| Subject: | A TCP connection for localhost is failing if the Ethernet connection is down. |
Hi all!
When eth0 is up the following IO-Socket-IP script works fine:
««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««
#!/usr/bin/perl
=head1 DESCRIPTION
This program based on L<IO::Socket::IP> works fine if the Ethernet interface
is enabled, and fails if it isn't (while lo is still fine). OTOH, doing
C<curl http://localhost:6300/notify> works.
=cut
use strict;
use warnings;
use autodie;
use Socket qw(:DEFAULT :crlf);
use IO::Socket::IP;
my $sock = IO::Socket::IP->new(
LocalHost => 'localhost',
PeerHost => 'localhost',
PeerPort => 6300,
Type => SOCK_STREAM,
)
or die "Cannot init socket - $@";
$sock->print("GET /notify$CRLF");
=head1 COPYRIGHT & LICENSE
Copyright 2015 by Shlomi Fish
This program is distributed under the MIT (X11) License:
L<http://www.opensource.org/licenses/mit-license.php>
Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.
=cut
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ifconfig -a displays this:
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root@telaviv1:~$ ifconfig -a
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 10.0.0.5 netmask 255.255.255.0 broadcast 10.0.0.255
inet6 fe80::222:15ff:feab:3f85 prefixlen 64 scopeid 0x20<link>
ether 00:22:15:ab:3f:85 txqueuelen 1000 (Ethernet)
RX packets 948475 bytes 505552443 (482.1 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 979625 bytes 609207173 (580.9 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device interrupt 20 memory 0xfe500000-fe520000
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 0 (Local Loopback)
RX packets 473772 bytes 112018554 (106.8 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 473772 bytes 112018554 (106.8 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
root@telaviv1:~$
»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»»
However, after I do:
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root@telaviv1:~$ ifconfig eth0 down
root@telaviv1:~$ ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::222:15ff:feab:3f85 prefixlen 64 scopeid 0x20<link>
ether 00:22:15:ab:3f:85 txqueuelen 1000 (Ethernet)
RX packets 949158 bytes 506116633 (482.6 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 980204 bytes 609298209 (581.0 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device interrupt 20 memory 0xfe500000-fe520000
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 0 (Local Loopback)
RX packets 473799 bytes 112020336 (106.8 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 473799 bytes 112020336 (106.8 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
root@telaviv1:~$
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I'm getting:
««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««
shlomif@telaviv1:~/IO-Socket-IP-0.37$ perl -Ilib ~/progs/perl/snippets/IO-Socket-IP-test-on-localhost.pl
Cannot init socket - Connection refused at /home/shlomif/progs/perl/snippets/IO-Socket-IP-test-on-localhost.pl line 19.
shlomif@telaviv1:~/IO-Socket-IP-0.37$
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However, doing:
$ curl 'http://localhost:6300/notify'
In this situation is working fine.
Please try to reproduce and investigate this problem.
I'm on Mageia Linux 5 x86-64.
Regards,
Shlomi Fish
| Subject: | IO-Socket-IP-test-on-localhost.pl |
#!/usr/bin/perl
=head1 DESCRIPTION
This program based on L<IO::Socket::IP> works fine if the Ethernet interface
is enabled, and fails if it isn't (while lo is still fine). OTOH, doing
C<curl http://localhost:6300/notify> works.
=cut
use strict;
use warnings;
use autodie;
use Socket qw(:DEFAULT :crlf);
use IO::Socket::IP;
my $sock = IO::Socket::IP->new(
LocalHost => 'localhost',
PeerHost => 'localhost',
PeerPort => 6300,
Type => SOCK_STREAM,
)
or die "Cannot init socket - $@";
$sock->print("GET /notify$CRLF");
=head1 COPYRIGHT & LICENSE
Copyright 2015 by Shlomi Fish
This program is distributed under the MIT (X11) License:
L<http://www.opensource.org/licenses/mit-license.php>
Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.
=cut