Files
netlinkrb/lib/linux/netlink/route/route_handler.rb
2012-07-05 14:54:42 +01:00

202 lines
6.9 KiB
Ruby

require 'linux/netlink/route'
require 'linux/netlink/route/handler'
module Linux
module Netlink
# struct rta_cacheinfo
RTACacheInfo = Struct.new :clntref, :lastuse, :expires, :error, :used, :id, :ts, :tsage
# struct rtmsg
class RT < RtattrMessage
code RTM_NEWROUTE, RTM_DELROUTE, RTM_GETROUTE,
RTM_NEWRULE, RTM_DELRULE, RTM_GETRULE
field :family, :uchar # Socket::AF_*
field :dst_len, :uchar
field :src_len, :uchar
field :tos, :uchar
field :table, :uchar # table id or RT_TABLE_*
field :protocol, :uchar # RTPROT_*
field :scope, :uchar # RT_SCOPE_*
field :type, :uchar # RTN_*
field :flags, :uint # RTM_F_*
rtattr :dst, RTA_DST, :l3addr
rtattr :src, RTA_SRC, :l3addr
rtattr :iif, RTA_IIF, :uint32
rtattr :oif, RTA_OIF, :uint32
rtattr :gateway, RTA_GATEWAY, :l3addr
rtattr :priority, RTA_PRIORITY, :uint32
rtattr :prefsrc, RTA_PREFSRC, :l3addr
rtattr :metrics, RTA_METRICS,
:unpack => lambda { |str,obj| RTAMetrics.parse(str) }
rtattr :multipath, RTA_MULTIPATH
rtattr :flow, RTA_FLOW
rtattr :cacheinfo, RTA_CACHEINFO,
:pack => lambda { |val,obj| val.to_a.pack("L*") },
:unpack => lambda { |str,obj| RTACacheInfo.new(*(str.unpack("L*"))) }
rtattr :table2, RTA_TABLE, :uint32 # NOTE: table in two places!
