1 /*
2  *
3  * Copyright 2015 gRPC authors.
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at
8  *
9  *     http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  *
17  */
18 
19 #include "src/core/lib/iomgr/resolve_address.h"
20 #include <grpc/grpc.h>
21 #include <grpc/support/alloc.h>
22 #include <grpc/support/log.h>
23 #include <grpc/support/sync.h>
24 #include <grpc/support/time.h>
25 
26 #include <address_sorting/address_sorting.h>
27 
28 #include <string.h>
29 
30 #include "src/core/ext/filters/client_channel/resolver/dns/dns_resolver_selection.h"
31 #include "src/core/lib/gpr/string.h"
32 #include "src/core/lib/iomgr/executor.h"
33 #include "src/core/lib/iomgr/iomgr.h"
34 #include "test/core/util/cmdline.h"
35 #include "test/core/util/test_config.h"
36 
test_deadline(void)37 static gpr_timespec test_deadline(void) {
38   return grpc_timeout_seconds_to_deadline(100);
39 }
40 
41 typedef struct args_struct {
42   gpr_event ev;
43   grpc_resolved_addresses* addrs;
44   gpr_atm done_atm;
45   gpr_mu* mu;
46   grpc_pollset* pollset;
47   grpc_pollset_set* pollset_set;
48 } args_struct;
49 
do_nothing(void * arg,grpc_error * error)50 static void do_nothing(void* arg, grpc_error* error) {}
51 
args_init(args_struct * args)52 void args_init(args_struct* args) {
53   gpr_event_init(&args->ev);
54   args->pollset = static_cast<grpc_pollset*>(gpr_zalloc(grpc_pollset_size()));
55   grpc_pollset_init(args->pollset, &args->mu);
56   args->pollset_set = grpc_pollset_set_create();
57   grpc_pollset_set_add_pollset(args->pollset_set, args->pollset);
58   args->addrs = nullptr;
59   gpr_atm_rel_store(&args->done_atm, 0);
60 }
61 
args_finish(args_struct * args)62 void args_finish(args_struct* args) {
63   GPR_ASSERT(gpr_event_wait(&args->ev, test_deadline()));
64   grpc_resolved_addresses_destroy(args->addrs);
65   grpc_pollset_set_del_pollset(args->pollset_set, args->pollset);
66   grpc_pollset_set_destroy(args->pollset_set);
67   grpc_closure do_nothing_cb;
68   GRPC_CLOSURE_INIT(&do_nothing_cb, do_nothing, nullptr,
69                     grpc_schedule_on_exec_ctx);
70   gpr_mu_lock(args->mu);
71   grpc_pollset_shutdown(args->pollset, &do_nothing_cb);
72   gpr_mu_unlock(args->mu);
73   // exec_ctx needs to be flushed before calling grpc_pollset_destroy()
74   grpc_core::ExecCtx::Get()->Flush();
75   grpc_pollset_destroy(args->pollset);
76   gpr_free(args->pollset);
77 }
78 
n_sec_deadline(int seconds)79 static grpc_millis n_sec_deadline(int seconds) {
80   return grpc_timespec_to_millis_round_up(
81       grpc_timeout_seconds_to_deadline(seconds));
82 }
83 
poll_pollset_until_request_done(args_struct * args)84 static void poll_pollset_until_request_done(args_struct* args) {
85   grpc_core::ExecCtx exec_ctx;
86   // Try to give enough time for c-ares to run through its retries
87   // a few times if needed.
