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Commit | Line | Data |
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15c0b25d AP |
1 | package getter |
2 | ||
3 | import ( | |
4 | "archive/tar" | |
5 | "fmt" | |
6 | "io" | |
7 | "os" | |
8 | "path/filepath" | |
107c1cdb | 9 | "time" |
15c0b25d AP |
10 | ) |
11 | ||
12 | // untar is a shared helper for untarring an archive. The reader should provide | |
13 | // an uncompressed view of the tar archive. | |
14 | func untar(input io.Reader, dst, src string, dir bool) error { | |
15 | tarR := tar.NewReader(input) | |
16 | done := false | |
17 | dirHdrs := []*tar.Header{} | |
107c1cdb | 18 | now := time.Now() |
15c0b25d AP |
19 | for { |
20 | hdr, err := tarR.Next() | |
21 | if err == io.EOF { | |
22 | if !done { | |
23 | // Empty archive | |
24 | return fmt.Errorf("empty archive: %s", src) | |
25 | } | |
26 | ||
27 | break | |
28 | } | |
29 | if err != nil { | |
30 | return err | |
31 | } | |
32 | ||
33 | if hdr.Typeflag == tar.TypeXGlobalHeader || hdr.Typeflag == tar.TypeXHeader { | |
34 | // don't unpack extended headers as files | |
35 | continue | |
36 | } | |
37 | ||
38 | path := dst | |
39 | if dir { | |
40 | // Disallow parent traversal | |
41 | if containsDotDot(hdr.Name) { | |
42 | return fmt.Errorf("entry contains '..': %s", hdr.Name) | |
43 | } | |
44 | ||
45 | path = filepath.Join(path, hdr.Name) | |
46 | } | |
47 | ||
48 | if hdr.FileInfo().IsDir() { | |
49 | if !dir { | |
50 | return fmt.Errorf("expected a single file: %s", src) | |
51 | } | |
52 | ||
53 | // A directory, just make the directory and continue unarchiving... | |
54 | if err := os.MkdirAll(path, 0755); err != nil { | |
55 | return err | |
56 | } | |
57 | ||
58 | // Record the directory information so that we may set its attributes | |
59 | // after all files have been extracted | |
60 | dirHdrs = append(dirHdrs, hdr) | |
61 | ||
62 | continue | |
63 | } else { | |
64 | // There is no ordering guarantee that a file in a directory is | |
65 | // listed before the directory | |
66 | dstPath := filepath.Dir(path) | |
67 | ||
68 | // Check that the directory exists, otherwise create it | |
69 | if _, err := os.Stat(dstPath); os.IsNotExist(err) { | |
70 | if err := os.MkdirAll(dstPath, 0755); err != nil { | |
71 | return err | |
72 | } | |
73 | } | |
74 | } | |
75 | ||
76 | // We have a file. If we already decoded, then it is an error | |
77 | if !dir && done { | |
78 | return fmt.Errorf("expected a single file, got multiple: %s", src) | |
79 | } | |
80 | ||
81 | // Mark that we're done so future in single file mode errors | |
82 | done = true | |
83 | ||
84 | // Open the file for writing | |
85 | dstF, err := os.Create(path) | |
86 | if err != nil { | |
87 | return err | |
88 | } | |
89 | _, err = io.Copy(dstF, tarR) | |
90 | dstF.Close() | |
91 | if err != nil { | |
92 | return err | |
93 | } | |
94 | ||
95 | // Chmod the file | |
96 | if err := os.Chmod(path, hdr.FileInfo().Mode()); err != nil { | |
97 | return err | |
98 | } | |
99 | ||
107c1cdb ND |
100 | // Set the access and modification time if valid, otherwise default to current time |
101 | aTime := now | |
102 | mTime := now | |
103 | if hdr.AccessTime.Unix() > 0 { | |
104 | aTime = hdr.AccessTime | |
105 | } | |
106 | if hdr.ModTime.Unix() > 0 { | |
107 | mTime = hdr.ModTime | |
108 | } | |
109 | if err := os.Chtimes(path, aTime, mTime); err != nil { | |
15c0b25d AP |
110 | return err |
111 | } | |
112 | } | |
113 | ||
107c1cdb | 114 | // Perform a final pass over extracted directories to update metadata |
15c0b25d AP |
115 | for _, dirHdr := range dirHdrs { |
116 | path := filepath.Join(dst, dirHdr.Name) | |
107c1cdb ND |
117 | // Chmod the directory since they might be created before we know the mode flags |
118 | if err := os.Chmod(path, dirHdr.FileInfo().Mode()); err != nil { | |
119 | return err | |
120 | } | |
121 | // Set the mtime/atime attributes since they would have been changed during extraction | |
122 | aTime := now | |
123 | mTime := now | |
124 | if dirHdr.AccessTime.Unix() > 0 { | |
125 | aTime = dirHdr.AccessTime | |
126 | } | |
127 | if dirHdr.ModTime.Unix() > 0 { | |
128 | mTime = dirHdr.ModTime | |
129 | } | |
130 | if err := os.Chtimes(path, aTime, mTime); err != nil { | |
15c0b25d AP |
131 | return err |
132 | } | |
133 | } | |
134 | ||
135 | return nil | |
136 | } | |
137 | ||
138 | // tarDecompressor is an implementation of Decompressor that can | |
139 | // unpack tar files. | |
140 | type tarDecompressor struct{} | |
141 | ||
142 | func (d *tarDecompressor) Decompress(dst, src string, dir bool) error { | |
143 | // If we're going into a directory we should make that first | |
144 | mkdir := dst | |
145 | if !dir { | |
146 | mkdir = filepath.Dir(dst) | |
147 | } | |
148 | if err := os.MkdirAll(mkdir, 0755); err != nil { | |
149 | return err | |
150 | } | |
151 | ||
152 | // File first | |
153 | f, err := os.Open(src) | |
154 | if err != nil { | |
155 | return err | |
156 | } | |
157 | defer f.Close() | |
158 | ||
159 | return untar(f, dst, src, dir) | |
160 | } |