107 lines
3.8 KiB
Ruby
107 lines
3.8 KiB
Ruby
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require 'netlink/message'
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module Netlink
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# struct rta_cacheinfo
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RTACacheInfo = Struct.new :clntref, :lastuse, :expires, :error, :used, :id, :ts, :tsage
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# struct rtmsg
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class RT < RtattrMessage
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code RTM_NEWROUTE, RTM_DELROUTE, RTM_GETROUTE
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field :family, :uchar # Socket::AF_*
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field :dst_len, :uchar
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field :src_len, :uchar
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field :tos, :uchar
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field :table, :uchar # table id or RT_TABLE_*
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field :protocol, :uchar # RTPROT_*
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field :scope, :uchar # RT_SCOPE_*
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field :type, :uchar # RTN_*
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field :flags, :uint # RTM_F_*
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rtattr :dst, RTA_DST, :l3addr
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rtattr :src, RTA_SRC, :l3addr
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rtattr :iif, RTA_IIF, :uint32
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rtattr :oif, RTA_OIF, :uint32
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rtattr :gateway, RTA_GATEWAY, :l3addr
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rtattr :priority, RTA_PRIORITY, :uint32
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rtattr :prefsrc, RTA_PREFSRC, :l3addr
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# Route metrics are themselves packed using the rtattr format.
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# In the kernel, the dst.metrics structure is an array of u32.
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METRIC_PACK = "SSL".freeze #:nodoc:
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METRIC_SIZE = [0,0,0].pack(METRIC_PACK).bytesize #:nodoc:
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rtattr :metrics, RTA_METRICS, # {RTAX_* => Integer}
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:pack => lambda { |metrics,obj|
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metrics.map { |code,val| [METRIC_SIZE,code,val].pack(METRIC_PACK) }.join
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},
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:unpack => lambda { |str,obj|
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res = {}
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RtattrMessage.unpack_rtattr(str) { |code,val| res[code] = val.unpack("L").first }
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res
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}
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rtattr :multipath, RTA_MULTIPATH
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rtattr :flow, RTA_FLOW
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rtattr :cacheinfo, RTA_CACHEINFO,
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:pack => lambda { |val,obj| val.to_a.pack("L*") },
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:unpack => lambda { |str,obj| RTACacheInfo.new(*(str.unpack("L*"))) }
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rtattr :table2, RTA_TABLE, :uint32 # NOTE: table in two places!
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end
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module Route
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# This class manipulates the
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class RTHandler
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def initialize(nlsocket = Netlink::Route::Socket.new)
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@nlsocket = nlsocket
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clear_cache
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end
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# Send message to download the kernel routing table. Either returns an
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# array of Netlink::RT objects, or yields them to the supplied block.
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#
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# A hash of kernel options may be supplied, but you might also have
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# to perform your own filtering. e.g.
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# read_routes(:family=>Socket::AF_INET) # works
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# read_routes(:protocol=>Netlink::RTPROT_STATIC) # ignored
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#
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# res = nl.rt.read_routes(:family => Socket::AF_INET)
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# p res
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# [#<Netlink::RT {:family=>2, :dst_len=>32, :src_len=>0, :tos=>0,
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# :table=>255, :protocol=>2, :scope=>253, :type=>3, :flags=>0, :table2=>255,
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# :dst=>#<IPAddr: IPv4:127.255.255.255/255.255.255.255>,
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# :prefsrc=>#<IPAddr: IPv4:127.0.0.1/255.255.255.255>, :oif=>1}>, ...]
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#
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# Note that not all attributes will always be present. In particular,
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# a defaultroute (dst_len=0) misses out the dst address completely:
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#
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# [#<Netlink::RT {:family=>2, :dst_len=>0, :src_len=>0, :tos=>0,
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# :table=>254, :protocol=>4, :scope=>0, :type=>1, :flags=>0, :table2=>254,
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# :gateway=>#<IPAddr: IPv4:10.69.255.253/255.255.255.255>, :oif=>2}>, ...]
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def read_routes(opt=nil, &blk)
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@nlsocket.send_request RTM_GETROUTE, RT.new(opt),
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NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST
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@nlsocket.receive_until_done(RTM_NEWROUTE, &blk)
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end
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def clear_cache
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@all = nil
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end
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# Return the complete memoized route table
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def all
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@all ||= read_routes
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end
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# Iterate over the memoized route table
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def each(&blk)
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all.each(&blk)
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end
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# Return just the routes for the given address family
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#
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# nl = Netlink::Route::Socket.new
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# nl.rt[Socket::AF_INET].each { |r| p r }
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def [](family)
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all.select { |r| r.family == family }
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end
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end
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end
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end
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