88   grpc_millis deadline = n_sec_deadline(90);
89   while (true) {
90     bool done = gpr_atm_acq_load(&args->done_atm) != 0;
91     if (done) {
92       break;
93     }
94     grpc_millis time_left = deadline - grpc_core::ExecCtx::Get()->Now();
95     gpr_log(GPR_DEBUG, "done=%d, time_left=%" PRId64, done, time_left);
96     GPR_ASSERT(time_left >= 0);
97     grpc_pollset_worker* worker = nullptr;
98     gpr_mu_lock(args->mu);
99     GRPC_LOG_IF_ERROR("pollset_work", grpc_pollset_work(args->pollset, &worker,
100                                                         n_sec_deadline(1)));
101     gpr_mu_unlock(args->mu);
102     grpc_core::ExecCtx::Get()->Flush();
103   }
104   gpr_event_set(&args->ev, (void*)1);
105 }
106 
must_succeed(void * argsp,grpc_error * err)107 static void must_succeed(void* argsp, grpc_error* err) {
108   args_struct* args = static_cast<args_struct*>(argsp);
109   GPR_ASSERT(err == GRPC_ERROR_NONE);
110   GPR_ASSERT(args->addrs != nullptr);
111   GPR_ASSERT(args->addrs->naddrs > 0);
112   gpr_atm_rel_store(&args->done_atm, 1);
113   gpr_mu_lock(args->mu);
114   GRPC_LOG_IF_ERROR("pollset_kick", grpc_pollset_kick(args->pollset, nullptr));
115   gpr_mu_unlock(args->mu);
116 }
117 
must_fail(void * argsp,grpc_error * err)118 static void must_fail(void* argsp, grpc_error* err) {
119   args_struct* args = static_cast<args_struct*>(argsp);
120   GPR_ASSERT(err != GRPC_ERROR_NONE);
121   gpr_atm_rel_store(&args->done_atm, 1);
122   gpr_mu_lock(args->mu);
123   GRPC_LOG_IF_ERROR("pollset_kick", grpc_pollset_kick(args->pollset, nullptr));
124   gpr_mu_unlock(args->mu);
125 }
126 
127 // This test assumes the environment has an ipv6 loopback
must_succeed_with_ipv6_first(void * argsp,grpc_error * err)128 static void must_succeed_with_ipv6_first(void* argsp, grpc_error* err) {
129   args_struct* args = static_cast<args_struct*>(argsp);
130   GPR_ASSERT(err == GRPC_ERROR_NONE);
131   GPR_ASSERT(args->addrs != nullptr);
132   GPR_ASSERT(args->addrs->naddrs > 0);
133   const struct sockaddr* first_address =
134       reinterpret_cast<const struct sockaddr*>(args->addrs->addrs[0].addr);
135   GPR_ASSERT(first_address->sa_family == AF_INET6);
136   gpr_atm_rel_store(&args->done_atm, 1);
137   gpr_mu_lock(args->mu);
138   GRPC_LOG_IF_ERROR("pollset_kick", grpc_pollset_kick(args->pollset, nullptr));
139   gpr_mu_unlock(args->mu);
140 }
141 
must_succeed_with_ipv4_first(void * argsp,grpc_error * err)142 static void must_succeed_with_ipv4_first(void* argsp, grpc_error* err) {
143   args_struct* args = static_cast<args_struct*>(argsp);
144   GPR_ASSERT(err == GRPC_ERROR_NONE);
145   GPR_ASSERT(args->addrs != nullptr);
146   GPR_ASSERT(args->addrs->naddrs > 0);
147   const struct sockaddr* first_address =
148       reinterpret_cast<const struct sockaddr*>(args->addrs->addrs[0].addr);
149   GPR_ASSERT(first_address->sa_family == AF_INET);
150   gpr_atm_rel_store(&args->done_atm, 1);
151   gpr_mu_lock(args->mu);
152   GRPC_LOG_IF_ERROR("pollset_kick", grpc_pollset_kick(args->pollset, nullptr));
153   gpr_mu_unlock(args->mu);
154 }
155 
test_localhost(void)156 static void test_localhost(void) {
157   grpc_core::ExecCtx exec_ctx;
158   args_struct args;
159   args_init(&args);
160   grpc_resolve_address(
161       "localhost:1", nullptr, args.pollset_set,
162       GRPC_CLOSURE_CREATE(must_succeed, &args, grpc_schedule_on_exec_ctx),
163       &args.addrs);
164   grpc_core::ExecCtx::Get()->Flush();
165   poll_pollset_until_request_done(&args);
166   args_finish(&args);
167 }
168 
test_default_port(void)169 static void test_default_port(void) {
170   grpc_core::ExecCtx exec_ctx;
171   args_struct args;
172   args_init(&args);
173   grpc_resolve_address(
174       "localhost", "1", args.pollset_set,
175       GRPC_CLOSURE_CREATE(must_succeed, &args, grpc_schedule_on_exec_ctx),
176       &args.addrs);
177   grpc_core::ExecCtx::Get()->Flush();
178   poll_pollset_until_request_done(&args);
179   args_finish(&args);
180 }
181 
test_localhost_result_has_ipv6_first(void)182 static void test_localhost_result_has_ipv6_first(void) {
183   grpc_core::ExecCtx exec_ctx;
184   args_struct args;
185   args_init(&args);
186   grpc_resolve_address("localhost:1", nullptr, args.pollset_set,
187                        GRPC_CLOSURE_CREATE(must_succeed_with_ipv6_first, &args,
188                                            grpc_schedule_on_exec_ctx),
189                        &args.addrs);
190   grpc_core::ExecCtx::Get()->Flush();
191   poll_pollset_until_request_done(&args);
192   args_finish(&args);
193 }
194 
test_localhost_result_has_ipv4_first_when_ipv6_isnt_available(void)195 static void test_localhost_result_has_ipv4_first_when_ipv6_isnt_available(
