/**

* MojoSetup; a portable, flexible installation application.

*

* Please see the file LICENSE.txt in the source's root directory.

*

* This file written by Ryan C. Gordon.

*/

// Specs for the tar format can be found here...

// http://www.gnu.org/software/tar/manual/html_section/Standard.html

#include "fileio.h"

#if !SUPPORT_TAR

MojoArchive *MojoArchive_createTAR(MojoInput *io) { return NULL; }

#else

// MojoInput implementation...

// Decompression is handled in the parent MojoInput, so this just needs to

// make sure we stay within the bounds of the tarfile entry.

typedef struct TARinput

} TARinput;

typedef struct TARinfo

} TARinfo;

static boolean MojoInput_tar_ready(MojoInput *io)

{

return true; // !!! FIXME: ready if there are bytes uncompressed.

} // MojoInput_tar_ready

static int64 MojoInput_tar_read(MojoInput *io, void *buf, uint32 bufsize)

{

TARinput *input = (TARinput *) io->opaque;

int64 pos = io->tell(io);

if ((pos + bufsize) > input->fsize)

bufsize = (uint32) (input->fsize - pos);

return input->ar->io->read(input->ar->io, buf, bufsize);

} // MojoInput_tar_read

static boolean MojoInput_tar_seek(MojoInput *io, uint64 pos)

{

TARinput *input = (TARinput *) io->opaque;

boolean retval = false;

if (pos < ((uint64) input->fsize))

retval = input->ar->io->seek(input->ar->io, input->offset + pos);

return retval;

} // MojoInput_tar_seek

static int64 MojoInput_tar_tell(MojoInput *io)

{

TARinput *input = (TARinput *) io->opaque;

return input->ar->io->tell(input->ar->io) - input->offset;

} // MojoInput_tar_tell

static int64 MojoInput_tar_length(MojoInput *io)

{

return ((TARinput *) io->opaque)->fsize;

} // MojoInput_tar_length

static MojoInput *MojoInput_tar_duplicate(MojoInput *io)

{

MojoInput *retval = NULL;

fatal(_("BUG: Can't duplicate tar inputs")); // !!! FIXME: why not?

#if 0

TARinput *input = (TARinput *) io->opaque;

MojoInput *origio = (MojoInput *) io->opaque;

MojoInput *newio = origio->duplicate(origio);

if (newio != NULL)

{

TARinput *newopaque = (TARinput *) xmalloc(sizeof (TARinput));

newopaque->origio = newio;

newopaque->fsize = input->fsize;

newopaque->offset = input->offset;

retval = (MojoInput *) xmalloc(sizeof (MojoInput));

memcpy(retval, io, sizeof (MojoInput));

retval->opaque = newopaque;

} // if

#endif

return retval;

} // MojoInput_tar_duplicate

static void MojoInput_tar_close(MojoInput *io)

{

TARinput *input = (TARinput *) io->opaque;

TARinfo *info = (TARinfo *) input->ar->opaque;

//input->ar->io->close(input->ar->io);

info->input = NULL;

free(input);

free(io);

} // MojoInput_tar_close

// MojoArchive implementation...

static boolean MojoArchive_tar_enumerate(MojoArchive *ar)

{

TARinfo *info = (TARinfo *) ar->opaque;

MojoArchive_resetEntry(&ar->prevEnum);

if (info->input != NULL)

fatal("BUG: tar entry still open on new enumeration");

info->curFileStart = info->nextEnumPos = 0;

return true;

} // MojoArchive_tar_enumerate

// These are byte offsets where fields start in the tar header blocks.

