1 
2 // Copyright (C) 2021 The Android Open Source Project
3 //
4 // Licensed under the Apache License, Version 2.0 (the "License");
5 // you may not use this file except in compliance with the License.
6 // You may obtain a copy of the License at
7 //
8 // http://www.apache.org/licenses/LICENSE-2.0
9 //
10 // Unless required by applicable law or agreed to in writing, software
11 // distributed under the License is distributed on an "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 // See the License for the specific language governing permissions and
14 // limitations under the License.
15 #include "net/posix/posix_async_socket_server.h"
16 
17 #include <errno.h>       // for errno
18 #include <netinet/in.h>  // for sockaddr_in, INADDR_ANY
19 #include <string.h>      // for strerror, NULL
20 #include <sys/socket.h>  // for accept, bind, getsockname
21 #include <unistd.h>      // for close
22 
23 #include <functional>   // for __base, function
24 #include <type_traits>  // for remove_extent_t
25 
26 #include "log.h"
27 #include "net/posix/posix_async_socket.h"  // for PosixAsyncSocket, AsyncMan...
28 
29 namespace android {
30 namespace net {
31 class AsyncDataChannel;
32 
PosixAsyncSocketServer(int port,AsyncManager * am)33 PosixAsyncSocketServer::PosixAsyncSocketServer(int port, AsyncManager* am)
34     : port_(port), am_(am) {
35   int listen_fd = 0;
36   struct sockaddr_in listen_address {};
37   socklen_t sockaddr_in_size = sizeof(struct sockaddr_in);
38 
39   do {
40     listen_fd = socket(AF_INET, SOCK_STREAM, 0);
41   } while (listen_fd == -1 && errno == EAGAIN);
42 
43   if (listen_fd < 0) {
44     INFO("Error creating socket for test channel.");
45     return;
46   }
47 
48   int enable = 1;
49   if (setsockopt(listen_fd, SOL_SOCKET, SO_REUSEADDR, &enable, sizeof(int)) <
50       0) {
51     ERROR("setsockopt(SO_REUSEADDR) failed: {}", strerror(errno));
52   }
53 
54   listen_address.sin_family = AF_INET;
55   listen_address.sin_port = htons(port_);
56   listen_address.sin_addr.s_addr = htonl(INADDR_ANY);
57 
58   if (bind(listen_fd, reinterpret_cast<sockaddr*>(&listen_address),
59            sockaddr_in_size) < 0) {
60     INFO("Error binding test channel listener socket to port: {}, {}", port,
61          strerror(errno));
62     close(listen_fd);
63     return;
64   }
65 
66   if (listen(listen_fd, 1) < 0) {
67     INFO("Error listening for test channel: {}", strerror(errno));
68     close(listen_fd);
69     return;
70   }
71 
72   struct sockaddr_in sin;
73   socklen_t slen = sizeof(sin);
74   if (getsockname(listen_fd, (struct sockaddr*)&sin, &slen) == -1) {
75     INFO("Error retrieving actual port: {}", strerror(errno));
76   } else {
77     port_ = ntohs(sin.sin_port);
78   }
79   INFO("Listening on: {} ({})", port_, listen_fd);
80   server_socket_ = std::make_shared<PosixAsyncSocket>(listen_fd, am_);
81 }
82 
StartListening()83 bool PosixAsyncSocketServer::StartListening() {
84   if (!server_socket_ || !callback_) {
85     return false;
86   }
87 
88   server_socket_->WatchForNonBlockingRead(
89       [this](AsyncDataChannel* /* socket */) { AcceptSocket(); });
90   return true;
91 }
92 
Close()93 void PosixAsyncSocketServer::Close() {
94   if (server_socket_) {
95     server_socket_->Close();
96   }
97 }
98 
Connected()99 bool PosixAsyncSocketServer::Connected() {
100   return server_socket_ && server_socket_->Connected();
101 }
102 
AcceptSocket()103 void PosixAsyncSocketServer::AcceptSocket() {
104   int accept_fd = 0;
105   REPEAT_UNTIL_NO_INTR(accept_fd = accept(server_socket_->fd(), NULL, NULL));
106 
107   if (accept_fd < 0) {
108     INFO("Error accepting test channel connection errno={} ({}).", errno,
109          strerror(errno));
110     return;
111   }
112 
113   INFO("accept_fd = {}.", accept_fd);
114   StopListening();
115   callback_(std::make_shared<PosixAsyncSocket>(accept_fd, am_), this);
116 }
117 
StopListening()118 void PosixAsyncSocketServer::StopListening() { server_socket_->StopWatching(); }
119 }  // namespace net
120 }  // namespace android
121