aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/core/lib/iomgr/tcp_server_posix.c
blob: f304642951ebe6d1cac348fca2930621121fbe3b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
/*
 *
 * Copyright 2015 gRPC authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

/* FIXME: "posix" files shouldn't be depending on _GNU_SOURCE */
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif

#include "src/core/lib/iomgr/port.h"

#ifdef GRPC_POSIX_SOCKET

#include "src/core/lib/iomgr/tcp_server.h"

#include <errno.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/string_util.h>
#include <grpc/support/sync.h>
#include <grpc/support/time.h>
#include <grpc/support/useful.h>

#include "src/core/lib/channel/channel_args.h"
#include "src/core/lib/iomgr/resolve_address.h"
#include "src/core/lib/iomgr/sockaddr.h"
#include "src/core/lib/iomgr/sockaddr_utils.h"
#include "src/core/lib/iomgr/socket_utils_posix.h"
#include "src/core/lib/iomgr/tcp_posix.h"
#include "src/core/lib/iomgr/tcp_server_utils_posix.h"
#include "src/core/lib/iomgr/unix_sockets_posix.h"
#include "src/core/lib/support/string.h"

static gpr_once check_init = GPR_ONCE_INIT;
static bool has_so_reuseport = false;

static void init(void) {
#ifndef GPR_MANYLINUX1
  int s = socket(AF_INET, SOCK_STREAM, 0);
  if (s >= 0) {
    has_so_reuseport = GRPC_LOG_IF_ERROR("check for SO_REUSEPORT",
                                         grpc_set_socket_reuse_port(s, 1));
    close(s);
  }
#endif
}

grpc_error *grpc_tcp_server_create(grpc_exec_ctx *exec_ctx,
                                   grpc_closure *shutdown_complete,
                                   const grpc_channel_args *args,
                                   grpc_tcp_server **server) {
  gpr_once_init(&check_init, init);

  grpc_tcp_server *s = gpr_zalloc(sizeof(grpc_tcp_server));
  s->so_reuseport = has_so_reuseport;
  s->expand_wildcard_addrs = false;
  for (size_t i = 0; i < (args == NULL ? 0 : args->num_args); i++) {
    if (0 == strcmp(GRPC_ARG_ALLOW_REUSEPORT, args->args[i].key)) {
      if (args->args[i].type == GRPC_ARG_INTEGER) {
        s->so_reuseport =
            has_so_reuseport && (args->args[i].value.integer != 0);
      } else {
        gpr_free(s);
        return GRPC_ERROR_CREATE_FROM_STATIC_STRING(GRPC_ARG_ALLOW_REUSEPORT
                                                    " must be an integer");
      }
    } else if (0 == strcmp(GRPC_ARG_EXPAND_WILDCARD_ADDRS, args->args[i].key)) {
      if (args->args[i].type == GRPC_ARG_INTEGER) {
        s->expand_wildcard_addrs = (args->args[i].value.integer != 0);
      } else {
        gpr_free(s);
        return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
            GRPC_ARG_EXPAND_WILDCARD_ADDRS " must be an integer");
      }
    }
  }
  gpr_ref_init(&s->refs, 1);
  gpr_mu_init(&s->mu);
  s->active_ports = 0;
  s->destroyed_ports = 0;
  s->shutdown = false;
  s->shutdown_starting.head = NULL;
  s->shutdown_starting.tail = NULL;
  s->shutdown_complete = shutdown_complete;
  s->on_accept_cb = NULL;
  s->on_accept_cb_arg = NULL;
  s->head = NULL;
  s->tail = NULL;
  s->nports = 0;
  s->channel_args = grpc_channel_args_copy(args);
  gpr_atm_no_barrier_store(&s->next_pollset_to_assign, 0);
  *server = s;
  return GRPC_ERROR_NONE;
}

static void finish_shutdown(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
  gpr_mu_lock(&s->mu);
  GPR_ASSERT(s->shutdown);
  gpr_mu_unlock(&s->mu);
  if (s->shutdown_complete != NULL) {
    GRPC_CLOSURE_SCHED(exec_ctx, s->shutdown_complete, GRPC_ERROR_NONE);
  }

  gpr_mu_destroy(&s->mu);

