1 /*
2 * libjingle
3 * Copyright 2012 Google Inc.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice,
9 * this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #include "talk/media/devices/deviceinfo.h"
29
30 #include "talk/media/devices/libudevsymboltable.h"
31 #include "webrtc/base/common.h" // for ASSERT
32
33 namespace cricket {
34
35 class ScopedLibUdev {
36 public:
Create()37 static ScopedLibUdev* Create() {
38 ScopedLibUdev* ret_val = new ScopedLibUdev();
39 if (!ret_val->Init()) {
40 delete ret_val;
41 return NULL;
42 }
43 return ret_val;
44 }
~ScopedLibUdev()45 ~ScopedLibUdev() {
46 libudev_.Unload();
47 }
48
instance()49 LibUDevSymbolTable* instance() { return &libudev_; }
50
51 private:
ScopedLibUdev()52 ScopedLibUdev() {}
53
Init()54 bool Init() {
55 return libudev_.Load() &&
56 !IsWrongLibUDevAbiVersion(libudev_.GetDllHandle());
57 }
58
59 LibUDevSymbolTable libudev_;
60 };
61
62 class ScopedUdev {
63 public:
ScopedUdev(LibUDevSymbolTable * libudev)64 explicit ScopedUdev(LibUDevSymbolTable* libudev) : libudev_(libudev) {
65 udev_ = libudev_->udev_new()();
66 }
~ScopedUdev()67 ~ScopedUdev() {
68 if (udev_) libudev_->udev_unref()(udev_);
69 }
70
instance()71 udev* instance() { return udev_; }
72
73 private:
74 LibUDevSymbolTable* libudev_;
75 udev* udev_;
76 };
77
78 class ScopedUdevEnumerate {
79 public:
ScopedUdevEnumerate(LibUDevSymbolTable * libudev,udev * udev)80 ScopedUdevEnumerate(LibUDevSymbolTable* libudev, udev* udev)
81 : libudev_(libudev) {
82 enumerate_ = libudev_->udev_enumerate_new()(udev);
83 }
~ScopedUdevEnumerate()84 ~ScopedUdevEnumerate() {
85 if (enumerate_) libudev_->udev_enumerate_unref()(enumerate_);
86 }
87
instance()88 udev_enumerate* instance() { return enumerate_; }
89
90 private:
91 LibUDevSymbolTable* libudev_;
92 udev_enumerate* enumerate_;
93 };
94
GetUsbProperty(const Device & device,const char * property_name,std::string * property)95 bool GetUsbProperty(const Device& device, const char* property_name,
96 std::string* property) {
97 rtc::scoped_ptr<ScopedLibUdev> libudev_context(ScopedLibUdev::Create());
98 if (!libudev_context) {
99 return false;
100 }
101 ScopedUdev udev_context(libudev_context->instance());
102 if (!udev_context.instance()) {
103 return false;
104 }
105 ScopedUdevEnumerate enumerate_context(libudev_context->instance(),
106 udev_context.instance());
107 if (!enumerate_context.instance()) {
108 return false;
109 }
110 libudev_context->instance()->udev_enumerate_add_match_subsystem()(
111 enumerate_context.instance(), "video4linux");
112 libudev_context->instance()->udev_enumerate_scan_devices()(
113 enumerate_context.instance());
114 udev_list_entry* devices =
115 libudev_context->instance()->udev_enumerate_get_list_entry()(
116 enumerate_context.instance());
117 if (!devices) {
118 return false;
119 }
120 udev_list_entry* dev_list_entry = NULL;
121 const char* property_value = NULL;
122 // Macro that expands to a for-loop over the devices.
123 for (dev_list_entry = devices; dev_list_entry != NULL;
124 dev_list_entry = libudev_context->instance()->
125 udev_list_entry_get_next()(dev_list_entry)) {
126 const char* path = libudev_context->instance()->udev_list_entry_get_name()(
127 dev_list_entry);
128 if (!path) continue;
129 udev_device* dev =
130 libudev_context->instance()->udev_device_new_from_syspath()(
131 udev_context.instance(), path);
132 if (!dev) continue;
133 const char* device_node =
134 libudev_context->instance()->udev_device_get_devnode()(dev);
135 if (!device_node || device.id.compare(device_node) != 0) {
136 continue;
137 }
138 dev = libudev_context->instance()->
139 udev_device_get_parent_with_subsystem_devtype()(
140 dev, "usb", "usb_device");
141 if (!dev) continue;
142 property_value = libudev_context->instance()->
143 udev_device_get_sysattr_value()(
144 dev, property_name);
145 break;
146 }
147 if (!property_value) {
148 return false;
149 }
150 property->assign(property_value);
151 return true;
152 }
153
GetUsbId(const Device & device,std::string * usb_id)154 bool GetUsbId(const Device& device, std::string* usb_id) {
155 std::string id_vendor;
156 std::string id_product;
157 if (!GetUsbProperty(device, "idVendor", &id_vendor)) {
158 return false;
159 }
160 if (!GetUsbProperty(device, "idProduct", &id_product)) {
161 return false;
162 }
163 usb_id->clear();
164 usb_id->append(id_vendor);
165 usb_id->append(":");
166 usb_id->append(id_product);
167 return true;
168 }
169
GetUsbVersion(const Device & device,std::string * usb_version)170 bool GetUsbVersion(const Device& device, std::string* usb_version) {
171 return GetUsbProperty(device, "version", usb_version);
172 }
173
174 } // namespace cricket
175