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Adding query source IP bindhost config params #4

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Adding query source IP bindhost config params #4

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98 changes: 74 additions & 24 deletions lib/resolv.rb
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Original file line number Diff line number Diff line change
Expand Up @@ -285,6 +285,16 @@ class DNS

UDPSize = 512

##
# Default source address for IPv4 queries

BindHost = '0.0.0.0'

##
# Default source address for IPv6 queries

BindHost6 = '::'

##
# Creates a new DNS resolver. See Resolv::DNS.new for argument details.
#
Expand All @@ -310,6 +320,8 @@ def self.open(*args)
# String:: Path to a file using /etc/resolv.conf's format.
# Hash:: Must contain :nameserver, :search and :ndots keys.
# :nameserver_port can be used to specify port number of nameserver address.
# :bindhost may specify a query IPv4 source address.
# :bindhost6 may specify a query IPv6 source address.
#
# The value of :nameserver should be an address string or
# an array of address strings.
Expand All @@ -320,11 +332,21 @@ def self.open(*args)
# pair of nameserver address and port number.
# - :nameserver_port => [['8.8.8.8', 53], ['8.8.4.4', 53]]
#
# Example:
# If included, :bindhost specifies an IPv4 address from which IPv4
# queries will originate. If :bindhost6 is included, IPv6 queries
# will originate from that address.
#
# Examples:
#
# Resolv::DNS.new(:nameserver => ['210.251.121.21'],
# :search => ['ruby-lang.org'],
# :ndots => 1)
# :ndots => 1,
# :bindhost => '192.0.2.50')
#
# Resolv::DNS.new(:nameserver => ['001:4860:4860::8888'],
# :search => ['ruby-lang.org'],
# :ndots => 1,
# :bindhost6 => '2001:DB8::53')

def initialize(config_info=nil)
@mutex = Thread::Mutex.new
Expand Down Expand Up @@ -559,14 +581,14 @@ def fetch_resource(name, typeclass)
def make_udp_requester # :nodoc:
nameserver_port = @config.nameserver_port
if nameserver_port.length == 1
Requester::ConnectedUDP.new(*nameserver_port[0])
Requester::ConnectedUDP.new(@config.bindhost, @config.bindhost6, *nameserver_port[0])
else
Requester::UnconnectedUDP.new(*nameserver_port)
Requester::UnconnectedUDP.new(@config.bindhost, @config.bindhost6, *nameserver_port)
end
end

def make_tcp_requester(host, port) # :nodoc:
return Requester::TCP.new(host, port)
return Requester::TCP.new(@config.bindhost, @config.bindhost6, host, port)
end

def extract_resources(msg, name, typeclass) # :nodoc:
Expand Down Expand Up @@ -617,10 +639,10 @@ def self.random(arg) # :nodoc:
RequestID = {} # :nodoc:
RequestIDMutex = Thread::Mutex.new # :nodoc:

def self.allocate_request_id(host, port) # :nodoc:
def self.allocate_request_id(host, port, bind_host) # :nodoc:
id = nil
RequestIDMutex.synchronize {
h = (RequestID[[host, port]] ||= {})
h = (RequestID[[host, port, bind_host]] ||= {})
begin
id = random(0x0000..0xffff)
end while h[id]
Expand All @@ -641,7 +663,7 @@ def self.free_request_id(host, port, id) # :nodoc:
}
end

def self.bind_random_port(udpsock, bind_host="0.0.0.0") # :nodoc:
def self.bind_random_port(udpsock, bind_host) # :nodoc:
begin
port = random(1024..65535)
udpsock.bind(bind_host, port)
Expand Down Expand Up @@ -724,8 +746,10 @@ def initialize(msg, data, sock)
end

class UnconnectedUDP < Requester # :nodoc:
def initialize(*nameserver_port)
def initialize(bindhost, bindhost6, *nameserver_port)
super()
@bindhost = bindhost
@bindhost6 = bindhost6
@nameserver_port = nameserver_port
@initialized = false
@mutex = Thread::Mutex.new
Expand All @@ -739,10 +763,10 @@ def lazy_initialize
@socks = []
@nameserver_port.each {|host, port|
if host.index(':')
bind_host = "::"
bind_host = @bindhost6
af = Socket::AF_INET6
else
bind_host = "0.0.0.0"
bind_host = @bindhost
af = Socket::AF_INET
end
next if @socks_hash[bind_host]
Expand All @@ -767,12 +791,13 @@ def recv_reply(readable_socks)
end

def sender(msg, data, host, port=Port)
bind_host = host.index(':') ? @bindhost6 : @bindhost
host = Addrinfo.ip(host).ip_address
lazy_initialize
sock = @socks_hash[host.index(':') ? "::" : "0.0.0.0"]
sock = @socks_hash[bind_host]
return nil if !sock
service = [host, port]
id = DNS.allocate_request_id(host, port)
id = DNS.allocate_request_id(host, port, bind_host)
request = msg.encode
request[0,2] = [id].pack('n')
return @senders[[service, id]] =
Expand Down Expand Up @@ -807,10 +832,12 @@ def send
end

