Skip to content

fix(xds): Allow and normalize trailing dot (FQDN) in matchHostName #12644

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
PetitBaguette wants to merge 2 commits into
base: master
Choose a base branch
from
+45 −4
Open

fix(xds): Allow and normalize trailing dot (FQDN) in matchHostName #12644

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
95ff63c
fix(xds): Allow and normalize trailing dot (FQDN) in matchHostName
Feb 4, 2026
1470dd2
style(xds): Fix line length in matchHostName_trailingDot test for che…
Feb 4, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
13 changes: 11 additions & 2 deletions xds/src/main/java/io/grpc/xds/RoutingUtils.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -92,15 +92,24 @@ static VirtualHost findVirtualHostForHostName(List<VirtualHost> virtualHosts, St
* </ol>
*/
private static boolean matchHostName(String hostName, String pattern) {
checkArgument(hostName.length() != 0 && !hostName.startsWith(".") && !hostName.endsWith("."),
checkArgument(hostName.length() != 0 && !hostName.startsWith("."),
"Invalid host name");
checkArgument(pattern.length() != 0 && !pattern.startsWith(".") && !pattern.endsWith("."),
checkArgument(pattern.length() != 0 && !pattern.startsWith("."),
"Invalid pattern/domain name");

hostName = hostName.toLowerCase(Locale.US);
pattern = pattern.toLowerCase(Locale.US);
// hostName and pattern are now in lower case -- domain names are case-insensitive.

// Strip trailing dot to normalize FQDN (e.g. "example.com.") to a relative form,
// as per RFC 1034 Section 3.1 the two are semantically equivalent.
if (hostName.endsWith(".")) {
hostName = hostName.substring(0, hostName.length() - 1);
}
if (pattern.endsWith(".")) {
pattern = pattern.substring(0, pattern.length() - 1);
}

if (!pattern.contains("*")) {
// Not a wildcard pattern -- hostName and pattern must match exactly.
return hostName.equals(pattern);
Expand Down
13 changes: 11 additions & 2 deletions xds/src/main/java/io/grpc/xds/XdsNameResolver.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -354,15 +354,24 @@ private void updateResolutionResult(XdsConfig xdsConfig) {
*/
@VisibleForTesting
static boolean matchHostName(String hostName, String pattern) {
checkArgument(hostName.length() != 0 && !hostName.startsWith(".") && !hostName.endsWith("."),
checkArgument(hostName.length() != 0 && !hostName.startsWith("."),
"Invalid host name");
checkArgument(pattern.length() != 0 && !pattern.startsWith(".") && !pattern.endsWith("."),
checkArgument(pattern.length() != 0 && !pattern.startsWith("."),
"Invalid pattern/domain name");

hostName = hostName.toLowerCase(Locale.US);
pattern = pattern.toLowerCase(Locale.US);
// hostName and pattern are now in lower case -- domain names are case-insensitive.

// Strip trailing dot to normalize FQDN (e.g. "example.com.") to a relative form,
// as per RFC 1034 Section 3.1 the two are semantically equivalent.
if (hostName.endsWith(".")) {
hostName = hostName.substring(0, hostName.length() - 1);
}
if (pattern.endsWith(".")) {
pattern = pattern.substring(0, pattern.length() - 1);
}

if (!pattern.contains("*")) {
// Not a wildcard pattern -- hostName and pattern must match exactly.
return hostName.equals(pattern);
Expand Down
23 changes: 23 additions & 0 deletions xds/src/test/java/io/grpc/xds/XdsNameResolverTest.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2062,6 +2062,29 @@ public void matchHostName_postfixWildCard() {
assertThat(XdsNameResolver.matchHostName("foo-bar", pattern)).isTrue();
}

@Test
public void matchHostName_trailingDot() {
// FQDN (trailing dot) is semantically equivalent to the relative form per RFC 1034 Section 3.1.
assertThat(XdsNameResolver.matchHostName("foo.googleapis.com.", "foo.googleapis.com")).isTrue();
assertThat(XdsNameResolver.matchHostName("foo.googleapis.com", "foo.googleapis.com.")).isTrue();
assertThat(XdsNameResolver.matchHostName("foo.googleapis.com.", "foo.googleapis.com."))
.isTrue();
assertThat(XdsNameResolver.matchHostName("bar.googleapis.com.", "foo.googleapis.com"))
.isFalse();

// Wildcard + trailing dot combinations.
String pattern = "*.foo.googleapis.com";
assertThat(XdsNameResolver.matchHostName("bar.foo.googleapis.com.", pattern)).isTrue();
assertThat(XdsNameResolver.matchHostName("bar.foo.googleapis.com", pattern + ".")).isTrue();
assertThat(XdsNameResolver.matchHostName("bar.foo.googleapis.com.", pattern + ".")).isTrue();
assertThat(XdsNameResolver.matchHostName("foo.googleapis.com.", pattern)).isFalse();

pattern = "foo.*";
assertThat(XdsNameResolver.matchHostName("foo.googleapis.com.", pattern)).isTrue();
assertThat(XdsNameResolver.matchHostName("foo.com.", pattern)).isTrue();
assertThat(XdsNameResolver.matchHostName("bar.googleapis.com.", pattern)).isFalse();
}

@Test
public void resolved_faultAbortInLdsUpdate() {
resolver.start(mockListener);
Expand Down
Loading