Merge "Replace manual buffer handling with std::span" (094d9ab7) · Commits · e / os / android_packages_modules_DnsResolver

DnsProxyListener.cpp

+22 −23

Original line number	Diff line number	Diff line
		@@ -39,7 +39,6 @@
		#include <cutils/multiuser.h>
		#include <netdutils/InternetAddresses.h>
		#include <netdutils/ResponseCode.h>
		#include <netdutils/Slice.h>
		#include <netdutils/Stopwatch.h>
		#include <netdutils/ThreadUtil.h>
		#include <private/android_filesystem_config.h> // AID_SYSTEM
		@@ -65,6 +64,7 @@ using aidl::android::net::metrics::INetdEventListener;
		using aidl::android::net::resolv::aidl::DnsHealthEventParcel;
		using aidl::android::net::resolv::aidl::IDnsResolverUnsolicitedEventListener;
		using android::net::NetworkDnsEventReported;
		using std::span;

		namespace android {

		@@ -147,11 +147,11 @@ void maybeFixupNetContext(android_net_context* ctx, pid_t pid) {
		void addIpAddrWithinLimit(std::vector<std::string>* ip_addrs, const sockaddr* addr,
		socklen_t addrlen);

		int extractResNsendAnswers(const uint8_t* answer, size_t anslen, int ipType,
		int extractResNsendAnswers(std::span<const uint8_t> answer, int ipType,
		std::vector<std::string>* ip_addrs) {
		int total_ip_addr_count = 0;
		ns_msg handle;
		if (ns_initparse((const uint8_t*)answer, anslen, &handle) < 0) {
		if (ns_initparse(answer.data(), answer.size(), &handle) < 0) {
		return 0;
		}
		int ancount = ns_msg_count(handle, ns_s_an);
		@@ -250,21 +250,20 @@ bool simpleStrtoul(const char* input, IntegralType* output, int base = 10) {
		return true;
		}

		bool setQueryId(uint8_t* msg, size_t msgLen, uint16_t query_id) {
		if (msgLen < sizeof(HEADER)) {
		bool setQueryId(span<uint8_t> msg, uint16_t query_id) {
		if ((size_t)msg.size() < sizeof(HEADER)) {
		errno = EINVAL;
		return false;
		}
		auto hp = reinterpret_cast<HEADER*>(msg);
		auto hp = reinterpret_cast<HEADER*>(msg.data());
		hp->id = htons(query_id);
		return true;
		}

		bool parseQuery(const uint8_t* msg, size_t msgLen, uint16_t* query_id, int* rr_type,
		std::string* rr_name) {
		bool parseQuery(span<const uint8_t> msg, uint16_t* query_id, int* rr_type, std::string* rr_name) {
		ns_msg handle;
		ns_rr rr;
		if (ns_initparse((const uint8_t*)msg, msgLen, &handle) < 0 \|\|
		if (ns_initparse(msg.data(), msg.size(), &handle) < 0 \|\|
		ns_parserr(&handle, ns_s_qd, 0, &rr) < 0) {
		return false;
		}
		@@ -927,8 +926,8 @@ void DnsProxyListener::ResNSendHandler::run() {
		uint16_t original_query_id = 0;

		// TODO: Handle the case which is msg contains more than one query
		if (!parseQuery(msg.data(), msgLen, &original_query_id, &rr_type, &rr_name) \|\|
		!setQueryId(msg.data(), msgLen, arc4random_uniform(65536))) {
		if (!parseQuery({msg.data(), msgLen}, &original_query_id, &rr_type, &rr_name) \|\|
		!setQueryId({msg.data(), msgLen}, arc4random_uniform(65536))) {
		// If the query couldn't be parsed, block the request.
		LOG(WARNING) << "ResNSendHandler::run: resnsend: from UID " << uid << ", invalid query";
		sendBE32(mClient, -EINVAL);
		@@ -938,21 +937,21 @@ void DnsProxyListener::ResNSendHandler::run() {
		// Send DNS query
		std::vector<uint8_t> ansBuf(MAXPACKET, 0);
		int rcode = ns_r_noerror;
		int nsendAns = -1;
		int ansLen = -1;
		NetworkDnsEventReported event;
		initDnsEvent(&event, mNetContext);
		if (queryLimiter.start(uid)) {
		if (evaluate_domain_name(mNetContext, rr_name.c_str())) {
		nsendAns = resolv_res_nsend(&mNetContext, msg.data(), msgLen, ansBuf.data(), MAXPACKET,
		&rcode, static_cast<ResNsendFlags>(mFlags), &event);
		ansLen = resolv_res_nsend(&mNetContext, {msg.data(), msgLen}, ansBuf, &rcode,
		static_cast<ResNsendFlags>(mFlags), &event);
		} else {
		nsendAns = -EAI_SYSTEM;
		ansLen = -EAI_SYSTEM;
		}
		queryLimiter.finish(uid);
		} else {
		LOG(WARNING) << "ResNSendHandler::run: resnsend: from UID " << uid
		<< ", max concurrent queries reached";
		nsendAns = -EBUSY;
		ansLen = -EBUSY;
		}

