Commit | Line | Data |
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e61a41a4 | 1 | #!/usr/bin/perl -w |
c215a4bc IJ |
2 | |
3 | # This file is part of secnet. | |
4 | # See README for full list of copyright holders. | |
5 | # | |
6 | # secnet is free software; you can redistribute it and/or modify it | |
7 | # under the terms of the GNU General Public License as published by | |
9c6a8729 | 8 | # the Free Software Foundation; either version 3 of the License, or |
c215a4bc IJ |
9 | # (at your option) any later version. |
10 | # | |
11 | # secnet is distributed in the hope that it will be useful, but | |
12 | # WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | # General Public License for more details. | |
15 | # | |
16 | # You should have received a copy of the GNU General Public License | |
17 | # version 3 along with secnet; if not, see | |
18 | # https://www.gnu.org/licenses/gpl.html. | |
19 | ||
e61a41a4 IJ |
20 | use strict; |
21 | use IO::Handle; | |
22 | ||
23 | my $us = $0; | |
24 | $us =~ s{.*/}{}; | |
25 | ||
90666d10 IJ |
26 | open DEBUG, ">/dev/null" or die $!; |
27 | ||
28 | if (@ARGV && $ARGV[0] eq '-D') { | |
29 | shift @ARGV; | |
30 | open DEBUG, ">&STDERR" or die $!; | |
31 | } | |
32 | ||
e61a41a4 IJ |
33 | die "$us: no arguments permitted\n" if @ARGV; |
34 | ||
35 | our ($monh,$monchild); | |
36 | ||
37 | our %reported; | |
38 | # no entry: not reported, does not exist | |
39 | # /ry+/: reported, entry exists | |
40 | # during processing only: | |
41 | # /r/: reported, may not still exist | |
42 | # /y+/: not reported, entry exists | |
43 | ||
44 | sub killmonitor () { | |
45 | return unless $monchild; | |
46 | kill 9, $monchild | |
47 | or warn "$us: cannot kill monitor child [$monchild]: $!\n"; | |
48 | $monchild=undef; | |
49 | close $monh; | |
50 | } | |
51 | ||
52 | END { killmonitor(); } | |
53 | ||
54 | my $restart; | |
55 | ||
56 | for (;;) { | |
57 | my $o; | |
58 | eval { | |
59 | if (!$monh) { | |
60 | killmonitor(); | |
61 | $monh = new IO::File; | |
62 | $monchild = open $monh, "-|", qw(ip -o monitor addr) | |
63 | or die "spawn monitor: $!\n"; | |
64 | sleep(1) if $restart++; | |
65 | } else { | |
66 | my $discard; | |
67 | my $got = sysread $monh, $discard, 4096; | |
68 | die "read monitor: $!\n" unless defined $got; | |
69 | die "monitor failed\n" unless $got; | |
70 | } | |
71 | $_='r' foreach values %reported; | |
90666d10 | 72 | print DEBUG "#########################################\n"; |
e61a41a4 | 73 | foreach my $ip (qw(4 6)) { |
90666d10 | 74 | print DEBUG "###### $ip:\n"; |
e61a41a4 IJ |
75 | my $addrh = new IO::File; |
76 | open $addrh, "-|", qw(ip -o), "-$ip", qw(addr show) | |
77 | or die "spawn addr $ip show: $!\n"; | |
78 | my $afstr = $ip==4 ? 'inet' : $ip==6 ? 'inet6' : die; | |
79 | while (<$addrh>) { | |
90666d10 | 80 | print DEBUG "#$_"; |
e61a41a4 | 81 | if (m{^\d+\:\s*(\S+)\s+$afstr\s+([0-9a-z.:]+)(?:/\d+)?\s}) { |
caa97633 | 82 | my $rhs=$'; #'; |
e61a41a4 | 83 | my $outline = "$ip $1 $2"; |
caa97633 IJ |
84 | # "ip -o addr show" has a ridiculous output format. In |
85 | # particular, it mixes output keywords which introduce | |
86 | # values with ones which don't, and there seems to be | |
87 | # no way to tell without knowing all the possible | |
88 | # keywords. We hope that before the \ there is nothing | |
89 | # which contains arbitrary text (specifically, which | |
90 | # might be `tentative' other than to specify IPv6 | |
91 | # tentativeness). We have to do this for IPv6 only | |
92 | # because in the IPv4 output, the interface name | |
93 | # appears here! | |
94 | next if $ip==6 && $rhs=~m{[^\\]* tentative\s}; | |
e61a41a4 IJ |
95 | $reported{$outline} .= "y"; |
96 | } else { | |
97 | chomp; | |
98 | warn "unexpected output from addr $ip show: $_\n"; | |
99 | } | |
100 | } | |
101 | my $r = close $addrh; | |
102 | die "addr $ip show failed $!\n" unless $r; | |
103 | $o = ''; | |
104 | } | |
105 | foreach my $k (keys %reported) { | |
106 | local $_ = $reported{$k}; | |
107 | if (m/^r$/) { | |
108 | $o .= "-$k\n"; | |
109 | delete $reported{$k}; | |
110 | } elsif (m/^y/) { | |
111 | $o .= "+$k\n"; | |
112 | } | |
113 | } | |
114 | }; | |
115 | if ($@) { | |
116 | print STDERR "$us: $@"; | |
117 | sleep 5; | |
118 | next; | |
119 | } | |
120 | print $o or die $!; | |
121 | STDOUT->flush or die $!; | |
122 | } |