
{
if (!open_file ())
{
/* Make sure the file descriptor is gone. */
close_file ();
return false;
}
if (flag_compressed)
elf = dwelf_elf_begin (file_fd);
else
elf = elf_begin (file_fd, ELF_C_READ, NULL);
if (elf == NULL)
{
elf_issue ("opening ELF file");
close_file ();
return false;
}
return true;
}
static void
close_elf (void)
{
if (elf != NULL)
{
elf_end (elf);
elf = NULL;
}
close_file ();
}
static const char *
elf_kind_string (int kind)
{
switch (kind)
{
case ELF_K_NONE:
return "ELF_K_NONE";
case ELF_K_AR:
return "ELF_K_AR";
case ELF_K_COFF:
return "ELF_K_COFF"; /* libelf doesn't really support this. */
case ELF_K_ELF:
return "ELF_K_ELF";
default:
return "<unknown>";
}
}
static const char *
elf_type_string (int type)
{
switch (type)
{
case ET_NONE:
return "ET_NONE";
case ET_REL:
return "ET_REL";
case ET_EXEC:
return "ET_EXEC";
case ET_DYN:
return "ET_DYN";
case ET_CORE:
return "ET_CORE";
default:
return "<unknown>";
}
}
static int elf_type;
static bool has_program_load;
static bool has_sections;
static bool has_bits_alloc;
static bool has_program_interpreter;
static bool has_dynamic;
static bool has_soname;
static bool has_pie_flag;
static bool has_dt_debug;
static bool has_symtab;
static bool has_debug_sections;
static bool has_modinfo;
static bool has_gnu_linkonce_this_module;
static bool
run_classify (void)
{
/* Reset to unanalyzed default. */
elf_type = 0;
has_program_load = false;
has_sections = false;
has_bits_alloc = false;
has_program_interpreter = false;
has_dynamic = false;
has_soname = false;
has_pie_flag = false;
has_dt_debug = false;
has_symtab = false;
has_debug_sections = false;
has_modinfo = false;
has_gnu_linkonce_this_module = false;
int kind = elf_kind (elf);
if (verbose > 0)
fprintf (stderr, "info: %s: ELF kind: %s (0x%x)\n", current_path,
elf_kind_string (kind), kind);
if (kind != ELF_K_ELF)
return true;
GElf_Ehdr ehdr_storage;
GElf_Ehdr *ehdr = gelf_getehdr (elf, &ehdr_storage);
if (ehdr == NULL)
{
elf_issue (N_("ELF header"));
return false;
}
elf_type = ehdr->e_type;
/* Examine program headers. */
GElf_Phdr dyn_seg = { .p_type = 0 };
{
size_t nphdrs;
if (elf_getphdrnum (elf, &nphdrs) != 0)
{
elf_issue (N_("program headers"));
return false;
}
for (size_t phdr_idx = 0; phdr_idx < nphdrs; ++phdr_idx)
{
GElf_Phdr phdr_storage;
GElf_Phdr *phdr = gelf_getphdr (elf, phdr_idx, &phdr_storage);
if (phdr == NULL)
{
elf_issue (N_("program header"));
return false;
}
if (phdr->p_type == PT_DYNAMIC)
{
dyn_seg = *phdr;
has_dynamic = true;
}
if (phdr->p_type == PT_INTERP)
has_program_interpreter = true;
if (phdr->p_type == PT_LOAD)
has_program_load = true;
}
}
/* Do we have sections? */
{
size_t nshdrs;
if (elf_getshdrnum (elf, &nshdrs) != 0)
{
elf_issue (N_("section headers"));
return false;
}
if (nshdrs > 0)
has_sections = true;
}
{
size_t shstrndx;
if (unlikely (elf_getshdrstrndx (elf, &shstrndx) < 0))
{
elf_issue (N_("section header string table index"));
