Add SLP.pm to perl-xCAT. Currently selectively does IPv6 SLP

TODO includes IPv4 SLP and reworked multi-srvtype support since RFC indicated behavior doesn't work (divide multiple srvtypes into separate packets to workaround)

git-svn-id: https://svn.code.sf.net/p/xcat/code/xcat-core/trunk@11884 8638fb3e-16cb-4fca-ae20-7b5d299a9bcd
This commit is contained in:
jbjohnso 2012-03-17 19:59:46 +00:00
parent 85a3468e0f
commit 2152035a14

150
perl-xCAT/xCAT/SLP.pm Normal file
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@ -0,0 +1,150 @@
package xCAT::SLP;
use strict;
my $ip6support = eval {
require IO::Socket::INET6;
require Socket6;
1;
};
use Socket;
unless ($ip6support) {
require IO::Socket::INET;
}
my $defaultsrvtypes = "service:management-hardware.IBM";
#TODO: somehow get at system headers to get the value, put in linux's for now
use constant IPV6_MULTICAST_IF => 17;
sub getmulticasthashes {
my %args = @_;
my $srvtypes;
if ($args{SrvTypes}) {
$srvtypes = $args{SrvTypes};
} else {
$srvtypes = $defaultsrvtypes;
}
my @types = split /,/,$srvtypes;
my @hashes;
foreach (@types) {
my $hash=0;
my @nums = unpack("C*",$_);
foreach my $num (@nums) {
$hash *= 33;
$hash += $num;
$hash &= 0xffff;
}
$hash &= 0x3ff;
$hash |= 0x1000;
push @hashes,sprintf("%04x",$hash);
}
return @hashes;
}
sub dodiscover {
my %args = @_;
my $packet = gendiscover(%args);
my @interfaces = get_interfaces(%args);
my $socket;
if ($args{'socket'}) {
$socket = $args{'socket'};
} elsif ($ip6support) {
$socket = IO::Socket::INET6->new(Proto => 'udp');
} else {
die "TODO: SLP without ipv6";
}
my @v6addrs;
if ($ip6support) {
foreach my $hash (getmulticasthashes(%args)) {
my $target = "ff02::1:$hash";
my ($fam, $type, $proto, $addr, $name) =
Socket6::getaddrinfo($target,"svrloc",Socket6::AF_INET6(),SOCK_DGRAM,0);
push @v6addrs,$addr;
}
}
foreach my $iface (@interfaces) {
if ($ip6support) {
setsockopt($socket,Socket6::IPPROTO_IPV6(),IPV6_MULTICAST_IF,pack("I",$iface));
foreach my $v6addr (@v6addrs) {
$socket->send($packet,0,$v6addr);
}
}
#TODO: IPv4 support
# setsockopt($socket,IPPROTO_IP,IP_MULTICAST_IF,
}
}
sub get_interfaces {
#TODO: AIX tolerance, no subprocess, include/exclude interface(s)
my @ipoutput = `ip link`;
my @ifaceoutput = grep(/MULTICAST/,@ipoutput);
my @interfaces;
foreach (@ifaceoutput) {
chomp;
s/:.*//;
push @interfaces,$_;
}
return @interfaces;
}
# discovery is "service request", rfc 2608
# 0 1 2 3
# 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
# +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
# | Service Location header (function = SrvRqst = 1) |
# +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
# | length of <PRList> | <PRList> String \
# +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
# | length of <service-type> | <service-type> String \
# +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
# | length of <scope-list> | <scope-list> String \
# +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
# | length of predicate string | Service Request <predicate> \
# +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
# | length of <SLP SPI> string | <SLP SPI> String \
# +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
sub gendiscover {
my %args = @_;
my $srvtypes;
if ($args{SrvTypes}) {
$srvtypes = $args{SrvTypes};
} else {
$srvtypes = $defaultsrvtypes;
}
my $scope = "DEFAULT";
if ($args{Scopes}) { $scope = $args{Scopes}; }
my $packet = pack("C*",0,0); #start with PRList, we have no prlist so zero
#TODO: actually accumulate PRList, particularly between IPv4 and IPv6 runs
my $length = length($srvtypes);
$packet .= pack("C*",($length>>8),($length&0xff));
$packet .= $srvtypes;
$length = length($scope);
$packet .= pack("C*",($length>>8),($length&0xff));
$packet .= $scope;
#no ldap predicates, and no auth, so zeroes..
$packet .= pack("C*",0,0,0,0);
my $header = genslpheader($packet,Multicast=>1,FunctionId=>1);
return $packet = $header.$packet;
}
# SLP header from RFC 2608
# 0 1 2 3
# 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
# +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
# | Version | Function-ID | Length |
# +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
# | Length, contd.|O|F|R| reserved |Next Ext Offset|
# +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
# | Next Extension Offset, contd.| XID |
# +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
# | Language Tag Length | Language Tag \
# +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
sub genslpheader {
my $packet = shift;
my %args = @_;
my $xid = rand(65535);
my $flaghigh=0;
my $flaglow=0; #this will probably never ever ever change
if ($args{Multicast}) { $flaghigh |= 0x20; }
my $length = length($packet)+16; #our header is 16 bytes due to lang tag invariance
if ($length > 1400) { die "Overflow not supported in xCAT SLP"; }
return pack("C*",2, $args{FunctionId}, ($length >> 16), ($length >> 8)&0xff, $length&0xff, $flaghigh, $flaglow,0,0,0,$xid>>8,$xid&0xff,0,2)."en";
}