#!/usr/bin/perl # # Copyright: 2018 Johannes Schauer # # Permission is hereby granted, free of charge, to any person obtaining a copy # of this software and associated documentation files (the "Software"), to # deal in the Software without restriction, including without limitation the # rights to use, copy, modify, merge, publish, distribute, sublicense, and/or # sell copies of the Software, and to permit persons to whom the Software is # furnished to do so, subject to the following conditions: # # The above copyright notice and this permission notice shall be included in # all copies or substantial portions of the Software. # # The software is provided "as is", without warranty of any kind, express or # implied, including but not limited to the warranties of merchantability, # fitness for a particular purpose and noninfringement. In no event shall the # authors or copyright holders be liable for any claim, damages or other # liability, whether in an action of contract, tort or otherwise, arising # from, out of or in connection with the software or the use or other dealings # in the software. use strict; use warnings; our $VERSION = '0.5.1'; use English; use Getopt::Long; use Pod::Usage; use File::Copy; use File::Path qw(make_path remove_tree); use File::Temp qw(tempfile tempdir); use File::Basename; use Cwd qw(abs_path); require "syscall.ph"; use Fcntl qw(S_IFCHR S_IFBLK FD_CLOEXEC F_GETFD F_SETFD); use List::Util qw(any none); use POSIX qw(SIGINT SIGHUP SIGPIPE SIGTERM SIG_BLOCK SIG_UNBLOCK); use Carp; use Term::ANSIColor; use Socket; # from sched.h use constant { CLONE_NEWNS => 0x20000, CLONE_NEWUTS => 0x4000000, CLONE_NEWIPC => 0x8000000, CLONE_NEWUSER => 0x10000000, CLONE_NEWPID => 0x20000000, CLONE_NEWNET => 0x40000000, }; # type codes: # 0 -> normal file # 1 -> hardlink # 2 -> symlink # 3 -> character special # 4 -> block special # 5 -> directory my @devfiles = ( # filename mode type link target major minor ["./dev/", 0755, 5, '', undef, undef], ["./dev/console", 0666, 3, '', 5, 1], ["./dev/fd", 0777, 2, '/proc/self/fd', undef, undef], ["./dev/full", 0666, 3, '', 1, 7], ["./dev/null", 0666, 3, '', 1, 3], ["./dev/ptmx", 0666, 3, '', 5, 2], ["./dev/pts/", 0755, 5, '', undef, undef], ["./dev/random", 0666, 3, '', 1, 8], ["./dev/shm/", 0755, 5, '', undef, undef], ["./dev/stderr", 0777, 2, '/proc/self/fd/2', undef, undef], ["./dev/stdin", 0777, 2, '/proc/self/fd/0', undef, undef], ["./dev/stdout", 0777, 2, '/proc/self/fd/1', undef, undef], ["./dev/tty", 0666, 3, '', 5, 0], ["./dev/urandom", 0666, 3, '', 1, 9], ["./dev/zero", 0666, 3, '', 1, 5], ); # verbosity levels: # 0 -> print nothing # 1 -> normal output and progress bars # 2 -> verbose output # 3 -> debug output my $verbosity_level = 1; my $is_covering = !!(eval 'Devel::Cover::get_coverage()'); sub debug { if ($verbosity_level < 3) { return; } my $msg = shift; my ($package, $filename, $line) = caller; $msg = "D: $PID $line $msg"; if (-t STDERR) { $msg = colored($msg, 'clear'); } print STDERR "$msg\n"; } sub info { if ($verbosity_level == 0) { return; } my $msg = shift; if ($verbosity_level >= 3) { my ($package, $filename, $line) = caller; $msg = "$PID $line $msg"; } $msg = "I: $msg"; if (-t STDERR) { $msg = colored($msg, 'green'); } print STDERR "$msg\n"; } sub warning { if ($verbosity_level == 0) { return; } my $msg = shift; $msg = "W: $msg"; if (-t STDERR) { $msg = colored($msg, 'bold yellow'); } print STDERR "$msg\n"; } sub error { if ($verbosity_level == 0) { return; } # if error() is called with the string from a previous error() that was # caught inside an eval(), then the string will have a newline which we # are stripping here chomp(my $msg = shift); $msg = "E: $msg"; if (-t STDERR) { $msg = colored($msg, 'bold red'); } if ($verbosity_level == 3) { croak $msg; # produces a backtrace } else { die "$msg\n"; } } # check whether a directory is mounted by comparing the device number of the # directory itself with its parent sub is_mountpoint($) { my $dir = shift; if (!-e $dir) { return 0; } my @a = stat "$dir/."; my @b = stat "$dir/.."; # if the device number is different, then the directory must be mounted if ($a[0] != $b[0]) { return 1; } # if the inode number is the same, then the directory must be mounted if ($a[1] == $b[1]) { return 1; } return 0; } # tar cannot figure out the decompression program when receiving data on # standard input, thus we do it ourselves. This is copied from tar's # src/suffix.c sub get_tar_compressor($) { my $filename = shift; if ($filename eq '-') { return undef; } elsif ($filename =~ /\.tar$/) { return undef; } elsif ($filename =~ /\.(gz|tgz|taz)$/) { return ['gzip']; } elsif ($filename =~ /\.(Z|taZ)$/) { return ['compress']; } elsif ($filename =~ /\.(bz2|tbz|tbz2|tz2)$/) { return ['bzip2']; } elsif ($filename =~ /\.lz$/) { return ['lzip']; } elsif ($filename =~ /\.(lzma|tlz)$/) { return ['lzma']; } elsif ($filename =~ /\.lzo$/) { return ['lzop']; } elsif ($filename =~ /\.lz4$/) { return ['lz4']; } elsif ($filename =~ /\.(xz|txz)$/) { return ['xz', '--threads=0']; } elsif ($filename =~ /\.zst$/) { return ['zstd']; } return undef; } sub test_unshare($) { my $verbose = shift; if ($EFFECTIVE_USER_ID == 0) { my $msg = "cannot use unshare mode when executing as root"; if ($verbose) { warning $msg; } else { debug $msg; } return 0; } # arguments to syscalls have to be stored in their own variable or # otherwise we will get "Modification of a read-only value attempted" my $unshare_flags = CLONE_NEWUSER; # we spawn a new per process because if unshare succeeds, we would # otherwise have unshared the mmdebstrap process itself which we don't want my $pid = fork() // error "fork() failed: $!"; if ($pid == 0) { my $ret = syscall &SYS_unshare, $unshare_flags; if ($ret == 0) { exit 0; } else { my $msg = "unshare syscall failed: $!"; if ($verbose) { warning $msg; } else { debug $msg; } exit 1; } } waitpid($pid, 0); if (($? >> 8) != 0) { return 0; } # if newuidmap and newgidmap exist, the exit status will be 1 when # executed without parameters system "newuidmap 2>/dev/null"; if (($? >> 8) != 1) { if (($? >> 8) == 127) { my $msg = "cannot find newuidmap"; if ($verbose) { warning $msg; } else { debug $msg; } } else { my $msg = "newuidmap returned unknown exit status: $?"; if ($verbose) { warning $msg; } else { debug $msg; } } return 0; } system "newgidmap 2>/dev/null"; if (($? >> 8) != 1) { if (($? >> 8) == 127) { my $msg = "cannot find newgidmap"; if ($verbose) { warning $msg; } else { debug $msg; } } else { my $msg = "newgidmap returned unknown exit status: $?"; if ($verbose) { warning $msg; } else { debug $msg; } } return 0; } return 1; } sub read_subuid_subgid() { my $username = getpwuid $<; my ($subid, $num_subid, $fh, $n); my @result = (); if (!-e "/etc/subuid") { warning "/etc/subuid doesn't exist"; return; } if (!-r "/etc/subuid") { warning "/etc/subuid is not readable"; return; } open $fh, "<", "/etc/subuid" or error "cannot open /etc/subuid for reading: $!"; while (my $line = <$fh>) { ($n, $subid, $num_subid) = split(/:/, $line, 3); last if ($n eq $username); } close $fh; push @result, ["u", 0, $subid, $num_subid]; if (scalar(@result) < 1) { warning "/etc/subuid does not contain an entry for $username"; return; } if (scalar(@result) > 1) { warning "/etc/subuid contains multiple entries for $username"; return; } open $fh, "<", "/etc/subgid" or error "cannot open /etc/subgid for reading: $!"; while (my $line = <$fh>) { ($n, $subid, $num_subid) = split(/:/, $line, 3); last if ($n eq $username); } close $fh; push @result, ["g", 0, $subid, $num_subid]; if (scalar(@result) < 2) { warning "/etc/subgid does not contain an entry for $username"; return; } if (scalar(@result) > 2) { warning "/etc/subgid contains multiple entries for $username"; return; } return @result; } # This function spawns two child processes forming the following process tree # # A # | # fork() # | \ # B C # | | # | fork() # | | \ # | D E # | | | # |unshare() # | close() # | | | # | | read() # | | newuidmap(D) # | | newgidmap(D) # | | / # | waitpid() # | | # | fork() # | | \ # | F G # | | | # | | exec() # | | / # | waitpid() # | / # waitpid() # # To better refer to each individual part, we give each process a new # identifier after calling fork(). Process A is the main process. After # executing fork() we call the parent and child B and C, respectively. This # first fork() is done because we do not want to modify A. B then remains # waiting for its child C to finish. C calls fork() again, splitting into # the parent D and its child E. In the parent D we call unshare() and close a # pipe shared by D and E to signal to E that D is done with calling unshare(). # E notices this by using read() and follows up with executing the tools # new[ug]idmap on D. E finishes and D continues with doing another fork(). # This is because when unsharing the PID namespace, we need a PID 1 to be kept # alive or otherwise any child processes cannot fork() anymore themselves. So # we keep F as PID 1 and finally call exec() in G. sub get_unshare_cmd(&$) { my $cmd = shift; my $idmap = shift; my $unshare_flags = CLONE_NEWUSER | CLONE_NEWNS | CLONE_NEWPID | CLONE_NEWUTS | CLONE_NEWIPC; if (0) { $unshare_flags |= CLONE_NEWNET; } # fork a new process and let the child get unshare()ed # we don't want to unshare the parent process my $gcpid = fork() // error "fork() failed: $!"; if ($gcpid == 0) { # Create a pipe for the parent process to signal the child process that # it is done with calling unshare() so that the child can go ahead # setting up uid_map and gid_map. pipe my $rfh, my $wfh; # We have to do this dance with forking a process and then modifying # the parent from the child because: # - new[ug]idmap can only be called on a process id after that process # has unshared the user namespace # - a process looses its capabilities if it performs an execve() with # nonzero user ids see the capabilities(7) man page for details. # - a process that unshared the user namespace by default does not # have the privileges to call new[ug]idmap on itself # # this also works the other way around (the child setting up a user # namespace and being modified from the parent) but that way, the # parent would have to stay around until the child exited (so a pid # would be wasted). Additionally, that variant would require an # additional pipe to let the parent signal the child that it is done # with calling new[ug]idmap. The way it is done here, this signaling # can instead be done by wait()-ing for the exit of the child. my $ppid = $$; my $cpid = fork() // error "fork() failed: $!"; if ($cpid == 0) { # child # Close the writing descriptor at our end of the pipe so that we # see EOF when parent closes its descriptor. close $wfh; # Wait for the parent process to finish its unshare() call by # waiting for an EOF. 0 == sysread $rfh, my $c, 1 or error "read() did not receive EOF"; # The program's new[ug]idmap have to be used because they are # setuid root. These privileges are needed to map the ids from # /etc/sub[ug]id to the user namespace set up by the parent. # Without these privileges, only the id of the user itself can be # mapped into the new namespace. # # Since new[ug]idmap is setuid root we also don't need to write # "deny" to /proc/$$/setgroups beforehand (this is otherwise # required for unprivileged processes trying to write to # /proc/$$/gid_map since kernel version 3.19 for security reasons) # and therefore the parent process keeps its ability to change its # own group here. # # Since /proc/$ppid/[ug]id_map can only be written to once, # respectively, instead of making multiple calls to new[ug]idmap, # we assemble a command line that makes one call each. my $uidmapcmd = ""; my $gidmapcmd = ""; foreach (@{$idmap}) { my ($t, $hostid, $nsid, $range) = @{$_}; if ($t ne "u" and $t ne "g" and $t ne "b") { error "invalid idmap type: $t"; } if ($t eq "u" or $t eq "b") { $uidmapcmd .= " $hostid $nsid $range"; } if ($t eq "g" or $t eq "b") { $gidmapcmd .= " $hostid $nsid $range"; } } my $idmapcmd = ''; if ($uidmapcmd ne "") { 0 == system "newuidmap $ppid $uidmapcmd" or error "newuidmap $ppid $uidmapcmd failed: $!"; } if ($gidmapcmd ne "") { 0 == system "newgidmap $ppid $gidmapcmd" or error "newgidmap $ppid $gidmapcmd failed: $!"; } exit 0; } # parent # After fork()-ing, the parent immediately calls unshare... 0 == syscall &SYS_unshare, $unshare_flags or error "unshare() failed: $!"; # .. and then signals the child process that we are done with the # unshare() call by sending an EOF. close $wfh; # Wait for the child process to finish its setup by waiting for its # exit. $cpid == waitpid $cpid, 0 or error "waitpid() failed: $!"; my $exit = $? >> 8; if ($exit != 0) { error "child had a non-zero exit status: $exit"; } # Currently we are nobody (uid and gid are 65534). So we become root # user and group instead. # # We are using direct syscalls instead of setting $(, $), $< and $> # because then perl would do additional stuff which we don't need or # want here, like checking /proc/sys/kernel/ngroups_max (which might # not exist). It would also also call setgroups() in a way that makes # the root user be part of the group unknown. 0 == syscall &SYS_setgid, 0 or error "setgid failed: $!"; 0 == syscall &SYS_setuid, 0 or error "setuid failed: $!"; 0 == syscall &SYS_setgroups, 0, 0 or error "setgroups failed: $!"; if (1) { # When the pid namespace is also unshared, then processes expect a # master pid to always be alive within the namespace. To achieve # this, we fork() here instead of exec() to always have one dummy # process running as pid 1 inside the namespace. This is also what # the unshare tool does when used with the --fork option. # # Otherwise, without a pid 1, new processes cannot be forked # anymore after pid 1 finished. my $cpid = fork() // error "fork() failed: $!"; if ($cpid != 0) { # The parent process will stay alive as pid 1 in this # namespace until the child finishes executing. This is # important because pid 1 must never die or otherwise nothing # new can be forked. $cpid == waitpid $cpid, 0 or error "waitpid() failed: $!"; exit($? >> 8); } } &{$cmd}(); exit 0; } # parent return $gcpid; } sub havemknod($) { my $root = shift; my $havemknod = 0; if (-e "$root/test-dev-null") { error "/test-dev-null already exists"; } TEST: { # we fork so that we can read STDERR my $pid = open my $fh, '-|' // error "failed to fork(): $!"; if ($pid == 0) { open(STDERR, '>&', STDOUT) or error "cannot open STDERR: $!"; # we use mknod(1) instead of the system call because creating the # right dev_t argument requires makedev(3) exec 'mknod', "$root/test-dev-null", 'c', '1', '3'; } chomp( my $content = do { local $/; <$fh> } ); close $fh; { last TEST unless $? == 0 and $content eq ''; last TEST unless -c "$root/test-dev-null"; last TEST unless open my $fh, '>', "$root/test-dev-null"; last TEST unless print $fh 'test'; } $havemknod = 1; } if (-e "$root/test-dev-null") { unlink "$root/test-dev-null" or error "cannot unlink /test-dev-null: $!"; } return $havemknod; } sub print_progress { if ($verbosity_level != 1) { return; } my $perc = shift; if (!