Snap for 6203617 from 71910b3a5c8e15bc954a5177f97b1a39091da0b0 to rvc-release (05be1c7d) · Commits · e / os / android_packages_modules_DnsResolver

res_cache.cpp

+1 −1

Original line number	Diff line number	Diff line
		@@ -1261,7 +1261,7 @@ ResolvCacheStatus resolv_cache_lookup(unsigned netid, const void* query, int que
		LOG(INFO) << __func__ << ": NOT IN CACHE (STALE ENTRY " << *lookup << "DISCARDED)";
		res_pquery(e->query, e->querylen);
		_cache_remove_p(cache, lookup);
		return RESOLV_CACHE_NOTFOUND;
		return (flags & ANDROID_RESOLV_NO_CACHE_STORE) ? RESOLV_CACHE_SKIP : RESOLV_CACHE_NOTFOUND;
		}

		*answerlen = e->answerlen;

res_init.cpp

+8 −35

Original line number	Diff line number	Diff line
		@@ -94,23 +94,11 @@

		void res_init(ResState* statp, const struct android_net_context* _Nonnull netcontext,
		android::net::NetworkDnsEventReported* _Nonnull event) {
		memset(statp, 0, sizeof *statp);

		statp->netid = netcontext->dns_netid;
		statp->uid = netcontext->uid;
		statp->pid = netcontext->pid;
		statp->nscount = 1;
		statp->id = arc4random_uniform(65536);
		statp->_mark = netcontext->dns_mark;
		statp->netcontext_flags = netcontext->flags;
		statp->event = event;

		statp->ndots = 1;
		statp->_vcsock = -1;

		for (int ns = 0; ns < MAXNS; ns++) {
		statp->nssocks[ns] = -1;
		}

		// 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.
		@@ -120,28 +108,13 @@ void res_init(ResState* statp, const struct android_net_context* _Nonnull netcon
		.sin.sin_port = htons(NAMESERVER_PORT),
		};
		memcpy(&statp->nsaddrs, &u, sizeof(u));
		statp->nscount = 1;
		}

		/*
		* This routine is for closing the socket if a virtual circuit is used and
		* the program wants to close it. This provides support for endhostent()
		* which expects to close the socket.
		*
		* This routine is not expected to be user visible.
		*/
		void res_nclose(res_state statp) {
		int ns;

		if (statp->_vcsock >= 0) {
		(void) close(statp->_vcsock);
		statp->_vcsock = -1;
		statp->_flags &= ~RES_F_VC;
		}
		for (ns = 0; ns < MAXNS; ns++) {
		if (statp->nssocks[ns] != -1) {
		close(statp->nssocks[ns]);
		statp->nssocks[ns] = -1;
		}
		for (auto& sock : statp->nssocks) {
		sock.reset();
		}
		statp->ndots = 1;
		statp->_mark = netcontext->dns_mark;
		statp->tcp_nssock.reset();
		statp->event = event;
		statp->netcontext_flags = netcontext->flags;
		}

res_send.cpp

+134 −151

Original line number	Diff line number	Diff line
		@@ -555,7 +555,7 @@ int res_nsend(res_state statp, const uint8_t* buf, int buflen, uint8_t* ans, int
		}
		if (resplen < 0) {
		_resolv_cache_query_failed(statp->netid, buf, buflen, flags);
		res_nclose(statp);
		statp->closeSockets();
		return -terrno;
		};

		@@ -565,11 +565,11 @@ int res_nsend(res_state statp, const uint8_t* buf, int buflen, uint8_t* ans, int
		if (cache_status == RESOLV_CACHE_NOTFOUND) {
		resolv_cache_add(statp->netid, buf, buflen, ans, resplen);
		}
		res_nclose(statp);
		statp->closeSockets();
		return (resplen);
		} // for each ns
		} // for each retry
		res_nclose(statp);
		statp->closeSockets();
		terrno = useTcp ? terrno : gotsomewhere ? ETIMEDOUT : ECONNREFUSED;
		// TODO: Remove errno once callers stop using it
		errno = useTcp ? terrno
		@@ -631,25 +631,24 @@ same_ns:
		struct timespec now = evNowTime();

