1 /*
2  *
3  * Copyright 2018 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 <grpc/support/port_platform.h>
20 
21 #include "src/core/lib/iomgr/port.h"
22 
23 #include <limits.h>
24 #include <string.h>
25 
26 #include <grpc/slice_buffer.h>
27 
28 #include <grpc/support/alloc.h>
29 #include <grpc/support/log.h>
30 #include <grpc/support/string_util.h>
31 
32 #include "src/core/lib/iomgr/error.h"
33 #include "src/core/lib/iomgr/iomgr_custom.h"
34 #include "src/core/lib/iomgr/network_status_tracker.h"
35 #include "src/core/lib/iomgr/resource_quota.h"
36 #include "src/core/lib/iomgr/tcp_client.h"
37 #include "src/core/lib/iomgr/tcp_custom.h"
38 #include "src/core/lib/iomgr/tcp_server.h"
39 #include "src/core/lib/slice/slice_internal.h"
40 #include "src/core/lib/slice/slice_string_helpers.h"
41 
42 #define GRPC_TCP_DEFAULT_READ_SLICE_SIZE 8192
43 
44 extern grpc_core::TraceFlag grpc_tcp_trace;
45 
46 grpc_socket_vtable* grpc_custom_socket_vtable = nullptr;
47 extern grpc_tcp_server_vtable custom_tcp_server_vtable;
48 extern grpc_tcp_client_vtable custom_tcp_client_vtable;
49 
grpc_custom_endpoint_init(grpc_socket_vtable * impl)50 void grpc_custom_endpoint_init(grpc_socket_vtable* impl) {
51   grpc_custom_socket_vtable = impl;
52   grpc_set_tcp_client_impl(&custom_tcp_client_vtable);
53   grpc_set_tcp_server_impl(&custom_tcp_server_vtable);
54 }
55 
56 typedef struct {
57   grpc_endpoint base;
58   gpr_refcount refcount;
59   grpc_custom_socket* socket;
60 
61   grpc_closure* read_cb;
62   grpc_closure* write_cb;
63 
64   grpc_slice_buffer* read_slices;
65   grpc_slice_buffer* write_slices;
66 
67   grpc_resource_user* resource_user;
68   grpc_resource_user_slice_allocator slice_allocator;
69 
70   bool shutting_down;
71 
72   char* peer_string;
73 } custom_tcp_endpoint;
74 
tcp_free(grpc_custom_socket * s)75 static void tcp_free(grpc_custom_socket* s) {
76   custom_tcp_endpoint* tcp = (custom_tcp_endpoint*)s->endpoint;
77   grpc_resource_user_unref(tcp->resource_user);
78   gpr_free(tcp->peer_string);
79   gpr_free(tcp);
80   s->refs--;
81   if (s->refs == 0) {
82     grpc_custom_socket_vtable->destroy(s);
83     gpr_free(s);
84   }
85 }
86 
87 #ifndef NDEBUG
88 #define TCP_UNREF(tcp, reason) tcp_unref((tcp), (reason), __FILE__, __LINE__)
89 #define TCP_REF(tcp, reason) tcp_ref((tcp), (reason), __FILE__, __LINE__)
tcp_unref(custom_tcp_endpoint * tcp,const char * reason,const char * file,int line)90 static void tcp_unref(custom_tcp_endpoint* tcp, const char* reason,
91                       const char* file, int line) {
92   if (grpc_tcp_trace.enabled()) {
93     gpr_atm val = gpr_atm_no_barrier_load(&tcp->refcount.count);
94     gpr_log(file, line, GPR_LOG_SEVERITY_ERROR,
95             "TCP unref %p : %s %" PRIdPTR " -> %" PRIdPTR, tcp->socket, reason,
96             val, val - 1);
97   }
98   if (gpr_unref(&tcp->refcount)) {
99     tcp_free(tcp->socket);
100   }
101 }
102 
tcp_ref(custom_tcp_endpoint * tcp,const char * reason,const char * file,int line)103 static void tcp_ref(custom_tcp_endpoint* tcp, const char* reason,
104                     const char* file, int line) {
105   if (grpc_tcp_trace.enabled()) {
106     gpr_atm val = gpr_atm_no_barrier_load(&tcp->refcount.count);
107     gpr_log(file, line, GPR_LOG_SEVERITY_ERROR,
108             "TCP   ref %p : %s %" PRIdPTR " -> %" PRIdPTR, tcp->socket, reason,
109             val, val + 1);
110   }
111   gpr_ref(&tcp->refcount);
112 }
113 #else
114 #define TCP_UNREF(tcp, reason) tcp_unref((tcp))
115 #define TCP_REF(tcp, reason) tcp_ref((tcp))
tcp_unref(custom_tcp_endpoint * tcp)116 static void tcp_unref(custom_tcp_endpoint* tcp) {
117   if (gpr_unref(&tcp->refcount)) {
118     tcp_free(tcp->socket);
