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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 <linux/if_packet.h>
     23 #include <net/ethernet.h>
     24 #include <net/if.h>
     25 #include <netdb.h>
     26 #include <netinet/in.h>
     27 #include <sys/ioctl.h>
     28 
     29 #include <algorithm>
     30 #include <map>
     31 #include <vector>
     32 
     33 TEST(ifaddrs, freeifaddrs_null) {
     34   freeifaddrs(nullptr);
     35 }
     36 
     37 // We can't statically say much about what network interfaces are available, but we can be pretty
     38 // sure there's a loopback interface, and that it has IPv4, IPv6, and AF_PACKET entries.
     39 TEST(ifaddrs, getifaddrs_lo) {
     40   ifaddrs* addrs = nullptr;
     41 
     42   ASSERT_EQ(0, getifaddrs(&addrs));
     43   ASSERT_TRUE(addrs != nullptr);
     44 
     45   ifaddrs* lo_inet4 = nullptr;
     46   ifaddrs* lo_inet6 = nullptr;
     47   ifaddrs* lo_packet = nullptr;
     48   for (ifaddrs* addr = addrs; addr != nullptr; addr = addr->ifa_next) {
     49     if (addr->ifa_name && strcmp(addr->ifa_name, "lo") == 0) {
     50       if (addr->ifa_addr && addr->ifa_addr->sa_family == AF_INET) lo_inet4 = addr;
     51       else if (addr->ifa_addr && addr->ifa_addr->sa_family == AF_INET6) lo_inet6 = addr;
     52       else if (addr->ifa_addr && addr->ifa_addr->sa_family == AF_PACKET) lo_packet = addr;
     53     }
     54   }
     55 
     56   // Does the IPv4 entry look right?
     57   ASSERT_TRUE(lo_inet4 != nullptr);
     58   const sockaddr_in* sa_inet4 = reinterpret_cast<const sockaddr_in*>(lo_inet4->ifa_addr);
     59   ASSERT_TRUE(ntohl(sa_inet4->sin_addr.s_addr) == INADDR_LOOPBACK);
     60 
     61   // Does the IPv6 entry look right?
     62   ASSERT_TRUE(lo_inet6 != nullptr);
     63   const sockaddr_in6* sa_inet6 = reinterpret_cast<const sockaddr_in6*>(lo_inet6->ifa_addr);
     64   ASSERT_TRUE(IN6_IS_ADDR_LOOPBACK(&sa_inet6->sin6_addr));
     65 
     66   // Does the AF_PACKET entry look right?
     67   ASSERT_TRUE(lo_packet != nullptr);
     68   const sockaddr_ll* sa_ll = reinterpret_cast<const sockaddr_ll*>(lo_packet->ifa_addr);
     69   ASSERT_EQ(6, sa_ll->sll_halen);
     70 
     71   freeifaddrs(addrs);
     72 }
     73 
     74 // Check that getifaddrs sees the same list of interfaces as /sys/class/net.
     75 TEST(ifaddrs, getifaddrs_interfaces) {
     76   std::vector<std::string> ifaddrs_socks;
     77   {
     78     ifaddrs* addrs;
     79     ASSERT_EQ(0, getifaddrs(&addrs));
     80 
     81     for (ifaddrs* addr = addrs; addr != nullptr; addr = addr->ifa_next) {
     82       int family = addr->ifa_addr ? addr->ifa_addr->sa_family :
     83           addr->ifa_broadaddr ? addr->ifa_broadaddr->sa_family :
     84           AF_UNSPEC;
     85 
     86       if (family == AF_PACKET || family == AF_UNSPEC) {
     87         ifaddrs_socks.push_back(std::string(addr->ifa_name));
     88       }
     89     }
     90 
     91     freeifaddrs(addrs);
     92   }
     93 
     94   std::vector<std::string> sys_class_net;
     95   {
     96     std::unique_ptr<DIR, decltype(&closedir)> d(opendir("/sys/class/net"), closedir);
     97     ASSERT_TRUE(d != nullptr);
     98     dirent* dir;
     99     while ((dir = readdir(d.get())) != nullptr) {
    100       if (dir->d_type == DT_LNK) {
    101         sys_class_net.push_back(std::string(dir->d_name));
    102       }
    103     }
    104   }
    105 
    106   ASSERT_TRUE(std::is_permutation(ifaddrs_socks.begin(), ifaddrs_socks.end(),
    107                                   sys_class_net.begin()));
    108 }
    109 
    110 static void CheckAddressIsInSet(const std::string& if_name, bool unicast,
    111                                 const std::set<in_addr_t>& addrs) {
    112   ifreq ifr;
    113   memset(&ifr, 0, sizeof(ifr));
    114   ifr.ifr_addr.sa_family = AF_INET;
    115   if_name.copy(ifr.ifr_name, IFNAMSIZ - 1);
    116 
    117   int fd = socket(AF_INET, SOCK_DGRAM, 0);
    118   ASSERT_TRUE(fd != -1);
    119 
    120   int request = SIOCGIFADDR;
    121   if (!unicast) {
    122     // For non-unicast, the specific ioctl to use depends on whether the IFF_BROADCAST flag is set.