  while (s->head) {
    grpc_tcp_listener *sp = s->head;
    s->head = sp->next;
    gpr_free(sp);
  }
  grpc_channel_args_destroy(exec_ctx, s->channel_args);

  gpr_free(s);
}

static void destroyed_port(grpc_exec_ctx *exec_ctx, void *server,
                           grpc_error *error) {
  grpc_tcp_server *s = server;
  gpr_mu_lock(&s->mu);
  s->destroyed_ports++;
  if (s->destroyed_ports == s->nports) {
    gpr_mu_unlock(&s->mu);
    finish_shutdown(exec_ctx, s);
  } else {
    GPR_ASSERT(s->destroyed_ports < s->nports);
    gpr_mu_unlock(&s->mu);
  }
}

/* called when all listening endpoints have been shutdown, so no further
   events will be received on them - at this point it's safe to destroy
   things */
static void deactivated_all_ports(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
  /* delete ALL the things */
  gpr_mu_lock(&s->mu);

  GPR_ASSERT(s->shutdown);

  if (s->head) {
    grpc_tcp_listener *sp;
    for (sp = s->head; sp; sp = sp->next) {
      grpc_unlink_if_unix_domain_socket(&sp->addr);
      GRPC_CLOSURE_INIT(&sp->destroyed_closure, destroyed_port, s,
                        grpc_schedule_on_exec_ctx);
      grpc_fd_orphan(exec_ctx, sp->emfd, &sp->destroyed_closure, NULL,
                     "tcp_listener_shutdown");
    }
    gpr_mu_unlock(&s->mu);
  } else {
    gpr_mu_unlock(&s->mu);
    finish_shutdown(exec_ctx, s);
  }
}

static void tcp_server_destroy(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
  gpr_mu_lock(&s->mu);

  GPR_ASSERT(!s->shutdown);
  s->shutdown = true;

  /* shutdown all fd's */
  if (s->active_ports) {
    grpc_tcp_listener *sp;
    for (sp = s->head; sp; sp = sp->next) {
      grpc_fd_shutdown(exec_ctx, sp->emfd, GRPC_ERROR_CREATE_FROM_STATIC_STRING(
                                               "Server destroyed"));
    }
    gpr_mu_unlock(&s->mu);
  } else {
    gpr_mu_unlock(&s->mu);
    deactivated_all_ports(exec_ctx, s);
  }
}

/* event manager callback when reads are ready */
static void on_read(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *err) {
  grpc_tcp_listener *sp = arg;

  if (err != GRPC_ERROR_NONE) {
    goto error;
  }

  grpc_pollset *read_notifier_pollset =
      sp->server->pollsets[(size_t)gpr_atm_no_barrier_fetch_add(
                               &sp->server->next_pollset_to_assign, 1) %
                           sp->server->pollset_count];

  /* loop until accept4 returns EAGAIN, and then re-arm notification */
  for (;;) {
    grpc_resolved_address addr;
    char *addr_str;
    char *name;
    addr.len = sizeof(struct sockaddr_storage);
    /* Note: If we ever decide to return this address to the user, remember to
       strip off the ::ffff:0.0.0.0/96 prefix first. */
    int fd = grpc_accept4(sp->fd, &addr, 1, 1);
    if (fd < 0) {
      switch (errno) {
        case EINTR:
          continue;
        case EAGAIN:
          grpc_fd_notify_on_read(exec_ctx, sp->emfd, &sp->read_closure);
          return;
        default:
          gpr_mu_lock(&sp->server->mu);
          if (!sp->server->shutdown_listeners) {
            gpr_log(GPR_ERROR, "Failed accept4: %s", strerror(errno));
          } else {
            /* if we have shutdown listeners, accept4 could fail, and we
               needn't notify users */
          }
          gpr_mu_unlock(&sp->server->mu);
          goto error;
      }
    }

    grpc_set_socket_no_sigpipe_if_possible(fd);

    addr_str = grpc_sockaddr_to_uri(&addr);
    gpr_asprintf(&name, "tcp-server-connection:%s", addr_str);

    if (GRPC_TRACER_ON(grpc_tcp_trace)) {
      gpr_log(GPR_DEBUG, "SERVER_CONNECT: incoming connection: %s", addr_str);
    }

    grpc_fd *fdobj = grpc_fd_create(fd, name);

    grpc_pollset_add_fd(exec_ctx, read_notifier_pollset, fdobj);

