1 // Copyright 2018 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #include "components/storage_monitor/storage_info_utils.h"
9 #include "base/files/file_path.h"
10 #include "base/strings/strcat.h"
11 #include "base/strings/string_number_conversions.h"
12 #include "base/strings/string_piece.h"
13 #include "base/strings/string_split.h"
14 #include "base/strings/utf_string_conversions.h"
15 #include "components/storage_monitor/removable_device_constants.h"
16 #include "components/storage_monitor/storage_info.h"
18 namespace storage_monitor {
22 // Device root path constant.
23 const char kRootPath[] = "/";
25 // Returns the storage identifier of the device from the given |storage_name|.
26 // E.g. If the |storage_name| is "usb:2,2:65537", the storage identifier is
28 std::string GetStorageIdFromStorageName(const std::string& storage_name) {
29 std::vector<base::StringPiece> name_parts = base::SplitStringPiece(
30 storage_name, ":", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
31 return name_parts.size() == 3 ? std::string(name_parts[2]) : std::string();
34 // Returns the |data_store_id| string in the required format.
35 // If the |data_store_id| is 65537, this function returns " (65537)".
36 std::string GetFormattedIdString(const std::string& data_store_id) {
37 return ("(" + data_store_id + ")");
42 // Constructs and returns the location of the device using the |storage_name|.
43 std::string GetDeviceLocationFromStorageName(const std::string& storage_name) {
44 // Construct a dummy device path using the storage name. This is only used
45 // for registering device media file system.
46 // E.g.: If the |storage_name| is "usb:2,2:12345" then "/usb:2,2:12345" is the
48 DCHECK(!storage_name.empty());
49 return kRootPath + storage_name;
52 // Returns a unique device id from the given |storage_info|.
53 std::string GetDeviceIdFromStorageInfo(
54 const device::mojom::MtpStorageInfo& storage_info) {
55 // We'll add a storage_id suffix to our return value. The function name says
56 // "device" but storage_monitor ultimately wants to identify a unit of
57 // logical storage, not necessarily identify a physical device.
59 // MTP devices (e.g. phones) can have multiple physical storages (e.g. disks)
60 // and each physical storage can have multiple logical storages.
62 // The storage_id returned by GetStorageIdFromStorageName often looks like
63 // "65537", the string form of 0x0001_0001 that encodes a pair of uint16_t
64 // identifiers for physical and logical storage. Zero values are reserved.
65 // See the MTP spec (MTPforUSB-IFv1.1.pdf) section 5.2.1 Storage IDs.
66 const std::string storage_id =
67 GetStorageIdFromStorageName(storage_info.storage_name);
68 if (storage_id.empty()) {
72 // The serial number (and the storage_id) should form a unique id.
73 if (!storage_info.serial_number.empty()) {
74 return StorageInfo::MakeDeviceId(
75 StorageInfo::MTP_OR_PTP,
76 base::StrCat({storage_info.serial_number, ":", storage_id}));
79 // If no serial number is available, fall back to a combination of vendor,
80 // model and volume (and the storage_id). This isn't always unique: attaching
81 // two "Google Pixel" phones to a Chromebook at the same time can produce the
82 // same (vendor, model, volume, storage) 4-tuple. The collision can cause
83 // problems with other code that assumes "device ids" are unique. See
84 // https://crbug.com/1184941
86 // Nonetheless, it's better than nothing. It also matches how Chrome OS
87 // behaved (not using the serial number) for some years up until 2022.
88 const std::string vendor_id = base::NumberToString(storage_info.vendor_id);
89 const std::string model_id = base::NumberToString(storage_info.product_id);
90 return StorageInfo::MakeDeviceId(
91 StorageInfo::MTP_OR_PTP,
92 base::StrCat({kVendorModelVolumeStoragePrefix, vendor_id, ":", model_id,
93 ":", storage_info.volume_identifier, ":", storage_id}));
96 // Helper function to get device label from storage information.
97 std::u16string GetDeviceLabelFromStorageInfo(
98 const device::mojom::MtpStorageInfo& storage_info) {
99 std::string device_label;
100 const std::string& vendor_name = storage_info.vendor;
101 device_label = vendor_name;
103 const std::string& product_name = storage_info.product;
104 if (!product_name.empty()) {
105 if (!device_label.empty())
107 device_label += product_name;
110 // Add the data store id to the device label.
111 if (!device_label.empty()) {
112 const std::string& volume_id = storage_info.volume_identifier;
113 if (!volume_id.empty()) {
114 device_label += GetFormattedIdString(volume_id);
116 const std::string data_store_id =
117 GetStorageIdFromStorageName(storage_info.storage_name);
118 if (!data_store_id.empty())
119 device_label += GetFormattedIdString(data_store_id);
122 return base::UTF8ToUTF16(device_label);
125 } // namespace storage_monitor