-t STDERR) { return; } if ($perc eq "done") { # \e[2K clears everything on the current line (i.e. the progress bar) print STDERR "\e[2Kdone\n"; return; } if ($perc >= 100) { $perc = 100; } my $width = 50; my $num_x = int($perc * $width / 100); my $bar = '=' x $num_x; if ($num_x != $width) { $bar .= '>'; $bar .= ' ' x ($width - $num_x - 1); } printf STDERR "%6.2f [%s]\r", $perc, $bar; } sub run_progress { my ($get_exec, $line_handler, $line_has_error, $chdir) = @_; pipe my $rfh, my $wfh; my $got_signal = 0; my $ignore = sub { info "run_progress() received signal $_[0]: waiting for child..."; }; # delay signals so that we can fork and change behaviour of the signal # handler in parent and child without getting interrupted my $sigset = POSIX::SigSet->new(SIGINT, SIGHUP, SIGPIPE, SIGTERM); POSIX::sigprocmask(SIG_BLOCK, $sigset) or error "Can't block signals: $!"; my $pid1 = open(my $pipe, '-|') // error "failed to fork(): $!"; if ($pid1 == 0) { # child: default signal handlers $SIG{'INT'} = 'DEFAULT'; $SIG{'HUP'} = 'DEFAULT'; $SIG{'PIPE'} = 'DEFAULT'; $SIG{'TERM'} = 'DEFAULT'; # unblock all delayed signals (and possibly handle them) POSIX::sigprocmask(SIG_UNBLOCK, $sigset) or error "Can't unblock signals: $!"; close $rfh; # Unset the close-on-exec flag, so that the file descriptor does not # get closed when we exec my $flags = fcntl($wfh, F_GETFD, 0) or error "fcntl F_GETFD: $!"; fcntl($wfh, F_SETFD, $flags & ~FD_CLOEXEC) or error "fcntl F_SETFD: $!"; my $fd = fileno $wfh; # redirect stderr to stdout so that we can capture it open(STDERR, '>&', STDOUT) or error "cannot open STDOUT: $!"; my @execargs = $get_exec->($fd); # before apt 1.5, "apt-get update" attempted to chdir() into the # working directory. This will fail if the current working directory # is not accessible by the user (for example in unshare mode). See # Debian bug #860738 if (defined $chdir) { chdir $chdir or error "failed chdir() to $chdir: $!"; } eval 'Devel::Cover::set_coverage("none")' if $is_covering; exec { $execargs[0] } @execargs or error 'cannot exec() ' . (join ' ', @execargs); } close $wfh; # spawn two processes: # parent will parse stdout to look for errors # child will parse $rfh for the progress meter my $pid2 = fork() // error "failed to fork(): $!"; if ($pid2 == 0) { # child: default signal handlers $SIG{'INT'} = 'IGNORE'; $SIG{'HUP'} = 'IGNORE'; $SIG{'PIPE'} = 'IGNORE'; $SIG{'TERM'} = 'IGNORE'; # unblock all delayed signals (and possibly handle them) POSIX::sigprocmask(SIG_UNBLOCK, $sigset) or error "Can't unblock signals: $!"; print_progress 0.0; while (my $line = <$rfh>) { my $output = $line_handler->($line); next unless $output; print_progress $output; } print_progress "done"; exit 0; } # parent: ignore signals # by using "local", the original is automatically restored once the # function returns local $SIG{'INT'} = $ignore; local $SIG{'HUP'} = $ignore; local $SIG{'PIPE'} = $ignore; local $SIG{'TERM'} = $ignore; # unblock all delayed signals (and possibly handle them) POSIX::sigprocmask(SIG_UNBLOCK, $sigset) or error "Can't unblock signals: $!"; my $output = ''; my $has_error = 0; while (my $line = <$pipe>) { $has_error = $line_has_error->($line); if ($verbosity_level >= 2) { print STDERR $line; } else { # forward captured apt output $output .= $line; } } close($pipe); my $fail = 0; if ($? != 0 or $has_error) { $fail = 1; } waitpid $pid2, 0; $? == 0 or error "progress parsing failed"; if ($got_signal) { error "run_progress() received signal: $got_signal"; } # only print failure after progress output finished or otherwise it # might interfere with the remaining output if ($fail) { if ($verbosity_level >= 1) { print STDERR $output; } error((join ' ', $get_exec->('<$fd>')) . ' failed'); } } sub run_dpkg_progress { my $options = shift; my @debs = @{ $options->{PKGS} // [] }; my $get_exec = sub { return @{ $options->{ARGV} }, "--status-fd=$_[0]", @debs; }; my $line_has_error = sub { return 0; }; my $num = 0; # each package has one install and one configure step, thus the total # number is twice the number of packages my $total = (scalar @debs) * 2; my $line_handler = sub { if ($_[0] =~ /^processing: (install|configure): /) { $num += 1; } return $num / $total * 100; }; run_progress $get_exec, $line_handler, $line_has_error; } sub run_apt_progress { my $options = shift; my @debs = @{ $options->{PKGS} // [] }; my $get_exec = sub { return ( @{ $options->{ARGV} }, "-oAPT::Status-Fd=$_[0]", # prevent apt from messing up the terminal and allow dpkg to # receive SIGINT and quit immediately without waiting for # maintainer script to finish '-oDpkg::Use-Pty=false', @debs ); }; my $line_has_error = sub { return 0; }; if ($options->{FIND_APT_WARNINGS}) { $line_has_error = sub { # apt-get doesn't report a non-zero exit if the update failed. # Thus, we have to parse its output. See #778357, #776152, #696335 # and #745735 if ($_[0] =~ /^(W: |Err:)/) { return 1; } return 0; }; } my $line_handler = sub { if ($_[0] =~ /(pmstatus|dlstatus):[^:]+:(\d+\.\d+):.*/) { return $2; } }; run_progress $get_exec, $line_handler, $line_has_error, $options->{CHDIR}; } sub run_chroot(&$) { my $cmd = shift; my $options = shift; my @cleanup_tasks = (); my $cleanup = sub { my $signal = $_[0]; while (my $task = pop @cleanup_tasks) { $task->(); } if ($signal) { warning "pid $PID cought signal: $signal"; exit 1; } }; local $SIG{INT} = $cleanup; local $SIG{HUP} = $cleanup; local $SIG{PIPE} = $cleanup; local $SIG{TERM} = $cleanup; eval { if (any { $_ eq $options->{mode} } ('root', 'unshare')) { # if more than essential should be installed, make the system look # more like a real one by creating or bind-mounting the device # nodes foreach my $file (@devfiles) { my ($fname, $mode, $type, $linkname, $devmajor, $devminor) = @{$file}; next if $fname eq './dev/'; if ($type == 0) { # normal file error "type 0 not implemented"; } elsif ($type == 1) { # hardlink error "type 1 not implemented"; } elsif ($type == 2) { # symlink if (!$options->{havemknod}) { if ( $options->{mode} eq 'fakechroot' and $linkname =~ /^\/proc/) { # there is no /proc in fakechroot mode next; } if ( any { $_ eq $options->{mode} } ('root', 'unshare') ) { push @cleanup_tasks, sub { unlink "$options->{root}/$fname" or warn "cannot unlink $fname: $!"; } } symlink $linkname, "$options->{root}/$fname" or error "cannot create symlink $fname"; } } elsif ($type == 3 or $type == 4) { # character/block special if (!$options->{havemknod}) { open my $fh, '>', "$options->{root}/$fname" or error "cannot open $options->{root}/$fname: $!"; close $fh; if ($options->{mode} eq 'unshare') { push @cleanup_tasks, sub { 0 == system('umount', '--no-mtab', "$options->{root}/$fname") or warn "umount $fname failed: $?"; unlink "$options->{root}/$fname" or warn "cannot unlink $fname: $!"; }; } elsif ($options->{mode} eq 'root') { push @cleanup_tasks, sub { 0 == system('umount', "$options->{root}/$fname") or warn "umount failed: $?"; unlink "$options->{root}/$fname" or warn "cannot unlink $fname: $!"; }; } else { error "unknown mode: $options->{mode}"; } 0 == system('mount', '-o', 'bind', "/$fname", "$options->{root}/$fname") or error "mount $fname failed: $?"; } } elsif ($type == 5) { # directory if (!$options->{havemknod}) { if ( any { $_ eq $options->{mode} } ('root', 'unshare') ) { push @cleanup_tasks, sub { rmdir "$options->{root}/$fname" or warn "cannot rmdir $fname: $!"; } } if (-e "$options->{root}/$fname") { if (!-d "$options->{root}/$fname") { error "$fname already exists but is not a" . " directory"; } } else { my $num_created = make_path "$options->{root}/$fname", { error => \my $err }; if ($err && @$err) { error( join "; ", ( map { "cannot create " . (join ": ", %{$_}) } @$err )); } elsif ($num_created == 0) { error "cannot create $options->{root}/$fname"; } } chmod $mode, "$options->{root}/$fname" or error "cannot chmod $fname: $!"; } if ($options->{mode} eq 'unshare') { push @cleanup_tasks, sub { 0 == system('umount', '--no-mtab', "$options->{root}/$fname") or warn "umount $fname failed: $?"; }; } elsif ($options->{mode} eq 'root') { push @cleanup_tasks, sub { 0 == system('umount', "$options->{root}/$fname") or warn "umount $fname failed: $?"; }; } else { error "unknown mode: $options->{mode}"; } 0 == system('mount', '-o', 'bind', "/$fname", "$options->{root}/$fname") or error "mount $fname failed: $?"; } else { error "unsupported type: $type"; } } } elsif ( any { $_ eq $options->{mode} } ('proot', 'fakechroot', 'chrootless') ) { # we cannot mount in fakechroot and proot mode # in proot mode we have /dev bind-mounted already through # --bind=/dev } else { error "unknown mode: $options->{mode}"; } # We can only mount /proc and /sys after extracting the essential # set because if we mount it before, then base-files will not be able # to extract those if ($options->{mode} eq 'root') { push @cleanup_tasks, sub { 0 == system('umount', "$options->{root}/sys") or warn "umount /sys failed: $?"; }; 0 == system( 'mount', '-t', 'sysfs', '-o', 'nosuid,nodev,noexec', 'sys', "$options->{root}/sys" ) or error "mount /sys failed: $?"; } elsif ($options->{mode} eq 'unshare') { # naturally we have to clean up after ourselves in sudo mode where # we do a real mount. But we also need to unmount in unshare mode # because otherwise, even with the --one-file-system tar option, # the permissions of the mount source will be stored and not the # mount target (the directory) push @cleanup_tasks, sub { # since we cannot write to /etc/mtab we need --no-mtab # unmounting /sys only seems to be successful with --lazy 0 == system('umount', '--no-mtab', '--lazy', "$options->{root}/sys") or warn "umount /sys failed: $?"; }; # without the network namespace unshared, we cannot mount a new # sysfs. Since we need network, we just bind-mount. # # we have to rbind because just using bind results in "wrong fs # type, bad option, bad superblock" error 0 == system('mount', '-o', 'rbind', '/sys', "$options->{root}/sys") or error "mount /sys failed: $?"; } elsif ( any { $_ eq $options->{mode} } ('proot', 'fakechroot', 'chrootless') ) { # we cannot mount in fakechroot and proot mode # in proot mode we have /proc bind-mounted already through # --bind=/proc } else { error "unknown mode: $options->{mode}"; } if ($options->{mode} eq 'root') { push @cleanup_tasks, sub { # some maintainer scripts mount additional stuff into /proc # which we need to unmount beforehand if (is_mountpoint("$options->{root}/proc/sys/fs/binfmt_misc")) { 0 == system('umount', "$options->{root}/proc/sys/fs/binfmt_misc") or error "umount /proc/sys/fs/binfmt_misc failed: $?"; } 0 == system('umount', "$options->{root}/proc") or error "umount /proc failed: $?"; }; 0 == system('mount', '-t', 'proc', 'proc', "$options->{root}/proc") or error "mount /proc failed: $?"; } elsif ($options->{mode} eq 'unshare') { # naturally we have to clean up after ourselves in sudo mode where # we do a real mount. But we also need to unmount in unshare mode # because otherwise, even with the --one-file-system tar option, # the permissions of the mount source will be stored and not the # mount target (the directory) push @cleanup_tasks, sub { # since we cannot write to /etc/mtab we need --no-mtab 0 == system('umount', '--no-mtab', "$options->{root}/proc") or error "umount /proc failed: $?"; }; 0 == system('mount', '-t', 'proc', 'proc', "$options->{root}/proc") or error "mount /proc failed: $?"; } elsif ( any { $_ eq $options->{mode} } ('proot', 'fakechroot', 'chrootless') ) { # we cannot mount in fakechroot and proot mode # in proot mode we have /sys bind-mounted already through # --bind=/sys } else { error "unknown mode: $options->{mode}"; } # prevent daemons from starting # the directory might not exist in custom variant, for example if (-d "$options->{root}/usr/sbin/") { open my $fh, '>', "$options->{root}/usr/sbin/policy-rc.d" or error "cannot open policy-rc.d: $!"; print $fh "#!/bin/sh\n"; print $fh "exit 101\n"; close $fh; chmod 0755, "$options->{root}/usr/sbin/policy-rc.d" or error "cannot chmod policy-rc.d: $!"; } # the file might not exist if it was removed in a hook if (-e "$options->{root}/sbin/start-stop-daemon") { if (-e "$options->{root}/sbin/start-stop-daemon.REAL") { error "$options->{root}/sbin/start-stop-daemon.REAL already" . " exists"; } move( "$options->{root}/sbin/start-stop-daemon", "$options->{root}/sbin/start-stop-daemon.REAL" ) or error "cannot move start-stop-daemon: $!"; open my $fh, '>', "$options->{root}/sbin/start-stop-daemon" or error "cannot open start-stop-daemon: $!"; print $fh "#!/bin/sh\n"; print $fh "echo \"Warning: Fake start-stop-daemon called, doing" . " nothing\">&2\n"; close $fh; chmod 0755, "$options->{root}/sbin/start-stop-daemon" or error "cannot chmod start-stop-daemon: $!"; } &{$cmd}(); # cleanup if (-e "$options->{root}/sbin/start-stop-daemon.REAL") { move( "$options->{root}/sbin/start-stop-daemon.REAL", "$options->{root}/sbin/start-stop-daemon" ) or error "cannot move start-stop-daemon: $!"; } if (-e "$options->{root}/usr/sbin/policy-rc.d") { unlink "$options->{root}/usr/sbin/policy-rc.d" or error "cannot unlink policy-rc.d: $!"; } }; my $error = $@; # we use the cleanup function to do the unmounting $cleanup->(0); if ($error) { error "run_chroot failed: $error"; } } sub run_hooks($$) { my $name = shift; my $options = shift; if (scalar @{ $options->{"${name}_hook"} } == 0) { return; } my $runner = sub { foreach my $script (@{ $options->{"${name}_hook"} }) { if ($script =~ /^(copy-in|copy-out|tar-in|tar-out|upload|download) /) { info "running special hook: $script"; if ( any { $_ eq $options->{variant} } ('extract', 'custom') and any { $_ eq $options->{mode} } ('fakechroot', 'proot') and $name ne 'setup' ) { info "the copy-in, copy-out, tar-in and tar-out commands" . " in fakechroot mode or proot mode might fail in" . " extract and custom variants because there might be" . " no tar inside the chroot"; } my $pid = fork() // error "fork() failed: $!"; if ($pid == 0) { # whatever the script writes on stdout is sent to the # socket # whatever is written to the socket, send to stdin open(STDOUT, '>&', $options->{hooksock}) or error "cannot open STDOUT: $!"; open(STDIN, '<&', $options->{hooksock}) or error "cannot open STDIN: $!"; # we execute ourselves under sh to avoid having to # implement a clever parser of the quoting used in $script # for the filenames my $prefix = ""; if ($is_covering) { $prefix = "$EXECUTABLE_NAME -MDevel::Cover=-silent,-nogcov "; } exec 'sh', '-c', "$prefix$PROGRAM_NAME --hook-helper" . " \"\$1\" \"\$2\" \"\$3\" \"\$4\" \"\$5\" $script", 'exec', $options->{root}, $options->{mode}, $name, ( defined $options->{qemu} ? "qemu-$options->{qemu}" : 'env', $verbosity_level ); } waitpid($pid, 0); $? == 0 or error "special hook failed with exit code $?"; } elsif (-x $script || $script !