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 <net/ethernet.h>
24 #include <net/if.h>
25 #include <netdb.h>
26 #include <netinet/in.h>
27 #include <sys/ioctl.h>
28 
29 // (glibc as of 2.37 has redefinitions if you include these before <net/if.h>.)
30 #include <linux/if.h>
31 #include <linux/if_packet.h>
32 
33 #include <algorithm>
34 #include <map>
35 #include <thread>
36 #include <vector>
37 
38 #include "utils.h"
39 
TEST(ifaddrs,freeifaddrs_null)40 TEST(ifaddrs, freeifaddrs_null) {
41   freeifaddrs(nullptr);
42 }
43 
44 // We can't statically say much about what network interfaces are available, but we can be pretty
45 // sure there's a loopback interface, and that it has IPv4, IPv6, and AF_PACKET entries.
TEST(ifaddrs,getifaddrs_lo)46 TEST(ifaddrs, getifaddrs_lo) {
47   ifaddrs* addrs = nullptr;
48 
49   ASSERT_EQ(0, getifaddrs(&addrs));
50   ASSERT_TRUE(addrs != nullptr);
51 
52   ifaddrs* lo_inet4 = nullptr;
53   ifaddrs* lo_inet6 = nullptr;
54   ifaddrs* lo_packet = nullptr;
55   for (ifaddrs* addr = addrs; addr != nullptr; addr = addr->ifa_next) {
56     if (addr->ifa_name && strcmp(addr->ifa_name, "lo") == 0) {
57       if (addr->ifa_addr && addr->ifa_addr->sa_family == AF_INET) lo_inet4 = addr;
58       else if (addr->ifa_addr && addr->ifa_addr->sa_family == AF_INET6) lo_inet6 = addr;
59       else if (addr->ifa_addr && addr->ifa_addr->sa_family == AF_PACKET) lo_packet = addr;
60     }
61   }
62 
63   // Does the IPv4 entry look right?
64   ASSERT_TRUE(lo_inet4 != nullptr);
65   const sockaddr_in* sa_inet4 = reinterpret_cast<const sockaddr_in*>(lo_inet4->ifa_addr);
66   ASSERT_TRUE(ntohl(sa_inet4->sin_addr.s_addr) == INADDR_LOOPBACK);
67 
68   // Does the IPv6 entry look right?
69   ASSERT_TRUE(lo_inet6 != nullptr);
70   const sockaddr_in6* sa_inet6 = reinterpret_cast<const sockaddr_in6*>(lo_inet6->ifa_addr);
71   ASSERT_TRUE(IN6_IS_ADDR_LOOPBACK(&sa_inet6->sin6_addr));
72 
73   // Does the AF_PACKET entry look right?
74   ASSERT_TRUE(lo_packet != nullptr);
75   const sockaddr_ll* sa_ll = reinterpret_cast<const sockaddr_ll*>(lo_packet->ifa_addr);
76   ASSERT_EQ(6, sa_ll->sll_halen);
77 
78   freeifaddrs(addrs);
79 }
80 
81 // Check that getifaddrs sees the same list of interfaces as /sys/class/net.
TEST(ifaddrs,getifaddrs_interfaces)82 TEST(ifaddrs, getifaddrs_interfaces) {
83   std::vector<std::string> ifaddrs_socks;
84   {
85     ifaddrs* addrs;
86     ASSERT_EQ(0, getifaddrs(&addrs));
87 
88     for (ifaddrs* addr = addrs; addr != nullptr; addr = addr->ifa_next) {
89       int family = addr->ifa_addr ? addr->ifa_addr->sa_family :
90           addr->ifa_broadaddr ? addr->ifa_broadaddr->sa_family :
91           AF_UNSPEC;
92 
93       if (family == AF_PACKET || family == AF_UNSPEC) {
94         ifaddrs_socks.push_back(std::string(addr->ifa_name));
95       }
96     }
97 
98     freeifaddrs(addrs);
99   }
100 
101   std::vector<std::string> sys_class_net;
102   {
103     std::unique_ptr<DIR, decltype(&closedir)> d(opendir("/sys/class/net"), closedir);
104     ASSERT_TRUE(d != nullptr);
105     dirent* dir;
106     while ((dir = readdir(d.get())) != nullptr) {
107       if (dir->d_type == DT_LNK) {
108         sys_class_net.push_back(std::string(dir->d_name));
109       }
110     }
111   }
112 
113   ASSERT_TRUE(std::is_permutation(ifaddrs_socks.begin(), ifaddrs_socks.end(),
114                                   sys_class_net.begin()));
115 }
116 
CheckAddressIsInSet(const std::string & if_name,bool unicast,const std::set<in_addr_t> & addrs)117 static void CheckAddressIsInSet(const std::string& if_name, bool unicast,
118                                 const std::set<in_addr_t>& addrs) {
119   ifreq ifr;
120   memset(&ifr, 0, sizeof(ifr));
121   ifr.ifr_addr.sa_family = AF_INET;
122   if_name.copy(ifr.ifr_name, IFNAMSIZ - 1);
123 
124   int fd = socket(AF_INET, SOCK_DGRAM, 0);
125   ASSERT_TRUE(fd != -1);
126 
127   int request = SIOCGIFADDR;
128   if (!unicast) {
129     // For non-unicast, the specific ioctl to use depends on whether the IFF_BROADCAST flag is set.
