grpc
/
grpc-java
mirror of https://github.com/grpc/grpc-java.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

core: Trim trailing dot from SRV hostnames 

The trailing dot denotes the hostname to be absolute. It is fine to
leave, but removing it makes the authority match the more common form
and hopefully reduces confusion.

This happens to works around SNI failures caused when using gRPC-LB,
since SNI prohibits the trailing dot. However, that is not the reason
for this change as we have to support users directly providing a
hostname with the trailing dot anyway (and doing so is not hard).

See #4912
This commit is contained in:
Eric Anderson 2018-10-15 12:50:16 -07:00
parent e8762c941c
commit e5339d25c6
2 changed files with 116 additions and 58 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

108
core/src/main/java/io/grpc/internal/JndiResourceResolverFactory.java
View File

@ -86,7 +86,7 @@ final class JndiResourceResolverFactory implements DnsNameResolver.ResourceResol
if (unavailabilityCause() != null) {
return null;
}
return new JndiResourceResolver();
return new JndiResourceResolver(new JndiRecordFetcher());
}
@Nullable
@ -95,6 +95,11 @@ final class JndiResourceResolverFactory implements DnsNameResolver.ResourceResol
return JNDI_UNAVAILABILITY_CAUSE;
}
@VisibleForTesting
interface RecordFetcher {
List<String> getAllRecords(String recordType, String name) throws NamingException;
}
@VisibleForTesting
static final class JndiResourceResolver implements DnsNameResolver.ResourceResolver {
private static final Logger logger =
@ -102,15 +107,20 @@ final class JndiResourceResolverFactory implements DnsNameResolver.ResourceResol
private static final Pattern whitespace = Pattern.compile("\\s+");
private final RecordFetcher recordFetcher;
public JndiResourceResolver(RecordFetcher recordFetcher) {
this.recordFetcher = recordFetcher;
}
@Override
public List<String> resolveTxt(String serviceConfigHostname) throws NamingException {
checkAvailable();
if (logger.isLoggable(Level.FINER)) {
logger.log(
Level.FINER, "About to query TXT records for {0}", new Object[]{serviceConfigHostname});
}
List<String> serviceConfigRawTxtRecords =
getAllRecords("TXT", "dns:///" + serviceConfigHostname);
recordFetcher.getAllRecords("TXT", "dns:///" + serviceConfigHostname);
if (logger.isLoggable(Level.FINER)) {
logger.log(
Level.FINER, "Found {0} TXT records", new Object[]{serviceConfigRawTxtRecords.size()});
@ -126,13 +136,12 @@ final class JndiResourceResolverFactory implements DnsNameResolver.ResourceResol
@Override
public List<EquivalentAddressGroup> resolveSrv(
AddressResolver addressResolver, String grpclbHostname) throws Exception {
checkAvailable();
if (logger.isLoggable(Level.FINER)) {
logger.log(
Level.FINER, "About to query SRV records for {0}", new Object[]{grpclbHostname});
}
List<String> grpclbSrvRecords =
getAllRecords("SRV", "dns:///" + grpclbHostname);
recordFetcher.getAllRecords("SRV", "dns:///" + grpclbHostname);
if (logger.isLoggable(Level.FINER)) {
logger.log(
Level.FINER, "Found {0} SRV records", new Object[]{grpclbSrvRecords.size()});
@ -144,14 +153,23 @@ final class JndiResourceResolverFactory implements DnsNameResolver.ResourceResol
for (String srvRecord : grpclbSrvRecords) {
try {
SrvRecord record = parseSrvRecord(srvRecord);
// SRV requires the host name to be absolute
if (!record.host.endsWith(".")) {
throw new RuntimeException("Returned SRV host does not end in period: " + record.host);
}
// Strip trailing dot for appearance's sake. It _should_ be fine either way, but most
// people expect to see it without the dot.
String authority = record.host.substring(0, record.host.length() - 1);
// But we want to use the trailing dot for the IP lookup. The dot makes the name absolute
