Import win32/resolv.rb that is required on Windows

.git-blame-ignore-revs

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+# This is a file used by GitHub to ignore the following commits on `git blame`.
+#
+# You can also do the same thing in your local repository with:
+# $ git config --local blame.ignoreRevsFile .git-blame-ignore-revs
+
+# Expand tabs
+9ae210665a8524554e7c868d3ec67af54b0958bb

ext/win32/resolv/extconf.rb

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+if have_library('iphlpapi', 'GetNetworkParams')
+  create_makefile('win32/resolv')
+end

ext/win32/resolv/lib/win32/resolv.rb

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+# frozen_string_literal: false
+=begin
+= Win32 DNS and DHCP I/F
+
+=end
+
+require 'win32/registry'
+
+module Win32
+  module Resolv
+    API = Registry::API
+    Error = Registry::Error
+
+    def self.get_hosts_path
+      path = get_hosts_dir
+      path = File.expand_path('hosts', path)
+      File.exist?(path) ? path : nil
+    end
+
+    def self.get_resolv_info
+      search, nameserver = get_info
+      if search.empty?
+        search = nil
+      else
+        search.delete("")
+        search.uniq!
+      end
+      if nameserver.empty?
+        nameserver = nil
+      else
+        nameserver.delete("")
+        nameserver.delete("0.0.0.0")
+        nameserver.uniq!
+      end
+      [ search, nameserver ]
+    end
+  end
+end
+
+begin
+  require 'win32/resolv.so'
+rescue LoadError
+end
+
+module Win32
+#====================================================================
+# Windows NT
+#====================================================================
+  module Resolv
+    module SZ
+      refine Registry do
+        # ad hoc workaround for broken registry
+        def read_s(key)
+          type, str = read(key)
+          unless type == Registry::REG_SZ
+            warn "Broken registry, #{name}\\#{key} was #{Registry.type2name(type)}, ignored"
+            return String.new
+          end
+          str
+        end
+      end
+    end
+    using SZ
+
+    TCPIP_NT = 'SYSTEM\CurrentControlSet\Services\Tcpip\Parameters'
+
+    class << self
+      private
+      def get_hosts_dir
+        Registry::HKEY_LOCAL_MACHINE.open(TCPIP_NT) do |reg|
+          reg.read_s_expand('DataBasePath')
+        end
+      end
+
+      def get_info
+        search = nil
+        nameserver = get_dns_server_list
+        Registry::HKEY_LOCAL_MACHINE.open(TCPIP_NT) do |reg|
+          begin
+            slist = reg.read_s('SearchList')
+            search = slist.split(/,\s*/) unless slist.empty?
+          rescue Registry::Error
+          end
+
+          if add_search = search.nil?
+            search = []
+            begin
+              nvdom = reg.read_s('NV Domain')
+              unless nvdom.empty?
+                @search = [ nvdom ]
+                if reg.read_i('UseDomainNameDevolution') != 0
+                  if /^\w+\./ =~ nvdom
+                    devo = $'
+                  end
+                end
+              end
+            rescue Registry::Error
+            end
+          end
+
+          reg.open('Interfaces') do |h|
+            h.each_key do |iface, |
+              h.open(iface) do |regif|
+                next unless ns = %w[NameServer DhcpNameServer].find do |key|
+                  begin
+                    ns = regif.read_s(key)
+                  rescue Registry::Error
+                  else
+                    break ns.split(/[,\s]\s*/) unless ns.empty?
+                  end
+                end
+                next if (nameserver & ns).empty?
+
+                if add_search
+                  begin
+                    [ 'Domain', 'DhcpDomain' ].each do |key|
+                      dom = regif.read_s(key)
+                      unless dom.empty?
+                        search.concat(dom.split(/,\s*/))
+                        break
+                      end
+                    end
+                  rescue Registry::Error
+                  end
+                end
+              end
+            end
+          end
+          search << devo if add_search and devo
+        end
+        [ search.uniq, nameserver.uniq ]
+      end
+    end
+  end
+end

ext/win32/resolv/resolv.c

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+#include <ruby.h>
+#include <ruby/encoding.h>
+#include <windows.h>
+#ifndef NTDDI_VERSION
+#define NTDDI_VERSION 0x06000000
+#endif
+#include <iphlpapi.h>
+
+static VALUE
+w32error_make_error(DWORD e)
+{
+    VALUE code = ULONG2NUM(e);
+    return rb_class_new_instance(1, &code, rb_path2class("Win32::Resolv::Error"));
+}
+
+static void
+w32error_raise(DWORD e)
+{
+    rb_exc_raise(w32error_make_error(e));
+}
+
+static VALUE
+get_dns_server_list(VALUE self)
+{
+    FIXED_INFO *fixedinfo = NULL;
+    ULONG buflen = 0;
+    DWORD ret;
+    VALUE buf, nameservers = Qnil;
+
+    ret = GetNetworkParams(NULL, &buflen);
+    if (ret != NO_ERROR && ret != ERROR_BUFFER_OVERFLOW) {
+        w32error_raise(ret);
+    }
+    fixedinfo = ALLOCV(buf, buflen);
+    ret = GetNetworkParams(fixedinfo, &buflen);
+    if (ret == NO_ERROR) {
+        const IP_ADDR_STRING *ipaddr = &fixedinfo->DnsServerList;
+        nameservers = rb_ary_new();
+        do {
+            const char *s = ipaddr->IpAddress.String;
+            if (!*s) continue;
+            if (strcmp(s, "0.0.0.0") == 0) continue;
+            rb_ary_push(nameservers, rb_str_new_cstr(s));
+        } while ((ipaddr = ipaddr->Next) != NULL);
+    }
+    ALLOCV_END(buf);
+    if (ret != NO_ERROR) w32error_raise(ret);
+
+    return nameservers;
+}
+
+void
+InitVM_resolv(void)
+{
+    VALUE mWin32 = rb_define_module("Win32");
+    VALUE resolv = rb_define_module_under(mWin32, "Resolv");
+    VALUE singl = rb_singleton_class(resolv);
+    rb_define_private_method(singl, "get_dns_server_list", get_dns_server_list, 0);
+}
+
+void
+Init_resolv(void)
+{
+    InitVM(resolv);
+}