# This package can either be a PSGI response body for a static file
# OR a standalone PSGI app which returns the above PSGI response body
# (or an HTML directory listing).
#
# It encapsulates the "autoindex", "index", and "gzip_static"
# functionality of nginx.
package PublicInbox::WwwStatic;
use strict;
use parent qw(Exporter);
use bytes ();
use Fcntl qw(SEEK_SET O_RDONLY O_NONBLOCK);
use POSIX qw(strftime);
use HTTP::Date qw(time2str);
use HTTP::Status qw(status_message);
use Errno qw(EACCES ENOTDIR ENOENT);
use URI::Escape qw(uri_escape_utf8);
use PublicInbox::Hval qw(ascii_html);
use Plack::MIME;
our @EXPORT_OK = qw(@NO_CACHE r path_info_raw);
our @NO_CACHE = ('Expires', 'Fri, 01 Jan 1980 00:00:00 GMT',
'Pragma', 'no-cache',
'Cache-Control', 'no-cache, max-age=0, must-revalidate');
our $STYLE = <<'EOF';
EOF
$STYLE =~ s/^\s*//gm;
$STYLE =~ tr/\n//d;
sub r ($;$) {
my ($code, $msg) = @_;
$msg ||= status_message($code);
[ $code, [ qw(Content-Type text/plain), 'Content-Length', length($msg),
@NO_CACHE ],
[ $msg ] ]
}
sub prepare_range {
my ($env, $in, $h, $beg, $end, $size) = @_;
my $code = 200;
my $len = $size;
if ($beg eq '') {
if ($end ne '') { # "bytes=-$end" => last N bytes
$beg = $size - $end;
$beg = 0 if $beg < 0;
$end = $size - 1;
$code = 206;
} else {
$code = 416;
}
} else {
if ($beg > $size) {
$code = 416;
} elsif ($end eq '' || $end >= $size) {
$end = $size - 1;
$code = 206;
} elsif ($end < $size) {
$code = 206;
} else {
$code = 416;
}
}
if ($code == 206) {
$len = $end - $beg + 1;
if ($len <= 0) {
$code = 416;
} else {
if ($in) {
sysseek($in, $beg, SEEK_SET) or return r(500);
}
push @$h, qw(Accept-Ranges bytes Content-Range);
push @$h, "bytes $beg-$end/$size";
# FIXME: Plack::Middleware::Deflater bug?
$env->{'psgix.no-compress'} = 1;
}
}
if ($code == 416) {
push @$h, 'Content-Range', "bytes */$size";
return [ 416, $h, [] ];
}
($code, $len);
}
# returns a PSGI arrayref response iff .gz and non-.gz mtimes match
sub try_gzip_static ($$$$) {
my ($env, $h, $path, $type) = @_;
return unless ($env->{HTTP_ACCEPT_ENCODING} // '') =~ /\bgzip\b/i;
my $mtime;
return unless -f $path && defined(($mtime = (stat(_))[9]));
my $gz = "$path.gz";
return unless -f $gz && (stat(_))[9] == $mtime;
my $res = response($env, $h, $gz, $type);
return if ($res->[0] > 300 || $res->[0] < 200);
push @{$res->[1]}, qw(Cache-Control no-transform Content-Encoding gzip);
$res;
}
sub response ($$$;$) {
my ($env, $h, $path, $type) = @_;
$type //= Plack::MIME->mime_type($path) // 'application/octet-stream';
if ($path !~ /\.gz\z/i) {
if (my $res = try_gzip_static($env, $h, $path, $type)) {
return $res;
}
}
my $in;
if ($env->{REQUEST_METHOD} eq 'HEAD') {
return r(404) unless -f $path && -r _; # in case it's a FIFO :P
} else { # GET, callers should've already filtered out other methods
if (!sysopen($in, $path, O_RDONLY|O_NONBLOCK)) {
return r(404) if $! == ENOENT || $! == ENOTDIR;
return r(403) if $! == EACCES;
return r(500);
}
return r(404) unless -f $in;
}
my $size = -s _; # bare "_" reuses "struct stat" from "-f" above
my $mtime = time2str((stat(_))[9]);
if (my $ims = $env->{HTTP_IF_MODIFIED_SINCE}) {
return [ 304, [], [] ] if $mtime eq $ims;
}
my $len = $size;
my $code = 200;
push @$h, 'Content-Type', $type;
if (($env->{HTTP_RANGE} || '') =~ /\bbytes=([0-9]*)-([0-9]*)\z/) {
($code, $len) = prepare_range($env, $in, $h, $1, $2, $size);
return $code if ref($code);
}
push @$h, 'Content-Length', $len, 'Last-Modified', $mtime;
my $body = $in ? bless {
initial_rd => 65536,
len => $len,
in => $in,
path => $path,
env => $env,
}, __PACKAGE__ : [];
[ $code, $h, $body ];
}
# called by PSGI servers on each response chunk:
sub getline {
my ($self) = @_;
my $len = $self->{len} or return; # undef, tells server we're done
my $n = delete($self->{initial_rd}) // 8192;
$n = $len if $len < $n;
my $r = sysread($self->{in}, my $buf, $n);
if (defined $r && $r > 0) { # success!
