Merge "Replace addrinfo with IPSockAddr to store dns addresses" (d8492a60) · Commits · e / os / android_packages_modules_DnsResolver

Android.bp

+1 −0

Original line number	Diff line number	Diff line
		@@ -51,6 +51,7 @@ cc_library {
		"res_query.cpp",
		"res_send.cpp",
		"res_stats.cpp",
		"util.cpp",
		"Dns64Configuration.cpp",
		"DnsProxyListener.cpp",
		"DnsResolver.cpp",

getaddrinfo.cpp

+1 −1

Original line number	Diff line number	Diff line
		@@ -1697,7 +1697,7 @@ static int res_searchN(const char* name, res_target* target, res_state res, int*
		* the domain stuff is tried. Will have a better
		* fix after thread pools are used.
		*/
		_resolv_populate_res_for_net(res);
		resolv_populate_res_for_net(res);

		for (const auto& domain : res->search_domains) {
		ret = res_querydomainN(name, domain.c_str(), target, res, herrno);

res_cache.cpp

+58 −79

Original line number	Diff line number	Diff line
		@@ -61,10 +61,14 @@
		#include "DnsStats.h"
		#include "res_debug.h"
		#include "resolv_private.h"
		#include "util.h"

		using android::base::StringAppendF;
		using android::net::DnsQueryEvent;
		using android::net::DnsStats;
		using android::net::PROTO_DOT;
		using android::net::PROTO_TCP;
		using android::net::PROTO_UDP;
		using android::netdutils::DumpWriter;
		using android::netdutils::IPSockAddr;

		@@ -936,7 +940,7 @@ struct resolv_cache_info {
		struct resolv_cache_info* next;
		int nscount;
		std::vector<std::string> nameservers;
		struct addrinfo* nsaddrinfo[MAXNS]; // TODO: Use struct sockaddr_storage.
		std::vector<IPSockAddr> nameserverSockAddrs;
		int revision_id; // # times the nameservers have been replaced
		res_params params;
		struct res_stats nsstats[MAXNS];
		@@ -1563,6 +1567,21 @@ std::vector<std::string> filter_nameservers(const std::vector<std::string>& serv
		return res;
		}

		bool isValidServer(const std::string& server) {
		const addrinfo hints = {
		.ai_family = AF_UNSPEC,
		.ai_socktype = SOCK_DGRAM,
		};
		addrinfo* result = nullptr;
		if (int err = getaddrinfo_numeric(server.c_str(), "53", hints, &result); err != 0) {
		LOG(WARNING) << __func__ << ": getaddrinfo_numeric(" << server
		<< ") = " << gai_strerror(err);
		return false;
		}
		freeaddrinfo(result);
		return true;
		}

		} // namespace

		int resolv_set_nameservers(unsigned netid, const std::vector<std::string>& servers,
		@@ -1574,24 +1593,11 @@ int resolv_set_nameservers(unsigned netid, const std::vector<std::string>& serve

		// Parse the addresses before actually locking or changing any state, in case there is an error.
		// As a side effect this also reduces the time the lock is kept.
		// TODO: find a better way to replace addrinfo*, something like std::vector<SafeAddrinfo>
		addrinfo* nsaddrinfo[MAXNS];
		for (int i = 0; i < numservers; i++) {
		// The addrinfo structures allocated here are freed in free_nameservers_locked().
		const addrinfo hints = {
		.ai_flags = AI_NUMERICHOST,
		.ai_family = AF_UNSPEC,
		.ai_socktype = SOCK_DGRAM,
		};
		const int rt = getaddrinfo_numeric(nameservers[i].c_str(), "53", hints, &nsaddrinfo[i]);
		if (rt != 0) {
		for (int j = 0; j < i; j++) {
		freeaddrinfo(nsaddrinfo[j]);
		}
		LOG(INFO) << __func__ << ": getaddrinfo_numeric(" << nameservers[i]
		<< ") = " << gai_strerror(rt);
		return -EINVAL;
		}
		std::vector<IPSockAddr> ipSockAddrs;
		ipSockAddrs.reserve(nameservers.size());
		for (const auto& server : nameservers) {
		if (!isValidServer(server)) return -EINVAL;
		ipSockAddrs.push_back(IPSockAddr::toIPSockAddr(server, 53));
		}

		std::lock_guard guard(cache_mutex);
		@@ -1607,10 +1613,10 @@ int resolv_set_nameservers(unsigned netid, const std::vector<std::string>& serve
		free_nameservers_locked(cache_info);
		cache_info->nameservers = std::move(nameservers);
		for (int i = 0; i < numservers; i++) {
		cache_info->nsaddrinfo[i] = nsaddrinfo[i];
		LOG(INFO) << __func__ << ": netid = " << netid
		<< ", addr = " << cache_info->nameservers[i];
		}
		cache_info->nameserverSockAddrs = std::move(ipSockAddrs);
		cache_info->nscount = numservers;
		} else {
		if (cache_info->params.max_samples != old_max_samples) {
		@@ -1621,23 +1627,15 @@ int resolv_set_nameservers(unsigned netid, const std::vector<std::string>& serve
		// under which servers are considered usable.
		res_cache_clear_stats_locked(cache_info);
		}
		for (int j = 0; j < numservers; j++) {
		freeaddrinfo(nsaddrinfo[j]);
		}
		}

