path: root/misc/alt-revdep-pax

#!/usr/bin/env python
#
#    alt-revdep-pax: this file is part of the elfix package
#    Copyright (C) 2011  Anthony G. Basile
#
#    This program 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.
#
#    This program 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/>.
#

#
# Note: This alternative way of doing revdep-pax only
# works on Gentoo systems where NEEDED.ELF.2 all the
# information we need generated by scanelf during emerge.
#
# See /usr/lib/portage/bin/misc-functions.sh ~line 520
# echo "${arch:3};${obj};${soname};${rpath};${needed}" >> "${PORTAGE_BUILDDIR}"/build-info/NEEDED.ELF.2
#

import getopt
import os
import sys
import pax

from link_map import LinkMap

def get_input(prompt):
    """ python2/3 compat input """
    if sys.hexversion > 0x03000000:
        return input(prompt)
    else:
        return raw_input(prompt)


def print_problems(sonames_missing_library):
    sonames_missing_library = set(sonames_missing_library)
    print('\n**** SONAMES without any library files ****')
    for m in sonames_missing_library:
        print('\t%s' % m)


def run_forward(verbose):
    (object_linkings, object_reverse_linkings, library2soname, soname2library) = LinkMap().get_maps()

    sonames_missing_library = []

    for abi in object_linkings:
        for elf in object_linkings[abi]:
            try:
                (elf_str_flags, elf_bin_flags) = pax.getflags(elf)
                sv = '%s :%s ( %s )' % (elf, abi, elf_str_flags)
                s = sv
            except pax.PaxError:
                sv = '%s :%s ( %s )' % (elf, abi, '****')
                s = sv
                continue

            count = 0
            for soname in object_linkings[abi][elf]:
                try:
                    library = soname2library[(soname, abi)]
                    try:
                        (library_str_flags, library_bin_flags) = pax.getflags(library)
                    except pax.PaxError:
                        library_str_flags = '****'
                    sv = '%s\n\t%s\t%s ( %s )' % (sv, soname, library, library_str_flags)
                    if elf_str_flags != library_str_flags:
                        s = '%s\n\t%s\t%s ( %s )' % (s, soname, library, library_str_flags)
                        count = count + 1
                except KeyError:
                    sonames_missing_library.append(soname)

            if verbose:
                print('%s\n' % sv)
                if count == 0:
                    print('\tNo mismatches\n\n')
                else:
                    print('\tMismatches\n\n')
            else:
                if count != 0:
                    print('%s\n\n' % s)

    if verbose:
        print_problems(sonames_missing_library)


def run_reverse(verbose, executable_only):
    (object_linkings, object_reverse_linkings, library2soname, soname2library) = LinkMap().get_maps()

    shell_path = path = os.getenv('PATH').split(':')

    sonames_missing_library = []

    for abi in object_reverse_linkings:
        for soname in object_reverse_linkings[abi]:
            try:
                library = soname2library[(soname, abi)]
                try:
                    (library_str_flags, library_bin_flags) = pax.getflags(library)
                except pax.PaxError:
                    library_str_flags = '****'
                sv = '%s\t%s :%s ( %s )' % (soname, library, abi, library_str_flags)
                s = sv
            except KeyError:
                sonames_missing_library.append(soname)

            count = 0
            for elf in object_reverse_linkings[abi][soname]:
                try:
                    (elf_str_flags, elf_bin_flags) = pax.getflags(elf)
                except pax.PaxError:
                    elf_str_flags = '****'
                if executable_only:
                    if os.path.dirname(elf) in shell_path:
                        sv = '%s\n\t%s ( %s )' % (sv, elf, elf_str_flags)
                        if library_str_flags != elf_str_flags:
                            s = '%s\n\t%s ( %s )' % (s, elf, elf_str_flags)
                            count = count + 1
                else:
                    sv = '%s\n\t%s ( %s )' % (sv, elf, elf_str_flags)
                    if library_str_flags != elf_str_flags:
                        s = '%s\n\t%s ( %s )' % (s, elf, elf_str_flags)
                        count = count + 1

            if verbose:
                print('%s\n' % sv)
                if count == 0:
                    print('\tNo mismatches\n\n')
                else:
                    print('\tMismatches\n\n')
            else:
                if count != 0:
                    print('%s\n\n' % s)

    if verbose:
        print_problems(sonames_missing_library)


def migrate_flags(importer, exporter_str_flags, exporter_bin_flags):
    # We implement the following logic for setting the pax flags
    # on the target elf object, the IMPORTER, given that the flags
    # from the elf object we want it to match to, the EXPORTER.
    #
    #    EXPORTER    IMPORTER    RESULT
    #       On          On         On
    #       On          Off        On + Warn
    #       On          -          On
    #       Off         On         On + Warn
    #       Off         Off        Off
    #       Off         -          Off
    #       -           On         On
    #       -           Off        Off
    #       -           -          -

