Add varz for QUIC 0-RTT acceptance/rejection reasons

PiperOrigin-RevId: 332327315
Change-Id: Id6f5304135042ccbe28c55c2317d68efc299dfcf

quic/core/crypto/crypto_utils.cc

diff --git a/quic/core/crypto/crypto_utils.cc b/quic/core/crypto/crypto_utils.cc
index fe1a5ee..365fb12 100644
--- a/quic/core/crypto/crypto_utils.cc
+++ b/quic/core/crypto/crypto_utils.cc
@@ -691,6 +691,30 @@
 }
 
 // static
+const char* CryptoUtils::EarlyDataReasonToString(
+    ssl_early_data_reason_t reason) {
+  switch (reason) {
+    RETURN_STRING_LITERAL(ssl_early_data_unknown);
+    RETURN_STRING_LITERAL(ssl_early_data_disabled);
+    RETURN_STRING_LITERAL(ssl_early_data_accepted);
+    RETURN_STRING_LITERAL(ssl_early_data_protocol_version);
+    RETURN_STRING_LITERAL(ssl_early_data_peer_declined);
+    RETURN_STRING_LITERAL(ssl_early_data_no_session_offered);
+    RETURN_STRING_LITERAL(ssl_early_data_session_not_resumed);
+    RETURN_STRING_LITERAL(ssl_early_data_unsupported_for_session);
+    RETURN_STRING_LITERAL(ssl_early_data_hello_retry_request);
+    RETURN_STRING_LITERAL(ssl_early_data_alpn_mismatch);
+    RETURN_STRING_LITERAL(ssl_early_data_channel_id);
+    RETURN_STRING_LITERAL(ssl_early_data_token_binding);
+    RETURN_STRING_LITERAL(ssl_early_data_ticket_age_skew);
+    RETURN_STRING_LITERAL(ssl_early_data_quic_parameter_mismatch);
+  }
+  QUIC_BUG_IF(reason < 0 || reason > ssl_early_data_reason_max_value)
+      << "Unknown ssl_early_data_reason_t " << reason;
+  return "unknown ssl_early_data_reason_t";
+}
+
+// static
 std::string CryptoUtils::HashHandshakeMessage(
     const CryptoHandshakeMessage& message,
     Perspective /*perspective*/) {

quic/core/crypto/crypto_utils.h

diff --git a/quic/core/crypto/crypto_utils.h b/quic/core/crypto/crypto_utils.h
index 6c167f8..964f81f 100644
--- a/quic/core/crypto/crypto_utils.h
+++ b/quic/core/crypto/crypto_utils.h
@@ -12,6 +12,7 @@
 #include <string>
 
 #include "third_party/boringssl/src/include/openssl/evp.h"
+#include "third_party/boringssl/src/include/openssl/ssl.h"
 #include "net/third_party/quiche/src/quic/core/crypto/crypto_handshake.h"
 #include "net/third_party/quiche/src/quic/core/crypto/crypto_handshake_message.h"
 #include "net/third_party/quiche/src/quic/core/crypto/crypto_protocol.h"
@@ -211,6 +212,9 @@
   static const char* HandshakeFailureReasonToString(
       HandshakeFailureReason reason);
 
+  // Returns the name of an ssl_early_data_reason_t as a char*
+  static const char* EarlyDataReasonToString(ssl_early_data_reason_t reason);
+
   // Returns a hash of the serialized |message|.
   static std::string HashHandshakeMessage(const CryptoHandshakeMessage& message,
                                           Perspective perspective);