1 /*
2 * Copyright (C) 2018 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "DnsTlsSessionCache.h"
18
19 #define LOG_TAG "resolv"
20
21 #include <android-base/logging.h>
22
23 namespace android {
24 namespace net {
25
prepareSsl(SSL * ssl)26 bool DnsTlsSessionCache::prepareSsl(SSL* ssl) {
27 // Add this cache as the 0-index extra data for the socket.
28 // This is used by newSessionCallback.
29 int ret = SSL_set_ex_data(ssl, 0, this);
30 return ret == 1;
31 }
32
prepareSslContext(SSL_CTX * ssl_ctx)33 void DnsTlsSessionCache::prepareSslContext(SSL_CTX* ssl_ctx) {
34 SSL_CTX_set_session_cache_mode(ssl_ctx, SSL_SESS_CACHE_CLIENT);
35 SSL_CTX_sess_set_new_cb(ssl_ctx, &DnsTlsSessionCache::newSessionCallback);
36 }
37
38 // static
newSessionCallback(SSL * ssl,SSL_SESSION * session)39 int DnsTlsSessionCache::newSessionCallback(SSL* ssl, SSL_SESSION* session) {
40 if (!ssl || !session) {
41 LOG(ERROR) << "Null SSL object in new session callback";
42 return 0;
43 }
44 DnsTlsSessionCache* cache = reinterpret_cast<DnsTlsSessionCache*>(
45 SSL_get_ex_data(ssl, 0));
46 if (!cache) {
47 LOG(ERROR) << "null transport in new session callback";
48 return 0;
49 }
50 LOG(DEBUG) << "Recording session";
51 cache->recordSession(session);
52 return 1; // Increment the refcount of session.
53 }
54
recordSession(SSL_SESSION * session)55 void DnsTlsSessionCache::recordSession(SSL_SESSION* session) {
56 std::lock_guard guard(mLock);
57 mSessions.emplace_front(session);
58 if (mSessions.size() > kMaxSize) {
59 LOG(DEBUG) << "Too many sessions; trimming";
60 mSessions.pop_back();
61 }
62 }
63
getSession()64 bssl::UniquePtr<SSL_SESSION> DnsTlsSessionCache::getSession() {
65 std::lock_guard guard(mLock);
66 if (mSessions.size() == 0) {
67 LOG(DEBUG) << "No known sessions";
68 return nullptr;
69 }
70 bssl::UniquePtr<SSL_SESSION> ret = std::move(mSessions.front());
71 mSessions.pop_front();
72 return ret;
73 }
74
75 } // end of namespace net
76 } // end of namespace android
77