		const int32_t latencyUs = saturate_cast<int32_t>(s.timeTakenUs());
		@@ -961,14 +960,14 @@ void DnsProxyListener::ResNSendHandler::run() {
		event.set_res_nsend_flags(static_cast<ResNsendFlags>(mFlags));

		// Fail, send -errno
		if (nsendAns < 0) {
		if (!sendBE32(mClient, nsendAns)) {
		if (ansLen < 0) {
		if (!sendBE32(mClient, ansLen)) {
		PLOG(WARNING) << "ResNSendHandler::run: resnsend: failed to send errno to uid " << uid
		<< " pid " << mClient->getPid();
		}
		if (rr_type == ns_t_a \|\| rr_type == ns_t_aaaa) {
		reportDnsEvent(INetdEventListener::EVENT_RES_NSEND, mNetContext, latencyUs,
		resNSendToAiError(nsendAns, rcode), event, rr_name);
		resNSendToAiError(ansLen, rcode), event, rr_name);
		}
		return;
		}
		@@ -981,8 +980,8 @@ void DnsProxyListener::ResNSendHandler::run() {
		}

		// Restore query id and send answer
		if (!setQueryId(ansBuf.data(), nsendAns, original_query_id) \|\|
		!sendLenAndData(mClient, nsendAns, ansBuf.data())) {
		if (!setQueryId({ansBuf.data(), ansLen}, original_query_id) \|\|
		!sendLenAndData(mClient, ansLen, ansBuf.data())) {
		PLOG(WARNING) << "ResNSendHandler::run: resnsend: failed to send answer to uid " << uid
		<< " pid " << mClient->getPid();
		return;
		@@ -991,9 +990,9 @@ void DnsProxyListener::ResNSendHandler::run() {
		if (rr_type == ns_t_a \|\| rr_type == ns_t_aaaa) {
		std::vector<std::string> ip_addrs;
		const int total_ip_addr_count =
		extractResNsendAnswers((uint8_t*)ansBuf.data(), nsendAns, rr_type, &ip_addrs);
		extractResNsendAnswers({ansBuf.data(), ansLen}, rr_type, &ip_addrs);
		reportDnsEvent(INetdEventListener::EVENT_RES_NSEND, mNetContext, latencyUs,
		resNSendToAiError(nsendAns, rcode), event, rr_name, ip_addrs,
		resNSendToAiError(ansLen, rcode), event, rr_name, ip_addrs,
		total_ip_addr_count);
		}
		}

DnsTlsDispatcher.cpp

+2 −1

Original line number	Diff line number	Diff line
		@@ -128,7 +128,8 @@ DnsTlsTransport::Response DnsTlsDispatcher::query(const std::list<DnsTlsServer>&
		dnsQueryEvent->set_dns_server_index(serverCount++);
		dnsQueryEvent->set_ip_version(ipFamilyToIPVersion(server.ss.ss_family));
		dnsQueryEvent->set_protocol(PROTO_DOT);
		dnsQueryEvent->set_type(getQueryType(query.base(), query.size()));
		std::span<const uint8_t> msg(query.base(), query.size());
		dnsQueryEvent->set_type(getQueryType(msg));
		dnsQueryEvent->set_connected(connectTriggered);

		switch (code) {

getaddrinfo.cpp

+8 −13

Original line number	Diff line number	Diff line
		@@ -1627,13 +1627,11 @@ QueryResult doQuery(const char* name, res_target* t, ResState* res,
		LOG(DEBUG) << __func__ << ": (" << cl << ", " << type << ")";