196     void) {
197   grpc_core::ExecCtx exec_ctx;
198   args_struct args;
199   args_init(&args);
200   grpc_resolve_address("localhost:1", nullptr, args.pollset_set,
201                        GRPC_CLOSURE_CREATE(must_succeed_with_ipv4_first, &args,
202                                            grpc_schedule_on_exec_ctx),
203                        &args.addrs);
204   grpc_core::ExecCtx::Get()->Flush();
205   poll_pollset_until_request_done(&args);
206   args_finish(&args);
207 }
208 
test_non_numeric_default_port(void)209 static void test_non_numeric_default_port(void) {
210   grpc_core::ExecCtx exec_ctx;
211   args_struct args;
212   args_init(&args);
213   grpc_resolve_address(
214       "localhost", "https", args.pollset_set,
215       GRPC_CLOSURE_CREATE(must_succeed, &args, grpc_schedule_on_exec_ctx),
216       &args.addrs);
217   grpc_core::ExecCtx::Get()->Flush();
218   poll_pollset_until_request_done(&args);
219   args_finish(&args);
220 }
221 
test_missing_default_port(void)222 static void test_missing_default_port(void) {
223   grpc_core::ExecCtx exec_ctx;
224   args_struct args;
225   args_init(&args);
226   grpc_resolve_address(
227       "localhost", nullptr, args.pollset_set,
228       GRPC_CLOSURE_CREATE(must_fail, &args, grpc_schedule_on_exec_ctx),
229       &args.addrs);
230   grpc_core::ExecCtx::Get()->Flush();
231   poll_pollset_until_request_done(&args);
232   args_finish(&args);
233 }
234 
test_ipv6_with_port(void)235 static void test_ipv6_with_port(void) {
236   grpc_core::ExecCtx exec_ctx;
237   args_struct args;
238   args_init(&args);
239   grpc_resolve_address(
240       "[2001:db8::1]:1", nullptr, args.pollset_set,
241       GRPC_CLOSURE_CREATE(must_succeed, &args, grpc_schedule_on_exec_ctx),
242       &args.addrs);
243   grpc_core::ExecCtx::Get()->Flush();
244   poll_pollset_until_request_done(&args);
245   args_finish(&args);
246 }
247 
test_ipv6_without_port(void)248 static void test_ipv6_without_port(void) {
249   const char* const kCases[] = {
250       "2001:db8::1",
251       "2001:db8::1.2.3.4",
252       "[2001:db8::1]",
253   };
254   unsigned i;
255   for (i = 0; i < sizeof(kCases) / sizeof(*kCases); i++) {
256     grpc_core::ExecCtx exec_ctx;
257     args_struct args;
258     args_init(&args);
259     grpc_resolve_address(
260         kCases[i], "80", args.pollset_set,
261         GRPC_CLOSURE_CREATE(must_succeed, &args, grpc_schedule_on_exec_ctx),
262         &args.addrs);
263     grpc_core::ExecCtx::Get()->Flush();
264     poll_pollset_until_request_done(&args);
265     args_finish(&args);
266   }
267 }
268 
test_invalid_ip_addresses(void)269 static void test_invalid_ip_addresses(void) {
270   const char* const kCases[] = {
271       "293.283.1238.3:1",
272       "[2001:db8::11111]:1",
273   };
274   unsigned i;
275   for (i = 0; i < sizeof(kCases) / sizeof(*kCases); i++) {
276     grpc_core::ExecCtx exec_ctx;
277     args_struct args;
278     args_init(&args);
279     grpc_resolve_address(
280         kCases[i], nullptr, args.pollset_set,
281         GRPC_CLOSURE_CREATE(must_fail, &args, grpc_schedule_on_exec_ctx),
282         &args.addrs);
283     grpc_core::ExecCtx::Get()->Flush();
284     poll_pollset_until_request_done(&args);
285     args_finish(&args);
286   }
287 }
288 
test_unparseable_hostports(void)289 static void test_unparseable_hostports(void) {
290   const char* const kCases[] = {
291       "[", "[::1", "[::1]bad", "[1.2.3.4]", "[localhost]", "[localhost]:1",
292   };
293   unsigned i;
294   for (i = 0; i < sizeof(kCases) / sizeof(*kCases); i++) {
295     grpc_core::ExecCtx exec_ctx;
296     args_struct args;
297     args_init(&args);
298     grpc_resolve_address(
299         kCases[i], "1", args.pollset_set,
300         GRPC_CLOSURE_CREATE(must_fail, &args, grpc_schedule_on_exec_ctx),
301         &args.addrs);
302     grpc_core::ExecCtx::Get()->Flush();
303     poll_pollset_until_request_done(&args);
304     args_finish(&args);
305   }
306 }
307 
308 typedef struct mock_ipv6_disabled_source_addr_factory {
309   address_sorting_source_addr_factory base;
310 } mock_ipv6_disabled_source_addr_factory;
311 
mock_ipv6_disabled_source_addr_factory_get_source_addr(address_sorting_source_addr_factory * factory,const address_sorting_address * dest_addr,address_sorting_address * source_addr)312 static bool mock_ipv6_disabled_source_addr_factory_get_source_addr(
313     address_sorting_source_addr_factory* factory,
314     const address_sorting_address* dest_addr,
315     address_sorting_address* source_addr) {
316   // Mock lack of IPv6. For IPv4, set the source addr to be the same
317   // as the destination; tests won't actually connect on the result anyways.
