1 /*
2 * Copyright (C) 2022 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 */
16 #include "io_vsock.h"
17
18 #include <android-base/file.h>
19 #include <android-base/logging.h>
20 #include <android-base/result.h>
21 #include <android-base/unique_fd.h>
22 #include <linux/vm_sockets.h>
23 #include <sys/socket.h>
24
25 using namespace android::base;
26
27 namespace io_vsock {
init_vsock_server(unsigned int port)28 Result<int> init_vsock_server(unsigned int port) {
29 int server_fd(TEMP_FAILURE_RETRY(socket(AF_VSOCK, SOCK_STREAM | SOCK_CLOEXEC, 0)));
30 if (server_fd < 0) {
31 return Error() << "VM:cannot create socket";
32 }
33 struct sockaddr_vm server_sa = (struct sockaddr_vm){
34 .svm_family = AF_VSOCK,
35 .svm_port = port,
36 .svm_cid = VMADDR_CID_ANY,
37 };
38 LOG(INFO) << "VM:Connecting on port " << port << "...";
39 int ret = TEMP_FAILURE_RETRY(bind(server_fd, (struct sockaddr *)&server_sa, sizeof(server_sa)));
40 if (ret < 0) {
41 return Error() << "VM:cannot bind an address with the socket";
42 }
43 ret = TEMP_FAILURE_RETRY(listen(server_fd, /*backlog=*/1));
44 if (ret < 0) {
45 return Error() << "VM:cannot listen to port";
46 }
47 LOG(INFO) << "Server now listening";
48 return server_fd;
49 }
50
run_vsock_server_and_receive_data(int server_fd,int num_bytes_to_receive)51 Result<void> run_vsock_server_and_receive_data(int server_fd, int num_bytes_to_receive) {
52 LOG(INFO) << "Accepting connection...";
53 struct sockaddr_vm client_sa;
54 socklen_t client_sa_len = sizeof(client_sa);
55 unique_fd client_fd(TEMP_FAILURE_RETRY(
56 accept4(server_fd, (struct sockaddr *)&client_sa, &client_sa_len, SOCK_CLOEXEC)));
57 if (client_fd < 0) {
58 return Error() << "Cannot retrieve connect requests";
59 }
60 LOG(INFO) << "VM:Connection from CID " << client_sa.svm_cid << " on port "
61 << client_sa.svm_port;
62
63 ssize_t total = 0;
64 char buf[4096];
65 for (;;) {
66 ssize_t n = TEMP_FAILURE_RETRY(read(client_fd.get(), buf, sizeof(buf)));
67 if (n < 0) {
68 return Error() << "Cannot get data from the host.";
69 }
70 if (n == 0) {
71 break;
72 }
73 total += n;
74 }
75
76 if (total != num_bytes_to_receive) {
77 return Error() << "Received data length(" << total << ") is not equal to "
78 << num_bytes_to_receive;
79 }
80 LOG(INFO) << "VM:Finished reading data.";
81 return {};
82 }
83 } // namespace io_vsock
84