Merge branch 'master' of git://git.exim.org/exim
[exim.git] / src / util / proxy_protocol_client.pl
1 #!/usr/bin/perl
2 #
3 # Copyright (C) 2014 Todd Lyons
4 # License GPLv2: GNU GPL version 2
5 # <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>
6 #
7 # This script emulates a proxy which uses Proxy Protocol to communicate
8 # to a backend server. It should be run from an IP which is configured
9 # to be a Proxy Protocol connection (or not, if you are testing error
10 # scenarios) because Proxy Protocol specs require not to fall back to a
11 # non-proxied mode.
12 #
13 # The script is interactive, so when you run it, you are expected to
14 # perform whatever conversation is required for the protocol being
15 # tested. It uses STDIN/STDOUT, so you can also pipe output to/from the
16 # script. It was originally written to test Exim's Proxy Protocol
17 # code, and it could be tested like this:
18 #
19 # swaks --pipe 'perl proxy_protocol_client.pl --server-ip
20 # host.internal.lan' --from user@example.com --to user@example.net
21 #
22 use strict;
23 use warnings;
24 use IO::Select;
25 use IO::Socket;
26 use Getopt::Long;
27 use Data::Dumper;
28
29 my %opts;
30 GetOptions( \%opts,
31 'help',
32 '6|ipv6',
33 'dest-ip:s',
34 'dest-port:i',
35 'source-ip:s',
36 'source-port:i',
37 'server-ip:s',
38 'server-port:i',
39 'version:i'
40 );
41 &usage() if ($opts{help} || !$opts{'server-ip'});
42
43 my ($dest_ip,$source_ip,$dest_port,$source_port);
44 my %socket_map;
45 my $status_line = "Testing Proxy Protocol Version " .
46 ($opts{version} ? $opts{version} : '2') .
47 ":\n";
48
49 # All ip's and ports are in network byte order in version 2 mode, but are
50 # simple strings when in version 1 mode. The binary_pack_*() functions
51 # return the required data for the Proxy Protocol version being used.
52
53 # Use provided source or fall back to www.mrball.net
54 $source_ip = $opts{'source-ip'} ? binary_pack_ip($opts{'source-ip'}) :
55 $opts{6} ?
56 binary_pack_ip("2001:470:d:367::50") :
57 binary_pack_ip("208.89.139.252");
58 $source_port = $opts{'source-port'} ?
59 binary_pack_port($opts{'source-port'}) :
60 binary_pack_port(43118);
61
62 $status_line .= "-> " if (!$opts{version} || $opts{version} == 2);
63
64 # Use provided dest or fall back to mail.exim.org
65 $dest_ip = $opts{'dest-ip'} ? binary_pack_ip($opts{'dest-ip'}) :
66 $opts{6} ?
67 binary_pack_ip("2001:630:212:8:204:23ff:fed6:b664") :
68 binary_pack_ip("131.111.8.192");
69 $dest_port = $opts{'dest-port'} ?
70 binary_pack_port($opts{'dest-port'}) :
71 binary_pack_port(25);
72
73 # The IP and port of the Proxy Protocol backend real server being tested,
74 # don't binary pack it.
