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wget/tests/FTPServer.pm
2010-02-25 21:47:53 +01:00

803 lines
22 KiB
Perl

# Part of this code was borrowed from Richard Jones's Net::FTPServer
# http://www.annexia.org/freeware/netftpserver
package FTPServer;
use strict;
use warnings;
use Cwd;
use Socket;
use IO::Socket::INET;
use IO::Seekable;
use POSIX qw(strftime);
my $log = undef;
my $GOT_SIGURG = 0;
# CONSTANTS
# connection states
my %_connection_states = (
'NEWCONN' => 0x01,
'WAIT4PWD' => 0x02,
'LOGGEDIN' => 0x04,
'TWOSOCKS' => 0x08,
);
# subset of FTP commands supported by these server and the respective
# connection states in which they are allowed
my %_commands = (
# Standard commands from RFC 959.
'CWD' => $_connection_states{LOGGEDIN} |
$_connection_states{TWOSOCKS},
# 'EPRT' => $_connection_states{LOGGEDIN},
# 'EPSV' => $_connection_states{LOGGEDIN},
'LIST' => $_connection_states{TWOSOCKS},
# 'LPRT' => $_connection_states{LOGGEDIN},
# 'LPSV' => $_connection_states{LOGGEDIN},
'PASS' => $_connection_states{WAIT4PWD},
'PASV' => $_connection_states{LOGGEDIN},
'PORT' => $_connection_states{LOGGEDIN},
'PWD' => $_connection_states{LOGGEDIN} |
$_connection_states{TWOSOCKS},
'QUIT' => $_connection_states{LOGGEDIN} |
$_connection_states{TWOSOCKS},
'REST' => $_connection_states{TWOSOCKS},
'RETR' => $_connection_states{TWOSOCKS},
'SYST' => $_connection_states{LOGGEDIN},
'TYPE' => $_connection_states{LOGGEDIN} |
$_connection_states{TWOSOCKS},
'USER' => $_connection_states{NEWCONN},
# From ftpexts Internet Draft.
'SIZE' => $_connection_states{LOGGEDIN} |
$_connection_states{TWOSOCKS},
);
# COMMAND-HANDLING ROUTINES
sub _CWD_command
{
my ($conn, $cmd, $path) = @_;
my $paths = $conn->{'paths'};
local $_;
my $new_path = FTPPaths::path_merge($conn->{'dir'}, $path);
# Split the path into its component parts and process each separately.
if (! $paths->dir_exists($new_path)) {
print {$conn->{socket}} "550 Directory not found.\r\n";
return;
}
$conn->{'dir'} = $new_path;
print {$conn->{socket}} "200 directory changed to $new_path.\r\n";
}
sub _LIST_command
{
my ($conn, $cmd, $path) = @_;
my $paths = $conn->{'paths'};
# This is something of a hack. Some clients expect a Unix server
# to respond to flags on the 'ls command line'. Remove these flags
# and ignore them. This is particularly an issue with ncftp 2.4.3.
$path =~ s/^-[a-zA-Z0-9]+\s?//;
my $dir = $conn->{'dir'};
print STDERR "_LIST_command - dir is: $dir\n";
# Parse the first elements of the path until we find the appropriate
# working directory.
local $_;
$dir = FTPPaths::path_merge($dir, $path);
my $listing = $paths->get_list($dir);
unless ($listing) {
print {$conn->{socket}} "550 File or directory not found.\r\n";
return;
}
print STDERR "_LIST_command - dir is: $dir\n" if $log;
print {$conn->{socket}} "150 Opening data connection for file listing.\r\n";
# Open a path back to the client.
my $sock = __open_data_connection ($conn);
unless ($sock) {
print {$conn->{socket}} "425 Can't open data connection.\r\n";
return;
}
for my $item (@$listing) {
print $sock "$item\r\n";
}
unless ($sock->close) {
print {$conn->{socket}} "550 Error closing data connection: $!\r\n";
return;
}
print {$conn->{socket}} "226 Listing complete. Data connection has been closed.\r\n";
}
sub _PASS_command
{
my ($conn, $cmd, $pass) = @_;
# TODO: implement authentication?
print STDERR "switching to LOGGEDIN state\n" if $log;
$conn->{state} = $_connection_states{LOGGEDIN};
if ($conn->{username} eq "anonymous") {
print {$conn->{socket}} "202 Anonymous user access is always granted.\r\n";
} else {
print {$conn->{socket}} "230 Authentication not implemented yet, access is always granted.\r\n";
}
}
sub _PASV_command
{
my ($conn, $cmd, $rest) = @_;
# Open a listening socket - but don't actually accept on it yet.
"0" =~ /(0)/; # Perl 5.7 / IO::Socket::INET bug workaround.