    #See /usr/include/elf.h for these values
    pf_flags = {
        'P':1<<4, 'p':1<<5,
        'S':1<<6, 's':1<<7,
        'M':1<<8, 'm':1<<9,
        'X':1<<10, 'x':1<<11,
        'E':1<<12, 'e':1<<13,
        'R':1<<14, 'r':1<<15
    }

    try:
        (importer_str_flags, importer_bin_flags) = pax.getflags(importer)
    except pax.PaxError:
        # The importer has no flags, so just set them
        pax.setbinflags(importer, exporter_bin_flags)
        return

    # Start with the exporter's flags
    result_bin_flags = exporter_bin_flags

    for i in range(len(importer_str_flags)):

        # The exporter's flag contradicts the importer's flag, so do nothing
        if (exporter_str_flags[i].isupper() and importer_str_flags[i].islower()) or \
           (exporter_str_flags[i].islower() and importer_str_flags[i].isupper()):

            # Revert the exporter's flag, use the importer's flag and warn
            result_bin_flags = result_bin_flags ^ pf_flags[exporter_str_flags[i]]
            result_bin_flags = result_bin_flags | pf_flags[importer_str_flags[i]]
            print('\t\tWarning: %s has %s, refusing to set to %s' % (
                importer, importer_str_flags[i], exporter_str_flags[i] )),

        # The exporter's flags is off, so use the importer's flag
        if (exporter_str_flags[i] == '-' and importer_str_flags[i] != '-'):
            result_bin_flags = result_bin_flags | pf_flags[importer_str_flags[i]]

    pax.setbinflags(importer, result_bin_flags)


def run_elf(elf, verbose, mark, allyes):
    if not os.path.exists(elf):
        print('%s\tNo such OBJECT' % elf)
        return

    try:
        (elf_str_flags, elf_bin_flags) = pax.getflags(elf)
        print('%s (%s)\n' % (elf, elf_str_flags))
    except pax.PaxError:
        print('%s: No PAX flags found\n' % elf)
        return

    (object_linkings, object_reverse_linkings, library2soname, soname2library) = LinkMap().get_maps()

    mismatched_libraries = []

    for abi in object_linkings:
        if not elf in object_linkings[abi]: # There may be no elf for that abi
            continue
        for soname in object_linkings[abi][elf]:
            try:
                library = soname2library[(soname,abi)]
                try:
                    (library_str_flags, library_bin_flags) = pax.getflags(library)
                except pax.PaxError:
                    library_str_flags = '****'
                if verbose:
                    print('\t%s\t%s :%s ( %s )' % (soname, library, abi, library_str_flags))
                if elf_str_flags != library_str_flags:
                    mismatched_libraries.append(library)
                    if not verbose:
                        print('\t%s\t%s :%s ( %s )' % (soname, library, abi, library_str_flags))
            except KeyError:
                print('%s :%s: file for soname not found' % (soname, abi))

        if len(mismatched_libraries) == 0:
            if not verbose:
                print('\tNo mismatches\n')
        else:
            print('')
            if mark:
                print('\tWill mark libraries with %s\n' % elf_str_flags)
                for library in mismatched_libraries:
                    do_marking = False
                    while True:
                        if allyes:
                            ans = 'y'
                        else:
                            ans = get_input('\tSet flags for %s :%s (y/n): ' % (library, abi))
                        if ans == 'y':
                            do_marking = True
                            break
                        elif ans == 'n':
                            do_marking = False
                            break
                        else:
                            print('\t\tPlease enter y or n')

                    if do_marking:
                        try:
                            migrate_flags(library, elf_str_flags, elf_bin_flags)
                        except pax.PaxError:
                            print('\n\tCould not set PAX flags on %s, text maybe busy' % (library, abi))

                        try:
                            (library_str_flags, library_bin_flags) = pax.getflags(library)
                            print('\n\t\t%s ( %s )\n' % (library, library_str_flags))
                        except pax.PaxError:
                            print('\n\t\t%s: Could not read PAX flags')


def run_soname(name, verbose, use_soname, mark, allyes, executable_only):
    shell_path = path = os.getenv('PATH').split(':')

    (object_linkings, object_reverse_linkings, library2soname, soname2library) = LinkMap().get_maps()

    if use_soname:
        soname = name
        abi_list = object_reverse_linkings.keys()
        for abi in abi_list:
            # There must be at least on abi with that soname
            if soname in object_reverse_linkings[abi]:
                break
        else:
            print('%s\tNo such SONAME' % soname)
            return
    else:
        try:
            (soname, abi) = library2soname[name]
            abi_list = [abi]
        except KeyError:
            print('%s\tNo such LIBRARY' % name)
            return


    mismatched_elfs = []

    for abi in abi_list:
        # An soname can belong to one or more abis
        if not soname in object_reverse_linkings[abi]:
            continue

        library = soname2library[(soname, abi)]

        try:
           (library_str_flags, library_bin_flags) = pax.getflags(library)
           print('%s\t%s :%s (%s)\n' % (soname, library, abi, library_str_flags))
        except pax.PaxError:
           print('%s :%s : No PAX flags found\n' % (library, abi))
           continue

