| /* |
| * Copyright (C) 2011 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" |
| #define DBG 0 |
| |
| #include <algorithm> |
| #include <cstdlib> |
| #include <map> |
| #include <mutex> |
| #include <set> |
| #include <string> |
| #include <thread> |
| #include <utility> |
| #include <vector> |
| #include <log/log.h> |
| #include <net/if.h> |
| #include <sys/socket.h> |
| #include <netdb.h> |
| |
| #include <arpa/inet.h> |
| |
| #include <android-base/strings.h> |
| #include <android-base/thread_annotations.h> |
| #include <android/net/INetd.h> |
| #include <android/net/metrics/INetdEventListener.h> |
| |
| #include "Controllers.h" |
| #include "DumpWriter.h" |
| #include "EventReporter.h" |
| #include "Fwmark.h" |
| #include "NetdConstants.h" |
| #include "Permission.h" |
| #include "ResolverController.h" |
| #include "ResolverStats.h" |
| #include "netd_resolv/params.h" |
| #include "netd_resolv/resolv.h" |
| #include "netd_resolv/stats.h" |
| |
| namespace android { |
| 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 onPrivateDnsValidation(unsigned netId, const char* server, const char* hostname, |
| bool success) { |
| // Send a validation event to NetdEventListenerService. |
| const auto netdEventListener = net::gCtls->eventReporter.getNetdEventListener(); |
| if (netdEventListener != nullptr) { |
| netdEventListener->onPrivateDnsValidationEvent(netId, android::String16(server), |
| android::String16(hostname), success); |
| if (DBG) { |
| ALOGD("Sending validation %s event on netId %u for %s with hostname %s", |
| success ? "success" : "failure", netId, server, hostname); |
| } |
| |
| } else { |
| ALOGE("Validation event not sent since NetdEventListenerService is unavailable."); |
| } |
| } |
| |
| bool allIPv6Only(const std::vector<std::string>& servers) { |
| for (const auto& server : servers) { |
| if (server.find(':') == std::string::npos) return false; |
| } |
| return !servers.empty(); |
| } |
| |
| } // namespace |
| |
| int ResolverController::setDnsServers(unsigned netId, const char* searchDomains, |
| const char** servers, int numservers, const __res_params* params) { |
| if (DBG) { |
| ALOGD("setDnsServers netId = %u, numservers = %d", netId, numservers); |
| } |
| return -resolv_set_nameservers_for_net(netId, servers, numservers, searchDomains, params); |
| } |
| |
| int ResolverController::clearDnsServers(unsigned netId) { |
| resolv_set_nameservers_for_net(netId, nullptr, 0, "", nullptr); |
| if (DBG) { |
| ALOGD("clearDnsServers netId = %u\n", netId); |
| } |
| mDns64Configuration.stopPrefixDiscovery(netId); |
| resolv_delete_private_dns_for_net(netId); |
| return 0; |
| } |
| |
| int ResolverController::flushDnsCache(unsigned netId) { |
| if (DBG) { |
| ALOGD("flushDnsCache netId = %u\n", netId); |
| } |
| |
| resolv_flush_cache_for_net(netId); |
| |
| return 0; |
| } |
| |
| int ResolverController::getDnsInfo(unsigned netId, std::vector<std::string>* servers, |
| std::vector<std::string>* domains, __res_params* params, |
| std::vector<android::net::ResolverStats>* stats) { |
| using android::net::ResolverStats; |
| using android::net::INetd; |
| static_assert(ResolverStats::STATS_SUCCESSES == INetd::RESOLVER_STATS_SUCCESSES && |
| ResolverStats::STATS_ERRORS == INetd::RESOLVER_STATS_ERRORS && |
| ResolverStats::STATS_TIMEOUTS == INetd::RESOLVER_STATS_TIMEOUTS && |
| ResolverStats::STATS_INTERNAL_ERRORS == INetd::RESOLVER_STATS_INTERNAL_ERRORS && |
| ResolverStats::STATS_RTT_AVG == INetd::RESOLVER_STATS_RTT_AVG && |
