tests/netdb_test.cpp - android_bionic - Gitiles

 /*
  * Copyright (C) 2013 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include <netdb.h>

 #include <gtest/gtest.h>

 #include <arpa/inet.h>
 #include <string.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>

 // https://code.google.com/p/android/issues/detail?id=13228
 TEST(netdb, freeaddrinfo_NULL) {
   freeaddrinfo(nullptr);
 }

 TEST(netdb, getaddrinfo_NULL_host) {
   // It's okay for the host argument to be NULL, as long as service isn't.
   addrinfo* ai = nullptr;
   ASSERT_EQ(0, getaddrinfo(nullptr, "smtp", nullptr, &ai));
   // (sockaddr_in::sin_port and sockaddr_in6::sin6_port overlap.)
   ASSERT_EQ(25U, ntohs(reinterpret_cast<sockaddr_in*>(ai->ai_addr)->sin_port));
   freeaddrinfo(ai);
 }

 TEST(netdb, getaddrinfo_NULL_service) {
   // It's okay for the service argument to be NULL, as long as host isn't.
   addrinfo* ai = nullptr;
   ASSERT_EQ(0, getaddrinfo("localhost", nullptr, nullptr, &ai));
   ASSERT_TRUE(ai != nullptr);
   freeaddrinfo(ai);
 }

 TEST(netdb, getaddrinfo_NULL_hints) {
   addrinfo* ai = nullptr;
   ASSERT_EQ(0, getaddrinfo("localhost", "9999", nullptr, &ai));

   bool saw_tcp = false;
   bool saw_udp = false;
   for (addrinfo* p = ai; p != nullptr; p = p->ai_next) {
     ASSERT_TRUE(p->ai_family == AF_INET || p->ai_family == AF_INET6);
     if (p->ai_socktype == SOCK_STREAM) {
       ASSERT_EQ(IPPROTO_TCP, p->ai_protocol);
       saw_tcp = true;
     } else if (p->ai_socktype == SOCK_DGRAM) {
       ASSERT_EQ(IPPROTO_UDP, p->ai_protocol);
       saw_udp = true;
     }
   }
   ASSERT_TRUE(saw_tcp);
   ASSERT_TRUE(saw_udp);

   freeaddrinfo(ai);
 }

 TEST(netdb, getaddrinfo_service_lookup) {
   addrinfo* ai = nullptr;
   ASSERT_EQ(0, getaddrinfo("localhost", "smtp", nullptr, &ai));
   ASSERT_EQ(SOCK_STREAM, ai->ai_socktype);
   ASSERT_EQ(IPPROTO_TCP, ai->ai_protocol);
   ASSERT_EQ(25, ntohs(reinterpret_cast<sockaddr_in*>(ai->ai_addr)->sin_port));
   freeaddrinfo(ai);
 }

 TEST(netdb, getaddrinfo_hints) {
   addrinfo hints;
   memset(&hints, 0, sizeof(hints));
   hints.ai_family = AF_INET;
   hints.ai_socktype = SOCK_STREAM;
   hints.ai_protocol = IPPROTO_TCP;

   addrinfo* ai = nullptr;
   ASSERT_EQ(0, getaddrinfo( "localhost", "9999", &hints, &ai));
   ASSERT_TRUE(ai != nullptr);
   // In glibc, getaddrinfo() converts ::1 to 127.0.0.1 for localhost,
   // so one or two addrinfo may be returned.
   addrinfo* tai = ai;
   while (tai != nullptr) {
     ASSERT_EQ(AF_INET, tai->ai_family);
     ASSERT_EQ(SOCK_STREAM, tai->ai_socktype);
     ASSERT_EQ(IPPROTO_TCP, tai->ai_protocol);
     tai = tai->ai_next;
   }
   freeaddrinfo(ai);
 }

 TEST(netdb, getaddrinfo_ip6_localhost) {
   addrinfo* ai = nullptr;
   ASSERT_EQ(0, getaddrinfo("ip6-localhost", nullptr, nullptr, &ai));
   ASSERT_TRUE(ai != nullptr);
   ASSERT_GE(ai->ai_addrlen, static_cast<socklen_t>(sizeof(sockaddr_in6)));
   ASSERT_TRUE(ai->ai_addr != nullptr);
   sockaddr_in6 *addr = reinterpret_cast<sockaddr_in6*>(ai->ai_addr);
   ASSERT_EQ(addr->sin6_family, AF_INET6);
   ASSERT_EQ(0, memcmp(&addr->sin6_addr, &in6addr_loopback, sizeof(in6_addr)));
   freeaddrinfo(ai);
 }

 TEST(netdb, getnameinfo_salen) {
   sockaddr_storage ss;
   memset(&ss, 0, sizeof(ss));
   sockaddr* sa = reinterpret_cast<sockaddr*>(&ss);
   char tmp[16];

   ss.ss_family = AF_INET;
   socklen_t too_much = sizeof(ss);
   socklen_t just_right = sizeof(sockaddr_in);
   socklen_t too_little = sizeof(sockaddr_in) - 1;