    // Create acceptor.
    grpc_tcp_server_acceptor *acceptor = gpr_malloc(sizeof(*acceptor));
    acceptor->from_server = sp->server;
    acceptor->port_index = sp->port_index;
    acceptor->fd_index = sp->fd_index;

    sp->server->on_accept_cb(
        exec_ctx, sp->server->on_accept_cb_arg,
        grpc_tcp_create(exec_ctx, fdobj, sp->server->channel_args, addr_str),
        read_notifier_pollset, acceptor);

    gpr_free(name);
    gpr_free(addr_str);
  }

  GPR_UNREACHABLE_CODE(return );

error:
  gpr_mu_lock(&sp->server->mu);
  if (0 == --sp->server->active_ports && sp->server->shutdown) {
    gpr_mu_unlock(&sp->server->mu);
    deactivated_all_ports(exec_ctx, sp->server);
  } else {
    gpr_mu_unlock(&sp->server->mu);
  }
}

/* Treat :: or 0.0.0.0 as a family-agnostic wildcard. */
static grpc_error *add_wildcard_addrs_to_server(grpc_tcp_server *s,
                                                unsigned port_index,
                                                int requested_port,
                                                int *out_port) {
  grpc_resolved_address wild4;
  grpc_resolved_address wild6;
  unsigned fd_index = 0;
  grpc_dualstack_mode dsmode;
  grpc_tcp_listener *sp = NULL;
  grpc_tcp_listener *sp2 = NULL;
  grpc_error *v6_err = GRPC_ERROR_NONE;
  grpc_error *v4_err = GRPC_ERROR_NONE;
  *out_port = -1;

  if (grpc_tcp_server_have_ifaddrs() && s->expand_wildcard_addrs) {
    return grpc_tcp_server_add_all_local_addrs(s, port_index, requested_port,
                                               out_port);
  }

  grpc_sockaddr_make_wildcards(requested_port, &wild4, &wild6);
  /* Try listening on IPv6 first. */
  if ((v6_err = grpc_tcp_server_add_addr(s, &wild6, port_index, fd_index,
                                         &dsmode, &sp)) == GRPC_ERROR_NONE) {
    ++fd_index;
    requested_port = *out_port = sp->port;
    if (dsmode == GRPC_DSMODE_DUALSTACK || dsmode == GRPC_DSMODE_IPV4) {
      return GRPC_ERROR_NONE;
    }
  }
  /* If we got a v6-only socket or nothing, try adding 0.0.0.0. */
  grpc_sockaddr_set_port(&wild4, requested_port);
  if ((v4_err = grpc_tcp_server_add_addr(s, &wild4, port_index, fd_index,
                                         &dsmode, &sp2)) == GRPC_ERROR_NONE) {
    *out_port = sp2->port;
    if (sp != NULL) {
      sp2->is_sibling = 1;
      sp->sibling = sp2;
    }
  }
  if (*out_port > 0) {
    if (v6_err != GRPC_ERROR_NONE) {
      gpr_log(GPR_INFO,
              "Failed to add :: listener, "
              "the environment may not support IPv6: %s",
              grpc_error_string(v6_err));
      GRPC_ERROR_UNREF(v6_err);
    }
    if (v4_err != GRPC_ERROR_NONE) {
      gpr_log(GPR_INFO,
              "Failed to add 0.0.0.0 listener, "
              "the environment may not support IPv4: %s",
              grpc_error_string(v4_err));
      GRPC_ERROR_UNREF(v4_err);
    }
    return GRPC_ERROR_NONE;
  } else {
    grpc_error *root_err = GRPC_ERROR_CREATE_FROM_STATIC_STRING(
        "Failed to add any wildcard listeners");
    GPR_ASSERT(v6_err != GRPC_ERROR_NONE && v4_err != GRPC_ERROR_NONE);
    root_err = grpc_error_add_child(root_err, v6_err);
    root_err = grpc_error_add_child(root_err, v4_err);
    return root_err;
  }
}

static grpc_error *clone_port(grpc_tcp_listener *listener, unsigned count) {
  grpc_tcp_listener *sp = NULL;
  char *addr_str;
  char *name;
  grpc_error *err;