| ResolverStats::STATS_LAST_SAMPLE_TIME == INetd::RESOLVER_STATS_LAST_SAMPLE_TIME && |
| ResolverStats::STATS_USABLE == INetd::RESOLVER_STATS_USABLE && |
| ResolverStats::STATS_COUNT == INetd::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 revision_id = android_net_res_stats_get_info_for_net(netId, &nscount, res_servers, &dcount, |
| res_domains, params, res_stats); |
| |
| // 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) { |
| ALOGE("%s: nscount=%d, dcount=%d", __FUNCTION__, nscount, 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 { |
| ALOGE("getnameinfo() failed for server #%d: %s", 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]); |
| } |
| return 0; |
| } |
| |
| int ResolverController::setResolverConfiguration(int32_t netId, |
| const std::vector<std::string>& servers, const std::vector<std::string>& domains, |
| const std::vector<int32_t>& params, const std::string& tlsName, |
| const std::vector<std::string>& tlsServers, |
| const std::set<std::vector<uint8_t>>& tlsFingerprints) { |
| using android::net::INetd; |
| // TODO: make RESOLVER_PARAMS_BASE_TIMEOUT_MSEC a mandatory parameter once all callers |
| // have been updated to specify it. |
| if (params.size() < INetd::RESOLVER_PARAMS_BASE_TIMEOUT_MSEC || |
| params.size() > INetd::RESOLVER_PARAMS_COUNT) { |
| ALOGE("%s: params.size()=%zu", __FUNCTION__, params.size()); |
| return -EINVAL; |
| } |
| |
| std::vector<const char*> server_ptrs; |
| size_t count = std::min<size_t>(MAXNS, tlsServers.size()); |
| server_ptrs.reserve(count); |
| for (size_t i = 0; i < count; i++) { |
| server_ptrs.push_back(tlsServers[i].data()); |
| } |
| |
| std::vector<const uint8_t*> fingerprint_ptrs; |
| count = tlsFingerprints.size(); |
| fingerprint_ptrs.reserve(count); |
| for (const auto& fp : tlsFingerprints) { |
| fingerprint_ptrs.push_back(fp.data()); |
| } |
| |
| // At private DNS validation time, we only know the netId, so we have to guess/compute the |
| // corresponding socket mark. |
| Fwmark fwmark; |
| fwmark.netId = netId; |
| fwmark.explicitlySelected = true; |
| fwmark.protectedFromVpn = true; |
| fwmark.permission = PERMISSION_SYSTEM; |
| |
| const int err = resolv_set_private_dns_for_net( |
| netId, fwmark.intValue, server_ptrs.data(), server_ptrs.size(), tlsName.c_str(), |
| fingerprint_ptrs.data(), fingerprint_ptrs.size()); |
| if (err != 0) { |
| return err; |
| } |
| resolv_register_private_dns_callback(&onPrivateDnsValidation); |
| |
| // Convert network-assigned server list to bionic's format. |
| server_ptrs.clear(); |
| count = std::min<size_t>(MAXNS, servers.size()); |
| server_ptrs.reserve(count); |
| for (size_t i = 0; i < count; ++i) { |
| server_ptrs.push_back(servers[i].c_str()); |
| } |
| |
| std::string domains_str; |
| if (!domains.empty()) { |
| domains_str = domains[0]; |
| for (size_t i = 1 ; i < domains.size() ; ++i) { |
| domains_str += " " + domains[i]; |
| } |
| } |
| |
| __res_params res_params = {}; |
| res_params.sample_validity = params[INetd::RESOLVER_PARAMS_SAMPLE_VALIDITY]; |
| res_params.success_threshold = params[INetd::RESOLVER_PARAMS_SUCCESS_THRESHOLD]; |
| res_params.min_samples = params[INetd::RESOLVER_PARAMS_MIN_SAMPLES]; |
| res_params.max_samples = params[INetd::RESOLVER_PARAMS_MAX_SAMPLES]; |
| if (params.size() > INetd::RESOLVER_PARAMS_BASE_TIMEOUT_MSEC) { |
| res_params.base_timeout_msec = params[INetd::RESOLVER_PARAMS_BASE_TIMEOUT_MSEC]; |
| } |
| |
| const auto rval = setDnsServers(netId, domains_str.c_str(), server_ptrs.data(), |