130     ASSERT_EQ(0, ioctl(fd, SIOCGIFFLAGS, &ifr)) << if_name << ' ' << strerror(errno);
131     request = ((ifr.ifr_flags & IFF_BROADCAST) != 0) ? SIOCGIFBRDADDR : SIOCGIFDSTADDR;
132   }
133 
134   ASSERT_EQ(0, ioctl(fd, request, &ifr)) << if_name << ' ' << strerror(errno);
135   close(fd);
136 
137   sockaddr_in* sock = reinterpret_cast<sockaddr_in*>(&ifr.ifr_addr);
138   in_addr_t addr = sock->sin_addr.s_addr;
139 
140   EXPECT_TRUE(addrs.find(addr) != addrs.end()) << if_name << ' ' << std::hex << ntohl(addr);
141 }
142 
TEST(ifaddrs,getifaddrs_INET)143 TEST(ifaddrs, getifaddrs_INET) {
144   std::map<std::string, std::set<in_addr_t>> inet_addrs;
145   std::map<std::string, std::set<in_addr_t>> broad_addrs;
146 
147   // Collect the IPv4 addresses for each interface.
148   ifaddrs* addrs;
149   ASSERT_EQ(0, getifaddrs(&addrs));
150   for (ifaddrs* addr = addrs; addr != nullptr; addr = addr->ifa_next) {
151     if (addr->ifa_name && addr->ifa_addr && addr->ifa_addr->sa_family == AF_INET) {
152       auto sock = reinterpret_cast<sockaddr_in*>(addr->ifa_addr);
153       inet_addrs[addr->ifa_name].insert(sock->sin_addr.s_addr);
154     }
155     if (addr->ifa_name && addr->ifa_broadaddr && addr->ifa_broadaddr->sa_family == AF_INET) {
156       auto sock = reinterpret_cast<sockaddr_in*>(addr->ifa_broadaddr);
157       broad_addrs[addr->ifa_name].insert(sock->sin_addr.s_addr);
158     }
159   }
160   freeifaddrs(addrs);
161 
162   // Check that the addresses returned by the SIOCGIFADDR and SIOCGIFBRDADDR/SIOCGIFDSTADDR ioctls
163   // are in our collections.
164   for (const auto& it : inet_addrs) CheckAddressIsInSet(it.first, true, it.second);
165   for (const auto& it : broad_addrs) CheckAddressIsInSet(it.first, false, it.second);
166 }
167 
print_sockaddr_ll(const char * what,const sockaddr * p)168 static void print_sockaddr_ll(const char* what, const sockaddr* p) {
169   const sockaddr_ll* s = reinterpret_cast<const sockaddr_ll*>(p);
170   printf("\t\t%s\t", what);
171   for (int i = 0; i < s->sll_halen; ++i) {
172     if (i > 0) printf(":");
173     printf("%02X", s->sll_addr[i]);
174   }
175   printf(" (%d bytes)\n", s->sll_halen);
176 }
177 
print_sockaddr_inet(const char * what,const sockaddr * addr)178 static void print_sockaddr_inet(const char* what, const sockaddr* addr) {
179   char host[NI_MAXHOST];
180   int family = addr->sa_family;
181   int error = getnameinfo(addr,
182                           (family == AF_INET) ? sizeof(sockaddr_in) : sizeof(sockaddr_in6),
183                           host, NI_MAXHOST, nullptr, 0, NI_NUMERICHOST);
184   if (error != 0) {
185     printf("%d getnameinfo() failed: %s\n", family, gai_strerror(error));
186     strcpy(host, "???");
187   }
188   printf("\t\t%s: <%s>\n", what, host);
189 }
190 
FamilyToName(int family)191 static const char* FamilyToName(int family) {
192   if (family == AF_INET) return "AF_INET";
193   if (family == AF_INET6) return "AF_INET6";
194   if (family == AF_PACKET) return "AF_PACKET";
195   if (family == AF_UNSPEC) return "AF_UNSPEC";
196   return "?";
197 }
198 
FlagsToString(short flags)199 static std::string FlagsToString(short flags) {
200   std::string result;
201   if ((flags & IFF_UP) != 0) result += " UP";
202   if ((flags & IFF_BROADCAST) != 0) result += " BROADCAST";
203   if ((flags & IFF_DEBUG) != 0) result += " DEBUG";
204   if ((flags & IFF_LOOPBACK) != 0) result += " LOOPBACK";
205   if ((flags & IFF_POINTOPOINT) != 0) result += " POINTOPOINT";
206   if ((flags & IFF_NOTRAILERS) != 0) result += " NOTRAILERS";
207   if ((flags & IFF_RUNNING) != 0) result += " RUNNING";
208   if ((flags & IFF_NOARP) != 0) result += " NOARP";
209   if ((flags & IFF_PROMISC) != 0) result += " PROMISC";
210   if ((flags & IFF_ALLMULTI) != 0) result += " ALLMULTI";
211   if ((flags & IFF_MASTER) != 0) result += " MASTER";
212   if ((flags & IFF_SLAVE) != 0) result += " SLAVE";
213   if ((flags & IFF_MULTICAST) != 0) result += " MULTICAST";
214   if ((flags & IFF_PORTSEL) != 0) result += " PORTSEL";
215   if ((flags & IFF_AUTOMEDIA) != 0) result += " AUTOMEDIA";
216   if ((flags & IFF_DYNAMIC) != 0) result += " DYNAMIC";
217   if ((flags & IFF_LOWER_UP) != 0) result += " LOWER_UP";
218   if ((flags & IFF_DORMANT) != 0) result += " DORMANT";
219   if ((flags & IFF_ECHO) != 0) result += " ECHO";
220   return result;
221 }
222 
223 // Not really a test, but a useful debugging tool.
