xcat-core/perl-xCAT/xCAT/SLP.pm
2012-04-26 15:33:24 +00:00

444 lines
15 KiB
Perl

package xCAT::SLP;
use Carp;
use IO::Select;
use strict;
my $ip6support = eval {
require IO::Socket::INET6;
require Socket6;
1;
};
use Socket;
unless ($ip6support) {
require IO::Socket::INET;
}
#TODO: somehow get at system headers to get the value, put in linux's for now
use constant IPV6_MULTICAST_IF => 17;
use constant IP_MULTICAST_IF => 32;
my %xid_to_srvtype_map;
my $xid;
sub getmulticasthash {
my $hash=0;
my @nums = unpack("C*",shift);
foreach my $num (@nums) {
$hash *= 33;
$hash += $num;
$hash &= 0xffff;
}
$hash &= 0x3ff;
$hash |= 0x1000;
return sprintf("%04x",$hash);
}
sub dodiscover {
my %args = @_;
$xid = int(rand(16384))+1;
unless ($args{'socket'}) {
if ($ip6support) {
$args{'socket'} = IO::Socket::INET6->new(Proto => 'udp');
} else {
$args{'socket'} = IO::Socket::INET->new(Proto => 'udp');
}
#make an extra effort to request biggest receive buffer OS is willing to give us
if (-r "/proc/sys/net/core/rmem_max") { # we can detect the maximum allowed socket, read it.
my $sysctl;
open ($sysctl,"<","/proc/sys/net/core/rmem_max");
my $maxrcvbuf=<$sysctl>;
my $rcvbuf = $args{'socket'}->sockopt(SO_RCVBUF);
if ($maxrcvbuf > $rcvbuf) {
$args{'socket'}->sockopt(SO_RCVBUF,$maxrcvbuf/2);
}
}
}
unless ($args{SrvTypes}) { croak "SrvTypes argument is required for xCAT::SLP::Dodiscover"; }
setsockopt($args{'socket'},SOL_SOCKET,SO_BROADCAST,1); #allow for broadcasts to be sent, we know what we are doing
my @srvtypes;
if (ref $args{SrvTypes}) {
@srvtypes = @{$args{SrvTypes}};
} else {
@srvtypes = split /,/,$args{SrvTypes};
}
my $interfaces = get_interfaces(%args);
if ($args{Ip}) {
my @ips = split /,/, $args{Ip};
foreach my $ip (@ips) {
foreach my $nic (keys %$interfaces) {
unless (${${$interfaces->{$nic}}{ipv4addrs}}[0] =~ $ip) {
delete $interfaces->{$nic};
}
}
}
}
foreach my $srvtype (@srvtypes) {
send_service_request_single(%args,ifacemap=>$interfaces,SrvType=>$srvtype);
}
unless ($args{NoWait}) { #in nowait, caller owns the responsibility..
