Class: OverSIP::SIP::RFC3263::Query

Inherits:

Object

• Object
• OverSIP::SIP::RFC3263::Query

Includes:

Logger

Defined in:

lib/oversip/sip/rfc3263.rb

Class Method Summary

• .class_init ⇒ Object

Instance Method Summary

• #callback(&block) ⇒ Object
• #errback(&block) ⇒ Object
• #initialize(dns_conf, id, uri_scheme, uri_host, uri_host_type, uri_port = nil, uri_transport = nil) ⇒ Query constructor

  A new instance of Query.

• #resolve ⇒ Object

  This method can return: - Target: in case host is a IP.

Methods included from Logger

fg_system_msg2str, load_methods, #log_id

Constructor Details

#initialize(dns_conf, id, uri_scheme, uri_host, uri_host_type, uri_port = nil, uri_transport = nil) ⇒ Query

Returns a new instance of Query.

# File 'lib/oversip/sip/rfc3263.rb', line 121

def initialize dns_conf, id, uri_scheme, uri_host, uri_host_type, uri_port=nil, uri_transport=nil
  @id = id
  @uri_scheme = uri_scheme
  @uri_host = uri_host
  @uri_host_type = uri_host_type
  @uri_port = uri_port
  @uri_transport = uri_transport

  @log_id ||= ("RFC3263" << " " << @id)

  @use_dns = dns_conf[:use_dns]
  @transport_preference = dns_conf[:transport_preference]

  @has_sip_ipv4 = dns_conf[:has_sip_ipv4]
  @has_sip_ipv6 = dns_conf[:has_sip_ipv6]
  @has_sip_udp = dns_conf[:has_sip_udp]
  @has_sip_tcp = dns_conf[:has_sip_tcp]
  @has_sip_tls = dns_conf[:has_sip_tls]

  # Just initialize these attributes if URI host is a domain.
  if uri_host_type == :domain
    @ip_type_preference = dns_conf[:ip_type_preference]
    @force_transport_preference = dns_conf[:force_transport_preference]
    @use_naptr = dns_conf[:use_naptr]
    @use_srv = dns_conf[:use_srv]
  end
end

Class Method Details

.class_init ⇒ Object

# File 'lib/oversip/sip/rfc3263.rb', line 117

def self.class_init
  @@fiber_pool = ::OverSIP::FiberPool.new 50
end

Instance Method Details

#callback(&block) ⇒ Object

# File 'lib/oversip/sip/rfc3263.rb', line 149

def callback &block
  @on_success_block = block
end

#errback(&block) ⇒ Object

# File 'lib/oversip/sip/rfc3263.rb', line 153

def errback &block
  @on_error_block = block
end

#resolve ⇒ Object

This method can return:

• Target: in case host is a IP.

• SrvTargets: in case SRV took place. Then the client must use SrvTargets#randomize and get a SrvRandomizedTargets (an Array of Target entries).

• MultiTargets: so each element can be one of the above elements.

• nil: result will be retrieved via callback/errback.

• Symbol: there is some error (domain does not exist, no records, IP is IPv6 but we don’t support it, invalid transport…).

# File 'lib/oversip/sip/rfc3263.rb', line 165

def resolve
  if not @use_dns and @uri_host_type == :domain
    return :rfc3263_no_dns
  end

  case @uri_scheme
  when :sip
  when :sips
    # If URI scheme is :sips and we don't support TLS then reject it.
    return :rfc3263_unsupported_scheme  unless @has_sip_tls
  else
    return :rfc3263_unsupported_scheme
  end

  dns_transport = nil
  dns_port = @uri_port

  # dns_transport means the transport type taken from the destination SIP URI.
  # If @uri_scheme is :sips and no @uri_transport is given (or it's :tcp), then
  # dns_transport is :tls.
  # So dns_transport can be :udp, :tcp or :tls, while @uri_transport should not be
  # :tls (according to RFC 3261) in case scheme is :sips, and maybe :udp, :tcp, :sctp
  # or whatever token. In case scheme is :sip then @uri_transport can be :tls so
  # dns_transport would be :tls.