  for (grpc_tcp_listener *l = listener->next; l && l->is_sibling; l = l->next) {
    l->fd_index += count;
  }

  for (unsigned i = 0; i < count; i++) {
    int fd = -1;
    int port = -1;
    grpc_dualstack_mode dsmode;
    err = grpc_create_dualstack_socket(&listener->addr, SOCK_STREAM, 0, &dsmode,
                                       &fd);
    if (err != GRPC_ERROR_NONE) return err;
    err = grpc_tcp_server_prepare_socket(fd, &listener->addr, true, &port);
    if (err != GRPC_ERROR_NONE) return err;
    listener->server->nports++;
    grpc_sockaddr_to_string(&addr_str, &listener->addr, 1);
    gpr_asprintf(&name, "tcp-server-listener:%s/clone-%d", addr_str, i);
    sp = gpr_malloc(sizeof(grpc_tcp_listener));
    sp->next = listener->next;
    listener->next = sp;
    /* sp (the new listener) is a sibling of 'listener' (the original
       listener). */
    sp->is_sibling = 1;
    sp->sibling = listener->sibling;
    listener->sibling = sp;
    sp->server = listener->server;
    sp->fd = fd;
    sp->emfd = grpc_fd_create(fd, name);
    memcpy(&sp->addr, &listener->addr, sizeof(grpc_resolved_address));
    sp->port = port;
    sp->port_index = listener->port_index;
    sp->fd_index = listener->fd_index + count - i;
    GPR_ASSERT(sp->emfd);
    while (listener->server->tail->next != NULL) {
      listener->server->tail = listener->server->tail->next;
    }
    gpr_free(addr_str);
    gpr_free(name);
  }

  return GRPC_ERROR_NONE;
}

grpc_error *grpc_tcp_server_add_port(grpc_tcp_server *s,
                                     const grpc_resolved_address *addr,
                                     int *out_port) {
  grpc_tcp_listener *sp;
  grpc_resolved_address sockname_temp;
  grpc_resolved_address addr6_v4mapped;
  int requested_port = grpc_sockaddr_get_port(addr);
  unsigned port_index = 0;
  grpc_dualstack_mode dsmode;
  grpc_error *err;
  *out_port = -1;
  if (s->tail != NULL) {
    port_index = s->tail->port_index + 1;
  }
  grpc_unlink_if_unix_domain_socket(addr);

  /* Check if this is a wildcard port, and if so, try to keep the port the same
     as some previously created listener. */
  if (requested_port == 0) {
    for (sp = s->head; sp; sp = sp->next) {
      sockname_temp.len = sizeof(struct sockaddr_storage);
      if (0 == getsockname(sp->fd, (struct sockaddr *)&sockname_temp.addr,
                           (socklen_t *)&sockname_temp.len)) {
        int used_port = grpc_sockaddr_get_port(&sockname_temp);
        if (used_port > 0) {
          memcpy(&sockname_temp, addr, sizeof(grpc_resolved_address));
          grpc_sockaddr_set_port(&sockname_temp, used_port);
          requested_port = used_port;
          addr = &sockname_temp;
          break;
        }
      }
    }
  }
  if (grpc_sockaddr_is_wildcard(addr, &requested_port)) {
    return add_wildcard_addrs_to_server(s, port_index, requested_port,
                                        out_port);
  }
  if (grpc_sockaddr_to_v4mapped(addr, &addr6_v4mapped)) {
    addr = &addr6_v4mapped;
  }
  if ((err = grpc_tcp_server_add_addr(s, addr, port_index, 0, &dsmode, &sp)) ==
      GRPC_ERROR_NONE) {
    *out_port = sp->port;
  }
  return err;
}

