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      1 /*
      2  * Copyright (C) 2015 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include <gtest/gtest.h>
     18 
     19 #include <ifaddrs.h>
     20 
     21 #include <dirent.h>
     22 #include <fcntl.h>
     23 #include <linux/if_packet.h>
     24 #include <net/ethernet.h>
     25 #include <net/if.h>
     26 #include <netdb.h>
     27 #include <netinet/in.h>
     28 #include <sys/ioctl.h>
     29 
     30 #include <algorithm>
     31 #include <map>
     32 #include <thread>
     33 #include <vector>
     34 
     35 TEST(ifaddrs, freeifaddrs_null) {
     36   freeifaddrs(nullptr);
     37 }
     38 
     39 // We can't statically say much about what network interfaces are available, but we can be pretty
     40 // sure there's a loopback interface, and that it has IPv4, IPv6, and AF_PACKET entries.
     41 TEST(ifaddrs, getifaddrs_lo) {
     42   ifaddrs* addrs = nullptr;
     43 
     44   ASSERT_EQ(0, getifaddrs(&addrs));
     45   ASSERT_TRUE(addrs != nullptr);
     46 
     47   ifaddrs* lo_inet4 = nullptr;
     48   ifaddrs* lo_inet6 = nullptr;
     49   ifaddrs* lo_packet = nullptr;
     50   for (ifaddrs* addr = addrs; addr != nullptr; addr = addr->ifa_next) {
     51     if (addr->ifa_name && strcmp(addr->ifa_name, "lo") == 0) {
     52       if (addr->ifa_addr && addr->ifa_addr->sa_family == AF_INET) lo_inet4 = addr;
     53       else if (addr->ifa_addr && addr->ifa_addr->sa_family == AF_INET6) lo_inet6 = addr;
     54       else if (addr->ifa_addr && addr->ifa_addr->sa_family == AF_PACKET) lo_packet = addr;
     55     }
     56   }
     57 
     58   // Does the IPv4 entry look right?
     59   ASSERT_TRUE(lo_inet4 != nullptr);
     60   const sockaddr_in* sa_inet4 = reinterpret_cast<const sockaddr_in*>(lo_inet4->ifa_addr);
     61   ASSERT_TRUE(ntohl(sa_inet4->sin_addr.s_addr) == INADDR_LOOPBACK);
     62 
     63   // Does the IPv6 entry look right?
     64   ASSERT_TRUE(lo_inet6 != nullptr);
     65   const sockaddr_in6* sa_inet6 = reinterpret_cast<const sockaddr_in6*>(lo_inet6->ifa_addr);
     66   ASSERT_TRUE(IN6_IS_ADDR_LOOPBACK(&sa_inet6->sin6_addr));
     67 
     68   // Does the AF_PACKET entry look right?
     69   ASSERT_TRUE(lo_packet != nullptr);
     70   const sockaddr_ll* sa_ll = reinterpret_cast<const sockaddr_ll*>(lo_packet->ifa_addr);
     71   ASSERT_EQ(6, sa_ll->sll_halen);
     72 
     73   freeifaddrs(addrs);
     74 }
     75 
     76 // Check that getifaddrs sees the same list of interfaces as /sys/class/net.
