GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: node_binding.cc Lines: 196 211 92.9 %
Date: 2022-08-16 04:20:39 Branches: 98 126 77.8 %

Line Branch Exec Source
1
#include "node_binding.h"
2
#include <atomic>
3
#include "env-inl.h"
4
#include "node_builtins.h"
5
#include "node_errors.h"
6
#include "node_external_reference.h"
7
#include "util.h"
8
9
#include <string>
10
11
#if HAVE_OPENSSL
12
#define NODE_BUILTIN_OPENSSL_MODULES(V) V(crypto) V(tls_wrap)
13
#else
14
#define NODE_BUILTIN_OPENSSL_MODULES(V)
15
#endif
16
17
#if NODE_HAVE_I18N_SUPPORT
18
#define NODE_BUILTIN_ICU_MODULES(V) V(icu)
19
#else
20
#define NODE_BUILTIN_ICU_MODULES(V)
21
#endif
22
23
#if HAVE_INSPECTOR
24
#define NODE_BUILTIN_PROFILER_MODULES(V) V(profiler)
25
#else
26
#define NODE_BUILTIN_PROFILER_MODULES(V)
27
#endif
28
29
// A list of built-in modules. In order to do module registration
30
// in node::Init(), need to add built-in modules in the following list.
31
// Then in binding::RegisterBuiltinModules(), it calls modules' registration
32
// function. This helps the built-in modules are loaded properly when
33
// node is built as static library. No need to depend on the
34
// __attribute__((constructor)) like mechanism in GCC.
35
#define NODE_BUILTIN_STANDARD_MODULES(V)                                       \
36
  V(async_wrap)                                                                \
37
  V(blob)                                                                      \
38
  V(block_list)                                                                \
39
  V(buffer)                                                                    \
40
  V(builtins)                                                                  \
41
  V(cares_wrap)                                                                \
42
  V(config)                                                                    \
43
  V(contextify)                                                                \
44
  V(credentials)                                                               \
45
  V(errors)                                                                    \
46
  V(fs)                                                                        \
47
  V(fs_dir)                                                                    \
48
  V(fs_event_wrap)                                                             \
49
  V(heap_utils)                                                                \
50
  V(http2)                                                                     \
51
  V(http_parser)                                                               \
52
  V(inspector)                                                                 \
53
  V(js_stream)                                                                 \
54
  V(js_udp_wrap)                                                               \
55
  V(messaging)                                                                 \
56
  V(module_wrap)                                                               \
57
  V(mksnapshot)                                                                \
58
  V(options)                                                                   \
59
  V(os)                                                                        \
60
  V(performance)                                                               \
61
  V(pipe_wrap)                                                                 \
62
  V(process_wrap)                                                              \
63
  V(process_methods)                                                           \
64
  V(report)                                                                    \
65
  V(serdes)                                                                    \
66
  V(signal_wrap)                                                               \
67
  V(spawn_sync)                                                                \
68
  V(stream_pipe)                                                               \
69
  V(stream_wrap)                                                               \
70
  V(string_decoder)                                                            \
71
  V(symbols)                                                                   \
72
  V(task_queue)                                                                \
73
  V(tcp_wrap)                                                                  \
74
  V(timers)                                                                    \
75
  V(trace_events)                                                              \
76
  V(tty_wrap)                                                                  \
77
  V(types)                                                                     \
78
  V(udp_wrap)                                                                  \
79
  V(url)                                                                       \
80
  V(util)                                                                      \
81
  V(uv)                                                                        \
82
  V(v8)                                                                        \
83
  V(wasi)                                                                      \
84
  V(wasm_web_api)                                                              \
85
  V(watchdog)                                                                  \
86
  V(worker)                                                                    \
87
  V(zlib)
88
89
#define NODE_BUILTIN_MODULES(V)                                                \
90
  NODE_BUILTIN_STANDARD_MODULES(V)                                             \
91
  NODE_BUILTIN_OPENSSL_MODULES(V)                                              \
92
  NODE_BUILTIN_ICU_MODULES(V)                                                  \
93
  NODE_BUILTIN_PROFILER_MODULES(V)
94
95
// This is used to load built-in modules. Instead of using
96
// __attribute__((constructor)), we call the _register_<modname>
97
// function for each built-in modules explicitly in
98
// binding::RegisterBuiltinModules(). This is only forward declaration.