| server_ptrs.size(), &res_params); |
| |
| if (rval == 0) { |
| // Start DNS64 discovery after successfully setting any new DNS servers |
| // as the cache may have been cleared (if the nameservers differ), and |
| // we might discover a different DNS64 prefix. If the cache has not been |
| // cleared, we may quickly rediscover the same prefix. |
| // |
| // Operators may choose to use a longer TTL in order to reduce repeated |
| // resolution (see also https://tools.ietf.org/html/rfc7050#section-5). |
| if (allIPv6Only(servers)) { |
| // TODO: Keep any existing discovered prefix around for use while |
| // re-discovery is in progress. Otherwise, whenever DNS servers are |
| // pushed to netd there can be gaps where it would appear there was |
| // no prefix64 when in fact we had previously discovered one (and |
| // are highly likely to rediscover the same one). |
| mDns64Configuration.startPrefixDiscovery(netId); |
| } else { |
| mDns64Configuration.stopPrefixDiscovery(netId); |
| } |
| } |
| |
| return rval; |
| } |
| |
| int ResolverController::getResolverInfo(int32_t netId, std::vector<std::string>* servers, |
| std::vector<std::string>* domains, std::vector<int32_t>* params, |
| std::vector<int32_t>* stats) { |
| using android::net::ResolverStats; |
| using android::net::INetd; |
| __res_params res_params; |
| std::vector<ResolverStats> res_stats; |
| int ret = getDnsInfo(netId, servers, domains, &res_params, &res_stats); |
| if (ret != 0) { |
| return ret; |
| } |
| |
| // Serialize the information for binder. |
| ResolverStats::encodeAll(res_stats, stats); |
| |
| params->resize(INetd::RESOLVER_PARAMS_COUNT); |
| (*params)[INetd::RESOLVER_PARAMS_SAMPLE_VALIDITY] = res_params.sample_validity; |
| (*params)[INetd::RESOLVER_PARAMS_SUCCESS_THRESHOLD] = res_params.success_threshold; |
| (*params)[INetd::RESOLVER_PARAMS_MIN_SAMPLES] = res_params.min_samples; |
| (*params)[INetd::RESOLVER_PARAMS_MAX_SAMPLES] = res_params.max_samples; |
| (*params)[INetd::RESOLVER_PARAMS_BASE_TIMEOUT_MSEC] = res_params.base_timeout_msec; |
| 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; |
| time_t now = time(nullptr); |
| int rv = getDnsInfo(netId, &servers, &domains, ¶ms, &stats); |
| 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("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", |
| params.sample_validity, static_cast<unsigned>(params.success_threshold), |
| static_cast<unsigned>(params.min_samples), |
| static_cast<unsigned>(params.max_samples), params.base_timeout_msec); |
| } |
| |
| mDns64Configuration.dump(dw, netId); |
| ExternalPrivateDnsStatus privateDnsStatus = {PrivateDnsMode::OFF, 0, {}}; |
| resolv_get_private_dns_status_for_net(netId, &privateDnsStatus); |
| dw.println("Private DNS mode: %s", |
| getPrivateDnsModeString(static_cast<PrivateDnsMode>(privateDnsStatus.mode))); |
| if (!privateDnsStatus.numServers) { |
| dw.println("No Private DNS servers configured"); |
| } else { |
| dw.println("Private DNS configuration (%u entries)", privateDnsStatus.numServers); |
| dw.incIndent(); |
| for (int i = 0; i < privateDnsStatus.numServers; i++) { |
| dw.println("%s name{%s} status{%s}", |
| addrToString(&(privateDnsStatus.serverStatus[i].ss)).c_str(), |
| privateDnsStatus.serverStatus[i].hostname, |
| validationStatusToString(static_cast<Validation>( |
| privateDnsStatus.serverStatus[i].validation))); |
| } |
| dw.decIndent(); |
| } |
| } |
| dw.decIndent(); |
| } |
| |
| } // namespace net |
| } // namespace android |