Change initial DTLS retransmission timer from 1 second to 50ms.

webrtc/base/opensslstreamadapter.cc

 /*
  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 16 matching lines @@
 
 #include "webrtc/base/common.h"
 #include "webrtc/base/logging.h"
 #include "webrtc/base/safe_conversions.h"
 #include "webrtc/base/stream.h"
 #include "webrtc/base/openssl.h"
 #include "webrtc/base/openssladapter.h"
 #include "webrtc/base/openssldigest.h"
 #include "webrtc/base/opensslidentity.h"
 #include "webrtc/base/stringutils.h"
+#include "webrtc/base/timeutils.h"
 #include "webrtc/base/thread.h"
 
 namespace rtc {
 
 #if (OPENSSL_VERSION_NUMBER >= 0x10001000L)
 #define HAVE_DTLS_SRTP
 #endif
 
 #ifdef HAVE_DTLS_SRTP
 // SRTP cipher suite table. |internal_name| is used to construct a
 // colon-separated profile strings which is needed by
 // SSL_CTX_set_tlsext_use_srtp().
 struct SrtpCipherMapEntry {
   const char* internal_name;
   const int id;
 };
 
 // This isn't elegant, but it's better than an external reference
 static SrtpCipherMapEntry SrtpCipherMap[] = {
     {"SRTP_AES128_CM_SHA1_80", SRTP_AES128_CM_SHA1_80},
     {"SRTP_AES128_CM_SHA1_32", SRTP_AES128_CM_SHA1_32},
     {nullptr, 0}};
 #endif
 
-#ifndef OPENSSL_IS_BORINGSSL
+#ifdef OPENSSL_IS_BORINGSSL
+static void TimeCallback(const SSL* ssl, struct timeval* out_clock) {
+  uint64_t time = TimeNanos();
+  out_clock->tv_sec = time / kNumNanosecsPerSec;
+  out_clock->tv_usec = time / kNumNanosecsPerMicrosec;
+}
+#else  // #ifdef OPENSSL_IS_BORINGSSL
 
 // Cipher name table. Maps internal OpenSSL cipher ids to the RFC name.
 struct SslCipherMapEntry {
   uint32_t openssl_id;
   const char* rfc_name;
 };
 
 #define DEFINE_CIPHER_ENTRY_SSL3(name)  {SSL3_CK_##name, "TLS_"#name}
 #define DEFINE_CIPHER_ENTRY_TLS1(name)  {TLS1_CK_##name, "TLS_"#name}
 
@@ skipping 692 matching lines @@
 
   ssl_ = SSL_new(ssl_ctx_);
   if (!ssl_) {
     BIO_free(bio);
     return -1;
   }
 
   SSL_set_app_data(ssl_, this);
 
   SSL_set_bio(ssl_, bio, bio);  // the SSL object owns the bio now.
-#ifndef OPENSSL_IS_BORINGSSL
   if (ssl_mode_ == SSL_MODE_DTLS) {
+#ifdef OPENSSL_IS_BORINGSSL
+    // Change the initial retransmission timer from 1 second to 50ms.
+    // This will likely result in some spurious retransmissions, but
+    // it's useful for ensuring a timely handshake when there's packet
+    // loss.
+    DTLSv1_set_initial_timeout_duration(ssl_, 50);
+#else
     // Enable read-ahead for DTLS so whole packets are read from internal BIO
     // before parsing. This is done internally by BoringSSL for DTLS.
     SSL_set_read_ahead(ssl_, 1);
+#endif
   }
-#endif
 
   SSL_set_mode(ssl_, SSL_MODE_ENABLE_PARTIAL_WRITE |
                SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 
 #if !defined(OPENSSL_IS_BORINGSSL)
   // Specify an ECDH group for ECDHE ciphers, otherwise OpenSSL cannot
   // negotiate them when acting as the server. Use NIST's P-256 which is
   // commonly supported. BoringSSL doesn't need explicit configuration and has
   // a reasonable default set.
   EC_KEY* ecdh = EC_KEY_new_by_curve_name(NID_X9_62_prime256v1);
@@ skipping 187 matching lines @@
     case SSL_PROTOCOL_TLS_11:
       SSL_CTX_set_max_version(ctx, ssl_mode_ == SSL_MODE_DTLS ?
           DTLS1_VERSION : TLS1_1_VERSION);
       break;
     case SSL_PROTOCOL_TLS_12:
     default:
       SSL_CTX_set_max_version(ctx, ssl_mode_ == SSL_MODE_DTLS ?
           DTLS1_2_VERSION : TLS1_2_VERSION);
       break;
   }
+  // Set a time callback for BoringSSL because:
+  // 1. Our time function is more accurate (doesn't just use gettimeofday).
+  // 2. This allows us to inject a fake clock for testing.
+  // SSL_CTX_set_current_time_cb(ctx, &TimeCallback);
+  ctx->current_time_cb = &TimeCallback;
 #endif
 
   if (identity_ && !identity_->ConfigureIdentity(ctx)) {
     SSL_CTX_free(ctx);
     return NULL;
   }
 
 #if !defined(NDEBUG)
   SSL_CTX_set_info_callback(ctx, OpenSSLAdapter::SSLInfoCallback);
 #endif
@@ skipping 122 matching lines @@
 }
 
 bool OpenSSLStreamAdapter::HaveExporter() {
 #ifdef HAVE_DTLS_SRTP
   return true;
 #else
   return false;
 #endif
 }
 
+bool OpenSSLStreamAdapter::IsBoringSsl() {
+#ifdef OPENSSL_IS_BORINGSSL
+  return true;
+#else
+  return false;
+#endif
+}
+
 #define CDEF(X) \
   { static_cast<uint16_t>(TLS1_CK_##X & 0xffff), "TLS_" #X }
 
 struct cipher_list {
   uint16_t cipher;
   const char* cipher_str;
 };
 
 // TODO(torbjorng): Perhaps add more cipher suites to these lists.
 static const cipher_list OK_RSA_ciphers[] = {
@@ skipping 54 matching lines @@
         return true;
     }
   }
 
   return false;
 }
 
 }  // namespace rtc
 
 #endif  // HAVE_OPENSSL_SSL_H