# header.h File Reference

An rpm header carries all information about a package. More...

`#include <stdio.h>`
`#include <rpmio.h>`
`#include <hdrinline.h>`

Go to the source code of this file.

## Defines

#define | RPM_MIN_TYPE 0
#define | RPM_MAX_TYPE 9
#define | HEADER_IMAGE 61
| Header private tags.
#define | HEADER_SIGNATURES 62
#define | HEADER_IMMUTABLE 63
#define | HEADER_REGIONS 64
#define | HEADER_I18NTABLE 100
#define | HEADER_SIGBASE 256
#define | HEADER_TAGBASE 1000

## Typedefs

typedef int | int_32
typedef short int | int_16
typedef char | int_8
typedef unsigned int | uint_32
typedef unsigned short | uint_16
typedef const char * | errmsg_t
typedef int_32 * | hTAG_t
typedef int_32 * | hTYP_t
typedef const void * | hPTR_t
typedef int_32 * | hCNT_t
typedef headerToken * | Header
typedef headerIteratorS * | HeaderIterator
typedef headerTagTableEntry_s * | headerTagTableEntry
typedef char *(* | headerTagFormatFunction )(int_32 type, const void *data, char *formatPrefix, int padding, int element)
typedef int(* | headerTagTagFunction )(Header h, hTYP_t type, hPTR_t *data, hCNT_t count, int *freeData)
typedef headerSprintfExtension_s * | headerSprintfExtension
typedef enum rpmTagType_e | rpmTagType
typedef enum rpmSubTagType_e | rpmSubTagType
typedef hRET_s * | hRET_t
typedef HE_s * | HE_t
typedef Header(* | HDRnew )(void)
typedef Header(* | HDRfree )(Header h)
typedef Header(* | HDRlink )(Header h)
typedef Header(* | HDRunlink )(Header h)
typedef void(* | HDRsort )(Header h)
typedef void(* | HDRunsort )(Header h)
typedef unsigned int(* | HDRsizeof )(Header h, enum hMagic magicp)
typedef void *(* | HDRunload )(Header h)
typedef Header(* | HDRreload )(Header h, int tag)
typedef Header(* | HDRcopy )(Header h)
typedef Header(* | HDRload )(void *uh)
typedef Header(* | HDRcopyload )(const void *uh)
typedef Header(* | HDRhdrread )(FD_t fd, enum hMagic magicp)
typedef int(* | HDRhdrwrite )(FD_t fd, Header h, enum hMagic magicp)
typedef int(* | HDRisentry )(Header h, int_32 tag)
typedef void *(* | HDRfreetag )(Header h, const void *data, rpmTagType type)
typedef int(* | HDRget )(Header h, int_32 tag, hTYP_t type, void **p, hCNT_t c)
typedef int(* | HDRgetmin )(Header h, int_32 tag, hTYP_t type, hPTR_t *p, hCNT_t c)
typedef int(* | HDRadd )(Header h, int_32 tag, int_32 type, const void *p, int_32 c)
typedef int(* | HDRappend )(Header h, int_32 tag, int_32 type, const void *p, int_32 c)
typedef int(* | HDRaddorappend )(Header h, int_32 tag, int_32 type, const void *p, int_32 c)
typedef int(* | HDRaddi18n )(Header h, int_32 tag, const char *string, const char *lang)
typedef int(* | HDRmodify )(Header h, int_32 tag, int_32 type, const void *p, int_32 c)
typedef int(* | HDRremove )(Header h, int_32 tag)
typedef char *(* | HDRhdrsprintf )(Header h, const char *fmt, const struct headerTagTableEntry_s *tags, const struct headerSprintfExtension_s *extensions, errmsg_t *errmsg)
typedef void(* | HDRcopytags )(Header headerFrom, Header headerTo, hTAG_t tagstocopy)
typedef HeaderIterator(* | HDRfreeiter )(HeaderIterator hi)
typedef HeaderIterator(* | HDRinititer )(Header h)
typedef int(* | HDRnextiter )(HeaderIterator hi, hTAG_t tag, hTYP_t type, hPTR_t *p, hCNT_t c)
typedef HV_s * | HV_t

## Enumerations

enum | headerSprintfExtenstionType { HEADER_EXT_LAST = 0, HEADER_EXT_FORMAT, HEADER_EXT_MORE, HEADER_EXT_TAG }
enum | hMagic { HEADER_MAGIC_NO = 0, HEADER_MAGIC_YES = 1 }
enum | rpmTagType_e { RPM_NULL_TYPE = 0, RPM_CHAR_TYPE = 1, RPM_INT8_TYPE = 2, RPM_INT16_TYPE = 3, RPM_INT32_TYPE = 4, RPM_STRING_TYPE = 6, RPM_BIN_TYPE = 7, RPM_STRING_ARRAY_TYPE = 8, RPM_I18NSTRING_TYPE }
enum | rpmSubTagType_e { RPM_REGION_TYPE = -10, RPM_BIN_ARRAY_TYPE = -11, RPM_XREF_TYPE = -12 }

## Functions

static void * | headerFreeData (const void *data, rpmTagType type)

## Variables

const struct headerSprintfExtension_s | headerDefaultFormats []

## Detailed Description

An rpm header carries all information about a package.

