| /* |
| * Copyright (C) 2019 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #define LOG_TAG "ResolverController" |
| |
| #include "ResolverController.h" |
| |
| #include <set> |
| #include <string> |
| #include <vector> |
| |
| #include <netdb.h> |
| |
| #include <Fwmark.h> |
| #include <aidl/android/net/IDnsResolver.h> |
| #include <android-base/logging.h> |
| #include <android-base/strings.h> |
| |
| #include "Dns64Configuration.h" |
| #include "DnsResolver.h" |
| #include "PrivateDnsConfiguration.h" |
| #include "ResolverEventReporter.h" |
| #include "ResolverStats.h" |
| #include "netd_resolv/stats.h" |
| #include "resolv_cache.h" |
| |
| using aidl::android::net::ResolverParamsParcel; |
| |
| namespace android { |
| |
| using netdutils::DumpWriter; |
| |
| namespace net { |
| |
| namespace { |
| |
| std::string addrToString(const sockaddr_storage* addr) { |
| char out[INET6_ADDRSTRLEN] = {0}; |
| getnameinfo((const sockaddr*)addr, sizeof(sockaddr_storage), out, INET6_ADDRSTRLEN, nullptr, 0, |
| NI_NUMERICHOST); |
| return std::string(out); |
| } |
| |
| const char* getPrivateDnsModeString(PrivateDnsMode mode) { |
| switch (mode) { |
| case PrivateDnsMode::OFF: |
| return "OFF"; |
| case PrivateDnsMode::OPPORTUNISTIC: |
| return "OPPORTUNISTIC"; |
| case PrivateDnsMode::STRICT: |
| return "STRICT"; |
| } |
| } |
| |
| constexpr const char* validationStatusToString(Validation value) { |
| switch (value) { |
| case Validation::in_process: |
| return "in_process"; |
| case Validation::success: |
| return "success"; |
| case Validation::fail: |
| return "fail"; |
| case Validation::unknown_server: |
| return "unknown_server"; |
| case Validation::unknown_netid: |
| return "unknown_netid"; |
| default: |
| return "unknown_status"; |
| } |
| } |
| |
| void sendNat64PrefixEvent(const Dns64Configuration::Nat64PrefixInfo& args) { |
| const auto& listeners = ResolverEventReporter::getInstance().getListeners(); |
| if (listeners.size() == 0) { |
| LOG(ERROR) << __func__ << ": No available listener. dropping NAT64 prefix event"; |
| return; |
| } |
| for (const auto& it : listeners) { |
| it->onNat64PrefixEvent(args.netId, args.added, args.prefixString, args.prefixLength); |
| } |
| } |
| |
| int getDnsInfo(unsigned netId, std::vector<std::string>* servers, std::vector<std::string>* domains, |
| res_params* params, std::vector<android::net::ResolverStats>* stats, |
| std::vector<int32_t>* wait_for_pending_req_timeout_count) { |
| using aidl::android::net::IDnsResolver; |
| using android::net::ResolverStats; |
| static_assert(ResolverStats::STATS_SUCCESSES == IDnsResolver::RESOLVER_STATS_SUCCESSES && |
| ResolverStats::STATS_ERRORS == IDnsResolver::RESOLVER_STATS_ERRORS && |
| ResolverStats::STATS_TIMEOUTS == IDnsResolver::RESOLVER_STATS_TIMEOUTS && |
| ResolverStats::STATS_INTERNAL_ERRORS == |
| IDnsResolver::RESOLVER_STATS_INTERNAL_ERRORS && |
| ResolverStats::STATS_RTT_AVG == IDnsResolver::RESOLVER_STATS_RTT_AVG && |
| ResolverStats::STATS_LAST_SAMPLE_TIME == |
| IDnsResolver::RESOLVER_STATS_LAST_SAMPLE_TIME && |
| ResolverStats::STATS_USABLE == IDnsResolver::RESOLVER_STATS_USABLE && |
| ResolverStats::STATS_COUNT == IDnsResolver::RESOLVER_STATS_COUNT, |
| "AIDL and ResolverStats.h out of sync"); |
| int nscount = -1; |
