[PATCH] 7006496: Use modern Windows API to retrieve OS DNS servers
Anuraag Agrawal
anuraaga at gmail.com
Wed Dec 18 06:08:23 UTC 2019
Hi Aleksei,
Thanks for all the reviews, it's really helped a lot. Just wondering, is
there anything we need to go to finish getting approvals?
Thanks,
- Anuraag
On Sat, Dec 14, 2019 at 12:35 AM Aleks Efimov <aleksej.efimov at oracle.com>
wrote:
> Hi Anuraag,
>
> Thank you for moving the site-local/link-local check to the native code.
> The latest version of your changes looks good to me. Webrev of it can be
> viewed here:
> http://cr.openjdk.java.net/~aefimov/anuraaga/7006496/03/
>
> Our CI system is also happy with it.
>
> With Best Regards,
> Aleksei
>
>
> On 12/12/2019 13:26, Anuraag Agrawal wrote:
>
> Hi Aleksei,
>
> I've gone ahead and moved the site-local check to native code - it does
> reduce the chance of filling up our buffer, though the code is a bit more
> complicated. To get sockaddr_in6, I went ahead and switched the imports to
> net_util.h, which I noticed was used in other files. Let me know if it
> looks ok.
>
> Inline patch follows
>
> diff --git
> a/src/java.base/windows/classes/sun/net/dns/ResolverConfigurationImpl.java
> b/src/java.base/windows/classes/sun/net/dns/ResolverConfigurationImpl.java
> index 2250b3158e..c3ebe09776 100644
> ---
> a/src/java.base/windows/classes/sun/net/dns/ResolverConfigurationImpl.java
> +++
> b/src/java.base/windows/classes/sun/net/dns/ResolverConfigurationImpl.java
> @@ -25,9 +25,9 @@
>
> package sun.net.dns;
>
> +import java.util.ArrayList;
> import java.util.List;
> -import java.util.LinkedList;
> -import java.util.StringTokenizer;
> +import java.util.concurrent.TimeUnit;
>
> /*
> * An implementation of sun.net.ResolverConfiguration for Windows.
> @@ -50,30 +50,55 @@ public class ResolverConfigurationImpl
>
> // Cache timeout (120 seconds) - should be converted into property
> // or configured as preference in the future.
> - private static final int TIMEOUT = 120000;
> + private static final long TIMEOUT_NANOS =
> TimeUnit.SECONDS.toNanos(120);
>
> // DNS suffix list and name servers populated by native method
> private static String os_searchlist;
> private static String os_nameservers;
>
> // Cached lists
> - private static LinkedList<String> searchlist;
> - private static LinkedList<String> nameservers;
> -
> - // Parse string that consists of token delimited by space or commas
> - // and return LinkedHashMap
> - private LinkedList<String> stringToList(String str) {
> - LinkedList<String> ll = new LinkedList<>();
> -
> - // comma and space are valid delimiters
> - StringTokenizer st = new StringTokenizer(str, ", ");
> - while (st.hasMoreTokens()) {
> - String s = st.nextToken();
> - if (!ll.contains(s)) {
> - ll.add(s);
> + private static ArrayList<String> searchlist;
> + private static ArrayList<String> nameservers;
> +
> + // Parse string that consists of token delimited by comma
> + // and return ArrayList. Refer to ResolverConfigurationImpl.c and
> + // strappend to see how the string is created.
> + private ArrayList<String> stringToList(String str) {
> + // String is delimited by comma.
> + String[] tokens = str.split(",");
> + ArrayList<String> l = new ArrayList<>(tokens.length);
> + for (String s : tokens) {
> + if (!l.contains(s)) {
> + l.add(s);
> }
> }
> - return ll;
> + l.trimToSize();
> + return l;
> + }
> +
> + // Parse string that consists of token delimited by comma
> + // and return ArrayList. Refer to ResolverConfigurationImpl.c and
> + // strappend to see how the string is created.
> + // In addition to splitting the string, converts IPv6 addresses to
> + // BSD-style.
> + private ArrayList<String> addressesToList(String str) {
> + // String is delimited by comma
> + String[] tokens = str.split(",");
> + ArrayList<String> l = new ArrayList<>(tokens.length);
> +
> + for (String s : tokens) {
> + if (!s.isEmpty()) {
> + if (s.indexOf(':') >= 0 && s.charAt(0) != '[') {
> + // Not BSD style
> + s = '[' + s + ']';
> + }
> + if (!l.contains(s)) {
> + l.add(s);
> + }
> + }
> + }
> + l.trimToSize();
> + return l;
> }
>
> // Load DNS configuration from OS
> @@ -81,28 +106,34 @@ public class ResolverConfigurationImpl
> private void loadConfig() {
> assert Thread.holdsLock(lock);
>
> - // if address have changed then DNS probably changed as well;
> - // otherwise check if cached settings have expired.
> - //
> + // A change in the network address of the machine usually
> indicates
> + // a change in DNS configuration too so we always refresh the
> config
> + // after such a change.
> if (changed) {
> changed = false;
> } else {
> + // Otherwise we refresh if TIMEOUT_NANOS has passed since last
> + // load.
> if (lastRefresh >= 0) {
> - long currTime = System.currentTimeMillis();
> - if ((currTime - lastRefresh) < TIMEOUT) {
> + long currTime = System.nanoTime();
> + if ((currTime - lastRefresh) < TIMEOUT_NANOS) {
> return;
> }
> }
> }
>
> - // load DNS configuration, update timestamp, create
> - // new HashMaps from the loaded configuration
> - //
> + // Native code that uses Windows API to find out the DNS server
> + // addresses and search suffixes. It builds a comma-delimited
> string
> + // of nameservers and domain suffixes and sets them to the static
> + // os_nameservers and os_searchlist. We then split these into Java
> + // Lists here.
> loadDNSconfig0();
>
> - lastRefresh = System.currentTimeMillis();
> + // Record the time of update and refresh the lists of addresses /
> + // domain suffixes.
> + lastRefresh = System.nanoTime();
> searchlist = stringToList(os_searchlist);
> - nameservers = stringToList(os_nameservers);
> + nameservers = addressesToList(os_nameservers);
> os_searchlist = null; // can be GC'ed
> os_nameservers = null;
> }
> diff --git a/src/java.base/windows/native/libnet/NetworkInterface_winXP.c
> b/src/java.base/windows/native/libnet/NetworkInterface_winXP.c
> index f2368bafcb..297a1561ef 100644
> --- a/src/java.base/windows/native/libnet/NetworkInterface_winXP.c
> +++ b/src/java.base/windows/native/libnet/NetworkInterface_winXP.c
> @@ -73,8 +73,8 @@ const int MAX_TRIES = 3;
> * for each adapter on the system. Returned in *adapters.
> * Buffer is malloc'd and must be freed (unless error returned)
> */
> -static int getAdapters (JNIEnv *env, IP_ADAPTER_ADDRESSES **adapters) {
> - DWORD ret, flags;
> +int getAdapters (JNIEnv *env, int flags, IP_ADAPTER_ADDRESSES **adapters)
> {
> + DWORD ret;
> IP_ADAPTER_ADDRESSES *adapterInfo;
> ULONG len;
> int try;
> @@ -87,9 +87,6 @@ static int getAdapters (JNIEnv *env,
> IP_ADAPTER_ADDRESSES **adapters) {
> }
>
> len = BUFF_SIZE;
> - flags = GAA_FLAG_SKIP_DNS_SERVER;
> - flags |= GAA_FLAG_SKIP_MULTICAST;
> - flags |= GAA_FLAG_INCLUDE_PREFIX;
> ret = GetAdaptersAddresses(AF_UNSPEC, flags, NULL, adapterInfo, &len);
>
> for (try = 0; ret == ERROR_BUFFER_OVERFLOW && try < MAX_TRIES; ++try)
> {
> @@ -240,7 +237,7 @@ static int ipinflen = 2048;
> */
> int getAllInterfacesAndAddresses (JNIEnv *env, netif **netifPP)
> {
> - DWORD ret;
> + DWORD ret, flags;
> MIB_IPADDRTABLE *tableP;
> IP_ADAPTER_ADDRESSES *ptr, *adapters=NULL;
> ULONG len=ipinflen, count=0;
> @@ -296,7 +293,11 @@ int getAllInterfacesAndAddresses (JNIEnv *env, netif
> **netifPP)
> }
> }
> free(tableP);
> - ret = getAdapters (env, &adapters);
> +
> + flags = GAA_FLAG_SKIP_DNS_SERVER;
> + flags |= GAA_FLAG_SKIP_MULTICAST;
> + flags |= GAA_FLAG_INCLUDE_PREFIX;
> + ret = getAdapters (env, flags, &adapters);
> if (ret != ERROR_SUCCESS) {
> goto err;
> }
> diff --git
> a/src/java.base/windows/native/libnet/ResolverConfigurationImpl.c
> b/src/java.base/windows/native/libnet/ResolverConfigurationImpl.c
> index 13b28044a5..580347540d 100644
> --- a/src/java.base/windows/native/libnet/ResolverConfigurationImpl.c
> +++ b/src/java.base/windows/native/libnet/ResolverConfigurationImpl.c
> @@ -1,5 +1,5 @@
> /*
> - * Copyright (c) 2002, 2013, Oracle and/or its affiliates. All rights
> reserved.
