differentiate fizz ALPN exception messages.

Summary: Use different message according to different AlpnMode in FizzException triggered by ALPN mismatch. Reviewed By: mingtaoy Differential Revision: D30578825 fbshipit-source-id: 690376fdb9a80371acaa621377d831dd665abec6
facebookincubator · Aug 26, 2021 · 7925b2e · 7925b2e
1 parent 0beab30
commit 7925b2e
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Showing 2 changed files with 6 additions and 5 deletions.
diff --git a/fizz/server/ServerProtocol.cpp b/fizz/server/ServerProtocol.cpp
@@ -777,9 +777,10 @@ static Optional<std::string> negotiateAlpn(
   if (!selected) {
     VLOG(6) << "ALPN mismatch";
     if (context.getAlpnMode() != AlpnMode::AllowMismatch) {
-      throw FizzException(
-          "ALPN mismatch when required",
-          AlertDescription::no_application_protocol);
+      auto msg = context.getAlpnMode() == AlpnMode::Optional
+          ? "Unable to negotiate ALPN, as required by policy. policy=AlpnMode::Optional"
+          : "Unable to negotiate ALPN, as required by policy. policy=AlpnMode::Required";
+      throw FizzException(msg, AlertDescription::no_application_protocol);
     }
   } else {
     VLOG(6) << "ALPN: " << *selected;

diff --git a/fizz/server/test/ServerProtocolTest.cpp b/fizz/server/test/ServerProtocolTest.cpp
@@ -3709,7 +3709,7 @@ TEST_F(ServerProtocolTest, TestClientHelloMismatchAlpnOptional) {
   expectError<FizzException>(
       actions,
       AlertDescription::no_application_protocol,
-      "ALPN mismatch when required");
+      "Unable to negotiate ALPN, as required by policy. policy=AlpnMode::Optional");
 }
 
 TEST_F(ServerProtocolTest, TestClientHelloNoAlpnRequired) {
@@ -3755,7 +3755,7 @@ TEST_F(ServerProtocolTest, TestClientHelloMismatchAlpnRequired) {
   expectError<FizzException>(
       actions,
       AlertDescription::no_application_protocol,
-      "ALPN mismatch when required");
+      "Unable to negotiate ALPN, as required by policy. policy=AlpnMode::Required");
 }
 
 TEST_F(ServerProtocolTest, TestClientHelloServerPref) {