119   }
120 }
121 
tcp_ref(custom_tcp_endpoint * tcp)122 static void tcp_ref(custom_tcp_endpoint* tcp) { gpr_ref(&tcp->refcount); }
123 #endif
124 
call_read_cb(custom_tcp_endpoint * tcp,grpc_error * error)125 static void call_read_cb(custom_tcp_endpoint* tcp, grpc_error* error) {
126   grpc_closure* cb = tcp->read_cb;
127   if (grpc_tcp_trace.enabled()) {
128     gpr_log(GPR_INFO, "TCP:%p call_cb %p %p:%p", tcp->socket, cb, cb->cb,
129             cb->cb_arg);
130     size_t i;
131     const char* str = grpc_error_string(error);
132     gpr_log(GPR_INFO, "read: error=%s", str);
133 
134     for (i = 0; i < tcp->read_slices->count; i++) {
135       char* dump = grpc_dump_slice(tcp->read_slices->slices[i],
136                                    GPR_DUMP_HEX | GPR_DUMP_ASCII);
137       gpr_log(GPR_INFO, "READ %p (peer=%s): %s", tcp, tcp->peer_string, dump);
138       gpr_free(dump);
139     }
140   }
141   TCP_UNREF(tcp, "read");
142   tcp->read_slices = nullptr;
143   tcp->read_cb = nullptr;
144   GRPC_CLOSURE_SCHED(cb, error);
145 }
146 
custom_read_callback(grpc_custom_socket * socket,size_t nread,grpc_error * error)147 static void custom_read_callback(grpc_custom_socket* socket, size_t nread,
148                                  grpc_error* error) {
149   grpc_core::ExecCtx exec_ctx;
150   grpc_slice_buffer garbage;
151   custom_tcp_endpoint* tcp = (custom_tcp_endpoint*)socket->endpoint;
152   if (error == GRPC_ERROR_NONE && nread == 0) {
153     error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("EOF");
154   }
155   if (error == GRPC_ERROR_NONE) {
156     // Successful read
157     if ((size_t)nread < tcp->read_slices->length) {
158       /* TODO(murgatroid99): Instead of discarding the unused part of the read
159        * buffer, reuse it as the next read buffer. */
160       grpc_slice_buffer_init(&garbage);
161       grpc_slice_buffer_trim_end(
162           tcp->read_slices, tcp->read_slices->length - (size_t)nread, &garbage);
163       grpc_slice_buffer_reset_and_unref_internal(&garbage);
164     }
165   } else {
166     grpc_slice_buffer_reset_and_unref_internal(tcp->read_slices);
167   }
168   call_read_cb(tcp, error);
169 }
170 
tcp_read_allocation_done(void * tcpp,grpc_error * error)171 static void tcp_read_allocation_done(void* tcpp, grpc_error* error) {
172   custom_tcp_endpoint* tcp = (custom_tcp_endpoint*)tcpp;
173   if (grpc_tcp_trace.enabled()) {
174     gpr_log(GPR_INFO, "TCP:%p read_allocation_done: %s", tcp->socket,
175             grpc_error_string(error));
176   }
177   if (error == GRPC_ERROR_NONE) {
178     /* Before calling read, we allocate a buffer with exactly one slice
179      * to tcp->read_slices and wait for the callback indicating that the
180      * allocation was successful. So slices[0] should always exist here */
181     char* buffer = (char*)GRPC_SLICE_START_PTR(tcp->read_slices->slices[0]);
182     size_t len = GRPC_SLICE_LENGTH(tcp->read_slices->slices[0]);
183     grpc_custom_socket_vtable->read(tcp->socket, buffer, len,
184                                     custom_read_callback);
185   } else {
186     grpc_slice_buffer_reset_and_unref_internal(tcp->read_slices);
187     call_read_cb(tcp, GRPC_ERROR_REF(error));
188   }
189   if (grpc_tcp_trace.enabled()) {
190     const char* str = grpc_error_string(error);
191     gpr_log(GPR_INFO, "Initiating read on %p: error=%s", tcp->socket, str);
192   }
193 }
194 
endpoint_read(grpc_endpoint * ep,grpc_slice_buffer * read_slices,grpc_closure * cb)195 static void endpoint_read(grpc_endpoint* ep, grpc_slice_buffer* read_slices,
196                           grpc_closure* cb) {
197   custom_tcp_endpoint* tcp = (custom_tcp_endpoint*)ep;
