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 #ifndef GRPC_SRC_CORE_LIB_IOMGR_SOCKET_MUTATOR_H
20 #define GRPC_SRC_CORE_LIB_IOMGR_SOCKET_MUTATOR_H
21 
22 #include <grpc/support/port_platform.h>
23 
24 #include <stdbool.h>
25 
26 #include <grpc/impl/grpc_types.h>
27 #include <grpc/support/sync.h>
28 
29 /// How is an fd to be used?
30 typedef enum {
31   /// Used for client connection
32   GRPC_FD_CLIENT_CONNECTION_USAGE,
33   /// Used for server listening
34   GRPC_FD_SERVER_LISTENER_USAGE,
35   /// Used for server connection
36   GRPC_FD_SERVER_CONNECTION_USAGE,
37 } grpc_fd_usage;
38 
39 /// Information about an fd to mutate
40 typedef struct {
41   /// File descriptor to mutate
42   int fd;
43   /// How the fd will be used
44   grpc_fd_usage usage;
45 } grpc_mutate_socket_info;
46 
47 /// The virtual table of grpc_socket_mutator
48 struct grpc_socket_mutator_vtable {
49   /// Mutates the socket options of \a fd -- deprecated, prefer mutate_fd_2
50   bool (*mutate_fd)(int fd, grpc_socket_mutator* mutator);
51   /// Compare socket mutator \a a and \a b
52   int (*compare)(grpc_socket_mutator* a, grpc_socket_mutator* b);
53   /// Destroys the socket mutator instance
54   void (*destroy)(grpc_socket_mutator* mutator);
55   /// Mutates the socket options of the fd in \a info - if set takes preference
56   /// to mutate_fd
57   bool (*mutate_fd_2)(const grpc_mutate_socket_info* info,
58                       grpc_socket_mutator* mutator);
59 };
60 
61 /// The Socket Mutator interface allows changes on socket options
62 struct grpc_socket_mutator {
63   const grpc_socket_mutator_vtable* vtable;
64   gpr_refcount refcount;
65 };
66 
67 /// called by concrete implementations to initialize the base struct
68 void grpc_socket_mutator_init(grpc_socket_mutator* mutator,
69                               const grpc_socket_mutator_vtable* vtable);
70 
71 /// Wrap \a mutator as a grpc_arg
72 grpc_arg grpc_socket_mutator_to_arg(grpc_socket_mutator* mutator);
73 
74 /// Perform the file descriptor mutation operation of \a mutator on \a fd
75 bool grpc_socket_mutator_mutate_fd(grpc_socket_mutator* mutator, int fd,
76                                    grpc_fd_usage usage);
77 
78 /// Compare if \a a and \a b are the same mutator or have same settings
79 int grpc_socket_mutator_compare(grpc_socket_mutator* a, grpc_socket_mutator* b);
80 
81 grpc_socket_mutator* grpc_socket_mutator_ref(grpc_socket_mutator* mutator);
82 void grpc_socket_mutator_unref(grpc_socket_mutator* mutator);
83 
84 #endif  // GRPC_SRC_CORE_LIB_IOMGR_SOCKET_MUTATOR_H
85