$self->{len} = $len - $r;
return $buf;
}
my $m = defined $r ? "EOF with $len bytes left" : "read error: $!";
my $env = $self->{env};
$env->{'psgi.errors'}->print("$self->{path} $m\n");
# drop the client on error
if (my $io = $env->{'psgix.io'}) {
$io->close; # this is likely PublicInbox::DS::close
} else { # for some PSGI servers w/o psgix.io
die "dropping client socket\n";
}
undef;
}
sub close {} # noop, called by PSGI server, just let everything go out-of-scope
# OO interface for use as a Plack app
sub new {
my ($class, %opt) = @_;
my $index = $opt{'index'} // [ 'index.html' ];
$index = [ $index ] if defined($index) && ref($index) ne 'ARRAY';
$index = undef if scalar(@$index) == 0;
my $style = $opt{style};
if (defined $style) {
$style = \$style unless ref($style);
}
my $docroot = $opt{docroot};
die "`docroot' not set" unless defined($docroot) && $docroot ne '';
bless {
docroot => $docroot,
index => $index,
autoindex => $opt{autoindex},
style => $style // \$STYLE,
}, $class;
}
# PATH_INFO is decoded, and we want the undecoded original
my %path_re_cache;
sub path_info_raw ($) {
my ($env) = @_;
my $sn = $env->{SCRIPT_NAME};
my $re = $path_re_cache{$sn} ||= do {
$sn = '/'.$sn unless index($sn, '/') == 0;
$sn =~ s!/\z!!;
qr!\A(?:https?://[^/]+)?\Q$sn\E(/[^\?\#]+)!;
};
$env->{REQUEST_URI} =~ $re ? $1 : $env->{PATH_INFO};
}
sub redirect_slash ($) {
my ($env) = @_;
my $url = $env->{'psgi.url_scheme'} . '://';
my $host_port = $env->{HTTP_HOST} //
"$env->{SERVER_NAME}:$env->{SERVER_PORT}";
$url .= $host_port . path_info_raw($env) . '/';
my $body = "Redirecting to $url\n";
[ 302, [ qw(Content-Type text/plain), 'Location', $url,
'Content-Length', length($body) ], [ $body ] ]
}
sub human_size ($) {
my ($size) = @_;
my $suffix = '';
for my $s (qw(K M G T P)) {
last if $size < 1024;
$size /= 1024;
if ($size <= 1024) {
$suffix = $s;
last;
}
}
sprintf('%lu', $size).$suffix;
}
# by default, this returns "index.html" if it exists for a given directory
# It'll generate a directory listing, (autoindex).
# May be disabled by setting autoindex => 0
sub dir_response ($$$) {
my ($self, $env, $fs_path) = @_;
if (my $index = $self->{'index'}) { # serve index.html or similar
for my $html (@$index) {
my $p = $fs_path . $html;
my $res = response($env, [], $p);
return $res if $res->[0] != 404;
}
}
return r(404) unless $self->{autoindex};
opendir(my $dh, $fs_path) or do {
return r(404) if ($! == ENOENT || $! == ENOTDIR);
return r(403) if $! == EACCES;
return r(500);
};
my @entries = grep(!/\A\./, readdir($dh));
$dh = undef;
my (%dirs, %other, %want_gz);
my $path_info = $env->{PATH_INFO};
push @entries, '..' if $path_info ne '/';
for my $base (@entries) {
my $href = ascii_html(uri_escape_utf8($base));
my $name = ascii_html($base);
my @st = stat($fs_path . $base) or next; # unlikely
my ($gzipped, $uncompressed, $hsize);
my $entry = '';
my $mtime = $st[9];
if (-d _) {
$href .= '/';
$name .= '/';
$hsize = '-';
$dirs{"$base\0$mtime"} = \$entry;
} elsif (-f _) {
$other{"$base\0$mtime"} = \$entry;
if ($base !~ /\.gz\z/i) {
$want_gz{"$base.gz\0$mtime"} = undef;
}
$hsize = human_size($st[7]);
} else {
next;
}
# 54 = 80 - (SP length(strftime(%Y-%m-%d %k:%M)) SP human_size)
$hsize = sprintf('% 8s', $hsize);
my $pad = 54 - length($name);
$pad = 1 if $pad <= 0;
$entry .= qq($name) . (' ' x $pad);
$mtime = strftime('%Y-%m-%d %k:%M', gmtime($mtime));
$entry .= $mtime . $hsize;
}
# filter out '.gz' files as long as the mtime matches the
# uncompressed version
delete(@other{keys %want_gz});
@entries = ((map { ${$dirs{$_}} } sort keys %dirs),
(map { ${$other{$_}} } sort keys %other));
my $path_info_html = ascii_html($path_info);
my $body = "Index of $path_info_html" .
${$self->{style}} .
"Index of $path_info_html
\n";
$body .= join("\n", @entries) . "
\n";
[ 200, [ qw(Content-Type text/html
Content-Length), bytes::length($body) ], [ $body ] ]
}
sub call { # PSGI app endpoint
my ($self, $env) = @_;
return r(405) if $env->{REQUEST_METHOD} !~ /\A(?:GET|HEAD)\z/;
my $path_info = $env->{PATH_INFO};
return r(403) if index($path_info, "\0") >= 0;
my (@parts) = split(m!/+!, $path_info, -1);
return r(403) if grep(/\A(?:\.\.)\z/, @parts) || $parts[0] ne '';
my $fs_path = join('/', $self->{docroot}, @parts);
return dir_response($self, $env, $fs_path) if $parts[-1] eq '';
my $res = response($env, [], $fs_path);
$res->[0] == 404 && -d $fs_path ? redirect_slash($env) : $res;
}
1;