        for elf in object_reverse_linkings[abi][soname]:
            try:
                (elf_str_flags, elf_bin_flags ) = pax.getflags(elf)
            except pax.PaxError:
                elf_str_flags = '****'
            if verbose:
                if executable_only:
                    if os.path.dirname(elf) in shell_path:
                        print('\t%s ( %s )' % (elf, elf_str_flags))
                else:
                    print('\t%s ( %s )' % (elf, elf_str_flags))
            if library_str_flags != elf_str_flags:
                if executable_only:
                    if os.path.dirname(elf) in shell_path:
                        mismatched_elfs.append(elf)
                        if not verbose:
                            print('\t%s ( %s )' % (elf, elf_str_flags))
                else:
                    mismatched_elfs.append(elf)
                    if not verbose:
                        print('\t%s ( %s )' % (elf, elf_str_flags))

        if len(mismatched_elfs) == 0:
            if not verbose:
                print('\tNo mismatches\n')
        else:
            print('')
            if mark:
                print('\tWill mark elf with %s\n' % library_str_flags)
                for elf in mismatched_elfs:
                    if executable_only:
                        if not os.path.dirname(elf) in shell_path:
                            continue
                    do_marking = False
                    while True:
                        if allyes:
                            ans = 'y'
                        else:
                            ans = get_input('\tSet flags for %s (y/n): ' % elf)
                        if ans == 'y':
                            do_marking = True
                            break
                        elif ans == 'n':
                            do_marking = False
                            break
                        else:
                            print('\t\tPlease enter y or n')
                    if do_marking:
                        try:
                            migrate_flags(elf, library_str_flags, library_bin_flags)
                        except pax.PaxError:
                            print('\n\tCould not set pax flags on %s, file is probably busy' % elf)
                            print('\tShut down all processes that use it and try again')
                        (elf_str_flags, elf_bin_flags) = pax.getflags(elf)
                        print('\n\t\t%s ( %s )\n' % (elf, elf_str_flags))


def run_usage():
    print('Package Name : elfix')
    print('Bug Reports  : http://bugs.gentoo.org/')
    print('Program Name : revdep-pax')
    print('Description  : Get or set pax flags on an ELF object')
    print('')
    print('Usage        : revdep-pax -f [-v]             print out all forward mappings for all system ELF objects')
    print('             : revdep-pax -r [-ve]            print out all reverse mappings for all system sonames')
    print('             : revdep-pax -b OBJECT  [-myv]   print all forward mappings only for OBJECT')
    print('             : revdep-pax -s SONAME  [-myve]  print all reverse mappings only for SONAME')
    print('             : revdep-pax -l LIBRARY [-myve]  print all reverse mappings only for LIBRARY file')
    print('             : revdep-pax [-h]                print out this help')
    print('             : -v                             verbose, otherwise just print mismatching objects')
    print('             : -e                             only print out executables in shell $PATH')
    print('             : -m                             don\'t just report, but mark the mismatching objects')
    print('             : -y                             assume "yes" to all prompts for marking (USE CAREFULLY!)')
    print('')


def main():
    # Are we root?
    uid = os.getuid()
    if uid != 0:
        print('This program must be run as root')
        sys.exit(1)

    try:
        opts, args = getopt.getopt(sys.argv[1:], 'hfrb:s:l:vemy')
    except getopt.GetoptError as err:
        print(str(err)) # will print something like 'option -a not recognized'
        run_usage()
        sys.exit(1)

    if len(opts) == 0:
        run_usage()
        sys.exit(1)

    do_usage   = False
    do_forward = False
    do_reverse = False

    elf     = None
    soname  = None
    library = None

    verbose = False
    executable_only = False
    mark = False
    allyes = False

    opt_count = 0

    for o, a in opts:
        if o == '-h':
            do_usage = True
            opt_count += 1
        elif o == '-f':
            do_forward = True
            opt_count += 1
        elif o == '-r':
            do_reverse = True
            opt_count += 1
        elif o == '-b':
            elf = a
            opt_count += 1
        elif o == '-s':
            soname = a
            opt_count += 1
        elif o == '-l':
            library = a
            opt_count += 1
        elif o == '-v':
            verbose = True
        elif o == '-e':
            executable_only = True
        elif o == '-m':
            mark = True
        elif o == '-y':
            allyes = True
        else:
            print('Option included in getopt but not handled here!')
            print('Please file a bug')
            sys.exit(1)

    # Only allow one of -h, -f -r -b -s
    if opt_count > 1 or do_usage:
        run_usage()
    elif do_forward:
        run_forward(verbose)
    elif do_reverse:
        run_reverse(verbose, executable_only)
    elif elf != None:
        run_elf(elf, verbose, mark, allyes)
    elif soname != None:
        run_soname(soname, verbose, True, mark, allyes, executable_only)
    elif library != None:
        library = os.path.realpath(library)
        run_soname(library, verbose, False, mark, allyes, executable_only)


if __name__ == '__main__':
    main()