   ASSERT_EQ(0, getnameinfo(sa, too_much, tmp, sizeof(tmp), nullptr, 0, NI_NUMERICHOST));
   ASSERT_STREQ("0.0.0.0", tmp);
   ASSERT_EQ(0, getnameinfo(sa, just_right, tmp, sizeof(tmp), nullptr, 0, NI_NUMERICHOST));
   ASSERT_STREQ("0.0.0.0", tmp);
   ASSERT_EQ(EAI_FAMILY, getnameinfo(sa, too_little, tmp, sizeof(tmp), nullptr, 0, NI_NUMERICHOST));

   ss.ss_family = AF_INET6;
   just_right = sizeof(sockaddr_in6);
   too_little = sizeof(sockaddr_in6) - 1;
   too_much = just_right + 1;

   ASSERT_EQ(0, getnameinfo(sa, too_much, tmp, sizeof(tmp), nullptr, 0, NI_NUMERICHOST));
   ASSERT_STREQ("::", tmp);
   ASSERT_EQ(0, getnameinfo(sa, just_right, tmp, sizeof(tmp), nullptr, 0, NI_NUMERICHOST));
   ASSERT_STREQ("::", tmp);
   ASSERT_EQ(EAI_FAMILY, getnameinfo(sa, too_little, tmp, sizeof(tmp), nullptr, 0, NI_NUMERICHOST));
 }

 TEST(netdb, getnameinfo_localhost) {
   sockaddr_in addr;
   char host[NI_MAXHOST];
   memset(&addr, 0, sizeof(sockaddr_in));
   addr.sin_family = AF_INET;
   addr.sin_addr.s_addr = htonl(0x7f000001);
   ASSERT_EQ(0, getnameinfo(reinterpret_cast<sockaddr*>(&addr), sizeof(addr),
                            host, sizeof(host), nullptr, 0, 0));
   ASSERT_STREQ(host, "localhost");
 }

 static void VerifyLocalhostName(const char* name) {
   // Test possible localhost name and aliases, which depend on /etc/hosts or /system/etc/hosts.
   ASSERT_TRUE(strcmp(name, "localhost") == 0 ||
               strcmp(name, "ip6-localhost") == 0 ||
               strcmp(name, "ip6-loopback") == 0) << name;
 }

 TEST(netdb, getnameinfo_ip6_localhost) {
   sockaddr_in6 addr;
   char host[NI_MAXHOST];
   memset(&addr, 0, sizeof(sockaddr_in6));
   addr.sin6_family = AF_INET6;
   addr.sin6_addr = in6addr_loopback;
   ASSERT_EQ(0, getnameinfo(reinterpret_cast<sockaddr*>(&addr), sizeof(addr),
                            host, sizeof(host), nullptr, 0, 0));
   VerifyLocalhostName(host);
 }

 static void VerifyLocalhost(hostent *hent) {
   ASSERT_TRUE(hent != nullptr);
   VerifyLocalhostName(hent->h_name);
   for (size_t i = 0; hent->h_aliases[i] != nullptr; ++i) {
     VerifyLocalhostName(hent->h_aliases[i]);
   }
   ASSERT_EQ(hent->h_addrtype, AF_INET);
   ASSERT_EQ(hent->h_addr[0], 127);
   ASSERT_EQ(hent->h_addr[1], 0);
   ASSERT_EQ(hent->h_addr[2], 0);
   ASSERT_EQ(hent->h_addr[3], 1);
 }

 TEST(netdb, gethostbyname) {
   hostent* hp = gethostbyname("localhost");
   VerifyLocalhost(hp);
 }

 TEST(netdb, gethostbyname2) {
   hostent* hp = gethostbyname2("localhost", AF_INET);
   VerifyLocalhost(hp);
 }

 TEST(netdb, gethostbyname_r) {
   hostent hent;
   hostent *hp;
   char buf[512];
   int err;
   int result = gethostbyname_r("localhost", &hent, buf, sizeof(buf), &hp, &err);
   ASSERT_EQ(0, result);
   VerifyLocalhost(hp);

   // Change hp->h_addr to test reentrancy.
   hp->h_addr[0] = 0;

   hostent hent2;
   hostent *hp2;
   char buf2[512];
   result = gethostbyname_r("localhost", &hent2, buf2, sizeof(buf2), &hp2, &err);
   ASSERT_EQ(0, result);
   VerifyLocalhost(hp2);

   ASSERT_EQ(0, hp->h_addr[0]);
 }

 TEST(netdb, gethostbyname2_r) {
   hostent hent;
   hostent *hp;
   char buf[512];
   int err;
   int result = gethostbyname2_r("localhost", AF_INET, &hent, buf, sizeof(buf), &hp, &err);
   ASSERT_EQ(0, result);
   VerifyLocalhost(hp);