return false;
}
Elf_Scn *scn = NULL;
while (true)
{
scn = elf_nextscn (elf, scn);
if (scn == NULL)
break;
GElf_Shdr shdr_storage;
GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_storage);
if (shdr == NULL)
{
elf_issue (N_("could not obtain section header"));
return false;
}
const char *section_name = elf_strptr (elf, shstrndx, shdr->sh_name);
if (section_name == NULL)
{
elf_issue(N_("could not obtain section name"));
return false;
}
if (verbose > 2)
fprintf (stderr, "debug: section header %s (type %d) found\n",
section_name, shdr->sh_type);
if (shdr->sh_type == SHT_SYMTAB)
{
if (verbose > 1)
fputs ("debug: symtab section found\n", stderr);
has_symtab = true;
}
/* NOBITS and NOTE sections can be in any file. We want to be
sure there is at least one other allocated section. */
if (shdr->sh_type != SHT_NOBITS
&& shdr->sh_type != SHT_NOTE
&& (shdr->sh_flags & SHF_ALLOC) != 0)
{
if (verbose > 1 && !has_bits_alloc)
fputs ("debug: allocated (non-nobits/note) section found\n",
stderr);
has_bits_alloc = true;
}
const char *debug_prefix = ".debug_";
const char *zdebug_prefix = ".zdebug_";
if (strncmp (section_name, debug_prefix, strlen (debug_prefix)) == 0
|| strncmp (section_name, zdebug_prefix,
strlen (zdebug_prefix)) == 0)
{
if (verbose > 1 && !has_debug_sections)
fputs ("debug: .debug_* section found\n", stderr);
has_debug_sections = true;
}
if (strcmp (section_name, ".modinfo") == 0)
{
if (verbose > 1)
fputs ("debug: .modinfo section found\n", stderr);
has_modinfo = true;
}
if (strcmp (section_name, ".gnu.linkonce.this_module") == 0)
{
if (verbose > 1)
fputs ("debug: .gnu.linkonce.this_module section found\n",
stderr);
has_gnu_linkonce_this_module = true;
}
}
}
/* Examine the dynamic section. */
if (has_dynamic)
{
Elf_Data *data = elf_getdata_rawchunk (elf, dyn_seg.p_offset,
dyn_seg.p_filesz,
ELF_T_DYN);
if (data != NULL)
for (int dyn_idx = 0; ; ++dyn_idx)
{
GElf_Dyn dyn_storage;
GElf_Dyn *dyn = gelf_getdyn (data, dyn_idx, &dyn_storage);
if (dyn == NULL)
break;
if (verbose > 2)
fprintf (stderr, "debug: dynamic entry %d"
" with tag %llu found\n",
dyn_idx, (unsigned long long int) dyn->d_tag);
if (dyn->d_tag == DT_SONAME)
has_soname = true;
if (dyn->d_tag == DT_FLAGS_1 && (dyn->d_un.d_val & DF_1_PIE))
has_pie_flag = true;
if (dyn->d_tag == DT_DEBUG)
has_dt_debug = true;
if (dyn->d_tag == DT_NULL)
break;
}
}
if (verbose > 0)
{
fprintf (stderr, "info: %s: ELF type: %s (0x%x)\n", current_path,
elf_type_string (elf_type), elf_type);
if (has_program_load)
fprintf (stderr, "info: %s: PT_LOAD found\n", current_path);
if (has_sections)
fprintf (stderr, "info: %s: has sections\n", current_path);
if (has_bits_alloc)
fprintf (stderr, "info: %s: allocated (real) section found\n",
current_path);
if (has_program_interpreter)
fprintf (stderr, "info: %s: program interpreter found\n",
current_path);
if (has_dynamic)
fprintf (stderr, "info: %s: dynamic segment found\n", current_path);