end
class RTAMetrics < RtattrMessage
rtattr :lock, RTAX_LOCK, :uint32
rtattr :mtu, RTAX_MTU, :uint32
rtattr :window, RTAX_WINDOW, :uint32
rtattr :rtt, RTAX_RTT, :uint32
rtattr :rttvar, RTAX_RTTVAR, :uint32
rtattr :ssthresh, RTAX_SSTHRESH, :uint32
rtattr :cwnd, RTAX_CWND, :uint32
rtattr :advmss, RTAX_ADVMSS, :uint32
rtattr :reordering, RTAX_REORDERING, :uint32
rtattr :hoplimit, RTAX_HOPLIMIT, :uint32
rtattr :initcwnd, RTAX_INITCWND, :uint32
rtattr :features, RTAX_FEATURES, :uint32
rtattr :rto_min, RTAX_RTO_MIN, :uint32
rtattr :initrwnd, RTAX_INITRWND, :uint32
end
module Route
# This class manipulates the kernel routing table
class RouteHandler < Handler
def clear_cache
@route = nil
end
# Send message to download the kernel routing table. Either returns an
# array of Netlink::RT objects, or yields them to the supplied block.
#
# A hash of kernel options may be supplied, but you might also have
# to perform your own filtering. e.g.
# read_route(:family=>Socket::AF_INET) # works
# read_route(:protocol=>Linux::RTPROT_STATIC) # ignored
#
# res = ip.route.read_route(:family => Socket::AF_INET)
# p res
# [#<Linux::Netlink::RT {:family=>2, :dst_len=>32, :src_len=>0, :tos=>0,
# :table=>255, :protocol=>2, :scope=>253, :type=>3, :flags=>0, :table2=>255,
# :dst=>#<IPAddr: IPv4:127.255.255.255/255.255.255.255>,
# :prefsrc=>#<IPAddr: IPv4:127.0.0.1/255.255.255.255>, :oif=>1}>, ...]
#
# Note that not all attributes will always be present. In particular,
# a defaultroute (dst_len=0) misses out the dst address completely:
#
# [#<Linux::Netlink::RT {:family=>2, :dst_len=>0, :src_len=>0, :tos=>0,
# :table=>254, :protocol=>4, :scope=>0, :type=>1, :flags=>0, :table2=>254,
# :gateway=>#<IPAddr: IPv4:10.69.255.253/255.255.255.255>, :oif=>2}>, ...]
def read_route(opt=nil, &blk)
@rtsocket.send_request RTM_GETROUTE, RT.new(opt),
NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST
@rtsocket.receive_until_done(RTM_NEWROUTE, &blk)
end
class Filter < BaseFilter #:nodoc:
filter(:family) { |o,v| o.family == v }
filter(:table) { |o,v| o.table == v }
filter(:protocol) { |o,v| o.protocol == v }
filter(:type) { |o,v| o.type == v }
filter(:scope) { |o,v| o.scope == v }
filter(:flags) { |o,v| (o.flags & v) == v }
filter(:noflags) { |o,v| (o.flags & v) == 0 }
filter(:oif) { |o,v| o.oif == v }
filter(:iif) { |o,v| o.iif == v }
end
# Return the memoized route table, filtered according to
# the optional criteria. Examples:
# :family => Socket::AF_INET
# :table => Linux::RT_TABLE_DEFAULT
# :protocol => Linux::RTPROT_STATIC
# :type => Linux::RTN_UNICAST
# :scope => Linux::RT_SCOPE_HOST
# :flags => Linux::RTM_F_NOTIFY
# :noflags => Linux::RTM_F_CLONED
# :oif => "eth0"
# :iif => "eth1"
def list(filter=nil, &blk)
@route ||= read_route
filter[:oif] = index(filter[:oif]) if filter && filter.has_key?(:oif)
filter[:iif] = index(filter[:iif]) if filter && filter.has_key?(:iif)
filter_list(@route, filter, &blk)
end
alias :each :list
def add(opt)
iproute_modify(RTM_NEWROUTE, NLM_F_CREATE|NLM_F_EXCL, opt)
end
def change(opt)
iproute_modify(RTM_NEWROUTE, NLM_F_REPLACE, opt)
end
def replace(opt)
iproute_modify(RTM_NEWROUTE, NLM_F_CREATE|NLM_F_REPLACE, opt)
end
def prepend(opt)
iproute_modify(RTM_NEWROUTE, NLM_F_CREATE, opt)
end
def append(opt)
iproute_modify(RTM_NEWROUTE, NLM_F_CREATE|NLM_F_APPEND, opt)
end
def test(opt)
iproute_modify(RTM_NEWROUTE, NLM_F_EXCL, opt)
end
def delete(opt)
iproute_modify(RTM_DELROUTE, 0, opt)
end
# Get route matching given criteria
def get(msg)
msg = RT.new(msg)
raise "Missing :dst" unless msg.dst
msg.iif = index(msg.iif) if msg.iif.is_a?(String)
msg.oif = index(msg.oif) if msg.oif.is_a?(String)
@rtsocket.cmd RTM_GETROUTE, msg, NLM_F_REQUEST, RTM_NEWROUTE
end
def iproute_modify(code, flags, msg) #:nodoc:
msg = RT.new(msg)
if code != RTM_DELROUTE
msg.protocol ||= RTPROT_BOOT
msg.type ||= RTN_UNICAST
end
# There is scary code in ip/iproute.c for setting defaults
unless msg.table
msg.table = case msg.type
when RTN_LOCAL, RTN_BROADCAST, RTN_NAT, RTN_ANYCAST
RT_TABLE_LOCAL
else
RT_TABLE_MAIN
end
end
unless msg.scope
msg.scope = (code != RTM_DELROUTE) ? RT_SCOPE_UNIVERSE : RT_SCOPE_NOWHERE
case msg.type
when RTN_LOCAL, RTN_NAT
msg.scope = RT_SCOPE_HOST
when RTN_BROADCAST, RTN_MULTICAST, RTN_ANYCAST
msg.scope RT_SCOPE_LINK
when RTN_UNICAST, RTN_UNSPEC
if code == RTM_DELROUTE
msg.scope = RT_SCOPE_NOWHERE
elsif !msg.gateway && !msg.multipath
msg.scope = RT_SCOPE_LINK
end
end
end
msg.iif = index(msg.iif) if msg.iif.is_a?(String)
msg.oif = index(msg.oif) if msg.oif.is_a?(String)
@rtsocket.cmd code, msg, flags|NLM_F_REQUEST
clear_cache
end
end
end
end
end # module Linux