  ### First select @transport.

  # If it's a domain with no port nor ;transport, then
  # transport will be inspected later with NAPTR.
  if not @uri_transport and ( @uri_host_type != :domain or @uri_port )
    case @uri_scheme
    when :sip
      if @has_sip_udp
        dns_transport = :udp
      # In case we don't support UDP then use TCP (why not? local policy).
      elsif @has_sip_tcp
        dns_transport = :tcp
      else
        return :rfc3263_unsupported_transport
      end
    when :sips
      dns_transport = :tls
    end
  end

  # If the URI has ;transport param, then set dns_transport.
  if @uri_transport
    case @uri_transport
    when :udp
      return :rfc3263_unsupported_transport  unless @has_sip_udp
      if @uri_scheme == :sip
        dns_transport = :udp
      # "sips" is not possible in UDP.
      else
        return :rfc3263_unsupported_transport
      end
    when :tcp
      case (dns_transport = ( @uri_scheme == :sips ? :tls : :tcp ))
        when :tcp ; return :rfc3263_unsupported_transport  unless @has_sip_tcp
        when :tls ; return :rfc3263_unsupported_transport  unless @has_sip_tls
        end
    when :tls
      return :rfc3263_unsupported_transport  unless @has_sip_tls
      dns_transport = :tls
    else
      return :rfc3263_unsupported_transport
    end
  end

  # If URI host is an IP, no DNS query must be done (so no Ruby Fiber must be created).
  unless @uri_host_type == :domain
    if @uri_host_type == :ipv4 and not @has_sip_ipv4
      return :rfc3263_no_ipv4
    elsif @uri_host_type == :ipv6 and not @has_sip_ipv6
      return :rfc3263_no_ipv6
    end

    dns_port ||= 5061 if dns_transport == :tls
    dns_port ||= case @uri_scheme
      when :sip  ; 5060
      when :sips ; 5061
    end

    return Target.new(dns_transport, @uri_host, @uri_host_type, dns_port)
  end


  # URI host is domain so at least a DNS query must be performed.
  # Let's create/use a Fiber then.
  @@fiber_pool.spawn do

    # If URI port is specified perform DNS A/AAAA (then transport has been
    # already set above).
    if @uri_port
      if (targets = resolve_A_AAAA(dns_transport, @uri_host, dns_port))
        if targets.size == 1
          @on_success_block && @on_success_block.call(targets[0])
        else
          @on_success_block && @on_success_block.call(targets)
        end
      else
        @on_error_block && @on_error_block.call(:rfc3263_domain_not_found)
      end


    # If the URI has no port but has ;transport param, then DNS SRV takes place.
    elsif @uri_transport
      if @use_srv
        if (targets = resolve_SRV(@uri_host, @uri_scheme, dns_transport))
          if targets.size == 1
            @on_success_block && @on_success_block.call(targets[0])
          else
            @on_success_block && @on_success_block.call(targets)
          end
        else
          @on_error_block && @on_error_block.call(:rfc3263_domain_not_found)
        end

      # If @use_srv is false then perform A/AAAA queries.
      else
        log_system_debug "SRV is disabled, performing A/AAAA queries"  if $oversip_debug

        port = 5061 if dns_transport == :tls
        port ||= case @uri_scheme
          when :sip  ; 5060
          when :sips ; 5061
        end

        if (targets = resolve_A_AAAA(dns_transport, @uri_host, port))
          if targets.size == 1
            @on_success_block && @on_success_block.call(targets[0])
          else
            @on_success_block && @on_success_block.call(targets)
          end
        else
          @on_error_block && @on_error_block.call(:rfc3263_domain_not_found)
        end

      end


    # If not, the URI has no port neither ;transport param. NAPTR is required.
    else
      # If @use_naptr is false then NAPTR must not be performed.
      if ! @use_naptr
        if @use_srv
          log_system_debug "NAPTR is disabled, performing SRV queries"  if $oversip_debug
          continue_with_SRV