   // Change hp->h_addr to test reentrancy.
   hp->h_addr[0] = 0;

   hostent hent2;
   hostent *hp2;
   char buf2[512];
   result = gethostbyname2_r("localhost", AF_INET, &hent2, buf2, sizeof(buf2), &hp2, &err);
   ASSERT_EQ(0, result);
   VerifyLocalhost(hp2);

   ASSERT_EQ(0, hp->h_addr[0]);
 }

 TEST(netdb, gethostbyaddr) {
   in_addr addr = { htonl(0x7f000001) };
   hostent *hp = gethostbyaddr(&addr, sizeof(addr), AF_INET);
   VerifyLocalhost(hp);
 }

 TEST(netdb, gethostbyaddr_r) {
   in_addr addr = { htonl(0x7f000001) };
   hostent hent;
   hostent *hp;
   char buf[512];
   int err;
   int result = gethostbyaddr_r(&addr, sizeof(addr), AF_INET, &hent, buf, sizeof(buf), &hp, &err);
   ASSERT_EQ(0, result);
   VerifyLocalhost(hp);

   // Change hp->h_addr to test reentrancy.
   hp->h_addr[0] = 0;

   hostent hent2;
   hostent *hp2;
   char buf2[512];
   result = gethostbyaddr_r(&addr, sizeof(addr), AF_INET, &hent2, buf2, sizeof(buf2), &hp2, &err);
   ASSERT_EQ(0, result);
   VerifyLocalhost(hp2);

   ASSERT_EQ(0, hp->h_addr[0]);
 }

 TEST(netdb, gethostbyname_r_ERANGE) {
   hostent hent;
   hostent *hp;
   char buf[4]; // Use too small buffer.
   int err;
   int result = gethostbyname_r("localhost", &hent, buf, sizeof(buf), &hp, &err);
   EXPECT_EQ(NETDB_INTERNAL, err);
   EXPECT_EQ(ERANGE, result);
   EXPECT_EQ(nullptr, hp);
 }

 TEST(netdb, gethostbyname2_r_ERANGE) {
   hostent hent;
   hostent *hp;
   char buf[4]; // Use too small buffer.
   int err;
   int result = gethostbyname2_r("localhost", AF_INET, &hent, buf, sizeof(buf), &hp, &err);
   EXPECT_EQ(NETDB_INTERNAL, err);
   EXPECT_EQ(ERANGE, result);
   EXPECT_EQ(nullptr, hp);
 }

 TEST(netdb, gethostbyaddr_r_ERANGE) {
   in_addr addr = { htonl(0x7f000001) };
   hostent hent;
   hostent *hp;
   char buf[4]; // Use too small buffer.
   int err;
   int result = gethostbyaddr_r(&addr, sizeof(addr), AF_INET, &hent, buf, sizeof(buf), &hp, &err);
   EXPECT_EQ(NETDB_INTERNAL, err);
   EXPECT_EQ(ERANGE, result);
   EXPECT_EQ(nullptr, hp);
 }

 TEST(netdb, gethostbyname_r_HOST_NOT_FOUND) {
   hostent hent;
   hostent *hp;
   char buf[BUFSIZ];
   int err;
   int result = gethostbyname_r("does.not.exist.google.com", &hent, buf, sizeof(buf), &hp, &err);
   EXPECT_EQ(HOST_NOT_FOUND, err);
   EXPECT_EQ(0, result);
   EXPECT_EQ(nullptr, hp);
 }

 TEST(netdb, gethostbyname2_r_HOST_NOT_FOUND) {
   hostent hent;
   hostent *hp;
   char buf[BUFSIZ];
   int err;
   int result = gethostbyname2_r("does.not.exist.google.com", AF_INET, &hent, buf, sizeof(buf), &hp, &err);
   EXPECT_EQ(HOST_NOT_FOUND, err);
   EXPECT_EQ(0, result);
   EXPECT_EQ(nullptr, hp);
 }

 TEST(netdb, gethostbyaddr_r_HOST_NOT_FOUND) {
   in_addr addr = { htonl(0xffffffff) };
   hostent hent;
   hostent *hp;
   char buf[BUFSIZ];
   int err;
   int result = gethostbyaddr_r(&addr, sizeof(addr), AF_INET, &hent, buf, sizeof(buf), &hp, &err);
   EXPECT_EQ(HOST_NOT_FOUND, err);
   EXPECT_EQ(0, result);
   EXPECT_EQ(nullptr, hp);
 }