		/* Are we still talking to whom we want to talk to? */
		if (statp->_vcsock >= 0 && (statp->_flags & RES_F_VC) != 0) {
		if (statp->tcp_nssock >= 0 && (statp->_flags & RES_F_VC) != 0) {
		struct sockaddr_storage peer;
		socklen_t size = sizeof peer;
		unsigned old_mark;
		socklen_t mark_size = sizeof(old_mark);
		if (getpeername(statp->_vcsock, (struct sockaddr) (void) &peer, &size) < 0 \|\|
		if (getpeername(statp->tcp_nssock, (struct sockaddr)(void)&peer, &size) < 0 \|\|
		!sock_eq((struct sockaddr)(void)&peer, nsap) \|\|
		getsockopt(statp->_vcsock, SOL_SOCKET, SO_MARK, &old_mark, &mark_size) < 0 \|\|
		getsockopt(statp->tcp_nssock, SOL_SOCKET, SO_MARK, &old_mark, &mark_size) < 0 \|\|
		old_mark != statp->_mark) {
		res_nclose(statp);
		statp->_flags &= ~RES_F_VC;
		statp->closeSockets();
		}
		}

		if (statp->_vcsock < 0 \|\| (statp->_flags & RES_F_VC) == 0) {
		if (statp->_vcsock >= 0) res_nclose(statp);
		if (statp->tcp_nssock < 0 \|\| (statp->_flags & RES_F_VC) == 0) {
		if (statp->tcp_nssock >= 0) statp->closeSockets();

		statp->_vcsock = socket(nsap->sa_family, SOCK_STREAM \| SOCK_CLOEXEC, 0);
		if (statp->_vcsock < 0) {
		statp->tcp_nssock.reset(socket(nsap->sa_family, SOCK_STREAM \| SOCK_CLOEXEC, 0));
		if (statp->tcp_nssock < 0) {
		switch (errno) {
		case EPROTONOSUPPORT:
		case EPFNOSUPPORT:
		@@ -662,9 +661,9 @@ same_ns:
		return -1;
		}
		}
		resolv_tag_socket(statp->_vcsock, statp->uid, statp->pid);
		resolv_tag_socket(statp->tcp_nssock, statp->uid, statp->pid);
		if (statp->_mark != MARK_UNSET) {
		if (setsockopt(statp->_vcsock, SOL_SOCKET, SO_MARK, &statp->_mark,
		if (setsockopt(statp->tcp_nssock, SOL_SOCKET, SO_MARK, &statp->_mark,
		sizeof(statp->_mark)) < 0) {
		*terrno = errno;
		PLOG(DEBUG) << __func__ << ": setsockopt: ";
		@@ -672,17 +671,17 @@ same_ns:
		}
		}
		errno = 0;
		if (random_bind(statp->_vcsock, nsap->sa_family) < 0) {
		if (random_bind(statp->tcp_nssock, nsap->sa_family) < 0) {
		*terrno = errno;
		dump_error("bind/vc", nsap, nsaplen);
		res_nclose(statp);
		statp->closeSockets();
		return (0);
		}
		if (connect_with_timeout(statp->_vcsock, nsap, (socklen_t) nsaplen,
		if (connect_with_timeout(statp->tcp_nssock, nsap, (socklen_t)nsaplen,
		get_timeout(statp, params, ns)) < 0) {
		*terrno = errno;
		dump_error("connect/vc", nsap, nsaplen);
		res_nclose(statp);
		statp->closeSockets();
		/*
		* The way connect_with_timeout() is implemented prevents us from reliably
		* determining whether this was really a timeout or e.g. ECONNREFUSED. Since
		@@ -705,10 +704,10 @@ same_ns:
		{.iov_base = &len, .iov_len = INT16SZ},
		{.iov_base = const_cast<uint8_t*>(buf), .iov_len = static_cast<size_t>(buflen)},
		};
		if (writev(statp->_vcsock, iov, 2) != (INT16SZ + buflen)) {
		if (writev(statp->tcp_nssock, iov, 2) != (INT16SZ + buflen)) {
		*terrno = errno;
		PLOG(DEBUG) << __func__ << ": write failed: ";
		res_nclose(statp);
		statp->closeSockets();
		return (0);
		}
		/*
		@@ -717,14 +716,14 @@ same_ns:
		read_len:
		cp = ans;
		len = INT16SZ;
		while ((n = read(statp->_vcsock, (char*) cp, (size_t) len)) > 0) {
		while ((n = read(statp->tcp_nssock, (char*)cp, (size_t)len)) > 0) {
		cp += n;
		if ((len -= n) == 0) break;
		}
		if (n <= 0) {
		*terrno = errno;
		PLOG(DEBUG) << __func__ << ": read failed: ";
		res_nclose(statp);
		statp->closeSockets();
		/*
		* A long running process might get its TCP
		* connection reset if the remote server was
		@@ -736,10 +735,8 @@ read_len:
		*/
		if (*terrno == ECONNRESET && !connreset) {
		connreset = 1;
		res_nclose(statp);
		goto same_ns;
		}
		res_nclose(statp);
		return (0);
		}
		uint16_t resplen = ntohs(reinterpret_cast<const uint16_t>(ans));
		@@ -755,18 +752,18 @@ read_len:
		*/
		LOG(DEBUG) << __func__ << ": undersized: " << len;
		*terrno = EMSGSIZE;
		res_nclose(statp);
		statp->closeSockets();
		return (0);
		}
		cp = ans;
		while (len != 0 && (n = read(statp->_vcsock, (char*) cp, (size_t) len)) > 0) {
		while (len != 0 && (n = read(statp->tcp_nssock, (char*)cp, (size_t)len)) > 0) {
		cp += n;
		len -= n;
		}
		if (n <= 0) {
		*terrno = errno;
		PLOG(DEBUG) << __func__ << ": read(vc): ";
		res_nclose(statp);
		statp->closeSockets();
		return (0);
		}