99
// The definitions are in each module's implementation when calling
100
// the NODE_MODULE_CONTEXT_AWARE_INTERNAL.
101
#define V(modname) void _register_##modname();
102
NODE_BUILTIN_MODULES(V)
103
#undef V
104
105
#ifdef _AIX
106
// On AIX, dlopen() behaves differently from other operating systems, in that
107
// it returns unique values from each call, rather than identical values, when
108
// loading the same handle.
109
// We try to work around that by providing wrappers for the dlopen() family of
110
// functions, and using st_dev and st_ino for the file that is to be loaded
111
// as keys for a cache.
112
113
namespace node {
114
namespace dlwrapper {
115
116
struct dl_wrap {
117
  uint64_t st_dev;
118
  uint64_t st_ino;
119
  uint64_t refcount;
120
  void* real_handle;
121
122
  struct hash {
123
    size_t operator()(const dl_wrap* wrap) const {
124
      return std::hash<uint64_t>()(wrap->st_dev) ^
125
             std::hash<uint64_t>()(wrap->st_ino);
126
    }
127
  };
128
129
  struct equal {
130
    bool operator()(const dl_wrap* a,
131
                    const dl_wrap* b) const {
132
      return a->st_dev == b->st_dev && a->st_ino == b->st_ino;
133
    }
134
  };
135
};
136
137
static Mutex dlhandles_mutex;
138
static std::unordered_set<dl_wrap*, dl_wrap::hash, dl_wrap::equal>
139
    dlhandles;
140
static thread_local std::string dlerror_storage;
141
142
char* wrapped_dlerror() {
143
  return &dlerror_storage[0];
144
}
145
146
void* wrapped_dlopen(const char* filename, int flags) {
147
  CHECK_NOT_NULL(filename);  // This deviates from the 'real' dlopen().
148
  Mutex::ScopedLock lock(dlhandles_mutex);
149
150
  uv_fs_t req;
151
  auto cleanup = OnScopeLeave([&]() { uv_fs_req_cleanup(&req); });
152
  int rc = uv_fs_stat(nullptr, &req, filename, nullptr);
153
154
  if (rc != 0) {
155
    dlerror_storage = uv_strerror(rc);
156
    return nullptr;
157
  }
158
159
  dl_wrap search = {
160
    req.statbuf.st_dev,
161
    req.statbuf.st_ino,
162
    0, nullptr
163
  };
164
165
  auto it = dlhandles.find(&search);
166
  if (it != dlhandles.end()) {
167
    (*it)->refcount++;
168
    return *it;
169
  }
170
171
  void* real_handle = dlopen(filename, flags);
172
  if (real_handle == nullptr) {
173
    dlerror_storage = dlerror();
174
    return nullptr;
175
  }
176
  dl_wrap* wrap = new dl_wrap();
177
  wrap->st_dev = req.statbuf.st_dev;
178
  wrap->st_ino = req.statbuf.st_ino;
179
  wrap->refcount = 1;
180
  wrap->real_handle = real_handle;
181
  dlhandles.insert(wrap);
182
  return wrap;
183
}
184
185
int wrapped_dlclose(void* handle) {
186
  Mutex::ScopedLock lock(dlhandles_mutex);
187
  dl_wrap* wrap = static_cast<dl_wrap*>(handle);
188
  int ret = 0;
189
  CHECK_GE(wrap->refcount, 1);
190
  if (--wrap->refcount == 0) {
191
    ret = dlclose(wrap->real_handle);
192
    if (ret != 0) dlerror_storage = dlerror();
193
    dlhandles.erase(wrap);
194
    delete wrap;
195
  }
196
  return ret;
197
}
198
199
void* wrapped_dlsym(void* handle, const char* symbol) {
200
  if (handle == RTLD_DEFAULT || handle == RTLD_NEXT)
201
    return dlsym(handle, symbol);
202
  dl_wrap* wrap = static_cast<dl_wrap*>(handle);
203
  return dlsym(wrap->real_handle, symbol);
204
}
205
206
#define dlopen node::dlwrapper::wrapped_dlopen
207
#define dlerror node::dlwrapper::wrapped_dlerror
208
#define dlclose node::dlwrapper::wrapped_dlclose
209
#define dlsym node::dlwrapper::wrapped_dlsym
210
211
}  // namespace dlwrapper
212
}  // namespace node
213
214
#endif  // _AIX
215
216
#ifdef __linux__
217
19
static bool libc_may_be_musl() {
218

19
  static std::atomic_bool retval;  // Cache the return value.
