~mdw / secnet / blame
| Commit | Line | Data |
|---|---|---|
| e61a41a4 IJ |
1 | #!/usr/bin/perl -w |
| 2 | use strict; | |
| 3 | use IO::Handle; | |
| 4 | ||
| 5 | my $us = $0; | |
| 6 | $us =~ s{.*/}{}; | |
| 7 | ||
| 90666d10 IJ |
8 | open DEBUG, ">/dev/null" or die $!; |
| 9 | ||
| 10 | if (@ARGV && $ARGV[0] eq '-D') { | |
| 11 | shift @ARGV; | |
| 12 | open DEBUG, ">&STDERR" or die $!; | |
| 13 | } | |
| 14 | ||
| e61a41a4 IJ |
15 | die "$us: no arguments permitted\n" if @ARGV; |
| 16 | ||
| 17 | our ($monh,$monchild); | |
| 18 | ||
| 19 | our %reported; | |
| 20 | # no entry: not reported, does not exist | |
| 21 | # /ry+/: reported, entry exists | |
| 22 | # during processing only: | |
| 23 | # /r/: reported, may not still exist | |
| 24 | # /y+/: not reported, entry exists | |
| 25 | ||
| 26 | sub killmonitor () { | |
| 27 | return unless $monchild; | |
| 28 | kill 9, $monchild | |
| 29 | or warn "$us: cannot kill monitor child [$monchild]: $!\n"; | |
| 30 | $monchild=undef; | |
| 31 | close $monh; | |
| 32 | } | |
| 33 | ||
| 34 | END { killmonitor(); } | |
| 35 | ||
| 36 | my $restart; | |
| 37 | ||
| 38 | for (;;) { | |
| 39 | my $o; | |
| 40 | eval { | |
| 41 | if (!$monh) { | |
| 42 | killmonitor(); | |
| 43 | $monh = new IO::File; | |
| 44 | $monchild = open $monh, "-|", qw(ip -o monitor addr) | |
| 45 | or die "spawn monitor: $!\n"; | |
| 46 | sleep(1) if $restart++; | |
| 47 | } else { | |
| 48 | my $discard; | |
| 49 | my $got = sysread $monh, $discard, 4096; | |
| 50 | die "read monitor: $!\n" unless defined $got; | |
| 51 | die "monitor failed\n" unless $got; | |
| 52 | } | |
| 53 | $_='r' foreach values %reported; | |
| 90666d10 | 54 | print DEBUG "#########################################\n"; |
| e61a41a4 | 55 | foreach my $ip (qw(4 6)) { |
| 90666d10 | 56 | print DEBUG "###### $ip:\n"; |
| e61a41a4 IJ |
57 | my $addrh = new IO::File; |
| 58 | open $addrh, "-|", qw(ip -o), "-$ip", qw(addr show) | |
| 59 | or die "spawn addr $ip show: $!\n"; | |
| 60 | my $afstr = $ip==4 ? 'inet' : $ip==6 ? 'inet6' : die; | |
| 61 | while (<$addrh>) { | |
| 90666d10 | 62 | print DEBUG "#$_"; |
| e61a41a4 | 63 | if (m{^\d+\:\s*(\S+)\s+$afstr\s+([0-9a-z.:]+)(?:/\d+)?\s}) { |
| caa97633 | 64 | my $rhs=$'; #'; |
| e61a41a4 | 65 | my $outline = "$ip $1 $2"; |
| caa97633 IJ |
66 | # "ip -o addr show" has a ridiculous output format. In |
| 67 | # particular, it mixes output keywords which introduce | |
| 68 | # values with ones which don't, and there seems to be | |
| 69 | # no way to tell without knowing all the possible | |
| 70 | # keywords. We hope that before the \ there is nothing | |
| 71 | # which contains arbitrary text (specifically, which | |
| 72 | # might be `tentative' other than to specify IPv6 | |
| 73 | # tentativeness). We have to do this for IPv6 only | |
| 74 | # because in the IPv4 output, the interface name | |
| 75 | # appears here! | |
| 76 | next if $ip==6 && $rhs=~m{[^\\]* tentative\s}; | |
| e61a41a4 IJ |
77 | $reported{$outline} .= "y"; |
| 78 | } else { | |
| 79 | chomp; | |
| 80 | warn "unexpected output from addr $ip show: $_\n"; | |
| 81 | } | |
| 82 | } | |
| 83 | my $r = close $addrh; | |
| 84 | die "addr $ip show failed $!\n" unless $r; | |
| 85 | $o = ''; | |
| 86 | } | |
| 87 | foreach my $k (keys %reported) { | |
| 88 | local $_ = $reported{$k}; | |
| 89 | if (m/^r$/) { | |
| 90 | $o .= "-$k\n"; | |
| 91 | delete $reported{$k}; | |
| 92 | } elsif (m/^y/) { | |
| 93 | $o .= "+$k\n"; | |
| 94 | } | |
| 95 | } | |
| 96 | }; | |
| 97 | if ($@) { | |
| 98 | print STDERR "$us: $@"; | |
| 99 | sleep 5; | |
| 100 | next; | |
| 101 | } | |
| 102 | print $o or die $!; | |
| 103 | STDOUT->flush or die $!; | |
| 104 | } |