Hi Chris,
Ah ok - I was worried it might be a backwards incompatible change,
but I guess these are internal classes anyways. I have updated the
patch, removing the exception handling logic so the errors propagate up.
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..e830b8e70b 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
@@ -24,17 +24,15 @@
*/
#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
+#define MAX_STR_LEN 1024
#define STS_NO_CONFIG 0x0 /* no configuration found */
#define STS_SL_FOUND 0x1 /* search list found */
@@ -48,9 +46,11 @@
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"
+ * Utility routine to append s2 to s1 with a comma delimiter.
+ * strappend(s1="abc", "def") => "abc,def"
* strappend(s1="", "def") => "def
*/
void strappend(char *s1, char *s2) {
@@ -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.
@@ -112,128 +103,74 @@ 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;
}
/*
- * Initialize JNI field IDs.
+ * Initialize JNI field IDs and classes.
*/
JNIEXPORT void JNICALL
Java_sun_net_dns_ResolverConfigurationImpl_init0(JNIEnv *env, jclass
cls)
@@ -260,7 +197,7 @@
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
@@ -272,8 +209,6 @@
Java_sun_net_dns_ResolverConfigurationImpl_loadDNSconfig0(JNIEnv
*env, jclass cl
obj = (*env)->NewStringUTF(env, nameservers);
CHECK_NULL(obj);
(*env)->SetStaticObjectField(env, cls, nameserversID, obj);
- } else {
- JNU_ThrowOutOfMemoryError(env, "native memory allocation
failed");
}
}
On Thu, Jan 9, 2020 at 12:27 AM Chris Hegarty
<chris.hega...@oracle.com <mailto:chris.hega...@oracle.com>> wrote:
On 8 Jan 2020, at 05:12, Anuraag Agrawal <anura...@gmail.com
<mailto:anura...@gmail.com>> wrote:
Hi Chris,
Happy new year - sorry for the long delay. I have made an
updated patch fixing the comment (missing comma), bumping
MAX_STR_LEN, and tweaking the exception behavior.
Basically, as you pointed out loadDNSConfig itself does not
throw any exception. The getAdapters function will throw a)
OutOfMemoryError if native memory allocation failed or b) Error
if the Windows SDK function randomly failed. I have gone ahead
and added code to check the exception thrown when getAdapters
failed and propagate it if it is OOME or clear it otherwise.
This should be the same behavior as the old version of
loadDNSConfig.
...
- if (adapterP) {
- free(adapterP);
+ free(adapters);
+ } else {
+ th = (*env)->ExceptionOccurred(env);
+ if (th != NULL) {
+ // We only throw errors if not able to allocate memory,
otherwise
+ // ignore ones related to Windows API usage itself.
+ (*env)->ExceptionClear(env);
+ if ((*env)->IsInstanceOf(env, th, outOfMemoryErrCl)) {
+ (*env)->Throw(env, th);
+ return STS_ERROR;
+ }
+ }
I think that it would be preferable to NOT clear the pending
exception, and just allow it to propagate up.
-Chris.