		uint8_t buf[MAXPACKET];

		int n = res_nmkquery(QUERY, name, cl, type, /data=/nullptr, /datalen=/0, buf, sizeof(buf),
		res->netcontext_flags);
		int n = res_nmkquery(QUERY, name, cl, type, {}, buf, res->netcontext_flags);

		if (n > 0 &&
		(res->netcontext_flags & (NET_CONTEXT_FLAG_USE_DNS_OVER_TLS \| NET_CONTEXT_FLAG_USE_EDNS))) {
		n = res_nopt(res, n, buf, sizeof(buf), anslen);
		n = res_nopt(res, n, buf, anslen);
		}

		NetworkDnsEventReported event;
		@@ -1651,7 +1649,7 @@ QueryResult doQuery(const char* name, res_target* t, ResState* res,
		ResState res_temp = res->clone(&event);

		int rcode = NOERROR;
		n = res_nsend(&res_temp, buf, n, t->answer.data(), anslen, &rcode, 0, sleepTimeMs);
		n = res_nsend(&res_temp, {buf, n}, {t->answer.data(), anslen}, &rcode, 0, sleepTimeMs);
		if (n < 0 \|\| hp->rcode != NOERROR \|\| ntohs(hp->ancount) == 0) {
		// To ensure that the rcode handling is identical to res_queryN().
		if (rcode != RCODE_TIMEOUT) rcode = hp->rcode;
		@@ -1660,9 +1658,8 @@ QueryResult doQuery(const char* name, res_target* t, ResState* res,
		(NET_CONTEXT_FLAG_USE_DNS_OVER_TLS \| NET_CONTEXT_FLAG_USE_EDNS)) &&
		(res_temp.flags & RES_F_EDNS0ERR)) {
		LOG(DEBUG) << __func__ << ": retry without EDNS0";
		n = res_nmkquery(QUERY, name, cl, type, /data=/nullptr, /datalen=/0, buf,
		sizeof(buf), res_temp.netcontext_flags);
		n = res_nsend(&res_temp, buf, n, t->answer.data(), anslen, &rcode, 0);
		n = res_nmkquery(QUERY, name, cl, type, {}, buf, res_temp.netcontext_flags);
		n = res_nsend(&res_temp, {buf, n}, {t->answer.data(), anslen}, &rcode, 0);
		}
		}

		@@ -1761,21 +1758,19 @@ static int res_queryN(const char* name, res_target* target, ResState* res, int*
		const int anslen = t->answer.size();

		LOG(DEBUG) << __func__ << ": (" << cl << ", " << type << ")";

		n = res_nmkquery(QUERY, name, cl, type, /data=/nullptr, /datalen=/0, buf, sizeof(buf),
		res->netcontext_flags);
		n = res_nmkquery(QUERY, name, cl, type, {}, buf, res->netcontext_flags);
		if (n > 0 &&
		(res->netcontext_flags &
		(NET_CONTEXT_FLAG_USE_DNS_OVER_TLS \| NET_CONTEXT_FLAG_USE_EDNS)) &&
		!retried) // TODO: remove the retry flag and provide a sufficient test coverage.
		n = res_nopt(res, n, buf, sizeof(buf), anslen);
		n = res_nopt(res, n, buf, anslen);
		if (n <= 0) {
		LOG(ERROR) << __func__ << ": res_nmkquery failed";
		*herrno = NO_RECOVERY;
		return n;
		}

		n = res_nsend(res, buf, n, t->answer.data(), anslen, &rcode, 0);
		n = res_nsend(res, {buf, n}, {t->answer.data(), anslen}, &rcode, 0);
		if (n < 0 \|\| hp->rcode != NOERROR \|\| ntohs(hp->ancount) == 0) {
		// Record rcode from DNS response header only if no timeout.
		// Keep rcode timeout for reporting later if any.