 TEST(netdb, getservbyname) {
   // smtp is TCP-only, so we know we'll get 25/tcp back.
   servent* s = getservbyname("smtp", nullptr);
   ASSERT_TRUE(s != nullptr);
   ASSERT_STREQ("smtp", s->s_name);
   ASSERT_EQ(25, ntohs(s->s_port));
   ASSERT_STREQ("tcp", s->s_proto);

   // We get the same result by explicitly asking for tcp.
   s = getservbyname("smtp", "tcp");
   ASSERT_TRUE(s != nullptr);
   ASSERT_STREQ("smtp", s->s_name);
   ASSERT_EQ(25, ntohs(s->s_port));
   ASSERT_STREQ("tcp", s->s_proto);

   // And we get a failure if we explicitly ask for udp.
   s = getservbyname("smtp", "udp");
   ASSERT_TRUE(s == nullptr);

   // But there are actually udp services.
   s = getservbyname("echo", "udp");
   ASSERT_TRUE(s != nullptr);
   ASSERT_STREQ("echo", s->s_name);
   ASSERT_EQ(7, ntohs(s->s_port));
   ASSERT_STREQ("udp", s->s_proto);
 }

 TEST(netdb, getservbyport) {
   // smtp is TCP-only, so we know we'll get 25/tcp back.
   servent* s = getservbyport(htons(25), nullptr);
   ASSERT_TRUE(s != nullptr);
   ASSERT_STREQ("smtp", s->s_name);
   ASSERT_EQ(25, ntohs(s->s_port));
   ASSERT_STREQ("tcp", s->s_proto);

   // We get the same result by explicitly asking for tcp.
   s = getservbyport(htons(25), "tcp");
   ASSERT_TRUE(s != nullptr);
   ASSERT_STREQ("smtp", s->s_name);
   ASSERT_EQ(25, ntohs(s->s_port));
   ASSERT_STREQ("tcp", s->s_proto);

   // And we get a failure if we explicitly ask for udp.
   s = getservbyport(htons(25), "udp");
   ASSERT_TRUE(s == nullptr);

   // But there are actually udp services.
   s = getservbyport(htons(7), "udp");
   ASSERT_TRUE(s != nullptr);
   ASSERT_STREQ("echo", s->s_name);
   ASSERT_EQ(7, ntohs(s->s_port));
   ASSERT_STREQ("udp", s->s_proto);
 }

 TEST(netdb, endnetent_getnetent_setnetent) {
   setnetent(0);
   setnetent(1);
   endnetent();
   while (getnetent() != nullptr) {
   }
 }

 TEST(netdb, getnetbyaddr) {
   getnetbyaddr(0, 0);
 }

 TEST(netdb, getnetbyname) {
   getnetbyname("x");
 }

 TEST(netdb, endprotoent_getprotoent_setprotoent) {
   setprotoent(0);
   setprotoent(1);
   endprotoent();
   while (getprotoent() != nullptr) {
   }
 }

 TEST(netdb, getprotobyname) {
   getprotobyname("tcp");
 }

 TEST(netdb, getprotobynumber) {
   getprotobynumber(6);
 }

 TEST(netdb, endservent_getservent_setservent) {
   setservent(0);
   setservent(1);
   endservent();
   size_t service_count = 0;
   while (getservent() != nullptr) {
     ++service_count;
   }
   ASSERT_GT(service_count, 0U);
 }

 TEST(netdb, getservbyname_getservent_conflicts) {
   // Calling getservbyname shouldn't affect getservent's iteration order.
   endservent();
   while (getservent() != nullptr) {
     ASSERT_TRUE(getservbyname("smtp", "tcp") != nullptr);
   }
 }

 TEST(netdb, getservbyport_getservent_conflicts) {
   // Calling getservbyport shouldn't affect getservent's iteration order.
   endservent();
   while (getservent() != nullptr) {
     ASSERT_TRUE(getservbyport(htons(25), "tcp") != nullptr);
   }
 }

 TEST(netdb, endservent_resets) {
   endservent();
   std::string first_service(getservent()->s_name);
   endservent();
   ASSERT_EQ(first_service, std::string(getservent()->s_name));
 }

 TEST(netdb, setservent_resets) {
   endservent();
   std::string first_service(getservent()->s_name);
   setservent(0);
   ASSERT_EQ(first_service, std::string(getservent()->s_name));
 }

 TEST(netdb, endhostent_gethostent_sethostent) {
   sethostent(0);
   sethostent(1);
   endhostent();
   size_t host_count = 0;
   while (gethostent() != nullptr) {
     ++host_count;
   }
   ASSERT_GT(host_count, 0U);
 }

 TEST(netdb, endhostent_resets) {
   endhostent();
   std::string first_host(gethostent()->h_name);
   endhostent();
   ASSERT_EQ(first_host, std::string(gethostent()->h_name));
 }

 TEST(netdb, sethostent_resets) {
   endhostent();
   std::string first_host(gethostent()->h_name);
   sethostent(0);
   ASSERT_EQ(first_host, std::string(gethostent()->h_name));
 }
	/*
	* Copyright (C) 2013 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include <netdb.h>