| sockaddr_storage res_servers[MAXNS]; |
| int dcount = -1; |
| char res_domains[MAXDNSRCH][MAXDNSRCHPATH]; |
| res_stats res_stats[MAXNS]; |
| servers->clear(); |
| domains->clear(); |
| *params = res_params{}; |
| stats->clear(); |
| int res_wait_for_pending_req_timeout_count; |
| int revision_id = android_net_res_stats_get_info_for_net( |
| netId, &nscount, res_servers, &dcount, res_domains, params, res_stats, |
| &res_wait_for_pending_req_timeout_count); |
| |
| // If the netId is unknown (which can happen for valid net IDs for which no DNS servers have |
| // yet been configured), there is no revision ID. In this case there is no data to return. |
| if (revision_id < 0) { |
| return 0; |
| } |
| |
| // Verify that the returned data is sane. |
| if (nscount < 0 || nscount > MAXNS || dcount < 0 || dcount > MAXDNSRCH) { |
| LOG(ERROR) << __func__ << ": nscount = " << nscount << ", dcount = " << dcount; |
| return -ENOTRECOVERABLE; |
| } |
| |
| // Determine which servers are considered usable by the resolver. |
| bool valid_servers[MAXNS]; |
| std::fill_n(valid_servers, MAXNS, false); |
| android_net_res_stats_get_usable_servers(params, res_stats, nscount, valid_servers); |
| |
| // Convert the server sockaddr structures to std::string. |
| stats->resize(nscount); |
| for (int i = 0; i < nscount; ++i) { |
| char hbuf[NI_MAXHOST]; |
| int rv = |
| getnameinfo(reinterpret_cast<const sockaddr*>(&res_servers[i]), |
| sizeof(res_servers[i]), hbuf, sizeof(hbuf), nullptr, 0, NI_NUMERICHOST); |
| std::string server_str; |
| if (rv == 0) { |
| server_str.assign(hbuf); |
| } else { |
| LOG(ERROR) << "getnameinfo() failed for server #" << i << ": " << gai_strerror(rv); |
| server_str.assign("<invalid>"); |
| } |
| servers->push_back(std::move(server_str)); |
| android::net::ResolverStats& cur_stats = (*stats)[i]; |
| android_net_res_stats_aggregate(&res_stats[i], &cur_stats.successes, &cur_stats.errors, |
| &cur_stats.timeouts, &cur_stats.internal_errors, |
| &cur_stats.rtt_avg, &cur_stats.last_sample_time); |
| cur_stats.usable = valid_servers[i]; |
| } |
| |
| // Convert the stack-allocated search domain strings to std::string. |
| for (int i = 0; i < dcount; ++i) { |
| domains->push_back(res_domains[i]); |
| } |
| |
| (*wait_for_pending_req_timeout_count)[0] = res_wait_for_pending_req_timeout_count; |
| return 0; |
| } |
| |
| } // namespace |
| |
| ResolverController::ResolverController() |
| : mDns64Configuration( |
| [](uint32_t netId, uint32_t uid, android_net_context* netcontext) { |
| gResNetdCallbacks.get_network_context(netId, uid, netcontext); |
| }, |
| std::bind(sendNat64PrefixEvent, std::placeholders::_1)) {} |
| |
| void ResolverController::destroyNetworkCache(unsigned netId) { |
| LOG(VERBOSE) << __func__ << ": netId = " << netId; |
| |
| resolv_delete_cache_for_net(netId); |
| mDns64Configuration.stopPrefixDiscovery(netId); |
| gPrivateDnsConfiguration.clear(netId); |
| } |
| |
| int ResolverController::createNetworkCache(unsigned netId) { |
| LOG(VERBOSE) << __func__ << ": netId = " << netId; |
| |
| return resolv_create_cache_for_net(netId); |
| } |
| |
| int ResolverController::setResolverConfiguration(const ResolverParamsParcel& resolverParams) { |
| using aidl::android::net::IDnsResolver; |
| |
| // At private DNS validation time, we only know the netId, so we have to guess/compute the |