my $sock = IO::Socket::INET->new (LocalHost => '127.0.0.1',
LocalPort => '0',
Listen => 1,
Reuse => 1,
Proto => 'tcp',
Type => SOCK_STREAM);
unless ($sock) {
# Return a code 550 here, even though this is not in the RFC. XXX
print {$conn->{socket}} "550 Can't open a listening socket.\r\n";
return;
}
$conn->{passive} = 1;
$conn->{passive_socket} = $sock;
# Get our port number.
my $sockport = $sock->sockport;
# Split the port number into high and low components.
my $p1 = int ($sockport / 256);
my $p2 = $sockport % 256;
$conn->{state} = $_connection_states{TWOSOCKS};
# We only accept connections from localhost.
print {$conn->{socket}} "227 Entering Passive Mode (127,0,0,1,$p1,$p2)\r\n";
}
sub _PORT_command
{
my ($conn, $cmd, $rest) = @_;
# The arguments to PORT are a1,a2,a3,a4,p1,p2 where a1 is the
# most significant part of the address (eg. 127,0,0,1) and
# p1 is the most significant part of the port.
unless ($rest =~ /^\s*(\d{1,3}),\s*(\d{1,3}),\s*(\d{1,3}),\s*(\d{1,3}),\s*(\d{1,3}),\s*(\d{1,3})/) {
print {$conn->{socket}} "501 Syntax error in PORT command.\r\n";
return;
}
# Check host address.
unless ($1 > 0 && $1 < 224 &&
$2 >= 0 && $2 < 256 &&
$3 >= 0 && $3 < 256 &&
$4 >= 0 && $4 < 256) {
print {$conn->{socket}} "501 Invalid host address.\r\n";
return;
}
# Construct host address and port number.
my $peeraddrstring = "$1.$2.$3.$4";
my $peerport = $5 * 256 + $6;
# Check port number.
unless ($peerport > 0 && $peerport < 65536) {
print {$conn->{socket}} "501 Invalid port number.\r\n";
}
$conn->{peeraddrstring} = $peeraddrstring;
$conn->{peeraddr} = inet_aton ($peeraddrstring);
$conn->{peerport} = $peerport;
$conn->{passive} = 0;
$conn->{state} = $_connection_states{TWOSOCKS};
print {$conn->{socket}} "200 PORT command OK.\r\n";
}
sub _PWD_command
{
my ($conn, $cmd, $rest) = @_;
# See RFC 959 Appendix II and draft-ietf-ftpext-mlst-11.txt section 6.2.1.
my $pathname = $conn->{dir};
$pathname =~ s,/+$,, unless $pathname eq "/";
$pathname =~ tr,/,/,s;
print {$conn->{socket}} "257 \"$pathname\"\r\n";
}
sub _REST_command
{
my ($conn, $cmd, $restart_from) = @_;
unless ($restart_from =~ /^([1-9][0-9]*|0)$/) {
print {$conn->{socket}} "501 REST command needs a numeric argument.\r\n";
return;
}
$conn->{restart} = $1;
print {$conn->{socket}} "350 Restarting next transfer at $1.\r\n";
}
sub _RETR_command
{
my ($conn, $cmd, $path) = @_;
$path = FTPPaths::path_merge($conn->{dir}, $path);
my $info = $conn->{'paths'}->get_info($path);
unless ($info->{'_type'} eq 'f') {
print {$conn->{socket}} "550 File not found.\r\n";
return;
}
print {$conn->{socket}} "150 Opening " .
($conn->{type} eq 'A' ? "ASCII mode" : "BINARY mode") .
" data connection.\r\n";
# Open a path back to the client.
my $sock = __open_data_connection ($conn);
unless ($sock) {
print {$conn->{socket}} "425 Can't open data connection.\r\n";
return;
}
my $content = $info->{'content'};
# Restart the connection from previous point?
if ($conn->{restart}) {
$content = substr($content, $conn->{restart});
$conn->{restart} = 0;
}
# What mode are we sending this file in?
unless ($conn->{type} eq 'A') # Binary type.
