nsbin/edit-server-text-aid-chromium

263 lines
6.8 KiB
Perl
Executable File

#!/usr/bin/perl
# A simple web server that just listens for textarea filter requests
# and runs an editor to manipulate the text. Is intended to be
# used with the TextAid extention for Chrome.
#
# NOTE: If you use this on a shared system, you should configure TextAid
# with a username & password and make sure that the saved authorization
# config file stays secret!
use strict;
use warnings;
use threads;
use Socket;
use IO::Select;
use File::Temp;
use Getopt::Long;
# If you don't want to require authentication, set $REQUIRE_AUTH to 0.
# When it is set to 1, the first authenticated request that is received
# will be saved to the $SAVE_AUTH_FILE file. All subsequent requests
# are compared to that value. To change your password, just remove the
# file and make a new edit-server request using the new auth info.
our $REQUIRE_AUTH = 1;
our $SAVE_AUTH_FILE = "$ENV{HOME}/.edit-server-auth";
# Only accept requests from something that claims to be a chrome-extension.
# Set this to 0 if you want other things to be able to use this script.
our $REQUIRE_CHROME_EXTENSION = 1;
# Configures the port we listen on and if we allow only localhost requests.
our $PORT = 8888;
our $LOCALHOST_ONLY = 1;
# Configure the program that you want to run to handle the requests.
# This editor invocation must NOT return control to this script until
# you are done editing.
#our $EDITOR_CMD = '/home/users/nico/bin/vim-term "%s"';
our $EDITOR_CMD = '/usr/bin/emacsclient -c "%s"';
# The settings to configure the temp dir and how soon old files are removed.
# If TMPTEMPLATE contains the string -URL64-, then up to 64 chars of the munged
# URL for the textarea's page will be included in the tmp file's filename.
our $TMPDIR = "$ENV{HOME}/.tmp";
our $TMPTEMPLATE = 'edit-server-URL64-XXXXXX';
our $TMPSUFFIX = '.txt';
our $CLEAN_AFTER_HOURS = 4;
&Getopt::Long::Configure('bundling');
GetOptions(
'verbose|v+' => \( my $verbosity = 0 ),
'help|h' => \( my $help_opt ),
) or usage();
usage() if $help_opt;
umask 0077; # Disables all "group" and "other" perms when saving files.
$| = 1;
local *S;
socket(S, PF_INET, SOCK_STREAM , getprotobyname('tcp')) or die "couldn't open socket: $!\n";
setsockopt(S, SOL_SOCKET, SO_REUSEADDR, 1);
if ($LOCALHOST_ONLY) {
bind(S, sockaddr_in($PORT, INADDR_LOOPBACK));
} else {
bind(S, sockaddr_in($PORT, INADDR_ANY));
}
listen(S, 5) or die "listen failed: $!\n";
my $sel = IO::Select->new();
$sel->add(*S);
while (1) {
my @con = $sel->can_read();
foreach my $con (@con) {
my $fh;
my $remote = accept($fh, $con);
my($port, $iaddr) = sockaddr_in($remote);
my $addr = inet_ntoa($iaddr);
my $t = threads->create(\&do_edit, $fh);
$t->detach();
}
}
exit;
# Read the text from the content body, edit it, and write it back as our output.
sub do_edit
{
my($fh) = @_;
binmode $fh;
local $_ = <$fh>;
my($method, $path, $ver) = /^(GET|HEAD|POST)\s+(.*?)\s+(HTTP\S+)/;
print "Path: $path\n" if $verbosity >= 1;
unless (defined $ver) {
http_header($fh, 500, 'Invalid request.');
close $fh;
return;
}
if ($method ne 'POST') {
http_header($fh, 200, 'OK', 'Server is up and running. To use it, issue a POST request with the file to edit as the content body.');
close $fh;
return;
}
my %header;
while (<$fh>) {
s/\r?\n$//;
last if $_ eq '';
my($name, $value) = /^(.*?): +(.*)/;
$header{lc($name)} = $value;
print "Header: \L$name\E = $value\n" if $verbosity >= 2;
}
print "-------------------------------------------------------------------\n" if $verbosity >= 2;
if ($REQUIRE_AUTH) {
my $authorized;
my $auth = $header{authorization}; # e.g. "Basic 01234567890ABCDEF=="
if (defined $auth) {
my $line;
if (open AUTH, '<', $SAVE_AUTH_FILE) {
chomp($line = <AUTH>);
close AUTH;