		@@ -779,7 +776,7 @@ read_len:
		while (len != 0) {
		char junk[PACKETSZ];

		n = read(statp->_vcsock, junk, (len > sizeof junk) ? sizeof junk : len);
		n = read(statp->tcp_nssock, junk, (len > sizeof junk) ? sizeof junk : len);
		if (n > 0)
		len -= n;
		else
		@@ -875,24 +872,39 @@ retry:
		return n;
		}

		bool ignoreInvalidAnswer(res_state statp, const sockaddr_storage& from, const uint8_t* buf,
		int buflen, uint8_t* ans, int anssiz) {
		const HEADER* hp = (const HEADER)(const void)buf;
		HEADER* anhp = (HEADER)(void)ans;
		if (hp->id != anhp->id) {
		// response from old query, ignore it.
		LOG(DEBUG) << __func__ << ": old answer:";
		return true;
		}
		if (!res_ourserver_p(statp, (sockaddr)(void)&from)) {
		// response from wrong server? ignore it.
		LOG(DEBUG) << __func__ << ": not our server:";
		return true;
		}
		if (!res_queriesmatch(buf, buf + buflen, ans, ans + anssiz)) {
		// response contains wrong query? ignore it.
		LOG(DEBUG) << __func__ << ": wrong query name:";
		return true;
		}
		return false;
		}

		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) {
		*at = time(NULL);
		*at = time(nullptr);
		*delay = 0;
		const HEADER* hp = (const HEADER) (const void) buf;
		HEADER* anhp = (HEADER) (void) ans;
		const struct sockaddr* nsap;
		int nsaplen;
		struct timespec now, timeout, finish, done;
		struct sockaddr_storage from;
		socklen_t fromlen;
		int resplen, n, s;

		nsap = get_nsaddr(statp, (size_t) ns);
		nsaplen = sockaddrSize(nsap);
		const sockaddr* nsap = get_nsaddr(statp, (size_t)ns);
		const int nsaplen = sockaddrSize(nsap);

		if (statp->nssocks[ns] == -1) {
		statp->nssocks[ns] = socket(nsap->sa_family, SOCK_DGRAM \| SOCK_CLOEXEC, 0);
		statp->nssocks[ns].reset(socket(nsap->sa_family, SOCK_DGRAM \| SOCK_CLOEXEC, 0));
		if (statp->nssocks[ns] < 0) {
		switch (errno) {
		case EPROTONOSUPPORT:
		@@ -911,7 +923,7 @@ static int send_dg(res_state statp, res_params* params, const uint8_t* buf, int
		if (statp->_mark != MARK_UNSET) {
		if (setsockopt(statp->nssocks[ns], SOL_SOCKET, SO_MARK, &(statp->_mark),
		sizeof(statp->_mark)) < 0) {
		res_nclose(statp);
		statp->closeSockets();
		return -1;
		}
		}
		@@ -921,30 +933,28 @@ static int send_dg(res_state statp, res_params* params, const uint8_t* buf, int
		// a nameserver without timing out.
		if (random_bind(statp->nssocks[ns], nsap->sa_family) < 0) {
		dump_error("bind(dg)", nsap, nsaplen);
		res_nclose(statp);
		statp->closeSockets();
		return (0);
		}
		if (connect(statp->nssocks[ns], nsap, (socklen_t)nsaplen) < 0) {
		dump_error("connect(dg)", nsap, nsaplen);
		res_nclose(statp);
		statp->closeSockets();
		return (0);
		}
		LOG(DEBUG) << __func__ << ": new DG socket";
		}
		s = statp->nssocks[ns];
		if (send(s, (const char*) buf, (size_t) buflen, 0) != buflen) {
		if (send(statp->nssocks[ns], (const char*)buf, (size_t)buflen, 0) != buflen) {
		PLOG(DEBUG) << __func__ << ": send: ";
		res_nclose(statp);
		statp->closeSockets();
		return 0;
		}

