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
      79     1235726 : tarPaddingBytesRequired(size_t len)
      80             : {
      81     1235726 :     return TYPEALIGN(TAR_BLOCK_SIZE, len) - len;
      82             : }
      83             : 
      84             : #endif