Remove nscount in ResState and NetConfig am: ecc52827de (d4f82bd0) · Commits · e / os / android_packages_modules_DnsResolver

res_cache.cpp

+23 −35

Original line number	Diff line number	Diff line
		@@ -984,9 +984,10 @@ struct NetConfig {
		dns_event_subsampling_map = resolv_get_dns_event_subsampling_map();
		}

		int nameserverCount() { return nameserverSockAddrs.size(); }

		const unsigned netid;
		std::unique_ptr<Cache> cache;
		int nscount = 0;
		std::vector<std::string> nameservers;
		std::vector<IPSockAddr> nameserverSockAddrs;
		int revision_id = 0; // # times the nameservers have been replaced
		@@ -1442,7 +1443,7 @@ static void res_cache_clear_stats_locked(NetConfig* netconfig);
		bool resolv_has_nameservers(unsigned netid) {
		std::lock_guard guard(cache_mutex);
		NetConfig* info = find_netconfig_locked(netid);
		return (info != nullptr) && (info->nscount > 0);
		return (info != nullptr) && (info->nameserverCount() > 0);
		}

		int resolv_create_cache_for_net(unsigned netid) {
		@@ -1603,7 +1604,6 @@ int resolv_set_nameservers(
		<< ", addr = " << netconfig->nameservers[i];
		}
		netconfig->nameserverSockAddrs = std::move(ipSockAddrs);
		netconfig->nscount = numservers;
		} else {
		if (netconfig->params.max_samples != old_max_samples) {
		// If the maximum number of samples changes, the overhead of keeping the most recent
		@@ -1655,7 +1655,6 @@ static bool resolv_is_nameservers_equal(const std::vector<std::string>& oldServe
		}

		static void free_nameservers_locked(NetConfig* netconfig) {
		netconfig->nscount = 0;
		netconfig->nameservers.clear();
		netconfig->nameserverSockAddrs.clear();
		res_cache_clear_stats_locked(netconfig);
		@@ -1671,7 +1670,6 @@ void resolv_populate_res_for_net(ResState* statp) {
		NetConfig* info = find_netconfig_locked(statp->netid);
		if (info == nullptr) return;

		statp->nscount = static_cast<int>(info->nameserverSockAddrs.size());
		statp->nsaddrs = info->nameserverSockAddrs;
		statp->search_domains = info->search_domains;
		statp->tc_mode = info->tc_mode;
		@@ -1712,42 +1710,32 @@ int android_net_res_stats_get_info_for_net(unsigned netid, int* nscount,
		char domains[MAXDNSRCH][MAXDNSRCHPATH],
		res_params* params, struct res_stats stats[MAXNS],
		int* wait_for_pending_req_timeout_count) {
		int revision_id = -1;
		std::lock_guard guard(cache_mutex);

		NetConfig* info = find_netconfig_locked(netid);
		if (info) {
		if (info->nscount > MAXNS) {
		LOG(INFO) << __func__ << ": nscount " << info->nscount << " > MAXNS " << MAXNS;
		errno = EFAULT;
		return -1;
		}
		int i;
		*nscount = info->nscount;
		if (!info) return -1;

		// It shouldn't happen, but just in case of buffer overflow.
		if (info->nscount != static_cast<int>(info->nameserverSockAddrs.size())) {
		LOG(INFO) << __func__ << ": nscount " << info->nscount
		<< " != " << info->nameserverSockAddrs.size();
		const int num = info->nameserverCount();
		if (num > MAXNS) {
		LOG(INFO) << __func__ << ": nscount " << num << " > MAXNS " << MAXNS;
		errno = EFAULT;
		return -1;
		}

		for (i = 0; i < info->nscount; i++) {
		servers[i] = info->nameserverSockAddrs.at(i);
		for (int i = 0; i < num; i++) {
		servers[i] = info->nameserverSockAddrs[i];
		stats[i] = info->nsstats[i];
		}

		for (i = 0; i < static_cast<int>(info->search_domains.size()); i++) {
		for (size_t i = 0; i < info->search_domains.size(); i++) {
		strlcpy(domains[i], info->search_domains[i].c_str(), MAXDNSRCHPATH);
		}
		*dcount = i;

		*nscount = num;
		*dcount = static_cast<int>(info->search_domains.size());
		*params = info->params;
		revision_id = info->revision_id;
		*wait_for_pending_req_timeout_count = info->wait_for_pending_req_timeout_count;
		}

		return revision_id;
		return info->revision_id;
		}

		std::vector<std::string> resolv_cache_dump_subsampling_map(unsigned netid) {

res_init.cpp

+0 −1

Original line number	Diff line number	Diff line
		@@ -97,7 +97,6 @@ void res_init(ResState* statp, const struct android_net_context* _Nonnull netcon
		statp->netid = netcontext->dns_netid;
		statp->uid = netcontext->uid;
		statp->pid = netcontext->pid;
		statp->nscount = 0;
		statp->id = arc4random_uniform(65536);

		for (auto& sock : statp->nssocks) {

res_send.cpp

+4 −4

Original line number	Diff line number	Diff line
		@@ -430,7 +430,7 @@ int res_nsend(res_state statp, const uint8_t* buf, int buflen, uint8_t* ans, int
		// data so the normal resolve path can do its thing
		resolv_populate_res_for_net(statp);
		}
		if (statp->nscount == 0) {
		if (statp->nameserverCount() == 0) {
		// We have no nameservers configured, so there's no point trying.
		// Tell the cache the query failed, or any retries and anyone else asking the same
		// question will block for PENDING_REQUEST_TIMEOUT seconds instead of failing fast.
		@@ -470,14 +470,14 @@ int res_nsend(res_state statp, const uint8_t* buf, int buflen, uint8_t* ans, int
		}
		bool usable_servers[MAXNS];
		int usableServersCount = android_net_res_stats_get_usable_servers(
		&params, stats, statp->nscount, usable_servers);
		&params, stats, statp->nameserverCount(), usable_servers);

		if ((flags & ANDROID_RESOLV_NO_RETRY) && usableServersCount > 1) {
		auto hp = reinterpret_cast<const HEADER*>(buf);

		// Select a random server based on the query id
		int selectedServer = (hp->id % usableServersCount) + 1;
		res_set_usable_server(selectedServer, statp->nscount, usable_servers);
		res_set_usable_server(selectedServer, statp->nameserverCount(), usable_servers);
		}

		// Send request, RETRY times, or until successful.
		@@ -587,7 +587,7 @@ static struct timespec get_timeout(res_state statp, const res_params* params, co
		// This has no effect with 1 or 2 nameservers
		msec = params->base_timeout_msec << ns;
		if (ns > 0) {
		msec /= statp->nscount;
		msec /= statp->nameserverCount();
		}
		// For safety, don't allow OEMs and experiments to configure a timeout shorter than 1s.
		if (msec < 1000) {

resolv_private.h

+3 −1

Original line number	Diff line number	Diff line
		@@ -94,11 +94,13 @@ struct ResState {
		sock.reset();
		}
		}

		int nameserverCount() { return nsaddrs.size(); }

		// clang-format off
		unsigned netid; // NetId: cache key and socket mark
		uid_t uid; // uid of the app that sent the DNS lookup
		pid_t pid; // pid of the app that sent the DNS lookup
		int nscount; // number of name srvers
		uint16_t id; // current message id
		std::vector<std::string> search_domains{}; // domains to search
		std::vector<android::netdutils::IPSockAddr> nsaddrs;