	#include <gtest/gtest.h>

	#include <arpa/inet.h>
	#include <string.h>
	#include <sys/types.h>
	#include <sys/socket.h>
	#include <netinet/in.h>

	// https://code.google.com/p/android/issues/detail?id=13228
	TEST(netdb, freeaddrinfo_NULL) {
	freeaddrinfo(nullptr);
	}

	TEST(netdb, getaddrinfo_NULL_host) {
	// It's okay for the host argument to be NULL, as long as service isn't.
	addrinfo* ai = nullptr;
	ASSERT_EQ(0, getaddrinfo(nullptr, "smtp", nullptr, &ai));
	// (sockaddr_in::sin_port and sockaddr_in6::sin6_port overlap.)
	ASSERT_EQ(25U, ntohs(reinterpret_cast<sockaddr_in*>(ai->ai_addr)->sin_port));
	freeaddrinfo(ai);
	}

	TEST(netdb, getaddrinfo_NULL_service) {
	// It's okay for the service argument to be NULL, as long as host isn't.
	addrinfo* ai = nullptr;
	ASSERT_EQ(0, getaddrinfo("localhost", nullptr, nullptr, &ai));
	ASSERT_TRUE(ai != nullptr);
	freeaddrinfo(ai);
	}

	TEST(netdb, getaddrinfo_NULL_hints) {
	addrinfo* ai = nullptr;
	ASSERT_EQ(0, getaddrinfo("localhost", "9999", nullptr, &ai));

	bool saw_tcp = false;
	bool saw_udp = false;
	for (addrinfo* p = ai; p != nullptr; p = p->ai_next) {
	ASSERT_TRUE(p->ai_family == AF_INET \|\| p->ai_family == AF_INET6);
	if (p->ai_socktype == SOCK_STREAM) {
	ASSERT_EQ(IPPROTO_TCP, p->ai_protocol);
	saw_tcp = true;
	} else if (p->ai_socktype == SOCK_DGRAM) {
	ASSERT_EQ(IPPROTO_UDP, p->ai_protocol);
	saw_udp = true;
	}
	}
	ASSERT_TRUE(saw_tcp);
	ASSERT_TRUE(saw_udp);

	freeaddrinfo(ai);
	}

	TEST(netdb, getaddrinfo_service_lookup) {
	addrinfo* ai = nullptr;
	ASSERT_EQ(0, getaddrinfo("localhost", "smtp", nullptr, &ai));
	ASSERT_EQ(SOCK_STREAM, ai->ai_socktype);
	ASSERT_EQ(IPPROTO_TCP, ai->ai_protocol);
	ASSERT_EQ(25, ntohs(reinterpret_cast<sockaddr_in*>(ai->ai_addr)->sin_port));
	freeaddrinfo(ai);
	}

	TEST(netdb, getaddrinfo_hints) {
	addrinfo hints;
	memset(&hints, 0, sizeof(hints));
	hints.ai_family = AF_INET;
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_protocol = IPPROTO_TCP;

	addrinfo* ai = nullptr;
	ASSERT_EQ(0, getaddrinfo( "localhost", "9999", &hints, &ai));
	ASSERT_TRUE(ai != nullptr);
	// In glibc, getaddrinfo() converts ::1 to 127.0.0.1 for localhost,
	// so one or two addrinfo may be returned.
	addrinfo* tai = ai;
	while (tai != nullptr) {
	ASSERT_EQ(AF_INET, tai->ai_family);
	ASSERT_EQ(SOCK_STREAM, tai->ai_socktype);
	ASSERT_EQ(IPPROTO_TCP, tai->ai_protocol);
	tai = tai->ai_next;
	}
	freeaddrinfo(ai);
	}

	TEST(netdb, getaddrinfo_ip6_localhost) {
	addrinfo* ai = nullptr;
	ASSERT_EQ(0, getaddrinfo("ip6-localhost", nullptr, nullptr, &ai));
	ASSERT_TRUE(ai != nullptr);
	ASSERT_GE(ai->ai_addrlen, static_cast<socklen_t>(sizeof(sockaddr_in6)));
	ASSERT_TRUE(ai->ai_addr != nullptr);
	sockaddr_in6 addr = reinterpret_cast<sockaddr_in6>(ai->ai_addr);
	ASSERT_EQ(addr->sin6_family, AF_INET6);
	ASSERT_EQ(0, memcmp(&addr->sin6_addr, &in6addr_loopback, sizeof(in6_addr)));
	freeaddrinfo(ai);
	}

