Refactor ResState to store nameserver addresses by IPSockAddr am: e48f7b54a5... (a4b047b6) · Commits · e / os / android_packages_modules_DnsResolver

res_cache.cpp

+6 −19

Original line number	Diff line number	Diff line
		@@ -1671,21 +1671,8 @@ void resolv_populate_res_for_net(ResState* statp) {
		NetConfig* info = find_netconfig_locked(statp->netid);
		if (info == nullptr) return;

		// TODO: Convert nsaddrs[] to c++ container and remove the size-checking.
		const int serverNum = std::min(MAXNS, static_cast<int>(info->nameserverSockAddrs.size()));

		for (int nserv = 0; nserv < serverNum; nserv++) {
		sockaddr_storage ss = info->nameserverSockAddrs.at(nserv);

		if (auto sockaddr_len = sockaddrSize(ss); sockaddr_len != 0) {
		memcpy(&statp->nsaddrs[nserv], &ss, sockaddr_len);
		} else {
		LOG(WARNING) << __func__ << ": can't get sa_len from "
		<< info->nameserverSockAddrs.at(nserv);
		}
		}

		statp->nscount = serverNum;
		statp->nscount = static_cast<int>(info->nameserverSockAddrs.size());
		statp->nsaddrs = info->nameserverSockAddrs;
		statp->search_domains = info->search_domains;
		statp->tc_mode = info->tc_mode;
		}
		@@ -1811,18 +1798,18 @@ int resolv_cache_get_resolver_stats(unsigned netid, res_params* params, res_stat
		return -1;
		}

		void resolv_cache_add_resolver_stats_sample(unsigned netid, int revision_id, const sockaddr* sa,
		void resolv_cache_add_resolver_stats_sample(unsigned netid, int revision_id,
		const IPSockAddr& serverSockAddr,
		const res_sample& sample, int max_samples) {
		if (max_samples <= 0 \|\| sa == nullptr) return;
		if (max_samples <= 0) return;

		std::lock_guard guard(cache_mutex);
		NetConfig* info = find_netconfig_locked(netid);

		if (info && info->revision_id == revision_id) {
		const int serverNum = std::min(MAXNS, static_cast<int>(info->nameserverSockAddrs.size()));
		const IPSockAddr ipsa = IPSockAddr::toIPSockAddr(*sa);
		for (int ns = 0; ns < serverNum; ns++) {
		if (ipsa == info->nameserverSockAddrs.at(ns)) {
		if (serverSockAddr == info->nameserverSockAddrs[ns]) {
		res_cache_add_stats_sample_locked(&info->nsstats[ns], sample, max_samples);
		return;
		}

res_init.cpp

+1 −10

Original line number	Diff line number	Diff line
		@@ -97,17 +97,8 @@ 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 = 1;
		statp->nscount = 0;
		statp->id = arc4random_uniform(65536);
		// The following dummy initialization is probably useless because
		// it's overwritten later by resolv_populate_res_for_net().
		// TODO: check if it's safe to remove.
		const sockaddr_union u{
		.sin.sin_addr.s_addr = INADDR_ANY,
		.sin.sin_family = AF_INET,
		.sin.sin_port = htons(NAMESERVER_PORT),
		};
		memcpy(&statp->nsaddrs, &u, sizeof(u));

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

res_send.cpp

+40 −35

Original line number	Diff line number	Diff line
		@@ -138,11 +138,13 @@ using android::netdutils::Stopwatch;

		static DnsTlsDispatcher sDnsTlsDispatcher;

		static struct sockaddr* get_nsaddr(res_state, size_t);
		static int send_vc(res_state, res_params* params, const uint8_t, int, uint8_t, int, int*, int,
		time_t, int, int*);
		static int send_dg(res_state, res_params* params, const uint8_t, int, uint8_t, int, int*, int,
		int, int, time_t, int, int*);
		static int send_vc(res_state statp, res_params* params, const uint8_t* buf, int buflen,
		uint8_t* ans, int anssiz, int* terrno, size_t ns, time_t* at, int* rcode,
		int* delay);
		static int send_dg(res_state statp, res_params* params, const uint8_t* buf, int buflen,
		uint8_t* ans, int anssiz, int* terrno, size_t ns, int* v_circuit,
		int* gotsomewhere, time_t* at, int* rcode, int* delay);

		static void dump_error(const char, const struct sockaddr, int);

		static int sock_eq(struct sockaddr, struct sockaddr);
		@@ -288,13 +290,13 @@ static void res_set_usable_server(int selectedServer, int nscount, bool usable_s
		static bool res_ourserver_p(res_state statp, const sockaddr* sa) {
		const sockaddr_in inp, srv;
		const sockaddr_in6 in6p, srv6;
		int ns;

