[PATCH] 7006496: Use modern Windows API to retrieve OS DNS servers
Aleks Efimov
aleksej.efimov at oracle.com
Mon Dec 2 16:24:22 UTC 2019
Hey Anuraag,
I've looked at the failures and I believe that your second patch
accidentally removed 'loadDNSconfig0()' native call.
Putting it back to
src/java.base/windows/classes/sun/net/dns/ResolverConfigurationImpl.java:145
resolves all these failures.
-Aleksei
On 02/12/2019 13:04, Aleks Efimov wrote:
> Hi Anuraag,
>
> I've submited your patch to our CI system and I'm observing a bunch of
> NPE failures with such stack trace:
> java.lang.NullPointerException
> at
> java.base/sun.net.dns.ResolverConfigurationImpl.allocateListForDelimitedString(ResolverConfigurationImpl.java:108)
> at
> java.base/sun.net.dns.ResolverConfigurationImpl.stringToList(ResolverConfigurationImpl.java:68)
> at
> java.base/sun.net.dns.ResolverConfigurationImpl.loadConfig(ResolverConfigurationImpl.java:149)
> at
> java.base/sun.net.dns.ResolverConfigurationImpl.nameservers(ResolverConfigurationImpl.java:172)
> at
> jdk.naming.dns/com.sun.jndi.dns.DnsContextFactory.platformServersAvailable(DnsContextFactory.java:94)
> at
> jdk.naming.dns/com.sun.jndi.dns.DnsContextFactory.platformServersUsed(DnsContextFactory.java:171)
> at
> jdk.naming.dns/com.sun.jndi.dns.DnsContextFactory.getContext(DnsContextFactory.java:83)
> at
> jdk.naming.dns/com.sun.jndi.dns.DnsContextFactory.urlToContext(DnsContextFactory.java:120)
> at
> jdk.naming.dns/com.sun.jndi.dns.DnsContextFactory.getInitialContext(DnsContextFactory.java:64)
> at
> java.naming/javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:730)
> at
> java.naming/javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:305)
> at
> java.naming/javax.naming.InitialContext.init(InitialContext.java:236)
> at
> java.naming/javax.naming.InitialContext.<init>(InitialContext.java:208)
> at
> java.naming/javax.naming.directory.InitialDirContext.<init>(InitialDirContext.java:130)
> at LookupWithAnyAttrProp.runTest(LookupWithAnyAttrProp.java:57)
> at TestBase.launch(TestBase.java:82)
> at TestBase.run(TestBase.java:50)
> at LookupWithAnyAttrProp.main(LookupWithAnyAttrProp.java:43)
> at
> java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native
> Method)
> at
> java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
> at
> java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> at java.base/java.lang.reflect.Method.invoke(Method.java:564)
> at
> com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:127)
> at java.base/java.lang.Thread.run(Thread.java:832)
>
> Few examples of failing tests:
> test/jdk/com/sun/jndi/dns/FedTests/ListSubInterior.java (and others in
> the same folder)
> test/jdk/com/sun/jndi/dns/FactoryTests/LookupWithAnyAttrProp.java (and
> others in the same folder)
>
> Test platform is: Windows Server 2012 R2 6.3
>
> With Best Regards,
> Aleksei
>
> On 25/11/2019 05:09, Anuraag Agrawal wrote:
>> Hi Bernd,
>>
>> Thanks for the look and suggestion. I have updated those comments, as
>> well as added several more to explain the native code aspects better
>> which I hope helps future readers of the code. Hope it looks better now.
>>
>> 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..18996f0ee0 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 +25,10 @@
>>
>> 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 +51,69 @@ 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;
>> + private static ArrayList<String> searchlist;
>> + private static ArrayList<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<>();
>> + // 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) {
>> + ArrayList<String> l = allocateListForDelimitedString(str);
>>
>> - // comma and space are valid delimiters
>> - StringTokenizer st = new StringTokenizer(str, ", ");
>> + // String is delimited by space.