if (has_soname)
fprintf (stderr, "info: %s: soname found\n", current_path);
if (has_pie_flag)
fprintf (stderr, "info: %s: DF_1_PIE flag found\n", current_path);
if (has_dt_debug)
fprintf (stderr, "info: %s: DT_DEBUG found\n", current_path);
if (has_symtab)
fprintf (stderr, "info: %s: symbol table found\n", current_path);
if (has_debug_sections)
fprintf (stderr, "info: %s: .debug_* section found\n", current_path);
if (has_modinfo)
fprintf (stderr, "info: %s: .modinfo section found\n", current_path);
if (has_gnu_linkonce_this_module)
fprintf (stderr,
"info: %s: .gnu.linkonce.this_module section found\n",
current_path);
}
return true;
}
static bool
is_elf (void)
{
return elf_kind (elf) != ELF_K_NONE;
}
static bool
is_elf_file (void)
{
return elf_kind (elf) == ELF_K_ELF;
}
static bool
is_elf_archive (void)
{
return elf_kind (elf) == ELF_K_AR;
}
static bool
is_core (void)
{
return elf_kind (elf) == ELF_K_ELF && elf_type == ET_CORE;
}
/* Return true if the file is a loadable object, which basically means
it is an ELF file, but not a relocatable object or a core dump
file. (The kernel and various userspace components can load ET_REL
files, but we disregard that for our classification purposes.) */
static bool
is_loadable (void)
{
return elf_kind (elf) == ELF_K_ELF
&& (elf_type == ET_EXEC || elf_type == ET_DYN)
&& has_program_load
&& (!has_sections || has_bits_alloc); /* It isn't debug-only. */
}
/* Return true if the file is an ELF file which has a symbol table or
.debug_* sections (and thus can be stripped futher). */
static bool
is_unstripped (void)
{
return elf_kind (elf) != ELF_K_NONE
&& (elf_type == ET_REL || elf_type == ET_EXEC || elf_type == ET_DYN)
&& (has_symtab || has_debug_sections);
}
/* Return true if the file contains only debuginfo, but no loadable
program bits. Then it is most likely a separate .debug file, a dwz
multi-file or a .dwo file. Note that it can still be loadable,
but in that case the phdrs shouldn't be trusted. */
static bool
is_debug_only (void)
{
return elf_kind (elf) != ELF_K_NONE
&& (elf_type == ET_REL || elf_type == ET_EXEC || elf_type == ET_DYN)
&& (has_debug_sections || has_symtab)
&& !has_bits_alloc;
}
static bool
is_shared (void)
{
if (!is_loadable ())
return false;
/* The ELF type is very clear: this is an executable. */
if (elf_type == ET_EXEC)
return false;
/* If there is no dynamic section, the file cannot be loaded as a
shared object. */
if (!has_dynamic)
return false;
/* If the object is marked as PIE, it is definitely an executable,
and not a loadlable shared object. */
if (has_pie_flag)
return false;
/* Treat a DT_SONAME tag as a strong indicator that this is a shared
object. */
if (has_soname)
return true;
/* This is probably a PIE program: there is no soname, but a program
interpreter. In theory, this file could be also a DSO with a
soname implied by its file name that can be run as a program.