198   GRPC_CUSTOM_IOMGR_ASSERT_SAME_THREAD();
199   GPR_ASSERT(tcp->read_cb == nullptr);
200   tcp->read_cb = cb;
201   tcp->read_slices = read_slices;
202   grpc_slice_buffer_reset_and_unref_internal(read_slices);
203   TCP_REF(tcp, "read");
204   grpc_resource_user_alloc_slices(&tcp->slice_allocator,
205                                   GRPC_TCP_DEFAULT_READ_SLICE_SIZE, 1,
206                                   tcp->read_slices);
207 }
208 
custom_write_callback(grpc_custom_socket * socket,grpc_error * error)209 static void custom_write_callback(grpc_custom_socket* socket,
210                                   grpc_error* error) {
211   grpc_core::ExecCtx exec_ctx;
212   custom_tcp_endpoint* tcp = (custom_tcp_endpoint*)socket->endpoint;
213   grpc_closure* cb = tcp->write_cb;
214   tcp->write_cb = nullptr;
215   if (grpc_tcp_trace.enabled()) {
216     const char* str = grpc_error_string(error);
217     gpr_log(GPR_INFO, "write complete on %p: error=%s", tcp->socket, str);
218   }
219   TCP_UNREF(tcp, "write");
220   GRPC_CLOSURE_SCHED(cb, error);
221 }
222 
endpoint_write(grpc_endpoint * ep,grpc_slice_buffer * write_slices,grpc_closure * cb,void * arg)223 static void endpoint_write(grpc_endpoint* ep, grpc_slice_buffer* write_slices,
224                            grpc_closure* cb, void* arg) {
225   custom_tcp_endpoint* tcp = (custom_tcp_endpoint*)ep;
226   GRPC_CUSTOM_IOMGR_ASSERT_SAME_THREAD();
227 
228   if (grpc_tcp_trace.enabled()) {
229     size_t j;
230 
231     for (j = 0; j < write_slices->count; j++) {
232       char* data = grpc_dump_slice(write_slices->slices[j],
233                                    GPR_DUMP_HEX | GPR_DUMP_ASCII);
234       gpr_log(GPR_INFO, "WRITE %p (peer=%s): %s", tcp->socket, tcp->peer_string,
235               data);
236       gpr_free(data);
237     }
238   }
239 
240   if (tcp->shutting_down) {
241     GRPC_CLOSURE_SCHED(cb, GRPC_ERROR_CREATE_FROM_STATIC_STRING(
242                                "TCP socket is shutting down"));
243     return;
244   }
245 
246   GPR_ASSERT(tcp->write_cb == nullptr);
247   tcp->write_slices = write_slices;
248   GPR_ASSERT(tcp->write_slices->count <= UINT_MAX);
249   if (tcp->write_slices->count == 0) {
250     // No slices means we don't have to do anything,
251     // and libuv doesn't like empty writes
252     GRPC_CLOSURE_SCHED(cb, GRPC_ERROR_NONE);
253     return;
254   }
255   tcp->write_cb = cb;
256   TCP_REF(tcp, "write");
257   grpc_custom_socket_vtable->write(tcp->socket, tcp->write_slices,
258                                    custom_write_callback);
259 }
260 
endpoint_add_to_pollset(grpc_endpoint * ep,grpc_pollset * pollset)261 static void endpoint_add_to_pollset(grpc_endpoint* ep, grpc_pollset* pollset) {
262   // No-op. We're ignoring pollsets currently
263   (void)ep;
264   (void)pollset;
265 }
266 
endpoint_add_to_pollset_set(grpc_endpoint * ep,grpc_pollset_set * pollset)267 static void endpoint_add_to_pollset_set(grpc_endpoint* ep,
268                                         grpc_pollset_set* pollset) {
269   // No-op. We're ignoring pollsets currently
270   (void)ep;
271   (void)pollset;
272 }
273 
endpoint_delete_from_pollset_set(grpc_endpoint * ep,grpc_pollset_set * pollset)274 static void endpoint_delete_from_pollset_set(grpc_endpoint* ep,
275                                              grpc_pollset_set* pollset) {
276   // No-op. We're ignoring pollsets currently
277   (void)ep;
278   (void)pollset;
279 }
280 
endpoint_shutdown(grpc_endpoint * ep,grpc_error * why)281 static void endpoint_shutdown(grpc_endpoint* ep, grpc_error* why) {
282   custom_tcp_endpoint* tcp = (custom_tcp_endpoint*)ep;
283   if (!tcp->shutting_down) {
284     if (grpc_tcp_trace.enabled()) {