A header is a collection of data elements called tags. Each tag has a data type, and includes 1 or more values.

Historical Issues

Here's a brief description of features/incompatibilities that have been added to headers and tags.

- version 1
  - Support for version 1 headers was removed in rpm-4.0.

- version 2

Todo:
  Document version2 headers.

- version 3 (added in rpm-3.0)
  - Added RPM_I18NSTRING_TYPE as an associative array reference for i18n locale dependent single element tags (i.e Group).
  - Added an 8 byte magic string to headers in packages on-disk. The magic string was not added to headers in the database.

- version 4 (added in rpm-4.0)
  - Represent file names as a (dirname/basename/dirindex) triple rather than as an absolute path name. Legacy package headers are converted when the header is read. Legacy database headers are converted when the database is rebuilt.
  - Simplify dependencies by eliminating the implict check on package name/version/release in favor of an explict check on package provides. Legacy package headers are converted when the header is read. Legacy database headers are converted when the database is rebuilt.
  - (rpm-4.0.2) The original package header (and all original metadata) is preserved in what's called an "immutable header region". The original header can be retrieved as an RPM_BIN_TYPE, just like any other tag, and the original header reconstituted using headerLoad().
  - (rpm-4.0.2) The signature tags are added (and renumbered to avoid tag value collisions) to the package header during package installation.
  - (rpm-4.0.3) A SHA1 digest of the original header is appended (i.e. detached digest) to the immutable header region to verify changes to the original header.
  - (rpm-4.0.3) Private methods (e.g. headerLoad(), headerUnload(), etc.) to permit header data to be manipulated opaquely through vectors.
  - (rpm-4.0.3) Sanity checks on header data to limit #tags to 65K, #bytes to 16Mb, and total metadata size to 32Mb added.

Development Issues

Here's a brief description of future features/incompatibilities that will be added to headers.

- Private header methods.
  - Private methods for the transaction element file info TFI_t may be used as proof-of-concept, binary XML may be implemented as a header format representation soon thereafter.
- DSA signature for header metadata.
  - The manner in which rpm packages are signed is going to change. The SHA1 digest in the header will be signed, equivalent to a DSA digital signature on the original header metadata. As the original header will contain "trusted" (i.e. because the header is signed with DSA) file MD5 digests, there will be little or no reason to sign the payload, but that may happen as well. Note that cpio headers in the payload are not used to install package metadata, only the name field in the cpio header is used to associate an archive file member with the corresponding entry for the file in header metadata.

Definition in file header.h.

## Define Documentation

#define HEADER_I18NTABLE 100

| Definition at line 258 of file header.h. Referenced by getTagString(), getTagVal(), hdrKeyList(), headerFindI18NString(), headerGetLangs(), initSourceHeader(), and regionSwab().

#define HEADER_IMAGE 61

Header private tags.

Note:
  General use tags should start at 1000 (RPM's tag space starts there).

Definition at line 254 of file header.h.

Referenced by copyEntry(), and regionSwab().

#define HEADER_IMMUTABLE 63

| Definition at line 256 of file header.h.

#define HEADER_REGIONS 64

| Definition at line 257 of file header.h.

#define HEADER_SIGBASE 256

| Definition at line 259 of file header.h. Referenced by headerMergeLegacySigs(), and headerRegenSigHeader().

#define HEADER_SIGNATURES 62

| Definition at line 255 of file header.h.

#define HEADER_TAGBASE 1000

| Definition at line 260 of file header.h. Referenced by headerMergeLegacySigs(), and headerRegenSigHeader().

#define RPM_MAX_TYPE 9

| Referenced by regionSwab().

#define RPM_MIN_TYPE 0

| Referenced by regionSwab().

## Typedef Documentation

typedef int_32* hCNT_t

| Definition at line 119 of file header.h.

typedef struct HE_s * HE_t

typedef const void* hPTR_t

| Definition at line 118 of file header.h.

typedef union hRET_s * hRET_t

typedef int_32* hTYP_t

| Definition at line 117 of file header.h.

typedef short int int_16

| Definition at line 102 of file header.h.

typedef int int_32

| Definition at line 101 of file header.h.

typedef char int_8

| Definition at line 103 of file header.h.

typedef unsigned short uint_16

| Definition at line 106 of file header.h.

typedef unsigned int uint_32

| Definition at line 105 of file header.h.