		// Always update the search paths. Cache-flushing however is not necessary,
		// since the stored cache entries do contain the domain, not just the host name.
		cache_info->search_domains = filter_domains(domains);

		std::vector<IPSockAddr> serverSockAddrs;
		serverSockAddrs.reserve(cache_info->nameservers.size());
		for (const auto& server : cache_info->nameservers) {
		serverSockAddrs.push_back(IPSockAddr::toIPSockAddr(server, 53));
		}

		if (!cache_info->dnsStats->setServers(serverSockAddrs, android::net::PROTO_TCP) \|\|
		!cache_info->dnsStats->setServers(serverSockAddrs, android::net::PROTO_UDP)) {
		// Setup stats for cleartext dns servers.
		if (!cache_info->dnsStats->setServers(cache_info->nameserverSockAddrs, PROTO_TCP) \|\|
		!cache_info->dnsStats->setServers(cache_info->nameserverSockAddrs, PROTO_UDP)) {
		LOG(WARNING) << __func__ << ": netid = " << netid << ", failed to set dns stats";
		return -EINVAL;
		}
		@@ -1659,45 +1657,39 @@ static bool resolv_is_nameservers_equal(const std::vector<std::string>& oldServe
		}

		static void free_nameservers_locked(resolv_cache_info* cache_info) {
		int i;
		for (i = 0; i < cache_info->nscount; i++) {
		cache_info->nameservers.clear();
		if (cache_info->nsaddrinfo[i] != nullptr) {
		freeaddrinfo(cache_info->nsaddrinfo[i]);
		cache_info->nsaddrinfo[i] = nullptr;
		}
		}
		cache_info->nscount = 0;
		cache_info->nameservers.clear();
		cache_info->nameserverSockAddrs.clear();
		res_cache_clear_stats_locked(cache_info);
		}

		void _resolv_populate_res_for_net(res_state statp) {
		if (statp == NULL) {
		void resolv_populate_res_for_net(ResState* statp) {
		if (statp == nullptr) {
		return;
		}
		LOG(INFO) << __func__ << ": netid=" << statp->netid;

		std::lock_guard guard(cache_mutex);
		resolv_cache_info* info = find_cache_info_locked(statp->netid);
		if (info != NULL) {
		int nserv;
		struct addrinfo* ai;
		for (nserv = 0; nserv < MAXNS; nserv++) {
		ai = info->nsaddrinfo[nserv];
		if (ai == NULL) {
		break;
		}
		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 ((size_t)ai->ai_addrlen <= sizeof(statp->nsaddrs[0])) {
		memcpy(&statp->nsaddrs[nserv], ai->ai_addr, ai->ai_addrlen);
		if (auto sockaddr_len = sockaddrSize(ss); sockaddr_len != 0) {
		memcpy(&statp->nsaddrs[nserv], &ss, sockaddr_len);
		} else {
		LOG(INFO) << __func__ << ": found too long addrlen";
		LOG(WARNING) << __func__ << ": can't get sa_len from "
		<< info->nameserverSockAddrs.at(nserv);
		}
		}
		statp->nscount = nserv;

		statp->nscount = serverNum;
		statp->search_domains = info->search_domains;
		}
		}

		/* Resolver reachability statistics. */

		@@ -1745,31 +1737,18 @@ int android_net_res_stats_get_info_for_net(unsigned netid, int* nscount,
		return -1;
		}
		int i;
		for (i = 0; i < info->nscount; i++) {
		// Verify that the following assumptions are held, failure indicates corruption:
		// - getaddrinfo() may never return a sockaddr > sockaddr_storage
		// - all addresses are valid
		// - there is only one address per addrinfo thanks to numeric resolution
		int addrlen = info->nsaddrinfo[i]->ai_addrlen;
		if (addrlen < (int) sizeof(struct sockaddr) \|\| addrlen > (int) sizeof(servers[0])) {
		LOG(INFO) << __func__ << ": nsaddrinfo[" << i << "].ai_addrlen == " << addrlen;
		errno = EMSGSIZE;
		return -1;
		}
		if (info->nsaddrinfo[i]->ai_addr == NULL) {
		LOG(INFO) << __func__ << ": nsaddrinfo[" << i << "].ai_addr == NULL";
		errno = ENOENT;
		return -1;
		}
		if (info->nsaddrinfo[i]->ai_next != NULL) {
		LOG(INFO) << __func__ << ": nsaddrinfo[" << i << "].ai_next != NULL";
		errno = ENOTUNIQ;
		*nscount = info->nscount;

		// 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();
		errno = EFAULT;
		return -1;
		}
		}
		*nscount = info->nscount;

		for (i = 0; i < info->nscount; i++) {
		memcpy(&servers[i], info->nsaddrinfo[i]->ai_addr, info->nsaddrinfo[i]->ai_addrlen);
		servers[i] = info->nameserverSockAddrs.at(i);
		stats[i] = info->nsstats[i];
		}

res_init.cpp

+1 −1

Original line number	Diff line number	Diff line
		@@ -112,7 +112,7 @@ void res_init(ResState* statp, const struct android_net_context* _Nonnull netcon
		}

		// The following dummy initialization is probably useless because
		// it's overwritten later by _resolv_populate_res_for_net().
		// 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,

res_query.cpp

+1 −1

Original line number	Diff line number	Diff line
		@@ -250,7 +250,7 @@ int res_nsearch(res_state statp, const char* name, /* domain name */
		* be loaded once for the thread instead of each
		* time a query is tried.
		*/
		_resolv_populate_res_for_net(statp);
		resolv_populate_res_for_net(statp);

		for (const auto& domain : statp->search_domains) {
		if (domain == "." \|\| domain == "") ++root_on_list;