class ConnectedUDP < Requester # :nodoc:
def initialize(host, port=Port)
def initialize(bindhost, bindhost6, host, port=Port)
super()
@host = host
@port = port
@bindhost = bindhost
@bindhost6 = bindhost6
@mutex = Thread::Mutex.new
@initialized = false
end
Expand All @@ -823,7 +850,7 @@ def lazy_initialize
sock = UDPSocket.new(is_ipv6 ? Socket::AF_INET6 : Socket::AF_INET)
@socks = [sock]
sock.do_not_reverse_lookup = true
DNS.bind_random_port(sock, is_ipv6 ? "::" : "0.0.0.0")
DNS.bind_random_port(sock, is_ipv6 ? @bindhost6 : @bindhost)
sock.connect(@host, @port)
}
self
Expand All @@ -835,12 +862,12 @@ def recv_reply(readable_socks)
return reply, nil
end

def sender(msg, data, host=@host, port=@port)
def sender(msg, data, host=@host, port=@port, bind_host=@bind_host)
lazy_initialize
unless host == @host && port == @port
raise RequestError.new("host/port don't match: #{host}:#{port}")
unless host == @host && port == @port && @bind_host == bind_host
raise RequestError.new("bind_host host:port don't match: #{bind_host} #{host}:#{port}")
end
id = DNS.allocate_request_id(@host, @port)
id = DNS.allocate_request_id(@host, @port, @bind_host)
request = msg.encode
request[0,2] = [id].pack('n')
return @senders[[nil,id]] = Sender.new(request, data, @socks[0])
Expand Down Expand Up @@ -869,11 +896,12 @@ def send

class MDNSOneShot < UnconnectedUDP # :nodoc:
def sender(msg, data, host, port=Port)
bind_host = host.index(':') ? @bindhost6 : @bindhost
lazy_initialize
id = DNS.allocate_request_id(host, port)
id = DNS.allocate_request_id(host, port, bind_host)
request = msg.encode
request[0,2] = [id].pack('n')
sock = @socks_hash[host.index(':') ? "::" : "0.0.0.0"]
sock = @socks_hash[bind_host]
return @senders[id] =
UnconnectedUDP::Sender.new(request, data, sock, host, port)
end
Expand All @@ -885,11 +913,13 @@ def sender_for(addr, msg)
end

class TCP < Requester # :nodoc:
def initialize(host, port=Port)
def initialize(bindhost, bindhost6, host, port=Port)
super()
@host = host
@port = port
sock = TCPSocket.new(@host, @port)
@bindhost = bindhost
@bindhost6 = bindhost6
sock = TCPSocket.new(@host, @port, @host.index(':') ? @bindhost6 : @bindhost)
@socks = [sock]
@senders = {}
end
Expand All @@ -904,7 +934,7 @@ def sender(msg, data, host=@host, port=@port)
unless host == @host && port == @port
raise RequestError.new("host/port don't match: #{host}:#{port}")
end
id = DNS.allocate_request_id(@host, @port)
id = DNS.allocate_request_id(@host, @port, @host.index(':') ? @bindhost6 : @bindhost)
request = msg.encode
request[0,2] = [request.length, id].pack('nn')
return @senders[[nil,id]] = Sender.new(request, data, @socks[0])
Expand Down Expand Up @@ -1006,6 +1036,8 @@ def lazy_initialize
@nameserver_port = []
@search = nil
@ndots = 1
@bindhost = nil
@bindhost6 = nil
case @config_info
when nil
config_hash = Config.default_config_hash
Expand All @@ -1030,6 +1062,8 @@ def lazy_initialize
end
@search = config_hash[:search] if config_hash.include? :search
@ndots = config_hash[:ndots] if config_hash.include? :ndots
@bindhost = config_hash[:bindhost] if config_hash.include? :bindhost
@bindhost6 = config_hash[:bindhost6] if config_hash.include? :bindhost6

if @nameserver_port.empty?
@nameserver_port << ['0.0.0.0', Port]
Expand All @@ -1055,6 +1089,14 @@ def lazy_initialize
raise ArgumentError.new("invalid nameserver config: #{@nameserver_port.inspect}")
end

if [email protected]? && ([email protected]_a?(String) || !IPv4::Regex.match(@bindhost))
raise ArgumentError.new("invalid bindhost config: #{@bindhost.inspect}")
end

if [email protected]? && ([email protected]_a?(String) || !IPv6::Regex.match(@bindhost6))
raise ArgumentError.new("invalid bindhost6 config: #{@bindhost6.inspect}")
end

if [email protected]_of?(Array) ||
[email protected]? {|ls| ls.all? {|l| Label::Str === l } }
raise ArgumentError.new("invalid search config: #{@search.inspect}")
Expand Down Expand Up @@ -1083,6 +1125,14 @@ def nameserver_port
@nameserver_port
end

def bindhost
@bindhost.nil? ? BindHost : @bindhost
end

def bindhost6
@bindhost6.nil? ? BindHost6 : @bindhost6
end

def generate_candidates(name)
candidates = nil
name = Name.create(name)
Expand Down