{
my ($r, $buffer, $n, $w);
# Copy data.
while ($buffer = substr($content, 0, 65536))
{
$r = length $buffer;
# Restart alarm clock timer.
alarm $conn->{idle_timeout};
for ($n = 0; $n < $r; )
{
$w = syswrite ($sock, $buffer, $r - $n, $n);
# Cleanup and exit if there was an error.
unless (defined $w) {
close $sock;
print {$conn->{socket}} "426 File retrieval error: $!. Data connection has been closed.\r\n";
return;
}
$n += $w;
}
# Transfer aborted by client?
if ($GOT_SIGURG) {
$GOT_SIGURG = 0;
close $sock;
print {$conn->{socket}} "426 Transfer aborted. Data connection closed.\r\n";
return;
}
}
# Cleanup and exit if there was an error.
unless (defined $r) {
close $sock;
print {$conn->{socket}} "426 File retrieval error: $!. Data connection has been closed.\r\n";
return;
}
} else { # ASCII type.
# Copy data.
my @lines = split /\r\n?|\n/, $content;
for (@lines) {
# Remove any native line endings.
s/[\n\r]+$//;
# Restart alarm clock timer.
alarm $conn->{idle_timeout};
# Write the line with telnet-format line endings.
print $sock "$_\r\n";
# Transfer aborted by client?
if ($GOT_SIGURG) {
$GOT_SIGURG = 0;
close $sock;
print {$conn->{socket}} "426 Transfer aborted. Data connection closed.\r\n";
return;
}
}
}
unless (close ($sock)) {
print {$conn->{socket}} "550 File retrieval error: $!.\r\n";
return;
}
print {$conn->{socket}} "226 File retrieval complete. Data connection has been closed.\r\n";
}
sub _SIZE_command
{
my ($conn, $cmd, $path) = @_;
$path = FTPPaths::path_merge($conn->{dir}, $path);
my $info = $conn->{'paths'}->get_info($path);
unless ($info) {
print {$conn->{socket}} "550 File or directory not found.\r\n";
return;
}
if ($info->{'_type'} eq 'd') {
print {$conn->{socket}} "550 SIZE command is not supported on directories.\r\n";
return;
}
my $size = length $info->{'content'};
print {$conn->{socket}} "213 $size\r\n";
}
sub _SYST_command
{
my ($conn, $cmd, $dummy) = @_;
print {$conn->{socket}} "215 UNIX Type: L8\r\n";
}
sub _TYPE_command
{
my ($conn, $cmd, $type) = @_;
# See RFC 959 section 5.3.2.
if ($type =~ /^([AI])$/i) {
$conn->{type} = 'A';
} elsif ($type =~ /^([AI])\sN$/i) {
$conn->{type} = 'A';
} elsif ($type =~ /^L\s8$/i) {
$conn->{type} = 'L8';
} else {
print {$conn->{socket}} "504 This server does not support TYPE $type.\r\n";
return;
}
print {$conn->{socket}} "200 TYPE changed to $type.\r\n";
}
sub _USER_command
{
my ($conn, $cmd, $username) = @_;
print STDERR "username: $username\n" if $log;
$conn->{username} = $username;
print STDERR "switching to WAIT4PWD state\n" if $log;
$conn->{state} = $_connection_states{WAIT4PWD};
if ($conn->{username} eq "anonymous") {
print {$conn->{socket}} "230 Anonymous user access granted.\r\n";
} else {
print {$conn->{socket}} "331 Password required.\r\n";
}
}
# HELPER ROUTINES
sub __open_data_connection
{
my $conn = shift;
my $sock;
if ($conn->{passive}) {
# Passive mode - wait for a connection from the client.
accept ($sock, $conn->{passive_socket}) or return undef;
} else {
# Active mode - connect back to the client.
"0" =~ /(0)/; # Perl 5.7 / IO::Socket::INET bug workaround.