		timespec timeout = get_timeout(statp, params, ns);
		timespec now = evNowTime();
		timespec finish = evAddTime(now, timeout);
		for (;;) {
		// Wait for reply.
		timeout = get_timeout(statp, params, ns);
		now = evNowTime();
		finish = evAddTime(now, timeout);
		retry:
		n = retrying_poll(s, POLLIN, &finish);

		int n = retrying_poll(statp->nssocks[ns], POLLIN, &finish);
		if (n == 0) {
		*rcode = RCODE_TIMEOUT;
		LOG(DEBUG) << __func__ << ": timeout";
		@@ -953,99 +963,72 @@ retry:
		}
		if (n < 0) {
		PLOG(DEBUG) << __func__ << ": poll: ";
		res_nclose(statp);
		statp->closeSockets();
		return 0;
		}

		errno = 0;
		fromlen = sizeof(from);
		resplen = recvfrom(s, (char) ans, (size_t) anssiz, 0, (struct sockaddr) (void*) &from,
		&fromlen);
		sockaddr_storage from;
		socklen_t fromlen = sizeof(from);
		int resplen = recvfrom(statp->nssocks[ns], (char*)ans, (size_t)anssiz, 0,
		(sockaddr)(void)&from, &fromlen);
		if (resplen <= 0) {
		PLOG(DEBUG) << __func__ << ": recvfrom: ";
		res_nclose(statp);
		statp->closeSockets();
		return 0;
		}
		*gotsomewhere = 1;
		if (resplen < HFIXEDSZ) {
		/*
		* Undersized message.
		*/
		// Undersized message.
		LOG(DEBUG) << __func__ << ": undersized: " << resplen;
		*terrno = EMSGSIZE;
		res_nclose(statp);
		statp->closeSockets();
		return 0;
		}
		if (hp->id != anhp->id) {
		/*
		* response from old query, ignore it.
		* XXX - potential security hazard could
		* be detected here.
		*/
		LOG(DEBUG) << __func__ << ": old answer:";
		res_pquery(ans, (resplen > anssiz) ? anssiz : resplen);
		goto retry;
		}
		if (!res_ourserver_p(statp, (struct sockaddr)(void)&from)) {
		/*
		* response from wrong server? ignore it.
		* XXX - potential security hazard could
		* be detected here.
		*/
		LOG(DEBUG) << __func__ << ": not our server:";

		if (ignoreInvalidAnswer(statp, from, buf, buflen, ans, anssiz)) {
		res_pquery(ans, (resplen > anssiz) ? anssiz : resplen);
		goto retry;
		continue;
		}

		HEADER* anhp = (HEADER)(void)ans;
		if (anhp->rcode == FORMERR && (statp->netcontext_flags & NET_CONTEXT_FLAG_USE_EDNS)) {
		/*
		* Do not retry if the server do not understand EDNS0.
		* The case has to be captured here, as FORMERR packet do not
		* carry query section, hence res_queriesmatch() returns 0.
		*/
		// Do not retry if the server do not understand EDNS0.
		// The case has to be captured here, as FORMERR packet do not
		// carry query section, hence res_queriesmatch() returns 0.
		LOG(DEBUG) << __func__ << ": server rejected query with EDNS0:";
		res_pquery(ans, (resplen > anssiz) ? anssiz : resplen);
		/* record the error */
		// record the error
		statp->_flags \|= RES_F_EDNS0ERR;
		res_nclose(statp);
		statp->closeSockets();
		return 0;
		}
		if (!res_queriesmatch(buf, buf + buflen, ans, ans + anssiz)) {
		/*
		* response contains wrong query? ignore it.
		* XXX - potential security hazard could
		* be detected here.
		*/
		LOG(DEBUG) << __func__ << ": wrong query name:";
		res_pquery(ans, (resplen > anssiz) ? anssiz : resplen);
		goto retry;
		}
		done = evNowTime();