~ m/[^\w@\%+=:,.\/-]/a) { info "running --$name-hook directly: $script $options->{root}"; # execute it directly if it's an executable file # or if it there are no shell metacharacters # (the /a regex modifier makes \w match only ASCII) 0 == system($script, $options->{root}) or error "command failed: $script"; } else { info "running --$name-hook in shell: sh -c '$script' exec" . " $options->{root}"; # otherwise, wrap everything in sh -c 0 == system('sh', '-c', $script, 'exec', $options->{root}) or error "command failed: $script"; } } }; if ($name eq 'setup') { # execute directly without mounting anything (the mount points do not # exist yet) &{$runner}(); } else { run_chroot \&$runner, $options; } } sub setup { my $options = shift; foreach my $key (sort keys %{$options}) { my $value = $options->{$key}; if (!defined $value) { next; } if (ref $value eq '') { debug "$key: $options->{$key}"; } elsif (ref $value eq 'ARRAY') { debug "$key: [" . (join ', ', @{$value}) . "]"; } elsif (ref $value eq 'GLOB') { debug "$key: GLOB"; } else { error "unknown type for key $key: " . (ref $value); } } my ($conf, $tmpfile) = tempfile(UNLINK => 1) or error "cannot open apt.conf: $!"; print $conf "Apt::Architecture \"$options->{nativearch}\";\n"; # the host system might have configured additional architectures # force only the native architecture if (scalar @{ $options->{foreignarchs} } > 0) { print $conf "Apt::Architectures { \"$options->{nativearch}\"; "; foreach my $arch (@{ $options->{foreignarchs} }) { print $conf "\"$arch\"; "; } print $conf "};\n"; } else { print $conf "Apt::Architectures \"$options->{nativearch}\";\n"; } print $conf "Dir \"$options->{root}\";\n"; # not needed anymore for apt 1.3 and newer print $conf "Dir::State::Status \"$options->{root}/var/lib/dpkg/status\";\n"; # for authentication, use the keyrings from the host print $conf "Dir::Etc::Trusted \"$options->{apttrusted}\";\n"; print $conf "Dir::Etc::TrustedParts \"$options->{apttrustedparts}\";\n"; if ($options->{variant} ne 'apt') { # apt considers itself essential. Thus, when generating an EDSP # document for an external solver, it will add the Essential:yes field # to the apt package stanza. This is unnecessary for any other variant # than 'apt' because in all other variants we compile the set of # packages we consider essential ourselves and for the 'essential' # variant it would even be wrong to add apt. This workaround is only # needed when apt is used with an external solver but doesn't hurt # otherwise and we don't have a good way to figure out whether apt is # using an external solver or not short of parsing the --aptopt # options. print $conf "pkgCacheGen::ForceEssential \",\";\n"; } close $conf; { my @directories = ( '/etc/apt/apt.conf.d', '/etc/apt/sources.list.d', '/etc/apt/preferences.d', '/var/cache/apt', '/var/lib/apt/lists/partial', '/var/lib/dpkg', '/etc/dpkg/dpkg.cfg.d/' ); # if dpkg and apt operate from the outside we need some more # directories because dpkg and apt might not even be installed inside # the chroot if ($options->{mode} eq 'chrootless') { push @directories, ( '/var/log/apt', '/var/lib/dpkg/triggers', '/var/lib/dpkg/info', '/var/lib/dpkg/alternatives', '/var/lib/dpkg/updates' ); } foreach my $dir (@directories) { if (-e "$options->{root}/$dir") { if (!-d "$options->{root}/$dir") { error "$dir already exists but is not a directory"; } } else { my $num_created = make_path "$options->{root}/$dir", { error => \my $err }; if ($err && @$err) { error( join "; ", (map { "cannot create " . (join ": ", %{$_}) } @$err)); } elsif ($num_created == 0) { error "cannot create $options->{root}/$dir"; } } } } # We put certain configuration items in their own configuration file # because they have to be valid for apt invocation from outside as well as # from inside the chroot. # The config filename is chosen such that any settings in it will be # overridden by what the user specified with --aptopt. { open my $fh, '>', "$options->{root}/etc/apt/apt.conf.d/00mmdebstrap" or error "cannot open /etc/apt/apt.conf.d/00mmdebstrap: $!"; print $fh "Apt::Install-Recommends false;\n"; print $fh "Acquire::Languages \"none\";\n"; close $fh; } { open my $fh, '>', "$options->{root}/var/lib/dpkg/status" or error "failed to open(): $!"; close $fh; } # /var/lib/dpkg/available is required to exist or otherwise package # removals will fail { open my $fh, '>', "$options->{root}/var/lib/dpkg/available" or error "failed to open(): $!"; close $fh; } # /var/lib/dpkg/cmethopt is used by dselect # see #930788 { open my $fh, '>', "$options->{root}/var/lib/dpkg/cmethopt" or error "failed to open(): $!"; print $fh "apt apt\n"; close $fh; } # we create /var/lib/dpkg/arch inside the chroot either if there is more # than the native architecture in the chroot or if chrootless mode is # used to create a chroot of a different architecture than the native # architecture outside the chroot. chomp(my $hostarch = `dpkg --print-architecture`); if ( scalar @{ $options->{foreignarchs} } > 0 or ( $options->{mode} eq 'chrootless' and $hostarch ne $options->{nativearch}) ) { open my $fh, '>', "$options->{root}/var/lib/dpkg/arch" or error "cannot open /var/lib/dpkg/arch: $!"; print $fh "$options->{nativearch}\n"; foreach my $arch (@{ $options->{foreignarchs} }) { print $fh "$arch\n"; } close $fh; } if (scalar @{ $options->{aptopts} } > 0) { open my $fh, '>', "$options->{root}/etc/apt/apt.conf.d/99mmdebstrap" or error "cannot open /etc/apt/apt.conf.d/99mmdebstrap: $!"; foreach my $opt (@{ $options->{aptopts} }) { if (-r $opt) { # flush handle because copy() uses syswrite() which bypasses # buffered IO $fh->flush(); copy $opt, $fh or error "cannot copy $opt: $!"; } else { print $fh $opt; if ($opt !~ /;$/) { print $fh ';'; } if ($opt !~ /\n$/) { print $fh "\n"; } } } close $fh; } if (scalar @{ $options->{dpkgopts} } > 0) { # FIXME: in chrootless mode, dpkg will only read the configuration # from the host open my $fh, '>', "$options->{root}/etc/dpkg/dpkg.cfg.d/99mmdebstrap" or error "cannot open /etc/dpkg/dpkg.cfg.d/99mmdebstrap: $!"; foreach my $opt (@{ $options->{dpkgopts} }) { if (-r $opt) { # flush handle because copy() uses syswrite() which bypasses # buffered IO $fh->flush(); copy $opt, $fh or error "cannot copy $opt: $!"; } else { print $fh $opt; if ($opt !~ /\n$/) { print $fh "\n"; } } } close $fh; } ## setup merged usr #my @amd64_dirs = ('lib32', 'lib64', 'libx32'); # only amd64 for now #foreach my $dir ("bin", "sbin", "lib", @amd64_dirs) { # symlink "usr/$dir", "$options->{root}/$dir" # or die "cannot create symlink: $!"; # make_path("$options->{root}/usr/$dir") # or die "cannot create /usr/$dir: $!"; #} { open my $fh, '>', "$options->{root}/etc/fstab" or error "cannot open fstab: $!"; print $fh "# UNCONFIGURED FSTAB FOR BASE SYSTEM\n"; close $fh; chmod 0644, "$options->{root}/etc/fstab" or error "cannot chmod fstab: $!"; } # write /etc/apt/sources.list { open my $fh, '>', "$options->{root}/etc/apt/sources.list" or error "cannot open /etc/apt/sources.list: $!"; print $fh $options->{sourceslist}; close $fh; } # allow network access from within if (-e "/etc/resolv.conf") { copy("/etc/resolv.conf", "$options->{root}/etc/resolv.conf") or error "cannot copy /etc/resolv.conf: $!"; } else { warning("Host system does not have a /etc/resolv.conf to copy into the" . " rootfs."); } if (-e "/etc/hostname") { copy("/etc/hostname", "$options->{root}/etc/hostname") or error "cannot copy /etc/hostname: $!"; } else { warning("Host system does not have a /etc/hostname to copy into the" . " rootfs."); } if ($options->{havemknod}) { foreach my $file (@devfiles) { my ($fname, $mode, $type, $linkname, $devmajor, $devminor) = @{$file}; if ($type == 0) { # normal file error "type 0 not implemented"; } elsif ($type == 1) { # hardlink error "type 1 not implemented"; } elsif ($type == 2) { # symlink if ( $options->{mode} eq 'fakechroot' and $linkname =~ /^\/proc/) { # there is no /proc in fakechroot mode next; } symlink $linkname, "$options->{root}/$fname" or error "cannot create symlink $fname"; next; # chmod cannot work on symlinks } elsif ($type == 3) { # character special 0 == system('mknod', "$options->{root}/$fname", 'c', $devmajor, $devminor) or error "mknod failed: $?"; } elsif ($type == 4) { # block special 0 == system('mknod', "$options->{root}/$fname", 'b', $devmajor, $devminor) or error "mknod failed: $?"; } elsif ($type == 5) { # directory if (-e "$options->{root}/$fname") { if (!-d "$options->{root}/$fname") { error "$fname already exists but is not a directory"; } } else { my $num_created = make_path "$options->{root}/$fname", { error => \my $err }; if ($err && @$err) { error( join "; ", ( map { "cannot create " . (join ": ", %{$_}) } @$err )); } elsif ($num_created == 0) { error "cannot create $options->{root}/$fname"; } } } else { error "unsupported type: $type"; } chmod $mode, "$options->{root}/$fname" or error "cannot chmod $fname: $!"; } } # we tell apt about the configuration via a config file passed via the # APT_CONFIG environment variable instead of using the --option command # line arguments because configuration settings like Dir::Etc have already # been evaluated at the time that apt takes its command line arguments # into account. $ENV{"APT_CONFIG"} = "$tmpfile"; # when apt-get update is run by the root user, then apt will attempt to # drop privileges to the _apt user. This will fail if the _apt user does # not have permissions to read the root directory. In that case, we have # to disable apt sandboxing. if ($options->{mode} eq 'root') { my $partial = '/var/lib/apt/lists/partial'; if ( system('/usr/lib/apt/apt-helper', 'drop-privs', '--', 'test', '-r', "$options->{root}$partial") != 0 ) { warning "Download is performed unsandboxed as root as file" . " $options->{root}$partial couldn't be accessed by user _apt"; open my $fh, '>>', $tmpfile or error "cannot open $tmpfile for appending: $!"; print $fh "APT::Sandbox::User \"root\";\n"; close $fh; } } # setting PATH for chroot, ldconfig, start-stop-daemon... if (defined $ENV{PATH} && $ENV{PATH} ne "") { $ENV{PATH} = "$ENV{PATH}:/usr/sbin:/usr/bin:/sbin:/bin"; } else { $ENV{PATH} = "/usr/sbin:/usr/bin:/sbin:/bin"; } # run setup hooks run_hooks('setup', $options); info "running apt-get update..."; run_apt_progress({ ARGV => ['apt-get', 'update'], CHDIR => $options->{root}, FIND_APT_WARNINGS => 1 }); # check if anything was downloaded at all { open my $fh, '-|', 'apt-get', 'indextargets' // error "failed to fork(): $!"; chomp( my $indextargets = do { local $/; <$fh> } ); close $fh; if ($indextargets eq '') { info "content of /etc/apt/sources.list:"; if ($verbosity_level >= 1) { copy("$options->{root}/etc/apt/sources.list", *STDERR); } error "apt-get update didn't download anything"; } } my @pkgs_to_install; for my $incl (@{ $options->{include} }) { for my $pkg (split /[,\s]+/, $incl) { # strip leading and trailing whitespace $pkg =~ s/^\s+|\s+$//g; # skip if the remainder is an empty string if ($pkg eq '') { next; } # do not append component if it's already in the list if (any { $_ eq $pkg } @pkgs_to_install) { next; } push @pkgs_to_install, $pkg; } } if ($options->{variant} eq 'buildd') { push @pkgs_to_install, 'build-essential'; } # To figure out the right package set for the apt variant we can use: # $ apt-get dist-upgrade -o dir::state::status=/dev/null # This is because that variants only contain essential packages and # apt and libapt treats apt as essential. If we want to install less # (essential variant) then we have to compute the package set ourselves. # Same if we want to install priority based variants. if (any { $_ eq $options->{variant} } ('extract', 'custom')) { info "downloading packages with apt..."; run_apt_progress({ ARGV => [ 'apt-get', '--yes', '-oApt::Get::Download-Only=true', 'install' ], PKGS => [@pkgs_to_install], }); } elsif ($options->{variant} eq 'apt') { # if we just want to install Essential:yes packages, apt and their # dependencies then we can make use of libapt treating apt as # implicitly essential. An upgrade with the (currently) empty status # file will trigger an installation of the essential packages plus apt. # # 2018-09-02, #debian-dpkg on OFTC, times in UTC+2 # 23:39 < josch> I'll just put it in my script and if it starts # breaking some time I just say it's apt's fault. :P # 23:42 < DonKult> that is how it usually works, so yes, do that :P (<- # and please add that line next to it so you can # remind me in 5+ years that I said that after I wrote # in the bugreport: "Are you crazy?!? Nobody in his # right mind would even suggest depending on it!") info "downloading packages with apt..."; run_apt_progress({ ARGV => [ 'apt-get', '--yes', '-oApt::Get::Download-Only=true', 'dist-upgrade' ], }); } elsif ( any { $_ eq $options->{variant} } ( 'essential', 'standard', 'important', 'required', 'buildd', 'minbase' ) ) { my %ess_pkgs; open(my $pipe_apt, '-|', 'apt-get', 'indextargets', '--format', '$(FILENAME)', 'Created-By: Packages') or error "cannot start apt-get indextargets: $!"; while (my $fname = <$pipe_apt>) { chomp $fname; open(my $pipe_cat, '-|', '/usr/lib/apt/apt-helper', 'cat-file', $fname) or error "cannot start apt-helper cat-file: $!"; my $pkgname; my $ess = ''; my $prio = 'optional'; my $arch = ''; while (my $line = <$pipe_cat>) { chomp $line; # Dpkg::Index takes 10 seconds to parse a typical Packages # file. Thus we instead use a simple parser that just retrieve # the information we need. if ($line ne "") { if ($line =~ /^Package: (.*)/) { $pkgname = $1; } elsif ($line =~ /^Essential: yes$/) { $ess = 'yes'; } elsif ($line =~ /^Priority: (.*)/) { $prio = $1; } elsif ($line =~ /^Architecture: (.