    123     ASSERT_EQ(0, ioctl(fd, SIOCGIFFLAGS, &ifr)) << if_name << ' ' << strerror(errno);
    124     request = ((ifr.ifr_flags & IFF_BROADCAST) != 0) ? SIOCGIFBRDADDR : SIOCGIFDSTADDR;
    125   }
    126 
    127   ASSERT_EQ(0, ioctl(fd, request, &ifr)) << if_name << ' ' << strerror(errno);
    128   close(fd);
    129 
    130   sockaddr_in* sock = reinterpret_cast<sockaddr_in*>(&ifr.ifr_addr);
    131   in_addr_t addr = sock->sin_addr.s_addr;
    132 
    133   EXPECT_TRUE(addrs.find(addr) != addrs.end()) << if_name << ' ' << std::hex << ntohl(addr);
    134 }
    135 
    136 TEST(ifaddrs, getifaddrs_INET) {
    137   std::map<std::string, std::set<in_addr_t>> inet_addrs;
    138   std::map<std::string, std::set<in_addr_t>> broad_addrs;
    139 
    140   // Collect the IPv4 addresses for each interface.
    141   ifaddrs* addrs;
    142   ASSERT_EQ(0, getifaddrs(&addrs));
    143   for (ifaddrs* addr = addrs; addr != nullptr; addr = addr->ifa_next) {
    144     if (addr->ifa_name && addr->ifa_addr && addr->ifa_addr->sa_family == AF_INET) {
    145       auto sock = reinterpret_cast<sockaddr_in*>(addr->ifa_addr);
    146       inet_addrs[addr->ifa_name].insert(sock->sin_addr.s_addr);
    147     }
    148     if (addr->ifa_name && addr->ifa_broadaddr && addr->ifa_broadaddr->sa_family == AF_INET) {
    149       auto sock = reinterpret_cast<sockaddr_in*>(addr->ifa_broadaddr);
    150       broad_addrs[addr->ifa_name].insert(sock->sin_addr.s_addr);
    151     }
    152   }
    153   freeifaddrs(addrs);
    154 
    155   // Check that the addresses returned by the SIOCGIFADDR and SIOCGIFBRDADDR/SIOCGIFDSTADDR ioctls
    156   // are in our collections.
    157   for (const auto& it : inet_addrs) CheckAddressIsInSet(it.first, true, it.second);
    158   for (const auto& it : broad_addrs) CheckAddressIsInSet(it.first, false, it.second);
    159 }
    160 
    161 static void print_sockaddr_ll(const char* what, const sockaddr* p) {
    162   const sockaddr_ll* s = reinterpret_cast<const sockaddr_ll*>(p);
    163   printf("\t\t%s\t", what);
    164   for (int i = 0; i < s->sll_halen; ++i) {
    165     if (i > 0) printf(":");
    166     printf("%02X", s->sll_addr[i]);
    167   }
    168   printf(" (%d bytes)\n", s->sll_halen);
    169 }
    170 
    171 static void print_sockaddr_inet(const char* what, const sockaddr* addr) {
    172   char host[NI_MAXHOST];
    173   int family = addr->sa_family;
    174   int error = getnameinfo(addr,
    175                           (family == AF_INET) ? sizeof(sockaddr_in) : sizeof(sockaddr_in6),
    176                           host, NI_MAXHOST, nullptr, 0, NI_NUMERICHOST);
    177   if (error != 0) {
    178     printf("%d getnameinfo() failed: %s\n", family, gai_strerror(error));
    179     strcpy(host, "???");
    180   }
    181   printf("\t\t%s: <%s>\n", what, host);
    182 }
    183 
    184 static const char* FamilyToName(int family) {
    185   if (family == AF_INET) return "AF_INET";
    186   if (family == AF_INET6) return "AF_INET6";
    187   if (family == AF_PACKET) return "AF_PACKET";
    188   if (family == AF_UNSPEC) return "AF_UNSPEC";
    189   return "?";
    190 }
    191 
    192 static std::string FlagsToString(short flags) {
    193   std::string result;
    194   if ((flags & IFF_UP) != 0) result += " UP";
    195   if ((flags & IFF_BROADCAST) != 0) result += " BROADCAST";
    196   if ((flags & IFF_DEBUG) != 0) result += " DEBUG";