gethnamaddr.cpp

+2 −2

Original line number	Diff line number	Diff line
		@@ -632,7 +632,7 @@ static int dns_gethtbyname(ResState* res, const char* name, int addr_type, getna

		int he;
		const unsigned qclass = isMdnsResolution(res->flags) ? C_IN \| C_UNICAST : C_IN;
		n = res_nsearch(res, name, qclass, type, buf->buf, (int)sizeof(buf->buf), &he);
		n = res_nsearch(res, name, qclass, type, {buf->buf, (int)sizeof(buf->buf)}, &he);
		if (n < 0) {
		LOG(DEBUG) << __func__ << ": res_nsearch failed (" << n << ")";
		// Return h_errno (he) to catch more detailed errors rather than EAI_NODATA.
		@@ -694,7 +694,7 @@ static int dns_gethtbyaddr(const unsigned char* uaddr, int len, int af,

		ResState res(netcontext, event);
		int he;
		n = res_nquery(&res, qbuf, C_IN, T_PTR, buf->buf, (int)sizeof(buf->buf), &he);
		n = res_nquery(&res, qbuf, C_IN, T_PTR, {buf->buf, (int)sizeof(buf->buf)}, &he);
		if (n < 0) {
		LOG(DEBUG) << __func__ << ": res_nquery failed (" << n << ")";
		// Note that res_nquery() doesn't set the pair NETDB_INTERNAL and errno.

res_cache.cpp

+23 −24

Original line number	Diff line number	Diff line
		@@ -78,6 +78,7 @@ using android::net::PROTO_UDP;
		using android::net::Protocol;
		using android::netdutils::DumpWriter;
		using android::netdutils::IPSockAddr;
		using std::span;

		/* This code implements a small and simple DNS resolver cache.
		*
		@@ -773,14 +774,14 @@ static uint32_t answer_getNegativeTTL(ns_msg handle) {
		* In case of parse error zero (0) is returned which
		* indicates that the answer shall not be cached.
		*/
		static uint32_t answer_getTTL(const void* answer, int answerlen) {
		static uint32_t answer_getTTL(span<const uint8_t> answer) {
		ns_msg handle;
		int ancount, n;
		uint32_t result, ttl;
		ns_rr rr;

		result = 0;
		if (ns_initparse((const uint8_t*) answer, answerlen, &handle) >= 0) {
		if (ns_initparse(answer.data(), answer.size(), &handle) >= 0) {
		// get number of answer records
		ancount = ns_msg_count(handle, ns_s_an);

		@@ -840,13 +841,13 @@ static unsigned entry_hash(const Entry* e) {

		/* initialize an Entry as a search key, this also checks the input query packet
		* returns 1 on success, or 0 in case of unsupported/malformed data */
		static int entry_init_key(Entry* e, const void* query, int querylen) {
		static int entry_init_key(Entry* e, span<const uint8_t> query) {
		DnsPacket pack[1];

		memset(e, 0, sizeof(*e));

		e->query = (const uint8_t*) query;
		e->querylen = querylen;
		e->query = query.data();
		e->querylen = query.size();
		e->hash = entry_hash(e);

		_dnsPacket_init(pack, e->query, e->querylen);
		@@ -855,11 +856,11 @@ static int entry_init_key(Entry* e, const void* query, int querylen) {
		}

		/* allocate a new entry as a cache node */
		static Entry* entry_alloc(const Entry* init, const void* answer, int answerlen) {
		static Entry* entry_alloc(const Entry* init, span<const uint8_t> answer) {
		Entry* e;
		int size;

		size = sizeof(*e) + init->querylen + answerlen;
		size = sizeof(*e) + init->querylen + answer.size();
		e = (Entry*) calloc(size, 1);
		if (e == NULL) return e;

		@@ -870,9 +871,9 @@ static Entry* entry_alloc(const Entry* init, const void* answer, int answerlen)
		memcpy((char*) e->query, init->query, e->querylen);

		e->answer = e->query + e->querylen;
		e->answerlen = answerlen;
		e->answerlen = answer.size();

		memcpy((char*) e->answer, answer, e->answerlen);
		memcpy((char*)e->answer, answer.data(), e->answerlen);

		return e;
		}
		@@ -1101,14 +1102,14 @@ static void cache_notify_waiting_tid_locked(struct Cache* cache, const Entry* ke
		}
		}

		void _resolv_cache_query_failed(unsigned netid, const void* query, int querylen, uint32_t flags) {
		void _resolv_cache_query_failed(unsigned netid, span<const uint8_t> query, uint32_t flags) {
		// We should not notify with these flags.
		if (flags & (ANDROID_RESOLV_NO_CACHE_STORE \| ANDROID_RESOLV_NO_CACHE_LOOKUP)) {
		return;
		}
		Entry key[1];

		if (!entry_init_key(key, query, querylen)) return;
		if (!entry_init_key(key, query)) return;

		std::lock_guard guard(cache_mutex);