*)/) { $arch = $1; } next; } # we are only interested of packages of native architecture or # Architecture:all if ($arch eq $options->{nativearch} or $arch eq 'all') { # the line is empty, thus a package stanza just finished # processing and we can handle it now if ($ess eq 'yes') { $ess_pkgs{$pkgname} = (); } elsif ($options->{variant} eq 'essential') { # for this variant we are only interested in the # essential packages } elsif ( any { $_ eq $options->{variant} } ( 'standard', 'important', 'required', 'buildd', 'minbase' ) ) { if ($prio eq 'optional' or $prio eq 'extra') { # always ignore packages of priority optional and # extra } elsif ($prio eq 'standard') { if ( none { $_ eq $options->{variant} } ('important', 'required', 'buildd', 'minbase') ) { push @pkgs_to_install, $pkgname; } } elsif ($prio eq 'important') { if ( none { $_ eq $options->{variant} } ('required', 'buildd', 'minbase') ) { push @pkgs_to_install, $pkgname; } } elsif ($prio eq 'required') { # required packages are part of all sets except # essential and apt push @pkgs_to_install, $pkgname; } else { error "unknown priority: $prio"; } } else { error "unknown variant: $options->{variant}"; } } # reset values undef $pkgname; $ess = ''; $prio = 'optional'; $arch = ''; } close $pipe_cat; $? == 0 or error "apt-helper cat-file failed: $?"; } close $pipe_apt; $? == 0 or error "apt-get indextargets failed: $?"; debug "Identified the following Essential:yes packages:"; foreach my $pkg (sort keys %ess_pkgs) { debug " $pkg"; } info "downloading packages with apt..."; run_apt_progress({ ARGV => [ 'apt-get', '--yes', '-oApt::Get::Download-Only=true', 'install' ], PKGS => [keys %ess_pkgs], }); } else { error "unknown variant: $options->{variant}"; } # extract the downloaded packages my @essential_pkgs; { my $apt_archives = "/var/cache/apt/archives/"; opendir my $dh, "$options->{root}/$apt_archives" or error "cannot read $apt_archives"; while (my $deb = readdir $dh) { if ($deb !~ /\.deb$/) { next; } $deb = "$apt_archives/$deb"; if (!-f "$options->{root}/$deb") { next; } push @essential_pkgs, $deb; } close $dh; } if (scalar @essential_pkgs == 0) { # check if a file:// URI was used open(my $pipe_apt, '-|', 'apt-get', 'indextargets', '--format', '$(URI)', 'Created-By: Packages') or error "cannot start apt-get indextargets: $!"; while (my $uri = <$pipe_apt>) { if ($uri =~ /^file:\/\//) { error "nothing got downloaded -- use copy:// instead of file://"; } } error "nothing got downloaded"; } # We have to extract the packages from @essential_pkgs either if we run in # chrootless mode and extract variant or in any other mode. # In other words, the only scenario in which the @essential_pkgs are not # extracted are in chrootless mode in any other than the extract variant. if ($options->{mode} eq 'chrootless' and $options->{variant} ne 'extract') { # nothing to do } else { info "extracting archives..."; print_progress 0.0; my $counter = 0; my $total = scalar @essential_pkgs; foreach my $deb (@essential_pkgs) { $counter += 1; # not using dpkg-deb --extract as that would replace the # merged-usr symlinks with plain directories pipe my $rfh, my $wfh; my $pid1 = fork() // error "fork() failed: $!"; if ($pid1 == 0) { open(STDOUT, '>&', $wfh) or error "cannot open STDOUT: $!"; debug("running dpkg-deb --fsys-tarfile $options->{root}/$deb"); eval 'Devel::Cover::set_coverage("none")' if $is_covering; exec 'dpkg-deb', '--fsys-tarfile', "$options->{root}/$deb"; } my $pid2 = fork() // error "fork() failed: $!"; if ($pid2 == 0) { open(STDIN, '<&', $rfh) or error "cannot open STDIN: $!"; debug( "running tar -C $options->{root}" . " --keep-directory-symlink --extract --file -"); eval 'Devel::Cover::set_coverage("none")' if $is_covering; exec 'tar', '-C', $options->{root}, '--keep-directory-symlink', '--extract', '--file', '-'; } waitpid($pid1, 0); $? == 0 or error "dpkg-deb --fsys-tarfile failed: $?"; waitpid($pid2, 0); $? == 0 or error "tar --extract failed: $?"; print_progress($counter / $total * 100); } print_progress "done"; } if ($options->{mode} eq 'chrootless') { info "installing packages..."; # FIXME: the dpkg config from the host is parsed before the command # line arguments are parsed and might break this mode # Example: if the host has --path-exclude set, then this will also # affect the chroot. my @chrootless_opts = ( '-oDPkg::Options::=--force-not-root', '-oDPkg::Options::=--force-script-chrootless', '-oDPkg::Options::=--root=' . $options->{root}, '-oDPkg::Options::=--log=' . "$options->{root}/var/log/dpkg.log" ); if (defined $options->{qemu}) { # The binfmt support on the outside is used, so qemu needs to know # where it has to look for shared libraries if (defined $ENV{QEMU_LD_PREFIX} && $ENV{QEMU_LD_PREFIX} ne "") { $ENV{QEMU_LD_PREFIX} = "$ENV{QEMU_LD_PREFIX}:$options->{root}"; } else { $ENV{QEMU_LD_PREFIX} = $options->{root}; } } if ($options->{variant} eq 'extract') { # nothing to do } else { run_apt_progress({ ARGV => ['apt-get', '--yes', @chrootless_opts, 'install'], PKGS => [map { "$options->{root}/$_" } @essential_pkgs], }); } if (any { $_ eq $options->{variant} } ('extract', 'custom')) { # nothing to do } elsif ( any { $_ eq $options->{variant} } ( 'essential', 'apt', 'standard', 'important', 'required', 'buildd', 'minbase' ) ) { # run essential hooks run_hooks('essential', $options); if (scalar @pkgs_to_install > 0) { run_apt_progress({ ARGV => ['apt-get', '--yes', @chrootless_opts, 'install'], PKGS => [@pkgs_to_install], }); } } else { error "unknown variant: $options->{variant}"; } } elsif ( any { $_ eq $options->{mode} } ('root', 'unshare', 'fakechroot', 'proot') ) { if (any { $_ eq $options->{variant} } ('extract')) { # nothing to do } elsif ( any { $_ eq $options->{variant} } ( 'custom', 'essential', 'apt', 'standard', 'important', 'required', 'buildd', 'minbase' ) ) { if ($options->{mode} eq 'fakechroot') { # this borrows from and extends # /etc/fakechroot/debootstrap.env and # /etc/fakechroot/chroot.env { my @fakechrootsubst = (); foreach my $dir ('/usr/sbin', '/usr/bin', '/sbin', '/bin') { push @fakechrootsubst, "$dir/chroot=/usr/sbin/chroot.fakechroot"; push @fakechrootsubst, "$dir/mkfifo=/bin/true"; push @fakechrootsubst, "$dir/ldconfig=/bin/true"; push @fakechrootsubst, "$dir/ldd=/usr/bin/ldd.fakechroot"; push @fakechrootsubst, "$dir/ischroot=/bin/true"; } if (defined $ENV{FAKECHROOT_CMD_SUBST} && $ENV{FAKECHROOT_CMD_SUBST} ne "") { push @fakechrootsubst, split /:/, $ENV{FAKECHROOT_CMD_SUBST}; } $ENV{FAKECHROOT_CMD_SUBST} = join ':', @fakechrootsubst; } if (defined $ENV{FAKECHROOT_EXCLUDE_PATH} && $ENV{FAKECHROOT_EXCLUDE_PATH} ne "") { $ENV{FAKECHROOT_EXCLUDE_PATH} = "$ENV{FAKECHROOT_EXCLUDE_PATH}:/dev:/proc:/sys"; } else { $ENV{FAKECHROOT_EXCLUDE_PATH} = '/dev:/proc:/sys'; } # workaround for long unix socket path if FAKECHROOT_BASE # exceeds the limit of 108 bytes $ENV{FAKECHROOT_AF_UNIX_PATH} = "/tmp"; { my @ldsoconf = ('/etc/ld.so.conf'); opendir(my $dh, '/etc/ld.so.conf.d') or error "Can't opendir(/etc/ld.so.conf.d): $!"; while (my $entry = readdir $dh) { # skip the "." and ".." entries next if $entry eq "."; next if $entry eq ".."; next if $entry !~ /\.conf$/; push @ldsoconf, "/etc/ld.so.conf.d/$entry"; } closedir($dh); my @ldlibpath = (); if (defined $ENV{LD_LIBRARY_PATH} && $ENV{LD_LIBRARY_PATH} ne "") { push @ldlibpath, (split /:/, $ENV{LD_LIBRARY_PATH}); } # FIXME: workaround allowing installation of systemd should # live in fakechroot, see #917920 push @ldlibpath, "/lib/systemd"; foreach my $fname (@ldsoconf) { open my $fh, "<", $fname or error "cannot open $fname for reading: $!"; while (my $line = <$fh>) { next if $line !~ /^\//; push @ldlibpath, $line; } close $fh; } $ENV{LD_LIBRARY_PATH} = join ':', @ldlibpath; } } # make sure that APT_CONFIG is not set when executing anything # inside the chroot my @chrootcmd = (); if ($options->{mode} eq 'proot') { push @chrootcmd, ( 'proot', '--root-id', '--bind=/dev', '--bind=/proc', '--bind=/sys', "--rootfs=$options->{root}", '--cwd=/' ); } elsif ( any { $_ eq $options->{mode} } ('root', 'unshare', 'fakechroot') ) { push @chrootcmd, ('/usr/sbin/chroot', $options->{root}); } else { error "unknown mode: $options->{mode}"; } # copy qemu-user-static binary into chroot or setup proot with # --qemu if (defined $options->{qemu}) { if ($options->{mode} eq 'proot') { push @chrootcmd, "--qemu=qemu-$options->{qemu}"; } elsif ($options->{mode} eq 'fakechroot') { # The binfmt support on the outside is used, so qemu needs # to know where it has to look for shared libraries if (defined $ENV{QEMU_LD_PREFIX} && $ENV{QEMU_LD_PREFIX} ne "") { $ENV{QEMU_LD_PREFIX} = "$ENV{QEMU_LD_PREFIX}:$options->{root}"; } else { $ENV{QEMU_LD_PREFIX} = $options->{root}; } # Make sure that the fakeroot and fakechroot shared # libraries exist for the right architecture open my $fh, '-|', 'dpkg-architecture', '-a', $options->{nativearch}, '-qDEB_HOST_MULTIARCH' // error "failed to fork(): $!"; chomp( my $deb_host_multiarch = do { local $/; <$fh> } ); close $fh; if ($? != 0 or !$deb_host_multiarch) { error "dpkg-architecture failed: $?"; } my $fakechrootdir = "/usr/lib/$deb_host_multiarch/fakechroot"; if (!-e "$fakechrootdir/libfakechroot.so") { error "$fakechrootdir/libfakechroot.so doesn't exist." . " Install libfakechroot:$options->{nativearch}" . " outside the chroot"; } my $fakerootdir = "/usr/lib/$deb_host_multiarch/libfakeroot"; if (!-e "$fakerootdir/libfakeroot-sysv.so") { error "$fakerootdir/libfakeroot-sysv.so doesn't exist." . " Install libfakeroot:$options->{nativearch}" . " outside the chroot"; } # fakechroot only fills LD_LIBRARY_PATH with the # directories of the host's architecture. We append the # directories of the chroot architecture. $ENV{LD_LIBRARY_PATH} .= ":$fakechrootdir:$fakerootdir"; } elsif (any { $_ eq $options->{mode} } ('root', 'unshare')) { # other modes require a static qemu-user binary my $qemubin = "/usr/bin/qemu-$options->{qemu}-static"; if (!-e $qemubin) { error "cannot find $qemubin"; } copy $qemubin, "$options->{root}/$qemubin" or error "cannot copy $qemubin: $!"; # File::Copy does not retain permissions but on some # platforms (like Travis CI) the binfmt interpreter must # have the executable bit set or otherwise execve will # fail with EACCES chmod 0755, "$options->{root}/$qemubin" or error "cannot chmod $qemubin: $!"; } else { error "unknown mode: $options->{mode}"; } } # some versions of coreutils use the renameat2 system call in mv. # This breaks certain versions of fakechroot and proot. Here we do # a sanity check and warn the user in case things might break. if (any { $_ eq $options->{mode} } ('fakechroot', 'proot') and -e "$options->{root}/bin/mv") { mkdir "$options->{root}/000-move-me" or error "cannot create directory: $!"; my $ret = system @chrootcmd, '/bin/mv', '/000-move-me', '/001-delete-me'; if ($ret != 0) { if ($options->{mode} eq 'proot') { info "the /bin/mv binary inside the chroot doesn't" . " work under proot"; info "this is likely due to missing support for" . " renameat2 in proot"; info "see https://github.com/proot-me/PRoot/issues/147"; } else { info "the /bin/mv binary inside the chroot doesn't" . " work under fakechroot"; info "with certain versions of coreutils and glibc," . " this is due to missing support for renameat2 in" . " fakechroot"; info "see https://github.com/dex4er/fakechroot/issues/60"; } info "expect package post installation scripts not to work"; rmdir "$options->{root}/000-move-me" or error "cannot rmdir: $!"; } else { rmdir "$options->{root}/001-delete-me" or error "cannot rmdir: $!"; } } # install the extracted packages properly # we need --force-depends because dpkg does not take Pre-Depends # into account and thus doesn't install them in the right order # And the --predep-package option is broken: #539133 info "installing packages..."; run_chroot { run_dpkg_progress({ ARGV => [ @chrootcmd, 'env', '--unset=TMPDIR', 'dpkg', '--install', '--force-depends' ], PKGS => \@essential_pkgs, }); } $options; # if the path-excluded option was added to the dpkg config, # reinstall all packages if (-e "$options->{root}/etc/dpkg/dpkg.cfg.d/99mmdebstrap") { open(my $fh, '<', "$options->{root}/etc/dpkg/dpkg.cfg.d/99mmdebstrap") or error "cannot open /etc/dpkg/dpkg.cfg.d/99mmdebstrap: $!"; my $num_matches = grep /^path-exclude=/, <$fh>; close $fh; if ($num_matches > 0) { # without --skip-same-version, dpkg will install the given # packages even though they are already installed info "re-installing packages because of path-exclude..."; run_dpkg_progress({ ARGV => [ @chrootcmd, 'env', '--unset=TMPDIR', 'dpkg', '--install', '--force-depends' ], PKGS => \@essential_pkgs, }); } } foreach my $deb (@essential_pkgs) { unlink "$options->{root}/$deb" or error "cannot unlink $deb: $!"; } # run essential hooks if ($options->{variant} ne 'custom') { run_hooks('essential', $options); } if ($options->{variant} ne 'custom' and scalar @pkgs_to_install > 0) { # some packages have to be installed from the outside before # anything can be installed from the inside. # # we do not need to install any *-archive-keyring packages # inside the chroot prior to installing the packages, because # the keyring is only used when doing "apt-get update" and that # was already done at the beginning using key material from the # outside. Since the apt cache is already filled and we are not # calling "apt-get update" again, the keyring can be installed # later during installation. But: if it's not installed during # installation, then we might end up with a fully installed # system without keyrings that are valid for its sources.list. my @pkgs_to_install_from_outside; # install apt if necessary if ($options->{variant} ne 'apt') { push @pkgs_to_install_from_outside, 'apt'; } # since apt will be run inside the chroot, make sure that # apt-transport-https and ca-certificates gets installed first # if any mirror is a https URI open(my $pipe_apt, '-|', 'apt-get', 'indextargets', '--format', '$(URI)', 'Created-By: Packages') or error "cannot start apt-get indextargets: $!"; while (my $uri = <$pipe_apt>) { if ($uri =~ /^https:\/\//) { # FIXME: support for https is part of apt >= 1.5 push @pkgs_to_install_from_outside, 'apt-transport-https'; push @pkgs_to_install_from_outside, 'ca-certificates'; last; } elsif ($uri =~ /^tor(\+[a-z]+)*:\/\//) { # tor URIs can be tor+http://, tor+https:// or even # tor+mirror+file:// push @pkgs_to_install_from_outside, 'apt-transport-tor'; last; } } close $pipe_apt; $? == 0 or error "apt-get indextargets failed"; if (scalar @pkgs_to_install_from_outside > 0) { info 'downloading ' . (join ', ', @pkgs_to_install_from_outside) . "..."; run_apt_progress({ ARGV => [ 'apt-get', '--yes', '-oApt::Get::Download-Only=true', 'install' ], PKGS => [@pkgs_to_install_from_outside], }); my @debs_to_install; my $apt_archives = "/var/cache/apt/archives/"; opendir my $dh, "$options->{root}/$apt_archives" or error "cannot read $apt_archives"; while (my $deb = readdir $dh) { if ($deb !