     77 TEST(ifaddrs, getifaddrs_interfaces) {
     78   std::vector<std::string> ifaddrs_socks;
     79   {
     80     ifaddrs* addrs;
     81     ASSERT_EQ(0, getifaddrs(&addrs));
     82 
     83     for (ifaddrs* addr = addrs; addr != nullptr; addr = addr->ifa_next) {
     84       int family = addr->ifa_addr ? addr->ifa_addr->sa_family :
     85           addr->ifa_broadaddr ? addr->ifa_broadaddr->sa_family :
     86           AF_UNSPEC;
     87 
     88       if (family == AF_PACKET || family == AF_UNSPEC) {
     89         ifaddrs_socks.push_back(std::string(addr->ifa_name));
     90       }
     91     }
     92 
     93     freeifaddrs(addrs);
     94   }
     95 
     96   std::vector<std::string> sys_class_net;
     97   {
     98     std::unique_ptr<DIR, decltype(&closedir)> d(opendir("/sys/class/net"), closedir);
     99     ASSERT_TRUE(d != nullptr);
    100     dirent* dir;
    101     while ((dir = readdir(d.get())) != nullptr) {
    102       if (dir->d_type == DT_LNK) {
    103         sys_class_net.push_back(std::string(dir->d_name));
    104       }
    105     }
    106   }
    107 
    108   ASSERT_TRUE(std::is_permutation(ifaddrs_socks.begin(), ifaddrs_socks.end(),
    109                                   sys_class_net.begin()));
    110 }
    111 
    112 static void CheckAddressIsInSet(const std::string& if_name, bool unicast,
    113                                 const std::set<in_addr_t>& addrs) {
    114   ifreq ifr;
    115   memset(&ifr, 0, sizeof(ifr));
    116   ifr.ifr_addr.sa_family = AF_INET;
    117   if_name.copy(ifr.ifr_name, IFNAMSIZ - 1);
    118 
    119   int fd = socket(AF_INET, SOCK_DGRAM, 0);
    120   ASSERT_TRUE(fd != -1);
    121 
    122   int request = SIOCGIFADDR;
    123   if (!unicast) {
    124     // For non-unicast, the specific ioctl to use depends on whether the IFF_BROADCAST flag is set.
    125     ASSERT_EQ(0, ioctl(fd, SIOCGIFFLAGS, &ifr)) << if_name << ' ' << strerror(errno);
    126     request = ((ifr.ifr_flags & IFF_BROADCAST) != 0) ? SIOCGIFBRDADDR : SIOCGIFDSTADDR;
    127   }
    128 
    129   ASSERT_EQ(0, ioctl(fd, request, &ifr)) << if_name << ' ' << strerror(errno);
    130   close(fd);
    131 
    132   sockaddr_in* sock = reinterpret_cast<sockaddr_in*>(&ifr.ifr_addr);
    133   in_addr_t addr = sock->sin_addr.s_addr;
    134 
    135   EXPECT_TRUE(addrs.find(addr) != addrs.end()) << if_name << ' ' << std::hex << ntohl(addr);
    136 }
    137 
    138 TEST(ifaddrs, getifaddrs_INET) {
    139   std::map<std::string, std::set<in_addr_t>> inet_addrs;
    140   std::map<std::string, std::set<in_addr_t>> broad_addrs;
    141 
    142   // Collect the IPv4 addresses for each interface.
    143   ifaddrs* addrs;
    144   ASSERT_EQ(0, getifaddrs(&addrs));
    145   for (ifaddrs* addr = addrs; addr != nullptr; addr = addr->ifa_next) {
    146     if (addr->ifa_name && addr->ifa_addr && addr->ifa_addr->sa_family == AF_INET) {
    147       auto sock = reinterpret_cast<sockaddr_in*>(addr->ifa_addr);
    148       inet_addrs[addr->ifa_name].insert(sock->sin_addr.s_addr);
    149     }
    150     if (addr->ifa_name && addr->ifa_broadaddr && addr->ifa_broadaddr->sa_family == AF_INET) {
    151       auto sock = reinterpret_cast<sockaddr_in*>(addr->ifa_broadaddr);
    152       broad_addrs[addr->ifa_name].insert(sock->sin_addr.s_addr);
    153     }
    154   }
    155   freeifaddrs(addrs);
    156 
    157   // Check that the addresses returned by the SIOCGIFADDR and SIOCGIFBRDADDR/SIOCGIFDSTADDR ioctls
    158   // are in our collections.