This situation is impossible to resolve in the general case. */
if (has_program_interpreter)
return false;
/* Roland McGrath mentions in
<https://www.sourceware.org/ml/libc-alpha/2015-03/msg00605.html>,
that “we defined a PIE as an ET_DYN with a DT_DEBUG”. This
matches current binutils behavior (version 2.32). DT_DEBUG is
added if bfd_link_executable returns true or if bfd_link_pic
returns false, depending on the architectures. However, DT_DEBUG
is not documented as being specific to executables, therefore use
it only as a low-priority discriminator. */
if (has_dt_debug)
return false;
return true;
}
static bool
is_executable (void)
{
if (!is_loadable ())
return false;
/* A loadable object which is not a shared object is treated as an
executable. */
return !is_shared ();
}
/* Like is_executable, but the object can also be a shared library at
the same time. */
static bool
is_program (void)
{
if (!is_loadable ())
return false;
/* The ELF type is very clear: this is an executable. */
if (elf_type == ET_EXEC)
return true;
/* If the object is marked as PIE, it is definitely an executable,
and not a loadlable shared object. */
if (has_pie_flag)
return true;
/* This is probably a PIE program. It isn't ET_EXEC, but has a
program interpreter. In theory, this file could be also a DSO
with a soname. This situation is impossible to resolve in the
general case. See is_shared. This is different from
is_executable. */
if (has_program_interpreter)
return true;
/* Roland McGrath mentions in
<https://www.sourceware.org/ml/libc-alpha/2015-03/msg00605.html>,
that “we defined a PIE as an ET_DYN with a DT_DEBUG”. This
matches current binutils behavior (version 2.32). DT_DEBUG is
added if bfd_link_executable returns true or if bfd_link_pic
returns false, depending on the architectures. However, DT_DEBUG
is not documented as being specific to executables, therefore use
it only as a low-priority discriminator. */
if (has_dt_debug)
return true;
return false;
}
/* Like is_shared but the library could also be an executable. */
static bool
is_library (void)
{
/* Only ET_DYN can be shared libraries. */
if (elf_type != ET_DYN)
return false;
if (!is_loadable ())
return false;
/* Without a PT_DYNAMIC segment the library cannot be loaded. */
if (!has_dynamic)
return false;
/* This really is a (PIE) executable. See is_shared. */
if (has_pie_flag || has_dt_debug)
return false;
/* It could still (also) be a (PIE) executable, but most likely you
can dlopen it just fine. */
return true;
}
/* Returns true if the file is a linux kernel module (is ET_REL and
has the two magic sections .modinfo and .gnu.linkonce.this_module). */
static bool
is_linux_kernel_module (void)
{
return (elf_kind (elf) == ELF_K_ELF
&& elf_type == ET_REL
&& has_modinfo
&& has_gnu_linkonce_this_module);
}
enum classify_requirement { do_not_care, required, forbidden };
enum classify_check
{
classify_elf,
classify_elf_file,
classify_elf_archive,
classify_core,
classify_unstripped,
classify_executable,
classify_program,
classify_shared,
classify_library,
classify_linux_kernel_module,
classify_debug_only,
classify_loadable,
classify_check_last = classify_loadable
};
enum
{
classify_check_offset = 1000,
classify_check_not_offset = 2000,
classify_flag_stdin = 3000,
classify_flag_stdin0,
classify_flag_no_stdin,
classify_flag_print,
classify_flag_print0,
classify_flag_no_print,
classify_flag_matching,
classify_flag_not_matching,
};
static bool
classify_check_positive (int key)
{
return key >= classify_check_offset
&& key <= classify_check_offset + classify_check_last;
}
static bool
classify_check_negative (int key)
{
return key >= classify_check_not_offset
&& key <= classify_check_not_offset + classify_check_last;
}
/* Set by parse_opt. */