~ /\.deb$/) { next; } $deb = "$apt_archives/$deb"; if (!-f "$options->{root}/$deb") { next; } push @debs_to_install, $deb; } close $dh; if (scalar @debs_to_install == 0) { warning "nothing got downloaded -- maybe the packages" . " were already installed?"; } else { # we need --force-depends because dpkg does not take # Pre-Depends into account and thus doesn't install # them in the right order info 'installing ' . (join ', ', @pkgs_to_install_from_outside) . "..."; run_dpkg_progress({ ARGV => [ @chrootcmd, 'env', '--unset=TMPDIR', 'dpkg', '--install', '--force-depends' ], PKGS => \@debs_to_install, }); foreach my $deb (@debs_to_install) { unlink "$options->{root}/$deb" or error "cannot unlink $deb: $!"; } } } run_chroot { info "installing remaining packages inside the chroot..."; run_apt_progress({ ARGV => [ @chrootcmd, 'env', '--unset=APT_CONFIG', '--unset=TMPDIR', 'apt-get', '--yes', 'install' ], PKGS => [@pkgs_to_install], }); } $options; } } else { error "unknown variant: $options->{variant}"; } } else { error "unknown mode: $options->{mode}"; } run_hooks('customize', $options); # clean up temporary configuration file unlink "$options->{root}/etc/apt/apt.conf.d/00mmdebstrap" or error "failed to unlink /etc/apt/apt.conf.d/00mmdebstrap: $!"; info "cleaning package lists and apt cache..."; run_apt_progress({ ARGV => [ 'apt-get', '--option', 'Dir::Etc::SourceList=/dev/null', '--option', 'Dir::Etc::SourceParts=/dev/null', 'update' ], CHDIR => $options->{root}, }); run_apt_progress( { ARGV => ['apt-get', 'clean'], CHDIR => $options->{root} }); # apt since 1.6 creates the auxfiles directory. If apt inside the chroot # is older than that, then it will not know how to clean it. if (-e "$options->{root}/var/lib/apt/lists/auxfiles") { rmdir "$options->{root}/var/lib/apt/lists/auxfiles" or die "cannot rmdir /var/lib/apt/lists/auxfiles: $!"; } if (defined $options->{qemu} and any { $_ eq $options->{mode} } ('root', 'unshare')) { unlink "$options->{root}/usr/bin/qemu-$options->{qemu}-static" or error "cannot unlink /usr/bin/qemu-$options->{qemu}-static: $!"; } # clean up certain files to make output reproducible foreach my $fname ( '/var/log/dpkg.log', '/var/log/apt/history.log', '/var/log/apt/term.log', '/var/log/alternatives.log', '/var/cache/ldconfig/aux-cache', '/var/log/apt/eipp.log.xz' ) { my $path = "$options->{root}$fname"; if (!-e $path) { next; } unlink $path or error "cannot unlink $path: $!"; } # remove any possible leftovers in /tmp but warn about it if (-d "$options->{root}/tmp") { opendir(my $dh, "$options->{root}/tmp") or error "Can't opendir($options->{root}/tmp): $!"; while (my $entry = readdir $dh) { # skip the "." and ".." entries next if $entry eq "."; next if $entry eq ".."; warning "deleting files in /tmp: $entry"; remove_tree("$options->{root}/tmp/$entry", { error => \my $err }); if (@$err) { for my $diag (@$err) { my ($file, $message) = %$diag; if ($file eq '') { warning "general error: $message"; } else { warning "problem unlinking $file: $message"; } } } } closedir($dh); } } # messages from process inside unshared namespace to the outside # openw -- open file for writing # untar -- extract tar into directory # write -- write data to last opened file or tar process # close -- finish file writing or tar extraction # adios -- last message and tear-down # messages from process outside unshared namespace to the inside # okthx -- success sub checkokthx { my $fh = shift; my $ret = read($fh, my $buf, 2 + 5) // error "cannot read from socket: $!"; if ($ret == 0) { error "received eof on socket"; } my ($len, $msg) = unpack("nA5", $buf); if ($msg ne "okthx") { error "expected okthx but got: $msg"; } if ($len != 0) { error "expected no payload but got $len bytes"; } } sub main() { umask 022; if (scalar @ARGV >= 7 && $ARGV[0] eq "--hook-helper") { my $root = $ARGV[1]; my $mode = $ARGV[2]; my $hook = $ARGV[3]; my $qemu = $ARGV[4]; $verbosity_level = $ARGV[5]; my $command = $ARGV[6]; # unless we are in the setup hook (where there is no tar inside the # chroot) we need to run tar on the inside because otherwise, possible # absolute symlinks in the path given via --directory are not # correctly resolved # # FIXME: the issue above can be fixed by a function that is able to # resolve absolute symlinks even inside the chroot directory to a full # path that is valid on the outside -- fakechroot and proot have their # own reasons, see below my @cmdprefix = (); my @tarcmd = ('tar'); if ($hook eq 'setup') { if ($mode eq 'proot') { # since we cannot run tar inside the chroot under proot during # the setup hook because the chroot is empty, we have to run # tar from the outside, which leads to all files being owned # by the user running mmdebstrap. To let the ownership # information not be completely off, we force all files be # owned by the root user. push @tarcmd, '--owner=root', '--group=root'; } } elsif (any { $_ eq $hook } ('essential', 'customize')) { if ($mode eq 'fakechroot') { # Fakechroot requires tar to run inside the chroot or # otherwise absolute symlinks will include the path to the # root directory push @cmdprefix, '/usr/sbin/chroot', $root; } elsif ($mode eq 'proot') { # proot requires tar to run inside proot or otherwise # permissions will be completely off push @cmdprefix, 'proot', '--root-id', "--rootfs=$root", '--cwd=/', "--qemu=$qemu"; } elsif (any { $_ eq $mode } ('root', 'chrootless', 'unshare')) { push @cmdprefix, '/usr/sbin/chroot', $root; } else { error "unknown mode: $mode"; } } else { error "unknown hook: $hook"; } if (any { $_ eq $command } ('copy-in', 'tar-in', 'upload')) { if (scalar @ARGV < 9) { error "copy-in and tar-in need at least one path on the" . " outside and the output path inside the chroot"; } my $outpath = $ARGV[-1]; for (my $i = 7 ; $i < $#ARGV ; $i++) { # the right argument for tar's --directory argument depends on # whether tar is called from inside the chroot or from the # outside my $directory; if ($hook eq 'setup') { $directory = "$root/$outpath"; } elsif (any { $_ eq $hook } ('essential', 'customize')) { $directory = $outpath; } else { error "unknown hook: $hook"; } # FIXME: here we would like to check if the path inside the # chroot given by $directory actually exists but we cannot # because we are missing a function that can resolve even # paths including absolute symlinks to paths that are valid # outside the chroot my $fh; if ($command eq 'upload') { # open the requested file for writing open $fh, '|-', @cmdprefix, 'sh', '-c', 'cat > "$1"', 'exec', $directory // error "failed to fork(): $!"; } else { # open a tar process that extracts the tarfile that we # supply it with on stdin to the output directory inside # the chroot open $fh, '|-', @cmdprefix, @tarcmd, '--directory', $directory, '--extract', '--file', '-' // error "failed to fork(): $!"; } if ($command eq 'copy-in') { # instruct the parent process to create a tarball of the # requested path outside the chroot debug "sending mktar"; print STDOUT ( pack("n", length $ARGV[$i]) . "mktar" . $ARGV[$i]); } else { # instruct parent process to open a tarball of the # requested path outside the chroot for reading debug "sending openr"; print STDOUT ( pack("n", length $ARGV[$i]) . "openr" . $ARGV[$i]); } STDOUT->flush(); debug "waiting for okthx"; checkokthx \*STDIN; # handle "write" messages from the parent process and feed # their payload into the tar process until a "close" message # is encountered while (1) { # receive the next message my $ret = read(STDIN, my $buf, 2 + 5) // error "cannot read from socket: $!"; if ($ret == 0) { error "received eof on socket"; } my ($len, $msg) = unpack("nA5", $buf); debug "received message: $msg"; if ($msg eq "close") { # finish the loop if ($len != 0) { error "expected no payload but got $len bytes"; } debug "sending okthx"; print STDOUT (pack("n", 0) . "okthx") or error "cannot write to socket: $!"; STDOUT->flush(); last; } elsif ($msg ne "write") { # we should not receive this message at this point print STDOUT (pack("n", 0) . "error") or error "cannot write to socket: $!"; STDOUT->flush(); error "expected write but got: $msg"; } # read the payload my $content; { my $ret = read(STDIN, $content, $len) // error "error cannot read from socket: $!"; if ($ret == 0) { error "received eof on socket"; } } # write the payload to the tar process print $fh $content or error "cannot write to tar process: $!"; debug "sending okthx"; print STDOUT (pack("n", 0) . "okthx") or error "cannot write to socket: $!"; STDOUT->flush(); } close $fh; if ($command ne 'upload' and $? != 0) { error "tar failed"; } } } elsif (any { $_ eq $command } ('copy-out', 'tar-out', 'download')) { if (scalar @ARGV < 9) { error "copy-out needs at least one path inside the chroot and" . " the output path on the outside"; } my $outpath = $ARGV[-1]; for (my $i = 7 ; $i < $#ARGV ; $i++) { # the right argument for tar's --directory argument depends on # whether tar is called from inside the chroot or from the # outside my $directory; if ($hook eq 'setup') { $directory = "$root/$ARGV[$i]"; } elsif (any { $_ eq $hook } ('essential', 'customize')) { $directory = $ARGV[$i]; } else { error "unknown hook: $hook"; } # FIXME: here we would like to check if the path inside the # chroot given by $directory actually exists but we cannot # because we are missing a function that can resolve even # paths including absolute symlinks to paths that are valid # outside the chroot my $fh; if ($command eq 'download') { # open the requested file for reading open $fh, '-|', @cmdprefix, 'sh', '-c', 'cat "$1"', 'exec', $directory // error "failed to fork(): $!"; } else { # Open a tar process that creates a tarfile of everything # in the requested directory inside the chroot and writes # it to stdout. To emulate the behaviour of cp, change to # the dirname of the requested path first. open $fh, '-|', @cmdprefix, @tarcmd, '--directory', dirname($directory), '--create', '--file', '-', basename($directory) // error "failed to fork(): $!"; } if ($command eq 'copy-out') { # instruct the parent process to extract a tarball to a # certain path outside the chroot debug "sending untar"; print STDOUT ( pack("n", length $outpath) . "untar" . $outpath); } else { # instruct parent process to open a tarball of the # requested path outside the chroot for writing debug "sending openw"; print STDOUT ( pack("n", length $outpath) . "openw" . $outpath); } STDOUT->flush(); debug "waiting for okthx"; checkokthx \*STDIN; # read from the tar process and send as payload to the parent # process while (1) { # read from tar my $ret = read($fh, my $cont, 4096) // error "cannot read from pipe: $!"; if ($ret == 0) { last; } debug "sending write"; # send to parent print STDOUT pack("n", $ret) . "write" . $cont; STDOUT->flush(); debug "waiting for okthx"; checkokthx \*STDIN; if ($ret < 4096) { last; } } # signal to the parent process that we are done debug "sending close"; print STDOUT pack("n", 0) . "close"; STDOUT->flush(); debug "waiting for okthx"; checkokthx \*STDIN; close $fh; if ($command ne 'download' and $? != 0) { error "tar failed"; } } } else { error "unknown command: $command"; } exit 0; } my $mtime = time; if (exists $ENV{SOURCE_DATE_EPOCH}) { $mtime = $ENV{SOURCE_DATE_EPOCH} + 0; } $ENV{DEBIAN_FRONTEND} = 'noninteractive'; $ENV{DEBCONF_NONINTERACTIVE_SEEN} = 'true'; $ENV{LC_ALL} = 'C.UTF-8'; $ENV{LANGUAGE} = 'C.UTF-8'; $ENV{LANG} = 'C.UTF-8'; # copy ARGV because getopt modifies it my @ARGVORIG = @ARGV; chomp(my $hostarch = `dpkg --print-architecture`); my $options = { components => ["main"], variant => "important", include => [], architectures => [$hostarch], mode => 'auto', dpkgopts => [], aptopts => [], apttrusted => "/etc/apt/trusted.gpg", apttrustedparts => "/etc/apt/trusted.gpg.d", noop => [], setup_hook => [], essential_hook => [], customize_hook => [], }; my $logfile = undef; Getopt::Long::Configure('default', 'bundling', 'auto_abbrev', 'ignore_case_always'); GetOptions( 'h|help' => sub { pod2usage(-exitval => 0, -verbose => 1) }, 'man' => sub { pod2usage(-exitval => 0, -verbose => 2) }, 'version' => sub { print STDOUT "mmdebstrap $VERSION\n"; exit 0; }, 'components=s@' => \$options->{components}, 'variant=s' => \$options->{variant}, 'include=s@' => \$options->{include}, 'architectures=s@' => \$options->{architectures}, 'mode=s' => \$options->{mode}, 'dpkgopt=s@' => \$options->{dpkgopts}, 'aptopt=s@' => \$options->{aptopts}, 'keyring=s' => sub { my ($opt_name, $opt_value) = @_; if ($opt_value =~ /"/) { error "--keyring: apt cannot handle paths with double quotes:" . " $opt_value"; } if (!