219
  static std::atomic_bool has_cached_retval { false };
220
19
  if (has_cached_retval) return retval;
221
18
  retval = dlsym(RTLD_DEFAULT, "gnu_get_libc_version") == nullptr;
222
18
  has_cached_retval = true;
223
18
  return retval;
224
}
225
#else  // __linux__
226
static bool libc_may_be_musl() { return false; }
227
#endif  // __linux__
228
229
namespace node {
230
231
using v8::Context;
232
using v8::Exception;
233
using v8::Function;
234
using v8::FunctionCallbackInfo;
235
using v8::Local;
236
using v8::Object;
237
using v8::String;
238
using v8::Value;
239
240
// Globals per process
241
static node_module* modlist_internal;
242
static node_module* modlist_linked;
243
static thread_local node_module* thread_local_modpending;
244
245
// This is set by node::Init() which is used by embedders
246
bool node_is_initialized = false;
247
248
303118
extern "C" void node_module_register(void* m) {
249
303118
  struct node_module* mp = reinterpret_cast<struct node_module*>(m);
250
251
303118
  if (mp->nm_flags & NM_F_INTERNAL) {
252
302960
    mp->nm_link = modlist_internal;
253
302960
    modlist_internal = mp;
254
158
  } else if (!node_is_initialized) {
255
    // "Linked" modules are included as part of the node project.
256
    // Like builtins they are registered *before* node::Init runs.
257
1
    mp->nm_flags = NM_F_LINKED;
258
1
    mp->nm_link = modlist_linked;
259
1
    modlist_linked = mp;
260
  } else {
261
157
    thread_local_modpending = mp;
262
  }
263
303118
}
264
265
namespace binding {
266
267
static struct global_handle_map_t {
268
 public:
269
156
  void set(void* handle, node_module* mod) {
270
156
    CHECK_NE(handle, nullptr);
271
156
    Mutex::ScopedLock lock(mutex_);
272
273
156
    map_[handle].module = mod;
274
    // We need to store this flag internally to avoid a chicken-and-egg problem
275
    // during cleanup. By the time we actually use the flag's value,
276
    // the shared object has been unloaded, and its memory would be gone,
277
    // making it impossible to access fields of `mod` --
278
    // unless `mod` *is* dynamically allocated, but we cannot know that
279
    // without checking the flag.