$sock = IO::Socket::INET->new (LocalAddr => '127.0.0.1',
PeerAddr => $conn->{peeraddrstring},
PeerPort => $conn->{peerport},
Proto => 'tcp',
Type => SOCK_STREAM) or return undef;
}
return $sock;
}
###########################################################################
# FTPSERVER CLASS
###########################################################################
{
my %_attr_data = ( # DEFAULT
_input => undef,
_localAddr => 'localhost',
_localPort => undef,
_reuseAddr => 1,
_rootDir => Cwd::getcwd(),
_server_behavior => {},
);
sub _default_for
{
my ($self, $attr) = @_;
$_attr_data{$attr};
}
sub _standard_keys
{
keys %_attr_data;
}
}
sub new {
my ($caller, %args) = @_;
my $caller_is_obj = ref($caller);
my $class = $caller_is_obj || $caller;
my $self = bless {}, $class;
foreach my $attrname ($self->_standard_keys()) {
my ($argname) = ($attrname =~ /^_(.*)/);
if (exists $args{$argname}) {
$self->{$attrname} = $args{$argname};
} elsif ($caller_is_obj) {
$self->{$attrname} = $caller->{$attrname};
} else {
$self->{$attrname} = $self->_default_for($attrname);
}
}
# create server socket
"0" =~ /(0)/; # Perl 5.7 / IO::Socket::INET bug workaround.
$self->{_server_sock}
= IO::Socket::INET->new (LocalHost => $self->{_localAddr},
LocalPort => $self->{_localPort},
Listen => 1,
Reuse => $self->{_reuseAddr},
Proto => 'tcp',
Type => SOCK_STREAM)
or die "bind: $!";
foreach my $file (keys %{$self->{_input}}) {
my $ref = \$self->{_input}{$file}{content};
$$ref =~ s/{{port}}/$self->sockport/eg;
}
return $self;
}
sub run
{
my ($self, $synch_callback) = @_;
my $initialized = 0;
# turn buffering off on STDERR
select((select(STDERR), $|=1)[0]);
# initialize command table
my $command_table = {};
foreach (keys %_commands) {
my $subname = "_${_}_command";
$command_table->{$_} = \&$subname;
}
my $old_ils = $/;
$/ = "\r\n";
if (!$initialized) {
$synch_callback->();
$initialized = 1;
}
$SIG{CHLD} = sub { wait };
my $server_sock = $self->{_server_sock};
# the accept loop
while (my $client_addr = accept (my $socket, $server_sock))
{
# turn buffering off on $socket
select((select($socket), $|=1)[0]);
# find out who connected
my ($client_port, $client_ip) = sockaddr_in ($client_addr);
my $client_ipnum = inet_ntoa ($client_ip);
# print who connected
print STDERR "got a connection from: $client_ipnum\n" if $log;
# fork off a process to handle this connection.
# my $pid = fork();
# unless (defined $pid) {
# warn "fork: $!";
# sleep 5; # Back off in case system is overloaded.
# next;
# }
if (1) { # Child process.
# install signals
$SIG{URG} = sub {
$GOT_SIGURG = 1;
};
$SIG{PIPE} = sub {
print STDERR "Client closed connection abruptly.\n";
exit;
};
$SIG{ALRM} = sub {
print STDERR "Connection idle timeout expired. Closing server.\n";
exit;
};
#$SIG{CHLD} = 'IGNORE';
print STDERR "in child\n" if $log;
my $conn = {
'paths' => FTPPaths->new($self->{'_input'},
$self->{'_server_behavior'}),
'socket' => $socket,
'state' => $_connection_states{NEWCONN},
'dir' => '/',
'restart' => 0,
'idle_timeout' => 60, # 1 minute timeout
'rootdir' => $self->{_rootDir},
};
print {$conn->{socket}} "220 GNU Wget Testing FTP Server ready.\r\n";
# command handling loop
for (;;) {
print STDERR "waiting for request\n" if $log;
last unless defined (my $req = <$socket>);
# Remove trailing CRLF.
$req =~ s/[\n\r]+$//;
print STDERR "received request $req\n" if $log;
# Get the command.
# See also RFC 2640 section 3.1.
unless ($req =~ m/^([A-Z]{3,4})\s?(.*)/i) {
# badly formed command
exit 0;