| // corresponding socket mark. |
| Fwmark fwmark; |
| fwmark.netId = resolverParams.netId; |
| fwmark.explicitlySelected = true; |
| fwmark.protectedFromVpn = true; |
| fwmark.permission = PERMISSION_SYSTEM; |
| |
| // Allow at most MAXNS private DNS servers in a network to prevent too many broken servers. |
| std::vector<std::string> tlsServers = resolverParams.tlsServers; |
| if (tlsServers.size() > MAXNS) { |
| tlsServers.resize(MAXNS); |
| } |
| const int err = |
| gPrivateDnsConfiguration.set(resolverParams.netId, fwmark.intValue, tlsServers, |
| resolverParams.tlsName, resolverParams.caCertificate); |
| |
| if (err != 0) { |
| return err; |
| } |
| |
| res_params res_params = {}; |
| res_params.sample_validity = resolverParams.sampleValiditySeconds; |
| res_params.success_threshold = resolverParams.successThreshold; |
| res_params.min_samples = resolverParams.minSamples; |
| res_params.max_samples = resolverParams.maxSamples; |
| res_params.base_timeout_msec = resolverParams.baseTimeoutMsec; |
| res_params.retry_count = resolverParams.retryCount; |
| |
| return resolv_set_nameservers(resolverParams.netId, resolverParams.servers, |
| resolverParams.domains, res_params); |
| } |
| |
| int ResolverController::getResolverInfo(int32_t netId, std::vector<std::string>* servers, |
| std::vector<std::string>* domains, |
| std::vector<std::string>* tlsServers, |
| std::vector<int32_t>* params, std::vector<int32_t>* stats, |
| std::vector<int32_t>* wait_for_pending_req_timeout_count) { |
| using aidl::android::net::IDnsResolver; |
| using android::net::ResolverStats; |
| res_params res_params; |
| std::vector<ResolverStats> res_stats; |
| int ret = getDnsInfo(netId, servers, domains, &res_params, &res_stats, |
| wait_for_pending_req_timeout_count); |
| if (ret != 0) { |
| return ret; |
| } |
| |
| // Serialize the information for binder. |
| ResolverStats::encodeAll(res_stats, stats); |
| |
| const auto privateDnsStatus = gPrivateDnsConfiguration.getStatus(netId); |
| for (const auto& pair : privateDnsStatus.serversMap) { |
| tlsServers->push_back(addrToString(&pair.first.ss)); |
| } |
| |
| params->resize(IDnsResolver::RESOLVER_PARAMS_COUNT); |
| (*params)[IDnsResolver::RESOLVER_PARAMS_SAMPLE_VALIDITY] = res_params.sample_validity; |
| (*params)[IDnsResolver::RESOLVER_PARAMS_SUCCESS_THRESHOLD] = res_params.success_threshold; |
| (*params)[IDnsResolver::RESOLVER_PARAMS_MIN_SAMPLES] = res_params.min_samples; |
| (*params)[IDnsResolver::RESOLVER_PARAMS_MAX_SAMPLES] = res_params.max_samples; |
| (*params)[IDnsResolver::RESOLVER_PARAMS_BASE_TIMEOUT_MSEC] = res_params.base_timeout_msec; |
| (*params)[IDnsResolver::RESOLVER_PARAMS_RETRY_COUNT] = res_params.retry_count; |
| return 0; |
| } |
| |
| void ResolverController::startPrefix64Discovery(int32_t netId) { |
| mDns64Configuration.startPrefixDiscovery(netId); |
| } |
| |
| void ResolverController::stopPrefix64Discovery(int32_t netId) { |
| return mDns64Configuration.stopPrefixDiscovery(netId); |
| } |
| |
| // TODO: use StatusOr<T> to wrap the result. |
| int ResolverController::getPrefix64(unsigned netId, netdutils::IPPrefix* prefix) { |
| netdutils::IPPrefix p = mDns64Configuration.getPrefix64(netId); |
| if (p.family() != AF_INET6 || p.length() == 0) { |