#by default, report all respondants within 3 seconds:
my %rethash;
my $waitforsocket = IO::Select->new();
$waitforsocket->add($args{'socket'});
my $retrytime = ($args{Retry}>0)?$args{Retry}+1:1;
for(my $i = 0; $i < $retrytime; $i++){
my $deadline=time()+3;
while ($deadline > time()) {
while ($waitforsocket->can_read(1)) {
my $slppacket;
my $peer = $args{'socket'}->recv($slppacket,1400);
my( $port,$flow,$ip6n,$ip4n,$scope);
my $peername;
if ($ip6support) {
( $port,$flow,$ip6n,$scope) = Socket6::unpack_sockaddr_in6_all($peer);
$peername = Socket6::inet_ntop(Socket6::AF_INET6(),$ip6n);
} else {
($port,$ip4n) = sockaddr_in($peer);
$peername = inet_ntoa($ip4n);
}
if ($rethash{$peername}) {
next; #got a dupe, discard
}
my $result = process_slp_packet(packet=>$slppacket,sockaddr=>$peer,'socket'=>$args{'socket'});
if ($result) {
if ($peername =~ /\./) { #ipv4
$peername =~ s/::ffff://;
}
$result->{peername} = $peername;
$result->{scopeid} = $scope;
$result->{sockaddr} = $peer;
my $hashkey;
if ($peername =~ /fe80/) {
$peername .= '%'.$scope;
}
$rethash{$peername} = $result;
if ($args{Callback}) {
$args{Callback}->($result);
}
}
}
foreach my $srvtype (@srvtypes) {
send_service_request_single(%args,ifacemap=>$interfaces,SrvType=>$srvtype);
}
}
}
return \%rethash;
}
}
sub process_slp_packet {
my %args = @_;
my $sockaddy = $args{sockaddr};
my $socket = $args{'socket'};
my $packet = $args{packet};
my $parsedpacket = removeslpheader($packet);
if ($parsedpacket->{FunctionId} == 2) {#Service Reply
parse_service_reply($parsedpacket->{payload},$parsedpacket);
unless (ref $parsedpacket->{service_urls} and scalar @{$parsedpacket->{service_urls}}) { return undef; }
#send_attribute_request('socket'=>$socket,url=>$parsedpacket->{service_urls}->[0],sockaddr=>$sockaddy);
if ($parsedpacket->{attributes}) { #service reply had ext
return $parsedpacket; #don't bother sending attrrequest, already got it in first packet
}
my $srvtype = $xid_to_srvtype_map{$parsedpacket->{Xid}};
my $packet = generate_attribute_request(%args,SrvType=>$srvtype);
$socket->send($packet,0,$sockaddy);
return undef;
} elsif ($parsedpacket->{FunctionId} == 7) { #attribute reply
$parsedpacket->{SrvType} = $xid_to_srvtype_map{$parsedpacket->{Xid}};
$parsedpacket->{attributes} = parse_attribute_reply($parsedpacket->{payload});
delete $parsedpacket->{payload};
return $parsedpacket;
} else {
return undef;
}
}
sub parse_attribute_reply {
my $contents = shift;
my @payload = unpack("C*",$contents);
if ($payload[0] != 0 or $payload[1] != 0) {
return {};
}
splice (@payload,0,2);
return parse_attribute_list(\@payload);
}
sub parse_attribute_list {
my $payload = shift;
my $attrlength = ($payload->[0]<<8)+$payload->[1];
splice(@$payload,0,2);
my @attributes = splice(@$payload,0,$attrlength);
my $attrstring = pack("C*",@attributes);
my %attribs;
#now we have a string...
my $lastattrstring;
while ($attrstring) {
if ($lastattrstring eq $attrstring) { #infinite loop
$attribs{unparsed_attribdata}=$attrstring;
last;
}
$lastattrstring=$attrstring;
if ($attrstring =~ /^\(/) {
$attrstring =~ s/([^)]*\)),?//;
my $attrib = $1;
$attrib =~ s/^\(//;
$attrib =~ s/\),?$//;
$attrib =~ s/=(.*)$//;
$attribs{$attrib}=[];
my $valstring = $1;
if (defined $valstring) {
foreach(split /,/,$valstring) {
push @{$attribs{$attrib}},$_;
}
}
} else {
$attrstring =~ s/([^,]*),?//;
$attribs{$1}=[];
}
}
return \%attribs;
}
sub generate_attribute_request {
my %args = @_;
my $srvtype = $args{SrvType};
my $scope = "DEFAULT";
if ($args{Scopes}) { $scope = $args{Scopes}; }
