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
|
//go:build linux
// +build linux
package libpod
import (
"os"
"path/filepath"
"strings"
"github.com/containers/buildah/copier"
"github.com/containers/podman/v4/libpod/define"
"github.com/containers/podman/v4/pkg/copy"
"github.com/pkg/errors"
)
// statInsideMount stats the specified path *inside* the container's mount and PID
// namespace. It returns the file info along with the resolved root ("/") and
// the resolved path (relative to the root).
func (c *Container) statInsideMount(containerPath string) (*copier.StatForItem, string, string, error) {
resolvedRoot := "/"
resolvedPath := c.pathAbs(containerPath)
var statInfo *copier.StatForItem
err := c.joinMountAndExec(
func() error {
var statErr error
statInfo, statErr = secureStat(resolvedRoot, resolvedPath)
return statErr
},
)
return statInfo, resolvedRoot, resolvedPath, err
}
// statOnHost stats the specified path *on the host*. It returns the file info
// along with the resolved root and the resolved path. Both paths are absolute
// to the host's root. Note that the paths may resolved outside the
// container's mount point (e.g., to a volume or bind mount).
func (c *Container) statOnHost(mountPoint string, containerPath string) (*copier.StatForItem, string, string, error) {
// Now resolve the container's path. It may hit a volume, it may hit a
// bind mount, it may be relative.
resolvedRoot, resolvedPath, err := c.resolvePath(mountPoint, containerPath)
if err != nil {
return nil, "", "", err
}
statInfo, err := secureStat(resolvedRoot, resolvedPath)
return statInfo, resolvedRoot, resolvedPath, err
}
func (c *Container) stat(containerMountPoint string, containerPath string) (*define.FileInfo, string, string, error) {
var (
resolvedRoot string
resolvedPath string
absContainerPath string
statInfo *copier.StatForItem
statErr error
)
// Make sure that "/" copies the *contents* of the mount point and not
// the directory.
if containerPath == "/" {
containerPath = "/."
}
// Wildcards are not allowed.
// TODO: it's now technically possible wildcards.
// We may consider enabling support in the future.
if strings.Contains(containerPath, "*") {
return nil, "", "", copy.ErrENOENT
}
if c.state.State == define.ContainerStateRunning {
// If the container is running, we need to join it's mount namespace
// and stat there.
statInfo, resolvedRoot, resolvedPath, statErr = c.statInsideMount(containerPath)
} else {
// If the container is NOT running, we need to resolve the path
// on the host.
statInfo, resolvedRoot, resolvedPath, statErr = c.statOnHost(containerMountPoint, containerPath)
}
if statErr != nil {
if statInfo == nil {
return nil, "", "", statErr
}
// Not all errors from secureStat map to ErrNotExist, so we
// have to look into the error string. Turning it into an
// ENOENT let's the API handlers return the correct status code
// which is crucial for the remote client.
if os.IsNotExist(statErr) || strings.Contains(statErr.Error(), "o such file or directory") {
statErr = copy.ErrENOENT
}
}
switch {
case statInfo.IsSymlink:
// Symlinks are already evaluated and always relative to the
// container's mount point.
absContainerPath = statInfo.ImmediateTarget
case strings.HasPrefix(resolvedPath, containerMountPoint):
// If the path is on the container's mount point, strip it off.
absContainerPath = strings.TrimPrefix(resolvedPath, containerMountPoint)
absContainerPath = filepath.Join("/", absContainerPath)
default:
// No symlink and not on the container's mount point, so let's
// move it back to the original input. It must have evaluated
// to a volume or bind mount but we cannot return host paths.
absContainerPath = containerPath
}
// Preserve the base path as specified by the user. The `filepath`
// packages likes to remove trailing slashes and dots that are crucial
// to the copy logic.
absContainerPath = copy.PreserveBasePath(containerPath, absContainerPath)
resolvedPath = copy.PreserveBasePath(containerPath, resolvedPath)
info := &define.FileInfo{
IsDir: statInfo.IsDir,
Name: filepath.Base(absContainerPath),
Size: statInfo.Size,
Mode: statInfo.Mode,
ModTime: statInfo.ModTime,
LinkTarget: absContainerPath,
}
return info, resolvedRoot, resolvedPath, statErr
}
// secureStat extracts file info for path in a chroot'ed environment in root.
func secureStat(root string, path string) (*copier.StatForItem, error) {
var glob string
var err error
// If root and path are equal, then dir must be empty and the glob must
// be ".".
if filepath.Clean(root) == filepath.Clean(path) {
glob = "."
} else {
glob, err = filepath.Rel(root, path)
if err != nil {
return nil, err
}
}
globStats, err := copier.Stat(root, "", copier.StatOptions{}, []string{glob})
if err != nil {
return nil, err
}
if len(globStats) != 1 {
return nil, errors.Errorf("internal error: secureStat: expected 1 item but got %d", len(globStats))
}
if len(globStats) != 1 {
return nil, errors.Errorf("internal error: secureStat: expected 1 result but got %d", len(globStats[0].Results))
}
// NOTE: the key in the map differ from `glob` when hitting symlink.
// Hence, we just take the first (and only) key/value pair.
for _, stat := range globStats[0].Results {
var statErr error
if stat.Error != "" {
statErr = errors.New(stat.Error)
}
// If necessary evaluate the symlink
if stat.IsSymlink {
target, err := copier.Eval(root, path, copier.EvalOptions{})
if err != nil {
return nil, errors.Wrap(err, "error evaluating symlink in container")
}
// Need to make sure the symlink is relative to the root!
target = strings.TrimPrefix(target, root)
target = filepath.Join("/", target)
stat.ImmediateTarget = target
}
return stat, statErr
}
// Nothing found!
return nil, copy.ErrENOENT
}
|