-e $opt_value) { error "keyring \"$opt_value\" does not exist"; } my $abs_path = abs_path($opt_value); if (!defined $abs_path) { error "unable to get absolute path of --keyring: $opt_value"; } # since abs_path resolved all symlinks for us, we can now test # what the actual target actually is if (-d $opt_value) { $options->{apttrustedparts} = $opt_value; } else { $options->{apttrusted} = $opt_value; } }, 's|silent' => sub { $verbosity_level = 0; }, 'q|quiet' => sub { $verbosity_level = 0; }, 'v|verbose' => sub { $verbosity_level = 2; }, 'd|debug' => sub { $verbosity_level = 3; }, 'logfile=s' => \$logfile, # no-op options so that mmdebstrap can be used with # sbuild-createchroot --debootstrap=mmdebstrap 'resolve-deps' => sub { push @{ $options->{noop} }, 'resolve-deps'; }, 'merged-usr' => sub { push @{ $options->{noop} }, 'merged-usr'; }, 'no-merged-usr' => sub { push @{ $options->{noop} }, 'no-merged-usr'; }, 'force-check-gpg' => sub { push @{ $options->{noop} }, 'force-check-gpg'; }, # hook options are hidden until I'm happy with them 'setup-hook=s@' => \$options->{setup_hook}, 'essential-hook=s@' => \$options->{essential_hook}, 'customize-hook=s@' => \$options->{customize_hook}, ) or pod2usage(-exitval => 2, -verbose => 1); if (defined($logfile)) { open(STDERR, '>', $logfile) or error "cannot open $logfile: $!"; } foreach my $arg (@{ $options->{noop} }) { info "The option --$arg is a no-op. It only exists for compatibility" . " with some debootstrap wrappers."; } my @valid_variants = ( 'extract', 'custom', 'essential', 'apt', 'required', 'minbase', 'buildd', 'important', 'debootstrap', '-', 'standard' ); if (none { $_ eq $options->{variant} } @valid_variants) { error "invalid variant. Choose from " . (join ', ', @valid_variants); } # debootstrap and - are an alias for important if (any { $_ eq $options->{variant} } ('-', 'debootstrap')) { $options->{variant} = 'important'; } if ($options->{variant} eq 'essential' and scalar @{ $options->{include} } > 0) { warning "cannot install extra packages with variant essential because" . " apt is missing"; } # fakeroot is an alias for fakechroot if ($options->{mode} eq 'fakeroot') { $options->{mode} = 'fakechroot'; } # sudo is an alias for root if ($options->{mode} eq 'sudo') { $options->{mode} = 'root'; } my @valid_modes = ('auto', 'root', 'unshare', 'fakechroot', 'proot', 'chrootless'); if (none { $_ eq $options->{mode} } @valid_modes) { error "invalid mode. Choose from " . (join ', ', @valid_modes); } my $check_fakechroot_running = sub { # test if we are inside fakechroot already # We fork a child process because setting FAKECHROOT_DETECT seems to # be an irreversible operation for fakechroot. my $pid = open my $rfh, '-|' // error "failed to fork(): $!"; if ($pid == 0) { # with the FAKECHROOT_DETECT environment variable set, any program # execution will be replaced with the output "fakeroot [version]" $ENV{FAKECHROOT_DETECT} = 0; exec 'echo', 'If fakechroot is running, this will not be printed'; } my $content = do { local $/; <$rfh> }; waitpid $pid, 0; my $result = 0; if ($? == 0 and $content =~ /^fakechroot \d\.\d+$/) { $result = 1; } return $result; }; # figure out the mode to use or test whether the chosen mode is legal if ($options->{mode} eq 'auto') { if (&{$check_fakechroot_running}()) { # if mmdebstrap is executed inside fakechroot, then we assume the # user expects fakechroot mode $options->{mode} = 'fakechroot'; } elsif ($EFFECTIVE_USER_ID == 0) { # if mmdebstrap is executed as root, we assume the user wants root # mode $options->{mode} = 'root'; } elsif (test_unshare(0)) { # otherwise, unshare mode is our best option if test_unshare() # succeeds $options->{mode} = 'unshare'; } elsif (system('fakechroot --version>/dev/null') == 0) { # the next fallback is fakechroot # exec ourselves again but within fakechroot my @prefix = (); if ($is_covering) { @prefix = ($EXECUTABLE_NAME, '-MDevel::Cover=-silent,-nogcov'); } exec 'fakechroot', 'fakeroot', @prefix, $PROGRAM_NAME, @ARGVORIG; } elsif (system('proot --version>/dev/null') == 0) { # and lastly, proot $options->{mode} = 'proot'; } else { error "unable to pick chroot mode automatically"; } info "automatically chosen mode: $options->{mode}"; } elsif ($options->{mode} eq 'root') { if ($EFFECTIVE_USER_ID != 0) { error "need to be root"; } } elsif ($options->{mode} eq 'proot') { if (system('proot --version>/dev/null') != 0) { error "need working proot binary"; } } elsif ($options->{mode} eq 'fakechroot') { if (&{$check_fakechroot_running}()) { # fakechroot is already running } elsif (system('fakechroot --version>/dev/null') != 0) { error "need working fakechroot binary"; } else { # exec ourselves again but within fakechroot my @prefix = (); if ($is_covering) { @prefix = ($EXECUTABLE_NAME, '-MDevel::Cover=-silent,-nogcov'); } exec 'fakechroot', 'fakeroot', @prefix, $PROGRAM_NAME, @ARGVORIG; } } elsif ($options->{mode} eq 'unshare') { if (!test_unshare(1)) { my $procfile = '/proc/sys/kernel/unprivileged_userns_clone'; open(my $fh, '<', $procfile) or error "failed to open $procfile: $!"; chomp( my $content = do { local $/; <$fh> } ); close($fh); if ($content ne "1") { info "/proc/sys/kernel/unprivileged_userns_clone is set to" . " $content"; info "Try running:"; info " sudo sysctl -w kernel.unprivileged_userns_clone=1"; info "or permanently enable unprivileged usernamespaces by" . " putting the setting into /etc/sysctl.d/"; info "see https://bugs.debian.org/cgi-bin/" . "bugreport.cgi?bug=898446"; } exit 1; } } elsif ($options->{mode} eq 'chrootless') { # nothing to do } else { error "unknown mode: $options->{mode}"; } my @architectures = (); foreach my $archs (@{ $options->{architectures} }) { foreach my $arch (split /[,\s]+/, $archs) { # strip leading and trailing whitespace $arch =~ s/^\s+|\s+$//g; # skip if the remainder is an empty string if ($arch eq '') { next; } # do not append component if it's already in the list if (any { $_ eq $arch } @architectures) { next; } push @architectures, $arch; } } $options->{nativearch} = $hostarch; $options->{foreignarchs} = []; if (scalar @architectures == 0) { warning "empty architecture list: falling back to native architecture" . " $hostarch"; } elsif (scalar @architectures == 1) { $options->{nativearch} = $architectures[0]; } else { $options->{nativearch} = $architectures[0]; push @{ $options->{foreignarchs} }, @architectures[1 .. $#architectures]; } debug "Native architecture (outside): $hostarch"; debug "Native architecture (inside): $options->{nativearch}"; debug("Foreign architectures (inside): " . (join ', ', @{ $options->{foreignarchs} })); { # FIXME: autogenerate this list my $deb2qemu = { alpha => 'alpha', amd64 => 'x86_64', arm => 'arm', arm64 => 'aarch64', armel => 'arm', armhf => 'arm', hppa => 'hppa', i386 => 'i386', m68k => 'm68k', mips => 'mips', mips64 => 'mips64', mips64el => 'mips64el', mipsel => 'mipsel', powerpc => 'ppc', ppc64 => 'ppc64', ppc64el => 'ppc64le', riscv64 => 'riscv64', s390x => 's390x', sh4 => 'sh4', sparc => 'sparc', sparc64 => 'sparc64', }; if ($hostarch ne $options->{nativearch}) { my $withemu = 0; my $noemu = 0; { my $pid = open my $fh, '-|' // error "failed to fork(): $!"; if ($pid == 0) { { no warnings ; # don't print a warning if the following fails exec 'arch-test', $options->{nativearch}; } # if exec didn't work (for example because the arch-test # program is missing) prepare for the worst and assume that # the architecture cannot be executed print "$options->{nativearch}: not supported on this" . " machine/kernel\n"; exit 1; } chomp( my $content = do { local $/; <$fh> } ); close $fh; if ($? == 0 and $content eq "$options->{nativearch}: ok") { $withemu = 1; } } { my $pid = open my $fh, '-|' // error "failed to fork(): $!"; if ($pid == 0) { { no warnings ; # don't print a warning if the following fails exec 'arch-test', '-n', $options->{nativearch}; } # if exec didn't work (for example because the arch-test # program is missing) prepare for the worst and assume that # the architecture cannot be executed print "$options->{nativearch}: not supported on this" . " machine/kernel\n"; exit 1; } chomp( my $content = do { local $/; <$fh> } ); close $fh; if ($? == 0 and $content eq "$options->{nativearch}: ok") { $noemu = 1; } } # four different outcomes, depending on whether arch-test # succeeded with or without emulation # # withemu | noemu | # --------+-------+----------------- # 0 | 0 | test why emu doesn't work and quit # 0 | 1 | should never happen # 1 | 0 | use qemu emulation # 1 | 1 | don't use qemu emulation if ($withemu == 0 and $noemu == 0) { { open my $fh, '<', '/proc/filesystems' or error "failed to open /proc/filesystems: $!"; unless (grep /^nodev\tbinfmt_misc$/, (<$fh>)) { warning "binfmt_misc not found in /proc/filesystems --" . " is the module loaded?"; } close $fh; } { open my $fh, '<', '/proc/mounts' or error "failed to open /proc/mounts: $!"; unless ( grep /^binfmt_misc \/proc\/sys\/fs\/binfmt_misc binfmt_misc/, (<$fh>) ) { warning "binfmt_misc not found in /proc/mounts -- not" . " mounted?"; } close $fh; } { if (!exists $deb2qemu->{ $options->{nativearch} }) { warning "no mapping from $options->{nativearch} to" . " qemu-user binary"; } else { my $binfmt_identifier = 'qemu-' . $deb2qemu->{ $options->{nativearch} }; open my $fh, '-|', '/usr/sbin/update-binfmts', '--display', $binfmt_identifier // error "failed to fork(): $!"; chomp( my $binfmts = do { local $/; <$fh> } ); close $fh; if ($binfmts eq '') { warning "$binfmt_identifier is not a supported" . " binfmt name"; } } } error "$options->{nativearch} can neither be executed natively" . " nor via qemu user emulation with binfmt_misc"; } elsif ($withemu == 0 and $noemu == 1) { error "arch-test succeeded without emu but not with emu"; } elsif ($withemu == 1 and $noemu == 0) { info "$options->{nativearch} cannot be executed, falling back" . " to qemu-user"; if (!exists $deb2qemu->{ $options->{nativearch} }) { error "no mapping from $options->{nativearch} to qemu-user" . " binary"; } $options->{qemu} = $deb2qemu->{ $options->{nativearch} }; } elsif ($withemu == 1 and $noemu == 1) { info "$options->{nativearch} is different from $hostarch but" . " can be executed natively"; } else { error "logic error"; } } else { info "chroot architecture $options->{nativearch} is equal to the" . " host's architecture"; } } { my $suite; if (scalar @ARGV > 0) { $suite = shift @ARGV; if (scalar @ARGV > 0) { $options->{target} = shift @ARGV; } else { $options->{target} = '-'; } } else { info "No SUITE specified, expecting sources.list on standard input"; $options->{target} = '-'; } my $sourceslist = ''; if (!defined $suite) { # If no suite was specified, then the whole sources.list has to # come from standard input info "Reading sources.list from standard input..."; $sourceslist = do { local $/; }; } else { my @components = (); foreach my $comp (@{ $options->{components} }) { my @comps = split /[,\s]+/, $comp; foreach my $c (@comps) { # strip leading and trailing whitespace $c =~ s/^\s+|\s+$//g; # skip if the remainder is an empty string if ($c eq "") { next; } # do not append component if it's already in the list if (any { $_ eq $c } @components) { next; } push @components, $c; } } my $compstr = join " ", @components; # if the currently selected apt keyrings do not contain the # necessary key material for the chosen suite, then attempt adding # a signed-by option my $signedby = ''; { # try to guess the right keyring path for the given suite my $keyring; if ( any { $_ eq $suite } ( 'potato', 'woody', 'sarge', 'etch', 'lenny', 'squeeze', 'wheezy' ) ) { $keyring = '/usr/share/keyrings/debian-archive-removed-keys.gpg'; } elsif ( any { $_ eq $suite } ('aequorea', 'bartholomea', 'chromodoris', 'dasyatis') ) { $keyring = '/usr/share/keyrings/tanglu-archive-keyring.gpg'; } elsif ( any { $_ eq $suite } ('kali-dev', 'kali-rolling', 'kali-bleeding-edge') ) { $keyring = '/usr/share/keyrings/kali-archive-keyring.gpg'; } elsif ( any { $_ eq $suite } ( 'trusty', 'xenial', 'zesty', 'artful', 'bionic', 'cosmic' ) ) { $keyring = '/usr/share/keyrings/ubuntu-archive-keyring.gpg'; } elsif ( any { $_ eq $suite } ( 'unstable', 'stable', 'oldstable', 'jessie', 'stretch', 'buster', 'bullseye', 'bookworm' ) ) { $keyring = '/usr/share/keyrings/debian-archive-keyring.gpg'; } # we can only check if we need the signed-by entry if we u # automatically chosen keyring exists if (defined $keyring && -e $keyring) { # we can only check key material if gpg is installed my $gpghome = tempdir( "mmdebstrap.gpghome.XXXXXXXXXXXX", TMPDIR => 1, CLEANUP => 1 ); my @gpgcmd = ( 'gpg', '--quiet', '--ignore-time-conflict', '--no-options', '--no-default-keyring', '--homedir', $gpghome, '--no-auto-check-trustdb', '--trust-model', 'always' ); my ($ret, $fh, $message); { # change warning handler to prevent message # Can't exec "gpg": No such file or directory local $SIG{__WARN__} = sub { $message = shift; }; $ret = open $fh, '-|', @gpgcmd, '--version'; } # we only want to check if the gpg command exists close $fh; if ($? == 0 && defined $ret && !defined $message) { # find all the fingerprints of the keys apt currently # knows about my @aptfingerprints = (); my $collect_fingerprints = sub { my $filename = shift; open my $fh, '-|', @gpgcmd, '--keyring', $filename, '--with-colons', '--list-keys' // error "failed to fork(): $!"; while (my $line = <$fh>) { if ($line !~ /^fpr:::::::::([^:]+):/) { next; } push @aptfingerprints, $1; } close $fh; }; opendir my $dh, "$options->{apttrustedparts}" or error "cannot read $options->{apttrustedparts}"; while (my $filename = readdir $dh) { if ($filename !~ /\.(asc|gpg)$/) { next; } $collect_fingerprints->( "$options->{apttrustedparts}/$filename"); } if (-e $options->{apttrusted}) { $collect_fingerprints->($options->{apttrusted}); } # check if all fingerprints from the keyring that we # guessed are known by apt and only add signed-by # option if that's not the case my @suitefingerprints = (); open my $suitefh, '-|', @gpgcmd, '--keyring', $keyring, '--with-colons', '--list-keys' // error "failed to fork(): $!"; while (my $line = <$suitefh>) { if ($line !~ /^fpr:::::::::([^:]+):/) { next; } # if this fingerprint is not known by apt, then we # need to add the signed-by option if (none { $_ eq $1 } @aptfingerprints) { $signedby = " [signed-by=\"$keyring\"]"; last; } } close $suitefh; if ($? != 0) { error "gpg failed"; } } else { info "gpg --version failed: cannot determine the right" . " signed-by value"; } remove_tree($gpghome, { error => \my $err }); if (@$err) { for my $diag (@$err) { my ($file, $message) = %$diag; if ($file eq '') { warning "general error: $message"; } else { warning "problem unlinking $file: $message"; } } } } } if (scalar @ARGV > 0) { for my $arg (@ARGV) { if ($arg eq '-') { info "Reading sources.list from standard input..."; $sourceslist .= do { local $/; }; } elsif ($arg =~ /^deb(-src)? /) { $sourceslist .= "$arg\n"; } elsif ($arg =~ /:\/\//) { $sourceslist .= "deb$signedby $arg $suite $compstr\n"; } elsif (-f $arg) { open my $fh, '<', $arg or error "cannot open $arg: $!"; while (my $line = <$fh>) { $sourceslist .= $line; } close $fh; } else { error "invalid mirror: $arg"; } } } else { my @debstable = ( 'oldoldstable', 'oldstable', 'stable', 'jessie', 'stretch', 'buster', 'bullseye', 'bookworm' ); my @ubuntustable = ('trusty', 'xenial', 'zesty', 'artful', 'bionic', 'cosmic'); my @tanglustable = ('aequorea', 'bartholomea', 'chromodoris', 'dasyatis'); my @kali = ('kali-dev', 'kali-rolling', 'kali-bleeding-edge'); my $mirror = 'http://deb.debian.org/debian'; my $secmirror = 'http://security.debian.org/debian-security'; if (any { $_ eq $suite } @ubuntustable) { if (any { $_ eq $options->{nativearch} } ('amd64', 'i386')) { $mirror = 'http://archive.ubuntu.com/ubuntu'; $secmirror = 'http://security.ubuntu.com/ubuntu'; } else { $mirror = 'http://ports.ubuntu.com/ubuntu-ports'; $secmirror = 'http://ports.ubuntu.com/ubuntu-ports'; } } elsif (any { $_ eq $suite } @tanglustable) { $mirror = 'http://archive.tanglu.org/tanglu'; } elsif (any { $_ eq $suite } @kali) { $mirror = 'https://http.kali.org/kali'; } $sourceslist .