}
# The following strange 'eval' is necessary to work around a
# very odd bug in Perl 5.6.0. The following assignment to
# $cmd will fail in some cases unless you use $1 in some sort
# of an expression beforehand.
# - RWMJ 2002-07-05.
eval '$1 eq $1';
my ($cmd, $rest) = (uc $1, $2);
# Got a command which matches in the table?
unless (exists $command_table->{$cmd}) {
print {$conn->{socket}} "500 Unrecognized command.\r\n";
next;
}
# Command requires user to be authenticated?
unless ($_commands{$cmd} | $conn->{state}) {
print {$conn->{socket}} "530 Not logged in.\r\n";
next;
}
# Handle the QUIT command specially.
if ($cmd eq "QUIT") {
print {$conn->{socket}} "221 Goodbye. Service closing connection.\r\n";
last;
}
if (defined ($self->{_server_behavior}{fail_on_pasv})
&& $cmd eq 'PASV') {
undef $self->{_server_behavior}{fail_on_pasv};
close $socket;
last;
}
# Run the command.
&{$command_table->{$cmd}} ($conn, $cmd, $rest);
}
} else { # Father
close $socket;
}
}
$/ = $old_ils;
}
sub sockport {
my $self = shift;
return $self->{_server_sock}->sockport;
}
package FTPPaths;
use POSIX qw(strftime);
# not a method
sub final_component {
my $path = shift;
$path =~ s|.*/||;
return $path;
}
# not a method
sub path_merge {
my ($a, $b) = @_;
return $a unless $b;
if ($b =~ m.^/.) {
$a = '';
$b =~ s.^/..;
}
$a =~ s./$..;
my @components = split('/', $b);
foreach my $c (@components) {
if ($c =~ /^\.?$/) {
next;
} elsif ($c eq '..') {
next if $a eq '';
$a =~ s|/[^/]*$||;
} else {
$a .= "/$c";
}
}
return $a;
}
sub new {
my ($this, @args) = @_;
my $class = ref($this) || $this;
my $self = {};
bless $self, $class;
$self->initialize(@args);
return $self;
}
sub initialize {
my ($self, $urls, $behavior) = @_;
my $paths = {_type => 'd'};
# From a path like '/foo/bar/baz.txt', construct $paths such that
# $paths->{'foo'}->{'bar'}->{'baz.txt'} is
# $urls->{'/foo/bar/baz.txt'}.
for my $path (keys %$urls) {
my @components = split('/', $path);
shift @components;
my $x = $paths;
for my $c (@components) {
unless (exists $x->{$c}) {
$x->{$c} = {_type => 'd'};
}
$x = $x->{$c};
}
%$x = %{$urls->{$path}};
$x->{_type} = 'f';
}
$self->{'_paths'} = $paths;
$self->{'_behavior'} = $behavior;
}
sub get_info {
my ($self, $path, $node) = @_;
$node = $self->{'_paths'} unless $node;
my @components = split('/', $path);
shift @components if @components && $components[0] eq '';
for my $c (@components) {
if ($node->{'_type'} eq 'd') {
$node = $node->{$c};
} else {
return undef;
}
}
return $node;
}
sub dir_exists {
my ($self, $path) = @_;
return $self->exists($path, 'd');
}
sub exists {
# type is optional, in which case we don't check it.
my ($self, $path, $type) = @_;
my $paths = $self->{'_paths'};
die "Invalid path $path (not absolute).\n" unless $path =~ m.^/.;
my $info = $self->get_info($path);
return 0 unless defined($info);
return $info->{'_type'} eq $type if defined($type);
return 1;
}
sub _format_for_list {
my ($self, $name, $info) = @_;
# XXX: mode should be specifyable as part of the node info.
my $mode_str;
if ($info->{'_type'} eq 'd') {
$mode_str = 'dr-xr-xr-x';
} else {
$mode_str = '-r--r--r--';
}
my $size = 0;
if ($info->{'_type'} eq 'f') {
$size = length $info->{'content'};
if ($self->{'_behavior'}{'bad_list'}) {
$size = 0;
}
}
my $date = strftime ("%b %e %H:%M", localtime);
return "$mode_str 1 0 0 $size $date $name";
}
sub get_list {
my ($self, $path) = @_;
my $info = $self->get_info($path);
return undef unless defined $info;
my $list = [];
if ($info->{'_type'} eq 'd') {
for my $item (keys %$info) {
next if $item =~ /^_/;
push @$list, $self->_format_for_list($item, $info->{$item});
}
} else {
push @$list, $self->_format_for_list(final_component($path), $info);
}
return $list;
}
1;
# vim: et ts=4 sw=4