280
156
    map_[handle].wants_delete_module = mod->nm_flags & NM_F_DELETEME;
281
156
    map_[handle].refcount++;
282
156
  }
283
284
6
  node_module* get_and_increase_refcount(void* handle) {
285
6
    CHECK_NE(handle, nullptr);
286
12
    Mutex::ScopedLock lock(mutex_);
287
288
6
    auto it = map_.find(handle);
289
6
    if (it == map_.end()) return nullptr;
290
5
    it->second.refcount++;
291
5
    return it->second.module;
292
  }
293
294
16
  void erase(void* handle) {
295
16
    CHECK_NE(handle, nullptr);
296
16
    Mutex::ScopedLock lock(mutex_);
297
298
16
    auto it = map_.find(handle);
299
16
    if (it == map_.end()) return;
300
15
    CHECK_GE(it->second.refcount, 1);
301
15
    if (--it->second.refcount == 0) {
302
10
      if (it->second.wants_delete_module)
303
4
        delete it->second.module;
304
10
      map_.erase(handle);
305
    }
306
  }
307
308
 private:
309
  Mutex mutex_;
310
  struct Entry {
311
    unsigned int refcount;
312
    bool wants_delete_module;
313
    node_module* module;
314
  };
315
  std::unordered_map<void*, Entry> map_;
316
} global_handle_map;
317
318
170
DLib::DLib(const char* filename, int flags)
319
170
    : filename_(filename), flags_(flags), handle_(nullptr) {}
320
321
#ifdef __POSIX__
322
170
bool DLib::Open() {
323
170
  handle_ = dlopen(filename_.c_str(), flags_);
324
170
  if (handle_ != nullptr) return true;
325
3
  errmsg_ = dlerror();
326
3
  return false;
327
}
328
329
22
void DLib::Close() {
330
22
  if (handle_ == nullptr) return;
331
332
19
  if (libc_may_be_musl()) {
333
    // musl libc implements dlclose() as a no-op which returns 0.
334
    // As a consequence, trying to re-load a previously closed addon at a later
335
    // point will not call its static constructors, which Node.js uses.
336
    // Therefore, when we may be using musl libc, we assume that the shared
337
    // object exists indefinitely and keep it in our handle map.
338
    return;
339
  }
340
341
19
  int err = dlclose(handle_);
342
19
  if (err == 0) {
343
19
    if (has_entry_in_global_handle_map_)
344
16
      global_handle_map.erase(handle_);
345
  }
346
19
  handle_ = nullptr;
347
}
348
349
22
void* DLib::GetSymbolAddress(const char* name) {
350
22
  return dlsym(handle_, name);
351
}
352
#else   // !__POSIX__
353
bool DLib::Open() {
354
  int ret = uv_dlopen(filename_.c_str(), &lib_);
355
  if (ret == 0) {
356
    handle_ = static_cast<void*>(lib_.handle);
357
    return true;
358
  }
359
  errmsg_ = uv_dlerror(&lib_);
360
  uv_dlclose(&lib_);
361
  return false;
362
}
363
364
void DLib::Close() {
365
  if (handle_ == nullptr) return;
366
  if (has_entry_in_global_handle_map_)
367
    global_handle_map.erase(handle_);
368
  uv_dlclose(&lib_);
369
  handle_ = nullptr;
370
}
371
372
void* DLib::GetSymbolAddress(const char* name) {
373
  void* address;
374
  if (0 == uv_dlsym(&lib_, name, &address)) return address;
375
  return nullptr;
376
}
377
#endif  // !__POSIX__
378
379
156
void DLib::SaveInGlobalHandleMap(node_module* mp) {
380
156
  has_entry_in_global_handle_map_ = true;
381
156
  global_handle_map.set(handle_, mp);
382
156
}
383
384
6
node_module* DLib::GetSavedModuleFromGlobalHandleMap() {
385
6
  has_entry_in_global_handle_map_ = true;
386
6
  return global_handle_map.get_and_increase_refcount(handle_);
387
}
388
389
using InitializerCallback = void (*)(Local<Object> exports,
390
                                     Local<Value> module,
391
                                     Local<Context> context);
392
393
13
inline InitializerCallback GetInitializerCallback(DLib* dlib) {
394
13
  const char* name = "node_register_module_v" STRINGIFY(NODE_MODULE_VERSION);
395
13
  return reinterpret_cast<InitializerCallback>(dlib->GetSymbolAddress(name));
396
}
397
398
9
inline napi_addon_register_func GetNapiInitializerCallback(DLib* dlib) {
399
9
  const char* name =
400
      STRINGIFY(NAPI_MODULE_INITIALIZER_BASE) STRINGIFY(NAPI_MODULE_VERSION);
401
  return reinterpret_cast<napi_addon_register_func>(
402
9
      dlib->GetSymbolAddress(name));
403
}
404
405
// DLOpen is process.dlopen(module, filename, flags).
406
// Used to load 'module.node' dynamically shared objects.