		switch (sa->sa_family) {
		case AF_INET:
		inp = (const struct sockaddr_in) (const void) sa;
		for (ns = 0; ns < statp->nscount; ns++) {
		srv = (struct sockaddr_in) (void) get_nsaddr(statp, (size_t) ns);
		for (const IPSockAddr& ipsa : statp->nsaddrs) {
		sockaddr_storage ss = ipsa;
		srv = reinterpret_cast<sockaddr_in*>(&ss);
		if (srv->sin_family == inp->sin_family && srv->sin_port == inp->sin_port &&
		(srv->sin_addr.s_addr == INADDR_ANY \|\|
		srv->sin_addr.s_addr == inp->sin_addr.s_addr))
		@@ -303,8 +305,9 @@ static bool res_ourserver_p(res_state statp, const sockaddr* sa) {
		break;
		case AF_INET6:
		in6p = (const struct sockaddr_in6) (const void) sa;
		for (ns = 0; ns < statp->nscount; ns++) {
		srv6 = (struct sockaddr_in6) (void) get_nsaddr(statp, (size_t) ns);
		for (const IPSockAddr& ipsa : statp->nsaddrs) {
		sockaddr_storage ss = ipsa;
		srv6 = reinterpret_cast<sockaddr_in6*>(&ss);
		if (srv6->sin6_family == in6p->sin6_family && srv6->sin6_port == in6p->sin6_port &&
		#ifdef HAVE_SIN6_SCOPE_ID
		(srv6->sin6_scope_id == 0 \|\| srv6->sin6_scope_id == in6p->sin6_scope_id) &&
		@@ -484,20 +487,15 @@ int res_nsend(res_state statp, const uint8_t* buf, int buflen, uint8_t* ans, int
		int terrno = ETIMEDOUT;

		for (int attempt = 0; attempt < retryTimes; ++attempt) {
		for (int ns = 0; ns < statp->nscount; ++ns) {
		for (size_t ns = 0; ns < statp->nsaddrs.size(); ++ns) {
		if (!usable_servers[ns]) continue;

		*rcode = RCODE_INTERNAL_ERROR;

		// Get server addr
		const sockaddr* nsap = get_nsaddr(statp, ns);
		const int nsaplen = sockaddrSize(nsap);

		static const int niflags = NI_NUMERICHOST \| NI_NUMERICSERV;
		char abuf[NI_MAXHOST];
		if (getnameinfo(nsap, (socklen_t)nsaplen, abuf, sizeof(abuf), NULL, 0, niflags) == 0)
		const IPSockAddr& serverSockAddr = statp->nsaddrs[ns];
		LOG(DEBUG) << __func__ << ": Querying server (# " << ns + 1
		<< ") address = " << abuf;
		<< ") address = " << serverSockAddr.toString();

		::android::net::Protocol query_proto = useTcp ? PROTO_TCP : PROTO_UDP;
		time_t now = 0;
		@@ -533,7 +531,7 @@ int res_nsend(res_state statp, const uint8_t* buf, int buflen, uint8_t* ans, int
		dnsQueryEvent->set_cache_hit(static_cast<CacheStatus>(cache_status));
		dnsQueryEvent->set_latency_micros(saturate_cast<int32_t>(queryStopwatch.timeTakenUs()));
		dnsQueryEvent->set_dns_server_index(ns);
		dnsQueryEvent->set_ip_version(ipFamilyToIPVersion(nsap->sa_family));
		dnsQueryEvent->set_ip_version(ipFamilyToIPVersion(serverSockAddr.family()));
		dnsQueryEvent->set_retry_times(retry_count_for_event);
		dnsQueryEvent->set_rcode(static_cast<NsRcode>(*rcode));
		dnsQueryEvent->set_protocol(query_proto);
		@@ -545,9 +543,9 @@ int res_nsend(res_state statp, const uint8_t* buf, int buflen, uint8_t* ans, int
		if (shouldRecordStats) {
		res_sample sample;
		_res_stats_set_sample(&sample, now, *rcode, delay);
		resolv_cache_add_resolver_stats_sample(statp->netid, revision_id, nsap, sample,
		params.max_samples);
		resolv_stats_add(statp->netid, IPSockAddr::toIPSockAddr(*nsap), dnsQueryEvent);
		resolv_cache_add_resolver_stats_sample(statp->netid, revision_id, serverSockAddr,
		sample, params.max_samples);
		resolv_stats_add(statp->netid, serverSockAddr, dnsQueryEvent);
		}

		if (resplen == 0) continue;
		@@ -582,12 +580,6 @@ int res_nsend(res_state statp, const uint8_t* buf, int buflen, uint8_t* ans, int
		return -terrno;
		}

		/* Private */

		static struct sockaddr* get_nsaddr(res_state statp, size_t n) {
		return (struct sockaddr)(void)&statp->nsaddrs[n];
		}

		static struct timespec get_timeout(res_state statp, const res_params* params, const int ns) {
		int msec;
		// Legacy algorithm which scales the timeout by nameserver number.
		@@ -610,7 +602,7 @@ static struct timespec get_timeout(res_state statp, const res_params* params, co
		}

		static int send_vc(res_state statp, res_params* params, const uint8_t* buf, int buflen,
		uint8_t* ans, int anssiz, int* terrno, int ns, time_t* at, int* rcode,
		uint8_t* ans, int anssiz, int* terrno, size_t ns, time_t* at, int* rcode,
		int* delay) {
		*at = time(NULL);
		*delay = 0;
		@@ -623,7 +615,14 @@ static int send_vc(res_state statp, res_params* params, const uint8_t* buf, int

