Fixing SSL error that occurs when underlying socket is blocked.

webrtc/base/openssladapter.h

 /*
  *  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.
  */
 
 #ifndef WEBRTC_BASE_OPENSSLADAPTER_H__
 #define WEBRTC_BASE_OPENSSLADAPTER_H__
 
 #include <string>
+#include "webrtc/base/buffer.h"
 #include "webrtc/base/messagehandler.h"
 #include "webrtc/base/messagequeue.h"
 #include "webrtc/base/ssladapter.h"
 
 typedef struct ssl_st SSL;
 typedef struct ssl_ctx_st SSL_CTX;
 typedef struct x509_store_ctx_st X509_STORE_CTX;
 
 namespace rtc {
 
@@ skipping 33 matching lines @@
     SSL_NONE, SSL_WAIT, SSL_CONNECTING, SSL_CONNECTED, SSL_ERROR
   };
 
   enum { MSG_TIMEOUT };
 
   int BeginSSL();
   int ContinueSSL();
   void Error(const char* context, int err, bool signal = true);
   void Cleanup();
 
+  // Return value and arguments have the same meanings as for Send.
+  int DoSslWrite(const void* pv, size_t cb);
+
   void OnMessage(Message* msg) override;
 
   static bool VerifyServerName(SSL* ssl, const char* host,
                                bool ignore_bad_cert);
   bool SSLPostConnectionCheck(SSL* ssl, const char* host);
 #if !defined(NDEBUG)
   static void SSLInfoCallback(const SSL* s, int where, int ret);
 #endif
   static int SSLVerifyCallback(int ok, X509_STORE_CTX* store);
   static VerificationCallback custom_verify_callback_;
   friend class OpenSSLStreamAdapter;  // for custom_verify_callback_;
 
   static bool ConfigureTrustedRootCertificates(SSL_CTX* ctx);
   SSL_CTX* SetupSSLContext();
 
   SSLState state_;
   bool ssl_read_needs_write_;
   bool ssl_write_needs_read_;
   // If true, socket will retain SSL configuration after Close.
   bool restartable_;
 
+  // Set to true if SSL_write fails with SSL_ERROR_WANT_WRITE, which means we
+  // need to keep retrying with *the same exact data* until it succeeds.
+  bool pending_write_ = false;
+  Buffer pending_data_;

[pthatcher1, 2017/06/02 04:58:21]

Why do we need both?  Can't the non-emptiness of pending_data_ be sufficient to
know there is pending data to write?

[Taylor Brandstetter, 2017/06/02 06:49:14]

Sure, done.

+
   SSL* ssl_;
   SSL_CTX* ssl_ctx_;
   std::string ssl_host_name_;
   // Do DTLS or not
   SSLMode ssl_mode_;
 
   bool custom_verification_succeeded_;
 };
 
 /////////////////////////////////////////////////////////////////////////////
 
 } // namespace rtc
 
 #endif // WEBRTC_BASE_OPENSSLADAPTER_H__