407
//
408
// FIXME(bnoordhuis) Not multi-context ready. TBD how to resolve the conflict
409
// when two contexts try to load the same shared object. Maybe have a shadow
410
// cache that's a plain C list or hash table that's shared across contexts?
411
177
void DLOpen(const FunctionCallbackInfo<Value>& args) {
412
177
  Environment* env = Environment::GetCurrent(args);
413
414
177
  if (env->no_native_addons()) {
415
6
    return THROW_ERR_DLOPEN_DISABLED(
416
7
      env, "Cannot load native addon because loading addons is disabled.");
417
  }
418
419
171
  auto context = env->context();
420
421
171
  CHECK_NULL(thread_local_modpending);
422
423
171
  if (args.Length() < 2) {
424
    return THROW_ERR_MISSING_ARGS(
425
        env, "process.dlopen needs at least 2 arguments");
426
  }
427
428
171
  int32_t flags = DLib::kDefaultFlags;
429

173
  if (args.Length() > 2 && !args[2]->Int32Value(context).To(&flags)) {
430
    return THROW_ERR_INVALID_ARG_TYPE(env, "flag argument must be an integer.");
431
  }
432
433
  Local<Object> module;
434
  Local<Object> exports;
435
  Local<Value> exports_v;
436
171
  if (!args[0]->ToObject(context).ToLocal(&module) ||
437

855
      !module->Get(context, env->exports_string()).ToLocal(&exports_v) ||
438

513
      !exports_v->ToObject(context).ToLocal(&exports)) {
439
1
    return;  // Exception pending.
440
  }
441
442
170
  node::Utf8Value filename(env->isolate(), args[1]);  // Cast
443
170
  env->TryLoadAddon(*filename, flags, [&](DLib* dlib) {
444

170
    static Mutex dlib_load_mutex;
445
340
    Mutex::ScopedLock lock(dlib_load_mutex);
446
447
170
    const bool is_opened = dlib->Open();
448
449
    // Objects containing v14 or later modules will have registered themselves
450
    // on the pending list.  Activate all of them now.  At present, only one
451
    // module per object is supported.
452
170
    node_module* mp = thread_local_modpending;
453
170
    thread_local_modpending = nullptr;
454
455
170
    if (!is_opened) {
456
3
      std::string errmsg = dlib->errmsg_.c_str();
457
3
      dlib->Close();
458
#ifdef _WIN32
459
      // Windows needs to add the filename into the error message
460
      errmsg += *filename;
461
#endif  // _WIN32
462
3
      THROW_ERR_DLOPEN_FAILED(env, errmsg.c_str());
463
3
      return false;
464
    }
465
466
167
    if (mp != nullptr) {
467
157
      if (mp->nm_context_register_func == nullptr) {
468
41
        if (env->force_context_aware()) {
469
1
          dlib->Close();
470
1
          THROW_ERR_NON_CONTEXT_AWARE_DISABLED(env);
471
1
          return false;
472
        }
473
      }
474
156
      mp->nm_dso_handle = dlib->handle_;
475
156
      dlib->SaveInGlobalHandleMap(mp);
476
    } else {
477
10
      if (auto callback = GetInitializerCallback(dlib)) {
478
4
        callback(exports, module, context);
479
1
        return true;
480
9
      } else if (auto napi_callback = GetNapiInitializerCallback(dlib)) {
481
3
        napi_module_register_by_symbol(exports, module, context, napi_callback);
482
3
        return true;
483
      } else {
484
6
        mp = dlib->GetSavedModuleFromGlobalHandleMap();
485

6
        if (mp == nullptr || mp->nm_context_register_func == nullptr) {
486
3
          dlib->Close();
487
          char errmsg[1024];
488
6
          snprintf(errmsg,
489
                   sizeof(errmsg),
490
                   "Module did not self-register: '%s'.",
491
3
                   *filename);
492
3
          THROW_ERR_DLOPEN_FAILED(env, errmsg);
493
3
          return false;
494
        }
495
      }
496
    }
497
498
    // -1 is used for N-API modules
499

159
    if ((mp->nm_version != -1) && (mp->nm_version != NODE_MODULE_VERSION)) {
500
      // Even if the module did self-register, it may have done so with the
501
      // wrong version. We must only give up after having checked to see if it
502
      // has an appropriate initializer callback.