		timespec done = evNowTime();
		*delay = _res_stats_calculate_rtt(&done, &now);
		if (anhp->rcode == SERVFAIL \|\| anhp->rcode == NOTIMP \|\| anhp->rcode == REFUSED) {
		LOG(DEBUG) << __func__ << ": server rejected query:";
		res_pquery(ans, (resplen > anssiz) ? anssiz : resplen);
		res_nclose(statp);
		statp->closeSockets();
		*rcode = anhp->rcode;
		return 0;
		}
		if (anhp->tc) {
		/*
		* To get the rest of answer,
		* use TCP with same server.
		*/
		// To get the rest of answer,
		// use TCP with same server.
		LOG(DEBUG) << __func__ << ": truncated answer";
		*v_circuit = 1;
		res_nclose(statp);
		statp->closeSockets();
		return 1;
		}
		/*
		* All is well, or the error is fatal. Signal that the
		* next nameserver ought not be tried.
		*/
		// All is well, or the error is fatal. Signal that the
		// next nameserver ought not be tried.
		if (resplen > 0) {
		*rcode = anhp->rcode;
		}
		return resplen;
		}
		}

		static void dump_error(const char* str, const struct sockaddr* address, int alen) {
		char hbuf[NI_MAXHOST];

resolv_private.h

+27 −17

Original line number	Diff line number	Diff line
		@@ -49,6 +49,7 @@
		#pragma once

		#include <android-base/logging.h>
		#include <android-base/unique_fd.h>
		#include <net/if.h>
		#include <time.h>
		#include <string>
		@@ -73,6 +74,10 @@
		#define RES_TIMEOUT 5000 /* min. milliseconds between retries */
		#define RES_DFLRETRY 2 /* Default #/tries. */

		// Flags for res_state->_flags
		#define RES_F_VC 0x00000001 // socket is TCP
		#define RES_F_EDNS0ERR 0x00000004 // EDNS0 caused errors

		// Holds either a sockaddr_in or a sockaddr_in6.
		union sockaddr_union {
		struct sockaddr sa;
		@@ -82,21 +87,31 @@ union sockaddr_union {
		constexpr int MAXPACKET = 8 * 1024;

		struct ResState {
		void closeSockets() {
		tcp_nssock.reset();
		_flags &= ~RES_F_VC;

		for (auto& sock : nssocks) {
		sock.reset();
		}
		}
		// 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<std::string> search_domains{}; // domains to search
		sockaddr_union nsaddrs[MAXNS];
		int nssocks[MAXNS]; // UDP sockets to nameservers
		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
		int _vcsock; // TCP socket (but why not one per nameserver?)
		uint32_t _flags; // See RES_F_* defines below
		android::base::unique_fd tcp_nssock; // TCP socket (but why not one per nameserver?)
		uint32_t _flags = 0; // See RES_F_* defines below
		android::net::NetworkDnsEventReported* event;
		uint32_t netcontext_flags;
		int tc_mode;
		int tc_mode = 0;
		// clang-format on
		};

		// TODO: remove these legacy aliases
		@@ -121,10 +136,6 @@ void _res_stats_set_sample(res_sample* sample, time_t now, int rcode, int rtt);

		/* End of stats related definitions */

		// Flags for res_state->_flags
		#define RES_F_VC 0x00000001 // socket is TCP
		#define RES_F_EDNS0ERR 0x00000004 // EDNS0 caused errors

		/*
		* Error code extending h_errno codes defined in bionic/libc/include/netdb.h.
		*
		@@ -146,7 +157,6 @@ int res_nquerydomain(res_state, const char, const char, int, int, uint8_t*, in
		int res_nmkquery(int op, const char* qname, int cl, int type, const uint8_t* data, int datalen,
		uint8_t* buf, int buflen, int netcontext_flags);
		int res_nsend(res_state, const uint8_t, int, uint8_t, int, int*, uint32_t);
		void res_nclose(res_state);
		int res_nopt(res_state, int, uint8_t*, int, int);

		int getaddrinfo_numeric(const char* hostname, const char* servname, addrinfo hints,

tests/dns_responder/dns_responder.cpp

+5 −1

Original line number	Diff line number	Diff line
		@@ -547,6 +547,10 @@ void DNSResponder::setEdns(Edns edns) {
		edns_ = edns;
		}

		void DNSResponder::setTtl(unsigned ttl) {
		answer_record_ttl_sec_ = ttl;
		}

		bool DNSResponder::running() const {
		return (udp_socket_.ok()) && (tcp_socket_.ok());
		}
		@@ -783,7 +787,7 @@ bool DNSResponder::addAnswerRecords(const DNSQuestion& question,
		.name = {.name = it->first.name},
		.rtype = it->first.type,
		.rclass = ns_class::ns_c_in,
		.ttl = kAnswerRecordTtlSec, // seconds
		.ttl = answer_record_ttl_sec_, // seconds
		};
		if (!fillRdata(it->second, record)) return false;
		answers->push_back(std::move(record));