/* Return listener at port_index or NULL. Should only be called with s->mu
   locked. */
static grpc_tcp_listener *get_port_index(grpc_tcp_server *s,
                                         unsigned port_index) {
  unsigned num_ports = 0;
  grpc_tcp_listener *sp;
  for (sp = s->head; sp; sp = sp->next) {
    if (!sp->is_sibling) {
      if (++num_ports > port_index) {
        return sp;
      }
    }
  }
  return NULL;
}

unsigned grpc_tcp_server_port_fd_count(grpc_tcp_server *s,
                                       unsigned port_index) {
  unsigned num_fds = 0;
  gpr_mu_lock(&s->mu);
  grpc_tcp_listener *sp = get_port_index(s, port_index);
  for (; sp; sp = sp->sibling) {
    ++num_fds;
  }
  gpr_mu_unlock(&s->mu);
  return num_fds;
}

int grpc_tcp_server_port_fd(grpc_tcp_server *s, unsigned port_index,
                            unsigned fd_index) {
  gpr_mu_lock(&s->mu);
  grpc_tcp_listener *sp = get_port_index(s, port_index);
  for (; sp; sp = sp->sibling, --fd_index) {
    if (fd_index == 0) {
      gpr_mu_unlock(&s->mu);
      return sp->fd;
    }
  }
  gpr_mu_unlock(&s->mu);
  return -1;
}

void grpc_tcp_server_start(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s,
                           grpc_pollset **pollsets, size_t pollset_count,
                           grpc_tcp_server_cb on_accept_cb,
                           void *on_accept_cb_arg) {
  size_t i;
  grpc_tcp_listener *sp;
  GPR_ASSERT(on_accept_cb);
  gpr_mu_lock(&s->mu);
  GPR_ASSERT(!s->on_accept_cb);
  GPR_ASSERT(s->active_ports == 0);
  s->on_accept_cb = on_accept_cb;
  s->on_accept_cb_arg = on_accept_cb_arg;
  s->pollsets = pollsets;
  s->pollset_count = pollset_count;
  sp = s->head;
  while (sp != NULL) {
    if (s->so_reuseport && !grpc_is_unix_socket(&sp->addr) &&
        pollset_count > 1) {
      GPR_ASSERT(GRPC_LOG_IF_ERROR(
          "clone_port", clone_port(sp, (unsigned)(pollset_count - 1))));
      for (i = 0; i < pollset_count; i++) {
        grpc_pollset_add_fd(exec_ctx, pollsets[i], sp->emfd);
        GRPC_CLOSURE_INIT(&sp->read_closure, on_read, sp,
                          grpc_schedule_on_exec_ctx);
        grpc_fd_notify_on_read(exec_ctx, sp->emfd, &sp->read_closure);
        s->active_ports++;
        sp = sp->next;
      }
    } else {
      for (i = 0; i < pollset_count; i++) {
        grpc_pollset_add_fd(exec_ctx, pollsets[i], sp->emfd);
      }
      GRPC_CLOSURE_INIT(&sp->read_closure, on_read, sp,
                        grpc_schedule_on_exec_ctx);
      grpc_fd_notify_on_read(exec_ctx, sp->emfd, &sp->read_closure);
      s->active_ports++;
      sp = sp->next;
    }
  }
  gpr_mu_unlock(&s->mu);
}

grpc_tcp_server *grpc_tcp_server_ref(grpc_tcp_server *s) {
  gpr_ref_non_zero(&s->refs);
  return s;
}

void grpc_tcp_server_shutdown_starting_add(grpc_tcp_server *s,
                                           grpc_closure *shutdown_starting) {
  gpr_mu_lock(&s->mu);
  grpc_closure_list_append(&s->shutdown_starting, shutdown_starting,
                           GRPC_ERROR_NONE);
  gpr_mu_unlock(&s->mu);
}

void grpc_tcp_server_unref(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
  if (gpr_unref(&s->refs)) {
    grpc_tcp_server_shutdown_listeners(exec_ctx, s);
    gpr_mu_lock(&s->mu);
    GRPC_CLOSURE_LIST_SCHED(exec_ctx, &s->shutdown_starting);
    gpr_mu_unlock(&s->mu);
    tcp_server_destroy(exec_ctx, s);
  }
}

void grpc_tcp_server_shutdown_listeners(grpc_exec_ctx *exec_ctx,
                                        grpc_tcp_server *s) {
  gpr_mu_lock(&s->mu);
  s->shutdown_listeners = true;
  /* shutdown all fd's */
  if (s->active_ports) {
    grpc_tcp_listener *sp;
    for (sp = s->head; sp; sp = sp->next) {
      grpc_fd_shutdown(exec_ctx, sp->emfd,
                       GRPC_ERROR_CREATE_FROM_STATIC_STRING("Server shutdown"));
    }
  }
  gpr_mu_unlock(&s->mu);
}

#endif