    159   for (const auto& it : inet_addrs) CheckAddressIsInSet(it.first, true, it.second);
    160   for (const auto& it : broad_addrs) CheckAddressIsInSet(it.first, false, it.second);
    161 }
    162 
    163 static void print_sockaddr_ll(const char* what, const sockaddr* p) {
    164   const sockaddr_ll* s = reinterpret_cast<const sockaddr_ll*>(p);
    165   printf("\t\t%s\t", what);
    166   for (int i = 0; i < s->sll_halen; ++i) {
    167     if (i > 0) printf(":");
    168     printf("%02X", s->sll_addr[i]);
    169   }
    170   printf(" (%d bytes)\n", s->sll_halen);
    171 }
    172 
    173 static void print_sockaddr_inet(const char* what, const sockaddr* addr) {
    174   char host[NI_MAXHOST];
    175   int family = addr->sa_family;
    176   int error = getnameinfo(addr,
    177                           (family == AF_INET) ? sizeof(sockaddr_in) : sizeof(sockaddr_in6),
    178                           host, NI_MAXHOST, nullptr, 0, NI_NUMERICHOST);
    179   if (error != 0) {
    180     printf("%d getnameinfo() failed: %s\n", family, gai_strerror(error));
    181     strcpy(host, "???");
    182   }
    183   printf("\t\t%s: <%s>\n", what, host);
    184 }
    185 
    186 static const char* FamilyToName(int family) {
    187   if (family == AF_INET) return "AF_INET";
    188   if (family == AF_INET6) return "AF_INET6";
    189   if (family == AF_PACKET) return "AF_PACKET";
    190   if (family == AF_UNSPEC) return "AF_UNSPEC";
    191   return "?";
    192 }
    193 
    194 static std::string FlagsToString(short flags) {
    195   std::string result;
    196   if ((flags & IFF_UP) != 0) result += " UP";
    197   if ((flags & IFF_BROADCAST) != 0) result += " BROADCAST";
    198   if ((flags & IFF_DEBUG) != 0) result += " DEBUG";
    199   if ((flags & IFF_LOOPBACK) != 0) result += " LOOPBACK";
    200   if ((flags & IFF_POINTOPOINT) != 0) result += " POINTOPOINT";
    201   if ((flags & IFF_NOTRAILERS) != 0) result += " NOTRAILERS";
    202   if ((flags & IFF_RUNNING) != 0) result += " RUNNING";
    203   if ((flags & IFF_NOARP) != 0) result += " NOARP";
    204   if ((flags & IFF_PROMISC) != 0) result += " PROMISC";
    205   if ((flags & IFF_ALLMULTI) != 0) result += " ALLMULTI";
    206   if ((flags & IFF_MASTER) != 0) result += " MASTER";
    207   if ((flags & IFF_SLAVE) != 0) result += " SLAVE";
    208   if ((flags & IFF_MULTICAST) != 0) result += " MULTICAST";
    209   if ((flags & IFF_PORTSEL) != 0) result += " PORTSEL";
    210   if ((flags & IFF_AUTOMEDIA) != 0) result += " AUTOMEDIA";
    211   if ((flags & IFF_DYNAMIC) != 0) result += " DYNAMIC";
    212 #if defined(IFF_LOWER_UP)
    213   if ((flags & IFF_LOWER_UP) != 0) result += " LOWER_UP";
    214 #endif
    215 #if defined(IFF_DORMANT)
    216   if ((flags & IFF_DORMANT) != 0) result += " DORMANT";
    217 #endif
    218 #if defined(IFF_ECHO)
    219   if ((flags & IFF_ECHO) != 0) result += " ECHO";
    220 #endif
    221   return result;
    222 }
    223 
    224 // Not really a test, but a useful debugging tool.