= "deb$signedby $mirror $suite $compstr\n"; if (any { $_ eq $suite } @ubuntustable) { $sourceslist .= "deb$signedby $mirror $suite-updates $compstr\n"; $sourceslist .= "deb$signedby $secmirror $suite-security $compstr\n"; } elsif (any { $_ eq $suite } @tanglustable) { $sourceslist .= "deb$signedby $secmirror $suite-updates $compstr\n"; } elsif (any { $_ eq $suite } @debstable) { $sourceslist .= "deb$signedby $mirror $suite-updates $compstr\n"; if ( any { $_ eq $suite } ( 'oldoldstable', 'oldstable', 'stable', 'jessie', 'stretch', 'buster' ) ) { $sourceslist .= "deb$signedby $secmirror $suite/updates" . " $compstr\n"; } else { # starting from bullseye use # https://lists.debian.org/87r26wqr2a.fsf@43-1.org $sourceslist .= "deb$signedby $secmirror $suite-security" . " $compstr\n"; } } } } if ($sourceslist eq '') { error "empty apt sources.list"; } $options->{sourceslist} = $sourceslist; } if ($options->{target} ne '-') { my $abs_path = abs_path($options->{target}); if (!defined $abs_path) { error "unable to get absolute path of target directory" . " $options->{target}"; } $options->{target} = $abs_path; } if ($options->{target} eq '/') { error "refusing to use the filesystem root as output directory"; } my $tar_compressor = get_tar_compressor($options->{target}); # figure out whether a tarball has to be created in the end $options->{maketar} = 0; $options->{makesqfs} = 0; if ( defined $tar_compressor or $options->{target} =~ /\.tar$/ or $options->{target} eq '-') { $options->{maketar} = 1; # check if the compressor is installed if (defined $tar_compressor) { my $pid = fork() // error "fork() failed: $!"; if ($pid == 0) { open(STDOUT, '>', '/dev/null') or error "cannot open /dev/null for writing: $!"; open(STDIN, '<', '/dev/null') or error "cannot open /dev/null for reading: $!"; exec { $tar_compressor->[0] } @{$tar_compressor} or error( "cannot exec " . (join " ", @{$tar_compressor}) . ": $!"); } waitpid $pid, 0; if ($? != 0) { error("failed to start " . (join " ", @{$tar_compressor})); } } } elsif ($options->{target} =~ /\.(squashfs|sqfs)$/) { $options->{makesqfs} = 1; # check if tar2sqfs is installed my $pid = fork() // error "fork() failed: $!"; if ($pid == 0) { open(STDOUT, '>', '/dev/null') or error "cannot open /dev/null for writing: $!"; open(STDIN, '<', '/dev/null') or error "cannot open /dev/null for reading: $!"; exec('tar2sqfs', '--version') or error("cannot exec tar2sqfs --version: $!"); } waitpid $pid, 0; if ($? != 0) { error("failed to start tar2sqfs --version"); } } if ($options->{maketar} or $options->{makesqfs}) { if ( any { $_ eq $options->{variant} } ('extract', 'custom') and any { $_ eq $options->{mode} } ('fakechroot', 'proot')) { info "creating a tarball or squashfs image in fakechroot mode or" . " proot mode might fail in extract and custom variants because" . " there might be no tar inside the chroot"; } # try to fail early if target tarball or squashfs image cannot be # opened for writing if ($options->{target} ne '-') { open my $fh, '>', $options->{target} or error "cannot open $options->{target} for writing: $!"; close $fh; } # since the output is a tarball, we create the rootfs in a temporary # directory $options->{root} = tempdir('mmdebstrap.XXXXXXXXXX', DIR => File::Spec->tmpdir); info "using $options->{root} as tempdir"; # in unshare and root mode, other users than the current user need to # access the rootfs, most prominently, the _apt user. Thus, make the # temporary directory world readable. if (any { $_ eq $options->{mode} } ('unshare', 'root')) { chmod 0755, $options->{root} or error "cannot chmod root: $!"; } } else { # user does not seem to have specified a tarball as output, thus work # directly in the supplied directory $options->{root} = $options->{target}; if (-e $options->{root}) { if (!-d $options->{root}) { error "$options->{root} exists and is not a directory"; } # check if the directory is empty or contains nothing more than an # empty lost+found directory. The latter exists on freshly created # ext3 and ext4 partitions. # rationale for requiring an empty directory: # https://bugs.debian.org/833525 opendir(my $dh, $options->{root}) or error "Can't opendir($options->{root}): $!"; while (my $entry = readdir $dh) { # skip the "." and ".." entries next if $entry eq "."; next if $entry eq ".."; # if the entry is a directory named "lost+found" then skip it # if it's empty if ($entry eq "lost+found" and -d "$options->{root}/$entry") { opendir(my $dh2, "$options->{root}/$entry"); # Attempt reading the directory thrice. If the third time # succeeds, then it has more entries than just "." and ".." # and must thus not be empty. readdir $dh2; readdir $dh2; # rationale for requiring an empty directory: # https://bugs.debian.org/833525 if (readdir $dh2) { error "$options->{root} contains a non-empty" . " lost+found directory"; } closedir($dh2); } else { error "$options->{root} is not empty"; } } closedir($dh); } else { my $num_created = make_path "$options->{root}", { error => \my $err }; if ($err && @$err) { error(join "; ", (map { "cannot create " . (join ": ", %{$_}) } @$err)); } elsif ($num_created == 0) { error "cannot create $options->{root}"; } } } # check for double quotes because apt doesn't allow to escape them and # thus paths with double quotes are invalid in the apt config if ($options->{root} =~ /"/) { error "apt cannot handle paths with double quotes"; } my @idmap; # for unshare mode the rootfs directory has to have appropriate # permissions if ($options->{mode} eq 'unshare') { @idmap = read_subuid_subgid; # sanity check if (scalar(@idmap) != 2 || $idmap[0][0] ne 'u' || $idmap[1][0] ne 'g') { error "invalid idmap"; } my $outer_gid = $REAL_GROUP_ID + 0; my $pid = get_unshare_cmd { chown 1, 1, $options->{root} } [ ['u', '0', $REAL_USER_ID, '1'], ['g', '0', $outer_gid, '1'], ['u', '1', $idmap[0][2], '1'], ['g', '1', $idmap[1][2], '1']]; waitpid $pid, 0; $? == 0 or error "chown failed"; } # figure out whether we have mknod $options->{havemknod} = 0; if ($options->{mode} eq 'unshare') { my $pid = get_unshare_cmd { $options->{havemknod} = havemknod($options->{root}); } \@idmap; waitpid $pid, 0; $? == 0 or error "havemknod failed"; } elsif ( any { $_ eq $options->{mode} } ('root', 'fakechroot', 'proot', 'chrootless') ) { $options->{havemknod} = havemknod($options->{root}); } else { error "unknown mode: $options->{mode}"; } my $devtar = ''; # We always craft the /dev entries ourselves if a tarball is to be created if ($options->{maketar} or $options->{makesqfs}) { foreach my $file (@devfiles) { my ($fname, $mode, $type, $linkname, $devmajor, $devminor) = @{$file}; my $entry = pack( 'a100 a8 a8 a8 a12 a12 A8 a1 a100 a8 a32 a32 a8 a8 a155 x12', $fname, sprintf('%07o', $mode), sprintf('%07o', 0), # uid sprintf('%07o', 0), # gid sprintf('%011o', 0), # size sprintf('%011o', $mtime), '', # checksum $type, $linkname, "ustar ", '', # username '', # groupname defined($devmajor) ? sprintf('%07o', $devmajor) : '', defined($devminor) ? sprintf('%07o', $devminor) : '', '', # prefix ); # compute and insert checksum substr($entry, 148, 7) = sprintf("%06o\0", unpack("%16C*", $entry)); $devtar .= $entry; } } my $exitstatus = 0; my @taropts = ( '--sort=name', "--mtime=\@$mtime", '--clamp-mtime', '--numeric-owner', '--one-file-system', '--xattrs', '-c', '--exclude=./dev' ); # disable signals so that we can fork and change behaviour of the signal # handler in the parent and child without getting interrupted my $sigset = POSIX::SigSet->new(SIGINT, SIGHUP, SIGPIPE, SIGTERM); POSIX::sigprocmask(SIG_BLOCK, $sigset) or error "Can't block signals: $!"; my $pid; # a pipe to transfer the final tarball from the child to the parent pipe my $rfh, my $wfh; # instead of two pipe calls, creating four file handles, we use socketpair socketpair my $childsock, my $parentsock, AF_UNIX, SOCK_STREAM, PF_UNSPEC or error "socketpair failed: $!"; $options->{hooksock} = $childsock; if ($options->{mode} eq 'unshare') { $pid = get_unshare_cmd { # child $SIG{'INT'} = 'DEFAULT'; $SIG{'HUP'} = 'DEFAULT'; $SIG{'PIPE'} = 'DEFAULT'; $SIG{'TERM'} = 'DEFAULT'; # unblock all delayed signals (and possibly handle them) POSIX::sigprocmask(SIG_UNBLOCK, $sigset) or error "Can't unblock signals: $!"; close $rfh; close $parentsock; open(STDOUT, '>&', STDERR) or error "cannot open STDOUT: $!"; setup($options); print $childsock (pack('n', 0) . 'adios'); $childsock->flush(); close $childsock; if ($options->{maketar} or $options->{makesqfs}) { info "creating tarball..."; # redirect tar output to the writing end of the pipe so that # the parent process can capture the output open(STDOUT, '>&', $wfh) or error "cannot open STDOUT: $!"; # Add ./dev as the first entries of the tar file. # We cannot add them after calling tar, because there is no way # to prevent tar from writing NULL entries at the end. print $devtar; # pack everything except ./dev 0 == system('tar', @taropts, '-C', $options->{root}, '.') or error "tar failed: $?"; info "done"; } exit 0; } \@idmap; } elsif ( any { $_ eq $options->{mode} } ('root', 'fakechroot', 'proot', 'chrootless') ) { $pid = fork() // error "fork() failed: $!"; if ($pid == 0) { $SIG{'INT'} = 'DEFAULT'; $SIG{'HUP'} = 'DEFAULT'; $SIG{'PIPE'} = 'DEFAULT'; $SIG{'TERM'} = 'DEFAULT'; # unblock all delayed signals (and possibly handle them) POSIX::sigprocmask(SIG_UNBLOCK, $sigset) or error "Can't unblock signals: $!"; close $rfh; close $parentsock; open(STDOUT, '>&', STDERR) or error "cannot open STDOUT: $!"; setup($options); print $childsock (pack('n', 0) . 'adios'); $childsock->flush(); close $childsock; if ($options->{maketar} or $options->{makesqfs}) { info "creating tarball..."; # redirect tar output to the writing end of the pipe so that # the parent process can capture the output open(STDOUT, '>&', $wfh) or error "cannot open STDOUT: $!"; # Add ./dev as the first entries of the tar file. # We cannot add them after calling tar, because there is no way # to prevent tar from writing NULL entries at the end. print $devtar; if ($options->{mode} eq 'fakechroot') { # Fakechroot requires tar to run inside the chroot or # otherwise absolute symlinks will include the path to the # root directory 0 == system('/usr/sbin/chroot', $options->{root}, 'tar', @taropts, '-C', '/', '.') or error "tar failed: $?"; } elsif ($options->{mode} eq 'proot') { # proot requires tar to run inside proot or otherwise # permissions will be completely off my @qemuopt = (); if (defined $options->{qemu}) { push @qemuopt, "--qemu=qemu-$options->{qemu}"; push @taropts, "--exclude=./host-rootfs"; } 0 == system('proot', '--root-id', "--rootfs=$options->{root}", '--cwd=/', @qemuopt, 'tar', @taropts, '-C', '/', '.') or error "tar failed: $?"; } elsif (any { $_ eq $options->{mode} } ('root', 'chrootless')) { # If the chroot directory is not owned by the root user, # then we assume that no measure was taken to fake root # permissions. Since the final tarball should contain # entries with root ownership, we instruct tar to do so. my @owneropts = (); if ((stat $options->{root})[4] != 0) { push @owneropts, '--owner=0', '--group=0', '--numeric-owner'; } 0 == system('tar', @taropts, @owneropts, '-C', $options->{root}, '.') or error "tar failed: $?"; } else { error "unknown mode: $options->{mode}"; } info "done"; } exit 0; } } else { error "unknown mode: $options->{mode}"; } # parent my $got_signal = 0; my $waiting_for = "setup"; my $ignore = sub { $got_signal = shift; info "main() received signal $got_signal: waiting for $waiting_for..."; }; $SIG{'INT'} = $ignore; $SIG{'HUP'} = $ignore; $SIG{'PIPE'} = $ignore; $SIG{'TERM'} = $ignore; # unblock all delayed signals (and possibly handle them) POSIX::sigprocmask(SIG_UNBLOCK, $sigset) or error "Can't unblock signals: $!"; close $wfh; close $childsock; debug "starting to listen for hooks"; # handle special hook commands via parentsock # we use eval() so that error() doesn't take this process down and # thus leaves the setup() process without a parent eval { while (1) { # get the next message my $msg = "error"; my $len = -1; { debug "reading from parentsock"; my $ret = read($parentsock, my $buf, 2 + 5) // error "cannot read from socket: $!"; debug "finished reading from parentsock"; if ($ret == 0) { error "received eof on socket"; } ($len, $msg) = unpack("nA5", $buf); } if ($msg eq "adios") { # setup finished, so we break out of the loop if ($len != 0) { error "expected no payload but got $len bytes"; } last; } elsif ($msg eq "openr") { # handle the openr message debug "received message: openr"; my $infile; { my $ret = read($parentsock, $infile, $len) // error "cannot read from socket: $!"; if ($ret == 0) { error "received eof on socket"; } } # make sure that the requested path exists outside the chroot if (!-e $infile) { print $parentsock (pack("n", 0) . "error") or error "cannot write to socket: $!"; $parentsock->flush(); error "$infile does not exist"; } debug "sending okthx"; print $parentsock (pack("n", 0) . "okthx") or error "cannot write to socket: $!"; $parentsock->flush(); open my $fh, '<', $infile or error "failed to open $infile for reading: $!"; # read from the file and send as payload to the child process while (1) { # read from file my $ret = read($fh, my $cont, 4096) // error "cannot read from pipe: $!"; if ($ret == 0) { last; } debug "sending write"; # send to child print $parentsock pack("n", $ret) . "write" . $cont; $parentsock->flush(); debug "waiting for okthx"; checkokthx $parentsock; if ($ret < 4096) { last; } } # signal to the child process that we are done debug "sending close"; print $parentsock pack("n", 0) . "close"; $parentsock->flush(); debug "waiting for okthx"; checkokthx $parentsock; close $fh; } elsif ($msg eq "openw") { debug "received message: openw"; # payload is the output directory my $outfile; { my $ret = read($parentsock, $outfile, $len) // error "cannot read from socket: $!"; if ($ret == 0) { error "received eof on socket"; } } # make sure that the directory exists my $outdir = dirname($outfile); if (-e $outdir) { if (!