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 
TEST(ifaddrs,freeifaddrs_null)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.
TEST(ifaddrs,getifaddrs_lo)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.
TEST(ifaddrs,getifaddrs_interfaces)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 
CheckAddressIsInSet(const std::string & if_name,bool unicast,const std::set<in_addr_t> & addrs)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 
TEST(ifaddrs,getifaddrs_INET)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 
print_sockaddr_ll(const char * what,const sockaddr * p)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 
print_sockaddr_inet(const char * what,const sockaddr * addr)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 
FamilyToName(int family)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 
FlagsToString(short flags)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.
TEST(ifaddrs,dump)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 
TEST(ifaddrs,inet6_scope_ids)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