static enum classify_requirement requirements[classify_check_last + 1];
static enum { no_stdin, do_stdin, do_stdin0 } flag_stdin;
static enum { no_print, do_print, do_print0 } flag_print;
static bool flag_print_matching = true;
static error_t
parse_opt (int key, char *arg __attribute__ ((unused)),
struct argp_state *state __attribute__ ((unused)))
{
if (classify_check_positive (key))
requirements[key - classify_check_offset] = required;
else if (classify_check_negative (key))
requirements[key - classify_check_not_offset] = forbidden;
else
switch (key)
{
case 'v':
++verbose;
break;
case 'q':
--verbose;
break;
case 'z':
flag_compressed = true;
break;
case 'f':
flag_only_regular_files = true;
break;
case classify_flag_stdin:
flag_stdin = do_stdin;
break;
case classify_flag_stdin0:
flag_stdin = do_stdin0;
break;
case classify_flag_no_stdin:
flag_stdin = no_stdin;
break;
case classify_flag_print:
flag_print = do_print;
break;
case classify_flag_print0:
flag_print = do_print0;
break;
case classify_flag_no_print:
flag_print = no_print;
break;
case classify_flag_matching:
flag_print_matching = true;
break;
case classify_flag_not_matching:
flag_print_matching = false;
break;
default:
return ARGP_ERR_UNKNOWN;
}
return 0;
}
/* Perform requested checks against the file at current_path. If
necessary, sets *STATUS to 1 if checks failed. */
static void
process_current_path (int *status)
{
bool checks_passed = true;
if (open_elf () && run_classify ())
{
bool checks[] =
{
[classify_elf] = is_elf (),
[classify_elf_file] = is_elf_file (),
[classify_elf_archive] = is_elf_archive (),
[classify_core] = is_core (),
[classify_unstripped] = is_unstripped (),
[classify_executable] = is_executable (),
[classify_program] = is_program (),
[classify_shared] = is_shared (),
[classify_library] = is_library (),
[classify_linux_kernel_module] = is_linux_kernel_module (),
[classify_debug_only] = is_debug_only (),
[classify_loadable] = is_loadable (),
};
if (verbose > 1)
{
if (checks[classify_elf])
fprintf (stderr, "debug: %s: elf\n", current_path);
if (checks[classify_elf_file])
fprintf (stderr, "debug: %s: elf_file\n", current_path);
if (checks[classify_elf_archive])
fprintf (stderr, "debug: %s: elf_archive\n", current_path);
if (checks[classify_core])
fprintf (stderr, "debug: %s: core\n", current_path);
if (checks[classify_unstripped])
fprintf (stderr, "debug: %s: unstripped\n", current_path);
if (checks[classify_executable])
fprintf (stderr, "debug: %s: executable\n", current_path);
if (checks[classify_program])
fprintf (stderr, "debug: %s: program\n", current_path);
if (checks[classify_shared])
fprintf (stderr, "debug: %s: shared\n", current_path);
if (checks[classify_library])
fprintf (stderr, "debug: %s: library\n", current_path);
if (checks[classify_linux_kernel_module])
fprintf (stderr, "debug: %s: linux kernel module\n", current_path);
if (checks[classify_debug_only])
fprintf (stderr, "debug: %s: debug-only\n", current_path);
if (checks[classify_loadable])
fprintf (stderr, "debug: %s: loadable\n", current_path);
}
for (enum classify_check check = 0;
check <= classify_check_last; ++check)
switch (requirements[check])
{
case required:
if (!checks[check])
checks_passed = false;
break;
case forbidden:
if (checks[check])
checks_passed = false;
break;
case do_not_care:
break;
}
}
else if (file_fd == -1)
checks_passed = false; /* There is nothing to check, bad file. */
else
{
for (enum classify_check check = 0;
check <= classify_check_last; ++check)
if (requirements[check] == required)
checks_passed = false;
}
close_elf ();
switch (flag_print)
{
case do_print:
if (checks_passed == flag_print_matching)
puts (current_path);
break;
case do_print0:
if (checks_passed == flag_print_matching)
if (fwrite (current_path, strlen (current_path) + 1, 1, stdout) < 1)
