1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
|
/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
* Copyright (C) 2019, Google Inc.
*
* v4l2_compat_manager.cpp - V4L2 compatibility manager
*/
#include "v4l2_compat_manager.h"
#include <dlfcn.h>
#include <fcntl.h>
#include <map>
#include <stdarg.h>
#include <string.h>
#include <sys/eventfd.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/sysmacros.h>
#include <sys/types.h>
#include <unistd.h>
#include <libcamera/base/log.h>
#include <libcamera/base/utils.h>
#include <libcamera/camera.h>
#include <libcamera/camera_manager.h>
#include "v4l2_camera_file.h"
using namespace libcamera;
LOG_DEFINE_CATEGORY(V4L2Compat)
namespace {
template<typename T>
void get_symbol(T &func, const char *name)
{
func = reinterpret_cast<T>(dlsym(RTLD_NEXT, name));
}
} /* namespace */
V4L2CompatManager::V4L2CompatManager()
: cm_(nullptr)
{
get_symbol(fops_.openat, "openat64");
get_symbol(fops_.dup, "dup");
get_symbol(fops_.close, "close");
get_symbol(fops_.ioctl, "ioctl");
get_symbol(fops_.mmap, "mmap64");
get_symbol(fops_.munmap, "munmap");
}
V4L2CompatManager::~V4L2CompatManager()
{
files_.clear();
mmaps_.clear();
if (cm_) {
proxies_.clear();
cm_->stop();
delete cm_;
cm_ = nullptr;
}
}
int V4L2CompatManager::start()
{
cm_ = new CameraManager();
int ret = cm_->start();
if (ret) {
LOG(V4L2Compat, Error) << "Failed to start camera manager: "
<< strerror(-ret);
delete cm_;
cm_ = nullptr;
return ret;
}
LOG(V4L2Compat, Debug) << "Started camera manager";
/*
* For each Camera registered in the system, a V4L2CameraProxy gets
* created here to wrap a camera device.
*/
auto cameras = cm_->cameras();
for (auto [index, camera] : utils::enumerate(cameras)) {
V4L2CameraProxy *proxy = new V4L2CameraProxy(index, camera);
proxies_.emplace_back(proxy);
}
return 0;
}
V4L2CompatManager *V4L2CompatManager::instance()
{
static V4L2CompatManager instance;
return &instance;
}
std::shared_ptr<V4L2CameraFile> V4L2CompatManager::cameraFile(int fd)
{
auto file = files_.find(fd);
if (file == files_.end())
return nullptr;
return file->second;
}
int V4L2CompatManager::getCameraIndex(int fd)
{
struct stat statbuf;
int ret = fstat(fd, &statbuf);
if (ret < 0)
return -1;
std::shared_ptr<Camera> target = cm_->get(statbuf.st_rdev);
if (!target)
return -1;
auto cameras = cm_->cameras();
for (auto [index, camera] : utils::enumerate(cameras)) {
if (camera == target)
return index;
}
return -1;
}
int V4L2CompatManager::openat(int dirfd, const char *path, int oflag, mode_t mode)
{
int fd = fops_.openat(dirfd, path, oflag, mode);
if (fd < 0)
return fd;
struct stat statbuf;
int ret = fstat(fd, &statbuf);
if (ret < 0 || (statbuf.st_mode & S_IFMT) != S_IFCHR ||
major(statbuf.st_rdev) != 81)
return fd;
if (!cm_)
start();
ret = getCameraIndex(fd);
if (ret < 0) {
LOG(V4L2Compat, Debug) << "No camera found for " << path;
return fd;
}
fops_.close(fd);
int efd = eventfd(0, EFD_SEMAPHORE |
((oflag & O_CLOEXEC) ? EFD_CLOEXEC : 0) |
((oflag & O_NONBLOCK) ? EFD_NONBLOCK : 0));
if (efd < 0)
return efd;
V4L2CameraProxy *proxy = proxies_[ret].get();
files_.emplace(efd, std::make_shared<V4L2CameraFile>(efd, oflag & O_NONBLOCK, proxy));
return efd;
}
int V4L2CompatManager::dup(int oldfd)
{
int newfd = fops_.dup(oldfd);
if (newfd < 0)
return newfd;
auto file = files_.find(oldfd);
if (file != files_.end())
files_[newfd] = file->second;
return newfd;
}
int V4L2CompatManager::close(int fd)
{
auto file = files_.find(fd);
if (file != files_.end())
files_.erase(file);
/* We still need to close the eventfd. */
return fops_.close(fd);
}
void *V4L2CompatManager::mmap(void *addr, size_t length, int prot, int flags,
int fd, off64_t offset)
{
std::shared_ptr<V4L2CameraFile> file = cameraFile(fd);
if (!file)
return fops_.mmap(addr, length, prot, flags, fd, offset);
void *map = file->proxy()->mmap(addr, length, prot, flags, offset);
if (map == MAP_FAILED)
return map;
/*
* Map to V4L2CameraProxy directly to prevent adding more references
* to V4L2CameraFile.
*/
mmaps_[map] = file->proxy();
return map;
}
int V4L2CompatManager::munmap(void *addr, size_t length)
{
auto device = mmaps_.find(addr);
if (device == mmaps_.end())
return fops_.munmap(addr, length);
V4L2CameraProxy *proxy = device->second;
int ret = proxy->munmap(addr, length);
if (ret < 0)
return ret;
mmaps_.erase(device);
return 0;
}
int V4L2CompatManager::ioctl(int fd, unsigned long request, void *arg)
{
std::shared_ptr<V4L2CameraFile> file = cameraFile(fd);
if (!file)
return fops_.ioctl(fd, request, arg);
return file->proxy()->ioctl(file.get(), request, arg);
}
|