> + * Copyright (c) 2002, 2019, Oracle and/or its affiliates. All rights
> reserved.
> * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
> *
> * This code is free software; you can redistribute it and/or modify it
> @@ -24,14 +24,12 @@
> */
>
> #include <stdlib.h>
> -#include <windows.h>
> #include <stdio.h>
> #include <stddef.h>
> -#include <iprtrmib.h>
> #include <time.h>
> #include <assert.h>
> -#include <iphlpapi.h>
>
> +#include "net_util.h"
> #include "jni_util.h"
>
> #define MAX_STR_LEN 256
> @@ -48,8 +46,10 @@
> static jfieldID searchlistID;
> static jfieldID nameserversID;
>
> +extern int getAdapters(JNIEnv *env, int flags, IP_ADAPTER_ADDRESSES
> **adapters);
> +
> /*
> - * Utility routine to append s2 to s1 with a space delimiter.
> + * Utility routine to append s2 to s1 with a comma delimiter.
> * strappend(s1="abc", "def") => "abc def"
> * strappend(s1="", "def") => "def
> */
> @@ -60,41 +60,32 @@ void strappend(char *s1, char *s2) {
> return;
>
> len = strlen(s1)+1;
> - if (s1[0] != 0) /* needs space character */
> + if (s1[0] != 0) /* needs comma character */
> len++;
> if (len + strlen(s2) > MAX_STR_LEN) /* insufficient space */
> return;
>
> if (s1[0] != 0) {
> - strcat(s1, " ");
> + strcat(s1, ",");
> }
> strcat(s1, s2);
> }
>
> /*
> - * Windows 2000/XP
> - *
> - * Use registry approach based on settings described in Appendix C
> - * of "Microsoft Windows 2000 TCP/IP Implementation Details".
> - *
> - * DNS suffix list is obtained from SearchList registry setting. If
> - * this is not specified we compile suffix list based on the
> - * per-connection domain suffix.
> - *
> - * DNS name servers and domain settings are on a per-connection
> - * basic. We therefore enumerate the network adapters to get the
> - * names of each adapter and then query the corresponding registry
> - * settings to obtain NameServer/DhcpNameServer and Domain/DhcpDomain.
> + * Use DNS server addresses returned by GetAdaptersAddresses for currently
> + * active interfaces.
> */
> -static int loadConfig(char *sl, char *ns) {
> - IP_ADAPTER_INFO *adapterP;
> - ULONG size;
> - DWORD ret;
> +static int loadConfig(JNIEnv *env, char *sl, char *ns) {
> + IP_ADAPTER_ADDRESSES *adapters, *adapter;
> + IP_ADAPTER_DNS_SERVER_ADDRESS *dnsServer;
> + WCHAR *suffix;
> + DWORD ret, flags;
> DWORD dwLen;
> ULONG ulType;
> char result[MAX_STR_LEN];
> HANDLE hKey;
> - int gotSearchList = 0;
> + SOCKADDR *sockAddr;
> + struct sockaddr_in6 *sockAddrIpv6;
>
> /*
> * First see if there is a global suffix list specified.
> @@ -112,122 +103,67 @@ static int loadConfig(char *sl, char *ns) {
> assert(ulType == REG_SZ);
> if (strlen(result) > 0) {
> strappend(sl, result);
> - gotSearchList = 1;
> }
> }
> RegCloseKey(hKey);
> }
>
> - /*
> - * Ask the IP Helper library to enumerate the adapters
> - */
> - size = sizeof(IP_ADAPTER_INFO);
> - adapterP = (IP_ADAPTER_INFO *)malloc(size);
> - if (adapterP == NULL) {
> - return STS_ERROR;
> - }
> - ret = GetAdaptersInfo(adapterP, &size);
> - if (ret == ERROR_BUFFER_OVERFLOW) {
> - IP_ADAPTER_INFO *newAdapterP = (IP_ADAPTER_INFO
> *)realloc(adapterP, size);
> - if (newAdapterP == NULL) {
> - free(adapterP);
> - return STS_ERROR;
> - }
> - adapterP = newAdapterP;
>
> - ret = GetAdaptersInfo(adapterP, &size);
> + // We only need DNS server addresses so skip everything else.
> + flags = GAA_FLAG_SKIP_UNICAST;
> + flags |= GAA_FLAG_SKIP_ANYCAST;
> + flags |= GAA_FLAG_SKIP_MULTICAST;
> + flags |= GAA_FLAG_SKIP_FRIENDLY_NAME;
> + ret = getAdapters(env, flags, &adapters);
> + if (ret != ERROR_SUCCESS) {
> + return STS_ERROR;
> }
>
> - /*
> - * Iterate through the list of adapters as registry settings are
> - * keyed on the adapter name (GUID).
> - */
> - if (ret == ERROR_SUCCESS) {
> - IP_ADAPTER_INFO *curr = adapterP;
> - while (curr != NULL) {
> - char key[MAX_STR_LEN];
> -
> - sprintf(key,
> -
> "SYSTEM\\CurrentControlSet\\Services\\Tcpip\\Parameters\\Interfaces\\%s",
> - curr->AdapterName);
> -
> - ret = RegOpenKeyEx(HKEY_LOCAL_MACHINE,
> - key,
> - 0,
> - KEY_READ,
> - (PHKEY)&hKey);
> - if (ret == ERROR_SUCCESS) {
> - DWORD enableDhcp = 0;
> -
> - /*
> - * Is DHCP enabled on this interface
> - */
> - dwLen = sizeof(enableDhcp);
> - ret = RegQueryValueEx(hKey, "EnableDhcp", NULL, &ulType,
> - (LPBYTE)&enableDhcp, &dwLen);
> -
> - /*
> - * If we don't have the suffix list when get the Domain
> - * or DhcpDomain. If DHCP is enabled then Domain overides
> - * DhcpDomain
> - */
> - if (!gotSearchList) {
> - result[0] = '\0';
> - dwLen = sizeof(result);
> - ret = RegQueryValueEx(hKey, "Domain", NULL, &ulType,
> - (LPBYTE)&result, &dwLen);
> - if (((ret != ERROR_SUCCESS) || (strlen(result) == 0))
> &&
> - enableDhcp) {
> - dwLen = sizeof(result);
> - ret = RegQueryValueEx(hKey, "DhcpDomain", NULL,
> &ulType,
> - (LPBYTE)&result, &dwLen);
> - }
> - if (ret == ERROR_SUCCESS) {
> - assert(ulType == REG_SZ);
> - strappend(sl, result);
> + adapter = adapters;
> + while (adapter != NULL) {
> + // Only load config from enabled adapters.
> + if (adapter->OperStatus == IfOperStatusUp) {
> + dnsServer = adapter->FirstDnsServerAddress;
> + while (dnsServer != NULL) {
> + sockAddr = dnsServer->Address.lpSockaddr;
> + if (sockAddr->sa_family == AF_INET6) {
> + sockAddrIpv6 = (struct sockaddr_in6 *)sockAddr;
> + if (sockAddrIpv6->sin6_scope_id != 0) {
> + // An address with a scope is either link-local or
> + // site-local, which aren't valid for DNS queries
> so
> + // we can skip them.
> + dnsServer = dnsServer->Next;
> + continue;
> }
> }
>
> - /*
> - * Get DNS servers based on NameServer or DhcpNameServer
> - * registry setting. If NameServer is set then it
> overrides
> - * DhcpNameServer (even if DHCP is enabled).
