check the mode earlier so that we can re-exec under fakechroot earlier

This commit is contained in:
Johannes 'josch' Schauer 2018-10-23 18:04:05 +02:00
parent 70c1468453
commit b8c63f8797
Signed by untrusted user: josch
GPG key ID: F2CBA5C78FBD83E1

View file

@ -1317,6 +1317,10 @@ sub main() {
$options->{variant} = 'important'; $options->{variant} = 'important';
} }
if ($options->{variant} eq 'essential' and defined $options->{include}) {
die "cannot install extra packages with variant essential because apt is missing";
}
# fakeroot is an alias for fakechroot # fakeroot is an alias for fakechroot
if ($options->{mode} eq 'fakeroot') { if ($options->{mode} eq 'fakeroot') {
$options->{mode} = 'fakechroot'; $options->{mode} = 'fakechroot';
@ -1331,8 +1335,85 @@ sub main() {
die "invalid mode. Choose from " . (join ', ', @valid_modes); die "invalid mode. Choose from " . (join ', ', @valid_modes);
} }
if ($options->{variant} eq 'essential' and defined $options->{include}) { # figure out the mode to use or test whether the chosen mode is legal
die "cannot install extra packages with variant essential because apt is missing"; if ($options->{mode} eq 'auto') {
if ($EFFECTIVE_USER_ID == 0) {
$options->{mode} = 'root';
} elsif (test_unshare()) {
$options->{mode} = 'unshare';
} elsif (system('proot --version>/dev/null') == 0) {
$options->{mode} = 'proot';
} elsif (system('fakechroot --version>/dev/null') == 0) {
$options->{mode} = 'fakechroot';
} else {
die "unable to pick chroot mode automatically";
}
print STDERR "I: automatically chosen mode: $options->{mode}\n";
} elsif ($options->{mode} eq 'root') {
if ($EFFECTIVE_USER_ID != 0) {
die "need to be root";
}
} elsif ($options->{mode} eq 'proot') {
if (system('proot --version>/dev/null') != 0) {
die "need working proot binary";
}
} elsif ($options->{mode} eq 'fakechroot') {
# 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, '-|' // die "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 $pid, 0;
if ($? == 0 and $content =~ /^fakechroot \d\.\d+$/) {
# fakechroot is already running
} elsif (system('fakechroot --version>/dev/null') != 0) {
die "need working fakechroot binary";
} else {
# exec ourselves again but within fakechroot
exec 'fakechroot', 'fakeroot', $PROGRAM_NAME, @ARGVORIG;
}
} elsif ($options->{mode} eq 'unshare') {
if (!test_unshare()) {
if ($EFFECTIVE_USER_ID == 0) {
print STDERR "I: cannot use unshare mode when executing as root\n";
}
system "newuidmap 2>/dev/null";
if (($? >> 8) != 1) {
if (($? >> 8) == 127) {
print STDERR "I: cannot find newuidmap\n";
} else {
print STDERR "I: newuidmap returned unknown exit status\n";
}
}
system "newgidmap 2>/dev/null";
if (($? >> 8) != 1) {
if (($? >> 8) == 127) {
print STDERR "I: cannot find newgidmap\n";
} else {
print STDERR "I: newgidmap returned unknown exit status\n";
}
}
my $procfile = '/proc/sys/kernel/unprivileged_userns_clone';
open(my $fh, '<', $procfile) or die "failed to open $procfile: $!";
chomp(my $content = do { local $/; <$fh> });
close($fh);
if ($content ne "1") {
print STDERR "I: /proc/sys/kernel/unprivileged_userns_clone is set to $content\n";
print STDERR "I: try running: sudo sysctl -w kernel.unprivileged_userns_clone=1\n";
print STDERR "I: or permanently enable unprivileged usernamespaces by putting the setting into /etc/sysctl.d/\n";
}
exit 1;
}
} elsif ($options->{mode} eq 'chrootless') {
# nothing to do
} else {
die "unknown mode: $options->{mode}";
} }
my ($nativearch, @foreignarchs) = split /,/, $options->{architectures}; my ($nativearch, @foreignarchs) = split /,/, $options->{architectures};
@ -1479,87 +1560,6 @@ sub main() {
die "refusing to use the filesystem root as output directory"; die "refusing to use the filesystem root as output directory";
} }
# figure out the mode to use or test whether the chosen mode is legal
if ($options->{mode} eq 'auto') {
if ($EFFECTIVE_USER_ID == 0) {
$options->{mode} = 'root';
} elsif (test_unshare()) {
$options->{mode} = 'unshare';
} elsif (system('proot --version>/dev/null') == 0) {
$options->{mode} = 'proot';
} elsif (system('fakechroot --version>/dev/null') == 0) {
$options->{mode} = 'fakechroot';
} else {
die "unable to pick chroot mode automatically";
}
print STDERR "I: automatically chosen mode: $options->{mode}\n";
} elsif ($options->{mode} eq 'root') {
if ($EFFECTIVE_USER_ID != 0) {
die "need to be root";
}
} elsif ($options->{mode} eq 'proot') {
if (system('proot --version>/dev/null') != 0) {
die "need working proot binary";
}
} elsif ($options->{mode} eq 'fakechroot') {
# 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, '-|' // die "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 $pid, 0;
if ($? == 0 and $content =~ /^fakechroot \d\.\d+$/) {
# fakechroot is already running
} elsif (system('fakechroot --version>/dev/null') != 0) {
die "need working fakechroot binary";
} else {
# exec ourselves again but within fakechroot
exec 'fakechroot', 'fakeroot', $PROGRAM_NAME, @ARGVORIG;
}
} elsif ($options->{mode} eq 'unshare') {
if (!test_unshare()) {
if ($EFFECTIVE_USER_ID == 0) {
print STDERR "I: cannot use unshare mode when executing as root\n";
}
system "newuidmap 2>/dev/null";
if (($? >> 8) != 1) {
if (($? >> 8) == 127) {
print STDERR "I: cannot find newuidmap\n";
} else {
print STDERR "I: newuidmap returned unknown exit status\n";
}
}
system "newgidmap 2>/dev/null";
if (($? >> 8) != 1) {
if (($? >> 8) == 127) {
print STDERR "I: cannot find newgidmap\n";
} else {
print STDERR "I: newgidmap returned unknown exit status\n";
}
}
my $procfile = '/proc/sys/kernel/unprivileged_userns_clone';
open(my $fh, '<', $procfile) or die "failed to open $procfile: $!";
chomp(my $content = do { local $/; <$fh> });
close($fh);
if ($content ne "1") {
print STDERR "I: /proc/sys/kernel/unprivileged_userns_clone is set to $content\n";
print STDERR "I: try running: sudo sysctl -w kernel.unprivileged_userns_clone=1\n";
print STDERR "I: or permanently enable unprivileged usernamespaces by putting the setting into /etc/sysctl.d/\n";
}
exit 1;
}
} elsif ($options->{mode} eq 'chrootless') {
# nothing to do
} else {
die "unknown mode: $options->{mode}";
}
my @tar_compress_opts = get_tar_compress_options($options->{target}); my @tar_compress_opts = get_tar_compress_options($options->{target});
# figure out whether a tarball has to be created in the end # figure out whether a tarball has to be created in the end