1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
|
#!/usr/local/bin/perl -w
#
# Copyright (c) 1996-2000 by John T. Beck <john@beck.org>
# All rights reserved.
#
# Copyright (c) 2000 by Sun Microsystems, Inc.
# All rights reserved.
#
#ident "@(#)etrn.pl 1.1 00/09/06 SMI"
require 5.005; # minimal Perl version required
use strict;
use English;
# hardcoded constants, should work fine for BSD-based systems
use Socket;
use Getopt::Std;
use vars qw($opt_v);
my $sockaddr = 'S n a4 x8';
# system requirements:
# must have 'hostname' program.
my $port = 'smtp';
select(STDERR);
chop(my $name = `hostname || uname -n`);
(my $hostname, my $aliases, my $type, my $len, undef) = gethostbyname($name);
my $usage = "Usage: $PROGRAM_NAME [-v] host [args]";
getopts('v');
my $verbose = $opt_v;
my $server = shift(@ARGV);
my @hosts = @ARGV;
die $usage unless $server;
my @cwfiles = ();
my $alarm_action = "";
if (!@hosts) {
push(@hosts, $hostname);
open(CF, "</etc/mail/sendmail.cf") ||
die "open /etc/mail/sendmail.cf: $ERRNO";
while (<CF>){
# look for a line starting with "Fw"
if (/^Fw.*$/) {
my $cwfile = $ARG;
chop($cwfile);
my $optional = /^Fw-o/;
# extract the file name
$cwfile =~ s,^Fw[^/]*,,;
# strip the options after the filename
$cwfile =~ s/ [^ ]+$//;
if (-r $cwfile) {
push (@cwfiles, $cwfile);
} else {
die "$cwfile is not readable" unless $optional;
}
}
# look for a line starting with "Cw"
if (/^Cw(.*)$/) {
my @cws = split (' ', $1);
while (@cws) {
my $thishost = shift(@cws);
push(@hosts, $thishost)
unless $thishost =~ "$hostname|localhost";
}
}
}
close(CF);
for my $cwfile (@cwfiles) {
if (open(CW, "<$cwfile")) {
while (<CW>) {
next if /^\#/;
my $thishost = $ARG;
chop($thishost);
push(@hosts, $thishost)
unless $thishost =~ $hostname;
}
close(CW);
} else {
die "open $cwfile: $ERRNO";
}
}
}
($name, $aliases, my $proto) = getprotobyname('tcp');
($name, $aliases, $port) = getservbyname($port, 'tcp')
unless $port =~ /^\d+/;
# look it up
($name, $aliases, $type, $len, my $thataddr) = gethostbyname($server);
(!defined($name)) && die "gethostbyname failed, unknown host $server";
# get a connection
my $that = pack($sockaddr, &AF_INET, $port, $thataddr);
socket(S, &AF_INET, &SOCK_STREAM, $proto)
|| die "socket: $ERRNO";
print "server = $server\n" if (defined($verbose));
&alarm("connect to $server");
if (! connect(S, $that)) {
die "cannot connect to $server: $ERRNO\n";
}
alarm(0);
select((select(S), $OUTPUT_AUTOFLUSH = 1)[0]); # don't buffer output to S
# read the greeting
&alarm("greeting with $server");
while (<S>) {
alarm(0);
print if $verbose;
if (/^(\d+)([- ])/) {
# SMTP's initial greeting response code is 220.
if ($1 != 220) {
&alarm("giving up after bad response from $server");
&read_response($2, $verbose);
alarm(0);
print STDERR "$server: NOT 220 greeting: $ARG"
if ($verbose);
}
last if ($2 eq " ");
} else {
print STDERR "$server: NOT 220 greeting: $ARG"
if ($verbose);
close(S);
}
&alarm("greeting with $server");
}
alarm(0);
&alarm("sending ehlo to $server");
&ps("ehlo $hostname");
my $etrn_support = 0;
while (<S>) {
if (/^250([- ])ETRN(.+)$/) {
$etrn_support = 1;
}
print if $verbose;
last if /^\d+ /;
}
alarm(0);
if ($etrn_support) {
print "ETRN supported\n" if ($verbose);
&alarm("sending etrn to $server");
while (@hosts) {
$server = shift(@hosts);
&ps("etrn $server");
while (<S>) {
print if $verbose;
last if /^\d+ /;
}
sleep(1);
}
} else {
print "\nETRN not supported\n\n"
}
&alarm("sending 'quit' to $server");
&ps("quit");
while (<S>) {
print if $verbose;
last if /^\d+ /;
}
close(S);
alarm(0);
select(STDOUT);
exit(0);
# print to the server (also to stdout, if -v)
sub ps
{
my ($p) = @_;
print ">>> $p\n" if $verbose;
print S "$p\n";
}
sub alarm
{
($alarm_action) = @_;
alarm(10);
$SIG{ALRM} = 'handle_alarm';
}
sub handle_alarm
{
&giveup($alarm_action);
}
sub giveup
{
my $reason = @_;
(my $pk, my $file, my $line);
($pk, $file, $line) = caller;
print "Timed out during $reason\n" if $verbose;
exit(1);
}
# read the rest of the current smtp daemon's response (and toss it away)
sub read_response
{
(my $done, $verbose) = @_;
(my @resp);
print my $s if $verbose;
while (($done eq "-") && ($s = <S>) && ($s =~ /^\d+([- ])/)) {
print $s if $verbose;
$done = $1;
push(@resp, $s);
}
return @resp;
}
|