>> + StringTokenizer st = new StringTokenizer(str, " ");
>> while (st.hasMoreTokens()) {
>> String s = st.nextToken();
>> - if (!ll.contains(s)) {
>> - ll.add(s);
>> + if (!l.contains(s)) {
>> + l.add(s);
>> }
>> }
>> - return ll;
>> + 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) {
>> + ArrayList<String> l = allocateListForDelimitedString(str);
>> +
>> + // String is delimited by space
>> + StringTokenizer st = new StringTokenizer(str, " ");
>> + while (st.hasMoreTokens()) {
>> + String s = st.nextToken();
>> + if (!s.isEmpty()) {
>> + if (s.indexOf(':') >= 0 && s.charAt(0) != '[') {
>> + // Not BSD style
>> + s = '[' + s + ']';
>> + }
>> + if (!l.contains(s)) {
>> + l.add(s);
>> + }
>> + }
>> + }
>> + return l;
>> + }
>> +
>> + private ArrayList<String> allocateListForDelimitedString(String
>> str) {
>> + int num = 0;
>> + for (int i = 0; i < str.length(); i++) {
>> + char c = str.charAt(i);
>> + // String is space separated list of items
>> + if (c == ' ') {
>> + num++;
>> + }
>> + }
>> + // Actual num is number of delimiters + 1
>> + return new ArrayList<String>(num + 1);
>> }
>>
>> // Load DNS configuration from OS
>> @@ -81,28 +121,33 @@ 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
>> - //
>> - loadDNSconfig0();
>> + // 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.
>>
>> - 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..83100aa9ad 100644
>> --- a/src/java.base/windows/native/libnet/ResolverConfigurationImpl.c
>> +++ b/src/java.base/windows/native/libnet/ResolverConfigurationImpl.c
>> @@ -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 Sun, Nov 24, 2019 at 11:21 PM Bernd Eckenfels
>> <ecki at zusammenkunft.net <mailto:ecki at zusammenkunft.net>> wrote:
>>
>> Hello Anuraag,
>>
>> The patch looks like a good idea (especially the additional
>> cleanup for nanos and arraylist) Just a minor thing I noticed
>> there are two comments talking about „comma and space“ but the
>> code below will only tokenize by space. Imguess the comment needs
>> to be fixed, for the next review round.
>>
>> Gruss
>> Bernd
>> --
>> http://bernd.eckenfels.net
>> ------------------------------------------------------------------------
>> *Von:* net-dev <net-dev-bounces at openjdk.java.net
>> <mailto:net-dev-bounces at openjdk.java.net>> im Auftrag von Anuraag
>> Agrawal <anuraaga at gmail.com <mailto:anuraaga at gmail.com>>
>> *Gesendet:* Sonntag, November 24, 2019 10:47 AM
>> *An:* net-dev at openjdk.java.net <mailto:net-dev at openjdk.java.net>
>> *Betreff:* [PATCH] 7006496: Use modern Windows API to retrieve OS
>> DNS servers
>> Hello,
>>
>> While investigating DNS resolution failure using Netty
>> (https://github.com/netty/netty/issues/9796), I came across an
>> old JDK bug where on Windows, the list of OS name servers
>> includes those for disabled interfaces
>> (https://bugs.openjdk.java.net/browse/JDK-7006496). This is
>> problematic since it will often include values from a previously
>> registered network that is not available anymore, hence
>> resolution requests would be guaranteed to fail.
>>
>> The current approach reads DNS name servers from the registry,
>> where it isn't possible to read whether an adapter is actually
>> enabled or not. However, Windows Vista+ (minimum JDK8+ supported
>> Windows) include an API that can be used to examine whether an
>> adapter is currently enabled, and also return its DNS servers. So
>> I've created this patch to update the name server lookup to use
>> this technique. I can confirm that now only name servers from
>> enabled adapters are loaded. A side effect is the previous
>> approach could only read IPv4 - now IPv6 DNS servers are also
>> loaded. The unix implementation seems to do this too, so I don't
>> think this should cause issues but I can filter to only IPv4 to
>> be more conservative if desired.