> - */
> - result[0] = '\0';
> dwLen = sizeof(result);
> - ret = RegQueryValueEx(hKey, "NameServer", NULL, &ulType,
> - (LPBYTE)&result, &dwLen);
> - if (((ret != ERROR_SUCCESS) || (strlen(result) == 0)) &&
> - enableDhcp) {
> - dwLen = sizeof(result);
> - ret = RegQueryValueEx(hKey, "DhcpNameServer", NULL,
> &ulType,
> - (LPBYTE)&result, &dwLen);
> - }
> - if (ret == ERROR_SUCCESS) {
> - assert(ulType == REG_SZ);
> + ret = WSAAddressToStringA(sockAddr,
> + dnsServer->Address.iSockaddrLength, NULL,
> + result, &dwLen);
> + if (ret == 0) {
> strappend(ns, result);
> }
>
> - /*
> - * Finished with this registry key
> - */
> - RegCloseKey(hKey);
> + dnsServer = dnsServer->Next;
> }
>
> - /*
> - * Onto the next adapeter
> - */
> - curr = curr->Next;
> + // Add connection-specific search domains in addition to
> global one.
> + suffix = adapter->DnsSuffix;
> + if (suffix != NULL) {
> + ret = WideCharToMultiByte(CP_UTF8, 0, suffix, -1,
> + result, sizeof(result), NULL, NULL);
> + if (ret != 0) {
> + strappend(sl, result);
> + }
> + }
> }
> - }
>
> - /*
> - * Free the adpater structure
> - */
> - if (adapterP) {
> - free(adapterP);
> + adapter = adapter->Next;
> }
>
> + free(adapters);
> +
> return STS_SL_FOUND & STS_NS_FOUND;
> }
>
> @@ -260,7 +196,7 @@
> Java_sun_net_dns_ResolverConfigurationImpl_loadDNSconfig0(JNIEnv *env,
> jclass cl
> searchlist[0] = '\0';
> nameservers[0] = '\0';
>
> - if (loadConfig(searchlist, nameservers) != STS_ERROR) {
> + if (loadConfig(env, searchlist, nameservers) != STS_ERROR) {
>
> /*
> * Populate static fields in sun.net.DefaultResolverConfiguration
>
> On Thu, Dec 12, 2019 at 1:49 AM Anuraag Agrawal <anuraaga at gmail.com>
> wrote:
>
>> Hi Aleksei,
>>
>> Thanks for the feedback. I had thought about it but felt that it might be
>> better to leave as much business logic to Java vs native as possible as a
>> general principle. But if it makes more sense to do it native here happy to
>> make the change :)
>>
>> Thanks,
>> - Anuraag
>>
>> On Thu, Dec 12, 2019, 01:18 Aleks Efimov <aleksej.efimov at oracle.com>
>> wrote:
>>
>>> Hi Anuraag,
>>>
>>> The webrev with the latest patch can be viewed here:
>>> http://cr.openjdk.java.net/~aefimov/anuraaga/7006496/02
>>>
>>> Thanks for replacing FirstDnsSuffix usages with DnsSuffix. I've double
>>> checked it with native application and can confirm that on my test host
>>> (Microsoft Windows Server 2016 Standard) the DnsSuffix contains correct
>>> information while the FirstDnsSuffix list is empty:
>>> DNS Suffix (From DnsSuffix field): test.domain.com
>>> Number of IP Adapter DNS suffix entries: 0
>>>
>>> DNS Suffix (From DnsSuffix field):
>>> Number of IP Adapter DNS suffix entries: 0
>>>
>>> DNS Suffix (From DnsSuffix field):
>>> Number of IP Adapter DNS suffix entries: 0
>>>
>>> DNS Suffix (From DnsSuffix field):
>>> Number of IP Adapter DNS suffix entries: 0
>>>
>>> DNS Suffix (From DnsSuffix field): test.domain.com
>>> Number of IP Adapter DNS suffix entries: 0
>>>
>>> About site-local addresses: Maybe we can move the site-local address
>>> check to native code? i.e. analyze dnsServer->Address.lpSockaddr and filter
>>> out site-local addresses.
>>>
>>> Testing:
>>> Run your latest patch though our CI system - no issues detected.
>>>
>>> -Aleksei
>>>
>>> On 10/12/2019 06:59, Anuraag Agrawal wrote:
>>>
>>> Hi Aleksei,
>>>
>>> Thanks for running the test. I had checked the global search list, but
>>> realize I didn't check connection-specific suffixes which were causing the
>>> issue you see. While the documentation states that FirstDnsSuffix is
>>> populated on Vista+, amazingly it doesn't seem to be
>>>
>>>
>>> https://docs.microsoft.com/en-us/windows/win32/api/iptypes/ns-iptypes-ip_adapter_addresses_lh
>>>
>>>
>>> Chromium has run into the same issue and just doesn't use the field
>>>
>>>
>>> https://cs.chromium.org/chromium/src/net/dns/dns_config_service_win.cc?q=firstdnssuffix&sq=package:chromium&dr=C&l=532
>>>
>>> So I have gone ahead and switched to using the normal DnsSuffix field.
>>> DnsSuffix and looking up the search list in the registry should generally
>>> give a full list.
>>>
>>> During this testing, other issues I found are that the search list
>>> returns a comma-separated list. So to keep the string list parsing simple,
>>> I changed the delimiter from space to comma. Also, on my machine I would
>>> always have DNS servers like fec0:0:0:ffff:1 on some adapters. At first, I
>>> assumed it is ok to return these, since they are configured by the OS and
>>> should be valid, but I learnt that these are deprecated IPv6 site-local
>>> addresses and should not be used.
>>>
>>> https://en.wikipedia.org/wiki/Unique_local_address
>>>
>>> I used the same check for site-local as Inet6Address, which just sees if
>>> the first bytes are fec0.
>>>
>>> Thanks again - inline patch follows.
>>>
>>> diff --git
>>> a/src/java.base/windows/classes/sun/net/dns/ResolverConfigurationImpl.java
>>> b/src/java.base/windows/classes/sun/net/dns/ResolverConfigurationImpl.java
>>> index 2250b3158e..b9a06461ab 100644
>>> ---
>>> a/src/java.base/windows/classes/sun/net/dns/ResolverConfigurationImpl.java
>>> +++
>>> b/src/java.base/windows/classes/sun/net/dns/ResolverConfigurationImpl.java
>>> @@ -25,9 +25,9 @@
>>>
>>> package sun.net.dns;
>>>
>>> +import java.util.ArrayList;
>>> import java.util.List;
>>> -import java.util.LinkedList;
>>> -import java.util.StringTokenizer;
>>> +import java.util.concurrent.TimeUnit;
>>>
>>> /*
>>> * An implementation of sun.net.ResolverConfiguration for Windows.
>>> @@ -50,30 +50,65 @@ public class ResolverConfigurationImpl
>>>
>>> // Cache timeout (120 seconds) - should be converted into property
>>> // or configured as preference in the future.
>>> - private static final int TIMEOUT = 120000;
>>> + private static final long TIMEOUT_NANOS =
>>> TimeUnit.SECONDS.toNanos(120);
>>>
>>> // DNS suffix list and name servers populated by native method
>>> private static String os_searchlist;
>>> private static String os_nameservers;
>>>
>>> // Cached lists
>>> - private static LinkedList<String> searchlist;
>>> - private static LinkedList<String> nameservers;
>>> -
>>> - // Parse string that consists of token delimited by space or commas
>>> - // and return LinkedHashMap
>>> - private LinkedList<String> stringToList(String str) {
>>> - LinkedList<String> ll = new LinkedList<>();
>>> -
>>> - // comma and space are valid delimiters
>>> - StringTokenizer st = new StringTokenizer(str, ", ");
>>> - while (st.hasMoreTokens()) {
>>> - String s = st.nextToken();
>>> - if (!ll.contains(s)) {
>>> - ll.add(s);
>>> + private static ArrayList<String> searchlist;
>>> + private static ArrayList<String> nameservers;
>>> +
>>> + // Parse string that consists of token delimited by comma
>>> + // and return ArrayList. Refer to ResolverConfigurationImpl.c and
>>> + // strappend to see how the string is created.
>>> + private ArrayList<String> stringToList(String str) {
>>> + // String is delimited by comma.