my $packet = pack("C*",0,0); #no prlist
my $service = $srvtype;
$service =~ s!://.*!!;
my $length = length($service);
$packet .= pack("C*",($length>>8),($length&0xff));
$length = length($scope);
$packet .= $service.pack("C*",($length>>8),($length&0xff)).$scope;
$packet .= pack("C*",0,0,0,0);
my $header = genslpheader($packet,FunctionId=>6);
$xid_to_srvtype_map{$xid++}=$srvtype;
return $header.$packet;
# $args{'socket'}->send($header.$packet,0,$args{sockaddry});
}
sub parse_service_reply {
my $packet = shift;
my $parsedpacket = shift;
my @reply = unpack("C*",$packet);
if ($reply[0] != 0 or $reply[1] != 0) {
return ();
}
if ($parsedpacket->{extoffset}) {
my @extdata = splice(@reply,$parsedpacket->{extoffset}-$parsedpacket->{currentoffset});
$parsedpacket->{currentoffset} = $parsedpacket->{extoffset};
parse_extension(\@extdata,$parsedpacket);
}
my $numurls = ($reply[2]<<8)+$reply[3];
splice (@reply,0,4);
while ($numurls--) {
push @{$parsedpacket->{service_urls}},extract_next_url(\@reply);
}
return;
}
sub parse_extension {
my $extdata = shift;
my $parsedpacket = shift;
my $extid = ($extdata->[0]<<8)+$extdata->[1];
my $nextext = (($extdata->[2])<<16)+(($extdata->[3])<<8)+$extdata->[4];
if ($nextext) {
my @nextext = splice(@$extdata,$nextext-$parsedpacket->{currentoffset});
$parsedpacket->{currentoffset} = $nextext;
parse_extension(\@nextext,$parsedpacket);
}
splice(@$extdata,0,5);
if ($extid == 2) {
#this is defined in RFC 3059, attribute list extension
#employed by AMM for one...
my $urllen = ((shift @$extdata)<<8)+(shift @$extdata);
splice @$extdata,0,$urllen; #throw this out for now..
$parsedpacket->{attributes} = parse_attribute_list($extdata);
}
}
sub extract_next_url { #section 4.3 url entries
my $payload = shift;
splice (@$payload,0,3); # discard reserved and lifetime which we will not bother using
my $urllength = ((shift @$payload)<<8)+(shift @$payload);
my @url = splice(@$payload,0,$urllength);
my $authblocks = shift @$payload;
unless ($authblocks == 0) {
$payload = []; #TODO: skip/use auth blocks if needed to get at more URLs
}
return pack("C*",@url);
}
sub send_service_request_single {
my %args = @_;
my $packet = generate_service_request(%args);
my $interfaces = $args{ifacemap}; #get_interfaces(%args);
my $socket = $args{'socket'};
my $v6addr;
if ($ip6support) {
my $hash=getmulticasthash($args{SrvType});
my $target = "ff02::1:$hash";
my ($fam, $type, $proto, $name);
($fam, $type, $proto, $v6addr, $name) =
Socket6::getaddrinfo($target,"svrloc",Socket6::AF_INET6(),SOCK_DGRAM,0);
}
my $ipv4mcastaddr = inet_aton("239.255.255.253"); #per rfc 2608
my $ipv4sockaddr = sockaddr_in(427,$ipv4mcastaddr);
foreach my $iface (keys %{$interfaces}) {
if ($ip6support) {
setsockopt($socket,Socket6::IPPROTO_IPV6(),IPV6_MULTICAST_IF,pack("I",$interfaces->{$iface}->{scopeidx}));
$socket->send($packet,0,$v6addr);
}
foreach my $sip (@{$interfaces->{$iface}->{ipv4addrs}}) {
my $ip = $sip;
$ip =~ s/\/(.*)//;
my $maskbits = $1;
my $ipn = inet_aton($ip); #we are ipv4 only, this is ok
my $ipnum=unpack("N",$ipn);
$ipnum= $ipnum | (2**(32-$maskbits))-1;
my $bcastn = pack("N",$ipnum);
my $bcastaddr = sockaddr_in(427,$bcastn);
setsockopt($socket,0,IP_MULTICAST_IF,$ipn);
$socket->send($packet,0,$ipv4sockaddr);
$socket->send($packet,0,$bcastaddr);
}
}
}
sub get_interfaces {
#TODO: AIX tolerance, no subprocess, include/exclude interface(s)
my @ipoutput = `ip addr`;
my %ifacemap;
my $payingattention=0;
my $interface;
my $keepcurrentiface;
foreach my $line (@ipoutput) {
if ($line =~ /^\d/) { # new interface, new context..
