Initial commit of sync engine code to browser/sync....

chrome/browser/sync/engine/net/openssl_init.cc

+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// OpenSSL multi-threading initialization
+
+#include "chrome/browser/sync/engine/net/openssl_init.h"
+
+#include <openssl/crypto.h>
+
+#include "base/logging.h"
+#include "chrome/browser/sync/util/compat-pthread.h"
+#include "chrome/browser/sync/util/pthread_helpers.h"
+
+// OpenSSL requires multithreading callbacks to be initialized prior to using
+// the library so that it can manage thread locking as necessary.
+
+// Dynamic lock type
+//
+// This needs to be a struct and in global scope because OpenSSL relies on some
+// macro magic.
+struct CRYPTO_dynlock_value {
+  PThreadMutex mutex;
+  void Lock() {
+    mutex.Lock();
+  }
+  void Unlock() {
+    mutex.Unlock();
+  }
+};
+
+namespace {
+
+// This array stores all of the mutexes available to OpenSSL
+PThreadMutex* mutex_buf = NULL;
+
+// OpenSSL mutex handling callback functions
+
+// OpenSSL Callback - Locks/unlocks the specified mutex held by OpenSSL.
+void OpenSslMutexLockControl(int mode, int n, const char* file, int line) {
+  if (mode & CRYPTO_LOCK) {
+    mutex_buf[n].Lock();
+  } else {
+    mutex_buf[n].Unlock();
+  }
+}
+
+// OpenSSL Callback - Returns the thread ID
+unsigned long OpenSslGetThreadID(void) {
+  return GetCurrentThreadId();
+}
+
+// Dynamic locking functions
+
+// Allocate a new lock
+struct CRYPTO_dynlock_value* dyn_create_function(const char* file, int line) {
+  return new CRYPTO_dynlock_value;
+}
+
+void dyn_lock_function(int mode, struct CRYPTO_dynlock_value* lock,
+                       const char* file, int line) {
+  if (mode & CRYPTO_LOCK) {
+    lock->Lock();
+  } else {
+    lock->Unlock();
+  }
+}
+
+void dyn_destroy_function(struct CRYPTO_dynlock_value* lock,
+                          const char* file, int line) {
+  delete lock;
+}
+
+}  // namespace
+
+// We want to log the version of the OpenSSL library being used, in particular
+// for the case where it's dynamically linked. We want the version from the
+// library, not from the header files. It seems the OpenSSL folks haven't
+// bothered with an accessor for this, so we just pluck it out.
+#ifdef OS_WINDOWS
+// TODO(sync): Figure out how to get the SSL version string on Windows.
+const char* SSL_version_str = "UNKNOWN";
+#else
+extern const char* SSL_version_str;
+#endif
+
+namespace browser_sync {
+
+// Initializes the OpenSSL multithreading callbacks. This isn't thread-safe,
+// but it is called early enough that it doesn't matter.
+void InitOpenSslMultithreading() {
+  LOG(INFO) << "Using OpenSSL headers version " << OPENSSL_VERSION_TEXT
+            << ", lib version " << SSL_version_str;
+
+  if (mutex_buf)
+    return;
+
+  mutex_buf = new PThreadMutex[CRYPTO_num_locks()];
+  CHECK(NULL != mutex_buf);
+
+  // OpenSSL has only one single global set of callbacks, so this
+  // initialization must be done only once, even though the OpenSSL lib may be
+  // used by multiple modules (jingle jabber connections and P2P tunnels).
+  CRYPTO_set_id_callback(OpenSslGetThreadID);
+  CRYPTO_set_locking_callback(OpenSslMutexLockControl);
+
+  CRYPTO_set_dynlock_create_callback(dyn_create_function);
+  CRYPTO_set_dynlock_lock_callback(dyn_lock_function);
+  CRYPTO_set_dynlock_destroy_callback(dyn_destroy_function);
+}
+
+// Cleans up the OpenSSL multithreading callbacks.
+void CleanupOpenSslMultithreading() {
+  if (!mutex_buf) {
+    return;
+  }
+
+  CRYPTO_set_dynlock_create_callback(NULL);
+  CRYPTO_set_dynlock_lock_callback(NULL);
+  CRYPTO_set_dynlock_destroy_callback(NULL);
+
+  CRYPTO_set_id_callback(NULL);
+  CRYPTO_set_locking_callback(NULL);
+
+  delete [] mutex_buf;
+  mutex_buf = NULL;
+}
+
+}  // namespace browser_sync