>>> + String[] tokens = str.split(",");
>>> + ArrayList<String> l = new ArrayList<>(tokens.length);
>>> + for (String s : tokens) {
>>> + if (!l.contains(s)) {
>>> + l.add(s);
>>> }
>>> }
>>> - return ll;
>>> + l.trimToSize();
>>> + return l;
>>> + }
>>> +
>>> + // Parse string that consists of token delimited by comma
>>> + // and return ArrayList. Refer to ResolverConfigurationImpl.c and
>>> + // strappend to see how the string is created.
>>> + // In addition to splitting the string, converts IPv6 addresses to
>>> + // BSD-style.
>>> + private ArrayList<String> addressesToList(String str) {
>>> + // String is delimited by comma
>>> + String[] tokens = str.split(",");
>>> + ArrayList<String> l = new ArrayList<>(tokens.length);
>>> +
>>> + for (String s : tokens) {
>>> + if (!s.isEmpty()) {
>>> + if (s.indexOf(':') >= 0) {
>>> + // IPv6
>>> + if (s.charAt(0) != '[') {
>>> + // Not BSD style
>>> + s = '[' + s + ']';
>>> + }
>>> + if (s.startsWith("[fec0:")) {
>>> + // Deprecated site-local address. Windows adds
>>> + // such addresses to IPv6 adapters without DNS
>>> + // configured, but these should not actually be
>>> + // used for queries.
>>> + continue;
>>> + }
>>> + }
>>> + if (!l.contains(s)) {
>>> + l.add(s);
>>> + }
>>> + }
>>> + }
>>> + l.trimToSize();
>>> + return l;
>>> }
>>>
>>> // Load DNS configuration from OS
>>> @@ -81,28 +116,34 @@ public class ResolverConfigurationImpl
>>> private void loadConfig() {
>>> assert Thread.holdsLock(lock);
>>>
>>> - // if address have changed then DNS probably changed as well;
>>> - // otherwise check if cached settings have expired.
>>> - //
>>> + // A change in the network address of the machine usually
>>> indicates
>>> + // a change in DNS configuration too so we always refresh the
>>> config
>>> + // after such a change.
>>> if (changed) {
>>> changed = false;
>>> } else {
>>> + // Otherwise we refresh if TIMEOUT_NANOS has passed since
>>> last
>>> + // load.
>>> if (lastRefresh >= 0) {
>>> - long currTime = System.currentTimeMillis();
>>> - if ((currTime - lastRefresh) < TIMEOUT) {
>>> + long currTime = System.nanoTime();
>>> + if ((currTime - lastRefresh) < TIMEOUT_NANOS) {
>>> return;
>>> }
>>> }
>>> }
>>>
>>> - // load DNS configuration, update timestamp, create
>>> - // new HashMaps from the loaded configuration
>>> - //
>>> + // Native code that uses Windows API to find out the DNS server
>>> + // addresses and search suffixes. It builds a comma-delimited
>>> string
>>> + // of nameservers and domain suffixes and sets them to the
>>> static
>>> + // os_nameservers and os_searchlist. We then split these into
>>> Java
>>> + // Lists here.
>>> loadDNSconfig0();
>>>
>>> - lastRefresh = System.currentTimeMillis();
>>> + // Record the time of update and refresh the lists of addresses
>>> /
>>> + // domain suffixes.
>>> + lastRefresh = System.nanoTime();
>>> searchlist = stringToList(os_searchlist);
>>> - nameservers = stringToList(os_nameservers);
>>> + nameservers = addressesToList(os_nameservers);
>>> os_searchlist = null; // can be GC'ed
>>> os_nameservers = null;
>>> }
>>> diff --git
>>> a/src/java.base/windows/native/libnet/NetworkInterface_winXP.c
>>> b/src/java.base/windows/native/libnet/NetworkInterface_winXP.c
>>> index f2368bafcb..297a1561ef 100644
>>> --- a/src/java.base/windows/native/libnet/NetworkInterface_winXP.c
>>> +++ b/src/java.base/windows/native/libnet/NetworkInterface_winXP.c
>>> @@ -73,8 +73,8 @@ const int MAX_TRIES = 3;
>>> * for each adapter on the system. Returned in *adapters.
>>> * Buffer is malloc'd and must be freed (unless error returned)
>>> */
>>> -static int getAdapters (JNIEnv *env, IP_ADAPTER_ADDRESSES **adapters) {
>>> - DWORD ret, flags;
>>> +int getAdapters (JNIEnv *env, int flags, IP_ADAPTER_ADDRESSES
>>> **adapters) {
>>> + DWORD ret;
>>> IP_ADAPTER_ADDRESSES *adapterInfo;
>>> ULONG len;
>>> int try;
>>> @@ -87,9 +87,6 @@ static int getAdapters (JNIEnv *env,
>>> IP_ADAPTER_ADDRESSES **adapters) {
>>> }
>>>
>>> len = BUFF_SIZE;
>>> - flags = GAA_FLAG_SKIP_DNS_SERVER;
>>> - flags |= GAA_FLAG_SKIP_MULTICAST;
>>> - flags |= GAA_FLAG_INCLUDE_PREFIX;
>>> ret = GetAdaptersAddresses(AF_UNSPEC, flags, NULL, adapterInfo,
>>> &len);
>>>
>>> for (try = 0; ret == ERROR_BUFFER_OVERFLOW && try < MAX_TRIES;
>>> ++try) {
>>> @@ -240,7 +237,7 @@ static int ipinflen = 2048;
>>> */
>>> int getAllInterfacesAndAddresses (JNIEnv *env, netif **netifPP)
>>> {
>>> - DWORD ret;
>>> + DWORD ret, flags;
>>> MIB_IPADDRTABLE *tableP;
>>> IP_ADAPTER_ADDRESSES *ptr, *adapters=NULL;
>>> ULONG len=ipinflen, count=0;
>>> @@ -296,7 +293,11 @@ int getAllInterfacesAndAddresses (JNIEnv *env,
>>> netif **netifPP)
>>> }
>>> }
>>> free(tableP);
>>> - ret = getAdapters (env, &adapters);
>>> +
>>> + flags = GAA_FLAG_SKIP_DNS_SERVER;
>>> + flags |= GAA_FLAG_SKIP_MULTICAST;
>>> + flags |= GAA_FLAG_INCLUDE_PREFIX;
>>> + ret = getAdapters (env, flags, &adapters);
>>> if (ret != ERROR_SUCCESS) {
>>> goto err;
>>> }
>>> diff --git
>>> a/src/java.base/windows/native/libnet/ResolverConfigurationImpl.c
>>> b/src/java.base/windows/native/libnet/ResolverConfigurationImpl.c
>>> index 13b28044a5..427d7c85eb 100644
>>> --- a/src/java.base/windows/native/libnet/ResolverConfigurationImpl.c
>>> +++ b/src/java.base/windows/native/libnet/ResolverConfigurationImpl.c
>>> @@ -1,5 +1,5 @@
>>> /*
>>> - * Copyright (c) 2002, 2013, Oracle and/or its affiliates. All rights
>>> reserved.
>>> + * Copyright (c) 2002, 2019, Oracle and/or its affiliates. All rights
>>> reserved.
>>> * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
>>> *
>>> * This code is free software; you can redistribute it and/or modify it
>>> @@ -30,6 +30,7 @@
>>> #include <iprtrmib.h>
>>> #include <time.h>
>>> #include <assert.h>
>>> +#include <winsock2.h>
>>> #include <iphlpapi.h>
>>>
>>> #include "jni_util.h"
>>> @@ -48,8 +49,10 @@
>>> static jfieldID searchlistID;
>>> static jfieldID nameserversID;
>>>
>>> +extern int getAdapters(JNIEnv *env, int flags, IP_ADAPTER_ADDRESSES
>>> **adapters);
>>> +
>>> /*
>>> - * Utility routine to append s2 to s1 with a space delimiter.
>>> + * Utility routine to append s2 to s1 with a comma delimiter.
>>> * strappend(s1="abc", "def") => "abc def"
>>> * strappend(s1="", "def") => "def
>>> */
>>> @@ -60,41 +63,30 @@ void strappend(char *s1, char *s2) {
>>> return;
>>>
>>> len = strlen(s1)+1;
>>> - if (s1[0] != 0) /* needs space character */
>>> + if (s1[0] != 0) /* needs comma character */
>>> len++;
>>> if (len + strlen(s2) > MAX_STR_LEN) /* insufficient space */
>>> return;
>>>
>>> if (s1[0] != 0) {
>>> - strcat(s1, " ");
>>> + strcat(s1, ",");
>>> }
>>> strcat(s1, s2);
>>> }
>>>
>>> /*
>>> - * Windows 2000/XP
>>> - *
>>> - * Use registry approach based on settings described in Appendix C
>>> - * of "Microsoft Windows 2000 TCP/IP Implementation Details".