503
3
      if (auto callback = GetInitializerCallback(dlib)) {
504
2
        callback(exports, module, context);
505
2
        return true;
506
      }
507
      char errmsg[1024];
508
1
      snprintf(errmsg,
509
               sizeof(errmsg),
510
               "The module '%s'"
511
               "\nwas compiled against a different Node.js version using"
512
               "\nNODE_MODULE_VERSION %d. This version of Node.js requires"
513
               "\nNODE_MODULE_VERSION %d. Please try re-compiling or "
514
               "re-installing\nthe module (for instance, using `npm rebuild` "
515
               "or `npm install`).",
516
               *filename,
517
               mp->nm_version,
518
               NODE_MODULE_VERSION);
519
520
      // NOTE: `mp` is allocated inside of the shared library's memory, calling
521
      // `dlclose` will deallocate it
522
1
      dlib->Close();
523
1
      THROW_ERR_DLOPEN_FAILED(env, errmsg);
524
1
      return false;
525
    }
526
156
    CHECK_EQ(mp->nm_flags & NM_F_BUILTIN, 0);
527
528
    // Do not keep the lock while running userland addon loading code.
529
312
    Mutex::ScopedUnlock unlock(lock);
530
156
    if (mp->nm_context_register_func != nullptr) {
531
118
      mp->nm_context_register_func(exports, module, context, mp->nm_priv);
532
38
    } else if (mp->nm_register_func != nullptr) {
533
38
      mp->nm_register_func(exports, module, mp->nm_priv);
534
    } else {
535
      dlib->Close();
536
      THROW_ERR_DLOPEN_FAILED(env, "Module has no declared entry point.");
537
      return false;
538
    }
539
540
156
    return true;
541
  });
542
543
  // Tell coverity that 'handle' should not be freed when we return.
544
  // coverity[leaked_storage]
545
}
546
547
87175
inline struct node_module* FindModule(struct node_module* list,
548
                                      const char* name,
549
                                      int flag) {
550
  struct node_module* mp;
551
552
2470980
  for (mp = list; mp != nullptr; mp = mp->nm_link) {
553
2470167
    if (strcmp(mp->nm_modname, name) == 0) break;
554
  }
555
556

87175
  CHECK(mp == nullptr || (mp->nm_flags & flag) != 0);
557
87175
  return mp;
558
}
559
560
86352
static Local<Object> InitModule(Environment* env,
561
                                node_module* mod,
562
                                Local<String> module) {
563
  // Internal bindings don't have a "module" object, only exports.
564
86352
  Local<Function> ctor = env->binding_data_ctor_template()
565
86352
                             ->GetFunction(env->context())
566
86352
                             .ToLocalChecked();
567
86352
  Local<Object> exports = ctor->NewInstance(env->context()).ToLocalChecked();
568
86352
  CHECK_NULL(mod->nm_register_func);
569
86352
  CHECK_NOT_NULL(mod->nm_context_register_func);
570
86352
  Local<Value> unused = Undefined(env->isolate());
571
86352
  mod->nm_context_register_func(exports, unused, env->context(), mod->nm_priv);
572
86352
  return exports;
573
}
574
575
87164
void GetInternalBinding(const FunctionCallbackInfo<Value>& args) {
576
87164
  Environment* env = Environment::GetCurrent(args);
577
578
174328
  CHECK(args[0]->IsString());
579
580
174328
  Local<String> module = args[0].As<String>();
581
87164
  node::Utf8Value module_v(env->isolate(), module);
582
  Local<Object> exports;
583
584
87164
  node_module* mod = FindModule(modlist_internal, *module_v, NM_F_INTERNAL);
585
87164
  if (mod != nullptr) {
586
86352
    exports = InitModule(env, mod, module);
587
86352
    env->internal_bindings.insert(mod);
588
812
  } else if (!strcmp(*module_v, "constants")) {
589
770