		@@ -1228,8 +1229,8 @@ static void _cache_remove_expired(Cache* cache) {
		// Get a NetConfig associated with a network, or nullptr if not found.
		static NetConfig* find_netconfig_locked(unsigned netid) REQUIRES(cache_mutex);

		ResolvCacheStatus resolv_cache_lookup(unsigned netid, const void* query, int querylen, void* answer,
		int answersize, int* answerlen, uint32_t flags) {
		ResolvCacheStatus resolv_cache_lookup(unsigned netid, span<const uint8_t> query,
		span<uint8_t> answer, int* answerlen, uint32_t flags) {
		// Skip cache lookup, return RESOLV_CACHE_NOTFOUND directly so that it is
		// possible to cache the answer of this query.
		// If ANDROID_RESOLV_NO_CACHE_STORE is set, return RESOLV_CACHE_SKIP to skip possible cache
		@@ -1247,7 +1248,7 @@ ResolvCacheStatus resolv_cache_lookup(unsigned netid, const void* query, int que
		LOG(INFO) << __func__ << ": lookup";

		/* we don't cache malformed queries */
		if (!entry_init_key(&key, query, querylen)) {
		if (!entry_init_key(&key, query)) {
		LOG(INFO) << __func__ << ": unsupported query";
		return RESOLV_CACHE_UNSUPPORTED;
		}
		@@ -1310,13 +1311,13 @@ ResolvCacheStatus resolv_cache_lookup(unsigned netid, const void* query, int que
		}

		*answerlen = e->answerlen;
		if (e->answerlen > answersize) {
		if (e->answerlen > answer.size()) {
		/* NOTE: we return UNSUPPORTED if the answer buffer is too short */
		LOG(INFO) << __func__ << ": ANSWER TOO LONG";
		return RESOLV_CACHE_UNSUPPORTED;
		}

		memcpy(answer, e->answer, e->answerlen);
		memcpy(answer.data(), e->answer, e->answerlen);

		/* bump up this entry to the top of the MRU list */
		if (e != cache->mru_list.mru_next) {
		@@ -1328,8 +1329,7 @@ ResolvCacheStatus resolv_cache_lookup(unsigned netid, const void* query, int que
		return RESOLV_CACHE_FOUND;
		}

		int resolv_cache_add(unsigned netid, const void* query, int querylen, const void* answer,
		int answerlen) {
		int resolv_cache_add(unsigned netid, span<const uint8_t> query, span<const uint8_t> answer) {
		Entry key[1];
		Entry* e;
		Entry** lookup;
		@@ -1338,7 +1338,7 @@ int resolv_cache_add(unsigned netid, const void* query, int querylen, const void

		/* don't assume that the query has already been cached
		*/
		if (!entry_init_key(key, query, querylen)) {
		if (!entry_init_key(key, query)) {
		LOG(INFO) << __func__ << ": passed invalid query?";
		return -EINVAL;
		}
		@@ -1375,9 +1375,9 @@ int resolv_cache_add(unsigned netid, const void* query, int querylen, const void
		}
		}

		ttl = answer_getTTL(answer, answerlen);
		ttl = answer_getTTL(answer);
		if (ttl > 0) {
		e = entry_alloc(key, answer, answerlen);
		e = entry_alloc(key, answer);
		if (e != NULL) {
		e->expires = ttl + _time_now();
		_cache_add_p(cache, lookup, e);
		@@ -1886,13 +1886,12 @@ bool has_named_cache(unsigned netid) {
		return find_named_cache_locked(netid) != nullptr;
		}

		int resolv_cache_get_expiration(unsigned netid, const std::vector<char>& query,
		time_t* expiration) {
		int resolv_cache_get_expiration(unsigned netid, span<const uint8_t> query, time_t* expiration) {
		Entry key;
		*expiration = -1;

		// A malformed query is not allowed.
		if (!entry_init_key(&key, query.data(), query.size())) {
		if (!entry_init_key(&key, query)) {
		LOG(WARNING) << __func__ << ": unsupported query";
		return -EINVAL;
		}