} elsif ($!{ENOENT} && open AUTH, '>', $SAVE_AUTH_FILE) {
# The first request w/o an auth file saves the auth info.
print AUTH $auth, "\n";
close AUTH;
$line = $auth;
} else {
http_header($fh, 501, 'Internal failure -- auth-file failed.');
close $fh;
return;
}
if ($line eq $auth) {
$authorized = 1;
}
}
unless ($authorized) {
http_header($fh, 401, 'Unauthorized!');
close $fh;
return;
}
}
if ($REQUIRE_CHROME_EXTENSION) {
my $origin = $header{origin};
unless (defined $origin && $origin =~ /^chrome-extension:/) {
http_header($fh, 401, 'Unauthorized.');
close $fh;
return;
}
}
my $len = $header{'content-length'};
unless (defined $len && $len =~ /^\d+$/) {
http_header($fh, 500, 'Invalid request -- no content-length.');
close $fh;
return;
}
my $got = read($fh, $_, $len);
if ($got != $len) {
http_header($fh, 500, 'Invalid request -- wrong content-length.');
close $fh;
return;
}
my($query) = $path =~ /\?(.+)/;
(my $template_fn = $TMPTEMPLATE) =~ s/-URL(\d+)-/ '-' . url_filename($query, $1) . '-' /e;
my $tmp = new File::Temp(
TEMPLATE => $template_fn,
DIR => $TMPDIR,
SUFFIX => $TMPSUFFIX,
UNLINK => 0,
);
my $name = $tmp->filename;
print $tmp $_;
close $tmp;
my $cmd = sprintf($EDITOR_CMD, $name);
system $cmd;
unless (open FILE, '<', $name) {
http_header($fh, 500, "Unable to re-open $name: $!");
close $fh;
return;
}
http_header($fh, 200, 'OK', '');
print $fh <FILE>;
close FILE;
close $fh;
# Clean-up old tmp files that have been around for a few hours.
if (opendir(DP, $TMPDIR)) {
(my $match = quotemeta($TMPTEMPLATE . $TMPSUFFIX)) =~ s/(.*[^X])(X+)/ $1 . ('\w' x length($2)) /e;
$match =~ s/\\-URL\d+\\-/-.*-/;
print "Match: $match\n" if $verbosity >= 3;
foreach my $fn (grep /^$match$/o, readdir DP) {
$fn = "$TMPDIR/$fn";
print "Fn: $fn\n" if $verbosity >= 3;
my $age = -M $fn;
if ($age > $CLEAN_AFTER_HOURS/24) {
unlink $fn;
} else {
print "Age: $age\n" if $verbosity >= 3;
}
}
closedir DP;
}
}
sub http_header
{
my $fh = shift;
my $status = shift;
my $status_txt = shift;
@_ = $status_txt unless @_;
print $fh "HTTP/1.0 $status $status_txt\r\n",
"Server: edit-server\r\n",
"Content-Type: text/plain\r\n",
"\r\n", @_;
}
sub url_filename
{
my($query, $max_chars) = @_;
print "Query: $query\n" if $verbosity >= 4;
if (defined $query) {
foreach my $var_val (split /&/, $query) {
my($var, $val) = split /=/, $var_val, 2;
if ($var eq 'url') {
print "Before: $val\n" if $verbosity >= 4;
$val =~ s/\%([0-9a-fA-F]{2})/ chr hex $1 /eg;
$val =~ s{^https?://}{};
$val =~ s/[^-\w.]+/_/g;
$val =~ s/^(.{1,$max_chars}).*/$1/;
print "After: $val\n" if $verbosity >= 4;
return $val;
}
}
}
return 'unknown-url';
}
sub usage
{
die <<EOT;
Usage: edit-server [OPTIONS]
Options:
-v, --verbose Increase debug verbosity (repeatable)
-h, --help Output this help message
EOT
}