issue (errno, N_("writing to standard output"));
break;
case no_print:
if (!checks_passed)
*status = 1;
break;
}
}
/* Called to process standard input if flag_stdin is not no_stdin. */
static void
process_stdin (int *status)
{
char delim;
if (flag_stdin == do_stdin0)
delim = '\0';
else
delim = '\n';
char *buffer = NULL;
size_t buffer_size = 0;
while (true)
{
ssize_t ret = getdelim (&buffer, &buffer_size, delim, stdin);
if (ferror (stdin))
{
current_path = NULL;
issue (errno, N_("reading from standard input"));
break;
}
if (feof (stdin))
break;
if (ret < 0)
abort (); /* Cannot happen due to error checks above. */
if (delim != '\0' && ret > 0 && buffer[ret - 1] == '\n')
buffer[ret - 1] = '\0';
current_path = buffer;
process_current_path (status);
}
free (buffer);
}
int
main (int argc, char **argv)
{
const struct argp_option options[] =
{
{ NULL, 0, NULL, OPTION_DOC, N_("Classification options"), 1 },
{ "elf", classify_check_offset + classify_elf, NULL, 0,
N_("File looks like an ELF object or archive/static library (default)")
, 1 },
{ "elf-file", classify_check_offset + classify_elf_file, NULL, 0,
N_("File is an regular ELF object (not an archive/static library)")
, 1 },
{ "elf-archive", classify_check_offset + classify_elf_archive, NULL, 0,
N_("File is an ELF archive or static library")
, 1 },
{ "core", classify_check_offset + classify_core, NULL, 0,
N_("File is an ELF core dump file")
, 1 },
{ "unstripped", classify_check_offset + classify_unstripped, NULL, 0,
N_("File is an ELF file with symbol table or .debug_* sections \
and can be stripped further"), 1 },
{ "executable", classify_check_offset + classify_executable, NULL, 0,
N_("File is (primarily) an ELF program executable \
(not primarily a DSO)"), 1 },
{ "program", classify_check_offset + classify_program, NULL, 0,
N_("File is an ELF program executable \
(might also be a DSO)"), 1 },
{ "shared", classify_check_offset + classify_shared, NULL, 0,
N_("File is (primarily) an ELF shared object (DSO) \
(not primarily an executable)"), 1 },
{ "library", classify_check_offset + classify_library, NULL, 0,
N_("File is an ELF shared object (DSO) \
(might also be an executable)"), 1 },
{ "linux-kernel-module", (classify_check_offset
+ classify_linux_kernel_module), NULL, 0,
N_("File is a linux kernel module"), 1 },
{ "debug-only", (classify_check_offset + classify_debug_only), NULL, 0,
N_("File is a debug only ELF file \
(separate .debug, .dwo or dwz multi-file)"), 1 },
{ "loadable", classify_check_offset + classify_loadable, NULL, 0,
N_("File is a loadable ELF object (program or shared object)"), 1 },
/* Negated versions of the above. */
{ "not-elf", classify_check_not_offset + classify_elf,
NULL, OPTION_HIDDEN, NULL, 1 },
{ "not-elf-file", classify_check_not_offset + classify_elf_file,
NULL, OPTION_HIDDEN, NULL, 1 },
{ "not-elf-archive", classify_check_not_offset + classify_elf_archive,
NULL, OPTION_HIDDEN, NULL, 1 },
{ "not-core", classify_check_not_offset + classify_core,
NULL, OPTION_HIDDEN, NULL, 1 },
{ "not-unstripped", classify_check_not_offset + classify_unstripped,
NULL, OPTION_HIDDEN, NULL, 1 },
{ "not-executable", classify_check_not_offset + classify_executable,
NULL, OPTION_HIDDEN, NULL, 1 },
{ "not-program", classify_check_not_offset + classify_program,
NULL, OPTION_HIDDEN, NULL, 1 },
{ "not-shared", classify_check_not_offset + classify_shared,
NULL, OPTION_HIDDEN, NULL, 1 },
{ "not-library", classify_check_not_offset + classify_library,
NULL, OPTION_HIDDEN, NULL, 1 },
{ "not-linux-kernel-module", (classify_check_not_offset
+ classify_linux_kernel_module),
NULL, OPTION_HIDDEN, NULL, 1 },
{ "not-debug-only", (classify_check_not_offset + classify_debug_only),
NULL, OPTION_HIDDEN, NULL, 1 },
{ "not-loadable", classify_check_not_offset + classify_loadable,