>>> - *
>>> - * DNS suffix list is obtained from SearchList registry setting. If
>>> - * this is not specified we compile suffix list based on the
>>> - * per-connection domain suffix.
>>> - *
>>> - * DNS name servers and domain settings are on a per-connection
>>> - * basic. We therefore enumerate the network adapters to get the
>>> - * names of each adapter and then query the corresponding registry
>>> - * settings to obtain NameServer/DhcpNameServer and Domain/DhcpDomain.
>>> + * Use DNS server addresses returned by GetAdaptersAddresses for
>>> currently
>>> + * active interfaces.
>>> */
>>> -static int loadConfig(char *sl, char *ns) {
>>> - IP_ADAPTER_INFO *adapterP;
>>> - ULONG size;
>>> - DWORD ret;
>>> +static int loadConfig(JNIEnv *env, char *sl, char *ns) {
>>> + IP_ADAPTER_ADDRESSES *adapters, *adapter;
>>> + IP_ADAPTER_DNS_SERVER_ADDRESS *dnsServer;
>>> + WCHAR *suffix;
>>> + DWORD ret, flags;
>>> DWORD dwLen;
>>> ULONG ulType;
>>> char result[MAX_STR_LEN];
>>> HANDLE hKey;
>>> - int gotSearchList = 0;
>>>
>>> /*
>>> * First see if there is a global suffix list specified.
>>> @@ -112,122 +104,55 @@ static int loadConfig(char *sl, char *ns) {
>>> assert(ulType == REG_SZ);
>>> if (strlen(result) > 0) {
>>> strappend(sl, result);
>>> - gotSearchList = 1;
>>> }
>>> }
>>> RegCloseKey(hKey);
>>> }
>>>
>>> - /*
>>> - * Ask the IP Helper library to enumerate the adapters
>>> - */
>>> - size = sizeof(IP_ADAPTER_INFO);
>>> - adapterP = (IP_ADAPTER_INFO *)malloc(size);
>>> - if (adapterP == NULL) {
>>> - return STS_ERROR;
>>> - }
>>> - ret = GetAdaptersInfo(adapterP, &size);
>>> - if (ret == ERROR_BUFFER_OVERFLOW) {
>>> - IP_ADAPTER_INFO *newAdapterP = (IP_ADAPTER_INFO
>>> *)realloc(adapterP, size);
>>> - if (newAdapterP == NULL) {
>>> - free(adapterP);
>>> - return STS_ERROR;
>>> - }
>>> - adapterP = newAdapterP;
>>>
>>> - ret = GetAdaptersInfo(adapterP, &size);
>>> + // We only need DNS server addresses so skip everything else.
>>> + flags = GAA_FLAG_SKIP_UNICAST;
>>> + flags |= GAA_FLAG_SKIP_ANYCAST;
>>> + flags |= GAA_FLAG_SKIP_MULTICAST;
>>> + flags |= GAA_FLAG_SKIP_FRIENDLY_NAME;
>>> + ret = getAdapters(env, flags, &adapters);
>>> + if (ret != ERROR_SUCCESS) {
>>> + return STS_ERROR;
>>> }
>>>
>>> - /*
>>> - * Iterate through the list of adapters as registry settings are
>>> - * keyed on the adapter name (GUID).
>>> - */
>>> - if (ret == ERROR_SUCCESS) {
>>> - IP_ADAPTER_INFO *curr = adapterP;
>>> - while (curr != NULL) {
>>> - char key[MAX_STR_LEN];
>>> -
>>> - sprintf(key,
>>> -
>>> "SYSTEM\\CurrentControlSet\\Services\\Tcpip\\Parameters\\Interfaces\\%s",
>>> - curr->AdapterName);
>>> -
>>> - ret = RegOpenKeyEx(HKEY_LOCAL_MACHINE,
>>> - key,
>>> - 0,
>>> - KEY_READ,
>>> - (PHKEY)&hKey);
>>> - if (ret == ERROR_SUCCESS) {
>>> - DWORD enableDhcp = 0;
>>> -
>>> - /*
>>> - * Is DHCP enabled on this interface
>>> - */
>>> - dwLen = sizeof(enableDhcp);
>>> - ret = RegQueryValueEx(hKey, "EnableDhcp", NULL, &ulType,
>>> - (LPBYTE)&enableDhcp, &dwLen);
>>> -
>>> - /*
>>> - * If we don't have the suffix list when get the Domain
>>> - * or DhcpDomain. If DHCP is enabled then Domain
>>> overides
>>> - * DhcpDomain
>>> - */
>>> - if (!gotSearchList) {
>>> - result[0] = '\0';
>>> - dwLen = sizeof(result);
>>> - ret = RegQueryValueEx(hKey, "Domain", NULL, &ulType,
>>> - (LPBYTE)&result, &dwLen);
>>> - if (((ret != ERROR_SUCCESS) || (strlen(result) ==
>>> 0)) &&
>>> - enableDhcp) {
>>> - dwLen = sizeof(result);
>>> - ret = RegQueryValueEx(hKey, "DhcpDomain", NULL,
>>> &ulType,
>>> - (LPBYTE)&result, &dwLen);
>>> - }
>>> - if (ret == ERROR_SUCCESS) {
>>> - assert(ulType == REG_SZ);
>>> - strappend(sl, result);
>>> - }
>>> - }
>>> -
>>> - /*
>>> - * Get DNS servers based on NameServer or DhcpNameServer
>>> - * registry setting. If NameServer is set then it
>>> overrides
>>> - * DhcpNameServer (even if DHCP is enabled).
>>> - */
>>> - result[0] = '\0';
>>> + adapter = adapters;
>>> + while (adapter != NULL) {
>>> + // Only load config from enabled adapters.
>>> + if (adapter->OperStatus == IfOperStatusUp) {
>>> + dnsServer = adapter->FirstDnsServerAddress;
>>> + while (dnsServer != NULL) {
>>> dwLen = sizeof(result);
>>> - ret = RegQueryValueEx(hKey, "NameServer", NULL, &ulType,
>>> - (LPBYTE)&result, &dwLen);
>>> - if (((ret != ERROR_SUCCESS) || (strlen(result) == 0)) &&
>>> - enableDhcp) {
>>> - dwLen = sizeof(result);
>>> - ret = RegQueryValueEx(hKey, "DhcpNameServer", NULL,
>>> &ulType,
>>> - (LPBYTE)&result, &dwLen);
>>> - }
>>> - if (ret == ERROR_SUCCESS) {
>>> - assert(ulType == REG_SZ);
>>> + ret = WSAAddressToStringA(dnsServer->Address.lpSockaddr,
>>> + dnsServer->Address.iSockaddrLength, NULL,
>>> + result, &dwLen);
>>> + if (ret == 0) {
>>> strappend(ns, result);
>>> }
>>>
>>> - /*
>>> - * Finished with this registry key
>>> - */
>>> - RegCloseKey(hKey);
>>> + dnsServer = dnsServer->Next;
>>> }
>>>
>>> - /*
>>> - * Onto the next adapeter
>>> - */
>>> - curr = curr->Next;
>>> + // Add connection-specific search domains in addition to
>>> global one.
>>> + suffix = adapter->DnsSuffix;
>>> + if (suffix != NULL) {
>>> + ret = WideCharToMultiByte(CP_UTF8, 0, suffix, -1,
>>> + result, sizeof(result), NULL, NULL);
>>> + if (ret != 0) {
>>> + strappend(sl, result);
>>> + }
>>> + }
>>> }
>>> - }
>>>
>>> - /*
>>> - * Free the adpater structure
>>> - */
>>> - if (adapterP) {
>>> - free(adapterP);
>>> + adapter = adapter->Next;
>>> }
>>>
>>> + free(adapters);
>>> +
>>> return STS_SL_FOUND & STS_NS_FOUND;
>>> }
>>>
>>> @@ -260,7 +185,7 @@
>>> Java_sun_net_dns_ResolverConfigurationImpl_loadDNSconfig0(JNIEnv *env,
>>> jclass cl
>>> searchlist[0] = '\0';
>>> nameservers[0] = '\0';
>>>
>>> - if (loadConfig(searchlist, nameservers) != STS_ERROR) {
>>> + if (loadConfig(env, searchlist, nameservers) != STS_ERROR) {
>>>
>>> /*
>>> * Populate static fields in
>>> sun.net.DefaultResolverConfiguration
>>>
>>> On Tue, Dec 10, 2019 at 1:29 AM Aleks Efimov <aleksej.efimov at oracle.com>
>>> wrote:
>>>
>>>> Hi Anuraag,
>>>>
>>>> The webrev with your latest changes can be found here:
>>>> http://cr.openjdk.java.net/~aefimov/anuraaga/7006496/01
>>>>
>>>> The copyright changes looks good.