        # If @use_srv is false then perform A/AAAA queries.
        else
          log_system_debug "NAPTR and SRV are disabled, performing A/AAAA queries"  if $oversip_debug
          case @uri_scheme
          when :sip
            if @has_sip_udp
              dns_transport = :udp
              port = 5060
            # In case we don't support UDP then use TCP (why not? local policy).
            elsif @has_sip_tcp
              dns_transport = :tcp
              port = 5060
            else
              @on_error_block && @on_error_block.call(:rfc3263_unsupported_transport)
            end
          when :sips
            dns_transport = :tls
            port = 5061
          end

          if (targets = resolve_A_AAAA(dns_transport, @uri_host, port))
            if targets.size == 1
              @on_success_block && @on_success_block.call(targets[0])
            else
              @on_success_block && @on_success_block.call(targets)
            end
          else
            @on_error_block && @on_error_block.call(:rfc3263_domain_not_found)
          end

        end

      # There are NAPTR records so inspect them (note that there still could be no valid SIP NAPTR records
      # so SRV should take place).
      elsif (naptrs = sync_resolve_NAPTR(@uri_host))

        # If URI scheme is :sips just SIPS+D2T must be searched.
        naptrs.select! do |naptr|
          naptr.flags.downcase == "s" and
          ( (@has_sip_tls and naptr.service.upcase == SIPS_D2T) or
            (@uri_scheme == :sip and @has_sip_tcp and naptr.service.upcase == SIP_D2T) or
            (@uri_scheme == :sip and @has_sip_udp and naptr.service.upcase == SIP_D2U) )
        end

        # There are NAPTR records, but not for SIP (or not for SIPS+D2T in case the URI scheme is :sips).
        # So perform SRV queries.
        if naptrs.empty?
          log_system_debug "cannot get valid NAPTR SIP records, performing SRV queries"  if $oversip_debug
          continue_with_SRV

        # There are NAPTR records for SIP.
        else
          # @force_transport_preference is false so let's use NAPTR preferences.
          unless @force_transport_preference
            # Order based on RR order and preference (just a bit).
            ordered_naptrs = naptrs.sort { |x,y| (x.order <=> y.order).nonzero? or y.preference <=> x.preference }

          # @force_transport_preference is true so let's use @transport_preference for ordering the records.
          else
            ordered_naptrs = []
            @transport_preference.each do |transport|
              service = TRANSPORT_TO_SERVICE[transport]
              ordered_naptrs.concat(naptrs.select { |naptr| naptr.service.upcase == service })
            end

          end

          srv_targets = MultiTargets.allocate
          ordered_naptrs.each do |naptr|
            naptr_transport = case naptr.service.upcase
              when SIPS_D2T ; :tls
              when SIP_D2T  ; :tcp
              when SIP_D2U  ; :udp
              end
            if (result = resolve_SRV(naptr.replacement, nil, nil, naptr_transport))
              case result
              when RFC3263::SrvTargets
                srv_targets << result
                srv_targets.has_srv_weight_targets = true
              # A RFC3263::MultiTargets or an array of RFC3263::Target.
              when RFC3263::MultiTargets, ::Array
                srv_targets.concat result
              end
            end
          end

          if srv_targets.size == 1
            @on_success_block && @on_success_block.call(srv_targets[0])
          else
            @on_success_block && @on_success_block.call(srv_targets)
          end

        end

      # There are not NAPTR records, so try SRV records in preference order.
      else
        log_system_debug "no NAPTR records, performing SRV queries"  if $oversip_debug
        continue_with_SRV

      end

    end

  end  # @@fiber_pool.spawn

  nil
end