		LOG(INFO) << __func__ << ": using send_vc";

		nsap = get_nsaddr(statp, (size_t) ns);
		// It should never happen, but just in case.
		if (ns >= statp->nsaddrs.size()) {
		LOG(ERROR) << __func__ << ": Out-of-bound indexing: " << ns;
		return -1;
		}

		sockaddr_storage ss = statp->nsaddrs[ns];
		nsap = reinterpret_cast<sockaddr*>(&ss);
		nsaplen = sockaddrSize(nsap);

		connreset = 0;
		@@ -897,12 +896,18 @@ bool ignoreInvalidAnswer(res_state statp, const sockaddr_storage& from, const ui
		}

		static int send_dg(res_state statp, res_params* params, const uint8_t* buf, int buflen,
		uint8_t* ans, int anssiz, int* terrno, int ns, int* v_circuit, int* gotsomewhere,
		time_t* at, int* rcode, int* delay) {
		uint8_t* ans, int anssiz, int* terrno, size_t ns, int* v_circuit,
		int* gotsomewhere, time_t* at, int* rcode, int* delay) {
		// It should never happen, but just in case.
		if (ns >= statp->nsaddrs.size()) {
		LOG(ERROR) << __func__ << ": Out-of-bound indexing: " << ns;
		return -1;
		}

		*at = time(nullptr);
		*delay = 0;

		const sockaddr* nsap = get_nsaddr(statp, (size_t)ns);
		const sockaddr_storage ss = statp->nsaddrs[ns];
		const sockaddr* nsap = reinterpret_cast<const sockaddr*>(&ss);
		const int nsaplen = sockaddrSize(nsap);

		if (statp->nssocks[ns] == -1) {

resolv_cache_unit_test.cpp

+5 −4

Original line number	Diff line number	Diff line
		@@ -38,6 +38,8 @@

		using namespace std::chrono_literals;

		using android::netdutils::IPSockAddr;

		constexpr int TEST_NETID = 30;
		constexpr int TEST_NETID_2 = 31;
		constexpr int DNS_PORT = 53;
		@@ -190,9 +192,9 @@ class ResolvCacheTest : public ::testing::Test {
		return resolv_set_nameservers(netId, setup.servers, setup.domains, setup.params);
		}

		void cacheAddStats(uint32_t netId, int revision_id, const sockaddr* sa,
		void cacheAddStats(uint32_t netId, int revision_id, const IPSockAddr& ipsa,
		const res_sample& sample, int max_samples) {
		resolv_cache_add_resolver_stats_sample(netId, revision_id, sa, sample, max_samples);
		resolv_cache_add_resolver_stats_sample(netId, revision_id, ipsa, sample, max_samples);
		}

		int cacheFlush(uint32_t netId) { return resolv_flush_cache_for_net(netId); }
		@@ -735,8 +737,7 @@ TEST_F(ResolvCacheTest, FlushCache) {
		res_sample sample = {.at = time(NULL), .rtt = 100, .rcode = ns_r_noerror};
		sockaddr_in sin = {.sin_family = AF_INET, .sin_port = htons(DNS_PORT)};
		ASSERT_TRUE(inet_pton(AF_INET, setup.servers[0].c_str(), &sin.sin_addr));
		cacheAddStats(TEST_NETID, 1 /revision_id/, (const sockaddr*)&sin, sample,
		setup.params.max_samples);
		cacheAddStats(TEST_NETID, 1 /revision_id/, IPSockAddr(sin), sample, setup.params.max_samples);

		const CacheStats cacheStats = {
		.setup = setup,

resolv_private.h

+5 −2

Original line number	Diff line number	Diff line
		@@ -55,6 +55,8 @@
		#include <string>
		#include <vector>

		#include <netdutils/InternetAddresses.h>

		#include "DnsResolver.h"
		#include "netd_resolv/resolv.h"
		#include "params.h"
		@@ -102,7 +104,7 @@ struct ResState {
		int nscount; // number of name srvers
		uint16_t id; // current message id
		std::vector<std::string> search_domains{}; // domains to search
		sockaddr_union nsaddrs[MAXNS];
		std::vector<android::netdutils::IPSockAddr> nsaddrs;
		android::base::unique_fd nssocks[MAXNS]; // UDP sockets to nameservers
		unsigned ndots : 4; // threshold for initial abs. query
		unsigned _mark; // If non-0 SET_MARK to _mark on all request sockets
		@@ -125,7 +127,8 @@ int resolv_cache_get_resolver_stats(unsigned netid, res_params* params, res_stat
		/* Add a sample to the shared struct for the given netid and server, provided that the
		* revision_id of the stored servers has not changed.
		*/
		void resolv_cache_add_resolver_stats_sample(unsigned netid, int revision_id, const sockaddr* sa,
		void resolv_cache_add_resolver_stats_sample(unsigned netid, int revision_id,
		const android::netdutils::IPSockAddr& serverSockAddr,
		const res_sample& sample, int max_samples);

		// Calculate the round-trip-time from start time t0 and end time t1.