blob: f7fcdfa6e8a5f0181b3be4810310dcc2df397d0c [file] [log] [blame]
// Copyright 2015 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.
#include "net/ssl/ssl_client_session_cache.h"
#include <utility>
#include "base/containers/flat_set.h"
#include "base/memory/memory_coordinator_client_registry.h"
#include "base/strings/stringprintf.h"
#include "base/time/clock.h"
#include "base/time/default_clock.h"
#include "base/trace_event/process_memory_dump.h"
#include "third_party/boringssl/src/include/openssl/ssl.h"
namespace net {
SSLClientSessionCache::SSLClientSessionCache(const Config& config)
: clock_(base::DefaultClock::GetInstance()),
config_(config),
cache_(config.max_entries),
lookups_since_flush_(0) {
memory_pressure_listener_.reset(new base::MemoryPressureListener(base::Bind(
&SSLClientSessionCache::OnMemoryPressure, base::Unretained(this))));
base::MemoryCoordinatorClientRegistry::GetInstance()->Register(this);
}
SSLClientSessionCache::~SSLClientSessionCache() {
Flush();
base::MemoryCoordinatorClientRegistry::GetInstance()->Unregister(this);
}
size_t SSLClientSessionCache::size() const {
return cache_.size();
}
bssl::UniquePtr<SSL_SESSION> SSLClientSessionCache::Lookup(
const std::string& cache_key) {
base::AutoLock lock(lock_);
// Expire stale sessions.
lookups_since_flush_++;
if (lookups_since_flush_ >= config_.expiration_check_count) {
lookups_since_flush_ = 0;
FlushExpiredSessions();
}
auto iter = cache_.Get(cache_key);
if (iter == cache_.end())
return nullptr;
time_t now = clock_->Now().ToTimeT();
bssl::UniquePtr<SSL_SESSION> session = iter->second.Pop();
if (iter->second.ExpireSessions(now))
cache_.Erase(iter);
if (IsExpired(session.get(), now))
session = nullptr;
return session;
}
void SSLClientSessionCache::ResetLookupCount(const std::string& cache_key) {
base::AutoLock lock(lock_);
// It's possible that the cached session for this key was deleted after the
// Lookup. If that's the case, don't do anything.
auto iter = cache_.Get(cache_key);
if (iter == cache_.end())
return;
}
void SSLClientSessionCache::Insert(const std::string& cache_key,
SSL_SESSION* session) {
base::AutoLock lock(lock_);
SSL_SESSION_up_ref(session);
auto iter = cache_.Get(cache_key);
if (iter == cache_.end())
iter = cache_.Put(cache_key, Entry());
iter->second.Push(bssl::UniquePtr<SSL_SESSION>(session));
}
void SSLClientSessionCache::Flush() {
base::AutoLock lock(lock_);
cache_.Clear();
}
void SSLClientSessionCache::SetClockForTesting(base::Clock* clock) {
clock_ = clock;
}
bool SSLClientSessionCache::IsExpired(SSL_SESSION* session, time_t now) {
if (now < 0)
return true;
uint64_t now_u64 = static_cast<uint64_t>(now);
return now_u64 < SSL_SESSION_get_time(session) ||
now_u64 >=
SSL_SESSION_get_time(session) + SSL_SESSION_get_timeout(session);
}
void SSLClientSessionCache::DumpMemoryStats(
base::trace_event::ProcessMemoryDump* pmd) {
std::string absolute_name = "net/ssl_session_cache";
base::trace_event::MemoryAllocatorDump* cache_dump =
pmd->GetAllocatorDump(absolute_name);
// This method can be reached from different URLRequestContexts. Since this is
// a singleton, only log memory stats once.
// TODO(xunjieli): Change this once crbug.com/458365 is fixed.
if (cache_dump)
return;
cache_dump = pmd->CreateAllocatorDump(absolute_name);
base::AutoLock lock(lock_);
size_t cert_size = 0;
size_t cert_count = 0;
size_t undeduped_cert_size = 0;
size_t undeduped_cert_count = 0;
for (const auto& pair : cache_) {
for (const auto& session : pair.second.sessions) {
if (!session)
continue;
undeduped_cert_count += sk_CRYPTO_BUFFER_num(session->certs);
}
}
// Use a flat_set here to avoid malloc upon insertion.
base::flat_set<const CRYPTO_BUFFER*> crypto_buffer_set;
crypto_buffer_set.reserve(undeduped_cert_count);
for (const auto& pair : cache_) {
for (const auto& session : pair.second.sessions) {
if (!session)
continue;
for (const CRYPTO_BUFFER* cert : session->certs) {
undeduped_cert_size += CRYPTO_BUFFER_len(cert);
auto result = crypto_buffer_set.insert(cert);
if (!result.second)
continue;
cert_size += CRYPTO_BUFFER_len(cert);
cert_count++;
}
}
}
cache_dump->AddScalar(base::trace_event::MemoryAllocatorDump::kNameSize,
base::trace_event::MemoryAllocatorDump::kUnitsBytes,
cert_size);
cache_dump->AddScalar("cert_size",
base::trace_event::MemoryAllocatorDump::kUnitsBytes,
cert_size);
cache_dump->AddScalar("cert_count",
base::trace_event::MemoryAllocatorDump::kUnitsObjects,
cert_count);
cache_dump->AddScalar("undeduped_cert_size",
base::trace_event::MemoryAllocatorDump::kUnitsBytes,
undeduped_cert_size);
cache_dump->AddScalar("undeduped_cert_count",
base::trace_event::MemoryAllocatorDump::kUnitsObjects,
undeduped_cert_count);
}
SSLClientSessionCache::Entry::Entry() = default;
SSLClientSessionCache::Entry::Entry(Entry&&) = default;
SSLClientSessionCache::Entry::~Entry() = default;
void SSLClientSessionCache::Entry::Push(bssl::UniquePtr<SSL_SESSION> session) {
if (sessions[0] != nullptr &&
SSL_SESSION_should_be_single_use(sessions[0].get())) {
sessions[1] = std::move(sessions[0]);
}
sessions[0] = std::move(session);
}
bssl::UniquePtr<SSL_SESSION> SSLClientSessionCache::Entry::Pop() {
if (sessions[0] == nullptr)
return nullptr;
SSL_SESSION* session = sessions[0].get();
SSL_SESSION_up_ref(session);
if (SSL_SESSION_should_be_single_use(session)) {
sessions[0] = std::move(sessions[1]);
sessions[1] = nullptr;
}
return bssl::UniquePtr<SSL_SESSION>(session);
}
bool SSLClientSessionCache::Entry::ExpireSessions(time_t now) {
if (sessions[0] == nullptr)
return true;
if (SSLClientSessionCache::IsExpired(sessions[0].get(), now)) {
return true;
}
if (sessions[1] != nullptr &&
SSLClientSessionCache::IsExpired(sessions[1].get(), now)) {
sessions[1] = nullptr;
}
return false;
}
void SSLClientSessionCache::FlushExpiredSessions() {
time_t now = clock_->Now().ToTimeT();
auto iter = cache_.begin();
while (iter != cache_.end()) {
if (iter->second.ExpireSessions(now)) {
iter = cache_.Erase(iter);
} else {
++iter;
}
}
}
void SSLClientSessionCache::OnMemoryPressure(
base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level) {
switch (memory_pressure_level) {
case base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE:
break;
case base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_MODERATE:
FlushExpiredSessions();
break;
case base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL:
Flush();
break;
}
}
void SSLClientSessionCache::OnPurgeMemory() {
Flush();
}
} // namespace net