#define TAR_FNAME 0

#define TAR_FNAMELEN 100

#define TAR_MODE 100

#define TAR_MODELEN 8

#define TAR_UID 108

#define TAR_UIDLEN 8

#define TAR_GID 116

#define TAR_GIDLEN 8

#define TAR_SIZE 124

#define TAR_SIZELEN 12

#define TAR_MTIME 136

#define TAR_MTIMELEN 12

#define TAR_CHKSUM 148

#define TAR_CHKSUMLEN 8

#define TAR_TYPE 156

#define TAR_TYPELEN 1

#define TAR_LINKNAME 157

#define TAR_LINKNAMELEN 100

#define TAR_MAGIC 257

#define TAR_MAGICLEN 6

#define TAR_VERSION 263

#define TAR_VERSIONLEN 2

#define TAR_UNAME 265

#define TAR_UNAMELEN 32

#define TAR_GNAME 297

#define TAR_GNAMELEN 32

#define TAR_DEVMAJOR 329

#define TAR_DEVMAJORLEN 8

#define TAR_DEVMINOR 337

#define TAR_DEVMINORLEN 8

#define TAR_FNAMEPRE 345

#define TAR_FNAMEPRELEN 155

// tar entry types...

#define TAR_TYPE_FILE '0'

#define TAR_TYPE_HARDLINK '1'

#define TAR_TYPE_SYMLINK '2'

#define TAR_TYPE_CHARDEV '3'

#define TAR_TYPE_BLOCKDEV '4'

#define TAR_TYPE_DIRECTORY '5'

#define TAR_TYPE_FIFO '6'

static boolean is_ustar(const uint8 *block)

{

return ( (memcmp(&block[TAR_MAGIC], "ustar ", TAR_MAGICLEN) == 0) ||

(memcmp(&block[TAR_MAGIC], "ustar\0", TAR_MAGICLEN) == 0) );

} // is_ustar

static int64 octal_convert(const uint8 *str, const size_t len)

{

int64 retval = 0;

int64 multiplier = 1;

const uint8 *end = str + len;

const uint8 *ptr;

while ((*str == ' ') && (str != end))

str++;

ptr = str;

while ((ptr != end) && (*ptr >= '0') && (*ptr <= '7'))

ptr++;

while (--ptr >= str)

{

uint64 val = *ptr - '0';

retval += val * multiplier;

multiplier *= 8;

} // while

return retval;

} // octal_convert

static const MojoArchiveEntry *MojoArchive_tar_enumNext(MojoArchive *ar)

{

TARinfo *info = (TARinfo *) ar->opaque;

boolean zeroes = true;

boolean ustar = false;

uint8 scratch[512];

uint8 block[512];

size_t fnamelen = 0;

int type = 0;

memset(scratch, '\0', sizeof (scratch));

MojoArchive_resetEntry(&ar->prevEnum);

if (info->input != NULL)

fatal("BUG: tar entry still open on new enumeration");

if (!ar->io->seek(ar->io, info->nextEnumPos))

return NULL;

// Find a non-zero block of data. Tarballs have two 512 blocks filled with

// null bytes at the end of the archive, but you can cat tarballs

// together, so you can't treat them as EOF indicators. Just skip them.

while (zeroes)

{

if (ar->io->read(ar->io, block, sizeof (block)) != sizeof (block))

return NULL; // !!! FIXME: fatal() ?

zeroes = (memcmp(block, scratch, sizeof (block)) == 0);

} // while

// !!! FIXME We should probably check the checksum.

ustar = is_ustar(block);

ar->prevEnum.perms = (uint16) octal_convert(&block[TAR_MODE], TAR_MODELEN);

ar->prevEnum.filesize = octal_convert(&block[TAR_SIZE], TAR_SIZELEN);

info->curFileStart = info->nextEnumPos + 512;

info->nextEnumPos += 512 + ar->prevEnum.filesize;

if (ar->prevEnum.filesize % 512)

info->nextEnumPos += 512 - (ar->prevEnum.filesize % 512);

// We count on (scratch) being zeroed out here!