	TEST(netdb, getnameinfo_salen) {
	sockaddr_storage ss;
	memset(&ss, 0, sizeof(ss));
	sockaddr* sa = reinterpret_cast<sockaddr*>(&ss);
	char tmp[16];

	ss.ss_family = AF_INET;
	socklen_t too_much = sizeof(ss);
	socklen_t just_right = sizeof(sockaddr_in);
	socklen_t too_little = sizeof(sockaddr_in) - 1;

	ASSERT_EQ(0, getnameinfo(sa, too_much, tmp, sizeof(tmp), nullptr, 0, NI_NUMERICHOST));
	ASSERT_STREQ("0.0.0.0", tmp);
	ASSERT_EQ(0, getnameinfo(sa, just_right, tmp, sizeof(tmp), nullptr, 0, NI_NUMERICHOST));
	ASSERT_STREQ("0.0.0.0", tmp);
	ASSERT_EQ(EAI_FAMILY, getnameinfo(sa, too_little, tmp, sizeof(tmp), nullptr, 0, NI_NUMERICHOST));

	ss.ss_family = AF_INET6;
	just_right = sizeof(sockaddr_in6);
	too_little = sizeof(sockaddr_in6) - 1;
	too_much = just_right + 1;

	ASSERT_EQ(0, getnameinfo(sa, too_much, tmp, sizeof(tmp), nullptr, 0, NI_NUMERICHOST));
	ASSERT_STREQ("::", tmp);
	ASSERT_EQ(0, getnameinfo(sa, just_right, tmp, sizeof(tmp), nullptr, 0, NI_NUMERICHOST));
	ASSERT_STREQ("::", tmp);
	ASSERT_EQ(EAI_FAMILY, getnameinfo(sa, too_little, tmp, sizeof(tmp), nullptr, 0, NI_NUMERICHOST));
	}

	TEST(netdb, getnameinfo_localhost) {
	sockaddr_in addr;
	char host[NI_MAXHOST];
	memset(&addr, 0, sizeof(sockaddr_in));
	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = htonl(0x7f000001);
	ASSERT_EQ(0, getnameinfo(reinterpret_cast<sockaddr*>(&addr), sizeof(addr),
	host, sizeof(host), nullptr, 0, 0));
	ASSERT_STREQ(host, "localhost");
	}

	static void VerifyLocalhostName(const char* name) {
	// Test possible localhost name and aliases, which depend on /etc/hosts or /system/etc/hosts.
	ASSERT_TRUE(strcmp(name, "localhost") == 0 \|\|
	strcmp(name, "ip6-localhost") == 0 \|\|
	strcmp(name, "ip6-loopback") == 0) << name;
	}

	TEST(netdb, getnameinfo_ip6_localhost) {
	sockaddr_in6 addr;
	char host[NI_MAXHOST];
	memset(&addr, 0, sizeof(sockaddr_in6));
	addr.sin6_family = AF_INET6;
	addr.sin6_addr = in6addr_loopback;
	ASSERT_EQ(0, getnameinfo(reinterpret_cast<sockaddr*>(&addr), sizeof(addr),
	host, sizeof(host), nullptr, 0, 0));
	VerifyLocalhostName(host);
	}

	static void VerifyLocalhost(hostent *hent) {
	ASSERT_TRUE(hent != nullptr);
	VerifyLocalhostName(hent->h_name);
	for (size_t i = 0; hent->h_aliases[i] != nullptr; ++i) {
	VerifyLocalhostName(hent->h_aliases[i]);
	}
	ASSERT_EQ(hent->h_addrtype, AF_INET);
	ASSERT_EQ(hent->h_addr[0], 127);
	ASSERT_EQ(hent->h_addr[1], 0);
	ASSERT_EQ(hent->h_addr[2], 0);
	ASSERT_EQ(hent->h_addr[3], 1);
	}

	TEST(netdb, gethostbyname) {
	hostent* hp = gethostbyname("localhost");
	VerifyLocalhost(hp);
	}

	TEST(netdb, gethostbyname2) {
	hostent* hp = gethostbyname2("localhost", AF_INET);
	VerifyLocalhost(hp);
	}

	TEST(netdb, gethostbyname_r) {
	hostent hent;
	hostent *hp;
	char buf[512];
	int err;
	int result = gethostbyname_r("localhost", &hent, buf, sizeof(buf), &hp, &err);
	ASSERT_EQ(0, result);
	VerifyLocalhost(hp);

	// Change hp->h_addr to test reentrancy.
	hp->h_addr[0] = 0;

	hostent hent2;
	hostent *hp2;
	char buf2[512];
	result = gethostbyname_r("localhost", &hent2, buf2, sizeof(buf2), &hp2, &err);
	ASSERT_EQ(0, result);
	VerifyLocalhost(hp2);

	ASSERT_EQ(0, hp->h_addr[0]);
	}

	TEST(netdb, gethostbyname2_r) {
	hostent hent;
	hostent *hp;
	char buf[512];
	int err;
	int result = gethostbyname2_r("localhost", AF_INET, &hent, buf, sizeof(buf), &hp, &err);
	ASSERT_EQ(0, result);
	VerifyLocalhost(hp);