>>
>> I have also cleaned some low hanging fruit in what seems to be
>> very old code
>>
>> - Use ArrayList instead of LinkedList since it can be accurately
>> preallocated and is not mutated
>> - Use nanoTime instead of currentTimeMillis for refresh timer to
>> not cause problems during OS time changes.
>> - Simplify tokenizer to only tokenize on space, there is never a
>> comma separated list passed to it as we create the list in our
>> JNI code
>>
>> This is my first patch for OpenJDK - happy to accept any feedback.
>>
>> Thanks for the consideration.
>>
>> Inlined patch follows (also attached but I've had attached patch
>> scrubbed when submitting to jmh-dev before...)
>>
>> 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..dde871cf19 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 +25,10 @@
>>
>> 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 +51,65 @@ 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;
>> + private static ArrayList<String> searchlist;
>> + private static ArrayList<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<>();
>> + // Parse string that consists of token delimited by space
>> + // and return ArrayList
>> + private ArrayList<String> stringToList(String str) {
>> + ArrayList<String> l = allocateListForDelimitedString(str);
>>
>> // comma and space are valid delimiters
>> - StringTokenizer st = new StringTokenizer(str, ", ");
>> + StringTokenizer st = new StringTokenizer(str, " ");
>> while (st.hasMoreTokens()) {
>> String s = st.nextToken();
>> - if (!ll.contains(s)) {
>> - ll.add(s);
>> + if (!l.contains(s)) {
>> + l.add(s);
>> }
>> }
>> - return ll;
>> + return l;
>> + }
>> +
>> + // Parse string that consists of token delimited by space
>> + // and return ArrayList. Converts IPv6 addresses to BSD-style.
>> + private ArrayList<String> addressesToList(String str) {
>> + ArrayList<String> l = allocateListForDelimitedString(str);
>> +
>> + // comma and space are valid delimiters
>> + StringTokenizer st = new StringTokenizer(str, " ");
>> + while (st.hasMoreTokens()) {
>> + String s = st.nextToken();
>> + if (!s.isEmpty()) {
>> + if (s.indexOf(':') >= 0 && s.charAt(0) != '[') {
>> + // Not BSD style
>> + s = '[' + s + ']';
>> + }
>> + if (!l.contains(s)) {
>> + l.add(s);
>> + }
>> + }
>> + }
>> + return l;
>> + }
>> +
>> + private ArrayList<String>
>> allocateListForDelimitedString(String str) {
>> + int num = 0;
>> + for (int i = 0; i < str.length(); i++) {
>> + char c = str.charAt(i);
>> + // String is space separated list of items
>> + if (c == ' ') {
>> + num++;
>> + }
>> + }
>> + // Actual num is number of delimiters + 1
>> + return new ArrayList<String>(num + 1);
>> }
>>
>> // Load DNS configuration from OS
>> @@ -88,8 +124,8 @@ public class ResolverConfigurationImpl
>> changed = false;
>> } else {
>> if (lastRefresh >= 0) {
>> - long currTime = System.currentTimeMillis();
>> - if ((currTime - lastRefresh) < TIMEOUT) {
>> + long currTime = System.nanoTime();
>> + if ((currTime - lastRefresh) < TIMEOUT_NANOS) {
>> return;
>> }
>> }
>> @@ -100,9 +136,9 @@ public class ResolverConfigurationImpl
>> //
>> loadDNSconfig0();
>>
>> - lastRefresh = System.currentTimeMillis();
>> + 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..83100aa9ad 100644
>> --- a/src/java.base/windows/native/libnet/ResolverConfigurationImpl.c
>> +++ b/src/java.base/windows/native/libnet/ResolverConfigurationImpl.c
>> @@ -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
>>
>
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