    225 TEST(ifaddrs, dump) {
    226   ifaddrs* addrs;
    227   ASSERT_EQ(0, getifaddrs(&addrs));
    228 
    229   for (ifaddrs* ifa = addrs; ifa != nullptr; ifa = ifa->ifa_next) {
    230     int family = ifa->ifa_addr ? ifa->ifa_addr->sa_family :
    231                                  ifa->ifa_broadaddr ? ifa->ifa_broadaddr->sa_family : AF_UNSPEC;
    232 
    233     printf("\t%s\n"
    234            "\t\t%s (%d) flags=%#x%s\n",
    235            ifa->ifa_name, FamilyToName(family), family,
    236            ifa->ifa_flags, FlagsToString(ifa->ifa_flags).c_str());
    237 
    238     if (family == AF_PACKET) {
    239       if (ifa->ifa_addr) print_sockaddr_ll("hwaddr", ifa->ifa_addr);
    240       if (ifa->ifa_broadaddr) print_sockaddr_ll("hwbroad", ifa->ifa_addr);
    241     } else if (family == AF_INET || family == AF_INET6) {
    242       if (ifa->ifa_addr) print_sockaddr_inet("address", ifa->ifa_addr);
    243       if (ifa->ifa_broadaddr && (ifa->ifa_flags & (IFF_BROADCAST | IFF_POINTOPOINT)) != 0) {
    244         print_sockaddr_inet((ifa->ifa_flags & IFF_BROADCAST) ? "broadcast" : "destination",
    245                             ifa->ifa_broadaddr);
    246       }
    247     }
    248 
    249     fflush(stdout);
    250   }
    251 
    252   freeifaddrs(addrs);
    253 }
    254 
    255 TEST(ifaddrs, inet6_scope_ids) {
    256   ifaddrs* addrs;
    257   ASSERT_EQ(0, getifaddrs(&addrs));
    258 
    259   for (ifaddrs* ifa = addrs; ifa != nullptr; ifa = ifa->ifa_next) {
    260     if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET6) {
    261       sockaddr_in6* sa6 = reinterpret_cast<sockaddr_in6*>(ifa->ifa_addr);
    262       // Any link-local IPv6 address should have a scope id. (http://b/27219454.)
    263       // 0 isn't a valid interface index, so that would mean the scope id wasn't set.
    264       if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr) || IN6_IS_ADDR_MC_LINKLOCAL(&sa6->sin6_addr)) {
    265         ASSERT_NE(sa6->sin6_scope_id, 0U);
    266       }
    267     }
    268   }
    269 
    270   freeifaddrs(addrs);
    271 }
    272 
    273 TEST(ifaddrs, kernel_bug_31038971) {
    274   // Some kernels had a bug that would lead to an NLMSG_ERROR response,
    275   // but bionic wasn't setting errno based on the value in the message.
    276   // This is the test for the kernel bug, but on a device with a bad
    277   // kernel this test was also useful for testing the bionic errno fix.
    278   std::vector<std::thread*> threads;
    279   for (size_t i = 0; i < 128; ++i) {
    280     threads.push_back(new std::thread([]() {
    281       ifaddrs* addrs = nullptr;
    282       ASSERT_EQ(0, getifaddrs(&addrs)) << strerror(errno);
    283       freeifaddrs(addrs);
    284     }));
    285   }
    286   for (auto& t : threads) {
    287     t->join();
    288     delete t;
    289   }
    290 }
    291 
    292 TEST(ifaddrs, errno_EMFILE) {
    293   std::vector<int> fds;
    294   while (true) {
    295     int fd = open("/dev/null", O_RDONLY|O_CLOEXEC);
    296     if (fd == -1) {
    297       ASSERT_EQ(EMFILE, errno);
    298       break;
    299     }
    300     fds.push_back(fd);
    301   }
    302 
    303   ifaddrs* addrs;
    304   EXPECT_EQ(-1, getifaddrs(&addrs));
    305   EXPECT_EQ(EMFILE, errno);
    306 
    307   for (int fd : fds) close(fd);
    308 }
    309