	// Change hp->h_addr to test reentrancy.
	hp->h_addr[0] = 0;

	hostent hent2;
	hostent *hp2;
	char buf2[512];
	result = gethostbyname2_r("localhost", AF_INET, &hent2, buf2, sizeof(buf2), &hp2, &err);
	ASSERT_EQ(0, result);
	VerifyLocalhost(hp2);

	ASSERT_EQ(0, hp->h_addr[0]);
	}

	TEST(netdb, gethostbyaddr) {
	in_addr addr = { htonl(0x7f000001) };
	hostent *hp = gethostbyaddr(&addr, sizeof(addr), AF_INET);
	VerifyLocalhost(hp);
	}

	TEST(netdb, gethostbyaddr_r) {
	in_addr addr = { htonl(0x7f000001) };
	hostent hent;
	hostent *hp;
	char buf[512];
	int err;
	int result = gethostbyaddr_r(&addr, sizeof(addr), AF_INET, &hent, buf, sizeof(buf), &hp, &err);
	ASSERT_EQ(0, result);
	VerifyLocalhost(hp);

	// Change hp->h_addr to test reentrancy.
	hp->h_addr[0] = 0;

	hostent hent2;
	hostent *hp2;
	char buf2[512];
	result = gethostbyaddr_r(&addr, sizeof(addr), AF_INET, &hent2, buf2, sizeof(buf2), &hp2, &err);
	ASSERT_EQ(0, result);
	VerifyLocalhost(hp2);

	ASSERT_EQ(0, hp->h_addr[0]);
	}

	TEST(netdb, gethostbyname_r_ERANGE) {
	hostent hent;
	hostent *hp;
	char buf[4]; // Use too small buffer.
	int err;
	int result = gethostbyname_r("localhost", &hent, buf, sizeof(buf), &hp, &err);
	EXPECT_EQ(NETDB_INTERNAL, err);
	EXPECT_EQ(ERANGE, result);
	EXPECT_EQ(nullptr, hp);
	}

	TEST(netdb, gethostbyname2_r_ERANGE) {
	hostent hent;
	hostent *hp;
	char buf[4]; // Use too small buffer.
	int err;
	int result = gethostbyname2_r("localhost", AF_INET, &hent, buf, sizeof(buf), &hp, &err);
	EXPECT_EQ(NETDB_INTERNAL, err);
	EXPECT_EQ(ERANGE, result);
	EXPECT_EQ(nullptr, hp);
	}

	TEST(netdb, gethostbyaddr_r_ERANGE) {
	in_addr addr = { htonl(0x7f000001) };
	hostent hent;
	hostent *hp;
	char buf[4]; // Use too small buffer.
	int err;
	int result = gethostbyaddr_r(&addr, sizeof(addr), AF_INET, &hent, buf, sizeof(buf), &hp, &err);
	EXPECT_EQ(NETDB_INTERNAL, err);
	EXPECT_EQ(ERANGE, result);
	EXPECT_EQ(nullptr, hp);
	}

	TEST(netdb, gethostbyname_r_HOST_NOT_FOUND) {
	hostent hent;
	hostent *hp;
	char buf[BUFSIZ];
	int err;
	int result = gethostbyname_r("does.not.exist.google.com", &hent, buf, sizeof(buf), &hp, &err);
	EXPECT_EQ(HOST_NOT_FOUND, err);
	EXPECT_EQ(0, result);
	EXPECT_EQ(nullptr, hp);
	}

	TEST(netdb, gethostbyname2_r_HOST_NOT_FOUND) {
	hostent hent;
	hostent *hp;
	char buf[BUFSIZ];
	int err;
	int result = gethostbyname2_r("does.not.exist.google.com", AF_INET, &hent, buf, sizeof(buf), &hp, &err);
	EXPECT_EQ(HOST_NOT_FOUND, err);
	EXPECT_EQ(0, result);
	EXPECT_EQ(nullptr, hp);
	}

	TEST(netdb, gethostbyaddr_r_HOST_NOT_FOUND) {
	in_addr addr = { htonl(0xffffffff) };
	hostent hent;
	hostent *hp;
	char buf[BUFSIZ];
	int err;
	int result = gethostbyaddr_r(&addr, sizeof(addr), AF_INET, &hent, buf, sizeof(buf), &hp, &err);
	EXPECT_EQ(HOST_NOT_FOUND, err);
	EXPECT_EQ(0, result);
	EXPECT_EQ(nullptr, hp);
	}

	TEST(netdb, getservbyname) {
	// smtp is TCP-only, so we know we'll get 25/tcp back.
	servent* s = getservbyname("smtp", nullptr);
	ASSERT_TRUE(s != nullptr);
	ASSERT_STREQ("smtp", s->s_name);
	ASSERT_EQ(25, ntohs(s->s_port));
	ASSERT_STREQ("tcp", s->s_proto);