>>>>
>>>> The split by space also looks good with assumption that we will never
>>>> get string with two spaces between IP addresses/DNS suffixes.
>>>>
>>>> I've also performed one test on Windows machine and it shows an issue
>>>> with the retrieval of DNS suffixes:
>>>> Method to call:
>>>> sun.net.dns.ResolverConfiguration.open().searchlist()
>>>>
>>>> Old implementation returns:
>>>> [test.domain.com]
>>>>
>>>> With the latest patch the suffixes list (searchlist) is empty:
>>>> []
>>>>
>>>> I've collected the following information on the test host that might
>>>> help you to fix the issue:
>>>>
>>>> The host OS: Microsoft Windows Server 2016 Standard
>>>>
>>>> Networking configuration (<---> is for masked addresses/info):
>>>> $ ipconfig /all
>>>>
>>>> Windows IP Configuration
>>>>
>>>> Host Name . . . . . . . . . . . . : host-name-1
>>>> Primary Dns Suffix . . . . . . . :
>>>> Node Type . . . . . . . . . . . . : Hybrid
>>>> IP Routing Enabled. . . . . . . . : No
>>>> WINS Proxy Enabled. . . . . . . . : No
>>>> DNS Suffix Search List. . . . . . : test.domain.com
>>>>
>>>> Ethernet adapter Ethernet:
>>>>
>>>> Connection-specific DNS Suffix . : test.domain.com
>>>> Description . . . . . . . . . . . : Broadcom NetXtreme-E Virtual
>>>> Function
>>>> Physical Address. . . . . . . . . : <------------>
>>>> DHCP Enabled. . . . . . . . . . . : Yes
>>>> Autoconfiguration Enabled . . . . : Yes
>>>> Link-local IPv6 Address . . . . . : <------------>
>>>> IPv4 Address. . . . . . . . . . . : <------------>
>>>> Subnet Mask . . . . . . . . . . . : <------------>
>>>> Lease Obtained. . . . . . . . . . : <------------>
>>>> Lease Expires . . . . . . . . . . : <------------>
>>>> Default Gateway . . . . . . . . . : <------------>
>>>> DHCP Server . . . . . . . . . . . : <------------>
>>>> DHCPv6 Client DUID. . . . . . . . : <------------>
>>>> DNS Servers . . . . . . . . . . . : <------------>
>>>> <------------>
>>>> NetBIOS over Tcpip. . . . . . . . : Disabled
>>>>
>>>> Tunnel adapter isatap.test.domain.com:
>>>>
>>>> Media State . . . . . . . . . . . : Media disconnected
>>>> Connection-specific DNS Suffix . : test.domain.com
>>>> Description . . . . . . . . . . . : Microsoft ISATAP Adapter #3
>>>> Physical Address. . . . . . . . . : <------------>
>>>> DHCP Enabled. . . . . . . . . . . : No
>>>> Autoconfiguration Enabled . . . . : Yes
>>>>
>>>>
>>>> - Aleksei
>>>>
>>>>
>>>> On 07/12/2019 09:44, Anuraag Agrawal wrote:
>>>>
>>>> Hi all,
>>>>
>>>> Thanks for the reviews. I've fixed the formatting errors, and I hope I
>>>> fixed the copyright issue. I couldn't find documentation on the format of
>>>> the copyright header, but assume the second number is the year of
>>>> modification to update. I found ResolverConfigurationImpl.c to have an old
>>>> one and updated it to 2019.
>>>>
>>>> I also found the note in the docs that StringTokenizer is deprecated
>>>> and shouldn't be used - I agree it's a good time to replace it. As we have
>>>> a simple split by space, I have gone ahead and used the simpler
>>>> String.split instead of regex, hope that makes sense. While in many code
>>>> I'd be a little concerned with the array allocation, this is only run very
>>>> infrequently so I think it should be ok.
>>>>
>>>> Inline diff follows
>>>>
>>>> diff --git
>>>> a/src/java.base/windows/classes/sun/net/dns/ResolverConfigurationImpl.java
>>>> b/src/java.base/windows/classes/sun/net/dns/ResolverConfigurationImpl.java
>>>> index 2250b3158e..47065e805e 100644
>>>> ---
>>>> a/src/java.base/windows/classes/sun/net/dns/ResolverConfigurationImpl.java
>>>> +++
>>>> b/src/java.base/windows/classes/sun/net/dns/ResolverConfigurationImpl.java
>>>> @@ -25,9 +25,9 @@
>>>>
>>>> package sun.net.dns;
>>>>
>>>> +import java.util.ArrayList;
>>>> import java.util.List;
>>>> -import java.util.LinkedList;
>>>> -import java.util.StringTokenizer;
>>>> +import java.util.concurrent.TimeUnit;
>>>>
>>>> /*
>>>> * An implementation of sun.net.ResolverConfiguration for Windows.
>>>> @@ -50,30 +50,55 @@ public class ResolverConfigurationImpl
>>>>
>>>> // Cache timeout (120 seconds) - should be converted into property
>>>> // or configured as preference in the future.
>>>> - private static final int TIMEOUT = 120000;
>>>> + private static final long TIMEOUT_NANOS =
>>>> TimeUnit.SECONDS.toNanos(120);
>>>>
>>>> // DNS suffix list and name servers populated by native method
>>>> private static String os_searchlist;
>>>> private static String os_nameservers;
>>>>
>>>> // Cached lists
>>>> - private static LinkedList<String> searchlist;
>>>> - private static LinkedList<String> nameservers;
>>>> -
>>>> - // Parse string that consists of token delimited by space or commas
>>>> - // and return LinkedHashMap
>>>> - private LinkedList<String> stringToList(String str) {
>>>> - LinkedList<String> ll = new LinkedList<>();
>>>> -
>>>> - // comma and space are valid delimiters
>>>> - StringTokenizer st = new StringTokenizer(str, ", ");
>>>> - while (st.hasMoreTokens()) {
>>>> - String s = st.nextToken();
>>>> - if (!ll.contains(s)) {
>>>> - ll.add(s);
>>>> + private static ArrayList<String> searchlist;
>>>> + private static ArrayList<String> nameservers;
>>>> +
>>>> + // Parse string that consists of token delimited by space
>>>> + // and return ArrayList. Refer to ResolverConfigurationImpl.c and
>>>> + // strappend to see how the string is created.
>>>> + private ArrayList<String> stringToList(String str) {
>>>> + // String is delimited by space.
>>>> + String[] tokens = str.split(" ");
>>>> + ArrayList<String> l = new ArrayList<>(tokens.length);
>>>> + for (String s : tokens) {
>>>> + if (!l.contains(s)) {
>>>> + l.add(s);
>>>> }
>>>> }
>>>> - return ll;
>>>> + l.trimToSize();
>>>> + return l;
>>>> + }
>>>> +
>>>> + // Parse string that consists of token delimited by space
>>>> + // and return ArrayList. Refer to ResolverConfigurationImpl.c and
>>>> + // strappend to see how the string is created.
>>>> + // In addition to splitting the string, converts IPv6 addresses to
>>>> + // BSD-style.
>>>> + private ArrayList<String> addressesToList(String str) {
>>>> + // String is delimited by space
>>>> + String[] tokens = str.split(" ");
>>>> + ArrayList<String> l = new ArrayList<>(tokens.length);
>>>> +
>>>> + for (String s : tokens) {
>>>> + if (!s.isEmpty()) {
>>>> + if (s.indexOf(':') >= 0 && s.charAt(0) != '[') {
>>>> + // Not BSD style
>>>> + s = '[' + s + ']';
>>>> + }
>>>> + if (!l.contains(s)) {
>>>> + l.add(s);
>>>> + }
>>>> + }
>>>> + }
>>>> + l.trimToSize();
>>>> + return l;
>>>> }
>>>>
>>>> // Load DNS configuration from OS
>>>> @@ -81,28 +106,34 @@ public class ResolverConfigurationImpl
>>>> private void loadConfig() {
>>>> assert Thread.holdsLock(lock);
>>>>
>>>> - // if address have changed then DNS probably changed as well;
>>>> - // otherwise check if cached settings have expired.