    197   if ((flags & IFF_LOOPBACK) != 0) result += " LOOPBACK";
    198   if ((flags & IFF_POINTOPOINT) != 0) result += " POINTOPOINT";
    199   if ((flags & IFF_NOTRAILERS) != 0) result += " NOTRAILERS";
    200   if ((flags & IFF_RUNNING) != 0) result += " RUNNING";
    201   if ((flags & IFF_NOARP) != 0) result += " NOARP";
    202   if ((flags & IFF_PROMISC) != 0) result += " PROMISC";
    203   if ((flags & IFF_ALLMULTI) != 0) result += " ALLMULTI";
    204   if ((flags & IFF_MASTER) != 0) result += " MASTER";
    205   if ((flags & IFF_SLAVE) != 0) result += " SLAVE";
    206   if ((flags & IFF_MULTICAST) != 0) result += " MULTICAST";
    207   if ((flags & IFF_PORTSEL) != 0) result += " PORTSEL";
    208   if ((flags & IFF_AUTOMEDIA) != 0) result += " AUTOMEDIA";
    209   if ((flags & IFF_DYNAMIC) != 0) result += " DYNAMIC";
    210 #if defined(IFF_LOWER_UP)
    211   if ((flags & IFF_LOWER_UP) != 0) result += " LOWER_UP";
    212 #endif
    213 #if defined(IFF_DORMANT)
    214   if ((flags & IFF_DORMANT) != 0) result += " DORMANT";
    215 #endif
    216 #if defined(IFF_ECHO)
    217   if ((flags & IFF_ECHO) != 0) result += " ECHO";
    218 #endif
    219   return result;
    220 }
    221 
    222 // Not really a test, but a useful debugging tool.
    223 TEST(ifaddrs, dump) {
    224   ifaddrs* addrs;
    225   ASSERT_EQ(0, getifaddrs(&addrs));
    226 
    227   for (ifaddrs* ifa = addrs; ifa != nullptr; ifa = ifa->ifa_next) {
    228     int family = ifa->ifa_addr ? ifa->ifa_addr->sa_family :
    229                                  ifa->ifa_broadaddr ? ifa->ifa_broadaddr->sa_family : AF_UNSPEC;
    230 
    231     printf("\t%s\n"
    232            "\t\t%s (%d) flags=%#x%s\n",
    233            ifa->ifa_name, FamilyToName(family), family,
    234            ifa->ifa_flags, FlagsToString(ifa->ifa_flags).c_str());
    235 
    236     if (family == AF_PACKET) {
    237       if (ifa->ifa_addr) print_sockaddr_ll("hwaddr", ifa->ifa_addr);
    238       if (ifa->ifa_broadaddr) print_sockaddr_ll("hwbroad", ifa->ifa_addr);
    239     } else if (family == AF_INET || family == AF_INET6) {
    240       if (ifa->ifa_addr) print_sockaddr_inet("address", ifa->ifa_addr);
    241       if (ifa->ifa_broadaddr && (ifa->ifa_flags & (IFF_BROADCAST | IFF_POINTOPOINT)) != 0) {
    242         print_sockaddr_inet((ifa->ifa_flags & IFF_BROADCAST) ? "broadcast" : "destination",
    243                             ifa->ifa_broadaddr);
    244       }
    245     }
    246 
    247     fflush(stdout);
    248   }
    249 
    250   freeifaddrs(addrs);
    251 }
    252 
    253 TEST(ifaddrs, inet6_scope_ids) {
    254   ifaddrs* addrs;
    255   ASSERT_EQ(0, getifaddrs(&addrs));
    256 
    257   for (ifaddrs* ifa = addrs; ifa != nullptr; ifa = ifa->ifa_next) {
    258     if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET6) {
    259       sockaddr_in6* sa6 = reinterpret_cast<sockaddr_in6*>(ifa->ifa_addr);
    260       // Any link-local IPv6 address should have a scope id. (http://b/27219454.)
    261       // 0 isn't a valid interface index, so that would mean the scope id wasn't set.
    262       if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr) || IN6_IS_ADDR_MC_LINKLOCAL(&sa6->sin6_addr)) {
    263         ASSERT_NE(sa6->sin6_scope_id, 0U);
    264       }
    265     }
    266   }
    267 
    268   freeifaddrs(addrs);
    269 }
    270