// instead of relative and so will avoid the search list like that in resolv.conf.
List<? extends InetAddress> addrs = addressResolver.resolveAddress(record.host);
List<SocketAddress> sockaddrs = new ArrayList<>(addrs.size());
for (InetAddress addr : addrs) {
sockaddrs.add(new InetSocketAddress(addr, record.port));
}
Attributes attrs = Attributes.newBuilder()
.set(GrpcAttributes.ATTR_LB_ADDR_AUTHORITY, record.host)
.set(GrpcAttributes.ATTR_LB_ADDR_AUTHORITY, authority)
.build();
balancerAddresses.add(
new EquivalentAddressGroup(Collections.unmodifiableList(sockaddrs), attrs));
@ -176,8 +194,7 @@ final class JndiResourceResolverFactory implements DnsNameResolver.ResourceResol
return Collections.unmodifiableList(balancerAddresses);
}
@VisibleForTesting
static final class SrvRecord {
private static final class SrvRecord {
SrvRecord(String host, int port) {
this.host = host;
this.port = port;
@ -187,17 +204,50 @@ final class JndiResourceResolverFactory implements DnsNameResolver.ResourceResol
final int port;
}
@VisibleForTesting
@SuppressWarnings("BetaApi") // Verify is only kinda beta
static SrvRecord parseSrvRecord(String rawRecord) {
private static SrvRecord parseSrvRecord(String rawRecord) {
String[] parts = whitespace.split(rawRecord);
Verify.verify(parts.length == 4, "Bad SRV Record: %s", rawRecord);
return new SrvRecord(parts[3], Integer.parseInt(parts[2]));
}
@IgnoreJRERequirement
private static List<String> getAllRecords(String recordType, String name)
throws NamingException {
/**
* Undo the quoting done in {@link com.sun.jndi.dns.ResourceRecord#decodeTxt}.
*/
@VisibleForTesting
static String unquote(String txtRecord) {
StringBuilder sb = new StringBuilder(txtRecord.length());
boolean inquote = false;
for (int i = 0; i < txtRecord.length(); i++) {
char c = txtRecord.charAt(i);
if (!inquote) {
if (c == ' ') {
continue;
} else if (c == '"') {
inquote = true;
continue;
}
} else {
if (c == '"') {
inquote = false;
continue;
} else if (c == '\\') {
c = txtRecord.charAt(++i);
assert c == '"' || c == '\\';
}
}
sb.append(c);
}
return sb.toString();
}
}
@VisibleForTesting
@IgnoreJRERequirement
static final class JndiRecordFetcher implements RecordFetcher {
@Override
public List<String> getAllRecords(String recordType, String name) throws NamingException {
checkAvailable();
String[] rrType = new String[]{recordType};
List<String> records = new ArrayList<>();
@ -237,7 +287,6 @@ final class JndiResourceResolverFactory implements DnsNameResolver.ResourceResol
return records;
}
@IgnoreJRERequirement
private static void closeThenThrow(NamingEnumeration<?> namingEnumeration, NamingException e)
throws NamingException {
try {
@ -248,7 +297,6 @@ final class JndiResourceResolverFactory implements DnsNameResolver.ResourceResol
throw e;
}
@IgnoreJRERequirement
private static void closeThenThrow(DirContext ctx, NamingException e) throws NamingException {
try {
ctx.close();
@ -258,36 +306,6 @@ final class JndiResourceResolverFactory implements DnsNameResolver.ResourceResol
throw e;
}
/**
* Undo the quoting done in {@link com.sun.jndi.dns.ResourceRecord#decodeTxt}.
*/
@VisibleForTesting
static String unquote(String txtRecord) {
StringBuilder sb = new StringBuilder(txtRecord.length());
boolean inquote = false;
for (int i = 0; i < txtRecord.length(); i++) {
char c = txtRecord.charAt(i);
if (!inquote) {
if (c == ' ') {
continue;
} else if (c == '"') {
inquote = true;
continue;
}
} else {
if (c == '"') {
inquote = false;
continue;
} else if (c == '\\') {
c = txtRecord.charAt(++i);
assert c == '"' || c == '\\';
}
}
sb.append(c);
}
return sb.toString();
}
private static void checkAvailable() {
if (JNDI_UNAVAILABILITY_CAUSE != null) {
throw new UnsupportedOperationException(