285       const char* str = grpc_error_string(why);
286       gpr_log(GPR_INFO, "TCP %p shutdown why=%s", tcp->socket, str);
287     }
288     tcp->shutting_down = true;
289     // GRPC_CLOSURE_SCHED(tcp->read_cb, GRPC_ERROR_REF(why));
290     // GRPC_CLOSURE_SCHED(tcp->write_cb, GRPC_ERROR_REF(why));
291     // tcp->read_cb = nullptr;
292     // tcp->write_cb = nullptr;
293     grpc_resource_user_shutdown(tcp->resource_user);
294     grpc_custom_socket_vtable->shutdown(tcp->socket);
295   }
296   GRPC_ERROR_UNREF(why);
297 }
298 
custom_close_callback(grpc_custom_socket * socket)299 static void custom_close_callback(grpc_custom_socket* socket) {
300   socket->refs--;
301   if (socket->refs == 0) {
302     grpc_custom_socket_vtable->destroy(socket);
303     gpr_free(socket);
304   } else if (socket->endpoint) {
305     grpc_core::ExecCtx exec_ctx;
306     custom_tcp_endpoint* tcp = (custom_tcp_endpoint*)socket->endpoint;
307     TCP_UNREF(tcp, "destroy");
308   }
309 }
310 
endpoint_destroy(grpc_endpoint * ep)311 static void endpoint_destroy(grpc_endpoint* ep) {
312   grpc_network_status_unregister_endpoint(ep);
313   custom_tcp_endpoint* tcp = (custom_tcp_endpoint*)ep;
314   grpc_custom_socket_vtable->close(tcp->socket, custom_close_callback);
315 }
316 
endpoint_get_peer(grpc_endpoint * ep)317 static char* endpoint_get_peer(grpc_endpoint* ep) {
318   custom_tcp_endpoint* tcp = (custom_tcp_endpoint*)ep;
319   return gpr_strdup(tcp->peer_string);
320 }
321 
endpoint_get_resource_user(grpc_endpoint * ep)322 static grpc_resource_user* endpoint_get_resource_user(grpc_endpoint* ep) {
323   custom_tcp_endpoint* tcp = (custom_tcp_endpoint*)ep;
324   return tcp->resource_user;
325 }
326 
endpoint_get_fd(grpc_endpoint * ep)327 static int endpoint_get_fd(grpc_endpoint* ep) { return -1; }
328 
329 static grpc_endpoint_vtable vtable = {endpoint_read,
330                                       endpoint_write,
331                                       endpoint_add_to_pollset,
332                                       endpoint_add_to_pollset_set,
333                                       endpoint_delete_from_pollset_set,
334                                       endpoint_shutdown,
335                                       endpoint_destroy,
336                                       endpoint_get_resource_user,
337                                       endpoint_get_peer,
338                                       endpoint_get_fd};
339 
custom_tcp_endpoint_create(grpc_custom_socket * socket,grpc_resource_quota * resource_quota,char * peer_string)340 grpc_endpoint* custom_tcp_endpoint_create(grpc_custom_socket* socket,
341                                           grpc_resource_quota* resource_quota,
342                                           char* peer_string) {
343   custom_tcp_endpoint* tcp =
344       (custom_tcp_endpoint*)gpr_malloc(sizeof(custom_tcp_endpoint));
345   grpc_core::ExecCtx exec_ctx;
346 
347   if (grpc_tcp_trace.enabled()) {
348     gpr_log(GPR_INFO, "Creating TCP endpoint %p", socket);
349   }
350   memset(tcp, 0, sizeof(custom_tcp_endpoint));
351   socket->refs++;
352   socket->endpoint = (grpc_endpoint*)tcp;
353   tcp->socket = socket;
354   tcp->base.vtable = &vtable;
355   gpr_ref_init(&tcp->refcount, 1);
356   tcp->peer_string = gpr_strdup(peer_string);
357   tcp->shutting_down = false;
358   tcp->resource_user = grpc_resource_user_create(resource_quota, peer_string);
359   grpc_resource_user_slice_allocator_init(
360       &tcp->slice_allocator, tcp->resource_user, tcp_read_allocation_done, tcp);
361   /* Tell network status tracking code about the new endpoint */
362   grpc_network_status_register_endpoint(&tcp->base);
363 
364   return &tcp->base;
365 }
366