if ($interface and not $keepcurrentiface) {
#don't bother reporting unusable nics
delete $ifacemap{$interface};
}
$keepcurrentiface=0;
unless ($line =~ /MULTICAST/) { #don't care if it isn't multicast capable
$payingattention=0;
next;
}
$payingattention=1;
$line =~ /^([^:]*): ([^:]*):/;
$interface=$2;
$ifacemap{$interface}->{scopeidx}=$1;
}
unless ($payingattention) { next; } #don't think about lines unless in context of paying attention.
if ($line =~ /inet/) {
$keepcurrentiface=1;
}
if ($line =~ /\s+inet\s+(\S+)\s/) { #got an ipv4 address, store it
push @{$ifacemap{$interface}->{ipv4addrs}},$1;
}
}
return \%ifacemap;
}
# 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 generate_service_request {
my %args = @_;
my $srvtype = $args{SrvType};
my $scope = "DEFAULT";
if ($args{Scopes}) { $scope = $args{Scopes}; }
my $prlist="";
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 $length = length($srvtype);
$packet .= pack("C*",($length>>8),($length&0xff));
$packet .= $srvtype;
$length = length($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);
$packet .= pack("C*",0,2,0,0,0,0,0,0,0,0);
my $extoffset = length($srvtype)+length($scope)+length($prlist)+10;
my $header = genslpheader($packet,Multicast=>1,FunctionId=>1,ExtOffset=>$extoffset);
$xid_to_srvtype_map{$xid++}=$srvtype;
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 removeslpheader {
my $packet = shift;
my %parsedheader;
my @payload = unpack("C*",$packet);
$parsedheader{Version} = shift @payload;
$parsedheader{FunctionId} = shift @payload;
splice(@payload,0,3); #remove length
splice(@payload,0,2); #TODO: parse flags
my $nextoffset = ((shift @payload)<<16)+((shift @payload)<<8)+(shift @payload);
$parsedheader{Xid} = ((shift @payload)<<8)+(shift @payload);
my $langlen = ((shift @payload)<<8)+(shift @payload);
$parsedheader{lang} = pack("C*",splice(@payload,0,$langlen));
$parsedheader{payload} = pack("C*",@payload);
if ($nextoffset != 0) {
#correct offset since header will be removed
$parsedheader{currentoffset} = 14+$langlen;
$parsedheader{extoffset}=$nextoffset;
}
return \%parsedheader;
}
sub genslpheader {
my $packet = shift;
my %args = @_;
my $flaghigh=0;
my $flaglow=0; #this will probably never ever ever change
if ($args{Multicast}) { $flaghigh |= 0x20; }
my $extoffset=0;
if ($args{ExtOffset}) {
$extoffset = $args{ExtOffset}+16;
}
my @extoffset=(($extoffset>>16),(($extoffset>>8)&0xff),($extoffset&0xff));
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, $flaglow,@extoffset,$xid>>8,$xid&0xff,0,2)."en";
}
unless (caller) {
#time to provide unit testing/example usage
#somewhat fancy invocation with multiple services and callback for
#results on-the-fly
require Data::Dumper;
Data::Dumper->import();
my $srvtypes = ["service:management-hardware.IBM:chassis-management-module","service:management-hardware.IBM:integrated-management-module2","service:management-hardware.IBM:management-module","service:management-hardware.IBM:cec-service-processor"];
xCAT::SLP::dodiscover(SrvTypes=>$srvtypes,Callback=>sub { print Dumper(@_) });
#example 2: simple invocation of a single service type
$srvtypes = "service:management-hardware.IBM:chassis-management-module";
print Dumper(xCAT::SLP::dodiscover(SrvTypes=>$srvtypes));
#TODO: pass-in socket and not wait inside SLP.pm example
}
1;