66
core/src/test/java/io/grpc/internal/JndiResourceResolverTest.java
View File

@ -18,11 +18,21 @@ package io.grpc.internal;
import static com.google.common.truth.Truth.assertThat;
import static org.junit.Assert.assertEquals;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;
import io.grpc.Attributes;
import io.grpc.EquivalentAddressGroup;
import io.grpc.internal.DnsNameResolver.AddressResolver;
import io.grpc.internal.GrpcAttributes;
import io.grpc.internal.JndiResourceResolverFactory.JndiRecordFetcher;
import io.grpc.internal.JndiResourceResolverFactory.JndiResourceResolver;
import io.grpc.internal.JndiResourceResolverFactory.JndiResourceResolver.SrvRecord;
import io.grpc.internal.JndiResourceResolverFactory.RecordFetcher;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.net.UnknownHostException;
import java.util.Arrays;
import java.util.List;
import org.junit.Assume;
import org.junit.Test;
@ -50,15 +60,9 @@ public class JndiResourceResolverTest {
public void jndiResolverWorks() throws Exception {
Assume.assumeNoException(new JndiResourceResolverFactory().unavailabilityCause());
AddressResolver addressResolver = new AddressResolver() {
@Override
public List<InetAddress> resolveAddress(String host) throws Exception {
return null;
}
};
JndiResourceResolver resolver = new JndiResourceResolver();
RecordFetcher recordFetcher = new JndiRecordFetcher();
try {
resolver.resolveSrv(addressResolver, "localhost");
recordFetcher.getAllRecords("SRV", "dns:///localhost");
} catch (javax.naming.CommunicationException e) {
Assume.assumeNoException(e);
} catch (javax.naming.NameNotFoundException e) {
@ -67,9 +71,45 @@ public class JndiResourceResolverTest {
}
@Test
public void parseSrvRecord() {
SrvRecord record = JndiResourceResolver.parseSrvRecord("0 0 1234 foo.bar.com");
assertThat(record.host).isEqualTo("foo.bar.com");
assertThat(record.port).isEqualTo(1234);
public void txtRecordLookup() throws Exception {
RecordFetcher recordFetcher = mock(RecordFetcher.class);
when(recordFetcher.getAllRecords("TXT", "dns:///service.example.com"))
.thenReturn(Arrays.asList("foo", "\"bar\""));
List<String> golden = Arrays.asList("foo", "bar");
JndiResourceResolver resolver = new JndiResourceResolver(recordFetcher);
assertThat(resolver.resolveTxt("service.example.com")).isEqualTo(golden);
}
@Test
public void srvRecordLookup() throws Exception {
AddressResolver addressResolver = mock(AddressResolver.class);
when(addressResolver.resolveAddress("foo.example.com."))
.thenReturn(Arrays.asList(InetAddress.getByName("127.1.2.3")));
when(addressResolver.resolveAddress("bar.example.com."))
.thenReturn(Arrays.asList(
InetAddress.getByName("127.3.2.1"), InetAddress.getByName("::1")));
when(addressResolver.resolveAddress("unknown.example.com."))
.thenThrow(new UnknownHostException("unknown.example.com."));
RecordFetcher recordFetcher = mock(RecordFetcher.class);
when(recordFetcher.getAllRecords("SRV", "dns:///service.example.com"))
.thenReturn(Arrays.asList(
"0 0 314 foo.example.com.", "0 0 42 bar.example.com.", "0 0 1 unknown.example.com."));
List<EquivalentAddressGroup> golden = Arrays.asList(
new EquivalentAddressGroup(
Arrays.<SocketAddress>asList(new InetSocketAddress("127.1.2.3", 314)),
Attributes.newBuilder()
.set(GrpcAttributes.ATTR_LB_ADDR_AUTHORITY, "foo.example.com")
.build()),
new EquivalentAddressGroup(
Arrays.<SocketAddress>asList(
new InetSocketAddress("127.3.2.1", 42),
new InetSocketAddress("::1", 42)),
Attributes.newBuilder()
.set(GrpcAttributes.ATTR_LB_ADDR_AUTHORITY, "bar.example.com")
.build()));
JndiResourceResolver resolver = new JndiResourceResolver(recordFetcher);
assertThat(resolver.resolveSrv(addressResolver, "service.example.com")).isEqualTo(golden);
}
}