	// We get the same result by explicitly asking for tcp.
	s = getservbyname("smtp", "tcp");
	ASSERT_TRUE(s != nullptr);
	ASSERT_STREQ("smtp", s->s_name);
	ASSERT_EQ(25, ntohs(s->s_port));
	ASSERT_STREQ("tcp", s->s_proto);

	// And we get a failure if we explicitly ask for udp.
	s = getservbyname("smtp", "udp");
	ASSERT_TRUE(s == nullptr);

	// But there are actually udp services.
	s = getservbyname("echo", "udp");
	ASSERT_TRUE(s != nullptr);
	ASSERT_STREQ("echo", s->s_name);
	ASSERT_EQ(7, ntohs(s->s_port));
	ASSERT_STREQ("udp", s->s_proto);
	}

	TEST(netdb, getservbyport) {
	// smtp is TCP-only, so we know we'll get 25/tcp back.
	servent* s = getservbyport(htons(25), nullptr);
	ASSERT_TRUE(s != nullptr);
	ASSERT_STREQ("smtp", s->s_name);
	ASSERT_EQ(25, ntohs(s->s_port));
	ASSERT_STREQ("tcp", s->s_proto);

	// We get the same result by explicitly asking for tcp.
	s = getservbyport(htons(25), "tcp");
	ASSERT_TRUE(s != nullptr);
	ASSERT_STREQ("smtp", s->s_name);
	ASSERT_EQ(25, ntohs(s->s_port));
	ASSERT_STREQ("tcp", s->s_proto);

	// And we get a failure if we explicitly ask for udp.
	s = getservbyport(htons(25), "udp");
	ASSERT_TRUE(s == nullptr);

	// But there are actually udp services.
	s = getservbyport(htons(7), "udp");
	ASSERT_TRUE(s != nullptr);
	ASSERT_STREQ("echo", s->s_name);
	ASSERT_EQ(7, ntohs(s->s_port));
	ASSERT_STREQ("udp", s->s_proto);
	}

	TEST(netdb, endnetent_getnetent_setnetent) {
	setnetent(0);
	setnetent(1);
	endnetent();
	while (getnetent() != nullptr) {
	}
	}

	TEST(netdb, getnetbyaddr) {
	getnetbyaddr(0, 0);
	}

	TEST(netdb, getnetbyname) {
	getnetbyname("x");
	}

	TEST(netdb, endprotoent_getprotoent_setprotoent) {
	setprotoent(0);
	setprotoent(1);
	endprotoent();
	while (getprotoent() != nullptr) {
	}
	}

	TEST(netdb, getprotobyname) {
	getprotobyname("tcp");
	}

	TEST(netdb, getprotobynumber) {
	getprotobynumber(6);
	}

	TEST(netdb, endservent_getservent_setservent) {
	setservent(0);
	setservent(1);
	endservent();
	size_t service_count = 0;
	while (getservent() != nullptr) {
	++service_count;
	}
	ASSERT_GT(service_count, 0U);
	}

	TEST(netdb, getservbyname_getservent_conflicts) {
	// Calling getservbyname shouldn't affect getservent's iteration order.
	endservent();
	while (getservent() != nullptr) {
	ASSERT_TRUE(getservbyname("smtp", "tcp") != nullptr);
	}
	}

	TEST(netdb, getservbyport_getservent_conflicts) {
	// Calling getservbyport shouldn't affect getservent's iteration order.
	endservent();
	while (getservent() != nullptr) {
	ASSERT_TRUE(getservbyport(htons(25), "tcp") != nullptr);
	}
	}

	TEST(netdb, endservent_resets) {
	endservent();
	std::string first_service(getservent()->s_name);
	endservent();
	ASSERT_EQ(first_service, std::string(getservent()->s_name));
	}

	TEST(netdb, setservent_resets) {
	endservent();
	std::string first_service(getservent()->s_name);
	setservent(0);
	ASSERT_EQ(first_service, std::string(getservent()->s_name));
	}

	TEST(netdb, endhostent_gethostent_sethostent) {
	sethostent(0);
	sethostent(1);
	endhostent();
	size_t host_count = 0;
	while (gethostent() != nullptr) {
	++host_count;
	}
	ASSERT_GT(host_count, 0U);
	}

	TEST(netdb, endhostent_resets) {
	endhostent();
	std::string first_host(gethostent()->h_name);
	endhostent();
	ASSERT_EQ(first_host, std::string(gethostent()->h_name));
	}

	TEST(netdb, sethostent_resets) {
	endhostent();
	std::string first_host(gethostent()->h_name);
	sethostent(0);
	ASSERT_EQ(first_host, std::string(gethostent()->h_name));
	}