-
Notifications
You must be signed in to change notification settings - Fork 562
/
initramfs_mounts_state.go
161 lines (141 loc) · 5.29 KB
/
initramfs_mounts_state.go
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
// -*- Mode: Go; indent-tabs-mode: t -*-
/*
* Copyright (C) 2020 Canonical Ltd
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 3 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
package main
import (
"errors"
"fmt"
"os"
"path/filepath"
"runtime"
"github.com/snapcore/snapd/asserts"
"github.com/snapcore/snapd/boot"
"github.com/snapcore/snapd/gadget"
"github.com/snapcore/snapd/logger"
"github.com/snapcore/snapd/osutil"
"github.com/snapcore/snapd/seed"
"github.com/snapcore/snapd/snap"
"github.com/snapcore/snapd/timings"
)
var (
osutilSetTime = osutil.SetTime
runtimeNumCPU = runtime.NumCPU
)
// initramfsMountsState helps tracking the state and progress
// of the mounting driving process.
type initramfsMountsState struct {
mode string
recoverySystem string
verifiedModel gadget.Model
seeds map[string]seed.Seed
}
var errRunModeNoImpliedRecoverySystem = errors.New("internal error: no implied recovery system in run mode")
// LoadSeed returns the seed for the recoverySystem.
// If recoverySystem is "" the implied one will be used (only for
// modes other than run).
func (mst *initramfsMountsState) LoadSeed(recoverySystem string) (seed.Seed, error) {
if recoverySystem == "" {
if mst.mode == "run" {
return nil, errRunModeNoImpliedRecoverySystem
}
recoverySystem = mst.recoverySystem
}
if mst.seeds == nil {
mst.seeds = make(map[string]seed.Seed)
}
foundSeed, hasSeed := mst.seeds[recoverySystem]
if hasSeed {
return foundSeed, nil
}
perf := timings.New(nil)
// get the current time to pass to ReadSystemEssentialAndBetterEarliestTime
// note that we trust the time we have from the system, because that time
// comes from either:
// * a RTC on the system that the kernel/systemd consulted and used to move
// time forward
// * systemd using a built-in timestamp from the initrd which was stamped
// when the initrd was built, giving a lower bound on the current time if
// the RTC does not have a battery or is otherwise unreliable, etc.
now := timeNow()
jobs := 1
if runtimeNumCPU() > 1 {
jobs = 2
}
seed20, newTrustedEarliestTime, err := seed.ReadSeedAndBetterEarliestTime(boot.InitramfsUbuntuSeedDir, recoverySystem, now, jobs, perf)
if err != nil {
return nil, err
}
// set the time on the system to move forward if it is in the future - never
// move the time backwards
if newTrustedEarliestTime.After(now) {
if err := osutilSetTime(newTrustedEarliestTime); err != nil {
// log the error but don't fail on it, we should be able to continue
// even if the time can't be moved forward
logger.Noticef("failed to move time forward from %s to %s: %v", now, newTrustedEarliestTime, err)
}
}
mst.seeds[recoverySystem] = seed20
return seed20, nil
}
// SetVerifiedBootModel sets the "verifiedModel" field. It should only
// be called after the model is verified. Either via a successful unlock
// of the encrypted data or after validating the seed in install/recover
// mode.
func (mst *initramfsMountsState) SetVerifiedBootModel(m gadget.Model) {
mst.verifiedModel = m
}
// UnverifiedBootModel returns the unverified model from the
// boot partition for run mode. The current and only use case
// is measuring the model for run mode. Otherwise no decisions
// should be based on an unverified model. Note that the model
// is verified at the time the key auth policy is computed.
func (mst *initramfsMountsState) UnverifiedBootModel() (*asserts.Model, error) {
if mst.mode != "run" {
return nil, fmt.Errorf("internal error: unverified boot model access is for limited run mode use")
}
mf, err := os.Open(filepath.Join(boot.InitramfsUbuntuBootDir, "device/model"))
if err != nil {
return nil, fmt.Errorf("cannot read model assertion: %v", err)
}
defer mf.Close()
ma, err := asserts.NewDecoder(mf).Decode()
if err != nil {
return nil, fmt.Errorf("cannot decode assertion: %v", err)
}
if ma.Type() != asserts.ModelType {
return nil, fmt.Errorf("unexpected assertion: %q", ma.Type().Name)
}
return ma.(*asserts.Model), nil
}
// EphemeralModeenvForModel generates a modeenv given the model and the snaps for the
// current mode and recovery system of the initramfsMountsState.
func (mst *initramfsMountsState) EphemeralModeenvForModel(model *asserts.Model, snaps map[snap.Type]*seed.Snap) (*boot.Modeenv, error) {
if mst.mode == "run" {
return nil, fmt.Errorf("internal error: initramfs should not write modeenv in run mode")
}
return &boot.Modeenv{
Mode: mst.mode,
RecoverySystem: mst.recoverySystem,
Base: snaps[snap.TypeBase].PlaceInfo().Filename(),
Gadget: snaps[snap.TypeGadget].PlaceInfo().Filename(),
Model: model.Model(),
BrandID: model.BrandID(),
Grade: string(model.Grade()),
// TODO:UC20: what about current kernel snaps, trusted boot assets and
// kernel command lines?
}, nil
}