1 # -*- encoding: binary -*-
3 # For reporting TCP ListenStats, users of older \Linux kernels need to ensure
4 # that the the "inet_diag" and "tcp_diag" kernel modules are loaded as they do
5 # not autoload correctly. The inet_diag facilities of \Raindrops is useful
6 # for periodic snapshot reporting of listen queue sizes.
8 # Instead of snapshotting, Raindrops::Aggregate::LastDataRecv may be used
9 # to aggregate statistics from +all+ accepted sockets as they arrive
10 # based on the +last_data_recv+ field in Raindrops::TCP_Info
13 module Raindrops::Linux
15 # The standard proc path for active UNIX domain sockets, feel free to call
16 # String#replace on this if your /proc is mounted in a non-standard location
18 PROC_NET_UNIX_ARGS = %w(/proc/net/unix)
19 defined?(::Encoding) and PROC_NET_UNIX_ARGS.push({ :encoding => "binary" })
21 # Get ListenStats from an array of +paths+
23 # Socket state mapping from integer => symbol, based on socket_state
24 # enum from include/linux/net.h in the \Linux kernel:
26 # SS_FREE = 0, /* not allocated */
27 # SS_UNCONNECTED, /* unconnected to any socket */
28 # SS_CONNECTING, /* in process of connecting */
29 # SS_CONNECTED, /* connected to socket */
30 # SS_DISCONNECTING /* in process of disconnecting */
32 # * SS_CONNECTING maps to ListenStats#queued
33 # * SS_CONNECTED maps to ListenStats#active
35 # This method may be significantly slower than its tcp_listener_stats
36 # counterpart due to the latter being able to use inet_diag via netlink.
37 # This parses /proc/net/unix as there is no other (known) way
38 # to expose Unix domain socket statistics over netlink.
39 def unix_listener_stats(paths = nil)
40 rv = Hash.new { |h,k| h[k.freeze] = Raindrops::ListenStats.new(0, 0) }
44 paths = paths.map do |path|
46 path = Pathname.new(path).realpath.to_s
47 path.force_encoding(Encoding::BINARY) if defined?(Encoding)
52 paths = /^\w+: \d+ \d+ 00000000 \d+ (\d+)\s+\d+ (#{paths.join('|')})$/n
54 # no point in pread since we can't stat for size on this file
55 File.read(*PROC_NET_UNIX_ARGS).scan(paths) do |s|
58 when 2 then rv[path].queued += 1
59 when 3 then rv[path].active += 1
65 module_function :unix_listener_stats
67 end # Raindrops::Linux