File: guest_os_mount_provider.cc

package info (click to toggle)
chromium 139.0.7258.138-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid
  • size: 6,120,676 kB
  • sloc: cpp: 35,100,869; ansic: 7,163,530; javascript: 4,103,002; python: 1,436,920; asm: 946,517; xml: 746,709; pascal: 187,653; perl: 88,691; sh: 88,436; objc: 79,953; sql: 51,488; cs: 44,583; fortran: 24,137; makefile: 22,147; tcl: 15,277; php: 13,980; yacc: 8,984; ruby: 7,485; awk: 3,720; lisp: 3,096; lex: 1,327; ada: 727; jsp: 228; sed: 36
file content (217 lines) | stat: -rw-r--r-- 8,400 bytes parent folder | download | duplicates (6)
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
// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/ash/guest_os/public/guest_os_mount_provider.h"

#include <memory>

#include "base/feature_list.h"
#include "base/functional/bind.h"
#include "base/functional/callback.h"
#include "base/functional/callback_forward.h"
#include "base/functional/callback_helpers.h"
#include "base/memory/raw_ptr.h"
#include "base/memory/weak_ptr.h"
#include "base/strings/stringprintf.h"
#include "chrome/browser/ash/file_manager/path_util.h"
#include "chrome/browser/ash/file_manager/volume_manager.h"
#include "chrome/browser/ash/guest_os/guest_id.h"
#include "chrome/browser/ash/guest_os/infra/cached_callback.h"
#include "chrome/browser/ash/guest_os/public/types.h"
#include "chrome/browser/ash/policy/skyvault/policy_utils.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/common/chrome_features.h"
#include "chromeos/ash/components/disks/disk_mount_manager.h"
#include "storage/browser/file_system/external_mount_points.h"

namespace guest_os {

// An RAII-style class controlling the lifetime of the SFTP volume. Will add the
// volume on creation and remove it on destruction.
class ScopedVolume {
 public:
  explicit ScopedVolume(
      Profile* profile,
      std::string display_name,
      std::string mount_label,
      base::FilePath remote_path,
      const ash::disks::DiskMountManager::MountPoint& mount_info,
      VmType vm_type)
      : profile_(profile),
        mount_label_(std::move(mount_label)),
        vm_type_(vm_type) {
    base::FilePath mount_path = base::FilePath(mount_info.mount_path);
    if (!storage::ExternalMountPoints::GetSystemInstance()->RegisterFileSystem(
            mount_label_, storage::kFileSystemTypeLocal,
            storage::FileSystemMountOption(), mount_path)) {
      // We don't revoke the filesystem on unmount and this call fails if a
      // filesystem of the same name already exists, so ignore errors.
      // TODO(crbug/1293229): This follows the logic of existing code, but we
      // can probably change it to revoke the filesystem on unmount.
    }
    auto* vmgr = file_manager::VolumeManager::Get(profile_);
    if (vmgr) {
      // vmgr is null in unit tests.
      vmgr->AddSftpGuestOsVolume(display_name, mount_path, remote_path,
                                 vm_type_);
    }
  }

  ~ScopedVolume() {
    if (profile_->ShutdownStarted()) {
      // We're shutting down or have shut down, but because we're not a keyed
      // service we don't get two-phase shutdown, we just can't call anything.
      // Either the whole system is shutting down (in which case everything
      // gets undone anyway) or it's just the browser (in which case it's
      // basically the same as a browser crash which we also need to handle).
      // So do nothing.
      return;
    }

    auto* vmgr = file_manager::VolumeManager::Get(profile_.get());
    if (vmgr) {
      // vmgr is null in unit tests. Also, this calls disk_manager to unmount
      // for us (and we never unregister the filesystem) hence unmount doesn't
      // seem symmetric with mount.
      vmgr->RemoveSftpGuestOsVolume(
          file_manager::util::GetGuestOsMountDirectory(mount_label_), vm_type_,
          base::DoNothing());
    }
  }

  raw_ptr<Profile> profile_;
  std::string mount_label_;
  const VmType vm_type_;
};

class GuestOsMountProviderInner : public CachedCallback<ScopedVolume, bool> {
 public:
  explicit GuestOsMountProviderInner(
      Profile* profile,
      std::string display_name,
      guest_os::GuestId container_id,
      VmType vm_type,
      base::RepeatingCallback<void(GuestOsMountProvider::PrepareCallback)>
          prepare)
      : profile_(profile),
        display_name_(std::move(display_name)),
        container_id_(std::move(container_id)),
        vm_type_(vm_type),
        prepare_(std::move(prepare)) {
    // This profile should be the user's primary profile, not an incognito one.
    DCHECK(!profile->IsOffTheRecord());
  }