318   if (address_sorting_abstract_get_family(dest_addr) ==
319       ADDRESS_SORTING_AF_INET6) {
320     return false;
321   }
322   memcpy(source_addr->addr, &dest_addr->addr, dest_addr->len);
323   source_addr->len = dest_addr->len;
324   return true;
325 }
326 
mock_ipv6_disabled_source_addr_factory_destroy(address_sorting_source_addr_factory * factory)327 void mock_ipv6_disabled_source_addr_factory_destroy(
328     address_sorting_source_addr_factory* factory) {
329   mock_ipv6_disabled_source_addr_factory* f =
330       reinterpret_cast<mock_ipv6_disabled_source_addr_factory*>(factory);
331   gpr_free(f);
332 }
333 
334 const address_sorting_source_addr_factory_vtable
335     kMockIpv6DisabledSourceAddrFactoryVtable = {
336         mock_ipv6_disabled_source_addr_factory_get_source_addr,
337         mock_ipv6_disabled_source_addr_factory_destroy,
338 };
339 
main(int argc,char ** argv)340 int main(int argc, char** argv) {
341   // First set the resolver type based off of --resolver
342   const char* resolver_type = nullptr;
343   gpr_cmdline* cl = gpr_cmdline_create("resolve address test");
344   gpr_cmdline_add_string(cl, "resolver", "Resolver type (ares or native)",
345                          &resolver_type);
346   // In case that there are more than one argument on the command line,
347   // --resolver will always be the first one, so only parse the first argument
348   // (other arguments may be unknown to cl)
349   gpr_cmdline_parse(cl, argc > 2 ? 2 : argc, argv);
350   grpc_core::UniquePtr<char> resolver =
351       GPR_GLOBAL_CONFIG_GET(grpc_dns_resolver);
352   if (strlen(resolver.get()) != 0) {
353     gpr_log(GPR_INFO, "Warning: overriding resolver setting of %s",
354             resolver.get());
355   }
356   if (gpr_stricmp(resolver_type, "native") == 0) {
357     GPR_GLOBAL_CONFIG_SET(grpc_dns_resolver, "native");
358   } else if (gpr_stricmp(resolver_type, "ares") == 0) {
359 #ifndef GRPC_UV
360     GPR_GLOBAL_CONFIG_SET(grpc_dns_resolver, "ares");
361 #endif
362   } else {
363     gpr_log(GPR_ERROR, "--resolver_type was not set to ares or native");
364     abort();
365   }
366   // Run the test.
367   grpc::testing::TestEnvironment env(argc, argv);
368   grpc_init();
369   {
370     grpc_core::ExecCtx exec_ctx;
371     test_localhost();
372     test_default_port();
373     test_non_numeric_default_port();
374     test_missing_default_port();
375     test_ipv6_with_port();
376     test_ipv6_without_port();
377     test_invalid_ip_addresses();
378     test_unparseable_hostports();
379     if (gpr_stricmp(resolver_type, "ares") == 0) {
380       // This behavior expectation is specific to c-ares.
381       test_localhost_result_has_ipv6_first();
382     }
383     grpc_core::Executor::ShutdownAll();
384   }
385   gpr_cmdline_destroy(cl);
386   grpc_shutdown();
387   // The following test uses
388   // "address_sorting_override_source_addr_factory_for_testing", which works
389   // on a per-grpc-init basis, and so it's simplest to run this next test
390   // within a standalone grpc_init/grpc_shutdown pair.
391   if (gpr_stricmp(resolver_type, "ares") == 0) {
392     // Run a test case in which c-ares's address sorter
393     // thinks that IPv4 is available and IPv6 isn't.
394     grpc_init();
395     mock_ipv6_disabled_source_addr_factory* factory =
396         static_cast<mock_ipv6_disabled_source_addr_factory*>(
397             gpr_malloc(sizeof(mock_ipv6_disabled_source_addr_factory)));
398     factory->base.vtable = &kMockIpv6DisabledSourceAddrFactoryVtable;
399     address_sorting_override_source_addr_factory_for_testing(&factory->base);
400     test_localhost_result_has_ipv4_first_when_ipv6_isnt_available();
401     grpc_shutdown();
402   }
403   return 0;
404 }
405