-d $outdir) { print $parentsock (pack("n", 0) . "error") or error "cannot write to socket: $!"; $parentsock->flush(); error "$outdir already exists but is not a directory"; } } else { my $num_created = make_path $outdir, { error => \my $err }; if ($err && @$err) { print $parentsock (pack("n", 0) . "error") or error "cannot write to socket: $!"; $parentsock->flush(); error( join "; ", ( map { "cannot create " . (join ": ", %{$_}) } @$err )); } elsif ($num_created == 0) { print $parentsock (pack("n", 0) . "error") or error "cannot write to socket: $!"; $parentsock->flush(); error "cannot create $outdir"; } } debug "sending okthx"; print $parentsock (pack("n", 0) . "okthx") or error "cannot write to socket: $!"; $parentsock->flush(); # now we expect one or more "write" messages containing the # tarball to write open my $fh, '>', $outfile or error "failed to open $outfile for writing: $!"; # handle "write" messages from the child process and feed # their payload into the file handle until a "close" message # is encountered while (1) { # receive the next message my $ret = read($parentsock, my $buf, 2 + 5) // error "cannot read from socket: $!"; if ($ret == 0) { error "received eof on socket"; } my ($len, $msg) = unpack("nA5", $buf); debug "received message: $msg"; if ($msg eq "close") { # finish the loop if ($len != 0) { error "expected no payload but got $len bytes"; } debug "sending okthx"; print $parentsock (pack("n", 0) . "okthx") or error "cannot write to socket: $!"; $parentsock->flush(); last; } elsif ($msg ne "write") { # we should not receive this message at this point print $parentsock (pack("n", 0) . "error") or error "cannot write to socket: $!"; $parentsock->flush(); error "expected write but got: $msg"; } # read the payload my $content; { my $ret = read($parentsock, $content, $len) // error "error cannot read from socket: $!"; if ($ret == 0) { error "received eof on socket"; } } # write the payload to the file handle print $fh $content or error "cannot write to file handle: $!"; debug "sending okthx"; print $parentsock (pack("n", 0) . "okthx") or error "cannot write to socket: $!"; $parentsock->flush(); } close $fh; } elsif ($msg eq "mktar") { # handle the mktar message debug "received message: mktar"; my $indir; { my $ret = read($parentsock, $indir, $len) // error "cannot read from socket: $!"; if ($ret == 0) { error "received eof on socket"; } } # make sure that the requested path exists outside the chroot if (!-e $indir) { print $parentsock (pack("n", 0) . "error") or error "cannot write to socket: $!"; $parentsock->flush(); error "$indir does not exist"; } debug "sending okthx"; print $parentsock (pack("n", 0) . "okthx") or error "cannot write to socket: $!"; $parentsock->flush(); # Open a tar process creating a tarfile of the instructed # path. To emulate the behaviour of cp, change to the # dirname of the requested path first. open my $fh, '-|', 'tar', '--directory', dirname($indir), '--create', '--file', '-', basename($indir) // error "failed to fork(): $!"; # read from the tar process and send as payload to the child # process while (1) { # read from tar my $ret = read($fh, my $cont, 4096) // error "cannot read from pipe: $!"; if ($ret == 0) { last; } debug "sending write"; # send to child print $parentsock pack("n", $ret) . "write" . $cont; $parentsock->flush(); debug "waiting for okthx"; checkokthx $parentsock; if ($ret < 4096) { last; } } # signal to the child process that we are done debug "sending close"; print $parentsock pack("n", 0) . "close"; $parentsock->flush(); debug "waiting for okthx"; checkokthx $parentsock; close $fh; if ($? != 0) { error "tar failed"; } } elsif ($msg eq "untar") { debug "received message: untar"; # payload is the output directory my $outdir; { my $ret = read($parentsock, $outdir, $len) // error "cannot read from socket: $!"; if ($ret == 0) { error "received eof on socket"; } } # make sure that the directory exists if (-e $outdir) { if (!-d $outdir) { print $parentsock (pack("n", 0) . "error") or error "cannot write to socket: $!"; $parentsock->flush(); error "$outdir already exists but is not a directory"; } } else { my $num_created = make_path $outdir, { error => \my $err }; if ($err && @$err) { print $parentsock (pack("n", 0) . "error") or error "cannot write to socket: $!"; $parentsock->flush(); error( join "; ", ( map { "cannot create " . (join ": ", %{$_}) } @$err )); } elsif ($num_created == 0) { print $parentsock (pack("n", 0) . "error") or error "cannot write to socket: $!"; $parentsock->flush(); error "cannot create $outdir"; } } debug "sending okthx"; print $parentsock (pack("n", 0) . "okthx") or error "cannot write to socket: $!"; $parentsock->flush(); # now we expect one or more "write" messages containing the # tarball to unpack open my $fh, '|-', 'tar', '--directory', $outdir, '--extract', '--file', '-' // error "failed to fork(): $!"; # handle "write" messages from the child process and feed # their payload into the tar process until a "close" message # is encountered while (1) { # receive the next message my $ret = read($parentsock, my $buf, 2 + 5) // error "cannot read from socket: $!"; if ($ret == 0) { error "received eof on socket"; } my ($len, $msg) = unpack("nA5", $buf); debug "received message: $msg"; if ($msg eq "close") { # finish the loop if ($len != 0) { error "expected no payload but got $len bytes"; } debug "sending okthx"; print $parentsock (pack("n", 0) . "okthx") or error "cannot write to socket: $!"; $parentsock->flush(); last; } elsif ($msg ne "write") { # we should not receive this message at this point print $parentsock (pack("n", 0) . "error") or error "cannot write to socket: $!"; $parentsock->flush(); error "expected write but got: $msg"; } # read the payload my $content; { my $ret = read($parentsock, $content, $len) // error "error cannot read from socket: $!"; if ($ret == 0) { error "received eof on socket"; } } # write the payload to the tar process print $fh $content or error "cannot write to tar process: $!"; debug "sending okthx"; print $parentsock (pack("n", 0) . "okthx") or error "cannot write to socket: $!"; $parentsock->flush(); } close $fh; if ($? != 0) { error "tar failed"; } } else { error "unknown message: $msg"; } } }; if ($@) { # we cannot die here because that would leave the other thread # running without a parent warning "listening on child socket failed: $@"; $exitstatus = 1; } debug "finish to listen for hooks"; close $parentsock; if ($options->{maketar} or $options->{makesqfs}) { # we use eval() so that error() doesn't take this process down and # thus leaves the setup() process without a parent eval { if ($options->{target} eq '-') { if (!copy($rfh, *STDOUT)) { error "cannot copy to standard output: $!"; } } else { if ($options->{makesqfs} or defined $tar_compressor) { my @argv = (); if ($options->{makesqfs}) { push @argv, 'tar2sqfs', '--quiet', '--no-skip', '--force', '--exportable', '--compressor', 'xz', '--block-size', '1048576', $options->{target}; } else { push @argv, @{$tar_compressor}; } POSIX::sigprocmask(SIG_BLOCK, $sigset) or error "Can't block signals: $!"; my $cpid = fork() // error "fork() failed: $!"; if ($cpid == 0) { # child: default signal handlers $SIG{'INT'} = 'DEFAULT'; $SIG{'HUP'} = 'DEFAULT'; $SIG{'PIPE'} = 'DEFAULT'; $SIG{'TERM'} = 'DEFAULT'; # unblock all delayed signals (and possibly handle # them) POSIX::sigprocmask(SIG_UNBLOCK, $sigset) or error "Can't unblock signals: $!"; if ($options->{makesqfs}) { open(STDOUT, '>', '/dev/null') or error "cannot open /dev/null for writing: $!"; } else { open(STDOUT, '>', $options->{target}) or error "cannot open $options->{target} for writing: $!"; } open(STDIN, '<&', $rfh) or error "cannot open file handle for reading: $!"; eval 'Devel::Cover::set_coverage("none")' if $is_covering; exec { $argv[0] } @argv or error("cannot exec " . (join " ", @argv) . ": $!"); } POSIX::sigprocmask(SIG_UNBLOCK, $sigset) or error "Can't unblock signals: $!"; waitpid $cpid, 0; if ($? != 0) { error("failed to start " . (join " ", @argv)); } } else { if (!copy($rfh, $options->{target})) { error "cannot copy to $options->{target}: $!"; } } } }; if ($@) { # we cannot die here because that would leave the other thread # running without a parent warning "creating tarball failed: $@"; $exitstatus = 1; } } close($rfh); waitpid $pid, 0; if ($? != 0) { $exitstatus = 1; } # change signal handler message $waiting_for = "cleanup"; if (($options->{maketar} or $options->{makesqfs}) and -e $options->{root}) { info "removing tempdir $options->{root}..."; if ($options->{mode} eq 'unshare') { # We don't have permissions to remove the directory outside # the unshared namespace, so we remove it here. # Since this is still inside the unshared namespace, there is # no risk of removing anything important. $pid = get_unshare_cmd { # File::Path will produce the error "cannot stat initial # working directory" if the working directory cannot be # accessed by the unprivileged unshared user. Thus, we first # navigate to the parent of the root directory. chdir "$options->{root}/.." or error "unable to chdir() to parent directory of" . " $options->{root}: $!"; remove_tree($options->{root}, { error => \my $err }); if (@$err) { for my $diag (@$err) { my ($file, $message) = %$diag; if ($file eq '') { warning "general error: $message"; } else { warning "problem unlinking $file: $message"; } } } } \@idmap; waitpid $pid, 0; $? == 0 or error "remove_tree failed"; } elsif ( any { $_ eq $options->{mode} } ('root', 'fakechroot', 'proot', 'chrootless') ) { # without unshare, we use the system's rm to recursively remove the # temporary directory just to make sure that we do not accidentally # remove more than we should by using --one-file-system. # # --interactive=never is needed when in proot mode, the # write-protected file /apt/apt.conf.d/01autoremove-kernels is to # be removed. 0 == system('rm', '--interactive=never', '--recursive', '--preserve-root', '--one-file-system', $options->{root}) or error "rm failed: $!"; } else { error "unknown mode: $options->{mode}"; } } if ($got_signal) { $exitstatus = 1; } exit $exitstatus; } main(); __END__ =head1 NAME mmdebstrap - multi-mirror Debian chroot creation =head1 SYNOPSIS B [B] [I [I [I...]]] =head1 DESCRIPTION B creates a Debian chroot of I into I from one or more Is. It is meant as an alternative to the debootstrap tool (see section B). In contrast to debootstrap it uses apt to resolve dependencies and is thus able to use more than one mirror and resolve more complex dependencies. If no I option is provided, L is used. If I is a stable release name and no I is specified, then mirrors for updates and security are automatically added. If a I option starts with "deb " or "deb-src " then it is used as a one-line-style format entry for apt's sources.list inside the chroot. If a I option contains a "://" then it is interpreted as a mirror URI and the apt line inside the chroot is assembled as "deb [arch=A] B C D" where A is the host's native architecture, B is the I, C is the given I and D is the components given via B<--components> (defaults to "main"). If a I option happens to be an existing file, then its contents are pasted into the chroot's sources.list. This can be used to supply a deb822 style sources.list. If I is C<-> then standard input is pasted into the chroot's sources.list. More than one mirror can be specified and are appended to the chroot's sources.list in the given order. If any mirror contains a https URI, then the packages apt-transport-https and ca-certificates will be installed inside the chroot. If any mirror contains a tor+xxx URI, then the apt-transport-tor package will be installed inside the chroot. The optional I argument can either be the path to a directory, the path to a tarball filename, the path to a squashfs image or C<->. If I ends with C<.tar>, or with any of the filename extensions listed in the section B, then I will be interpreted as a path to a tarball filename. If I ends with C<.squashfs> or C<.sqfs>, then I will be interpreted as a path to a squashfs image. If I is the path to a tarball filename or a squashfs image or if I is C<-> or if no I was specified, B will create a temporary chroot directory in C<$TMPDIR> or F. If I is the path to a tarball filename, B will create a tarball of that directory and store it as I, optionally applying a compression algorithm as indicated by its filename extension. If I is C<-> or if no I was specified, then an uncompressed tarball of that directory will be sent to standard output. When B creates a tarball it also stores extended attributes. To preserve the extended attributes, you have to pass B<--xattrs --xattrs-include='*'> to tar when extracting the tarball. If I is the path to a squashfs image, B will create an xz compressed image with a blocksize of 1048576 bytes. If I does neither end with C<.tar> nor with any of the filename extensions listed in the section B, nor with C<.squashfs> or C<.sqfs>, then I will be interpreted as the path to a directory. If the directory already exists, it must either be empty or only contain an empty C directory. If a directory is chosen as output in any other mode than B, then its contents will have wrong ownership information and special device files will be missing. The I may be a valid release code name (eg, sid, stretch, jessie) or a symbolic name (eg, unstable, testing, stable, oldstable). Any suite name that works with apt on the given mirror will work. If no I was specified, then a single I C<-> is added and thus the information of the desired suite has to come from standard input as part of a valid apt sources.list file. All status output is printed to standard error unless B<--logfile> is used to redirect it to a file or B<--quiet> or B<--silent> is used to suppress any output on standard error. Help and version information will be printed to standard error with the B<--help> and B<--version> options, respectively. Otherwise, an uncompressed tarball might be sent to standard output if I is C<-> or if no I was specified. =head1 OPTIONS Options are case insensitive. Short options may be bundled. Long options require a double dash and may be abbreviated to uniqueness. =over 8 =item B<-h,--help> Print synopsis and options of this man page and exit. =item B<--man> Show the full man page as generated from Perl POD in a pager. This requires the perldoc program from the perl-doc package. This is the same as running: pod2man /usr/bin/mmdebstrap | man -l - =item B<--version> Print the B version and exit. =item B<--variant>=I Choose which package set to install. Valid variant Is are B, B, B, B, B, B, B, B, B, B<->, and B. The default variant is B. See the section B for more information. =item B<--mode>=I Choose how to perform the chroot operation and create a filesystem with ownership information different from the current user. Valid mode Is are B, B, B, B, B, B and B. The default mode is B. See the section B for more information. =item B<--aptopt>=I