Age Owner TLA Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * pgtar.h
4 : * Functions for manipulating tarfile datastructures (src/port/tar.c)
5 : *
6 : *
7 : * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
8 : * Portions Copyright (c) 1994, Regents of the University of California
9 : *
10 : * src/include/pgtar.h
11 : *
12 : *-------------------------------------------------------------------------
13 : */
14 : #ifndef PG_TAR_H
15 : #define PG_TAR_H
16 :
17 : #define TAR_BLOCK_SIZE 512
18 :
19 : enum tarError
20 : {
21 : TAR_OK = 0,
22 : TAR_NAME_TOO_LONG,
23 : TAR_SYMLINK_TOO_LONG,
24 : };
25 :
26 : /*
27 : * Offsets of fields within a 512-byte tar header.
28 : *
29 : * "tar number" values should be generated using print_tar_number() and can be
30 : * read using read_tar_number(). Fields that contain strings are generally
31 : * both filled and read using strlcpy().
32 : *
33 : * The value for the checksum field can be computed using tarChecksum().
34 : *
35 : * Some fields are not used by PostgreSQL; see tarCreateHeader().
36 : */
37 : enum tarHeaderOffset
38 : {
39 : TAR_OFFSET_NAME = 0, /* 100 byte string */
40 : TAR_OFFSET_MODE = 100, /* 8 byte tar number, excludes S_IFMT */
41 : TAR_OFFSET_UID = 108, /* 8 byte tar number */
42 : TAR_OFFSET_GID = 116, /* 8 byte tar number */
43 : TAR_OFFSET_SIZE = 124, /* 8 byte tar number */
44 : TAR_OFFSET_MTIME = 136, /* 12 byte tar number */
45 : TAR_OFFSET_CHECKSUM = 148, /* 8 byte tar number */
46 : TAR_OFFSET_TYPEFLAG = 156, /* 1 byte file type, see TAR_FILETYPE_* */
47 : TAR_OFFSET_LINKNAME = 157, /* 100 byte string */
48 : TAR_OFFSET_MAGIC = 257, /* "ustar" with terminating zero byte */
49 : TAR_OFFSET_VERSION = 263, /* "00" */
50 : TAR_OFFSET_UNAME = 265, /* 32 byte string */
51 : TAR_OFFSET_GNAME = 297, /* 32 byte string */
52 : TAR_OFFSET_DEVMAJOR = 329, /* 8 byte tar number */
53 : TAR_OFFSET_DEVMINOR = 337, /* 8 byte tar number */
54 : TAR_OFFSET_PREFIX = 345, /* 155 byte string */
55 : /* last 12 bytes of the 512-byte block are unassigned */
56 : };
57 :
58 : enum tarFileType
59 : {
60 : TAR_FILETYPE_PLAIN = '0',
61 : TAR_FILETYPE_SYMLINK = '2',
62 : TAR_FILETYPE_DIRECTORY = '5',
63 : };
64 :
65 : extern enum tarError tarCreateHeader(char *h, const char *filename,
66 : const char *linktarget, pgoff_t size,
67 : mode_t mode, uid_t uid, gid_t gid,
68 : time_t mtime);
69 : extern uint64 read_tar_number(const char *s, int len);
70 : extern void print_tar_number(char *s, int len, uint64 val);
71 : extern int tarChecksum(char *header);
72 :
73 : /*
74 : * Compute the number of padding bytes required for an entry in a tar
75 : * archive. We must pad out to a multiple of TAR_BLOCK_SIZE. Since that's
76 : * a power of 2, we can use TYPEALIGN().
77 : */
78 : static inline size_t
1961 rhaas@postgresql.org 79 CBC 638629 : tarPaddingBytesRequired(size_t len)
80 : {
81 638629 : return TYPEALIGN(TAR_BLOCK_SIZE, len) - len;
82 : }
83 :
84 : #endif
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