  // Mount.
  void Build(RealCallback callback) override {
    prepare_.Run(base::BindOnce(&GuestOsMountProviderInner::MountPath,
                                weak_ptr_factory_.GetWeakPtr(),
                                std::move(callback)));
  }

  void MountPath(RealCallback callback,
                 bool success,
                 int cid,
                 int port,
                 base::FilePath remote_path) {
    if (!success) {
      LOG(ERROR) << "Error mounting, failed to prepare VM";
      std::move(callback).Run(Failure(false));
      return;
    }
    mount_label_ =
        file_manager::util::GetGuestOsMountPointName(profile_, container_id_);
    auto* dmgr = ash::disks::DiskMountManager::GetInstance();

    // Call to sshfs to mount.
    std::string source_path = base::StringPrintf("sftp://%d:%d", cid, port);

    dmgr->MountPath(source_path, "", mount_label_, {},
                    ash::MountType::kNetworkStorage,
                    ash::MountAccessMode::kReadWrite,
                    base::BindOnce(&GuestOsMountProviderInner::OnMountEvent,
                                   weak_ptr_factory_.GetWeakPtr(),
                                   std::move(callback), remote_path));
  }

  void OnMountEvent(
      RealCallback callback,
      base::FilePath remote_path,
      ash::MountError error_code,
      const ash::disks::DiskMountManager::MountPoint& mount_info) {
    if (error_code != ash::MountError::kSuccess) {
      LOG(ERROR) << "Error mounting Guest OS container: error_code="
                 << error_code << ", source_path=" << mount_info.source_path
                 << ", mount_path=" << mount_info.mount_path
                 << ", mount_type=" << static_cast<int>(mount_info.mount_type)
                 << ", mount_error=" << mount_info.mount_error;
      std::move(callback).Run(Failure(false));
      return;
    }
    auto scoped_volume =
        std::make_unique<ScopedVolume>(profile_, display_name_, mount_label_,
                                       remote_path, mount_info, vm_type_);

    // CachedCallback magic keeps the scope alive until we're destroyed or it's
    // invalidated.
    std::move(callback).Run(RealResult(std::move(scoped_volume)));
  }

  raw_ptr<Profile> profile_;
  const std::string display_name_;
  const guest_os::GuestId container_id_;
  std::string mount_label_;
  const VmType vm_type_;
  // Callback to prepare the VM for mounting.
  const base::RepeatingCallback<void(GuestOsMountProvider::PrepareCallback)>
      prepare_;

  // Note: This should remain the last member so it'll be destroyed and
  // invalidate its weak pointers before any other members are destroyed.
  base::WeakPtrFactory<GuestOsMountProviderInner> weak_ptr_factory_{this};
};

void GuestOsMountProvider::Mount(base::OnceCallback<void(bool)> callback) {
  const bool local_files_allowed =
      policy::local_user_files::LocalUserFilesAllowed();

  // If SkyVaultV2 is enabled (GA version), block all VMs regardless of the
  // type.
  if (!local_files_allowed &&
      base::FeatureList::IsEnabled(features::kSkyVaultV2)) {
    LOG(ERROR) << "Error mounting Guest OS container with guest id="
               << this->GuestId() << ": local user files are disabled";
    std::move(callback).Run(false);
    return;
  }

  // If SkyVaultV2 is disabled (TT version), only block ARC.
  if (!local_files_allowed && vm_type() == VmType::ARCVM) {
    LOG(ERROR) << "Error mounting Guest OS container with guest id="
               << this->GuestId() << ": local user files are disabled";
    std::move(callback).Run(false);
    return;
  }

  if (!callback_) {
    callback_ = std::make_unique<GuestOsMountProviderInner>(
        profile(), DisplayName(), GuestId(), vm_type(),
        base::BindRepeating(&GuestOsMountProvider::Prepare,
                            weak_ptr_factory_.GetWeakPtr()));
  }
  callback_->Get(base::BindOnce(
      [](base::OnceCallback<void(bool)> callback,
         guest_os::GuestOsMountProviderInner::Result result) {
        std::move(callback).Run(result.has_value());
      },
      std::move(callback)));
}

void GuestOsMountProvider::Unmount() {
  callback_->Invalidate();
}

GuestOsMountProvider::GuestOsMountProvider() = default;
GuestOsMountProvider::~GuestOsMountProvider() = default;
}  // namespace guest_os