TEST(ifaddrs,dump)224 TEST(ifaddrs, dump) {
225   ifaddrs* addrs;
226   ASSERT_EQ(0, getifaddrs(&addrs));
227 
228   for (ifaddrs* ifa = addrs; ifa != nullptr; ifa = ifa->ifa_next) {
229     int family = ifa->ifa_addr ? ifa->ifa_addr->sa_family :
230                                  ifa->ifa_broadaddr ? ifa->ifa_broadaddr->sa_family : AF_UNSPEC;
231 
232     printf("\t%s\n"
233            "\t\t%s (%d) flags=%#x%s\n",
234            ifa->ifa_name, FamilyToName(family), family,
235            ifa->ifa_flags, FlagsToString(ifa->ifa_flags).c_str());
236 
237     if (family == AF_PACKET) {
238       if (ifa->ifa_addr) print_sockaddr_ll("hwaddr", ifa->ifa_addr);
239       if (ifa->ifa_broadaddr) print_sockaddr_ll("hwbroad", ifa->ifa_addr);
240     } else if (family == AF_INET || family == AF_INET6) {
241       if (ifa->ifa_addr) print_sockaddr_inet("address", ifa->ifa_addr);
242       if (ifa->ifa_broadaddr && (ifa->ifa_flags & (IFF_BROADCAST | IFF_POINTOPOINT)) != 0) {
243         print_sockaddr_inet((ifa->ifa_flags & IFF_BROADCAST) ? "broadcast" : "destination",
244                             ifa->ifa_broadaddr);
245       }
246     }
247 
248     fflush(stdout);
249   }
250 
251   freeifaddrs(addrs);
252 }
253 
TEST(ifaddrs,inet6_scope_ids)254 TEST(ifaddrs, inet6_scope_ids) {
255   ifaddrs* addrs;
256   ASSERT_EQ(0, getifaddrs(&addrs));
257 
258   for (ifaddrs* ifa = addrs; ifa != nullptr; ifa = ifa->ifa_next) {
259     if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET6) {
260       sockaddr_in6* sa6 = reinterpret_cast<sockaddr_in6*>(ifa->ifa_addr);
261       // Any link-local IPv6 address should have a scope id. (http://b/27219454.)
262       // 0 isn't a valid interface index, so that would mean the scope id wasn't set.
263       if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr) || IN6_IS_ADDR_MC_LINKLOCAL(&sa6->sin6_addr)) {
264         ASSERT_NE(sa6->sin6_scope_id, 0U);
265       }
266     }
267   }
268 
269   freeifaddrs(addrs);
270 }
271 
TEST(ifaddrs,kernel_bug_31038971)272 TEST(ifaddrs, kernel_bug_31038971) {
273   // Some kernels had a bug that would lead to an NLMSG_ERROR response,
274   // but bionic wasn't setting errno based on the value in the message.
275   // This is the test for the kernel bug, but on a device with a bad
276   // kernel this test was also useful for testing the bionic errno fix.
277   std::vector<std::thread*> threads;
278   for (size_t i = 0; i < 128; ++i) {
279     threads.push_back(new std::thread([]() {
280       ifaddrs* addrs = nullptr;
281       ASSERT_EQ(0, getifaddrs(&addrs)) << strerror(errno);
282       freeifaddrs(addrs);
283     }));
284   }
285   for (auto& t : threads) {
286     t->join();
287     delete t;
288   }
289 }
290 
TEST(ifaddrs,errno_EMFILE)291 TEST(ifaddrs, errno_EMFILE) {
292   std::vector<int> fds;
293   while (true) {
294     int fd = open("/dev/null", O_RDONLY|O_CLOEXEC);
295     if (fd == -1) {
296       ASSERT_ERRNO(EMFILE);
297       break;
298     }
299     fds.push_back(fd);
300   }
301 
302   ifaddrs* addrs;
303   EXPECT_EQ(-1, getifaddrs(&addrs));
304   EXPECT_ERRNO(EMFILE);
305 
306   for (int fd : fds) close(fd);
307 }
308