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
|
package git
import (
"context"
"fmt"
"os"
"path/filepath"
"strings"
"github.com/grpc-ecosystem/go-grpc-middleware/logging/logrus/ctxlogrus"
)
// alternateOutsideStorageError is returned when an alternates file contains an
// alternate which is not within the storage's root.
type alternateOutsideStorageError string
func (path alternateOutsideStorageError) Error() string {
return fmt.Sprintf("alternate %q is outside the storage root", string(path))
}
// ObjectDirectories looks for Git object directories, including
// alternates specified in objects/info/alternates.
//
// CAVEAT Git supports quoted strings in here, but we do not. We should
// never need those on a Gitaly server.
func ObjectDirectories(ctx context.Context, storageRoot, repoPath string) ([]string, error) {
objDir := filepath.Join(repoPath, "objects")
return altObjectDirs(ctx, storageRoot+string(os.PathSeparator), objDir, 0)
}
// AlternateObjectDirectories reads the alternates file of the repository and returns absolute paths
// to its alternate object directories, if any. The returned directories are verified to exist and that
// they are within the storage root. The alternate directories are returned recursively, not only the
// immediate alternates.
func AlternateObjectDirectories(ctx context.Context, storageRoot, repoPath string) ([]string, error) {
dirs, err := ObjectDirectories(ctx, storageRoot, repoPath)
if err != nil {
return nil, err
}
// first directory is the repository's own object dir
return dirs[1:], nil
}
func altObjectDirs(ctx context.Context, storagePrefix, objDir string, depth int) ([]string, error) {
logEntry := ctxlogrus.Extract(ctx)
const maxAlternatesDepth = 5 // Taken from https://github.com/git/git/blob/v2.23.0/sha1-file.c#L575
if depth > maxAlternatesDepth {
logEntry.WithField("objdir", objDir).Warn("ignoring deeply nested alternate object directory")
return nil, nil
}
fi, err := os.Stat(objDir)
if os.IsNotExist(err) {
logEntry.WithField("objdir", objDir).Warn("object directory not found")
return nil, nil
}
if err != nil {
return nil, err
}
if !fi.IsDir() {
return nil, nil
}
dirs := []string{objDir}
alternates, err := os.ReadFile(filepath.Join(objDir, "info", "alternates"))
if os.IsNotExist(err) {
return dirs, nil
}
if err != nil {
return nil, err
}
for _, newDir := range strings.Split(string(alternates), "\n") {
if len(newDir) == 0 || newDir[0] == '#' {
continue
}
if !filepath.IsAbs(newDir) {
newDir = filepath.Join(objDir, newDir)
}
if !strings.HasPrefix(newDir, storagePrefix) {
return nil, alternateOutsideStorageError(newDir)
}
nestedDirs, err := altObjectDirs(ctx, storagePrefix, newDir, depth+1)
if err != nil {
return nil, err
}
dirs = append(dirs, nestedDirs...)
}
return dirs, nil
}
|