// prefix of filename is at the end for legacy compat.

if (ustar)

memcpy(scratch, &block[TAR_FNAMEPRE], TAR_FNAMEPRELEN);

fnamelen = strlen((const char *) scratch);

memcpy(&scratch[fnamelen], &block[TAR_FNAME], TAR_FNAMELEN);

fnamelen += strlen((const char *) &scratch[fnamelen]);

if (fnamelen == 0)

return NULL; // corrupt file. !!! FIXME: fatal() ?

ar->prevEnum.filename = xstrdup((const char *) scratch);

type = block[TAR_TYPE];

if (type == 0) // some archivers do the file type as 0 instead of '0'.

type = TAR_TYPE_FILE;

if (ar->prevEnum.filename[fnamelen-1] == '/')

{

while (ar->prevEnum.filename[fnamelen-1] == '/')

ar->prevEnum.filename[--fnamelen] = '\0';

// legacy tar entries don't have a dir type, they just append a '/' to

// the filename...

if ((!ustar) && (type == TAR_TYPE_FILE))

type = TAR_TYPE_DIRECTORY;

} // if

ar->prevEnum.type = MOJOARCHIVE_ENTRY_UNKNOWN;

if (type == TAR_TYPE_FILE)

ar->prevEnum.type = MOJOARCHIVE_ENTRY_FILE;

else if (type == TAR_TYPE_DIRECTORY)

ar->prevEnum.type = MOJOARCHIVE_ENTRY_DIR;

else if (type == TAR_TYPE_SYMLINK)

{

ar->prevEnum.type = MOJOARCHIVE_ENTRY_SYMLINK;

memcpy(scratch, &block[TAR_LINKNAME], TAR_LINKNAMELEN);

scratch[TAR_LINKNAMELEN] = '\0'; // just in case.

ar->prevEnum.linkdest = xstrdup((const char *) scratch);

} // else if

return &ar->prevEnum;

} // MojoArchive_tar_enumNext

static MojoInput *MojoArchive_tar_openCurrentEntry(MojoArchive *ar)

{

TARinfo *info = (TARinfo *) ar->opaque;

MojoInput *io = NULL;

TARinput *opaque = NULL;

if (info->curFileStart == 0)

return NULL;

// Can't open multiple, since we would end up decompressing twice

// to enumerate the next file, so I imposed this limitation for now.

if (info->input != NULL)

fatal("BUG: tar entry double open");

// !!! FIXME: replace this with MojoInput_newFromSubset()?

opaque = (TARinput *) xmalloc(sizeof (TARinput));

opaque->ar = ar;

opaque->fsize = ar->prevEnum.filesize;

opaque->offset = info->curFileStart;

io = (MojoInput *) xmalloc(sizeof (MojoInput));

io->ready = MojoInput_tar_ready;

io->read = MojoInput_tar_read;

io->seek = MojoInput_tar_seek;

io->tell = MojoInput_tar_tell;

io->length = MojoInput_tar_length;

io->duplicate = MojoInput_tar_duplicate;

io->close = MojoInput_tar_close;

io->opaque = opaque;

info->input = io;

return io;

} // MojoArchive_tar_openCurrentEntry

static void MojoArchive_tar_close(MojoArchive *ar)

{

TARinfo *info = (TARinfo *) ar->opaque;

MojoArchive_resetEntry(&ar->prevEnum);

ar->io->close(ar->io);

free(info);

free(ar);

} // MojoArchive_tar_close

MojoArchive *MojoArchive_createTAR(MojoInput *io)

{

MojoArchive *ar = NULL;

uint8 sig[512];

const int64 br = io->read(io, sig, sizeof (sig));

// See if this is a tar archive. We only support "USTAR" format,

// since it has a detectable header. GNU and BSD tar has been creating

// these for years, so it's okay to ignore other ones, I guess.

if ((!io->seek(io, 0)) || (br != sizeof (sig)) || (!is_ustar(sig)) )

return NULL;

// okay, it's a tarball, we're good to go.

ar = (MojoArchive *) xmalloc(sizeof (MojoArchive));

ar->opaque = (TARinfo *) xmalloc(sizeof (TARinfo));

ar->enumerate = MojoArchive_tar_enumerate;

ar->enumNext = MojoArchive_tar_enumNext;

ar->openCurrentEntry = MojoArchive_tar_openCurrentEntry;

ar->close = MojoArchive_tar_close;

ar->io = io;

return ar;

} // MojoArchive_createTAR

#endif // SUPPORT_TAR

// end of archive_tar.c ...