NULL, OPTION_HIDDEN, NULL, 1 },
{ NULL, 0, NULL, OPTION_DOC, N_("Input flags"), 2 },
{ "file", 'f', NULL, 0,
N_("Only classify regular (not symlink nor special device) files"), 2 },
{ "stdin", classify_flag_stdin, NULL, 0,
N_("Also read file names to process from standard input, \
separated by newlines"), 2 },
{ "stdin0", classify_flag_stdin0, NULL, 0,
N_("Also read file names to process from standard input, \
separated by ASCII NUL bytes"), 2 },
{ "no-stdin", classify_flag_stdin, NULL, 0,
N_("Do not read files from standard input (default)"), 2 },
{ "compressed", 'z', NULL, 0,
N_("Try to open compressed files or embedded (kernel) ELF images"),
2 },
{ NULL, 0, NULL, OPTION_DOC, N_("Output flags"), 3 },
{ "print", classify_flag_print, NULL, 0,
N_("Output names of files, separated by newline"), 3 },
{ "print0", classify_flag_print0, NULL, 0,
N_("Output names of files, separated by ASCII NUL"), 3 },
{ "no-print", classify_flag_no_print, NULL, 0,
N_("Do not output file names"), 3 },
{ "matching", classify_flag_matching, NULL, 0,
N_("If printing file names, print matching files (default)"), 3 },
{ "not-matching", classify_flag_not_matching, NULL, 0,
N_("If printing file names, print files that do not match"), 3 },
{ NULL, 0, NULL, OPTION_DOC, N_("Additional flags"), 4 },
{ "verbose", 'v', NULL, 0,
N_("Output additional information (can be specified multiple times)"), 4 },
{ "quiet", 'q', NULL, 0,
N_("Suppress some error output (counterpart to --verbose)"), 4 },
{ NULL, 0, NULL, 0, NULL, 0 }
};
const struct argp argp =
{
.options = options,
.parser = parse_opt,
.args_doc = N_("FILE..."),
.doc = N_("\
Determine the type of an ELF file.\
\n\n\
All of the classification options must apply at the same time to a \
particular file. Classification options can be negated using a \
\"--not-\" prefix.\
\n\n\
Since modern ELF does not clearly distinguish between programs and \
dynamic shared objects, you should normally use either --executable or \
--shared to identify the primary purpose of a file. \
Only one of the --shared and --executable checks can pass for a file.\
\n\n\
If you want to know whether an ELF object might a program or a \
shared library (but could be both), then use --program or --library. \
Some ELF files will classify as both a program and a library.\
\n\n\
If you just want to know whether an ELF file is loadable (as program \
or library) use --loadable. Note that files that only contain \
(separate) debug information (--debug-only) are never --loadable (even \
though they might contain program headers). Linux kernel modules are \
also not --loadable (in the normal sense).\
\n\n\
Without any of the --print options, the program exits with status 0 \
if the requested checks pass for all input files, with 1 if a check \
fails for any file, and 2 if there is an environmental issue (such \
as a file read error or a memory allocation error).\
\n\n\
When printing file names, the program exits with status 0 even if \
no file names are printed, and exits with status 2 if there is an \
environmental issue.\
\n\n\
On usage error (e.g. a bad option was given), the program exits with \
a status code larger than 2.\
\n\n\
The --quiet or -q option suppresses some error warning output, but \
doesn't change the exit status.\
")
};
/* Require that the file is an ELF file by default. User can
disable with --not-elf. */
requirements[classify_elf] = required;
int remaining;
if (argp_parse (&argp, argc, argv, 0, &remaining, NULL) != 0)
return 2;
elf_version (EV_CURRENT);
int status = 0;
for (int i = remaining; i < argc; ++i)
{
current_path = argv[i];
process_current_path (&status);
}
if (flag_stdin != no_stdin)
process_stdin (&status);
if (issue_found)
return 2;
return status;
}