>>>> - //
>>>> + // A change in the network address of the machine usually
>>>> indicates
>>>> + // a change in DNS configuration too so we always refresh the
>>>> config
>>>> + // after such a change.
>>>> if (changed) {
>>>> changed = false;
>>>> } else {
>>>> + // Otherwise we refresh if TIMEOUT_NANOS has passed since
>>>> last
>>>> + // load.
>>>> if (lastRefresh >= 0) {
>>>> - long currTime = System.currentTimeMillis();
>>>> - if ((currTime - lastRefresh) < TIMEOUT) {
>>>> + long currTime = System.nanoTime();
>>>> + if ((currTime - lastRefresh) < TIMEOUT_NANOS) {
>>>> return;
>>>> }
>>>> }
>>>> }
>>>>
>>>> - // load DNS configuration, update timestamp, create
>>>> - // new HashMaps from the loaded configuration
>>>> - //
>>>> + // Native code that uses Windows API to find out the DNS server
>>>> + // addresses and search suffixes. It builds a space-delimited
>>>> string
>>>> + // of nameservers and domain suffixes and sets them to the
>>>> static
>>>> + // os_nameservers and os_searchlist. We then split these into
>>>> Java
>>>> + // Lists here.
>>>> loadDNSconfig0();
>>>>
>>>> - lastRefresh = System.currentTimeMillis();
>>>> + // Record the time of update and refresh the lists of
>>>> addresses /
>>>> + // domain suffixes.
>>>> + lastRefresh = System.nanoTime();
>>>> searchlist = stringToList(os_searchlist);
>>>> - nameservers = stringToList(os_nameservers);
>>>> + nameservers = addressesToList(os_nameservers);
>>>> os_searchlist = null; // can be GC'ed
>>>> os_nameservers = null;
>>>> }
>>>> diff --git
>>>> a/src/java.base/windows/native/libnet/NetworkInterface_winXP.c
>>>> b/src/java.base/windows/native/libnet/NetworkInterface_winXP.c
>>>> index f2368bafcb..297a1561ef 100644
>>>> --- a/src/java.base/windows/native/libnet/NetworkInterface_winXP.c
>>>> +++ b/src/java.base/windows/native/libnet/NetworkInterface_winXP.c
>>>> @@ -73,8 +73,8 @@ const int MAX_TRIES = 3;
>>>> * for each adapter on the system. Returned in *adapters.
>>>> * Buffer is malloc'd and must be freed (unless error returned)
>>>> */
>>>> -static int getAdapters (JNIEnv *env, IP_ADAPTER_ADDRESSES **adapters) {
>>>> - DWORD ret, flags;
>>>> +int getAdapters (JNIEnv *env, int flags, IP_ADAPTER_ADDRESSES
>>>> **adapters) {
>>>> + DWORD ret;
>>>> IP_ADAPTER_ADDRESSES *adapterInfo;
>>>> ULONG len;
>>>> int try;
>>>> @@ -87,9 +87,6 @@ static int getAdapters (JNIEnv *env,
>>>> IP_ADAPTER_ADDRESSES **adapters) {
>>>> }
>>>>
>>>> len = BUFF_SIZE;
>>>> - flags = GAA_FLAG_SKIP_DNS_SERVER;
>>>> - flags |= GAA_FLAG_SKIP_MULTICAST;
>>>> - flags |= GAA_FLAG_INCLUDE_PREFIX;
>>>> ret = GetAdaptersAddresses(AF_UNSPEC, flags, NULL, adapterInfo,
>>>> &len);
>>>>
>>>> for (try = 0; ret == ERROR_BUFFER_OVERFLOW && try < MAX_TRIES;
>>>> ++try) {
>>>> @@ -240,7 +237,7 @@ static int ipinflen = 2048;
>>>> */
>>>> int getAllInterfacesAndAddresses (JNIEnv *env, netif **netifPP)
>>>> {
>>>> - DWORD ret;
>>>> + DWORD ret, flags;
>>>> MIB_IPADDRTABLE *tableP;
>>>> IP_ADAPTER_ADDRESSES *ptr, *adapters=NULL;
>>>> ULONG len=ipinflen, count=0;
>>>> @@ -296,7 +293,11 @@ int getAllInterfacesAndAddresses (JNIEnv *env,
>>>> netif **netifPP)
>>>> }
>>>> }
>>>> free(tableP);
>>>> - ret = getAdapters (env, &adapters);
>>>> +
>>>> + flags = GAA_FLAG_SKIP_DNS_SERVER;
>>>> + flags |= GAA_FLAG_SKIP_MULTICAST;
>>>> + flags |= GAA_FLAG_INCLUDE_PREFIX;
>>>> + ret = getAdapters (env, flags, &adapters);
>>>> if (ret != ERROR_SUCCESS) {
>>>> goto err;
>>>> }
>>>> diff --git
>>>> a/src/java.base/windows/native/libnet/ResolverConfigurationImpl.c
>>>> b/src/java.base/windows/native/libnet/ResolverConfigurationImpl.c
>>>> index 13b28044a5..85a7935314 100644
>>>> --- a/src/java.base/windows/native/libnet/ResolverConfigurationImpl.c
>>>> +++ b/src/java.base/windows/native/libnet/ResolverConfigurationImpl.c
>>>> @@ -1,5 +1,5 @@
>>>> /*
>>>> - * Copyright (c) 2002, 2013, Oracle and/or its affiliates. All rights
>>>> reserved.
>>>> + * Copyright (c) 2002, 2019, Oracle and/or its affiliates. All rights
>>>> reserved.
>>>> * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
>>>> *
>>>> * This code is free software; you can redistribute it and/or modify it
>>>> @@ -30,6 +30,7 @@
>>>> #include <iprtrmib.h>
>>>> #include <time.h>
>>>> #include <assert.h>
>>>> +#include <winsock2.h>
>>>> #include <iphlpapi.h>
>>>>
>>>> #include "jni_util.h"
>>>> @@ -48,6 +49,8 @@
>>>> static jfieldID searchlistID;
>>>> static jfieldID nameserversID;
>>>>
>>>> +extern int getAdapters(JNIEnv *env, int flags, IP_ADAPTER_ADDRESSES
>>>> **adapters);
>>>> +
>>>> /*
>>>> * Utility routine to append s2 to s1 with a space delimiter.
>>>> * strappend(s1="abc", "def") => "abc def"
>>>> @@ -72,29 +75,19 @@ void strappend(char *s1, char *s2) {
>>>> }
>>>>
>>>> /*
>>>> - * Windows 2000/XP
>>>> - *
>>>> - * Use registry approach based on settings described in Appendix C
>>>> - * of "Microsoft Windows 2000 TCP/IP Implementation Details".
>>>> - *
>>>> - * DNS suffix list is obtained from SearchList registry setting. If
>>>> - * this is not specified we compile suffix list based on the
>>>> - * per-connection domain suffix.
>>>> - *
>>>> - * DNS name servers and domain settings are on a per-connection
>>>> - * basic. We therefore enumerate the network adapters to get the
>>>> - * names of each adapter and then query the corresponding registry
>>>> - * settings to obtain NameServer/DhcpNameServer and Domain/DhcpDomain.
>>>> + * Use DNS server addresses returned by GetAdaptersAddresses for
>>>> currently
>>>> + * active interfaces.
>>>> */
>>>> -static int loadConfig(char *sl, char *ns) {
>>>> - IP_ADAPTER_INFO *adapterP;
>>>> - ULONG size;
>>>> - DWORD ret;
>>>> +static int loadConfig(JNIEnv *env, char *sl, char *ns) {
>>>> + IP_ADAPTER_ADDRESSES *adapters, *adapter;
>>>> + IP_ADAPTER_DNS_SERVER_ADDRESS *dnsServer;
>>>> + SOCKADDR *address;
>>>> + IP_ADAPTER_DNS_SUFFIX *suffix;
>>>> + DWORD ret, flags;
>>>> DWORD dwLen;
>>>> ULONG ulType;
>>>> char result[MAX_STR_LEN];
>>>> HANDLE hKey;
>>>> - int gotSearchList = 0;
>>>>
>>>> /*
>>>> * First see if there is a global suffix list specified.