    exports = Object::New(env->isolate());
590
2310
    CHECK(
591
        exports->SetPrototype(env->context(), Null(env->isolate())).FromJust());
592
770
    DefineConstants(env->isolate(), exports);
593
42
  } else if (!strcmp(*module_v, "natives")) {
594
42
    exports = builtins::BuiltinLoader::GetSourceObject(env->context());
595
    // Legacy feature: process.binding('natives').config contains stringified
596
    // config.gypi
597
168
    CHECK(exports
598
              ->Set(env->context(),
599
                    env->config_string(),
600
                    builtins::BuiltinLoader::GetConfigString(env->isolate()))
601
              .FromJust());
602
  } else {
603
    char errmsg[1024];
604
    snprintf(errmsg, sizeof(errmsg), "No such module: %s", *module_v);
605
    return THROW_ERR_INVALID_MODULE(env, errmsg);
606
  }
607
608
174328
  args.GetReturnValue().Set(exports);
609
}
610
611
10
void GetLinkedBinding(const FunctionCallbackInfo<Value>& args) {
612
10
  Environment* env = Environment::GetCurrent(args);
613
614
20
  CHECK(args[0]->IsString());
615
616
20
  Local<String> module_name = args[0].As<String>();
617
618
10
  node::Utf8Value module_name_v(env->isolate(), module_name);
619
10
  const char* name = *module_name_v;
620
10
  node_module* mod = nullptr;
621
622
  // Iterate from here to the nearest non-Worker Environment to see if there's
623
  // a linked binding defined locally rather than through the global list.
624
10
  Environment* cur_env = env;
625

20
  while (mod == nullptr && cur_env != nullptr) {
626
20
    Mutex::ScopedLock lock(cur_env->extra_linked_bindings_mutex());
627
10
    mod = FindModule(cur_env->extra_linked_bindings_head(), name, NM_F_LINKED);
628
10
    cur_env = cur_env->worker_parent_env();
629
  }
630
631
10
  if (mod == nullptr)
632
1
    mod = FindModule(modlist_linked, name, NM_F_LINKED);
633
634
10
  if (mod == nullptr) {
635
    char errmsg[1024];
636
    snprintf(errmsg,
637
             sizeof(errmsg),
638
             "No such module was linked: %s",
639
             *module_name_v);
640
    return THROW_ERR_INVALID_MODULE(env, errmsg);
641
  }
642
643
10
  Local<Object> module = Object::New(env->isolate());
644
10
  Local<Object> exports = Object::New(env->isolate());
645
  Local<String> exports_prop =
646
10
      String::NewFromUtf8Literal(env->isolate(), "exports");
647
10
  module->Set(env->context(), exports_prop, exports).Check();
648
649
10
  if (mod->nm_context_register_func != nullptr) {
650
20
    mod->nm_context_register_func(
651
        exports, module, env->context(), mod->nm_priv);
652
  } else if (mod->nm_register_func != nullptr) {
653
    mod->nm_register_func(exports, module, mod->nm_priv);
654
  } else {
655
    return THROW_ERR_INVALID_MODULE(
656
        env,
657
        "Linked moduled has no declared entry point.");
658
  }
659
660
  auto effective_exports =
661
20
      module->Get(env->context(), exports_prop).ToLocalChecked();
662
663
20
  args.GetReturnValue().Set(effective_exports);
664
}
665
666
// Call built-in modules' _register_<module name> function to
667
// do module registration explicitly.
668
5410
void RegisterBuiltinModules() {
669
#define V(modname) _register_##modname();
670
5410
  NODE_BUILTIN_MODULES(V)
671
#undef V
672
5410
}
673
674
5338
void RegisterExternalReferences(ExternalReferenceRegistry* registry) {
675
5338
  registry->Register(GetLinkedBinding);
676
5338
  registry->Register(GetInternalBinding);
677
5338
}
678
679
}  // namespace binding
680
}  // namespace node
681
682
5338
NODE_MODULE_EXTERNAL_REFERENCE(binding,
683
                               node::binding::RegisterExternalReferences)