75 my $server_ip = $opts{'server-ip'};
76 my $server_port = $opts{'server-port'} ? $opts{'server-port'} : 25;
77
78 my $s = IO::Select->new(); # for socket polling
79
80 sub generate_preamble {
81 my @preamble;
82 if (!$opts{version} || $opts{version} == 2) {
83 @preamble = (
84 "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A", # 12 byte v2 header
85 "\x02", # declares v2
86 "\x01", # connection is proxied
87 $opts{6} ? "\x21" : "\x11", # inet6/4 and TCP (stream)
88 $opts{6} ? "\x24" : "\x0b", # 36 bytes / 12 bytes
89 $source_ip,
90 $dest_ip,
91 $source_port,
92 $dest_port
93 );
94 }
95 else {
96 @preamble = (
97 "PROXY", " ", # Request proxy mode
98 $opts{6} ? "TCP6" : "TCP4", " ", # inet6/4 and TCP (stream)
99 $source_ip, " ",
100 $dest_ip, " ",
101 $source_port, " ",
102 $dest_port,
103 "\x0d\x0a"
104 );
105 $status_line .= join "", @preamble;
106 }
107 print "\n", $status_line, "\n";
108 print "\n" if (!$opts{version} || $opts{version} == 2);
109 return @preamble;
110 }
111
112 sub binary_pack_port {
113 my $port = shift();
114 if ($opts{version} && $opts{version} == 1) {
115 return $port
116 if ($port && $port =~ /^\d+$/ && $port > 0 && $port < 65536);
117 die "Not a valid port: $port";
118 }
119 $status_line .= $port." ";
120 $port = pack "S", $port;
121 return $port;
122 }
123
124 sub binary_pack_ip {
125 my $ip = shift();
126 if ( $ip =~ m/\./ && !$opts{6}) {
127 if (IP4_valid($ip)) {
128 return $ip if ($opts{version} && $opts{version} == 1);
129 $status_line .= $ip.":";
130 $ip = pack "C*", split /\./, $ip;
131 }
132 else { die "Invalid IPv4: $ip"; }
133 }
134 elsif ($ip =~ m/:/ && $opts{6}) {
135 $ip = pad_ipv6($ip);
136 if (IP6_valid($ip)) {
137 return $ip if ($opts{version} && $opts{version} == 1);
138 $status_line .= $ip.":";
139 $ip = pack "S>*", map hex, split /:/, $ip;
140 }
141 else { die "Invalid IPv6: $ip"; }
142 }
143 else { die "Mismatching IP families passed: $ip"; }
144 return $ip;
145 }
146
147 sub pad_ipv6 {
148 my $ip = shift();
149 my @ip = split /:/, $ip;
150 my $segments = scalar @ip;
151 return $ip if ($segments == 8);
152 $ip = "";
153 for (my $count=1; $count <= $segments; $count++) {
154 my $block = $ip[$count-1];
155 if ($block) {
156 $ip .= $block;
157 $ip .= ":" unless $count == $segments;
158 }
159 elsif ($count == 1) {
160 # Somebody passed us ::1, fix it, but it's not really valid
161 $ip = "0:";
162 }
163 else {
164 $ip .= join ":", map "0", 0..(8-$segments);
165 $ip .= ":";
166 }
167 }
168 return $ip;
169 }
170
171 sub IP6_valid {
172 my $ip = shift;
173 $ip = lc($ip);
174 return 0 unless ($ip =~ /^[0-9a-f:]+$/);
175 my @ip = split /:/, $ip;
176 return 0 if (scalar @ip != 8);
177 return 1;
178 }
179
180 sub IP4_valid {
181 my $ip = shift;
182 $ip =~ /^(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})$/;
183 foreach ($1,$2,$3,$4){
184 if ($_ <256 && $_ >0) {next;}
185 return 0;
186 }
187 return 1;
188 }
189
190 sub go_interactive {
191 my $continue = 1;
192 while($continue) {
193 # Check for input on both ends, recheck every 5 sec
194 for my $socket ($s->can_read(5)) {
195 my $remote = $socket_map{$socket};
196 my $buffer;
197 my $read = $socket->sysread($buffer, 4096);
198 if ($read) {
199 $remote->syswrite($buffer);
200 }
201 else {
202 $continue = 0;
203 }
204 }
205 }
206 }
207
208 sub connect_stdin_to_proxy {
209 my $sock = new IO::Socket::INET(
210 PeerAddr => $server_ip,
211 PeerPort => $server_port,
212 Proto => 'tcp'
213 );
214
215 die "Could not create socket: $!\n" unless $sock;
216 # Add sockets to the Select group
217 $s->add(\*STDIN);
218 $s->add($sock);
219 # Tie the sockets together using this hash
220 $socket_map{\*STDIN} = $sock;
221 $socket_map{$sock} = \*STDOUT;
222 return $sock;
223 }
224
225 sub usage {
226 chomp(my $prog = `basename $0`);
227 print <<EOF;
228 Usage: $prog [required] [optional]
229 Required:
230 --server-ip IP of server to test proxy configuration,
231 a hostname is ok, but for only this setting
232 Optional:
233 --server-port Port server is listening on (default 25)
234 --6 IPv6 source/dest (default IPv4), if none specified,
235 some default, reverse resolvable IP's are used for
236 the source and dest ip/port
237 --dest-ip Public IP of the proxy server
238 --dest-port Port of public IP of proxy server
239 --source-ip IP connecting to the proxy server
240 --source-port Port of IP connecting to the proxy server
241 --help This output
242 EOF
243 exit;
244 }
245
246
247 my $sock = connect_stdin_to_proxy();
248 my @preamble = generate_preamble();
249 print $sock @preamble;
250 go_interactive();