>>>> @@ -112,122 +105,58 @@ static int loadConfig(char *sl, char *ns) {
>>>> assert(ulType == REG_SZ);
>>>> if (strlen(result) > 0) {
>>>> strappend(sl, result);
>>>> - gotSearchList = 1;
>>>> }
>>>> }
>>>> RegCloseKey(hKey);
>>>> }
>>>>
>>>> - /*
>>>> - * Ask the IP Helper library to enumerate the adapters
>>>> - */
>>>> - size = sizeof(IP_ADAPTER_INFO);
>>>> - adapterP = (IP_ADAPTER_INFO *)malloc(size);
>>>> - if (adapterP == NULL) {
>>>> - return STS_ERROR;
>>>> - }
>>>> - ret = GetAdaptersInfo(adapterP, &size);
>>>> - if (ret == ERROR_BUFFER_OVERFLOW) {
>>>> - IP_ADAPTER_INFO *newAdapterP = (IP_ADAPTER_INFO
>>>> *)realloc(adapterP, size);
>>>> - if (newAdapterP == NULL) {
>>>> - free(adapterP);
>>>> - return STS_ERROR;
>>>> - }
>>>> - adapterP = newAdapterP;
>>>>
>>>> - ret = GetAdaptersInfo(adapterP, &size);
>>>> + // We only need DNS server addresses so skip everything else.
>>>> + flags = GAA_FLAG_SKIP_UNICAST;
>>>> + flags |= GAA_FLAG_SKIP_ANYCAST;
>>>> + flags |= GAA_FLAG_SKIP_MULTICAST;
>>>> + flags |= GAA_FLAG_SKIP_FRIENDLY_NAME;
>>>> + ret = getAdapters(env, flags, &adapters);
>>>> + if (ret != ERROR_SUCCESS) {
>>>> + return STS_ERROR;
>>>> }
>>>>
>>>> - /*
>>>> - * Iterate through the list of adapters as registry settings are
>>>> - * keyed on the adapter name (GUID).
>>>> - */
>>>> - if (ret == ERROR_SUCCESS) {
>>>> - IP_ADAPTER_INFO *curr = adapterP;
>>>> - while (curr != NULL) {
>>>> - char key[MAX_STR_LEN];
>>>> -
>>>> - sprintf(key,
>>>> -
>>>> "SYSTEM\\CurrentControlSet\\Services\\Tcpip\\Parameters\\Interfaces\\%s",
>>>> - curr->AdapterName);
>>>> -
>>>> - ret = RegOpenKeyEx(HKEY_LOCAL_MACHINE,
>>>> - key,
>>>> - 0,
>>>> - KEY_READ,
>>>> - (PHKEY)&hKey);
>>>> - if (ret == ERROR_SUCCESS) {
>>>> - DWORD enableDhcp = 0;
>>>> -
>>>> - /*
>>>> - * Is DHCP enabled on this interface
>>>> - */
>>>> - dwLen = sizeof(enableDhcp);
>>>> - ret = RegQueryValueEx(hKey, "EnableDhcp", NULL,
>>>> &ulType,
>>>> - (LPBYTE)&enableDhcp, &dwLen);
>>>> -
>>>> - /*
>>>> - * If we don't have the suffix list when get the Domain
>>>> - * or DhcpDomain. If DHCP is enabled then Domain
>>>> overides
>>>> - * DhcpDomain
>>>> - */
>>>> - if (!gotSearchList) {
>>>> - result[0] = '\0';
>>>> - dwLen = sizeof(result);
>>>> - ret = RegQueryValueEx(hKey, "Domain", NULL,
>>>> &ulType,
>>>> - (LPBYTE)&result, &dwLen);
>>>> - if (((ret != ERROR_SUCCESS) || (strlen(result) ==
>>>> 0)) &&
>>>> - enableDhcp) {
>>>> - dwLen = sizeof(result);
>>>> - ret = RegQueryValueEx(hKey, "DhcpDomain",
>>>> NULL, &ulType,
>>>> - (LPBYTE)&result, &dwLen);
>>>> - }
>>>> - if (ret == ERROR_SUCCESS) {
>>>> - assert(ulType == REG_SZ);
>>>> - strappend(sl, result);
>>>> - }
>>>> - }
>>>> -
>>>> - /*
>>>> - * Get DNS servers based on NameServer or
>>>> DhcpNameServer
>>>> - * registry setting. If NameServer is set then it
>>>> overrides
>>>> - * DhcpNameServer (even if DHCP is enabled).
>>>> - */
>>>> - result[0] = '\0';
>>>> + adapter = adapters;
>>>> + while (adapter != NULL) {
>>>> + // Only load config from enabled adapters.
>>>> + if (adapter->OperStatus == IfOperStatusUp) {
>>>> + dnsServer = adapter->FirstDnsServerAddress;
>>>> + while (dnsServer != NULL) {
>>>> + address = dnsServer->Address.lpSockaddr;
>>>> dwLen = sizeof(result);
>>>> - ret = RegQueryValueEx(hKey, "NameServer", NULL,
>>>> &ulType,
>>>> - (LPBYTE)&result, &dwLen);
>>>> - if (((ret != ERROR_SUCCESS) || (strlen(result) == 0))
>>>> &&
>>>> - enableDhcp) {
>>>> - dwLen = sizeof(result);
>>>> - ret = RegQueryValueEx(hKey, "DhcpNameServer",
>>>> NULL, &ulType,
>>>> - (LPBYTE)&result, &dwLen);
>>>> - }
>>>> - if (ret == ERROR_SUCCESS) {
>>>> - assert(ulType == REG_SZ);
>>>> + ret =
>>>> WSAAddressToStringA(dnsServer->Address.lpSockaddr,
>>>> + dnsServer->Address.iSockaddrLength, NULL,
>>>> + result, &dwLen);
>>>> + if (ret == 0) {
>>>> strappend(ns, result);
>>>> }
>>>>
>>>> - /*
>>>> - * Finished with this registry key
>>>> - */
>>>> - RegCloseKey(hKey);
>>>> + dnsServer = dnsServer->Next;
>>>> }
>>>>
>>>> - /*
>>>> - * Onto the next adapeter
>>>> - */
>>>> - curr = curr->Next;
>>>> + // Add connection-specific search domains in addition to
>>>> global one.
>>>> + suffix = adapter->FirstDnsSuffix;
>>>> + while (suffix != NULL) {
>>>> + ret = WideCharToMultiByte(CP_UTF8, 0, suffix->String,
>>>> -1,
>>>> + result, sizeof(result), NULL, NULL);
>>>> + if (ret != 0) {
>>>> + strappend(sl, result);
>>>> + }
>>>> +
>>>> + suffix = suffix->Next;
>>>> + }
>>>> }
>>>> - }
>>>>
>>>> - /*
>>>> - * Free the adpater structure
>>>> - */
>>>> - if (adapterP) {
>>>> - free(adapterP);
>>>> + adapter = adapter->Next;
>>>> }
>>>>
>>>> + free(adapters);
>>>> +
>>>> return STS_SL_FOUND & STS_NS_FOUND;
>>>> }
>>>>
>>>> @@ -260,7 +189,7 @@
>>>> Java_sun_net_dns_ResolverConfigurationImpl_loadDNSconfig0(JNIEnv *env,
>>>> jclass cl
>>>> searchlist[0] = '\0';
>>>> nameservers[0] = '\0';
>>>>
>>>> - if (loadConfig(searchlist, nameservers) != STS_ERROR) {
>>>> + if (loadConfig(env, searchlist, nameservers) != STS_ERROR) {
>>>>
>>>> /*
>>>> * Populate static fields in
>>>> sun.net.DefaultResolverConfiguration
>>>>
>>>> On Sat, Dec 7, 2019 at 12:41 AM Alan Bateman <Alan.Bateman at oracle.com>
>>>> wrote:
>>>>
>>>>> On 06/12/2019 15:34, Aleks Efimov wrote:
>>>>> > :
>>>>> >
>>>>> > I've created webrev with your latest changes - it could be
>>>>> convenient
>>>>> > for other reviewers:
>>>>> > http://cr.openjdk.java.net/~aefimov/anuraaga/7006496/00
>>>>> >
>>>>> > I will happily sponsor this change once it gets necessary approvals
>>>>> This could be split into two issues but since the code using
>>>>> StringTokenizer is changing significantly then we should replace it
>>>>> with
>>>>> regex while we there.
>>>>>
>>>>> -Alan
>>>>>
>>>>
>>>>
>>>
>
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