1 /*
2 * Copyright (C) 2020 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
17 #include <errno.h>
18 #include <fcntl.h>
19 #include <stdio.h>
20 #include <string.h>
21 #include <sys/stat.h>
22 #include <qemud.h>
23 #include <qemu_pipe_bp.h>
24 #include <unistd.h>
25
26 #include <arpa/inet.h>
27
qemud_channel_open(const char * name)28 int qemud_channel_open(const char* name) {
29 return qemu_pipe_open_ns("qemud", name, O_RDWR);
30 }
31
qemud_channel_send(int pipe,const void * msg,int size)32 int qemud_channel_send(int pipe, const void* msg, int size) {
33 char header[5];
34
35 if (size < 0)
36 size = strlen((const char*)msg);
37
38 if (size == 0)
39 return 0;
40
41 if(size >= 64 * 1024) { // use binary encoding
42 uint32_t length32be = htonl(size | (1U << 31));
43 memcpy(header, &length32be, 4);
44 } else { // use hex digit encoding
45 snprintf(header, sizeof(header), "%04x", size);
46 }
47
48 if (qemu_pipe_write_fully(pipe, header, 4)) {
49 return -1;
50 }
51
52 if (qemu_pipe_write_fully(pipe, msg, size)) {
53 return -1;
54 }
55
56 return 0;
57 }
58
qemud_channel_recv(int pipe,void * msg,int maxsize)59 int qemud_channel_recv(int pipe, void* msg, int maxsize) {
60 char header[5];
61 int size;
62
63 if (qemu_pipe_read_fully(pipe, header, 4)) {
64 return -1;
65 }
66 header[4] = 0;
67
68 if (sscanf(header, "%04x", &size) != 1) {
69 return -1;
70 }
71 if (size > maxsize) {
72 return -1;
73 }
74
75 if (qemu_pipe_read_fully(pipe, msg, size)) {
76 return -1;
77 }
78
79 return size;
80 }
81