| LOG(ERROR) << "No valid NAT64 prefix (" << netId << ", " << p.toString().c_str() << ")"; |
| |
| return -ENOENT; |
| } |
| *prefix = p; |
| return 0; |
| } |
| |
| void ResolverController::dump(DumpWriter& dw, unsigned netId) { |
| // No lock needed since Bionic's resolver locks all accessed data structures internally. |
| using android::net::ResolverStats; |
| std::vector<std::string> servers; |
| std::vector<std::string> domains; |
| res_params params = {}; |
| std::vector<ResolverStats> stats; |
| std::vector<int32_t> wait_for_pending_req_timeout_count(1, 0); |
| time_t now = time(nullptr); |
| int rv = getDnsInfo(netId, &servers, &domains, ¶ms, &stats, |
| &wait_for_pending_req_timeout_count); |
| dw.incIndent(); |
| if (rv != 0) { |
| dw.println("getDnsInfo() failed for netid %u", netId); |
| } else { |
| if (servers.empty()) { |
| dw.println("No DNS servers defined"); |
| } else { |
| dw.println("DnsEvent subsampling map: " + |
| android::base::Join(resolv_cache_dump_subsampling_map(netId), ' ')); |
| dw.println( |
| "DNS servers: # IP (total, successes, errors, timeouts, internal errors, " |
| "RTT avg, last sample)"); |
| dw.incIndent(); |
| for (size_t i = 0; i < servers.size(); ++i) { |
| if (i < stats.size()) { |
| const ResolverStats& s = stats[i]; |
| int total = s.successes + s.errors + s.timeouts + s.internal_errors; |
| if (total > 0) { |
| int time_delta = (s.last_sample_time > 0) ? now - s.last_sample_time : -1; |
| dw.println("%s (%d, %d, %d, %d, %d, %dms, %ds)%s", servers[i].c_str(), |
| total, s.successes, s.errors, s.timeouts, s.internal_errors, |
| s.rtt_avg, time_delta, s.usable ? "" : " BROKEN"); |
| } else { |
| dw.println("%s <no data>", servers[i].c_str()); |
| } |
| } else { |
| dw.println("%s <no stats>", servers[i].c_str()); |
| } |
| } |
| dw.decIndent(); |
| } |
| if (domains.empty()) { |
| dw.println("No search domains defined"); |
| } else { |
| std::string domains_str = android::base::Join(domains, ", "); |
| dw.println("search domains: %s", domains_str.c_str()); |
| } |
| if (params.sample_validity != 0) { |
| dw.println( |
| "DNS parameters: sample validity = %us, success threshold = %u%%, " |
| "samples (min, max) = (%u, %u), base_timeout = %dmsec, retry count = " |
| "%dtimes", |
| params.sample_validity, params.success_threshold, params.min_samples, |
| params.max_samples, params.base_timeout_msec, params.retry_count); |
| } |
| |
| mDns64Configuration.dump(dw, netId); |
| const auto privateDnsStatus = gPrivateDnsConfiguration.getStatus(netId); |
| dw.println("Private DNS mode: %s", getPrivateDnsModeString(privateDnsStatus.mode)); |
| if (privateDnsStatus.serversMap.size() == 0) { |
| dw.println("No Private DNS servers configured"); |
| } else { |
| dw.println("Private DNS configuration (%u entries)", |
| static_cast<uint32_t>(privateDnsStatus.serversMap.size())); |
| dw.incIndent(); |
| for (const auto& pair : privateDnsStatus.serversMap) { |
| dw.println("%s name{%s} status{%s}", addrToString(&pair.first.ss).c_str(), |
| pair.first.name.c_str(), validationStatusToString(pair.second)); |
| } |
| dw.decIndent(); |
| } |
| dw.println("Concurrent DNS query timeout: %d", wait_for_pending_req_timeout_count[0]); |
| } |
| dw.decIndent(); |
| } |
| |
| } // namespace net |
| } // namespace android |
