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 <errno.h>
27
28#ifndef D
29#  define  D(...)   do{}while(0)
30#endif
31
32/* Try to open a new Qemu fast-pipe. This function returns a file descriptor
33 * that can be used to communicate with a named service managed by the
34 * emulator.
35 *
36 * This file descriptor can be used as a standard pipe/socket descriptor.
37 *
38 * 'pipeName' is the name of the emulator service you want to connect to.
39 * E.g. 'opengles' or 'camera'.
40 *
41 * On success, return a valid file descriptor
42 * Returns -1 on error, and errno gives the error code, e.g.:
43 *
44 *    EINVAL  -> unknown/unsupported pipeName
45 *    ENOSYS  -> fast pipes not available in this system.
46 *
47 * ENOSYS should never happen, except if you're trying to run within a
48 * misconfigured emulator.
49 *
50 * You should be able to open several pipes to the same pipe service,
51 * except for a few special cases (e.g. GSM modem), where EBUSY will be
52 * returned if more than one client tries to connect to it.
53 */
54static __inline__ int
55qemu_pipe_open(const char*  pipeName)
56{
57    char  buff[256];
58    int   buffLen;
59    int   fd, ret;
60
61    if (pipeName == NULL || pipeName[0] == '\0') {
62        errno = EINVAL;
63        return -1;
64    }
65
66    snprintf(buff, sizeof buff, "pipe:%s", pipeName);
67
68    fd = open("/dev/qemu_pipe", O_RDWR);
69    if (fd < 0) {
70        D("%s: Could not open /dev/qemu_pipe: %s", __FUNCTION__, strerror(errno));
71        //errno = ENOSYS;
72        return -1;
73    }
74
75    buffLen = strlen(buff);
76
77    ret = TEMP_FAILURE_RETRY(write(fd, buff, buffLen+1));
78    if (ret != buffLen+1) {
79        D("%s: Could not connect to %s pipe service: %s", __FUNCTION__, pipeName, strerror(errno));
80        if (ret == 0) {
81            errno = ECONNRESET;
82        } else if (ret > 0) {
83            errno = EINVAL;
84        }
85        return -1;
86    }
87
88    return fd;
89}
90
91#endif /* ANDROID_INCLUDE_HARDWARE_QEMUD_PIPE_H */
92