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=head1 NAME |
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|
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Linux::NBD - interface to the linux network block device. |
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|
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=head1 SYNOPSIS |
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|
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# Kernel 2.4+ is required |
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use Linux::NBD; |
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|
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=head1 DESCRIPTION |
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|
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See L<Linux::NBD::Client> and L<Linux::NBD::Server>, or no, better idea: |
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use the source :) |
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|
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NOTICE: Only the Linux 2.4 and newer nbd device is supported by this |
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module. For older kernels you are on your own. |
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|
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=head1 FUNCTIONS |
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|
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=over 4 |
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|
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=cut |
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|
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package Linux::NBD; |
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|
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BEGIN { |
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$VERSION = '1.0'; |
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|
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require XSLoader; |
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XSLoader::load Linux::NBD, $VERSION; |
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} |
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|
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use Socket; |
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|
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=item ($a, $b) = tcp_socketpair; |
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|
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Creates a pair of interconnected tcp sockets, which is extremely ugly, so be |
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happy that this function exists. |
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|
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=cut |
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|
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sub tcp_socketpair { |
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open my $fh, "</dev/urandom" or die "/dev/urandom: $!"; |
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|
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# this works by creating a listening socket |
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# and connect to it, then exchange a 256 bit random cookie |
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# to authentify. |
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# the server is created first, and thus cannot be spoofed. i think. |
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while () { |
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socket my $a, PF_INET, SOCK_STREAM, 0 or die "tcp_socketpair/socket: $!"; |
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bind $a, sockaddr_in (0, inet_aton "127.0.0.1") or die "tcp_socketpair/bind $!"; |
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listen $a, 1 or die "tcp_socketpair/listen $!"; |
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socket my $b, PF_INET, SOCK_STREAM, 0 or die "tcp_socketpair/socket: $!"; |
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connect $b, getsockname $a or die "tcp_socketpair/connect: $!"; |
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accept $a, $a or die "tcp_socketpair/accept: $!"; |
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|
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sysread $fh, (my $rand), 32; |
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syswrite $b, $rand or die "tcp_socketpair/write_cookie: $!"; |
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sysread $a, (my $cookie), 32 or die "tcp_socketpair/read_cookie: $!"; |
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|
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return ($a, $b) if $rand eq $cookie; |
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} |
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} |
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|
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1; |
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|
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=back |
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|
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=head1 AUTHOR |
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|
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Marc Lehmann <schmorp@schmorp.de> |
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http://home.schmorp.de/ |
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|
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=cut |
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