1 /*
2 * Copyright (C) 2011 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 #ifndef ANDROID_INCLUDE_HARDWARE_QEMU_PIPE_H
17 #define ANDROID_INCLUDE_HARDWARE_QEMU_PIPE_H
18
19 #include <sys/cdefs.h>
20 #include <unistd.h>
21 #include <fcntl.h>
22 #include <sys/mman.h>
23 #include <pthread.h> /* for pthread_once() */
24 #include <stdlib.h>
25 #include <stdio.h>
26 #include <string.h>
27 #include <errno.h>
28
29 #ifndef D
30 # define D(...) do{}while(0)
31 #endif
32
ReadFully(int fd,void * data,size_t byte_count)33 static bool ReadFully(int fd, void* data, size_t byte_count) {
34 uint8_t* p = (uint8_t*)(data);
35 size_t remaining = byte_count;
36 while (remaining > 0) {
37 ssize_t n = TEMP_FAILURE_RETRY(read(fd, p, remaining));
38 if (n <= 0) return false;
39 p += n;
40 remaining -= n;
41 }
42 return true;
43 }
44
WriteFully(int fd,const void * data,size_t byte_count)45 static bool WriteFully(int fd, const void* data, size_t byte_count) {
46 const uint8_t* p = (const uint8_t*)(data);
47 size_t remaining = byte_count;
48 while (remaining > 0) {
49 ssize_t n = TEMP_FAILURE_RETRY(write(fd, p, remaining));
50 if (n == -1) return false;
51 p += n;
52 remaining -= n;
53 }
54 return true;
55 }
56
57 /* Try to open a new Qemu fast-pipe. This function returns a file descriptor
58 * that can be used to communicate with a named service managed by the
59 * emulator.
60 *
61 * This file descriptor can be used as a standard pipe/socket descriptor.
62 *
63 * 'pipeName' is the name of the emulator service you want to connect to.
64 * E.g. 'opengles' or 'camera'.
65 *
66 * On success, return a valid file descriptor
67 * Returns -1 on error, and errno gives the error code, e.g.:
68 *
69 * EINVAL -> unknown/unsupported pipeName
70 * ENOSYS -> fast pipes not available in this system.
71 *
72 * ENOSYS should never happen, except if you're trying to run within a
73 * misconfigured emulator.
74 *
75 * You should be able to open several pipes to the same pipe service,
76 * except for a few special cases (e.g. GSM modem), where EBUSY will be
77 * returned if more than one client tries to connect to it.
78 */
79 static __inline__ int
qemu_pipe_open(const char * pipeName)80 qemu_pipe_open(const char* pipeName)
81 {
82 char buff[256];
83 int buffLen;
84 int fd, ret;
85
86 if (pipeName == NULL || pipeName[0] == '\0') {
87 errno = EINVAL;
88 return -1;
89 }
90
91 snprintf(buff, sizeof buff, "pipe:%s", pipeName);
92
93 fd = TEMP_FAILURE_RETRY(open("/dev/qemu_pipe", O_RDWR));
94 if (fd < 0 && errno == ENOENT)
95 fd = TEMP_FAILURE_RETRY(open("/dev/goldfish_pipe", O_RDWR));
96 if (fd < 0) {
97 D("%s: Could not open /dev/qemu_pipe: %s", __FUNCTION__, strerror(errno));
98 //errno = ENOSYS;
99 return -1;
100 }
101
102 buffLen = strlen(buff);
103
104 if (!WriteFully(fd, buff, buffLen + 1)) {
105 D("%s: Could not connect to %s pipe service: %s", __FUNCTION__, pipeName, strerror(errno));
106 return -1;
107 }
108
109 return fd;
110 }
111
112 #endif /* ANDROID_INCLUDE_HARDWARE_QEMUD_PIPE_H */
113